drivers/block/rbd.c

   1
   2 /*
   3    rbd.c -- Export ceph rados objects as a Linux block device
   4
   5
   6    based on drivers/block/osdblk.c:
   7
   8    Copyright 2009 Red Hat, Inc.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; see the file COPYING.  If not, write to
  21    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  22
  23
  24
  25    For usage instructions, please refer to:
  26
  27                  Documentation/ABI/testing/sysfs-bus-rbd
  28
  29  */
  30
  31 #include <linux/ceph/libceph.h>
  32 #include <linux/ceph/osd_client.h>
  33 #include <linux/ceph/mon_client.h>
  34 #include <linux/ceph/cls_lock_client.h>
  35 #include <linux/ceph/striper.h>
  36 #include <linux/ceph/decode.h>
  37 #include <linux/fs_parser.h>
  38 #include <linux/bsearch.h>
  39
  40 #include <linux/kernel.h>
  41 #include <linux/device.h>
  42 #include <linux/module.h>
  43 #include <linux/blk-mq.h>
  44 #include <linux/fs.h>
  45 #include <linux/blkdev.h>
  46 #include <linux/slab.h>
  47 #include <linux/idr.h>
  48 #include <linux/workqueue.h>
  49
  50 #include "rbd_types.h"
  51
  52 #define RBD_DEBUG       /* Activate rbd_assert() calls */
  53
  54 /*
  55  * Increment the given counter and return its updated value.
  56  * If the counter is already 0 it will not be incremented.
  57  * If the counter is already at its maximum value returns
  58  * -EINVAL without updating it.
  59  */
  60 static int atomic_inc_return_safe(atomic_t *v)
  61 {
  62         unsigned int counter;
  63
  64         counter = (unsigned int)atomic_fetch_add_unless(v, 1, 0);
  65         if (counter <= (unsigned int)INT_MAX)
  66                 return (int)counter;
  67
  68         atomic_dec(v);
  69
  70         return -EINVAL;
  71 }
  72
  73 /* Decrement the counter.  Return the resulting value, or -EINVAL */
  74 static int atomic_dec_return_safe(atomic_t *v)
  75 {
  76         int counter;
  77
  78         counter = atomic_dec_return(v);
  79         if (counter >= 0)
  80                 return counter;
  81
  82         atomic_inc(v);
  83
  84         return -EINVAL;
  85 }
  86
  87 #define RBD_DRV_NAME "rbd"
  88
  89 #define RBD_MINORS_PER_MAJOR            256
  90 #define RBD_SINGLE_MAJOR_PART_SHIFT     4
  91
  92 #define RBD_MAX_PARENT_CHAIN_LEN        16
  93
  94 #define RBD_SNAP_DEV_NAME_PREFIX        "snap_"
  95 #define RBD_MAX_SNAP_NAME_LEN   \
  96                         (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
  97
  98 #define RBD_MAX_SNAP_COUNT      510     /* allows max snapc to fit in 4KB */
  99
 100 #define RBD_SNAP_HEAD_NAME      "-"
 101
 102 #define BAD_SNAP_INDEX  U32_MAX         /* invalid index into snap array */
 103
 104 /* This allows a single page to hold an image name sent by OSD */
 105 #define RBD_IMAGE_NAME_LEN_MAX  (PAGE_SIZE - sizeof (__le32) - 1)
 106 #define RBD_IMAGE_ID_LEN_MAX    64
 107
 108 #define RBD_OBJ_PREFIX_LEN_MAX  64
 109
 110 #define RBD_NOTIFY_TIMEOUT      5       /* seconds */
 111 #define RBD_RETRY_DELAY         msecs_to_jiffies(1000)
 112
 113 /* Feature bits */
 114
 115 #define RBD_FEATURE_LAYERING            (1ULL<<0)
 116 #define RBD_FEATURE_STRIPINGV2          (1ULL<<1)
 117 #define RBD_FEATURE_EXCLUSIVE_LOCK      (1ULL<<2)
 118 #define RBD_FEATURE_OBJECT_MAP          (1ULL<<3)
 119 #define RBD_FEATURE_FAST_DIFF           (1ULL<<4)
 120 #define RBD_FEATURE_DEEP_FLATTEN        (1ULL<<5)
 121 #define RBD_FEATURE_DATA_POOL           (1ULL<<7)
 122 #define RBD_FEATURE_OPERATIONS          (1ULL<<8)
 123
 124 #define RBD_FEATURES_ALL        (RBD_FEATURE_LAYERING |         \
 125                                  RBD_FEATURE_STRIPINGV2 |       \
 126                                  RBD_FEATURE_EXCLUSIVE_LOCK |   \
 127                                  RBD_FEATURE_OBJECT_MAP |       \
 128                                  RBD_FEATURE_FAST_DIFF |        \
 129                                  RBD_FEATURE_DEEP_FLATTEN |     \
 130                                  RBD_FEATURE_DATA_POOL |        \
 131                                  RBD_FEATURE_OPERATIONS)
 132
 133 /* Features supported by this (client software) implementation. */
 134
 135 #define RBD_FEATURES_SUPPORTED  (RBD_FEATURES_ALL)
 136
 137 /*
 138  * An RBD device name will be "rbd#", where the "rbd" comes from
 139  * RBD_DRV_NAME above, and # is a unique integer identifier.
 140  */
 141 #define DEV_NAME_LEN            32
 142
 143 /*
 144  * block device image metadata (in-memory version)
 145  */
 146 struct rbd_image_header {
 147         /* These six fields never change for a given rbd image */
 148         char *object_prefix;
 149         __u8 obj_order;
 150         u64 stripe_unit;
 151         u64 stripe_count;
 152         s64 data_pool_id;
 153         u64 features;           /* Might be changeable someday? */
 154
 155         /* The remaining fields need to be updated occasionally */
 156         u64 image_size;
 157         struct ceph_snap_context *snapc;
 158         char *snap_names;       /* format 1 only */
 159         u64 *snap_sizes;        /* format 1 only */
 160 };
 161
 162 /*
 163  * An rbd image specification.
 164  *
 165  * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
 166  * identify an image.  Each rbd_dev structure includes a pointer to
 167  * an rbd_spec structure that encapsulates this identity.
 168  *
 169  * Each of the id's in an rbd_spec has an associated name.  For a
 170  * user-mapped image, the names are supplied and the id's associated
 171  * with them are looked up.  For a layered image, a parent image is
 172  * defined by the tuple, and the names are looked up.
 173  *
 174  * An rbd_dev structure contains a parent_spec pointer which is
 175  * non-null if the image it represents is a child in a layered
 176  * image.  This pointer will refer to the rbd_spec structure used
 177  * by the parent rbd_dev for its own identity (i.e., the structure
 178  * is shared between the parent and child).
 179  *
 180  * Since these structures are populated once, during the discovery
 181  * phase of image construction, they are effectively immutable so
 182  * we make no effort to synchronize access to them.
 183  *
 184  * Note that code herein does not assume the image name is known (it
 185  * could be a null pointer).
 186  */
 187 struct rbd_spec {
 188         u64             pool_id;
 189         const char      *pool_name;
 190         const char      *pool_ns;       /* NULL if default, never "" */
 191
 192         const char      *image_id;
 193         const char      *image_name;
 194
 195         u64             snap_id;
 196         const char      *snap_name;
 197
 198         struct kref     kref;
 199 };
 200
 201 /*
 202  * an instance of the client.  multiple devices may share an rbd client.
 203  */
 204 struct rbd_client {
 205         struct ceph_client      *client;
 206         struct kref             kref;
 207         struct list_head        node;
 208 };
 209
 210 struct pending_result {
 211         int                     result;         /* first nonzero result */
 212         int                     num_pending;
 213 };
 214
 215 struct rbd_img_request;
 216
 217 enum obj_request_type {
 218         OBJ_REQUEST_NODATA = 1,
 219         OBJ_REQUEST_BIO,        /* pointer into provided bio (list) */
 220         OBJ_REQUEST_BVECS,      /* pointer into provided bio_vec array */
 221         OBJ_REQUEST_OWN_BVECS,  /* private bio_vec array, doesn't own pages */
 222 };
 223
 224 enum obj_operation_type {
 225         OBJ_OP_READ = 1,
 226         OBJ_OP_WRITE,
 227         OBJ_OP_DISCARD,
 228         OBJ_OP_ZEROOUT,
 229 };
 230
 231 #define RBD_OBJ_FLAG_DELETION                   (1U << 0)
 232 #define RBD_OBJ_FLAG_COPYUP_ENABLED             (1U << 1)
 233 #define RBD_OBJ_FLAG_COPYUP_ZEROS               (1U << 2)
 234 #define RBD_OBJ_FLAG_MAY_EXIST                  (1U << 3)
 235 #define RBD_OBJ_FLAG_NOOP_FOR_NONEXISTENT       (1U << 4)
 236
 237 enum rbd_obj_read_state {
 238         RBD_OBJ_READ_START = 1,
 239         RBD_OBJ_READ_OBJECT,
 240         RBD_OBJ_READ_PARENT,
 241 };
 242
 243 /*
 244  * Writes go through the following state machine to deal with
 245  * layering:
 246  *
 247  *            . . . . . RBD_OBJ_WRITE_GUARD. . . . . . . . . . . . . .
 248  *            .                 |                                    .
 249  *            .                 v                                    .
 250  *            .    RBD_OBJ_WRITE_READ_FROM_PARENT. . .               .
 251  *            .                 |                    .               .
 252  *            .                 v                    v (deep-copyup  .
 253  *    (image  .   RBD_OBJ_WRITE_COPYUP_EMPTY_SNAPC   .  not needed)  .
 254  * flattened) v                 |                    .               .
 255  *            .                 v                    .               .
 256  *            . . . .RBD_OBJ_WRITE_COPYUP_OPS. . . . .      (copyup  .
 257  *                              |                        not needed) v
 258  *                              v                                    .
 259  *                            done . . . . . . . . . . . . . . . . . .
 260  *                              ^
 261  *                              |
 262  *                     RBD_OBJ_WRITE_FLAT
 263  *
 264  * Writes start in RBD_OBJ_WRITE_GUARD or _FLAT, depending on whether
 265  * assert_exists guard is needed or not (in some cases it's not needed
 266  * even if there is a parent).
 267  */
 268 enum rbd_obj_write_state {
 269         RBD_OBJ_WRITE_START = 1,
 270         RBD_OBJ_WRITE_PRE_OBJECT_MAP,
 271         RBD_OBJ_WRITE_OBJECT,
 272         __RBD_OBJ_WRITE_COPYUP,
 273         RBD_OBJ_WRITE_COPYUP,
 274         RBD_OBJ_WRITE_POST_OBJECT_MAP,
 275 };
 276
 277 enum rbd_obj_copyup_state {
 278         RBD_OBJ_COPYUP_START = 1,
 279         RBD_OBJ_COPYUP_READ_PARENT,
 280         __RBD_OBJ_COPYUP_OBJECT_MAPS,
 281         RBD_OBJ_COPYUP_OBJECT_MAPS,
 282         __RBD_OBJ_COPYUP_WRITE_OBJECT,
 283         RBD_OBJ_COPYUP_WRITE_OBJECT,
 284 };
 285
 286 struct rbd_obj_request {
 287         struct ceph_object_extent ex;
 288         unsigned int            flags;  /* RBD_OBJ_FLAG_* */
 289         union {
 290                 enum rbd_obj_read_state  read_state;    /* for reads */
 291                 enum rbd_obj_write_state write_state;   /* for writes */
 292         };
 293
 294         struct rbd_img_request  *img_request;
 295         struct ceph_file_extent *img_extents;
 296         u32                     num_img_extents;
 297
 298         union {
 299                 struct ceph_bio_iter    bio_pos;
 300                 struct {
 301                         struct ceph_bvec_iter   bvec_pos;
 302                         u32                     bvec_count;
 303                         u32                     bvec_idx;
 304                 };
 305         };
 306
 307         enum rbd_obj_copyup_state copyup_state;
 308         struct bio_vec          *copyup_bvecs;
 309         u32                     copyup_bvec_count;
 310
 311         struct list_head        osd_reqs;       /* w/ r_private_item */
 312
 313         struct mutex            state_mutex;
 314         struct pending_result   pending;
 315         struct kref             kref;
 316 };
 317
 318 enum img_req_flags {
 319         IMG_REQ_CHILD,          /* initiator: block = 0, child image = 1 */
 320         IMG_REQ_LAYERED,        /* ENOENT handling: normal = 0, layered = 1 */
 321 };
 322
 323 enum rbd_img_state {
 324         RBD_IMG_START = 1,
 325         RBD_IMG_EXCLUSIVE_LOCK,
 326         __RBD_IMG_OBJECT_REQUESTS,
 327         RBD_IMG_OBJECT_REQUESTS,
 328 };
 329
 330 struct rbd_img_request {
 331         struct rbd_device       *rbd_dev;
 332         enum obj_operation_type op_type;
 333         enum obj_request_type   data_type;
 334         unsigned long           flags;
 335         enum rbd_img_state      state;
 336         union {
 337                 u64                     snap_id;        /* for reads */
 338                 struct ceph_snap_context *snapc;        /* for writes */
 339         };
 340         struct rbd_obj_request  *obj_request;   /* obj req initiator */
 341
 342         struct list_head        lock_item;
 343         struct list_head        object_extents; /* obj_req.ex structs */
 344
 345         struct mutex            state_mutex;
 346         struct pending_result   pending;
 347         struct work_struct      work;
 348         int                     work_result;
 349 };
 350
 351 #define for_each_obj_request(ireq, oreq) \
 352         list_for_each_entry(oreq, &(ireq)->object_extents, ex.oe_item)
 353 #define for_each_obj_request_safe(ireq, oreq, n) \
 354         list_for_each_entry_safe(oreq, n, &(ireq)->object_extents, ex.oe_item)
 355
 356 enum rbd_watch_state {
 357         RBD_WATCH_STATE_UNREGISTERED,
 358         RBD_WATCH_STATE_REGISTERED,
 359         RBD_WATCH_STATE_ERROR,
 360 };
 361
 362 enum rbd_lock_state {
 363         RBD_LOCK_STATE_UNLOCKED,
 364         RBD_LOCK_STATE_LOCKED,
 365         RBD_LOCK_STATE_RELEASING,
 366 };
 367
 368 /* WatchNotify::ClientId */
 369 struct rbd_client_id {
 370         u64 gid;
 371         u64 handle;
 372 };
 373
 374 struct rbd_mapping {
 375         u64                     size;
 376 };
 377
 378 /*
 379  * a single device
 380  */
 381 struct rbd_device {
 382         int                     dev_id;         /* blkdev unique id */
 383
 384         int                     major;          /* blkdev assigned major */
 385         int                     minor;
 386         struct gendisk          *disk;          /* blkdev's gendisk and rq */
 387
 388         u32                     image_format;   /* Either 1 or 2 */
 389         struct rbd_client       *rbd_client;
 390
 391         char                    name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
 392
 393         spinlock_t              lock;           /* queue, flags, open_count */
 394
 395         struct rbd_image_header header;
 396         unsigned long           flags;          /* possibly lock protected */
 397         struct rbd_spec         *spec;
 398         struct rbd_options      *opts;
 399         char                    *config_info;   /* add{,_single_major} string */
 400
 401         struct ceph_object_id   header_oid;
 402         struct ceph_object_locator header_oloc;
 403
 404         struct ceph_file_layout layout;         /* used for all rbd requests */
 405
 406         struct mutex            watch_mutex;
 407         enum rbd_watch_state    watch_state;
 408         struct ceph_osd_linger_request *watch_handle;
 409         u64                     watch_cookie;
 410         struct delayed_work     watch_dwork;
 411
 412         struct rw_semaphore     lock_rwsem;
 413         enum rbd_lock_state     lock_state;
 414         char                    lock_cookie[32];
 415         struct rbd_client_id    owner_cid;
 416         struct work_struct      acquired_lock_work;
 417         struct work_struct      released_lock_work;
 418         struct delayed_work     lock_dwork;
 419         struct work_struct      unlock_work;
 420         spinlock_t              lock_lists_lock;
 421         struct list_head        acquiring_list;
 422         struct list_head        running_list;
 423         struct completion       acquire_wait;
 424         int                     acquire_err;
 425         struct completion       releasing_wait;
 426
 427         spinlock_t              object_map_lock;
 428         u8                      *object_map;
 429         u64                     object_map_size;        /* in objects */
 430         u64                     object_map_flags;
 431
 432         struct workqueue_struct *task_wq;
 433
 434         struct rbd_spec         *parent_spec;
 435         u64                     parent_overlap;
 436         atomic_t                parent_ref;
 437         struct rbd_device       *parent;
 438
 439         /* Block layer tags. */
 440         struct blk_mq_tag_set   tag_set;
 441
 442         /* protects updating the header */
 443         struct rw_semaphore     header_rwsem;
 444
 445         struct rbd_mapping      mapping;
 446
 447         struct list_head        node;
 448
 449         /* sysfs related */
 450         struct device           dev;
 451         unsigned long           open_count;     /* protected by lock */
 452 };
 453
 454 /*
 455  * Flag bits for rbd_dev->flags:
 456  * - REMOVING (which is coupled with rbd_dev->open_count) is protected
 457  *   by rbd_dev->lock
 458  */
 459 enum rbd_dev_flags {
 460         RBD_DEV_FLAG_EXISTS,    /* rbd_dev_device_setup() ran */
 461         RBD_DEV_FLAG_REMOVING,  /* this mapping is being removed */
 462         RBD_DEV_FLAG_READONLY,  /* -o ro or snapshot */
 463 };
 464
 465 static DEFINE_MUTEX(client_mutex);      /* Serialize client creation */
 466
 467 static LIST_HEAD(rbd_dev_list);    /* devices */
 468 static DEFINE_SPINLOCK(rbd_dev_list_lock);
 469
 470 static LIST_HEAD(rbd_client_list);              /* clients */
 471 static DEFINE_SPINLOCK(rbd_client_list_lock);
 472
 473 /* Slab caches for frequently-allocated structures */
 474
 475 static struct kmem_cache        *rbd_img_request_cache;
 476 static struct kmem_cache        *rbd_obj_request_cache;
 477
 478 static int rbd_major;
 479 static DEFINE_IDA(rbd_dev_id_ida);
 480
 481 static struct workqueue_struct *rbd_wq;
 482
 483 static struct ceph_snap_context rbd_empty_snapc = {
 484         .nref = REFCOUNT_INIT(1),
 485 };
 486
 487 /*
 488  * single-major requires >= 0.75 version of userspace rbd utility.
 489  */
 490 static bool single_major = true;
 491 module_param(single_major, bool, 0444);
 492 MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: true)");
 493
 494 static ssize_t add_store(struct bus_type *bus, const char *buf, size_t count);
 495 static ssize_t remove_store(struct bus_type *bus, const char *buf,
 496                             size_t count);
 497 static ssize_t add_single_major_store(struct bus_type *bus, const char *buf,
 498                                       size_t count);
 499 static ssize_t remove_single_major_store(struct bus_type *bus, const char *buf,
 500                                          size_t count);
 501 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth);
 502
 503 static int rbd_dev_id_to_minor(int dev_id)
 504 {
 505         return dev_id << RBD_SINGLE_MAJOR_PART_SHIFT;
 506 }
 507
 508 static int minor_to_rbd_dev_id(int minor)
 509 {
 510         return minor >> RBD_SINGLE_MAJOR_PART_SHIFT;
 511 }
 512
 513 static bool rbd_is_ro(struct rbd_device *rbd_dev)
 514 {
 515         return test_bit(RBD_DEV_FLAG_READONLY, &rbd_dev->flags);
 516 }
 517
 518 static bool rbd_is_snap(struct rbd_device *rbd_dev)
 519 {
 520         return rbd_dev->spec->snap_id != CEPH_NOSNAP;
 521 }
 522
 523 static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
 524 {
 525         lockdep_assert_held(&rbd_dev->lock_rwsem);
 526
 527         return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED ||
 528                rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING;
 529 }
 530
 531 static bool rbd_is_lock_owner(struct rbd_device *rbd_dev)
 532 {
 533         bool is_lock_owner;
 534
 535         down_read(&rbd_dev->lock_rwsem);
 536         is_lock_owner = __rbd_is_lock_owner(rbd_dev);
 537         up_read(&rbd_dev->lock_rwsem);
 538         return is_lock_owner;
 539 }
 540
 541 static ssize_t supported_features_show(struct bus_type *bus, char *buf)
 542 {
 543         return sprintf(buf, "0x%llx\n", RBD_FEATURES_SUPPORTED);
 544 }
 545
 546 static BUS_ATTR_WO(add);
 547 static BUS_ATTR_WO(remove);
 548 static BUS_ATTR_WO(add_single_major);
 549 static BUS_ATTR_WO(remove_single_major);
 550 static BUS_ATTR_RO(supported_features);
 551
 552 static struct attribute *rbd_bus_attrs[] = {
 553         &bus_attr_add.attr,
 554         &bus_attr_remove.attr,
 555         &bus_attr_add_single_major.attr,
 556         &bus_attr_remove_single_major.attr,
 557         &bus_attr_supported_features.attr,
 558         NULL,
 559 };
 560
 561 static umode_t rbd_bus_is_visible(struct kobject *kobj,
 562                                   struct attribute *attr, int index)
 563 {
 564         if (!single_major &&
 565             (attr == &bus_attr_add_single_major.attr ||
 566              attr == &bus_attr_remove_single_major.attr))
 567                 return 0;
 568
 569         return attr->mode;
 570 }
 571
 572 static const struct attribute_group rbd_bus_group = {
 573         .attrs = rbd_bus_attrs,
 574         .is_visible = rbd_bus_is_visible,
 575 };
 576 __ATTRIBUTE_GROUPS(rbd_bus);
 577
 578 static struct bus_type rbd_bus_type = {
 579         .name           = "rbd",
 580         .bus_groups     = rbd_bus_groups,
 581 };
 582
 583 static void rbd_root_dev_release(struct device *dev)
 584 {
 585 }
 586
 587 static struct device rbd_root_dev = {
 588         .init_name =    "rbd",
 589         .release =      rbd_root_dev_release,
 590 };
 591
 592 static __printf(2, 3)
 593 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
 594 {
 595         struct va_format vaf;
 596         va_list args;
 597
 598         va_start(args, fmt);
 599         vaf.fmt = fmt;
 600         vaf.va = &args;
 601
 602         if (!rbd_dev)
 603                 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
 604         else if (rbd_dev->disk)
 605                 printk(KERN_WARNING "%s: %s: %pV\n",
 606                         RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
 607         else if (rbd_dev->spec && rbd_dev->spec->image_name)
 608                 printk(KERN_WARNING "%s: image %s: %pV\n",
 609                         RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
 610         else if (rbd_dev->spec && rbd_dev->spec->image_id)
 611                 printk(KERN_WARNING "%s: id %s: %pV\n",
 612                         RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
 613         else    /* punt */
 614                 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
 615                         RBD_DRV_NAME, rbd_dev, &vaf);
 616         va_end(args);
 617 }
 618
 619 #ifdef RBD_DEBUG
 620 #define rbd_assert(expr)                                                \
 621                 if (unlikely(!(expr))) {                                \
 622                         printk(KERN_ERR "\nAssertion failure in %s() "  \
 623                                                 "at line %d:\n\n"       \
 624                                         "\trbd_assert(%s);\n\n",        \
 625                                         __func__, __LINE__, #expr);     \
 626                         BUG();                                          \
 627                 }
 628 #else /* !RBD_DEBUG */
 629 #  define rbd_assert(expr)      ((void) 0)
 630 #endif /* !RBD_DEBUG */
 631
 632 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
 633
 634 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
 635 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
 636 static int rbd_dev_header_info(struct rbd_device *rbd_dev);
 637 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
 638 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
 639                                         u64 snap_id);
 640 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
 641                                 u8 *order, u64 *snap_size);
 642 static int rbd_dev_v2_get_flags(struct rbd_device *rbd_dev);
 643
 644 static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result);
 645 static void rbd_img_handle_request(struct rbd_img_request *img_req, int result);
 646
 647 /*
 648  * Return true if nothing else is pending.
 649  */
 650 static bool pending_result_dec(struct pending_result *pending, int *result)
 651 {
 652         rbd_assert(pending->num_pending > 0);
 653
 654         if (*result && !pending->result)
 655                 pending->result = *result;
 656         if (--pending->num_pending)
 657                 return false;
 658
 659         *result = pending->result;
 660         return true;
 661 }
 662
 663 static int rbd_open(struct block_device *bdev, fmode_t mode)
 664 {
 665         struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
 666         bool removing = false;
 667
 668         spin_lock_irq(&rbd_dev->lock);
 669         if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
 670                 removing = true;
 671         else
 672                 rbd_dev->open_count++;
 673         spin_unlock_irq(&rbd_dev->lock);
 674         if (removing)
 675                 return -ENOENT;
 676
 677         (void) get_device(&rbd_dev->dev);
 678
 679         return 0;
 680 }
 681
 682 static void rbd_release(struct gendisk *disk, fmode_t mode)
 683 {
 684         struct rbd_device *rbd_dev = disk->private_data;
 685         unsigned long open_count_before;
 686
 687         spin_lock_irq(&rbd_dev->lock);
 688         open_count_before = rbd_dev->open_count--;
 689         spin_unlock_irq(&rbd_dev->lock);
 690         rbd_assert(open_count_before > 0);
 691
 692         put_device(&rbd_dev->dev);
 693 }
 694
 695 static const struct block_device_operations rbd_bd_ops = {
 696         .owner                  = THIS_MODULE,
 697         .open                   = rbd_open,
 698         .release                = rbd_release,
 699 };
 700
 701 /*
 702  * Initialize an rbd client instance.  Success or not, this function
 703  * consumes ceph_opts.  Caller holds client_mutex.
 704  */
 705 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
 706 {
 707         struct rbd_client *rbdc;
 708         int ret = -ENOMEM;
 709
 710         dout("%s:\n", __func__);
 711         rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
 712         if (!rbdc)
 713                 goto out_opt;
 714
 715         kref_init(&rbdc->kref);
 716         INIT_LIST_HEAD(&rbdc->node);
 717
 718         rbdc->client = ceph_create_client(ceph_opts, rbdc);
 719         if (IS_ERR(rbdc->client))
 720                 goto out_rbdc;
 721         ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
 722
 723         ret = ceph_open_session(rbdc->client);
 724         if (ret < 0)
 725                 goto out_client;
 726
 727         spin_lock(&rbd_client_list_lock);
 728         list_add_tail(&rbdc->node, &rbd_client_list);
 729         spin_unlock(&rbd_client_list_lock);
 730
 731         dout("%s: rbdc %p\n", __func__, rbdc);
 732
 733         return rbdc;
 734 out_client:
 735         ceph_destroy_client(rbdc->client);
 736 out_rbdc:
 737         kfree(rbdc);
 738 out_opt:
 739         if (ceph_opts)
 740                 ceph_destroy_options(ceph_opts);
 741         dout("%s: error %d\n", __func__, ret);
 742
 743         return ERR_PTR(ret);
 744 }
 745
 746 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
 747 {
 748         kref_get(&rbdc->kref);
 749
 750         return rbdc;
 751 }
 752
 753 /*
 754  * Find a ceph client with specific addr and configuration.  If
 755  * found, bump its reference count.
 756  */
 757 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
 758 {
 759         struct rbd_client *client_node;
 760         bool found = false;
 761
 762         if (ceph_opts->flags & CEPH_OPT_NOSHARE)
 763                 return NULL;
 764
 765         spin_lock(&rbd_client_list_lock);
 766         list_for_each_entry(client_node, &rbd_client_list, node) {
 767                 if (!ceph_compare_options(ceph_opts, client_node->client)) {
 768                         __rbd_get_client(client_node);
 769
 770                         found = true;
 771                         break;
 772                 }
 773         }
 774         spin_unlock(&rbd_client_list_lock);
 775
 776         return found ? client_node : NULL;
 777 }
 778
 779 /*
 780  * (Per device) rbd map options
 781  */
 782 enum {
 783         Opt_queue_depth,
 784         Opt_alloc_size,
 785         Opt_lock_timeout,
 786         /* int args above */
 787         Opt_pool_ns,
 788         Opt_compression_hint,
 789         /* string args above */
 790         Opt_read_only,
 791         Opt_read_write,
 792         Opt_lock_on_read,
 793         Opt_exclusive,
 794         Opt_notrim,
 795 };
 796
 797 enum {
 798         Opt_compression_hint_none,
 799         Opt_compression_hint_compressible,
 800         Opt_compression_hint_incompressible,
 801 };
 802
 803 static const struct constant_table rbd_param_compression_hint[] = {
 804         {"none",                Opt_compression_hint_none},
 805         {"compressible",        Opt_compression_hint_compressible},
 806         {"incompressible",      Opt_compression_hint_incompressible},
 807         {}
 808 };
 809
 810 static const struct fs_parameter_spec rbd_parameters[] = {
 811         fsparam_u32     ("alloc_size",                  Opt_alloc_size),
 812         fsparam_enum    ("compression_hint",            Opt_compression_hint,
 813                          rbd_param_compression_hint),
 814         fsparam_flag    ("exclusive",                   Opt_exclusive),
 815         fsparam_flag    ("lock_on_read",                Opt_lock_on_read),
 816         fsparam_u32     ("lock_timeout",                Opt_lock_timeout),
 817         fsparam_flag    ("notrim",                      Opt_notrim),
 818         fsparam_string  ("_pool_ns",                    Opt_pool_ns),
 819         fsparam_u32     ("queue_depth",                 Opt_queue_depth),
 820         fsparam_flag    ("read_only",                   Opt_read_only),
 821         fsparam_flag    ("read_write",                  Opt_read_write),
 822         fsparam_flag    ("ro",                          Opt_read_only),
 823         fsparam_flag    ("rw",                          Opt_read_write),
 824         {}
 825 };
 826
 827 struct rbd_options {
 828         int     queue_depth;
 829         int     alloc_size;
 830         unsigned long   lock_timeout;
 831         bool    read_only;
 832         bool    lock_on_read;
 833         bool    exclusive;
 834         bool    trim;
 835
 836         u32 alloc_hint_flags;  /* CEPH_OSD_OP_ALLOC_HINT_FLAG_* */
 837 };
 838
 839 #define RBD_QUEUE_DEPTH_DEFAULT BLKDEV_MAX_RQ
 840 #define RBD_ALLOC_SIZE_DEFAULT  (64 * 1024)
 841 #define RBD_LOCK_TIMEOUT_DEFAULT 0  /* no timeout */
 842 #define RBD_READ_ONLY_DEFAULT   false
 843 #define RBD_LOCK_ON_READ_DEFAULT false
 844 #define RBD_EXCLUSIVE_DEFAULT   false
 845 #define RBD_TRIM_DEFAULT        true
 846
 847 struct rbd_parse_opts_ctx {
 848         struct rbd_spec         *spec;
 849         struct ceph_options     *copts;
 850         struct rbd_options      *opts;
 851 };
 852
 853 static char* obj_op_name(enum obj_operation_type op_type)
 854 {
 855         switch (op_type) {
 856         case OBJ_OP_READ:
 857                 return "read";
 858         case OBJ_OP_WRITE:
 859                 return "write";
 860         case OBJ_OP_DISCARD:
 861                 return "discard";
 862         case OBJ_OP_ZEROOUT:
 863                 return "zeroout";
 864         default:
 865                 return "???";
 866         }
 867 }
 868
 869 /*
 870  * Destroy ceph client
 871  *
 872  * Caller must hold rbd_client_list_lock.
 873  */
 874 static void rbd_client_release(struct kref *kref)
 875 {
 876         struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
 877
 878         dout("%s: rbdc %p\n", __func__, rbdc);
 879         spin_lock(&rbd_client_list_lock);
 880         list_del(&rbdc->node);
 881         spin_unlock(&rbd_client_list_lock);
 882
 883         ceph_destroy_client(rbdc->client);
 884         kfree(rbdc);
 885 }
 886
 887 /*
 888  * Drop reference to ceph client node. If it's not referenced anymore, release
 889  * it.
 890  */
 891 static void rbd_put_client(struct rbd_client *rbdc)
 892 {
 893         if (rbdc)
 894                 kref_put(&rbdc->kref, rbd_client_release);
 895 }
 896
 897 /*
 898  * Get a ceph client with specific addr and configuration, if one does
 899  * not exist create it.  Either way, ceph_opts is consumed by this
 900  * function.
 901  */
 902 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
 903 {
 904         struct rbd_client *rbdc;
 905         int ret;
 906
 907         mutex_lock(&client_mutex);
 908         rbdc = rbd_client_find(ceph_opts);
 909         if (rbdc) {
 910                 ceph_destroy_options(ceph_opts);
 911
 912                 /*
 913                  * Using an existing client.  Make sure ->pg_pools is up to
 914                  * date before we look up the pool id in do_rbd_add().
 915                  */
 916                 ret = ceph_wait_for_latest_osdmap(rbdc->client,
 917                                         rbdc->client->options->mount_timeout);
 918                 if (ret) {
 919                         rbd_warn(NULL, "failed to get latest osdmap: %d", ret);
 920                         rbd_put_client(rbdc);
 921                         rbdc = ERR_PTR(ret);
 922                 }
 923         } else {
 924                 rbdc = rbd_client_create(ceph_opts);
 925         }
 926         mutex_unlock(&client_mutex);
 927
 928         return rbdc;
 929 }
 930
 931 static bool rbd_image_format_valid(u32 image_format)
 932 {
 933         return image_format == 1 || image_format == 2;
 934 }
 935
 936 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
 937 {
 938         size_t size;
 939         u32 snap_count;
 940
 941         /* The header has to start with the magic rbd header text */
 942         if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
 943                 return false;
 944
 945         /* The bio layer requires at least sector-sized I/O */
 946
 947         if (ondisk->options.order < SECTOR_SHIFT)
 948                 return false;
 949
 950         /* If we use u64 in a few spots we may be able to loosen this */
 951
 952         if (ondisk->options.order > 8 * sizeof (int) - 1)
 953                 return false;
 954
 955         /*
 956          * The size of a snapshot header has to fit in a size_t, and
 957          * that limits the number of snapshots.
 958          */
 959         snap_count = le32_to_cpu(ondisk->snap_count);
 960         size = SIZE_MAX - sizeof (struct ceph_snap_context);
 961         if (snap_count > size / sizeof (__le64))
 962                 return false;
 963
 964         /*
 965          * Not only that, but the size of the entire the snapshot
 966          * header must also be representable in a size_t.
 967          */
 968         size -= snap_count * sizeof (__le64);
 969         if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
 970                 return false;
 971
 972         return true;
 973 }
 974
 975 /*
 976  * returns the size of an object in the image
 977  */
 978 static u32 rbd_obj_bytes(struct rbd_image_header *header)
 979 {
 980         return 1U << header->obj_order;
 981 }
 982
 983 static void rbd_init_layout(struct rbd_device *rbd_dev)
 984 {
 985         if (rbd_dev->header.stripe_unit == 0 ||
 986             rbd_dev->header.stripe_count == 0) {
 987                 rbd_dev->header.stripe_unit = rbd_obj_bytes(&rbd_dev->header);
 988                 rbd_dev->header.stripe_count = 1;
 989         }
 990
 991         rbd_dev->layout.stripe_unit = rbd_dev->header.stripe_unit;
 992         rbd_dev->layout.stripe_count = rbd_dev->header.stripe_count;
 993         rbd_dev->layout.object_size = rbd_obj_bytes(&rbd_dev->header);
 994         rbd_dev->layout.pool_id = rbd_dev->header.data_pool_id == CEPH_NOPOOL ?
 995                           rbd_dev->spec->pool_id : rbd_dev->header.data_pool_id;
 996         RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
 997 }
 998
 999 /*
1000  * Fill an rbd image header with information from the given format 1
1001  * on-disk header.
1002  */
1003 static int rbd_header_from_disk(struct rbd_device *rbd_dev,
1004                                  struct rbd_image_header_ondisk *ondisk)
1005 {
1006         struct rbd_image_header *header = &rbd_dev->header;
1007         bool first_time = header->object_prefix == NULL;
1008         struct ceph_snap_context *snapc;
1009         char *object_prefix = NULL;
1010         char *snap_names = NULL;
1011         u64 *snap_sizes = NULL;
1012         u32 snap_count;
1013         int ret = -ENOMEM;
1014         u32 i;
1015
1016         /* Allocate this now to avoid having to handle failure below */
1017
1018         if (first_time) {
1019                 object_prefix = kstrndup(ondisk->object_prefix,
1020                                          sizeof(ondisk->object_prefix),
1021                                          GFP_KERNEL);
1022                 if (!object_prefix)
1023                         return -ENOMEM;
1024         }
1025
1026         /* Allocate the snapshot context and fill it in */
1027
1028         snap_count = le32_to_cpu(ondisk->snap_count);
1029         snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
1030         if (!snapc)
1031                 goto out_err;
1032         snapc->seq = le64_to_cpu(ondisk->snap_seq);
1033         if (snap_count) {
1034                 struct rbd_image_snap_ondisk *snaps;
1035                 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
1036
1037                 /* We'll keep a copy of the snapshot names... */
1038
1039                 if (snap_names_len > (u64)SIZE_MAX)
1040                         goto out_2big;
1041                 snap_names = kmalloc(snap_names_len, GFP_KERNEL);
1042                 if (!snap_names)
1043                         goto out_err;
1044
1045                 /* ...as well as the array of their sizes. */
1046                 snap_sizes = kmalloc_array(snap_count,
1047                                            sizeof(*header->snap_sizes),
1048                                            GFP_KERNEL);
1049                 if (!snap_sizes)
1050                         goto out_err;
1051
1052                 /*
1053                  * Copy the names, and fill in each snapshot's id
1054                  * and size.
1055                  *
1056                  * Note that rbd_dev_v1_header_info() guarantees the
1057                  * ondisk buffer we're working with has
1058                  * snap_names_len bytes beyond the end of the
1059                  * snapshot id array, this memcpy() is safe.
1060                  */
1061                 memcpy(snap_names, &ondisk->snaps[snap_count], snap_names_len);
1062                 snaps = ondisk->snaps;
1063                 for (i = 0; i < snap_count; i++) {
1064                         snapc->snaps[i] = le64_to_cpu(snaps[i].id);
1065                         snap_sizes[i] = le64_to_cpu(snaps[i].image_size);
1066                 }
1067         }
1068
1069         /* We won't fail any more, fill in the header */
1070
1071         if (first_time) {
1072                 header->object_prefix = object_prefix;
1073                 header->obj_order = ondisk->options.order;
1074                 rbd_init_layout(rbd_dev);
1075         } else {
1076                 ceph_put_snap_context(header->snapc);
1077                 kfree(header->snap_names);
1078                 kfree(header->snap_sizes);
1079         }
1080
1081         /* The remaining fields always get updated (when we refresh) */
1082
1083         header->image_size = le64_to_cpu(ondisk->image_size);
1084         header->snapc = snapc;
1085         header->snap_names = snap_names;
1086         header->snap_sizes = snap_sizes;
1087
1088         return 0;
1089 out_2big:
1090         ret = -EIO;
1091 out_err:
1092         kfree(snap_sizes);
1093         kfree(snap_names);
1094         ceph_put_snap_context(snapc);
1095         kfree(object_prefix);
1096
1097         return ret;
1098 }
1099
1100 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
1101 {
1102         const char *snap_name;
1103
1104         rbd_assert(which < rbd_dev->header.snapc->num_snaps);
1105
1106         /* Skip over names until we find the one we are looking for */
1107
1108         snap_name = rbd_dev->header.snap_names;
1109         while (which--)
1110                 snap_name += strlen(snap_name) + 1;
1111
1112         return kstrdup(snap_name, GFP_KERNEL);
1113 }
1114
1115 /*
1116  * Snapshot id comparison function for use with qsort()/bsearch().
1117  * Note that result is for snapshots in *descending* order.
1118  */
1119 static int snapid_compare_reverse(const void *s1, const void *s2)
1120 {
1121         u64 snap_id1 = *(u64 *)s1;
1122         u64 snap_id2 = *(u64 *)s2;
1123
1124         if (snap_id1 < snap_id2)
1125                 return 1;
1126         return snap_id1 == snap_id2 ? 0 : -1;
1127 }
1128
1129 /*
1130  * Search a snapshot context to see if the given snapshot id is
1131  * present.
1132  *
1133  * Returns the position of the snapshot id in the array if it's found,
1134  * or BAD_SNAP_INDEX otherwise.
1135  *
1136  * Note: The snapshot array is in kept sorted (by the osd) in
1137  * reverse order, highest snapshot id first.
1138  */
1139 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
1140 {
1141         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1142         u64 *found;
1143
1144         found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
1145                                 sizeof (snap_id), snapid_compare_reverse);
1146
1147         return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1148 }
1149
1150 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
1151                                         u64 snap_id)
1152 {
1153         u32 which;
1154         const char *snap_name;
1155
1156         which = rbd_dev_snap_index(rbd_dev, snap_id);
1157         if (which == BAD_SNAP_INDEX)
1158                 return ERR_PTR(-ENOENT);
1159
1160         snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
1161         return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1162 }
1163
1164 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
1165 {
1166         if (snap_id == CEPH_NOSNAP)
1167                 return RBD_SNAP_HEAD_NAME;
1168
1169         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1170         if (rbd_dev->image_format == 1)
1171                 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
1172
1173         return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1174 }
1175
1176 static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
1177                                 u64 *snap_size)
1178 {
1179         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1180         if (snap_id == CEPH_NOSNAP) {
1181                 *snap_size = rbd_dev->header.image_size;
1182         } else if (rbd_dev->image_format == 1) {
1183                 u32 which;
1184
1185                 which = rbd_dev_snap_index(rbd_dev, snap_id);
1186                 if (which == BAD_SNAP_INDEX)
1187                         return -ENOENT;
1188
1189                 *snap_size = rbd_dev->header.snap_sizes[which];
1190         } else {
1191                 u64 size = 0;
1192                 int ret;
1193
1194                 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
1195                 if (ret)
1196                         return ret;
1197
1198                 *snap_size = size;
1199         }
1200         return 0;
1201 }
1202
1203 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
1204 {
1205         u64 snap_id = rbd_dev->spec->snap_id;
1206         u64 size = 0;
1207         int ret;
1208
1209         ret = rbd_snap_size(rbd_dev, snap_id, &size);
1210         if (ret)
1211                 return ret;
1212
1213         rbd_dev->mapping.size = size;
1214         return 0;
1215 }
1216
1217 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
1218 {
1219         rbd_dev->mapping.size = 0;
1220 }
1221
1222 static void zero_bvec(struct bio_vec *bv)
1223 {
1224         void *buf;
1225         unsigned long flags;
1226
1227         buf = bvec_kmap_irq(bv, &flags);
1228         memset(buf, 0, bv->bv_len);
1229         flush_dcache_page(bv->bv_page);
1230         bvec_kunmap_irq(buf, &flags);
1231 }
1232
1233 static void zero_bios(struct ceph_bio_iter *bio_pos, u32 off, u32 bytes)
1234 {
1235         struct ceph_bio_iter it = *bio_pos;
1236
1237         ceph_bio_iter_advance(&it, off);
1238         ceph_bio_iter_advance_step(&it, bytes, ({
1239                 zero_bvec(&bv);
1240         }));
1241 }
1242
1243 static void zero_bvecs(struct ceph_bvec_iter *bvec_pos, u32 off, u32 bytes)
1244 {
1245         struct ceph_bvec_iter it = *bvec_pos;
1246
1247         ceph_bvec_iter_advance(&it, off);
1248         ceph_bvec_iter_advance_step(&it, bytes, ({
1249                 zero_bvec(&bv);
1250         }));
1251 }
1252
1253 /*
1254  * Zero a range in @obj_req data buffer defined by a bio (list) or
1255  * (private) bio_vec array.
1256  *
1257  * @off is relative to the start of the data buffer.
1258  */
1259 static void rbd_obj_zero_range(struct rbd_obj_request *obj_req, u32 off,
1260                                u32 bytes)
1261 {
1262         dout("%s %p data buf %u~%u\n", __func__, obj_req, off, bytes);
1263
1264         switch (obj_req->img_request->data_type) {
1265         case OBJ_REQUEST_BIO:
1266                 zero_bios(&obj_req->bio_pos, off, bytes);
1267                 break;
1268         case OBJ_REQUEST_BVECS:
1269         case OBJ_REQUEST_OWN_BVECS:
1270                 zero_bvecs(&obj_req->bvec_pos, off, bytes);
1271                 break;
1272         default:
1273                 BUG();
1274         }
1275 }
1276
1277 static void rbd_obj_request_destroy(struct kref *kref);
1278 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1279 {
1280         rbd_assert(obj_request != NULL);
1281         dout("%s: obj %p (was %d)\n", __func__, obj_request,
1282                 kref_read(&obj_request->kref));
1283         kref_put(&obj_request->kref, rbd_obj_request_destroy);
1284 }
1285
1286 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1287                                         struct rbd_obj_request *obj_request)
1288 {
1289         rbd_assert(obj_request->img_request == NULL);
1290
1291         /* Image request now owns object's original reference */
1292         obj_request->img_request = img_request;
1293         dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1294 }
1295
1296 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1297                                         struct rbd_obj_request *obj_request)
1298 {
1299         dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
1300         list_del(&obj_request->ex.oe_item);
1301         rbd_assert(obj_request->img_request == img_request);
1302         rbd_obj_request_put(obj_request);
1303 }
1304
1305 static void rbd_osd_submit(struct ceph_osd_request *osd_req)
1306 {
1307         struct rbd_obj_request *obj_req = osd_req->r_priv;
1308
1309         dout("%s osd_req %p for obj_req %p objno %llu %llu~%llu\n",
1310              __func__, osd_req, obj_req, obj_req->ex.oe_objno,
1311              obj_req->ex.oe_off, obj_req->ex.oe_len);
1312         ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
1313 }
1314
1315 /*
1316  * The default/initial value for all image request flags is 0.  Each
1317  * is conditionally set to 1 at image request initialization time
1318  * and currently never change thereafter.
1319  */
1320 static void img_request_layered_set(struct rbd_img_request *img_request)
1321 {
1322         set_bit(IMG_REQ_LAYERED, &img_request->flags);
1323 }
1324
1325 static bool img_request_layered_test(struct rbd_img_request *img_request)
1326 {
1327         return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1328 }
1329
1330 static bool rbd_obj_is_entire(struct rbd_obj_request *obj_req)
1331 {
1332         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
1333
1334         return !obj_req->ex.oe_off &&
1335                obj_req->ex.oe_len == rbd_dev->layout.object_size;
1336 }
1337
1338 static bool rbd_obj_is_tail(struct rbd_obj_request *obj_req)
1339 {
1340         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
1341
1342         return obj_req->ex.oe_off + obj_req->ex.oe_len ==
1343                                         rbd_dev->layout.object_size;
1344 }
1345
1346 /*
1347  * Must be called after rbd_obj_calc_img_extents().
1348  */
1349 static bool rbd_obj_copyup_enabled(struct rbd_obj_request *obj_req)
1350 {
1351         if (!obj_req->num_img_extents ||
1352             (rbd_obj_is_entire(obj_req) &&
1353              !obj_req->img_request->snapc->num_snaps))
1354                 return false;
1355
1356         return true;
1357 }
1358
1359 static u64 rbd_obj_img_extents_bytes(struct rbd_obj_request *obj_req)
1360 {
1361         return ceph_file_extents_bytes(obj_req->img_extents,
1362                                        obj_req->num_img_extents);
1363 }
1364
1365 static bool rbd_img_is_write(struct rbd_img_request *img_req)
1366 {
1367         switch (img_req->op_type) {
1368         case OBJ_OP_READ:
1369                 return false;
1370         case OBJ_OP_WRITE:
1371         case OBJ_OP_DISCARD:
1372         case OBJ_OP_ZEROOUT:
1373                 return true;
1374         default:
1375                 BUG();
1376         }
1377 }
1378
1379 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
1380 {
1381         struct rbd_obj_request *obj_req = osd_req->r_priv;
1382         int result;
1383
1384         dout("%s osd_req %p result %d for obj_req %p\n", __func__, osd_req,
1385              osd_req->r_result, obj_req);
1386
1387         /*
1388          * Writes aren't allowed to return a data payload.  In some
1389          * guarded write cases (e.g. stat + zero on an empty object)
1390          * a stat response makes it through, but we don't care.
1391          */
1392         if (osd_req->r_result > 0 && rbd_img_is_write(obj_req->img_request))
1393                 result = 0;
1394         else
1395                 result = osd_req->r_result;
1396
1397         rbd_obj_handle_request(obj_req, result);
1398 }
1399
1400 static void rbd_osd_format_read(struct ceph_osd_request *osd_req)
1401 {
1402         struct rbd_obj_request *obj_request = osd_req->r_priv;
1403         struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
1404         struct ceph_options *opt = rbd_dev->rbd_client->client->options;
1405
1406         osd_req->r_flags = CEPH_OSD_FLAG_READ | opt->read_from_replica;
1407         osd_req->r_snapid = obj_request->img_request->snap_id;
1408 }
1409
1410 static void rbd_osd_format_write(struct ceph_osd_request *osd_req)
1411 {
1412         struct rbd_obj_request *obj_request = osd_req->r_priv;
1413
1414         osd_req->r_flags = CEPH_OSD_FLAG_WRITE;
1415         ktime_get_real_ts64(&osd_req->r_mtime);
1416         osd_req->r_data_offset = obj_request->ex.oe_off;
1417 }
1418
1419 static struct ceph_osd_request *
1420 __rbd_obj_add_osd_request(struct rbd_obj_request *obj_req,
1421                           struct ceph_snap_context *snapc, int num_ops)
1422 {
1423         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
1424         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
1425         struct ceph_osd_request *req;
1426         const char *name_format = rbd_dev->image_format == 1 ?
1427                                       RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
1428         int ret;
1429
1430         req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false, GFP_NOIO);
1431         if (!req)
1432                 return ERR_PTR(-ENOMEM);
1433
1434         list_add_tail(&req->r_private_item, &obj_req->osd_reqs);
1435         req->r_callback = rbd_osd_req_callback;
1436         req->r_priv = obj_req;
1437
1438         /*
1439          * Data objects may be stored in a separate pool, but always in
1440          * the same namespace in that pool as the header in its pool.
1441          */
1442         ceph_oloc_copy(&req->r_base_oloc, &rbd_dev->header_oloc);
1443         req->r_base_oloc.pool = rbd_dev->layout.pool_id;
1444
1445         ret = ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, name_format,
1446                                rbd_dev->header.object_prefix,
1447                                obj_req->ex.oe_objno);
1448         if (ret)
1449                 return ERR_PTR(ret);
1450
1451         return req;
1452 }
1453
1454 static struct ceph_osd_request *
1455 rbd_obj_add_osd_request(struct rbd_obj_request *obj_req, int num_ops)
1456 {
1457         return __rbd_obj_add_osd_request(obj_req, obj_req->img_request->snapc,
1458                                          num_ops);
1459 }
1460
1461 static struct rbd_obj_request *rbd_obj_request_create(void)
1462 {
1463         struct rbd_obj_request *obj_request;
1464
1465         obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
1466         if (!obj_request)
1467                 return NULL;
1468
1469         ceph_object_extent_init(&obj_request->ex);
1470         INIT_LIST_HEAD(&obj_request->osd_reqs);
1471         mutex_init(&obj_request->state_mutex);
1472         kref_init(&obj_request->kref);
1473
1474         dout("%s %p\n", __func__, obj_request);
1475         return obj_request;
1476 }
1477
1478 static void rbd_obj_request_destroy(struct kref *kref)
1479 {
1480         struct rbd_obj_request *obj_request;
1481         struct ceph_osd_request *osd_req;
1482         u32 i;
1483
1484         obj_request = container_of(kref, struct rbd_obj_request, kref);
1485
1486         dout("%s: obj %p\n", __func__, obj_request);
1487
1488         while (!list_empty(&obj_request->osd_reqs)) {
1489                 osd_req = list_first_entry(&obj_request->osd_reqs,
1490                                     struct ceph_osd_request, r_private_item);
1491                 list_del_init(&osd_req->r_private_item);
1492                 ceph_osdc_put_request(osd_req);
1493         }
1494
1495         switch (obj_request->img_request->data_type) {
1496         case OBJ_REQUEST_NODATA:
1497         case OBJ_REQUEST_BIO:
1498         case OBJ_REQUEST_BVECS:
1499                 break;          /* Nothing to do */
1500         case OBJ_REQUEST_OWN_BVECS:
1501                 kfree(obj_request->bvec_pos.bvecs);
1502                 break;
1503         default:
1504                 BUG();
1505         }
1506
1507         kfree(obj_request->img_extents);
1508         if (obj_request->copyup_bvecs) {
1509                 for (i = 0; i < obj_request->copyup_bvec_count; i++) {
1510                         if (obj_request->copyup_bvecs[i].bv_page)
1511                                 __free_page(obj_request->copyup_bvecs[i].bv_page);
1512                 }
1513                 kfree(obj_request->copyup_bvecs);
1514         }
1515
1516         kmem_cache_free(rbd_obj_request_cache, obj_request);
1517 }
1518
1519 /* It's OK to call this for a device with no parent */
1520
1521 static void rbd_spec_put(struct rbd_spec *spec);
1522 static void rbd_dev_unparent(struct rbd_device *rbd_dev)
1523 {
1524         rbd_dev_remove_parent(rbd_dev);
1525         rbd_spec_put(rbd_dev->parent_spec);
1526         rbd_dev->parent_spec = NULL;
1527         rbd_dev->parent_overlap = 0;
1528 }
1529
1530 /*
1531  * Parent image reference counting is used to determine when an
1532  * image's parent fields can be safely torn down--after there are no
1533  * more in-flight requests to the parent image.  When the last
1534  * reference is dropped, cleaning them up is safe.
1535  */
1536 static void rbd_dev_parent_put(struct rbd_device *rbd_dev)
1537 {
1538         int counter;
1539
1540         if (!rbd_dev->parent_spec)
1541                 return;
1542
1543         counter = atomic_dec_return_safe(&rbd_dev->parent_ref);
1544         if (counter > 0)
1545                 return;
1546
1547         /* Last reference; clean up parent data structures */
1548
1549         if (!counter)
1550                 rbd_dev_unparent(rbd_dev);
1551         else
1552                 rbd_warn(rbd_dev, "parent reference underflow");
1553 }
1554
1555 /*
1556  * If an image has a non-zero parent overlap, get a reference to its
1557  * parent.
1558  *
1559  * Returns true if the rbd device has a parent with a non-zero
1560  * overlap and a reference for it was successfully taken, or
1561  * false otherwise.
1562  */
1563 static bool rbd_dev_parent_get(struct rbd_device *rbd_dev)
1564 {
1565         int counter = 0;
1566
1567         if (!rbd_dev->parent_spec)
1568                 return false;
1569
1570         if (rbd_dev->parent_overlap)
1571                 counter = atomic_inc_return_safe(&rbd_dev->parent_ref);
1572
1573         if (counter < 0)
1574                 rbd_warn(rbd_dev, "parent reference overflow");
1575
1576         return counter > 0;
1577 }
1578
1579 static void rbd_img_request_init(struct rbd_img_request *img_request,
1580                                  struct rbd_device *rbd_dev,
1581                                  enum obj_operation_type op_type)
1582 {
1583         memset(img_request, 0, sizeof(*img_request));
1584
1585         img_request->rbd_dev = rbd_dev;
1586         img_request->op_type = op_type;
1587
1588         INIT_LIST_HEAD(&img_request->lock_item);
1589         INIT_LIST_HEAD(&img_request->object_extents);
1590         mutex_init(&img_request->state_mutex);
1591 }
1592
1593 static void rbd_img_capture_header(struct rbd_img_request *img_req)
1594 {
1595         struct rbd_device *rbd_dev = img_req->rbd_dev;
1596
1597         lockdep_assert_held(&rbd_dev->header_rwsem);
1598
1599         if (rbd_img_is_write(img_req))
1600                 img_req->snapc = ceph_get_snap_context(rbd_dev->header.snapc);
1601         else
1602                 img_req->snap_id = rbd_dev->spec->snap_id;
1603
1604         if (rbd_dev_parent_get(rbd_dev))
1605                 img_request_layered_set(img_req);
1606 }
1607
1608 static void rbd_img_request_destroy(struct rbd_img_request *img_request)
1609 {
1610         struct rbd_obj_request *obj_request;
1611         struct rbd_obj_request *next_obj_request;
1612
1613         dout("%s: img %p\n", __func__, img_request);
1614
1615         WARN_ON(!list_empty(&img_request->lock_item));
1616         for_each_obj_request_safe(img_request, obj_request, next_obj_request)
1617                 rbd_img_obj_request_del(img_request, obj_request);
1618
1619         if (img_request_layered_test(img_request))
1620                 rbd_dev_parent_put(img_request->rbd_dev);
1621
1622         if (rbd_img_is_write(img_request))
1623                 ceph_put_snap_context(img_request->snapc);
1624
1625         if (test_bit(IMG_REQ_CHILD, &img_request->flags))
1626                 kmem_cache_free(rbd_img_request_cache, img_request);
1627 }
1628
1629 #define BITS_PER_OBJ    2
1630 #define OBJS_PER_BYTE   (BITS_PER_BYTE / BITS_PER_OBJ)
1631 #define OBJ_MASK        ((1 << BITS_PER_OBJ) - 1)
1632
1633 static void __rbd_object_map_index(struct rbd_device *rbd_dev, u64 objno,
1634                                    u64 *index, u8 *shift)
1635 {
1636         u32 off;
1637
1638         rbd_assert(objno < rbd_dev->object_map_size);
1639         *index = div_u64_rem(objno, OBJS_PER_BYTE, &off);
1640         *shift = (OBJS_PER_BYTE - off - 1) * BITS_PER_OBJ;
1641 }
1642
1643 static u8 __rbd_object_map_get(struct rbd_device *rbd_dev, u64 objno)
1644 {
1645         u64 index;
1646         u8 shift;
1647
1648         lockdep_assert_held(&rbd_dev->object_map_lock);
1649         __rbd_object_map_index(rbd_dev, objno, &index, &shift);
1650         return (rbd_dev->object_map[index] >> shift) & OBJ_MASK;
1651 }
1652
1653 static void __rbd_object_map_set(struct rbd_device *rbd_dev, u64 objno, u8 val)
1654 {
1655         u64 index;
1656         u8 shift;
1657         u8 *p;
1658
1659         lockdep_assert_held(&rbd_dev->object_map_lock);
1660         rbd_assert(!(val & ~OBJ_MASK));
1661
1662         __rbd_object_map_index(rbd_dev, objno, &index, &shift);
1663         p = &rbd_dev->object_map[index];
1664         *p = (*p & ~(OBJ_MASK << shift)) | (val << shift);
1665 }
1666
1667 static u8 rbd_object_map_get(struct rbd_device *rbd_dev, u64 objno)
1668 {
1669         u8 state;
1670
1671         spin_lock(&rbd_dev->object_map_lock);
1672         state = __rbd_object_map_get(rbd_dev, objno);
1673         spin_unlock(&rbd_dev->object_map_lock);
1674         return state;
1675 }
1676
1677 static bool use_object_map(struct rbd_device *rbd_dev)
1678 {
1679         /*
1680          * An image mapped read-only can't use the object map -- it isn't
1681          * loaded because the header lock isn't acquired.  Someone else can
1682          * write to the image and update the object map behind our back.
1683          *
1684          * A snapshot can't be written to, so using the object map is always
1685          * safe.
1686          */
1687         if (!rbd_is_snap(rbd_dev) && rbd_is_ro(rbd_dev))
1688                 return false;
1689
1690         return ((rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP) &&
1691                 !(rbd_dev->object_map_flags & RBD_FLAG_OBJECT_MAP_INVALID));
1692 }
1693
1694 static bool rbd_object_map_may_exist(struct rbd_device *rbd_dev, u64 objno)
1695 {
1696         u8 state;
1697
1698         /* fall back to default logic if object map is disabled or invalid */
1699         if (!use_object_map(rbd_dev))
1700                 return true;
1701
1702         state = rbd_object_map_get(rbd_dev, objno);
1703         return state != OBJECT_NONEXISTENT;
1704 }
1705
1706 static void rbd_object_map_name(struct rbd_device *rbd_dev, u64 snap_id,
1707                                 struct ceph_object_id *oid)
1708 {
1709         if (snap_id == CEPH_NOSNAP)
1710                 ceph_oid_printf(oid, "%s%s", RBD_OBJECT_MAP_PREFIX,
1711                                 rbd_dev->spec->image_id);
1712         else
1713                 ceph_oid_printf(oid, "%s%s.%016llx", RBD_OBJECT_MAP_PREFIX,
1714                                 rbd_dev->spec->image_id, snap_id);
1715 }
1716
1717 static int rbd_object_map_lock(struct rbd_device *rbd_dev)
1718 {
1719         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
1720         CEPH_DEFINE_OID_ONSTACK(oid);
1721         u8 lock_type;
1722         char *lock_tag;
1723         struct ceph_locker *lockers;
1724         u32 num_lockers;
1725         bool broke_lock = false;
1726         int ret;
1727
1728         rbd_object_map_name(rbd_dev, CEPH_NOSNAP, &oid);
1729
1730 again:
1731         ret = ceph_cls_lock(osdc, &oid, &rbd_dev->header_oloc, RBD_LOCK_NAME,
1732                             CEPH_CLS_LOCK_EXCLUSIVE, "", "", "", 0);
1733         if (ret != -EBUSY || broke_lock) {
1734                 if (ret == -EEXIST)
1735                         ret = 0; /* already locked by myself */
1736                 if (ret)
1737                         rbd_warn(rbd_dev, "failed to lock object map: %d", ret);
1738                 return ret;
1739         }
1740
1741         ret = ceph_cls_lock_info(osdc, &oid, &rbd_dev->header_oloc,
1742                                  RBD_LOCK_NAME, &lock_type, &lock_tag,
1743                                  &lockers, &num_lockers);
1744         if (ret) {
1745                 if (ret == -ENOENT)
1746                         goto again;
1747
1748                 rbd_warn(rbd_dev, "failed to get object map lockers: %d", ret);
1749                 return ret;
1750         }
1751
1752         kfree(lock_tag);
1753         if (num_lockers == 0)
1754                 goto again;
1755
1756         rbd_warn(rbd_dev, "breaking object map lock owned by %s%llu",
1757                  ENTITY_NAME(lockers[0].id.name));
1758
1759         ret = ceph_cls_break_lock(osdc, &oid, &rbd_dev->header_oloc,
1760                                   RBD_LOCK_NAME, lockers[0].id.cookie,
1761                                   &lockers[0].id.name);
1762         ceph_free_lockers(lockers, num_lockers);
1763         if (ret) {
1764                 if (ret == -ENOENT)
1765                         goto again;
1766
1767                 rbd_warn(rbd_dev, "failed to break object map lock: %d", ret);
1768                 return ret;
1769         }
1770
1771         broke_lock = true;
1772         goto again;
1773 }
1774
1775 static void rbd_object_map_unlock(struct rbd_device *rbd_dev)
1776 {
1777         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
1778         CEPH_DEFINE_OID_ONSTACK(oid);
1779         int ret;
1780
1781         rbd_object_map_name(rbd_dev, CEPH_NOSNAP, &oid);
1782
1783         ret = ceph_cls_unlock(osdc, &oid, &rbd_dev->header_oloc, RBD_LOCK_NAME,
1784                               "");
1785         if (ret && ret != -ENOENT)
1786                 rbd_warn(rbd_dev, "failed to unlock object map: %d", ret);
1787 }
1788
1789 static int decode_object_map_header(void **p, void *end, u64 *object_map_size)
1790 {
1791         u8 struct_v;
1792         u32 struct_len;
1793         u32 header_len;
1794         void *header_end;
1795         int ret;
1796
1797         ceph_decode_32_safe(p, end, header_len, e_inval);
1798         header_end = *p + header_len;
1799
1800         ret = ceph_start_decoding(p, end, 1, "BitVector header", &struct_v,
1801                                   &struct_len);
1802         if (ret)
1803                 return ret;
1804
1805         ceph_decode_64_safe(p, end, *object_map_size, e_inval);
1806
1807         *p = header_end;
1808         return 0;
1809
1810 e_inval:
1811         return -EINVAL;
1812 }
1813
1814 static int __rbd_object_map_load(struct rbd_device *rbd_dev)
1815 {
1816         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
1817         CEPH_DEFINE_OID_ONSTACK(oid);
1818         struct page **pages;
1819         void *p, *end;
1820         size_t reply_len;
1821         u64 num_objects;
1822         u64 object_map_bytes;
1823         u64 object_map_size;
1824         int num_pages;
1825         int ret;
1826
1827         rbd_assert(!rbd_dev->object_map && !rbd_dev->object_map_size);
1828
1829         num_objects = ceph_get_num_objects(&rbd_dev->layout,
1830                                            rbd_dev->mapping.size);
1831         object_map_bytes = DIV_ROUND_UP_ULL(num_objects * BITS_PER_OBJ,
1832                                             BITS_PER_BYTE);
1833         num_pages = calc_pages_for(0, object_map_bytes) + 1;
1834         pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
1835         if (IS_ERR(pages))
1836                 return PTR_ERR(pages);
1837
1838         reply_len = num_pages * PAGE_SIZE;
1839         rbd_object_map_name(rbd_dev, rbd_dev->spec->snap_id, &oid);
1840         ret = ceph_osdc_call(osdc, &oid, &rbd_dev->header_oloc,
1841                              "rbd", "object_map_load", CEPH_OSD_FLAG_READ,
1842                              NULL, 0, pages, &reply_len);
1843         if (ret)
1844                 goto out;
1845
1846         p = page_address(pages[0]);
1847         end = p + min(reply_len, (size_t)PAGE_SIZE);
1848         ret = decode_object_map_header(&p, end, &object_map_size);
1849         if (ret)
1850                 goto out;
1851
1852         if (object_map_size != num_objects) {
1853                 rbd_warn(rbd_dev, "object map size mismatch: %llu vs %llu",
1854                          object_map_size, num_objects);
1855                 ret = -EINVAL;
1856                 goto out;
1857         }
1858
1859         if (offset_in_page(p) + object_map_bytes > reply_len) {
1860                 ret = -EINVAL;
1861                 goto out;
1862         }
1863
1864         rbd_dev->object_map = kvmalloc(object_map_bytes, GFP_KERNEL);
1865         if (!rbd_dev->object_map) {
1866                 ret = -ENOMEM;
1867                 goto out;
1868         }
1869
1870         rbd_dev->object_map_size = object_map_size;
1871         ceph_copy_from_page_vector(pages, rbd_dev->object_map,
1872                                    offset_in_page(p), object_map_bytes);
1873
1874 out:
1875         ceph_release_page_vector(pages, num_pages);
1876         return ret;
1877 }
1878
1879 static void rbd_object_map_free(struct rbd_device *rbd_dev)
1880 {
1881         kvfree(rbd_dev->object_map);
1882         rbd_dev->object_map = NULL;
1883         rbd_dev->object_map_size = 0;
1884 }
1885
1886 static int rbd_object_map_load(struct rbd_device *rbd_dev)
1887 {
1888         int ret;
1889
1890         ret = __rbd_object_map_load(rbd_dev);
1891         if (ret)
1892                 return ret;
1893
1894         ret = rbd_dev_v2_get_flags(rbd_dev);
1895         if (ret) {
1896                 rbd_object_map_free(rbd_dev);
1897                 return ret;
1898         }
1899
1900         if (rbd_dev->object_map_flags & RBD_FLAG_OBJECT_MAP_INVALID)
1901                 rbd_warn(rbd_dev, "object map is invalid");
1902
1903         return 0;
1904 }
1905
1906 static int rbd_object_map_open(struct rbd_device *rbd_dev)
1907 {
1908         int ret;
1909
1910         ret = rbd_object_map_lock(rbd_dev);
1911         if (ret)
1912                 return ret;
1913
1914         ret = rbd_object_map_load(rbd_dev);
1915         if (ret) {
1916                 rbd_object_map_unlock(rbd_dev);
1917                 return ret;
1918         }
1919
1920         return 0;
1921 }
1922
1923 static void rbd_object_map_close(struct rbd_device *rbd_dev)
1924 {
1925         rbd_object_map_free(rbd_dev);
1926         rbd_object_map_unlock(rbd_dev);
1927 }
1928
1929 /*
1930  * This function needs snap_id (or more precisely just something to
1931  * distinguish between HEAD and snapshot object maps), new_state and
1932  * current_state that were passed to rbd_object_map_update().
1933  *
1934  * To avoid allocating and stashing a context we piggyback on the OSD
1935  * request.  A HEAD update has two ops (assert_locked).  For new_state
1936  * and current_state we decode our own object_map_update op, encoded in
1937  * rbd_cls_object_map_update().
1938  */
1939 static int rbd_object_map_update_finish(struct rbd_obj_request *obj_req,
1940                                         struct ceph_osd_request *osd_req)
1941 {
1942         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
1943         struct ceph_osd_data *osd_data;
1944         u64 objno;
1945         u8 state, new_state, current_state;
1946         bool has_current_state;
1947         void *p;
1948
1949         if (osd_req->r_result)
1950                 return osd_req->r_result;
1951
1952         /*
1953          * Nothing to do for a snapshot object map.
1954          */
1955         if (osd_req->r_num_ops == 1)
1956                 return 0;
1957
1958         /*
1959          * Update in-memory HEAD object map.
1960          */
1961         rbd_assert(osd_req->r_num_ops == 2);
1962         osd_data = osd_req_op_data(osd_req, 1, cls, request_data);
1963         rbd_assert(osd_data->type == CEPH_OSD_DATA_TYPE_PAGES);
1964
1965         p = page_address(osd_data->pages[0]);
1966         objno = ceph_decode_64(&p);
1967         rbd_assert(objno == obj_req->ex.oe_objno);
1968         rbd_assert(ceph_decode_64(&p) == objno + 1);
1969         new_state = ceph_decode_8(&p);
1970         has_current_state = ceph_decode_8(&p);
1971         if (has_current_state)
1972                 current_state = ceph_decode_8(&p);
1973
1974         spin_lock(&rbd_dev->object_map_lock);
1975         state = __rbd_object_map_get(rbd_dev, objno);
1976         if (!has_current_state || current_state == state ||
1977             (current_state == OBJECT_EXISTS && state == OBJECT_EXISTS_CLEAN))
1978                 __rbd_object_map_set(rbd_dev, objno, new_state);
1979         spin_unlock(&rbd_dev->object_map_lock);
1980
1981         return 0;
1982 }
1983
1984 static void rbd_object_map_callback(struct ceph_osd_request *osd_req)
1985 {
1986         struct rbd_obj_request *obj_req = osd_req->r_priv;
1987         int result;
1988
1989         dout("%s osd_req %p result %d for obj_req %p\n", __func__, osd_req,
1990              osd_req->r_result, obj_req);
1991
1992         result = rbd_object_map_update_finish(obj_req, osd_req);
1993         rbd_obj_handle_request(obj_req, result);
1994 }
1995
1996 static bool update_needed(struct rbd_device *rbd_dev, u64 objno, u8 new_state)
1997 {
1998         u8 state = rbd_object_map_get(rbd_dev, objno);
1999
2000         if (state == new_state ||
2001             (new_state == OBJECT_PENDING && state == OBJECT_NONEXISTENT) ||
2002             (new_state == OBJECT_NONEXISTENT && state != OBJECT_PENDING))
2003                 return false;
2004
2005         return true;
2006 }
2007
2008 static int rbd_cls_object_map_update(struct ceph_osd_request *req,
2009                                      int which, u64 objno, u8 new_state,
2010                                      const u8 *current_state)
2011 {
2012         struct page **pages;
2013         void *p, *start;
2014         int ret;
2015
2016         ret = osd_req_op_cls_init(req, which, "rbd", "object_map_update");
2017         if (ret)
2018                 return ret;
2019
2020         pages = ceph_alloc_page_vector(1, GFP_NOIO);
2021         if (IS_ERR(pages))
2022                 return PTR_ERR(pages);
2023
2024         p = start = page_address(pages[0]);
2025         ceph_encode_64(&p, objno);
2026         ceph_encode_64(&p, objno + 1);
2027         ceph_encode_8(&p, new_state);
2028         if (current_state) {
2029                 ceph_encode_8(&p, 1);
2030                 ceph_encode_8(&p, *current_state);
2031         } else {
2032                 ceph_encode_8(&p, 0);
2033         }
2034
2035         osd_req_op_cls_request_data_pages(req, which, pages, p - start, 0,
2036                                           false, true);
2037         return 0;
2038 }
2039
2040 /*
2041  * Return:
2042  *   0 - object map update sent
2043  *   1 - object map update isn't needed
2044  *  <0 - error
2045  */
2046 static int rbd_object_map_update(struct rbd_obj_request *obj_req, u64 snap_id,
2047                                  u8 new_state, const u8 *current_state)
2048 {
2049         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
2050         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
2051         struct ceph_osd_request *req;
2052         int num_ops = 1;
2053         int which = 0;
2054         int ret;
2055
2056         if (snap_id == CEPH_NOSNAP) {
2057                 if (!update_needed(rbd_dev, obj_req->ex.oe_objno, new_state))
2058                         return 1;
2059
2060                 num_ops++; /* assert_locked */
2061         }
2062
2063         req = ceph_osdc_alloc_request(osdc, NULL, num_ops, false, GFP_NOIO);
2064         if (!req)
2065                 return -ENOMEM;
2066
2067         list_add_tail(&req->r_private_item, &obj_req->osd_reqs);
2068         req->r_callback = rbd_object_map_callback;
2069         req->r_priv = obj_req;
2070
2071         rbd_object_map_name(rbd_dev, snap_id, &req->r_base_oid);
2072         ceph_oloc_copy(&req->r_base_oloc, &rbd_dev->header_oloc);
2073         req->r_flags = CEPH_OSD_FLAG_WRITE;
2074         ktime_get_real_ts64(&req->r_mtime);
2075
2076         if (snap_id == CEPH_NOSNAP) {
2077                 /*
2078                  * Protect against possible race conditions during lock
2079                  * ownership transitions.
2080                  */
2081                 ret = ceph_cls_assert_locked(req, which++, RBD_LOCK_NAME,
2082                                              CEPH_CLS_LOCK_EXCLUSIVE, "", "");
2083                 if (ret)
2084                         return ret;
2085         }
2086
2087         ret = rbd_cls_object_map_update(req, which, obj_req->ex.oe_objno,
2088                                         new_state, current_state);
2089         if (ret)
2090                 return ret;
2091
2092         ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
2093         if (ret)
2094                 return ret;
2095
2096         ceph_osdc_start_request(osdc, req, false);
2097         return 0;
2098 }
2099
2100 static void prune_extents(struct ceph_file_extent *img_extents,
2101                           u32 *num_img_extents, u64 overlap)
2102 {
2103         u32 cnt = *num_img_extents;
2104
2105         /* drop extents completely beyond the overlap */
2106         while (cnt && img_extents[cnt - 1].fe_off >= overlap)
2107                 cnt--;
2108
2109         if (cnt) {
2110                 struct ceph_file_extent *ex = &img_extents[cnt - 1];
2111
2112                 /* trim final overlapping extent */
2113                 if (ex->fe_off + ex->fe_len > overlap)
2114                         ex->fe_len = overlap - ex->fe_off;
2115         }
2116
2117         *num_img_extents = cnt;
2118 }
2119
2120 /*
2121  * Determine the byte range(s) covered by either just the object extent
2122  * or the entire object in the parent image.
2123  */
2124 static int rbd_obj_calc_img_extents(struct rbd_obj_request *obj_req,
2125                                     bool entire)
2126 {
2127         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
2128         int ret;
2129
2130         if (!rbd_dev->parent_overlap)
2131                 return 0;
2132
2133         ret = ceph_extent_to_file(&rbd_dev->layout, obj_req->ex.oe_objno,
2134                                   entire ? 0 : obj_req->ex.oe_off,
2135                                   entire ? rbd_dev->layout.object_size :
2136                                                         obj_req->ex.oe_len,
2137                                   &obj_req->img_extents,
2138                                   &obj_req->num_img_extents);
2139         if (ret)
2140                 return ret;
2141
2142         prune_extents(obj_req->img_extents, &obj_req->num_img_extents,
2143                       rbd_dev->parent_overlap);
2144         return 0;
2145 }
2146
2147 static void rbd_osd_setup_data(struct ceph_osd_request *osd_req, int which)
2148 {
2149         struct rbd_obj_request *obj_req = osd_req->r_priv;
2150
2151         switch (obj_req->img_request->data_type) {
2152         case OBJ_REQUEST_BIO:
2153                 osd_req_op_extent_osd_data_bio(osd_req, which,
2154                                                &obj_req->bio_pos,
2155                                                obj_req->ex.oe_len);
2156                 break;
2157         case OBJ_REQUEST_BVECS:
2158         case OBJ_REQUEST_OWN_BVECS:
2159                 rbd_assert(obj_req->bvec_pos.iter.bi_size ==
2160                                                         obj_req->ex.oe_len);
2161                 rbd_assert(obj_req->bvec_idx == obj_req->bvec_count);
2162                 osd_req_op_extent_osd_data_bvec_pos(osd_req, which,
2163                                                     &obj_req->bvec_pos);
2164                 break;
2165         default:
2166                 BUG();
2167         }
2168 }
2169
2170 static int rbd_osd_setup_stat(struct ceph_osd_request *osd_req, int which)
2171 {
2172         struct page **pages;
2173
2174         /*
2175          * The response data for a STAT call consists of:
2176          *     le64 length;
2177          *     struct {
2178          *         le32 tv_sec;
2179          *         le32 tv_nsec;
2180          *     } mtime;
2181          */
2182         pages = ceph_alloc_page_vector(1, GFP_NOIO);
2183         if (IS_ERR(pages))
2184                 return PTR_ERR(pages);
2185
2186         osd_req_op_init(osd_req, which, CEPH_OSD_OP_STAT, 0);
2187         osd_req_op_raw_data_in_pages(osd_req, which, pages,
2188                                      8 + sizeof(struct ceph_timespec),
2189                                      0, false, true);
2190         return 0;
2191 }
2192
2193 static int rbd_osd_setup_copyup(struct ceph_osd_request *osd_req, int which,
2194                                 u32 bytes)
2195 {
2196         struct rbd_obj_request *obj_req = osd_req->r_priv;
2197         int ret;
2198
2199         ret = osd_req_op_cls_init(osd_req, which, "rbd", "copyup");
2200         if (ret)
2201                 return ret;
2202
2203         osd_req_op_cls_request_data_bvecs(osd_req, which, obj_req->copyup_bvecs,
2204                                           obj_req->copyup_bvec_count, bytes);
2205         return 0;
2206 }
2207
2208 static int rbd_obj_init_read(struct rbd_obj_request *obj_req)
2209 {
2210         obj_req->read_state = RBD_OBJ_READ_START;
2211         return 0;
2212 }
2213
2214 static void __rbd_osd_setup_write_ops(struct ceph_osd_request *osd_req,
2215                                       int which)
2216 {
2217         struct rbd_obj_request *obj_req = osd_req->r_priv;
2218         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
2219         u16 opcode;
2220
2221         if (!use_object_map(rbd_dev) ||
2222             !(obj_req->flags & RBD_OBJ_FLAG_MAY_EXIST)) {
2223                 osd_req_op_alloc_hint_init(osd_req, which++,
2224                                            rbd_dev->layout.object_size,
2225                                            rbd_dev->layout.object_size,
2226                                            rbd_dev->opts->alloc_hint_flags);
2227         }
2228
2229         if (rbd_obj_is_entire(obj_req))
2230                 opcode = CEPH_OSD_OP_WRITEFULL;
2231         else
2232                 opcode = CEPH_OSD_OP_WRITE;
2233
2234         osd_req_op_extent_init(osd_req, which, opcode,
2235                                obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0);
2236         rbd_osd_setup_data(osd_req, which);
2237 }
2238
2239 static int rbd_obj_init_write(struct rbd_obj_request *obj_req)
2240 {
2241         int ret;
2242
2243         /* reverse map the entire object onto the parent */
2244         ret = rbd_obj_calc_img_extents(obj_req, true);
2245         if (ret)
2246                 return ret;
2247
2248         if (rbd_obj_copyup_enabled(obj_req))
2249                 obj_req->flags |= RBD_OBJ_FLAG_COPYUP_ENABLED;
2250
2251         obj_req->write_state = RBD_OBJ_WRITE_START;
2252         return 0;
2253 }
2254
2255 static u16 truncate_or_zero_opcode(struct rbd_obj_request *obj_req)
2256 {
2257         return rbd_obj_is_tail(obj_req) ? CEPH_OSD_OP_TRUNCATE :
2258                                           CEPH_OSD_OP_ZERO;
2259 }
2260
2261 static void __rbd_osd_setup_discard_ops(struct ceph_osd_request *osd_req,
2262                                         int which)
2263 {
2264         struct rbd_obj_request *obj_req = osd_req->r_priv;
2265
2266         if (rbd_obj_is_entire(obj_req) && !obj_req->num_img_extents) {
2267                 rbd_assert(obj_req->flags & RBD_OBJ_FLAG_DELETION);
2268                 osd_req_op_init(osd_req, which, CEPH_OSD_OP_DELETE, 0);
2269         } else {
2270                 osd_req_op_extent_init(osd_req, which,
2271                                        truncate_or_zero_opcode(obj_req),
2272                                        obj_req->ex.oe_off, obj_req->ex.oe_len,
2273                                        0, 0);
2274         }
2275 }
2276
2277 static int rbd_obj_init_discard(struct rbd_obj_request *obj_req)
2278 {
2279         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
2280         u64 off, next_off;
2281         int ret;
2282
2283         /*
2284          * Align the range to alloc_size boundary and punt on discards
2285          * that are too small to free up any space.
2286          *
2287          * alloc_size == object_size && is_tail() is a special case for
2288          * filestore with filestore_punch_hole = false, needed to allow
2289          * truncate (in addition to delete).
2290          */
2291         if (rbd_dev->opts->alloc_size != rbd_dev->layout.object_size ||
2292             !rbd_obj_is_tail(obj_req)) {
2293                 off = round_up(obj_req->ex.oe_off, rbd_dev->opts->alloc_size);
2294                 next_off = round_down(obj_req->ex.oe_off + obj_req->ex.oe_len,
2295                                       rbd_dev->opts->alloc_size);
2296                 if (off >= next_off)
2297                         return 1;
2298
2299                 dout("%s %p %llu~%llu -> %llu~%llu\n", __func__,
2300                      obj_req, obj_req->ex.oe_off, obj_req->ex.oe_len,
2301                      off, next_off - off);
2302                 obj_req->ex.oe_off = off;
2303                 obj_req->ex.oe_len = next_off - off;
2304         }
2305
2306         /* reverse map the entire object onto the parent */
2307         ret = rbd_obj_calc_img_extents(obj_req, true);
2308         if (ret)
2309                 return ret;
2310
2311         obj_req->flags |= RBD_OBJ_FLAG_NOOP_FOR_NONEXISTENT;
2312         if (rbd_obj_is_entire(obj_req) && !obj_req->num_img_extents)
2313                 obj_req->flags |= RBD_OBJ_FLAG_DELETION;
2314
2315         obj_req->write_state = RBD_OBJ_WRITE_START;
2316         return 0;
2317 }
2318
2319 static void __rbd_osd_setup_zeroout_ops(struct ceph_osd_request *osd_req,
2320                                         int which)
2321 {
2322         struct rbd_obj_request *obj_req = osd_req->r_priv;
2323         u16 opcode;
2324
2325         if (rbd_obj_is_entire(obj_req)) {
2326                 if (obj_req->num_img_extents) {
2327                         if (!(obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED))
2328                                 osd_req_op_init(osd_req, which++,
2329                                                 CEPH_OSD_OP_CREATE, 0);
2330                         opcode = CEPH_OSD_OP_TRUNCATE;
2331                 } else {
2332                         rbd_assert(obj_req->flags & RBD_OBJ_FLAG_DELETION);
2333                         osd_req_op_init(osd_req, which++,
2334                                         CEPH_OSD_OP_DELETE, 0);
2335                         opcode = 0;
2336                 }
2337         } else {
2338                 opcode = truncate_or_zero_opcode(obj_req);
2339         }
2340
2341         if (opcode)
2342                 osd_req_op_extent_init(osd_req, which, opcode,
2343                                        obj_req->ex.oe_off, obj_req->ex.oe_len,
2344                                        0, 0);
2345 }
2346
2347 static int rbd_obj_init_zeroout(struct rbd_obj_request *obj_req)
2348 {
2349         int ret;
2350
2351         /* reverse map the entire object onto the parent */
2352         ret = rbd_obj_calc_img_extents(obj_req, true);
2353         if (ret)
2354                 return ret;
2355
2356         if (rbd_obj_copyup_enabled(obj_req))
2357                 obj_req->flags |= RBD_OBJ_FLAG_COPYUP_ENABLED;
2358         if (!obj_req->num_img_extents) {
2359                 obj_req->flags |= RBD_OBJ_FLAG_NOOP_FOR_NONEXISTENT;
2360                 if (rbd_obj_is_entire(obj_req))
2361                         obj_req->flags |= RBD_OBJ_FLAG_DELETION;
2362         }
2363
2364         obj_req->write_state = RBD_OBJ_WRITE_START;
2365         return 0;
2366 }
2367
2368 static int count_write_ops(struct rbd_obj_request *obj_req)
2369 {
2370         struct rbd_img_request *img_req = obj_req->img_request;
2371
2372         switch (img_req->op_type) {
2373         case OBJ_OP_WRITE:
2374                 if (!use_object_map(img_req->rbd_dev) ||
2375                     !(obj_req->flags & RBD_OBJ_FLAG_MAY_EXIST))
2376                         return 2; /* setallochint + write/writefull */
2377
2378                 return 1; /* write/writefull */
2379         case OBJ_OP_DISCARD:
2380                 return 1; /* delete/truncate/zero */
2381         case OBJ_OP_ZEROOUT:
2382                 if (rbd_obj_is_entire(obj_req) && obj_req->num_img_extents &&
2383                     !(obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED))
2384                         return 2; /* create + truncate */
2385
2386                 return 1; /* delete/truncate/zero */
2387         default:
2388                 BUG();
2389         }
2390 }
2391
2392 static void rbd_osd_setup_write_ops(struct ceph_osd_request *osd_req,
2393                                     int which)
2394 {
2395         struct rbd_obj_request *obj_req = osd_req->r_priv;
2396
2397         switch (obj_req->img_request->op_type) {
2398         case OBJ_OP_WRITE:
2399                 __rbd_osd_setup_write_ops(osd_req, which);
2400                 break;
2401         case OBJ_OP_DISCARD:
2402                 __rbd_osd_setup_discard_ops(osd_req, which);
2403                 break;
2404         case OBJ_OP_ZEROOUT:
2405                 __rbd_osd_setup_zeroout_ops(osd_req, which);
2406                 break;
2407         default:
2408                 BUG();
2409         }
2410 }
2411
2412 /*
2413  * Prune the list of object requests (adjust offset and/or length, drop
2414  * redundant requests).  Prepare object request state machines and image
2415  * request state machine for execution.
2416  */
2417 static int __rbd_img_fill_request(struct rbd_img_request *img_req)
2418 {
2419         struct rbd_obj_request *obj_req, *next_obj_req;
2420         int ret;
2421
2422         for_each_obj_request_safe(img_req, obj_req, next_obj_req) {
2423                 switch (img_req->op_type) {
2424                 case OBJ_OP_READ:
2425                         ret = rbd_obj_init_read(obj_req);
2426                         break;
2427                 case OBJ_OP_WRITE:
2428                         ret = rbd_obj_init_write(obj_req);
2429                         break;
2430                 case OBJ_OP_DISCARD:
2431                         ret = rbd_obj_init_discard(obj_req);
2432                         break;
2433                 case OBJ_OP_ZEROOUT:
2434                         ret = rbd_obj_init_zeroout(obj_req);
2435                         break;
2436                 default:
2437                         BUG();
2438                 }
2439                 if (ret < 0)
2440                         return ret;
2441                 if (ret > 0) {
2442                         rbd_img_obj_request_del(img_req, obj_req);
2443                         continue;
2444                 }
2445         }
2446
2447         img_req->state = RBD_IMG_START;
2448         return 0;
2449 }
2450
2451 union rbd_img_fill_iter {
2452         struct ceph_bio_iter    bio_iter;
2453         struct ceph_bvec_iter   bvec_iter;
2454 };
2455
2456 struct rbd_img_fill_ctx {
2457         enum obj_request_type   pos_type;
2458         union rbd_img_fill_iter *pos;
2459         union rbd_img_fill_iter iter;
2460         ceph_object_extent_fn_t set_pos_fn;
2461         ceph_object_extent_fn_t count_fn;
2462         ceph_object_extent_fn_t copy_fn;
2463 };
2464
2465 static struct ceph_object_extent *alloc_object_extent(void *arg)
2466 {
2467         struct rbd_img_request *img_req = arg;
2468         struct rbd_obj_request *obj_req;
2469
2470         obj_req = rbd_obj_request_create();
2471         if (!obj_req)
2472                 return NULL;
2473
2474         rbd_img_obj_request_add(img_req, obj_req);
2475         return &obj_req->ex;
2476 }
2477
2478 /*
2479  * While su != os && sc == 1 is technically not fancy (it's the same
2480  * layout as su == os && sc == 1), we can't use the nocopy path for it
2481  * because ->set_pos_fn() should be called only once per object.
2482  * ceph_file_to_extents() invokes action_fn once per stripe unit, so
2483  * treat su != os && sc == 1 as fancy.
2484  */
2485 static bool rbd_layout_is_fancy(struct ceph_file_layout *l)
2486 {
2487         return l->stripe_unit != l->object_size;
2488 }
2489
2490 static int rbd_img_fill_request_nocopy(struct rbd_img_request *img_req,
2491                                        struct ceph_file_extent *img_extents,
2492                                        u32 num_img_extents,
2493                                        struct rbd_img_fill_ctx *fctx)
2494 {
2495         u32 i;
2496         int ret;
2497
2498         img_req->data_type = fctx->pos_type;
2499
2500         /*
2501          * Create object requests and set each object request's starting
2502          * position in the provided bio (list) or bio_vec array.
2503          */
2504         fctx->iter = *fctx->pos;
2505         for (i = 0; i < num_img_extents; i++) {
2506                 ret = ceph_file_to_extents(&img_req->rbd_dev->layout,
2507                                            img_extents[i].fe_off,
2508                                            img_extents[i].fe_len,
2509                                            &img_req->object_extents,
2510                                            alloc_object_extent, img_req,
2511                                            fctx->set_pos_fn, &fctx->iter);
2512                 if (ret)
2513                         return ret;
2514         }
2515
2516         return __rbd_img_fill_request(img_req);
2517 }
2518
2519 /*
2520  * Map a list of image extents to a list of object extents, create the
2521  * corresponding object requests (normally each to a different object,
2522  * but not always) and add them to @img_req.  For each object request,
2523  * set up its data descriptor to point to the corresponding chunk(s) of
2524  * @fctx->pos data buffer.
2525  *
2526  * Because ceph_file_to_extents() will merge adjacent object extents
2527  * together, each object request's data descriptor may point to multiple
2528  * different chunks of @fctx->pos data buffer.
2529  *
2530  * @fctx->pos data buffer is assumed to be large enough.
2531  */
2532 static int rbd_img_fill_request(struct rbd_img_request *img_req,
2533                                 struct ceph_file_extent *img_extents,
2534                                 u32 num_img_extents,
2535                                 struct rbd_img_fill_ctx *fctx)
2536 {
2537         struct rbd_device *rbd_dev = img_req->rbd_dev;
2538         struct rbd_obj_request *obj_req;
2539         u32 i;
2540         int ret;
2541
2542         if (fctx->pos_type == OBJ_REQUEST_NODATA ||
2543             !rbd_layout_is_fancy(&rbd_dev->layout))
2544                 return rbd_img_fill_request_nocopy(img_req, img_extents,
2545                                                    num_img_extents, fctx);
2546
2547         img_req->data_type = OBJ_REQUEST_OWN_BVECS;
2548
2549         /*
2550          * Create object requests and determine ->bvec_count for each object
2551          * request.  Note that ->bvec_count sum over all object requests may
2552          * be greater than the number of bio_vecs in the provided bio (list)
2553          * or bio_vec array because when mapped, those bio_vecs can straddle
2554          * stripe unit boundaries.
2555          */
2556         fctx->iter = *fctx->pos;
2557         for (i = 0; i < num_img_extents; i++) {
2558                 ret = ceph_file_to_extents(&rbd_dev->layout,
2559                                            img_extents[i].fe_off,
2560                                            img_extents[i].fe_len,
2561                                            &img_req->object_extents,
2562                                            alloc_object_extent, img_req,
2563                                            fctx->count_fn, &fctx->iter);
2564                 if (ret)
2565                         return ret;
2566         }
2567
2568         for_each_obj_request(img_req, obj_req) {
2569                 obj_req->bvec_pos.bvecs = kmalloc_array(obj_req->bvec_count,
2570                                               sizeof(*obj_req->bvec_pos.bvecs),
2571                                               GFP_NOIO);
2572                 if (!obj_req->bvec_pos.bvecs)
2573                         return -ENOMEM;
2574         }
2575
2576         /*
2577          * Fill in each object request's private bio_vec array, splitting and
2578          * rearranging the provided bio_vecs in stripe unit chunks as needed.
2579          */
2580         fctx->iter = *fctx->pos;
2581         for (i = 0; i < num_img_extents; i++) {
2582                 ret = ceph_iterate_extents(&rbd_dev->layout,
2583                                            img_extents[i].fe_off,
2584                                            img_extents[i].fe_len,
2585                                            &img_req->object_extents,
2586                                            fctx->copy_fn, &fctx->iter);
2587                 if (ret)
2588                         return ret;
2589         }
2590
2591         return __rbd_img_fill_request(img_req);
2592 }
2593
2594 static int rbd_img_fill_nodata(struct rbd_img_request *img_req,
2595                                u64 off, u64 len)
2596 {
2597         struct ceph_file_extent ex = { off, len };
2598         union rbd_img_fill_iter dummy = {};
2599         struct rbd_img_fill_ctx fctx = {
2600                 .pos_type = OBJ_REQUEST_NODATA,
2601                 .pos = &dummy,
2602         };
2603
2604         return rbd_img_fill_request(img_req, &ex, 1, &fctx);
2605 }
2606
2607 static void set_bio_pos(struct ceph_object_extent *ex, u32 bytes, void *arg)
2608 {
2609         struct rbd_obj_request *obj_req =
2610             container_of(ex, struct rbd_obj_request, ex);
2611         struct ceph_bio_iter *it = arg;
2612
2613         dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
2614         obj_req->bio_pos = *it;
2615         ceph_bio_iter_advance(it, bytes);
2616 }
2617
2618 static void count_bio_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
2619 {
2620         struct rbd_obj_request *obj_req =
2621             container_of(ex, struct rbd_obj_request, ex);
2622         struct ceph_bio_iter *it = arg;
2623
2624         dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
2625         ceph_bio_iter_advance_step(it, bytes, ({
2626                 obj_req->bvec_count++;
2627         }));
2628
2629 }
2630
2631 static void copy_bio_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
2632 {
2633         struct rbd_obj_request *obj_req =
2634             container_of(ex, struct rbd_obj_request, ex);
2635         struct ceph_bio_iter *it = arg;
2636
2637         dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
2638         ceph_bio_iter_advance_step(it, bytes, ({
2639                 obj_req->bvec_pos.bvecs[obj_req->bvec_idx++] = bv;
2640                 obj_req->bvec_pos.iter.bi_size += bv.bv_len;
2641         }));
2642 }
2643
2644 static int __rbd_img_fill_from_bio(struct rbd_img_request *img_req,
2645                                    struct ceph_file_extent *img_extents,
2646                                    u32 num_img_extents,
2647                                    struct ceph_bio_iter *bio_pos)
2648 {
2649         struct rbd_img_fill_ctx fctx = {
2650                 .pos_type = OBJ_REQUEST_BIO,
2651                 .pos = (union rbd_img_fill_iter *)bio_pos,
2652                 .set_pos_fn = set_bio_pos,
2653                 .count_fn = count_bio_bvecs,
2654                 .copy_fn = copy_bio_bvecs,
2655         };
2656
2657         return rbd_img_fill_request(img_req, img_extents, num_img_extents,
2658                                     &fctx);
2659 }
2660
2661 static int rbd_img_fill_from_bio(struct rbd_img_request *img_req,
2662                                  u64 off, u64 len, struct bio *bio)
2663 {
2664         struct ceph_file_extent ex = { off, len };
2665         struct ceph_bio_iter it = { .bio = bio, .iter = bio->bi_iter };
2666
2667         return __rbd_img_fill_from_bio(img_req, &ex, 1, &it);
2668 }
2669
2670 static void set_bvec_pos(struct ceph_object_extent *ex, u32 bytes, void *arg)
2671 {
2672         struct rbd_obj_request *obj_req =
2673             container_of(ex, struct rbd_obj_request, ex);
2674         struct ceph_bvec_iter *it = arg;
2675
2676         obj_req->bvec_pos = *it;
2677         ceph_bvec_iter_shorten(&obj_req->bvec_pos, bytes);
2678         ceph_bvec_iter_advance(it, bytes);
2679 }
2680
2681 static void count_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
2682 {
2683         struct rbd_obj_request *obj_req =
2684             container_of(ex, struct rbd_obj_request, ex);
2685         struct ceph_bvec_iter *it = arg;
2686
2687         ceph_bvec_iter_advance_step(it, bytes, ({
2688                 obj_req->bvec_count++;
2689         }));
2690 }
2691
2692 static void copy_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
2693 {
2694         struct rbd_obj_request *obj_req =
2695             container_of(ex, struct rbd_obj_request, ex);
2696         struct ceph_bvec_iter *it = arg;
2697
2698         ceph_bvec_iter_advance_step(it, bytes, ({
2699                 obj_req->bvec_pos.bvecs[obj_req->bvec_idx++] = bv;
2700                 obj_req->bvec_pos.iter.bi_size += bv.bv_len;
2701         }));
2702 }
2703
2704 static int __rbd_img_fill_from_bvecs(struct rbd_img_request *img_req,
2705                                      struct ceph_file_extent *img_extents,
2706                                      u32 num_img_extents,
2707                                      struct ceph_bvec_iter *bvec_pos)
2708 {
2709         struct rbd_img_fill_ctx fctx = {
2710                 .pos_type = OBJ_REQUEST_BVECS,
2711                 .pos = (union rbd_img_fill_iter *)bvec_pos,
2712                 .set_pos_fn = set_bvec_pos,
2713                 .count_fn = count_bvecs,
2714                 .copy_fn = copy_bvecs,
2715         };
2716
2717         return rbd_img_fill_request(img_req, img_extents, num_img_extents,
2718                                     &fctx);
2719 }
2720
2721 static int rbd_img_fill_from_bvecs(struct rbd_img_request *img_req,
2722                                    struct ceph_file_extent *img_extents,
2723                                    u32 num_img_extents,
2724                                    struct bio_vec *bvecs)
2725 {
2726         struct ceph_bvec_iter it = {
2727                 .bvecs = bvecs,
2728                 .iter = { .bi_size = ceph_file_extents_bytes(img_extents,
2729                                                              num_img_extents) },
2730         };
2731
2732         return __rbd_img_fill_from_bvecs(img_req, img_extents, num_img_extents,
2733                                          &it);
2734 }
2735
2736 static void rbd_img_handle_request_work(struct work_struct *work)
2737 {
2738         struct rbd_img_request *img_req =
2739             container_of(work, struct rbd_img_request, work);
2740
2741         rbd_img_handle_request(img_req, img_req->work_result);
2742 }
2743
2744 static void rbd_img_schedule(struct rbd_img_request *img_req, int result)
2745 {
2746         INIT_WORK(&img_req->work, rbd_img_handle_request_work);
2747         img_req->work_result = result;
2748         queue_work(rbd_wq, &img_req->work);
2749 }
2750
2751 static bool rbd_obj_may_exist(struct rbd_obj_request *obj_req)
2752 {
2753         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
2754
2755         if (rbd_object_map_may_exist(rbd_dev, obj_req->ex.oe_objno)) {
2756                 obj_req->flags |= RBD_OBJ_FLAG_MAY_EXIST;
2757                 return true;
2758         }
2759
2760         dout("%s %p objno %llu assuming dne\n", __func__, obj_req,
2761              obj_req->ex.oe_objno);
2762         return false;
2763 }
2764
2765 static int rbd_obj_read_object(struct rbd_obj_request *obj_req)
2766 {
2767         struct ceph_osd_request *osd_req;
2768         int ret;
2769
2770         osd_req = __rbd_obj_add_osd_request(obj_req, NULL, 1);
2771         if (IS_ERR(osd_req))
2772                 return PTR_ERR(osd_req);
2773
2774         osd_req_op_extent_init(osd_req, 0, CEPH_OSD_OP_READ,
2775                                obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0);
2776         rbd_osd_setup_data(osd_req, 0);
2777         rbd_osd_format_read(osd_req);
2778
2779         ret = ceph_osdc_alloc_messages(osd_req, GFP_NOIO);
2780         if (ret)
2781                 return ret;
2782
2783         rbd_osd_submit(osd_req);
2784         return 0;
2785 }
2786
2787 static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
2788 {
2789         struct rbd_img_request *img_req = obj_req->img_request;
2790         struct rbd_device *parent = img_req->rbd_dev->parent;
2791         struct rbd_img_request *child_img_req;
2792         int ret;
2793
2794         child_img_req = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
2795         if (!child_img_req)
2796                 return -ENOMEM;
2797
2798         rbd_img_request_init(child_img_req, parent, OBJ_OP_READ);
2799         __set_bit(IMG_REQ_CHILD, &child_img_req->flags);
2800         child_img_req->obj_request = obj_req;
2801
2802         down_read(&parent->header_rwsem);
2803         rbd_img_capture_header(child_img_req);
2804         up_read(&parent->header_rwsem);
2805
2806         dout("%s child_img_req %p for obj_req %p\n", __func__, child_img_req,
2807              obj_req);
2808
2809         if (!rbd_img_is_write(img_req)) {
2810                 switch (img_req->data_type) {
2811                 case OBJ_REQUEST_BIO:
2812                         ret = __rbd_img_fill_from_bio(child_img_req,
2813                                                       obj_req->img_extents,
2814                                                       obj_req->num_img_extents,
2815                                                       &obj_req->bio_pos);
2816                         break;
2817                 case OBJ_REQUEST_BVECS:
2818                 case OBJ_REQUEST_OWN_BVECS:
2819                         ret = __rbd_img_fill_from_bvecs(child_img_req,
2820                                                       obj_req->img_extents,
2821                                                       obj_req->num_img_extents,
2822                                                       &obj_req->bvec_pos);
2823                         break;
2824                 default:
2825                         BUG();
2826                 }
2827         } else {
2828                 ret = rbd_img_fill_from_bvecs(child_img_req,
2829                                               obj_req->img_extents,
2830                                               obj_req->num_img_extents,
2831                                               obj_req->copyup_bvecs);
2832         }
2833         if (ret) {
2834                 rbd_img_request_destroy(child_img_req);
2835                 return ret;
2836         }
2837
2838         /* avoid parent chain recursion */
2839         rbd_img_schedule(child_img_req, 0);
2840         return 0;
2841 }
2842
2843 static bool rbd_obj_advance_read(struct rbd_obj_request *obj_req, int *result)
2844 {
2845         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
2846         int ret;
2847
2848 again:
2849         switch (obj_req->read_state) {
2850         case RBD_OBJ_READ_START:
2851                 rbd_assert(!*result);
2852
2853                 if (!rbd_obj_may_exist(obj_req)) {
2854                         *result = -ENOENT;
2855                         obj_req->read_state = RBD_OBJ_READ_OBJECT;
2856                         goto again;
2857                 }
2858
2859                 ret = rbd_obj_read_object(obj_req);
2860                 if (ret) {
2861                         *result = ret;
2862                         return true;
2863                 }
2864                 obj_req->read_state = RBD_OBJ_READ_OBJECT;
2865                 return false;
2866         case RBD_OBJ_READ_OBJECT:
2867                 if (*result == -ENOENT && rbd_dev->parent_overlap) {
2868                         /* reverse map this object extent onto the parent */
2869                         ret = rbd_obj_calc_img_extents(obj_req, false);
2870                         if (ret) {
2871                                 *result = ret;
2872                                 return true;
2873                         }
2874                         if (obj_req->num_img_extents) {
2875                                 ret = rbd_obj_read_from_parent(obj_req);
2876                                 if (ret) {
2877                                         *result = ret;
2878                                         return true;
2879                                 }
2880                                 obj_req->read_state = RBD_OBJ_READ_PARENT;
2881                                 return false;
2882                         }
2883                 }
2884
2885                 /*
2886                  * -ENOENT means a hole in the image -- zero-fill the entire
2887                  * length of the request.  A short read also implies zero-fill
2888                  * to the end of the request.
2889                  */
2890                 if (*result == -ENOENT) {
2891                         rbd_obj_zero_range(obj_req, 0, obj_req->ex.oe_len);
2892                         *result = 0;
2893                 } else if (*result >= 0) {
2894                         if (*result < obj_req->ex.oe_len)
2895                                 rbd_obj_zero_range(obj_req, *result,
2896                                                 obj_req->ex.oe_len - *result);
2897                         else
2898                                 rbd_assert(*result == obj_req->ex.oe_len);
2899                         *result = 0;
2900                 }
2901                 return true;
2902         case RBD_OBJ_READ_PARENT:
2903                 /*
2904                  * The parent image is read only up to the overlap -- zero-fill
2905                  * from the overlap to the end of the request.
2906                  */
2907                 if (!*result) {
2908                         u32 obj_overlap = rbd_obj_img_extents_bytes(obj_req);
2909
2910                         if (obj_overlap < obj_req->ex.oe_len)
2911                                 rbd_obj_zero_range(obj_req, obj_overlap,
2912                                             obj_req->ex.oe_len - obj_overlap);
2913                 }
2914                 return true;
2915         default:
2916                 BUG();
2917         }
2918 }
2919
2920 static bool rbd_obj_write_is_noop(struct rbd_obj_request *obj_req)
2921 {
2922         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
2923
2924         if (rbd_object_map_may_exist(rbd_dev, obj_req->ex.oe_objno))
2925                 obj_req->flags |= RBD_OBJ_FLAG_MAY_EXIST;
2926
2927         if (!(obj_req->flags & RBD_OBJ_FLAG_MAY_EXIST) &&
2928             (obj_req->flags & RBD_OBJ_FLAG_NOOP_FOR_NONEXISTENT)) {
2929                 dout("%s %p noop for nonexistent\n", __func__, obj_req);
2930                 return true;
2931         }
2932
2933         return false;
2934 }
2935
2936 /*
2937  * Return:
2938  *   0 - object map update sent
2939  *   1 - object map update isn't needed
2940  *  <0 - error
2941  */
2942 static int rbd_obj_write_pre_object_map(struct rbd_obj_request *obj_req)
2943 {
2944         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
2945         u8 new_state;
2946
2947         if (!(rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP))
2948                 return 1;
2949
2950         if (obj_req->flags & RBD_OBJ_FLAG_DELETION)
2951                 new_state = OBJECT_PENDING;
2952         else
2953                 new_state = OBJECT_EXISTS;
2954
2955         return rbd_object_map_update(obj_req, CEPH_NOSNAP, new_state, NULL);
2956 }
2957
2958 static int rbd_obj_write_object(struct rbd_obj_request *obj_req)
2959 {
2960         struct ceph_osd_request *osd_req;
2961         int num_ops = count_write_ops(obj_req);
2962         int which = 0;
2963         int ret;
2964
2965         if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED)
2966                 num_ops++; /* stat */
2967
2968         osd_req = rbd_obj_add_osd_request(obj_req, num_ops);
2969         if (IS_ERR(osd_req))
2970                 return PTR_ERR(osd_req);
2971
2972         if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED) {
2973                 ret = rbd_osd_setup_stat(osd_req, which++);
2974                 if (ret)
2975                         return ret;
2976         }
2977
2978         rbd_osd_setup_write_ops(osd_req, which);
2979         rbd_osd_format_write(osd_req);
2980
2981         ret = ceph_osdc_alloc_messages(osd_req, GFP_NOIO);
2982         if (ret)
2983                 return ret;
2984
2985         rbd_osd_submit(osd_req);
2986         return 0;
2987 }
2988
2989 /*
2990  * copyup_bvecs pages are never highmem pages
2991  */
2992 static bool is_zero_bvecs(struct bio_vec *bvecs, u32 bytes)
2993 {
2994         struct ceph_bvec_iter it = {
2995                 .bvecs = bvecs,
2996                 .iter = { .bi_size = bytes },
2997         };
2998
2999         ceph_bvec_iter_advance_step(&it, bytes, ({
3000                 if (memchr_inv(page_address(bv.bv_page) + bv.bv_offset, 0,
3001                                bv.bv_len))
3002                         return false;
3003         }));
3004         return true;
3005 }
3006
3007 #define MODS_ONLY       U32_MAX
3008
3009 static int rbd_obj_copyup_empty_snapc(struct rbd_obj_request *obj_req,
3010                                       u32 bytes)
3011 {
3012         struct ceph_osd_request *osd_req;
3013         int ret;
3014
3015         dout("%s obj_req %p bytes %u\n", __func__, obj_req, bytes);
3016         rbd_assert(bytes > 0 && bytes != MODS_ONLY);
3017
3018         osd_req = __rbd_obj_add_osd_request(obj_req, &rbd_empty_snapc, 1);
3019         if (IS_ERR(osd_req))
3020                 return PTR_ERR(osd_req);
3021
3022         ret = rbd_osd_setup_copyup(osd_req, 0, bytes);
3023         if (ret)
3024                 return ret;
3025
3026         rbd_osd_format_write(osd_req);
3027
3028         ret = ceph_osdc_alloc_messages(osd_req, GFP_NOIO);
3029         if (ret)
3030                 return ret;
3031
3032         rbd_osd_submit(osd_req);
3033         return 0;
3034 }
3035
3036 static int rbd_obj_copyup_current_snapc(struct rbd_obj_request *obj_req,
3037                                         u32 bytes)
3038 {
3039         struct ceph_osd_request *osd_req;
3040         int num_ops = count_write_ops(obj_req);
3041         int which = 0;
3042         int ret;
3043
3044         dout("%s obj_req %p bytes %u\n", __func__, obj_req, bytes);
3045
3046         if (bytes != MODS_ONLY)
3047                 num_ops++; /* copyup */
3048
3049         osd_req = rbd_obj_add_osd_request(obj_req, num_ops);
3050         if (IS_ERR(osd_req))
3051                 return PTR_ERR(osd_req);
3052
3053         if (bytes != MODS_ONLY) {
3054                 ret = rbd_osd_setup_copyup(osd_req, which++, bytes);
3055                 if (ret)
3056                         return ret;
3057         }
3058
3059         rbd_osd_setup_write_ops(osd_req, which);
3060         rbd_osd_format_write(osd_req);
3061
3062         ret = ceph_osdc_alloc_messages(osd_req, GFP_NOIO);
3063         if (ret)
3064                 return ret;
3065
3066         rbd_osd_submit(osd_req);
3067         return 0;
3068 }
3069
3070 static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap)
3071 {
3072         u32 i;
3073
3074         rbd_assert(!obj_req->copyup_bvecs);
3075         obj_req->copyup_bvec_count = calc_pages_for(0, obj_overlap);
3076         obj_req->copyup_bvecs = kcalloc(obj_req->copyup_bvec_count,
3077                                         sizeof(*obj_req->copyup_bvecs),
3078                                         GFP_NOIO);
3079         if (!obj_req->copyup_bvecs)
3080                 return -ENOMEM;
3081
3082         for (i = 0; i < obj_req->copyup_bvec_count; i++) {
3083                 unsigned int len = min(obj_overlap, (u64)PAGE_SIZE);
3084
3085                 obj_req->copyup_bvecs[i].bv_page = alloc_page(GFP_NOIO);
3086                 if (!obj_req->copyup_bvecs[i].bv_page)
3087                         return -ENOMEM;
3088
3089                 obj_req->copyup_bvecs[i].bv_offset = 0;
3090                 obj_req->copyup_bvecs[i].bv_len = len;
3091                 obj_overlap -= len;
3092         }
3093
3094         rbd_assert(!obj_overlap);
3095         return 0;
3096 }
3097
3098 /*
3099  * The target object doesn't exist.  Read the data for the entire
3100  * target object up to the overlap point (if any) from the parent,
3101  * so we can use it for a copyup.
3102  */
3103 static int rbd_obj_copyup_read_parent(struct rbd_obj_request *obj_req)
3104 {
3105         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
3106         int ret;
3107
3108         rbd_assert(obj_req->num_img_extents);
3109         prune_extents(obj_req->img_extents, &obj_req->num_img_extents,
3110                       rbd_dev->parent_overlap);
3111         if (!obj_req->num_img_extents) {
3112                 /*
3113                  * The overlap has become 0 (most likely because the
3114                  * image has been flattened).  Re-submit the original write
3115                  * request -- pass MODS_ONLY since the copyup isn't needed
3116                  * anymore.
3117                  */
3118                 return rbd_obj_copyup_current_snapc(obj_req, MODS_ONLY);
3119         }
3120
3121         ret = setup_copyup_bvecs(obj_req, rbd_obj_img_extents_bytes(obj_req));
3122         if (ret)
3123                 return ret;
3124
3125         return rbd_obj_read_from_parent(obj_req);
3126 }
3127
3128 static void rbd_obj_copyup_object_maps(struct rbd_obj_request *obj_req)
3129 {
3130         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
3131         struct ceph_snap_context *snapc = obj_req->img_request->snapc;
3132         u8 new_state;
3133         u32 i;
3134         int ret;
3135
3136         rbd_assert(!obj_req->pending.result && !obj_req->pending.num_pending);
3137
3138         if (!(rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP))
3139                 return;
3140
3141         if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ZEROS)
3142                 return;
3143
3144         for (i = 0; i < snapc->num_snaps; i++) {
3145                 if ((rbd_dev->header.features & RBD_FEATURE_FAST_DIFF) &&
3146                     i + 1 < snapc->num_snaps)
3147                         new_state = OBJECT_EXISTS_CLEAN;
3148                 else
3149                         new_state = OBJECT_EXISTS;
3150
3151                 ret = rbd_object_map_update(obj_req, snapc->snaps[i],
3152                                             new_state, NULL);
3153                 if (ret < 0) {
3154                         obj_req->pending.result = ret;
3155                         return;
3156                 }
3157
3158                 rbd_assert(!ret);
3159                 obj_req->pending.num_pending++;
3160         }
3161 }
3162
3163 static void rbd_obj_copyup_write_object(struct rbd_obj_request *obj_req)
3164 {
3165         u32 bytes = rbd_obj_img_extents_bytes(obj_req);
3166         int ret;
3167
3168         rbd_assert(!obj_req->pending.result && !obj_req->pending.num_pending);
3169
3170         /*
3171          * Only send non-zero copyup data to save some I/O and network
3172          * bandwidth -- zero copyup data is equivalent to the object not
3173          * existing.
3174          */
3175         if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ZEROS)
3176                 bytes = 0;
3177
3178         if (obj_req->img_request->snapc->num_snaps && bytes > 0) {
3179                 /*
3180                  * Send a copyup request with an empty snapshot context to
3181                  * deep-copyup the object through all existing snapshots.
3182                  * A second request with the current snapshot context will be
3183                  * sent for the actual modification.
3184                  */
3185                 ret = rbd_obj_copyup_empty_snapc(obj_req, bytes);
3186                 if (ret) {
3187                         obj_req->pending.result = ret;
3188                         return;
3189                 }
3190
3191                 obj_req->pending.num_pending++;
3192                 bytes = MODS_ONLY;
3193         }
3194
3195         ret = rbd_obj_copyup_current_snapc(obj_req, bytes);
3196         if (ret) {
3197                 obj_req->pending.result = ret;
3198                 return;
3199         }
3200
3201         obj_req->pending.num_pending++;
3202 }
3203
3204 static bool rbd_obj_advance_copyup(struct rbd_obj_request *obj_req, int *result)
3205 {
3206         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
3207         int ret;
3208
3209 again:
3210         switch (obj_req->copyup_state) {
3211         case RBD_OBJ_COPYUP_START:
3212                 rbd_assert(!*result);
3213
3214                 ret = rbd_obj_copyup_read_parent(obj_req);
3215                 if (ret) {
3216                         *result = ret;
3217                         return true;
3218                 }
3219                 if (obj_req->num_img_extents)
3220                         obj_req->copyup_state = RBD_OBJ_COPYUP_READ_PARENT;
3221                 else
3222                         obj_req->copyup_state = RBD_OBJ_COPYUP_WRITE_OBJECT;
3223                 return false;
3224         case RBD_OBJ_COPYUP_READ_PARENT:
3225                 if (*result)
3226                         return true;
3227
3228                 if (is_zero_bvecs(obj_req->copyup_bvecs,
3229                                   rbd_obj_img_extents_bytes(obj_req))) {
3230                         dout("%s %p detected zeros\n", __func__, obj_req);
3231                         obj_req->flags |= RBD_OBJ_FLAG_COPYUP_ZEROS;
3232                 }
3233
3234                 rbd_obj_copyup_object_maps(obj_req);
3235                 if (!obj_req->pending.num_pending) {
3236                         *result = obj_req->pending.result;
3237                         obj_req->copyup_state = RBD_OBJ_COPYUP_OBJECT_MAPS;
3238                         goto again;
3239                 }
3240                 obj_req->copyup_state = __RBD_OBJ_COPYUP_OBJECT_MAPS;
3241                 return false;
3242         case __RBD_OBJ_COPYUP_OBJECT_MAPS:
3243                 if (!pending_result_dec(&obj_req->pending, result))
3244                         return false;
3245                 fallthrough;
3246         case RBD_OBJ_COPYUP_OBJECT_MAPS:
3247                 if (*result) {
3248                         rbd_warn(rbd_dev, "snap object map update failed: %d",
3249                                  *result);
3250                         return true;
3251                 }
3252
3253                 rbd_obj_copyup_write_object(obj_req);
3254                 if (!obj_req->pending.num_pending) {
3255                         *result = obj_req->pending.result;
3256                         obj_req->copyup_state = RBD_OBJ_COPYUP_WRITE_OBJECT;
3257                         goto again;
3258                 }
3259                 obj_req->copyup_state = __RBD_OBJ_COPYUP_WRITE_OBJECT;
3260                 return false;
3261         case __RBD_OBJ_COPYUP_WRITE_OBJECT:
3262                 if (!pending_result_dec(&obj_req->pending, result))
3263                         return false;
3264                 fallthrough;
3265         case RBD_OBJ_COPYUP_WRITE_OBJECT:
3266                 return true;
3267         default:
3268                 BUG();
3269         }
3270 }
3271
3272 /*
3273  * Return:
3274  *   0 - object map update sent
3275  *   1 - object map update isn't needed
3276  *  <0 - error
3277  */
3278 static int rbd_obj_write_post_object_map(struct rbd_obj_request *obj_req)
3279 {
3280         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
3281         u8 current_state = OBJECT_PENDING;
3282
3283         if (!(rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP))
3284                 return 1;
3285
3286         if (!(obj_req->flags & RBD_OBJ_FLAG_DELETION))
3287                 return 1;
3288
3289         return rbd_object_map_update(obj_req, CEPH_NOSNAP, OBJECT_NONEXISTENT,
3290                                      &current_state);
3291 }
3292
3293 static bool rbd_obj_advance_write(struct rbd_obj_request *obj_req, int *result)
3294 {
3295         struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
3296         int ret;
3297
3298 again:
3299         switch (obj_req->write_state) {
3300         case RBD_OBJ_WRITE_START:
3301                 rbd_assert(!*result);
3302
3303                 if (rbd_obj_write_is_noop(obj_req))
3304                         return true;
3305
3306                 ret = rbd_obj_write_pre_object_map(obj_req);
3307                 if (ret < 0) {
3308                         *result = ret;
3309                         return true;
3310                 }
3311                 obj_req->write_state = RBD_OBJ_WRITE_PRE_OBJECT_MAP;
3312                 if (ret > 0)
3313                         goto again;
3314                 return false;
3315         case RBD_OBJ_WRITE_PRE_OBJECT_MAP:
3316                 if (*result) {
3317                         rbd_warn(rbd_dev, "pre object map update failed: %d",
3318                                  *result);
3319                         return true;
3320                 }
3321                 ret = rbd_obj_write_object(obj_req);
3322                 if (ret) {
3323                         *result = ret;
3324                         return true;
3325                 }
3326                 obj_req->write_state = RBD_OBJ_WRITE_OBJECT;
3327                 return false;
3328         case RBD_OBJ_WRITE_OBJECT:
3329                 if (*result == -ENOENT) {
3330                         if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED) {
3331                                 *result = 0;
3332                                 obj_req->copyup_state = RBD_OBJ_COPYUP_START;
3333                                 obj_req->write_state = __RBD_OBJ_WRITE_COPYUP;
3334                                 goto again;
3335                         }
3336                         /*
3337                          * On a non-existent object:
3338                          *   delete - -ENOENT, truncate/zero - 0
3339                          */
3340                         if (obj_req->flags & RBD_OBJ_FLAG_DELETION)
3341                                 *result = 0;
3342                 }
3343                 if (*result)
3344                         return true;
3345
3346                 obj_req->write_state = RBD_OBJ_WRITE_COPYUP;
3347                 goto again;
3348         case __RBD_OBJ_WRITE_COPYUP:
3349                 if (!rbd_obj_advance_copyup(obj_req, result))
3350                         return false;
3351                 fallthrough;
3352         case RBD_OBJ_WRITE_COPYUP:
3353                 if (*result) {
3354                         rbd_warn(rbd_dev, "copyup failed: %d", *result);
3355                         return true;
3356                 }
3357                 ret = rbd_obj_write_post_object_map(obj_req);
3358                 if (ret < 0) {
3359                         *result = ret;
3360                         return true;
3361                 }
3362                 obj_req->write_state = RBD_OBJ_WRITE_POST_OBJECT_MAP;
3363                 if (ret > 0)
3364                         goto again;
3365                 return false;
3366         case RBD_OBJ_WRITE_POST_OBJECT_MAP:
3367                 if (*result)
3368                         rbd_warn(rbd_dev, "post object map update failed: %d",
3369                                  *result);
3370                 return true;
3371         default:
3372                 BUG();
3373         }
3374 }
3375
3376 /*
3377  * Return true if @obj_req is completed.
3378  */
3379 static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req,
3380                                      int *result)
3381 {
3382         struct rbd_img_request *img_req = obj_req->img_request;
3383         struct rbd_device *rbd_dev = img_req->rbd_dev;
3384         bool done;
3385
3386         mutex_lock(&obj_req->state_mutex);
3387         if (!rbd_img_is_write(img_req))
3388                 done = rbd_obj_advance_read(obj_req, result);
3389         else
3390                 done = rbd_obj_advance_write(obj_req, result);
3391         mutex_unlock(&obj_req->state_mutex);
3392
3393         if (done && *result) {
3394                 rbd_assert(*result < 0);
3395                 rbd_warn(rbd_dev, "%s at objno %llu %llu~%llu result %d",
3396                          obj_op_name(img_req->op_type), obj_req->ex.oe_objno,
3397                          obj_req->ex.oe_off, obj_req->ex.oe_len, *result);
3398         }
3399         return done;
3400 }
3401
3402 /*
3403  * This is open-coded in rbd_img_handle_request() to avoid parent chain
3404  * recursion.
3405  */
3406 static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result)
3407 {
3408         if (__rbd_obj_handle_request(obj_req, &result))
3409                 rbd_img_handle_request(obj_req->img_request, result);
3410 }
3411
3412 static bool need_exclusive_lock(struct rbd_img_request *img_req)
3413 {
3414         struct rbd_device *rbd_dev = img_req->rbd_dev;
3415
3416         if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK))
3417                 return false;
3418
3419         if (rbd_is_ro(rbd_dev))
3420                 return false;
3421
3422         rbd_assert(!test_bit(IMG_REQ_CHILD, &img_req->flags));
3423         if (rbd_dev->opts->lock_on_read ||
3424             (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP))
3425                 return true;
3426
3427         return rbd_img_is_write(img_req);
3428 }
3429
3430 static bool rbd_lock_add_request(struct rbd_img_request *img_req)
3431 {
3432         struct rbd_device *rbd_dev = img_req->rbd_dev;
3433         bool locked;
3434
3435         lockdep_assert_held(&rbd_dev->lock_rwsem);
3436         locked = rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED;
3437         spin_lock(&rbd_dev->lock_lists_lock);
3438         rbd_assert(list_empty(&img_req->lock_item));
3439         if (!locked)
3440                 list_add_tail(&img_req->lock_item, &rbd_dev->acquiring_list);
3441         else
3442                 list_add_tail(&img_req->lock_item, &rbd_dev->running_list);
3443         spin_unlock(&rbd_dev->lock_lists_lock);
3444         return locked;
3445 }
3446
3447 static void rbd_lock_del_request(struct rbd_img_request *img_req)
3448 {
3449         struct rbd_device *rbd_dev = img_req->rbd_dev;
3450         bool need_wakeup;
3451
3452         lockdep_assert_held(&rbd_dev->lock_rwsem);
3453         spin_lock(&rbd_dev->lock_lists_lock);
3454         rbd_assert(!list_empty(&img_req->lock_item));
3455         list_del_init(&img_req->lock_item);
3456         need_wakeup = (rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING &&
3457                        list_empty(&rbd_dev->running_list));
3458         spin_unlock(&rbd_dev->lock_lists_lock);
3459         if (need_wakeup)
3460                 complete(&rbd_dev->releasing_wait);
3461 }
3462
3463 static int rbd_img_exclusive_lock(struct rbd_img_request *img_req)
3464 {
3465         struct rbd_device *rbd_dev = img_req->rbd_dev;
3466
3467         if (!need_exclusive_lock(img_req))
3468                 return 1;
3469
3470         if (rbd_lock_add_request(img_req))
3471                 return 1;
3472
3473         if (rbd_dev->opts->exclusive) {
3474                 WARN_ON(1); /* lock got released? */
3475                 return -EROFS;
3476         }
3477
3478         /*
3479          * Note the use of mod_delayed_work() in rbd_acquire_lock()
3480          * and cancel_delayed_work() in wake_lock_waiters().
3481          */
3482         dout("%s rbd_dev %p queueing lock_dwork\n", __func__, rbd_dev);
3483         queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
3484         return 0;
3485 }
3486
3487 static void rbd_img_object_requests(struct rbd_img_request *img_req)
3488 {
3489         struct rbd_obj_request *obj_req;
3490
3491         rbd_assert(!img_req->pending.result && !img_req->pending.num_pending);
3492
3493         for_each_obj_request(img_req, obj_req) {
3494                 int result = 0;
3495
3496                 if (__rbd_obj_handle_request(obj_req, &result)) {
3497                         if (result) {
3498                                 img_req->pending.result = result;
3499                                 return;
3500                         }
3501                 } else {
3502                         img_req->pending.num_pending++;
3503                 }
3504         }
3505 }
3506
3507 static bool rbd_img_advance(struct rbd_img_request *img_req, int *result)
3508 {
3509         struct rbd_device *rbd_dev = img_req->rbd_dev;
3510         int ret;
3511
3512 again:
3513         switch (img_req->state) {
3514         case RBD_IMG_START:
3515                 rbd_assert(!*result);
3516
3517                 ret = rbd_img_exclusive_lock(img_req);
3518                 if (ret < 0) {
3519                         *result = ret;
3520                         return true;
3521                 }
3522                 img_req->state = RBD_IMG_EXCLUSIVE_LOCK;
3523                 if (ret > 0)
3524                         goto again;
3525                 return false;
3526         case RBD_IMG_EXCLUSIVE_LOCK:
3527                 if (*result)
3528                         return true;
3529
3530                 rbd_assert(!need_exclusive_lock(img_req) ||
3531                            __rbd_is_lock_owner(rbd_dev));
3532
3533                 rbd_img_object_requests(img_req);
3534                 if (!img_req->pending.num_pending) {
3535                         *result = img_req->pending.result;
3536                         img_req->state = RBD_IMG_OBJECT_REQUESTS;
3537                         goto again;
3538                 }
3539                 img_req->state = __RBD_IMG_OBJECT_REQUESTS;
3540                 return false;
3541         case __RBD_IMG_OBJECT_REQUESTS:
3542                 if (!pending_result_dec(&img_req->pending, result))
3543                         return false;
3544                 fallthrough;
3545         case RBD_IMG_OBJECT_REQUESTS:
3546                 return true;
3547         default:
3548                 BUG();
3549         }
3550 }
3551
3552 /*
3553  * Return true if @img_req is completed.
3554  */
3555 static bool __rbd_img_handle_request(struct rbd_img_request *img_req,
3556                                      int *result)
3557 {
3558         struct rbd_device *rbd_dev = img_req->rbd_dev;
3559         bool done;
3560
3561         if (need_exclusive_lock(img_req)) {
3562                 down_read(&rbd_dev->lock_rwsem);
3563                 mutex_lock(&img_req->state_mutex);
3564                 done = rbd_img_advance(img_req, result);
3565                 if (done)
3566                         rbd_lock_del_request(img_req);
3567                 mutex_unlock(&img_req->state_mutex);
3568                 up_read(&rbd_dev->lock_rwsem);
3569         } else {
3570                 mutex_lock(&img_req->state_mutex);
3571                 done = rbd_img_advance(img_req, result);
3572                 mutex_unlock(&img_req->state_mutex);
3573         }
3574
3575         if (done && *result) {
3576                 rbd_assert(*result < 0);
3577                 rbd_warn(rbd_dev, "%s%s result %d",
3578                       test_bit(IMG_REQ_CHILD, &img_req->flags) ? "child " : "",
3579                       obj_op_name(img_req->op_type), *result);
3580         }
3581         return done;
3582 }
3583
3584 static void rbd_img_handle_request(struct rbd_img_request *img_req, int result)
3585 {
3586 again:
3587         if (!__rbd_img_handle_request(img_req, &result))
3588                 return;
3589
3590         if (test_bit(IMG_REQ_CHILD, &img_req->flags)) {
3591                 struct rbd_obj_request *obj_req = img_req->obj_request;
3592
3593                 rbd_img_request_destroy(img_req);
3594                 if (__rbd_obj_handle_request(obj_req, &result)) {
3595                         img_req = obj_req->img_request;
3596                         goto again;
3597                 }
3598         } else {
3599                 struct request *rq = blk_mq_rq_from_pdu(img_req);
3600
3601                 rbd_img_request_destroy(img_req);
3602                 blk_mq_end_request(rq, errno_to_blk_status(result));
3603         }
3604 }
3605
3606 static const struct rbd_client_id rbd_empty_cid;
3607
3608 static bool rbd_cid_equal(const struct rbd_client_id *lhs,
3609                           const struct rbd_client_id *rhs)
3610 {
3611         return lhs->gid == rhs->gid && lhs->handle == rhs->handle;
3612 }
3613
3614 static struct rbd_client_id rbd_get_cid(struct rbd_device *rbd_dev)
3615 {
3616         struct rbd_client_id cid;
3617
3618         mutex_lock(&rbd_dev->watch_mutex);
3619         cid.gid = ceph_client_gid(rbd_dev->rbd_client->client);
3620         cid.handle = rbd_dev->watch_cookie;
3621         mutex_unlock(&rbd_dev->watch_mutex);
3622         return cid;
3623 }
3624
3625 /*
3626  * lock_rwsem must be held for write
3627  */
3628 static void rbd_set_owner_cid(struct rbd_device *rbd_dev,
3629                               const struct rbd_client_id *cid)
3630 {
3631         dout("%s rbd_dev %p %llu-%llu -> %llu-%llu\n", __func__, rbd_dev,
3632              rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle,
3633              cid->gid, cid->handle);
3634         rbd_dev->owner_cid = *cid; /* struct */
3635 }
3636
3637 static void format_lock_cookie(struct rbd_device *rbd_dev, char *buf)
3638 {
3639         mutex_lock(&rbd_dev->watch_mutex);
3640         sprintf(buf, "%s %llu", RBD_LOCK_COOKIE_PREFIX, rbd_dev->watch_cookie);
3641         mutex_unlock(&rbd_dev->watch_mutex);
3642 }
3643
3644 static void __rbd_lock(struct rbd_device *rbd_dev, const char *cookie)
3645 {
3646         struct rbd_client_id cid = rbd_get_cid(rbd_dev);
3647
3648         rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
3649         strcpy(rbd_dev->lock_cookie, cookie);
3650         rbd_set_owner_cid(rbd_dev, &cid);
3651         queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
3652 }
3653
3654 /*
3655  * lock_rwsem must be held for write
3656  */
3657 static int rbd_lock(struct rbd_device *rbd_dev)
3658 {
3659         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3660         char cookie[32];
3661         int ret;
3662
3663         WARN_ON(__rbd_is_lock_owner(rbd_dev) ||
3664                 rbd_dev->lock_cookie[0] != '\0');
3665
3666         format_lock_cookie(rbd_dev, cookie);
3667         ret = ceph_cls_lock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
3668                             RBD_LOCK_NAME, CEPH_CLS_LOCK_EXCLUSIVE, cookie,
3669                             RBD_LOCK_TAG, "", 0);
3670         if (ret)
3671                 return ret;
3672
3673         __rbd_lock(rbd_dev, cookie);
3674         return 0;
3675 }
3676
3677 /*
3678  * lock_rwsem must be held for write
3679  */
3680 static void rbd_unlock(struct rbd_device *rbd_dev)
3681 {
3682         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3683         int ret;
3684
3685         WARN_ON(!__rbd_is_lock_owner(rbd_dev) ||
3686                 rbd_dev->lock_cookie[0] == '\0');
3687
3688         ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
3689                               RBD_LOCK_NAME, rbd_dev->lock_cookie);
3690         if (ret && ret != -ENOENT)
3691                 rbd_warn(rbd_dev, "failed to unlock header: %d", ret);
3692
3693         /* treat errors as the image is unlocked */
3694         rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
3695         rbd_dev->lock_cookie[0] = '\0';
3696         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
3697         queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
3698 }
3699
3700 static int __rbd_notify_op_lock(struct rbd_device *rbd_dev,
3701                                 enum rbd_notify_op notify_op,
3702                                 struct page ***preply_pages,
3703                                 size_t *preply_len)
3704 {
3705         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3706         struct rbd_client_id cid = rbd_get_cid(rbd_dev);
3707         char buf[4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN];
3708         int buf_size = sizeof(buf);
3709         void *p = buf;
3710
3711         dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
3712
3713         /* encode *LockPayload NotifyMessage (op + ClientId) */
3714         ceph_start_encoding(&p, 2, 1, buf_size - CEPH_ENCODING_START_BLK_LEN);
3715         ceph_encode_32(&p, notify_op);
3716         ceph_encode_64(&p, cid.gid);
3717         ceph_encode_64(&p, cid.handle);
3718
3719         return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
3720                                 &rbd_dev->header_oloc, buf, buf_size,
3721                                 RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
3722 }
3723
3724 static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
3725                                enum rbd_notify_op notify_op)
3726 {
3727         __rbd_notify_op_lock(rbd_dev, notify_op, NULL, NULL);
3728 }
3729
3730 static void rbd_notify_acquired_lock(struct work_struct *work)
3731 {
3732         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
3733                                                   acquired_lock_work);
3734
3735         rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
3736 }
3737
3738 static void rbd_notify_released_lock(struct work_struct *work)
3739 {
3740         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
3741                                                   released_lock_work);
3742
3743         rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
3744 }
3745
3746 static int rbd_request_lock(struct rbd_device *rbd_dev)
3747 {
3748         struct page **reply_pages;
3749         size_t reply_len;
3750         bool lock_owner_responded = false;
3751         int ret;
3752
3753         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3754
3755         ret = __rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_REQUEST_LOCK,
3756                                    &reply_pages, &reply_len);
3757         if (ret && ret != -ETIMEDOUT) {
3758                 rbd_warn(rbd_dev, "failed to request lock: %d", ret);
3759                 goto out;
3760         }
3761
3762         if (reply_len > 0 && reply_len <= PAGE_SIZE) {
3763                 void *p = page_address(reply_pages[0]);
3764                 void *const end = p + reply_len;
3765                 u32 n;
3766
3767                 ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
3768                 while (n--) {
3769                         u8 struct_v;
3770                         u32 len;
3771
3772                         ceph_decode_need(&p, end, 8 + 8, e_inval);
3773                         p += 8 + 8; /* skip gid and cookie */
3774
3775                         ceph_decode_32_safe(&p, end, len, e_inval);
3776                         if (!len)
3777                                 continue;
3778
3779                         if (lock_owner_responded) {
3780                                 rbd_warn(rbd_dev,
3781                                          "duplicate lock owners detected");
3782                                 ret = -EIO;
3783                                 goto out;
3784                         }
3785
3786                         lock_owner_responded = true;
3787                         ret = ceph_start_decoding(&p, end, 1, "ResponseMessage",
3788                                                   &struct_v, &len);
3789                         if (ret) {
3790                                 rbd_warn(rbd_dev,
3791                                          "failed to decode ResponseMessage: %d",
3792                                          ret);
3793                                 goto e_inval;
3794                         }
3795
3796                         ret = ceph_decode_32(&p);
3797                 }
3798         }
3799
3800         if (!lock_owner_responded) {
3801                 rbd_warn(rbd_dev, "no lock owners detected");
3802                 ret = -ETIMEDOUT;
3803         }
3804
3805 out:
3806         ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
3807         return ret;
3808
3809 e_inval:
3810         ret = -EINVAL;
3811         goto out;
3812 }
3813
3814 /*
3815  * Either image request state machine(s) or rbd_add_acquire_lock()
3816  * (i.e. "rbd map").
3817  */
3818 static void wake_lock_waiters(struct rbd_device *rbd_dev, int result)
3819 {
3820         struct rbd_img_request *img_req;
3821
3822         dout("%s rbd_dev %p result %d\n", __func__, rbd_dev, result);
3823         lockdep_assert_held_write(&rbd_dev->lock_rwsem);
3824
3825         cancel_delayed_work(&rbd_dev->lock_dwork);
3826         if (!completion_done(&rbd_dev->acquire_wait)) {
3827                 rbd_assert(list_empty(&rbd_dev->acquiring_list) &&
3828                            list_empty(&rbd_dev->running_list));
3829                 rbd_dev->acquire_err = result;
3830                 complete_all(&rbd_dev->acquire_wait);
3831                 return;
3832         }
3833
3834         list_for_each_entry(img_req, &rbd_dev->acquiring_list, lock_item) {
3835                 mutex_lock(&img_req->state_mutex);
3836                 rbd_assert(img_req->state == RBD_IMG_EXCLUSIVE_LOCK);
3837                 rbd_img_schedule(img_req, result);
3838                 mutex_unlock(&img_req->state_mutex);
3839         }
3840
3841         list_splice_tail_init(&rbd_dev->acquiring_list, &rbd_dev->running_list);
3842 }
3843
3844 static int get_lock_owner_info(struct rbd_device *rbd_dev,
3845                                struct ceph_locker **lockers, u32 *num_lockers)
3846 {
3847         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3848         u8 lock_type;
3849         char *lock_tag;
3850         int ret;
3851
3852         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3853
3854         ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid,
3855                                  &rbd_dev->header_oloc, RBD_LOCK_NAME,
3856                                  &lock_type, &lock_tag, lockers, num_lockers);
3857         if (ret)
3858                 return ret;
3859
3860         if (*num_lockers == 0) {
3861                 dout("%s rbd_dev %p no lockers detected\n", __func__, rbd_dev);
3862                 goto out;
3863         }
3864
3865         if (strcmp(lock_tag, RBD_LOCK_TAG)) {
3866                 rbd_warn(rbd_dev, "locked by external mechanism, tag %s",
3867                          lock_tag);
3868                 ret = -EBUSY;
3869                 goto out;
3870         }
3871
3872         if (lock_type == CEPH_CLS_LOCK_SHARED) {
3873                 rbd_warn(rbd_dev, "shared lock type detected");
3874                 ret = -EBUSY;
3875                 goto out;
3876         }
3877
3878         if (strncmp((*lockers)[0].id.cookie, RBD_LOCK_COOKIE_PREFIX,
3879                     strlen(RBD_LOCK_COOKIE_PREFIX))) {
3880                 rbd_warn(rbd_dev, "locked by external mechanism, cookie %s",
3881                          (*lockers)[0].id.cookie);
3882                 ret = -EBUSY;
3883                 goto out;
3884         }
3885
3886 out:
3887         kfree(lock_tag);
3888         return ret;
3889 }
3890
3891 static int find_watcher(struct rbd_device *rbd_dev,
3892                         const struct ceph_locker *locker)
3893 {
3894         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3895         struct ceph_watch_item *watchers;
3896         u32 num_watchers;
3897         u64 cookie;
3898         int i;
3899         int ret;
3900
3901         ret = ceph_osdc_list_watchers(osdc, &rbd_dev->header_oid,
3902                                       &rbd_dev->header_oloc, &watchers,
3903                                       &num_watchers);
3904         if (ret)
3905                 return ret;
3906
3907         sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie);
3908         for (i = 0; i < num_watchers; i++) {
3909                 /*
3910                  * Ignore addr->type while comparing.  This mimics
3911                  * entity_addr_t::get_legacy_str() + strcmp().
3912                  */
3913                 if (ceph_addr_equal_no_type(&watchers[i].addr,
3914                                             &locker->info.addr) &&
3915                     watchers[i].cookie == cookie) {
3916                         struct rbd_client_id cid = {
3917                                 .gid = le64_to_cpu(watchers[i].name.num),
3918                                 .handle = cookie,
3919                         };
3920
3921                         dout("%s rbd_dev %p found cid %llu-%llu\n", __func__,
3922                              rbd_dev, cid.gid, cid.handle);
3923                         rbd_set_owner_cid(rbd_dev, &cid);
3924                         ret = 1;
3925                         goto out;
3926                 }
3927         }
3928
3929         dout("%s rbd_dev %p no watchers\n", __func__, rbd_dev);
3930         ret = 0;
3931 out:
3932         kfree(watchers);
3933         return ret;
3934 }
3935
3936 /*
3937  * lock_rwsem must be held for write
3938  */
3939 static int rbd_try_lock(struct rbd_device *rbd_dev)
3940 {
3941         struct ceph_client *client = rbd_dev->rbd_client->client;
3942         struct ceph_locker *lockers;
3943         u32 num_lockers;
3944         int ret;
3945
3946         for (;;) {
3947                 ret = rbd_lock(rbd_dev);
3948                 if (ret != -EBUSY)
3949                         return ret;
3950
3951                 /* determine if the current lock holder is still alive */
3952                 ret = get_lock_owner_info(rbd_dev, &lockers, &num_lockers);
3953                 if (ret)
3954                         return ret;
3955
3956                 if (num_lockers == 0)
3957                         goto again;
3958
3959                 ret = find_watcher(rbd_dev, lockers);
3960                 if (ret)
3961                         goto out; /* request lock or error */
3962
3963                 rbd_warn(rbd_dev, "breaking header lock owned by %s%llu",
3964                          ENTITY_NAME(lockers[0].id.name));
3965
3966                 ret = ceph_monc_blocklist_add(&client->monc,
3967                                               &lockers[0].info.addr);
3968                 if (ret) {
3969                         rbd_warn(rbd_dev, "blocklist of %s%llu failed: %d",
3970                                  ENTITY_NAME(lockers[0].id.name), ret);
3971                         goto out;
3972                 }
3973
3974                 ret = ceph_cls_break_lock(&client->osdc, &rbd_dev->header_oid,
3975                                           &rbd_dev->header_oloc, RBD_LOCK_NAME,
3976                                           lockers[0].id.cookie,
3977                                           &lockers[0].id.name);
3978                 if (ret && ret != -ENOENT)
3979                         goto out;
3980
3981 again:
3982                 ceph_free_lockers(lockers, num_lockers);
3983         }
3984
3985 out:
3986         ceph_free_lockers(lockers, num_lockers);
3987         return ret;
3988 }
3989
3990 static int rbd_post_acquire_action(struct rbd_device *rbd_dev)
3991 {
3992         int ret;
3993
3994         if (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP) {
3995                 ret = rbd_object_map_open(rbd_dev);
3996                 if (ret)
3997                         return ret;
3998         }
3999
4000         return 0;
4001 }
4002
4003 /*
4004  * Return:
4005  *   0 - lock acquired
4006  *   1 - caller should call rbd_request_lock()
4007  *  <0 - error
4008  */
4009 static int rbd_try_acquire_lock(struct rbd_device *rbd_dev)
4010 {
4011         int ret;
4012
4013         down_read(&rbd_dev->lock_rwsem);
4014         dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
4015              rbd_dev->lock_state);
4016         if (__rbd_is_lock_owner(rbd_dev)) {
4017                 up_read(&rbd_dev->lock_rwsem);
4018                 return 0;
4019         }
4020
4021         up_read(&rbd_dev->lock_rwsem);
4022         down_write(&rbd_dev->lock_rwsem);
4023         dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
4024              rbd_dev->lock_state);
4025         if (__rbd_is_lock_owner(rbd_dev)) {
4026                 up_write(&rbd_dev->lock_rwsem);
4027                 return 0;
4028         }
4029
4030         ret = rbd_try_lock(rbd_dev);
4031         if (ret < 0) {
4032                 rbd_warn(rbd_dev, "failed to lock header: %d", ret);
4033                 if (ret == -EBLOCKLISTED)
4034                         goto out;
4035
4036                 ret = 1; /* request lock anyway */
4037         }
4038         if (ret > 0) {
4039                 up_write(&rbd_dev->lock_rwsem);
4040                 return ret;
4041         }
4042
4043         rbd_assert(rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED);
4044         rbd_assert(list_empty(&rbd_dev->running_list));
4045
4046         ret = rbd_post_acquire_action(rbd_dev);
4047         if (ret) {
4048                 rbd_warn(rbd_dev, "post-acquire action failed: %d", ret);
4049                 /*
4050                  * Can't stay in RBD_LOCK_STATE_LOCKED because
4051                  * rbd_lock_add_request() would let the request through,
4052                  * assuming that e.g. object map is locked and loaded.
4053                  */
4054                 rbd_unlock(rbd_dev);
4055         }
4056
4057 out:
4058         wake_lock_waiters(rbd_dev, ret);
4059         up_write(&rbd_dev->lock_rwsem);
4060         return ret;
4061 }
4062
4063 static void rbd_acquire_lock(struct work_struct *work)
4064 {
4065         struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
4066                                             struct rbd_device, lock_dwork);
4067         int ret;
4068
4069         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4070 again:
4071         ret = rbd_try_acquire_lock(rbd_dev);
4072         if (ret <= 0) {
4073                 dout("%s rbd_dev %p ret %d - done\n", __func__, rbd_dev, ret);
4074                 return;
4075         }
4076
4077         ret = rbd_request_lock(rbd_dev);
4078         if (ret == -ETIMEDOUT) {
4079                 goto again; /* treat this as a dead client */
4080         } else if (ret == -EROFS) {
4081                 rbd_warn(rbd_dev, "peer will not release lock");
4082                 down_write(&rbd_dev->lock_rwsem);
4083                 wake_lock_waiters(rbd_dev, ret);
4084                 up_write(&rbd_dev->lock_rwsem);
4085         } else if (ret < 0) {
4086                 rbd_warn(rbd_dev, "error requesting lock: %d", ret);
4087                 mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
4088                                  RBD_RETRY_DELAY);
4089         } else {
4090                 /*
4091                  * lock owner acked, but resend if we don't see them
4092                  * release the lock
4093                  */
4094                 dout("%s rbd_dev %p requeuing lock_dwork\n", __func__,
4095                      rbd_dev);
4096                 mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
4097                     msecs_to_jiffies(2 * RBD_NOTIFY_TIMEOUT * MSEC_PER_SEC));
4098         }
4099 }
4100
4101 static bool rbd_quiesce_lock(struct rbd_device *rbd_dev)
4102 {
4103         bool need_wait;
4104
4105         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4106         lockdep_assert_held_write(&rbd_dev->lock_rwsem);
4107
4108         if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
4109                 return false;
4110
4111         /*
4112          * Ensure that all in-flight IO is flushed.
4113          */
4114         rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING;
4115         rbd_assert(!completion_done(&rbd_dev->releasing_wait));
4116         need_wait = !list_empty(&rbd_dev->running_list);
4117         downgrade_write(&rbd_dev->lock_rwsem);
4118         if (need_wait)
4119                 wait_for_completion(&rbd_dev->releasing_wait);
4120         up_read(&rbd_dev->lock_rwsem);
4121
4122         down_write(&rbd_dev->lock_rwsem);
4123         if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
4124                 return false;
4125
4126         rbd_assert(list_empty(&rbd_dev->running_list));
4127         return true;
4128 }
4129
4130 static void rbd_pre_release_action(struct rbd_device *rbd_dev)
4131 {
4132         if (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP)
4133                 rbd_object_map_close(rbd_dev);
4134 }
4135
4136 static void __rbd_release_lock(struct rbd_device *rbd_dev)
4137 {
4138         rbd_assert(list_empty(&rbd_dev->running_list));
4139
4140         rbd_pre_release_action(rbd_dev);
4141         rbd_unlock(rbd_dev);
4142 }
4143
4144 /*
4145  * lock_rwsem must be held for write
4146  */
4147 static void rbd_release_lock(struct rbd_device *rbd_dev)
4148 {
4149         if (!rbd_quiesce_lock(rbd_dev))
4150                 return;
4151
4152         __rbd_release_lock(rbd_dev);
4153
4154         /*
4155          * Give others a chance to grab the lock - we would re-acquire
4156          * almost immediately if we got new IO while draining the running
4157          * list otherwise.  We need to ack our own notifications, so this
4158          * lock_dwork will be requeued from rbd_handle_released_lock() by
4159          * way of maybe_kick_acquire().
4160          */
4161         cancel_delayed_work(&rbd_dev->lock_dwork);
4162 }
4163
4164 static void rbd_release_lock_work(struct work_struct *work)
4165 {
4166         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
4167                                                   unlock_work);
4168
4169         down_write(&rbd_dev->lock_rwsem);
4170         rbd_release_lock(rbd_dev);
4171         up_write(&rbd_dev->lock_rwsem);
4172 }
4173
4174 static void maybe_kick_acquire(struct rbd_device *rbd_dev)
4175 {
4176         bool have_requests;
4177
4178         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4179         if (__rbd_is_lock_owner(rbd_dev))
4180                 return;
4181
4182         spin_lock(&rbd_dev->lock_lists_lock);
4183         have_requests = !list_empty(&rbd_dev->acquiring_list);
4184         spin_unlock(&rbd_dev->lock_lists_lock);
4185         if (have_requests || delayed_work_pending(&rbd_dev->lock_dwork)) {
4186                 dout("%s rbd_dev %p kicking lock_dwork\n", __func__, rbd_dev);
4187                 mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
4188         }
4189 }
4190
4191 static void rbd_handle_acquired_lock(struct rbd_device *rbd_dev, u8 struct_v,
4192                                      void **p)
4193 {
4194         struct rbd_client_id cid = { 0 };
4195
4196         if (struct_v >= 2) {
4197                 cid.gid = ceph_decode_64(p);
4198                 cid.handle = ceph_decode_64(p);
4199         }
4200
4201         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
4202              cid.handle);
4203         if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
4204                 down_write(&rbd_dev->lock_rwsem);
4205                 if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
4206                         dout("%s rbd_dev %p cid %llu-%llu == owner_cid\n",
4207                              __func__, rbd_dev, cid.gid, cid.handle);
4208                 } else {
4209                         rbd_set_owner_cid(rbd_dev, &cid);
4210                 }
4211                 downgrade_write(&rbd_dev->lock_rwsem);
4212         } else {
4213                 down_read(&rbd_dev->lock_rwsem);
4214         }
4215
4216         maybe_kick_acquire(rbd_dev);
4217         up_read(&rbd_dev->lock_rwsem);
4218 }
4219
4220 static void rbd_handle_released_lock(struct rbd_device *rbd_dev, u8 struct_v,
4221                                      void **p)
4222 {
4223         struct rbd_client_id cid = { 0 };
4224
4225         if (struct_v >= 2) {
4226                 cid.gid = ceph_decode_64(p);
4227                 cid.handle = ceph_decode_64(p);
4228         }
4229
4230         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
4231              cid.handle);
4232         if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
4233                 down_write(&rbd_dev->lock_rwsem);
4234                 if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
4235                         dout("%s rbd_dev %p cid %llu-%llu != owner_cid %llu-%llu\n",
4236                              __func__, rbd_dev, cid.gid, cid.handle,
4237                              rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle);
4238                 } else {
4239                         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
4240                 }
4241                 downgrade_write(&rbd_dev->lock_rwsem);
4242         } else {
4243                 down_read(&rbd_dev->lock_rwsem);
4244         }
4245
4246         maybe_kick_acquire(rbd_dev);
4247         up_read(&rbd_dev->lock_rwsem);
4248 }
4249
4250 /*
4251  * Returns result for ResponseMessage to be encoded (<= 0), or 1 if no
4252  * ResponseMessage is needed.
4253  */
4254 static int rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
4255                                    void **p)
4256 {
4257         struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
4258         struct rbd_client_id cid = { 0 };
4259         int result = 1;
4260
4261         if (struct_v >= 2) {
4262                 cid.gid = ceph_decode_64(p);
4263                 cid.handle = ceph_decode_64(p);
4264         }
4265
4266         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
4267              cid.handle);
4268         if (rbd_cid_equal(&cid, &my_cid))
4269                 return result;
4270
4271         down_read(&rbd_dev->lock_rwsem);
4272         if (__rbd_is_lock_owner(rbd_dev)) {
4273                 if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED &&
4274                     rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid))
4275                         goto out_unlock;
4276
4277                 /*
4278                  * encode ResponseMessage(0) so the peer can detect
4279                  * a missing owner
4280                  */
4281                 result = 0;
4282
4283                 if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
4284                         if (!rbd_dev->opts->exclusive) {
4285                                 dout("%s rbd_dev %p queueing unlock_work\n",
4286                                      __func__, rbd_dev);
4287                                 queue_work(rbd_dev->task_wq,
4288                                            &rbd_dev->unlock_work);
4289                         } else {
4290                                 /* refuse to release the lock */
4291                                 result = -EROFS;
4292                         }
4293                 }
4294         }
4295
4296 out_unlock:
4297         up_read(&rbd_dev->lock_rwsem);
4298         return result;
4299 }
4300
4301 static void __rbd_acknowledge_notify(struct rbd_device *rbd_dev,
4302                                      u64 notify_id, u64 cookie, s32 *result)
4303 {
4304         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4305         char buf[4 + CEPH_ENCODING_START_BLK_LEN];
4306         int buf_size = sizeof(buf);
4307         int ret;
4308
4309         if (result) {
4310                 void *p = buf;
4311
4312                 /* encode ResponseMessage */
4313                 ceph_start_encoding(&p, 1, 1,
4314                                     buf_size - CEPH_ENCODING_START_BLK_LEN);
4315                 ceph_encode_32(&p, *result);
4316         } else {
4317                 buf_size = 0;
4318         }
4319
4320         ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
4321                                    &rbd_dev->header_oloc, notify_id, cookie,
4322                                    buf, buf_size);
4323         if (ret)
4324                 rbd_warn(rbd_dev, "acknowledge_notify failed: %d", ret);
4325 }
4326
4327 static void rbd_acknowledge_notify(struct rbd_device *rbd_dev, u64 notify_id,
4328                                    u64 cookie)
4329 {
4330         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4331         __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, NULL);
4332 }
4333
4334 static void rbd_acknowledge_notify_result(struct rbd_device *rbd_dev,
4335                                           u64 notify_id, u64 cookie, s32 result)
4336 {
4337         dout("%s rbd_dev %p result %d\n", __func__, rbd_dev, result);
4338         __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, &result);
4339 }
4340
4341 static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie,
4342                          u64 notifier_id, void *data, size_t data_len)
4343 {
4344         struct rbd_device *rbd_dev = arg;
4345         void *p = data;
4346         void *const end = p + data_len;
4347         u8 struct_v = 0;
4348         u32 len;
4349         u32 notify_op;
4350         int ret;
4351
4352         dout("%s rbd_dev %p cookie %llu notify_id %llu data_len %zu\n",
4353              __func__, rbd_dev, cookie, notify_id, data_len);
4354         if (data_len) {
4355                 ret = ceph_start_decoding(&p, end, 1, "NotifyMessage",
4356                                           &struct_v, &len);
4357                 if (ret) {
4358                         rbd_warn(rbd_dev, "failed to decode NotifyMessage: %d",
4359                                  ret);
4360                         return;
4361                 }
4362
4363                 notify_op = ceph_decode_32(&p);
4364         } else {
4365                 /* legacy notification for header updates */
4366                 notify_op = RBD_NOTIFY_OP_HEADER_UPDATE;
4367                 len = 0;
4368         }
4369
4370         dout("%s rbd_dev %p notify_op %u\n", __func__, rbd_dev, notify_op);
4371         switch (notify_op) {
4372         case RBD_NOTIFY_OP_ACQUIRED_LOCK:
4373                 rbd_handle_acquired_lock(rbd_dev, struct_v, &p);
4374                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4375                 break;
4376         case RBD_NOTIFY_OP_RELEASED_LOCK:
4377                 rbd_handle_released_lock(rbd_dev, struct_v, &p);
4378                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4379                 break;
4380         case RBD_NOTIFY_OP_REQUEST_LOCK:
4381                 ret = rbd_handle_request_lock(rbd_dev, struct_v, &p);
4382                 if (ret <= 0)
4383                         rbd_acknowledge_notify_result(rbd_dev, notify_id,
4384                                                       cookie, ret);
4385                 else
4386                         rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4387                 break;
4388         case RBD_NOTIFY_OP_HEADER_UPDATE:
4389                 ret = rbd_dev_refresh(rbd_dev);
4390                 if (ret)
4391                         rbd_warn(rbd_dev, "refresh failed: %d", ret);
4392
4393                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4394                 break;
4395         default:
4396                 if (rbd_is_lock_owner(rbd_dev))
4397                         rbd_acknowledge_notify_result(rbd_dev, notify_id,
4398                                                       cookie, -EOPNOTSUPP);
4399                 else
4400                         rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4401                 break;
4402         }
4403 }
4404
4405 static void __rbd_unregister_watch(struct rbd_device *rbd_dev);
4406
4407 static void rbd_watch_errcb(void *arg, u64 cookie, int err)
4408 {
4409         struct rbd_device *rbd_dev = arg;
4410
4411         rbd_warn(rbd_dev, "encountered watch error: %d", err);
4412
4413         down_write(&rbd_dev->lock_rwsem);
4414         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
4415         up_write(&rbd_dev->lock_rwsem);
4416
4417         mutex_lock(&rbd_dev->watch_mutex);
4418         if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED) {
4419                 __rbd_unregister_watch(rbd_dev);
4420                 rbd_dev->watch_state = RBD_WATCH_STATE_ERROR;
4421
4422                 queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
4423         }
4424         mutex_unlock(&rbd_dev->watch_mutex);
4425 }
4426
4427 /*
4428  * watch_mutex must be locked
4429  */
4430 static int __rbd_register_watch(struct rbd_device *rbd_dev)
4431 {
4432         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4433         struct ceph_osd_linger_request *handle;
4434
4435         rbd_assert(!rbd_dev->watch_handle);
4436         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4437
4438         handle = ceph_osdc_watch(osdc, &rbd_dev->header_oid,
4439                                  &rbd_dev->header_oloc, rbd_watch_cb,
4440                                  rbd_watch_errcb, rbd_dev);
4441         if (IS_ERR(handle))
4442                 return PTR_ERR(handle);
4443
4444         rbd_dev->watch_handle = handle;
4445         return 0;
4446 }
4447
4448 /*
4449  * watch_mutex must be locked
4450  */
4451 static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
4452 {
4453         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4454         int ret;
4455
4456         rbd_assert(rbd_dev->watch_handle);
4457         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4458
4459         ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
4460         if (ret)
4461                 rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
4462
4463         rbd_dev->watch_handle = NULL;
4464 }
4465
4466 static int rbd_register_watch(struct rbd_device *rbd_dev)
4467 {
4468         int ret;
4469
4470         mutex_lock(&rbd_dev->watch_mutex);
4471         rbd_assert(rbd_dev->watch_state == RBD_WATCH_STATE_UNREGISTERED);
4472         ret = __rbd_register_watch(rbd_dev);
4473         if (ret)
4474                 goto out;
4475
4476         rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
4477         rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
4478
4479 out:
4480         mutex_unlock(&rbd_dev->watch_mutex);
4481         return ret;
4482 }
4483
4484 static void cancel_tasks_sync(struct rbd_device *rbd_dev)
4485 {
4486         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4487
4488         cancel_work_sync(&rbd_dev->acquired_lock_work);
4489         cancel_work_sync(&rbd_dev->released_lock_work);
4490         cancel_delayed_work_sync(&rbd_dev->lock_dwork);
4491         cancel_work_sync(&rbd_dev->unlock_work);
4492 }
4493
4494 /*
4495  * header_rwsem must not be held to avoid a deadlock with
4496  * rbd_dev_refresh() when flushing notifies.
4497  */
4498 static void rbd_unregister_watch(struct rbd_device *rbd_dev)
4499 {
4500         cancel_tasks_sync(rbd_dev);
4501
4502         mutex_lock(&rbd_dev->watch_mutex);
4503         if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED)
4504                 __rbd_unregister_watch(rbd_dev);
4505         rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
4506         mutex_unlock(&rbd_dev->watch_mutex);
4507
4508         cancel_delayed_work_sync(&rbd_dev->watch_dwork);
4509         ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
4510 }
4511
4512 /*
4513  * lock_rwsem must be held for write
4514  */
4515 static void rbd_reacquire_lock(struct rbd_device *rbd_dev)
4516 {
4517         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4518         char cookie[32];
4519         int ret;
4520
4521         if (!rbd_quiesce_lock(rbd_dev))
4522                 return;
4523
4524         format_lock_cookie(rbd_dev, cookie);
4525         ret = ceph_cls_set_cookie(osdc, &rbd_dev->header_oid,
4526                                   &rbd_dev->header_oloc, RBD_LOCK_NAME,
4527                                   CEPH_CLS_LOCK_EXCLUSIVE, rbd_dev->lock_cookie,
4528                                   RBD_LOCK_TAG, cookie);
4529         if (ret) {
4530                 if (ret != -EOPNOTSUPP)
4531                         rbd_warn(rbd_dev, "failed to update lock cookie: %d",
4532                                  ret);
4533
4534                 /*
4535                  * Lock cookie cannot be updated on older OSDs, so do
4536                  * a manual release and queue an acquire.
4537                  */
4538                 __rbd_release_lock(rbd_dev);
4539                 queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
4540         } else {
4541                 __rbd_lock(rbd_dev, cookie);
4542                 wake_lock_waiters(rbd_dev, 0);
4543         }
4544 }
4545
4546 static void rbd_reregister_watch(struct work_struct *work)
4547 {
4548         struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
4549                                             struct rbd_device, watch_dwork);
4550         int ret;
4551
4552         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4553
4554         mutex_lock(&rbd_dev->watch_mutex);
4555         if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
4556                 mutex_unlock(&rbd_dev->watch_mutex);
4557                 return;
4558         }
4559
4560         ret = __rbd_register_watch(rbd_dev);
4561         if (ret) {
4562                 rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
4563                 if (ret != -EBLOCKLISTED && ret != -ENOENT) {
4564                         queue_delayed_work(rbd_dev->task_wq,
4565                                            &rbd_dev->watch_dwork,
4566                                            RBD_RETRY_DELAY);
4567                         mutex_unlock(&rbd_dev->watch_mutex);
4568                         return;
4569                 }
4570
4571                 mutex_unlock(&rbd_dev->watch_mutex);
4572                 down_write(&rbd_dev->lock_rwsem);
4573                 wake_lock_waiters(rbd_dev, ret);
4574                 up_write(&rbd_dev->lock_rwsem);
4575                 return;
4576         }
4577
4578         rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
4579         rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
4580         mutex_unlock(&rbd_dev->watch_mutex);
4581
4582         down_write(&rbd_dev->lock_rwsem);
4583         if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
4584                 rbd_reacquire_lock(rbd_dev);
4585         up_write(&rbd_dev->lock_rwsem);
4586
4587         ret = rbd_dev_refresh(rbd_dev);
4588         if (ret)
4589                 rbd_warn(rbd_dev, "reregistration refresh failed: %d", ret);
4590 }
4591
4592 /*
4593  * Synchronous osd object method call.  Returns the number of bytes
4594  * returned in the outbound buffer, or a negative error code.
4595  */
4596 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
4597                              struct ceph_object_id *oid,
4598                              struct ceph_object_locator *oloc,
4599                              const char *method_name,
4600                              const void *outbound,
4601                              size_t outbound_size,
4602                              void *inbound,
4603                              size_t inbound_size)
4604 {
4605         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4606         struct page *req_page = NULL;
4607         struct page *reply_page;
4608         int ret;
4609
4610         /*
4611          * Method calls are ultimately read operations.  The result
4612          * should placed into the inbound buffer provided.  They
4613          * also supply outbound data--parameters for the object
4614          * method.  Currently if this is present it will be a
4615          * snapshot id.
4616          */
4617         if (outbound) {
4618                 if (outbound_size > PAGE_SIZE)
4619                         return -E2BIG;
4620
4621                 req_page = alloc_page(GFP_KERNEL);
4622                 if (!req_page)
4623                         return -ENOMEM;
4624
4625                 memcpy(page_address(req_page), outbound, outbound_size);
4626         }
4627
4628         reply_page = alloc_page(GFP_KERNEL);
4629         if (!reply_page) {
4630                 if (req_page)
4631                         __free_page(req_page);
4632                 return -ENOMEM;
4633         }
4634
4635         ret = ceph_osdc_call(osdc, oid, oloc, RBD_DRV_NAME, method_name,
4636                              CEPH_OSD_FLAG_READ, req_page, outbound_size,
4637                              &reply_page, &inbound_size);
4638         if (!ret) {
4639                 memcpy(inbound, page_address(reply_page), inbound_size);
4640                 ret = inbound_size;
4641         }
4642
4643         if (req_page)
4644                 __free_page(req_page);
4645         __free_page(reply_page);
4646         return ret;
4647 }
4648
4649 static void rbd_queue_workfn(struct work_struct *work)
4650 {
4651         struct rbd_img_request *img_request =
4652             container_of(work, struct rbd_img_request, work);
4653         struct rbd_device *rbd_dev = img_request->rbd_dev;
4654         enum obj_operation_type op_type = img_request->op_type;
4655         struct request *rq = blk_mq_rq_from_pdu(img_request);
4656         u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
4657         u64 length = blk_rq_bytes(rq);
4658         u64 mapping_size;
4659         int result;
4660
4661         /* Ignore/skip any zero-length requests */
4662         if (!length) {
4663                 dout("%s: zero-length request\n", __func__);
4664                 result = 0;
4665                 goto err_img_request;
4666         }
4667
4668         blk_mq_start_request(rq);
4669
4670         down_read(&rbd_dev->header_rwsem);
4671         mapping_size = rbd_dev->mapping.size;
4672         rbd_img_capture_header(img_request);
4673         up_read(&rbd_dev->header_rwsem);
4674
4675         if (offset + length > mapping_size) {
4676                 rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4677                          length, mapping_size);
4678                 result = -EIO;
4679                 goto err_img_request;
4680         }
4681
4682         dout("%s rbd_dev %p img_req %p %s %llu~%llu\n", __func__, rbd_dev,
4683              img_request, obj_op_name(op_type), offset, length);
4684
4685         if (op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_ZEROOUT)
4686                 result = rbd_img_fill_nodata(img_request, offset, length);
4687         else
4688                 result = rbd_img_fill_from_bio(img_request, offset, length,
4689                                                rq->bio);
4690         if (result)
4691                 goto err_img_request;
4692
4693         rbd_img_handle_request(img_request, 0);
4694         return;
4695
4696 err_img_request:
4697         rbd_img_request_destroy(img_request);
4698         if (result)
4699                 rbd_warn(rbd_dev, "%s %llx at %llx result %d",
4700                          obj_op_name(op_type), length, offset, result);
4701         blk_mq_end_request(rq, errno_to_blk_status(result));
4702 }
4703
4704 static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
4705                 const struct blk_mq_queue_data *bd)
4706 {
4707         struct rbd_device *rbd_dev = hctx->queue->queuedata;
4708         struct rbd_img_request *img_req = blk_mq_rq_to_pdu(bd->rq);
4709         enum obj_operation_type op_type;
4710
4711         switch (req_op(bd->rq)) {
4712         case REQ_OP_DISCARD:
4713                 op_type = OBJ_OP_DISCARD;
4714                 break;
4715         case REQ_OP_WRITE_ZEROES:
4716                 op_type = OBJ_OP_ZEROOUT;
4717                 break;
4718         case REQ_OP_WRITE:
4719                 op_type = OBJ_OP_WRITE;
4720                 break;
4721         case REQ_OP_READ:
4722                 op_type = OBJ_OP_READ;
4723                 break;
4724         default:
4725                 rbd_warn(rbd_dev, "unknown req_op %d", req_op(bd->rq));
4726                 return BLK_STS_IOERR;
4727         }
4728
4729         rbd_img_request_init(img_req, rbd_dev, op_type);
4730
4731         if (rbd_img_is_write(img_req)) {
4732                 if (rbd_is_ro(rbd_dev)) {
4733                         rbd_warn(rbd_dev, "%s on read-only mapping",
4734                                  obj_op_name(img_req->op_type));
4735                         return BLK_STS_IOERR;
4736                 }
4737                 rbd_assert(!rbd_is_snap(rbd_dev));
4738         }
4739
4740         INIT_WORK(&img_req->work, rbd_queue_workfn);
4741         queue_work(rbd_wq, &img_req->work);
4742         return BLK_STS_OK;
4743 }
4744
4745 static void rbd_free_disk(struct rbd_device *rbd_dev)
4746 {
4747         blk_cleanup_disk(rbd_dev->disk);
4748         blk_mq_free_tag_set(&rbd_dev->tag_set);
4749         rbd_dev->disk = NULL;
4750 }
4751
4752 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
4753                              struct ceph_object_id *oid,
4754                              struct ceph_object_locator *oloc,
4755                              void *buf, int buf_len)
4756
4757 {
4758         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4759         struct ceph_osd_request *req;
4760         struct page **pages;
4761         int num_pages = calc_pages_for(0, buf_len);
4762         int ret;
4763
4764         req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
4765         if (!req)
4766                 return -ENOMEM;
4767
4768         ceph_oid_copy(&req->r_base_oid, oid);
4769         ceph_oloc_copy(&req->r_base_oloc, oloc);
4770         req->r_flags = CEPH_OSD_FLAG_READ;
4771
4772         pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
4773         if (IS_ERR(pages)) {
4774                 ret = PTR_ERR(pages);
4775                 goto out_req;
4776         }
4777
4778         osd_req_op_extent_init(req, 0, CEPH_OSD_OP_READ, 0, buf_len, 0, 0);
4779         osd_req_op_extent_osd_data_pages(req, 0, pages, buf_len, 0, false,
4780                                          true);
4781
4782         ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
4783         if (ret)
4784                 goto out_req;
4785
4786         ceph_osdc_start_request(osdc, req, false);
4787         ret = ceph_osdc_wait_request(osdc, req);
4788         if (ret >= 0)
4789                 ceph_copy_from_page_vector(pages, buf, 0, ret);
4790
4791 out_req:
4792         ceph_osdc_put_request(req);
4793         return ret;
4794 }
4795
4796 /*
4797  * Read the complete header for the given rbd device.  On successful
4798  * return, the rbd_dev->header field will contain up-to-date
4799  * information about the image.
4800  */
4801 static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4802 {
4803         struct rbd_image_header_ondisk *ondisk = NULL;
4804         u32 snap_count = 0;
4805         u64 names_size = 0;
4806         u32 want_count;
4807         int ret;
4808
4809         /*
4810          * The complete header will include an array of its 64-bit
4811          * snapshot ids, followed by the names of those snapshots as
4812          * a contiguous block of NUL-terminated strings.  Note that
4813          * the number of snapshots could change by the time we read
4814          * it in, in which case we re-read it.
4815          */
4816         do {
4817                 size_t size;
4818
4819                 kfree(ondisk);
4820
4821                 size = sizeof (*ondisk);
4822                 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
4823                 size += names_size;
4824                 ondisk = kmalloc(size, GFP_KERNEL);
4825                 if (!ondisk)
4826                         return -ENOMEM;
4827
4828                 ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
4829                                         &rbd_dev->header_oloc, ondisk, size);
4830                 if (ret < 0)
4831                         goto out;
4832                 if ((size_t)ret < size) {
4833                         ret = -ENXIO;
4834                         rbd_warn(rbd_dev, "short header read (want %zd got %d)",
4835                                 size, ret);
4836                         goto out;
4837                 }
4838                 if (!rbd_dev_ondisk_valid(ondisk)) {
4839                         ret = -ENXIO;
4840                         rbd_warn(rbd_dev, "invalid header");
4841                         goto out;
4842                 }
4843
4844                 names_size = le64_to_cpu(ondisk->snap_names_len);
4845                 want_count = snap_count;
4846                 snap_count = le32_to_cpu(ondisk->snap_count);
4847         } while (snap_count != want_count);
4848
4849         ret = rbd_header_from_disk(rbd_dev, ondisk);
4850 out:
4851         kfree(ondisk);
4852
4853         return ret;
4854 }
4855
4856 static void rbd_dev_update_size(struct rbd_device *rbd_dev)
4857 {
4858         sector_t size;
4859
4860         /*
4861          * If EXISTS is not set, rbd_dev->disk may be NULL, so don't
4862          * try to update its size.  If REMOVING is set, updating size
4863          * is just useless work since the device can't be opened.
4864          */
4865         if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
4866             !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4867                 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
4868                 dout("setting size to %llu sectors", (unsigned long long)size);
4869                 set_capacity_and_notify(rbd_dev->disk, size);
4870         }
4871 }
4872
4873 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
4874 {
4875         u64 mapping_size;
4876         int ret;
4877
4878         down_write(&rbd_dev->header_rwsem);
4879         mapping_size = rbd_dev->mapping.size;
4880
4881         ret = rbd_dev_header_info(rbd_dev);
4882         if (ret)
4883                 goto out;
4884
4885         /*
4886          * If there is a parent, see if it has disappeared due to the
4887          * mapped image getting flattened.
4888          */
4889         if (rbd_dev->parent) {
4890                 ret = rbd_dev_v2_parent_info(rbd_dev);
4891                 if (ret)
4892                         goto out;
4893         }
4894
4895         rbd_assert(!rbd_is_snap(rbd_dev));
4896         rbd_dev->mapping.size = rbd_dev->header.image_size;
4897
4898 out:
4899         up_write(&rbd_dev->header_rwsem);
4900         if (!ret && mapping_size != rbd_dev->mapping.size)
4901                 rbd_dev_update_size(rbd_dev);
4902
4903         return ret;
4904 }
4905
4906 static const struct blk_mq_ops rbd_mq_ops = {
4907         .queue_rq       = rbd_queue_rq,
4908 };
4909
4910 static int rbd_init_disk(struct rbd_device *rbd_dev)
4911 {
4912         struct gendisk *disk;
4913         struct request_queue *q;
4914         unsigned int objset_bytes =
4915             rbd_dev->layout.object_size * rbd_dev->layout.stripe_count;
4916         int err;
4917
4918         memset(&rbd_dev->tag_set, 0, sizeof(rbd_dev->tag_set));
4919         rbd_dev->tag_set.ops = &rbd_mq_ops;
4920         rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
4921         rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
4922         rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
4923         rbd_dev->tag_set.nr_hw_queues = num_present_cpus();
4924         rbd_dev->tag_set.cmd_size = sizeof(struct rbd_img_request);
4925
4926         err = blk_mq_alloc_tag_set(&rbd_dev->tag_set);
4927         if (err)
4928                 return err;
4929
4930         disk = blk_mq_alloc_disk(&rbd_dev->tag_set, rbd_dev);
4931         if (IS_ERR(disk)) {
4932                 err = PTR_ERR(disk);
4933                 goto out_tag_set;
4934         }
4935         q = disk->queue;
4936
4937         snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
4938                  rbd_dev->dev_id);
4939         disk->major = rbd_dev->major;
4940         disk->first_minor = rbd_dev->minor;
4941         if (single_major) {
4942                 disk->minors = (1 << RBD_SINGLE_MAJOR_PART_SHIFT);
4943                 disk->flags |= GENHD_FL_EXT_DEVT;
4944         } else {
4945                 disk->minors = RBD_MINORS_PER_MAJOR;
4946         }
4947         disk->fops = &rbd_bd_ops;
4948
4949         blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
4950         /* QUEUE_FLAG_ADD_RANDOM is off by default for blk-mq */
4951
4952         blk_queue_max_hw_sectors(q, objset_bytes >> SECTOR_SHIFT);
4953         q->limits.max_sectors = queue_max_hw_sectors(q);
4954         blk_queue_max_segments(q, USHRT_MAX);
4955         blk_queue_max_segment_size(q, UINT_MAX);
4956         blk_queue_io_min(q, rbd_dev->opts->alloc_size);
4957         blk_queue_io_opt(q, rbd_dev->opts->alloc_size);
4958
4959         if (rbd_dev->opts->trim) {
4960                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
4961                 q->limits.discard_granularity = rbd_dev->opts->alloc_size;
4962                 blk_queue_max_discard_sectors(q, objset_bytes >> SECTOR_SHIFT);
4963                 blk_queue_max_write_zeroes_sectors(q, objset_bytes >> SECTOR_SHIFT);
4964         }
4965
4966         if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
4967                 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
4968
4969         rbd_dev->disk = disk;
4970
4971         return 0;
4972 out_tag_set:
4973         blk_mq_free_tag_set(&rbd_dev->tag_set);
4974         return err;
4975 }
4976
4977 /*
4978   sysfs
4979 */
4980
4981 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
4982 {
4983         return container_of(dev, struct rbd_device, dev);
4984 }
4985
4986 static ssize_t rbd_size_show(struct device *dev,
4987                              struct device_attribute *attr, char *buf)
4988 {
4989         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4990
4991         return sprintf(buf, "%llu\n",
4992                 (unsigned long long)rbd_dev->mapping.size);
4993 }
4994
4995 static ssize_t rbd_features_show(struct device *dev,
4996                              struct device_attribute *attr, char *buf)
4997 {
4998         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4999
5000         return sprintf(buf, "0x%016llx\n", rbd_dev->header.features);
5001 }
5002
5003 static ssize_t rbd_major_show(struct device *dev,
5004                               struct device_attribute *attr, char *buf)
5005 {
5006         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5007
5008         if (rbd_dev->major)
5009                 return sprintf(buf, "%d\n", rbd_dev->major);
5010
5011         return sprintf(buf, "(none)\n");
5012 }
5013
5014 static ssize_t rbd_minor_show(struct device *dev,
5015                               struct device_attribute *attr, char *buf)
5016 {
5017         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5018
5019         return sprintf(buf, "%d\n", rbd_dev->minor);
5020 }
5021
5022 static ssize_t rbd_client_addr_show(struct device *dev,
5023                                     struct device_attribute *attr, char *buf)
5024 {
5025         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5026         struct ceph_entity_addr *client_addr =
5027             ceph_client_addr(rbd_dev->rbd_client->client);
5028
5029         return sprintf(buf, "%pISpc/%u\n", &client_addr->in_addr,
5030                        le32_to_cpu(client_addr->nonce));
5031 }
5032
5033 static ssize_t rbd_client_id_show(struct device *dev,
5034                                   struct device_attribute *attr, char *buf)
5035 {
5036         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5037
5038         return sprintf(buf, "client%lld\n",
5039                        ceph_client_gid(rbd_dev->rbd_client->client));
5040 }
5041
5042 static ssize_t rbd_cluster_fsid_show(struct device *dev,
5043                                      struct device_attribute *attr, char *buf)
5044 {
5045         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5046
5047         return sprintf(buf, "%pU\n", &rbd_dev->rbd_client->client->fsid);
5048 }
5049
5050 static ssize_t rbd_config_info_show(struct device *dev,
5051                                     struct device_attribute *attr, char *buf)
5052 {
5053         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5054
5055         if (!capable(CAP_SYS_ADMIN))
5056                 return -EPERM;
5057
5058         return sprintf(buf, "%s\n", rbd_dev->config_info);
5059 }
5060
5061 static ssize_t rbd_pool_show(struct device *dev,
5062                              struct device_attribute *attr, char *buf)
5063 {
5064         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5065
5066         return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
5067 }
5068
5069 static ssize_t rbd_pool_id_show(struct device *dev,
5070                              struct device_attribute *attr, char *buf)
5071 {
5072         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5073
5074         return sprintf(buf, "%llu\n",
5075                         (unsigned long long) rbd_dev->spec->pool_id);
5076 }
5077
5078 static ssize_t rbd_pool_ns_show(struct device *dev,
5079                                 struct device_attribute *attr, char *buf)
5080 {
5081         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5082
5083         return sprintf(buf, "%s\n", rbd_dev->spec->pool_ns ?: "");
5084 }
5085
5086 static ssize_t rbd_name_show(struct device *dev,
5087                              struct device_attribute *attr, char *buf)
5088 {
5089         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5090
5091         if (rbd_dev->spec->image_name)
5092                 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
5093
5094         return sprintf(buf, "(unknown)\n");
5095 }
5096
5097 static ssize_t rbd_image_id_show(struct device *dev,
5098                              struct device_attribute *attr, char *buf)
5099 {
5100         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5101
5102         return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
5103 }
5104
5105 /*
5106  * Shows the name of the currently-mapped snapshot (or
5107  * RBD_SNAP_HEAD_NAME for the base image).
5108  */
5109 static ssize_t rbd_snap_show(struct device *dev,
5110                              struct device_attribute *attr,
5111                              char *buf)
5112 {
5113         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5114
5115         return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
5116 }
5117
5118 static ssize_t rbd_snap_id_show(struct device *dev,
5119                                 struct device_attribute *attr, char *buf)
5120 {
5121         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5122
5123         return sprintf(buf, "%llu\n", rbd_dev->spec->snap_id);
5124 }
5125
5126 /*
5127  * For a v2 image, shows the chain of parent images, separated by empty
5128  * lines.  For v1 images or if there is no parent, shows "(no parent
5129  * image)".
5130  */
5131 static ssize_t rbd_parent_show(struct device *dev,
5132                                struct device_attribute *attr,
5133                                char *buf)
5134 {
5135         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5136         ssize_t count = 0;
5137
5138         if (!rbd_dev->parent)
5139                 return sprintf(buf, "(no parent image)\n");
5140
5141         for ( ; rbd_dev->parent; rbd_dev = rbd_dev->parent) {
5142                 struct rbd_spec *spec = rbd_dev->parent_spec;
5143
5144                 count += sprintf(&buf[count], "%s"
5145                             "pool_id %llu\npool_name %s\n"
5146                             "pool_ns %s\n"
5147                             "image_id %s\nimage_name %s\n"
5148                             "snap_id %llu\nsnap_name %s\n"
5149                             "overlap %llu\n",
5150                             !count ? "" : "\n", /* first? */
5151                             spec->pool_id, spec->pool_name,
5152                             spec->pool_ns ?: "",
5153                             spec->image_id, spec->image_name ?: "(unknown)",
5154                             spec->snap_id, spec->snap_name,
5155                             rbd_dev->parent_overlap);
5156         }
5157
5158         return count;
5159 }
5160
5161 static ssize_t rbd_image_refresh(struct device *dev,
5162                                  struct device_attribute *attr,
5163                                  const char *buf,
5164                                  size_t size)
5165 {
5166         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5167         int ret;
5168
5169         if (!capable(CAP_SYS_ADMIN))
5170                 return -EPERM;
5171
5172         ret = rbd_dev_refresh(rbd_dev);
5173         if (ret)
5174                 return ret;
5175
5176         return size;
5177 }
5178
5179 static DEVICE_ATTR(size, 0444, rbd_size_show, NULL);
5180 static DEVICE_ATTR(features, 0444, rbd_features_show, NULL);
5181 static DEVICE_ATTR(major, 0444, rbd_major_show, NULL);
5182 static DEVICE_ATTR(minor, 0444, rbd_minor_show, NULL);
5183 static DEVICE_ATTR(client_addr, 0444, rbd_client_addr_show, NULL);
5184 static DEVICE_ATTR(client_id, 0444, rbd_client_id_show, NULL);
5185 static DEVICE_ATTR(cluster_fsid, 0444, rbd_cluster_fsid_show, NULL);
5186 static DEVICE_ATTR(config_info, 0400, rbd_config_info_show, NULL);
5187 static DEVICE_ATTR(pool, 0444, rbd_pool_show, NULL);
5188 static DEVICE_ATTR(pool_id, 0444, rbd_pool_id_show, NULL);
5189 static DEVICE_ATTR(pool_ns, 0444, rbd_pool_ns_show, NULL);
5190 static DEVICE_ATTR(name, 0444, rbd_name_show, NULL);
5191 static DEVICE_ATTR(image_id, 0444, rbd_image_id_show, NULL);
5192 static DEVICE_ATTR(refresh, 0200, NULL, rbd_image_refresh);
5193 static DEVICE_ATTR(current_snap, 0444, rbd_snap_show, NULL);
5194 static DEVICE_ATTR(snap_id, 0444, rbd_snap_id_show, NULL);
5195 static DEVICE_ATTR(parent, 0444, rbd_parent_show, NULL);
5196
5197 static struct attribute *rbd_attrs[] = {
5198         &dev_attr_size.attr,
5199         &dev_attr_features.attr,
5200         &dev_attr_major.attr,
5201         &dev_attr_minor.attr,
5202         &dev_attr_client_addr.attr,
5203         &dev_attr_client_id.attr,
5204         &dev_attr_cluster_fsid.attr,
5205         &dev_attr_config_info.attr,
5206         &dev_attr_pool.attr,
5207         &dev_attr_pool_id.attr,
5208         &dev_attr_pool_ns.attr,
5209         &dev_attr_name.attr,
5210         &dev_attr_image_id.attr,
5211         &dev_attr_current_snap.attr,
5212         &dev_attr_snap_id.attr,
5213         &dev_attr_parent.attr,
5214         &dev_attr_refresh.attr,
5215         NULL
5216 };
5217
5218 static struct attribute_group rbd_attr_group = {
5219         .attrs = rbd_attrs,
5220 };
5221
5222 static const struct attribute_group *rbd_attr_groups[] = {
5223         &rbd_attr_group,
5224         NULL
5225 };
5226
5227 static void rbd_dev_release(struct device *dev);
5228
5229 static const struct device_type rbd_device_type = {
5230         .name           = "rbd",
5231         .groups         = rbd_attr_groups,
5232         .release        = rbd_dev_release,
5233 };
5234
5235 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
5236 {
5237         kref_get(&spec->kref);
5238
5239         return spec;
5240 }
5241
5242 static void rbd_spec_free(struct kref *kref);
5243 static void rbd_spec_put(struct rbd_spec *spec)
5244 {
5245         if (spec)
5246                 kref_put(&spec->kref, rbd_spec_free);
5247 }
5248
5249 static struct rbd_spec *rbd_spec_alloc(void)
5250 {
5251         struct rbd_spec *spec;
5252
5253         spec = kzalloc(sizeof (*spec), GFP_KERNEL);
5254         if (!spec)
5255                 return NULL;
5256
5257         spec->pool_id = CEPH_NOPOOL;
5258         spec->snap_id = CEPH_NOSNAP;
5259         kref_init(&spec->kref);
5260
5261         return spec;
5262 }
5263
5264 static void rbd_spec_free(struct kref *kref)
5265 {
5266         struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
5267
5268         kfree(spec->pool_name);
5269         kfree(spec->pool_ns);
5270         kfree(spec->image_id);
5271         kfree(spec->image_name);
5272         kfree(spec->snap_name);
5273         kfree(spec);
5274 }
5275
5276 static void rbd_dev_free(struct rbd_device *rbd_dev)
5277 {
5278         WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
5279         WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
5280
5281         ceph_oid_destroy(&rbd_dev->header_oid);
5282         ceph_oloc_destroy(&rbd_dev->header_oloc);
5283         kfree(rbd_dev->config_info);
5284
5285         rbd_put_client(rbd_dev->rbd_client);
5286         rbd_spec_put(rbd_dev->spec);
5287         kfree(rbd_dev->opts);
5288         kfree(rbd_dev);
5289 }
5290
5291 static void rbd_dev_release(struct device *dev)
5292 {
5293         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5294         bool need_put = !!rbd_dev->opts;
5295
5296         if (need_put) {
5297                 destroy_workqueue(rbd_dev->task_wq);
5298                 ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
5299         }
5300
5301         rbd_dev_free(rbd_dev);
5302
5303         /*
5304          * This is racy, but way better than putting module outside of
5305          * the release callback.  The race window is pretty small, so
5306          * doing something similar to dm (dm-builtin.c) is overkill.
5307          */
5308         if (need_put)
5309                 module_put(THIS_MODULE);
5310 }
5311
5312 static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
5313                                            struct rbd_spec *spec)
5314 {
5315         struct rbd_device *rbd_dev;
5316
5317         rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
5318         if (!rbd_dev)
5319                 return NULL;
5320
5321         spin_lock_init(&rbd_dev->lock);
5322         INIT_LIST_HEAD(&rbd_dev->node);
5323         init_rwsem(&rbd_dev->header_rwsem);
5324
5325         rbd_dev->header.data_pool_id = CEPH_NOPOOL;
5326         ceph_oid_init(&rbd_dev->header_oid);
5327         rbd_dev->header_oloc.pool = spec->pool_id;
5328         if (spec->pool_ns) {
5329                 WARN_ON(!*spec->pool_ns);
5330                 rbd_dev->header_oloc.pool_ns =
5331                     ceph_find_or_create_string(spec->pool_ns,
5332                                                strlen(spec->pool_ns));
5333         }
5334
5335         mutex_init(&rbd_dev->watch_mutex);
5336         rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
5337         INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);
5338
5339         init_rwsem(&rbd_dev->lock_rwsem);
5340         rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
5341         INIT_WORK(&rbd_dev->acquired_lock_work, rbd_notify_acquired_lock);
5342         INIT_WORK(&rbd_dev->released_lock_work, rbd_notify_released_lock);
5343         INIT_DELAYED_WORK(&rbd_dev->lock_dwork, rbd_acquire_lock);
5344         INIT_WORK(&rbd_dev->unlock_work, rbd_release_lock_work);
5345         spin_lock_init(&rbd_dev->lock_lists_lock);
5346         INIT_LIST_HEAD(&rbd_dev->acquiring_list);
5347         INIT_LIST_HEAD(&rbd_dev->running_list);
5348         init_completion(&rbd_dev->acquire_wait);
5349         init_completion(&rbd_dev->releasing_wait);
5350
5351         spin_lock_init(&rbd_dev->object_map_lock);
5352
5353         rbd_dev->dev.bus = &rbd_bus_type;
5354         rbd_dev->dev.type = &rbd_device_type;
5355         rbd_dev->dev.parent = &rbd_root_dev;
5356         device_initialize(&rbd_dev->dev);
5357
5358         rbd_dev->rbd_client = rbdc;
5359         rbd_dev->spec = spec;
5360
5361         return rbd_dev;
5362 }
5363
5364 /*
5365  * Create a mapping rbd_dev.
5366  */
5367 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
5368                                          struct rbd_spec *spec,
5369                                          struct rbd_options *opts)
5370 {
5371         struct rbd_device *rbd_dev;
5372
5373         rbd_dev = __rbd_dev_create(rbdc, spec);
5374         if (!rbd_dev)
5375                 return NULL;
5376
5377         rbd_dev->opts = opts;
5378
5379         /* get an id and fill in device name */
5380         rbd_dev->dev_id = ida_simple_get(&rbd_dev_id_ida, 0,
5381                                          minor_to_rbd_dev_id(1 << MINORBITS),
5382                                          GFP_KERNEL);
5383         if (rbd_dev->dev_id < 0)
5384                 goto fail_rbd_dev;
5385
5386         sprintf(rbd_dev->name, RBD_DRV_NAME "%d", rbd_dev->dev_id);
5387         rbd_dev->task_wq = alloc_ordered_workqueue("%s-tasks", WQ_MEM_RECLAIM,
5388                                                    rbd_dev->name);
5389         if (!rbd_dev->task_wq)
5390                 goto fail_dev_id;
5391
5392         /* we have a ref from do_rbd_add() */
5393         __module_get(THIS_MODULE);
5394
5395         dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
5396         return rbd_dev;
5397
5398 fail_dev_id:
5399         ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
5400 fail_rbd_dev:
5401         rbd_dev_free(rbd_dev);
5402         return NULL;
5403 }
5404
5405 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
5406 {
5407         if (rbd_dev)
5408                 put_device(&rbd_dev->dev);
5409 }
5410
5411 /*
5412  * Get the size and object order for an image snapshot, or if
5413  * snap_id is CEPH_NOSNAP, gets this information for the base
5414  * image.
5415  */
5416 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
5417                                 u8 *order, u64 *snap_size)
5418 {
5419         __le64 snapid = cpu_to_le64(snap_id);
5420         int ret;
5421         struct {
5422                 u8 order;
5423                 __le64 size;
5424         } __attribute__ ((packed)) size_buf = { 0 };
5425
5426         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5427                                   &rbd_dev->header_oloc, "get_size",
5428                                   &snapid, sizeof(snapid),
5429                                   &size_buf, sizeof(size_buf));
5430         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5431         if (ret < 0)
5432                 return ret;
5433         if (ret < sizeof (size_buf))
5434                 return -ERANGE;
5435
5436         if (order) {
5437                 *order = size_buf.order;
5438                 dout("  order %u", (unsigned int)*order);
5439         }
5440         *snap_size = le64_to_cpu(size_buf.size);
5441
5442         dout("  snap_id 0x%016llx snap_size = %llu\n",
5443                 (unsigned long long)snap_id,
5444                 (unsigned long long)*snap_size);
5445
5446         return 0;
5447 }
5448
5449 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
5450 {
5451         return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
5452                                         &rbd_dev->header.obj_order,
5453                                         &rbd_dev->header.image_size);
5454 }
5455
5456 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
5457 {
5458         size_t size;
5459         void *reply_buf;
5460         int ret;
5461         void *p;
5462
5463         /* Response will be an encoded string, which includes a length */
5464         size = sizeof(__le32) + RBD_OBJ_PREFIX_LEN_MAX;
5465         reply_buf = kzalloc(size, GFP_KERNEL);
5466         if (!reply_buf)
5467                 return -ENOMEM;
5468
5469         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5470                                   &rbd_dev->header_oloc, "get_object_prefix",
5471                                   NULL, 0, reply_buf, size);
5472         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5473         if (ret < 0)
5474                 goto out;
5475
5476         p = reply_buf;
5477         rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
5478                                                 p + ret, NULL, GFP_NOIO);
5479         ret = 0;
5480
5481         if (IS_ERR(rbd_dev->header.object_prefix)) {
5482                 ret = PTR_ERR(rbd_dev->header.object_prefix);
5483                 rbd_dev->header.object_prefix = NULL;
5484         } else {
5485                 dout("  object_prefix = %s\n", rbd_dev->header.object_prefix);
5486         }
5487 out:
5488         kfree(reply_buf);
5489
5490         return ret;
5491 }
5492
5493 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
5494                                      bool read_only, u64 *snap_features)
5495 {
5496         struct {
5497                 __le64 snap_id;
5498                 u8 read_only;
5499         } features_in;
5500         struct {
5501                 __le64 features;
5502                 __le64 incompat;
5503         } __attribute__ ((packed)) features_buf = { 0 };
5504         u64 unsup;
5505         int ret;
5506
5507         features_in.snap_id = cpu_to_le64(snap_id);
5508         features_in.read_only = read_only;
5509
5510         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5511                                   &rbd_dev->header_oloc, "get_features",
5512                                   &features_in, sizeof(features_in),
5513                                   &features_buf, sizeof(features_buf));
5514         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5515         if (ret < 0)
5516                 return ret;
5517         if (ret < sizeof (features_buf))
5518                 return -ERANGE;
5519
5520         unsup = le64_to_cpu(features_buf.incompat) & ~RBD_FEATURES_SUPPORTED;
5521         if (unsup) {
5522                 rbd_warn(rbd_dev, "image uses unsupported features: 0x%llx",
5523                          unsup);
5524                 return -ENXIO;
5525         }
5526
5527         *snap_features = le64_to_cpu(features_buf.features);
5528
5529         dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
5530                 (unsigned long long)snap_id,
5531                 (unsigned long long)*snap_features,
5532                 (unsigned long long)le64_to_cpu(features_buf.incompat));
5533
5534         return 0;
5535 }
5536
5537 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
5538 {
5539         return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
5540                                          rbd_is_ro(rbd_dev),
5541                                          &rbd_dev->header.features);
5542 }
5543
5544 /*
5545  * These are generic image flags, but since they are used only for
5546  * object map, store them in rbd_dev->object_map_flags.
5547  *
5548  * For the same reason, this function is called only on object map
5549  * (re)load and not on header refresh.
5550  */
5551 static int rbd_dev_v2_get_flags(struct rbd_device *rbd_dev)
5552 {
5553         __le64 snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5554         __le64 flags;
5555         int ret;
5556
5557         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5558                                   &rbd_dev->header_oloc, "get_flags",
5559                                   &snapid, sizeof(snapid),
5560                                   &flags, sizeof(flags));
5561         if (ret < 0)
5562                 return ret;
5563         if (ret < sizeof(flags))
5564                 return -EBADMSG;
5565
5566         rbd_dev->object_map_flags = le64_to_cpu(flags);
5567         return 0;
5568 }
5569
5570 struct parent_image_info {
5571         u64             pool_id;
5572         const char      *pool_ns;
5573         const char      *image_id;
5574         u64             snap_id;
5575
5576         bool            has_overlap;
5577         u64             overlap;
5578 };
5579
5580 /*
5581  * The caller is responsible for @pii.
5582  */
5583 static int decode_parent_image_spec(void **p, void *end,
5584                                     struct parent_image_info *pii)
5585 {
5586         u8 struct_v;
5587         u32 struct_len;
5588         int ret;
5589
5590         ret = ceph_start_decoding(p, end, 1, "ParentImageSpec",
5591                                   &struct_v, &struct_len);
5592         if (ret)
5593                 return ret;
5594
5595         ceph_decode_64_safe(p, end, pii->pool_id, e_inval);
5596         pii->pool_ns = ceph_extract_encoded_string(p, end, NULL, GFP_KERNEL);
5597         if (IS_ERR(pii->pool_ns)) {
5598                 ret = PTR_ERR(pii->pool_ns);
5599                 pii->pool_ns = NULL;
5600                 return ret;
5601         }
5602         pii->image_id = ceph_extract_encoded_string(p, end, NULL, GFP_KERNEL);
5603         if (IS_ERR(pii->image_id)) {
5604                 ret = PTR_ERR(pii->image_id);
5605                 pii->image_id = NULL;
5606                 return ret;
5607         }
5608         ceph_decode_64_safe(p, end, pii->snap_id, e_inval);
5609         return 0;
5610
5611 e_inval:
5612         return -EINVAL;
5613 }
5614
5615 static int __get_parent_info(struct rbd_device *rbd_dev,
5616                              struct page *req_page,
5617                              struct page *reply_page,
5618                              struct parent_image_info *pii)
5619 {
5620         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
5621         size_t reply_len = PAGE_SIZE;
5622         void *p, *end;
5623         int ret;
5624
5625         ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
5626                              "rbd", "parent_get", CEPH_OSD_FLAG_READ,
5627                              req_page, sizeof(u64), &reply_page, &reply_len);
5628         if (ret)
5629                 return ret == -EOPNOTSUPP ? 1 : ret;
5630
5631         p = page_address(reply_page);
5632         end = p + reply_len;
5633         ret = decode_parent_image_spec(&p, end, pii);
5634         if (ret)
5635                 return ret;
5636
5637         ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
5638                              "rbd", "parent_overlap_get", CEPH_OSD_FLAG_READ,
5639                              req_page, sizeof(u64), &reply_page, &reply_len);
5640         if (ret)
5641                 return ret;
5642
5643         p = page_address(reply_page);
5644         end = p + reply_len;
5645         ceph_decode_8_safe(&p, end, pii->has_overlap, e_inval);
5646         if (pii->has_overlap)
5647                 ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
5648
5649         return 0;
5650
5651 e_inval:
5652         return -EINVAL;
5653 }
5654
5655 /*
5656  * The caller is responsible for @pii.
5657  */
5658 static int __get_parent_info_legacy(struct rbd_device *rbd_dev,
5659                                     struct page *req_page,
5660                                     struct page *reply_page,
5661                                     struct parent_image_info *pii)
5662 {
5663         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
5664         size_t reply_len = PAGE_SIZE;
5665         void *p, *end;
5666         int ret;
5667
5668         ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
5669                              "rbd", "get_parent", CEPH_OSD_FLAG_READ,
5670                              req_page, sizeof(u64), &reply_page, &reply_len);
5671         if (ret)
5672                 return ret;
5673
5674         p = page_address(reply_page);
5675         end = p + reply_len;
5676         ceph_decode_64_safe(&p, end, pii->pool_id, e_inval);
5677         pii->image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5678         if (IS_ERR(pii->image_id)) {
5679                 ret = PTR_ERR(pii->image_id);
5680                 pii->image_id = NULL;
5681                 return ret;
5682         }
5683         ceph_decode_64_safe(&p, end, pii->snap_id, e_inval);
5684         pii->has_overlap = true;
5685         ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
5686
5687         return 0;
5688
5689 e_inval:
5690         return -EINVAL;
5691 }
5692
5693 static int get_parent_info(struct rbd_device *rbd_dev,
5694                            struct parent_image_info *pii)
5695 {
5696         struct page *req_page, *reply_page;
5697         void *p;
5698         int ret;
5699
5700         req_page = alloc_page(GFP_KERNEL);
5701         if (!req_page)
5702                 return -ENOMEM;
5703
5704         reply_page = alloc_page(GFP_KERNEL);
5705         if (!reply_page) {
5706                 __free_page(req_page);
5707                 return -ENOMEM;
5708         }
5709
5710         p = page_address(req_page);
5711         ceph_encode_64(&p, rbd_dev->spec->snap_id);
5712         ret = __get_parent_info(rbd_dev, req_page, reply_page, pii);
5713         if (ret > 0)
5714                 ret = __get_parent_info_legacy(rbd_dev, req_page, reply_page,
5715                                                pii);
5716
5717         __free_page(req_page);
5718         __free_page(reply_page);
5719         return ret;
5720 }
5721
5722 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
5723 {
5724         struct rbd_spec *parent_spec;
5725         struct parent_image_info pii = { 0 };
5726         int ret;
5727
5728         parent_spec = rbd_spec_alloc();
5729         if (!parent_spec)
5730                 return -ENOMEM;
5731
5732         ret = get_parent_info(rbd_dev, &pii);
5733         if (ret)
5734                 goto out_err;
5735
5736         dout("%s pool_id %llu pool_ns %s image_id %s snap_id %llu has_overlap %d overlap %llu\n",
5737              __func__, pii.pool_id, pii.pool_ns, pii.image_id, pii.snap_id,
5738              pii.has_overlap, pii.overlap);
5739
5740         if (pii.pool_id == CEPH_NOPOOL || !pii.has_overlap) {
5741                 /*
5742                  * Either the parent never existed, or we have
5743                  * record of it but the image got flattened so it no
5744                  * longer has a parent.  When the parent of a
5745                  * layered image disappears we immediately set the
5746                  * overlap to 0.  The effect of this is that all new
5747                  * requests will be treated as if the image had no
5748                  * parent.
5749                  *
5750                  * If !pii.has_overlap, the parent image spec is not
5751                  * applicable.  It's there to avoid duplication in each
5752                  * snapshot record.
5753                  */
5754                 if (rbd_dev->parent_overlap) {
5755                         rbd_dev->parent_overlap = 0;
5756                         rbd_dev_parent_put(rbd_dev);
5757                         pr_info("%s: clone image has been flattened\n",
5758                                 rbd_dev->disk->disk_name);
5759                 }
5760
5761                 goto out;       /* No parent?  No problem. */
5762         }
5763
5764         /* The ceph file layout needs to fit pool id in 32 bits */
5765
5766         ret = -EIO;
5767         if (pii.pool_id > (u64)U32_MAX) {
5768                 rbd_warn(NULL, "parent pool id too large (%llu > %u)",
5769                         (unsigned long long)pii.pool_id, U32_MAX);
5770                 goto out_err;
5771         }
5772
5773         /*
5774          * The parent won't change (except when the clone is
5775          * flattened, already handled that).  So we only need to
5776          * record the parent spec we have not already done so.
5777          */
5778         if (!rbd_dev->parent_spec) {
5779                 parent_spec->pool_id = pii.pool_id;
5780                 if (pii.pool_ns && *pii.pool_ns) {
5781                         parent_spec->pool_ns = pii.pool_ns;
5782                         pii.pool_ns = NULL;
5783                 }
5784                 parent_spec->image_id = pii.image_id;
5785                 pii.image_id = NULL;
5786                 parent_spec->snap_id = pii.snap_id;
5787
5788                 rbd_dev->parent_spec = parent_spec;
5789                 parent_spec = NULL;     /* rbd_dev now owns this */
5790         }
5791
5792         /*
5793          * We always update the parent overlap.  If it's zero we issue
5794          * a warning, as we will proceed as if there was no parent.
5795          */
5796         if (!pii.overlap) {
5797                 if (parent_spec) {
5798                         /* refresh, careful to warn just once */
5799                         if (rbd_dev->parent_overlap)
5800                                 rbd_warn(rbd_dev,
5801                                     "clone now standalone (overlap became 0)");
5802                 } else {
5803                         /* initial probe */
5804                         rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5805                 }
5806         }
5807         rbd_dev->parent_overlap = pii.overlap;
5808
5809 out:
5810         ret = 0;
5811 out_err:
5812         kfree(pii.pool_ns);
5813         kfree(pii.image_id);
5814         rbd_spec_put(parent_spec);
5815         return ret;
5816 }
5817
5818 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
5819 {
5820         struct {
5821                 __le64 stripe_unit;
5822                 __le64 stripe_count;
5823         } __attribute__ ((packed)) striping_info_buf = { 0 };
5824         size_t size = sizeof (striping_info_buf);
5825         void *p;
5826         int ret;
5827
5828         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5829                                 &rbd_dev->header_oloc, "get_stripe_unit_count",
5830                                 NULL, 0, &striping_info_buf, size);
5831         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5832         if (ret < 0)
5833                 return ret;
5834         if (ret < size)
5835                 return -ERANGE;
5836
5837         p = &striping_info_buf;
5838         rbd_dev->header.stripe_unit = ceph_decode_64(&p);
5839         rbd_dev->header.stripe_count = ceph_decode_64(&p);
5840         return 0;
5841 }
5842
5843 static int rbd_dev_v2_data_pool(struct rbd_device *rbd_dev)
5844 {
5845         __le64 data_pool_id;
5846         int ret;
5847
5848         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5849                                   &rbd_dev->header_oloc, "get_data_pool",
5850                                   NULL, 0, &data_pool_id, sizeof(data_pool_id));
5851         if (ret < 0)
5852                 return ret;
5853         if (ret < sizeof(data_pool_id))
5854                 return -EBADMSG;
5855
5856         rbd_dev->header.data_pool_id = le64_to_cpu(data_pool_id);
5857         WARN_ON(rbd_dev->header.data_pool_id == CEPH_NOPOOL);
5858         return 0;
5859 }
5860
5861 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
5862 {
5863         CEPH_DEFINE_OID_ONSTACK(oid);
5864         size_t image_id_size;
5865         char *image_id;
5866         void *p;
5867         void *end;
5868         size_t size;
5869         void *reply_buf = NULL;
5870         size_t len = 0;
5871         char *image_name = NULL;
5872         int ret;
5873
5874         rbd_assert(!rbd_dev->spec->image_name);
5875
5876         len = strlen(rbd_dev->spec->image_id);
5877         image_id_size = sizeof (__le32) + len;
5878         image_id = kmalloc(image_id_size, GFP_KERNEL);
5879         if (!image_id)
5880                 return NULL;
5881
5882         p = image_id;
5883         end = image_id + image_id_size;
5884         ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5885
5886         size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
5887         reply_buf = kmalloc(size, GFP_KERNEL);
5888         if (!reply_buf)
5889                 goto out;
5890
5891         ceph_oid_printf(&oid, "%s", RBD_DIRECTORY);
5892         ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
5893                                   "dir_get_name", image_id, image_id_size,
5894                                   reply_buf, size);
5895         if (ret < 0)
5896                 goto out;
5897         p = reply_buf;
5898         end = reply_buf + ret;
5899
5900         image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
5901         if (IS_ERR(image_name))
5902                 image_name = NULL;
5903         else
5904                 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
5905 out:
5906         kfree(reply_buf);
5907         kfree(image_id);
5908
5909         return image_name;
5910 }
5911
5912 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5913 {
5914         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
5915         const char *snap_name;
5916         u32 which = 0;
5917
5918         /* Skip over names until we find the one we are looking for */
5919
5920         snap_name = rbd_dev->header.snap_names;
5921         while (which < snapc->num_snaps) {
5922                 if (!strcmp(name, snap_name))
5923                         return snapc->snaps[which];
5924                 snap_name += strlen(snap_name) + 1;
5925                 which++;
5926         }
5927         return CEPH_NOSNAP;
5928 }
5929
5930 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5931 {
5932         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
5933         u32 which;
5934         bool found = false;
5935         u64 snap_id;
5936
5937         for (which = 0; !found && which < snapc->num_snaps; which++) {
5938                 const char *snap_name;
5939
5940                 snap_id = snapc->snaps[which];
5941                 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
5942                 if (IS_ERR(snap_name)) {
5943                         /* ignore no-longer existing snapshots */
5944                         if (PTR_ERR(snap_name) == -ENOENT)
5945                                 continue;
5946                         else
5947                                 break;
5948                 }
5949                 found = !strcmp(name, snap_name);
5950                 kfree(snap_name);
5951         }
5952         return found ? snap_id : CEPH_NOSNAP;
5953 }
5954
5955 /*
5956  * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
5957  * no snapshot by that name is found, or if an error occurs.
5958  */
5959 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5960 {
5961         if (rbd_dev->image_format == 1)
5962                 return rbd_v1_snap_id_by_name(rbd_dev, name);
5963
5964         return rbd_v2_snap_id_by_name(rbd_dev, name);
5965 }
5966
5967 /*
5968  * An image being mapped will have everything but the snap id.
5969  */
5970 static int rbd_spec_fill_snap_id(struct rbd_device *rbd_dev)
5971 {
5972         struct rbd_spec *spec = rbd_dev->spec;
5973
5974         rbd_assert(spec->pool_id != CEPH_NOPOOL && spec->pool_name);
5975         rbd_assert(spec->image_id && spec->image_name);
5976         rbd_assert(spec->snap_name);
5977
5978         if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
5979                 u64 snap_id;
5980
5981                 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
5982                 if (snap_id == CEPH_NOSNAP)
5983                         return -ENOENT;
5984
5985                 spec->snap_id = snap_id;
5986         } else {
5987                 spec->snap_id = CEPH_NOSNAP;
5988         }
5989
5990         return 0;
5991 }
5992
5993 /*
5994  * A parent image will have all ids but none of the names.
5995  *
5996  * All names in an rbd spec are dynamically allocated.  It's OK if we
5997  * can't figure out the name for an image id.
5998  */
5999 static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
6000 {
6001         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
6002         struct rbd_spec *spec = rbd_dev->spec;
6003         const char *pool_name;
6004         const char *image_name;
6005         const char *snap_name;
6006         int ret;
6007
6008         rbd_assert(spec->pool_id != CEPH_NOPOOL);
6009         rbd_assert(spec->image_id);
6010         rbd_assert(spec->snap_id != CEPH_NOSNAP);
6011
6012         /* Get the pool name; we have to make our own copy of this */
6013
6014         pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
6015         if (!pool_name) {
6016                 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
6017                 return -EIO;
6018         }
6019         pool_name = kstrdup(pool_name, GFP_KERNEL);
6020         if (!pool_name)
6021                 return -ENOMEM;
6022
6023         /* Fetch the image name; tolerate failure here */
6024
6025         image_name = rbd_dev_image_name(rbd_dev);
6026         if (!image_name)
6027                 rbd_warn(rbd_dev, "unable to get image name");
6028
6029         /* Fetch the snapshot name */
6030
6031         snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
6032         if (IS_ERR(snap_name)) {
6033                 ret = PTR_ERR(snap_name);
6034                 goto out_err;
6035         }
6036
6037         spec->pool_name = pool_name;
6038         spec->image_name = image_name;
6039         spec->snap_name = snap_name;
6040
6041         return 0;
6042
6043 out_err:
6044         kfree(image_name);
6045         kfree(pool_name);
6046         return ret;
6047 }
6048
6049 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
6050 {
6051         size_t size;
6052         int ret;
6053         void *reply_buf;
6054         void *p;
6055         void *end;
6056         u64 seq;
6057         u32 snap_count;
6058         struct ceph_snap_context *snapc;
6059         u32 i;
6060
6061         /*
6062          * We'll need room for the seq value (maximum snapshot id),
6063          * snapshot count, and array of that many snapshot ids.
6064          * For now we have a fixed upper limit on the number we're
6065          * prepared to receive.
6066          */
6067         size = sizeof (__le64) + sizeof (__le32) +
6068                         RBD_MAX_SNAP_COUNT * sizeof (__le64);
6069         reply_buf = kzalloc(size, GFP_KERNEL);
6070         if (!reply_buf)
6071                 return -ENOMEM;
6072
6073         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
6074                                   &rbd_dev->header_oloc, "get_snapcontext",
6075                                   NULL, 0, reply_buf, size);
6076         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
6077         if (ret < 0)
6078                 goto out;
6079
6080         p = reply_buf;
6081         end = reply_buf + ret;
6082         ret = -ERANGE;
6083         ceph_decode_64_safe(&p, end, seq, out);
6084         ceph_decode_32_safe(&p, end, snap_count, out);
6085
6086         /*
6087          * Make sure the reported number of snapshot ids wouldn't go
6088          * beyond the end of our buffer.  But before checking that,
6089          * make sure the computed size of the snapshot context we
6090          * allocate is representable in a size_t.
6091          */
6092         if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
6093                                  / sizeof (u64)) {
6094                 ret = -EINVAL;
6095                 goto out;
6096         }
6097         if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
6098                 goto out;
6099         ret = 0;
6100
6101         snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
6102         if (!snapc) {
6103                 ret = -ENOMEM;
6104                 goto out;
6105         }
6106         snapc->seq = seq;
6107         for (i = 0; i < snap_count; i++)
6108                 snapc->snaps[i] = ceph_decode_64(&p);
6109
6110         ceph_put_snap_context(rbd_dev->header.snapc);
6111         rbd_dev->header.snapc = snapc;
6112
6113         dout("  snap context seq = %llu, snap_count = %u\n",
6114                 (unsigned long long)seq, (unsigned int)snap_count);
6115 out:
6116         kfree(reply_buf);
6117
6118         return ret;
6119 }
6120
6121 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
6122                                         u64 snap_id)
6123 {
6124         size_t size;
6125         void *reply_buf;
6126         __le64 snapid;
6127         int ret;
6128         void *p;
6129         void *end;
6130         char *snap_name;
6131
6132         size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
6133         reply_buf = kmalloc(size, GFP_KERNEL);
6134         if (!reply_buf)
6135                 return ERR_PTR(-ENOMEM);
6136
6137         snapid = cpu_to_le64(snap_id);
6138         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
6139                                   &rbd_dev->header_oloc, "get_snapshot_name",
6140                                   &snapid, sizeof(snapid), reply_buf, size);
6141         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
6142         if (ret < 0) {
6143                 snap_name = ERR_PTR(ret);
6144                 goto out;
6145         }
6146
6147         p = reply_buf;
6148         end = reply_buf + ret;
6149         snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
6150         if (IS_ERR(snap_name))
6151                 goto out;
6152
6153         dout("  snap_id 0x%016llx snap_name = %s\n",
6154                 (unsigned long long)snap_id, snap_name);
6155 out:
6156         kfree(reply_buf);
6157
6158         return snap_name;
6159 }
6160
6161 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
6162 {
6163         bool first_time = rbd_dev->header.object_prefix == NULL;
6164         int ret;
6165
6166         ret = rbd_dev_v2_image_size(rbd_dev);
6167         if (ret)
6168                 return ret;
6169
6170         if (first_time) {
6171                 ret = rbd_dev_v2_header_onetime(rbd_dev);
6172                 if (ret)
6173                         return ret;
6174         }
6175
6176         ret = rbd_dev_v2_snap_context(rbd_dev);
6177         if (ret && first_time) {
6178                 kfree(rbd_dev->header.object_prefix);
6179                 rbd_dev->header.object_prefix = NULL;
6180         }
6181
6182         return ret;
6183 }
6184
6185 static int rbd_dev_header_info(struct rbd_device *rbd_dev)
6186 {
6187         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
6188
6189         if (rbd_dev->image_format == 1)
6190                 return rbd_dev_v1_header_info(rbd_dev);
6191
6192         return rbd_dev_v2_header_info(rbd_dev);
6193 }
6194
6195 /*
6196  * Skips over white space at *buf, and updates *buf to point to the
6197  * first found non-space character (if any). Returns the length of
6198  * the token (string of non-white space characters) found.  Note
6199  * that *buf must be terminated with '\0'.
6200  */
6201 static inline size_t next_token(const char **buf)
6202 {
6203         /*
6204         * These are the characters that produce nonzero for
6205         * isspace() in the "C" and "POSIX" locales.
6206         */
6207         const char *spaces = " \f\n\r\t\v";
6208
6209         *buf += strspn(*buf, spaces);   /* Find start of token */
6210
6211         return strcspn(*buf, spaces);   /* Return token length */
6212 }
6213
6214 /*
6215  * Finds the next token in *buf, dynamically allocates a buffer big
6216  * enough to hold a copy of it, and copies the token into the new
6217  * buffer.  The copy is guaranteed to be terminated with '\0'.  Note
6218  * that a duplicate buffer is created even for a zero-length token.
6219  *
6220  * Returns a pointer to the newly-allocated duplicate, or a null
6221  * pointer if memory for the duplicate was not available.  If
6222  * the lenp argument is a non-null pointer, the length of the token
6223  * (not including the '\0') is returned in *lenp.
6224  *
6225  * If successful, the *buf pointer will be updated to point beyond
6226  * the end of the found token.
6227  *
6228  * Note: uses GFP_KERNEL for allocation.
6229  */
6230 static inline char *dup_token(const char **buf, size_t *lenp)
6231 {
6232         char *dup;
6233         size_t len;
6234
6235         len = next_token(buf);
6236         dup = kmemdup(*buf, len + 1, GFP_KERNEL);
6237         if (!dup)
6238                 return NULL;
6239         *(dup + len) = '\0';
6240         *buf += len;
6241
6242         if (lenp)
6243                 *lenp = len;
6244
6245         return dup;
6246 }
6247
6248 static int rbd_parse_param(struct fs_parameter *param,
6249                             struct rbd_parse_opts_ctx *pctx)
6250 {
6251         struct rbd_options *opt = pctx->opts;
6252         struct fs_parse_result result;
6253         struct p_log log = {.prefix = "rbd"};
6254         int token, ret;
6255
6256         ret = ceph_parse_param(param, pctx->copts, NULL);
6257         if (ret != -ENOPARAM)
6258                 return ret;
6259
6260         token = __fs_parse(&log, rbd_parameters, param, &result);
6261         dout("%s fs_parse '%s' token %d\n", __func__, param->key, token);
6262         if (token < 0) {
6263                 if (token == -ENOPARAM)
6264                         return inval_plog(&log, "Unknown parameter '%s'",
6265                                           param->key);
6266                 return token;
6267         }
6268
6269         switch (token) {
6270         case Opt_queue_depth:
6271                 if (result.uint_32 < 1)
6272                         goto out_of_range;
6273                 opt->queue_depth = result.uint_32;
6274                 break;
6275         case Opt_alloc_size:
6276                 if (result.uint_32 < SECTOR_SIZE)
6277                         goto out_of_range;
6278                 if (!is_power_of_2(result.uint_32))
6279                         return inval_plog(&log, "alloc_size must be a power of 2");
6280                 opt->alloc_size = result.uint_32;
6281                 break;
6282         case Opt_lock_timeout:
6283                 /* 0 is "wait forever" (i.e. infinite timeout) */
6284                 if (result.uint_32 > INT_MAX / 1000)
6285                         goto out_of_range;
6286                 opt->lock_timeout = msecs_to_jiffies(result.uint_32 * 1000);
6287                 break;
6288         case Opt_pool_ns:
6289                 kfree(pctx->spec->pool_ns);
6290                 pctx->spec->pool_ns = param->string;
6291                 param->string = NULL;
6292                 break;
6293         case Opt_compression_hint:
6294                 switch (result.uint_32) {
6295                 case Opt_compression_hint_none:
6296                         opt->alloc_hint_flags &=
6297                             ~(CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE |
6298                               CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE);
6299                         break;
6300                 case Opt_compression_hint_compressible:
6301                         opt->alloc_hint_flags |=
6302                             CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE;
6303                         opt->alloc_hint_flags &=
6304                             ~CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE;
6305                         break;
6306                 case Opt_compression_hint_incompressible:
6307                         opt->alloc_hint_flags |=
6308                             CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE;
6309                         opt->alloc_hint_flags &=
6310                             ~CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE;
6311                         break;
6312                 default:
6313                         BUG();
6314                 }
6315                 break;
6316         case Opt_read_only:
6317                 opt->read_only = true;
6318                 break;
6319         case Opt_read_write:
6320                 opt->read_only = false;
6321                 break;
6322         case Opt_lock_on_read:
6323                 opt->lock_on_read = true;
6324                 break;
6325         case Opt_exclusive:
6326                 opt->exclusive = true;
6327                 break;
6328         case Opt_notrim:
6329                 opt->trim = false;
6330                 break;
6331         default:
6332                 BUG();
6333         }
6334
6335         return 0;
6336
6337 out_of_range:
6338         return inval_plog(&log, "%s out of range", param->key);
6339 }
6340
6341 /*
6342  * This duplicates most of generic_parse_monolithic(), untying it from
6343  * fs_context and skipping standard superblock and security options.
6344  */
6345 static int rbd_parse_options(char *options, struct rbd_parse_opts_ctx *pctx)
6346 {
6347         char *key;
6348         int ret = 0;
6349
6350         dout("%s '%s'\n", __func__, options);
6351         while ((key = strsep(&options, ",")) != NULL) {
6352                 if (*key) {
6353                         struct fs_parameter param = {
6354                                 .key    = key,
6355                                 .type   = fs_value_is_flag,
6356                         };
6357                         char *value = strchr(key, '=');
6358                         size_t v_len = 0;
6359
6360                         if (value) {
6361                                 if (value == key)
6362                                         continue;
6363                                 *value++ = 0;
6364                                 v_len = strlen(value);
6365                                 param.string = kmemdup_nul(value, v_len,
6366                                                            GFP_KERNEL);
6367                                 if (!param.string)
6368                                         return -ENOMEM;
6369                                 param.type = fs_value_is_string;
6370                         }
6371                         param.size = v_len;
6372
6373                         ret = rbd_parse_param(&param, pctx);
6374                         kfree(param.string);
6375                         if (ret)
6376                                 break;
6377                 }
6378         }
6379
6380         return ret;
6381 }
6382
6383 /*
6384  * Parse the options provided for an "rbd add" (i.e., rbd image
6385  * mapping) request.  These arrive via a write to /sys/bus/rbd/add,
6386  * and the data written is passed here via a NUL-terminated buffer.
6387  * Returns 0 if successful or an error code otherwise.
6388  *
6389  * The information extracted from these options is recorded in
6390  * the other parameters which return dynamically-allocated
6391  * structures:
6392  *  ceph_opts
6393  *      The address of a pointer that will refer to a ceph options
6394  *      structure.  Caller must release the returned pointer using
6395  *      ceph_destroy_options() when it is no longer needed.
6396  *  rbd_opts
6397  *      Address of an rbd options pointer.  Fully initialized by
6398  *      this function; caller must release with kfree().
6399  *  spec
6400  *      Address of an rbd image specification pointer.  Fully
6401  *      initialized by this function based on parsed options.
6402  *      Caller must release with rbd_spec_put().
6403  *
6404  * The options passed take this form:
6405  *  <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
6406  * where:
6407  *  <mon_addrs>
6408  *      A comma-separated list of one or more monitor addresses.
6409  *      A monitor address is an ip address, optionally followed
6410  *      by a port number (separated by a colon).
6411  *        I.e.:  ip1[:port1][,ip2[:port2]...]
6412  *  <options>
6413  *      A comma-separated list of ceph and/or rbd options.
6414  *  <pool_name>
6415  *      The name of the rados pool containing the rbd image.
6416  *  <image_name>
6417  *      The name of the image in that pool to map.
6418  *  <snap_id>
6419  *      An optional snapshot id.  If provided, the mapping will
6420  *      present data from the image at the time that snapshot was
6421  *      created.  The image head is used if no snapshot id is
6422  *      provided.  Snapshot mappings are always read-only.
6423  */
6424 static int rbd_add_parse_args(const char *buf,
6425                                 struct ceph_options **ceph_opts,
6426                                 struct rbd_options **opts,
6427                                 struct rbd_spec **rbd_spec)
6428 {
6429         size_t len;
6430         char *options;
6431         const char *mon_addrs;
6432         char *snap_name;
6433         size_t mon_addrs_size;
6434         struct rbd_parse_opts_ctx pctx = { 0 };
6435         int ret;
6436
6437         /* The first four tokens are required */
6438
6439         len = next_token(&buf);
6440         if (!len) {
6441                 rbd_warn(NULL, "no monitor address(es) provided");
6442                 return -EINVAL;
6443         }
6444         mon_addrs = buf;
6445         mon_addrs_size = len;
6446         buf += len;
6447
6448         ret = -EINVAL;
6449         options = dup_token(&buf, NULL);
6450         if (!options)
6451                 return -ENOMEM;
6452         if (!*options) {
6453                 rbd_warn(NULL, "no options provided");
6454                 goto out_err;
6455         }
6456
6457         pctx.spec = rbd_spec_alloc();
6458         if (!pctx.spec)
6459                 goto out_mem;
6460
6461         pctx.spec->pool_name = dup_token(&buf, NULL);
6462         if (!pctx.spec->pool_name)
6463                 goto out_mem;
6464         if (!*pctx.spec->pool_name) {
6465                 rbd_warn(NULL, "no pool name provided");
6466                 goto out_err;
6467         }
6468
6469         pctx.spec->image_name = dup_token(&buf, NULL);
6470         if (!pctx.spec->image_name)
6471                 goto out_mem;
6472         if (!*pctx.spec->image_name) {
6473                 rbd_warn(NULL, "no image name provided");
6474                 goto out_err;
6475         }
6476
6477         /*
6478          * Snapshot name is optional; default is to use "-"
6479          * (indicating the head/no snapshot).
6480          */
6481         len = next_token(&buf);
6482         if (!len) {
6483                 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
6484                 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
6485         } else if (len > RBD_MAX_SNAP_NAME_LEN) {
6486                 ret = -ENAMETOOLONG;
6487                 goto out_err;
6488         }
6489         snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
6490         if (!snap_name)
6491                 goto out_mem;
6492         *(snap_name + len) = '\0';
6493         pctx.spec->snap_name = snap_name;
6494
6495         pctx.copts = ceph_alloc_options();
6496         if (!pctx.copts)
6497                 goto out_mem;
6498
6499         /* Initialize all rbd options to the defaults */
6500
6501         pctx.opts = kzalloc(sizeof(*pctx.opts), GFP_KERNEL);
6502         if (!pctx.opts)
6503                 goto out_mem;
6504
6505         pctx.opts->read_only = RBD_READ_ONLY_DEFAULT;
6506         pctx.opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
6507         pctx.opts->alloc_size = RBD_ALLOC_SIZE_DEFAULT;
6508         pctx.opts->lock_timeout = RBD_LOCK_TIMEOUT_DEFAULT;
6509         pctx.opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
6510         pctx.opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
6511         pctx.opts->trim = RBD_TRIM_DEFAULT;
6512
6513         ret = ceph_parse_mon_ips(mon_addrs, mon_addrs_size, pctx.copts, NULL);
6514         if (ret)
6515                 goto out_err;
6516
6517         ret = rbd_parse_options(options, &pctx);
6518         if (ret)
6519                 goto out_err;
6520
6521         *ceph_opts = pctx.copts;
6522         *opts = pctx.opts;
6523         *rbd_spec = pctx.spec;
6524         kfree(options);
6525         return 0;
6526
6527 out_mem:
6528         ret = -ENOMEM;
6529 out_err:
6530         kfree(pctx.opts);
6531         ceph_destroy_options(pctx.copts);
6532         rbd_spec_put(pctx.spec);
6533         kfree(options);
6534         return ret;
6535 }
6536
6537 static void rbd_dev_image_unlock(struct rbd_device *rbd_dev)
6538 {
6539         down_write(&rbd_dev->lock_rwsem);
6540         if (__rbd_is_lock_owner(rbd_dev))
6541                 __rbd_release_lock(rbd_dev);
6542         up_write(&rbd_dev->lock_rwsem);
6543 }
6544
6545 /*
6546  * If the wait is interrupted, an error is returned even if the lock
6547  * was successfully acquired.  rbd_dev_image_unlock() will release it
6548  * if needed.
6549  */
6550 static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
6551 {
6552         long ret;
6553
6554         if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) {
6555                 if (!rbd_dev->opts->exclusive && !rbd_dev->opts->lock_on_read)
6556                         return 0;
6557
6558                 rbd_warn(rbd_dev, "exclusive-lock feature is not enabled");
6559                 return -EINVAL;
6560         }
6561
6562         if (rbd_is_ro(rbd_dev))
6563                 return 0;
6564
6565         rbd_assert(!rbd_is_lock_owner(rbd_dev));
6566         queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
6567         ret = wait_for_completion_killable_timeout(&rbd_dev->acquire_wait,
6568                             ceph_timeout_jiffies(rbd_dev->opts->lock_timeout));
6569         if (ret > 0) {
6570                 ret = rbd_dev->acquire_err;
6571         } else {
6572                 cancel_delayed_work_sync(&rbd_dev->lock_dwork);
6573                 if (!ret)
6574                         ret = -ETIMEDOUT;
6575         }
6576
6577         if (ret) {
6578                 rbd_warn(rbd_dev, "failed to acquire exclusive lock: %ld", ret);
6579                 return ret;
6580         }
6581
6582         /*
6583          * The lock may have been released by now, unless automatic lock
6584          * transitions are disabled.
6585          */
6586         rbd_assert(!rbd_dev->opts->exclusive || rbd_is_lock_owner(rbd_dev));
6587         return 0;
6588 }
6589
6590 /*
6591  * An rbd format 2 image has a unique identifier, distinct from the
6592  * name given to it by the user.  Internally, that identifier is
6593  * what's used to specify the names of objects related to the image.
6594  *
6595  * A special "rbd id" object is used to map an rbd image name to its
6596  * id.  If that object doesn't exist, then there is no v2 rbd image
6597  * with the supplied name.
6598  *
6599  * This function will record the given rbd_dev's image_id field if
6600  * it can be determined, and in that case will return 0.  If any
6601  * errors occur a negative errno will be returned and the rbd_dev's
6602  * image_id field will be unchanged (and should be NULL).
6603  */
6604 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
6605 {
6606         int ret;
6607         size_t size;
6608         CEPH_DEFINE_OID_ONSTACK(oid);
6609         void *response;
6610         char *image_id;
6611
6612         /*
6613          * When probing a parent image, the image id is already
6614          * known (and the image name likely is not).  There's no
6615          * need to fetch the image id again in this case.  We
6616          * do still need to set the image format though.
6617          */
6618         if (rbd_dev->spec->image_id) {
6619                 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
6620
6621                 return 0;
6622         }
6623
6624         /*
6625          * First, see if the format 2 image id file exists, and if
6626          * so, get the image's persistent id from it.
6627          */
6628         ret = ceph_oid_aprintf(&oid, GFP_KERNEL, "%s%s", RBD_ID_PREFIX,
6629                                rbd_dev->spec->image_name);
6630         if (ret)
6631                 return ret;
6632
6633         dout("rbd id object name is %s\n", oid.name);
6634
6635         /* Response will be an encoded string, which includes a length */
6636         size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
6637         response = kzalloc(size, GFP_NOIO);
6638         if (!response) {
6639                 ret = -ENOMEM;
6640                 goto out;
6641         }
6642
6643         /* If it doesn't exist we'll assume it's a format 1 image */
6644
6645         ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
6646                                   "get_id", NULL, 0,
6647                                   response, size);
6648         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
6649         if (ret == -ENOENT) {
6650                 image_id = kstrdup("", GFP_KERNEL);
6651                 ret = image_id ? 0 : -ENOMEM;
6652                 if (!ret)
6653                         rbd_dev->image_format = 1;
6654         } else if (ret >= 0) {
6655                 void *p = response;
6656
6657                 image_id = ceph_extract_encoded_string(&p, p + ret,
6658                                                 NULL, GFP_NOIO);
6659                 ret = PTR_ERR_OR_ZERO(image_id);
6660                 if (!ret)
6661                         rbd_dev->image_format = 2;
6662         }
6663
6664         if (!ret) {
6665                 rbd_dev->spec->image_id = image_id;
6666                 dout("image_id is %s\n", image_id);
6667         }
6668 out:
6669         kfree(response);
6670         ceph_oid_destroy(&oid);
6671         return ret;
6672 }
6673
6674 /*
6675  * Undo whatever state changes are made by v1 or v2 header info
6676  * call.
6677  */
6678 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
6679 {
6680         struct rbd_image_header *header;
6681
6682         rbd_dev_parent_put(rbd_dev);
6683         rbd_object_map_free(rbd_dev);
6684         rbd_dev_mapping_clear(rbd_dev);
6685
6686         /* Free dynamic fields from the header, then zero it out */
6687
6688         header = &rbd_dev->header;
6689         ceph_put_snap_context(header->snapc);
6690         kfree(header->snap_sizes);
6691         kfree(header->snap_names);
6692         kfree(header->object_prefix);
6693         memset(header, 0, sizeof (*header));
6694 }
6695
6696 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
6697 {
6698         int ret;
6699
6700         ret = rbd_dev_v2_object_prefix(rbd_dev);
6701         if (ret)
6702                 goto out_err;
6703
6704         /*
6705          * Get the and check features for the image.  Currently the
6706          * features are assumed to never change.
6707          */
6708         ret = rbd_dev_v2_features(rbd_dev);
6709         if (ret)
6710                 goto out_err;
6711
6712         /* If the image supports fancy striping, get its parameters */
6713
6714         if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
6715                 ret = rbd_dev_v2_striping_info(rbd_dev);
6716                 if (ret < 0)
6717                         goto out_err;
6718         }
6719
6720         if (rbd_dev->header.features & RBD_FEATURE_DATA_POOL) {
6721                 ret = rbd_dev_v2_data_pool(rbd_dev);
6722                 if (ret)
6723                         goto out_err;
6724         }
6725
6726         rbd_init_layout(rbd_dev);
6727         return 0;
6728
6729 out_err:
6730         rbd_dev->header.features = 0;
6731         kfree(rbd_dev->header.object_prefix);
6732         rbd_dev->header.object_prefix = NULL;
6733         return ret;
6734 }
6735
6736 /*
6737  * @depth is rbd_dev_image_probe() -> rbd_dev_probe_parent() ->
6738  * rbd_dev_image_probe() recursion depth, which means it's also the
6739  * length of the already discovered part of the parent chain.
6740  */
6741 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
6742 {
6743         struct rbd_device *parent = NULL;
6744         int ret;
6745
6746         if (!rbd_dev->parent_spec)
6747                 return 0;
6748
6749         if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
6750                 pr_info("parent chain is too long (%d)\n", depth);
6751                 ret = -EINVAL;
6752                 goto out_err;
6753         }
6754
6755         parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
6756         if (!parent) {
6757                 ret = -ENOMEM;
6758                 goto out_err;
6759         }
6760
6761         /*
6762          * Images related by parent/child relationships always share
6763          * rbd_client and spec/parent_spec, so bump their refcounts.
6764          */
6765         __rbd_get_client(rbd_dev->rbd_client);
6766         rbd_spec_get(rbd_dev->parent_spec);
6767
6768         __set_bit(RBD_DEV_FLAG_READONLY, &parent->flags);
6769
6770         ret = rbd_dev_image_probe(parent, depth);
6771         if (ret < 0)
6772                 goto out_err;
6773
6774         rbd_dev->parent = parent;
6775         atomic_set(&rbd_dev->parent_ref, 1);
6776         return 0;
6777
6778 out_err:
6779         rbd_dev_unparent(rbd_dev);
6780         rbd_dev_destroy(parent);
6781         return ret;
6782 }
6783
6784 static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6785 {
6786         clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6787         rbd_free_disk(rbd_dev);
6788         if (!single_major)
6789                 unregister_blkdev(rbd_dev->major, rbd_dev->name);
6790 }
6791
6792 /*
6793  * rbd_dev->header_rwsem must be locked for write and will be unlocked
6794  * upon return.
6795  */
6796 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
6797 {
6798         int ret;
6799
6800         /* Record our major and minor device numbers. */
6801
6802         if (!single_major) {
6803                 ret = register_blkdev(0, rbd_dev->name);
6804                 if (ret < 0)
6805                         goto err_out_unlock;
6806
6807                 rbd_dev->major = ret;
6808                 rbd_dev->minor = 0;
6809         } else {
6810                 rbd_dev->major = rbd_major;
6811                 rbd_dev->minor = rbd_dev_id_to_minor(rbd_dev->dev_id);
6812         }
6813
6814         /* Set up the blkdev mapping. */
6815
6816         ret = rbd_init_disk(rbd_dev);
6817         if (ret)
6818                 goto err_out_blkdev;
6819
6820         set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
6821         set_disk_ro(rbd_dev->disk, rbd_is_ro(rbd_dev));
6822
6823         ret = dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
6824         if (ret)
6825                 goto err_out_disk;
6826
6827         set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6828         up_write(&rbd_dev->header_rwsem);
6829         return 0;
6830
6831 err_out_disk:
6832         rbd_free_disk(rbd_dev);
6833 err_out_blkdev:
6834         if (!single_major)
6835                 unregister_blkdev(rbd_dev->major, rbd_dev->name);
6836 err_out_unlock:
6837         up_write(&rbd_dev->header_rwsem);
6838         return ret;
6839 }
6840
6841 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
6842 {
6843         struct rbd_spec *spec = rbd_dev->spec;
6844         int ret;
6845
6846         /* Record the header object name for this rbd image. */
6847
6848         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
6849         if (rbd_dev->image_format == 1)
6850                 ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
6851                                        spec->image_name, RBD_SUFFIX);
6852         else
6853                 ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
6854                                        RBD_HEADER_PREFIX, spec->image_id);
6855
6856         return ret;
6857 }
6858
6859 static void rbd_print_dne(struct rbd_device *rbd_dev, bool is_snap)
6860 {
6861         if (!is_snap) {
6862                 pr_info("image %s/%s%s%s does not exist\n",
6863                         rbd_dev->spec->pool_name,
6864                         rbd_dev->spec->pool_ns ?: "",
6865                         rbd_dev->spec->pool_ns ? "/" : "",
6866                         rbd_dev->spec->image_name);
6867         } else {
6868                 pr_info("snap %s/%s%s%s@%s does not exist\n",
6869                         rbd_dev->spec->pool_name,
6870                         rbd_dev->spec->pool_ns ?: "",
6871                         rbd_dev->spec->pool_ns ? "/" : "",
6872                         rbd_dev->spec->image_name,
6873                         rbd_dev->spec->snap_name);
6874         }
6875 }
6876
6877 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
6878 {
6879         if (!rbd_is_ro(rbd_dev))
6880                 rbd_unregister_watch(rbd_dev);
6881
6882         rbd_dev_unprobe(rbd_dev);
6883         rbd_dev->image_format = 0;
6884         kfree(rbd_dev->spec->image_id);
6885         rbd_dev->spec->image_id = NULL;
6886 }
6887
6888 /*
6889  * Probe for the existence of the header object for the given rbd
6890  * device.  If this image is the one being mapped (i.e., not a
6891  * parent), initiate a watch on its header object before using that
6892  * object to get detailed information about the rbd image.
6893  *
6894  * On success, returns with header_rwsem held for write if called
6895  * with @depth == 0.
6896  */
6897 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6898 {
6899         bool need_watch = !rbd_is_ro(rbd_dev);
6900         int ret;
6901
6902         /*
6903          * Get the id from the image id object.  Unless there's an
6904          * error, rbd_dev->spec->image_id will be filled in with
6905          * a dynamically-allocated string, and rbd_dev->image_format
6906          * will be set to either 1 or 2.
6907          */
6908         ret = rbd_dev_image_id(rbd_dev);
6909         if (ret)
6910                 return ret;
6911
6912         ret = rbd_dev_header_name(rbd_dev);
6913         if (ret)
6914                 goto err_out_format;
6915
6916         if (need_watch) {
6917                 ret = rbd_register_watch(rbd_dev);
6918                 if (ret) {
6919                         if (ret == -ENOENT)
6920                                 rbd_print_dne(rbd_dev, false);
6921                         goto err_out_format;
6922                 }
6923         }
6924
6925         if (!depth)
6926                 down_write(&rbd_dev->header_rwsem);
6927
6928         ret = rbd_dev_header_info(rbd_dev);
6929         if (ret) {
6930                 if (ret == -ENOENT && !need_watch)
6931                         rbd_print_dne(rbd_dev, false);
6932                 goto err_out_probe;
6933         }
6934
6935         /*
6936          * If this image is the one being mapped, we have pool name and
6937          * id, image name and id, and snap name - need to fill snap id.
6938          * Otherwise this is a parent image, identified by pool, image
6939          * and snap ids - need to fill in names for those ids.
6940          */
6941         if (!depth)
6942                 ret = rbd_spec_fill_snap_id(rbd_dev);
6943         else
6944                 ret = rbd_spec_fill_names(rbd_dev);
6945         if (ret) {
6946                 if (ret == -ENOENT)
6947                         rbd_print_dne(rbd_dev, true);
6948                 goto err_out_probe;
6949         }
6950
6951         ret = rbd_dev_mapping_set(rbd_dev);
6952         if (ret)
6953                 goto err_out_probe;
6954
6955         if (rbd_is_snap(rbd_dev) &&
6956             (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP)) {
6957                 ret = rbd_object_map_load(rbd_dev);
6958                 if (ret)
6959                         goto err_out_probe;
6960         }
6961
6962         if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
6963                 ret = rbd_dev_v2_parent_info(rbd_dev);
6964                 if (ret)
6965                         goto err_out_probe;
6966         }
6967
6968         ret = rbd_dev_probe_parent(rbd_dev, depth);
6969         if (ret)
6970                 goto err_out_probe;
6971
6972         dout("discovered format %u image, header name is %s\n",
6973                 rbd_dev->image_format, rbd_dev->header_oid.name);
6974         return 0;
6975
6976 err_out_probe:
6977         if (!depth)
6978                 up_write(&rbd_dev->header_rwsem);
6979         if (need_watch)
6980                 rbd_unregister_watch(rbd_dev);
6981         rbd_dev_unprobe(rbd_dev);
6982 err_out_format:
6983         rbd_dev->image_format = 0;
6984         kfree(rbd_dev->spec->image_id);
6985         rbd_dev->spec->image_id = NULL;
6986         return ret;
6987 }
6988
6989 static ssize_t do_rbd_add(struct bus_type *bus,
6990                           const char *buf,
6991                           size_t count)
6992 {
6993         struct rbd_device *rbd_dev = NULL;
6994         struct ceph_options *ceph_opts = NULL;
6995         struct rbd_options *rbd_opts = NULL;
6996         struct rbd_spec *spec = NULL;
6997         struct rbd_client *rbdc;
6998         int rc;
6999
7000         if (!capable(CAP_SYS_ADMIN))
7001                 return -EPERM;
7002
7003         if (!try_module_get(THIS_MODULE))
7004                 return -ENODEV;
7005
7006         /* parse add command */
7007         rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
7008         if (rc < 0)
7009                 goto out;
7010
7011         rbdc = rbd_get_client(ceph_opts);
7012         if (IS_ERR(rbdc)) {
7013                 rc = PTR_ERR(rbdc);
7014                 goto err_out_args;
7015         }
7016
7017         /* pick the pool */
7018         rc = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, spec->pool_name);
7019         if (rc < 0) {
7020                 if (rc == -ENOENT)
7021                         pr_info("pool %s does not exist\n", spec->pool_name);
7022                 goto err_out_client;
7023         }
7024         spec->pool_id = (u64)rc;
7025
7026         rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
7027         if (!rbd_dev) {
7028                 rc = -ENOMEM;
7029                 goto err_out_client;
7030         }
7031         rbdc = NULL;            /* rbd_dev now owns this */
7032         spec = NULL;            /* rbd_dev now owns this */
7033         rbd_opts = NULL;        /* rbd_dev now owns this */
7034
7035         /* if we are mapping a snapshot it will be a read-only mapping */
7036         if (rbd_dev->opts->read_only ||
7037             strcmp(rbd_dev->spec->snap_name, RBD_SNAP_HEAD_NAME))
7038                 __set_bit(RBD_DEV_FLAG_READONLY, &rbd_dev->flags);
7039
7040         rbd_dev->config_info = kstrdup(buf, GFP_KERNEL);
7041         if (!rbd_dev->config_info) {
7042                 rc = -ENOMEM;
7043                 goto err_out_rbd_dev;
7044         }
7045
7046         rc = rbd_dev_image_probe(rbd_dev, 0);
7047         if (rc < 0)
7048                 goto err_out_rbd_dev;
7049
7050         if (rbd_dev->opts->alloc_size > rbd_dev->layout.object_size) {
7051                 rbd_warn(rbd_dev, "alloc_size adjusted to %u",
7052                          rbd_dev->layout.object_size);
7053                 rbd_dev->opts->alloc_size = rbd_dev->layout.object_size;
7054         }
7055
7056         rc = rbd_dev_device_setup(rbd_dev);
7057         if (rc)
7058                 goto err_out_image_probe;
7059
7060         rc = rbd_add_acquire_lock(rbd_dev);
7061         if (rc)
7062                 goto err_out_image_lock;
7063
7064         /* Everything's ready.  Announce the disk to the world. */
7065
7066         rc = device_add(&rbd_dev->dev);
7067         if (rc)
7068                 goto err_out_image_lock;
7069
7070         device_add_disk(&rbd_dev->dev, rbd_dev->disk, NULL);
7071
7072         spin_lock(&rbd_dev_list_lock);
7073         list_add_tail(&rbd_dev->node, &rbd_dev_list);
7074         spin_unlock(&rbd_dev_list_lock);
7075
7076         pr_info("%s: capacity %llu features 0x%llx\n", rbd_dev->disk->disk_name,
7077                 (unsigned long long)get_capacity(rbd_dev->disk) << SECTOR_SHIFT,
7078                 rbd_dev->header.features);
7079         rc = count;
7080 out:
7081         module_put(THIS_MODULE);
7082         return rc;
7083
7084 err_out_image_lock:
7085         rbd_dev_image_unlock(rbd_dev);
7086         rbd_dev_device_release(rbd_dev);
7087 err_out_image_probe:
7088         rbd_dev_image_release(rbd_dev);
7089 err_out_rbd_dev:
7090         rbd_dev_destroy(rbd_dev);
7091 err_out_client:
7092         rbd_put_client(rbdc);
7093 err_out_args:
7094         rbd_spec_put(spec);
7095         kfree(rbd_opts);
7096         goto out;
7097 }
7098
7099 static ssize_t add_store(struct bus_type *bus, const char *buf, size_t count)
7100 {
7101         if (single_major)
7102                 return -EINVAL;
7103
7104         return do_rbd_add(bus, buf, count);
7105 }
7106
7107 static ssize_t add_single_major_store(struct bus_type *bus, const char *buf,
7108                                       size_t count)
7109 {
7110         return do_rbd_add(bus, buf, count);
7111 }
7112
7113 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
7114 {
7115         while (rbd_dev->parent) {
7116                 struct rbd_device *first = rbd_dev;
7117                 struct rbd_device *second = first->parent;
7118                 struct rbd_device *third;
7119
7120                 /*
7121                  * Follow to the parent with no grandparent and
7122                  * remove it.
7123                  */
7124                 while (second && (third = second->parent)) {
7125                         first = second;
7126                         second = third;
7127                 }
7128                 rbd_assert(second);
7129                 rbd_dev_image_release(second);
7130                 rbd_dev_destroy(second);
7131                 first->parent = NULL;
7132                 first->parent_overlap = 0;
7133
7134                 rbd_assert(first->parent_spec);
7135                 rbd_spec_put(first->parent_spec);
7136                 first->parent_spec = NULL;
7137         }
7138 }
7139
7140 static ssize_t do_rbd_remove(struct bus_type *bus,
7141                              const char *buf,
7142                              size_t count)
7143 {
7144         struct rbd_device *rbd_dev = NULL;
7145         struct list_head *tmp;
7146         int dev_id;
7147         char opt_buf[6];
7148         bool force = false;
7149         int ret;
7150
7151         if (!capable(CAP_SYS_ADMIN))
7152                 return -EPERM;
7153
7154         dev_id = -1;
7155         opt_buf[0] = '\0';
7156         sscanf(buf, "%d %5s", &dev_id, opt_buf);
7157         if (dev_id < 0) {
7158                 pr_err("dev_id out of range\n");
7159                 return -EINVAL;
7160         }
7161         if (opt_buf[0] != '\0') {
7162                 if (!strcmp(opt_buf, "force")) {
7163                         force = true;
7164                 } else {
7165                         pr_err("bad remove option at '%s'\n", opt_buf);
7166                         return -EINVAL;
7167                 }
7168         }
7169
7170         ret = -ENOENT;
7171         spin_lock(&rbd_dev_list_lock);
7172         list_for_each(tmp, &rbd_dev_list) {
7173                 rbd_dev = list_entry(tmp, struct rbd_device, node);
7174                 if (rbd_dev->dev_id == dev_id) {
7175                         ret = 0;
7176                         break;
7177                 }
7178         }
7179         if (!ret) {
7180                 spin_lock_irq(&rbd_dev->lock);
7181                 if (rbd_dev->open_count && !force)
7182                         ret = -EBUSY;
7183                 else if (test_and_set_bit(RBD_DEV_FLAG_REMOVING,
7184                                           &rbd_dev->flags))
7185                         ret = -EINPROGRESS;
7186                 spin_unlock_irq(&rbd_dev->lock);
7187         }
7188         spin_unlock(&rbd_dev_list_lock);
7189         if (ret)
7190                 return ret;
7191
7192         if (force) {
7193                 /*
7194                  * Prevent new IO from being queued and wait for existing
7195                  * IO to complete/fail.
7196                  */
7197                 blk_mq_freeze_queue(rbd_dev->disk->queue);
7198                 blk_set_queue_dying(rbd_dev->disk->queue);
7199         }
7200
7201         del_gendisk(rbd_dev->disk);
7202         spin_lock(&rbd_dev_list_lock);
7203         list_del_init(&rbd_dev->node);
7204         spin_unlock(&rbd_dev_list_lock);
7205         device_del(&rbd_dev->dev);
7206
7207         rbd_dev_image_unlock(rbd_dev);
7208         rbd_dev_device_release(rbd_dev);
7209         rbd_dev_image_release(rbd_dev);
7210         rbd_dev_destroy(rbd_dev);
7211         return count;
7212 }
7213
7214 static ssize_t remove_store(struct bus_type *bus, const char *buf, size_t count)
7215 {
7216         if (single_major)
7217                 return -EINVAL;
7218
7219         return do_rbd_remove(bus, buf, count);
7220 }
7221
7222 static ssize_t remove_single_major_store(struct bus_type *bus, const char *buf,
7223                                          size_t count)
7224 {
7225         return do_rbd_remove(bus, buf, count);
7226 }
7227
7228 /*
7229  * create control files in sysfs
7230  * /sys/bus/rbd/...
7231  */
7232 static int __init rbd_sysfs_init(void)
7233 {
7234         int ret;
7235
7236         ret = device_register(&rbd_root_dev);
7237         if (ret < 0)
7238                 return ret;
7239
7240         ret = bus_register(&rbd_bus_type);
7241         if (ret < 0)
7242                 device_unregister(&rbd_root_dev);
7243
7244         return ret;
7245 }
7246
7247 static void __exit rbd_sysfs_cleanup(void)
7248 {
7249         bus_unregister(&rbd_bus_type);
7250         device_unregister(&rbd_root_dev);
7251 }
7252
7253 static int __init rbd_slab_init(void)
7254 {
7255         rbd_assert(!rbd_img_request_cache);
7256         rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
7257         if (!rbd_img_request_cache)
7258                 return -ENOMEM;
7259
7260         rbd_assert(!rbd_obj_request_cache);
7261         rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
7262         if (!rbd_obj_request_cache)
7263                 goto out_err;
7264
7265         return 0;
7266
7267 out_err:
7268         kmem_cache_destroy(rbd_img_request_cache);
7269         rbd_img_request_cache = NULL;
7270         return -ENOMEM;
7271 }
7272
7273 static void rbd_slab_exit(void)
7274 {
7275         rbd_assert(rbd_obj_request_cache);
7276         kmem_cache_destroy(rbd_obj_request_cache);
7277         rbd_obj_request_cache = NULL;
7278
7279         rbd_assert(rbd_img_request_cache);
7280         kmem_cache_destroy(rbd_img_request_cache);
7281         rbd_img_request_cache = NULL;
7282 }
7283
7284 static int __init rbd_init(void)
7285 {
7286         int rc;
7287
7288         if (!libceph_compatible(NULL)) {
7289                 rbd_warn(NULL, "libceph incompatibility (quitting)");
7290                 return -EINVAL;
7291         }
7292
7293         rc = rbd_slab_init();
7294         if (rc)
7295                 return rc;
7296
7297         /*
7298          * The number of active work items is limited by the number of
7299          * rbd devices * queue depth, so leave @max_active at default.
7300          */
7301         rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
7302         if (!rbd_wq) {
7303                 rc = -ENOMEM;
7304                 goto err_out_slab;
7305         }
7306
7307         if (single_major) {
7308                 rbd_major = register_blkdev(0, RBD_DRV_NAME);
7309                 if (rbd_major < 0) {
7310                         rc = rbd_major;
7311                         goto err_out_wq;
7312                 }
7313         }
7314
7315         rc = rbd_sysfs_init();
7316         if (rc)
7317                 goto err_out_blkdev;
7318
7319         if (single_major)
7320                 pr_info("loaded (major %d)\n", rbd_major);
7321         else
7322                 pr_info("loaded\n");
7323
7324         return 0;
7325
7326 err_out_blkdev:
7327         if (single_major)
7328                 unregister_blkdev(rbd_major, RBD_DRV_NAME);
7329 err_out_wq:
7330         destroy_workqueue(rbd_wq);
7331 err_out_slab:
7332         rbd_slab_exit();
7333         return rc;
7334 }
7335
7336 static void __exit rbd_exit(void)
7337 {
7338         ida_destroy(&rbd_dev_id_ida);
7339         rbd_sysfs_cleanup();
7340         if (single_major)
7341                 unregister_blkdev(rbd_major, RBD_DRV_NAME);
7342         destroy_workqueue(rbd_wq);
7343         rbd_slab_exit();
7344 }
7345
7346 module_init(rbd_init);
7347 module_exit(rbd_exit);
7348
7349 MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
7350 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
7351 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
7352 /* following authorship retained from original osdblk.c */
7353 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
7354
7355 MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
7356 MODULE_LICENSE("GPL");