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         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4104         lockdep_assert_held_write(&rbd_dev->lock_rwsem);
4105
4106         if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
4107                 return false;
4108
4109         /*
4110          * Ensure that all in-flight IO is flushed.
4111          */
4112         rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING;
4113         rbd_assert(!completion_done(&rbd_dev->releasing_wait));
4114         if (list_empty(&rbd_dev->running_list))
4115                 return true;
4116
4117         up_write(&rbd_dev->lock_rwsem);
4118         wait_for_completion(&rbd_dev->releasing_wait);
4119
4120         down_write(&rbd_dev->lock_rwsem);
4121         if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
4122                 return false;
4123
4124         rbd_assert(list_empty(&rbd_dev->running_list));
4125         return true;
4126 }
4127
4128 static void rbd_pre_release_action(struct rbd_device *rbd_dev)
4129 {
4130         if (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP)
4131                 rbd_object_map_close(rbd_dev);
4132 }
4133
4134 static void __rbd_release_lock(struct rbd_device *rbd_dev)
4135 {
4136         rbd_assert(list_empty(&rbd_dev->running_list));
4137
4138         rbd_pre_release_action(rbd_dev);
4139         rbd_unlock(rbd_dev);
4140 }
4141
4142 /*
4143  * lock_rwsem must be held for write
4144  */
4145 static void rbd_release_lock(struct rbd_device *rbd_dev)
4146 {
4147         if (!rbd_quiesce_lock(rbd_dev))
4148                 return;
4149
4150         __rbd_release_lock(rbd_dev);
4151
4152         /*
4153          * Give others a chance to grab the lock - we would re-acquire
4154          * almost immediately if we got new IO while draining the running
4155          * list otherwise.  We need to ack our own notifications, so this
4156          * lock_dwork will be requeued from rbd_handle_released_lock() by
4157          * way of maybe_kick_acquire().
4158          */
4159         cancel_delayed_work(&rbd_dev->lock_dwork);
4160 }
4161
4162 static void rbd_release_lock_work(struct work_struct *work)
4163 {
4164         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
4165                                                   unlock_work);
4166
4167         down_write(&rbd_dev->lock_rwsem);
4168         rbd_release_lock(rbd_dev);
4169         up_write(&rbd_dev->lock_rwsem);
4170 }
4171
4172 static void maybe_kick_acquire(struct rbd_device *rbd_dev)
4173 {
4174         bool have_requests;
4175
4176         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4177         if (__rbd_is_lock_owner(rbd_dev))
4178                 return;
4179
4180         spin_lock(&rbd_dev->lock_lists_lock);
4181         have_requests = !list_empty(&rbd_dev->acquiring_list);
4182         spin_unlock(&rbd_dev->lock_lists_lock);
4183         if (have_requests || delayed_work_pending(&rbd_dev->lock_dwork)) {
4184                 dout("%s rbd_dev %p kicking lock_dwork\n", __func__, rbd_dev);
4185                 mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
4186         }
4187 }
4188
4189 static void rbd_handle_acquired_lock(struct rbd_device *rbd_dev, u8 struct_v,
4190                                      void **p)
4191 {
4192         struct rbd_client_id cid = { 0 };
4193
4194         if (struct_v >= 2) {
4195                 cid.gid = ceph_decode_64(p);
4196                 cid.handle = ceph_decode_64(p);
4197         }
4198
4199         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
4200              cid.handle);
4201         if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
4202                 down_write(&rbd_dev->lock_rwsem);
4203                 if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
4204                         dout("%s rbd_dev %p cid %llu-%llu == owner_cid\n",
4205                              __func__, rbd_dev, cid.gid, cid.handle);
4206                 } else {
4207                         rbd_set_owner_cid(rbd_dev, &cid);
4208                 }
4209                 downgrade_write(&rbd_dev->lock_rwsem);
4210         } else {
4211                 down_read(&rbd_dev->lock_rwsem);
4212         }
4213
4214         maybe_kick_acquire(rbd_dev);
4215         up_read(&rbd_dev->lock_rwsem);
4216 }
4217
4218 static void rbd_handle_released_lock(struct rbd_device *rbd_dev, u8 struct_v,
4219                                      void **p)
4220 {
4221         struct rbd_client_id cid = { 0 };
4222
4223         if (struct_v >= 2) {
4224                 cid.gid = ceph_decode_64(p);
4225                 cid.handle = ceph_decode_64(p);
4226         }
4227
4228         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
4229              cid.handle);
4230         if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
4231                 down_write(&rbd_dev->lock_rwsem);
4232                 if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
4233                         dout("%s rbd_dev %p cid %llu-%llu != owner_cid %llu-%llu\n",
4234                              __func__, rbd_dev, cid.gid, cid.handle,
4235                              rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle);
4236                 } else {
4237                         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
4238                 }
4239                 downgrade_write(&rbd_dev->lock_rwsem);
4240         } else {
4241                 down_read(&rbd_dev->lock_rwsem);
4242         }
4243
4244         maybe_kick_acquire(rbd_dev);
4245         up_read(&rbd_dev->lock_rwsem);
4246 }
4247
4248 /*
4249  * Returns result for ResponseMessage to be encoded (<= 0), or 1 if no
4250  * ResponseMessage is needed.
4251  */
4252 static int rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
4253                                    void **p)
4254 {
4255         struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
4256         struct rbd_client_id cid = { 0 };
4257         int result = 1;
4258
4259         if (struct_v >= 2) {
4260                 cid.gid = ceph_decode_64(p);
4261                 cid.handle = ceph_decode_64(p);
4262         }
4263
4264         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
4265              cid.handle);
4266         if (rbd_cid_equal(&cid, &my_cid))
4267                 return result;
4268
4269         down_read(&rbd_dev->lock_rwsem);
4270         if (__rbd_is_lock_owner(rbd_dev)) {
4271                 if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED &&
4272                     rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid))
4273                         goto out_unlock;
4274
4275                 /*
4276                  * encode ResponseMessage(0) so the peer can detect
4277                  * a missing owner
4278                  */
4279                 result = 0;
4280
4281                 if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
4282                         if (!rbd_dev->opts->exclusive) {
4283                                 dout("%s rbd_dev %p queueing unlock_work\n",
4284                                      __func__, rbd_dev);
4285                                 queue_work(rbd_dev->task_wq,
4286                                            &rbd_dev->unlock_work);
4287                         } else {
4288                                 /* refuse to release the lock */
4289                                 result = -EROFS;
4290                         }
4291                 }
4292         }
4293
4294 out_unlock:
4295         up_read(&rbd_dev->lock_rwsem);
4296         return result;
4297 }
4298
4299 static void __rbd_acknowledge_notify(struct rbd_device *rbd_dev,
4300                                      u64 notify_id, u64 cookie, s32 *result)
4301 {
4302         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4303         char buf[4 + CEPH_ENCODING_START_BLK_LEN];
4304         int buf_size = sizeof(buf);
4305         int ret;
4306
4307         if (result) {
4308                 void *p = buf;
4309
4310                 /* encode ResponseMessage */
4311                 ceph_start_encoding(&p, 1, 1,
4312                                     buf_size - CEPH_ENCODING_START_BLK_LEN);
4313                 ceph_encode_32(&p, *result);
4314         } else {
4315                 buf_size = 0;
4316         }
4317
4318         ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
4319                                    &rbd_dev->header_oloc, notify_id, cookie,
4320                                    buf, buf_size);
4321         if (ret)
4322                 rbd_warn(rbd_dev, "acknowledge_notify failed: %d", ret);
4323 }
4324
4325 static void rbd_acknowledge_notify(struct rbd_device *rbd_dev, u64 notify_id,
4326                                    u64 cookie)
4327 {
4328         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4329         __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, NULL);
4330 }
4331
4332 static void rbd_acknowledge_notify_result(struct rbd_device *rbd_dev,
4333                                           u64 notify_id, u64 cookie, s32 result)
4334 {
4335         dout("%s rbd_dev %p result %d\n", __func__, rbd_dev, result);
4336         __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, &result);
4337 }
4338
4339 static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie,
4340                          u64 notifier_id, void *data, size_t data_len)
4341 {
4342         struct rbd_device *rbd_dev = arg;
4343         void *p = data;
4344         void *const end = p + data_len;
4345         u8 struct_v = 0;
4346         u32 len;
4347         u32 notify_op;
4348         int ret;
4349
4350         dout("%s rbd_dev %p cookie %llu notify_id %llu data_len %zu\n",
4351              __func__, rbd_dev, cookie, notify_id, data_len);
4352         if (data_len) {
4353                 ret = ceph_start_decoding(&p, end, 1, "NotifyMessage",
4354                                           &struct_v, &len);
4355                 if (ret) {
4356                         rbd_warn(rbd_dev, "failed to decode NotifyMessage: %d",
4357                                  ret);
4358                         return;
4359                 }
4360
4361                 notify_op = ceph_decode_32(&p);
4362         } else {
4363                 /* legacy notification for header updates */
4364                 notify_op = RBD_NOTIFY_OP_HEADER_UPDATE;
4365                 len = 0;
4366         }
4367
4368         dout("%s rbd_dev %p notify_op %u\n", __func__, rbd_dev, notify_op);
4369         switch (notify_op) {
4370         case RBD_NOTIFY_OP_ACQUIRED_LOCK:
4371                 rbd_handle_acquired_lock(rbd_dev, struct_v, &p);
4372                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4373                 break;
4374         case RBD_NOTIFY_OP_RELEASED_LOCK:
4375                 rbd_handle_released_lock(rbd_dev, struct_v, &p);
4376                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4377                 break;
4378         case RBD_NOTIFY_OP_REQUEST_LOCK:
4379                 ret = rbd_handle_request_lock(rbd_dev, struct_v, &p);
4380                 if (ret <= 0)
4381                         rbd_acknowledge_notify_result(rbd_dev, notify_id,
4382                                                       cookie, ret);
4383                 else
4384                         rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4385                 break;
4386         case RBD_NOTIFY_OP_HEADER_UPDATE:
4387                 ret = rbd_dev_refresh(rbd_dev);
4388                 if (ret)
4389                         rbd_warn(rbd_dev, "refresh failed: %d", ret);
4390
4391                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4392                 break;
4393         default:
4394                 if (rbd_is_lock_owner(rbd_dev))
4395                         rbd_acknowledge_notify_result(rbd_dev, notify_id,
4396                                                       cookie, -EOPNOTSUPP);
4397                 else
4398                         rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
4399                 break;
4400         }
4401 }
4402
4403 static void __rbd_unregister_watch(struct rbd_device *rbd_dev);
4404
4405 static void rbd_watch_errcb(void *arg, u64 cookie, int err)
4406 {
4407         struct rbd_device *rbd_dev = arg;
4408
4409         rbd_warn(rbd_dev, "encountered watch error: %d", err);
4410
4411         down_write(&rbd_dev->lock_rwsem);
4412         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
4413         up_write(&rbd_dev->lock_rwsem);
4414
4415         mutex_lock(&rbd_dev->watch_mutex);
4416         if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED) {
4417                 __rbd_unregister_watch(rbd_dev);
4418                 rbd_dev->watch_state = RBD_WATCH_STATE_ERROR;
4419
4420                 queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
4421         }
4422         mutex_unlock(&rbd_dev->watch_mutex);
4423 }
4424
4425 /*
4426  * watch_mutex must be locked
4427  */
4428 static int __rbd_register_watch(struct rbd_device *rbd_dev)
4429 {
4430         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4431         struct ceph_osd_linger_request *handle;
4432
4433         rbd_assert(!rbd_dev->watch_handle);
4434         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4435
4436         handle = ceph_osdc_watch(osdc, &rbd_dev->header_oid,
4437                                  &rbd_dev->header_oloc, rbd_watch_cb,
4438                                  rbd_watch_errcb, rbd_dev);
4439         if (IS_ERR(handle))
4440                 return PTR_ERR(handle);
4441
4442         rbd_dev->watch_handle = handle;
4443         return 0;
4444 }
4445
4446 /*
4447  * watch_mutex must be locked
4448  */
4449 static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
4450 {
4451         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4452         int ret;
4453
4454         rbd_assert(rbd_dev->watch_handle);
4455         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4456
4457         ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
4458         if (ret)
4459                 rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
4460
4461         rbd_dev->watch_handle = NULL;
4462 }
4463
4464 static int rbd_register_watch(struct rbd_device *rbd_dev)
4465 {
4466         int ret;
4467
4468         mutex_lock(&rbd_dev->watch_mutex);
4469         rbd_assert(rbd_dev->watch_state == RBD_WATCH_STATE_UNREGISTERED);
4470         ret = __rbd_register_watch(rbd_dev);
4471         if (ret)
4472                 goto out;
4473
4474         rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
4475         rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
4476
4477 out:
4478         mutex_unlock(&rbd_dev->watch_mutex);
4479         return ret;
4480 }
4481
4482 static void cancel_tasks_sync(struct rbd_device *rbd_dev)
4483 {
4484         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4485
4486         cancel_work_sync(&rbd_dev->acquired_lock_work);
4487         cancel_work_sync(&rbd_dev->released_lock_work);
4488         cancel_delayed_work_sync(&rbd_dev->lock_dwork);
4489         cancel_work_sync(&rbd_dev->unlock_work);
4490 }
4491
4492 /*
4493  * header_rwsem must not be held to avoid a deadlock with
4494  * rbd_dev_refresh() when flushing notifies.
4495  */
4496 static void rbd_unregister_watch(struct rbd_device *rbd_dev)
4497 {
4498         cancel_tasks_sync(rbd_dev);
4499
4500         mutex_lock(&rbd_dev->watch_mutex);
4501         if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED)
4502                 __rbd_unregister_watch(rbd_dev);
4503         rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
4504         mutex_unlock(&rbd_dev->watch_mutex);
4505
4506         cancel_delayed_work_sync(&rbd_dev->watch_dwork);
4507         ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
4508 }
4509
4510 /*
4511  * lock_rwsem must be held for write
4512  */
4513 static void rbd_reacquire_lock(struct rbd_device *rbd_dev)
4514 {
4515         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4516         char cookie[32];
4517         int ret;
4518
4519         if (!rbd_quiesce_lock(rbd_dev))
4520                 return;
4521
4522         format_lock_cookie(rbd_dev, cookie);
4523         ret = ceph_cls_set_cookie(osdc, &rbd_dev->header_oid,
4524                                   &rbd_dev->header_oloc, RBD_LOCK_NAME,
4525                                   CEPH_CLS_LOCK_EXCLUSIVE, rbd_dev->lock_cookie,
4526                                   RBD_LOCK_TAG, cookie);
4527         if (ret) {
4528                 if (ret != -EOPNOTSUPP)
4529                         rbd_warn(rbd_dev, "failed to update lock cookie: %d",
4530                                  ret);
4531
4532                 /*
4533                  * Lock cookie cannot be updated on older OSDs, so do
4534                  * a manual release and queue an acquire.
4535                  */
4536                 __rbd_release_lock(rbd_dev);
4537                 queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
4538         } else {
4539                 __rbd_lock(rbd_dev, cookie);
4540                 wake_lock_waiters(rbd_dev, 0);
4541         }
4542 }
4543
4544 static void rbd_reregister_watch(struct work_struct *work)
4545 {
4546         struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
4547                                             struct rbd_device, watch_dwork);
4548         int ret;
4549
4550         dout("%s rbd_dev %p\n", __func__, rbd_dev);
4551
4552         mutex_lock(&rbd_dev->watch_mutex);
4553         if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
4554                 mutex_unlock(&rbd_dev->watch_mutex);
4555                 return;
4556         }
4557
4558         ret = __rbd_register_watch(rbd_dev);
4559         if (ret) {
4560                 rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
4561                 if (ret != -EBLOCKLISTED && ret != -ENOENT) {
4562                         queue_delayed_work(rbd_dev->task_wq,
4563                                            &rbd_dev->watch_dwork,
4564                                            RBD_RETRY_DELAY);
4565                         mutex_unlock(&rbd_dev->watch_mutex);
4566                         return;
4567                 }
4568
4569                 mutex_unlock(&rbd_dev->watch_mutex);
4570                 down_write(&rbd_dev->lock_rwsem);
4571                 wake_lock_waiters(rbd_dev, ret);
4572                 up_write(&rbd_dev->lock_rwsem);
4573                 return;
4574         }
4575
4576         rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
4577         rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
4578         mutex_unlock(&rbd_dev->watch_mutex);
4579
4580         down_write(&rbd_dev->lock_rwsem);
4581         if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
4582                 rbd_reacquire_lock(rbd_dev);
4583         up_write(&rbd_dev->lock_rwsem);
4584
4585         ret = rbd_dev_refresh(rbd_dev);
4586         if (ret)
4587                 rbd_warn(rbd_dev, "reregistration refresh failed: %d", ret);
4588 }
4589
4590 /*
4591  * Synchronous osd object method call.  Returns the number of bytes
4592  * returned in the outbound buffer, or a negative error code.
4593  */
4594 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
4595                              struct ceph_object_id *oid,
4596                              struct ceph_object_locator *oloc,
4597                              const char *method_name,
4598                              const void *outbound,
4599                              size_t outbound_size,
4600                              void *inbound,
4601                              size_t inbound_size)
4602 {
4603         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4604         struct page *req_page = NULL;
4605         struct page *reply_page;
4606         int ret;
4607
4608         /*
4609          * Method calls are ultimately read operations.  The result
4610          * should placed into the inbound buffer provided.  They
4611          * also supply outbound data--parameters for the object
4612          * method.  Currently if this is present it will be a
4613          * snapshot id.
4614          */
4615         if (outbound) {
4616                 if (outbound_size > PAGE_SIZE)
4617                         return -E2BIG;
4618
4619                 req_page = alloc_page(GFP_KERNEL);
4620                 if (!req_page)
4621                         return -ENOMEM;
4622
4623                 memcpy(page_address(req_page), outbound, outbound_size);
4624         }
4625
4626         reply_page = alloc_page(GFP_KERNEL);
4627         if (!reply_page) {
4628                 if (req_page)
4629                         __free_page(req_page);
4630                 return -ENOMEM;
4631         }
4632
4633         ret = ceph_osdc_call(osdc, oid, oloc, RBD_DRV_NAME, method_name,
4634                              CEPH_OSD_FLAG_READ, req_page, outbound_size,
4635                              &reply_page, &inbound_size);
4636         if (!ret) {
4637                 memcpy(inbound, page_address(reply_page), inbound_size);
4638                 ret = inbound_size;
4639         }
4640
4641         if (req_page)
4642                 __free_page(req_page);
4643         __free_page(reply_page);
4644         return ret;
4645 }
4646
4647 static void rbd_queue_workfn(struct work_struct *work)
4648 {
4649         struct rbd_img_request *img_request =
4650             container_of(work, struct rbd_img_request, work);
4651         struct rbd_device *rbd_dev = img_request->rbd_dev;
4652         enum obj_operation_type op_type = img_request->op_type;
4653         struct request *rq = blk_mq_rq_from_pdu(img_request);
4654         u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
4655         u64 length = blk_rq_bytes(rq);
4656         u64 mapping_size;
4657         int result;
4658
4659         /* Ignore/skip any zero-length requests */
4660         if (!length) {
4661                 dout("%s: zero-length request\n", __func__);
4662                 result = 0;
4663                 goto err_img_request;
4664         }
4665
4666         blk_mq_start_request(rq);
4667
4668         down_read(&rbd_dev->header_rwsem);
4669         mapping_size = rbd_dev->mapping.size;
4670         rbd_img_capture_header(img_request);
4671         up_read(&rbd_dev->header_rwsem);
4672
4673         if (offset + length > mapping_size) {
4674                 rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4675                          length, mapping_size);
4676                 result = -EIO;
4677                 goto err_img_request;
4678         }
4679
4680         dout("%s rbd_dev %p img_req %p %s %llu~%llu\n", __func__, rbd_dev,
4681              img_request, obj_op_name(op_type), offset, length);
4682
4683         if (op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_ZEROOUT)
4684                 result = rbd_img_fill_nodata(img_request, offset, length);
4685         else
4686                 result = rbd_img_fill_from_bio(img_request, offset, length,
4687                                                rq->bio);
4688         if (result)
4689                 goto err_img_request;
4690
4691         rbd_img_handle_request(img_request, 0);
4692         return;
4693
4694 err_img_request:
4695         rbd_img_request_destroy(img_request);
4696         if (result)
4697                 rbd_warn(rbd_dev, "%s %llx at %llx result %d",
4698                          obj_op_name(op_type), length, offset, result);
4699         blk_mq_end_request(rq, errno_to_blk_status(result));
4700 }
4701
4702 static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
4703                 const struct blk_mq_queue_data *bd)
4704 {
4705         struct rbd_device *rbd_dev = hctx->queue->queuedata;
4706         struct rbd_img_request *img_req = blk_mq_rq_to_pdu(bd->rq);
4707         enum obj_operation_type op_type;
4708
4709         switch (req_op(bd->rq)) {
4710         case REQ_OP_DISCARD:
4711                 op_type = OBJ_OP_DISCARD;
4712                 break;
4713         case REQ_OP_WRITE_ZEROES:
4714                 op_type = OBJ_OP_ZEROOUT;
4715                 break;
4716         case REQ_OP_WRITE:
4717                 op_type = OBJ_OP_WRITE;
4718                 break;
4719         case REQ_OP_READ:
4720                 op_type = OBJ_OP_READ;
4721                 break;
4722         default:
4723                 rbd_warn(rbd_dev, "unknown req_op %d", req_op(bd->rq));
4724                 return BLK_STS_IOERR;
4725         }
4726
4727         rbd_img_request_init(img_req, rbd_dev, op_type);
4728
4729         if (rbd_img_is_write(img_req)) {
4730                 if (rbd_is_ro(rbd_dev)) {
4731                         rbd_warn(rbd_dev, "%s on read-only mapping",
4732                                  obj_op_name(img_req->op_type));
4733                         return BLK_STS_IOERR;
4734                 }
4735                 rbd_assert(!rbd_is_snap(rbd_dev));
4736         }
4737
4738         INIT_WORK(&img_req->work, rbd_queue_workfn);
4739         queue_work(rbd_wq, &img_req->work);
4740         return BLK_STS_OK;
4741 }
4742
4743 static void rbd_free_disk(struct rbd_device *rbd_dev)
4744 {
4745         blk_cleanup_disk(rbd_dev->disk);
4746         blk_mq_free_tag_set(&rbd_dev->tag_set);
4747         rbd_dev->disk = NULL;
4748 }
4749
4750 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
4751                              struct ceph_object_id *oid,
4752                              struct ceph_object_locator *oloc,
4753                              void *buf, int buf_len)
4754
4755 {
4756         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
4757         struct ceph_osd_request *req;
4758         struct page **pages;
4759         int num_pages = calc_pages_for(0, buf_len);
4760         int ret;
4761
4762         req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
4763         if (!req)
4764                 return -ENOMEM;
4765
4766         ceph_oid_copy(&req->r_base_oid, oid);
4767         ceph_oloc_copy(&req->r_base_oloc, oloc);
4768         req->r_flags = CEPH_OSD_FLAG_READ;
4769
4770         pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
4771         if (IS_ERR(pages)) {
4772                 ret = PTR_ERR(pages);
4773                 goto out_req;
4774         }
4775
4776         osd_req_op_extent_init(req, 0, CEPH_OSD_OP_READ, 0, buf_len, 0, 0);
4777         osd_req_op_extent_osd_data_pages(req, 0, pages, buf_len, 0, false,
4778                                          true);
4779
4780         ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
4781         if (ret)
4782                 goto out_req;
4783
4784         ceph_osdc_start_request(osdc, req, false);
4785         ret = ceph_osdc_wait_request(osdc, req);
4786         if (ret >= 0)
4787                 ceph_copy_from_page_vector(pages, buf, 0, ret);
4788
4789 out_req:
4790         ceph_osdc_put_request(req);
4791         return ret;
4792 }
4793
4794 /*
4795  * Read the complete header for the given rbd device.  On successful
4796  * return, the rbd_dev->header field will contain up-to-date
4797  * information about the image.
4798  */
4799 static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4800 {
4801         struct rbd_image_header_ondisk *ondisk = NULL;
4802         u32 snap_count = 0;
4803         u64 names_size = 0;
4804         u32 want_count;
4805         int ret;
4806
4807         /*
4808          * The complete header will include an array of its 64-bit
4809          * snapshot ids, followed by the names of those snapshots as
4810          * a contiguous block of NUL-terminated strings.  Note that
4811          * the number of snapshots could change by the time we read
4812          * it in, in which case we re-read it.
4813          */
4814         do {
4815                 size_t size;
4816
4817                 kfree(ondisk);
4818
4819                 size = sizeof (*ondisk);
4820                 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
4821                 size += names_size;
4822                 ondisk = kmalloc(size, GFP_KERNEL);
4823                 if (!ondisk)
4824                         return -ENOMEM;
4825
4826                 ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
4827                                         &rbd_dev->header_oloc, ondisk, size);
4828                 if (ret < 0)
4829                         goto out;
4830                 if ((size_t)ret < size) {
4831                         ret = -ENXIO;
4832                         rbd_warn(rbd_dev, "short header read (want %zd got %d)",
4833                                 size, ret);
4834                         goto out;
4835                 }
4836                 if (!rbd_dev_ondisk_valid(ondisk)) {
4837                         ret = -ENXIO;
4838                         rbd_warn(rbd_dev, "invalid header");
4839                         goto out;
4840                 }
4841
4842                 names_size = le64_to_cpu(ondisk->snap_names_len);
4843                 want_count = snap_count;
4844                 snap_count = le32_to_cpu(ondisk->snap_count);
4845         } while (snap_count != want_count);
4846
4847         ret = rbd_header_from_disk(rbd_dev, ondisk);
4848 out:
4849         kfree(ondisk);
4850
4851         return ret;
4852 }
4853
4854 static void rbd_dev_update_size(struct rbd_device *rbd_dev)
4855 {
4856         sector_t size;
4857
4858         /*
4859          * If EXISTS is not set, rbd_dev->disk may be NULL, so don't
4860          * try to update its size.  If REMOVING is set, updating size
4861          * is just useless work since the device can't be opened.
4862          */
4863         if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
4864             !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4865                 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
4866                 dout("setting size to %llu sectors", (unsigned long long)size);
4867                 set_capacity_and_notify(rbd_dev->disk, size);
4868         }
4869 }
4870
4871 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
4872 {
4873         u64 mapping_size;
4874         int ret;
4875
4876         down_write(&rbd_dev->header_rwsem);
4877         mapping_size = rbd_dev->mapping.size;
4878
4879         ret = rbd_dev_header_info(rbd_dev);
4880         if (ret)
4881                 goto out;
4882
4883         /*
4884          * If there is a parent, see if it has disappeared due to the
4885          * mapped image getting flattened.
4886          */
4887         if (rbd_dev->parent) {
4888                 ret = rbd_dev_v2_parent_info(rbd_dev);
4889                 if (ret)
4890                         goto out;
4891         }
4892
4893         rbd_assert(!rbd_is_snap(rbd_dev));
4894         rbd_dev->mapping.size = rbd_dev->header.image_size;
4895
4896 out:
4897         up_write(&rbd_dev->header_rwsem);
4898         if (!ret && mapping_size != rbd_dev->mapping.size)
4899                 rbd_dev_update_size(rbd_dev);
4900
4901         return ret;
4902 }
4903
4904 static const struct blk_mq_ops rbd_mq_ops = {
4905         .queue_rq       = rbd_queue_rq,
4906 };
4907
4908 static int rbd_init_disk(struct rbd_device *rbd_dev)
4909 {
4910         struct gendisk *disk;
4911         struct request_queue *q;
4912         unsigned int objset_bytes =
4913             rbd_dev->layout.object_size * rbd_dev->layout.stripe_count;
4914         int err;
4915
4916         memset(&rbd_dev->tag_set, 0, sizeof(rbd_dev->tag_set));
4917         rbd_dev->tag_set.ops = &rbd_mq_ops;
4918         rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
4919         rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
4920         rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
4921         rbd_dev->tag_set.nr_hw_queues = num_present_cpus();
4922         rbd_dev->tag_set.cmd_size = sizeof(struct rbd_img_request);
4923
4924         err = blk_mq_alloc_tag_set(&rbd_dev->tag_set);
4925         if (err)
4926                 return err;
4927
4928         disk = blk_mq_alloc_disk(&rbd_dev->tag_set, rbd_dev);
4929         if (IS_ERR(disk)) {
4930                 err = PTR_ERR(disk);
4931                 goto out_tag_set;
4932         }
4933         q = disk->queue;
4934
4935         snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
4936                  rbd_dev->dev_id);
4937         disk->major = rbd_dev->major;
4938         disk->first_minor = rbd_dev->minor;
4939         if (single_major) {
4940                 disk->minors = (1 << RBD_SINGLE_MAJOR_PART_SHIFT);
4941                 disk->flags |= GENHD_FL_EXT_DEVT;
4942         } else {
4943                 disk->minors = RBD_MINORS_PER_MAJOR;
4944         }
4945         disk->fops = &rbd_bd_ops;
4946         disk->private_data = rbd_dev;
4947
4948         blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
4949         /* QUEUE_FLAG_ADD_RANDOM is off by default for blk-mq */
4950
4951         blk_queue_max_hw_sectors(q, objset_bytes >> SECTOR_SHIFT);
4952         q->limits.max_sectors = queue_max_hw_sectors(q);
4953         blk_queue_max_segments(q, USHRT_MAX);
4954         blk_queue_max_segment_size(q, UINT_MAX);
4955         blk_queue_io_min(q, rbd_dev->opts->alloc_size);
4956         blk_queue_io_opt(q, rbd_dev->opts->alloc_size);
4957
4958         if (rbd_dev->opts->trim) {
4959                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
4960                 q->limits.discard_granularity = rbd_dev->opts->alloc_size;
4961                 blk_queue_max_discard_sectors(q, objset_bytes >> SECTOR_SHIFT);
4962                 blk_queue_max_write_zeroes_sectors(q, objset_bytes >> SECTOR_SHIFT);
4963         }
4964
4965         if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
4966                 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
4967
4968         rbd_dev->disk = disk;
4969
4970         return 0;
4971 out_tag_set:
4972         blk_mq_free_tag_set(&rbd_dev->tag_set);
4973         return err;
4974 }
4975
4976 /*
4977   sysfs
4978 */
4979
4980 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
4981 {
4982         return container_of(dev, struct rbd_device, dev);
4983 }
4984
4985 static ssize_t rbd_size_show(struct device *dev,
4986                              struct device_attribute *attr, char *buf)
4987 {
4988         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4989
4990         return sprintf(buf, "%llu\n",
4991                 (unsigned long long)rbd_dev->mapping.size);
4992 }
4993
4994 static ssize_t rbd_features_show(struct device *dev,
4995                              struct device_attribute *attr, char *buf)
4996 {
4997         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4998
4999         return sprintf(buf, "0x%016llx\n", rbd_dev->header.features);
5000 }
5001
5002 static ssize_t rbd_major_show(struct device *dev,
5003                               struct device_attribute *attr, char *buf)
5004 {
5005         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5006
5007         if (rbd_dev->major)
5008                 return sprintf(buf, "%d\n", rbd_dev->major);
5009
5010         return sprintf(buf, "(none)\n");
5011 }
5012
5013 static ssize_t rbd_minor_show(struct device *dev,
5014                               struct device_attribute *attr, char *buf)
5015 {
5016         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5017
5018         return sprintf(buf, "%d\n", rbd_dev->minor);
5019 }
5020
5021 static ssize_t rbd_client_addr_show(struct device *dev,
5022                                     struct device_attribute *attr, char *buf)
5023 {
5024         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5025         struct ceph_entity_addr *client_addr =
5026             ceph_client_addr(rbd_dev->rbd_client->client);
5027
5028         return sprintf(buf, "%pISpc/%u\n", &client_addr->in_addr,
5029                        le32_to_cpu(client_addr->nonce));
5030 }
5031
5032 static ssize_t rbd_client_id_show(struct device *dev,
5033                                   struct device_attribute *attr, char *buf)
5034 {
5035         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5036
5037         return sprintf(buf, "client%lld\n",
5038                        ceph_client_gid(rbd_dev->rbd_client->client));
5039 }
5040
5041 static ssize_t rbd_cluster_fsid_show(struct device *dev,
5042                                      struct device_attribute *attr, char *buf)
5043 {
5044         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5045
5046         return sprintf(buf, "%pU\n", &rbd_dev->rbd_client->client->fsid);
5047 }
5048
5049 static ssize_t rbd_config_info_show(struct device *dev,
5050                                     struct device_attribute *attr, char *buf)
5051 {
5052         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5053
5054         if (!capable(CAP_SYS_ADMIN))
5055                 return -EPERM;
5056
5057         return sprintf(buf, "%s\n", rbd_dev->config_info);
5058 }
5059
5060 static ssize_t rbd_pool_show(struct device *dev,
5061                              struct device_attribute *attr, char *buf)
5062 {
5063         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5064
5065         return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
5066 }
5067
5068 static ssize_t rbd_pool_id_show(struct device *dev,
5069                              struct device_attribute *attr, char *buf)
5070 {
5071         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5072
5073         return sprintf(buf, "%llu\n",
5074                         (unsigned long long) rbd_dev->spec->pool_id);
5075 }
5076
5077 static ssize_t rbd_pool_ns_show(struct device *dev,
5078                                 struct device_attribute *attr, char *buf)
5079 {
5080         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5081
5082         return sprintf(buf, "%s\n", rbd_dev->spec->pool_ns ?: "");
5083 }
5084
5085 static ssize_t rbd_name_show(struct device *dev,
5086                              struct device_attribute *attr, char *buf)
5087 {
5088         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5089
5090         if (rbd_dev->spec->image_name)
5091                 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
5092
5093         return sprintf(buf, "(unknown)\n");
5094 }
5095
5096 static ssize_t rbd_image_id_show(struct device *dev,
5097                              struct device_attribute *attr, char *buf)
5098 {
5099         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5100
5101         return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
5102 }
5103
5104 /*
5105  * Shows the name of the currently-mapped snapshot (or
5106  * RBD_SNAP_HEAD_NAME for the base image).
5107  */
5108 static ssize_t rbd_snap_show(struct device *dev,
5109                              struct device_attribute *attr,
5110                              char *buf)
5111 {
5112         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5113
5114         return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
5115 }
5116
5117 static ssize_t rbd_snap_id_show(struct device *dev,
5118                                 struct device_attribute *attr, char *buf)
5119 {
5120         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5121
5122         return sprintf(buf, "%llu\n", rbd_dev->spec->snap_id);
5123 }
5124
5125 /*
5126  * For a v2 image, shows the chain of parent images, separated by empty
5127  * lines.  For v1 images or if there is no parent, shows "(no parent
5128  * image)".
5129  */
5130 static ssize_t rbd_parent_show(struct device *dev,
5131                                struct device_attribute *attr,
5132                                char *buf)
5133 {
5134         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5135         ssize_t count = 0;
5136
5137         if (!rbd_dev->parent)
5138                 return sprintf(buf, "(no parent image)\n");
5139
5140         for ( ; rbd_dev->parent; rbd_dev = rbd_dev->parent) {
5141                 struct rbd_spec *spec = rbd_dev->parent_spec;
5142
5143                 count += sprintf(&buf[count], "%s"
5144                             "pool_id %llu\npool_name %s\n"
5145                             "pool_ns %s\n"
5146                             "image_id %s\nimage_name %s\n"
5147                             "snap_id %llu\nsnap_name %s\n"
5148                             "overlap %llu\n",
5149                             !count ? "" : "\n", /* first? */
5150                             spec->pool_id, spec->pool_name,
5151                             spec->pool_ns ?: "",
5152                             spec->image_id, spec->image_name ?: "(unknown)",
5153                             spec->snap_id, spec->snap_name,
5154                             rbd_dev->parent_overlap);
5155         }
5156
5157         return count;
5158 }
5159
5160 static ssize_t rbd_image_refresh(struct device *dev,
5161                                  struct device_attribute *attr,
5162                                  const char *buf,
5163                                  size_t size)
5164 {
5165         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5166         int ret;
5167
5168         if (!capable(CAP_SYS_ADMIN))
5169                 return -EPERM;
5170
5171         ret = rbd_dev_refresh(rbd_dev);
5172         if (ret)
5173                 return ret;
5174
5175         return size;
5176 }
5177
5178 static DEVICE_ATTR(size, 0444, rbd_size_show, NULL);
5179 static DEVICE_ATTR(features, 0444, rbd_features_show, NULL);
5180 static DEVICE_ATTR(major, 0444, rbd_major_show, NULL);
5181 static DEVICE_ATTR(minor, 0444, rbd_minor_show, NULL);
5182 static DEVICE_ATTR(client_addr, 0444, rbd_client_addr_show, NULL);
5183 static DEVICE_ATTR(client_id, 0444, rbd_client_id_show, NULL);
5184 static DEVICE_ATTR(cluster_fsid, 0444, rbd_cluster_fsid_show, NULL);
5185 static DEVICE_ATTR(config_info, 0400, rbd_config_info_show, NULL);
5186 static DEVICE_ATTR(pool, 0444, rbd_pool_show, NULL);
5187 static DEVICE_ATTR(pool_id, 0444, rbd_pool_id_show, NULL);
5188 static DEVICE_ATTR(pool_ns, 0444, rbd_pool_ns_show, NULL);
5189 static DEVICE_ATTR(name, 0444, rbd_name_show, NULL);
5190 static DEVICE_ATTR(image_id, 0444, rbd_image_id_show, NULL);
5191 static DEVICE_ATTR(refresh, 0200, NULL, rbd_image_refresh);
5192 static DEVICE_ATTR(current_snap, 0444, rbd_snap_show, NULL);
5193 static DEVICE_ATTR(snap_id, 0444, rbd_snap_id_show, NULL);
5194 static DEVICE_ATTR(parent, 0444, rbd_parent_show, NULL);
5195
5196 static struct attribute *rbd_attrs[] = {
5197         &dev_attr_size.attr,
5198         &dev_attr_features.attr,
5199         &dev_attr_major.attr,
5200         &dev_attr_minor.attr,
5201         &dev_attr_client_addr.attr,
5202         &dev_attr_client_id.attr,
5203         &dev_attr_cluster_fsid.attr,
5204         &dev_attr_config_info.attr,
5205         &dev_attr_pool.attr,
5206         &dev_attr_pool_id.attr,
5207         &dev_attr_pool_ns.attr,
5208         &dev_attr_name.attr,
5209         &dev_attr_image_id.attr,
5210         &dev_attr_current_snap.attr,
5211         &dev_attr_snap_id.attr,
5212         &dev_attr_parent.attr,
5213         &dev_attr_refresh.attr,
5214         NULL
5215 };
5216
5217 static struct attribute_group rbd_attr_group = {
5218         .attrs = rbd_attrs,
5219 };
5220
5221 static const struct attribute_group *rbd_attr_groups[] = {
5222         &rbd_attr_group,
5223         NULL
5224 };
5225
5226 static void rbd_dev_release(struct device *dev);
5227
5228 static const struct device_type rbd_device_type = {
5229         .name           = "rbd",
5230         .groups         = rbd_attr_groups,
5231         .release        = rbd_dev_release,
5232 };
5233
5234 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
5235 {
5236         kref_get(&spec->kref);
5237
5238         return spec;
5239 }
5240
5241 static void rbd_spec_free(struct kref *kref);
5242 static void rbd_spec_put(struct rbd_spec *spec)
5243 {
5244         if (spec)
5245                 kref_put(&spec->kref, rbd_spec_free);
5246 }
5247
5248 static struct rbd_spec *rbd_spec_alloc(void)
5249 {
5250         struct rbd_spec *spec;
5251
5252         spec = kzalloc(sizeof (*spec), GFP_KERNEL);
5253         if (!spec)
5254                 return NULL;
5255
5256         spec->pool_id = CEPH_NOPOOL;
5257         spec->snap_id = CEPH_NOSNAP;
5258         kref_init(&spec->kref);
5259
5260         return spec;
5261 }
5262
5263 static void rbd_spec_free(struct kref *kref)
5264 {
5265         struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
5266
5267         kfree(spec->pool_name);
5268         kfree(spec->pool_ns);
5269         kfree(spec->image_id);
5270         kfree(spec->image_name);
5271         kfree(spec->snap_name);
5272         kfree(spec);
5273 }
5274
5275 static void rbd_dev_free(struct rbd_device *rbd_dev)
5276 {
5277         WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
5278         WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
5279
5280         ceph_oid_destroy(&rbd_dev->header_oid);
5281         ceph_oloc_destroy(&rbd_dev->header_oloc);
5282         kfree(rbd_dev->config_info);
5283
5284         rbd_put_client(rbd_dev->rbd_client);
5285         rbd_spec_put(rbd_dev->spec);
5286         kfree(rbd_dev->opts);
5287         kfree(rbd_dev);
5288 }
5289
5290 static void rbd_dev_release(struct device *dev)
5291 {
5292         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
5293         bool need_put = !!rbd_dev->opts;
5294
5295         if (need_put) {
5296                 destroy_workqueue(rbd_dev->task_wq);
5297                 ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
5298         }
5299
5300         rbd_dev_free(rbd_dev);
5301
5302         /*
5303          * This is racy, but way better than putting module outside of
5304          * the release callback.  The race window is pretty small, so
5305          * doing something similar to dm (dm-builtin.c) is overkill.
5306          */
5307         if (need_put)
5308                 module_put(THIS_MODULE);
5309 }
5310
5311 static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
5312                                            struct rbd_spec *spec)
5313 {
5314         struct rbd_device *rbd_dev;
5315
5316         rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
5317         if (!rbd_dev)
5318                 return NULL;
5319
5320         spin_lock_init(&rbd_dev->lock);
5321         INIT_LIST_HEAD(&rbd_dev->node);
5322         init_rwsem(&rbd_dev->header_rwsem);
5323
5324         rbd_dev->header.data_pool_id = CEPH_NOPOOL;
5325         ceph_oid_init(&rbd_dev->header_oid);
5326         rbd_dev->header_oloc.pool = spec->pool_id;
5327         if (spec->pool_ns) {
5328                 WARN_ON(!*spec->pool_ns);
5329                 rbd_dev->header_oloc.pool_ns =
5330                     ceph_find_or_create_string(spec->pool_ns,
5331                                                strlen(spec->pool_ns));
5332         }
5333
5334         mutex_init(&rbd_dev->watch_mutex);
5335         rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
5336         INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);
5337
5338         init_rwsem(&rbd_dev->lock_rwsem);
5339         rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
5340         INIT_WORK(&rbd_dev->acquired_lock_work, rbd_notify_acquired_lock);
5341         INIT_WORK(&rbd_dev->released_lock_work, rbd_notify_released_lock);
5342         INIT_DELAYED_WORK(&rbd_dev->lock_dwork, rbd_acquire_lock);
5343         INIT_WORK(&rbd_dev->unlock_work, rbd_release_lock_work);
5344         spin_lock_init(&rbd_dev->lock_lists_lock);
5345         INIT_LIST_HEAD(&rbd_dev->acquiring_list);
5346         INIT_LIST_HEAD(&rbd_dev->running_list);
5347         init_completion(&rbd_dev->acquire_wait);
5348         init_completion(&rbd_dev->releasing_wait);
5349
5350         spin_lock_init(&rbd_dev->object_map_lock);
5351
5352         rbd_dev->dev.bus = &rbd_bus_type;
5353         rbd_dev->dev.type = &rbd_device_type;
5354         rbd_dev->dev.parent = &rbd_root_dev;
5355         device_initialize(&rbd_dev->dev);
5356
5357         rbd_dev->rbd_client = rbdc;
5358         rbd_dev->spec = spec;
5359
5360         return rbd_dev;
5361 }
5362
5363 /*
5364  * Create a mapping rbd_dev.
5365  */
5366 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
5367                                          struct rbd_spec *spec,
5368                                          struct rbd_options *opts)
5369 {
5370         struct rbd_device *rbd_dev;
5371
5372         rbd_dev = __rbd_dev_create(rbdc, spec);
5373         if (!rbd_dev)
5374                 return NULL;
5375
5376         rbd_dev->opts = opts;
5377
5378         /* get an id and fill in device name */
5379         rbd_dev->dev_id = ida_simple_get(&rbd_dev_id_ida, 0,
5380                                          minor_to_rbd_dev_id(1 << MINORBITS),
5381                                          GFP_KERNEL);
5382         if (rbd_dev->dev_id < 0)
5383                 goto fail_rbd_dev;
5384
5385         sprintf(rbd_dev->name, RBD_DRV_NAME "%d", rbd_dev->dev_id);
5386         rbd_dev->task_wq = alloc_ordered_workqueue("%s-tasks", WQ_MEM_RECLAIM,
5387                                                    rbd_dev->name);
5388         if (!rbd_dev->task_wq)
5389                 goto fail_dev_id;
5390
5391         /* we have a ref from do_rbd_add() */
5392         __module_get(THIS_MODULE);
5393
5394         dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
5395         return rbd_dev;
5396
5397 fail_dev_id:
5398         ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
5399 fail_rbd_dev:
5400         rbd_dev_free(rbd_dev);
5401         return NULL;
5402 }
5403
5404 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
5405 {
5406         if (rbd_dev)
5407                 put_device(&rbd_dev->dev);
5408 }
5409
5410 /*
5411  * Get the size and object order for an image snapshot, or if
5412  * snap_id is CEPH_NOSNAP, gets this information for the base
5413  * image.
5414  */
5415 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
5416                                 u8 *order, u64 *snap_size)
5417 {
5418         __le64 snapid = cpu_to_le64(snap_id);
5419         int ret;
5420         struct {
5421                 u8 order;
5422                 __le64 size;
5423         } __attribute__ ((packed)) size_buf = { 0 };
5424
5425         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5426                                   &rbd_dev->header_oloc, "get_size",
5427                                   &snapid, sizeof(snapid),
5428                                   &size_buf, sizeof(size_buf));
5429         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5430         if (ret < 0)
5431                 return ret;
5432         if (ret < sizeof (size_buf))
5433                 return -ERANGE;
5434
5435         if (order) {
5436                 *order = size_buf.order;
5437                 dout("  order %u", (unsigned int)*order);
5438         }
5439         *snap_size = le64_to_cpu(size_buf.size);
5440
5441         dout("  snap_id 0x%016llx snap_size = %llu\n",
5442                 (unsigned long long)snap_id,
5443                 (unsigned long long)*snap_size);
5444
5445         return 0;
5446 }
5447
5448 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
5449 {
5450         return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
5451                                         &rbd_dev->header.obj_order,
5452                                         &rbd_dev->header.image_size);
5453 }
5454
5455 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
5456 {
5457         size_t size;
5458         void *reply_buf;
5459         int ret;
5460         void *p;
5461
5462         /* Response will be an encoded string, which includes a length */
5463         size = sizeof(__le32) + RBD_OBJ_PREFIX_LEN_MAX;
5464         reply_buf = kzalloc(size, GFP_KERNEL);
5465         if (!reply_buf)
5466                 return -ENOMEM;
5467
5468         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5469                                   &rbd_dev->header_oloc, "get_object_prefix",
5470                                   NULL, 0, reply_buf, size);
5471         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5472         if (ret < 0)
5473                 goto out;
5474
5475         p = reply_buf;
5476         rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
5477                                                 p + ret, NULL, GFP_NOIO);
5478         ret = 0;
5479
5480         if (IS_ERR(rbd_dev->header.object_prefix)) {
5481                 ret = PTR_ERR(rbd_dev->header.object_prefix);
5482                 rbd_dev->header.object_prefix = NULL;
5483         } else {
5484                 dout("  object_prefix = %s\n", rbd_dev->header.object_prefix);
5485         }
5486 out:
5487         kfree(reply_buf);
5488
5489         return ret;
5490 }
5491
5492 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
5493                                      bool read_only, u64 *snap_features)
5494 {
5495         struct {
5496                 __le64 snap_id;
5497                 u8 read_only;
5498         } features_in;
5499         struct {
5500                 __le64 features;
5501                 __le64 incompat;
5502         } __attribute__ ((packed)) features_buf = { 0 };
5503         u64 unsup;
5504         int ret;
5505
5506         features_in.snap_id = cpu_to_le64(snap_id);
5507         features_in.read_only = read_only;
5508
5509         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5510                                   &rbd_dev->header_oloc, "get_features",
5511                                   &features_in, sizeof(features_in),
5512                                   &features_buf, sizeof(features_buf));
5513         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5514         if (ret < 0)
5515                 return ret;
5516         if (ret < sizeof (features_buf))
5517                 return -ERANGE;
5518
5519         unsup = le64_to_cpu(features_buf.incompat) & ~RBD_FEATURES_SUPPORTED;
5520         if (unsup) {
5521                 rbd_warn(rbd_dev, "image uses unsupported features: 0x%llx",
5522                          unsup);
5523                 return -ENXIO;
5524         }
5525
5526         *snap_features = le64_to_cpu(features_buf.features);
5527
5528         dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
5529                 (unsigned long long)snap_id,
5530                 (unsigned long long)*snap_features,
5531                 (unsigned long long)le64_to_cpu(features_buf.incompat));
5532
5533         return 0;
5534 }
5535
5536 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
5537 {
5538         return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
5539                                          rbd_is_ro(rbd_dev),
5540                                          &rbd_dev->header.features);
5541 }
5542
5543 /*
5544  * These are generic image flags, but since they are used only for
5545  * object map, store them in rbd_dev->object_map_flags.
5546  *
5547  * For the same reason, this function is called only on object map
5548  * (re)load and not on header refresh.
5549  */
5550 static int rbd_dev_v2_get_flags(struct rbd_device *rbd_dev)
5551 {
5552         __le64 snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5553         __le64 flags;
5554         int ret;
5555
5556         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5557                                   &rbd_dev->header_oloc, "get_flags",
5558                                   &snapid, sizeof(snapid),
5559                                   &flags, sizeof(flags));
5560         if (ret < 0)
5561                 return ret;
5562         if (ret < sizeof(flags))
5563                 return -EBADMSG;
5564
5565         rbd_dev->object_map_flags = le64_to_cpu(flags);
5566         return 0;
5567 }
5568
5569 struct parent_image_info {
5570         u64             pool_id;
5571         const char      *pool_ns;
5572         const char      *image_id;
5573         u64             snap_id;
5574
5575         bool            has_overlap;
5576         u64             overlap;
5577 };
5578
5579 /*
5580  * The caller is responsible for @pii.
5581  */
5582 static int decode_parent_image_spec(void **p, void *end,
5583                                     struct parent_image_info *pii)
5584 {
5585         u8 struct_v;
5586         u32 struct_len;
5587         int ret;
5588
5589         ret = ceph_start_decoding(p, end, 1, "ParentImageSpec",
5590                                   &struct_v, &struct_len);
5591         if (ret)
5592                 return ret;
5593
5594         ceph_decode_64_safe(p, end, pii->pool_id, e_inval);
5595         pii->pool_ns = ceph_extract_encoded_string(p, end, NULL, GFP_KERNEL);
5596         if (IS_ERR(pii->pool_ns)) {
5597                 ret = PTR_ERR(pii->pool_ns);
5598                 pii->pool_ns = NULL;
5599                 return ret;
5600         }
5601         pii->image_id = ceph_extract_encoded_string(p, end, NULL, GFP_KERNEL);
5602         if (IS_ERR(pii->image_id)) {
5603                 ret = PTR_ERR(pii->image_id);
5604                 pii->image_id = NULL;
5605                 return ret;
5606         }
5607         ceph_decode_64_safe(p, end, pii->snap_id, e_inval);
5608         return 0;
5609
5610 e_inval:
5611         return -EINVAL;
5612 }
5613
5614 static int __get_parent_info(struct rbd_device *rbd_dev,
5615                              struct page *req_page,
5616                              struct page *reply_page,
5617                              struct parent_image_info *pii)
5618 {
5619         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
5620         size_t reply_len = PAGE_SIZE;
5621         void *p, *end;
5622         int ret;
5623
5624         ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
5625                              "rbd", "parent_get", CEPH_OSD_FLAG_READ,
5626                              req_page, sizeof(u64), &reply_page, &reply_len);
5627         if (ret)
5628                 return ret == -EOPNOTSUPP ? 1 : ret;
5629
5630         p = page_address(reply_page);
5631         end = p + reply_len;
5632         ret = decode_parent_image_spec(&p, end, pii);
5633         if (ret)
5634                 return ret;
5635
5636         ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
5637                              "rbd", "parent_overlap_get", CEPH_OSD_FLAG_READ,
5638                              req_page, sizeof(u64), &reply_page, &reply_len);
5639         if (ret)
5640                 return ret;
5641
5642         p = page_address(reply_page);
5643         end = p + reply_len;
5644         ceph_decode_8_safe(&p, end, pii->has_overlap, e_inval);
5645         if (pii->has_overlap)
5646                 ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
5647
5648         return 0;
5649
5650 e_inval:
5651         return -EINVAL;
5652 }
5653
5654 /*
5655  * The caller is responsible for @pii.
5656  */
5657 static int __get_parent_info_legacy(struct rbd_device *rbd_dev,
5658                                     struct page *req_page,
5659                                     struct page *reply_page,
5660                                     struct parent_image_info *pii)
5661 {
5662         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
5663         size_t reply_len = PAGE_SIZE;
5664         void *p, *end;
5665         int ret;
5666
5667         ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
5668                              "rbd", "get_parent", CEPH_OSD_FLAG_READ,
5669                              req_page, sizeof(u64), &reply_page, &reply_len);
5670         if (ret)
5671                 return ret;
5672
5673         p = page_address(reply_page);
5674         end = p + reply_len;
5675         ceph_decode_64_safe(&p, end, pii->pool_id, e_inval);
5676         pii->image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5677         if (IS_ERR(pii->image_id)) {
5678                 ret = PTR_ERR(pii->image_id);
5679                 pii->image_id = NULL;
5680                 return ret;
5681         }
5682         ceph_decode_64_safe(&p, end, pii->snap_id, e_inval);
5683         pii->has_overlap = true;
5684         ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
5685
5686         return 0;
5687
5688 e_inval:
5689         return -EINVAL;
5690 }
5691
5692 static int get_parent_info(struct rbd_device *rbd_dev,
5693                            struct parent_image_info *pii)
5694 {
5695         struct page *req_page, *reply_page;
5696         void *p;
5697         int ret;
5698
5699         req_page = alloc_page(GFP_KERNEL);
5700         if (!req_page)
5701                 return -ENOMEM;
5702
5703         reply_page = alloc_page(GFP_KERNEL);
5704         if (!reply_page) {
5705                 __free_page(req_page);
5706                 return -ENOMEM;
5707         }
5708
5709         p = page_address(req_page);
5710         ceph_encode_64(&p, rbd_dev->spec->snap_id);
5711         ret = __get_parent_info(rbd_dev, req_page, reply_page, pii);
5712         if (ret > 0)
5713                 ret = __get_parent_info_legacy(rbd_dev, req_page, reply_page,
5714                                                pii);
5715
5716         __free_page(req_page);
5717         __free_page(reply_page);
5718         return ret;
5719 }
5720
5721 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
5722 {
5723         struct rbd_spec *parent_spec;
5724         struct parent_image_info pii = { 0 };
5725         int ret;
5726
5727         parent_spec = rbd_spec_alloc();
5728         if (!parent_spec)
5729                 return -ENOMEM;
5730
5731         ret = get_parent_info(rbd_dev, &pii);
5732         if (ret)
5733                 goto out_err;
5734
5735         dout("%s pool_id %llu pool_ns %s image_id %s snap_id %llu has_overlap %d overlap %llu\n",
5736              __func__, pii.pool_id, pii.pool_ns, pii.image_id, pii.snap_id,
5737              pii.has_overlap, pii.overlap);
5738
5739         if (pii.pool_id == CEPH_NOPOOL || !pii.has_overlap) {
5740                 /*
5741                  * Either the parent never existed, or we have
5742                  * record of it but the image got flattened so it no
5743                  * longer has a parent.  When the parent of a
5744                  * layered image disappears we immediately set the
5745                  * overlap to 0.  The effect of this is that all new
5746                  * requests will be treated as if the image had no
5747                  * parent.
5748                  *
5749                  * If !pii.has_overlap, the parent image spec is not
5750                  * applicable.  It's there to avoid duplication in each
5751                  * snapshot record.
5752                  */
5753                 if (rbd_dev->parent_overlap) {
5754                         rbd_dev->parent_overlap = 0;
5755                         rbd_dev_parent_put(rbd_dev);
5756                         pr_info("%s: clone image has been flattened\n",
5757                                 rbd_dev->disk->disk_name);
5758                 }
5759
5760                 goto out;       /* No parent?  No problem. */
5761         }
5762
5763         /* The ceph file layout needs to fit pool id in 32 bits */
5764
5765         ret = -EIO;
5766         if (pii.pool_id > (u64)U32_MAX) {
5767                 rbd_warn(NULL, "parent pool id too large (%llu > %u)",
5768                         (unsigned long long)pii.pool_id, U32_MAX);
5769                 goto out_err;
5770         }
5771
5772         /*
5773          * The parent won't change (except when the clone is
5774          * flattened, already handled that).  So we only need to
5775          * record the parent spec we have not already done so.
5776          */
5777         if (!rbd_dev->parent_spec) {
5778                 parent_spec->pool_id = pii.pool_id;
5779                 if (pii.pool_ns && *pii.pool_ns) {
5780                         parent_spec->pool_ns = pii.pool_ns;
5781                         pii.pool_ns = NULL;
5782                 }
5783                 parent_spec->image_id = pii.image_id;
5784                 pii.image_id = NULL;
5785                 parent_spec->snap_id = pii.snap_id;
5786
5787                 rbd_dev->parent_spec = parent_spec;
5788                 parent_spec = NULL;     /* rbd_dev now owns this */
5789         }
5790
5791         /*
5792          * We always update the parent overlap.  If it's zero we issue
5793          * a warning, as we will proceed as if there was no parent.
5794          */
5795         if (!pii.overlap) {
5796                 if (parent_spec) {
5797                         /* refresh, careful to warn just once */
5798                         if (rbd_dev->parent_overlap)
5799                                 rbd_warn(rbd_dev,
5800                                     "clone now standalone (overlap became 0)");
5801                 } else {
5802                         /* initial probe */
5803                         rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5804                 }
5805         }
5806         rbd_dev->parent_overlap = pii.overlap;
5807
5808 out:
5809         ret = 0;
5810 out_err:
5811         kfree(pii.pool_ns);
5812         kfree(pii.image_id);
5813         rbd_spec_put(parent_spec);
5814         return ret;
5815 }
5816
5817 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
5818 {
5819         struct {
5820                 __le64 stripe_unit;
5821                 __le64 stripe_count;
5822         } __attribute__ ((packed)) striping_info_buf = { 0 };
5823         size_t size = sizeof (striping_info_buf);
5824         void *p;
5825         int ret;
5826
5827         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5828                                 &rbd_dev->header_oloc, "get_stripe_unit_count",
5829                                 NULL, 0, &striping_info_buf, size);
5830         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5831         if (ret < 0)
5832                 return ret;
5833         if (ret < size)
5834                 return -ERANGE;
5835
5836         p = &striping_info_buf;
5837         rbd_dev->header.stripe_unit = ceph_decode_64(&p);
5838         rbd_dev->header.stripe_count = ceph_decode_64(&p);
5839         return 0;
5840 }
5841
5842 static int rbd_dev_v2_data_pool(struct rbd_device *rbd_dev)
5843 {
5844         __le64 data_pool_id;
5845         int ret;
5846
5847         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
5848                                   &rbd_dev->header_oloc, "get_data_pool",
5849                                   NULL, 0, &data_pool_id, sizeof(data_pool_id));
5850         if (ret < 0)
5851                 return ret;
5852         if (ret < sizeof(data_pool_id))
5853                 return -EBADMSG;
5854
5855         rbd_dev->header.data_pool_id = le64_to_cpu(data_pool_id);
5856         WARN_ON(rbd_dev->header.data_pool_id == CEPH_NOPOOL);
5857         return 0;
5858 }
5859
5860 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
5861 {
5862         CEPH_DEFINE_OID_ONSTACK(oid);
5863         size_t image_id_size;
5864         char *image_id;
5865         void *p;
5866         void *end;
5867         size_t size;
5868         void *reply_buf = NULL;
5869         size_t len = 0;
5870         char *image_name = NULL;
5871         int ret;
5872
5873         rbd_assert(!rbd_dev->spec->image_name);
5874
5875         len = strlen(rbd_dev->spec->image_id);
5876         image_id_size = sizeof (__le32) + len;
5877         image_id = kmalloc(image_id_size, GFP_KERNEL);
5878         if (!image_id)
5879                 return NULL;
5880
5881         p = image_id;
5882         end = image_id + image_id_size;
5883         ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5884
5885         size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
5886         reply_buf = kmalloc(size, GFP_KERNEL);
5887         if (!reply_buf)
5888                 goto out;
5889
5890         ceph_oid_printf(&oid, "%s", RBD_DIRECTORY);
5891         ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
5892                                   "dir_get_name", image_id, image_id_size,
5893                                   reply_buf, size);
5894         if (ret < 0)
5895                 goto out;
5896         p = reply_buf;
5897         end = reply_buf + ret;
5898
5899         image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
5900         if (IS_ERR(image_name))
5901                 image_name = NULL;
5902         else
5903                 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
5904 out:
5905         kfree(reply_buf);
5906         kfree(image_id);
5907
5908         return image_name;
5909 }
5910
5911 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5912 {
5913         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
5914         const char *snap_name;
5915         u32 which = 0;
5916
5917         /* Skip over names until we find the one we are looking for */
5918
5919         snap_name = rbd_dev->header.snap_names;
5920         while (which < snapc->num_snaps) {
5921                 if (!strcmp(name, snap_name))
5922                         return snapc->snaps[which];
5923                 snap_name += strlen(snap_name) + 1;
5924                 which++;
5925         }
5926         return CEPH_NOSNAP;
5927 }
5928
5929 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5930 {
5931         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
5932         u32 which;
5933         bool found = false;
5934         u64 snap_id;
5935
5936         for (which = 0; !found && which < snapc->num_snaps; which++) {
5937                 const char *snap_name;
5938
5939                 snap_id = snapc->snaps[which];
5940                 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
5941                 if (IS_ERR(snap_name)) {
5942                         /* ignore no-longer existing snapshots */
5943                         if (PTR_ERR(snap_name) == -ENOENT)
5944                                 continue;
5945                         else
5946                                 break;
5947                 }
5948                 found = !strcmp(name, snap_name);
5949                 kfree(snap_name);
5950         }
5951         return found ? snap_id : CEPH_NOSNAP;
5952 }
5953
5954 /*
5955  * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
5956  * no snapshot by that name is found, or if an error occurs.
5957  */
5958 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5959 {
5960         if (rbd_dev->image_format == 1)
5961                 return rbd_v1_snap_id_by_name(rbd_dev, name);
5962
5963         return rbd_v2_snap_id_by_name(rbd_dev, name);
5964 }
5965
5966 /*
5967  * An image being mapped will have everything but the snap id.
5968  */
5969 static int rbd_spec_fill_snap_id(struct rbd_device *rbd_dev)
5970 {
5971         struct rbd_spec *spec = rbd_dev->spec;
5972
5973         rbd_assert(spec->pool_id != CEPH_NOPOOL && spec->pool_name);
5974         rbd_assert(spec->image_id && spec->image_name);
5975         rbd_assert(spec->snap_name);
5976
5977         if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
5978                 u64 snap_id;
5979
5980                 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
5981                 if (snap_id == CEPH_NOSNAP)
5982                         return -ENOENT;
5983
5984                 spec->snap_id = snap_id;
5985         } else {
5986                 spec->snap_id = CEPH_NOSNAP;
5987         }
5988
5989         return 0;
5990 }
5991
5992 /*
5993  * A parent image will have all ids but none of the names.
5994  *
5995  * All names in an rbd spec are dynamically allocated.  It's OK if we
5996  * can't figure out the name for an image id.
5997  */
5998 static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5999 {
6000         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
6001         struct rbd_spec *spec = rbd_dev->spec;
6002         const char *pool_name;
6003         const char *image_name;
6004         const char *snap_name;
6005         int ret;
6006
6007         rbd_assert(spec->pool_id != CEPH_NOPOOL);
6008         rbd_assert(spec->image_id);
6009         rbd_assert(spec->snap_id != CEPH_NOSNAP);
6010
6011         /* Get the pool name; we have to make our own copy of this */
6012
6013         pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
6014         if (!pool_name) {
6015                 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
6016                 return -EIO;
6017         }
6018         pool_name = kstrdup(pool_name, GFP_KERNEL);
6019         if (!pool_name)
6020                 return -ENOMEM;
6021
6022         /* Fetch the image name; tolerate failure here */
6023
6024         image_name = rbd_dev_image_name(rbd_dev);
6025         if (!image_name)
6026                 rbd_warn(rbd_dev, "unable to get image name");
6027
6028         /* Fetch the snapshot name */
6029
6030         snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
6031         if (IS_ERR(snap_name)) {
6032                 ret = PTR_ERR(snap_name);
6033                 goto out_err;
6034         }
6035
6036         spec->pool_name = pool_name;
6037         spec->image_name = image_name;
6038         spec->snap_name = snap_name;
6039
6040         return 0;
6041
6042 out_err:
6043         kfree(image_name);
6044         kfree(pool_name);
6045         return ret;
6046 }
6047
6048 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
6049 {
6050         size_t size;
6051         int ret;
6052         void *reply_buf;
6053         void *p;
6054         void *end;
6055         u64 seq;
6056         u32 snap_count;
6057         struct ceph_snap_context *snapc;
6058         u32 i;
6059
6060         /*
6061          * We'll need room for the seq value (maximum snapshot id),
6062          * snapshot count, and array of that many snapshot ids.
6063          * For now we have a fixed upper limit on the number we're
6064          * prepared to receive.
6065          */
6066         size = sizeof (__le64) + sizeof (__le32) +
6067                         RBD_MAX_SNAP_COUNT * sizeof (__le64);
6068         reply_buf = kzalloc(size, GFP_KERNEL);
6069         if (!reply_buf)
6070                 return -ENOMEM;
6071
6072         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
6073                                   &rbd_dev->header_oloc, "get_snapcontext",
6074                                   NULL, 0, reply_buf, size);
6075         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
6076         if (ret < 0)
6077                 goto out;
6078
6079         p = reply_buf;
6080         end = reply_buf + ret;
6081         ret = -ERANGE;
6082         ceph_decode_64_safe(&p, end, seq, out);
6083         ceph_decode_32_safe(&p, end, snap_count, out);
6084
6085         /*
6086          * Make sure the reported number of snapshot ids wouldn't go
6087          * beyond the end of our buffer.  But before checking that,
6088          * make sure the computed size of the snapshot context we
6089          * allocate is representable in a size_t.
6090          */
6091         if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
6092                                  / sizeof (u64)) {
6093                 ret = -EINVAL;
6094                 goto out;
6095         }
6096         if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
6097                 goto out;
6098         ret = 0;
6099
6100         snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
6101         if (!snapc) {
6102                 ret = -ENOMEM;
6103                 goto out;
6104         }
6105         snapc->seq = seq;
6106         for (i = 0; i < snap_count; i++)
6107                 snapc->snaps[i] = ceph_decode_64(&p);
6108
6109         ceph_put_snap_context(rbd_dev->header.snapc);
6110         rbd_dev->header.snapc = snapc;
6111
6112         dout("  snap context seq = %llu, snap_count = %u\n",
6113                 (unsigned long long)seq, (unsigned int)snap_count);
6114 out:
6115         kfree(reply_buf);
6116
6117         return ret;
6118 }
6119
6120 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
6121                                         u64 snap_id)
6122 {
6123         size_t size;
6124         void *reply_buf;
6125         __le64 snapid;
6126         int ret;
6127         void *p;
6128         void *end;
6129         char *snap_name;
6130
6131         size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
6132         reply_buf = kmalloc(size, GFP_KERNEL);
6133         if (!reply_buf)
6134                 return ERR_PTR(-ENOMEM);
6135
6136         snapid = cpu_to_le64(snap_id);
6137         ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
6138                                   &rbd_dev->header_oloc, "get_snapshot_name",
6139                                   &snapid, sizeof(snapid), reply_buf, size);
6140         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
6141         if (ret < 0) {
6142                 snap_name = ERR_PTR(ret);
6143                 goto out;
6144         }
6145
6146         p = reply_buf;
6147         end = reply_buf + ret;
6148         snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
6149         if (IS_ERR(snap_name))
6150                 goto out;
6151
6152         dout("  snap_id 0x%016llx snap_name = %s\n",
6153                 (unsigned long long)snap_id, snap_name);
6154 out:
6155         kfree(reply_buf);
6156
6157         return snap_name;
6158 }
6159
6160 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
6161 {
6162         bool first_time = rbd_dev->header.object_prefix == NULL;
6163         int ret;
6164
6165         ret = rbd_dev_v2_image_size(rbd_dev);
6166         if (ret)
6167                 return ret;
6168
6169         if (first_time) {
6170                 ret = rbd_dev_v2_header_onetime(rbd_dev);
6171                 if (ret)
6172                         return ret;
6173         }
6174
6175         ret = rbd_dev_v2_snap_context(rbd_dev);
6176         if (ret && first_time) {
6177                 kfree(rbd_dev->header.object_prefix);
6178                 rbd_dev->header.object_prefix = NULL;
6179         }
6180
6181         return ret;
6182 }
6183
6184 static int rbd_dev_header_info(struct rbd_device *rbd_dev)
6185 {
6186         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
6187
6188         if (rbd_dev->image_format == 1)
6189                 return rbd_dev_v1_header_info(rbd_dev);
6190
6191         return rbd_dev_v2_header_info(rbd_dev);
6192 }
6193
6194 /*
6195  * Skips over white space at *buf, and updates *buf to point to the
6196  * first found non-space character (if any). Returns the length of
6197  * the token (string of non-white space characters) found.  Note
6198  * that *buf must be terminated with '\0'.
6199  */
6200 static inline size_t next_token(const char **buf)
6201 {
6202         /*
6203         * These are the characters that produce nonzero for
6204         * isspace() in the "C" and "POSIX" locales.
6205         */
6206         const char *spaces = " \f\n\r\t\v";
6207
6208         *buf += strspn(*buf, spaces);   /* Find start of token */
6209
6210         return strcspn(*buf, spaces);   /* Return token length */
6211 }
6212
6213 /*
6214  * Finds the next token in *buf, dynamically allocates a buffer big
6215  * enough to hold a copy of it, and copies the token into the new
6216  * buffer.  The copy is guaranteed to be terminated with '\0'.  Note
6217  * that a duplicate buffer is created even for a zero-length token.
6218  *
6219  * Returns a pointer to the newly-allocated duplicate, or a null
6220  * pointer if memory for the duplicate was not available.  If
6221  * the lenp argument is a non-null pointer, the length of the token
6222  * (not including the '\0') is returned in *lenp.
6223  *
6224  * If successful, the *buf pointer will be updated to point beyond
6225  * the end of the found token.
6226  *
6227  * Note: uses GFP_KERNEL for allocation.
6228  */
6229 static inline char *dup_token(const char **buf, size_t *lenp)
6230 {
6231         char *dup;
6232         size_t len;
6233
6234         len = next_token(buf);
6235         dup = kmemdup(*buf, len + 1, GFP_KERNEL);
6236         if (!dup)
6237                 return NULL;
6238         *(dup + len) = '\0';
6239         *buf += len;
6240
6241         if (lenp)
6242                 *lenp = len;
6243
6244         return dup;
6245 }
6246
6247 static int rbd_parse_param(struct fs_parameter *param,
6248                             struct rbd_parse_opts_ctx *pctx)
6249 {
6250         struct rbd_options *opt = pctx->opts;
6251         struct fs_parse_result result;
6252         struct p_log log = {.prefix = "rbd"};
6253         int token, ret;
6254
6255         ret = ceph_parse_param(param, pctx->copts, NULL);
6256         if (ret != -ENOPARAM)
6257                 return ret;
6258
6259         token = __fs_parse(&log, rbd_parameters, param, &result);
6260         dout("%s fs_parse '%s' token %d\n", __func__, param->key, token);
6261         if (token < 0) {
6262                 if (token == -ENOPARAM)
6263                         return inval_plog(&log, "Unknown parameter '%s'",
6264                                           param->key);
6265                 return token;
6266         }
6267
6268         switch (token) {
6269         case Opt_queue_depth:
6270                 if (result.uint_32 < 1)
6271                         goto out_of_range;
6272                 opt->queue_depth = result.uint_32;
6273                 break;
6274         case Opt_alloc_size:
6275                 if (result.uint_32 < SECTOR_SIZE)
6276                         goto out_of_range;
6277                 if (!is_power_of_2(result.uint_32))
6278                         return inval_plog(&log, "alloc_size must be a power of 2");
6279                 opt->alloc_size = result.uint_32;
6280                 break;
6281         case Opt_lock_timeout:
6282                 /* 0 is "wait forever" (i.e. infinite timeout) */
6283                 if (result.uint_32 > INT_MAX / 1000)
6284                         goto out_of_range;
6285                 opt->lock_timeout = msecs_to_jiffies(result.uint_32 * 1000);
6286                 break;
6287         case Opt_pool_ns:
6288                 kfree(pctx->spec->pool_ns);
6289                 pctx->spec->pool_ns = param->string;
6290                 param->string = NULL;
6291                 break;
6292         case Opt_compression_hint:
6293                 switch (result.uint_32) {
6294                 case Opt_compression_hint_none:
6295                         opt->alloc_hint_flags &=
6296                             ~(CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE |
6297                               CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE);
6298                         break;
6299                 case Opt_compression_hint_compressible:
6300                         opt->alloc_hint_flags |=
6301                             CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE;
6302                         opt->alloc_hint_flags &=
6303                             ~CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE;
6304                         break;
6305                 case Opt_compression_hint_incompressible:
6306                         opt->alloc_hint_flags |=
6307                             CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE;
6308                         opt->alloc_hint_flags &=
6309                             ~CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE;
6310                         break;
6311                 default:
6312                         BUG();
6313                 }
6314                 break;
6315         case Opt_read_only:
6316                 opt->read_only = true;
6317                 break;
6318         case Opt_read_write:
6319                 opt->read_only = false;
6320                 break;
6321         case Opt_lock_on_read:
6322                 opt->lock_on_read = true;
6323                 break;
6324         case Opt_exclusive:
6325                 opt->exclusive = true;
6326                 break;
6327         case Opt_notrim:
6328                 opt->trim = false;
6329                 break;
6330         default:
6331                 BUG();
6332         }
6333
6334         return 0;
6335
6336 out_of_range:
6337         return inval_plog(&log, "%s out of range", param->key);
6338 }
6339
6340 /*
6341  * This duplicates most of generic_parse_monolithic(), untying it from
6342  * fs_context and skipping standard superblock and security options.
6343  */
6344 static int rbd_parse_options(char *options, struct rbd_parse_opts_ctx *pctx)
6345 {
6346         char *key;
6347         int ret = 0;
6348
6349         dout("%s '%s'\n", __func__, options);
6350         while ((key = strsep(&options, ",")) != NULL) {
6351                 if (*key) {
6352                         struct fs_parameter param = {
6353                                 .key    = key,
6354                                 .type   = fs_value_is_flag,
6355                         };
6356                         char *value = strchr(key, '=');
6357                         size_t v_len = 0;
6358
6359                         if (value) {
6360                                 if (value == key)
6361                                         continue;
6362                                 *value++ = 0;
6363                                 v_len = strlen(value);
6364                                 param.string = kmemdup_nul(value, v_len,
6365                                                            GFP_KERNEL);
6366                                 if (!param.string)
6367                                         return -ENOMEM;
6368                                 param.type = fs_value_is_string;
6369                         }
6370                         param.size = v_len;
6371
6372                         ret = rbd_parse_param(&param, pctx);
6373                         kfree(param.string);
6374                         if (ret)
6375                                 break;
6376                 }
6377         }
6378
6379         return ret;
6380 }
6381
6382 /*
6383  * Parse the options provided for an "rbd add" (i.e., rbd image
6384  * mapping) request.  These arrive via a write to /sys/bus/rbd/add,
6385  * and the data written is passed here via a NUL-terminated buffer.
6386  * Returns 0 if successful or an error code otherwise.
6387  *
6388  * The information extracted from these options is recorded in
6389  * the other parameters which return dynamically-allocated
6390  * structures:
6391  *  ceph_opts
6392  *      The address of a pointer that will refer to a ceph options
6393  *      structure.  Caller must release the returned pointer using
6394  *      ceph_destroy_options() when it is no longer needed.
6395  *  rbd_opts
6396  *      Address of an rbd options pointer.  Fully initialized by
6397  *      this function; caller must release with kfree().
6398  *  spec
6399  *      Address of an rbd image specification pointer.  Fully
6400  *      initialized by this function based on parsed options.
6401  *      Caller must release with rbd_spec_put().
6402  *
6403  * The options passed take this form:
6404  *  <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
6405  * where:
6406  *  <mon_addrs>
6407  *      A comma-separated list of one or more monitor addresses.
6408  *      A monitor address is an ip address, optionally followed
6409  *      by a port number (separated by a colon).
6410  *        I.e.:  ip1[:port1][,ip2[:port2]...]
6411  *  <options>
6412  *      A comma-separated list of ceph and/or rbd options.
6413  *  <pool_name>
6414  *      The name of the rados pool containing the rbd image.
6415  *  <image_name>
6416  *      The name of the image in that pool to map.
6417  *  <snap_id>
6418  *      An optional snapshot id.  If provided, the mapping will
6419  *      present data from the image at the time that snapshot was
6420  *      created.  The image head is used if no snapshot id is
6421  *      provided.  Snapshot mappings are always read-only.
6422  */
6423 static int rbd_add_parse_args(const char *buf,
6424                                 struct ceph_options **ceph_opts,
6425                                 struct rbd_options **opts,
6426                                 struct rbd_spec **rbd_spec)
6427 {
6428         size_t len;
6429         char *options;
6430         const char *mon_addrs;
6431         char *snap_name;
6432         size_t mon_addrs_size;
6433         struct rbd_parse_opts_ctx pctx = { 0 };
6434         int ret;
6435
6436         /* The first four tokens are required */
6437
6438         len = next_token(&buf);
6439         if (!len) {
6440                 rbd_warn(NULL, "no monitor address(es) provided");
6441                 return -EINVAL;
6442         }
6443         mon_addrs = buf;
6444         mon_addrs_size = len;
6445         buf += len;
6446
6447         ret = -EINVAL;
6448         options = dup_token(&buf, NULL);
6449         if (!options)
6450                 return -ENOMEM;
6451         if (!*options) {
6452                 rbd_warn(NULL, "no options provided");
6453                 goto out_err;
6454         }
6455
6456         pctx.spec = rbd_spec_alloc();
6457         if (!pctx.spec)
6458                 goto out_mem;
6459
6460         pctx.spec->pool_name = dup_token(&buf, NULL);
6461         if (!pctx.spec->pool_name)
6462                 goto out_mem;
6463         if (!*pctx.spec->pool_name) {
6464                 rbd_warn(NULL, "no pool name provided");
6465                 goto out_err;
6466         }
6467
6468         pctx.spec->image_name = dup_token(&buf, NULL);
6469         if (!pctx.spec->image_name)
6470                 goto out_mem;
6471         if (!*pctx.spec->image_name) {
6472                 rbd_warn(NULL, "no image name provided");
6473                 goto out_err;
6474         }
6475
6476         /*
6477          * Snapshot name is optional; default is to use "-"
6478          * (indicating the head/no snapshot).
6479          */
6480         len = next_token(&buf);
6481         if (!len) {
6482                 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
6483                 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
6484         } else if (len > RBD_MAX_SNAP_NAME_LEN) {
6485                 ret = -ENAMETOOLONG;
6486                 goto out_err;
6487         }
6488         snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
6489         if (!snap_name)
6490                 goto out_mem;
6491         *(snap_name + len) = '\0';
6492         pctx.spec->snap_name = snap_name;
6493
6494         pctx.copts = ceph_alloc_options();
6495         if (!pctx.copts)
6496                 goto out_mem;
6497
6498         /* Initialize all rbd options to the defaults */
6499
6500         pctx.opts = kzalloc(sizeof(*pctx.opts), GFP_KERNEL);
6501         if (!pctx.opts)
6502                 goto out_mem;
6503
6504         pctx.opts->read_only = RBD_READ_ONLY_DEFAULT;
6505         pctx.opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
6506         pctx.opts->alloc_size = RBD_ALLOC_SIZE_DEFAULT;
6507         pctx.opts->lock_timeout = RBD_LOCK_TIMEOUT_DEFAULT;
6508         pctx.opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
6509         pctx.opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
6510         pctx.opts->trim = RBD_TRIM_DEFAULT;
6511
6512         ret = ceph_parse_mon_ips(mon_addrs, mon_addrs_size, pctx.copts, NULL);
6513         if (ret)
6514                 goto out_err;
6515
6516         ret = rbd_parse_options(options, &pctx);
6517         if (ret)
6518                 goto out_err;
6519
6520         *ceph_opts = pctx.copts;
6521         *opts = pctx.opts;
6522         *rbd_spec = pctx.spec;
6523         kfree(options);
6524         return 0;
6525
6526 out_mem:
6527         ret = -ENOMEM;
6528 out_err:
6529         kfree(pctx.opts);
6530         ceph_destroy_options(pctx.copts);
6531         rbd_spec_put(pctx.spec);
6532         kfree(options);
6533         return ret;
6534 }
6535
6536 static void rbd_dev_image_unlock(struct rbd_device *rbd_dev)
6537 {
6538         down_write(&rbd_dev->lock_rwsem);
6539         if (__rbd_is_lock_owner(rbd_dev))
6540                 __rbd_release_lock(rbd_dev);
6541         up_write(&rbd_dev->lock_rwsem);
6542 }
6543
6544 /*
6545  * If the wait is interrupted, an error is returned even if the lock
6546  * was successfully acquired.  rbd_dev_image_unlock() will release it
6547  * if needed.
6548  */
6549 static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
6550 {
6551         long ret;
6552
6553         if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) {
6554                 if (!rbd_dev->opts->exclusive && !rbd_dev->opts->lock_on_read)
6555                         return 0;
6556
6557                 rbd_warn(rbd_dev, "exclusive-lock feature is not enabled");
6558                 return -EINVAL;
6559         }
6560
6561         if (rbd_is_ro(rbd_dev))
6562                 return 0;
6563
6564         rbd_assert(!rbd_is_lock_owner(rbd_dev));
6565         queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
6566         ret = wait_for_completion_killable_timeout(&rbd_dev->acquire_wait,
6567                             ceph_timeout_jiffies(rbd_dev->opts->lock_timeout));
6568         if (ret > 0) {
6569                 ret = rbd_dev->acquire_err;
6570         } else {
6571                 cancel_delayed_work_sync(&rbd_dev->lock_dwork);
6572                 if (!ret)
6573                         ret = -ETIMEDOUT;
6574         }
6575
6576         if (ret) {
6577                 rbd_warn(rbd_dev, "failed to acquire exclusive lock: %ld", ret);
6578                 return ret;
6579         }
6580
6581         /*
6582          * The lock may have been released by now, unless automatic lock
6583          * transitions are disabled.
6584          */
6585         rbd_assert(!rbd_dev->opts->exclusive || rbd_is_lock_owner(rbd_dev));
6586         return 0;
6587 }
6588
6589 /*
6590  * An rbd format 2 image has a unique identifier, distinct from the
6591  * name given to it by the user.  Internally, that identifier is
6592  * what's used to specify the names of objects related to the image.
6593  *
6594  * A special "rbd id" object is used to map an rbd image name to its
6595  * id.  If that object doesn't exist, then there is no v2 rbd image
6596  * with the supplied name.
6597  *
6598  * This function will record the given rbd_dev's image_id field if
6599  * it can be determined, and in that case will return 0.  If any
6600  * errors occur a negative errno will be returned and the rbd_dev's
6601  * image_id field will be unchanged (and should be NULL).
6602  */
6603 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
6604 {
6605         int ret;
6606         size_t size;
6607         CEPH_DEFINE_OID_ONSTACK(oid);
6608         void *response;
6609         char *image_id;
6610
6611         /*
6612          * When probing a parent image, the image id is already
6613          * known (and the image name likely is not).  There's no
6614          * need to fetch the image id again in this case.  We
6615          * do still need to set the image format though.
6616          */
6617         if (rbd_dev->spec->image_id) {
6618                 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
6619
6620                 return 0;
6621         }
6622
6623         /*
6624          * First, see if the format 2 image id file exists, and if
6625          * so, get the image's persistent id from it.
6626          */
6627         ret = ceph_oid_aprintf(&oid, GFP_KERNEL, "%s%s", RBD_ID_PREFIX,
6628                                rbd_dev->spec->image_name);
6629         if (ret)
6630                 return ret;
6631
6632         dout("rbd id object name is %s\n", oid.name);
6633
6634         /* Response will be an encoded string, which includes a length */
6635         size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
6636         response = kzalloc(size, GFP_NOIO);
6637         if (!response) {
6638                 ret = -ENOMEM;
6639                 goto out;
6640         }
6641
6642         /* If it doesn't exist we'll assume it's a format 1 image */
6643
6644         ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
6645                                   "get_id", NULL, 0,
6646                                   response, size);
6647         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
6648         if (ret == -ENOENT) {
6649                 image_id = kstrdup("", GFP_KERNEL);
6650                 ret = image_id ? 0 : -ENOMEM;
6651                 if (!ret)
6652                         rbd_dev->image_format = 1;
6653         } else if (ret >= 0) {
6654                 void *p = response;
6655
6656                 image_id = ceph_extract_encoded_string(&p, p + ret,
6657                                                 NULL, GFP_NOIO);
6658                 ret = PTR_ERR_OR_ZERO(image_id);
6659                 if (!ret)
6660                         rbd_dev->image_format = 2;
6661         }
6662
6663         if (!ret) {
6664                 rbd_dev->spec->image_id = image_id;
6665                 dout("image_id is %s\n", image_id);
6666         }
6667 out:
6668         kfree(response);
6669         ceph_oid_destroy(&oid);
6670         return ret;
6671 }
6672
6673 /*
6674  * Undo whatever state changes are made by v1 or v2 header info
6675  * call.
6676  */
6677 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
6678 {
6679         struct rbd_image_header *header;
6680
6681         rbd_dev_parent_put(rbd_dev);
6682         rbd_object_map_free(rbd_dev);
6683         rbd_dev_mapping_clear(rbd_dev);
6684
6685         /* Free dynamic fields from the header, then zero it out */
6686
6687         header = &rbd_dev->header;
6688         ceph_put_snap_context(header->snapc);
6689         kfree(header->snap_sizes);
6690         kfree(header->snap_names);
6691         kfree(header->object_prefix);
6692         memset(header, 0, sizeof (*header));
6693 }
6694
6695 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
6696 {
6697         int ret;
6698
6699         ret = rbd_dev_v2_object_prefix(rbd_dev);
6700         if (ret)
6701                 goto out_err;
6702
6703         /*
6704          * Get the and check features for the image.  Currently the
6705          * features are assumed to never change.
6706          */
6707         ret = rbd_dev_v2_features(rbd_dev);
6708         if (ret)
6709                 goto out_err;
6710
6711         /* If the image supports fancy striping, get its parameters */
6712
6713         if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
6714                 ret = rbd_dev_v2_striping_info(rbd_dev);
6715                 if (ret < 0)
6716                         goto out_err;
6717         }
6718
6719         if (rbd_dev->header.features & RBD_FEATURE_DATA_POOL) {
6720                 ret = rbd_dev_v2_data_pool(rbd_dev);
6721                 if (ret)
6722                         goto out_err;
6723         }
6724
6725         rbd_init_layout(rbd_dev);
6726         return 0;
6727
6728 out_err:
6729         rbd_dev->header.features = 0;
6730         kfree(rbd_dev->header.object_prefix);
6731         rbd_dev->header.object_prefix = NULL;
6732         return ret;
6733 }
6734
6735 /*
6736  * @depth is rbd_dev_image_probe() -> rbd_dev_probe_parent() ->
6737  * rbd_dev_image_probe() recursion depth, which means it's also the
6738  * length of the already discovered part of the parent chain.
6739  */
6740 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
6741 {
6742         struct rbd_device *parent = NULL;
6743         int ret;
6744
6745         if (!rbd_dev->parent_spec)
6746                 return 0;
6747
6748         if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
6749                 pr_info("parent chain is too long (%d)\n", depth);
6750                 ret = -EINVAL;
6751                 goto out_err;
6752         }
6753
6754         parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
6755         if (!parent) {
6756                 ret = -ENOMEM;
6757                 goto out_err;
6758         }
6759
6760         /*
6761          * Images related by parent/child relationships always share
6762          * rbd_client and spec/parent_spec, so bump their refcounts.
6763          */
6764         __rbd_get_client(rbd_dev->rbd_client);
6765         rbd_spec_get(rbd_dev->parent_spec);
6766
6767         __set_bit(RBD_DEV_FLAG_READONLY, &parent->flags);
6768
6769         ret = rbd_dev_image_probe(parent, depth);
6770         if (ret < 0)
6771                 goto out_err;
6772
6773         rbd_dev->parent = parent;
6774         atomic_set(&rbd_dev->parent_ref, 1);
6775         return 0;
6776
6777 out_err:
6778         rbd_dev_unparent(rbd_dev);
6779         rbd_dev_destroy(parent);
6780         return ret;
6781 }
6782
6783 static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6784 {
6785         clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6786         rbd_free_disk(rbd_dev);
6787         if (!single_major)
6788                 unregister_blkdev(rbd_dev->major, rbd_dev->name);
6789 }
6790
6791 /*
6792  * rbd_dev->header_rwsem must be locked for write and will be unlocked
6793  * upon return.
6794  */
6795 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
6796 {
6797         int ret;
6798
6799         /* Record our major and minor device numbers. */
6800
6801         if (!single_major) {
6802                 ret = register_blkdev(0, rbd_dev->name);
6803                 if (ret < 0)
6804                         goto err_out_unlock;
6805
6806                 rbd_dev->major = ret;
6807                 rbd_dev->minor = 0;
6808         } else {
6809                 rbd_dev->major = rbd_major;
6810                 rbd_dev->minor = rbd_dev_id_to_minor(rbd_dev->dev_id);
6811         }
6812
6813         /* Set up the blkdev mapping. */
6814
6815         ret = rbd_init_disk(rbd_dev);
6816         if (ret)
6817                 goto err_out_blkdev;
6818
6819         set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
6820         set_disk_ro(rbd_dev->disk, rbd_is_ro(rbd_dev));
6821
6822         ret = dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
6823         if (ret)
6824                 goto err_out_disk;
6825
6826         set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6827         up_write(&rbd_dev->header_rwsem);
6828         return 0;
6829
6830 err_out_disk:
6831         rbd_free_disk(rbd_dev);
6832 err_out_blkdev:
6833         if (!single_major)
6834                 unregister_blkdev(rbd_dev->major, rbd_dev->name);
6835 err_out_unlock:
6836         up_write(&rbd_dev->header_rwsem);
6837         return ret;
6838 }
6839
6840 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
6841 {
6842         struct rbd_spec *spec = rbd_dev->spec;
6843         int ret;
6844
6845         /* Record the header object name for this rbd image. */
6846
6847         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
6848         if (rbd_dev->image_format == 1)
6849                 ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
6850                                        spec->image_name, RBD_SUFFIX);
6851         else
6852                 ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
6853                                        RBD_HEADER_PREFIX, spec->image_id);
6854
6855         return ret;
6856 }
6857
6858 static void rbd_print_dne(struct rbd_device *rbd_dev, bool is_snap)
6859 {
6860         if (!is_snap) {
6861                 pr_info("image %s/%s%s%s does not exist\n",
6862                         rbd_dev->spec->pool_name,
6863                         rbd_dev->spec->pool_ns ?: "",
6864                         rbd_dev->spec->pool_ns ? "/" : "",
6865                         rbd_dev->spec->image_name);
6866         } else {
6867                 pr_info("snap %s/%s%s%s@%s does not exist\n",
6868                         rbd_dev->spec->pool_name,
6869                         rbd_dev->spec->pool_ns ?: "",
6870                         rbd_dev->spec->pool_ns ? "/" : "",
6871                         rbd_dev->spec->image_name,
6872                         rbd_dev->spec->snap_name);
6873         }
6874 }
6875
6876 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
6877 {
6878         if (!rbd_is_ro(rbd_dev))
6879                 rbd_unregister_watch(rbd_dev);
6880
6881         rbd_dev_unprobe(rbd_dev);
6882         rbd_dev->image_format = 0;
6883         kfree(rbd_dev->spec->image_id);
6884         rbd_dev->spec->image_id = NULL;
6885 }
6886
6887 /*
6888  * Probe for the existence of the header object for the given rbd
6889  * device.  If this image is the one being mapped (i.e., not a
6890  * parent), initiate a watch on its header object before using that
6891  * object to get detailed information about the rbd image.
6892  *
6893  * On success, returns with header_rwsem held for write if called
6894  * with @depth == 0.
6895  */
6896 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6897 {
6898         bool need_watch = !rbd_is_ro(rbd_dev);
6899         int ret;
6900
6901         /*
6902          * Get the id from the image id object.  Unless there's an
6903          * error, rbd_dev->spec->image_id will be filled in with
6904          * a dynamically-allocated string, and rbd_dev->image_format
6905          * will be set to either 1 or 2.
6906          */
6907         ret = rbd_dev_image_id(rbd_dev);
6908         if (ret)
6909                 return ret;
6910
6911         ret = rbd_dev_header_name(rbd_dev);
6912         if (ret)
6913                 goto err_out_format;
6914
6915         if (need_watch) {
6916                 ret = rbd_register_watch(rbd_dev);
6917                 if (ret) {
6918                         if (ret == -ENOENT)
6919                                 rbd_print_dne(rbd_dev, false);
6920                         goto err_out_format;
6921                 }
6922         }
6923
6924         if (!depth)
6925                 down_write(&rbd_dev->header_rwsem);
6926
6927         ret = rbd_dev_header_info(rbd_dev);
6928         if (ret) {
6929                 if (ret == -ENOENT && !need_watch)
6930                         rbd_print_dne(rbd_dev, false);
6931                 goto err_out_probe;
6932         }
6933
6934         /*
6935          * If this image is the one being mapped, we have pool name and
6936          * id, image name and id, and snap name - need to fill snap id.
6937          * Otherwise this is a parent image, identified by pool, image
6938          * and snap ids - need to fill in names for those ids.
6939          */
6940         if (!depth)
6941                 ret = rbd_spec_fill_snap_id(rbd_dev);
6942         else
6943                 ret = rbd_spec_fill_names(rbd_dev);
6944         if (ret) {
6945                 if (ret == -ENOENT)
6946                         rbd_print_dne(rbd_dev, true);
6947                 goto err_out_probe;
6948         }
6949
6950         ret = rbd_dev_mapping_set(rbd_dev);
6951         if (ret)
6952                 goto err_out_probe;
6953
6954         if (rbd_is_snap(rbd_dev) &&
6955             (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP)) {
6956                 ret = rbd_object_map_load(rbd_dev);
6957                 if (ret)
6958                         goto err_out_probe;
6959         }
6960
6961         if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
6962                 ret = rbd_dev_v2_parent_info(rbd_dev);
6963                 if (ret)
6964                         goto err_out_probe;
6965         }
6966
6967         ret = rbd_dev_probe_parent(rbd_dev, depth);
6968         if (ret)
6969                 goto err_out_probe;
6970
6971         dout("discovered format %u image, header name is %s\n",
6972                 rbd_dev->image_format, rbd_dev->header_oid.name);
6973         return 0;
6974
6975 err_out_probe:
6976         if (!depth)
6977                 up_write(&rbd_dev->header_rwsem);
6978         if (need_watch)
6979                 rbd_unregister_watch(rbd_dev);
6980         rbd_dev_unprobe(rbd_dev);
6981 err_out_format:
6982         rbd_dev->image_format = 0;
6983         kfree(rbd_dev->spec->image_id);
6984         rbd_dev->spec->image_id = NULL;
6985         return ret;
6986 }
6987
6988 static ssize_t do_rbd_add(struct bus_type *bus,
6989                           const char *buf,
6990                           size_t count)
6991 {
6992         struct rbd_device *rbd_dev = NULL;
6993         struct ceph_options *ceph_opts = NULL;
6994         struct rbd_options *rbd_opts = NULL;
6995         struct rbd_spec *spec = NULL;
6996         struct rbd_client *rbdc;
6997         int rc;
6998
6999         if (!capable(CAP_SYS_ADMIN))
7000                 return -EPERM;
7001
7002         if (!try_module_get(THIS_MODULE))
7003                 return -ENODEV;
7004
7005         /* parse add command */
7006         rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
7007         if (rc < 0)
7008                 goto out;
7009
7010         rbdc = rbd_get_client(ceph_opts);
7011         if (IS_ERR(rbdc)) {
7012                 rc = PTR_ERR(rbdc);
7013                 goto err_out_args;
7014         }
7015
7016         /* pick the pool */
7017         rc = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, spec->pool_name);
7018         if (rc < 0) {
7019                 if (rc == -ENOENT)
7020                         pr_info("pool %s does not exist\n", spec->pool_name);
7021                 goto err_out_client;
7022         }
7023         spec->pool_id = (u64)rc;
7024
7025         rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
7026         if (!rbd_dev) {
7027                 rc = -ENOMEM;
7028                 goto err_out_client;
7029         }
7030         rbdc = NULL;            /* rbd_dev now owns this */
7031         spec = NULL;            /* rbd_dev now owns this */
7032         rbd_opts = NULL;        /* rbd_dev now owns this */
7033
7034         /* if we are mapping a snapshot it will be a read-only mapping */
7035         if (rbd_dev->opts->read_only ||
7036             strcmp(rbd_dev->spec->snap_name, RBD_SNAP_HEAD_NAME))
7037                 __set_bit(RBD_DEV_FLAG_READONLY, &rbd_dev->flags);
7038
7039         rbd_dev->config_info = kstrdup(buf, GFP_KERNEL);
7040         if (!rbd_dev->config_info) {
7041                 rc = -ENOMEM;
7042                 goto err_out_rbd_dev;
7043         }
7044
7045         rc = rbd_dev_image_probe(rbd_dev, 0);
7046         if (rc < 0)
7047                 goto err_out_rbd_dev;
7048
7049         if (rbd_dev->opts->alloc_size > rbd_dev->layout.object_size) {
7050                 rbd_warn(rbd_dev, "alloc_size adjusted to %u",
7051                          rbd_dev->layout.object_size);
7052                 rbd_dev->opts->alloc_size = rbd_dev->layout.object_size;
7053         }
7054
7055         rc = rbd_dev_device_setup(rbd_dev);
7056         if (rc)
7057                 goto err_out_image_probe;
7058
7059         rc = rbd_add_acquire_lock(rbd_dev);
7060         if (rc)
7061                 goto err_out_image_lock;
7062
7063         /* Everything's ready.  Announce the disk to the world. */
7064
7065         rc = device_add(&rbd_dev->dev);
7066         if (rc)
7067                 goto err_out_image_lock;
7068
7069         device_add_disk(&rbd_dev->dev, rbd_dev->disk, NULL);
7070
7071         spin_lock(&rbd_dev_list_lock);
7072         list_add_tail(&rbd_dev->node, &rbd_dev_list);
7073         spin_unlock(&rbd_dev_list_lock);
7074
7075         pr_info("%s: capacity %llu features 0x%llx\n", rbd_dev->disk->disk_name,
7076                 (unsigned long long)get_capacity(rbd_dev->disk) << SECTOR_SHIFT,
7077                 rbd_dev->header.features);
7078         rc = count;
7079 out:
7080         module_put(THIS_MODULE);
7081         return rc;
7082
7083 err_out_image_lock:
7084         rbd_dev_image_unlock(rbd_dev);
7085         rbd_dev_device_release(rbd_dev);
7086 err_out_image_probe:
7087         rbd_dev_image_release(rbd_dev);
7088 err_out_rbd_dev:
7089         rbd_dev_destroy(rbd_dev);
7090 err_out_client:
7091         rbd_put_client(rbdc);
7092 err_out_args:
7093         rbd_spec_put(spec);
7094         kfree(rbd_opts);
7095         goto out;
7096 }
7097
7098 static ssize_t add_store(struct bus_type *bus, const char *buf, size_t count)
7099 {
7100         if (single_major)
7101                 return -EINVAL;
7102
7103         return do_rbd_add(bus, buf, count);
7104 }
7105
7106 static ssize_t add_single_major_store(struct bus_type *bus, const char *buf,
7107                                       size_t count)
7108 {
7109         return do_rbd_add(bus, buf, count);
7110 }
7111
7112 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
7113 {
7114         while (rbd_dev->parent) {
7115                 struct rbd_device *first = rbd_dev;
7116                 struct rbd_device *second = first->parent;
7117                 struct rbd_device *third;
7118
7119                 /*
7120                  * Follow to the parent with no grandparent and
7121                  * remove it.
7122                  */
7123                 while (second && (third = second->parent)) {
7124                         first = second;
7125                         second = third;
7126                 }
7127                 rbd_assert(second);
7128                 rbd_dev_image_release(second);
7129                 rbd_dev_destroy(second);
7130                 first->parent = NULL;
7131                 first->parent_overlap = 0;
7132
7133                 rbd_assert(first->parent_spec);
7134                 rbd_spec_put(first->parent_spec);
7135                 first->parent_spec = NULL;
7136         }
7137 }
7138
7139 static ssize_t do_rbd_remove(struct bus_type *bus,
7140                              const char *buf,
7141                              size_t count)
7142 {
7143         struct rbd_device *rbd_dev = NULL;
7144         struct list_head *tmp;
7145         int dev_id;
7146         char opt_buf[6];
7147         bool force = false;
7148         int ret;
7149
7150         if (!capable(CAP_SYS_ADMIN))
7151                 return -EPERM;
7152
7153         dev_id = -1;
7154         opt_buf[0] = '\0';
7155         sscanf(buf, "%d %5s", &dev_id, opt_buf);
7156         if (dev_id < 0) {
7157                 pr_err("dev_id out of range\n");
7158                 return -EINVAL;
7159         }
7160         if (opt_buf[0] != '\0') {
7161                 if (!strcmp(opt_buf, "force")) {
7162                         force = true;
7163                 } else {
7164                         pr_err("bad remove option at '%s'\n", opt_buf);
7165                         return -EINVAL;
7166                 }
7167         }
7168
7169         ret = -ENOENT;
7170         spin_lock(&rbd_dev_list_lock);
7171         list_for_each(tmp, &rbd_dev_list) {
7172                 rbd_dev = list_entry(tmp, struct rbd_device, node);
7173                 if (rbd_dev->dev_id == dev_id) {
7174                         ret = 0;
7175                         break;
7176                 }
7177         }
7178         if (!ret) {
7179                 spin_lock_irq(&rbd_dev->lock);
7180                 if (rbd_dev->open_count && !force)
7181                         ret = -EBUSY;
7182                 else if (test_and_set_bit(RBD_DEV_FLAG_REMOVING,
7183                                           &rbd_dev->flags))
7184                         ret = -EINPROGRESS;
7185                 spin_unlock_irq(&rbd_dev->lock);
7186         }
7187         spin_unlock(&rbd_dev_list_lock);
7188         if (ret)
7189                 return ret;
7190
7191         if (force) {
7192                 /*
7193                  * Prevent new IO from being queued and wait for existing
7194                  * IO to complete/fail.
7195                  */
7196                 blk_mq_freeze_queue(rbd_dev->disk->queue);
7197                 blk_set_queue_dying(rbd_dev->disk->queue);
7198         }
7199
7200         del_gendisk(rbd_dev->disk);
7201         spin_lock(&rbd_dev_list_lock);
7202         list_del_init(&rbd_dev->node);
7203         spin_unlock(&rbd_dev_list_lock);
7204         device_del(&rbd_dev->dev);
7205
7206         rbd_dev_image_unlock(rbd_dev);
7207         rbd_dev_device_release(rbd_dev);
7208         rbd_dev_image_release(rbd_dev);
7209         rbd_dev_destroy(rbd_dev);
7210         return count;
7211 }
7212
7213 static ssize_t remove_store(struct bus_type *bus, const char *buf, size_t count)
7214 {
7215         if (single_major)
7216                 return -EINVAL;
7217
7218         return do_rbd_remove(bus, buf, count);
7219 }
7220
7221 static ssize_t remove_single_major_store(struct bus_type *bus, const char *buf,
7222                                          size_t count)
7223 {
7224         return do_rbd_remove(bus, buf, count);
7225 }
7226
7227 /*
7228  * create control files in sysfs
7229  * /sys/bus/rbd/...
7230  */
7231 static int __init rbd_sysfs_init(void)
7232 {
7233         int ret;
7234
7235         ret = device_register(&rbd_root_dev);
7236         if (ret < 0)
7237                 return ret;
7238
7239         ret = bus_register(&rbd_bus_type);
7240         if (ret < 0)
7241                 device_unregister(&rbd_root_dev);
7242
7243         return ret;
7244 }
7245
7246 static void __exit rbd_sysfs_cleanup(void)
7247 {
7248         bus_unregister(&rbd_bus_type);
7249         device_unregister(&rbd_root_dev);
7250 }
7251
7252 static int __init rbd_slab_init(void)
7253 {
7254         rbd_assert(!rbd_img_request_cache);
7255         rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
7256         if (!rbd_img_request_cache)
7257                 return -ENOMEM;
7258
7259         rbd_assert(!rbd_obj_request_cache);
7260         rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
7261         if (!rbd_obj_request_cache)
7262                 goto out_err;
7263
7264         return 0;
7265
7266 out_err:
7267         kmem_cache_destroy(rbd_img_request_cache);
7268         rbd_img_request_cache = NULL;
7269         return -ENOMEM;
7270 }
7271
7272 static void rbd_slab_exit(void)
7273 {
7274         rbd_assert(rbd_obj_request_cache);
7275         kmem_cache_destroy(rbd_obj_request_cache);
7276         rbd_obj_request_cache = NULL;
7277
7278         rbd_assert(rbd_img_request_cache);
7279         kmem_cache_destroy(rbd_img_request_cache);
7280         rbd_img_request_cache = NULL;
7281 }
7282
7283 static int __init rbd_init(void)
7284 {
7285         int rc;
7286
7287         if (!libceph_compatible(NULL)) {
7288                 rbd_warn(NULL, "libceph incompatibility (quitting)");
7289                 return -EINVAL;
7290         }
7291
7292         rc = rbd_slab_init();
7293         if (rc)
7294                 return rc;
7295
7296         /*
7297          * The number of active work items is limited by the number of
7298          * rbd devices * queue depth, so leave @max_active at default.
7299          */
7300         rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
7301         if (!rbd_wq) {
7302                 rc = -ENOMEM;
7303                 goto err_out_slab;
7304         }
7305
7306         if (single_major) {
7307                 rbd_major = register_blkdev(0, RBD_DRV_NAME);
7308                 if (rbd_major < 0) {
7309                         rc = rbd_major;
7310                         goto err_out_wq;
7311                 }
7312         }
7313
7314         rc = rbd_sysfs_init();
7315         if (rc)
7316                 goto err_out_blkdev;
7317
7318         if (single_major)
7319                 pr_info("loaded (major %d)\n", rbd_major);
7320         else
7321                 pr_info("loaded\n");
7322
7323         return 0;
7324
7325 err_out_blkdev:
7326         if (single_major)
7327                 unregister_blkdev(rbd_major, RBD_DRV_NAME);
7328 err_out_wq:
7329         destroy_workqueue(rbd_wq);
7330 err_out_slab:
7331         rbd_slab_exit();
7332         return rc;
7333 }
7334
7335 static void __exit rbd_exit(void)
7336 {
7337         ida_destroy(&rbd_dev_id_ida);
7338         rbd_sysfs_cleanup();
7339         if (single_major)
7340                 unregister_blkdev(rbd_major, RBD_DRV_NAME);
7341         destroy_workqueue(rbd_wq);
7342         rbd_slab_exit();
7343 }
7344
7345 module_init(rbd_init);
7346 module_exit(rbd_exit);
7347
7348 MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
7349 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
7350 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
7351 /* following authorship retained from original osdblk.c */
7352 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
7353
7354 MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
7355 MODULE_LICENSE("GPL");