fs/btrfs/check-integrity.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) STRATO AG 2011.  All rights reserved.
   4  */
   5
   6 /*
   7  * This module can be used to catch cases when the btrfs kernel
   8  * code executes write requests to the disk that bring the file
   9  * system in an inconsistent state. In such a state, a power-loss
  10  * or kernel panic event would cause that the data on disk is
  11  * lost or at least damaged.
  12  *
  13  * Code is added that examines all block write requests during
  14  * runtime (including writes of the super block). Three rules
  15  * are verified and an error is printed on violation of the
  16  * rules:
  17  * 1. It is not allowed to write a disk block which is
  18  *    currently referenced by the super block (either directly
  19  *    or indirectly).
  20  * 2. When a super block is written, it is verified that all
  21  *    referenced (directly or indirectly) blocks fulfill the
  22  *    following requirements:
  23  *    2a. All referenced blocks have either been present when
  24  *        the file system was mounted, (i.e., they have been
  25  *        referenced by the super block) or they have been
  26  *        written since then and the write completion callback
  27  *        was called and no write error was indicated and a
  28  *        FLUSH request to the device where these blocks are
  29  *        located was received and completed.
  30  *    2b. All referenced blocks need to have a generation
  31  *        number which is equal to the parent's number.
  32  *
  33  * One issue that was found using this module was that the log
  34  * tree on disk became temporarily corrupted because disk blocks
  35  * that had been in use for the log tree had been freed and
  36  * reused too early, while being referenced by the written super
  37  * block.
  38  *
  39  * The search term in the kernel log that can be used to filter
  40  * on the existence of detected integrity issues is
  41  * "btrfs: attempt".
  42  *
  43  * The integrity check is enabled via mount options. These
  44  * mount options are only supported if the integrity check
  45  * tool is compiled by defining BTRFS_FS_CHECK_INTEGRITY.
  46  *
  47  * Example #1, apply integrity checks to all metadata:
  48  * mount /dev/sdb1 /mnt -o check_int
  49  *
  50  * Example #2, apply integrity checks to all metadata and
  51  * to data extents:
  52  * mount /dev/sdb1 /mnt -o check_int_data
  53  *
  54  * Example #3, apply integrity checks to all metadata and dump
  55  * the tree that the super block references to kernel messages
  56  * each time after a super block was written:
  57  * mount /dev/sdb1 /mnt -o check_int,check_int_print_mask=263
  58  *
  59  * If the integrity check tool is included and activated in
  60  * the mount options, plenty of kernel memory is used, and
  61  * plenty of additional CPU cycles are spent. Enabling this
  62  * functionality is not intended for normal use. In most
  63  * cases, unless you are a btrfs developer who needs to verify
  64  * the integrity of (super)-block write requests, do not
  65  * enable the config option BTRFS_FS_CHECK_INTEGRITY to
  66  * include and compile the integrity check tool.
  67  *
  68  * Expect millions of lines of information in the kernel log with an
  69  * enabled check_int_print_mask. Therefore set LOG_BUF_SHIFT in the
  70  * kernel config to at least 26 (which is 64MB). Usually the value is
  71  * limited to 21 (which is 2MB) in init/Kconfig. The file needs to be
  72  * changed like this before LOG_BUF_SHIFT can be set to a high value:
  73  * config LOG_BUF_SHIFT
  74  *       int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
  75  *       range 12 30
  76  */
  77
  78 #include <linux/sched.h>
  79 #include <linux/slab.h>
  80 #include <linux/buffer_head.h>
  81 #include <linux/mutex.h>
  82 #include <linux/genhd.h>
  83 #include <linux/blkdev.h>
  84 #include <linux/mm.h>
  85 #include <linux/string.h>
  86 #include <crypto/hash.h>
  87 #include "ctree.h"
  88 #include "disk-io.h"
  89 #include "transaction.h"
  90 #include "extent_io.h"
  91 #include "volumes.h"
  92 #include "print-tree.h"
  93 #include "locking.h"
  94 #include "check-integrity.h"
  95 #include "rcu-string.h"
  96 #include "compression.h"
  97
  98 #define BTRFSIC_BLOCK_HASHTABLE_SIZE 0x10000
  99 #define BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE 0x10000
 100 #define BTRFSIC_DEV2STATE_HASHTABLE_SIZE 0x100
 101 #define BTRFSIC_BLOCK_MAGIC_NUMBER 0x14491051
 102 #define BTRFSIC_BLOCK_LINK_MAGIC_NUMBER 0x11070807
 103 #define BTRFSIC_DEV2STATE_MAGIC_NUMBER 0x20111530
 104 #define BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER 20111300
 105 #define BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL (200 - 6)    /* in characters,
 106                                                          * excluding " [...]" */
 107 #define BTRFSIC_GENERATION_UNKNOWN ((u64)-1)
 108
 109 /*
 110  * The definition of the bitmask fields for the print_mask.
 111  * They are specified with the mount option check_integrity_print_mask.
 112  */
 113 #define BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE                     0x00000001
 114 #define BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION         0x00000002
 115 #define BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE                  0x00000004
 116 #define BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE                 0x00000008
 117 #define BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH                        0x00000010
 118 #define BTRFSIC_PRINT_MASK_END_IO_BIO_BH                        0x00000020
 119 #define BTRFSIC_PRINT_MASK_VERBOSE                              0x00000040
 120 #define BTRFSIC_PRINT_MASK_VERY_VERBOSE                         0x00000080
 121 #define BTRFSIC_PRINT_MASK_INITIAL_TREE                         0x00000100
 122 #define BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES                    0x00000200
 123 #define BTRFSIC_PRINT_MASK_INITIAL_DATABASE                     0x00000400
 124 #define BTRFSIC_PRINT_MASK_NUM_COPIES                           0x00000800
 125 #define BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS                0x00001000
 126 #define BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE                0x00002000
 127
 128 struct btrfsic_dev_state;
 129 struct btrfsic_state;
 130
 131 struct btrfsic_block {
 132         u32 magic_num;          /* only used for debug purposes */
 133         unsigned int is_metadata:1;     /* if it is meta-data, not data-data */
 134         unsigned int is_superblock:1;   /* if it is one of the superblocks */
 135         unsigned int is_iodone:1;       /* if is done by lower subsystem */
 136         unsigned int iodone_w_error:1;  /* error was indicated to endio */
 137         unsigned int never_written:1;   /* block was added because it was
 138                                          * referenced, not because it was
 139                                          * written */
 140         unsigned int mirror_num;        /* large enough to hold
 141                                          * BTRFS_SUPER_MIRROR_MAX */
 142         struct btrfsic_dev_state *dev_state;
 143         u64 dev_bytenr;         /* key, physical byte num on disk */
 144         u64 logical_bytenr;     /* logical byte num on disk */
 145         u64 generation;
 146         struct btrfs_disk_key disk_key; /* extra info to print in case of
 147                                          * issues, will not always be correct */
 148         struct list_head collision_resolving_node;      /* list node */
 149         struct list_head all_blocks_node;       /* list node */
 150
 151         /* the following two lists contain block_link items */
 152         struct list_head ref_to_list;   /* list */
 153         struct list_head ref_from_list; /* list */
 154         struct btrfsic_block *next_in_same_bio;
 155         void *orig_bio_bh_private;
 156         union {
 157                 bio_end_io_t *bio;
 158                 bh_end_io_t *bh;
 159         } orig_bio_bh_end_io;
 160         int submit_bio_bh_rw;
 161         u64 flush_gen; /* only valid if !never_written */
 162 };
 163
 164 /*
 165  * Elements of this type are allocated dynamically and required because
 166  * each block object can refer to and can be ref from multiple blocks.
 167  * The key to lookup them in the hashtable is the dev_bytenr of
 168  * the block ref to plus the one from the block referred from.
 169  * The fact that they are searchable via a hashtable and that a
 170  * ref_cnt is maintained is not required for the btrfs integrity
 171  * check algorithm itself, it is only used to make the output more
 172  * beautiful in case that an error is detected (an error is defined
 173  * as a write operation to a block while that block is still referenced).
 174  */
 175 struct btrfsic_block_link {
 176         u32 magic_num;          /* only used for debug purposes */
 177         u32 ref_cnt;
 178         struct list_head node_ref_to;   /* list node */
 179         struct list_head node_ref_from; /* list node */
 180         struct list_head collision_resolving_node;      /* list node */
 181         struct btrfsic_block *block_ref_to;
 182         struct btrfsic_block *block_ref_from;
 183         u64 parent_generation;
 184 };
 185
 186 struct btrfsic_dev_state {
 187         u32 magic_num;          /* only used for debug purposes */
 188         struct block_device *bdev;
 189         struct btrfsic_state *state;
 190         struct list_head collision_resolving_node;      /* list node */
 191         struct btrfsic_block dummy_block_for_bio_bh_flush;
 192         u64 last_flush_gen;
 193         char name[BDEVNAME_SIZE];
 194 };
 195
 196 struct btrfsic_block_hashtable {
 197         struct list_head table[BTRFSIC_BLOCK_HASHTABLE_SIZE];
 198 };
 199
 200 struct btrfsic_block_link_hashtable {
 201         struct list_head table[BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE];
 202 };
 203
 204 struct btrfsic_dev_state_hashtable {
 205         struct list_head table[BTRFSIC_DEV2STATE_HASHTABLE_SIZE];
 206 };
 207
 208 struct btrfsic_block_data_ctx {
 209         u64 start;              /* virtual bytenr */
 210         u64 dev_bytenr;         /* physical bytenr on device */
 211         u32 len;
 212         struct btrfsic_dev_state *dev;
 213         char **datav;
 214         struct page **pagev;
 215         void *mem_to_free;
 216 };
 217
 218 /* This structure is used to implement recursion without occupying
 219  * any stack space, refer to btrfsic_process_metablock() */
 220 struct btrfsic_stack_frame {
 221         u32 magic;
 222         u32 nr;
 223         int error;
 224         int i;
 225         int limit_nesting;
 226         int num_copies;
 227         int mirror_num;
 228         struct btrfsic_block *block;
 229         struct btrfsic_block_data_ctx *block_ctx;
 230         struct btrfsic_block *next_block;
 231         struct btrfsic_block_data_ctx next_block_ctx;
 232         struct btrfs_header *hdr;
 233         struct btrfsic_stack_frame *prev;
 234 };
 235
 236 /* Some state per mounted filesystem */
 237 struct btrfsic_state {
 238         u32 print_mask;
 239         int include_extent_data;
 240         int csum_size;
 241         struct list_head all_blocks_list;
 242         struct btrfsic_block_hashtable block_hashtable;
 243         struct btrfsic_block_link_hashtable block_link_hashtable;
 244         struct btrfs_fs_info *fs_info;
 245         u64 max_superblock_generation;
 246         struct btrfsic_block *latest_superblock;
 247         u32 metablock_size;
 248         u32 datablock_size;
 249 };
 250
 251 static void btrfsic_block_init(struct btrfsic_block *b);
 252 static struct btrfsic_block *btrfsic_block_alloc(void);
 253 static void btrfsic_block_free(struct btrfsic_block *b);
 254 static void btrfsic_block_link_init(struct btrfsic_block_link *n);
 255 static struct btrfsic_block_link *btrfsic_block_link_alloc(void);
 256 static void btrfsic_block_link_free(struct btrfsic_block_link *n);
 257 static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds);
 258 static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void);
 259 static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds);
 260 static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h);
 261 static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
 262                                         struct btrfsic_block_hashtable *h);
 263 static void btrfsic_block_hashtable_remove(struct btrfsic_block *b);
 264 static struct btrfsic_block *btrfsic_block_hashtable_lookup(
 265                 struct block_device *bdev,
 266                 u64 dev_bytenr,
 267                 struct btrfsic_block_hashtable *h);
 268 static void btrfsic_block_link_hashtable_init(
 269                 struct btrfsic_block_link_hashtable *h);
 270 static void btrfsic_block_link_hashtable_add(
 271                 struct btrfsic_block_link *l,
 272                 struct btrfsic_block_link_hashtable *h);
 273 static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l);
 274 static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
 275                 struct block_device *bdev_ref_to,
 276                 u64 dev_bytenr_ref_to,
 277                 struct block_device *bdev_ref_from,
 278                 u64 dev_bytenr_ref_from,
 279                 struct btrfsic_block_link_hashtable *h);
 280 static void btrfsic_dev_state_hashtable_init(
 281                 struct btrfsic_dev_state_hashtable *h);
 282 static void btrfsic_dev_state_hashtable_add(
 283                 struct btrfsic_dev_state *ds,
 284                 struct btrfsic_dev_state_hashtable *h);
 285 static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds);
 286 static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(dev_t dev,
 287                 struct btrfsic_dev_state_hashtable *h);
 288 static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void);
 289 static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf);
 290 static int btrfsic_process_superblock(struct btrfsic_state *state,
 291                                       struct btrfs_fs_devices *fs_devices);
 292 static int btrfsic_process_metablock(struct btrfsic_state *state,
 293                                      struct btrfsic_block *block,
 294                                      struct btrfsic_block_data_ctx *block_ctx,
 295                                      int limit_nesting, int force_iodone_flag);
 296 static void btrfsic_read_from_block_data(
 297         struct btrfsic_block_data_ctx *block_ctx,
 298         void *dst, u32 offset, size_t len);
 299 static int btrfsic_create_link_to_next_block(
 300                 struct btrfsic_state *state,
 301                 struct btrfsic_block *block,
 302                 struct btrfsic_block_data_ctx
 303                 *block_ctx, u64 next_bytenr,
 304                 int limit_nesting,
 305                 struct btrfsic_block_data_ctx *next_block_ctx,
 306                 struct btrfsic_block **next_blockp,
 307                 int force_iodone_flag,
 308                 int *num_copiesp, int *mirror_nump,
 309                 struct btrfs_disk_key *disk_key,
 310                 u64 parent_generation);
 311 static int btrfsic_handle_extent_data(struct btrfsic_state *state,
 312                                       struct btrfsic_block *block,
 313                                       struct btrfsic_block_data_ctx *block_ctx,
 314                                       u32 item_offset, int force_iodone_flag);
 315 static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
 316                              struct btrfsic_block_data_ctx *block_ctx_out,
 317                              int mirror_num);
 318 static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx);
 319 static int btrfsic_read_block(struct btrfsic_state *state,
 320                               struct btrfsic_block_data_ctx *block_ctx);
 321 static void btrfsic_dump_database(struct btrfsic_state *state);
 322 static int btrfsic_test_for_metadata(struct btrfsic_state *state,
 323                                      char **datav, unsigned int num_pages);
 324 static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
 325                                           u64 dev_bytenr, char **mapped_datav,
 326                                           unsigned int num_pages,
 327                                           struct bio *bio, int *bio_is_patched,
 328                                           struct buffer_head *bh,
 329                                           int submit_bio_bh_rw);
 330 static int btrfsic_process_written_superblock(
 331                 struct btrfsic_state *state,
 332                 struct btrfsic_block *const block,
 333                 struct btrfs_super_block *const super_hdr);
 334 static void btrfsic_bio_end_io(struct bio *bp);
 335 static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate);
 336 static int btrfsic_is_block_ref_by_superblock(const struct btrfsic_state *state,
 337                                               const struct btrfsic_block *block,
 338                                               int recursion_level);
 339 static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
 340                                         struct btrfsic_block *const block,
 341                                         int recursion_level);
 342 static void btrfsic_print_add_link(const struct btrfsic_state *state,
 343                                    const struct btrfsic_block_link *l);
 344 static void btrfsic_print_rem_link(const struct btrfsic_state *state,
 345                                    const struct btrfsic_block_link *l);
 346 static char btrfsic_get_block_type(const struct btrfsic_state *state,
 347                                    const struct btrfsic_block *block);
 348 static void btrfsic_dump_tree(const struct btrfsic_state *state);
 349 static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
 350                                   const struct btrfsic_block *block,
 351                                   int indent_level);
 352 static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
 353                 struct btrfsic_state *state,
 354                 struct btrfsic_block_data_ctx *next_block_ctx,
 355                 struct btrfsic_block *next_block,
 356                 struct btrfsic_block *from_block,
 357                 u64 parent_generation);
 358 static struct btrfsic_block *btrfsic_block_lookup_or_add(
 359                 struct btrfsic_state *state,
 360                 struct btrfsic_block_data_ctx *block_ctx,
 361                 const char *additional_string,
 362                 int is_metadata,
 363                 int is_iodone,
 364                 int never_written,
 365                 int mirror_num,
 366                 int *was_created);
 367 static int btrfsic_process_superblock_dev_mirror(
 368                 struct btrfsic_state *state,
 369                 struct btrfsic_dev_state *dev_state,
 370                 struct btrfs_device *device,
 371                 int superblock_mirror_num,
 372                 struct btrfsic_dev_state **selected_dev_state,
 373                 struct btrfs_super_block *selected_super);
 374 static struct btrfsic_dev_state *btrfsic_dev_state_lookup(dev_t dev);
 375 static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
 376                                            u64 bytenr,
 377                                            struct btrfsic_dev_state *dev_state,
 378                                            u64 dev_bytenr);
 379
 380 static struct mutex btrfsic_mutex;
 381 static int btrfsic_is_initialized;
 382 static struct btrfsic_dev_state_hashtable btrfsic_dev_state_hashtable;
 383
 384
 385 static void btrfsic_block_init(struct btrfsic_block *b)
 386 {
 387         b->magic_num = BTRFSIC_BLOCK_MAGIC_NUMBER;
 388         b->dev_state = NULL;
 389         b->dev_bytenr = 0;
 390         b->logical_bytenr = 0;
 391         b->generation = BTRFSIC_GENERATION_UNKNOWN;
 392         b->disk_key.objectid = 0;
 393         b->disk_key.type = 0;
 394         b->disk_key.offset = 0;
 395         b->is_metadata = 0;
 396         b->is_superblock = 0;
 397         b->is_iodone = 0;
 398         b->iodone_w_error = 0;
 399         b->never_written = 0;
 400         b->mirror_num = 0;
 401         b->next_in_same_bio = NULL;
 402         b->orig_bio_bh_private = NULL;
 403         b->orig_bio_bh_end_io.bio = NULL;
 404         INIT_LIST_HEAD(&b->collision_resolving_node);
 405         INIT_LIST_HEAD(&b->all_blocks_node);
 406         INIT_LIST_HEAD(&b->ref_to_list);
 407         INIT_LIST_HEAD(&b->ref_from_list);
 408         b->submit_bio_bh_rw = 0;
 409         b->flush_gen = 0;
 410 }
 411
 412 static struct btrfsic_block *btrfsic_block_alloc(void)
 413 {
 414         struct btrfsic_block *b;
 415
 416         b = kzalloc(sizeof(*b), GFP_NOFS);
 417         if (NULL != b)
 418                 btrfsic_block_init(b);
 419
 420         return b;
 421 }
 422
 423 static void btrfsic_block_free(struct btrfsic_block *b)
 424 {
 425         BUG_ON(!(NULL == b || BTRFSIC_BLOCK_MAGIC_NUMBER == b->magic_num));
 426         kfree(b);
 427 }
 428
 429 static void btrfsic_block_link_init(struct btrfsic_block_link *l)
 430 {
 431         l->magic_num = BTRFSIC_BLOCK_LINK_MAGIC_NUMBER;
 432         l->ref_cnt = 1;
 433         INIT_LIST_HEAD(&l->node_ref_to);
 434         INIT_LIST_HEAD(&l->node_ref_from);
 435         INIT_LIST_HEAD(&l->collision_resolving_node);
 436         l->block_ref_to = NULL;
 437         l->block_ref_from = NULL;
 438 }
 439
 440 static struct btrfsic_block_link *btrfsic_block_link_alloc(void)
 441 {
 442         struct btrfsic_block_link *l;
 443
 444         l = kzalloc(sizeof(*l), GFP_NOFS);
 445         if (NULL != l)
 446                 btrfsic_block_link_init(l);
 447
 448         return l;
 449 }
 450
 451 static void btrfsic_block_link_free(struct btrfsic_block_link *l)
 452 {
 453         BUG_ON(!(NULL == l || BTRFSIC_BLOCK_LINK_MAGIC_NUMBER == l->magic_num));
 454         kfree(l);
 455 }
 456
 457 static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds)
 458 {
 459         ds->magic_num = BTRFSIC_DEV2STATE_MAGIC_NUMBER;
 460         ds->bdev = NULL;
 461         ds->state = NULL;
 462         ds->name[0] = '\0';
 463         INIT_LIST_HEAD(&ds->collision_resolving_node);
 464         ds->last_flush_gen = 0;
 465         btrfsic_block_init(&ds->dummy_block_for_bio_bh_flush);
 466         ds->dummy_block_for_bio_bh_flush.is_iodone = 1;
 467         ds->dummy_block_for_bio_bh_flush.dev_state = ds;
 468 }
 469
 470 static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void)
 471 {
 472         struct btrfsic_dev_state *ds;
 473
 474         ds = kzalloc(sizeof(*ds), GFP_NOFS);
 475         if (NULL != ds)
 476                 btrfsic_dev_state_init(ds);
 477
 478         return ds;
 479 }
 480
 481 static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds)
 482 {
 483         BUG_ON(!(NULL == ds ||
 484                  BTRFSIC_DEV2STATE_MAGIC_NUMBER == ds->magic_num));
 485         kfree(ds);
 486 }
 487
 488 static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h)
 489 {
 490         int i;
 491
 492         for (i = 0; i < BTRFSIC_BLOCK_HASHTABLE_SIZE; i++)
 493                 INIT_LIST_HEAD(h->table + i);
 494 }
 495
 496 static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
 497                                         struct btrfsic_block_hashtable *h)
 498 {
 499         const unsigned int hashval =
 500             (((unsigned int)(b->dev_bytenr >> 16)) ^
 501              ((unsigned int)((uintptr_t)b->dev_state->bdev))) &
 502              (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
 503
 504         list_add(&b->collision_resolving_node, h->table + hashval);
 505 }
 506
 507 static void btrfsic_block_hashtable_remove(struct btrfsic_block *b)
 508 {
 509         list_del(&b->collision_resolving_node);
 510 }
 511
 512 static struct btrfsic_block *btrfsic_block_hashtable_lookup(
 513                 struct block_device *bdev,
 514                 u64 dev_bytenr,
 515                 struct btrfsic_block_hashtable *h)
 516 {
 517         const unsigned int hashval =
 518             (((unsigned int)(dev_bytenr >> 16)) ^
 519              ((unsigned int)((uintptr_t)bdev))) &
 520              (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
 521         struct btrfsic_block *b;
 522
 523         list_for_each_entry(b, h->table + hashval, collision_resolving_node) {
 524                 if (b->dev_state->bdev == bdev && b->dev_bytenr == dev_bytenr)
 525                         return b;
 526         }
 527
 528         return NULL;
 529 }
 530
 531 static void btrfsic_block_link_hashtable_init(
 532                 struct btrfsic_block_link_hashtable *h)
 533 {
 534         int i;
 535
 536         for (i = 0; i < BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE; i++)
 537                 INIT_LIST_HEAD(h->table + i);
 538 }
 539
 540 static void btrfsic_block_link_hashtable_add(
 541                 struct btrfsic_block_link *l,
 542                 struct btrfsic_block_link_hashtable *h)
 543 {
 544         const unsigned int hashval =
 545             (((unsigned int)(l->block_ref_to->dev_bytenr >> 16)) ^
 546              ((unsigned int)(l->block_ref_from->dev_bytenr >> 16)) ^
 547              ((unsigned int)((uintptr_t)l->block_ref_to->dev_state->bdev)) ^
 548              ((unsigned int)((uintptr_t)l->block_ref_from->dev_state->bdev)))
 549              & (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
 550
 551         BUG_ON(NULL == l->block_ref_to);
 552         BUG_ON(NULL == l->block_ref_from);
 553         list_add(&l->collision_resolving_node, h->table + hashval);
 554 }
 555
 556 static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l)
 557 {
 558         list_del(&l->collision_resolving_node);
 559 }
 560
 561 static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
 562                 struct block_device *bdev_ref_to,
 563                 u64 dev_bytenr_ref_to,
 564                 struct block_device *bdev_ref_from,
 565                 u64 dev_bytenr_ref_from,
 566                 struct btrfsic_block_link_hashtable *h)
 567 {
 568         const unsigned int hashval =
 569             (((unsigned int)(dev_bytenr_ref_to >> 16)) ^
 570              ((unsigned int)(dev_bytenr_ref_from >> 16)) ^
 571              ((unsigned int)((uintptr_t)bdev_ref_to)) ^
 572              ((unsigned int)((uintptr_t)bdev_ref_from))) &
 573              (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
 574         struct btrfsic_block_link *l;
 575
 576         list_for_each_entry(l, h->table + hashval, collision_resolving_node) {
 577                 BUG_ON(NULL == l->block_ref_to);
 578                 BUG_ON(NULL == l->block_ref_from);
 579                 if (l->block_ref_to->dev_state->bdev == bdev_ref_to &&
 580                     l->block_ref_to->dev_bytenr == dev_bytenr_ref_to &&
 581                     l->block_ref_from->dev_state->bdev == bdev_ref_from &&
 582                     l->block_ref_from->dev_bytenr == dev_bytenr_ref_from)
 583                         return l;
 584         }
 585
 586         return NULL;
 587 }
 588
 589 static void btrfsic_dev_state_hashtable_init(
 590                 struct btrfsic_dev_state_hashtable *h)
 591 {
 592         int i;
 593
 594         for (i = 0; i < BTRFSIC_DEV2STATE_HASHTABLE_SIZE; i++)
 595                 INIT_LIST_HEAD(h->table + i);
 596 }
 597
 598 static void btrfsic_dev_state_hashtable_add(
 599                 struct btrfsic_dev_state *ds,
 600                 struct btrfsic_dev_state_hashtable *h)
 601 {
 602         const unsigned int hashval =
 603             (((unsigned int)((uintptr_t)ds->bdev->bd_dev)) &
 604              (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1));
 605
 606         list_add(&ds->collision_resolving_node, h->table + hashval);
 607 }
 608
 609 static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds)
 610 {
 611         list_del(&ds->collision_resolving_node);
 612 }
 613
 614 static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(dev_t dev,
 615                 struct btrfsic_dev_state_hashtable *h)
 616 {
 617         const unsigned int hashval =
 618                 dev & (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1);
 619         struct btrfsic_dev_state *ds;
 620
 621         list_for_each_entry(ds, h->table + hashval, collision_resolving_node) {
 622                 if (ds->bdev->bd_dev == dev)
 623                         return ds;
 624         }
 625
 626         return NULL;
 627 }
 628
 629 static int btrfsic_process_superblock(struct btrfsic_state *state,
 630                                       struct btrfs_fs_devices *fs_devices)
 631 {
 632         struct btrfs_super_block *selected_super;
 633         struct list_head *dev_head = &fs_devices->devices;
 634         struct btrfs_device *device;
 635         struct btrfsic_dev_state *selected_dev_state = NULL;
 636         int ret = 0;
 637         int pass;
 638
 639         selected_super = kzalloc(sizeof(*selected_super), GFP_NOFS);
 640         if (NULL == selected_super) {
 641                 pr_info("btrfsic: error, kmalloc failed!\n");
 642                 return -ENOMEM;
 643         }
 644
 645         list_for_each_entry(device, dev_head, dev_list) {
 646                 int i;
 647                 struct btrfsic_dev_state *dev_state;
 648
 649                 if (!device->bdev || !device->name)
 650                         continue;
 651
 652                 dev_state = btrfsic_dev_state_lookup(device->bdev->bd_dev);
 653                 BUG_ON(NULL == dev_state);
 654                 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
 655                         ret = btrfsic_process_superblock_dev_mirror(
 656                                         state, dev_state, device, i,
 657                                         &selected_dev_state, selected_super);
 658                         if (0 != ret && 0 == i) {
 659                                 kfree(selected_super);
 660                                 return ret;
 661                         }
 662                 }
 663         }
 664
 665         if (NULL == state->latest_superblock) {
 666                 pr_info("btrfsic: no superblock found!\n");
 667                 kfree(selected_super);
 668                 return -1;
 669         }
 670
 671         state->csum_size = btrfs_super_csum_size(selected_super);
 672
 673         for (pass = 0; pass < 3; pass++) {
 674                 int num_copies;
 675                 int mirror_num;
 676                 u64 next_bytenr;
 677
 678                 switch (pass) {
 679                 case 0:
 680                         next_bytenr = btrfs_super_root(selected_super);
 681                         if (state->print_mask &
 682                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 683                                 pr_info("root@%llu\n", next_bytenr);
 684                         break;
 685                 case 1:
 686                         next_bytenr = btrfs_super_chunk_root(selected_super);
 687                         if (state->print_mask &
 688                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 689                                 pr_info("chunk@%llu\n", next_bytenr);
 690                         break;
 691                 case 2:
 692                         next_bytenr = btrfs_super_log_root(selected_super);
 693                         if (0 == next_bytenr)
 694                                 continue;
 695                         if (state->print_mask &
 696                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 697                                 pr_info("log@%llu\n", next_bytenr);
 698                         break;
 699                 }
 700
 701                 num_copies = btrfs_num_copies(state->fs_info, next_bytenr,
 702                                               state->metablock_size);
 703                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
 704                         pr_info("num_copies(log_bytenr=%llu) = %d\n",
 705                                next_bytenr, num_copies);
 706
 707                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
 708                         struct btrfsic_block *next_block;
 709                         struct btrfsic_block_data_ctx tmp_next_block_ctx;
 710                         struct btrfsic_block_link *l;
 711
 712                         ret = btrfsic_map_block(state, next_bytenr,
 713                                                 state->metablock_size,
 714                                                 &tmp_next_block_ctx,
 715                                                 mirror_num);
 716                         if (ret) {
 717                                 pr_info("btrfsic: btrfsic_map_block(root @%llu, mirror %d) failed!\n",
 718                                        next_bytenr, mirror_num);
 719                                 kfree(selected_super);
 720                                 return -1;
 721                         }
 722
 723                         next_block = btrfsic_block_hashtable_lookup(
 724                                         tmp_next_block_ctx.dev->bdev,
 725                                         tmp_next_block_ctx.dev_bytenr,
 726                                         &state->block_hashtable);
 727                         BUG_ON(NULL == next_block);
 728
 729                         l = btrfsic_block_link_hashtable_lookup(
 730                                         tmp_next_block_ctx.dev->bdev,
 731                                         tmp_next_block_ctx.dev_bytenr,
 732                                         state->latest_superblock->dev_state->
 733                                         bdev,
 734                                         state->latest_superblock->dev_bytenr,
 735                                         &state->block_link_hashtable);
 736                         BUG_ON(NULL == l);
 737
 738                         ret = btrfsic_read_block(state, &tmp_next_block_ctx);
 739                         if (ret < (int)PAGE_SIZE) {
 740                                 pr_info("btrfsic: read @logical %llu failed!\n",
 741                                        tmp_next_block_ctx.start);
 742                                 btrfsic_release_block_ctx(&tmp_next_block_ctx);
 743                                 kfree(selected_super);
 744                                 return -1;
 745                         }
 746
 747                         ret = btrfsic_process_metablock(state,
 748                                                         next_block,
 749                                                         &tmp_next_block_ctx,
 750                                                         BTRFS_MAX_LEVEL + 3, 1);
 751                         btrfsic_release_block_ctx(&tmp_next_block_ctx);
 752                 }
 753         }
 754
 755         kfree(selected_super);
 756         return ret;
 757 }
 758
 759 static int btrfsic_process_superblock_dev_mirror(
 760                 struct btrfsic_state *state,
 761                 struct btrfsic_dev_state *dev_state,
 762                 struct btrfs_device *device,
 763                 int superblock_mirror_num,
 764                 struct btrfsic_dev_state **selected_dev_state,
 765                 struct btrfs_super_block *selected_super)
 766 {
 767         struct btrfs_fs_info *fs_info = state->fs_info;
 768         struct btrfs_super_block *super_tmp;
 769         u64 dev_bytenr;
 770         struct buffer_head *bh;
 771         struct btrfsic_block *superblock_tmp;
 772         int pass;
 773         struct block_device *const superblock_bdev = device->bdev;
 774
 775         /* super block bytenr is always the unmapped device bytenr */
 776         dev_bytenr = btrfs_sb_offset(superblock_mirror_num);
 777         if (dev_bytenr + BTRFS_SUPER_INFO_SIZE > device->commit_total_bytes)
 778                 return -1;
 779         bh = __bread(superblock_bdev, dev_bytenr / BTRFS_BDEV_BLOCKSIZE,
 780                      BTRFS_SUPER_INFO_SIZE);
 781         if (NULL == bh)
 782                 return -1;
 783         super_tmp = (struct btrfs_super_block *)
 784             (bh->b_data + (dev_bytenr & (BTRFS_BDEV_BLOCKSIZE - 1)));
 785
 786         if (btrfs_super_bytenr(super_tmp) != dev_bytenr ||
 787             btrfs_super_magic(super_tmp) != BTRFS_MAGIC ||
 788             memcmp(device->uuid, super_tmp->dev_item.uuid, BTRFS_UUID_SIZE) ||
 789             btrfs_super_nodesize(super_tmp) != state->metablock_size ||
 790             btrfs_super_sectorsize(super_tmp) != state->datablock_size) {
 791                 brelse(bh);
 792                 return 0;
 793         }
 794
 795         superblock_tmp =
 796             btrfsic_block_hashtable_lookup(superblock_bdev,
 797                                            dev_bytenr,
 798                                            &state->block_hashtable);
 799         if (NULL == superblock_tmp) {
 800                 superblock_tmp = btrfsic_block_alloc();
 801                 if (NULL == superblock_tmp) {
 802                         pr_info("btrfsic: error, kmalloc failed!\n");
 803                         brelse(bh);
 804                         return -1;
 805                 }
 806                 /* for superblock, only the dev_bytenr makes sense */
 807                 superblock_tmp->dev_bytenr = dev_bytenr;
 808                 superblock_tmp->dev_state = dev_state;
 809                 superblock_tmp->logical_bytenr = dev_bytenr;
 810                 superblock_tmp->generation = btrfs_super_generation(super_tmp);
 811                 superblock_tmp->is_metadata = 1;
 812                 superblock_tmp->is_superblock = 1;
 813                 superblock_tmp->is_iodone = 1;
 814                 superblock_tmp->never_written = 0;
 815                 superblock_tmp->mirror_num = 1 + superblock_mirror_num;
 816                 if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
 817                         btrfs_info_in_rcu(fs_info,
 818                                 "new initial S-block (bdev %p, %s) @%llu (%s/%llu/%d)",
 819                                      superblock_bdev,
 820                                      rcu_str_deref(device->name), dev_bytenr,
 821                                      dev_state->name, dev_bytenr,
 822                                      superblock_mirror_num);
 823                 list_add(&superblock_tmp->all_blocks_node,
 824                          &state->all_blocks_list);
 825                 btrfsic_block_hashtable_add(superblock_tmp,
 826                                             &state->block_hashtable);
 827         }
 828
 829         /* select the one with the highest generation field */
 830         if (btrfs_super_generation(super_tmp) >
 831             state->max_superblock_generation ||
 832             0 == state->max_superblock_generation) {
 833                 memcpy(selected_super, super_tmp, sizeof(*selected_super));
 834                 *selected_dev_state = dev_state;
 835                 state->max_superblock_generation =
 836                     btrfs_super_generation(super_tmp);
 837                 state->latest_superblock = superblock_tmp;
 838         }
 839
 840         for (pass = 0; pass < 3; pass++) {
 841                 u64 next_bytenr;
 842                 int num_copies;
 843                 int mirror_num;
 844                 const char *additional_string = NULL;
 845                 struct btrfs_disk_key tmp_disk_key;
 846
 847                 tmp_disk_key.type = BTRFS_ROOT_ITEM_KEY;
 848                 tmp_disk_key.offset = 0;
 849                 switch (pass) {
 850                 case 0:
 851                         btrfs_set_disk_key_objectid(&tmp_disk_key,
 852                                                     BTRFS_ROOT_TREE_OBJECTID);
 853                         additional_string = "initial root ";
 854                         next_bytenr = btrfs_super_root(super_tmp);
 855                         break;
 856                 case 1:
 857                         btrfs_set_disk_key_objectid(&tmp_disk_key,
 858                                                     BTRFS_CHUNK_TREE_OBJECTID);
 859                         additional_string = "initial chunk ";
 860                         next_bytenr = btrfs_super_chunk_root(super_tmp);
 861                         break;
 862                 case 2:
 863                         btrfs_set_disk_key_objectid(&tmp_disk_key,
 864                                                     BTRFS_TREE_LOG_OBJECTID);
 865                         additional_string = "initial log ";
 866                         next_bytenr = btrfs_super_log_root(super_tmp);
 867                         if (0 == next_bytenr)
 868                                 continue;
 869                         break;
 870                 }
 871
 872                 num_copies = btrfs_num_copies(fs_info, next_bytenr,
 873                                               state->metablock_size);
 874                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
 875                         pr_info("num_copies(log_bytenr=%llu) = %d\n",
 876                                next_bytenr, num_copies);
 877                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
 878                         struct btrfsic_block *next_block;
 879                         struct btrfsic_block_data_ctx tmp_next_block_ctx;
 880                         struct btrfsic_block_link *l;
 881
 882                         if (btrfsic_map_block(state, next_bytenr,
 883                                               state->metablock_size,
 884                                               &tmp_next_block_ctx,
 885                                               mirror_num)) {
 886                                 pr_info("btrfsic: btrfsic_map_block(bytenr @%llu, mirror %d) failed!\n",
 887                                        next_bytenr, mirror_num);
 888                                 brelse(bh);
 889                                 return -1;
 890                         }
 891
 892                         next_block = btrfsic_block_lookup_or_add(
 893                                         state, &tmp_next_block_ctx,
 894                                         additional_string, 1, 1, 0,
 895                                         mirror_num, NULL);
 896                         if (NULL == next_block) {
 897                                 btrfsic_release_block_ctx(&tmp_next_block_ctx);
 898                                 brelse(bh);
 899                                 return -1;
 900                         }
 901
 902                         next_block->disk_key = tmp_disk_key;
 903                         next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
 904                         l = btrfsic_block_link_lookup_or_add(
 905                                         state, &tmp_next_block_ctx,
 906                                         next_block, superblock_tmp,
 907                                         BTRFSIC_GENERATION_UNKNOWN);
 908                         btrfsic_release_block_ctx(&tmp_next_block_ctx);
 909                         if (NULL == l) {
 910                                 brelse(bh);
 911                                 return -1;
 912                         }
 913                 }
 914         }
 915         if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES)
 916                 btrfsic_dump_tree_sub(state, superblock_tmp, 0);
 917
 918         brelse(bh);
 919         return 0;
 920 }
 921
 922 static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void)
 923 {
 924         struct btrfsic_stack_frame *sf;
 925
 926         sf = kzalloc(sizeof(*sf), GFP_NOFS);
 927         if (NULL == sf)
 928                 pr_info("btrfsic: alloc memory failed!\n");
 929         else
 930                 sf->magic = BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER;
 931         return sf;
 932 }
 933
 934 static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf)
 935 {
 936         BUG_ON(!(NULL == sf ||
 937                  BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER == sf->magic));
 938         kfree(sf);
 939 }
 940
 941 static noinline_for_stack int btrfsic_process_metablock(
 942                 struct btrfsic_state *state,
 943                 struct btrfsic_block *const first_block,
 944                 struct btrfsic_block_data_ctx *const first_block_ctx,
 945                 int first_limit_nesting, int force_iodone_flag)
 946 {
 947         struct btrfsic_stack_frame initial_stack_frame = { 0 };
 948         struct btrfsic_stack_frame *sf;
 949         struct btrfsic_stack_frame *next_stack;
 950         struct btrfs_header *const first_hdr =
 951                 (struct btrfs_header *)first_block_ctx->datav[0];
 952
 953         BUG_ON(!first_hdr);
 954         sf = &initial_stack_frame;
 955         sf->error = 0;
 956         sf->i = -1;
 957         sf->limit_nesting = first_limit_nesting;
 958         sf->block = first_block;
 959         sf->block_ctx = first_block_ctx;
 960         sf->next_block = NULL;
 961         sf->hdr = first_hdr;
 962         sf->prev = NULL;
 963
 964 continue_with_new_stack_frame:
 965         sf->block->generation = le64_to_cpu(sf->hdr->generation);
 966         if (0 == sf->hdr->level) {
 967                 struct btrfs_leaf *const leafhdr =
 968                     (struct btrfs_leaf *)sf->hdr;
 969
 970                 if (-1 == sf->i) {
 971                         sf->nr = btrfs_stack_header_nritems(&leafhdr->header);
 972
 973                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
 974                                 pr_info("leaf %llu items %d generation %llu owner %llu\n",
 975                                        sf->block_ctx->start, sf->nr,
 976                                        btrfs_stack_header_generation(
 977                                                &leafhdr->header),
 978                                        btrfs_stack_header_owner(
 979                                                &leafhdr->header));
 980                 }
 981
 982 continue_with_current_leaf_stack_frame:
 983                 if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
 984                         sf->i++;
 985                         sf->num_copies = 0;
 986                 }
 987
 988                 if (sf->i < sf->nr) {
 989                         struct btrfs_item disk_item;
 990                         u32 disk_item_offset =
 991                                 (uintptr_t)(leafhdr->items + sf->i) -
 992                                 (uintptr_t)leafhdr;
 993                         struct btrfs_disk_key *disk_key;
 994                         u8 type;
 995                         u32 item_offset;
 996                         u32 item_size;
 997
 998                         if (disk_item_offset + sizeof(struct btrfs_item) >
 999                             sf->block_ctx->len) {
1000 leaf_item_out_of_bounce_error:
1001                                 pr_info("btrfsic: leaf item out of bounce at logical %llu, dev %s\n",
1002                                        sf->block_ctx->start,
1003                                        sf->block_ctx->dev->name);
1004                                 goto one_stack_frame_backwards;
1005                         }
1006                         btrfsic_read_from_block_data(sf->block_ctx,
1007                                                      &disk_item,
1008                                                      disk_item_offset,
1009                                                      sizeof(struct btrfs_item));
1010                         item_offset = btrfs_stack_item_offset(&disk_item);
1011                         item_size = btrfs_stack_item_size(&disk_item);
1012                         disk_key = &disk_item.key;
1013                         type = btrfs_disk_key_type(disk_key);
1014
1015                         if (BTRFS_ROOT_ITEM_KEY == type) {
1016                                 struct btrfs_root_item root_item;
1017                                 u32 root_item_offset;
1018                                 u64 next_bytenr;
1019
1020                                 root_item_offset = item_offset +
1021                                         offsetof(struct btrfs_leaf, items);
1022                                 if (root_item_offset + item_size >
1023                                     sf->block_ctx->len)
1024                                         goto leaf_item_out_of_bounce_error;
1025                                 btrfsic_read_from_block_data(
1026                                         sf->block_ctx, &root_item,
1027                                         root_item_offset,
1028                                         item_size);
1029                                 next_bytenr = btrfs_root_bytenr(&root_item);
1030
1031                                 sf->error =
1032                                     btrfsic_create_link_to_next_block(
1033                                                 state,
1034                                                 sf->block,
1035                                                 sf->block_ctx,
1036                                                 next_bytenr,
1037                                                 sf->limit_nesting,
1038                                                 &sf->next_block_ctx,
1039                                                 &sf->next_block,
1040                                                 force_iodone_flag,
1041                                                 &sf->num_copies,
1042                                                 &sf->mirror_num,
1043                                                 disk_key,
1044                                                 btrfs_root_generation(
1045                                                 &root_item));
1046                                 if (sf->error)
1047                                         goto one_stack_frame_backwards;
1048
1049                                 if (NULL != sf->next_block) {
1050                                         struct btrfs_header *const next_hdr =
1051                                             (struct btrfs_header *)
1052                                             sf->next_block_ctx.datav[0];
1053
1054                                         next_stack =
1055                                             btrfsic_stack_frame_alloc();
1056                                         if (NULL == next_stack) {
1057                                                 sf->error = -1;
1058                                                 btrfsic_release_block_ctx(
1059                                                                 &sf->
1060                                                                 next_block_ctx);
1061                                                 goto one_stack_frame_backwards;
1062                                         }
1063
1064                                         next_stack->i = -1;
1065                                         next_stack->block = sf->next_block;
1066                                         next_stack->block_ctx =
1067                                             &sf->next_block_ctx;
1068                                         next_stack->next_block = NULL;
1069                                         next_stack->hdr = next_hdr;
1070                                         next_stack->limit_nesting =
1071                                             sf->limit_nesting - 1;
1072                                         next_stack->prev = sf;
1073                                         sf = next_stack;
1074                                         goto continue_with_new_stack_frame;
1075                                 }
1076                         } else if (BTRFS_EXTENT_DATA_KEY == type &&
1077                                    state->include_extent_data) {
1078                                 sf->error = btrfsic_handle_extent_data(
1079                                                 state,
1080                                                 sf->block,
1081                                                 sf->block_ctx,
1082                                                 item_offset,
1083                                                 force_iodone_flag);
1084                                 if (sf->error)
1085                                         goto one_stack_frame_backwards;
1086                         }
1087
1088                         goto continue_with_current_leaf_stack_frame;
1089                 }
1090         } else {
1091                 struct btrfs_node *const nodehdr = (struct btrfs_node *)sf->hdr;
1092
1093                 if (-1 == sf->i) {
1094                         sf->nr = btrfs_stack_header_nritems(&nodehdr->header);
1095
1096                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1097                                 pr_info("node %llu level %d items %d generation %llu owner %llu\n",
1098                                        sf->block_ctx->start,
1099                                        nodehdr->header.level, sf->nr,
1100                                        btrfs_stack_header_generation(
1101                                        &nodehdr->header),
1102                                        btrfs_stack_header_owner(
1103                                        &nodehdr->header));
1104                 }
1105
1106 continue_with_current_node_stack_frame:
1107                 if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1108                         sf->i++;
1109                         sf->num_copies = 0;
1110                 }
1111
1112                 if (sf->i < sf->nr) {
1113                         struct btrfs_key_ptr key_ptr;
1114                         u32 key_ptr_offset;
1115                         u64 next_bytenr;
1116
1117                         key_ptr_offset = (uintptr_t)(nodehdr->ptrs + sf->i) -
1118                                           (uintptr_t)nodehdr;
1119                         if (key_ptr_offset + sizeof(struct btrfs_key_ptr) >
1120                             sf->block_ctx->len) {
1121                                 pr_info("btrfsic: node item out of bounce at logical %llu, dev %s\n",
1122                                        sf->block_ctx->start,
1123                                        sf->block_ctx->dev->name);
1124                                 goto one_stack_frame_backwards;
1125                         }
1126                         btrfsic_read_from_block_data(
1127                                 sf->block_ctx, &key_ptr, key_ptr_offset,
1128                                 sizeof(struct btrfs_key_ptr));
1129                         next_bytenr = btrfs_stack_key_blockptr(&key_ptr);
1130
1131                         sf->error = btrfsic_create_link_to_next_block(
1132                                         state,
1133                                         sf->block,
1134                                         sf->block_ctx,
1135                                         next_bytenr,
1136                                         sf->limit_nesting,
1137                                         &sf->next_block_ctx,
1138                                         &sf->next_block,
1139                                         force_iodone_flag,
1140                                         &sf->num_copies,
1141                                         &sf->mirror_num,
1142                                         &key_ptr.key,
1143                                         btrfs_stack_key_generation(&key_ptr));
1144                         if (sf->error)
1145                                 goto one_stack_frame_backwards;
1146
1147                         if (NULL != sf->next_block) {
1148                                 struct btrfs_header *const next_hdr =
1149                                     (struct btrfs_header *)
1150                                     sf->next_block_ctx.datav[0];
1151
1152                                 next_stack = btrfsic_stack_frame_alloc();
1153                                 if (NULL == next_stack) {
1154                                         sf->error = -1;
1155                                         goto one_stack_frame_backwards;
1156                                 }
1157
1158                                 next_stack->i = -1;
1159                                 next_stack->block = sf->next_block;
1160                                 next_stack->block_ctx = &sf->next_block_ctx;
1161                                 next_stack->next_block = NULL;
1162                                 next_stack->hdr = next_hdr;
1163                                 next_stack->limit_nesting =
1164                                     sf->limit_nesting - 1;
1165                                 next_stack->prev = sf;
1166                                 sf = next_stack;
1167                                 goto continue_with_new_stack_frame;
1168                         }
1169
1170                         goto continue_with_current_node_stack_frame;
1171                 }
1172         }
1173
1174 one_stack_frame_backwards:
1175         if (NULL != sf->prev) {
1176                 struct btrfsic_stack_frame *const prev = sf->prev;
1177
1178                 /* the one for the initial block is freed in the caller */
1179                 btrfsic_release_block_ctx(sf->block_ctx);
1180
1181                 if (sf->error) {
1182                         prev->error = sf->error;
1183                         btrfsic_stack_frame_free(sf);
1184                         sf = prev;
1185                         goto one_stack_frame_backwards;
1186                 }
1187
1188                 btrfsic_stack_frame_free(sf);
1189                 sf = prev;
1190                 goto continue_with_new_stack_frame;
1191         } else {
1192                 BUG_ON(&initial_stack_frame != sf);
1193         }
1194
1195         return sf->error;
1196 }
1197
1198 static void btrfsic_read_from_block_data(
1199         struct btrfsic_block_data_ctx *block_ctx,
1200         void *dstv, u32 offset, size_t len)
1201 {
1202         size_t cur;
1203         size_t pgoff;
1204         char *kaddr;
1205         char *dst = (char *)dstv;
1206         size_t start_offset = offset_in_page(block_ctx->start);
1207         unsigned long i = (start_offset + offset) >> PAGE_SHIFT;
1208
1209         WARN_ON(offset + len > block_ctx->len);
1210         pgoff = offset_in_page(start_offset + offset);
1211
1212         while (len > 0) {
1213                 cur = min(len, ((size_t)PAGE_SIZE - pgoff));
1214                 BUG_ON(i >= DIV_ROUND_UP(block_ctx->len, PAGE_SIZE));
1215                 kaddr = block_ctx->datav[i];
1216                 memcpy(dst, kaddr + pgoff, cur);
1217
1218                 dst += cur;
1219                 len -= cur;
1220                 pgoff = 0;
1221                 i++;
1222         }
1223 }
1224
1225 static int btrfsic_create_link_to_next_block(
1226                 struct btrfsic_state *state,
1227                 struct btrfsic_block *block,
1228                 struct btrfsic_block_data_ctx *block_ctx,
1229                 u64 next_bytenr,
1230                 int limit_nesting,
1231                 struct btrfsic_block_data_ctx *next_block_ctx,
1232                 struct btrfsic_block **next_blockp,
1233                 int force_iodone_flag,
1234                 int *num_copiesp, int *mirror_nump,
1235                 struct btrfs_disk_key *disk_key,
1236                 u64 parent_generation)
1237 {
1238         struct btrfs_fs_info *fs_info = state->fs_info;
1239         struct btrfsic_block *next_block = NULL;
1240         int ret;
1241         struct btrfsic_block_link *l;
1242         int did_alloc_block_link;
1243         int block_was_created;
1244
1245         *next_blockp = NULL;
1246         if (0 == *num_copiesp) {
1247                 *num_copiesp = btrfs_num_copies(fs_info, next_bytenr,
1248                                                 state->metablock_size);
1249                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1250                         pr_info("num_copies(log_bytenr=%llu) = %d\n",
1251                                next_bytenr, *num_copiesp);
1252                 *mirror_nump = 1;
1253         }
1254
1255         if (*mirror_nump > *num_copiesp)
1256                 return 0;
1257
1258         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1259                 pr_info("btrfsic_create_link_to_next_block(mirror_num=%d)\n",
1260                        *mirror_nump);
1261         ret = btrfsic_map_block(state, next_bytenr,
1262                                 state->metablock_size,
1263                                 next_block_ctx, *mirror_nump);
1264         if (ret) {
1265                 pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
1266                        next_bytenr, *mirror_nump);
1267                 btrfsic_release_block_ctx(next_block_ctx);
1268                 *next_blockp = NULL;
1269                 return -1;
1270         }
1271
1272         next_block = btrfsic_block_lookup_or_add(state,
1273                                                  next_block_ctx, "referenced ",
1274                                                  1, force_iodone_flag,
1275                                                  !force_iodone_flag,
1276                                                  *mirror_nump,
1277                                                  &block_was_created);
1278         if (NULL == next_block) {
1279                 btrfsic_release_block_ctx(next_block_ctx);
1280                 *next_blockp = NULL;
1281                 return -1;
1282         }
1283         if (block_was_created) {
1284                 l = NULL;
1285                 next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
1286         } else {
1287                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1288                         if (next_block->logical_bytenr != next_bytenr &&
1289                             !(!next_block->is_metadata &&
1290                               0 == next_block->logical_bytenr))
1291                                 pr_info("Referenced block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1292                                        next_bytenr, next_block_ctx->dev->name,
1293                                        next_block_ctx->dev_bytenr, *mirror_nump,
1294                                        btrfsic_get_block_type(state,
1295                                                               next_block),
1296                                        next_block->logical_bytenr);
1297                         else
1298                                 pr_info("Referenced block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1299                                        next_bytenr, next_block_ctx->dev->name,
1300                                        next_block_ctx->dev_bytenr, *mirror_nump,
1301                                        btrfsic_get_block_type(state,
1302                                                               next_block));
1303                 }
1304                 next_block->logical_bytenr = next_bytenr;
1305
1306                 next_block->mirror_num = *mirror_nump;
1307                 l = btrfsic_block_link_hashtable_lookup(
1308                                 next_block_ctx->dev->bdev,
1309                                 next_block_ctx->dev_bytenr,
1310                                 block_ctx->dev->bdev,
1311                                 block_ctx->dev_bytenr,
1312                                 &state->block_link_hashtable);
1313         }
1314
1315         next_block->disk_key = *disk_key;
1316         if (NULL == l) {
1317                 l = btrfsic_block_link_alloc();
1318                 if (NULL == l) {
1319                         pr_info("btrfsic: error, kmalloc failed!\n");
1320                         btrfsic_release_block_ctx(next_block_ctx);
1321                         *next_blockp = NULL;
1322                         return -1;
1323                 }
1324
1325                 did_alloc_block_link = 1;
1326                 l->block_ref_to = next_block;
1327                 l->block_ref_from = block;
1328                 l->ref_cnt = 1;
1329                 l->parent_generation = parent_generation;
1330
1331                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1332                         btrfsic_print_add_link(state, l);
1333
1334                 list_add(&l->node_ref_to, &block->ref_to_list);
1335                 list_add(&l->node_ref_from, &next_block->ref_from_list);
1336
1337                 btrfsic_block_link_hashtable_add(l,
1338                                                  &state->block_link_hashtable);
1339         } else {
1340                 did_alloc_block_link = 0;
1341                 if (0 == limit_nesting) {
1342                         l->ref_cnt++;
1343                         l->parent_generation = parent_generation;
1344                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1345                                 btrfsic_print_add_link(state, l);
1346                 }
1347         }
1348
1349         if (limit_nesting > 0 && did_alloc_block_link) {
1350                 ret = btrfsic_read_block(state, next_block_ctx);
1351                 if (ret < (int)next_block_ctx->len) {
1352                         pr_info("btrfsic: read block @logical %llu failed!\n",
1353                                next_bytenr);
1354                         btrfsic_release_block_ctx(next_block_ctx);
1355                         *next_blockp = NULL;
1356                         return -1;
1357                 }
1358
1359                 *next_blockp = next_block;
1360         } else {
1361                 *next_blockp = NULL;
1362         }
1363         (*mirror_nump)++;
1364
1365         return 0;
1366 }
1367
1368 static int btrfsic_handle_extent_data(
1369                 struct btrfsic_state *state,
1370                 struct btrfsic_block *block,
1371                 struct btrfsic_block_data_ctx *block_ctx,
1372                 u32 item_offset, int force_iodone_flag)
1373 {
1374         struct btrfs_fs_info *fs_info = state->fs_info;
1375         struct btrfs_file_extent_item file_extent_item;
1376         u64 file_extent_item_offset;
1377         u64 next_bytenr;
1378         u64 num_bytes;
1379         u64 generation;
1380         struct btrfsic_block_link *l;
1381         int ret;
1382
1383         file_extent_item_offset = offsetof(struct btrfs_leaf, items) +
1384                                   item_offset;
1385         if (file_extent_item_offset +
1386             offsetof(struct btrfs_file_extent_item, disk_num_bytes) >
1387             block_ctx->len) {
1388                 pr_info("btrfsic: file item out of bounce at logical %llu, dev %s\n",
1389                        block_ctx->start, block_ctx->dev->name);
1390                 return -1;
1391         }
1392
1393         btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1394                 file_extent_item_offset,
1395                 offsetof(struct btrfs_file_extent_item, disk_num_bytes));
1396         if (BTRFS_FILE_EXTENT_REG != file_extent_item.type ||
1397             btrfs_stack_file_extent_disk_bytenr(&file_extent_item) == 0) {
1398                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1399                         pr_info("extent_data: type %u, disk_bytenr = %llu\n",
1400                                file_extent_item.type,
1401                                btrfs_stack_file_extent_disk_bytenr(
1402                                &file_extent_item));
1403                 return 0;
1404         }
1405
1406         if (file_extent_item_offset + sizeof(struct btrfs_file_extent_item) >
1407             block_ctx->len) {
1408                 pr_info("btrfsic: file item out of bounce at logical %llu, dev %s\n",
1409                        block_ctx->start, block_ctx->dev->name);
1410                 return -1;
1411         }
1412         btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1413                                      file_extent_item_offset,
1414                                      sizeof(struct btrfs_file_extent_item));
1415         next_bytenr = btrfs_stack_file_extent_disk_bytenr(&file_extent_item);
1416         if (btrfs_stack_file_extent_compression(&file_extent_item) ==
1417             BTRFS_COMPRESS_NONE) {
1418                 next_bytenr += btrfs_stack_file_extent_offset(&file_extent_item);
1419                 num_bytes = btrfs_stack_file_extent_num_bytes(&file_extent_item);
1420         } else {
1421                 num_bytes = btrfs_stack_file_extent_disk_num_bytes(&file_extent_item);
1422         }
1423         generation = btrfs_stack_file_extent_generation(&file_extent_item);
1424
1425         if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1426                 pr_info("extent_data: type %u, disk_bytenr = %llu, offset = %llu, num_bytes = %llu\n",
1427                        file_extent_item.type,
1428                        btrfs_stack_file_extent_disk_bytenr(&file_extent_item),
1429                        btrfs_stack_file_extent_offset(&file_extent_item),
1430                        num_bytes);
1431         while (num_bytes > 0) {
1432                 u32 chunk_len;
1433                 int num_copies;
1434                 int mirror_num;
1435
1436                 if (num_bytes > state->datablock_size)
1437                         chunk_len = state->datablock_size;
1438                 else
1439                         chunk_len = num_bytes;
1440
1441                 num_copies = btrfs_num_copies(fs_info, next_bytenr,
1442                                               state->datablock_size);
1443                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1444                         pr_info("num_copies(log_bytenr=%llu) = %d\n",
1445                                next_bytenr, num_copies);
1446                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
1447                         struct btrfsic_block_data_ctx next_block_ctx;
1448                         struct btrfsic_block *next_block;
1449                         int block_was_created;
1450
1451                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1452                                 pr_info("btrfsic_handle_extent_data(mirror_num=%d)\n",
1453                                         mirror_num);
1454                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1455                                 pr_info("\tdisk_bytenr = %llu, num_bytes %u\n",
1456                                        next_bytenr, chunk_len);
1457                         ret = btrfsic_map_block(state, next_bytenr,
1458                                                 chunk_len, &next_block_ctx,
1459                                                 mirror_num);
1460                         if (ret) {
1461                                 pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
1462                                        next_bytenr, mirror_num);
1463                                 return -1;
1464                         }
1465
1466                         next_block = btrfsic_block_lookup_or_add(
1467                                         state,
1468                                         &next_block_ctx,
1469                                         "referenced ",
1470                                         0,
1471                                         force_iodone_flag,
1472                                         !force_iodone_flag,
1473                                         mirror_num,
1474                                         &block_was_created);
1475                         if (NULL == next_block) {
1476                                 pr_info("btrfsic: error, kmalloc failed!\n");
1477                                 btrfsic_release_block_ctx(&next_block_ctx);
1478                                 return -1;
1479                         }
1480                         if (!block_was_created) {
1481                                 if ((state->print_mask &
1482                                      BTRFSIC_PRINT_MASK_VERBOSE) &&
1483                                     next_block->logical_bytenr != next_bytenr &&
1484                                     !(!next_block->is_metadata &&
1485                                       0 == next_block->logical_bytenr)) {
1486                                         pr_info("Referenced block @%llu (%s/%llu/%d) found in hash table, D, bytenr mismatch (!= stored %llu).\n",
1487                                                next_bytenr,
1488                                                next_block_ctx.dev->name,
1489                                                next_block_ctx.dev_bytenr,
1490                                                mirror_num,
1491                                                next_block->logical_bytenr);
1492                                 }
1493                                 next_block->logical_bytenr = next_bytenr;
1494                                 next_block->mirror_num = mirror_num;
1495                         }
1496
1497                         l = btrfsic_block_link_lookup_or_add(state,
1498                                                              &next_block_ctx,
1499                                                              next_block, block,
1500                                                              generation);
1501                         btrfsic_release_block_ctx(&next_block_ctx);
1502                         if (NULL == l)
1503                                 return -1;
1504                 }
1505
1506                 next_bytenr += chunk_len;
1507                 num_bytes -= chunk_len;
1508         }
1509
1510         return 0;
1511 }
1512
1513 static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
1514                              struct btrfsic_block_data_ctx *block_ctx_out,
1515                              int mirror_num)
1516 {
1517         struct btrfs_fs_info *fs_info = state->fs_info;
1518         int ret;
1519         u64 length;
1520         struct btrfs_bio *multi = NULL;
1521         struct btrfs_device *device;
1522
1523         length = len;
1524         ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
1525                               bytenr, &length, &multi, mirror_num);
1526
1527         if (ret) {
1528                 block_ctx_out->start = 0;
1529                 block_ctx_out->dev_bytenr = 0;
1530                 block_ctx_out->len = 0;
1531                 block_ctx_out->dev = NULL;
1532                 block_ctx_out->datav = NULL;
1533                 block_ctx_out->pagev = NULL;
1534                 block_ctx_out->mem_to_free = NULL;
1535
1536                 return ret;
1537         }
1538
1539         device = multi->stripes[0].dev;
1540         if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state) ||
1541             !device->bdev || !device->name)
1542                 block_ctx_out->dev = NULL;
1543         else
1544                 block_ctx_out->dev = btrfsic_dev_state_lookup(
1545                                                         device->bdev->bd_dev);
1546         block_ctx_out->dev_bytenr = multi->stripes[0].physical;
1547         block_ctx_out->start = bytenr;
1548         block_ctx_out->len = len;
1549         block_ctx_out->datav = NULL;
1550         block_ctx_out->pagev = NULL;
1551         block_ctx_out->mem_to_free = NULL;
1552
1553         kfree(multi);
1554         if (NULL == block_ctx_out->dev) {
1555                 ret = -ENXIO;
1556                 pr_info("btrfsic: error, cannot lookup dev (#1)!\n");
1557         }
1558
1559         return ret;
1560 }
1561
1562 static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx)
1563 {
1564         if (block_ctx->mem_to_free) {
1565                 unsigned int num_pages;
1566
1567                 BUG_ON(!block_ctx->datav);
1568                 BUG_ON(!block_ctx->pagev);
1569                 num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
1570                             PAGE_SHIFT;
1571                 while (num_pages > 0) {
1572                         num_pages--;
1573                         if (block_ctx->datav[num_pages]) {
1574                                 kunmap(block_ctx->pagev[num_pages]);
1575                                 block_ctx->datav[num_pages] = NULL;
1576                         }
1577                         if (block_ctx->pagev[num_pages]) {
1578                                 __free_page(block_ctx->pagev[num_pages]);
1579                                 block_ctx->pagev[num_pages] = NULL;
1580                         }
1581                 }
1582
1583                 kfree(block_ctx->mem_to_free);
1584                 block_ctx->mem_to_free = NULL;
1585                 block_ctx->pagev = NULL;
1586                 block_ctx->datav = NULL;
1587         }
1588 }
1589
1590 static int btrfsic_read_block(struct btrfsic_state *state,
1591                               struct btrfsic_block_data_ctx *block_ctx)
1592 {
1593         unsigned int num_pages;
1594         unsigned int i;
1595         size_t size;
1596         u64 dev_bytenr;
1597         int ret;
1598
1599         BUG_ON(block_ctx->datav);
1600         BUG_ON(block_ctx->pagev);
1601         BUG_ON(block_ctx->mem_to_free);
1602         if (!PAGE_ALIGNED(block_ctx->dev_bytenr)) {
1603                 pr_info("btrfsic: read_block() with unaligned bytenr %llu\n",
1604                        block_ctx->dev_bytenr);
1605                 return -1;
1606         }
1607
1608         num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
1609                     PAGE_SHIFT;
1610         size = sizeof(*block_ctx->datav) + sizeof(*block_ctx->pagev);
1611         block_ctx->mem_to_free = kcalloc(num_pages, size, GFP_NOFS);
1612         if (!block_ctx->mem_to_free)
1613                 return -ENOMEM;
1614         block_ctx->datav = block_ctx->mem_to_free;
1615         block_ctx->pagev = (struct page **)(block_ctx->datav + num_pages);
1616         for (i = 0; i < num_pages; i++) {
1617                 block_ctx->pagev[i] = alloc_page(GFP_NOFS);
1618                 if (!block_ctx->pagev[i])
1619                         return -1;
1620         }
1621
1622         dev_bytenr = block_ctx->dev_bytenr;
1623         for (i = 0; i < num_pages;) {
1624                 struct bio *bio;
1625                 unsigned int j;
1626
1627                 bio = btrfs_io_bio_alloc(num_pages - i);
1628                 bio_set_dev(bio, block_ctx->dev->bdev);
1629                 bio->bi_iter.bi_sector = dev_bytenr >> 9;
1630                 bio->bi_opf = REQ_OP_READ;
1631
1632                 for (j = i; j < num_pages; j++) {
1633                         ret = bio_add_page(bio, block_ctx->pagev[j],
1634                                            PAGE_SIZE, 0);
1635                         if (PAGE_SIZE != ret)
1636                                 break;
1637                 }
1638                 if (j == i) {
1639                         pr_info("btrfsic: error, failed to add a single page!\n");
1640                         return -1;
1641                 }
1642                 if (submit_bio_wait(bio)) {
1643                         pr_info("btrfsic: read error at logical %llu dev %s!\n",
1644                                block_ctx->start, block_ctx->dev->name);
1645                         bio_put(bio);
1646                         return -1;
1647                 }
1648                 bio_put(bio);
1649                 dev_bytenr += (j - i) * PAGE_SIZE;
1650                 i = j;
1651         }
1652         for (i = 0; i < num_pages; i++)
1653                 block_ctx->datav[i] = kmap(block_ctx->pagev[i]);
1654
1655         return block_ctx->len;
1656 }
1657
1658 static void btrfsic_dump_database(struct btrfsic_state *state)
1659 {
1660         const struct btrfsic_block *b_all;
1661
1662         BUG_ON(NULL == state);
1663
1664         pr_info("all_blocks_list:\n");
1665         list_for_each_entry(b_all, &state->all_blocks_list, all_blocks_node) {
1666                 const struct btrfsic_block_link *l;
1667
1668                 pr_info("%c-block @%llu (%s/%llu/%d)\n",
1669                        btrfsic_get_block_type(state, b_all),
1670                        b_all->logical_bytenr, b_all->dev_state->name,
1671                        b_all->dev_bytenr, b_all->mirror_num);
1672
1673                 list_for_each_entry(l, &b_all->ref_to_list, node_ref_to) {
1674                         pr_info(" %c @%llu (%s/%llu/%d) refers %u* to %c @%llu (%s/%llu/%d)\n",
1675                                btrfsic_get_block_type(state, b_all),
1676                                b_all->logical_bytenr, b_all->dev_state->name,
1677                                b_all->dev_bytenr, b_all->mirror_num,
1678                                l->ref_cnt,
1679                                btrfsic_get_block_type(state, l->block_ref_to),
1680                                l->block_ref_to->logical_bytenr,
1681                                l->block_ref_to->dev_state->name,
1682                                l->block_ref_to->dev_bytenr,
1683                                l->block_ref_to->mirror_num);
1684                 }
1685
1686                 list_for_each_entry(l, &b_all->ref_from_list, node_ref_from) {
1687                         pr_info(" %c @%llu (%s/%llu/%d) is ref %u* from %c @%llu (%s/%llu/%d)\n",
1688                                btrfsic_get_block_type(state, b_all),
1689                                b_all->logical_bytenr, b_all->dev_state->name,
1690                                b_all->dev_bytenr, b_all->mirror_num,
1691                                l->ref_cnt,
1692                                btrfsic_get_block_type(state, l->block_ref_from),
1693                                l->block_ref_from->logical_bytenr,
1694                                l->block_ref_from->dev_state->name,
1695                                l->block_ref_from->dev_bytenr,
1696                                l->block_ref_from->mirror_num);
1697                 }
1698
1699                 pr_info("\n");
1700         }
1701 }
1702
1703 /*
1704  * Test whether the disk block contains a tree block (leaf or node)
1705  * (note that this test fails for the super block)
1706  */
1707 static noinline_for_stack int btrfsic_test_for_metadata(
1708                 struct btrfsic_state *state,
1709                 char **datav, unsigned int num_pages)
1710 {
1711         struct btrfs_fs_info *fs_info = state->fs_info;
1712         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1713         struct btrfs_header *h;
1714         u8 csum[BTRFS_CSUM_SIZE];
1715         unsigned int i;
1716
1717         if (num_pages * PAGE_SIZE < state->metablock_size)
1718                 return 1; /* not metadata */
1719         num_pages = state->metablock_size >> PAGE_SHIFT;
1720         h = (struct btrfs_header *)datav[0];
1721
1722         if (memcmp(h->fsid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE))
1723                 return 1;
1724
1725         shash->tfm = fs_info->csum_shash;
1726         crypto_shash_init(shash);
1727
1728         for (i = 0; i < num_pages; i++) {
1729                 u8 *data = i ? datav[i] : (datav[i] + BTRFS_CSUM_SIZE);
1730                 size_t sublen = i ? PAGE_SIZE :
1731                                     (PAGE_SIZE - BTRFS_CSUM_SIZE);
1732
1733                 crypto_shash_update(shash, data, sublen);
1734         }
1735         crypto_shash_final(shash, csum);
1736         if (memcmp(csum, h->csum, state->csum_size))
1737                 return 1;
1738
1739         return 0; /* is metadata */
1740 }
1741
1742 static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
1743                                           u64 dev_bytenr, char **mapped_datav,
1744                                           unsigned int num_pages,
1745                                           struct bio *bio, int *bio_is_patched,
1746                                           struct buffer_head *bh,
1747                                           int submit_bio_bh_rw)
1748 {
1749         int is_metadata;
1750         struct btrfsic_block *block;
1751         struct btrfsic_block_data_ctx block_ctx;
1752         int ret;
1753         struct btrfsic_state *state = dev_state->state;
1754         struct block_device *bdev = dev_state->bdev;
1755         unsigned int processed_len;
1756
1757         if (NULL != bio_is_patched)
1758                 *bio_is_patched = 0;
1759
1760 again:
1761         if (num_pages == 0)
1762                 return;
1763
1764         processed_len = 0;
1765         is_metadata = (0 == btrfsic_test_for_metadata(state, mapped_datav,
1766                                                       num_pages));
1767
1768         block = btrfsic_block_hashtable_lookup(bdev, dev_bytenr,
1769                                                &state->block_hashtable);
1770         if (NULL != block) {
1771                 u64 bytenr = 0;
1772                 struct btrfsic_block_link *l, *tmp;
1773
1774                 if (block->is_superblock) {
1775                         bytenr = btrfs_super_bytenr((struct btrfs_super_block *)
1776                                                     mapped_datav[0]);
1777                         if (num_pages * PAGE_SIZE <
1778                             BTRFS_SUPER_INFO_SIZE) {
1779                                 pr_info("btrfsic: cannot work with too short bios!\n");
1780                                 return;
1781                         }
1782                         is_metadata = 1;
1783                         BUG_ON(!PAGE_ALIGNED(BTRFS_SUPER_INFO_SIZE));
1784                         processed_len = BTRFS_SUPER_INFO_SIZE;
1785                         if (state->print_mask &
1786                             BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE) {
1787                                 pr_info("[before new superblock is written]:\n");
1788                                 btrfsic_dump_tree_sub(state, block, 0);
1789                         }
1790                 }
1791                 if (is_metadata) {
1792                         if (!block->is_superblock) {
1793                                 if (num_pages * PAGE_SIZE <
1794                                     state->metablock_size) {
1795                                         pr_info("btrfsic: cannot work with too short bios!\n");
1796                                         return;
1797                                 }
1798                                 processed_len = state->metablock_size;
1799                                 bytenr = btrfs_stack_header_bytenr(
1800                                                 (struct btrfs_header *)
1801                                                 mapped_datav[0]);
1802                                 btrfsic_cmp_log_and_dev_bytenr(state, bytenr,
1803                                                                dev_state,
1804                                                                dev_bytenr);
1805                         }
1806                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1807                                 if (block->logical_bytenr != bytenr &&
1808                                     !(!block->is_metadata &&
1809                                       block->logical_bytenr == 0))
1810                                         pr_info("Written block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1811                                                bytenr, dev_state->name,
1812                                                dev_bytenr,
1813                                                block->mirror_num,
1814                                                btrfsic_get_block_type(state,
1815                                                                       block),
1816                                                block->logical_bytenr);
1817                                 else
1818                                         pr_info("Written block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1819                                                bytenr, dev_state->name,
1820                                                dev_bytenr, block->mirror_num,
1821                                                btrfsic_get_block_type(state,
1822                                                                       block));
1823                         }
1824                         block->logical_bytenr = bytenr;
1825                 } else {
1826                         if (num_pages * PAGE_SIZE <
1827                             state->datablock_size) {
1828                                 pr_info("btrfsic: cannot work with too short bios!\n");
1829                                 return;
1830                         }
1831                         processed_len = state->datablock_size;
1832                         bytenr = block->logical_bytenr;
1833                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1834                                 pr_info("Written block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1835                                        bytenr, dev_state->name, dev_bytenr,
1836                                        block->mirror_num,
1837                                        btrfsic_get_block_type(state, block));
1838                 }
1839
1840                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1841                         pr_info("ref_to_list: %cE, ref_from_list: %cE\n",
1842                                list_empty(&block->ref_to_list) ? ' ' : '!',
1843                                list_empty(&block->ref_from_list) ? ' ' : '!');
1844                 if (btrfsic_is_block_ref_by_superblock(state, block, 0)) {
1845                         pr_info("btrfs: attempt to overwrite %c-block @%llu (%s/%llu/%d), old(gen=%llu, objectid=%llu, type=%d, offset=%llu), new(gen=%llu), which is referenced by most recent superblock (superblockgen=%llu)!\n",
1846                                btrfsic_get_block_type(state, block), bytenr,
1847                                dev_state->name, dev_bytenr, block->mirror_num,
1848                                block->generation,
1849                                btrfs_disk_key_objectid(&block->disk_key),
1850                                block->disk_key.type,
1851                                btrfs_disk_key_offset(&block->disk_key),
1852                                btrfs_stack_header_generation(
1853                                        (struct btrfs_header *) mapped_datav[0]),
1854                                state->max_superblock_generation);
1855                         btrfsic_dump_tree(state);
1856                 }
1857
1858                 if (!block->is_iodone && !block->never_written) {
1859                         pr_info("btrfs: attempt to overwrite %c-block @%llu (%s/%llu/%d), oldgen=%llu, newgen=%llu, which is not yet iodone!\n",
1860                                btrfsic_get_block_type(state, block), bytenr,
1861                                dev_state->name, dev_bytenr, block->mirror_num,
1862                                block->generation,
1863                                btrfs_stack_header_generation(
1864                                        (struct btrfs_header *)
1865                                        mapped_datav[0]));
1866                         /* it would not be safe to go on */
1867                         btrfsic_dump_tree(state);
1868                         goto continue_loop;
1869                 }
1870
1871                 /*
1872                  * Clear all references of this block. Do not free
1873                  * the block itself even if is not referenced anymore
1874                  * because it still carries valuable information
1875                  * like whether it was ever written and IO completed.
1876                  */
1877                 list_for_each_entry_safe(l, tmp, &block->ref_to_list,
1878                                          node_ref_to) {
1879                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1880                                 btrfsic_print_rem_link(state, l);
1881                         l->ref_cnt--;
1882                         if (0 == l->ref_cnt) {
1883                                 list_del(&l->node_ref_to);
1884                                 list_del(&l->node_ref_from);
1885                                 btrfsic_block_link_hashtable_remove(l);
1886                                 btrfsic_block_link_free(l);
1887                         }
1888                 }
1889
1890                 block_ctx.dev = dev_state;
1891                 block_ctx.dev_bytenr = dev_bytenr;
1892                 block_ctx.start = bytenr;
1893                 block_ctx.len = processed_len;
1894                 block_ctx.pagev = NULL;
1895                 block_ctx.mem_to_free = NULL;
1896                 block_ctx.datav = mapped_datav;
1897
1898                 if (is_metadata || state->include_extent_data) {
1899                         block->never_written = 0;
1900                         block->iodone_w_error = 0;
1901                         if (NULL != bio) {
1902                                 block->is_iodone = 0;
1903                                 BUG_ON(NULL == bio_is_patched);
1904                                 if (!*bio_is_patched) {
1905                                         block->orig_bio_bh_private =
1906                                             bio->bi_private;
1907                                         block->orig_bio_bh_end_io.bio =
1908                                             bio->bi_end_io;
1909                                         block->next_in_same_bio = NULL;
1910                                         bio->bi_private = block;
1911                                         bio->bi_end_io = btrfsic_bio_end_io;
1912                                         *bio_is_patched = 1;
1913                                 } else {
1914                                         struct btrfsic_block *chained_block =
1915                                             (struct btrfsic_block *)
1916                                             bio->bi_private;
1917
1918                                         BUG_ON(NULL == chained_block);
1919                                         block->orig_bio_bh_private =
1920                                             chained_block->orig_bio_bh_private;
1921                                         block->orig_bio_bh_end_io.bio =
1922                                             chained_block->orig_bio_bh_end_io.
1923                                             bio;
1924                                         block->next_in_same_bio = chained_block;
1925                                         bio->bi_private = block;
1926                                 }
1927                         } else if (NULL != bh) {
1928                                 block->is_iodone = 0;
1929                                 block->orig_bio_bh_private = bh->b_private;
1930                                 block->orig_bio_bh_end_io.bh = bh->b_end_io;
1931                                 block->next_in_same_bio = NULL;
1932                                 bh->b_private = block;
1933                                 bh->b_end_io = btrfsic_bh_end_io;
1934                         } else {
1935                                 block->is_iodone = 1;
1936                                 block->orig_bio_bh_private = NULL;
1937                                 block->orig_bio_bh_end_io.bio = NULL;
1938                                 block->next_in_same_bio = NULL;
1939                         }
1940                 }
1941
1942                 block->flush_gen = dev_state->last_flush_gen + 1;
1943                 block->submit_bio_bh_rw = submit_bio_bh_rw;
1944                 if (is_metadata) {
1945                         block->logical_bytenr = bytenr;
1946                         block->is_metadata = 1;
1947                         if (block->is_superblock) {
1948                                 BUG_ON(PAGE_SIZE !=
1949                                        BTRFS_SUPER_INFO_SIZE);
1950                                 ret = btrfsic_process_written_superblock(
1951                                                 state,
1952                                                 block,
1953                                                 (struct btrfs_super_block *)
1954                                                 mapped_datav[0]);
1955                                 if (state->print_mask &
1956                                     BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE) {
1957                                         pr_info("[after new superblock is written]:\n");
1958                                         btrfsic_dump_tree_sub(state, block, 0);
1959                                 }
1960                         } else {
1961                                 block->mirror_num = 0;  /* unknown */
1962                                 ret = btrfsic_process_metablock(
1963                                                 state,
1964                                                 block,
1965                                                 &block_ctx,
1966                                                 0, 0);
1967                         }
1968                         if (ret)
1969                                 pr_info("btrfsic: btrfsic_process_metablock(root @%llu) failed!\n",
1970                                        dev_bytenr);
1971                 } else {
1972                         block->is_metadata = 0;
1973                         block->mirror_num = 0;  /* unknown */
1974                         block->generation = BTRFSIC_GENERATION_UNKNOWN;
1975                         if (!state->include_extent_data
1976                             && list_empty(&block->ref_from_list)) {
1977                                 /*
1978                                  * disk block is overwritten with extent
1979                                  * data (not meta data) and we are configured
1980                                  * to not include extent data: take the
1981                                  * chance and free the block's memory
1982                                  */
1983                                 btrfsic_block_hashtable_remove(block);
1984                                 list_del(&block->all_blocks_node);
1985                                 btrfsic_block_free(block);
1986                         }
1987                 }
1988                 btrfsic_release_block_ctx(&block_ctx);
1989         } else {
1990                 /* block has not been found in hash table */
1991                 u64 bytenr;
1992
1993                 if (!is_metadata) {
1994                         processed_len = state->datablock_size;
1995                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1996                                 pr_info("Written block (%s/%llu/?) !found in hash table, D.\n",
1997                                        dev_state->name, dev_bytenr);
1998                         if (!state->include_extent_data) {
1999                                 /* ignore that written D block */
2000                                 goto continue_loop;
2001                         }
2002
2003                         /* this is getting ugly for the
2004                          * include_extent_data case... */
2005                         bytenr = 0;     /* unknown */
2006                 } else {
2007                         processed_len = state->metablock_size;
2008                         bytenr = btrfs_stack_header_bytenr(
2009                                         (struct btrfs_header *)
2010                                         mapped_datav[0]);
2011                         btrfsic_cmp_log_and_dev_bytenr(state, bytenr, dev_state,
2012                                                        dev_bytenr);
2013                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2014                                 pr_info("Written block @%llu (%s/%llu/?) !found in hash table, M.\n",
2015                                        bytenr, dev_state->name, dev_bytenr);
2016                 }
2017
2018                 block_ctx.dev = dev_state;
2019                 block_ctx.dev_bytenr = dev_bytenr;
2020                 block_ctx.start = bytenr;
2021                 block_ctx.len = processed_len;
2022                 block_ctx.pagev = NULL;
2023                 block_ctx.mem_to_free = NULL;
2024                 block_ctx.datav = mapped_datav;
2025
2026                 block = btrfsic_block_alloc();
2027                 if (NULL == block) {
2028                         pr_info("btrfsic: error, kmalloc failed!\n");
2029                         btrfsic_release_block_ctx(&block_ctx);
2030                         goto continue_loop;
2031                 }
2032                 block->dev_state = dev_state;
2033                 block->dev_bytenr = dev_bytenr;
2034                 block->logical_bytenr = bytenr;
2035                 block->is_metadata = is_metadata;
2036                 block->never_written = 0;
2037                 block->iodone_w_error = 0;
2038                 block->mirror_num = 0;  /* unknown */
2039                 block->flush_gen = dev_state->last_flush_gen + 1;
2040                 block->submit_bio_bh_rw = submit_bio_bh_rw;
2041                 if (NULL != bio) {
2042                         block->is_iodone = 0;
2043                         BUG_ON(NULL == bio_is_patched);
2044                         if (!*bio_is_patched) {
2045                                 block->orig_bio_bh_private = bio->bi_private;
2046                                 block->orig_bio_bh_end_io.bio = bio->bi_end_io;
2047                                 block->next_in_same_bio = NULL;
2048                                 bio->bi_private = block;
2049                                 bio->bi_end_io = btrfsic_bio_end_io;
2050                                 *bio_is_patched = 1;
2051                         } else {
2052                                 struct btrfsic_block *chained_block =
2053                                     (struct btrfsic_block *)
2054                                     bio->bi_private;
2055
2056                                 BUG_ON(NULL == chained_block);
2057                                 block->orig_bio_bh_private =
2058                                     chained_block->orig_bio_bh_private;
2059                                 block->orig_bio_bh_end_io.bio =
2060                                     chained_block->orig_bio_bh_end_io.bio;
2061                                 block->next_in_same_bio = chained_block;
2062                                 bio->bi_private = block;
2063                         }
2064                 } else if (NULL != bh) {
2065                         block->is_iodone = 0;
2066                         block->orig_bio_bh_private = bh->b_private;
2067                         block->orig_bio_bh_end_io.bh = bh->b_end_io;
2068                         block->next_in_same_bio = NULL;
2069                         bh->b_private = block;
2070                         bh->b_end_io = btrfsic_bh_end_io;
2071                 } else {
2072                         block->is_iodone = 1;
2073                         block->orig_bio_bh_private = NULL;
2074                         block->orig_bio_bh_end_io.bio = NULL;
2075                         block->next_in_same_bio = NULL;
2076                 }
2077                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2078                         pr_info("New written %c-block @%llu (%s/%llu/%d)\n",
2079                                is_metadata ? 'M' : 'D',
2080                                block->logical_bytenr, block->dev_state->name,
2081                                block->dev_bytenr, block->mirror_num);
2082                 list_add(&block->all_blocks_node, &state->all_blocks_list);
2083                 btrfsic_block_hashtable_add(block, &state->block_hashtable);
2084
2085                 if (is_metadata) {
2086                         ret = btrfsic_process_metablock(state, block,
2087                                                         &block_ctx, 0, 0);
2088                         if (ret)
2089                                 pr_info("btrfsic: process_metablock(root @%llu) failed!\n",
2090                                        dev_bytenr);
2091                 }
2092                 btrfsic_release_block_ctx(&block_ctx);
2093         }
2094
2095 continue_loop:
2096         BUG_ON(!processed_len);
2097         dev_bytenr += processed_len;
2098         mapped_datav += processed_len >> PAGE_SHIFT;
2099         num_pages -= processed_len >> PAGE_SHIFT;
2100         goto again;
2101 }
2102
2103 static void btrfsic_bio_end_io(struct bio *bp)
2104 {
2105         struct btrfsic_block *block = (struct btrfsic_block *)bp->bi_private;
2106         int iodone_w_error;
2107
2108         /* mutex is not held! This is not save if IO is not yet completed
2109          * on umount */
2110         iodone_w_error = 0;
2111         if (bp->bi_status)
2112                 iodone_w_error = 1;
2113
2114         BUG_ON(NULL == block);
2115         bp->bi_private = block->orig_bio_bh_private;
2116         bp->bi_end_io = block->orig_bio_bh_end_io.bio;
2117
2118         do {
2119                 struct btrfsic_block *next_block;
2120                 struct btrfsic_dev_state *const dev_state = block->dev_state;
2121
2122                 if ((dev_state->state->print_mask &
2123                      BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2124                         pr_info("bio_end_io(err=%d) for %c @%llu (%s/%llu/%d)\n",
2125                                bp->bi_status,
2126                                btrfsic_get_block_type(dev_state->state, block),
2127                                block->logical_bytenr, dev_state->name,
2128                                block->dev_bytenr, block->mirror_num);
2129                 next_block = block->next_in_same_bio;
2130                 block->iodone_w_error = iodone_w_error;
2131                 if (block->submit_bio_bh_rw & REQ_PREFLUSH) {
2132                         dev_state->last_flush_gen++;
2133                         if ((dev_state->state->print_mask &
2134                              BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2135                                 pr_info("bio_end_io() new %s flush_gen=%llu\n",
2136                                        dev_state->name,
2137                                        dev_state->last_flush_gen);
2138                 }
2139                 if (block->submit_bio_bh_rw & REQ_FUA)
2140                         block->flush_gen = 0; /* FUA completed means block is
2141                                                * on disk */
2142                 block->is_iodone = 1; /* for FLUSH, this releases the block */
2143                 block = next_block;
2144         } while (NULL != block);
2145
2146         bp->bi_end_io(bp);
2147 }
2148
2149 static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate)
2150 {
2151         struct btrfsic_block *block = (struct btrfsic_block *)bh->b_private;
2152         int iodone_w_error = !uptodate;
2153         struct btrfsic_dev_state *dev_state;
2154
2155         BUG_ON(NULL == block);
2156         dev_state = block->dev_state;
2157         if ((dev_state->state->print_mask & BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2158                 pr_info("bh_end_io(error=%d) for %c @%llu (%s/%llu/%d)\n",
2159                        iodone_w_error,
2160                        btrfsic_get_block_type(dev_state->state, block),
2161                        block->logical_bytenr, block->dev_state->name,
2162                        block->dev_bytenr, block->mirror_num);
2163
2164         block->iodone_w_error = iodone_w_error;
2165         if (block->submit_bio_bh_rw & REQ_PREFLUSH) {
2166                 dev_state->last_flush_gen++;
2167                 if ((dev_state->state->print_mask &
2168                      BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2169                         pr_info("bh_end_io() new %s flush_gen=%llu\n",
2170                                dev_state->name, dev_state->last_flush_gen);
2171         }
2172         if (block->submit_bio_bh_rw & REQ_FUA)
2173                 block->flush_gen = 0; /* FUA completed means block is on disk */
2174
2175         bh->b_private = block->orig_bio_bh_private;
2176         bh->b_end_io = block->orig_bio_bh_end_io.bh;
2177         block->is_iodone = 1; /* for FLUSH, this releases the block */
2178         bh->b_end_io(bh, uptodate);
2179 }
2180
2181 static int btrfsic_process_written_superblock(
2182                 struct btrfsic_state *state,
2183                 struct btrfsic_block *const superblock,
2184                 struct btrfs_super_block *const super_hdr)
2185 {
2186         struct btrfs_fs_info *fs_info = state->fs_info;
2187         int pass;
2188
2189         superblock->generation = btrfs_super_generation(super_hdr);
2190         if (!(superblock->generation > state->max_superblock_generation ||
2191               0 == state->max_superblock_generation)) {
2192                 if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2193                         pr_info("btrfsic: superblock @%llu (%s/%llu/%d) with old gen %llu <= %llu\n",
2194                                superblock->logical_bytenr,
2195                                superblock->dev_state->name,
2196                                superblock->dev_bytenr, superblock->mirror_num,
2197                                btrfs_super_generation(super_hdr),
2198                                state->max_superblock_generation);
2199         } else {
2200                 if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2201                         pr_info("btrfsic: got new superblock @%llu (%s/%llu/%d) with new gen %llu > %llu\n",
2202                                superblock->logical_bytenr,
2203                                superblock->dev_state->name,
2204                                superblock->dev_bytenr, superblock->mirror_num,
2205                                btrfs_super_generation(super_hdr),
2206                                state->max_superblock_generation);
2207
2208                 state->max_superblock_generation =
2209                     btrfs_super_generation(super_hdr);
2210                 state->latest_superblock = superblock;
2211         }
2212
2213         for (pass = 0; pass < 3; pass++) {
2214                 int ret;
2215                 u64 next_bytenr;
2216                 struct btrfsic_block *next_block;
2217                 struct btrfsic_block_data_ctx tmp_next_block_ctx;
2218                 struct btrfsic_block_link *l;
2219                 int num_copies;
2220                 int mirror_num;
2221                 const char *additional_string = NULL;
2222                 struct btrfs_disk_key tmp_disk_key = {0};
2223
2224                 btrfs_set_disk_key_objectid(&tmp_disk_key,
2225                                             BTRFS_ROOT_ITEM_KEY);
2226                 btrfs_set_disk_key_objectid(&tmp_disk_key, 0);
2227
2228                 switch (pass) {
2229                 case 0:
2230                         btrfs_set_disk_key_objectid(&tmp_disk_key,
2231                                                     BTRFS_ROOT_TREE_OBJECTID);
2232                         additional_string = "root ";
2233                         next_bytenr = btrfs_super_root(super_hdr);
2234                         if (state->print_mask &
2235                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2236                                 pr_info("root@%llu\n", next_bytenr);
2237                         break;
2238                 case 1:
2239                         btrfs_set_disk_key_objectid(&tmp_disk_key,
2240                                                     BTRFS_CHUNK_TREE_OBJECTID);
2241                         additional_string = "chunk ";
2242                         next_bytenr = btrfs_super_chunk_root(super_hdr);
2243                         if (state->print_mask &
2244                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2245                                 pr_info("chunk@%llu\n", next_bytenr);
2246                         break;
2247                 case 2:
2248                         btrfs_set_disk_key_objectid(&tmp_disk_key,
2249                                                     BTRFS_TREE_LOG_OBJECTID);
2250                         additional_string = "log ";
2251                         next_bytenr = btrfs_super_log_root(super_hdr);
2252                         if (0 == next_bytenr)
2253                                 continue;
2254                         if (state->print_mask &
2255                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2256                                 pr_info("log@%llu\n", next_bytenr);
2257                         break;
2258                 }
2259
2260                 num_copies = btrfs_num_copies(fs_info, next_bytenr,
2261                                               BTRFS_SUPER_INFO_SIZE);
2262                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
2263                         pr_info("num_copies(log_bytenr=%llu) = %d\n",
2264                                next_bytenr, num_copies);
2265                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2266                         int was_created;
2267
2268                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2269                                 pr_info("btrfsic_process_written_superblock(mirror_num=%d)\n", mirror_num);
2270                         ret = btrfsic_map_block(state, next_bytenr,
2271                                                 BTRFS_SUPER_INFO_SIZE,
2272                                                 &tmp_next_block_ctx,
2273                                                 mirror_num);
2274                         if (ret) {
2275                                 pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
2276                                        next_bytenr, mirror_num);
2277                                 return -1;
2278                         }
2279
2280                         next_block = btrfsic_block_lookup_or_add(
2281                                         state,
2282                                         &tmp_next_block_ctx,
2283                                         additional_string,
2284                                         1, 0, 1,
2285                                         mirror_num,
2286                                         &was_created);
2287                         if (NULL == next_block) {
2288                                 pr_info("btrfsic: error, kmalloc failed!\n");
2289                                 btrfsic_release_block_ctx(&tmp_next_block_ctx);
2290                                 return -1;
2291                         }
2292
2293                         next_block->disk_key = tmp_disk_key;
2294                         if (was_created)
2295                                 next_block->generation =
2296                                     BTRFSIC_GENERATION_UNKNOWN;
2297                         l = btrfsic_block_link_lookup_or_add(
2298                                         state,
2299                                         &tmp_next_block_ctx,
2300                                         next_block,
2301                                         superblock,
2302                                         BTRFSIC_GENERATION_UNKNOWN);
2303                         btrfsic_release_block_ctx(&tmp_next_block_ctx);
2304                         if (NULL == l)
2305                                 return -1;
2306                 }
2307         }
2308
2309         if (WARN_ON(-1 == btrfsic_check_all_ref_blocks(state, superblock, 0)))
2310                 btrfsic_dump_tree(state);
2311
2312         return 0;
2313 }
2314
2315 static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
2316                                         struct btrfsic_block *const block,
2317                                         int recursion_level)
2318 {
2319         const struct btrfsic_block_link *l;
2320         int ret = 0;
2321
2322         if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2323                 /*
2324                  * Note that this situation can happen and does not
2325                  * indicate an error in regular cases. It happens
2326                  * when disk blocks are freed and later reused.
2327                  * The check-integrity module is not aware of any
2328                  * block free operations, it just recognizes block
2329                  * write operations. Therefore it keeps the linkage
2330                  * information for a block until a block is
2331                  * rewritten. This can temporarily cause incorrect
2332                  * and even circular linkage information. This
2333                  * causes no harm unless such blocks are referenced
2334                  * by the most recent super block.
2335                  */
2336                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2337                         pr_info("btrfsic: abort cyclic linkage (case 1).\n");
2338
2339                 return ret;
2340         }
2341
2342         /*
2343          * This algorithm is recursive because the amount of used stack
2344          * space is very small and the max recursion depth is limited.
2345          */
2346         list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
2347                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2348                         pr_info("rl=%d, %c @%llu (%s/%llu/%d) %u* refers to %c @%llu (%s/%llu/%d)\n",
2349                                recursion_level,
2350                                btrfsic_get_block_type(state, block),
2351                                block->logical_bytenr, block->dev_state->name,
2352                                block->dev_bytenr, block->mirror_num,
2353                                l->ref_cnt,
2354                                btrfsic_get_block_type(state, l->block_ref_to),
2355                                l->block_ref_to->logical_bytenr,
2356                                l->block_ref_to->dev_state->name,
2357                                l->block_ref_to->dev_bytenr,
2358                                l->block_ref_to->mirror_num);
2359                 if (l->block_ref_to->never_written) {
2360                         pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which is never written!\n",
2361                                btrfsic_get_block_type(state, l->block_ref_to),
2362                                l->block_ref_to->logical_bytenr,
2363                                l->block_ref_to->dev_state->name,
2364                                l->block_ref_to->dev_bytenr,
2365                                l->block_ref_to->mirror_num);
2366                         ret = -1;
2367                 } else if (!l->block_ref_to->is_iodone) {
2368                         pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which is not yet iodone!\n",
2369                                btrfsic_get_block_type(state, l->block_ref_to),
2370                                l->block_ref_to->logical_bytenr,
2371                                l->block_ref_to->dev_state->name,
2372                                l->block_ref_to->dev_bytenr,
2373                                l->block_ref_to->mirror_num);
2374                         ret = -1;
2375                 } else if (l->block_ref_to->iodone_w_error) {
2376                         pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which has write error!\n",
2377                                btrfsic_get_block_type(state, l->block_ref_to),
2378                                l->block_ref_to->logical_bytenr,
2379                                l->block_ref_to->dev_state->name,
2380                                l->block_ref_to->dev_bytenr,
2381                                l->block_ref_to->mirror_num);
2382                         ret = -1;
2383                 } else if (l->parent_generation !=
2384                            l->block_ref_to->generation &&
2385                            BTRFSIC_GENERATION_UNKNOWN !=
2386                            l->parent_generation &&
2387                            BTRFSIC_GENERATION_UNKNOWN !=
2388                            l->block_ref_to->generation) {
2389                         pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) with generation %llu != parent generation %llu!\n",
2390                                btrfsic_get_block_type(state, l->block_ref_to),
2391                                l->block_ref_to->logical_bytenr,
2392                                l->block_ref_to->dev_state->name,
2393                                l->block_ref_to->dev_bytenr,
2394                                l->block_ref_to->mirror_num,
2395                                l->block_ref_to->generation,
2396                                l->parent_generation);
2397                         ret = -1;
2398                 } else if (l->block_ref_to->flush_gen >
2399                            l->block_ref_to->dev_state->last_flush_gen) {
2400                         pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which is not flushed out of disk's write cache (block flush_gen=%llu, dev->flush_gen=%llu)!\n",
2401                                btrfsic_get_block_type(state, l->block_ref_to),
2402                                l->block_ref_to->logical_bytenr,
2403                                l->block_ref_to->dev_state->name,
2404                                l->block_ref_to->dev_bytenr,
2405                                l->block_ref_to->mirror_num, block->flush_gen,
2406                                l->block_ref_to->dev_state->last_flush_gen);
2407                         ret = -1;
2408                 } else if (-1 == btrfsic_check_all_ref_blocks(state,
2409                                                               l->block_ref_to,
2410                                                               recursion_level +
2411                                                               1)) {
2412                         ret = -1;
2413                 }
2414         }
2415
2416         return ret;
2417 }
2418
2419 static int btrfsic_is_block_ref_by_superblock(
2420                 const struct btrfsic_state *state,
2421                 const struct btrfsic_block *block,
2422                 int recursion_level)
2423 {
2424         const struct btrfsic_block_link *l;
2425
2426         if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2427                 /* refer to comment at "abort cyclic linkage (case 1)" */
2428                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2429                         pr_info("btrfsic: abort cyclic linkage (case 2).\n");
2430
2431                 return 0;
2432         }
2433
2434         /*
2435          * This algorithm is recursive because the amount of used stack space
2436          * is very small and the max recursion depth is limited.
2437          */
2438         list_for_each_entry(l, &block->ref_from_list, node_ref_from) {
2439                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2440                         pr_info("rl=%d, %c @%llu (%s/%llu/%d) is ref %u* from %c @%llu (%s/%llu/%d)\n",
2441                                recursion_level,
2442                                btrfsic_get_block_type(state, block),
2443                                block->logical_bytenr, block->dev_state->name,
2444                                block->dev_bytenr, block->mirror_num,
2445                                l->ref_cnt,
2446                                btrfsic_get_block_type(state, l->block_ref_from),
2447                                l->block_ref_from->logical_bytenr,
2448                                l->block_ref_from->dev_state->name,
2449                                l->block_ref_from->dev_bytenr,
2450                                l->block_ref_from->mirror_num);
2451                 if (l->block_ref_from->is_superblock &&
2452                     state->latest_superblock->dev_bytenr ==
2453                     l->block_ref_from->dev_bytenr &&
2454                     state->latest_superblock->dev_state->bdev ==
2455                     l->block_ref_from->dev_state->bdev)
2456                         return 1;
2457                 else if (btrfsic_is_block_ref_by_superblock(state,
2458                                                             l->block_ref_from,
2459                                                             recursion_level +
2460                                                             1))
2461                         return 1;
2462         }
2463
2464         return 0;
2465 }
2466
2467 static void btrfsic_print_add_link(const struct btrfsic_state *state,
2468                                    const struct btrfsic_block_link *l)
2469 {
2470         pr_info("Add %u* link from %c @%llu (%s/%llu/%d) to %c @%llu (%s/%llu/%d).\n",
2471                l->ref_cnt,
2472                btrfsic_get_block_type(state, l->block_ref_from),
2473                l->block_ref_from->logical_bytenr,
2474                l->block_ref_from->dev_state->name,
2475                l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2476                btrfsic_get_block_type(state, l->block_ref_to),
2477                l->block_ref_to->logical_bytenr,
2478                l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2479                l->block_ref_to->mirror_num);
2480 }
2481
2482 static void btrfsic_print_rem_link(const struct btrfsic_state *state,
2483                                    const struct btrfsic_block_link *l)
2484 {
2485         pr_info("Rem %u* link from %c @%llu (%s/%llu/%d) to %c @%llu (%s/%llu/%d).\n",
2486                l->ref_cnt,
2487                btrfsic_get_block_type(state, l->block_ref_from),
2488                l->block_ref_from->logical_bytenr,
2489                l->block_ref_from->dev_state->name,
2490                l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2491                btrfsic_get_block_type(state, l->block_ref_to),
2492                l->block_ref_to->logical_bytenr,
2493                l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2494                l->block_ref_to->mirror_num);
2495 }
2496
2497 static char btrfsic_get_block_type(const struct btrfsic_state *state,
2498                                    const struct btrfsic_block *block)
2499 {
2500         if (block->is_superblock &&
2501             state->latest_superblock->dev_bytenr == block->dev_bytenr &&
2502             state->latest_superblock->dev_state->bdev == block->dev_state->bdev)
2503                 return 'S';
2504         else if (block->is_superblock)
2505                 return 's';
2506         else if (block->is_metadata)
2507                 return 'M';
2508         else
2509                 return 'D';
2510 }
2511
2512 static void btrfsic_dump_tree(const struct btrfsic_state *state)
2513 {
2514         btrfsic_dump_tree_sub(state, state->latest_superblock, 0);
2515 }
2516
2517 static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
2518                                   const struct btrfsic_block *block,
2519                                   int indent_level)
2520 {
2521         const struct btrfsic_block_link *l;
2522         int indent_add;
2523         static char buf[80];
2524         int cursor_position;
2525
2526         /*
2527          * Should better fill an on-stack buffer with a complete line and
2528          * dump it at once when it is time to print a newline character.
2529          */
2530
2531         /*
2532          * This algorithm is recursive because the amount of used stack space
2533          * is very small and the max recursion depth is limited.
2534          */
2535         indent_add = sprintf(buf, "%c-%llu(%s/%llu/%u)",
2536                              btrfsic_get_block_type(state, block),
2537                              block->logical_bytenr, block->dev_state->name,
2538                              block->dev_bytenr, block->mirror_num);
2539         if (indent_level + indent_add > BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2540                 printk("[...]\n");
2541                 return;
2542         }
2543         printk(buf);
2544         indent_level += indent_add;
2545         if (list_empty(&block->ref_to_list)) {
2546                 printk("\n");
2547                 return;
2548         }
2549         if (block->mirror_num > 1 &&
2550             !(state->print_mask & BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS)) {
2551                 printk(" [...]\n");
2552                 return;
2553         }
2554
2555         cursor_position = indent_level;
2556         list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
2557                 while (cursor_position < indent_level) {
2558                         printk(" ");
2559                         cursor_position++;
2560                 }
2561                 if (l->ref_cnt > 1)
2562                         indent_add = sprintf(buf, " %d*--> ", l->ref_cnt);
2563                 else
2564                         indent_add = sprintf(buf, " --> ");
2565                 if (indent_level + indent_add >
2566                     BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2567                         printk("[...]\n");
2568                         cursor_position = 0;
2569                         continue;
2570                 }
2571
2572                 printk(buf);
2573
2574                 btrfsic_dump_tree_sub(state, l->block_ref_to,
2575                                       indent_level + indent_add);
2576                 cursor_position = 0;
2577         }
2578 }
2579
2580 static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
2581                 struct btrfsic_state *state,
2582                 struct btrfsic_block_data_ctx *next_block_ctx,
2583                 struct btrfsic_block *next_block,
2584                 struct btrfsic_block *from_block,
2585                 u64 parent_generation)
2586 {
2587         struct btrfsic_block_link *l;
2588
2589         l = btrfsic_block_link_hashtable_lookup(next_block_ctx->dev->bdev,
2590                                                 next_block_ctx->dev_bytenr,
2591                                                 from_block->dev_state->bdev,
2592                                                 from_block->dev_bytenr,
2593                                                 &state->block_link_hashtable);
2594         if (NULL == l) {
2595                 l = btrfsic_block_link_alloc();
2596                 if (NULL == l) {
2597                         pr_info("btrfsic: error, kmalloc failed!\n");
2598                         return NULL;
2599                 }
2600
2601                 l->block_ref_to = next_block;
2602                 l->block_ref_from = from_block;
2603                 l->ref_cnt = 1;
2604                 l->parent_generation = parent_generation;
2605
2606                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2607                         btrfsic_print_add_link(state, l);
2608
2609                 list_add(&l->node_ref_to, &from_block->ref_to_list);
2610                 list_add(&l->node_ref_from, &next_block->ref_from_list);
2611
2612                 btrfsic_block_link_hashtable_add(l,
2613                                                  &state->block_link_hashtable);
2614         } else {
2615                 l->ref_cnt++;
2616                 l->parent_generation = parent_generation;
2617                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2618                         btrfsic_print_add_link(state, l);
2619         }
2620
2621         return l;
2622 }
2623
2624 static struct btrfsic_block *btrfsic_block_lookup_or_add(
2625                 struct btrfsic_state *state,
2626                 struct btrfsic_block_data_ctx *block_ctx,
2627                 const char *additional_string,
2628                 int is_metadata,
2629                 int is_iodone,
2630                 int never_written,
2631                 int mirror_num,
2632                 int *was_created)
2633 {
2634         struct btrfsic_block *block;
2635
2636         block = btrfsic_block_hashtable_lookup(block_ctx->dev->bdev,
2637                                                block_ctx->dev_bytenr,
2638                                                &state->block_hashtable);
2639         if (NULL == block) {
2640                 struct btrfsic_dev_state *dev_state;
2641
2642                 block = btrfsic_block_alloc();
2643                 if (NULL == block) {
2644                         pr_info("btrfsic: error, kmalloc failed!\n");
2645                         return NULL;
2646                 }
2647                 dev_state = btrfsic_dev_state_lookup(block_ctx->dev->bdev->bd_dev);
2648                 if (NULL == dev_state) {
2649                         pr_info("btrfsic: error, lookup dev_state failed!\n");
2650                         btrfsic_block_free(block);
2651                         return NULL;
2652                 }
2653                 block->dev_state = dev_state;
2654                 block->dev_bytenr = block_ctx->dev_bytenr;
2655                 block->logical_bytenr = block_ctx->start;
2656                 block->is_metadata = is_metadata;
2657                 block->is_iodone = is_iodone;
2658                 block->never_written = never_written;
2659                 block->mirror_num = mirror_num;
2660                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2661                         pr_info("New %s%c-block @%llu (%s/%llu/%d)\n",
2662                                additional_string,
2663                                btrfsic_get_block_type(state, block),
2664                                block->logical_bytenr, dev_state->name,
2665                                block->dev_bytenr, mirror_num);
2666                 list_add(&block->all_blocks_node, &state->all_blocks_list);
2667                 btrfsic_block_hashtable_add(block, &state->block_hashtable);
2668                 if (NULL != was_created)
2669                         *was_created = 1;
2670         } else {
2671                 if (NULL != was_created)
2672                         *was_created = 0;
2673         }
2674
2675         return block;
2676 }
2677
2678 static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
2679                                            u64 bytenr,
2680                                            struct btrfsic_dev_state *dev_state,
2681                                            u64 dev_bytenr)
2682 {
2683         struct btrfs_fs_info *fs_info = state->fs_info;
2684         struct btrfsic_block_data_ctx block_ctx;
2685         int num_copies;
2686         int mirror_num;
2687         int match = 0;
2688         int ret;
2689
2690         num_copies = btrfs_num_copies(fs_info, bytenr, state->metablock_size);
2691
2692         for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2693                 ret = btrfsic_map_block(state, bytenr, state->metablock_size,
2694                                         &block_ctx, mirror_num);
2695                 if (ret) {
2696                         pr_info("btrfsic: btrfsic_map_block(logical @%llu, mirror %d) failed!\n",
2697                                bytenr, mirror_num);
2698                         continue;
2699                 }
2700
2701                 if (dev_state->bdev == block_ctx.dev->bdev &&
2702                     dev_bytenr == block_ctx.dev_bytenr) {
2703                         match++;
2704                         btrfsic_release_block_ctx(&block_ctx);
2705                         break;
2706                 }
2707                 btrfsic_release_block_ctx(&block_ctx);
2708         }
2709
2710         if (WARN_ON(!match)) {
2711                 pr_info("btrfs: attempt to write M-block which contains logical bytenr that doesn't map to dev+physical bytenr of submit_bio, buffer->log_bytenr=%llu, submit_bio(bdev=%s, phys_bytenr=%llu)!\n",
2712                        bytenr, dev_state->name, dev_bytenr);
2713                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2714                         ret = btrfsic_map_block(state, bytenr,
2715                                                 state->metablock_size,
2716                                                 &block_ctx, mirror_num);
2717                         if (ret)
2718                                 continue;
2719
2720                         pr_info("Read logical bytenr @%llu maps to (%s/%llu/%d)\n",
2721                                bytenr, block_ctx.dev->name,
2722                                block_ctx.dev_bytenr, mirror_num);
2723                 }
2724         }
2725 }
2726
2727 static struct btrfsic_dev_state *btrfsic_dev_state_lookup(dev_t dev)
2728 {
2729         return btrfsic_dev_state_hashtable_lookup(dev,
2730                                                   &btrfsic_dev_state_hashtable);
2731 }
2732
2733 int btrfsic_submit_bh(int op, int op_flags, struct buffer_head *bh)
2734 {
2735         struct btrfsic_dev_state *dev_state;
2736
2737         if (!btrfsic_is_initialized)
2738                 return submit_bh(op, op_flags, bh);
2739
2740         mutex_lock(&btrfsic_mutex);
2741         /* since btrfsic_submit_bh() might also be called before
2742          * btrfsic_mount(), this might return NULL */
2743         dev_state = btrfsic_dev_state_lookup(bh->b_bdev->bd_dev);
2744
2745         /* Only called to write the superblock (incl. FLUSH/FUA) */
2746         if (NULL != dev_state &&
2747             (op == REQ_OP_WRITE) && bh->b_size > 0) {
2748                 u64 dev_bytenr;
2749
2750                 dev_bytenr = BTRFS_BDEV_BLOCKSIZE * bh->b_blocknr;
2751                 if (dev_state->state->print_mask &
2752                     BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2753                         pr_info("submit_bh(op=0x%x,0x%x, blocknr=%llu (bytenr %llu), size=%zu, data=%p, bdev=%p)\n",
2754                                op, op_flags, (unsigned long long)bh->b_blocknr,
2755                                dev_bytenr, bh->b_size, bh->b_data, bh->b_bdev);
2756                 btrfsic_process_written_block(dev_state, dev_bytenr,
2757                                               &bh->b_data, 1, NULL,
2758                                               NULL, bh, op_flags);
2759         } else if (NULL != dev_state && (op_flags & REQ_PREFLUSH)) {
2760                 if (dev_state->state->print_mask &
2761                     BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2762                         pr_info("submit_bh(op=0x%x,0x%x FLUSH, bdev=%p)\n",
2763                                op, op_flags, bh->b_bdev);
2764                 if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
2765                         if ((dev_state->state->print_mask &
2766                              (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
2767                               BTRFSIC_PRINT_MASK_VERBOSE)))
2768                                 pr_info("btrfsic_submit_bh(%s) with FLUSH but dummy block already in use (ignored)!\n",
2769                                        dev_state->name);
2770                 } else {
2771                         struct btrfsic_block *const block =
2772                                 &dev_state->dummy_block_for_bio_bh_flush;
2773
2774                         block->is_iodone = 0;
2775                         block->never_written = 0;
2776                         block->iodone_w_error = 0;
2777                         block->flush_gen = dev_state->last_flush_gen + 1;
2778                         block->submit_bio_bh_rw = op_flags;
2779                         block->orig_bio_bh_private = bh->b_private;
2780                         block->orig_bio_bh_end_io.bh = bh->b_end_io;
2781                         block->next_in_same_bio = NULL;
2782                         bh->b_private = block;
2783                         bh->b_end_io = btrfsic_bh_end_io;
2784                 }
2785         }
2786         mutex_unlock(&btrfsic_mutex);
2787         return submit_bh(op, op_flags, bh);
2788 }
2789
2790 static void __btrfsic_submit_bio(struct bio *bio)
2791 {
2792         struct btrfsic_dev_state *dev_state;
2793
2794         if (!btrfsic_is_initialized)
2795                 return;
2796
2797         mutex_lock(&btrfsic_mutex);
2798         /* since btrfsic_submit_bio() is also called before
2799          * btrfsic_mount(), this might return NULL */
2800         dev_state = btrfsic_dev_state_lookup(bio_dev(bio) + bio->bi_partno);
2801         if (NULL != dev_state &&
2802             (bio_op(bio) == REQ_OP_WRITE) && bio_has_data(bio)) {
2803                 unsigned int i = 0;
2804                 u64 dev_bytenr;
2805                 u64 cur_bytenr;
2806                 struct bio_vec bvec;
2807                 struct bvec_iter iter;
2808                 int bio_is_patched;
2809                 char **mapped_datav;
2810                 unsigned int segs = bio_segments(bio);
2811
2812                 dev_bytenr = 512 * bio->bi_iter.bi_sector;
2813                 bio_is_patched = 0;
2814                 if (dev_state->state->print_mask &
2815                     BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2816                         pr_info("submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_disk=%p)\n",
2817                                bio_op(bio), bio->bi_opf, segs,
2818                                (unsigned long long)bio->bi_iter.bi_sector,
2819                                dev_bytenr, bio->bi_disk);
2820
2821                 mapped_datav = kmalloc_array(segs,
2822                                              sizeof(*mapped_datav), GFP_NOFS);
2823                 if (!mapped_datav)
2824                         goto leave;
2825                 cur_bytenr = dev_bytenr;
2826
2827                 bio_for_each_segment(bvec, bio, iter) {
2828                         BUG_ON(bvec.bv_len != PAGE_SIZE);
2829                         mapped_datav[i] = kmap(bvec.bv_page);
2830                         i++;
2831
2832                         if (dev_state->state->print_mask &
2833                             BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE)
2834                                 pr_info("#%u: bytenr=%llu, len=%u, offset=%u\n",
2835                                        i, cur_bytenr, bvec.bv_len, bvec.bv_offset);
2836                         cur_bytenr += bvec.bv_len;
2837                 }
2838                 btrfsic_process_written_block(dev_state, dev_bytenr,
2839                                               mapped_datav, segs,
2840                                               bio, &bio_is_patched,
2841                                               NULL, bio->bi_opf);
2842                 bio_for_each_segment(bvec, bio, iter)
2843                         kunmap(bvec.bv_page);
2844                 kfree(mapped_datav);
2845         } else if (NULL != dev_state && (bio->bi_opf & REQ_PREFLUSH)) {
2846                 if (dev_state->state->print_mask &
2847                     BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2848                         pr_info("submit_bio(rw=%d,0x%x FLUSH, disk=%p)\n",
2849                                bio_op(bio), bio->bi_opf, bio->bi_disk);
2850                 if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
2851                         if ((dev_state->state->print_mask &
2852                              (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
2853                               BTRFSIC_PRINT_MASK_VERBOSE)))
2854                                 pr_info("btrfsic_submit_bio(%s) with FLUSH but dummy block already in use (ignored)!\n",
2855                                        dev_state->name);
2856                 } else {
2857                         struct btrfsic_block *const block =
2858                                 &dev_state->dummy_block_for_bio_bh_flush;
2859
2860                         block->is_iodone = 0;
2861                         block->never_written = 0;
2862                         block->iodone_w_error = 0;
2863                         block->flush_gen = dev_state->last_flush_gen + 1;
2864                         block->submit_bio_bh_rw = bio->bi_opf;
2865                         block->orig_bio_bh_private = bio->bi_private;
2866                         block->orig_bio_bh_end_io.bio = bio->bi_end_io;
2867                         block->next_in_same_bio = NULL;
2868                         bio->bi_private = block;
2869                         bio->bi_end_io = btrfsic_bio_end_io;
2870                 }
2871         }
2872 leave:
2873         mutex_unlock(&btrfsic_mutex);
2874 }
2875
2876 void btrfsic_submit_bio(struct bio *bio)
2877 {
2878         __btrfsic_submit_bio(bio);
2879         submit_bio(bio);
2880 }
2881
2882 int btrfsic_submit_bio_wait(struct bio *bio)
2883 {
2884         __btrfsic_submit_bio(bio);
2885         return submit_bio_wait(bio);
2886 }
2887
2888 int btrfsic_mount(struct btrfs_fs_info *fs_info,
2889                   struct btrfs_fs_devices *fs_devices,
2890                   int including_extent_data, u32 print_mask)
2891 {
2892         int ret;
2893         struct btrfsic_state *state;
2894         struct list_head *dev_head = &fs_devices->devices;
2895         struct btrfs_device *device;
2896
2897         if (!PAGE_ALIGNED(fs_info->nodesize)) {
2898                 pr_info("btrfsic: cannot handle nodesize %d not being a multiple of PAGE_SIZE %ld!\n",
2899                        fs_info->nodesize, PAGE_SIZE);
2900                 return -1;
2901         }
2902         if (!PAGE_ALIGNED(fs_info->sectorsize)) {
2903                 pr_info("btrfsic: cannot handle sectorsize %d not being a multiple of PAGE_SIZE %ld!\n",
2904                        fs_info->sectorsize, PAGE_SIZE);
2905                 return -1;
2906         }
2907         state = kvzalloc(sizeof(*state), GFP_KERNEL);
2908         if (!state) {
2909                 pr_info("btrfs check-integrity: allocation failed!\n");
2910                 return -ENOMEM;
2911         }
2912
2913         if (!btrfsic_is_initialized) {
2914                 mutex_init(&btrfsic_mutex);
2915                 btrfsic_dev_state_hashtable_init(&btrfsic_dev_state_hashtable);
2916                 btrfsic_is_initialized = 1;
2917         }
2918         mutex_lock(&btrfsic_mutex);
2919         state->fs_info = fs_info;
2920         state->print_mask = print_mask;
2921         state->include_extent_data = including_extent_data;
2922         state->csum_size = 0;
2923         state->metablock_size = fs_info->nodesize;
2924         state->datablock_size = fs_info->sectorsize;
2925         INIT_LIST_HEAD(&state->all_blocks_list);
2926         btrfsic_block_hashtable_init(&state->block_hashtable);
2927         btrfsic_block_link_hashtable_init(&state->block_link_hashtable);
2928         state->max_superblock_generation = 0;
2929         state->latest_superblock = NULL;
2930
2931         list_for_each_entry(device, dev_head, dev_list) {
2932                 struct btrfsic_dev_state *ds;
2933                 const char *p;
2934
2935                 if (!device->bdev || !device->name)
2936                         continue;
2937
2938                 ds = btrfsic_dev_state_alloc();
2939                 if (NULL == ds) {
2940                         pr_info("btrfs check-integrity: kmalloc() failed!\n");
2941                         mutex_unlock(&btrfsic_mutex);
2942                         return -ENOMEM;
2943                 }
2944                 ds->bdev = device->bdev;
2945                 ds->state = state;
2946                 bdevname(ds->bdev, ds->name);
2947                 ds->name[BDEVNAME_SIZE - 1] = '\0';
2948                 p = kbasename(ds->name);
2949                 strlcpy(ds->name, p, sizeof(ds->name));
2950                 btrfsic_dev_state_hashtable_add(ds,
2951                                                 &btrfsic_dev_state_hashtable);
2952         }
2953
2954         ret = btrfsic_process_superblock(state, fs_devices);
2955         if (0 != ret) {
2956                 mutex_unlock(&btrfsic_mutex);
2957                 btrfsic_unmount(fs_devices);
2958                 return ret;
2959         }
2960
2961         if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_DATABASE)
2962                 btrfsic_dump_database(state);
2963         if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_TREE)
2964                 btrfsic_dump_tree(state);
2965
2966         mutex_unlock(&btrfsic_mutex);
2967         return 0;
2968 }
2969
2970 void btrfsic_unmount(struct btrfs_fs_devices *fs_devices)
2971 {
2972         struct btrfsic_block *b_all, *tmp_all;
2973         struct btrfsic_state *state;
2974         struct list_head *dev_head = &fs_devices->devices;
2975         struct btrfs_device *device;
2976
2977         if (!btrfsic_is_initialized)
2978                 return;
2979
2980         mutex_lock(&btrfsic_mutex);
2981
2982         state = NULL;
2983         list_for_each_entry(device, dev_head, dev_list) {
2984                 struct btrfsic_dev_state *ds;
2985
2986                 if (!device->bdev || !device->name)
2987                         continue;
2988
2989                 ds = btrfsic_dev_state_hashtable_lookup(
2990                                 device->bdev->bd_dev,
2991                                 &btrfsic_dev_state_hashtable);
2992                 if (NULL != ds) {
2993                         state = ds->state;
2994                         btrfsic_dev_state_hashtable_remove(ds);
2995                         btrfsic_dev_state_free(ds);
2996                 }
2997         }
2998
2999         if (NULL == state) {
3000                 pr_info("btrfsic: error, cannot find state information on umount!\n");
3001                 mutex_unlock(&btrfsic_mutex);
3002                 return;
3003         }
3004
3005         /*
3006          * Don't care about keeping the lists' state up to date,
3007          * just free all memory that was allocated dynamically.
3008          * Free the blocks and the block_links.
3009          */
3010         list_for_each_entry_safe(b_all, tmp_all, &state->all_blocks_list,
3011                                  all_blocks_node) {
3012                 struct btrfsic_block_link *l, *tmp;
3013
3014                 list_for_each_entry_safe(l, tmp, &b_all->ref_to_list,
3015                                          node_ref_to) {
3016                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
3017                                 btrfsic_print_rem_link(state, l);
3018
3019                         l->ref_cnt--;
3020                         if (0 == l->ref_cnt)
3021                                 btrfsic_block_link_free(l);
3022                 }
3023
3024                 if (b_all->is_iodone || b_all->never_written)
3025                         btrfsic_block_free(b_all);
3026                 else
3027                         pr_info("btrfs: attempt to free %c-block @%llu (%s/%llu/%d) on umount which is not yet iodone!\n",
3028                                btrfsic_get_block_type(state, b_all),
3029                                b_all->logical_bytenr, b_all->dev_state->name,
3030                                b_all->dev_bytenr, b_all->mirror_num);
3031         }
3032
3033         mutex_unlock(&btrfsic_mutex);
3034
3035         kvfree(state);
3036 }