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