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