fs/btrfs/check-integrity.c

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