fs/btrfs/check-integrity.c

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