fs/btrfs/check-integrity.c

   1 /*
   2  * Copyright (C) STRATO AG 2011.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 /*
  20  * This module can be used to catch cases when the btrfs kernel
  21  * code executes write requests to the disk that bring the file
  22  * system in an inconsistent state. In such a state, a power-loss
  23  * or kernel panic event would cause that the data on disk is
  24  * lost or at least damaged.
  25  *
  26  * Code is added that examines all block write requests during
  27  * runtime (including writes of the super block). Three rules
  28  * are verified and an error is printed on violation of the
  29  * rules:
  30  * 1. It is not allowed to write a disk block which is
  31  *    currently referenced by the super block (either directly
  32  *    or indirectly).
  33  * 2. When a super block is written, it is verified that all
  34  *    referenced (directly or indirectly) blocks fulfill the
  35  *    following requirements:
  36  *    2a. All referenced blocks have either been present when
  37  *        the file system was mounted, (i.e., they have been
  38  *        referenced by the super block) or they have been
  39  *        written since then and the write completion callback
  40  *        was called and no write error was indicated and a
  41  *        FLUSH request to the device where these blocks are
  42  *        located was received and completed.
  43  *    2b. All referenced blocks need to have a generation
  44  *        number which is equal to the parent's number.
  45  *
  46  * One issue that was found using this module was that the log
  47  * tree on disk became temporarily corrupted because disk blocks
  48  * that had been in use for the log tree had been freed and
  49  * reused too early, while being referenced by the written super
  50  * block.
  51  *
  52  * The search term in the kernel log that can be used to filter
  53  * on the existence of detected integrity issues is
  54  * "btrfs: attempt".
  55  *
  56  * The integrity check is enabled via mount options. These
  57  * mount options are only supported if the integrity check
  58  * tool is compiled by defining BTRFS_FS_CHECK_INTEGRITY.
  59  *
  60  * Example #1, apply integrity checks to all metadata:
  61  * mount /dev/sdb1 /mnt -o check_int
  62  *
  63  * Example #2, apply integrity checks to all metadata and
  64  * to data extents:
  65  * mount /dev/sdb1 /mnt -o check_int_data
  66  *
  67  * Example #3, apply integrity checks to all metadata and dump
  68  * the tree that the super block references to kernel messages
  69  * each time after a super block was written:
  70  * mount /dev/sdb1 /mnt -o check_int,check_int_print_mask=263
  71  *
  72  * If the integrity check tool is included and activated in
  73  * the mount options, plenty of kernel memory is used, and
  74  * plenty of additional CPU cycles are spent. Enabling this
  75  * functionality is not intended for normal use. In most
  76  * cases, unless you are a btrfs developer who needs to verify
  77  * the integrity of (super)-block write requests, do not
  78  * enable the config option BTRFS_FS_CHECK_INTEGRITY to
  79  * include and compile the integrity check tool.
  80  */
  81
  82 #include <linux/sched.h>
  83 #include <linux/slab.h>
  84 #include <linux/buffer_head.h>
  85 #include <linux/mutex.h>
  86 #include <linux/crc32c.h>
  87 #include <linux/genhd.h>
  88 #include <linux/blkdev.h>
  89 #include "ctree.h"
  90 #include "disk-io.h"
  91 #include "transaction.h"
  92 #include "extent_io.h"
  93 #include "volumes.h"
  94 #include "print-tree.h"
  95 #include "locking.h"
  96 #include "check-integrity.h"
  97 #include "rcu-string.h"
  98
  99 #define BTRFSIC_BLOCK_HASHTABLE_SIZE 0x10000
 100 #define BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE 0x10000
 101 #define BTRFSIC_DEV2STATE_HASHTABLE_SIZE 0x100
 102 #define BTRFSIC_BLOCK_MAGIC_NUMBER 0x14491051
 103 #define BTRFSIC_BLOCK_LINK_MAGIC_NUMBER 0x11070807
 104 #define BTRFSIC_DEV2STATE_MAGIC_NUMBER 0x20111530
 105 #define BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER 20111300
 106 #define BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL (200 - 6)    /* in characters,
 107                                                          * excluding " [...]" */
 108 #define BTRFSIC_GENERATION_UNKNOWN ((u64)-1)
 109
 110 /*
 111  * The definition of the bitmask fields for the print_mask.
 112  * They are specified with the mount option check_integrity_print_mask.
 113  */
 114 #define BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE                     0x00000001
 115 #define BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION         0x00000002
 116 #define BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE                  0x00000004
 117 #define BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE                 0x00000008
 118 #define BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH                        0x00000010
 119 #define BTRFSIC_PRINT_MASK_END_IO_BIO_BH                        0x00000020
 120 #define BTRFSIC_PRINT_MASK_VERBOSE                              0x00000040
 121 #define BTRFSIC_PRINT_MASK_VERY_VERBOSE                         0x00000080
 122 #define BTRFSIC_PRINT_MASK_INITIAL_TREE                         0x00000100
 123 #define BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES                    0x00000200
 124 #define BTRFSIC_PRINT_MASK_INITIAL_DATABASE                     0x00000400
 125 #define BTRFSIC_PRINT_MASK_NUM_COPIES                           0x00000800
 126 #define BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS                0x00001000
 127
 128 struct btrfsic_dev_state;
 129 struct btrfsic_state;
 130
 131 struct btrfsic_block {
 132         u32 magic_num;          /* only used for debug purposes */
 133         unsigned int is_metadata:1;     /* if it is meta-data, not data-data */
 134         unsigned int is_superblock:1;   /* if it is one of the superblocks */
 135         unsigned int is_iodone:1;       /* if is done by lower subsystem */
 136         unsigned int iodone_w_error:1;  /* error was indicated to endio */
 137         unsigned int never_written:1;   /* block was added because it was
 138                                          * referenced, not because it was
 139                                          * written */
 140         unsigned int mirror_num;        /* large enough to hold
 141                                          * BTRFS_SUPER_MIRROR_MAX */
 142         struct btrfsic_dev_state *dev_state;
 143         u64 dev_bytenr;         /* key, physical byte num on disk */
 144         u64 logical_bytenr;     /* logical byte num on disk */
 145         u64 generation;
 146         struct btrfs_disk_key disk_key; /* extra info to print in case of
 147                                          * issues, will not always be correct */
 148         struct list_head collision_resolving_node;      /* list node */
 149         struct list_head all_blocks_node;       /* list node */
 150
 151         /* the following two lists contain block_link items */
 152         struct list_head ref_to_list;   /* list */
 153         struct list_head ref_from_list; /* list */
 154         struct btrfsic_block *next_in_same_bio;
 155         void *orig_bio_bh_private;
 156         union {
 157                 bio_end_io_t *bio;
 158                 bh_end_io_t *bh;
 159         } orig_bio_bh_end_io;
 160         int submit_bio_bh_rw;
 161         u64 flush_gen; /* only valid if !never_written */
 162 };
 163
 164 /*
 165  * Elements of this type are allocated dynamically and required because
 166  * each block object can refer to and can be ref from multiple blocks.
 167  * The key to lookup them in the hashtable is the dev_bytenr of
 168  * the block ref to plus the one from the block refered from.
 169  * The fact that they are searchable via a hashtable and that a
 170  * ref_cnt is maintained is not required for the btrfs integrity
 171  * check algorithm itself, it is only used to make the output more
 172  * beautiful in case that an error is detected (an error is defined
 173  * as a write operation to a block while that block is still referenced).
 174  */
 175 struct btrfsic_block_link {
 176         u32 magic_num;          /* only used for debug purposes */
 177         u32 ref_cnt;
 178         struct list_head node_ref_to;   /* list node */
 179         struct list_head node_ref_from; /* list node */
 180         struct list_head collision_resolving_node;      /* list node */
 181         struct btrfsic_block *block_ref_to;
 182         struct btrfsic_block *block_ref_from;
 183         u64 parent_generation;
 184 };
 185
 186 struct btrfsic_dev_state {
 187         u32 magic_num;          /* only used for debug purposes */
 188         struct block_device *bdev;
 189         struct btrfsic_state *state;
 190         struct list_head collision_resolving_node;      /* list node */
 191         struct btrfsic_block dummy_block_for_bio_bh_flush;
 192         u64 last_flush_gen;
 193         char name[BDEVNAME_SIZE];
 194 };
 195
 196 struct btrfsic_block_hashtable {
 197         struct list_head table[BTRFSIC_BLOCK_HASHTABLE_SIZE];
 198 };
 199
 200 struct btrfsic_block_link_hashtable {
 201         struct list_head table[BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE];
 202 };
 203
 204 struct btrfsic_dev_state_hashtable {
 205         struct list_head table[BTRFSIC_DEV2STATE_HASHTABLE_SIZE];
 206 };
 207
 208 struct btrfsic_block_data_ctx {
 209         u64 start;              /* virtual bytenr */
 210         u64 dev_bytenr;         /* physical bytenr on device */
 211         u32 len;
 212         struct btrfsic_dev_state *dev;
 213         char **datav;
 214         struct page **pagev;
 215         void *mem_to_free;
 216 };
 217
 218 /* This structure is used to implement recursion without occupying
 219  * any stack space, refer to btrfsic_process_metablock() */
 220 struct btrfsic_stack_frame {
 221         u32 magic;
 222         u32 nr;
 223         int error;
 224         int i;
 225         int limit_nesting;
 226         int num_copies;
 227         int mirror_num;
 228         struct btrfsic_block *block;
 229         struct btrfsic_block_data_ctx *block_ctx;
 230         struct btrfsic_block *next_block;
 231         struct btrfsic_block_data_ctx next_block_ctx;
 232         struct btrfs_header *hdr;
 233         struct btrfsic_stack_frame *prev;
 234 };
 235
 236 /* Some state per mounted filesystem */
 237 struct btrfsic_state {
 238         u32 print_mask;
 239         int include_extent_data;
 240         int csum_size;
 241         struct list_head all_blocks_list;
 242         struct btrfsic_block_hashtable block_hashtable;
 243         struct btrfsic_block_link_hashtable block_link_hashtable;
 244         struct btrfs_root *root;
 245         u64 max_superblock_generation;
 246         struct btrfsic_block *latest_superblock;
 247         u32 metablock_size;
 248         u32 datablock_size;
 249 };
 250
 251 static void btrfsic_block_init(struct btrfsic_block *b);
 252 static struct btrfsic_block *btrfsic_block_alloc(void);
 253 static void btrfsic_block_free(struct btrfsic_block *b);
 254 static void btrfsic_block_link_init(struct btrfsic_block_link *n);
 255 static struct btrfsic_block_link *btrfsic_block_link_alloc(void);
 256 static void btrfsic_block_link_free(struct btrfsic_block_link *n);
 257 static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds);
 258 static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void);
 259 static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds);
 260 static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h);
 261 static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
 262                                         struct btrfsic_block_hashtable *h);
 263 static void btrfsic_block_hashtable_remove(struct btrfsic_block *b);
 264 static struct btrfsic_block *btrfsic_block_hashtable_lookup(
 265                 struct block_device *bdev,
 266                 u64 dev_bytenr,
 267                 struct btrfsic_block_hashtable *h);
 268 static void btrfsic_block_link_hashtable_init(
 269                 struct btrfsic_block_link_hashtable *h);
 270 static void btrfsic_block_link_hashtable_add(
 271                 struct btrfsic_block_link *l,
 272                 struct btrfsic_block_link_hashtable *h);
 273 static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l);
 274 static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
 275                 struct block_device *bdev_ref_to,
 276                 u64 dev_bytenr_ref_to,
 277                 struct block_device *bdev_ref_from,
 278                 u64 dev_bytenr_ref_from,
 279                 struct btrfsic_block_link_hashtable *h);
 280 static void btrfsic_dev_state_hashtable_init(
 281                 struct btrfsic_dev_state_hashtable *h);
 282 static void btrfsic_dev_state_hashtable_add(
 283                 struct btrfsic_dev_state *ds,
 284                 struct btrfsic_dev_state_hashtable *h);
 285 static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds);
 286 static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(
 287                 struct block_device *bdev,
 288                 struct btrfsic_dev_state_hashtable *h);
 289 static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void);
 290 static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf);
 291 static int btrfsic_process_superblock(struct btrfsic_state *state,
 292                                       struct btrfs_fs_devices *fs_devices);
 293 static int btrfsic_process_metablock(struct btrfsic_state *state,
 294                                      struct btrfsic_block *block,
 295                                      struct btrfsic_block_data_ctx *block_ctx,
 296                                      int limit_nesting, int force_iodone_flag);
 297 static void btrfsic_read_from_block_data(
 298         struct btrfsic_block_data_ctx *block_ctx,
 299         void *dst, u32 offset, size_t len);
 300 static int btrfsic_create_link_to_next_block(
 301                 struct btrfsic_state *state,
 302                 struct btrfsic_block *block,
 303                 struct btrfsic_block_data_ctx
 304                 *block_ctx, u64 next_bytenr,
 305                 int limit_nesting,
 306                 struct btrfsic_block_data_ctx *next_block_ctx,
 307                 struct btrfsic_block **next_blockp,
 308                 int force_iodone_flag,
 309                 int *num_copiesp, int *mirror_nump,
 310                 struct btrfs_disk_key *disk_key,
 311                 u64 parent_generation);
 312 static int btrfsic_handle_extent_data(struct btrfsic_state *state,
 313                                       struct btrfsic_block *block,
 314                                       struct btrfsic_block_data_ctx *block_ctx,
 315                                       u32 item_offset, int force_iodone_flag);
 316 static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
 317                              struct btrfsic_block_data_ctx *block_ctx_out,
 318                              int mirror_num);
 319 static int btrfsic_map_superblock(struct btrfsic_state *state, u64 bytenr,
 320                                   u32 len, struct block_device *bdev,
 321                                   struct btrfsic_block_data_ctx *block_ctx_out);
 322 static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx);
 323 static int btrfsic_read_block(struct btrfsic_state *state,
 324                               struct btrfsic_block_data_ctx *block_ctx);
 325 static void btrfsic_dump_database(struct btrfsic_state *state);
 326 static void btrfsic_complete_bio_end_io(struct bio *bio, int err);
 327 static int btrfsic_test_for_metadata(struct btrfsic_state *state,
 328                                      char **datav, unsigned int num_pages);
 329 static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
 330                                           u64 dev_bytenr, char **mapped_datav,
 331                                           unsigned int num_pages,
 332                                           struct bio *bio, int *bio_is_patched,
 333                                           struct buffer_head *bh,
 334                                           int submit_bio_bh_rw);
 335 static int btrfsic_process_written_superblock(
 336                 struct btrfsic_state *state,
 337                 struct btrfsic_block *const block,
 338                 struct btrfs_super_block *const super_hdr);
 339 static void btrfsic_bio_end_io(struct bio *bp, int bio_error_status);
 340 static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate);
 341 static int btrfsic_is_block_ref_by_superblock(const struct btrfsic_state *state,
 342                                               const struct btrfsic_block *block,
 343                                               int recursion_level);
 344 static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
 345                                         struct btrfsic_block *const block,
 346                                         int recursion_level);
 347 static void btrfsic_print_add_link(const struct btrfsic_state *state,
 348                                    const struct btrfsic_block_link *l);
 349 static void btrfsic_print_rem_link(const struct btrfsic_state *state,
 350                                    const struct btrfsic_block_link *l);
 351 static char btrfsic_get_block_type(const struct btrfsic_state *state,
 352                                    const struct btrfsic_block *block);
 353 static void btrfsic_dump_tree(const struct btrfsic_state *state);
 354 static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
 355                                   const struct btrfsic_block *block,
 356                                   int indent_level);
 357 static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
 358                 struct btrfsic_state *state,
 359                 struct btrfsic_block_data_ctx *next_block_ctx,
 360                 struct btrfsic_block *next_block,
 361                 struct btrfsic_block *from_block,
 362                 u64 parent_generation);
 363 static struct btrfsic_block *btrfsic_block_lookup_or_add(
 364                 struct btrfsic_state *state,
 365                 struct btrfsic_block_data_ctx *block_ctx,
 366                 const char *additional_string,
 367                 int is_metadata,
 368                 int is_iodone,
 369                 int never_written,
 370                 int mirror_num,
 371                 int *was_created);
 372 static int btrfsic_process_superblock_dev_mirror(
 373                 struct btrfsic_state *state,
 374                 struct btrfsic_dev_state *dev_state,
 375                 struct btrfs_device *device,
 376                 int superblock_mirror_num,
 377                 struct btrfsic_dev_state **selected_dev_state,
 378                 struct btrfs_super_block *selected_super);
 379 static struct btrfsic_dev_state *btrfsic_dev_state_lookup(
 380                 struct block_device *bdev);
 381 static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
 382                                            u64 bytenr,
 383                                            struct btrfsic_dev_state *dev_state,
 384                                            u64 dev_bytenr);
 385
 386 static struct mutex btrfsic_mutex;
 387 static int btrfsic_is_initialized;
 388 static struct btrfsic_dev_state_hashtable btrfsic_dev_state_hashtable;
 389
 390
 391 static void btrfsic_block_init(struct btrfsic_block *b)
 392 {
 393         b->magic_num = BTRFSIC_BLOCK_MAGIC_NUMBER;
 394         b->dev_state = NULL;
 395         b->dev_bytenr = 0;
 396         b->logical_bytenr = 0;
 397         b->generation = BTRFSIC_GENERATION_UNKNOWN;
 398         b->disk_key.objectid = 0;
 399         b->disk_key.type = 0;
 400         b->disk_key.offset = 0;
 401         b->is_metadata = 0;
 402         b->is_superblock = 0;
 403         b->is_iodone = 0;
 404         b->iodone_w_error = 0;
 405         b->never_written = 0;
 406         b->mirror_num = 0;
 407         b->next_in_same_bio = NULL;
 408         b->orig_bio_bh_private = NULL;
 409         b->orig_bio_bh_end_io.bio = NULL;
 410         INIT_LIST_HEAD(&b->collision_resolving_node);
 411         INIT_LIST_HEAD(&b->all_blocks_node);
 412         INIT_LIST_HEAD(&b->ref_to_list);
 413         INIT_LIST_HEAD(&b->ref_from_list);
 414         b->submit_bio_bh_rw = 0;
 415         b->flush_gen = 0;
 416 }
 417
 418 static struct btrfsic_block *btrfsic_block_alloc(void)
 419 {
 420         struct btrfsic_block *b;
 421
 422         b = kzalloc(sizeof(*b), GFP_NOFS);
 423         if (NULL != b)
 424                 btrfsic_block_init(b);
 425
 426         return b;
 427 }
 428
 429 static void btrfsic_block_free(struct btrfsic_block *b)
 430 {
 431         BUG_ON(!(NULL == b || BTRFSIC_BLOCK_MAGIC_NUMBER == b->magic_num));
 432         kfree(b);
 433 }
 434
 435 static void btrfsic_block_link_init(struct btrfsic_block_link *l)
 436 {
 437         l->magic_num = BTRFSIC_BLOCK_LINK_MAGIC_NUMBER;
 438         l->ref_cnt = 1;
 439         INIT_LIST_HEAD(&l->node_ref_to);
 440         INIT_LIST_HEAD(&l->node_ref_from);
 441         INIT_LIST_HEAD(&l->collision_resolving_node);
 442         l->block_ref_to = NULL;
 443         l->block_ref_from = NULL;
 444 }
 445
 446 static struct btrfsic_block_link *btrfsic_block_link_alloc(void)
 447 {
 448         struct btrfsic_block_link *l;
 449
 450         l = kzalloc(sizeof(*l), GFP_NOFS);
 451         if (NULL != l)
 452                 btrfsic_block_link_init(l);
 453
 454         return l;
 455 }
 456
 457 static void btrfsic_block_link_free(struct btrfsic_block_link *l)
 458 {
 459         BUG_ON(!(NULL == l || BTRFSIC_BLOCK_LINK_MAGIC_NUMBER == l->magic_num));
 460         kfree(l);
 461 }
 462
 463 static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds)
 464 {
 465         ds->magic_num = BTRFSIC_DEV2STATE_MAGIC_NUMBER;
 466         ds->bdev = NULL;
 467         ds->state = NULL;
 468         ds->name[0] = '\0';
 469         INIT_LIST_HEAD(&ds->collision_resolving_node);
 470         ds->last_flush_gen = 0;
 471         btrfsic_block_init(&ds->dummy_block_for_bio_bh_flush);
 472         ds->dummy_block_for_bio_bh_flush.is_iodone = 1;
 473         ds->dummy_block_for_bio_bh_flush.dev_state = ds;
 474 }
 475
 476 static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void)
 477 {
 478         struct btrfsic_dev_state *ds;
 479
 480         ds = kzalloc(sizeof(*ds), GFP_NOFS);
 481         if (NULL != ds)
 482                 btrfsic_dev_state_init(ds);
 483
 484         return ds;
 485 }
 486
 487 static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds)
 488 {
 489         BUG_ON(!(NULL == ds ||
 490                  BTRFSIC_DEV2STATE_MAGIC_NUMBER == ds->magic_num));
 491         kfree(ds);
 492 }
 493
 494 static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h)
 495 {
 496         int i;
 497
 498         for (i = 0; i < BTRFSIC_BLOCK_HASHTABLE_SIZE; i++)
 499                 INIT_LIST_HEAD(h->table + i);
 500 }
 501
 502 static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
 503                                         struct btrfsic_block_hashtable *h)
 504 {
 505         const unsigned int hashval =
 506             (((unsigned int)(b->dev_bytenr >> 16)) ^
 507              ((unsigned int)((uintptr_t)b->dev_state->bdev))) &
 508              (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
 509
 510         list_add(&b->collision_resolving_node, h->table + hashval);
 511 }
 512
 513 static void btrfsic_block_hashtable_remove(struct btrfsic_block *b)
 514 {
 515         list_del(&b->collision_resolving_node);
 516 }
 517
 518 static struct btrfsic_block *btrfsic_block_hashtable_lookup(
 519                 struct block_device *bdev,
 520                 u64 dev_bytenr,
 521                 struct btrfsic_block_hashtable *h)
 522 {
 523         const unsigned int hashval =
 524             (((unsigned int)(dev_bytenr >> 16)) ^
 525              ((unsigned int)((uintptr_t)bdev))) &
 526              (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
 527         struct list_head *elem;
 528
 529         list_for_each(elem, h->table + hashval) {
 530                 struct btrfsic_block *const b =
 531                     list_entry(elem, struct btrfsic_block,
 532                                collision_resolving_node);
 533
 534                 if (b->dev_state->bdev == bdev && b->dev_bytenr == dev_bytenr)
 535                         return b;
 536         }
 537
 538         return NULL;
 539 }
 540
 541 static void btrfsic_block_link_hashtable_init(
 542                 struct btrfsic_block_link_hashtable *h)
 543 {
 544         int i;
 545
 546         for (i = 0; i < BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE; i++)
 547                 INIT_LIST_HEAD(h->table + i);
 548 }
 549
 550 static void btrfsic_block_link_hashtable_add(
 551                 struct btrfsic_block_link *l,
 552                 struct btrfsic_block_link_hashtable *h)
 553 {
 554         const unsigned int hashval =
 555             (((unsigned int)(l->block_ref_to->dev_bytenr >> 16)) ^
 556              ((unsigned int)(l->block_ref_from->dev_bytenr >> 16)) ^
 557              ((unsigned int)((uintptr_t)l->block_ref_to->dev_state->bdev)) ^
 558              ((unsigned int)((uintptr_t)l->block_ref_from->dev_state->bdev)))
 559              & (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
 560
 561         BUG_ON(NULL == l->block_ref_to);
 562         BUG_ON(NULL == l->block_ref_from);
 563         list_add(&l->collision_resolving_node, h->table + hashval);
 564 }
 565
 566 static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l)
 567 {
 568         list_del(&l->collision_resolving_node);
 569 }
 570
 571 static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
 572                 struct block_device *bdev_ref_to,
 573                 u64 dev_bytenr_ref_to,
 574                 struct block_device *bdev_ref_from,
 575                 u64 dev_bytenr_ref_from,
 576                 struct btrfsic_block_link_hashtable *h)
 577 {
 578         const unsigned int hashval =
 579             (((unsigned int)(dev_bytenr_ref_to >> 16)) ^
 580              ((unsigned int)(dev_bytenr_ref_from >> 16)) ^
 581              ((unsigned int)((uintptr_t)bdev_ref_to)) ^
 582              ((unsigned int)((uintptr_t)bdev_ref_from))) &
 583              (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
 584         struct list_head *elem;
 585
 586         list_for_each(elem, h->table + hashval) {
 587                 struct btrfsic_block_link *const l =
 588                     list_entry(elem, struct btrfsic_block_link,
 589                                collision_resolving_node);
 590
 591                 BUG_ON(NULL == l->block_ref_to);
 592                 BUG_ON(NULL == l->block_ref_from);
 593                 if (l->block_ref_to->dev_state->bdev == bdev_ref_to &&
 594                     l->block_ref_to->dev_bytenr == dev_bytenr_ref_to &&
 595                     l->block_ref_from->dev_state->bdev == bdev_ref_from &&
 596                     l->block_ref_from->dev_bytenr == dev_bytenr_ref_from)
 597                         return l;
 598         }
 599
 600         return NULL;
 601 }
 602
 603 static void btrfsic_dev_state_hashtable_init(
 604                 struct btrfsic_dev_state_hashtable *h)
 605 {
 606         int i;
 607
 608         for (i = 0; i < BTRFSIC_DEV2STATE_HASHTABLE_SIZE; i++)
 609                 INIT_LIST_HEAD(h->table + i);
 610 }
 611
 612 static void btrfsic_dev_state_hashtable_add(
 613                 struct btrfsic_dev_state *ds,
 614                 struct btrfsic_dev_state_hashtable *h)
 615 {
 616         const unsigned int hashval =
 617             (((unsigned int)((uintptr_t)ds->bdev)) &
 618              (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1));
 619
 620         list_add(&ds->collision_resolving_node, h->table + hashval);
 621 }
 622
 623 static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds)
 624 {
 625         list_del(&ds->collision_resolving_node);
 626 }
 627
 628 static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(
 629                 struct block_device *bdev,
 630                 struct btrfsic_dev_state_hashtable *h)
 631 {
 632         const unsigned int hashval =
 633             (((unsigned int)((uintptr_t)bdev)) &
 634              (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1));
 635         struct list_head *elem;
 636
 637         list_for_each(elem, h->table + hashval) {
 638                 struct btrfsic_dev_state *const ds =
 639                     list_entry(elem, struct btrfsic_dev_state,
 640                                collision_resolving_node);
 641
 642                 if (ds->bdev == bdev)
 643                         return ds;
 644         }
 645
 646         return NULL;
 647 }
 648
 649 static int btrfsic_process_superblock(struct btrfsic_state *state,
 650                                       struct btrfs_fs_devices *fs_devices)
 651 {
 652         int ret = 0;
 653         struct btrfs_super_block *selected_super;
 654         struct list_head *dev_head = &fs_devices->devices;
 655         struct btrfs_device *device;
 656         struct btrfsic_dev_state *selected_dev_state = NULL;
 657         int pass;
 658
 659         BUG_ON(NULL == state);
 660         selected_super = kzalloc(sizeof(*selected_super), GFP_NOFS);
 661         if (NULL == selected_super) {
 662                 printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
 663                 return -1;
 664         }
 665
 666         list_for_each_entry(device, dev_head, dev_list) {
 667                 int i;
 668                 struct btrfsic_dev_state *dev_state;
 669
 670                 if (!device->bdev || !device->name)
 671                         continue;
 672
 673                 dev_state = btrfsic_dev_state_lookup(device->bdev);
 674                 BUG_ON(NULL == dev_state);
 675                 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
 676                         ret = btrfsic_process_superblock_dev_mirror(
 677                                         state, dev_state, device, i,
 678                                         &selected_dev_state, selected_super);
 679                         if (0 != ret && 0 == i) {
 680                                 kfree(selected_super);
 681                                 return ret;
 682                         }
 683                 }
 684         }
 685
 686         if (NULL == state->latest_superblock) {
 687                 printk(KERN_INFO "btrfsic: no superblock found!\n");
 688                 kfree(selected_super);
 689                 return -1;
 690         }
 691
 692         state->csum_size = btrfs_super_csum_size(selected_super);
 693
 694         for (pass = 0; pass < 3; pass++) {
 695                 int num_copies;
 696                 int mirror_num;
 697                 u64 next_bytenr;
 698
 699                 switch (pass) {
 700                 case 0:
 701                         next_bytenr = btrfs_super_root(selected_super);
 702                         if (state->print_mask &
 703                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 704                                 printk(KERN_INFO "root@%llu\n",
 705                                        (unsigned long long)next_bytenr);
 706                         break;
 707                 case 1:
 708                         next_bytenr = btrfs_super_chunk_root(selected_super);
 709                         if (state->print_mask &
 710                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 711                                 printk(KERN_INFO "chunk@%llu\n",
 712                                        (unsigned long long)next_bytenr);
 713                         break;
 714                 case 2:
 715                         next_bytenr = btrfs_super_log_root(selected_super);
 716                         if (0 == next_bytenr)
 717                                 continue;
 718                         if (state->print_mask &
 719                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 720                                 printk(KERN_INFO "log@%llu\n",
 721                                        (unsigned long long)next_bytenr);
 722                         break;
 723                 }
 724
 725                 num_copies =
 726                     btrfs_num_copies(state->root->fs_info,
 727                                      next_bytenr, state->metablock_size);
 728                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
 729                         printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
 730                                (unsigned long long)next_bytenr, num_copies);
 731
 732                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
 733                         struct btrfsic_block *next_block;
 734                         struct btrfsic_block_data_ctx tmp_next_block_ctx;
 735                         struct btrfsic_block_link *l;
 736
 737                         ret = btrfsic_map_block(state, next_bytenr,
 738                                                 state->metablock_size,
 739                                                 &tmp_next_block_ctx,
 740                                                 mirror_num);
 741                         if (ret) {
 742                                 printk(KERN_INFO "btrfsic:"
 743                                        " btrfsic_map_block(root @%llu,"
 744                                        " mirror %d) failed!\n",
 745                                        (unsigned long long)next_bytenr,
 746                                        mirror_num);
 747                                 kfree(selected_super);
 748                                 return -1;
 749                         }
 750
 751                         next_block = btrfsic_block_hashtable_lookup(
 752                                         tmp_next_block_ctx.dev->bdev,
 753                                         tmp_next_block_ctx.dev_bytenr,
 754                                         &state->block_hashtable);
 755                         BUG_ON(NULL == next_block);
 756
 757                         l = btrfsic_block_link_hashtable_lookup(
 758                                         tmp_next_block_ctx.dev->bdev,
 759                                         tmp_next_block_ctx.dev_bytenr,
 760                                         state->latest_superblock->dev_state->
 761                                         bdev,
 762                                         state->latest_superblock->dev_bytenr,
 763                                         &state->block_link_hashtable);
 764                         BUG_ON(NULL == l);
 765
 766                         ret = btrfsic_read_block(state, &tmp_next_block_ctx);
 767                         if (ret < (int)PAGE_CACHE_SIZE) {
 768                                 printk(KERN_INFO
 769                                        "btrfsic: read @logical %llu failed!\n",
 770                                        (unsigned long long)
 771                                        tmp_next_block_ctx.start);
 772                                 btrfsic_release_block_ctx(&tmp_next_block_ctx);
 773                                 kfree(selected_super);
 774                                 return -1;
 775                         }
 776
 777                         ret = btrfsic_process_metablock(state,
 778                                                         next_block,
 779                                                         &tmp_next_block_ctx,
 780                                                         BTRFS_MAX_LEVEL + 3, 1);
 781                         btrfsic_release_block_ctx(&tmp_next_block_ctx);
 782                 }
 783         }
 784
 785         kfree(selected_super);
 786         return ret;
 787 }
 788
 789 static int btrfsic_process_superblock_dev_mirror(
 790                 struct btrfsic_state *state,
 791                 struct btrfsic_dev_state *dev_state,
 792                 struct btrfs_device *device,
 793                 int superblock_mirror_num,
 794                 struct btrfsic_dev_state **selected_dev_state,
 795                 struct btrfs_super_block *selected_super)
 796 {
 797         struct btrfs_super_block *super_tmp;
 798         u64 dev_bytenr;
 799         struct buffer_head *bh;
 800         struct btrfsic_block *superblock_tmp;
 801         int pass;
 802         struct block_device *const superblock_bdev = device->bdev;
 803
 804         /* super block bytenr is always the unmapped device bytenr */
 805         dev_bytenr = btrfs_sb_offset(superblock_mirror_num);
 806         if (dev_bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
 807                 return -1;
 808         bh = __bread(superblock_bdev, dev_bytenr / 4096,
 809                      BTRFS_SUPER_INFO_SIZE);
 810         if (NULL == bh)
 811                 return -1;
 812         super_tmp = (struct btrfs_super_block *)
 813             (bh->b_data + (dev_bytenr & 4095));
 814
 815         if (btrfs_super_bytenr(super_tmp) != dev_bytenr ||
 816             btrfs_super_magic(super_tmp) != BTRFS_MAGIC ||
 817             memcmp(device->uuid, super_tmp->dev_item.uuid, BTRFS_UUID_SIZE) ||
 818             btrfs_super_nodesize(super_tmp) != state->metablock_size ||
 819             btrfs_super_leafsize(super_tmp) != state->metablock_size ||
 820             btrfs_super_sectorsize(super_tmp) != state->datablock_size) {
 821                 brelse(bh);
 822                 return 0;
 823         }
 824
 825         superblock_tmp =
 826             btrfsic_block_hashtable_lookup(superblock_bdev,
 827                                            dev_bytenr,
 828                                            &state->block_hashtable);
 829         if (NULL == superblock_tmp) {
 830                 superblock_tmp = btrfsic_block_alloc();
 831                 if (NULL == superblock_tmp) {
 832                         printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
 833                         brelse(bh);
 834                         return -1;
 835                 }
 836                 /* for superblock, only the dev_bytenr makes sense */
 837                 superblock_tmp->dev_bytenr = dev_bytenr;
 838                 superblock_tmp->dev_state = dev_state;
 839                 superblock_tmp->logical_bytenr = dev_bytenr;
 840                 superblock_tmp->generation = btrfs_super_generation(super_tmp);
 841                 superblock_tmp->is_metadata = 1;
 842                 superblock_tmp->is_superblock = 1;
 843                 superblock_tmp->is_iodone = 1;
 844                 superblock_tmp->never_written = 0;
 845                 superblock_tmp->mirror_num = 1 + superblock_mirror_num;
 846                 if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
 847                         printk_in_rcu(KERN_INFO "New initial S-block (bdev %p, %s)"
 848                                      " @%llu (%s/%llu/%d)\n",
 849                                      superblock_bdev,
 850                                      rcu_str_deref(device->name),
 851                                      (unsigned long long)dev_bytenr,
 852                                      dev_state->name,
 853                                      (unsigned long long)dev_bytenr,
 854                                      superblock_mirror_num);
 855                 list_add(&superblock_tmp->all_blocks_node,
 856                          &state->all_blocks_list);
 857                 btrfsic_block_hashtable_add(superblock_tmp,
 858                                             &state->block_hashtable);
 859         }
 860
 861         /* select the one with the highest generation field */
 862         if (btrfs_super_generation(super_tmp) >
 863             state->max_superblock_generation ||
 864             0 == state->max_superblock_generation) {
 865                 memcpy(selected_super, super_tmp, sizeof(*selected_super));
 866                 *selected_dev_state = dev_state;
 867                 state->max_superblock_generation =
 868                     btrfs_super_generation(super_tmp);
 869                 state->latest_superblock = superblock_tmp;
 870         }
 871
 872         for (pass = 0; pass < 3; pass++) {
 873                 u64 next_bytenr;
 874                 int num_copies;
 875                 int mirror_num;
 876                 const char *additional_string = NULL;
 877                 struct btrfs_disk_key tmp_disk_key;
 878
 879                 tmp_disk_key.type = BTRFS_ROOT_ITEM_KEY;
 880                 tmp_disk_key.offset = 0;
 881                 switch (pass) {
 882                 case 0:
 883                         btrfs_set_disk_key_objectid(&tmp_disk_key,
 884                                                     BTRFS_ROOT_TREE_OBJECTID);
 885                         additional_string = "initial root ";
 886                         next_bytenr = btrfs_super_root(super_tmp);
 887                         break;
 888                 case 1:
 889                         btrfs_set_disk_key_objectid(&tmp_disk_key,
 890                                                     BTRFS_CHUNK_TREE_OBJECTID);
 891                         additional_string = "initial chunk ";
 892                         next_bytenr = btrfs_super_chunk_root(super_tmp);
 893                         break;
 894                 case 2:
 895                         btrfs_set_disk_key_objectid(&tmp_disk_key,
 896                                                     BTRFS_TREE_LOG_OBJECTID);
 897                         additional_string = "initial log ";
 898                         next_bytenr = btrfs_super_log_root(super_tmp);
 899                         if (0 == next_bytenr)
 900                                 continue;
 901                         break;
 902                 }
 903
 904                 num_copies =
 905                     btrfs_num_copies(state->root->fs_info,
 906                                      next_bytenr, state->metablock_size);
 907                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
 908                         printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
 909                                (unsigned long long)next_bytenr, num_copies);
 910                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
 911                         struct btrfsic_block *next_block;
 912                         struct btrfsic_block_data_ctx tmp_next_block_ctx;
 913                         struct btrfsic_block_link *l;
 914
 915                         if (btrfsic_map_block(state, next_bytenr,
 916                                               state->metablock_size,
 917                                               &tmp_next_block_ctx,
 918                                               mirror_num)) {
 919                                 printk(KERN_INFO "btrfsic: btrfsic_map_block("
 920                                        "bytenr @%llu, mirror %d) failed!\n",
 921                                        (unsigned long long)next_bytenr,
 922                                        mirror_num);
 923                                 brelse(bh);
 924                                 return -1;
 925                         }
 926
 927                         next_block = btrfsic_block_lookup_or_add(
 928                                         state, &tmp_next_block_ctx,
 929                                         additional_string, 1, 1, 0,
 930                                         mirror_num, NULL);
 931                         if (NULL == next_block) {
 932                                 btrfsic_release_block_ctx(&tmp_next_block_ctx);
 933                                 brelse(bh);
 934                                 return -1;
 935                         }
 936
 937                         next_block->disk_key = tmp_disk_key;
 938                         next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
 939                         l = btrfsic_block_link_lookup_or_add(
 940                                         state, &tmp_next_block_ctx,
 941                                         next_block, superblock_tmp,
 942                                         BTRFSIC_GENERATION_UNKNOWN);
 943                         btrfsic_release_block_ctx(&tmp_next_block_ctx);
 944                         if (NULL == l) {
 945                                 brelse(bh);
 946                                 return -1;
 947                         }
 948                 }
 949         }
 950         if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES)
 951                 btrfsic_dump_tree_sub(state, superblock_tmp, 0);
 952
 953         brelse(bh);
 954         return 0;
 955 }
 956
 957 static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void)
 958 {
 959         struct btrfsic_stack_frame *sf;
 960
 961         sf = kzalloc(sizeof(*sf), GFP_NOFS);
 962         if (NULL == sf)
 963                 printk(KERN_INFO "btrfsic: alloc memory failed!\n");
 964         else
 965                 sf->magic = BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER;
 966         return sf;
 967 }
 968
 969 static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf)
 970 {
 971         BUG_ON(!(NULL == sf ||
 972                  BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER == sf->magic));
 973         kfree(sf);
 974 }
 975
 976 static int btrfsic_process_metablock(
 977                 struct btrfsic_state *state,
 978                 struct btrfsic_block *const first_block,
 979                 struct btrfsic_block_data_ctx *const first_block_ctx,
 980                 int first_limit_nesting, int force_iodone_flag)
 981 {
 982         struct btrfsic_stack_frame initial_stack_frame = { 0 };
 983         struct btrfsic_stack_frame *sf;
 984         struct btrfsic_stack_frame *next_stack;
 985         struct btrfs_header *const first_hdr =
 986                 (struct btrfs_header *)first_block_ctx->datav[0];
 987
 988         BUG_ON(!first_hdr);
 989         sf = &initial_stack_frame;
 990         sf->error = 0;
 991         sf->i = -1;
 992         sf->limit_nesting = first_limit_nesting;
 993         sf->block = first_block;
 994         sf->block_ctx = first_block_ctx;
 995         sf->next_block = NULL;
 996         sf->hdr = first_hdr;
 997         sf->prev = NULL;
 998
 999 continue_with_new_stack_frame:
1000         sf->block->generation = le64_to_cpu(sf->hdr->generation);
1001         if (0 == sf->hdr->level) {
1002                 struct btrfs_leaf *const leafhdr =
1003                     (struct btrfs_leaf *)sf->hdr;
1004
1005                 if (-1 == sf->i) {
1006                         sf->nr = btrfs_stack_header_nritems(&leafhdr->header);
1007
1008                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1009                                 printk(KERN_INFO
1010                                        "leaf %llu items %d generation %llu"
1011                                        " owner %llu\n",
1012                                        (unsigned long long)
1013                                        sf->block_ctx->start,
1014                                        sf->nr,
1015                                        (unsigned long long)
1016                                        btrfs_stack_header_generation(
1017                                                &leafhdr->header),
1018                                        (unsigned long long)
1019                                        btrfs_stack_header_owner(
1020                                                &leafhdr->header));
1021                 }
1022
1023 continue_with_current_leaf_stack_frame:
1024                 if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1025                         sf->i++;
1026                         sf->num_copies = 0;
1027                 }
1028
1029                 if (sf->i < sf->nr) {
1030                         struct btrfs_item disk_item;
1031                         u32 disk_item_offset =
1032                                 (uintptr_t)(leafhdr->items + sf->i) -
1033                                 (uintptr_t)leafhdr;
1034                         struct btrfs_disk_key *disk_key;
1035                         u8 type;
1036                         u32 item_offset;
1037                         u32 item_size;
1038
1039                         if (disk_item_offset + sizeof(struct btrfs_item) >
1040                             sf->block_ctx->len) {
1041 leaf_item_out_of_bounce_error:
1042                                 printk(KERN_INFO
1043                                        "btrfsic: leaf item out of bounce at logical %llu, dev %s\n",
1044                                        sf->block_ctx->start,
1045                                        sf->block_ctx->dev->name);
1046                                 goto one_stack_frame_backwards;
1047                         }
1048                         btrfsic_read_from_block_data(sf->block_ctx,
1049                                                      &disk_item,
1050                                                      disk_item_offset,
1051                                                      sizeof(struct btrfs_item));
1052                         item_offset = btrfs_stack_item_offset(&disk_item);
1053                         item_size = btrfs_stack_item_offset(&disk_item);
1054                         disk_key = &disk_item.key;
1055                         type = btrfs_disk_key_type(disk_key);
1056
1057                         if (BTRFS_ROOT_ITEM_KEY == type) {
1058                                 struct btrfs_root_item root_item;
1059                                 u32 root_item_offset;
1060                                 u64 next_bytenr;
1061
1062                                 root_item_offset = item_offset +
1063                                         offsetof(struct btrfs_leaf, items);
1064                                 if (root_item_offset + item_size >
1065                                     sf->block_ctx->len)
1066                                         goto leaf_item_out_of_bounce_error;
1067                                 btrfsic_read_from_block_data(
1068                                         sf->block_ctx, &root_item,
1069                                         root_item_offset,
1070                                         item_size);
1071                                 next_bytenr = btrfs_root_bytenr(&root_item);
1072
1073                                 sf->error =
1074                                     btrfsic_create_link_to_next_block(
1075                                                 state,
1076                                                 sf->block,
1077                                                 sf->block_ctx,
1078                                                 next_bytenr,
1079                                                 sf->limit_nesting,
1080                                                 &sf->next_block_ctx,
1081                                                 &sf->next_block,
1082                                                 force_iodone_flag,
1083                                                 &sf->num_copies,
1084                                                 &sf->mirror_num,
1085                                                 disk_key,
1086                                                 btrfs_root_generation(
1087                                                 &root_item));
1088                                 if (sf->error)
1089                                         goto one_stack_frame_backwards;
1090
1091                                 if (NULL != sf->next_block) {
1092                                         struct btrfs_header *const next_hdr =
1093                                             (struct btrfs_header *)
1094                                             sf->next_block_ctx.datav[0];
1095
1096                                         next_stack =
1097                                             btrfsic_stack_frame_alloc();
1098                                         if (NULL == next_stack) {
1099                                                 btrfsic_release_block_ctx(
1100                                                                 &sf->
1101                                                                 next_block_ctx);
1102                                                 goto one_stack_frame_backwards;
1103                                         }
1104
1105                                         next_stack->i = -1;
1106                                         next_stack->block = sf->next_block;
1107                                         next_stack->block_ctx =
1108                                             &sf->next_block_ctx;
1109                                         next_stack->next_block = NULL;
1110                                         next_stack->hdr = next_hdr;
1111                                         next_stack->limit_nesting =
1112                                             sf->limit_nesting - 1;
1113                                         next_stack->prev = sf;
1114                                         sf = next_stack;
1115                                         goto continue_with_new_stack_frame;
1116                                 }
1117                         } else if (BTRFS_EXTENT_DATA_KEY == type &&
1118                                    state->include_extent_data) {
1119                                 sf->error = btrfsic_handle_extent_data(
1120                                                 state,
1121                                                 sf->block,
1122                                                 sf->block_ctx,
1123                                                 item_offset,
1124                                                 force_iodone_flag);
1125                                 if (sf->error)
1126                                         goto one_stack_frame_backwards;
1127                         }
1128
1129                         goto continue_with_current_leaf_stack_frame;
1130                 }
1131         } else {
1132                 struct btrfs_node *const nodehdr = (struct btrfs_node *)sf->hdr;
1133
1134                 if (-1 == sf->i) {
1135                         sf->nr = btrfs_stack_header_nritems(&nodehdr->header);
1136
1137                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1138                                 printk(KERN_INFO "node %llu level %d items %d"
1139                                        " generation %llu owner %llu\n",
1140                                        (unsigned long long)
1141                                        sf->block_ctx->start,
1142                                        nodehdr->header.level, sf->nr,
1143                                        (unsigned long long)
1144                                        btrfs_stack_header_generation(
1145                                        &nodehdr->header),
1146                                        (unsigned long long)
1147                                        btrfs_stack_header_owner(
1148                                        &nodehdr->header));
1149                 }
1150
1151 continue_with_current_node_stack_frame:
1152                 if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1153                         sf->i++;
1154                         sf->num_copies = 0;
1155                 }
1156
1157                 if (sf->i < sf->nr) {
1158                         struct btrfs_key_ptr key_ptr;
1159                         u32 key_ptr_offset;
1160                         u64 next_bytenr;
1161
1162                         key_ptr_offset = (uintptr_t)(nodehdr->ptrs + sf->i) -
1163                                           (uintptr_t)nodehdr;
1164                         if (key_ptr_offset + sizeof(struct btrfs_key_ptr) >
1165                             sf->block_ctx->len) {
1166                                 printk(KERN_INFO
1167                                        "btrfsic: node item out of bounce at logical %llu, dev %s\n",
1168                                        sf->block_ctx->start,
1169                                        sf->block_ctx->dev->name);
1170                                 goto one_stack_frame_backwards;
1171                         }
1172                         btrfsic_read_from_block_data(
1173                                 sf->block_ctx, &key_ptr, key_ptr_offset,
1174                                 sizeof(struct btrfs_key_ptr));
1175                         next_bytenr = btrfs_stack_key_blockptr(&key_ptr);
1176
1177                         sf->error = btrfsic_create_link_to_next_block(
1178                                         state,
1179                                         sf->block,
1180                                         sf->block_ctx,
1181                                         next_bytenr,
1182                                         sf->limit_nesting,
1183                                         &sf->next_block_ctx,
1184                                         &sf->next_block,
1185                                         force_iodone_flag,
1186                                         &sf->num_copies,
1187                                         &sf->mirror_num,
1188                                         &key_ptr.key,
1189                                         btrfs_stack_key_generation(&key_ptr));
1190                         if (sf->error)
1191                                 goto one_stack_frame_backwards;
1192
1193                         if (NULL != sf->next_block) {
1194                                 struct btrfs_header *const next_hdr =
1195                                     (struct btrfs_header *)
1196                                     sf->next_block_ctx.datav[0];
1197
1198                                 next_stack = btrfsic_stack_frame_alloc();
1199                                 if (NULL == next_stack)
1200                                         goto one_stack_frame_backwards;
1201
1202                                 next_stack->i = -1;
1203                                 next_stack->block = sf->next_block;
1204                                 next_stack->block_ctx = &sf->next_block_ctx;
1205                                 next_stack->next_block = NULL;
1206                                 next_stack->hdr = next_hdr;
1207                                 next_stack->limit_nesting =
1208                                     sf->limit_nesting - 1;
1209                                 next_stack->prev = sf;
1210                                 sf = next_stack;
1211                                 goto continue_with_new_stack_frame;
1212                         }
1213
1214                         goto continue_with_current_node_stack_frame;
1215                 }
1216         }
1217
1218 one_stack_frame_backwards:
1219         if (NULL != sf->prev) {
1220                 struct btrfsic_stack_frame *const prev = sf->prev;
1221
1222                 /* the one for the initial block is freed in the caller */
1223                 btrfsic_release_block_ctx(sf->block_ctx);
1224
1225                 if (sf->error) {
1226                         prev->error = sf->error;
1227                         btrfsic_stack_frame_free(sf);
1228                         sf = prev;
1229                         goto one_stack_frame_backwards;
1230                 }
1231
1232                 btrfsic_stack_frame_free(sf);
1233                 sf = prev;
1234                 goto continue_with_new_stack_frame;
1235         } else {
1236                 BUG_ON(&initial_stack_frame != sf);
1237         }
1238
1239         return sf->error;
1240 }
1241
1242 static void btrfsic_read_from_block_data(
1243         struct btrfsic_block_data_ctx *block_ctx,
1244         void *dstv, u32 offset, size_t len)
1245 {
1246         size_t cur;
1247         size_t offset_in_page;
1248         char *kaddr;
1249         char *dst = (char *)dstv;
1250         size_t start_offset = block_ctx->start & ((u64)PAGE_CACHE_SIZE - 1);
1251         unsigned long i = (start_offset + offset) >> PAGE_CACHE_SHIFT;
1252
1253         WARN_ON(offset + len > block_ctx->len);
1254         offset_in_page = (start_offset + offset) &
1255                          ((unsigned long)PAGE_CACHE_SIZE - 1);
1256
1257         while (len > 0) {
1258                 cur = min(len, ((size_t)PAGE_CACHE_SIZE - offset_in_page));
1259                 BUG_ON(i >= (block_ctx->len + PAGE_CACHE_SIZE - 1) >>
1260                             PAGE_CACHE_SHIFT);
1261                 kaddr = block_ctx->datav[i];
1262                 memcpy(dst, kaddr + offset_in_page, cur);
1263
1264                 dst += cur;
1265                 len -= cur;
1266                 offset_in_page = 0;
1267                 i++;
1268         }
1269 }
1270
1271 static int btrfsic_create_link_to_next_block(
1272                 struct btrfsic_state *state,
1273                 struct btrfsic_block *block,
1274                 struct btrfsic_block_data_ctx *block_ctx,
1275                 u64 next_bytenr,
1276                 int limit_nesting,
1277                 struct btrfsic_block_data_ctx *next_block_ctx,
1278                 struct btrfsic_block **next_blockp,
1279                 int force_iodone_flag,
1280                 int *num_copiesp, int *mirror_nump,
1281                 struct btrfs_disk_key *disk_key,
1282                 u64 parent_generation)
1283 {
1284         struct btrfsic_block *next_block = NULL;
1285         int ret;
1286         struct btrfsic_block_link *l;
1287         int did_alloc_block_link;
1288         int block_was_created;
1289
1290         *next_blockp = NULL;
1291         if (0 == *num_copiesp) {
1292                 *num_copiesp =
1293                     btrfs_num_copies(state->root->fs_info,
1294                                      next_bytenr, state->metablock_size);
1295                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1296                         printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
1297                                (unsigned long long)next_bytenr, *num_copiesp);
1298                 *mirror_nump = 1;
1299         }
1300
1301         if (*mirror_nump > *num_copiesp)
1302                 return 0;
1303
1304         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1305                 printk(KERN_INFO
1306                        "btrfsic_create_link_to_next_block(mirror_num=%d)\n",
1307                        *mirror_nump);
1308         ret = btrfsic_map_block(state, next_bytenr,
1309                                 state->metablock_size,
1310                                 next_block_ctx, *mirror_nump);
1311         if (ret) {
1312                 printk(KERN_INFO
1313                        "btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
1314                        (unsigned long long)next_bytenr, *mirror_nump);
1315                 btrfsic_release_block_ctx(next_block_ctx);
1316                 *next_blockp = NULL;
1317                 return -1;
1318         }
1319
1320         next_block = btrfsic_block_lookup_or_add(state,
1321                                                  next_block_ctx, "referenced ",
1322                                                  1, force_iodone_flag,
1323                                                  !force_iodone_flag,
1324                                                  *mirror_nump,
1325                                                  &block_was_created);
1326         if (NULL == next_block) {
1327                 btrfsic_release_block_ctx(next_block_ctx);
1328                 *next_blockp = NULL;
1329                 return -1;
1330         }
1331         if (block_was_created) {
1332                 l = NULL;
1333                 next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
1334         } else {
1335                 if (next_block->logical_bytenr != next_bytenr &&
1336                     !(!next_block->is_metadata &&
1337                       0 == next_block->logical_bytenr)) {
1338                         printk(KERN_INFO
1339                                "Referenced block @%llu (%s/%llu/%d)"
1340                                " found in hash table, %c,"
1341                                " bytenr mismatch (!= stored %llu).\n",
1342                                (unsigned long long)next_bytenr,
1343                                next_block_ctx->dev->name,
1344                                (unsigned long long)next_block_ctx->dev_bytenr,
1345                                *mirror_nump,
1346                                btrfsic_get_block_type(state, next_block),
1347                                (unsigned long long)next_block->logical_bytenr);
1348                 } else if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1349                         printk(KERN_INFO
1350                                "Referenced block @%llu (%s/%llu/%d)"
1351                                " found in hash table, %c.\n",
1352                                (unsigned long long)next_bytenr,
1353                                next_block_ctx->dev->name,
1354                                (unsigned long long)next_block_ctx->dev_bytenr,
1355                                *mirror_nump,
1356                                btrfsic_get_block_type(state, next_block));
1357                 next_block->logical_bytenr = next_bytenr;
1358
1359                 next_block->mirror_num = *mirror_nump;
1360                 l = btrfsic_block_link_hashtable_lookup(
1361                                 next_block_ctx->dev->bdev,
1362                                 next_block_ctx->dev_bytenr,
1363                                 block_ctx->dev->bdev,
1364                                 block_ctx->dev_bytenr,
1365                                 &state->block_link_hashtable);
1366         }
1367
1368         next_block->disk_key = *disk_key;
1369         if (NULL == l) {
1370                 l = btrfsic_block_link_alloc();
1371                 if (NULL == l) {
1372                         printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
1373                         btrfsic_release_block_ctx(next_block_ctx);
1374                         *next_blockp = NULL;
1375                         return -1;
1376                 }
1377
1378                 did_alloc_block_link = 1;
1379                 l->block_ref_to = next_block;
1380                 l->block_ref_from = block;
1381                 l->ref_cnt = 1;
1382                 l->parent_generation = parent_generation;
1383
1384                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1385                         btrfsic_print_add_link(state, l);
1386
1387                 list_add(&l->node_ref_to, &block->ref_to_list);
1388                 list_add(&l->node_ref_from, &next_block->ref_from_list);
1389
1390                 btrfsic_block_link_hashtable_add(l,
1391                                                  &state->block_link_hashtable);
1392         } else {
1393                 did_alloc_block_link = 0;
1394                 if (0 == limit_nesting) {
1395                         l->ref_cnt++;
1396                         l->parent_generation = parent_generation;
1397                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1398                                 btrfsic_print_add_link(state, l);
1399                 }
1400         }
1401
1402         if (limit_nesting > 0 && did_alloc_block_link) {
1403                 ret = btrfsic_read_block(state, next_block_ctx);
1404                 if (ret < (int)next_block_ctx->len) {
1405                         printk(KERN_INFO
1406                                "btrfsic: read block @logical %llu failed!\n",
1407                                (unsigned long long)next_bytenr);
1408                         btrfsic_release_block_ctx(next_block_ctx);
1409                         *next_blockp = NULL;
1410                         return -1;
1411                 }
1412
1413                 *next_blockp = next_block;
1414         } else {
1415                 *next_blockp = NULL;
1416         }
1417         (*mirror_nump)++;
1418
1419         return 0;
1420 }
1421
1422 static int btrfsic_handle_extent_data(
1423                 struct btrfsic_state *state,
1424                 struct btrfsic_block *block,
1425                 struct btrfsic_block_data_ctx *block_ctx,
1426                 u32 item_offset, int force_iodone_flag)
1427 {
1428         int ret;
1429         struct btrfs_file_extent_item file_extent_item;
1430         u64 file_extent_item_offset;
1431         u64 next_bytenr;
1432         u64 num_bytes;
1433         u64 generation;
1434         struct btrfsic_block_link *l;
1435
1436         file_extent_item_offset = offsetof(struct btrfs_leaf, items) +
1437                                   item_offset;
1438         if (file_extent_item_offset +
1439             offsetof(struct btrfs_file_extent_item, disk_num_bytes) >
1440             block_ctx->len) {
1441                 printk(KERN_INFO
1442                        "btrfsic: file item out of bounce at logical %llu, dev %s\n",
1443                        block_ctx->start, block_ctx->dev->name);
1444                 return -1;
1445         }
1446
1447         btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1448                 file_extent_item_offset,
1449                 offsetof(struct btrfs_file_extent_item, disk_num_bytes));
1450         if (BTRFS_FILE_EXTENT_REG != file_extent_item.type ||
1451             btrfs_stack_file_extent_disk_bytenr(&file_extent_item) == 0) {
1452                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1453                         printk(KERN_INFO "extent_data: type %u, disk_bytenr = %llu\n",
1454                                file_extent_item.type,
1455                                (unsigned long long)
1456                                btrfs_stack_file_extent_disk_bytenr(
1457                                &file_extent_item));
1458                 return 0;
1459         }
1460
1461         if (file_extent_item_offset + sizeof(struct btrfs_file_extent_item) >
1462             block_ctx->len) {
1463                 printk(KERN_INFO
1464                        "btrfsic: file item out of bounce at logical %llu, dev %s\n",
1465                        block_ctx->start, block_ctx->dev->name);
1466                 return -1;
1467         }
1468         btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1469                                      file_extent_item_offset,
1470                                      sizeof(struct btrfs_file_extent_item));
1471         next_bytenr = btrfs_stack_file_extent_disk_bytenr(&file_extent_item) +
1472                       btrfs_stack_file_extent_offset(&file_extent_item);
1473         generation = btrfs_stack_file_extent_generation(&file_extent_item);
1474         num_bytes = btrfs_stack_file_extent_num_bytes(&file_extent_item);
1475         generation = btrfs_stack_file_extent_generation(&file_extent_item);
1476
1477         if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1478                 printk(KERN_INFO "extent_data: type %u, disk_bytenr = %llu,"
1479                        " offset = %llu, num_bytes = %llu\n",
1480                        file_extent_item.type,
1481                        (unsigned long long)
1482                        btrfs_stack_file_extent_disk_bytenr(&file_extent_item),
1483                        (unsigned long long)
1484                        btrfs_stack_file_extent_offset(&file_extent_item),
1485                        (unsigned long long)num_bytes);
1486         while (num_bytes > 0) {
1487                 u32 chunk_len;
1488                 int num_copies;
1489                 int mirror_num;
1490
1491                 if (num_bytes > state->datablock_size)
1492                         chunk_len = state->datablock_size;
1493                 else
1494                         chunk_len = num_bytes;
1495
1496                 num_copies =
1497                     btrfs_num_copies(state->root->fs_info,
1498                                      next_bytenr, state->datablock_size);
1499                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1500                         printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
1501                                (unsigned long long)next_bytenr, num_copies);
1502                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
1503                         struct btrfsic_block_data_ctx next_block_ctx;
1504                         struct btrfsic_block *next_block;
1505                         int block_was_created;
1506
1507                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1508                                 printk(KERN_INFO "btrfsic_handle_extent_data("
1509                                        "mirror_num=%d)\n", mirror_num);
1510                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1511                                 printk(KERN_INFO
1512                                        "\tdisk_bytenr = %llu, num_bytes %u\n",
1513                                        (unsigned long long)next_bytenr,
1514                                        chunk_len);
1515                         ret = btrfsic_map_block(state, next_bytenr,
1516                                                 chunk_len, &next_block_ctx,
1517                                                 mirror_num);
1518                         if (ret) {
1519                                 printk(KERN_INFO
1520                                        "btrfsic: btrfsic_map_block(@%llu,"
1521                                        " mirror=%d) failed!\n",
1522                                        (unsigned long long)next_bytenr,
1523                                        mirror_num);
1524                                 return -1;
1525                         }
1526
1527                         next_block = btrfsic_block_lookup_or_add(
1528                                         state,
1529                                         &next_block_ctx,
1530                                         "referenced ",
1531                                         0,
1532                                         force_iodone_flag,
1533                                         !force_iodone_flag,
1534                                         mirror_num,
1535                                         &block_was_created);
1536                         if (NULL == next_block) {
1537                                 printk(KERN_INFO
1538                                        "btrfsic: error, kmalloc failed!\n");
1539                                 btrfsic_release_block_ctx(&next_block_ctx);
1540                                 return -1;
1541                         }
1542                         if (!block_was_created) {
1543                                 if (next_block->logical_bytenr != next_bytenr &&
1544                                     !(!next_block->is_metadata &&
1545                                       0 == next_block->logical_bytenr)) {
1546                                         printk(KERN_INFO
1547                                                "Referenced block"
1548                                                " @%llu (%s/%llu/%d)"
1549                                                " found in hash table, D,"
1550                                                " bytenr mismatch"
1551                                                " (!= stored %llu).\n",
1552                                                (unsigned long long)next_bytenr,
1553                                                next_block_ctx.dev->name,
1554                                                (unsigned long long)
1555                                                next_block_ctx.dev_bytenr,
1556                                                mirror_num,
1557                                                (unsigned long long)
1558                                                next_block->logical_bytenr);
1559                                 }
1560                                 next_block->logical_bytenr = next_bytenr;
1561                                 next_block->mirror_num = mirror_num;
1562                         }
1563
1564                         l = btrfsic_block_link_lookup_or_add(state,
1565                                                              &next_block_ctx,
1566                                                              next_block, block,
1567                                                              generation);
1568                         btrfsic_release_block_ctx(&next_block_ctx);
1569                         if (NULL == l)
1570                                 return -1;
1571                 }
1572
1573                 next_bytenr += chunk_len;
1574                 num_bytes -= chunk_len;
1575         }
1576
1577         return 0;
1578 }
1579
1580 static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
1581                              struct btrfsic_block_data_ctx *block_ctx_out,
1582                              int mirror_num)
1583 {
1584         int ret;
1585         u64 length;
1586         struct btrfs_bio *multi = NULL;
1587         struct btrfs_device *device;
1588
1589         length = len;
1590         ret = btrfs_map_block(state->root->fs_info, READ,
1591                               bytenr, &length, &multi, mirror_num);
1592
1593         if (ret) {
1594                 block_ctx_out->start = 0;
1595                 block_ctx_out->dev_bytenr = 0;
1596                 block_ctx_out->len = 0;
1597                 block_ctx_out->dev = NULL;
1598                 block_ctx_out->datav = NULL;
1599                 block_ctx_out->pagev = NULL;
1600                 block_ctx_out->mem_to_free = NULL;
1601
1602                 return ret;
1603         }
1604
1605         device = multi->stripes[0].dev;
1606         block_ctx_out->dev = btrfsic_dev_state_lookup(device->bdev);
1607         block_ctx_out->dev_bytenr = multi->stripes[0].physical;
1608         block_ctx_out->start = bytenr;
1609         block_ctx_out->len = len;
1610         block_ctx_out->datav = NULL;
1611         block_ctx_out->pagev = NULL;
1612         block_ctx_out->mem_to_free = NULL;
1613
1614         kfree(multi);
1615         if (NULL == block_ctx_out->dev) {
1616                 ret = -ENXIO;
1617                 printk(KERN_INFO "btrfsic: error, cannot lookup dev (#1)!\n");
1618         }
1619
1620         return ret;
1621 }
1622
1623 static int btrfsic_map_superblock(struct btrfsic_state *state, u64 bytenr,
1624                                   u32 len, struct block_device *bdev,
1625                                   struct btrfsic_block_data_ctx *block_ctx_out)
1626 {
1627         block_ctx_out->dev = btrfsic_dev_state_lookup(bdev);
1628         block_ctx_out->dev_bytenr = bytenr;
1629         block_ctx_out->start = bytenr;
1630         block_ctx_out->len = len;
1631         block_ctx_out->datav = NULL;
1632         block_ctx_out->pagev = NULL;
1633         block_ctx_out->mem_to_free = NULL;
1634         if (NULL != block_ctx_out->dev) {
1635                 return 0;
1636         } else {
1637                 printk(KERN_INFO "btrfsic: error, cannot lookup dev (#2)!\n");
1638                 return -ENXIO;
1639         }
1640 }
1641
1642 static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx)
1643 {
1644         if (block_ctx->mem_to_free) {
1645                 unsigned int num_pages;
1646
1647                 BUG_ON(!block_ctx->datav);
1648                 BUG_ON(!block_ctx->pagev);
1649                 num_pages = (block_ctx->len + (u64)PAGE_CACHE_SIZE - 1) >>
1650                             PAGE_CACHE_SHIFT;
1651                 while (num_pages > 0) {
1652                         num_pages--;
1653                         if (block_ctx->datav[num_pages]) {
1654                                 kunmap(block_ctx->pagev[num_pages]);
1655                                 block_ctx->datav[num_pages] = NULL;
1656                         }
1657                         if (block_ctx->pagev[num_pages]) {
1658                                 __free_page(block_ctx->pagev[num_pages]);
1659                                 block_ctx->pagev[num_pages] = NULL;
1660                         }
1661                 }
1662
1663                 kfree(block_ctx->mem_to_free);
1664                 block_ctx->mem_to_free = NULL;
1665                 block_ctx->pagev = NULL;
1666                 block_ctx->datav = NULL;
1667         }
1668 }
1669
1670 static int btrfsic_read_block(struct btrfsic_state *state,
1671                               struct btrfsic_block_data_ctx *block_ctx)
1672 {
1673         unsigned int num_pages;
1674         unsigned int i;
1675         u64 dev_bytenr;
1676         int ret;
1677
1678         BUG_ON(block_ctx->datav);
1679         BUG_ON(block_ctx->pagev);
1680         BUG_ON(block_ctx->mem_to_free);
1681         if (block_ctx->dev_bytenr & ((u64)PAGE_CACHE_SIZE - 1)) {
1682                 printk(KERN_INFO
1683                        "btrfsic: read_block() with unaligned bytenr %llu\n",
1684                        (unsigned long long)block_ctx->dev_bytenr);
1685                 return -1;
1686         }
1687
1688         num_pages = (block_ctx->len + (u64)PAGE_CACHE_SIZE - 1) >>
1689                     PAGE_CACHE_SHIFT;
1690         block_ctx->mem_to_free = kzalloc((sizeof(*block_ctx->datav) +
1691                                           sizeof(*block_ctx->pagev)) *
1692                                          num_pages, GFP_NOFS);
1693         if (!block_ctx->mem_to_free)
1694                 return -1;
1695         block_ctx->datav = block_ctx->mem_to_free;
1696         block_ctx->pagev = (struct page **)(block_ctx->datav + num_pages);
1697         for (i = 0; i < num_pages; i++) {
1698                 block_ctx->pagev[i] = alloc_page(GFP_NOFS);
1699                 if (!block_ctx->pagev[i])
1700                         return -1;
1701         }
1702
1703         dev_bytenr = block_ctx->dev_bytenr;
1704         for (i = 0; i < num_pages;) {
1705                 struct bio *bio;
1706                 unsigned int j;
1707                 DECLARE_COMPLETION_ONSTACK(complete);
1708
1709                 bio = btrfs_io_bio_alloc(GFP_NOFS, num_pages - i);
1710                 if (!bio) {
1711                         printk(KERN_INFO
1712                                "btrfsic: bio_alloc() for %u pages failed!\n",
1713                                num_pages - i);
1714                         return -1;
1715                 }
1716                 bio->bi_bdev = block_ctx->dev->bdev;
1717                 bio->bi_sector = dev_bytenr >> 9;
1718                 bio->bi_end_io = btrfsic_complete_bio_end_io;
1719                 bio->bi_private = &complete;
1720
1721                 for (j = i; j < num_pages; j++) {
1722                         ret = bio_add_page(bio, block_ctx->pagev[j],
1723                                            PAGE_CACHE_SIZE, 0);
1724                         if (PAGE_CACHE_SIZE != ret)
1725                                 break;
1726                 }
1727                 if (j == i) {
1728                         printk(KERN_INFO
1729                                "btrfsic: error, failed to add a single page!\n");
1730                         return -1;
1731                 }
1732                 submit_bio(READ, bio);
1733
1734                 /* this will also unplug the queue */
1735                 wait_for_completion(&complete);
1736
1737                 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
1738                         printk(KERN_INFO
1739                                "btrfsic: read error at logical %llu dev %s!\n",
1740                                block_ctx->start, block_ctx->dev->name);
1741                         bio_put(bio);
1742                         return -1;
1743                 }
1744                 bio_put(bio);
1745                 dev_bytenr += (j - i) * PAGE_CACHE_SIZE;
1746                 i = j;
1747         }
1748         for (i = 0; i < num_pages; i++) {
1749                 block_ctx->datav[i] = kmap(block_ctx->pagev[i]);
1750                 if (!block_ctx->datav[i]) {
1751                         printk(KERN_INFO "btrfsic: kmap() failed (dev %s)!\n",
1752                                block_ctx->dev->name);
1753                         return -1;
1754                 }
1755         }
1756
1757         return block_ctx->len;
1758 }
1759
1760 static void btrfsic_complete_bio_end_io(struct bio *bio, int err)
1761 {
1762         complete((struct completion *)bio->bi_private);
1763 }
1764
1765 static void btrfsic_dump_database(struct btrfsic_state *state)
1766 {
1767         struct list_head *elem_all;
1768
1769         BUG_ON(NULL == state);
1770
1771         printk(KERN_INFO "all_blocks_list:\n");
1772         list_for_each(elem_all, &state->all_blocks_list) {
1773                 const struct btrfsic_block *const b_all =
1774                     list_entry(elem_all, struct btrfsic_block,
1775                                all_blocks_node);
1776                 struct list_head *elem_ref_to;
1777                 struct list_head *elem_ref_from;
1778
1779                 printk(KERN_INFO "%c-block @%llu (%s/%llu/%d)\n",
1780                        btrfsic_get_block_type(state, b_all),
1781                        (unsigned long long)b_all->logical_bytenr,
1782                        b_all->dev_state->name,
1783                        (unsigned long long)b_all->dev_bytenr,
1784                        b_all->mirror_num);
1785
1786                 list_for_each(elem_ref_to, &b_all->ref_to_list) {
1787                         const struct btrfsic_block_link *const l =
1788                             list_entry(elem_ref_to,
1789                                        struct btrfsic_block_link,
1790                                        node_ref_to);
1791
1792                         printk(KERN_INFO " %c @%llu (%s/%llu/%d)"
1793                                " refers %u* to"
1794                                " %c @%llu (%s/%llu/%d)\n",
1795                                btrfsic_get_block_type(state, b_all),
1796                                (unsigned long long)b_all->logical_bytenr,
1797                                b_all->dev_state->name,
1798                                (unsigned long long)b_all->dev_bytenr,
1799                                b_all->mirror_num,
1800                                l->ref_cnt,
1801                                btrfsic_get_block_type(state, l->block_ref_to),
1802                                (unsigned long long)
1803                                l->block_ref_to->logical_bytenr,
1804                                l->block_ref_to->dev_state->name,
1805                                (unsigned long long)l->block_ref_to->dev_bytenr,
1806                                l->block_ref_to->mirror_num);
1807                 }
1808
1809                 list_for_each(elem_ref_from, &b_all->ref_from_list) {
1810                         const struct btrfsic_block_link *const l =
1811                             list_entry(elem_ref_from,
1812                                        struct btrfsic_block_link,
1813                                        node_ref_from);
1814
1815                         printk(KERN_INFO " %c @%llu (%s/%llu/%d)"
1816                                " is ref %u* from"
1817                                " %c @%llu (%s/%llu/%d)\n",
1818                                btrfsic_get_block_type(state, b_all),
1819                                (unsigned long long)b_all->logical_bytenr,
1820                                b_all->dev_state->name,
1821                                (unsigned long long)b_all->dev_bytenr,
1822                                b_all->mirror_num,
1823                                l->ref_cnt,
1824                                btrfsic_get_block_type(state, l->block_ref_from),
1825                                (unsigned long long)
1826                                l->block_ref_from->logical_bytenr,
1827                                l->block_ref_from->dev_state->name,
1828                                (unsigned long long)
1829                                l->block_ref_from->dev_bytenr,
1830                                l->block_ref_from->mirror_num);
1831                 }
1832
1833                 printk(KERN_INFO "\n");
1834         }
1835 }
1836
1837 /*
1838  * Test whether the disk block contains a tree block (leaf or node)
1839  * (note that this test fails for the super block)
1840  */
1841 static int btrfsic_test_for_metadata(struct btrfsic_state *state,
1842                                      char **datav, unsigned int num_pages)
1843 {
1844         struct btrfs_header *h;
1845         u8 csum[BTRFS_CSUM_SIZE];
1846         u32 crc = ~(u32)0;
1847         unsigned int i;
1848
1849         if (num_pages * PAGE_CACHE_SIZE < state->metablock_size)
1850                 return 1; /* not metadata */
1851         num_pages = state->metablock_size >> PAGE_CACHE_SHIFT;
1852         h = (struct btrfs_header *)datav[0];
1853
1854         if (memcmp(h->fsid, state->root->fs_info->fsid, BTRFS_UUID_SIZE))
1855                 return 1;
1856
1857         for (i = 0; i < num_pages; i++) {
1858                 u8 *data = i ? datav[i] : (datav[i] + BTRFS_CSUM_SIZE);
1859                 size_t sublen = i ? PAGE_CACHE_SIZE :
1860                                     (PAGE_CACHE_SIZE - BTRFS_CSUM_SIZE);
1861
1862                 crc = crc32c(crc, data, sublen);
1863         }
1864         btrfs_csum_final(crc, csum);
1865         if (memcmp(csum, h->csum, state->csum_size))
1866                 return 1;
1867
1868         return 0; /* is metadata */
1869 }
1870
1871 static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
1872                                           u64 dev_bytenr, char **mapped_datav,
1873                                           unsigned int num_pages,
1874                                           struct bio *bio, int *bio_is_patched,
1875                                           struct buffer_head *bh,
1876                                           int submit_bio_bh_rw)
1877 {
1878         int is_metadata;
1879         struct btrfsic_block *block;
1880         struct btrfsic_block_data_ctx block_ctx;
1881         int ret;
1882         struct btrfsic_state *state = dev_state->state;
1883         struct block_device *bdev = dev_state->bdev;
1884         unsigned int processed_len;
1885
1886         if (NULL != bio_is_patched)
1887                 *bio_is_patched = 0;
1888
1889 again:
1890         if (num_pages == 0)
1891                 return;
1892
1893         processed_len = 0;
1894         is_metadata = (0 == btrfsic_test_for_metadata(state, mapped_datav,
1895                                                       num_pages));
1896
1897         block = btrfsic_block_hashtable_lookup(bdev, dev_bytenr,
1898                                                &state->block_hashtable);
1899         if (NULL != block) {
1900                 u64 bytenr = 0;
1901                 struct list_head *elem_ref_to;
1902                 struct list_head *tmp_ref_to;
1903
1904                 if (block->is_superblock) {
1905                         bytenr = btrfs_super_bytenr((struct btrfs_super_block *)
1906                                                     mapped_datav[0]);
1907                         if (num_pages * PAGE_CACHE_SIZE <
1908                             BTRFS_SUPER_INFO_SIZE) {
1909                                 printk(KERN_INFO
1910                                        "btrfsic: cannot work with too short bios!\n");
1911                                 return;
1912                         }
1913                         is_metadata = 1;
1914                         BUG_ON(BTRFS_SUPER_INFO_SIZE & (PAGE_CACHE_SIZE - 1));
1915                         processed_len = BTRFS_SUPER_INFO_SIZE;
1916                         if (state->print_mask &
1917                             BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE) {
1918                                 printk(KERN_INFO
1919                                        "[before new superblock is written]:\n");
1920                                 btrfsic_dump_tree_sub(state, block, 0);
1921                         }
1922                 }
1923                 if (is_metadata) {
1924                         if (!block->is_superblock) {
1925                                 if (num_pages * PAGE_CACHE_SIZE <
1926                                     state->metablock_size) {
1927                                         printk(KERN_INFO
1928                                                "btrfsic: cannot work with too short bios!\n");
1929                                         return;
1930                                 }
1931                                 processed_len = state->metablock_size;
1932                                 bytenr = btrfs_stack_header_bytenr(
1933                                                 (struct btrfs_header *)
1934                                                 mapped_datav[0]);
1935                                 btrfsic_cmp_log_and_dev_bytenr(state, bytenr,
1936                                                                dev_state,
1937                                                                dev_bytenr);
1938                         }
1939                         if (block->logical_bytenr != bytenr) {
1940                                 printk(KERN_INFO
1941                                        "Written block @%llu (%s/%llu/%d)"
1942                                        " found in hash table, %c,"
1943                                        " bytenr mismatch"
1944                                        " (!= stored %llu).\n",
1945                                        (unsigned long long)bytenr,
1946                                        dev_state->name,
1947                                        (unsigned long long)dev_bytenr,
1948                                        block->mirror_num,
1949                                        btrfsic_get_block_type(state, block),
1950                                        (unsigned long long)
1951                                        block->logical_bytenr);
1952                                 block->logical_bytenr = bytenr;
1953                         } else if (state->print_mask &
1954                                    BTRFSIC_PRINT_MASK_VERBOSE)
1955                                 printk(KERN_INFO
1956                                        "Written block @%llu (%s/%llu/%d)"
1957                                        " found in hash table, %c.\n",
1958                                        (unsigned long long)bytenr,
1959                                        dev_state->name,
1960                                        (unsigned long long)dev_bytenr,
1961                                        block->mirror_num,
1962                                        btrfsic_get_block_type(state, block));
1963                 } else {
1964                         if (num_pages * PAGE_CACHE_SIZE <
1965                             state->datablock_size) {
1966                                 printk(KERN_INFO
1967                                        "btrfsic: cannot work with too short bios!\n");
1968                                 return;
1969                         }
1970                         processed_len = state->datablock_size;
1971                         bytenr = block->logical_bytenr;
1972                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1973                                 printk(KERN_INFO
1974                                        "Written block @%llu (%s/%llu/%d)"
1975                                        " found in hash table, %c.\n",
1976                                        (unsigned long long)bytenr,
1977                                        dev_state->name,
1978                                        (unsigned long long)dev_bytenr,
1979                                        block->mirror_num,
1980                                        btrfsic_get_block_type(state, block));
1981                 }
1982
1983                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1984                         printk(KERN_INFO
1985                                "ref_to_list: %cE, ref_from_list: %cE\n",
1986                                list_empty(&block->ref_to_list) ? ' ' : '!',
1987                                list_empty(&block->ref_from_list) ? ' ' : '!');
1988                 if (btrfsic_is_block_ref_by_superblock(state, block, 0)) {
1989                         printk(KERN_INFO "btrfs: attempt to overwrite %c-block"
1990                                " @%llu (%s/%llu/%d), old(gen=%llu,"
1991                                " objectid=%llu, type=%d, offset=%llu),"
1992                                " new(gen=%llu),"
1993                                " which is referenced by most recent superblock"
1994                                " (superblockgen=%llu)!\n",
1995                                btrfsic_get_block_type(state, block),
1996                                (unsigned long long)bytenr,
1997                                dev_state->name,
1998                                (unsigned long long)dev_bytenr,
1999                                block->mirror_num,
2000                                (unsigned long long)block->generation,
2001                                (unsigned long long)
2002                                btrfs_disk_key_objectid(&block->disk_key),
2003                                block->disk_key.type,
2004                                (unsigned long long)
2005                                btrfs_disk_key_offset(&block->disk_key),
2006                                (unsigned long long)
2007                                btrfs_stack_header_generation(
2008                                        (struct btrfs_header *) mapped_datav[0]),
2009                                (unsigned long long)
2010                                state->max_superblock_generation);
2011                         btrfsic_dump_tree(state);
2012                 }
2013
2014                 if (!block->is_iodone && !block->never_written) {
2015                         printk(KERN_INFO "btrfs: attempt to overwrite %c-block"
2016                                " @%llu (%s/%llu/%d), oldgen=%llu, newgen=%llu,"
2017                                " which is not yet iodone!\n",
2018                                btrfsic_get_block_type(state, block),
2019                                (unsigned long long)bytenr,
2020                                dev_state->name,
2021                                (unsigned long long)dev_bytenr,
2022                                block->mirror_num,
2023                                (unsigned long long)block->generation,
2024                                (unsigned long long)
2025                                btrfs_stack_header_generation(
2026                                        (struct btrfs_header *)
2027                                        mapped_datav[0]));
2028                         /* it would not be safe to go on */
2029                         btrfsic_dump_tree(state);
2030                         goto continue_loop;
2031                 }
2032
2033                 /*
2034                  * Clear all references of this block. Do not free
2035                  * the block itself even if is not referenced anymore
2036                  * because it still carries valueable information
2037                  * like whether it was ever written and IO completed.
2038                  */
2039                 list_for_each_safe(elem_ref_to, tmp_ref_to,
2040                                    &block->ref_to_list) {
2041                         struct btrfsic_block_link *const l =
2042                             list_entry(elem_ref_to,
2043                                        struct btrfsic_block_link,
2044                                        node_ref_to);
2045
2046                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2047                                 btrfsic_print_rem_link(state, l);
2048                         l->ref_cnt--;
2049                         if (0 == l->ref_cnt) {
2050                                 list_del(&l->node_ref_to);
2051                                 list_del(&l->node_ref_from);
2052                                 btrfsic_block_link_hashtable_remove(l);
2053                                 btrfsic_block_link_free(l);
2054                         }
2055                 }
2056
2057                 if (block->is_superblock)
2058                         ret = btrfsic_map_superblock(state, bytenr,
2059                                                      processed_len,
2060                                                      bdev, &block_ctx);
2061                 else
2062                         ret = btrfsic_map_block(state, bytenr, processed_len,
2063                                                 &block_ctx, 0);
2064                 if (ret) {
2065                         printk(KERN_INFO
2066                                "btrfsic: btrfsic_map_block(root @%llu)"
2067                                " failed!\n", (unsigned long long)bytenr);
2068                         goto continue_loop;
2069                 }
2070                 block_ctx.datav = mapped_datav;
2071                 /* the following is required in case of writes to mirrors,
2072                  * use the same that was used for the lookup */
2073                 block_ctx.dev = dev_state;
2074                 block_ctx.dev_bytenr = dev_bytenr;
2075
2076                 if (is_metadata || state->include_extent_data) {
2077                         block->never_written = 0;
2078                         block->iodone_w_error = 0;
2079                         if (NULL != bio) {
2080                                 block->is_iodone = 0;
2081                                 BUG_ON(NULL == bio_is_patched);
2082                                 if (!*bio_is_patched) {
2083                                         block->orig_bio_bh_private =
2084                                             bio->bi_private;
2085                                         block->orig_bio_bh_end_io.bio =
2086                                             bio->bi_end_io;
2087                                         block->next_in_same_bio = NULL;
2088                                         bio->bi_private = block;
2089                                         bio->bi_end_io = btrfsic_bio_end_io;
2090                                         *bio_is_patched = 1;
2091                                 } else {
2092                                         struct btrfsic_block *chained_block =
2093                                             (struct btrfsic_block *)
2094                                             bio->bi_private;
2095
2096                                         BUG_ON(NULL == chained_block);
2097                                         block->orig_bio_bh_private =
2098                                             chained_block->orig_bio_bh_private;
2099                                         block->orig_bio_bh_end_io.bio =
2100                                             chained_block->orig_bio_bh_end_io.
2101                                             bio;
2102                                         block->next_in_same_bio = chained_block;
2103                                         bio->bi_private = block;
2104                                 }
2105                         } else if (NULL != bh) {
2106                                 block->is_iodone = 0;
2107                                 block->orig_bio_bh_private = bh->b_private;
2108                                 block->orig_bio_bh_end_io.bh = bh->b_end_io;
2109                                 block->next_in_same_bio = NULL;
2110                                 bh->b_private = block;
2111                                 bh->b_end_io = btrfsic_bh_end_io;
2112                         } else {
2113                                 block->is_iodone = 1;
2114                                 block->orig_bio_bh_private = NULL;
2115                                 block->orig_bio_bh_end_io.bio = NULL;
2116                                 block->next_in_same_bio = NULL;
2117                         }
2118                 }
2119
2120                 block->flush_gen = dev_state->last_flush_gen + 1;
2121                 block->submit_bio_bh_rw = submit_bio_bh_rw;
2122                 if (is_metadata) {
2123                         block->logical_bytenr = bytenr;
2124                         block->is_metadata = 1;
2125                         if (block->is_superblock) {
2126                                 BUG_ON(PAGE_CACHE_SIZE !=
2127                                        BTRFS_SUPER_INFO_SIZE);
2128                                 ret = btrfsic_process_written_superblock(
2129                                                 state,
2130                                                 block,
2131                                                 (struct btrfs_super_block *)
2132                                                 mapped_datav[0]);
2133                                 if (state->print_mask &
2134                                     BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE) {
2135                                         printk(KERN_INFO
2136                                         "[after new superblock is written]:\n");
2137                                         btrfsic_dump_tree_sub(state, block, 0);
2138                                 }
2139                         } else {
2140                                 block->mirror_num = 0;  /* unknown */
2141                                 ret = btrfsic_process_metablock(
2142                                                 state,
2143                                                 block,
2144                                                 &block_ctx,
2145                                                 0, 0);
2146                         }
2147                         if (ret)
2148                                 printk(KERN_INFO
2149                                        "btrfsic: btrfsic_process_metablock"
2150                                        "(root @%llu) failed!\n",
2151                                        (unsigned long long)dev_bytenr);
2152                 } else {
2153                         block->is_metadata = 0;
2154                         block->mirror_num = 0;  /* unknown */
2155                         block->generation = BTRFSIC_GENERATION_UNKNOWN;
2156                         if (!state->include_extent_data
2157                             && list_empty(&block->ref_from_list)) {
2158                                 /*
2159                                  * disk block is overwritten with extent
2160                                  * data (not meta data) and we are configured
2161                                  * to not include extent data: take the
2162                                  * chance and free the block's memory
2163                                  */
2164                                 btrfsic_block_hashtable_remove(block);
2165                                 list_del(&block->all_blocks_node);
2166                                 btrfsic_block_free(block);
2167                         }
2168                 }
2169                 btrfsic_release_block_ctx(&block_ctx);
2170         } else {
2171                 /* block has not been found in hash table */
2172                 u64 bytenr;
2173
2174                 if (!is_metadata) {
2175                         processed_len = state->datablock_size;
2176                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2177                                 printk(KERN_INFO "Written block (%s/%llu/?)"
2178                                        " !found in hash table, D.\n",
2179                                        dev_state->name,
2180                                        (unsigned long long)dev_bytenr);
2181                         if (!state->include_extent_data) {
2182                                 /* ignore that written D block */
2183                                 goto continue_loop;
2184                         }
2185
2186                         /* this is getting ugly for the
2187                          * include_extent_data case... */
2188                         bytenr = 0;     /* unknown */
2189                         block_ctx.start = bytenr;
2190                         block_ctx.len = processed_len;
2191                         block_ctx.mem_to_free = NULL;
2192                         block_ctx.pagev = NULL;
2193                 } else {
2194                         processed_len = state->metablock_size;
2195                         bytenr = btrfs_stack_header_bytenr(
2196                                         (struct btrfs_header *)
2197                                         mapped_datav[0]);
2198                         btrfsic_cmp_log_and_dev_bytenr(state, bytenr, dev_state,
2199                                                        dev_bytenr);
2200                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2201                                 printk(KERN_INFO
2202                                        "Written block @%llu (%s/%llu/?)"
2203                                        " !found in hash table, M.\n",
2204                                        (unsigned long long)bytenr,
2205                                        dev_state->name,
2206                                        (unsigned long long)dev_bytenr);
2207
2208                         ret = btrfsic_map_block(state, bytenr, processed_len,
2209                                                 &block_ctx, 0);
2210                         if (ret) {
2211                                 printk(KERN_INFO
2212                                        "btrfsic: btrfsic_map_block(root @%llu)"
2213                                        " failed!\n",
2214                                        (unsigned long long)dev_bytenr);
2215                                 goto continue_loop;
2216                         }
2217                 }
2218                 block_ctx.datav = mapped_datav;
2219                 /* the following is required in case of writes to mirrors,
2220                  * use the same that was used for the lookup */
2221                 block_ctx.dev = dev_state;
2222                 block_ctx.dev_bytenr = dev_bytenr;
2223
2224                 block = btrfsic_block_alloc();
2225                 if (NULL == block) {
2226                         printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
2227                         btrfsic_release_block_ctx(&block_ctx);
2228                         goto continue_loop;
2229                 }
2230                 block->dev_state = dev_state;
2231                 block->dev_bytenr = dev_bytenr;
2232                 block->logical_bytenr = bytenr;
2233                 block->is_metadata = is_metadata;
2234                 block->never_written = 0;
2235                 block->iodone_w_error = 0;
2236                 block->mirror_num = 0;  /* unknown */
2237                 block->flush_gen = dev_state->last_flush_gen + 1;
2238                 block->submit_bio_bh_rw = submit_bio_bh_rw;
2239                 if (NULL != bio) {
2240                         block->is_iodone = 0;
2241                         BUG_ON(NULL == bio_is_patched);
2242                         if (!*bio_is_patched) {
2243                                 block->orig_bio_bh_private = bio->bi_private;
2244                                 block->orig_bio_bh_end_io.bio = bio->bi_end_io;
2245                                 block->next_in_same_bio = NULL;
2246                                 bio->bi_private = block;
2247                                 bio->bi_end_io = btrfsic_bio_end_io;
2248                                 *bio_is_patched = 1;
2249                         } else {
2250                                 struct btrfsic_block *chained_block =
2251                                     (struct btrfsic_block *)
2252                                     bio->bi_private;
2253
2254                                 BUG_ON(NULL == chained_block);
2255                                 block->orig_bio_bh_private =
2256                                     chained_block->orig_bio_bh_private;
2257                                 block->orig_bio_bh_end_io.bio =
2258                                     chained_block->orig_bio_bh_end_io.bio;
2259                                 block->next_in_same_bio = chained_block;
2260                                 bio->bi_private = block;
2261                         }
2262                 } else if (NULL != bh) {
2263                         block->is_iodone = 0;
2264                         block->orig_bio_bh_private = bh->b_private;
2265                         block->orig_bio_bh_end_io.bh = bh->b_end_io;
2266                         block->next_in_same_bio = NULL;
2267                         bh->b_private = block;
2268                         bh->b_end_io = btrfsic_bh_end_io;
2269                 } else {
2270                         block->is_iodone = 1;
2271                         block->orig_bio_bh_private = NULL;
2272                         block->orig_bio_bh_end_io.bio = NULL;
2273                         block->next_in_same_bio = NULL;
2274                 }
2275                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2276                         printk(KERN_INFO
2277                                "New written %c-block @%llu (%s/%llu/%d)\n",
2278                                is_metadata ? 'M' : 'D',
2279                                (unsigned long long)block->logical_bytenr,
2280                                block->dev_state->name,
2281                                (unsigned long long)block->dev_bytenr,
2282                                block->mirror_num);
2283                 list_add(&block->all_blocks_node, &state->all_blocks_list);
2284                 btrfsic_block_hashtable_add(block, &state->block_hashtable);
2285
2286                 if (is_metadata) {
2287                         ret = btrfsic_process_metablock(state, block,
2288                                                         &block_ctx, 0, 0);
2289                         if (ret)
2290                                 printk(KERN_INFO
2291                                        "btrfsic: process_metablock(root @%llu)"
2292                                        " failed!\n",
2293                                        (unsigned long long)dev_bytenr);
2294                 }
2295                 btrfsic_release_block_ctx(&block_ctx);
2296         }
2297
2298 continue_loop:
2299         BUG_ON(!processed_len);
2300         dev_bytenr += processed_len;
2301         mapped_datav += processed_len >> PAGE_CACHE_SHIFT;
2302         num_pages -= processed_len >> PAGE_CACHE_SHIFT;
2303         goto again;
2304 }
2305
2306 static void btrfsic_bio_end_io(struct bio *bp, int bio_error_status)
2307 {
2308         struct btrfsic_block *block = (struct btrfsic_block *)bp->bi_private;
2309         int iodone_w_error;
2310
2311         /* mutex is not held! This is not save if IO is not yet completed
2312          * on umount */
2313         iodone_w_error = 0;
2314         if (bio_error_status)
2315                 iodone_w_error = 1;
2316
2317         BUG_ON(NULL == block);
2318         bp->bi_private = block->orig_bio_bh_private;
2319         bp->bi_end_io = block->orig_bio_bh_end_io.bio;
2320
2321         do {
2322                 struct btrfsic_block *next_block;
2323                 struct btrfsic_dev_state *const dev_state = block->dev_state;
2324
2325                 if ((dev_state->state->print_mask &
2326                      BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2327                         printk(KERN_INFO
2328                                "bio_end_io(err=%d) for %c @%llu (%s/%llu/%d)\n",
2329                                bio_error_status,
2330                                btrfsic_get_block_type(dev_state->state, block),
2331                                (unsigned long long)block->logical_bytenr,
2332                                dev_state->name,
2333                                (unsigned long long)block->dev_bytenr,
2334                                block->mirror_num);
2335                 next_block = block->next_in_same_bio;
2336                 block->iodone_w_error = iodone_w_error;
2337                 if (block->submit_bio_bh_rw & REQ_FLUSH) {
2338                         dev_state->last_flush_gen++;
2339                         if ((dev_state->state->print_mask &
2340                              BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2341                                 printk(KERN_INFO
2342                                        "bio_end_io() new %s flush_gen=%llu\n",
2343                                        dev_state->name,
2344                                        (unsigned long long)
2345                                        dev_state->last_flush_gen);
2346                 }
2347                 if (block->submit_bio_bh_rw & REQ_FUA)
2348                         block->flush_gen = 0; /* FUA completed means block is
2349                                                * on disk */
2350                 block->is_iodone = 1; /* for FLUSH, this releases the block */
2351                 block = next_block;
2352         } while (NULL != block);
2353
2354         bp->bi_end_io(bp, bio_error_status);
2355 }
2356
2357 static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate)
2358 {
2359         struct btrfsic_block *block = (struct btrfsic_block *)bh->b_private;
2360         int iodone_w_error = !uptodate;
2361         struct btrfsic_dev_state *dev_state;
2362
2363         BUG_ON(NULL == block);
2364         dev_state = block->dev_state;
2365         if ((dev_state->state->print_mask & BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2366                 printk(KERN_INFO
2367                        "bh_end_io(error=%d) for %c @%llu (%s/%llu/%d)\n",
2368                        iodone_w_error,
2369                        btrfsic_get_block_type(dev_state->state, block),
2370                        (unsigned long long)block->logical_bytenr,
2371                        block->dev_state->name,
2372                        (unsigned long long)block->dev_bytenr,
2373                        block->mirror_num);
2374
2375         block->iodone_w_error = iodone_w_error;
2376         if (block->submit_bio_bh_rw & REQ_FLUSH) {
2377                 dev_state->last_flush_gen++;
2378                 if ((dev_state->state->print_mask &
2379                      BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2380                         printk(KERN_INFO
2381                                "bh_end_io() new %s flush_gen=%llu\n",
2382                                dev_state->name,
2383                                (unsigned long long)dev_state->last_flush_gen);
2384         }
2385         if (block->submit_bio_bh_rw & REQ_FUA)
2386                 block->flush_gen = 0; /* FUA completed means block is on disk */
2387
2388         bh->b_private = block->orig_bio_bh_private;
2389         bh->b_end_io = block->orig_bio_bh_end_io.bh;
2390         block->is_iodone = 1; /* for FLUSH, this releases the block */
2391         bh->b_end_io(bh, uptodate);
2392 }
2393
2394 static int btrfsic_process_written_superblock(
2395                 struct btrfsic_state *state,
2396                 struct btrfsic_block *const superblock,
2397                 struct btrfs_super_block *const super_hdr)
2398 {
2399         int pass;
2400
2401         superblock->generation = btrfs_super_generation(super_hdr);
2402         if (!(superblock->generation > state->max_superblock_generation ||
2403               0 == state->max_superblock_generation)) {
2404                 if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2405                         printk(KERN_INFO
2406                                "btrfsic: superblock @%llu (%s/%llu/%d)"
2407                                " with old gen %llu <= %llu\n",
2408                                (unsigned long long)superblock->logical_bytenr,
2409                                superblock->dev_state->name,
2410                                (unsigned long long)superblock->dev_bytenr,
2411                                superblock->mirror_num,
2412                                (unsigned long long)
2413                                btrfs_super_generation(super_hdr),
2414                                (unsigned long long)
2415                                state->max_superblock_generation);
2416         } else {
2417                 if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2418                         printk(KERN_INFO
2419                                "btrfsic: got new superblock @%llu (%s/%llu/%d)"
2420                                " with new gen %llu > %llu\n",
2421                                (unsigned long long)superblock->logical_bytenr,
2422                                superblock->dev_state->name,
2423                                (unsigned long long)superblock->dev_bytenr,
2424                                superblock->mirror_num,
2425                                (unsigned long long)
2426                                btrfs_super_generation(super_hdr),
2427                                (unsigned long long)
2428                                state->max_superblock_generation);
2429
2430                 state->max_superblock_generation =
2431                     btrfs_super_generation(super_hdr);
2432                 state->latest_superblock = superblock;
2433         }
2434
2435         for (pass = 0; pass < 3; pass++) {
2436                 int ret;
2437                 u64 next_bytenr;
2438                 struct btrfsic_block *next_block;
2439                 struct btrfsic_block_data_ctx tmp_next_block_ctx;
2440                 struct btrfsic_block_link *l;
2441                 int num_copies;
2442                 int mirror_num;
2443                 const char *additional_string = NULL;
2444                 struct btrfs_disk_key tmp_disk_key;
2445
2446                 btrfs_set_disk_key_objectid(&tmp_disk_key,
2447                                             BTRFS_ROOT_ITEM_KEY);
2448                 btrfs_set_disk_key_objectid(&tmp_disk_key, 0);
2449
2450                 switch (pass) {
2451                 case 0:
2452                         btrfs_set_disk_key_objectid(&tmp_disk_key,
2453                                                     BTRFS_ROOT_TREE_OBJECTID);
2454                         additional_string = "root ";
2455                         next_bytenr = btrfs_super_root(super_hdr);
2456                         if (state->print_mask &
2457                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2458                                 printk(KERN_INFO "root@%llu\n",
2459                                        (unsigned long long)next_bytenr);
2460                         break;
2461                 case 1:
2462                         btrfs_set_disk_key_objectid(&tmp_disk_key,
2463                                                     BTRFS_CHUNK_TREE_OBJECTID);
2464                         additional_string = "chunk ";
2465                         next_bytenr = btrfs_super_chunk_root(super_hdr);
2466                         if (state->print_mask &
2467                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2468                                 printk(KERN_INFO "chunk@%llu\n",
2469                                        (unsigned long long)next_bytenr);
2470                         break;
2471                 case 2:
2472                         btrfs_set_disk_key_objectid(&tmp_disk_key,
2473                                                     BTRFS_TREE_LOG_OBJECTID);
2474                         additional_string = "log ";
2475                         next_bytenr = btrfs_super_log_root(super_hdr);
2476                         if (0 == next_bytenr)
2477                                 continue;
2478                         if (state->print_mask &
2479                             BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2480                                 printk(KERN_INFO "log@%llu\n",
2481                                        (unsigned long long)next_bytenr);
2482                         break;
2483                 }
2484
2485                 num_copies =
2486                     btrfs_num_copies(state->root->fs_info,
2487                                      next_bytenr, BTRFS_SUPER_INFO_SIZE);
2488                 if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
2489                         printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
2490                                (unsigned long long)next_bytenr, num_copies);
2491                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2492                         int was_created;
2493
2494                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2495                                 printk(KERN_INFO
2496                                        "btrfsic_process_written_superblock("
2497                                        "mirror_num=%d)\n", mirror_num);
2498                         ret = btrfsic_map_block(state, next_bytenr,
2499                                                 BTRFS_SUPER_INFO_SIZE,
2500                                                 &tmp_next_block_ctx,
2501                                                 mirror_num);
2502                         if (ret) {
2503                                 printk(KERN_INFO
2504                                        "btrfsic: btrfsic_map_block(@%llu,"
2505                                        " mirror=%d) failed!\n",
2506                                        (unsigned long long)next_bytenr,
2507                                        mirror_num);
2508                                 return -1;
2509                         }
2510
2511                         next_block = btrfsic_block_lookup_or_add(
2512                                         state,
2513                                         &tmp_next_block_ctx,
2514                                         additional_string,
2515                                         1, 0, 1,
2516                                         mirror_num,
2517                                         &was_created);
2518                         if (NULL == next_block) {
2519                                 printk(KERN_INFO
2520                                        "btrfsic: error, kmalloc failed!\n");
2521                                 btrfsic_release_block_ctx(&tmp_next_block_ctx);
2522                                 return -1;
2523                         }
2524
2525                         next_block->disk_key = tmp_disk_key;
2526                         if (was_created)
2527                                 next_block->generation =
2528                                     BTRFSIC_GENERATION_UNKNOWN;
2529                         l = btrfsic_block_link_lookup_or_add(
2530                                         state,
2531                                         &tmp_next_block_ctx,
2532                                         next_block,
2533                                         superblock,
2534                                         BTRFSIC_GENERATION_UNKNOWN);
2535                         btrfsic_release_block_ctx(&tmp_next_block_ctx);
2536                         if (NULL == l)
2537                                 return -1;
2538                 }
2539         }
2540
2541         if (-1 == btrfsic_check_all_ref_blocks(state, superblock, 0)) {
2542                 WARN_ON(1);
2543                 btrfsic_dump_tree(state);
2544         }
2545
2546         return 0;
2547 }
2548
2549 static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
2550                                         struct btrfsic_block *const block,
2551                                         int recursion_level)
2552 {
2553         struct list_head *elem_ref_to;
2554         int ret = 0;
2555
2556         if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2557                 /*
2558                  * Note that this situation can happen and does not
2559                  * indicate an error in regular cases. It happens
2560                  * when disk blocks are freed and later reused.
2561                  * The check-integrity module is not aware of any
2562                  * block free operations, it just recognizes block
2563                  * write operations. Therefore it keeps the linkage
2564                  * information for a block until a block is
2565                  * rewritten. This can temporarily cause incorrect
2566                  * and even circular linkage informations. This
2567                  * causes no harm unless such blocks are referenced
2568                  * by the most recent super block.
2569                  */
2570                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2571                         printk(KERN_INFO
2572                                "btrfsic: abort cyclic linkage (case 1).\n");
2573
2574                 return ret;
2575         }
2576
2577         /*
2578          * This algorithm is recursive because the amount of used stack
2579          * space is very small and the max recursion depth is limited.
2580          */
2581         list_for_each(elem_ref_to, &block->ref_to_list) {
2582                 const struct btrfsic_block_link *const l =
2583                     list_entry(elem_ref_to, struct btrfsic_block_link,
2584                                node_ref_to);
2585
2586                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2587                         printk(KERN_INFO
2588                                "rl=%d, %c @%llu (%s/%llu/%d)"
2589                                " %u* refers to %c @%llu (%s/%llu/%d)\n",
2590                                recursion_level,
2591                                btrfsic_get_block_type(state, block),
2592                                (unsigned long long)block->logical_bytenr,
2593                                block->dev_state->name,
2594                                (unsigned long long)block->dev_bytenr,
2595                                block->mirror_num,
2596                                l->ref_cnt,
2597                                btrfsic_get_block_type(state, l->block_ref_to),
2598                                (unsigned long long)
2599                                l->block_ref_to->logical_bytenr,
2600                                l->block_ref_to->dev_state->name,
2601                                (unsigned long long)l->block_ref_to->dev_bytenr,
2602                                l->block_ref_to->mirror_num);
2603                 if (l->block_ref_to->never_written) {
2604                         printk(KERN_INFO "btrfs: attempt to write superblock"
2605                                " which references block %c @%llu (%s/%llu/%d)"
2606                                " which is never written!\n",
2607                                btrfsic_get_block_type(state, l->block_ref_to),
2608                                (unsigned long long)
2609                                l->block_ref_to->logical_bytenr,
2610                                l->block_ref_to->dev_state->name,
2611                                (unsigned long long)l->block_ref_to->dev_bytenr,
2612                                l->block_ref_to->mirror_num);
2613                         ret = -1;
2614                 } else if (!l->block_ref_to->is_iodone) {
2615                         printk(KERN_INFO "btrfs: attempt to write superblock"
2616                                " which references block %c @%llu (%s/%llu/%d)"
2617                                " which is not yet iodone!\n",
2618                                btrfsic_get_block_type(state, l->block_ref_to),
2619                                (unsigned long long)
2620                                l->block_ref_to->logical_bytenr,
2621                                l->block_ref_to->dev_state->name,
2622                                (unsigned long long)l->block_ref_to->dev_bytenr,
2623                                l->block_ref_to->mirror_num);
2624                         ret = -1;
2625                 } else if (l->block_ref_to->iodone_w_error) {
2626                         printk(KERN_INFO "btrfs: attempt to write superblock"
2627                                " which references block %c @%llu (%s/%llu/%d)"
2628                                " which has write error!\n",
2629                                btrfsic_get_block_type(state, l->block_ref_to),
2630                                (unsigned long long)
2631                                l->block_ref_to->logical_bytenr,
2632                                l->block_ref_to->dev_state->name,
2633                                (unsigned long long)l->block_ref_to->dev_bytenr,
2634                                l->block_ref_to->mirror_num);
2635                         ret = -1;
2636                 } else if (l->parent_generation !=
2637                            l->block_ref_to->generation &&
2638                            BTRFSIC_GENERATION_UNKNOWN !=
2639                            l->parent_generation &&
2640                            BTRFSIC_GENERATION_UNKNOWN !=
2641                            l->block_ref_to->generation) {
2642                         printk(KERN_INFO "btrfs: attempt to write superblock"
2643                                " which references block %c @%llu (%s/%llu/%d)"
2644                                " with generation %llu !="
2645                                " parent generation %llu!\n",
2646                                btrfsic_get_block_type(state, l->block_ref_to),
2647                                (unsigned long long)
2648                                l->block_ref_to->logical_bytenr,
2649                                l->block_ref_to->dev_state->name,
2650                                (unsigned long long)l->block_ref_to->dev_bytenr,
2651                                l->block_ref_to->mirror_num,
2652                                (unsigned long long)l->block_ref_to->generation,
2653                                (unsigned long long)l->parent_generation);
2654                         ret = -1;
2655                 } else if (l->block_ref_to->flush_gen >
2656                            l->block_ref_to->dev_state->last_flush_gen) {
2657                         printk(KERN_INFO "btrfs: attempt to write superblock"
2658                                " which references block %c @%llu (%s/%llu/%d)"
2659                                " which is not flushed out of disk's write cache"
2660                                " (block flush_gen=%llu,"
2661                                " dev->flush_gen=%llu)!\n",
2662                                btrfsic_get_block_type(state, l->block_ref_to),
2663                                (unsigned long long)
2664                                l->block_ref_to->logical_bytenr,
2665                                l->block_ref_to->dev_state->name,
2666                                (unsigned long long)l->block_ref_to->dev_bytenr,
2667                                l->block_ref_to->mirror_num,
2668                                (unsigned long long)block->flush_gen,
2669                                (unsigned long long)
2670                                l->block_ref_to->dev_state->last_flush_gen);
2671                         ret = -1;
2672                 } else if (-1 == btrfsic_check_all_ref_blocks(state,
2673                                                               l->block_ref_to,
2674                                                               recursion_level +
2675                                                               1)) {
2676                         ret = -1;
2677                 }
2678         }
2679
2680         return ret;
2681 }
2682
2683 static int btrfsic_is_block_ref_by_superblock(
2684                 const struct btrfsic_state *state,
2685                 const struct btrfsic_block *block,
2686                 int recursion_level)
2687 {
2688         struct list_head *elem_ref_from;
2689
2690         if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2691                 /* refer to comment at "abort cyclic linkage (case 1)" */
2692                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2693                         printk(KERN_INFO
2694                                "btrfsic: abort cyclic linkage (case 2).\n");
2695
2696                 return 0;
2697         }
2698
2699         /*
2700          * This algorithm is recursive because the amount of used stack space
2701          * is very small and the max recursion depth is limited.
2702          */
2703         list_for_each(elem_ref_from, &block->ref_from_list) {
2704                 const struct btrfsic_block_link *const l =
2705                     list_entry(elem_ref_from, struct btrfsic_block_link,
2706                                node_ref_from);
2707
2708                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2709                         printk(KERN_INFO
2710                                "rl=%d, %c @%llu (%s/%llu/%d)"
2711                                " is ref %u* from %c @%llu (%s/%llu/%d)\n",
2712                                recursion_level,
2713                                btrfsic_get_block_type(state, block),
2714                                (unsigned long long)block->logical_bytenr,
2715                                block->dev_state->name,
2716                                (unsigned long long)block->dev_bytenr,
2717                                block->mirror_num,
2718                                l->ref_cnt,
2719                                btrfsic_get_block_type(state, l->block_ref_from),
2720                                (unsigned long long)
2721                                l->block_ref_from->logical_bytenr,
2722                                l->block_ref_from->dev_state->name,
2723                                (unsigned long long)
2724                                l->block_ref_from->dev_bytenr,
2725                                l->block_ref_from->mirror_num);
2726                 if (l->block_ref_from->is_superblock &&
2727                     state->latest_superblock->dev_bytenr ==
2728                     l->block_ref_from->dev_bytenr &&
2729                     state->latest_superblock->dev_state->bdev ==
2730                     l->block_ref_from->dev_state->bdev)
2731                         return 1;
2732                 else if (btrfsic_is_block_ref_by_superblock(state,
2733                                                             l->block_ref_from,
2734                                                             recursion_level +
2735                                                             1))
2736                         return 1;
2737         }
2738
2739         return 0;
2740 }
2741
2742 static void btrfsic_print_add_link(const struct btrfsic_state *state,
2743                                    const struct btrfsic_block_link *l)
2744 {
2745         printk(KERN_INFO
2746                "Add %u* link from %c @%llu (%s/%llu/%d)"
2747                " to %c @%llu (%s/%llu/%d).\n",
2748                l->ref_cnt,
2749                btrfsic_get_block_type(state, l->block_ref_from),
2750                (unsigned long long)l->block_ref_from->logical_bytenr,
2751                l->block_ref_from->dev_state->name,
2752                (unsigned long long)l->block_ref_from->dev_bytenr,
2753                l->block_ref_from->mirror_num,
2754                btrfsic_get_block_type(state, l->block_ref_to),
2755                (unsigned long long)l->block_ref_to->logical_bytenr,
2756                l->block_ref_to->dev_state->name,
2757                (unsigned long long)l->block_ref_to->dev_bytenr,
2758                l->block_ref_to->mirror_num);
2759 }
2760
2761 static void btrfsic_print_rem_link(const struct btrfsic_state *state,
2762                                    const struct btrfsic_block_link *l)
2763 {
2764         printk(KERN_INFO
2765                "Rem %u* link from %c @%llu (%s/%llu/%d)"
2766                " to %c @%llu (%s/%llu/%d).\n",
2767                l->ref_cnt,
2768                btrfsic_get_block_type(state, l->block_ref_from),
2769                (unsigned long long)l->block_ref_from->logical_bytenr,
2770                l->block_ref_from->dev_state->name,
2771                (unsigned long long)l->block_ref_from->dev_bytenr,
2772                l->block_ref_from->mirror_num,
2773                btrfsic_get_block_type(state, l->block_ref_to),
2774                (unsigned long long)l->block_ref_to->logical_bytenr,
2775                l->block_ref_to->dev_state->name,
2776                (unsigned long long)l->block_ref_to->dev_bytenr,
2777                l->block_ref_to->mirror_num);
2778 }
2779
2780 static char btrfsic_get_block_type(const struct btrfsic_state *state,
2781                                    const struct btrfsic_block *block)
2782 {
2783         if (block->is_superblock &&
2784             state->latest_superblock->dev_bytenr == block->dev_bytenr &&
2785             state->latest_superblock->dev_state->bdev == block->dev_state->bdev)
2786                 return 'S';
2787         else if (block->is_superblock)
2788                 return 's';
2789         else if (block->is_metadata)
2790                 return 'M';
2791         else
2792                 return 'D';
2793 }
2794
2795 static void btrfsic_dump_tree(const struct btrfsic_state *state)
2796 {
2797         btrfsic_dump_tree_sub(state, state->latest_superblock, 0);
2798 }
2799
2800 static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
2801                                   const struct btrfsic_block *block,
2802                                   int indent_level)
2803 {
2804         struct list_head *elem_ref_to;
2805         int indent_add;
2806         static char buf[80];
2807         int cursor_position;
2808
2809         /*
2810          * Should better fill an on-stack buffer with a complete line and
2811          * dump it at once when it is time to print a newline character.
2812          */
2813
2814         /*
2815          * This algorithm is recursive because the amount of used stack space
2816          * is very small and the max recursion depth is limited.
2817          */
2818         indent_add = sprintf(buf, "%c-%llu(%s/%llu/%d)",
2819                              btrfsic_get_block_type(state, block),
2820                              (unsigned long long)block->logical_bytenr,
2821                              block->dev_state->name,
2822                              (unsigned long long)block->dev_bytenr,
2823                              block->mirror_num);
2824         if (indent_level + indent_add > BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2825                 printk("[...]\n");
2826                 return;
2827         }
2828         printk(buf);
2829         indent_level += indent_add;
2830         if (list_empty(&block->ref_to_list)) {
2831                 printk("\n");
2832                 return;
2833         }
2834         if (block->mirror_num > 1 &&
2835             !(state->print_mask & BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS)) {
2836                 printk(" [...]\n");
2837                 return;
2838         }
2839
2840         cursor_position = indent_level;
2841         list_for_each(elem_ref_to, &block->ref_to_list) {
2842                 const struct btrfsic_block_link *const l =
2843                     list_entry(elem_ref_to, struct btrfsic_block_link,
2844                                node_ref_to);
2845
2846                 while (cursor_position < indent_level) {
2847                         printk(" ");
2848                         cursor_position++;
2849                 }
2850                 if (l->ref_cnt > 1)
2851                         indent_add = sprintf(buf, " %d*--> ", l->ref_cnt);
2852                 else
2853                         indent_add = sprintf(buf, " --> ");
2854                 if (indent_level + indent_add >
2855                     BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2856                         printk("[...]\n");
2857                         cursor_position = 0;
2858                         continue;
2859                 }
2860
2861                 printk(buf);
2862
2863                 btrfsic_dump_tree_sub(state, l->block_ref_to,
2864                                       indent_level + indent_add);
2865                 cursor_position = 0;
2866         }
2867 }
2868
2869 static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
2870                 struct btrfsic_state *state,
2871                 struct btrfsic_block_data_ctx *next_block_ctx,
2872                 struct btrfsic_block *next_block,
2873                 struct btrfsic_block *from_block,
2874                 u64 parent_generation)
2875 {
2876         struct btrfsic_block_link *l;
2877
2878         l = btrfsic_block_link_hashtable_lookup(next_block_ctx->dev->bdev,
2879                                                 next_block_ctx->dev_bytenr,
2880                                                 from_block->dev_state->bdev,
2881                                                 from_block->dev_bytenr,
2882                                                 &state->block_link_hashtable);
2883         if (NULL == l) {
2884                 l = btrfsic_block_link_alloc();
2885                 if (NULL == l) {
2886                         printk(KERN_INFO
2887                                "btrfsic: error, kmalloc" " failed!\n");
2888                         return NULL;
2889                 }
2890
2891                 l->block_ref_to = next_block;
2892                 l->block_ref_from = from_block;
2893                 l->ref_cnt = 1;
2894                 l->parent_generation = parent_generation;
2895
2896                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2897                         btrfsic_print_add_link(state, l);
2898
2899                 list_add(&l->node_ref_to, &from_block->ref_to_list);
2900                 list_add(&l->node_ref_from, &next_block->ref_from_list);
2901
2902                 btrfsic_block_link_hashtable_add(l,
2903                                                  &state->block_link_hashtable);
2904         } else {
2905                 l->ref_cnt++;
2906                 l->parent_generation = parent_generation;
2907                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2908                         btrfsic_print_add_link(state, l);
2909         }
2910
2911         return l;
2912 }
2913
2914 static struct btrfsic_block *btrfsic_block_lookup_or_add(
2915                 struct btrfsic_state *state,
2916                 struct btrfsic_block_data_ctx *block_ctx,
2917                 const char *additional_string,
2918                 int is_metadata,
2919                 int is_iodone,
2920                 int never_written,
2921                 int mirror_num,
2922                 int *was_created)
2923 {
2924         struct btrfsic_block *block;
2925
2926         block = btrfsic_block_hashtable_lookup(block_ctx->dev->bdev,
2927                                                block_ctx->dev_bytenr,
2928                                                &state->block_hashtable);
2929         if (NULL == block) {
2930                 struct btrfsic_dev_state *dev_state;
2931
2932                 block = btrfsic_block_alloc();
2933                 if (NULL == block) {
2934                         printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
2935                         return NULL;
2936                 }
2937                 dev_state = btrfsic_dev_state_lookup(block_ctx->dev->bdev);
2938                 if (NULL == dev_state) {
2939                         printk(KERN_INFO
2940                                "btrfsic: error, lookup dev_state failed!\n");
2941                         btrfsic_block_free(block);
2942                         return NULL;
2943                 }
2944                 block->dev_state = dev_state;
2945                 block->dev_bytenr = block_ctx->dev_bytenr;
2946                 block->logical_bytenr = block_ctx->start;
2947                 block->is_metadata = is_metadata;
2948                 block->is_iodone = is_iodone;
2949                 block->never_written = never_written;
2950                 block->mirror_num = mirror_num;
2951                 if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2952                         printk(KERN_INFO
2953                                "New %s%c-block @%llu (%s/%llu/%d)\n",
2954                                additional_string,
2955                                btrfsic_get_block_type(state, block),
2956                                (unsigned long long)block->logical_bytenr,
2957                                dev_state->name,
2958                                (unsigned long long)block->dev_bytenr,
2959                                mirror_num);
2960                 list_add(&block->all_blocks_node, &state->all_blocks_list);
2961                 btrfsic_block_hashtable_add(block, &state->block_hashtable);
2962                 if (NULL != was_created)
2963                         *was_created = 1;
2964         } else {
2965                 if (NULL != was_created)
2966                         *was_created = 0;
2967         }
2968
2969         return block;
2970 }
2971
2972 static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
2973                                            u64 bytenr,
2974                                            struct btrfsic_dev_state *dev_state,
2975                                            u64 dev_bytenr)
2976 {
2977         int num_copies;
2978         int mirror_num;
2979         int ret;
2980         struct btrfsic_block_data_ctx block_ctx;
2981         int match = 0;
2982
2983         num_copies = btrfs_num_copies(state->root->fs_info,
2984                                       bytenr, state->metablock_size);
2985
2986         for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2987                 ret = btrfsic_map_block(state, bytenr, state->metablock_size,
2988                                         &block_ctx, mirror_num);
2989                 if (ret) {
2990                         printk(KERN_INFO "btrfsic:"
2991                                " btrfsic_map_block(logical @%llu,"
2992                                " mirror %d) failed!\n",
2993                                (unsigned long long)bytenr, mirror_num);
2994                         continue;
2995                 }
2996
2997                 if (dev_state->bdev == block_ctx.dev->bdev &&
2998                     dev_bytenr == block_ctx.dev_bytenr) {
2999                         match++;
3000                         btrfsic_release_block_ctx(&block_ctx);
3001                         break;
3002                 }
3003                 btrfsic_release_block_ctx(&block_ctx);
3004         }
3005
3006         if (!match) {
3007                 printk(KERN_INFO "btrfs: attempt to write M-block which contains logical bytenr that doesn't map to dev+physical bytenr of submit_bio,"
3008                        " buffer->log_bytenr=%llu, submit_bio(bdev=%s,"
3009                        " phys_bytenr=%llu)!\n",
3010                        (unsigned long long)bytenr, dev_state->name,
3011                        (unsigned long long)dev_bytenr);
3012                 for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
3013                         ret = btrfsic_map_block(state, bytenr,
3014                                                 state->metablock_size,
3015                                                 &block_ctx, mirror_num);
3016                         if (ret)
3017                                 continue;
3018
3019                         printk(KERN_INFO "Read logical bytenr @%llu maps to"
3020                                " (%s/%llu/%d)\n",
3021                                (unsigned long long)bytenr,
3022                                block_ctx.dev->name,
3023                                (unsigned long long)block_ctx.dev_bytenr,
3024                                mirror_num);
3025                 }
3026                 WARN_ON(1);
3027         }
3028 }
3029
3030 static struct btrfsic_dev_state *btrfsic_dev_state_lookup(
3031                 struct block_device *bdev)
3032 {
3033         struct btrfsic_dev_state *ds;
3034
3035         ds = btrfsic_dev_state_hashtable_lookup(bdev,
3036                                                 &btrfsic_dev_state_hashtable);
3037         return ds;
3038 }
3039
3040 int btrfsic_submit_bh(int rw, struct buffer_head *bh)
3041 {
3042         struct btrfsic_dev_state *dev_state;
3043
3044         if (!btrfsic_is_initialized)
3045                 return submit_bh(rw, bh);
3046
3047         mutex_lock(&btrfsic_mutex);
3048         /* since btrfsic_submit_bh() might also be called before
3049          * btrfsic_mount(), this might return NULL */
3050         dev_state = btrfsic_dev_state_lookup(bh->b_bdev);
3051
3052         /* Only called to write the superblock (incl. FLUSH/FUA) */
3053         if (NULL != dev_state &&
3054             (rw & WRITE) && bh->b_size > 0) {
3055                 u64 dev_bytenr;
3056
3057                 dev_bytenr = 4096 * bh->b_blocknr;
3058                 if (dev_state->state->print_mask &
3059                     BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
3060                         printk(KERN_INFO
3061                                "submit_bh(rw=0x%x, blocknr=%lu (bytenr %llu),"
3062                                " size=%lu, data=%p, bdev=%p)\n",
3063                                rw, (unsigned long)bh->b_blocknr,
3064                                (unsigned long long)dev_bytenr,
3065                                (unsigned long)bh->b_size, bh->b_data,
3066                                bh->b_bdev);
3067                 btrfsic_process_written_block(dev_state, dev_bytenr,
3068                                               &bh->b_data, 1, NULL,
3069                                               NULL, bh, rw);
3070         } else if (NULL != dev_state && (rw & REQ_FLUSH)) {
3071                 if (dev_state->state->print_mask &
3072                     BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
3073                         printk(KERN_INFO
3074                                "submit_bh(rw=0x%x FLUSH, bdev=%p)\n",
3075                                rw, bh->b_bdev);
3076                 if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
3077                         if ((dev_state->state->print_mask &
3078                              (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
3079                               BTRFSIC_PRINT_MASK_VERBOSE)))
3080                                 printk(KERN_INFO
3081                                        "btrfsic_submit_bh(%s) with FLUSH"
3082                                        " but dummy block already in use"
3083                                        " (ignored)!\n",
3084                                        dev_state->name);
3085                 } else {
3086                         struct btrfsic_block *const block =
3087                                 &dev_state->dummy_block_for_bio_bh_flush;
3088
3089                         block->is_iodone = 0;
3090                         block->never_written = 0;
3091                         block->iodone_w_error = 0;
3092                         block->flush_gen = dev_state->last_flush_gen + 1;
3093                         block->submit_bio_bh_rw = rw;
3094                         block->orig_bio_bh_private = bh->b_private;
3095                         block->orig_bio_bh_end_io.bh = bh->b_end_io;
3096                         block->next_in_same_bio = NULL;
3097                         bh->b_private = block;
3098                         bh->b_end_io = btrfsic_bh_end_io;
3099                 }
3100         }
3101         mutex_unlock(&btrfsic_mutex);
3102         return submit_bh(rw, bh);
3103 }
3104
3105 void btrfsic_submit_bio(int rw, struct bio *bio)
3106 {
3107         struct btrfsic_dev_state *dev_state;
3108
3109         if (!btrfsic_is_initialized) {
3110                 submit_bio(rw, bio);
3111                 return;
3112         }
3113
3114         mutex_lock(&btrfsic_mutex);
3115         /* since btrfsic_submit_bio() is also called before
3116          * btrfsic_mount(), this might return NULL */
3117         dev_state = btrfsic_dev_state_lookup(bio->bi_bdev);
3118         if (NULL != dev_state &&
3119             (rw & WRITE) && NULL != bio->bi_io_vec) {
3120                 unsigned int i;
3121                 u64 dev_bytenr;
3122                 int bio_is_patched;
3123                 char **mapped_datav;
3124
3125                 dev_bytenr = 512 * bio->bi_sector;
3126                 bio_is_patched = 0;
3127                 if (dev_state->state->print_mask &
3128                     BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
3129                         printk(KERN_INFO
3130                                "submit_bio(rw=0x%x, bi_vcnt=%u,"
3131                                " bi_sector=%lu (bytenr %llu), bi_bdev=%p)\n",
3132                                rw, bio->bi_vcnt, (unsigned long)bio->bi_sector,
3133                                (unsigned long long)dev_bytenr,
3134                                bio->bi_bdev);
3135
3136                 mapped_datav = kmalloc(sizeof(*mapped_datav) * bio->bi_vcnt,
3137                                        GFP_NOFS);
3138                 if (!mapped_datav)
3139                         goto leave;
3140                 for (i = 0; i < bio->bi_vcnt; i++) {
3141                         BUG_ON(bio->bi_io_vec[i].bv_len != PAGE_CACHE_SIZE);
3142                         mapped_datav[i] = kmap(bio->bi_io_vec[i].bv_page);
3143                         if (!mapped_datav[i]) {
3144                                 while (i > 0) {
3145                                         i--;
3146                                         kunmap(bio->bi_io_vec[i].bv_page);
3147                                 }
3148                                 kfree(mapped_datav);
3149                                 goto leave;
3150                         }
3151                         if ((BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
3152                              BTRFSIC_PRINT_MASK_VERBOSE) ==
3153                             (dev_state->state->print_mask &
3154                              (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
3155                               BTRFSIC_PRINT_MASK_VERBOSE)))
3156                                 printk(KERN_INFO
3157                                        "#%u: page=%p, len=%u, offset=%u\n",
3158                                        i, bio->bi_io_vec[i].bv_page,
3159                                        bio->bi_io_vec[i].bv_len,
3160                                        bio->bi_io_vec[i].bv_offset);
3161                 }
3162                 btrfsic_process_written_block(dev_state, dev_bytenr,
3163                                               mapped_datav, bio->bi_vcnt,
3164                                               bio, &bio_is_patched,
3165                                               NULL, rw);
3166                 while (i > 0) {
3167                         i--;
3168                         kunmap(bio->bi_io_vec[i].bv_page);
3169                 }
3170                 kfree(mapped_datav);
3171         } else if (NULL != dev_state && (rw & REQ_FLUSH)) {
3172                 if (dev_state->state->print_mask &
3173                     BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
3174                         printk(KERN_INFO
3175                                "submit_bio(rw=0x%x FLUSH, bdev=%p)\n",
3176                                rw, bio->bi_bdev);
3177                 if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
3178                         if ((dev_state->state->print_mask &
3179                              (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
3180                               BTRFSIC_PRINT_MASK_VERBOSE)))
3181                                 printk(KERN_INFO
3182                                        "btrfsic_submit_bio(%s) with FLUSH"
3183                                        " but dummy block already in use"
3184                                        " (ignored)!\n",
3185                                        dev_state->name);
3186                 } else {
3187                         struct btrfsic_block *const block =
3188                                 &dev_state->dummy_block_for_bio_bh_flush;
3189
3190                         block->is_iodone = 0;
3191                         block->never_written = 0;
3192                         block->iodone_w_error = 0;
3193                         block->flush_gen = dev_state->last_flush_gen + 1;
3194                         block->submit_bio_bh_rw = rw;
3195                         block->orig_bio_bh_private = bio->bi_private;
3196                         block->orig_bio_bh_end_io.bio = bio->bi_end_io;
3197                         block->next_in_same_bio = NULL;
3198                         bio->bi_private = block;
3199                         bio->bi_end_io = btrfsic_bio_end_io;
3200                 }
3201         }
3202 leave:
3203         mutex_unlock(&btrfsic_mutex);
3204
3205         submit_bio(rw, bio);
3206 }
3207
3208 int btrfsic_mount(struct btrfs_root *root,
3209                   struct btrfs_fs_devices *fs_devices,
3210                   int including_extent_data, u32 print_mask)
3211 {
3212         int ret;
3213         struct btrfsic_state *state;
3214         struct list_head *dev_head = &fs_devices->devices;
3215         struct btrfs_device *device;
3216
3217         if (root->nodesize != root->leafsize) {
3218                 printk(KERN_INFO
3219                        "btrfsic: cannot handle nodesize %d != leafsize %d!\n",
3220                        root->nodesize, root->leafsize);
3221                 return -1;
3222         }
3223         if (root->nodesize & ((u64)PAGE_CACHE_SIZE - 1)) {
3224                 printk(KERN_INFO
3225                        "btrfsic: cannot handle nodesize %d not being a multiple of PAGE_CACHE_SIZE %ld!\n",
3226                        root->nodesize, (unsigned long)PAGE_CACHE_SIZE);
3227                 return -1;
3228         }
3229         if (root->leafsize & ((u64)PAGE_CACHE_SIZE - 1)) {
3230                 printk(KERN_INFO
3231                        "btrfsic: cannot handle leafsize %d not being a multiple of PAGE_CACHE_SIZE %ld!\n",
3232                        root->leafsize, (unsigned long)PAGE_CACHE_SIZE);
3233                 return -1;
3234         }
3235         if (root->sectorsize & ((u64)PAGE_CACHE_SIZE - 1)) {
3236                 printk(KERN_INFO
3237                        "btrfsic: cannot handle sectorsize %d not being a multiple of PAGE_CACHE_SIZE %ld!\n",
3238                        root->sectorsize, (unsigned long)PAGE_CACHE_SIZE);
3239                 return -1;
3240         }
3241         state = kzalloc(sizeof(*state), GFP_NOFS);
3242         if (NULL == state) {
3243                 printk(KERN_INFO "btrfs check-integrity: kmalloc() failed!\n");
3244                 return -1;
3245         }
3246
3247         if (!btrfsic_is_initialized) {
3248                 mutex_init(&btrfsic_mutex);
3249                 btrfsic_dev_state_hashtable_init(&btrfsic_dev_state_hashtable);
3250                 btrfsic_is_initialized = 1;
3251         }
3252         mutex_lock(&btrfsic_mutex);
3253         state->root = root;
3254         state->print_mask = print_mask;
3255         state->include_extent_data = including_extent_data;
3256         state->csum_size = 0;
3257         state->metablock_size = root->nodesize;
3258         state->datablock_size = root->sectorsize;
3259         INIT_LIST_HEAD(&state->all_blocks_list);
3260         btrfsic_block_hashtable_init(&state->block_hashtable);
3261         btrfsic_block_link_hashtable_init(&state->block_link_hashtable);
3262         state->max_superblock_generation = 0;
3263         state->latest_superblock = NULL;
3264
3265         list_for_each_entry(device, dev_head, dev_list) {
3266                 struct btrfsic_dev_state *ds;
3267                 char *p;
3268
3269                 if (!device->bdev || !device->name)
3270                         continue;
3271
3272                 ds = btrfsic_dev_state_alloc();
3273                 if (NULL == ds) {
3274                         printk(KERN_INFO
3275                                "btrfs check-integrity: kmalloc() failed!\n");
3276                         mutex_unlock(&btrfsic_mutex);
3277                         return -1;
3278                 }
3279                 ds->bdev = device->bdev;
3280                 ds->state = state;
3281                 bdevname(ds->bdev, ds->name);
3282                 ds->name[BDEVNAME_SIZE - 1] = '\0';
3283                 for (p = ds->name; *p != '\0'; p++);
3284                 while (p > ds->name && *p != '/')
3285                         p--;
3286                 if (*p == '/')
3287                         p++;
3288                 strlcpy(ds->name, p, sizeof(ds->name));
3289                 btrfsic_dev_state_hashtable_add(ds,
3290                                                 &btrfsic_dev_state_hashtable);
3291         }
3292
3293         ret = btrfsic_process_superblock(state, fs_devices);
3294         if (0 != ret) {
3295                 mutex_unlock(&btrfsic_mutex);
3296                 btrfsic_unmount(root, fs_devices);
3297                 return ret;
3298         }
3299
3300         if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_DATABASE)
3301                 btrfsic_dump_database(state);
3302         if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_TREE)
3303                 btrfsic_dump_tree(state);
3304
3305         mutex_unlock(&btrfsic_mutex);
3306         return 0;
3307 }
3308
3309 void btrfsic_unmount(struct btrfs_root *root,
3310                      struct btrfs_fs_devices *fs_devices)
3311 {
3312         struct list_head *elem_all;
3313         struct list_head *tmp_all;
3314         struct btrfsic_state *state;
3315         struct list_head *dev_head = &fs_devices->devices;
3316         struct btrfs_device *device;
3317
3318         if (!btrfsic_is_initialized)
3319                 return;
3320
3321         mutex_lock(&btrfsic_mutex);
3322
3323         state = NULL;
3324         list_for_each_entry(device, dev_head, dev_list) {
3325                 struct btrfsic_dev_state *ds;
3326
3327                 if (!device->bdev || !device->name)
3328                         continue;
3329
3330                 ds = btrfsic_dev_state_hashtable_lookup(
3331                                 device->bdev,
3332                                 &btrfsic_dev_state_hashtable);
3333                 if (NULL != ds) {
3334                         state = ds->state;
3335                         btrfsic_dev_state_hashtable_remove(ds);
3336                         btrfsic_dev_state_free(ds);
3337                 }
3338         }
3339
3340         if (NULL == state) {
3341                 printk(KERN_INFO
3342                        "btrfsic: error, cannot find state information"
3343                        " on umount!\n");
3344                 mutex_unlock(&btrfsic_mutex);
3345                 return;
3346         }
3347
3348         /*
3349          * Don't care about keeping the lists' state up to date,
3350          * just free all memory that was allocated dynamically.
3351          * Free the blocks and the block_links.
3352          */
3353         list_for_each_safe(elem_all, tmp_all, &state->all_blocks_list) {
3354                 struct btrfsic_block *const b_all =
3355                     list_entry(elem_all, struct btrfsic_block,
3356                                all_blocks_node);
3357                 struct list_head *elem_ref_to;
3358                 struct list_head *tmp_ref_to;
3359
3360                 list_for_each_safe(elem_ref_to, tmp_ref_to,
3361                                    &b_all->ref_to_list) {
3362                         struct btrfsic_block_link *const l =
3363                             list_entry(elem_ref_to,
3364                                        struct btrfsic_block_link,
3365                                        node_ref_to);
3366
3367                         if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
3368                                 btrfsic_print_rem_link(state, l);
3369
3370                         l->ref_cnt--;
3371                         if (0 == l->ref_cnt)
3372                                 btrfsic_block_link_free(l);
3373                 }
3374
3375                 if (b_all->is_iodone || b_all->never_written)
3376                         btrfsic_block_free(b_all);
3377                 else
3378                         printk(KERN_INFO "btrfs: attempt to free %c-block"
3379                                " @%llu (%s/%llu/%d) on umount which is"
3380                                " not yet iodone!\n",
3381                                btrfsic_get_block_type(state, b_all),
3382                                (unsigned long long)b_all->logical_bytenr,
3383                                b_all->dev_state->name,
3384                                (unsigned long long)b_all->dev_bytenr,
3385                                b_all->mirror_num);
3386         }
3387
3388         mutex_unlock(&btrfsic_mutex);
3389
3390         kfree(state);
3391 }