fs/btrfs/check-integrity.c

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