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   1/*
   2 * Copyright (C) STRATO AG 2011.  All rights reserved.
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public
   6 * License v2 as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 * General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public
  14 * License along with this program; if not, write to the
  15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16 * Boston, MA 021110-1307, USA.
  17 */
  18
  19/*
  20 * This module can be used to catch cases when the btrfs kernel
  21 * code executes write requests to the disk that bring the file
  22 * system in an inconsistent state. In such a state, a power-loss
  23 * or kernel panic event would cause that the data on disk is
  24 * lost or at least damaged.
  25 *
  26 * Code is added that examines all block write requests during
  27 * runtime (including writes of the super block). Three rules
  28 * are verified and an error is printed on violation of the
  29 * rules:
  30 * 1. It is not allowed to write a disk block which is
  31 *    currently referenced by the super block (either directly
  32 *    or indirectly).
  33 * 2. When a super block is written, it is verified that all
  34 *    referenced (directly or indirectly) blocks fulfill the
  35 *    following requirements:
  36 *    2a. All referenced blocks have either been present when
  37 *        the file system was mounted, (i.e., they have been
  38 *        referenced by the super block) or they have been
  39 *        written since then and the write completion callback
  40 *        was called and no write error was indicated and a
  41 *        FLUSH request to the device where these blocks are
  42 *        located was received and completed.
  43 *    2b. All referenced blocks need to have a generation
  44 *        number which is equal to the parent's number.
  45 *
  46 * One issue that was found using this module was that the log
  47 * tree on disk became temporarily corrupted because disk blocks
  48 * that had been in use for the log tree had been freed and
  49 * reused too early, while being referenced by the written super
  50 * block.
  51 *
  52 * The search term in the kernel log that can be used to filter
  53 * on the existence of detected integrity issues is
  54 * "btrfs: attempt".
  55 *
  56 * The integrity check is enabled via mount options. These
  57 * mount options are only supported if the integrity check
  58 * tool is compiled by defining BTRFS_FS_CHECK_INTEGRITY.
  59 *
  60 * Example #1, apply integrity checks to all metadata:
  61 * mount /dev/sdb1 /mnt -o check_int
  62 *
  63 * Example #2, apply integrity checks to all metadata and
  64 * to data extents:
  65 * mount /dev/sdb1 /mnt -o check_int_data
  66 *
  67 * Example #3, apply integrity checks to all metadata and dump
  68 * the tree that the super block references to kernel messages
  69 * each time after a super block was written:
  70 * mount /dev/sdb1 /mnt -o check_int,check_int_print_mask=263
  71 *
  72 * If the integrity check tool is included and activated in
  73 * the mount options, plenty of kernel memory is used, and
  74 * plenty of additional CPU cycles are spent. Enabling this
  75 * functionality is not intended for normal use. In most
  76 * cases, unless you are a btrfs developer who needs to verify
  77 * the integrity of (super)-block write requests, do not
  78 * enable the config option BTRFS_FS_CHECK_INTEGRITY to
  79 * include and compile the integrity check tool.
  80 *
  81 * Expect millions of lines of information in the kernel log with an
  82 * enabled check_int_print_mask. Therefore set LOG_BUF_SHIFT in the
  83 * kernel config to at least 26 (which is 64MB). Usually the value is
  84 * limited to 21 (which is 2MB) in init/Kconfig. The file needs to be
  85 * changed like this before LOG_BUF_SHIFT can be set to a high value:
  86 * config LOG_BUF_SHIFT
  87 *       int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
  88 *       range 12 30
  89 */
  90
  91#include <linux/sched.h>
  92#include <linux/slab.h>
  93#include <linux/buffer_head.h>
  94#include <linux/mutex.h>
  95#include <linux/genhd.h>
  96#include <linux/blkdev.h>
  97#include <linux/vmalloc.h>
  98#include <linux/string.h>
  99#include "ctree.h"
 100#include "disk-io.h"
 101#include "hash.h"
 102#include "transaction.h"
 103#include "extent_io.h"
 104#include "volumes.h"
 105#include "print-tree.h"
 106#include "locking.h"
 107#include "check-integrity.h"
 108#include "rcu-string.h"
 109#include "compression.h"
 110
 111#define BTRFSIC_BLOCK_HASHTABLE_SIZE 0x10000
 112#define BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE 0x10000
 113#define BTRFSIC_DEV2STATE_HASHTABLE_SIZE 0x100
 114#define BTRFSIC_BLOCK_MAGIC_NUMBER 0x14491051
 115#define BTRFSIC_BLOCK_LINK_MAGIC_NUMBER 0x11070807
 116#define BTRFSIC_DEV2STATE_MAGIC_NUMBER 0x20111530
 117#define BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER 20111300
 118#define BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL (200 - 6)	/* in characters,
 119							 * excluding " [...]" */
 120#define BTRFSIC_GENERATION_UNKNOWN ((u64)-1)
 121
 122/*
 123 * The definition of the bitmask fields for the print_mask.
 124 * They are specified with the mount option check_integrity_print_mask.
 125 */
 126#define BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE			0x00000001
 127#define BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION		0x00000002
 128#define BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE			0x00000004
 129#define BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE			0x00000008
 130#define BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH			0x00000010
 131#define BTRFSIC_PRINT_MASK_END_IO_BIO_BH			0x00000020
 132#define BTRFSIC_PRINT_MASK_VERBOSE				0x00000040
 133#define BTRFSIC_PRINT_MASK_VERY_VERBOSE				0x00000080
 134#define BTRFSIC_PRINT_MASK_INITIAL_TREE				0x00000100
 135#define BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES			0x00000200
 136#define BTRFSIC_PRINT_MASK_INITIAL_DATABASE			0x00000400
 137#define BTRFSIC_PRINT_MASK_NUM_COPIES				0x00000800
 138#define BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS		0x00001000
 139#define BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE		0x00002000
 140
 141struct btrfsic_dev_state;
 142struct btrfsic_state;
 143
 144struct btrfsic_block {
 145	u32 magic_num;		/* only used for debug purposes */
 146	unsigned int is_metadata:1;	/* if it is meta-data, not data-data */
 147	unsigned int is_superblock:1;	/* if it is one of the superblocks */
 148	unsigned int is_iodone:1;	/* if is done by lower subsystem */
 149	unsigned int iodone_w_error:1;	/* error was indicated to endio */
 150	unsigned int never_written:1;	/* block was added because it was
 151					 * referenced, not because it was
 152					 * written */
 153	unsigned int mirror_num;	/* large enough to hold
 154					 * BTRFS_SUPER_MIRROR_MAX */
 155	struct btrfsic_dev_state *dev_state;
 156	u64 dev_bytenr;		/* key, physical byte num on disk */
 157	u64 logical_bytenr;	/* logical byte num on disk */
 158	u64 generation;
 159	struct btrfs_disk_key disk_key;	/* extra info to print in case of
 160					 * issues, will not always be correct */
 161	struct list_head collision_resolving_node;	/* list node */
 162	struct list_head all_blocks_node;	/* list node */
 163
 164	/* the following two lists contain block_link items */
 165	struct list_head ref_to_list;	/* list */
 166	struct list_head ref_from_list;	/* list */
 167	struct btrfsic_block *next_in_same_bio;
 168	void *orig_bio_bh_private;
 169	union {
 170		bio_end_io_t *bio;
 171		bh_end_io_t *bh;
 172	} orig_bio_bh_end_io;
 173	int submit_bio_bh_rw;
 174	u64 flush_gen; /* only valid if !never_written */
 175};
 176
 177/*
 178 * Elements of this type are allocated dynamically and required because
 179 * each block object can refer to and can be ref from multiple blocks.
 180 * The key to lookup them in the hashtable is the dev_bytenr of
 181 * the block ref to plus the one from the block referred from.
 182 * The fact that they are searchable via a hashtable and that a
 183 * ref_cnt is maintained is not required for the btrfs integrity
 184 * check algorithm itself, it is only used to make the output more
 185 * beautiful in case that an error is detected (an error is defined
 186 * as a write operation to a block while that block is still referenced).
 187 */
 188struct btrfsic_block_link {
 189	u32 magic_num;		/* only used for debug purposes */
 190	u32 ref_cnt;
 191	struct list_head node_ref_to;	/* list node */
 192	struct list_head node_ref_from;	/* list node */
 193	struct list_head collision_resolving_node;	/* list node */
 194	struct btrfsic_block *block_ref_to;
 195	struct btrfsic_block *block_ref_from;
 196	u64 parent_generation;
 197};
 198
 199struct btrfsic_dev_state {
 200	u32 magic_num;		/* only used for debug purposes */
 201	struct block_device *bdev;
 202	struct btrfsic_state *state;
 203	struct list_head collision_resolving_node;	/* list node */
 204	struct btrfsic_block dummy_block_for_bio_bh_flush;
 205	u64 last_flush_gen;
 206	char name[BDEVNAME_SIZE];
 207};
 208
 209struct btrfsic_block_hashtable {
 210	struct list_head table[BTRFSIC_BLOCK_HASHTABLE_SIZE];
 211};
 212
 213struct btrfsic_block_link_hashtable {
 214	struct list_head table[BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE];
 215};
 216
 217struct btrfsic_dev_state_hashtable {
 218	struct list_head table[BTRFSIC_DEV2STATE_HASHTABLE_SIZE];
 219};
 220
 221struct btrfsic_block_data_ctx {
 222	u64 start;		/* virtual bytenr */
 223	u64 dev_bytenr;		/* physical bytenr on device */
 224	u32 len;
 225	struct btrfsic_dev_state *dev;
 226	char **datav;
 227	struct page **pagev;
 228	void *mem_to_free;
 229};
 230
 231/* This structure is used to implement recursion without occupying
 232 * any stack space, refer to btrfsic_process_metablock() */
 233struct btrfsic_stack_frame {
 234	u32 magic;
 235	u32 nr;
 236	int error;
 237	int i;
 238	int limit_nesting;
 239	int num_copies;
 240	int mirror_num;
 241	struct btrfsic_block *block;
 242	struct btrfsic_block_data_ctx *block_ctx;
 243	struct btrfsic_block *next_block;
 244	struct btrfsic_block_data_ctx next_block_ctx;
 245	struct btrfs_header *hdr;
 246	struct btrfsic_stack_frame *prev;
 247};
 248
 249/* Some state per mounted filesystem */
 250struct btrfsic_state {
 251	u32 print_mask;
 252	int include_extent_data;
 253	int csum_size;
 254	struct list_head all_blocks_list;
 255	struct btrfsic_block_hashtable block_hashtable;
 256	struct btrfsic_block_link_hashtable block_link_hashtable;
 257	struct btrfs_fs_info *fs_info;
 258	u64 max_superblock_generation;
 259	struct btrfsic_block *latest_superblock;
 260	u32 metablock_size;
 261	u32 datablock_size;
 262};
 263
 264static void btrfsic_block_init(struct btrfsic_block *b);
 265static struct btrfsic_block *btrfsic_block_alloc(void);
 266static void btrfsic_block_free(struct btrfsic_block *b);
 267static void btrfsic_block_link_init(struct btrfsic_block_link *n);
 268static struct btrfsic_block_link *btrfsic_block_link_alloc(void);
 269static void btrfsic_block_link_free(struct btrfsic_block_link *n);
 270static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds);
 271static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void);
 272static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds);
 273static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h);
 274static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
 275					struct btrfsic_block_hashtable *h);
 276static void btrfsic_block_hashtable_remove(struct btrfsic_block *b);
 277static struct btrfsic_block *btrfsic_block_hashtable_lookup(
 278		struct block_device *bdev,
 279		u64 dev_bytenr,
 280		struct btrfsic_block_hashtable *h);
 281static void btrfsic_block_link_hashtable_init(
 282		struct btrfsic_block_link_hashtable *h);
 283static void btrfsic_block_link_hashtable_add(
 284		struct btrfsic_block_link *l,
 285		struct btrfsic_block_link_hashtable *h);
 286static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l);
 287static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
 288		struct block_device *bdev_ref_to,
 289		u64 dev_bytenr_ref_to,
 290		struct block_device *bdev_ref_from,
 291		u64 dev_bytenr_ref_from,
 292		struct btrfsic_block_link_hashtable *h);
 293static void btrfsic_dev_state_hashtable_init(
 294		struct btrfsic_dev_state_hashtable *h);
 295static void btrfsic_dev_state_hashtable_add(
 296		struct btrfsic_dev_state *ds,
 297		struct btrfsic_dev_state_hashtable *h);
 298static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds);
 299static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(
 300		struct block_device *bdev,
 301		struct btrfsic_dev_state_hashtable *h);
 302static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void);
 303static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf);
 304static int btrfsic_process_superblock(struct btrfsic_state *state,
 305				      struct btrfs_fs_devices *fs_devices);
 306static int btrfsic_process_metablock(struct btrfsic_state *state,
 307				     struct btrfsic_block *block,
 308				     struct btrfsic_block_data_ctx *block_ctx,
 309				     int limit_nesting, int force_iodone_flag);
 310static void btrfsic_read_from_block_data(
 311	struct btrfsic_block_data_ctx *block_ctx,
 312	void *dst, u32 offset, size_t len);
 313static int btrfsic_create_link_to_next_block(
 314		struct btrfsic_state *state,
 315		struct btrfsic_block *block,
 316		struct btrfsic_block_data_ctx
 317		*block_ctx, u64 next_bytenr,
 318		int limit_nesting,
 319		struct btrfsic_block_data_ctx *next_block_ctx,
 320		struct btrfsic_block **next_blockp,
 321		int force_iodone_flag,
 322		int *num_copiesp, int *mirror_nump,
 323		struct btrfs_disk_key *disk_key,
 324		u64 parent_generation);
 325static int btrfsic_handle_extent_data(struct btrfsic_state *state,
 326				      struct btrfsic_block *block,
 327				      struct btrfsic_block_data_ctx *block_ctx,
 328				      u32 item_offset, int force_iodone_flag);
 329static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
 330			     struct btrfsic_block_data_ctx *block_ctx_out,
 331			     int mirror_num);
 332static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx);
 333static int btrfsic_read_block(struct btrfsic_state *state,
 334			      struct btrfsic_block_data_ctx *block_ctx);
 335static void btrfsic_dump_database(struct btrfsic_state *state);
 336static int btrfsic_test_for_metadata(struct btrfsic_state *state,
 337				     char **datav, unsigned int num_pages);
 338static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
 339					  u64 dev_bytenr, char **mapped_datav,
 340					  unsigned int num_pages,
 341					  struct bio *bio, int *bio_is_patched,
 342					  struct buffer_head *bh,
 343					  int submit_bio_bh_rw);
 344static int btrfsic_process_written_superblock(
 345		struct btrfsic_state *state,
 346		struct btrfsic_block *const block,
 347		struct btrfs_super_block *const super_hdr);
 348static void btrfsic_bio_end_io(struct bio *bp);
 349static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate);
 350static int btrfsic_is_block_ref_by_superblock(const struct btrfsic_state *state,
 351					      const struct btrfsic_block *block,
 352					      int recursion_level);
 353static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
 354					struct btrfsic_block *const block,
 355					int recursion_level);
 356static void btrfsic_print_add_link(const struct btrfsic_state *state,
 357				   const struct btrfsic_block_link *l);
 358static void btrfsic_print_rem_link(const struct btrfsic_state *state,
 359				   const struct btrfsic_block_link *l);
 360static char btrfsic_get_block_type(const struct btrfsic_state *state,
 361				   const struct btrfsic_block *block);
 362static void btrfsic_dump_tree(const struct btrfsic_state *state);
 363static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
 364				  const struct btrfsic_block *block,
 365				  int indent_level);
 366static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
 367		struct btrfsic_state *state,
 368		struct btrfsic_block_data_ctx *next_block_ctx,
 369		struct btrfsic_block *next_block,
 370		struct btrfsic_block *from_block,
 371		u64 parent_generation);
 372static struct btrfsic_block *btrfsic_block_lookup_or_add(
 373		struct btrfsic_state *state,
 374		struct btrfsic_block_data_ctx *block_ctx,
 375		const char *additional_string,
 376		int is_metadata,
 377		int is_iodone,
 378		int never_written,
 379		int mirror_num,
 380		int *was_created);
 381static int btrfsic_process_superblock_dev_mirror(
 382		struct btrfsic_state *state,
 383		struct btrfsic_dev_state *dev_state,
 384		struct btrfs_device *device,
 385		int superblock_mirror_num,
 386		struct btrfsic_dev_state **selected_dev_state,
 387		struct btrfs_super_block *selected_super);
 388static struct btrfsic_dev_state *btrfsic_dev_state_lookup(
 389		struct block_device *bdev);
 390static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
 391					   u64 bytenr,
 392					   struct btrfsic_dev_state *dev_state,
 393					   u64 dev_bytenr);
 394
 395static struct mutex btrfsic_mutex;
 396static int btrfsic_is_initialized;
 397static struct btrfsic_dev_state_hashtable btrfsic_dev_state_hashtable;
 398
 399
 400static void btrfsic_block_init(struct btrfsic_block *b)
 401{
 402	b->magic_num = BTRFSIC_BLOCK_MAGIC_NUMBER;
 403	b->dev_state = NULL;
 404	b->dev_bytenr = 0;
 405	b->logical_bytenr = 0;
 406	b->generation = BTRFSIC_GENERATION_UNKNOWN;
 407	b->disk_key.objectid = 0;
 408	b->disk_key.type = 0;
 409	b->disk_key.offset = 0;
 410	b->is_metadata = 0;
 411	b->is_superblock = 0;
 412	b->is_iodone = 0;
 413	b->iodone_w_error = 0;
 414	b->never_written = 0;
 415	b->mirror_num = 0;
 416	b->next_in_same_bio = NULL;
 417	b->orig_bio_bh_private = NULL;
 418	b->orig_bio_bh_end_io.bio = NULL;
 419	INIT_LIST_HEAD(&b->collision_resolving_node);
 420	INIT_LIST_HEAD(&b->all_blocks_node);
 421	INIT_LIST_HEAD(&b->ref_to_list);
 422	INIT_LIST_HEAD(&b->ref_from_list);
 423	b->submit_bio_bh_rw = 0;
 424	b->flush_gen = 0;
 425}
 426
 427static struct btrfsic_block *btrfsic_block_alloc(void)
 428{
 429	struct btrfsic_block *b;
 430
 431	b = kzalloc(sizeof(*b), GFP_NOFS);
 432	if (NULL != b)
 433		btrfsic_block_init(b);
 434
 435	return b;
 436}
 437
 438static void btrfsic_block_free(struct btrfsic_block *b)
 439{
 440	BUG_ON(!(NULL == b || BTRFSIC_BLOCK_MAGIC_NUMBER == b->magic_num));
 441	kfree(b);
 442}
 443
 444static void btrfsic_block_link_init(struct btrfsic_block_link *l)
 445{
 446	l->magic_num = BTRFSIC_BLOCK_LINK_MAGIC_NUMBER;
 447	l->ref_cnt = 1;
 448	INIT_LIST_HEAD(&l->node_ref_to);
 449	INIT_LIST_HEAD(&l->node_ref_from);
 450	INIT_LIST_HEAD(&l->collision_resolving_node);
 451	l->block_ref_to = NULL;
 452	l->block_ref_from = NULL;
 453}
 454
 455static struct btrfsic_block_link *btrfsic_block_link_alloc(void)
 456{
 457	struct btrfsic_block_link *l;
 458
 459	l = kzalloc(sizeof(*l), GFP_NOFS);
 460	if (NULL != l)
 461		btrfsic_block_link_init(l);
 462
 463	return l;
 464}
 465
 466static void btrfsic_block_link_free(struct btrfsic_block_link *l)
 467{
 468	BUG_ON(!(NULL == l || BTRFSIC_BLOCK_LINK_MAGIC_NUMBER == l->magic_num));
 469	kfree(l);
 470}
 471
 472static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds)
 473{
 474	ds->magic_num = BTRFSIC_DEV2STATE_MAGIC_NUMBER;
 475	ds->bdev = NULL;
 476	ds->state = NULL;
 477	ds->name[0] = '\0';
 478	INIT_LIST_HEAD(&ds->collision_resolving_node);
 479	ds->last_flush_gen = 0;
 480	btrfsic_block_init(&ds->dummy_block_for_bio_bh_flush);
 481	ds->dummy_block_for_bio_bh_flush.is_iodone = 1;
 482	ds->dummy_block_for_bio_bh_flush.dev_state = ds;
 483}
 484
 485static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void)
 486{
 487	struct btrfsic_dev_state *ds;
 488
 489	ds = kzalloc(sizeof(*ds), GFP_NOFS);
 490	if (NULL != ds)
 491		btrfsic_dev_state_init(ds);
 492
 493	return ds;
 494}
 495
 496static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds)
 497{
 498	BUG_ON(!(NULL == ds ||
 499		 BTRFSIC_DEV2STATE_MAGIC_NUMBER == ds->magic_num));
 500	kfree(ds);
 501}
 502
 503static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h)
 504{
 505	int i;
 506
 507	for (i = 0; i < BTRFSIC_BLOCK_HASHTABLE_SIZE; i++)
 508		INIT_LIST_HEAD(h->table + i);
 509}
 510
 511static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
 512					struct btrfsic_block_hashtable *h)
 513{
 514	const unsigned int hashval =
 515	    (((unsigned int)(b->dev_bytenr >> 16)) ^
 516	     ((unsigned int)((uintptr_t)b->dev_state->bdev))) &
 517	     (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
 518
 519	list_add(&b->collision_resolving_node, h->table + hashval);
 520}
 521
 522static void btrfsic_block_hashtable_remove(struct btrfsic_block *b)
 523{
 524	list_del(&b->collision_resolving_node);
 525}
 526
 527static struct btrfsic_block *btrfsic_block_hashtable_lookup(
 528		struct block_device *bdev,
 529		u64 dev_bytenr,
 530		struct btrfsic_block_hashtable *h)
 531{
 532	const unsigned int hashval =
 533	    (((unsigned int)(dev_bytenr >> 16)) ^
 534	     ((unsigned int)((uintptr_t)bdev))) &
 535	     (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
 536	struct btrfsic_block *b;
 537
 538	list_for_each_entry(b, h->table + hashval, collision_resolving_node) {
 539		if (b->dev_state->bdev == bdev && b->dev_bytenr == dev_bytenr)
 540			return b;
 541	}
 542
 543	return NULL;
 544}
 545
 546static void btrfsic_block_link_hashtable_init(
 547		struct btrfsic_block_link_hashtable *h)
 548{
 549	int i;
 550
 551	for (i = 0; i < BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE; i++)
 552		INIT_LIST_HEAD(h->table + i);
 553}
 554
 555static void btrfsic_block_link_hashtable_add(
 556		struct btrfsic_block_link *l,
 557		struct btrfsic_block_link_hashtable *h)
 558{
 559	const unsigned int hashval =
 560	    (((unsigned int)(l->block_ref_to->dev_bytenr >> 16)) ^
 561	     ((unsigned int)(l->block_ref_from->dev_bytenr >> 16)) ^
 562	     ((unsigned int)((uintptr_t)l->block_ref_to->dev_state->bdev)) ^
 563	     ((unsigned int)((uintptr_t)l->block_ref_from->dev_state->bdev)))
 564	     & (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
 565
 566	BUG_ON(NULL == l->block_ref_to);
 567	BUG_ON(NULL == l->block_ref_from);
 568	list_add(&l->collision_resolving_node, h->table + hashval);
 569}
 570
 571static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l)
 572{
 573	list_del(&l->collision_resolving_node);
 574}
 575
 576static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
 577		struct block_device *bdev_ref_to,
 578		u64 dev_bytenr_ref_to,
 579		struct block_device *bdev_ref_from,
 580		u64 dev_bytenr_ref_from,
 581		struct btrfsic_block_link_hashtable *h)
 582{
 583	const unsigned int hashval =
 584	    (((unsigned int)(dev_bytenr_ref_to >> 16)) ^
 585	     ((unsigned int)(dev_bytenr_ref_from >> 16)) ^
 586	     ((unsigned int)((uintptr_t)bdev_ref_to)) ^
 587	     ((unsigned int)((uintptr_t)bdev_ref_from))) &
 588	     (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
 589	struct btrfsic_block_link *l;
 590
 591	list_for_each_entry(l, h->table + hashval, collision_resolving_node) {
 592		BUG_ON(NULL == l->block_ref_to);
 593		BUG_ON(NULL == l->block_ref_from);
 594		if (l->block_ref_to->dev_state->bdev == bdev_ref_to &&
 595		    l->block_ref_to->dev_bytenr == dev_bytenr_ref_to &&
 596		    l->block_ref_from->dev_state->bdev == bdev_ref_from &&
 597		    l->block_ref_from->dev_bytenr == dev_bytenr_ref_from)
 598			return l;
 599	}
 600
 601	return NULL;
 602}
 603
 604static void btrfsic_dev_state_hashtable_init(
 605		struct btrfsic_dev_state_hashtable *h)
 606{
 607	int i;
 608
 609	for (i = 0; i < BTRFSIC_DEV2STATE_HASHTABLE_SIZE; i++)
 610		INIT_LIST_HEAD(h->table + i);
 611}
 612
 613static void btrfsic_dev_state_hashtable_add(
 614		struct btrfsic_dev_state *ds,
 615		struct btrfsic_dev_state_hashtable *h)
 616{
 617	const unsigned int hashval =
 618	    (((unsigned int)((uintptr_t)ds->bdev)) &
 619	     (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1));
 620
 621	list_add(&ds->collision_resolving_node, h->table + hashval);
 622}
 623
 624static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds)
 625{
 626	list_del(&ds->collision_resolving_node);
 627}
 628
 629static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(
 630		struct block_device *bdev,
 631		struct btrfsic_dev_state_hashtable *h)
 632{
 633	const unsigned int hashval =
 634	    (((unsigned int)((uintptr_t)bdev)) &
 635	     (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1));
 636	struct btrfsic_dev_state *ds;
 637
 638	list_for_each_entry(ds, h->table + hashval, collision_resolving_node) {
 639		if (ds->bdev == bdev)
 640			return ds;
 641	}
 642
 643	return NULL;
 644}
 645
 646static int btrfsic_process_superblock(struct btrfsic_state *state,
 647				      struct btrfs_fs_devices *fs_devices)
 648{
 649	struct btrfs_fs_info *fs_info = state->fs_info;
 650	struct btrfs_super_block *selected_super;
 651	struct list_head *dev_head = &fs_devices->devices;
 652	struct btrfs_device *device;
 653	struct btrfsic_dev_state *selected_dev_state = NULL;
 654	int ret = 0;
 655	int pass;
 656
 657	BUG_ON(NULL == state);
 658	selected_super = kzalloc(sizeof(*selected_super), GFP_NOFS);
 659	if (NULL == selected_super) {
 660		pr_info("btrfsic: error, kmalloc failed!\n");
 661		return -ENOMEM;
 662	}
 663
 664	list_for_each_entry(device, dev_head, dev_list) {
 665		int i;
 666		struct btrfsic_dev_state *dev_state;
 667
 668		if (!device->bdev || !device->name)
 669			continue;
 670
 671		dev_state = btrfsic_dev_state_lookup(device->bdev);
 672		BUG_ON(NULL == dev_state);
 673		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
 674			ret = btrfsic_process_superblock_dev_mirror(
 675					state, dev_state, device, i,
 676					&selected_dev_state, selected_super);
 677			if (0 != ret && 0 == i) {
 678				kfree(selected_super);
 679				return ret;
 680			}
 681		}
 682	}
 683
 684	if (NULL == state->latest_superblock) {
 685		pr_info("btrfsic: no superblock found!\n");
 686		kfree(selected_super);
 687		return -1;
 688	}
 689
 690	state->csum_size = btrfs_super_csum_size(selected_super);
 691
 692	for (pass = 0; pass < 3; pass++) {
 693		int num_copies;
 694		int mirror_num;
 695		u64 next_bytenr;
 696
 697		switch (pass) {
 698		case 0:
 699			next_bytenr = btrfs_super_root(selected_super);
 700			if (state->print_mask &
 701			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 702				pr_info("root@%llu\n", next_bytenr);
 703			break;
 704		case 1:
 705			next_bytenr = btrfs_super_chunk_root(selected_super);
 706			if (state->print_mask &
 707			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 708				pr_info("chunk@%llu\n", next_bytenr);
 709			break;
 710		case 2:
 711			next_bytenr = btrfs_super_log_root(selected_super);
 712			if (0 == next_bytenr)
 713				continue;
 714			if (state->print_mask &
 715			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 716				pr_info("log@%llu\n", next_bytenr);
 717			break;
 718		}
 719
 720		num_copies = btrfs_num_copies(fs_info, next_bytenr,
 721					      state->metablock_size);
 722		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
 723			pr_info("num_copies(log_bytenr=%llu) = %d\n",
 724			       next_bytenr, num_copies);
 725
 726		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
 727			struct btrfsic_block *next_block;
 728			struct btrfsic_block_data_ctx tmp_next_block_ctx;
 729			struct btrfsic_block_link *l;
 730
 731			ret = btrfsic_map_block(state, next_bytenr,
 732						state->metablock_size,
 733						&tmp_next_block_ctx,
 734						mirror_num);
 735			if (ret) {
 736				pr_info("btrfsic: btrfsic_map_block(root @%llu, mirror %d) failed!\n",
 737				       next_bytenr, mirror_num);
 738				kfree(selected_super);
 739				return -1;
 740			}
 741
 742			next_block = btrfsic_block_hashtable_lookup(
 743					tmp_next_block_ctx.dev->bdev,
 744					tmp_next_block_ctx.dev_bytenr,
 745					&state->block_hashtable);
 746			BUG_ON(NULL == next_block);
 747
 748			l = btrfsic_block_link_hashtable_lookup(
 749					tmp_next_block_ctx.dev->bdev,
 750					tmp_next_block_ctx.dev_bytenr,
 751					state->latest_superblock->dev_state->
 752					bdev,
 753					state->latest_superblock->dev_bytenr,
 754					&state->block_link_hashtable);
 755			BUG_ON(NULL == l);
 756
 757			ret = btrfsic_read_block(state, &tmp_next_block_ctx);
 758			if (ret < (int)PAGE_SIZE) {
 759				pr_info("btrfsic: read @logical %llu failed!\n",
 760				       tmp_next_block_ctx.start);
 761				btrfsic_release_block_ctx(&tmp_next_block_ctx);
 762				kfree(selected_super);
 763				return -1;
 764			}
 765
 766			ret = btrfsic_process_metablock(state,
 767							next_block,
 768							&tmp_next_block_ctx,
 769							BTRFS_MAX_LEVEL + 3, 1);
 770			btrfsic_release_block_ctx(&tmp_next_block_ctx);
 771		}
 772	}
 773
 774	kfree(selected_super);
 775	return ret;
 776}
 777
 778static int btrfsic_process_superblock_dev_mirror(
 779		struct btrfsic_state *state,
 780		struct btrfsic_dev_state *dev_state,
 781		struct btrfs_device *device,
 782		int superblock_mirror_num,
 783		struct btrfsic_dev_state **selected_dev_state,
 784		struct btrfs_super_block *selected_super)
 785{
 786	struct btrfs_fs_info *fs_info = state->fs_info;
 787	struct btrfs_super_block *super_tmp;
 788	u64 dev_bytenr;
 789	struct buffer_head *bh;
 790	struct btrfsic_block *superblock_tmp;
 791	int pass;
 792	struct block_device *const superblock_bdev = device->bdev;
 793
 794	/* super block bytenr is always the unmapped device bytenr */
 795	dev_bytenr = btrfs_sb_offset(superblock_mirror_num);
 796	if (dev_bytenr + BTRFS_SUPER_INFO_SIZE > device->commit_total_bytes)
 797		return -1;
 798	bh = __bread(superblock_bdev, dev_bytenr / 4096,
 799		     BTRFS_SUPER_INFO_SIZE);
 800	if (NULL == bh)
 801		return -1;
 802	super_tmp = (struct btrfs_super_block *)
 803	    (bh->b_data + (dev_bytenr & 4095));
 804
 805	if (btrfs_super_bytenr(super_tmp) != dev_bytenr ||
 806	    btrfs_super_magic(super_tmp) != BTRFS_MAGIC ||
 807	    memcmp(device->uuid, super_tmp->dev_item.uuid, BTRFS_UUID_SIZE) ||
 808	    btrfs_super_nodesize(super_tmp) != state->metablock_size ||
 809	    btrfs_super_sectorsize(super_tmp) != state->datablock_size) {
 810		brelse(bh);
 811		return 0;
 812	}
 813
 814	superblock_tmp =
 815	    btrfsic_block_hashtable_lookup(superblock_bdev,
 816					   dev_bytenr,
 817					   &state->block_hashtable);
 818	if (NULL == superblock_tmp) {
 819		superblock_tmp = btrfsic_block_alloc();
 820		if (NULL == superblock_tmp) {
 821			pr_info("btrfsic: error, kmalloc failed!\n");
 822			brelse(bh);
 823			return -1;
 824		}
 825		/* for superblock, only the dev_bytenr makes sense */
 826		superblock_tmp->dev_bytenr = dev_bytenr;
 827		superblock_tmp->dev_state = dev_state;
 828		superblock_tmp->logical_bytenr = dev_bytenr;
 829		superblock_tmp->generation = btrfs_super_generation(super_tmp);
 830		superblock_tmp->is_metadata = 1;
 831		superblock_tmp->is_superblock = 1;
 832		superblock_tmp->is_iodone = 1;
 833		superblock_tmp->never_written = 0;
 834		superblock_tmp->mirror_num = 1 + superblock_mirror_num;
 835		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
 836			btrfs_info_in_rcu(fs_info,
 837				"new initial S-block (bdev %p, %s) @%llu (%s/%llu/%d)",
 838				     superblock_bdev,
 839				     rcu_str_deref(device->name), dev_bytenr,
 840				     dev_state->name, dev_bytenr,
 841				     superblock_mirror_num);
 842		list_add(&superblock_tmp->all_blocks_node,
 843			 &state->all_blocks_list);
 844		btrfsic_block_hashtable_add(superblock_tmp,
 845					    &state->block_hashtable);
 846	}
 847
 848	/* select the one with the highest generation field */
 849	if (btrfs_super_generation(super_tmp) >
 850	    state->max_superblock_generation ||
 851	    0 == state->max_superblock_generation) {
 852		memcpy(selected_super, super_tmp, sizeof(*selected_super));
 853		*selected_dev_state = dev_state;
 854		state->max_superblock_generation =
 855		    btrfs_super_generation(super_tmp);
 856		state->latest_superblock = superblock_tmp;
 857	}
 858
 859	for (pass = 0; pass < 3; pass++) {
 860		u64 next_bytenr;
 861		int num_copies;
 862		int mirror_num;
 863		const char *additional_string = NULL;
 864		struct btrfs_disk_key tmp_disk_key;
 865
 866		tmp_disk_key.type = BTRFS_ROOT_ITEM_KEY;
 867		tmp_disk_key.offset = 0;
 868		switch (pass) {
 869		case 0:
 870			btrfs_set_disk_key_objectid(&tmp_disk_key,
 871						    BTRFS_ROOT_TREE_OBJECTID);
 872			additional_string = "initial root ";
 873			next_bytenr = btrfs_super_root(super_tmp);
 874			break;
 875		case 1:
 876			btrfs_set_disk_key_objectid(&tmp_disk_key,
 877						    BTRFS_CHUNK_TREE_OBJECTID);
 878			additional_string = "initial chunk ";
 879			next_bytenr = btrfs_super_chunk_root(super_tmp);
 880			break;
 881		case 2:
 882			btrfs_set_disk_key_objectid(&tmp_disk_key,
 883						    BTRFS_TREE_LOG_OBJECTID);
 884			additional_string = "initial log ";
 885			next_bytenr = btrfs_super_log_root(super_tmp);
 886			if (0 == next_bytenr)
 887				continue;
 888			break;
 889		}
 890
 891		num_copies = btrfs_num_copies(fs_info, next_bytenr,
 892					      state->metablock_size);
 893		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
 894			pr_info("num_copies(log_bytenr=%llu) = %d\n",
 895			       next_bytenr, num_copies);
 896		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
 897			struct btrfsic_block *next_block;
 898			struct btrfsic_block_data_ctx tmp_next_block_ctx;
 899			struct btrfsic_block_link *l;
 900
 901			if (btrfsic_map_block(state, next_bytenr,
 902					      state->metablock_size,
 903					      &tmp_next_block_ctx,
 904					      mirror_num)) {
 905				pr_info("btrfsic: btrfsic_map_block(bytenr @%llu, mirror %d) failed!\n",
 906				       next_bytenr, mirror_num);
 907				brelse(bh);
 908				return -1;
 909			}
 910
 911			next_block = btrfsic_block_lookup_or_add(
 912					state, &tmp_next_block_ctx,
 913					additional_string, 1, 1, 0,
 914					mirror_num, NULL);
 915			if (NULL == next_block) {
 916				btrfsic_release_block_ctx(&tmp_next_block_ctx);
 917				brelse(bh);
 918				return -1;
 919			}
 920
 921			next_block->disk_key = tmp_disk_key;
 922			next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
 923			l = btrfsic_block_link_lookup_or_add(
 924					state, &tmp_next_block_ctx,
 925					next_block, superblock_tmp,
 926					BTRFSIC_GENERATION_UNKNOWN);
 927			btrfsic_release_block_ctx(&tmp_next_block_ctx);
 928			if (NULL == l) {
 929				brelse(bh);
 930				return -1;
 931			}
 932		}
 933	}
 934	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES)
 935		btrfsic_dump_tree_sub(state, superblock_tmp, 0);
 936
 937	brelse(bh);
 938	return 0;
 939}
 940
 941static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void)
 942{
 943	struct btrfsic_stack_frame *sf;
 944
 945	sf = kzalloc(sizeof(*sf), GFP_NOFS);
 946	if (NULL == sf)
 947		pr_info("btrfsic: alloc memory failed!\n");
 948	else
 949		sf->magic = BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER;
 950	return sf;
 951}
 952
 953static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf)
 954{
 955	BUG_ON(!(NULL == sf ||
 956		 BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER == sf->magic));
 957	kfree(sf);
 958}
 959
 960static int btrfsic_process_metablock(
 961		struct btrfsic_state *state,
 962		struct btrfsic_block *const first_block,
 963		struct btrfsic_block_data_ctx *const first_block_ctx,
 964		int first_limit_nesting, int force_iodone_flag)
 965{
 966	struct btrfsic_stack_frame initial_stack_frame = { 0 };
 967	struct btrfsic_stack_frame *sf;
 968	struct btrfsic_stack_frame *next_stack;
 969	struct btrfs_header *const first_hdr =
 970		(struct btrfs_header *)first_block_ctx->datav[0];
 971
 972	BUG_ON(!first_hdr);
 973	sf = &initial_stack_frame;
 974	sf->error = 0;
 975	sf->i = -1;
 976	sf->limit_nesting = first_limit_nesting;
 977	sf->block = first_block;
 978	sf->block_ctx = first_block_ctx;
 979	sf->next_block = NULL;
 980	sf->hdr = first_hdr;
 981	sf->prev = NULL;
 982
 983continue_with_new_stack_frame:
 984	sf->block->generation = le64_to_cpu(sf->hdr->generation);
 985	if (0 == sf->hdr->level) {
 986		struct btrfs_leaf *const leafhdr =
 987		    (struct btrfs_leaf *)sf->hdr;
 988
 989		if (-1 == sf->i) {
 990			sf->nr = btrfs_stack_header_nritems(&leafhdr->header);
 991
 992			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
 993				pr_info("leaf %llu items %d generation %llu owner %llu\n",
 994				       sf->block_ctx->start, sf->nr,
 995				       btrfs_stack_header_generation(
 996					       &leafhdr->header),
 997				       btrfs_stack_header_owner(
 998					       &leafhdr->header));
 999		}
1000
1001continue_with_current_leaf_stack_frame:
1002		if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1003			sf->i++;
1004			sf->num_copies = 0;
1005		}
1006
1007		if (sf->i < sf->nr) {
1008			struct btrfs_item disk_item;
1009			u32 disk_item_offset =
1010				(uintptr_t)(leafhdr->items + sf->i) -
1011				(uintptr_t)leafhdr;
1012			struct btrfs_disk_key *disk_key;
1013			u8 type;
1014			u32 item_offset;
1015			u32 item_size;
1016
1017			if (disk_item_offset + sizeof(struct btrfs_item) >
1018			    sf->block_ctx->len) {
1019leaf_item_out_of_bounce_error:
1020				pr_info("btrfsic: leaf item out of bounce at logical %llu, dev %s\n",
1021				       sf->block_ctx->start,
1022				       sf->block_ctx->dev->name);
1023				goto one_stack_frame_backwards;
1024			}
1025			btrfsic_read_from_block_data(sf->block_ctx,
1026						     &disk_item,
1027						     disk_item_offset,
1028						     sizeof(struct btrfs_item));
1029			item_offset = btrfs_stack_item_offset(&disk_item);
1030			item_size = btrfs_stack_item_size(&disk_item);
1031			disk_key = &disk_item.key;
1032			type = btrfs_disk_key_type(disk_key);
1033
1034			if (BTRFS_ROOT_ITEM_KEY == type) {
1035				struct btrfs_root_item root_item;
1036				u32 root_item_offset;
1037				u64 next_bytenr;
1038
1039				root_item_offset = item_offset +
1040					offsetof(struct btrfs_leaf, items);
1041				if (root_item_offset + item_size >
1042				    sf->block_ctx->len)
1043					goto leaf_item_out_of_bounce_error;
1044				btrfsic_read_from_block_data(
1045					sf->block_ctx, &root_item,
1046					root_item_offset,
1047					item_size);
1048				next_bytenr = btrfs_root_bytenr(&root_item);
1049
1050				sf->error =
1051				    btrfsic_create_link_to_next_block(
1052						state,
1053						sf->block,
1054						sf->block_ctx,
1055						next_bytenr,
1056						sf->limit_nesting,
1057						&sf->next_block_ctx,
1058						&sf->next_block,
1059						force_iodone_flag,
1060						&sf->num_copies,
1061						&sf->mirror_num,
1062						disk_key,
1063						btrfs_root_generation(
1064						&root_item));
1065				if (sf->error)
1066					goto one_stack_frame_backwards;
1067
1068				if (NULL != sf->next_block) {
1069					struct btrfs_header *const next_hdr =
1070					    (struct btrfs_header *)
1071					    sf->next_block_ctx.datav[0];
1072
1073					next_stack =
1074					    btrfsic_stack_frame_alloc();
1075					if (NULL == next_stack) {
1076						sf->error = -1;
1077						btrfsic_release_block_ctx(
1078								&sf->
1079								next_block_ctx);
1080						goto one_stack_frame_backwards;
1081					}
1082
1083					next_stack->i = -1;
1084					next_stack->block = sf->next_block;
1085					next_stack->block_ctx =
1086					    &sf->next_block_ctx;
1087					next_stack->next_block = NULL;
1088					next_stack->hdr = next_hdr;
1089					next_stack->limit_nesting =
1090					    sf->limit_nesting - 1;
1091					next_stack->prev = sf;
1092					sf = next_stack;
1093					goto continue_with_new_stack_frame;
1094				}
1095			} else if (BTRFS_EXTENT_DATA_KEY == type &&
1096				   state->include_extent_data) {
1097				sf->error = btrfsic_handle_extent_data(
1098						state,
1099						sf->block,
1100						sf->block_ctx,
1101						item_offset,
1102						force_iodone_flag);
1103				if (sf->error)
1104					goto one_stack_frame_backwards;
1105			}
1106
1107			goto continue_with_current_leaf_stack_frame;
1108		}
1109	} else {
1110		struct btrfs_node *const nodehdr = (struct btrfs_node *)sf->hdr;
1111
1112		if (-1 == sf->i) {
1113			sf->nr = btrfs_stack_header_nritems(&nodehdr->header);
1114
1115			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1116				pr_info("node %llu level %d items %d generation %llu owner %llu\n",
1117				       sf->block_ctx->start,
1118				       nodehdr->header.level, sf->nr,
1119				       btrfs_stack_header_generation(
1120				       &nodehdr->header),
1121				       btrfs_stack_header_owner(
1122				       &nodehdr->header));
1123		}
1124
1125continue_with_current_node_stack_frame:
1126		if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1127			sf->i++;
1128			sf->num_copies = 0;
1129		}
1130
1131		if (sf->i < sf->nr) {
1132			struct btrfs_key_ptr key_ptr;
1133			u32 key_ptr_offset;
1134			u64 next_bytenr;
1135
1136			key_ptr_offset = (uintptr_t)(nodehdr->ptrs + sf->i) -
1137					  (uintptr_t)nodehdr;
1138			if (key_ptr_offset + sizeof(struct btrfs_key_ptr) >
1139			    sf->block_ctx->len) {
1140				pr_info("btrfsic: node item out of bounce at logical %llu, dev %s\n",
1141				       sf->block_ctx->start,
1142				       sf->block_ctx->dev->name);
1143				goto one_stack_frame_backwards;
1144			}
1145			btrfsic_read_from_block_data(
1146				sf->block_ctx, &key_ptr, key_ptr_offset,
1147				sizeof(struct btrfs_key_ptr));
1148			next_bytenr = btrfs_stack_key_blockptr(&key_ptr);
1149
1150			sf->error = btrfsic_create_link_to_next_block(
1151					state,
1152					sf->block,
1153					sf->block_ctx,
1154					next_bytenr,
1155					sf->limit_nesting,
1156					&sf->next_block_ctx,
1157					&sf->next_block,
1158					force_iodone_flag,
1159					&sf->num_copies,
1160					&sf->mirror_num,
1161					&key_ptr.key,
1162					btrfs_stack_key_generation(&key_ptr));
1163			if (sf->error)
1164				goto one_stack_frame_backwards;
1165
1166			if (NULL != sf->next_block) {
1167				struct btrfs_header *const next_hdr =
1168				    (struct btrfs_header *)
1169				    sf->next_block_ctx.datav[0];
1170
1171				next_stack = btrfsic_stack_frame_alloc();
1172				if (NULL == next_stack) {
1173					sf->error = -1;
1174					goto one_stack_frame_backwards;
1175				}
1176
1177				next_stack->i = -1;
1178				next_stack->block = sf->next_block;
1179				next_stack->block_ctx = &sf->next_block_ctx;
1180				next_stack->next_block = NULL;
1181				next_stack->hdr = next_hdr;
1182				next_stack->limit_nesting =
1183				    sf->limit_nesting - 1;
1184				next_stack->prev = sf;
1185				sf = next_stack;
1186				goto continue_with_new_stack_frame;
1187			}
1188
1189			goto continue_with_current_node_stack_frame;
1190		}
1191	}
1192
1193one_stack_frame_backwards:
1194	if (NULL != sf->prev) {
1195		struct btrfsic_stack_frame *const prev = sf->prev;
1196
1197		/* the one for the initial block is freed in the caller */
1198		btrfsic_release_block_ctx(sf->block_ctx);
1199
1200		if (sf->error) {
1201			prev->error = sf->error;
1202			btrfsic_stack_frame_free(sf);
1203			sf = prev;
1204			goto one_stack_frame_backwards;
1205		}
1206
1207		btrfsic_stack_frame_free(sf);
1208		sf = prev;
1209		goto continue_with_new_stack_frame;
1210	} else {
1211		BUG_ON(&initial_stack_frame != sf);
1212	}
1213
1214	return sf->error;
1215}
1216
1217static void btrfsic_read_from_block_data(
1218	struct btrfsic_block_data_ctx *block_ctx,
1219	void *dstv, u32 offset, size_t len)
1220{
1221	size_t cur;
1222	size_t offset_in_page;
1223	char *kaddr;
1224	char *dst = (char *)dstv;
1225	size_t start_offset = block_ctx->start & ((u64)PAGE_SIZE - 1);
1226	unsigned long i = (start_offset + offset) >> PAGE_SHIFT;
1227
1228	WARN_ON(offset + len > block_ctx->len);
1229	offset_in_page = (start_offset + offset) & (PAGE_SIZE - 1);
1230
1231	while (len > 0) {
1232		cur = min(len, ((size_t)PAGE_SIZE - offset_in_page));
1233		BUG_ON(i >= DIV_ROUND_UP(block_ctx->len, PAGE_SIZE));
1234		kaddr = block_ctx->datav[i];
1235		memcpy(dst, kaddr + offset_in_page, cur);
1236
1237		dst += cur;
1238		len -= cur;
1239		offset_in_page = 0;
1240		i++;
1241	}
1242}
1243
1244static int btrfsic_create_link_to_next_block(
1245		struct btrfsic_state *state,
1246		struct btrfsic_block *block,
1247		struct btrfsic_block_data_ctx *block_ctx,
1248		u64 next_bytenr,
1249		int limit_nesting,
1250		struct btrfsic_block_data_ctx *next_block_ctx,
1251		struct btrfsic_block **next_blockp,
1252		int force_iodone_flag,
1253		int *num_copiesp, int *mirror_nump,
1254		struct btrfs_disk_key *disk_key,
1255		u64 parent_generation)
1256{
1257	struct btrfs_fs_info *fs_info = state->fs_info;
1258	struct btrfsic_block *next_block = NULL;
1259	int ret;
1260	struct btrfsic_block_link *l;
1261	int did_alloc_block_link;
1262	int block_was_created;
1263
1264	*next_blockp = NULL;
1265	if (0 == *num_copiesp) {
1266		*num_copiesp = btrfs_num_copies(fs_info, next_bytenr,
1267						state->metablock_size);
1268		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1269			pr_info("num_copies(log_bytenr=%llu) = %d\n",
1270			       next_bytenr, *num_copiesp);
1271		*mirror_nump = 1;
1272	}
1273
1274	if (*mirror_nump > *num_copiesp)
1275		return 0;
1276
1277	if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1278		pr_info("btrfsic_create_link_to_next_block(mirror_num=%d)\n",
1279		       *mirror_nump);
1280	ret = btrfsic_map_block(state, next_bytenr,
1281				state->metablock_size,
1282				next_block_ctx, *mirror_nump);
1283	if (ret) {
1284		pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
1285		       next_bytenr, *mirror_nump);
1286		btrfsic_release_block_ctx(next_block_ctx);
1287		*next_blockp = NULL;
1288		return -1;
1289	}
1290
1291	next_block = btrfsic_block_lookup_or_add(state,
1292						 next_block_ctx, "referenced ",
1293						 1, force_iodone_flag,
1294						 !force_iodone_flag,
1295						 *mirror_nump,
1296						 &block_was_created);
1297	if (NULL == next_block) {
1298		btrfsic_release_block_ctx(next_block_ctx);
1299		*next_blockp = NULL;
1300		return -1;
1301	}
1302	if (block_was_created) {
1303		l = NULL;
1304		next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
1305	} else {
1306		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1307			if (next_block->logical_bytenr != next_bytenr &&
1308			    !(!next_block->is_metadata &&
1309			      0 == next_block->logical_bytenr))
1310				pr_info("Referenced block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1311				       next_bytenr, next_block_ctx->dev->name,
1312				       next_block_ctx->dev_bytenr, *mirror_nump,
1313				       btrfsic_get_block_type(state,
1314							      next_block),
1315				       next_block->logical_bytenr);
1316			else
1317				pr_info("Referenced block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1318				       next_bytenr, next_block_ctx->dev->name,
1319				       next_block_ctx->dev_bytenr, *mirror_nump,
1320				       btrfsic_get_block_type(state,
1321							      next_block));
1322		}
1323		next_block->logical_bytenr = next_bytenr;
1324
1325		next_block->mirror_num = *mirror_nump;
1326		l = btrfsic_block_link_hashtable_lookup(
1327				next_block_ctx->dev->bdev,
1328				next_block_ctx->dev_bytenr,
1329				block_ctx->dev->bdev,
1330				block_ctx->dev_bytenr,
1331				&state->block_link_hashtable);
1332	}
1333
1334	next_block->disk_key = *disk_key;
1335	if (NULL == l) {
1336		l = btrfsic_block_link_alloc();
1337		if (NULL == l) {
1338			pr_info("btrfsic: error, kmalloc failed!\n");
1339			btrfsic_release_block_ctx(next_block_ctx);
1340			*next_blockp = NULL;
1341			return -1;
1342		}
1343
1344		did_alloc_block_link = 1;
1345		l->block_ref_to = next_block;
1346		l->block_ref_from = block;
1347		l->ref_cnt = 1;
1348		l->parent_generation = parent_generation;
1349
1350		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1351			btrfsic_print_add_link(state, l);
1352
1353		list_add(&l->node_ref_to, &block->ref_to_list);
1354		list_add(&l->node_ref_from, &next_block->ref_from_list);
1355
1356		btrfsic_block_link_hashtable_add(l,
1357						 &state->block_link_hashtable);
1358	} else {
1359		did_alloc_block_link = 0;
1360		if (0 == limit_nesting) {
1361			l->ref_cnt++;
1362			l->parent_generation = parent_generation;
1363			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1364				btrfsic_print_add_link(state, l);
1365		}
1366	}
1367
1368	if (limit_nesting > 0 && did_alloc_block_link) {
1369		ret = btrfsic_read_block(state, next_block_ctx);
1370		if (ret < (int)next_block_ctx->len) {
1371			pr_info("btrfsic: read block @logical %llu failed!\n",
1372			       next_bytenr);
1373			btrfsic_release_block_ctx(next_block_ctx);
1374			*next_blockp = NULL;
1375			return -1;
1376		}
1377
1378		*next_blockp = next_block;
1379	} else {
1380		*next_blockp = NULL;
1381	}
1382	(*mirror_nump)++;
1383
1384	return 0;
1385}
1386
1387static int btrfsic_handle_extent_data(
1388		struct btrfsic_state *state,
1389		struct btrfsic_block *block,
1390		struct btrfsic_block_data_ctx *block_ctx,
1391		u32 item_offset, int force_iodone_flag)
1392{
1393	struct btrfs_fs_info *fs_info = state->fs_info;
1394	struct btrfs_file_extent_item file_extent_item;
1395	u64 file_extent_item_offset;
1396	u64 next_bytenr;
1397	u64 num_bytes;
1398	u64 generation;
1399	struct btrfsic_block_link *l;
1400	int ret;
1401
1402	file_extent_item_offset = offsetof(struct btrfs_leaf, items) +
1403				  item_offset;
1404	if (file_extent_item_offset +
1405	    offsetof(struct btrfs_file_extent_item, disk_num_bytes) >
1406	    block_ctx->len) {
1407		pr_info("btrfsic: file item out of bounce at logical %llu, dev %s\n",
1408		       block_ctx->start, block_ctx->dev->name);
1409		return -1;
1410	}
1411
1412	btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1413		file_extent_item_offset,
1414		offsetof(struct btrfs_file_extent_item, disk_num_bytes));
1415	if (BTRFS_FILE_EXTENT_REG != file_extent_item.type ||
1416	    btrfs_stack_file_extent_disk_bytenr(&file_extent_item) == 0) {
1417		if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1418			pr_info("extent_data: type %u, disk_bytenr = %llu\n",
1419			       file_extent_item.type,
1420			       btrfs_stack_file_extent_disk_bytenr(
1421			       &file_extent_item));
1422		return 0;
1423	}
1424
1425	if (file_extent_item_offset + sizeof(struct btrfs_file_extent_item) >
1426	    block_ctx->len) {
1427		pr_info("btrfsic: file item out of bounce at logical %llu, dev %s\n",
1428		       block_ctx->start, block_ctx->dev->name);
1429		return -1;
1430	}
1431	btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1432				     file_extent_item_offset,
1433				     sizeof(struct btrfs_file_extent_item));
1434	next_bytenr = btrfs_stack_file_extent_disk_bytenr(&file_extent_item);
1435	if (btrfs_stack_file_extent_compression(&file_extent_item) ==
1436	    BTRFS_COMPRESS_NONE) {
1437		next_bytenr += btrfs_stack_file_extent_offset(&file_extent_item);
1438		num_bytes = btrfs_stack_file_extent_num_bytes(&file_extent_item);
1439	} else {
1440		num_bytes = btrfs_stack_file_extent_disk_num_bytes(&file_extent_item);
1441	}
1442	generation = btrfs_stack_file_extent_generation(&file_extent_item);
1443
1444	if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1445		pr_info("extent_data: type %u, disk_bytenr = %llu, offset = %llu, num_bytes = %llu\n",
1446		       file_extent_item.type,
1447		       btrfs_stack_file_extent_disk_bytenr(&file_extent_item),
1448		       btrfs_stack_file_extent_offset(&file_extent_item),
1449		       num_bytes);
1450	while (num_bytes > 0) {
1451		u32 chunk_len;
1452		int num_copies;
1453		int mirror_num;
1454
1455		if (num_bytes > state->datablock_size)
1456			chunk_len = state->datablock_size;
1457		else
1458			chunk_len = num_bytes;
1459
1460		num_copies = btrfs_num_copies(fs_info, next_bytenr,
1461					      state->datablock_size);
1462		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1463			pr_info("num_copies(log_bytenr=%llu) = %d\n",
1464			       next_bytenr, num_copies);
1465		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
1466			struct btrfsic_block_data_ctx next_block_ctx;
1467			struct btrfsic_block *next_block;
1468			int block_was_created;
1469
1470			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1471				pr_info("btrfsic_handle_extent_data(mirror_num=%d)\n",
1472					mirror_num);
1473			if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1474				pr_info("\tdisk_bytenr = %llu, num_bytes %u\n",
1475				       next_bytenr, chunk_len);
1476			ret = btrfsic_map_block(state, next_bytenr,
1477						chunk_len, &next_block_ctx,
1478						mirror_num);
1479			if (ret) {
1480				pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
1481				       next_bytenr, mirror_num);
1482				return -1;
1483			}
1484
1485			next_block = btrfsic_block_lookup_or_add(
1486					state,
1487					&next_block_ctx,
1488					"referenced ",
1489					0,
1490					force_iodone_flag,
1491					!force_iodone_flag,
1492					mirror_num,
1493					&block_was_created);
1494			if (NULL == next_block) {
1495				pr_info("btrfsic: error, kmalloc failed!\n");
1496				btrfsic_release_block_ctx(&next_block_ctx);
1497				return -1;
1498			}
1499			if (!block_was_created) {
1500				if ((state->print_mask &
1501				     BTRFSIC_PRINT_MASK_VERBOSE) &&
1502				    next_block->logical_bytenr != next_bytenr &&
1503				    !(!next_block->is_metadata &&
1504				      0 == next_block->logical_bytenr)) {
1505					pr_info("Referenced block @%llu (%s/%llu/%d) found in hash table, D, bytenr mismatch (!= stored %llu).\n",
1506					       next_bytenr,
1507					       next_block_ctx.dev->name,
1508					       next_block_ctx.dev_bytenr,
1509					       mirror_num,
1510					       next_block->logical_bytenr);
1511				}
1512				next_block->logical_bytenr = next_bytenr;
1513				next_block->mirror_num = mirror_num;
1514			}
1515
1516			l = btrfsic_block_link_lookup_or_add(state,
1517							     &next_block_ctx,
1518							     next_block, block,
1519							     generation);
1520			btrfsic_release_block_ctx(&next_block_ctx);
1521			if (NULL == l)
1522				return -1;
1523		}
1524
1525		next_bytenr += chunk_len;
1526		num_bytes -= chunk_len;
1527	}
1528
1529	return 0;
1530}
1531
1532static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
1533			     struct btrfsic_block_data_ctx *block_ctx_out,
1534			     int mirror_num)
1535{
1536	struct btrfs_fs_info *fs_info = state->fs_info;
1537	int ret;
1538	u64 length;
1539	struct btrfs_bio *multi = NULL;
1540	struct btrfs_device *device;
1541
1542	length = len;
1543	ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
1544			      bytenr, &length, &multi, mirror_num);
1545
1546	if (ret) {
1547		block_ctx_out->start = 0;
1548		block_ctx_out->dev_bytenr = 0;
1549		block_ctx_out->len = 0;
1550		block_ctx_out->dev = NULL;
1551		block_ctx_out->datav = NULL;
1552		block_ctx_out->pagev = NULL;
1553		block_ctx_out->mem_to_free = NULL;
1554
1555		return ret;
1556	}
1557
1558	device = multi->stripes[0].dev;
1559	block_ctx_out->dev = btrfsic_dev_state_lookup(device->bdev);
1560	block_ctx_out->dev_bytenr = multi->stripes[0].physical;
1561	block_ctx_out->start = bytenr;
1562	block_ctx_out->len = len;
1563	block_ctx_out->datav = NULL;
1564	block_ctx_out->pagev = NULL;
1565	block_ctx_out->mem_to_free = NULL;
1566
1567	kfree(multi);
1568	if (NULL == block_ctx_out->dev) {
1569		ret = -ENXIO;
1570		pr_info("btrfsic: error, cannot lookup dev (#1)!\n");
1571	}
1572
1573	return ret;
1574}
1575
1576static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx)
1577{
1578	if (block_ctx->mem_to_free) {
1579		unsigned int num_pages;
1580
1581		BUG_ON(!block_ctx->datav);
1582		BUG_ON(!block_ctx->pagev);
1583		num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
1584			    PAGE_SHIFT;
1585		while (num_pages > 0) {
1586			num_pages--;
1587			if (block_ctx->datav[num_pages]) {
1588				kunmap(block_ctx->pagev[num_pages]);
1589				block_ctx->datav[num_pages] = NULL;
1590			}
1591			if (block_ctx->pagev[num_pages]) {
1592				__free_page(block_ctx->pagev[num_pages]);
1593				block_ctx->pagev[num_pages] = NULL;
1594			}
1595		}
1596
1597		kfree(block_ctx->mem_to_free);
1598		block_ctx->mem_to_free = NULL;
1599		block_ctx->pagev = NULL;
1600		block_ctx->datav = NULL;
1601	}
1602}
1603
1604static int btrfsic_read_block(struct btrfsic_state *state,
1605			      struct btrfsic_block_data_ctx *block_ctx)
1606{
1607	unsigned int num_pages;
1608	unsigned int i;
1609	u64 dev_bytenr;
1610	int ret;
1611
1612	BUG_ON(block_ctx->datav);
1613	BUG_ON(block_ctx->pagev);
1614	BUG_ON(block_ctx->mem_to_free);
1615	if (block_ctx->dev_bytenr & ((u64)PAGE_SIZE - 1)) {
1616		pr_info("btrfsic: read_block() with unaligned bytenr %llu\n",
1617		       block_ctx->dev_bytenr);
1618		return -1;
1619	}
1620
1621	num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
1622		    PAGE_SHIFT;
1623	block_ctx->mem_to_free = kzalloc((sizeof(*block_ctx->datav) +
1624					  sizeof(*block_ctx->pagev)) *
1625					 num_pages, GFP_NOFS);
1626	if (!block_ctx->mem_to_free)
1627		return -ENOMEM;
1628	block_ctx->datav = block_ctx->mem_to_free;
1629	block_ctx->pagev = (struct page **)(block_ctx->datav + num_pages);
1630	for (i = 0; i < num_pages; i++) {
1631		block_ctx->pagev[i] = alloc_page(GFP_NOFS);
1632		if (!block_ctx->pagev[i])
1633			return -1;
1634	}
1635
1636	dev_bytenr = block_ctx->dev_bytenr;
1637	for (i = 0; i < num_pages;) {
1638		struct bio *bio;
1639		unsigned int j;
1640
1641		bio = btrfs_io_bio_alloc(GFP_NOFS, num_pages - i);
1642		if (!bio) {
1643			pr_info("btrfsic: bio_alloc() for %u pages failed!\n",
1644			       num_pages - i);
1645			return -1;
1646		}
1647		bio->bi_bdev = block_ctx->dev->bdev;
1648		bio->bi_iter.bi_sector = dev_bytenr >> 9;
1649		bio_set_op_attrs(bio, REQ_OP_READ, 0);
1650
1651		for (j = i; j < num_pages; j++) {
1652			ret = bio_add_page(bio, block_ctx->pagev[j],
1653					   PAGE_SIZE, 0);
1654			if (PAGE_SIZE != ret)
1655				break;
1656		}
1657		if (j == i) {
1658			pr_info("btrfsic: error, failed to add a single page!\n");
1659			return -1;
1660		}
1661		if (submit_bio_wait(bio)) {
1662			pr_info("btrfsic: read error at logical %llu dev %s!\n",
1663			       block_ctx->start, block_ctx->dev->name);
1664			bio_put(bio);
1665			return -1;
1666		}
1667		bio_put(bio);
1668		dev_bytenr += (j - i) * PAGE_SIZE;
1669		i = j;
1670	}
1671	for (i = 0; i < num_pages; i++) {
1672		block_ctx->datav[i] = kmap(block_ctx->pagev[i]);
1673		if (!block_ctx->datav[i]) {
1674			pr_info("btrfsic: kmap() failed (dev %s)!\n",
1675			       block_ctx->dev->name);
1676			return -1;
1677		}
1678	}
1679
1680	return block_ctx->len;
1681}
1682
1683static void btrfsic_dump_database(struct btrfsic_state *state)
1684{
1685	const struct btrfsic_block *b_all;
1686
1687	BUG_ON(NULL == state);
1688
1689	pr_info("all_blocks_list:\n");
1690	list_for_each_entry(b_all, &state->all_blocks_list, all_blocks_node) {
1691		const struct btrfsic_block_link *l;
1692
1693		pr_info("%c-block @%llu (%s/%llu/%d)\n",
1694		       btrfsic_get_block_type(state, b_all),
1695		       b_all->logical_bytenr, b_all->dev_state->name,
1696		       b_all->dev_bytenr, b_all->mirror_num);
1697
1698		list_for_each_entry(l, &b_all->ref_to_list, node_ref_to) {
1699			pr_info(" %c @%llu (%s/%llu/%d) refers %u* to %c @%llu (%s/%llu/%d)\n",
1700			       btrfsic_get_block_type(state, b_all),
1701			       b_all->logical_bytenr, b_all->dev_state->name,
1702			       b_all->dev_bytenr, b_all->mirror_num,
1703			       l->ref_cnt,
1704			       btrfsic_get_block_type(state, l->block_ref_to),
1705			       l->block_ref_to->logical_bytenr,
1706			       l->block_ref_to->dev_state->name,
1707			       l->block_ref_to->dev_bytenr,
1708			       l->block_ref_to->mirror_num);
1709		}
1710
1711		list_for_each_entry(l, &b_all->ref_from_list, node_ref_from) {
1712			pr_info(" %c @%llu (%s/%llu/%d) is ref %u* from %c @%llu (%s/%llu/%d)\n",
1713			       btrfsic_get_block_type(state, b_all),
1714			       b_all->logical_bytenr, b_all->dev_state->name,
1715			       b_all->dev_bytenr, b_all->mirror_num,
1716			       l->ref_cnt,
1717			       btrfsic_get_block_type(state, l->block_ref_from),
1718			       l->block_ref_from->logical_bytenr,
1719			       l->block_ref_from->dev_state->name,
1720			       l->block_ref_from->dev_bytenr,
1721			       l->block_ref_from->mirror_num);
1722		}
1723
1724		pr_info("\n");
1725	}
1726}
1727
1728/*
1729 * Test whether the disk block contains a tree block (leaf or node)
1730 * (note that this test fails for the super block)
1731 */
1732static int btrfsic_test_for_metadata(struct btrfsic_state *state,
1733				     char **datav, unsigned int num_pages)
1734{
1735	struct btrfs_fs_info *fs_info = state->fs_info;
1736	struct btrfs_header *h;
1737	u8 csum[BTRFS_CSUM_SIZE];
1738	u32 crc = ~(u32)0;
1739	unsigned int i;
1740
1741	if (num_pages * PAGE_SIZE < state->metablock_size)
1742		return 1; /* not metadata */
1743	num_pages = state->metablock_size >> PAGE_SHIFT;
1744	h = (struct btrfs_header *)datav[0];
1745
1746	if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1747		return 1;
1748
1749	for (i = 0; i < num_pages; i++) {
1750		u8 *data = i ? datav[i] : (datav[i] + BTRFS_CSUM_SIZE);
1751		size_t sublen = i ? PAGE_SIZE :
1752				    (PAGE_SIZE - BTRFS_CSUM_SIZE);
1753
1754		crc = btrfs_crc32c(crc, data, sublen);
1755	}
1756	btrfs_csum_final(crc, csum);
1757	if (memcmp(csum, h->csum, state->csum_size))
1758		return 1;
1759
1760	return 0; /* is metadata */
1761}
1762
1763static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
1764					  u64 dev_bytenr, char **mapped_datav,
1765					  unsigned int num_pages,
1766					  struct bio *bio, int *bio_is_patched,
1767					  struct buffer_head *bh,
1768					  int submit_bio_bh_rw)
1769{
1770	int is_metadata;
1771	struct btrfsic_block *block;
1772	struct btrfsic_block_data_ctx block_ctx;
1773	int ret;
1774	struct btrfsic_state *state = dev_state->state;
1775	struct block_device *bdev = dev_state->bdev;
1776	unsigned int processed_len;
1777
1778	if (NULL != bio_is_patched)
1779		*bio_is_patched = 0;
1780
1781again:
1782	if (num_pages == 0)
1783		return;
1784
1785	processed_len = 0;
1786	is_metadata = (0 == btrfsic_test_for_metadata(state, mapped_datav,
1787						      num_pages));
1788
1789	block = btrfsic_block_hashtable_lookup(bdev, dev_bytenr,
1790					       &state->block_hashtable);
1791	if (NULL != block) {
1792		u64 bytenr = 0;
1793		struct btrfsic_block_link *l, *tmp;
1794
1795		if (block->is_superblock) {
1796			bytenr = btrfs_super_bytenr((struct btrfs_super_block *)
1797						    mapped_datav[0]);
1798			if (num_pages * PAGE_SIZE <
1799			    BTRFS_SUPER_INFO_SIZE) {
1800				pr_info("btrfsic: cannot work with too short bios!\n");
1801				return;
1802			}
1803			is_metadata = 1;
1804			BUG_ON(BTRFS_SUPER_INFO_SIZE & (PAGE_SIZE - 1));
1805			processed_len = BTRFS_SUPER_INFO_SIZE;
1806			if (state->print_mask &
1807			    BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE) {
1808				pr_info("[before new superblock is written]:\n");
1809				btrfsic_dump_tree_sub(state, block, 0);
1810			}
1811		}
1812		if (is_metadata) {
1813			if (!block->is_superblock) {
1814				if (num_pages * PAGE_SIZE <
1815				    state->metablock_size) {
1816					pr_info("btrfsic: cannot work with too short bios!\n");
1817					return;
1818				}
1819				processed_len = state->metablock_size;
1820				bytenr = btrfs_stack_header_bytenr(
1821						(struct btrfs_header *)
1822						mapped_datav[0]);
1823				btrfsic_cmp_log_and_dev_bytenr(state, bytenr,
1824							       dev_state,
1825							       dev_bytenr);
1826			}
1827			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1828				if (block->logical_bytenr != bytenr &&
1829				    !(!block->is_metadata &&
1830				      block->logical_bytenr == 0))
1831					pr_info("Written block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1832					       bytenr, dev_state->name,
1833					       dev_bytenr,
1834					       block->mirror_num,
1835					       btrfsic_get_block_type(state,
1836								      block),
1837					       block->logical_bytenr);
1838				else
1839					pr_info("Written block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1840					       bytenr, dev_state->name,
1841					       dev_bytenr, block->mirror_num,
1842					       btrfsic_get_block_type(state,
1843								      block));
1844			}
1845			block->logical_bytenr = bytenr;
1846		} else {
1847			if (num_pages * PAGE_SIZE <
1848			    state->datablock_size) {
1849				pr_info("btrfsic: cannot work with too short bios!\n");
1850				return;
1851			}
1852			processed_len = state->datablock_size;
1853			bytenr = block->logical_bytenr;
1854			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1855				pr_info("Written block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1856				       bytenr, dev_state->name, dev_bytenr,
1857				       block->mirror_num,
1858				       btrfsic_get_block_type(state, block));
1859		}
1860
1861		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1862			pr_info("ref_to_list: %cE, ref_from_list: %cE\n",
1863			       list_empty(&block->ref_to_list) ? ' ' : '!',
1864			       list_empty(&block->ref_from_list) ? ' ' : '!');
1865		if (btrfsic_is_block_ref_by_superblock(state, block, 0)) {
1866			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",
1867			       btrfsic_get_block_type(state, block), bytenr,
1868			       dev_state->name, dev_bytenr, block->mirror_num,
1869			       block->generation,
1870			       btrfs_disk_key_objectid(&block->disk_key),
1871			       block->disk_key.type,
1872			       btrfs_disk_key_offset(&block->disk_key),
1873			       btrfs_stack_header_generation(
1874				       (struct btrfs_header *) mapped_datav[0]),
1875			       state->max_superblock_generation);
1876			btrfsic_dump_tree(state);
1877		}
1878
1879		if (!block->is_iodone && !block->never_written) {
1880			pr_info("btrfs: attempt to overwrite %c-block @%llu (%s/%llu/%d), oldgen=%llu, newgen=%llu, which is not yet iodone!\n",
1881			       btrfsic_get_block_type(state, block), bytenr,
1882			       dev_state->name, dev_bytenr, block->mirror_num,
1883			       block->generation,
1884			       btrfs_stack_header_generation(
1885				       (struct btrfs_header *)
1886				       mapped_datav[0]));
1887			/* it would not be safe to go on */
1888			btrfsic_dump_tree(state);
1889			goto continue_loop;
1890		}
1891
1892		/*
1893		 * Clear all references of this block. Do not free
1894		 * the block itself even if is not referenced anymore
1895		 * because it still carries valuable information
1896		 * like whether it was ever written and IO completed.
1897		 */
1898		list_for_each_entry_safe(l, tmp, &block->ref_to_list,
1899					 node_ref_to) {
1900			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1901				btrfsic_print_rem_link(state, l);
1902			l->ref_cnt--;
1903			if (0 == l->ref_cnt) {
1904				list_del(&l->node_ref_to);
1905				list_del(&l->node_ref_from);
1906				btrfsic_block_link_hashtable_remove(l);
1907				btrfsic_block_link_free(l);
1908			}
1909		}
1910
1911		block_ctx.dev = dev_state;
1912		block_ctx.dev_bytenr = dev_bytenr;
1913		block_ctx.start = bytenr;
1914		block_ctx.len = processed_len;
1915		block_ctx.pagev = NULL;
1916		block_ctx.mem_to_free = NULL;
1917		block_ctx.datav = mapped_datav;
1918
1919		if (is_metadata || state->include_extent_data) {
1920			block->never_written = 0;
1921			block->iodone_w_error = 0;
1922			if (NULL != bio) {
1923				block->is_iodone = 0;
1924				BUG_ON(NULL == bio_is_patched);
1925				if (!*bio_is_patched) {
1926					block->orig_bio_bh_private =
1927					    bio->bi_private;
1928					block->orig_bio_bh_end_io.bio =
1929					    bio->bi_end_io;
1930					block->next_in_same_bio = NULL;
1931					bio->bi_private = block;
1932					bio->bi_end_io = btrfsic_bio_end_io;
1933					*bio_is_patched = 1;
1934				} else {
1935					struct btrfsic_block *chained_block =
1936					    (struct btrfsic_block *)
1937					    bio->bi_private;
1938
1939					BUG_ON(NULL == chained_block);
1940					block->orig_bio_bh_private =
1941					    chained_block->orig_bio_bh_private;
1942					block->orig_bio_bh_end_io.bio =
1943					    chained_block->orig_bio_bh_end_io.
1944					    bio;
1945					block->next_in_same_bio = chained_block;
1946					bio->bi_private = block;
1947				}
1948			} else if (NULL != bh) {
1949				block->is_iodone = 0;
1950				block->orig_bio_bh_private = bh->b_private;
1951				block->orig_bio_bh_end_io.bh = bh->b_end_io;
1952				block->next_in_same_bio = NULL;
1953				bh->b_private = block;
1954				bh->b_end_io = btrfsic_bh_end_io;
1955			} else {
1956				block->is_iodone = 1;
1957				block->orig_bio_bh_private = NULL;
1958				block->orig_bio_bh_end_io.bio = NULL;
1959				block->next_in_same_bio = NULL;
1960			}
1961		}
1962
1963		block->flush_gen = dev_state->last_flush_gen + 1;
1964		block->submit_bio_bh_rw = submit_bio_bh_rw;
1965		if (is_metadata) {
1966			block->logical_bytenr = bytenr;
1967			block->is_metadata = 1;
1968			if (block->is_superblock) {
1969				BUG_ON(PAGE_SIZE !=
1970				       BTRFS_SUPER_INFO_SIZE);
1971				ret = btrfsic_process_written_superblock(
1972						state,
1973						block,
1974						(struct btrfs_super_block *)
1975						mapped_datav[0]);
1976				if (state->print_mask &
1977				    BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE) {
1978					pr_info("[after new superblock is written]:\n");
1979					btrfsic_dump_tree_sub(state, block, 0);
1980				}
1981			} else {
1982				block->mirror_num = 0;	/* unknown */
1983				ret = btrfsic_process_metablock(
1984						state,
1985						block,
1986						&block_ctx,
1987						0, 0);
1988			}
1989			if (ret)
1990				pr_info("btrfsic: btrfsic_process_metablock(root @%llu) failed!\n",
1991				       dev_bytenr);
1992		} else {
1993			block->is_metadata = 0;
1994			block->mirror_num = 0;	/* unknown */
1995			block->generation = BTRFSIC_GENERATION_UNKNOWN;
1996			if (!state->include_extent_data
1997			    && list_empty(&block->ref_from_list)) {
1998				/*
1999				 * disk block is overwritten with extent
2000				 * data (not meta data) and we are configured
2001				 * to not include extent data: take the
2002				 * chance and free the block's memory
2003				 */
2004				btrfsic_block_hashtable_remove(block);
2005				list_del(&block->all_blocks_node);
2006				btrfsic_block_free(block);
2007			}
2008		}
2009		btrfsic_release_block_ctx(&block_ctx);
2010	} else {
2011		/* block has not been found in hash table */
2012		u64 bytenr;
2013
2014		if (!is_metadata) {
2015			processed_len = state->datablock_size;
2016			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2017				pr_info("Written block (%s/%llu/?) !found in hash table, D.\n",
2018				       dev_state->name, dev_bytenr);
2019			if (!state->include_extent_data) {
2020				/* ignore that written D block */
2021				goto continue_loop;
2022			}
2023
2024			/* this is getting ugly for the
2025			 * include_extent_data case... */
2026			bytenr = 0;	/* unknown */
2027		} else {
2028			processed_len = state->metablock_size;
2029			bytenr = btrfs_stack_header_bytenr(
2030					(struct btrfs_header *)
2031					mapped_datav[0]);
2032			btrfsic_cmp_log_and_dev_bytenr(state, bytenr, dev_state,
2033						       dev_bytenr);
2034			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2035				pr_info("Written block @%llu (%s/%llu/?) !found in hash table, M.\n",
2036				       bytenr, dev_state->name, dev_bytenr);
2037		}
2038
2039		block_ctx.dev = dev_state;
2040		block_ctx.dev_bytenr = dev_bytenr;
2041		block_ctx.start = bytenr;
2042		block_ctx.len = processed_len;
2043		block_ctx.pagev = NULL;
2044		block_ctx.mem_to_free = NULL;
2045		block_ctx.datav = mapped_datav;
2046
2047		block = btrfsic_block_alloc();
2048		if (NULL == block) {
2049			pr_info("btrfsic: error, kmalloc failed!\n");
2050			btrfsic_release_block_ctx(&block_ctx);
2051			goto continue_loop;
2052		}
2053		block->dev_state = dev_state;
2054		block->dev_bytenr = dev_bytenr;
2055		block->logical_bytenr = bytenr;
2056		block->is_metadata = is_metadata;
2057		block->never_written = 0;
2058		block->iodone_w_error = 0;
2059		block->mirror_num = 0;	/* unknown */
2060		block->flush_gen = dev_state->last_flush_gen + 1;
2061		block->submit_bio_bh_rw = submit_bio_bh_rw;
2062		if (NULL != bio) {
2063			block->is_iodone = 0;
2064			BUG_ON(NULL == bio_is_patched);
2065			if (!*bio_is_patched) {
2066				block->orig_bio_bh_private = bio->bi_private;
2067				block->orig_bio_bh_end_io.bio = bio->bi_end_io;
2068				block->next_in_same_bio = NULL;
2069				bio->bi_private = block;
2070				bio->bi_end_io = btrfsic_bio_end_io;
2071				*bio_is_patched = 1;
2072			} else {
2073				struct btrfsic_block *chained_block =
2074				    (struct btrfsic_block *)
2075				    bio->bi_private;
2076
2077				BUG_ON(NULL == chained_block);
2078				block->orig_bio_bh_private =
2079				    chained_block->orig_bio_bh_private;
2080				block->orig_bio_bh_end_io.bio =
2081				    chained_block->orig_bio_bh_end_io.bio;
2082				block->next_in_same_bio = chained_block;
2083				bio->bi_private = block;
2084			}
2085		} else if (NULL != bh) {
2086			block->is_iodone = 0;
2087			block->orig_bio_bh_private = bh->b_private;
2088			block->orig_bio_bh_end_io.bh = bh->b_end_io;
2089			block->next_in_same_bio = NULL;
2090			bh->b_private = block;
2091			bh->b_end_io = btrfsic_bh_end_io;
2092		} else {
2093			block->is_iodone = 1;
2094			block->orig_bio_bh_private = NULL;
2095			block->orig_bio_bh_end_io.bio = NULL;
2096			block->next_in_same_bio = NULL;
2097		}
2098		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2099			pr_info("New written %c-block @%llu (%s/%llu/%d)\n",
2100			       is_metadata ? 'M' : 'D',
2101			       block->logical_bytenr, block->dev_state->name,
2102			       block->dev_bytenr, block->mirror_num);
2103		list_add(&block->all_blocks_node, &state->all_blocks_list);
2104		btrfsic_block_hashtable_add(block, &state->block_hashtable);
2105
2106		if (is_metadata) {
2107			ret = btrfsic_process_metablock(state, block,
2108							&block_ctx, 0, 0);
2109			if (ret)
2110				pr_info("btrfsic: process_metablock(root @%llu) failed!\n",
2111				       dev_bytenr);
2112		}
2113		btrfsic_release_block_ctx(&block_ctx);
2114	}
2115
2116continue_loop:
2117	BUG_ON(!processed_len);
2118	dev_bytenr += processed_len;
2119	mapped_datav += processed_len >> PAGE_SHIFT;
2120	num_pages -= processed_len >> PAGE_SHIFT;
2121	goto again;
2122}
2123
2124static void btrfsic_bio_end_io(struct bio *bp)
2125{
2126	struct btrfsic_block *block = (struct btrfsic_block *)bp->bi_private;
2127	int iodone_w_error;
2128
2129	/* mutex is not held! This is not save if IO is not yet completed
2130	 * on umount */
2131	iodone_w_error = 0;
2132	if (bp->bi_error)
2133		iodone_w_error = 1;
2134
2135	BUG_ON(NULL == block);
2136	bp->bi_private = block->orig_bio_bh_private;
2137	bp->bi_end_io = block->orig_bio_bh_end_io.bio;
2138
2139	do {
2140		struct btrfsic_block *next_block;
2141		struct btrfsic_dev_state *const dev_state = block->dev_state;
2142
2143		if ((dev_state->state->print_mask &
2144		     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2145			pr_info("bio_end_io(err=%d) for %c @%llu (%s/%llu/%d)\n",
2146			       bp->bi_error,
2147			       btrfsic_get_block_type(dev_state->state, block),
2148			       block->logical_bytenr, dev_state->name,
2149			       block->dev_bytenr, block->mirror_num);
2150		next_block = block->next_in_same_bio;
2151		block->iodone_w_error = iodone_w_error;
2152		if (block->submit_bio_bh_rw & REQ_PREFLUSH) {
2153			dev_state->last_flush_gen++;
2154			if ((dev_state->state->print_mask &
2155			     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2156				pr_info("bio_end_io() new %s flush_gen=%llu\n",
2157				       dev_state->name,
2158				       dev_state->last_flush_gen);
2159		}
2160		if (block->submit_bio_bh_rw & REQ_FUA)
2161			block->flush_gen = 0; /* FUA completed means block is
2162					       * on disk */
2163		block->is_iodone = 1; /* for FLUSH, this releases the block */
2164		block = next_block;
2165	} while (NULL != block);
2166
2167	bp->bi_end_io(bp);
2168}
2169
2170static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate)
2171{
2172	struct btrfsic_block *block = (struct btrfsic_block *)bh->b_private;
2173	int iodone_w_error = !uptodate;
2174	struct btrfsic_dev_state *dev_state;
2175
2176	BUG_ON(NULL == block);
2177	dev_state = block->dev_state;
2178	if ((dev_state->state->print_mask & BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2179		pr_info("bh_end_io(error=%d) for %c @%llu (%s/%llu/%d)\n",
2180		       iodone_w_error,
2181		       btrfsic_get_block_type(dev_state->state, block),
2182		       block->logical_bytenr, block->dev_state->name,
2183		       block->dev_bytenr, block->mirror_num);
2184
2185	block->iodone_w_error = iodone_w_error;
2186	if (block->submit_bio_bh_rw & REQ_PREFLUSH) {
2187		dev_state->last_flush_gen++;
2188		if ((dev_state->state->print_mask &
2189		     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2190			pr_info("bh_end_io() new %s flush_gen=%llu\n",
2191			       dev_state->name, dev_state->last_flush_gen);
2192	}
2193	if (block->submit_bio_bh_rw & REQ_FUA)
2194		block->flush_gen = 0; /* FUA completed means block is on disk */
2195
2196	bh->b_private = block->orig_bio_bh_private;
2197	bh->b_end_io = block->orig_bio_bh_end_io.bh;
2198	block->is_iodone = 1; /* for FLUSH, this releases the block */
2199	bh->b_end_io(bh, uptodate);
2200}
2201
2202static int btrfsic_process_written_superblock(
2203		struct btrfsic_state *state,
2204		struct btrfsic_block *const superblock,
2205		struct btrfs_super_block *const super_hdr)
2206{
2207	struct btrfs_fs_info *fs_info = state->fs_info;
2208	int pass;
2209
2210	superblock->generation = btrfs_super_generation(super_hdr);
2211	if (!(superblock->generation > state->max_superblock_generation ||
2212	      0 == state->max_superblock_generation)) {
2213		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2214			pr_info("btrfsic: superblock @%llu (%s/%llu/%d) with old gen %llu <= %llu\n",
2215			       superblock->logical_bytenr,
2216			       superblock->dev_state->name,
2217			       superblock->dev_bytenr, superblock->mirror_num,
2218			       btrfs_super_generation(super_hdr),
2219			       state->max_superblock_generation);
2220	} else {
2221		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2222			pr_info("btrfsic: got new superblock @%llu (%s/%llu/%d) with new gen %llu > %llu\n",
2223			       superblock->logical_bytenr,
2224			       superblock->dev_state->name,
2225			       superblock->dev_bytenr, superblock->mirror_num,
2226			       btrfs_super_generation(super_hdr),
2227			       state->max_superblock_generation);
2228
2229		state->max_superblock_generation =
2230		    btrfs_super_generation(super_hdr);
2231		state->latest_superblock = superblock;
2232	}
2233
2234	for (pass = 0; pass < 3; pass++) {
2235		int ret;
2236		u64 next_bytenr;
2237		struct btrfsic_block *next_block;
2238		struct btrfsic_block_data_ctx tmp_next_block_ctx;
2239		struct btrfsic_block_link *l;
2240		int num_copies;
2241		int mirror_num;
2242		const char *additional_string = NULL;
2243		struct btrfs_disk_key tmp_disk_key = {0};
2244
2245		btrfs_set_disk_key_objectid(&tmp_disk_key,
2246					    BTRFS_ROOT_ITEM_KEY);
2247		btrfs_set_disk_key_objectid(&tmp_disk_key, 0);
2248
2249		switch (pass) {
2250		case 0:
2251			btrfs_set_disk_key_objectid(&tmp_disk_key,
2252						    BTRFS_ROOT_TREE_OBJECTID);
2253			additional_string = "root ";
2254			next_bytenr = btrfs_super_root(super_hdr);
2255			if (state->print_mask &
2256			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2257				pr_info("root@%llu\n", next_bytenr);
2258			break;
2259		case 1:
2260			btrfs_set_disk_key_objectid(&tmp_disk_key,
2261						    BTRFS_CHUNK_TREE_OBJECTID);
2262			additional_string = "chunk ";
2263			next_bytenr = btrfs_super_chunk_root(super_hdr);
2264			if (state->print_mask &
2265			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2266				pr_info("chunk@%llu\n", next_bytenr);
2267			break;
2268		case 2:
2269			btrfs_set_disk_key_objectid(&tmp_disk_key,
2270						    BTRFS_TREE_LOG_OBJECTID);
2271			additional_string = "log ";
2272			next_bytenr = btrfs_super_log_root(super_hdr);
2273			if (0 == next_bytenr)
2274				continue;
2275			if (state->print_mask &
2276			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2277				pr_info("log@%llu\n", next_bytenr);
2278			break;
2279		}
2280
2281		num_copies = btrfs_num_copies(fs_info, next_bytenr,
2282					      BTRFS_SUPER_INFO_SIZE);
2283		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
2284			pr_info("num_copies(log_bytenr=%llu) = %d\n",
2285			       next_bytenr, num_copies);
2286		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2287			int was_created;
2288
2289			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2290				pr_info("btrfsic_process_written_superblock(mirror_num=%d)\n", mirror_num);
2291			ret = btrfsic_map_block(state, next_bytenr,
2292						BTRFS_SUPER_INFO_SIZE,
2293						&tmp_next_block_ctx,
2294						mirror_num);
2295			if (ret) {
2296				pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
2297				       next_bytenr, mirror_num);
2298				return -1;
2299			}
2300
2301			next_block = btrfsic_block_lookup_or_add(
2302					state,
2303					&tmp_next_block_ctx,
2304					additional_string,
2305					1, 0, 1,
2306					mirror_num,
2307					&was_created);
2308			if (NULL == next_block) {
2309				pr_info("btrfsic: error, kmalloc failed!\n");
2310				btrfsic_release_block_ctx(&tmp_next_block_ctx);
2311				return -1;
2312			}
2313
2314			next_block->disk_key = tmp_disk_key;
2315			if (was_created)
2316				next_block->generation =
2317				    BTRFSIC_GENERATION_UNKNOWN;
2318			l = btrfsic_block_link_lookup_or_add(
2319					state,
2320					&tmp_next_block_ctx,
2321					next_block,
2322					superblock,
2323					BTRFSIC_GENERATION_UNKNOWN);
2324			btrfsic_release_block_ctx(&tmp_next_block_ctx);
2325			if (NULL == l)
2326				return -1;
2327		}
2328	}
2329
2330	if (WARN_ON(-1 == btrfsic_check_all_ref_blocks(state, superblock, 0)))
2331		btrfsic_dump_tree(state);
2332
2333	return 0;
2334}
2335
2336static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
2337					struct btrfsic_block *const block,
2338					int recursion_level)
2339{
2340	const struct btrfsic_block_link *l;
2341	int ret = 0;
2342
2343	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2344		/*
2345		 * Note that this situation can happen and does not
2346		 * indicate an error in regular cases. It happens
2347		 * when disk blocks are freed and later reused.
2348		 * The check-integrity module is not aware of any
2349		 * block free operations, it just recognizes block
2350		 * write operations. Therefore it keeps the linkage
2351		 * information for a block until a block is
2352		 * rewritten. This can temporarily cause incorrect
2353		 * and even circular linkage informations. This
2354		 * causes no harm unless such blocks are referenced
2355		 * by the most recent super block.
2356		 */
2357		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2358			pr_info("btrfsic: abort cyclic linkage (case 1).\n");
2359
2360		return ret;
2361	}
2362
2363	/*
2364	 * This algorithm is recursive because the amount of used stack
2365	 * space is very small and the max recursion depth is limited.
2366	 */
2367	list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
2368		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2369			pr_info("rl=%d, %c @%llu (%s/%llu/%d) %u* refers to %c @%llu (%s/%llu/%d)\n",
2370			       recursion_level,
2371			       btrfsic_get_block_type(state, block),
2372			       block->logical_bytenr, block->dev_state->name,
2373			       block->dev_bytenr, block->mirror_num,
2374			       l->ref_cnt,
2375			       btrfsic_get_block_type(state, l->block_ref_to),
2376			       l->block_ref_to->logical_bytenr,
2377			       l->block_ref_to->dev_state->name,
2378			       l->block_ref_to->dev_bytenr,
2379			       l->block_ref_to->mirror_num);
2380		if (l->block_ref_to->never_written) {
2381			pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which is never written!\n",
2382			       btrfsic_get_block_type(state, l->block_ref_to),
2383			       l->block_ref_to->logical_bytenr,
2384			       l->block_ref_to->dev_state->name,
2385			       l->block_ref_to->dev_bytenr,
2386			       l->block_ref_to->mirror_num);
2387			ret = -1;
2388		} else if (!l->block_ref_to->is_iodone) {
2389			pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which is not yet iodone!\n",
2390			       btrfsic_get_block_type(state, l->block_ref_to),
2391			       l->block_ref_to->logical_bytenr,
2392			       l->block_ref_to->dev_state->name,
2393			       l->block_ref_to->dev_bytenr,
2394			       l->block_ref_to->mirror_num);
2395			ret = -1;
2396		} else if (l->block_ref_to->iodone_w_error) {
2397			pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which has write error!\n",
2398			       btrfsic_get_block_type(state, l->block_ref_to),
2399			       l->block_ref_to->logical_bytenr,
2400			       l->block_ref_to->dev_state->name,
2401			       l->block_ref_to->dev_bytenr,
2402			       l->block_ref_to->mirror_num);
2403			ret = -1;
2404		} else if (l->parent_generation !=
2405			   l->block_ref_to->generation &&
2406			   BTRFSIC_GENERATION_UNKNOWN !=
2407			   l->parent_generation &&
2408			   BTRFSIC_GENERATION_UNKNOWN !=
2409			   l->block_ref_to->generation) {
2410			pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) with generation %llu != parent generation %llu!\n",
2411			       btrfsic_get_block_type(state, l->block_ref_to),
2412			       l->block_ref_to->logical_bytenr,
2413			       l->block_ref_to->dev_state->name,
2414			       l->block_ref_to->dev_bytenr,
2415			       l->block_ref_to->mirror_num,
2416			       l->block_ref_to->generation,
2417			       l->parent_generation);
2418			ret = -1;
2419		} else if (l->block_ref_to->flush_gen >
2420			   l->block_ref_to->dev_state->last_flush_gen) {
2421			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",
2422			       btrfsic_get_block_type(state, l->block_ref_to),
2423			       l->block_ref_to->logical_bytenr,
2424			       l->block_ref_to->dev_state->name,
2425			       l->block_ref_to->dev_bytenr,
2426			       l->block_ref_to->mirror_num, block->flush_gen,
2427			       l->block_ref_to->dev_state->last_flush_gen);
2428			ret = -1;
2429		} else if (-1 == btrfsic_check_all_ref_blocks(state,
2430							      l->block_ref_to,
2431							      recursion_level +
2432							      1)) {
2433			ret = -1;
2434		}
2435	}
2436
2437	return ret;
2438}
2439
2440static int btrfsic_is_block_ref_by_superblock(
2441		const struct btrfsic_state *state,
2442		const struct btrfsic_block *block,
2443		int recursion_level)
2444{
2445	const struct btrfsic_block_link *l;
2446
2447	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2448		/* refer to comment at "abort cyclic linkage (case 1)" */
2449		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2450			pr_info("btrfsic: abort cyclic linkage (case 2).\n");
2451
2452		return 0;
2453	}
2454
2455	/*
2456	 * This algorithm is recursive because the amount of used stack space
2457	 * is very small and the max recursion depth is limited.
2458	 */
2459	list_for_each_entry(l, &block->ref_from_list, node_ref_from) {
2460		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2461			pr_info("rl=%d, %c @%llu (%s/%llu/%d) is ref %u* from %c @%llu (%s/%llu/%d)\n",
2462			       recursion_level,
2463			       btrfsic_get_block_type(state, block),
2464			       block->logical_bytenr, block->dev_state->name,
2465			       block->dev_bytenr, block->mirror_num,
2466			       l->ref_cnt,
2467			       btrfsic_get_block_type(state, l->block_ref_from),
2468			       l->block_ref_from->logical_bytenr,
2469			       l->block_ref_from->dev_state->name,
2470			       l->block_ref_from->dev_bytenr,
2471			       l->block_ref_from->mirror_num);
2472		if (l->block_ref_from->is_superblock &&
2473		    state->latest_superblock->dev_bytenr ==
2474		    l->block_ref_from->dev_bytenr &&
2475		    state->latest_superblock->dev_state->bdev ==
2476		    l->block_ref_from->dev_state->bdev)
2477			return 1;
2478		else if (btrfsic_is_block_ref_by_superblock(state,
2479							    l->block_ref_from,
2480							    recursion_level +
2481							    1))
2482			return 1;
2483	}
2484
2485	return 0;
2486}
2487
2488static void btrfsic_print_add_link(const struct btrfsic_state *state,
2489				   const struct btrfsic_block_link *l)
2490{
2491	pr_info("Add %u* link from %c @%llu (%s/%llu/%d) to %c @%llu (%s/%llu/%d).\n",
2492	       l->ref_cnt,
2493	       btrfsic_get_block_type(state, l->block_ref_from),
2494	       l->block_ref_from->logical_bytenr,
2495	       l->block_ref_from->dev_state->name,
2496	       l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2497	       btrfsic_get_block_type(state, l->block_ref_to),
2498	       l->block_ref_to->logical_bytenr,
2499	       l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2500	       l->block_ref_to->mirror_num);
2501}
2502
2503static void btrfsic_print_rem_link(const struct btrfsic_state *state,
2504				   const struct btrfsic_block_link *l)
2505{
2506	pr_info("Rem %u* link from %c @%llu (%s/%llu/%d) to %c @%llu (%s/%llu/%d).\n",
2507	       l->ref_cnt,
2508	       btrfsic_get_block_type(state, l->block_ref_from),
2509	       l->block_ref_from->logical_bytenr,
2510	       l->block_ref_from->dev_state->name,
2511	       l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2512	       btrfsic_get_block_type(state, l->block_ref_to),
2513	       l->block_ref_to->logical_bytenr,
2514	       l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2515	       l->block_ref_to->mirror_num);
2516}
2517
2518static char btrfsic_get_block_type(const struct btrfsic_state *state,
2519				   const struct btrfsic_block *block)
2520{
2521	if (block->is_superblock &&
2522	    state->latest_superblock->dev_bytenr == block->dev_bytenr &&
2523	    state->latest_superblock->dev_state->bdev == block->dev_state->bdev)
2524		return 'S';
2525	else if (block->is_superblock)
2526		return 's';
2527	else if (block->is_metadata)
2528		return 'M';
2529	else
2530		return 'D';
2531}
2532
2533static void btrfsic_dump_tree(const struct btrfsic_state *state)
2534{
2535	btrfsic_dump_tree_sub(state, state->latest_superblock, 0);
2536}
2537
2538static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
2539				  const struct btrfsic_block *block,
2540				  int indent_level)
2541{
2542	const struct btrfsic_block_link *l;
2543	int indent_add;
2544	static char buf[80];
2545	int cursor_position;
2546
2547	/*
2548	 * Should better fill an on-stack buffer with a complete line and
2549	 * dump it at once when it is time to print a newline character.
2550	 */
2551
2552	/*
2553	 * This algorithm is recursive because the amount of used stack space
2554	 * is very small and the max recursion depth is limited.
2555	 */
2556	indent_add = sprintf(buf, "%c-%llu(%s/%llu/%u)",
2557			     btrfsic_get_block_type(state, block),
2558			     block->logical_bytenr, block->dev_state->name,
2559			     block->dev_bytenr, block->mirror_num);
2560	if (indent_level + indent_add > BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2561		printk("[...]\n");
2562		return;
2563	}
2564	printk(buf);
2565	indent_level += indent_add;
2566	if (list_empty(&block->ref_to_list)) {
2567		printk("\n");
2568		return;
2569	}
2570	if (block->mirror_num > 1 &&
2571	    !(state->print_mask & BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS)) {
2572		printk(" [...]\n");
2573		return;
2574	}
2575
2576	cursor_position = indent_level;
2577	list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
2578		while (cursor_position < indent_level) {
2579			printk(" ");
2580			cursor_position++;
2581		}
2582		if (l->ref_cnt > 1)
2583			indent_add = sprintf(buf, " %d*--> ", l->ref_cnt);
2584		else
2585			indent_add = sprintf(buf, " --> ");
2586		if (indent_level + indent_add >
2587		    BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2588			printk("[...]\n");
2589			cursor_position = 0;
2590			continue;
2591		}
2592
2593		printk(buf);
2594
2595		btrfsic_dump_tree_sub(state, l->block_ref_to,
2596				      indent_level + indent_add);
2597		cursor_position = 0;
2598	}
2599}
2600
2601static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
2602		struct btrfsic_state *state,
2603		struct btrfsic_block_data_ctx *next_block_ctx,
2604		struct btrfsic_block *next_block,
2605		struct btrfsic_block *from_block,
2606		u64 parent_generation)
2607{
2608	struct btrfsic_block_link *l;
2609
2610	l = btrfsic_block_link_hashtable_lookup(next_block_ctx->dev->bdev,
2611						next_block_ctx->dev_bytenr,
2612						from_block->dev_state->bdev,
2613						from_block->dev_bytenr,
2614						&state->block_link_hashtable);
2615	if (NULL == l) {
2616		l = btrfsic_block_link_alloc();
2617		if (NULL == l) {
2618			pr_info("btrfsic: error, kmalloc failed!\n");
2619			return NULL;
2620		}
2621
2622		l->block_ref_to = next_block;
2623		l->block_ref_from = from_block;
2624		l->ref_cnt = 1;
2625		l->parent_generation = parent_generation;
2626
2627		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2628			btrfsic_print_add_link(state, l);
2629
2630		list_add(&l->node_ref_to, &from_block->ref_to_list);
2631		list_add(&l->node_ref_from, &next_block->ref_from_list);
2632
2633		btrfsic_block_link_hashtable_add(l,
2634						 &state->block_link_hashtable);
2635	} else {
2636		l->ref_cnt++;
2637		l->parent_generation = parent_generation;
2638		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2639			btrfsic_print_add_link(state, l);
2640	}
2641
2642	return l;
2643}
2644
2645static struct btrfsic_block *btrfsic_block_lookup_or_add(
2646		struct btrfsic_state *state,
2647		struct btrfsic_block_data_ctx *block_ctx,
2648		const char *additional_string,
2649		int is_metadata,
2650		int is_iodone,
2651		int never_written,
2652		int mirror_num,
2653		int *was_created)
2654{
2655	struct btrfsic_block *block;
2656
2657	block = btrfsic_block_hashtable_lookup(block_ctx->dev->bdev,
2658					       block_ctx->dev_bytenr,
2659					       &state->block_hashtable);
2660	if (NULL == block) {
2661		struct btrfsic_dev_state *dev_state;
2662
2663		block = btrfsic_block_alloc();
2664		if (NULL == block) {
2665			pr_info("btrfsic: error, kmalloc failed!\n");
2666			return NULL;
2667		}
2668		dev_state = btrfsic_dev_state_lookup(block_ctx->dev->bdev);
2669		if (NULL == dev_state) {
2670			pr_info("btrfsic: error, lookup dev_state failed!\n");
2671			btrfsic_block_free(block);
2672			return NULL;
2673		}
2674		block->dev_state = dev_state;
2675		block->dev_bytenr = block_ctx->dev_bytenr;
2676		block->logical_bytenr = block_ctx->start;
2677		block->is_metadata = is_metadata;
2678		block->is_iodone = is_iodone;
2679		block->never_written = never_written;
2680		block->mirror_num = mirror_num;
2681		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2682			pr_info("New %s%c-block @%llu (%s/%llu/%d)\n",
2683			       additional_string,
2684			       btrfsic_get_block_type(state, block),
2685			       block->logical_bytenr, dev_state->name,
2686			       block->dev_bytenr, mirror_num);
2687		list_add(&block->all_blocks_node, &state->all_blocks_list);
2688		btrfsic_block_hashtable_add(block, &state->block_hashtable);
2689		if (NULL != was_created)
2690			*was_created = 1;
2691	} else {
2692		if (NULL != was_created)
2693			*was_created = 0;
2694	}
2695
2696	return block;
2697}
2698
2699static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
2700					   u64 bytenr,
2701					   struct btrfsic_dev_state *dev_state,
2702					   u64 dev_bytenr)
2703{
2704	struct btrfs_fs_info *fs_info = state->fs_info;
2705	struct btrfsic_block_data_ctx block_ctx;
2706	int num_copies;
2707	int mirror_num;
2708	int match = 0;
2709	int ret;
2710
2711	num_copies = btrfs_num_copies(fs_info, bytenr, state->metablock_size);
2712
2713	for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2714		ret = btrfsic_map_block(state, bytenr, state->metablock_size,
2715					&block_ctx, mirror_num);
2716		if (ret) {
2717			pr_info("btrfsic: btrfsic_map_block(logical @%llu, mirror %d) failed!\n",
2718			       bytenr, mirror_num);
2719			continue;
2720		}
2721
2722		if (dev_state->bdev == block_ctx.dev->bdev &&
2723		    dev_bytenr == block_ctx.dev_bytenr) {
2724			match++;
2725			btrfsic_release_block_ctx(&block_ctx);
2726			break;
2727		}
2728		btrfsic_release_block_ctx(&block_ctx);
2729	}
2730
2731	if (WARN_ON(!match)) {
2732		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",
2733		       bytenr, dev_state->name, dev_bytenr);
2734		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2735			ret = btrfsic_map_block(state, bytenr,
2736						state->metablock_size,
2737						&block_ctx, mirror_num);
2738			if (ret)
2739				continue;
2740
2741			pr_info("Read logical bytenr @%llu maps to (%s/%llu/%d)\n",
2742			       bytenr, block_ctx.dev->name,
2743			       block_ctx.dev_bytenr, mirror_num);
2744		}
2745	}
2746}
2747
2748static struct btrfsic_dev_state *btrfsic_dev_state_lookup(
2749		struct block_device *bdev)
2750{
2751	return btrfsic_dev_state_hashtable_lookup(bdev,
2752						  &btrfsic_dev_state_hashtable);
2753}
2754
2755int btrfsic_submit_bh(int op, int op_flags, struct buffer_head *bh)
2756{
2757	struct btrfsic_dev_state *dev_state;
2758
2759	if (!btrfsic_is_initialized)
2760		return submit_bh(op, op_flags, bh);
2761
2762	mutex_lock(&btrfsic_mutex);
2763	/* since btrfsic_submit_bh() might also be called before
2764	 * btrfsic_mount(), this might return NULL */
2765	dev_state = btrfsic_dev_state_lookup(bh->b_bdev);
2766
2767	/* Only called to write the superblock (incl. FLUSH/FUA) */
2768	if (NULL != dev_state &&
2769	    (op == REQ_OP_WRITE) && bh->b_size > 0) {
2770		u64 dev_bytenr;
2771
2772		dev_bytenr = 4096 * bh->b_blocknr;
2773		if (dev_state->state->print_mask &
2774		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2775			pr_info("submit_bh(op=0x%x,0x%x, blocknr=%llu (bytenr %llu), size=%zu, data=%p, bdev=%p)\n",
2776			       op, op_flags, (unsigned long long)bh->b_blocknr,
2777			       dev_bytenr, bh->b_size, bh->b_data, bh->b_bdev);
2778		btrfsic_process_written_block(dev_state, dev_bytenr,
2779					      &bh->b_data, 1, NULL,
2780					      NULL, bh, op_flags);
2781	} else if (NULL != dev_state && (op_flags & REQ_PREFLUSH)) {
2782		if (dev_state->state->print_mask &
2783		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2784			pr_info("submit_bh(op=0x%x,0x%x FLUSH, bdev=%p)\n",
2785			       op, op_flags, bh->b_bdev);
2786		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
2787			if ((dev_state->state->print_mask &
2788			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
2789			      BTRFSIC_PRINT_MASK_VERBOSE)))
2790				pr_info("btrfsic_submit_bh(%s) with FLUSH but dummy block already in use (ignored)!\n",
2791				       dev_state->name);
2792		} else {
2793			struct btrfsic_block *const block =
2794				&dev_state->dummy_block_for_bio_bh_flush;
2795
2796			block->is_iodone = 0;
2797			block->never_written = 0;
2798			block->iodone_w_error = 0;
2799			block->flush_gen = dev_state->last_flush_gen + 1;
2800			block->submit_bio_bh_rw = op_flags;
2801			block->orig_bio_bh_private = bh->b_private;
2802			block->orig_bio_bh_end_io.bh = bh->b_end_io;
2803			block->next_in_same_bio = NULL;
2804			bh->b_private = block;
2805			bh->b_end_io = btrfsic_bh_end_io;
2806		}
2807	}
2808	mutex_unlock(&btrfsic_mutex);
2809	return submit_bh(op, op_flags, bh);
2810}
2811
2812static void __btrfsic_submit_bio(struct bio *bio)
2813{
2814	struct btrfsic_dev_state *dev_state;
2815
2816	if (!btrfsic_is_initialized)
2817		return;
2818
2819	mutex_lock(&btrfsic_mutex);
2820	/* since btrfsic_submit_bio() is also called before
2821	 * btrfsic_mount(), this might return NULL */
2822	dev_state = btrfsic_dev_state_lookup(bio->bi_bdev);
2823	if (NULL != dev_state &&
2824	    (bio_op(bio) == REQ_OP_WRITE) && bio_has_data(bio)) {
2825		unsigned int i;
2826		u64 dev_bytenr;
2827		u64 cur_bytenr;
2828		struct bio_vec *bvec;
2829		int bio_is_patched;
2830		char **mapped_datav;
2831
2832		dev_bytenr = 512 * bio->bi_iter.bi_sector;
2833		bio_is_patched = 0;
2834		if (dev_state->state->print_mask &
2835		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2836			pr_info("submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
2837			       bio_op(bio), bio->bi_opf, bio->bi_vcnt,
2838			       (unsigned long long)bio->bi_iter.bi_sector,
2839			       dev_bytenr, bio->bi_bdev);
2840
2841		mapped_datav = kmalloc_array(bio->bi_vcnt,
2842					     sizeof(*mapped_datav), GFP_NOFS);
2843		if (!mapped_datav)
2844			goto leave;
2845		cur_bytenr = dev_bytenr;
2846
2847		bio_for_each_segment_all(bvec, bio, i) {
2848			BUG_ON(bvec->bv_len != PAGE_SIZE);
2849			mapped_datav[i] = kmap(bvec->bv_page);
2850
2851			if (dev_state->state->print_mask &
2852			    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE)
2853				pr_info("#%u: bytenr=%llu, len=%u, offset=%u\n",
2854				       i, cur_bytenr, bvec->bv_len, bvec->bv_offset);
2855			cur_bytenr += bvec->bv_len;
2856		}
2857		btrfsic_process_written_block(dev_state, dev_bytenr,
2858					      mapped_datav, bio->bi_vcnt,
2859					      bio, &bio_is_patched,
2860					      NULL, bio->bi_opf);
2861		bio_for_each_segment_all(bvec, bio, i)
2862			kunmap(bvec->bv_page);
2863		kfree(mapped_datav);
2864	} else if (NULL != dev_state && (bio->bi_opf & REQ_PREFLUSH)) {
2865		if (dev_state->state->print_mask &
2866		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2867			pr_info("submit_bio(rw=%d,0x%x FLUSH, bdev=%p)\n",
2868			       bio_op(bio), bio->bi_opf, bio->bi_bdev);
2869		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
2870			if ((dev_state->state->print_mask &
2871			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
2872			      BTRFSIC_PRINT_MASK_VERBOSE)))
2873				pr_info("btrfsic_submit_bio(%s) with FLUSH but dummy block already in use (ignored)!\n",
2874				       dev_state->name);
2875		} else {
2876			struct btrfsic_block *const block =
2877				&dev_state->dummy_block_for_bio_bh_flush;
2878
2879			block->is_iodone = 0;
2880			block->never_written = 0;
2881			block->iodone_w_error = 0;
2882			block->flush_gen = dev_state->last_flush_gen + 1;
2883			block->submit_bio_bh_rw = bio->bi_opf;
2884			block->orig_bio_bh_private = bio->bi_private;
2885			block->orig_bio_bh_end_io.bio = bio->bi_end_io;
2886			block->next_in_same_bio = NULL;
2887			bio->bi_private = block;
2888			bio->bi_end_io = btrfsic_bio_end_io;
2889		}
2890	}
2891leave:
2892	mutex_unlock(&btrfsic_mutex);
2893}
2894
2895void btrfsic_submit_bio(struct bio *bio)
2896{
2897	__btrfsic_submit_bio(bio);
2898	submit_bio(bio);
2899}
2900
2901int btrfsic_submit_bio_wait(struct bio *bio)
2902{
2903	__btrfsic_submit_bio(bio);
2904	return submit_bio_wait(bio);
2905}
2906
2907int btrfsic_mount(struct btrfs_fs_info *fs_info,
2908		  struct btrfs_fs_devices *fs_devices,
2909		  int including_extent_data, u32 print_mask)
2910{
2911	int ret;
2912	struct btrfsic_state *state;
2913	struct list_head *dev_head = &fs_devices->devices;
2914	struct btrfs_device *device;
2915
2916	if (fs_info->nodesize & ((u64)PAGE_SIZE - 1)) {
2917		pr_info("btrfsic: cannot handle nodesize %d not being a multiple of PAGE_SIZE %ld!\n",
2918		       fs_info->nodesize, PAGE_SIZE);
2919		return -1;
2920	}
2921	if (fs_info->sectorsize & ((u64)PAGE_SIZE - 1)) {
2922		pr_info("btrfsic: cannot handle sectorsize %d not being a multiple of PAGE_SIZE %ld!\n",
2923		       fs_info->sectorsize, PAGE_SIZE);
2924		return -1;
2925	}
2926	state = kzalloc(sizeof(*state), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
2927	if (!state) {
2928		state = vzalloc(sizeof(*state));
2929		if (!state) {
2930			pr_info("btrfs check-integrity: vzalloc() failed!\n");
2931			return -1;
2932		}
2933	}
2934
2935	if (!btrfsic_is_initialized) {
2936		mutex_init(&btrfsic_mutex);
2937		btrfsic_dev_state_hashtable_init(&btrfsic_dev_state_hashtable);
2938		btrfsic_is_initialized = 1;
2939	}
2940	mutex_lock(&btrfsic_mutex);
2941	state->fs_info = fs_info;
2942	state->print_mask = print_mask;
2943	state->include_extent_data = including_extent_data;
2944	state->csum_size = 0;
2945	state->metablock_size = fs_info->nodesize;
2946	state->datablock_size = fs_info->sectorsize;
2947	INIT_LIST_HEAD(&state->all_blocks_list);
2948	btrfsic_block_hashtable_init(&state->block_hashtable);
2949	btrfsic_block_link_hashtable_init(&state->block_link_hashtable);
2950	state->max_superblock_generation = 0;
2951	state->latest_superblock = NULL;
2952
2953	list_for_each_entry(device, dev_head, dev_list) {
2954		struct btrfsic_dev_state *ds;
2955		const char *p;
2956
2957		if (!device->bdev || !device->name)
2958			continue;
2959
2960		ds = btrfsic_dev_state_alloc();
2961		if (NULL == ds) {
2962			pr_info("btrfs check-integrity: kmalloc() failed!\n");
2963			mutex_unlock(&btrfsic_mutex);
2964			return -1;
2965		}
2966		ds->bdev = device->bdev;
2967		ds->state = state;
2968		bdevname(ds->bdev, ds->name);
2969		ds->name[BDEVNAME_SIZE - 1] = '\0';
2970		p = kbasename(ds->name);
2971		strlcpy(ds->name, p, sizeof(ds->name));
2972		btrfsic_dev_state_hashtable_add(ds,
2973						&btrfsic_dev_state_hashtable);
2974	}
2975
2976	ret = btrfsic_process_superblock(state, fs_devices);
2977	if (0 != ret) {
2978		mutex_unlock(&btrfsic_mutex);
2979		btrfsic_unmount(fs_devices);
2980		return ret;
2981	}
2982
2983	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_DATABASE)
2984		btrfsic_dump_database(state);
2985	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_TREE)
2986		btrfsic_dump_tree(state);
2987
2988	mutex_unlock(&btrfsic_mutex);
2989	return 0;
2990}
2991
2992void btrfsic_unmount(struct btrfs_fs_devices *fs_devices)
2993{
2994	struct btrfsic_block *b_all, *tmp_all;
2995	struct btrfsic_state *state;
2996	struct list_head *dev_head = &fs_devices->devices;
2997	struct btrfs_device *device;
2998
2999	if (!btrfsic_is_initialized)
3000		return;
3001
3002	mutex_lock(&btrfsic_mutex);
3003
3004	state = NULL;
3005	list_for_each_entry(device, dev_head, dev_list) {
3006		struct btrfsic_dev_state *ds;
3007
3008		if (!device->bdev || !device->name)
3009			continue;
3010
3011		ds = btrfsic_dev_state_hashtable_lookup(
3012				device->bdev,
3013				&btrfsic_dev_state_hashtable);
3014		if (NULL != ds) {
3015			state = ds->state;
3016			btrfsic_dev_state_hashtable_remove(ds);
3017			btrfsic_dev_state_free(ds);
3018		}
3019	}
3020
3021	if (NULL == state) {
3022		pr_info("btrfsic: error, cannot find state information on umount!\n");
3023		mutex_unlock(&btrfsic_mutex);
3024		return;
3025	}
3026
3027	/*
3028	 * Don't care about keeping the lists' state up to date,
3029	 * just free all memory that was allocated dynamically.
3030	 * Free the blocks and the block_links.
3031	 */
3032	list_for_each_entry_safe(b_all, tmp_all, &state->all_blocks_list,
3033				 all_blocks_node) {
3034		struct btrfsic_block_link *l, *tmp;
3035
3036		list_for_each_entry_safe(l, tmp, &b_all->ref_to_list,
3037					 node_ref_to) {
3038			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
3039				btrfsic_print_rem_link(state, l);
3040
3041			l->ref_cnt--;
3042			if (0 == l->ref_cnt)
3043				btrfsic_block_link_free(l);
3044		}
3045
3046		if (b_all->is_iodone || b_all->never_written)
3047			btrfsic_block_free(b_all);
3048		else
3049			pr_info("btrfs: attempt to free %c-block @%llu (%s/%llu/%d) on umount which is not yet iodone!\n",
3050			       btrfsic_get_block_type(state, b_all),
3051			       b_all->logical_bytenr, b_all->dev_state->name,
3052			       b_all->dev_bytenr, b_all->mirror_num);
3053	}
3054
3055	mutex_unlock(&btrfsic_mutex);
3056
3057	kvfree(state);
3058}