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_root *root;
 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	int ret = 0;
 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 pass;
 655
 656	BUG_ON(NULL == state);
 657	selected_super = kzalloc(sizeof(*selected_super), GFP_NOFS);
 658	if (NULL == selected_super) {
 659		printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
 660		return -ENOMEM;
 661	}
 662
 663	list_for_each_entry(device, dev_head, dev_list) {
 664		int i;
 665		struct btrfsic_dev_state *dev_state;
 666
 667		if (!device->bdev || !device->name)
 668			continue;
 669
 670		dev_state = btrfsic_dev_state_lookup(device->bdev);
 671		BUG_ON(NULL == dev_state);
 672		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
 673			ret = btrfsic_process_superblock_dev_mirror(
 674					state, dev_state, device, i,
 675					&selected_dev_state, selected_super);
 676			if (0 != ret && 0 == i) {
 677				kfree(selected_super);
 678				return ret;
 679			}
 680		}
 681	}
 682
 683	if (NULL == state->latest_superblock) {
 684		printk(KERN_INFO "btrfsic: no superblock found!\n");
 685		kfree(selected_super);
 686		return -1;
 687	}
 688
 689	state->csum_size = btrfs_super_csum_size(selected_super);
 690
 691	for (pass = 0; pass < 3; pass++) {
 692		int num_copies;
 693		int mirror_num;
 694		u64 next_bytenr;
 695
 696		switch (pass) {
 697		case 0:
 698			next_bytenr = btrfs_super_root(selected_super);
 699			if (state->print_mask &
 700			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 701				printk(KERN_INFO "root@%llu\n", next_bytenr);
 702			break;
 703		case 1:
 704			next_bytenr = btrfs_super_chunk_root(selected_super);
 705			if (state->print_mask &
 706			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 707				printk(KERN_INFO "chunk@%llu\n", next_bytenr);
 708			break;
 709		case 2:
 710			next_bytenr = btrfs_super_log_root(selected_super);
 711			if (0 == next_bytenr)
 712				continue;
 713			if (state->print_mask &
 714			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
 715				printk(KERN_INFO "log@%llu\n", next_bytenr);
 716			break;
 717		}
 718
 719		num_copies =
 720		    btrfs_num_copies(state->root->fs_info,
 721				     next_bytenr, state->metablock_size);
 722		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
 723			printk(KERN_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				printk(KERN_INFO "btrfsic:"
 737				       " btrfsic_map_block(root @%llu,"
 738				       " mirror %d) failed!\n",
 739				       next_bytenr, mirror_num);
 740				kfree(selected_super);
 741				return -1;
 742			}
 743
 744			next_block = btrfsic_block_hashtable_lookup(
 745					tmp_next_block_ctx.dev->bdev,
 746					tmp_next_block_ctx.dev_bytenr,
 747					&state->block_hashtable);
 748			BUG_ON(NULL == next_block);
 749
 750			l = btrfsic_block_link_hashtable_lookup(
 751					tmp_next_block_ctx.dev->bdev,
 752					tmp_next_block_ctx.dev_bytenr,
 753					state->latest_superblock->dev_state->
 754					bdev,
 755					state->latest_superblock->dev_bytenr,
 756					&state->block_link_hashtable);
 757			BUG_ON(NULL == l);
 758
 759			ret = btrfsic_read_block(state, &tmp_next_block_ctx);
 760			if (ret < (int)PAGE_SIZE) {
 761				printk(KERN_INFO
 762				       "btrfsic: read @logical %llu failed!\n",
 763				       tmp_next_block_ctx.start);
 764				btrfsic_release_block_ctx(&tmp_next_block_ctx);
 765				kfree(selected_super);
 766				return -1;
 767			}
 768
 769			ret = btrfsic_process_metablock(state,
 770							next_block,
 771							&tmp_next_block_ctx,
 772							BTRFS_MAX_LEVEL + 3, 1);
 773			btrfsic_release_block_ctx(&tmp_next_block_ctx);
 774		}
 775	}
 776
 777	kfree(selected_super);
 778	return ret;
 779}
 780
 781static int btrfsic_process_superblock_dev_mirror(
 782		struct btrfsic_state *state,
 783		struct btrfsic_dev_state *dev_state,
 784		struct btrfs_device *device,
 785		int superblock_mirror_num,
 786		struct btrfsic_dev_state **selected_dev_state,
 787		struct btrfs_super_block *selected_super)
 788{
 789	struct btrfs_super_block *super_tmp;
 790	u64 dev_bytenr;
 791	struct buffer_head *bh;
 792	struct btrfsic_block *superblock_tmp;
 793	int pass;
 794	struct block_device *const superblock_bdev = device->bdev;
 795
 796	/* super block bytenr is always the unmapped device bytenr */
 797	dev_bytenr = btrfs_sb_offset(superblock_mirror_num);
 798	if (dev_bytenr + BTRFS_SUPER_INFO_SIZE > device->commit_total_bytes)
 799		return -1;
 800	bh = __bread(superblock_bdev, dev_bytenr / 4096,
 801		     BTRFS_SUPER_INFO_SIZE);
 802	if (NULL == bh)
 803		return -1;
 804	super_tmp = (struct btrfs_super_block *)
 805	    (bh->b_data + (dev_bytenr & 4095));
 806
 807	if (btrfs_super_bytenr(super_tmp) != dev_bytenr ||
 808	    btrfs_super_magic(super_tmp) != BTRFS_MAGIC ||
 809	    memcmp(device->uuid, super_tmp->dev_item.uuid, BTRFS_UUID_SIZE) ||
 810	    btrfs_super_nodesize(super_tmp) != state->metablock_size ||
 811	    btrfs_super_sectorsize(super_tmp) != state->datablock_size) {
 812		brelse(bh);
 813		return 0;
 814	}
 815
 816	superblock_tmp =
 817	    btrfsic_block_hashtable_lookup(superblock_bdev,
 818					   dev_bytenr,
 819					   &state->block_hashtable);
 820	if (NULL == superblock_tmp) {
 821		superblock_tmp = btrfsic_block_alloc();
 822		if (NULL == superblock_tmp) {
 823			printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
 824			brelse(bh);
 825			return -1;
 826		}
 827		/* for superblock, only the dev_bytenr makes sense */
 828		superblock_tmp->dev_bytenr = dev_bytenr;
 829		superblock_tmp->dev_state = dev_state;
 830		superblock_tmp->logical_bytenr = dev_bytenr;
 831		superblock_tmp->generation = btrfs_super_generation(super_tmp);
 832		superblock_tmp->is_metadata = 1;
 833		superblock_tmp->is_superblock = 1;
 834		superblock_tmp->is_iodone = 1;
 835		superblock_tmp->never_written = 0;
 836		superblock_tmp->mirror_num = 1 + superblock_mirror_num;
 837		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
 838			btrfs_info_in_rcu(device->dev_root->fs_info,
 839				"new initial S-block (bdev %p, %s) @%llu (%s/%llu/%d)",
 840				     superblock_bdev,
 841				     rcu_str_deref(device->name), dev_bytenr,
 842				     dev_state->name, dev_bytenr,
 843				     superblock_mirror_num);
 844		list_add(&superblock_tmp->all_blocks_node,
 845			 &state->all_blocks_list);
 846		btrfsic_block_hashtable_add(superblock_tmp,
 847					    &state->block_hashtable);
 848	}
 849
 850	/* select the one with the highest generation field */
 851	if (btrfs_super_generation(super_tmp) >
 852	    state->max_superblock_generation ||
 853	    0 == state->max_superblock_generation) {
 854		memcpy(selected_super, super_tmp, sizeof(*selected_super));
 855		*selected_dev_state = dev_state;
 856		state->max_superblock_generation =
 857		    btrfs_super_generation(super_tmp);
 858		state->latest_superblock = superblock_tmp;
 859	}
 860
 861	for (pass = 0; pass < 3; pass++) {
 862		u64 next_bytenr;
 863		int num_copies;
 864		int mirror_num;
 865		const char *additional_string = NULL;
 866		struct btrfs_disk_key tmp_disk_key;
 867
 868		tmp_disk_key.type = BTRFS_ROOT_ITEM_KEY;
 869		tmp_disk_key.offset = 0;
 870		switch (pass) {
 871		case 0:
 872			btrfs_set_disk_key_objectid(&tmp_disk_key,
 873						    BTRFS_ROOT_TREE_OBJECTID);
 874			additional_string = "initial root ";
 875			next_bytenr = btrfs_super_root(super_tmp);
 876			break;
 877		case 1:
 878			btrfs_set_disk_key_objectid(&tmp_disk_key,
 879						    BTRFS_CHUNK_TREE_OBJECTID);
 880			additional_string = "initial chunk ";
 881			next_bytenr = btrfs_super_chunk_root(super_tmp);
 882			break;
 883		case 2:
 884			btrfs_set_disk_key_objectid(&tmp_disk_key,
 885						    BTRFS_TREE_LOG_OBJECTID);
 886			additional_string = "initial log ";
 887			next_bytenr = btrfs_super_log_root(super_tmp);
 888			if (0 == next_bytenr)
 889				continue;
 890			break;
 891		}
 892
 893		num_copies =
 894		    btrfs_num_copies(state->root->fs_info,
 895				     next_bytenr, state->metablock_size);
 896		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
 897			printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
 898			       next_bytenr, num_copies);
 899		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
 900			struct btrfsic_block *next_block;
 901			struct btrfsic_block_data_ctx tmp_next_block_ctx;
 902			struct btrfsic_block_link *l;
 903
 904			if (btrfsic_map_block(state, next_bytenr,
 905					      state->metablock_size,
 906					      &tmp_next_block_ctx,
 907					      mirror_num)) {
 908				printk(KERN_INFO "btrfsic: btrfsic_map_block("
 909				       "bytenr @%llu, mirror %d) failed!\n",
 910				       next_bytenr, mirror_num);
 911				brelse(bh);
 912				return -1;
 913			}
 914
 915			next_block = btrfsic_block_lookup_or_add(
 916					state, &tmp_next_block_ctx,
 917					additional_string, 1, 1, 0,
 918					mirror_num, NULL);
 919			if (NULL == next_block) {
 920				btrfsic_release_block_ctx(&tmp_next_block_ctx);
 921				brelse(bh);
 922				return -1;
 923			}
 924
 925			next_block->disk_key = tmp_disk_key;
 926			next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
 927			l = btrfsic_block_link_lookup_or_add(
 928					state, &tmp_next_block_ctx,
 929					next_block, superblock_tmp,
 930					BTRFSIC_GENERATION_UNKNOWN);
 931			btrfsic_release_block_ctx(&tmp_next_block_ctx);
 932			if (NULL == l) {
 933				brelse(bh);
 934				return -1;
 935			}
 936		}
 937	}
 938	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES)
 939		btrfsic_dump_tree_sub(state, superblock_tmp, 0);
 940
 941	brelse(bh);
 942	return 0;
 943}
 944
 945static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void)
 946{
 947	struct btrfsic_stack_frame *sf;
 948
 949	sf = kzalloc(sizeof(*sf), GFP_NOFS);
 950	if (NULL == sf)
 951		printk(KERN_INFO "btrfsic: alloc memory failed!\n");
 952	else
 953		sf->magic = BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER;
 954	return sf;
 955}
 956
 957static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf)
 958{
 959	BUG_ON(!(NULL == sf ||
 960		 BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER == sf->magic));
 961	kfree(sf);
 962}
 963
 964static int btrfsic_process_metablock(
 965		struct btrfsic_state *state,
 966		struct btrfsic_block *const first_block,
 967		struct btrfsic_block_data_ctx *const first_block_ctx,
 968		int first_limit_nesting, int force_iodone_flag)
 969{
 970	struct btrfsic_stack_frame initial_stack_frame = { 0 };
 971	struct btrfsic_stack_frame *sf;
 972	struct btrfsic_stack_frame *next_stack;
 973	struct btrfs_header *const first_hdr =
 974		(struct btrfs_header *)first_block_ctx->datav[0];
 975
 976	BUG_ON(!first_hdr);
 977	sf = &initial_stack_frame;
 978	sf->error = 0;
 979	sf->i = -1;
 980	sf->limit_nesting = first_limit_nesting;
 981	sf->block = first_block;
 982	sf->block_ctx = first_block_ctx;
 983	sf->next_block = NULL;
 984	sf->hdr = first_hdr;
 985	sf->prev = NULL;
 986
 987continue_with_new_stack_frame:
 988	sf->block->generation = le64_to_cpu(sf->hdr->generation);
 989	if (0 == sf->hdr->level) {
 990		struct btrfs_leaf *const leafhdr =
 991		    (struct btrfs_leaf *)sf->hdr;
 992
 993		if (-1 == sf->i) {
 994			sf->nr = btrfs_stack_header_nritems(&leafhdr->header);
 995
 996			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
 997				printk(KERN_INFO
 998				       "leaf %llu items %d generation %llu"
 999				       " owner %llu\n",
1000				       sf->block_ctx->start, sf->nr,
1001				       btrfs_stack_header_generation(
1002					       &leafhdr->header),
1003				       btrfs_stack_header_owner(
1004					       &leafhdr->header));
1005		}
1006
1007continue_with_current_leaf_stack_frame:
1008		if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1009			sf->i++;
1010			sf->num_copies = 0;
1011		}
1012
1013		if (sf->i < sf->nr) {
1014			struct btrfs_item disk_item;
1015			u32 disk_item_offset =
1016				(uintptr_t)(leafhdr->items + sf->i) -
1017				(uintptr_t)leafhdr;
1018			struct btrfs_disk_key *disk_key;
1019			u8 type;
1020			u32 item_offset;
1021			u32 item_size;
1022
1023			if (disk_item_offset + sizeof(struct btrfs_item) >
1024			    sf->block_ctx->len) {
1025leaf_item_out_of_bounce_error:
1026				printk(KERN_INFO
1027				       "btrfsic: leaf item out of bounce at logical %llu, dev %s\n",
1028				       sf->block_ctx->start,
1029				       sf->block_ctx->dev->name);
1030				goto one_stack_frame_backwards;
1031			}
1032			btrfsic_read_from_block_data(sf->block_ctx,
1033						     &disk_item,
1034						     disk_item_offset,
1035						     sizeof(struct btrfs_item));
1036			item_offset = btrfs_stack_item_offset(&disk_item);
1037			item_size = btrfs_stack_item_size(&disk_item);
1038			disk_key = &disk_item.key;
1039			type = btrfs_disk_key_type(disk_key);
1040
1041			if (BTRFS_ROOT_ITEM_KEY == type) {
1042				struct btrfs_root_item root_item;
1043				u32 root_item_offset;
1044				u64 next_bytenr;
1045
1046				root_item_offset = item_offset +
1047					offsetof(struct btrfs_leaf, items);
1048				if (root_item_offset + item_size >
1049				    sf->block_ctx->len)
1050					goto leaf_item_out_of_bounce_error;
1051				btrfsic_read_from_block_data(
1052					sf->block_ctx, &root_item,
1053					root_item_offset,
1054					item_size);
1055				next_bytenr = btrfs_root_bytenr(&root_item);
1056
1057				sf->error =
1058				    btrfsic_create_link_to_next_block(
1059						state,
1060						sf->block,
1061						sf->block_ctx,
1062						next_bytenr,
1063						sf->limit_nesting,
1064						&sf->next_block_ctx,
1065						&sf->next_block,
1066						force_iodone_flag,
1067						&sf->num_copies,
1068						&sf->mirror_num,
1069						disk_key,
1070						btrfs_root_generation(
1071						&root_item));
1072				if (sf->error)
1073					goto one_stack_frame_backwards;
1074
1075				if (NULL != sf->next_block) {
1076					struct btrfs_header *const next_hdr =
1077					    (struct btrfs_header *)
1078					    sf->next_block_ctx.datav[0];
1079
1080					next_stack =
1081					    btrfsic_stack_frame_alloc();
1082					if (NULL == next_stack) {
1083						sf->error = -1;
1084						btrfsic_release_block_ctx(
1085								&sf->
1086								next_block_ctx);
1087						goto one_stack_frame_backwards;
1088					}
1089
1090					next_stack->i = -1;
1091					next_stack->block = sf->next_block;
1092					next_stack->block_ctx =
1093					    &sf->next_block_ctx;
1094					next_stack->next_block = NULL;
1095					next_stack->hdr = next_hdr;
1096					next_stack->limit_nesting =
1097					    sf->limit_nesting - 1;
1098					next_stack->prev = sf;
1099					sf = next_stack;
1100					goto continue_with_new_stack_frame;
1101				}
1102			} else if (BTRFS_EXTENT_DATA_KEY == type &&
1103				   state->include_extent_data) {
1104				sf->error = btrfsic_handle_extent_data(
1105						state,
1106						sf->block,
1107						sf->block_ctx,
1108						item_offset,
1109						force_iodone_flag);
1110				if (sf->error)
1111					goto one_stack_frame_backwards;
1112			}
1113
1114			goto continue_with_current_leaf_stack_frame;
1115		}
1116	} else {
1117		struct btrfs_node *const nodehdr = (struct btrfs_node *)sf->hdr;
1118
1119		if (-1 == sf->i) {
1120			sf->nr = btrfs_stack_header_nritems(&nodehdr->header);
1121
1122			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1123				printk(KERN_INFO "node %llu level %d items %d"
1124				       " generation %llu owner %llu\n",
1125				       sf->block_ctx->start,
1126				       nodehdr->header.level, sf->nr,
1127				       btrfs_stack_header_generation(
1128				       &nodehdr->header),
1129				       btrfs_stack_header_owner(
1130				       &nodehdr->header));
1131		}
1132
1133continue_with_current_node_stack_frame:
1134		if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1135			sf->i++;
1136			sf->num_copies = 0;
1137		}
1138
1139		if (sf->i < sf->nr) {
1140			struct btrfs_key_ptr key_ptr;
1141			u32 key_ptr_offset;
1142			u64 next_bytenr;
1143
1144			key_ptr_offset = (uintptr_t)(nodehdr->ptrs + sf->i) -
1145					  (uintptr_t)nodehdr;
1146			if (key_ptr_offset + sizeof(struct btrfs_key_ptr) >
1147			    sf->block_ctx->len) {
1148				printk(KERN_INFO
1149				       "btrfsic: node item out of bounce at logical %llu, dev %s\n",
1150				       sf->block_ctx->start,
1151				       sf->block_ctx->dev->name);
1152				goto one_stack_frame_backwards;
1153			}
1154			btrfsic_read_from_block_data(
1155				sf->block_ctx, &key_ptr, key_ptr_offset,
1156				sizeof(struct btrfs_key_ptr));
1157			next_bytenr = btrfs_stack_key_blockptr(&key_ptr);
1158
1159			sf->error = btrfsic_create_link_to_next_block(
1160					state,
1161					sf->block,
1162					sf->block_ctx,
1163					next_bytenr,
1164					sf->limit_nesting,
1165					&sf->next_block_ctx,
1166					&sf->next_block,
1167					force_iodone_flag,
1168					&sf->num_copies,
1169					&sf->mirror_num,
1170					&key_ptr.key,
1171					btrfs_stack_key_generation(&key_ptr));
1172			if (sf->error)
1173				goto one_stack_frame_backwards;
1174
1175			if (NULL != sf->next_block) {
1176				struct btrfs_header *const next_hdr =
1177				    (struct btrfs_header *)
1178				    sf->next_block_ctx.datav[0];
1179
1180				next_stack = btrfsic_stack_frame_alloc();
1181				if (NULL == next_stack) {
1182					sf->error = -1;
1183					goto one_stack_frame_backwards;
1184				}
1185
1186				next_stack->i = -1;
1187				next_stack->block = sf->next_block;
1188				next_stack->block_ctx = &sf->next_block_ctx;
1189				next_stack->next_block = NULL;
1190				next_stack->hdr = next_hdr;
1191				next_stack->limit_nesting =
1192				    sf->limit_nesting - 1;
1193				next_stack->prev = sf;
1194				sf = next_stack;
1195				goto continue_with_new_stack_frame;
1196			}
1197
1198			goto continue_with_current_node_stack_frame;
1199		}
1200	}
1201
1202one_stack_frame_backwards:
1203	if (NULL != sf->prev) {
1204		struct btrfsic_stack_frame *const prev = sf->prev;
1205
1206		/* the one for the initial block is freed in the caller */
1207		btrfsic_release_block_ctx(sf->block_ctx);
1208
1209		if (sf->error) {
1210			prev->error = sf->error;
1211			btrfsic_stack_frame_free(sf);
1212			sf = prev;
1213			goto one_stack_frame_backwards;
1214		}
1215
1216		btrfsic_stack_frame_free(sf);
1217		sf = prev;
1218		goto continue_with_new_stack_frame;
1219	} else {
1220		BUG_ON(&initial_stack_frame != sf);
1221	}
1222
1223	return sf->error;
1224}
1225
1226static void btrfsic_read_from_block_data(
1227	struct btrfsic_block_data_ctx *block_ctx,
1228	void *dstv, u32 offset, size_t len)
1229{
1230	size_t cur;
1231	size_t offset_in_page;
1232	char *kaddr;
1233	char *dst = (char *)dstv;
1234	size_t start_offset = block_ctx->start & ((u64)PAGE_SIZE - 1);
1235	unsigned long i = (start_offset + offset) >> PAGE_SHIFT;
1236
1237	WARN_ON(offset + len > block_ctx->len);
1238	offset_in_page = (start_offset + offset) & (PAGE_SIZE - 1);
1239
1240	while (len > 0) {
1241		cur = min(len, ((size_t)PAGE_SIZE - offset_in_page));
1242		BUG_ON(i >= DIV_ROUND_UP(block_ctx->len, PAGE_SIZE));
1243		kaddr = block_ctx->datav[i];
1244		memcpy(dst, kaddr + offset_in_page, cur);
1245
1246		dst += cur;
1247		len -= cur;
1248		offset_in_page = 0;
1249		i++;
1250	}
1251}
1252
1253static int btrfsic_create_link_to_next_block(
1254		struct btrfsic_state *state,
1255		struct btrfsic_block *block,
1256		struct btrfsic_block_data_ctx *block_ctx,
1257		u64 next_bytenr,
1258		int limit_nesting,
1259		struct btrfsic_block_data_ctx *next_block_ctx,
1260		struct btrfsic_block **next_blockp,
1261		int force_iodone_flag,
1262		int *num_copiesp, int *mirror_nump,
1263		struct btrfs_disk_key *disk_key,
1264		u64 parent_generation)
1265{
1266	struct btrfsic_block *next_block = NULL;
1267	int ret;
1268	struct btrfsic_block_link *l;
1269	int did_alloc_block_link;
1270	int block_was_created;
1271
1272	*next_blockp = NULL;
1273	if (0 == *num_copiesp) {
1274		*num_copiesp =
1275		    btrfs_num_copies(state->root->fs_info,
1276				     next_bytenr, state->metablock_size);
1277		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1278			printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
1279			       next_bytenr, *num_copiesp);
1280		*mirror_nump = 1;
1281	}
1282
1283	if (*mirror_nump > *num_copiesp)
1284		return 0;
1285
1286	if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1287		printk(KERN_INFO
1288		       "btrfsic_create_link_to_next_block(mirror_num=%d)\n",
1289		       *mirror_nump);
1290	ret = btrfsic_map_block(state, next_bytenr,
1291				state->metablock_size,
1292				next_block_ctx, *mirror_nump);
1293	if (ret) {
1294		printk(KERN_INFO
1295		       "btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
1296		       next_bytenr, *mirror_nump);
1297		btrfsic_release_block_ctx(next_block_ctx);
1298		*next_blockp = NULL;
1299		return -1;
1300	}
1301
1302	next_block = btrfsic_block_lookup_or_add(state,
1303						 next_block_ctx, "referenced ",
1304						 1, force_iodone_flag,
1305						 !force_iodone_flag,
1306						 *mirror_nump,
1307						 &block_was_created);
1308	if (NULL == next_block) {
1309		btrfsic_release_block_ctx(next_block_ctx);
1310		*next_blockp = NULL;
1311		return -1;
1312	}
1313	if (block_was_created) {
1314		l = NULL;
1315		next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
1316	} else {
1317		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1318			if (next_block->logical_bytenr != next_bytenr &&
1319			    !(!next_block->is_metadata &&
1320			      0 == next_block->logical_bytenr))
1321				printk(KERN_INFO
1322				       "Referenced block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1323				       next_bytenr, next_block_ctx->dev->name,
1324				       next_block_ctx->dev_bytenr, *mirror_nump,
1325				       btrfsic_get_block_type(state,
1326							      next_block),
1327				       next_block->logical_bytenr);
1328			else
1329				printk(KERN_INFO
1330				       "Referenced block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1331				       next_bytenr, next_block_ctx->dev->name,
1332				       next_block_ctx->dev_bytenr, *mirror_nump,
1333				       btrfsic_get_block_type(state,
1334							      next_block));
1335		}
1336		next_block->logical_bytenr = next_bytenr;
1337
1338		next_block->mirror_num = *mirror_nump;
1339		l = btrfsic_block_link_hashtable_lookup(
1340				next_block_ctx->dev->bdev,
1341				next_block_ctx->dev_bytenr,
1342				block_ctx->dev->bdev,
1343				block_ctx->dev_bytenr,
1344				&state->block_link_hashtable);
1345	}
1346
1347	next_block->disk_key = *disk_key;
1348	if (NULL == l) {
1349		l = btrfsic_block_link_alloc();
1350		if (NULL == l) {
1351			printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
1352			btrfsic_release_block_ctx(next_block_ctx);
1353			*next_blockp = NULL;
1354			return -1;
1355		}
1356
1357		did_alloc_block_link = 1;
1358		l->block_ref_to = next_block;
1359		l->block_ref_from = block;
1360		l->ref_cnt = 1;
1361		l->parent_generation = parent_generation;
1362
1363		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1364			btrfsic_print_add_link(state, l);
1365
1366		list_add(&l->node_ref_to, &block->ref_to_list);
1367		list_add(&l->node_ref_from, &next_block->ref_from_list);
1368
1369		btrfsic_block_link_hashtable_add(l,
1370						 &state->block_link_hashtable);
1371	} else {
1372		did_alloc_block_link = 0;
1373		if (0 == limit_nesting) {
1374			l->ref_cnt++;
1375			l->parent_generation = parent_generation;
1376			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1377				btrfsic_print_add_link(state, l);
1378		}
1379	}
1380
1381	if (limit_nesting > 0 && did_alloc_block_link) {
1382		ret = btrfsic_read_block(state, next_block_ctx);
1383		if (ret < (int)next_block_ctx->len) {
1384			printk(KERN_INFO
1385			       "btrfsic: read block @logical %llu failed!\n",
1386			       next_bytenr);
1387			btrfsic_release_block_ctx(next_block_ctx);
1388			*next_blockp = NULL;
1389			return -1;
1390		}
1391
1392		*next_blockp = next_block;
1393	} else {
1394		*next_blockp = NULL;
1395	}
1396	(*mirror_nump)++;
1397
1398	return 0;
1399}
1400
1401static int btrfsic_handle_extent_data(
1402		struct btrfsic_state *state,
1403		struct btrfsic_block *block,
1404		struct btrfsic_block_data_ctx *block_ctx,
1405		u32 item_offset, int force_iodone_flag)
1406{
1407	int ret;
1408	struct btrfs_file_extent_item file_extent_item;
1409	u64 file_extent_item_offset;
1410	u64 next_bytenr;
1411	u64 num_bytes;
1412	u64 generation;
1413	struct btrfsic_block_link *l;
1414
1415	file_extent_item_offset = offsetof(struct btrfs_leaf, items) +
1416				  item_offset;
1417	if (file_extent_item_offset +
1418	    offsetof(struct btrfs_file_extent_item, disk_num_bytes) >
1419	    block_ctx->len) {
1420		printk(KERN_INFO
1421		       "btrfsic: file item out of bounce at logical %llu, dev %s\n",
1422		       block_ctx->start, block_ctx->dev->name);
1423		return -1;
1424	}
1425
1426	btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1427		file_extent_item_offset,
1428		offsetof(struct btrfs_file_extent_item, disk_num_bytes));
1429	if (BTRFS_FILE_EXTENT_REG != file_extent_item.type ||
1430	    btrfs_stack_file_extent_disk_bytenr(&file_extent_item) == 0) {
1431		if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1432			printk(KERN_INFO "extent_data: type %u, disk_bytenr = %llu\n",
1433			       file_extent_item.type,
1434			       btrfs_stack_file_extent_disk_bytenr(
1435			       &file_extent_item));
1436		return 0;
1437	}
1438
1439	if (file_extent_item_offset + sizeof(struct btrfs_file_extent_item) >
1440	    block_ctx->len) {
1441		printk(KERN_INFO
1442		       "btrfsic: file item out of bounce at logical %llu, dev %s\n",
1443		       block_ctx->start, block_ctx->dev->name);
1444		return -1;
1445	}
1446	btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1447				     file_extent_item_offset,
1448				     sizeof(struct btrfs_file_extent_item));
1449	next_bytenr = btrfs_stack_file_extent_disk_bytenr(&file_extent_item);
1450	if (btrfs_stack_file_extent_compression(&file_extent_item) ==
1451	    BTRFS_COMPRESS_NONE) {
1452		next_bytenr += btrfs_stack_file_extent_offset(&file_extent_item);
1453		num_bytes = btrfs_stack_file_extent_num_bytes(&file_extent_item);
1454	} else {
1455		num_bytes = btrfs_stack_file_extent_disk_num_bytes(&file_extent_item);
1456	}
1457	generation = btrfs_stack_file_extent_generation(&file_extent_item);
1458
1459	if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1460		printk(KERN_INFO "extent_data: type %u, disk_bytenr = %llu,"
1461		       " offset = %llu, num_bytes = %llu\n",
1462		       file_extent_item.type,
1463		       btrfs_stack_file_extent_disk_bytenr(&file_extent_item),
1464		       btrfs_stack_file_extent_offset(&file_extent_item),
1465		       num_bytes);
1466	while (num_bytes > 0) {
1467		u32 chunk_len;
1468		int num_copies;
1469		int mirror_num;
1470
1471		if (num_bytes > state->datablock_size)
1472			chunk_len = state->datablock_size;
1473		else
1474			chunk_len = num_bytes;
1475
1476		num_copies =
1477		    btrfs_num_copies(state->root->fs_info,
1478				     next_bytenr, state->datablock_size);
1479		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1480			printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
1481			       next_bytenr, num_copies);
1482		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
1483			struct btrfsic_block_data_ctx next_block_ctx;
1484			struct btrfsic_block *next_block;
1485			int block_was_created;
1486
1487			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1488				printk(KERN_INFO "btrfsic_handle_extent_data("
1489				       "mirror_num=%d)\n", mirror_num);
1490			if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1491				printk(KERN_INFO
1492				       "\tdisk_bytenr = %llu, num_bytes %u\n",
1493				       next_bytenr, chunk_len);
1494			ret = btrfsic_map_block(state, next_bytenr,
1495						chunk_len, &next_block_ctx,
1496						mirror_num);
1497			if (ret) {
1498				printk(KERN_INFO
1499				       "btrfsic: btrfsic_map_block(@%llu,"
1500				       " mirror=%d) failed!\n",
1501				       next_bytenr, mirror_num);
1502				return -1;
1503			}
1504
1505			next_block = btrfsic_block_lookup_or_add(
1506					state,
1507					&next_block_ctx,
1508					"referenced ",
1509					0,
1510					force_iodone_flag,
1511					!force_iodone_flag,
1512					mirror_num,
1513					&block_was_created);
1514			if (NULL == next_block) {
1515				printk(KERN_INFO
1516				       "btrfsic: error, kmalloc failed!\n");
1517				btrfsic_release_block_ctx(&next_block_ctx);
1518				return -1;
1519			}
1520			if (!block_was_created) {
1521				if ((state->print_mask &
1522				     BTRFSIC_PRINT_MASK_VERBOSE) &&
1523				    next_block->logical_bytenr != next_bytenr &&
1524				    !(!next_block->is_metadata &&
1525				      0 == next_block->logical_bytenr)) {
1526					printk(KERN_INFO
1527					       "Referenced block"
1528					       " @%llu (%s/%llu/%d)"
1529					       " found in hash table, D,"
1530					       " bytenr mismatch"
1531					       " (!= stored %llu).\n",
1532					       next_bytenr,
1533					       next_block_ctx.dev->name,
1534					       next_block_ctx.dev_bytenr,
1535					       mirror_num,
1536					       next_block->logical_bytenr);
1537				}
1538				next_block->logical_bytenr = next_bytenr;
1539				next_block->mirror_num = mirror_num;
1540			}
1541
1542			l = btrfsic_block_link_lookup_or_add(state,
1543							     &next_block_ctx,
1544							     next_block, block,
1545							     generation);
1546			btrfsic_release_block_ctx(&next_block_ctx);
1547			if (NULL == l)
1548				return -1;
1549		}
1550
1551		next_bytenr += chunk_len;
1552		num_bytes -= chunk_len;
1553	}
1554
1555	return 0;
1556}
1557
1558static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
1559			     struct btrfsic_block_data_ctx *block_ctx_out,
1560			     int mirror_num)
1561{
1562	int ret;
1563	u64 length;
1564	struct btrfs_bio *multi = NULL;
1565	struct btrfs_device *device;
1566
1567	length = len;
1568	ret = btrfs_map_block(state->root->fs_info, READ,
1569			      bytenr, &length, &multi, mirror_num);
1570
1571	if (ret) {
1572		block_ctx_out->start = 0;
1573		block_ctx_out->dev_bytenr = 0;
1574		block_ctx_out->len = 0;
1575		block_ctx_out->dev = NULL;
1576		block_ctx_out->datav = NULL;
1577		block_ctx_out->pagev = NULL;
1578		block_ctx_out->mem_to_free = NULL;
1579
1580		return ret;
1581	}
1582
1583	device = multi->stripes[0].dev;
1584	block_ctx_out->dev = btrfsic_dev_state_lookup(device->bdev);
1585	block_ctx_out->dev_bytenr = multi->stripes[0].physical;
1586	block_ctx_out->start = bytenr;
1587	block_ctx_out->len = len;
1588	block_ctx_out->datav = NULL;
1589	block_ctx_out->pagev = NULL;
1590	block_ctx_out->mem_to_free = NULL;
1591
1592	kfree(multi);
1593	if (NULL == block_ctx_out->dev) {
1594		ret = -ENXIO;
1595		printk(KERN_INFO "btrfsic: error, cannot lookup dev (#1)!\n");
1596	}
1597
1598	return ret;
1599}
1600
1601static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx)
1602{
1603	if (block_ctx->mem_to_free) {
1604		unsigned int num_pages;
1605
1606		BUG_ON(!block_ctx->datav);
1607		BUG_ON(!block_ctx->pagev);
1608		num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
1609			    PAGE_SHIFT;
1610		while (num_pages > 0) {
1611			num_pages--;
1612			if (block_ctx->datav[num_pages]) {
1613				kunmap(block_ctx->pagev[num_pages]);
1614				block_ctx->datav[num_pages] = NULL;
1615			}
1616			if (block_ctx->pagev[num_pages]) {
1617				__free_page(block_ctx->pagev[num_pages]);
1618				block_ctx->pagev[num_pages] = NULL;
1619			}
1620		}
1621
1622		kfree(block_ctx->mem_to_free);
1623		block_ctx->mem_to_free = NULL;
1624		block_ctx->pagev = NULL;
1625		block_ctx->datav = NULL;
1626	}
1627}
1628
1629static int btrfsic_read_block(struct btrfsic_state *state,
1630			      struct btrfsic_block_data_ctx *block_ctx)
1631{
1632	unsigned int num_pages;
1633	unsigned int i;
1634	u64 dev_bytenr;
1635	int ret;
1636
1637	BUG_ON(block_ctx->datav);
1638	BUG_ON(block_ctx->pagev);
1639	BUG_ON(block_ctx->mem_to_free);
1640	if (block_ctx->dev_bytenr & ((u64)PAGE_SIZE - 1)) {
1641		printk(KERN_INFO
1642		       "btrfsic: read_block() with unaligned bytenr %llu\n",
1643		       block_ctx->dev_bytenr);
1644		return -1;
1645	}
1646
1647	num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
1648		    PAGE_SHIFT;
1649	block_ctx->mem_to_free = kzalloc((sizeof(*block_ctx->datav) +
1650					  sizeof(*block_ctx->pagev)) *
1651					 num_pages, GFP_NOFS);
1652	if (!block_ctx->mem_to_free)
1653		return -ENOMEM;
1654	block_ctx->datav = block_ctx->mem_to_free;
1655	block_ctx->pagev = (struct page **)(block_ctx->datav + num_pages);
1656	for (i = 0; i < num_pages; i++) {
1657		block_ctx->pagev[i] = alloc_page(GFP_NOFS);
1658		if (!block_ctx->pagev[i])
1659			return -1;
1660	}
1661
1662	dev_bytenr = block_ctx->dev_bytenr;
1663	for (i = 0; i < num_pages;) {
1664		struct bio *bio;
1665		unsigned int j;
1666
1667		bio = btrfs_io_bio_alloc(GFP_NOFS, num_pages - i);
1668		if (!bio) {
1669			printk(KERN_INFO
1670			       "btrfsic: bio_alloc() for %u pages failed!\n",
1671			       num_pages - i);
1672			return -1;
1673		}
1674		bio->bi_bdev = block_ctx->dev->bdev;
1675		bio->bi_iter.bi_sector = dev_bytenr >> 9;
1676
1677		for (j = i; j < num_pages; j++) {
1678			ret = bio_add_page(bio, block_ctx->pagev[j],
1679					   PAGE_SIZE, 0);
1680			if (PAGE_SIZE != ret)
1681				break;
1682		}
1683		if (j == i) {
1684			printk(KERN_INFO
1685			       "btrfsic: error, failed to add a single page!\n");
1686			return -1;
1687		}
1688		if (submit_bio_wait(READ, bio)) {
1689			printk(KERN_INFO
1690			       "btrfsic: read error at logical %llu dev %s!\n",
1691			       block_ctx->start, block_ctx->dev->name);
1692			bio_put(bio);
1693			return -1;
1694		}
1695		bio_put(bio);
1696		dev_bytenr += (j - i) * PAGE_SIZE;
1697		i = j;
1698	}
1699	for (i = 0; i < num_pages; i++) {
1700		block_ctx->datav[i] = kmap(block_ctx->pagev[i]);
1701		if (!block_ctx->datav[i]) {
1702			printk(KERN_INFO "btrfsic: kmap() failed (dev %s)!\n",
1703			       block_ctx->dev->name);
1704			return -1;
1705		}
1706	}
1707
1708	return block_ctx->len;
1709}
1710
1711static void btrfsic_dump_database(struct btrfsic_state *state)
1712{
1713	const struct btrfsic_block *b_all;
1714
1715	BUG_ON(NULL == state);
1716
1717	printk(KERN_INFO "all_blocks_list:\n");
1718	list_for_each_entry(b_all, &state->all_blocks_list, all_blocks_node) {
1719		const struct btrfsic_block_link *l;
1720
1721		printk(KERN_INFO "%c-block @%llu (%s/%llu/%d)\n",
1722		       btrfsic_get_block_type(state, b_all),
1723		       b_all->logical_bytenr, b_all->dev_state->name,
1724		       b_all->dev_bytenr, b_all->mirror_num);
1725
1726		list_for_each_entry(l, &b_all->ref_to_list, node_ref_to) {
1727			printk(KERN_INFO " %c @%llu (%s/%llu/%d)"
1728			       " refers %u* to"
1729			       " %c @%llu (%s/%llu/%d)\n",
1730			       btrfsic_get_block_type(state, b_all),
1731			       b_all->logical_bytenr, b_all->dev_state->name,
1732			       b_all->dev_bytenr, b_all->mirror_num,
1733			       l->ref_cnt,
1734			       btrfsic_get_block_type(state, l->block_ref_to),
1735			       l->block_ref_to->logical_bytenr,
1736			       l->block_ref_to->dev_state->name,
1737			       l->block_ref_to->dev_bytenr,
1738			       l->block_ref_to->mirror_num);
1739		}
1740
1741		list_for_each_entry(l, &b_all->ref_from_list, node_ref_from) {
1742			printk(KERN_INFO " %c @%llu (%s/%llu/%d)"
1743			       " is ref %u* from"
1744			       " %c @%llu (%s/%llu/%d)\n",
1745			       btrfsic_get_block_type(state, b_all),
1746			       b_all->logical_bytenr, b_all->dev_state->name,
1747			       b_all->dev_bytenr, b_all->mirror_num,
1748			       l->ref_cnt,
1749			       btrfsic_get_block_type(state, l->block_ref_from),
1750			       l->block_ref_from->logical_bytenr,
1751			       l->block_ref_from->dev_state->name,
1752			       l->block_ref_from->dev_bytenr,
1753			       l->block_ref_from->mirror_num);
1754		}
1755
1756		printk(KERN_INFO "\n");
1757	}
1758}
1759
1760/*
1761 * Test whether the disk block contains a tree block (leaf or node)
1762 * (note that this test fails for the super block)
1763 */
1764static int btrfsic_test_for_metadata(struct btrfsic_state *state,
1765				     char **datav, unsigned int num_pages)
1766{
1767	struct btrfs_header *h;
1768	u8 csum[BTRFS_CSUM_SIZE];
1769	u32 crc = ~(u32)0;
1770	unsigned int i;
1771
1772	if (num_pages * PAGE_SIZE < state->metablock_size)
1773		return 1; /* not metadata */
1774	num_pages = state->metablock_size >> PAGE_SHIFT;
1775	h = (struct btrfs_header *)datav[0];
1776
1777	if (memcmp(h->fsid, state->root->fs_info->fsid, BTRFS_UUID_SIZE))
1778		return 1;
1779
1780	for (i = 0; i < num_pages; i++) {
1781		u8 *data = i ? datav[i] : (datav[i] + BTRFS_CSUM_SIZE);
1782		size_t sublen = i ? PAGE_SIZE :
1783				    (PAGE_SIZE - BTRFS_CSUM_SIZE);
1784
1785		crc = btrfs_crc32c(crc, data, sublen);
1786	}
1787	btrfs_csum_final(crc, csum);
1788	if (memcmp(csum, h->csum, state->csum_size))
1789		return 1;
1790
1791	return 0; /* is metadata */
1792}
1793
1794static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
1795					  u64 dev_bytenr, char **mapped_datav,
1796					  unsigned int num_pages,
1797					  struct bio *bio, int *bio_is_patched,
1798					  struct buffer_head *bh,
1799					  int submit_bio_bh_rw)
1800{
1801	int is_metadata;
1802	struct btrfsic_block *block;
1803	struct btrfsic_block_data_ctx block_ctx;
1804	int ret;
1805	struct btrfsic_state *state = dev_state->state;
1806	struct block_device *bdev = dev_state->bdev;
1807	unsigned int processed_len;
1808
1809	if (NULL != bio_is_patched)
1810		*bio_is_patched = 0;
1811
1812again:
1813	if (num_pages == 0)
1814		return;
1815
1816	processed_len = 0;
1817	is_metadata = (0 == btrfsic_test_for_metadata(state, mapped_datav,
1818						      num_pages));
1819
1820	block = btrfsic_block_hashtable_lookup(bdev, dev_bytenr,
1821					       &state->block_hashtable);
1822	if (NULL != block) {
1823		u64 bytenr = 0;
1824		struct btrfsic_block_link *l, *tmp;
1825
1826		if (block->is_superblock) {
1827			bytenr = btrfs_super_bytenr((struct btrfs_super_block *)
1828						    mapped_datav[0]);
1829			if (num_pages * PAGE_SIZE <
1830			    BTRFS_SUPER_INFO_SIZE) {
1831				printk(KERN_INFO
1832				       "btrfsic: cannot work with too short bios!\n");
1833				return;
1834			}
1835			is_metadata = 1;
1836			BUG_ON(BTRFS_SUPER_INFO_SIZE & (PAGE_SIZE - 1));
1837			processed_len = BTRFS_SUPER_INFO_SIZE;
1838			if (state->print_mask &
1839			    BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE) {
1840				printk(KERN_INFO
1841				       "[before new superblock is written]:\n");
1842				btrfsic_dump_tree_sub(state, block, 0);
1843			}
1844		}
1845		if (is_metadata) {
1846			if (!block->is_superblock) {
1847				if (num_pages * PAGE_SIZE <
1848				    state->metablock_size) {
1849					printk(KERN_INFO
1850					       "btrfsic: cannot work with too short bios!\n");
1851					return;
1852				}
1853				processed_len = state->metablock_size;
1854				bytenr = btrfs_stack_header_bytenr(
1855						(struct btrfs_header *)
1856						mapped_datav[0]);
1857				btrfsic_cmp_log_and_dev_bytenr(state, bytenr,
1858							       dev_state,
1859							       dev_bytenr);
1860			}
1861			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1862				if (block->logical_bytenr != bytenr &&
1863				    !(!block->is_metadata &&
1864				      block->logical_bytenr == 0))
1865					printk(KERN_INFO
1866					       "Written block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1867					       bytenr, dev_state->name,
1868					       dev_bytenr,
1869					       block->mirror_num,
1870					       btrfsic_get_block_type(state,
1871								      block),
1872					       block->logical_bytenr);
1873				else
1874					printk(KERN_INFO
1875					       "Written block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1876					       bytenr, dev_state->name,
1877					       dev_bytenr, block->mirror_num,
1878					       btrfsic_get_block_type(state,
1879								      block));
1880			}
1881			block->logical_bytenr = bytenr;
1882		} else {
1883			if (num_pages * PAGE_SIZE <
1884			    state->datablock_size) {
1885				printk(KERN_INFO
1886				       "btrfsic: cannot work with too short bios!\n");
1887				return;
1888			}
1889			processed_len = state->datablock_size;
1890			bytenr = block->logical_bytenr;
1891			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1892				printk(KERN_INFO
1893				       "Written block @%llu (%s/%llu/%d)"
1894				       " found in hash table, %c.\n",
1895				       bytenr, dev_state->name, dev_bytenr,
1896				       block->mirror_num,
1897				       btrfsic_get_block_type(state, block));
1898		}
1899
1900		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1901			printk(KERN_INFO
1902			       "ref_to_list: %cE, ref_from_list: %cE\n",
1903			       list_empty(&block->ref_to_list) ? ' ' : '!',
1904			       list_empty(&block->ref_from_list) ? ' ' : '!');
1905		if (btrfsic_is_block_ref_by_superblock(state, block, 0)) {
1906			printk(KERN_INFO "btrfs: attempt to overwrite %c-block"
1907			       " @%llu (%s/%llu/%d), old(gen=%llu,"
1908			       " objectid=%llu, type=%d, offset=%llu),"
1909			       " new(gen=%llu),"
1910			       " which is referenced by most recent superblock"
1911			       " (superblockgen=%llu)!\n",
1912			       btrfsic_get_block_type(state, block), bytenr,
1913			       dev_state->name, dev_bytenr, block->mirror_num,
1914			       block->generation,
1915			       btrfs_disk_key_objectid(&block->disk_key),
1916			       block->disk_key.type,
1917			       btrfs_disk_key_offset(&block->disk_key),
1918			       btrfs_stack_header_generation(
1919				       (struct btrfs_header *) mapped_datav[0]),
1920			       state->max_superblock_generation);
1921			btrfsic_dump_tree(state);
1922		}
1923
1924		if (!block->is_iodone && !block->never_written) {
1925			printk(KERN_INFO "btrfs: attempt to overwrite %c-block"
1926			       " @%llu (%s/%llu/%d), oldgen=%llu, newgen=%llu,"
1927			       " which is not yet iodone!\n",
1928			       btrfsic_get_block_type(state, block), bytenr,
1929			       dev_state->name, dev_bytenr, block->mirror_num,
1930			       block->generation,
1931			       btrfs_stack_header_generation(
1932				       (struct btrfs_header *)
1933				       mapped_datav[0]));
1934			/* it would not be safe to go on */
1935			btrfsic_dump_tree(state);
1936			goto continue_loop;
1937		}
1938
1939		/*
1940		 * Clear all references of this block. Do not free
1941		 * the block itself even if is not referenced anymore
1942		 * because it still carries valueable information
1943		 * like whether it was ever written and IO completed.
1944		 */
1945		list_for_each_entry_safe(l, tmp, &block->ref_to_list,
1946					 node_ref_to) {
1947			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1948				btrfsic_print_rem_link(state, l);
1949			l->ref_cnt--;
1950			if (0 == l->ref_cnt) {
1951				list_del(&l->node_ref_to);
1952				list_del(&l->node_ref_from);
1953				btrfsic_block_link_hashtable_remove(l);
1954				btrfsic_block_link_free(l);
1955			}
1956		}
1957
1958		block_ctx.dev = dev_state;
1959		block_ctx.dev_bytenr = dev_bytenr;
1960		block_ctx.start = bytenr;
1961		block_ctx.len = processed_len;
1962		block_ctx.pagev = NULL;
1963		block_ctx.mem_to_free = NULL;
1964		block_ctx.datav = mapped_datav;
1965
1966		if (is_metadata || state->include_extent_data) {
1967			block->never_written = 0;
1968			block->iodone_w_error = 0;
1969			if (NULL != bio) {
1970				block->is_iodone = 0;
1971				BUG_ON(NULL == bio_is_patched);
1972				if (!*bio_is_patched) {
1973					block->orig_bio_bh_private =
1974					    bio->bi_private;
1975					block->orig_bio_bh_end_io.bio =
1976					    bio->bi_end_io;
1977					block->next_in_same_bio = NULL;
1978					bio->bi_private = block;
1979					bio->bi_end_io = btrfsic_bio_end_io;
1980					*bio_is_patched = 1;
1981				} else {
1982					struct btrfsic_block *chained_block =
1983					    (struct btrfsic_block *)
1984					    bio->bi_private;
1985
1986					BUG_ON(NULL == chained_block);
1987					block->orig_bio_bh_private =
1988					    chained_block->orig_bio_bh_private;
1989					block->orig_bio_bh_end_io.bio =
1990					    chained_block->orig_bio_bh_end_io.
1991					    bio;
1992					block->next_in_same_bio = chained_block;
1993					bio->bi_private = block;
1994				}
1995			} else if (NULL != bh) {
1996				block->is_iodone = 0;
1997				block->orig_bio_bh_private = bh->b_private;
1998				block->orig_bio_bh_end_io.bh = bh->b_end_io;
1999				block->next_in_same_bio = NULL;
2000				bh->b_private = block;
2001				bh->b_end_io = btrfsic_bh_end_io;
2002			} else {
2003				block->is_iodone = 1;
2004				block->orig_bio_bh_private = NULL;
2005				block->orig_bio_bh_end_io.bio = NULL;
2006				block->next_in_same_bio = NULL;
2007			}
2008		}
2009
2010		block->flush_gen = dev_state->last_flush_gen + 1;
2011		block->submit_bio_bh_rw = submit_bio_bh_rw;
2012		if (is_metadata) {
2013			block->logical_bytenr = bytenr;
2014			block->is_metadata = 1;
2015			if (block->is_superblock) {
2016				BUG_ON(PAGE_SIZE !=
2017				       BTRFS_SUPER_INFO_SIZE);
2018				ret = btrfsic_process_written_superblock(
2019						state,
2020						block,
2021						(struct btrfs_super_block *)
2022						mapped_datav[0]);
2023				if (state->print_mask &
2024				    BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE) {
2025					printk(KERN_INFO
2026					"[after new superblock is written]:\n");
2027					btrfsic_dump_tree_sub(state, block, 0);
2028				}
2029			} else {
2030				block->mirror_num = 0;	/* unknown */
2031				ret = btrfsic_process_metablock(
2032						state,
2033						block,
2034						&block_ctx,
2035						0, 0);
2036			}
2037			if (ret)
2038				printk(KERN_INFO
2039				       "btrfsic: btrfsic_process_metablock"
2040				       "(root @%llu) failed!\n",
2041				       dev_bytenr);
2042		} else {
2043			block->is_metadata = 0;
2044			block->mirror_num = 0;	/* unknown */
2045			block->generation = BTRFSIC_GENERATION_UNKNOWN;
2046			if (!state->include_extent_data
2047			    && list_empty(&block->ref_from_list)) {
2048				/*
2049				 * disk block is overwritten with extent
2050				 * data (not meta data) and we are configured
2051				 * to not include extent data: take the
2052				 * chance and free the block's memory
2053				 */
2054				btrfsic_block_hashtable_remove(block);
2055				list_del(&block->all_blocks_node);
2056				btrfsic_block_free(block);
2057			}
2058		}
2059		btrfsic_release_block_ctx(&block_ctx);
2060	} else {
2061		/* block has not been found in hash table */
2062		u64 bytenr;
2063
2064		if (!is_metadata) {
2065			processed_len = state->datablock_size;
2066			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2067				printk(KERN_INFO "Written block (%s/%llu/?)"
2068				       " !found in hash table, D.\n",
2069				       dev_state->name, dev_bytenr);
2070			if (!state->include_extent_data) {
2071				/* ignore that written D block */
2072				goto continue_loop;
2073			}
2074
2075			/* this is getting ugly for the
2076			 * include_extent_data case... */
2077			bytenr = 0;	/* unknown */
2078		} else {
2079			processed_len = state->metablock_size;
2080			bytenr = btrfs_stack_header_bytenr(
2081					(struct btrfs_header *)
2082					mapped_datav[0]);
2083			btrfsic_cmp_log_and_dev_bytenr(state, bytenr, dev_state,
2084						       dev_bytenr);
2085			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2086				printk(KERN_INFO
2087				       "Written block @%llu (%s/%llu/?)"
2088				       " !found in hash table, M.\n",
2089				       bytenr, dev_state->name, dev_bytenr);
2090		}
2091
2092		block_ctx.dev = dev_state;
2093		block_ctx.dev_bytenr = dev_bytenr;
2094		block_ctx.start = bytenr;
2095		block_ctx.len = processed_len;
2096		block_ctx.pagev = NULL;
2097		block_ctx.mem_to_free = NULL;
2098		block_ctx.datav = mapped_datav;
2099
2100		block = btrfsic_block_alloc();
2101		if (NULL == block) {
2102			printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
2103			btrfsic_release_block_ctx(&block_ctx);
2104			goto continue_loop;
2105		}
2106		block->dev_state = dev_state;
2107		block->dev_bytenr = dev_bytenr;
2108		block->logical_bytenr = bytenr;
2109		block->is_metadata = is_metadata;
2110		block->never_written = 0;
2111		block->iodone_w_error = 0;
2112		block->mirror_num = 0;	/* unknown */
2113		block->flush_gen = dev_state->last_flush_gen + 1;
2114		block->submit_bio_bh_rw = submit_bio_bh_rw;
2115		if (NULL != bio) {
2116			block->is_iodone = 0;
2117			BUG_ON(NULL == bio_is_patched);
2118			if (!*bio_is_patched) {
2119				block->orig_bio_bh_private = bio->bi_private;
2120				block->orig_bio_bh_end_io.bio = bio->bi_end_io;
2121				block->next_in_same_bio = NULL;
2122				bio->bi_private = block;
2123				bio->bi_end_io = btrfsic_bio_end_io;
2124				*bio_is_patched = 1;
2125			} else {
2126				struct btrfsic_block *chained_block =
2127				    (struct btrfsic_block *)
2128				    bio->bi_private;
2129
2130				BUG_ON(NULL == chained_block);
2131				block->orig_bio_bh_private =
2132				    chained_block->orig_bio_bh_private;
2133				block->orig_bio_bh_end_io.bio =
2134				    chained_block->orig_bio_bh_end_io.bio;
2135				block->next_in_same_bio = chained_block;
2136				bio->bi_private = block;
2137			}
2138		} else if (NULL != bh) {
2139			block->is_iodone = 0;
2140			block->orig_bio_bh_private = bh->b_private;
2141			block->orig_bio_bh_end_io.bh = bh->b_end_io;
2142			block->next_in_same_bio = NULL;
2143			bh->b_private = block;
2144			bh->b_end_io = btrfsic_bh_end_io;
2145		} else {
2146			block->is_iodone = 1;
2147			block->orig_bio_bh_private = NULL;
2148			block->orig_bio_bh_end_io.bio = NULL;
2149			block->next_in_same_bio = NULL;
2150		}
2151		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2152			printk(KERN_INFO
2153			       "New written %c-block @%llu (%s/%llu/%d)\n",
2154			       is_metadata ? 'M' : 'D',
2155			       block->logical_bytenr, block->dev_state->name,
2156			       block->dev_bytenr, block->mirror_num);
2157		list_add(&block->all_blocks_node, &state->all_blocks_list);
2158		btrfsic_block_hashtable_add(block, &state->block_hashtable);
2159
2160		if (is_metadata) {
2161			ret = btrfsic_process_metablock(state, block,
2162							&block_ctx, 0, 0);
2163			if (ret)
2164				printk(KERN_INFO
2165				       "btrfsic: process_metablock(root @%llu)"
2166				       " failed!\n",
2167				       dev_bytenr);
2168		}
2169		btrfsic_release_block_ctx(&block_ctx);
2170	}
2171
2172continue_loop:
2173	BUG_ON(!processed_len);
2174	dev_bytenr += processed_len;
2175	mapped_datav += processed_len >> PAGE_SHIFT;
2176	num_pages -= processed_len >> PAGE_SHIFT;
2177	goto again;
2178}
2179
2180static void btrfsic_bio_end_io(struct bio *bp)
2181{
2182	struct btrfsic_block *block = (struct btrfsic_block *)bp->bi_private;
2183	int iodone_w_error;
2184
2185	/* mutex is not held! This is not save if IO is not yet completed
2186	 * on umount */
2187	iodone_w_error = 0;
2188	if (bp->bi_error)
2189		iodone_w_error = 1;
2190
2191	BUG_ON(NULL == block);
2192	bp->bi_private = block->orig_bio_bh_private;
2193	bp->bi_end_io = block->orig_bio_bh_end_io.bio;
2194
2195	do {
2196		struct btrfsic_block *next_block;
2197		struct btrfsic_dev_state *const dev_state = block->dev_state;
2198
2199		if ((dev_state->state->print_mask &
2200		     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2201			printk(KERN_INFO
2202			       "bio_end_io(err=%d) for %c @%llu (%s/%llu/%d)\n",
2203			       bp->bi_error,
2204			       btrfsic_get_block_type(dev_state->state, block),
2205			       block->logical_bytenr, dev_state->name,
2206			       block->dev_bytenr, block->mirror_num);
2207		next_block = block->next_in_same_bio;
2208		block->iodone_w_error = iodone_w_error;
2209		if (block->submit_bio_bh_rw & REQ_FLUSH) {
2210			dev_state->last_flush_gen++;
2211			if ((dev_state->state->print_mask &
2212			     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2213				printk(KERN_INFO
2214				       "bio_end_io() new %s flush_gen=%llu\n",
2215				       dev_state->name,
2216				       dev_state->last_flush_gen);
2217		}
2218		if (block->submit_bio_bh_rw & REQ_FUA)
2219			block->flush_gen = 0; /* FUA completed means block is
2220					       * on disk */
2221		block->is_iodone = 1; /* for FLUSH, this releases the block */
2222		block = next_block;
2223	} while (NULL != block);
2224
2225	bp->bi_end_io(bp);
2226}
2227
2228static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate)
2229{
2230	struct btrfsic_block *block = (struct btrfsic_block *)bh->b_private;
2231	int iodone_w_error = !uptodate;
2232	struct btrfsic_dev_state *dev_state;
2233
2234	BUG_ON(NULL == block);
2235	dev_state = block->dev_state;
2236	if ((dev_state->state->print_mask & BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2237		printk(KERN_INFO
2238		       "bh_end_io(error=%d) for %c @%llu (%s/%llu/%d)\n",
2239		       iodone_w_error,
2240		       btrfsic_get_block_type(dev_state->state, block),
2241		       block->logical_bytenr, block->dev_state->name,
2242		       block->dev_bytenr, block->mirror_num);
2243
2244	block->iodone_w_error = iodone_w_error;
2245	if (block->submit_bio_bh_rw & REQ_FLUSH) {
2246		dev_state->last_flush_gen++;
2247		if ((dev_state->state->print_mask &
2248		     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2249			printk(KERN_INFO
2250			       "bh_end_io() new %s flush_gen=%llu\n",
2251			       dev_state->name, dev_state->last_flush_gen);
2252	}
2253	if (block->submit_bio_bh_rw & REQ_FUA)
2254		block->flush_gen = 0; /* FUA completed means block is on disk */
2255
2256	bh->b_private = block->orig_bio_bh_private;
2257	bh->b_end_io = block->orig_bio_bh_end_io.bh;
2258	block->is_iodone = 1; /* for FLUSH, this releases the block */
2259	bh->b_end_io(bh, uptodate);
2260}
2261
2262static int btrfsic_process_written_superblock(
2263		struct btrfsic_state *state,
2264		struct btrfsic_block *const superblock,
2265		struct btrfs_super_block *const super_hdr)
2266{
2267	int pass;
2268
2269	superblock->generation = btrfs_super_generation(super_hdr);
2270	if (!(superblock->generation > state->max_superblock_generation ||
2271	      0 == state->max_superblock_generation)) {
2272		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2273			printk(KERN_INFO
2274			       "btrfsic: superblock @%llu (%s/%llu/%d)"
2275			       " with old gen %llu <= %llu\n",
2276			       superblock->logical_bytenr,
2277			       superblock->dev_state->name,
2278			       superblock->dev_bytenr, superblock->mirror_num,
2279			       btrfs_super_generation(super_hdr),
2280			       state->max_superblock_generation);
2281	} else {
2282		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2283			printk(KERN_INFO
2284			       "btrfsic: got new superblock @%llu (%s/%llu/%d)"
2285			       " with new gen %llu > %llu\n",
2286			       superblock->logical_bytenr,
2287			       superblock->dev_state->name,
2288			       superblock->dev_bytenr, superblock->mirror_num,
2289			       btrfs_super_generation(super_hdr),
2290			       state->max_superblock_generation);
2291
2292		state->max_superblock_generation =
2293		    btrfs_super_generation(super_hdr);
2294		state->latest_superblock = superblock;
2295	}
2296
2297	for (pass = 0; pass < 3; pass++) {
2298		int ret;
2299		u64 next_bytenr;
2300		struct btrfsic_block *next_block;
2301		struct btrfsic_block_data_ctx tmp_next_block_ctx;
2302		struct btrfsic_block_link *l;
2303		int num_copies;
2304		int mirror_num;
2305		const char *additional_string = NULL;
2306		struct btrfs_disk_key tmp_disk_key = {0};
2307
2308		btrfs_set_disk_key_objectid(&tmp_disk_key,
2309					    BTRFS_ROOT_ITEM_KEY);
2310		btrfs_set_disk_key_objectid(&tmp_disk_key, 0);
2311
2312		switch (pass) {
2313		case 0:
2314			btrfs_set_disk_key_objectid(&tmp_disk_key,
2315						    BTRFS_ROOT_TREE_OBJECTID);
2316			additional_string = "root ";
2317			next_bytenr = btrfs_super_root(super_hdr);
2318			if (state->print_mask &
2319			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2320				printk(KERN_INFO "root@%llu\n", next_bytenr);
2321			break;
2322		case 1:
2323			btrfs_set_disk_key_objectid(&tmp_disk_key,
2324						    BTRFS_CHUNK_TREE_OBJECTID);
2325			additional_string = "chunk ";
2326			next_bytenr = btrfs_super_chunk_root(super_hdr);
2327			if (state->print_mask &
2328			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2329				printk(KERN_INFO "chunk@%llu\n", next_bytenr);
2330			break;
2331		case 2:
2332			btrfs_set_disk_key_objectid(&tmp_disk_key,
2333						    BTRFS_TREE_LOG_OBJECTID);
2334			additional_string = "log ";
2335			next_bytenr = btrfs_super_log_root(super_hdr);
2336			if (0 == next_bytenr)
2337				continue;
2338			if (state->print_mask &
2339			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2340				printk(KERN_INFO "log@%llu\n", next_bytenr);
2341			break;
2342		}
2343
2344		num_copies =
2345		    btrfs_num_copies(state->root->fs_info,
2346				     next_bytenr, BTRFS_SUPER_INFO_SIZE);
2347		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
2348			printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
2349			       next_bytenr, num_copies);
2350		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2351			int was_created;
2352
2353			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2354				printk(KERN_INFO
2355				       "btrfsic_process_written_superblock("
2356				       "mirror_num=%d)\n", mirror_num);
2357			ret = btrfsic_map_block(state, next_bytenr,
2358						BTRFS_SUPER_INFO_SIZE,
2359						&tmp_next_block_ctx,
2360						mirror_num);
2361			if (ret) {
2362				printk(KERN_INFO
2363				       "btrfsic: btrfsic_map_block(@%llu,"
2364				       " mirror=%d) failed!\n",
2365				       next_bytenr, mirror_num);
2366				return -1;
2367			}
2368
2369			next_block = btrfsic_block_lookup_or_add(
2370					state,
2371					&tmp_next_block_ctx,
2372					additional_string,
2373					1, 0, 1,
2374					mirror_num,
2375					&was_created);
2376			if (NULL == next_block) {
2377				printk(KERN_INFO
2378				       "btrfsic: error, kmalloc failed!\n");
2379				btrfsic_release_block_ctx(&tmp_next_block_ctx);
2380				return -1;
2381			}
2382
2383			next_block->disk_key = tmp_disk_key;
2384			if (was_created)
2385				next_block->generation =
2386				    BTRFSIC_GENERATION_UNKNOWN;
2387			l = btrfsic_block_link_lookup_or_add(
2388					state,
2389					&tmp_next_block_ctx,
2390					next_block,
2391					superblock,
2392					BTRFSIC_GENERATION_UNKNOWN);
2393			btrfsic_release_block_ctx(&tmp_next_block_ctx);
2394			if (NULL == l)
2395				return -1;
2396		}
2397	}
2398
2399	if (WARN_ON(-1 == btrfsic_check_all_ref_blocks(state, superblock, 0)))
2400		btrfsic_dump_tree(state);
2401
2402	return 0;
2403}
2404
2405static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
2406					struct btrfsic_block *const block,
2407					int recursion_level)
2408{
2409	const struct btrfsic_block_link *l;
2410	int ret = 0;
2411
2412	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2413		/*
2414		 * Note that this situation can happen and does not
2415		 * indicate an error in regular cases. It happens
2416		 * when disk blocks are freed and later reused.
2417		 * The check-integrity module is not aware of any
2418		 * block free operations, it just recognizes block
2419		 * write operations. Therefore it keeps the linkage
2420		 * information for a block until a block is
2421		 * rewritten. This can temporarily cause incorrect
2422		 * and even circular linkage informations. This
2423		 * causes no harm unless such blocks are referenced
2424		 * by the most recent super block.
2425		 */
2426		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2427			printk(KERN_INFO
2428			       "btrfsic: abort cyclic linkage (case 1).\n");
2429
2430		return ret;
2431	}
2432
2433	/*
2434	 * This algorithm is recursive because the amount of used stack
2435	 * space is very small and the max recursion depth is limited.
2436	 */
2437	list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
2438		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2439			printk(KERN_INFO
2440			       "rl=%d, %c @%llu (%s/%llu/%d)"
2441			       " %u* refers to %c @%llu (%s/%llu/%d)\n",
2442			       recursion_level,
2443			       btrfsic_get_block_type(state, block),
2444			       block->logical_bytenr, block->dev_state->name,
2445			       block->dev_bytenr, block->mirror_num,
2446			       l->ref_cnt,
2447			       btrfsic_get_block_type(state, l->block_ref_to),
2448			       l->block_ref_to->logical_bytenr,
2449			       l->block_ref_to->dev_state->name,
2450			       l->block_ref_to->dev_bytenr,
2451			       l->block_ref_to->mirror_num);
2452		if (l->block_ref_to->never_written) {
2453			printk(KERN_INFO "btrfs: attempt to write superblock"
2454			       " which references block %c @%llu (%s/%llu/%d)"
2455			       " which is never written!\n",
2456			       btrfsic_get_block_type(state, l->block_ref_to),
2457			       l->block_ref_to->logical_bytenr,
2458			       l->block_ref_to->dev_state->name,
2459			       l->block_ref_to->dev_bytenr,
2460			       l->block_ref_to->mirror_num);
2461			ret = -1;
2462		} else if (!l->block_ref_to->is_iodone) {
2463			printk(KERN_INFO "btrfs: attempt to write superblock"
2464			       " which references block %c @%llu (%s/%llu/%d)"
2465			       " which is not yet iodone!\n",
2466			       btrfsic_get_block_type(state, l->block_ref_to),
2467			       l->block_ref_to->logical_bytenr,
2468			       l->block_ref_to->dev_state->name,
2469			       l->block_ref_to->dev_bytenr,
2470			       l->block_ref_to->mirror_num);
2471			ret = -1;
2472		} else if (l->block_ref_to->iodone_w_error) {
2473			printk(KERN_INFO "btrfs: attempt to write superblock"
2474			       " which references block %c @%llu (%s/%llu/%d)"
2475			       " which has write error!\n",
2476			       btrfsic_get_block_type(state, l->block_ref_to),
2477			       l->block_ref_to->logical_bytenr,
2478			       l->block_ref_to->dev_state->name,
2479			       l->block_ref_to->dev_bytenr,
2480			       l->block_ref_to->mirror_num);
2481			ret = -1;
2482		} else if (l->parent_generation !=
2483			   l->block_ref_to->generation &&
2484			   BTRFSIC_GENERATION_UNKNOWN !=
2485			   l->parent_generation &&
2486			   BTRFSIC_GENERATION_UNKNOWN !=
2487			   l->block_ref_to->generation) {
2488			printk(KERN_INFO "btrfs: attempt to write superblock"
2489			       " which references block %c @%llu (%s/%llu/%d)"
2490			       " with generation %llu !="
2491			       " parent generation %llu!\n",
2492			       btrfsic_get_block_type(state, l->block_ref_to),
2493			       l->block_ref_to->logical_bytenr,
2494			       l->block_ref_to->dev_state->name,
2495			       l->block_ref_to->dev_bytenr,
2496			       l->block_ref_to->mirror_num,
2497			       l->block_ref_to->generation,
2498			       l->parent_generation);
2499			ret = -1;
2500		} else if (l->block_ref_to->flush_gen >
2501			   l->block_ref_to->dev_state->last_flush_gen) {
2502			printk(KERN_INFO "btrfs: attempt to write superblock"
2503			       " which references block %c @%llu (%s/%llu/%d)"
2504			       " which is not flushed out of disk's write cache"
2505			       " (block flush_gen=%llu,"
2506			       " dev->flush_gen=%llu)!\n",
2507			       btrfsic_get_block_type(state, l->block_ref_to),
2508			       l->block_ref_to->logical_bytenr,
2509			       l->block_ref_to->dev_state->name,
2510			       l->block_ref_to->dev_bytenr,
2511			       l->block_ref_to->mirror_num, block->flush_gen,
2512			       l->block_ref_to->dev_state->last_flush_gen);
2513			ret = -1;
2514		} else if (-1 == btrfsic_check_all_ref_blocks(state,
2515							      l->block_ref_to,
2516							      recursion_level +
2517							      1)) {
2518			ret = -1;
2519		}
2520	}
2521
2522	return ret;
2523}
2524
2525static int btrfsic_is_block_ref_by_superblock(
2526		const struct btrfsic_state *state,
2527		const struct btrfsic_block *block,
2528		int recursion_level)
2529{
2530	const struct btrfsic_block_link *l;
2531
2532	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2533		/* refer to comment at "abort cyclic linkage (case 1)" */
2534		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2535			printk(KERN_INFO
2536			       "btrfsic: abort cyclic linkage (case 2).\n");
2537
2538		return 0;
2539	}
2540
2541	/*
2542	 * This algorithm is recursive because the amount of used stack space
2543	 * is very small and the max recursion depth is limited.
2544	 */
2545	list_for_each_entry(l, &block->ref_from_list, node_ref_from) {
2546		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2547			printk(KERN_INFO
2548			       "rl=%d, %c @%llu (%s/%llu/%d)"
2549			       " is ref %u* from %c @%llu (%s/%llu/%d)\n",
2550			       recursion_level,
2551			       btrfsic_get_block_type(state, block),
2552			       block->logical_bytenr, block->dev_state->name,
2553			       block->dev_bytenr, block->mirror_num,
2554			       l->ref_cnt,
2555			       btrfsic_get_block_type(state, l->block_ref_from),
2556			       l->block_ref_from->logical_bytenr,
2557			       l->block_ref_from->dev_state->name,
2558			       l->block_ref_from->dev_bytenr,
2559			       l->block_ref_from->mirror_num);
2560		if (l->block_ref_from->is_superblock &&
2561		    state->latest_superblock->dev_bytenr ==
2562		    l->block_ref_from->dev_bytenr &&
2563		    state->latest_superblock->dev_state->bdev ==
2564		    l->block_ref_from->dev_state->bdev)
2565			return 1;
2566		else if (btrfsic_is_block_ref_by_superblock(state,
2567							    l->block_ref_from,
2568							    recursion_level +
2569							    1))
2570			return 1;
2571	}
2572
2573	return 0;
2574}
2575
2576static void btrfsic_print_add_link(const struct btrfsic_state *state,
2577				   const struct btrfsic_block_link *l)
2578{
2579	printk(KERN_INFO
2580	       "Add %u* link from %c @%llu (%s/%llu/%d)"
2581	       " to %c @%llu (%s/%llu/%d).\n",
2582	       l->ref_cnt,
2583	       btrfsic_get_block_type(state, l->block_ref_from),
2584	       l->block_ref_from->logical_bytenr,
2585	       l->block_ref_from->dev_state->name,
2586	       l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2587	       btrfsic_get_block_type(state, l->block_ref_to),
2588	       l->block_ref_to->logical_bytenr,
2589	       l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2590	       l->block_ref_to->mirror_num);
2591}
2592
2593static void btrfsic_print_rem_link(const struct btrfsic_state *state,
2594				   const struct btrfsic_block_link *l)
2595{
2596	printk(KERN_INFO
2597	       "Rem %u* link from %c @%llu (%s/%llu/%d)"
2598	       " to %c @%llu (%s/%llu/%d).\n",
2599	       l->ref_cnt,
2600	       btrfsic_get_block_type(state, l->block_ref_from),
2601	       l->block_ref_from->logical_bytenr,
2602	       l->block_ref_from->dev_state->name,
2603	       l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2604	       btrfsic_get_block_type(state, l->block_ref_to),
2605	       l->block_ref_to->logical_bytenr,
2606	       l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2607	       l->block_ref_to->mirror_num);
2608}
2609
2610static char btrfsic_get_block_type(const struct btrfsic_state *state,
2611				   const struct btrfsic_block *block)
2612{
2613	if (block->is_superblock &&
2614	    state->latest_superblock->dev_bytenr == block->dev_bytenr &&
2615	    state->latest_superblock->dev_state->bdev == block->dev_state->bdev)
2616		return 'S';
2617	else if (block->is_superblock)
2618		return 's';
2619	else if (block->is_metadata)
2620		return 'M';
2621	else
2622		return 'D';
2623}
2624
2625static void btrfsic_dump_tree(const struct btrfsic_state *state)
2626{
2627	btrfsic_dump_tree_sub(state, state->latest_superblock, 0);
2628}
2629
2630static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
2631				  const struct btrfsic_block *block,
2632				  int indent_level)
2633{
2634	const struct btrfsic_block_link *l;
2635	int indent_add;
2636	static char buf[80];
2637	int cursor_position;
2638
2639	/*
2640	 * Should better fill an on-stack buffer with a complete line and
2641	 * dump it at once when it is time to print a newline character.
2642	 */
2643
2644	/*
2645	 * This algorithm is recursive because the amount of used stack space
2646	 * is very small and the max recursion depth is limited.
2647	 */
2648	indent_add = sprintf(buf, "%c-%llu(%s/%llu/%d)",
2649			     btrfsic_get_block_type(state, block),
2650			     block->logical_bytenr, block->dev_state->name,
2651			     block->dev_bytenr, block->mirror_num);
2652	if (indent_level + indent_add > BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2653		printk("[...]\n");
2654		return;
2655	}
2656	printk(buf);
2657	indent_level += indent_add;
2658	if (list_empty(&block->ref_to_list)) {
2659		printk("\n");
2660		return;
2661	}
2662	if (block->mirror_num > 1 &&
2663	    !(state->print_mask & BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS)) {
2664		printk(" [...]\n");
2665		return;
2666	}
2667
2668	cursor_position = indent_level;
2669	list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
2670		while (cursor_position < indent_level) {
2671			printk(" ");
2672			cursor_position++;
2673		}
2674		if (l->ref_cnt > 1)
2675			indent_add = sprintf(buf, " %d*--> ", l->ref_cnt);
2676		else
2677			indent_add = sprintf(buf, " --> ");
2678		if (indent_level + indent_add >
2679		    BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2680			printk("[...]\n");
2681			cursor_position = 0;
2682			continue;
2683		}
2684
2685		printk(buf);
2686
2687		btrfsic_dump_tree_sub(state, l->block_ref_to,
2688				      indent_level + indent_add);
2689		cursor_position = 0;
2690	}
2691}
2692
2693static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
2694		struct btrfsic_state *state,
2695		struct btrfsic_block_data_ctx *next_block_ctx,
2696		struct btrfsic_block *next_block,
2697		struct btrfsic_block *from_block,
2698		u64 parent_generation)
2699{
2700	struct btrfsic_block_link *l;
2701
2702	l = btrfsic_block_link_hashtable_lookup(next_block_ctx->dev->bdev,
2703						next_block_ctx->dev_bytenr,
2704						from_block->dev_state->bdev,
2705						from_block->dev_bytenr,
2706						&state->block_link_hashtable);
2707	if (NULL == l) {
2708		l = btrfsic_block_link_alloc();
2709		if (NULL == l) {
2710			printk(KERN_INFO
2711			       "btrfsic: error, kmalloc" " failed!\n");
2712			return NULL;
2713		}
2714
2715		l->block_ref_to = next_block;
2716		l->block_ref_from = from_block;
2717		l->ref_cnt = 1;
2718		l->parent_generation = parent_generation;
2719
2720		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2721			btrfsic_print_add_link(state, l);
2722
2723		list_add(&l->node_ref_to, &from_block->ref_to_list);
2724		list_add(&l->node_ref_from, &next_block->ref_from_list);
2725
2726		btrfsic_block_link_hashtable_add(l,
2727						 &state->block_link_hashtable);
2728	} else {
2729		l->ref_cnt++;
2730		l->parent_generation = parent_generation;
2731		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2732			btrfsic_print_add_link(state, l);
2733	}
2734
2735	return l;
2736}
2737
2738static struct btrfsic_block *btrfsic_block_lookup_or_add(
2739		struct btrfsic_state *state,
2740		struct btrfsic_block_data_ctx *block_ctx,
2741		const char *additional_string,
2742		int is_metadata,
2743		int is_iodone,
2744		int never_written,
2745		int mirror_num,
2746		int *was_created)
2747{
2748	struct btrfsic_block *block;
2749
2750	block = btrfsic_block_hashtable_lookup(block_ctx->dev->bdev,
2751					       block_ctx->dev_bytenr,
2752					       &state->block_hashtable);
2753	if (NULL == block) {
2754		struct btrfsic_dev_state *dev_state;
2755
2756		block = btrfsic_block_alloc();
2757		if (NULL == block) {
2758			printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
2759			return NULL;
2760		}
2761		dev_state = btrfsic_dev_state_lookup(block_ctx->dev->bdev);
2762		if (NULL == dev_state) {
2763			printk(KERN_INFO
2764			       "btrfsic: error, lookup dev_state failed!\n");
2765			btrfsic_block_free(block);
2766			return NULL;
2767		}
2768		block->dev_state = dev_state;
2769		block->dev_bytenr = block_ctx->dev_bytenr;
2770		block->logical_bytenr = block_ctx->start;
2771		block->is_metadata = is_metadata;
2772		block->is_iodone = is_iodone;
2773		block->never_written = never_written;
2774		block->mirror_num = mirror_num;
2775		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2776			printk(KERN_INFO
2777			       "New %s%c-block @%llu (%s/%llu/%d)\n",
2778			       additional_string,
2779			       btrfsic_get_block_type(state, block),
2780			       block->logical_bytenr, dev_state->name,
2781			       block->dev_bytenr, mirror_num);
2782		list_add(&block->all_blocks_node, &state->all_blocks_list);
2783		btrfsic_block_hashtable_add(block, &state->block_hashtable);
2784		if (NULL != was_created)
2785			*was_created = 1;
2786	} else {
2787		if (NULL != was_created)
2788			*was_created = 0;
2789	}
2790
2791	return block;
2792}
2793
2794static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
2795					   u64 bytenr,
2796					   struct btrfsic_dev_state *dev_state,
2797					   u64 dev_bytenr)
2798{
2799	int num_copies;
2800	int mirror_num;
2801	int ret;
2802	struct btrfsic_block_data_ctx block_ctx;
2803	int match = 0;
2804
2805	num_copies = btrfs_num_copies(state->root->fs_info,
2806				      bytenr, state->metablock_size);
2807
2808	for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2809		ret = btrfsic_map_block(state, bytenr, state->metablock_size,
2810					&block_ctx, mirror_num);
2811		if (ret) {
2812			printk(KERN_INFO "btrfsic:"
2813			       " btrfsic_map_block(logical @%llu,"
2814			       " mirror %d) failed!\n",
2815			       bytenr, mirror_num);
2816			continue;
2817		}
2818
2819		if (dev_state->bdev == block_ctx.dev->bdev &&
2820		    dev_bytenr == block_ctx.dev_bytenr) {
2821			match++;
2822			btrfsic_release_block_ctx(&block_ctx);
2823			break;
2824		}
2825		btrfsic_release_block_ctx(&block_ctx);
2826	}
2827
2828	if (WARN_ON(!match)) {
2829		printk(KERN_INFO "btrfs: attempt to write M-block which contains logical bytenr that doesn't map to dev+physical bytenr of submit_bio,"
2830		       " buffer->log_bytenr=%llu, submit_bio(bdev=%s,"
2831		       " phys_bytenr=%llu)!\n",
2832		       bytenr, dev_state->name, dev_bytenr);
2833		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2834			ret = btrfsic_map_block(state, bytenr,
2835						state->metablock_size,
2836						&block_ctx, mirror_num);
2837			if (ret)
2838				continue;
2839
2840			printk(KERN_INFO "Read logical bytenr @%llu maps to"
2841			       " (%s/%llu/%d)\n",
2842			       bytenr, block_ctx.dev->name,
2843			       block_ctx.dev_bytenr, mirror_num);
2844		}
2845	}
2846}
2847
2848static struct btrfsic_dev_state *btrfsic_dev_state_lookup(
2849		struct block_device *bdev)
2850{
2851	struct btrfsic_dev_state *ds;
2852
2853	ds = btrfsic_dev_state_hashtable_lookup(bdev,
2854						&btrfsic_dev_state_hashtable);
2855	return ds;
2856}
2857
2858int btrfsic_submit_bh(int rw, struct buffer_head *bh)
2859{
2860	struct btrfsic_dev_state *dev_state;
2861
2862	if (!btrfsic_is_initialized)
2863		return submit_bh(rw, bh);
2864
2865	mutex_lock(&btrfsic_mutex);
2866	/* since btrfsic_submit_bh() might also be called before
2867	 * btrfsic_mount(), this might return NULL */
2868	dev_state = btrfsic_dev_state_lookup(bh->b_bdev);
2869
2870	/* Only called to write the superblock (incl. FLUSH/FUA) */
2871	if (NULL != dev_state &&
2872	    (rw & WRITE) && bh->b_size > 0) {
2873		u64 dev_bytenr;
2874
2875		dev_bytenr = 4096 * bh->b_blocknr;
2876		if (dev_state->state->print_mask &
2877		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2878			printk(KERN_INFO
2879			       "submit_bh(rw=0x%x, blocknr=%llu (bytenr %llu),"
2880			       " size=%zu, data=%p, bdev=%p)\n",
2881			       rw, (unsigned long long)bh->b_blocknr,
2882			       dev_bytenr, bh->b_size, bh->b_data, bh->b_bdev);
2883		btrfsic_process_written_block(dev_state, dev_bytenr,
2884					      &bh->b_data, 1, NULL,
2885					      NULL, bh, rw);
2886	} else if (NULL != dev_state && (rw & REQ_FLUSH)) {
2887		if (dev_state->state->print_mask &
2888		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2889			printk(KERN_INFO
2890			       "submit_bh(rw=0x%x FLUSH, bdev=%p)\n",
2891			       rw, bh->b_bdev);
2892		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
2893			if ((dev_state->state->print_mask &
2894			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
2895			      BTRFSIC_PRINT_MASK_VERBOSE)))
2896				printk(KERN_INFO
2897				       "btrfsic_submit_bh(%s) with FLUSH"
2898				       " but dummy block already in use"
2899				       " (ignored)!\n",
2900				       dev_state->name);
2901		} else {
2902			struct btrfsic_block *const block =
2903				&dev_state->dummy_block_for_bio_bh_flush;
2904
2905			block->is_iodone = 0;
2906			block->never_written = 0;
2907			block->iodone_w_error = 0;
2908			block->flush_gen = dev_state->last_flush_gen + 1;
2909			block->submit_bio_bh_rw = rw;
2910			block->orig_bio_bh_private = bh->b_private;
2911			block->orig_bio_bh_end_io.bh = bh->b_end_io;
2912			block->next_in_same_bio = NULL;
2913			bh->b_private = block;
2914			bh->b_end_io = btrfsic_bh_end_io;
2915		}
2916	}
2917	mutex_unlock(&btrfsic_mutex);
2918	return submit_bh(rw, bh);
2919}
2920
2921static void __btrfsic_submit_bio(int rw, struct bio *bio)
2922{
2923	struct btrfsic_dev_state *dev_state;
2924
2925	if (!btrfsic_is_initialized)
2926		return;
2927
2928	mutex_lock(&btrfsic_mutex);
2929	/* since btrfsic_submit_bio() is also called before
2930	 * btrfsic_mount(), this might return NULL */
2931	dev_state = btrfsic_dev_state_lookup(bio->bi_bdev);
2932	if (NULL != dev_state &&
2933	    (rw & WRITE) && NULL != bio->bi_io_vec) {
2934		unsigned int i;
2935		u64 dev_bytenr;
2936		u64 cur_bytenr;
2937		int bio_is_patched;
2938		char **mapped_datav;
2939
2940		dev_bytenr = 512 * bio->bi_iter.bi_sector;
2941		bio_is_patched = 0;
2942		if (dev_state->state->print_mask &
2943		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2944			printk(KERN_INFO
2945			       "submit_bio(rw=0x%x, bi_vcnt=%u,"
2946			       " bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
2947			       rw, bio->bi_vcnt,
2948			       (unsigned long long)bio->bi_iter.bi_sector,
2949			       dev_bytenr, bio->bi_bdev);
2950
2951		mapped_datav = kmalloc_array(bio->bi_vcnt,
2952					     sizeof(*mapped_datav), GFP_NOFS);
2953		if (!mapped_datav)
2954			goto leave;
2955		cur_bytenr = dev_bytenr;
2956		for (i = 0; i < bio->bi_vcnt; i++) {
2957			BUG_ON(bio->bi_io_vec[i].bv_len != PAGE_SIZE);
2958			mapped_datav[i] = kmap(bio->bi_io_vec[i].bv_page);
2959			if (!mapped_datav[i]) {
2960				while (i > 0) {
2961					i--;
2962					kunmap(bio->bi_io_vec[i].bv_page);
2963				}
2964				kfree(mapped_datav);
2965				goto leave;
2966			}
2967			if (dev_state->state->print_mask &
2968			    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE)
2969				printk(KERN_INFO
2970				       "#%u: bytenr=%llu, len=%u, offset=%u\n",
2971				       i, cur_bytenr, bio->bi_io_vec[i].bv_len,
2972				       bio->bi_io_vec[i].bv_offset);
2973			cur_bytenr += bio->bi_io_vec[i].bv_len;
2974		}
2975		btrfsic_process_written_block(dev_state, dev_bytenr,
2976					      mapped_datav, bio->bi_vcnt,
2977					      bio, &bio_is_patched,
2978					      NULL, rw);
2979		while (i > 0) {
2980			i--;
2981			kunmap(bio->bi_io_vec[i].bv_page);
2982		}
2983		kfree(mapped_datav);
2984	} else if (NULL != dev_state && (rw & REQ_FLUSH)) {
2985		if (dev_state->state->print_mask &
2986		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2987			printk(KERN_INFO
2988			       "submit_bio(rw=0x%x FLUSH, bdev=%p)\n",
2989			       rw, bio->bi_bdev);
2990		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
2991			if ((dev_state->state->print_mask &
2992			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
2993			      BTRFSIC_PRINT_MASK_VERBOSE)))
2994				printk(KERN_INFO
2995				       "btrfsic_submit_bio(%s) with FLUSH"
2996				       " but dummy block already in use"
2997				       " (ignored)!\n",
2998				       dev_state->name);
2999		} else {
3000			struct btrfsic_block *const block =
3001				&dev_state->dummy_block_for_bio_bh_flush;
3002
3003			block->is_iodone = 0;
3004			block->never_written = 0;
3005			block->iodone_w_error = 0;
3006			block->flush_gen = dev_state->last_flush_gen + 1;
3007			block->submit_bio_bh_rw = rw;
3008			block->orig_bio_bh_private = bio->bi_private;
3009			block->orig_bio_bh_end_io.bio = bio->bi_end_io;
3010			block->next_in_same_bio = NULL;
3011			bio->bi_private = block;
3012			bio->bi_end_io = btrfsic_bio_end_io;
3013		}
3014	}
3015leave:
3016	mutex_unlock(&btrfsic_mutex);
3017}
3018
3019void btrfsic_submit_bio(int rw, struct bio *bio)
3020{
3021	__btrfsic_submit_bio(rw, bio);
3022	submit_bio(rw, bio);
3023}
3024
3025int btrfsic_submit_bio_wait(int rw, struct bio *bio)
3026{
3027	__btrfsic_submit_bio(rw, bio);
3028	return submit_bio_wait(rw, bio);
3029}
3030
3031int btrfsic_mount(struct btrfs_root *root,
3032		  struct btrfs_fs_devices *fs_devices,
3033		  int including_extent_data, u32 print_mask)
3034{
3035	int ret;
3036	struct btrfsic_state *state;
3037	struct list_head *dev_head = &fs_devices->devices;
3038	struct btrfs_device *device;
3039
3040	if (root->nodesize & ((u64)PAGE_SIZE - 1)) {
3041		printk(KERN_INFO
3042		       "btrfsic: cannot handle nodesize %d not being a multiple of PAGE_SIZE %ld!\n",
3043		       root->nodesize, PAGE_SIZE);
3044		return -1;
3045	}
3046	if (root->sectorsize & ((u64)PAGE_SIZE - 1)) {
3047		printk(KERN_INFO
3048		       "btrfsic: cannot handle sectorsize %d not being a multiple of PAGE_SIZE %ld!\n",
3049		       root->sectorsize, PAGE_SIZE);
3050		return -1;
3051	}
3052	state = kzalloc(sizeof(*state), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
3053	if (!state) {
3054		state = vzalloc(sizeof(*state));
3055		if (!state) {
3056			printk(KERN_INFO "btrfs check-integrity: vzalloc() failed!\n");
3057			return -1;
3058		}
3059	}
3060
3061	if (!btrfsic_is_initialized) {
3062		mutex_init(&btrfsic_mutex);
3063		btrfsic_dev_state_hashtable_init(&btrfsic_dev_state_hashtable);
3064		btrfsic_is_initialized = 1;
3065	}
3066	mutex_lock(&btrfsic_mutex);
3067	state->root = root;
3068	state->print_mask = print_mask;
3069	state->include_extent_data = including_extent_data;
3070	state->csum_size = 0;
3071	state->metablock_size = root->nodesize;
3072	state->datablock_size = root->sectorsize;
3073	INIT_LIST_HEAD(&state->all_blocks_list);
3074	btrfsic_block_hashtable_init(&state->block_hashtable);
3075	btrfsic_block_link_hashtable_init(&state->block_link_hashtable);
3076	state->max_superblock_generation = 0;
3077	state->latest_superblock = NULL;
3078
3079	list_for_each_entry(device, dev_head, dev_list) {
3080		struct btrfsic_dev_state *ds;
3081		const char *p;
3082
3083		if (!device->bdev || !device->name)
3084			continue;
3085
3086		ds = btrfsic_dev_state_alloc();
3087		if (NULL == ds) {
3088			printk(KERN_INFO
3089			       "btrfs check-integrity: kmalloc() failed!\n");
3090			mutex_unlock(&btrfsic_mutex);
3091			return -1;
3092		}
3093		ds->bdev = device->bdev;
3094		ds->state = state;
3095		bdevname(ds->bdev, ds->name);
3096		ds->name[BDEVNAME_SIZE - 1] = '\0';
3097		p = kbasename(ds->name);
3098		strlcpy(ds->name, p, sizeof(ds->name));
3099		btrfsic_dev_state_hashtable_add(ds,
3100						&btrfsic_dev_state_hashtable);
3101	}
3102
3103	ret = btrfsic_process_superblock(state, fs_devices);
3104	if (0 != ret) {
3105		mutex_unlock(&btrfsic_mutex);
3106		btrfsic_unmount(root, fs_devices);
3107		return ret;
3108	}
3109
3110	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_DATABASE)
3111		btrfsic_dump_database(state);
3112	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_TREE)
3113		btrfsic_dump_tree(state);
3114
3115	mutex_unlock(&btrfsic_mutex);
3116	return 0;
3117}
3118
3119void btrfsic_unmount(struct btrfs_root *root,
3120		     struct btrfs_fs_devices *fs_devices)
3121{
3122	struct btrfsic_block *b_all, *tmp_all;
3123	struct btrfsic_state *state;
3124	struct list_head *dev_head = &fs_devices->devices;
3125	struct btrfs_device *device;
3126
3127	if (!btrfsic_is_initialized)
3128		return;
3129
3130	mutex_lock(&btrfsic_mutex);
3131
3132	state = NULL;
3133	list_for_each_entry(device, dev_head, dev_list) {
3134		struct btrfsic_dev_state *ds;
3135
3136		if (!device->bdev || !device->name)
3137			continue;
3138
3139		ds = btrfsic_dev_state_hashtable_lookup(
3140				device->bdev,
3141				&btrfsic_dev_state_hashtable);
3142		if (NULL != ds) {
3143			state = ds->state;
3144			btrfsic_dev_state_hashtable_remove(ds);
3145			btrfsic_dev_state_free(ds);
3146		}
3147	}
3148
3149	if (NULL == state) {
3150		printk(KERN_INFO
3151		       "btrfsic: error, cannot find state information"
3152		       " on umount!\n");
3153		mutex_unlock(&btrfsic_mutex);
3154		return;
3155	}
3156
3157	/*
3158	 * Don't care about keeping the lists' state up to date,
3159	 * just free all memory that was allocated dynamically.
3160	 * Free the blocks and the block_links.
3161	 */
3162	list_for_each_entry_safe(b_all, tmp_all, &state->all_blocks_list,
3163				 all_blocks_node) {
3164		struct btrfsic_block_link *l, *tmp;
3165
3166		list_for_each_entry_safe(l, tmp, &b_all->ref_to_list,
3167					 node_ref_to) {
3168			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
3169				btrfsic_print_rem_link(state, l);
3170
3171			l->ref_cnt--;
3172			if (0 == l->ref_cnt)
3173				btrfsic_block_link_free(l);
3174		}
3175
3176		if (b_all->is_iodone || b_all->never_written)
3177			btrfsic_block_free(b_all);
3178		else
3179			printk(KERN_INFO "btrfs: attempt to free %c-block"
3180			       " @%llu (%s/%llu/%d) on umount which is"
3181			       " not yet iodone!\n",
3182			       btrfsic_get_block_type(state, b_all),
3183			       b_all->logical_bytenr, b_all->dev_state->name,
3184			       b_all->dev_bytenr, b_all->mirror_num);
3185	}
3186
3187	mutex_unlock(&btrfsic_mutex);
3188
3189	kvfree(state);
3190}