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 "ctree.h"
99#include "disk-io.h"
100#include "hash.h"
101#include "transaction.h"
102#include "extent_io.h"
103#include "volumes.h"
104#include "print-tree.h"
105#include "locking.h"
106#include "check-integrity.h"
107#include "rcu-string.h"
108
109#define BTRFSIC_BLOCK_HASHTABLE_SIZE 0x10000
110#define BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE 0x10000
111#define BTRFSIC_DEV2STATE_HASHTABLE_SIZE 0x100
112#define BTRFSIC_BLOCK_MAGIC_NUMBER 0x14491051
113#define BTRFSIC_BLOCK_LINK_MAGIC_NUMBER 0x11070807
114#define BTRFSIC_DEV2STATE_MAGIC_NUMBER 0x20111530
115#define BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER 20111300
116#define BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL (200 - 6)	/* in characters,
117							 * excluding " [...]" */
118#define BTRFSIC_GENERATION_UNKNOWN ((u64)-1)
119
120/*
121 * The definition of the bitmask fields for the print_mask.
122 * They are specified with the mount option check_integrity_print_mask.
123 */
124#define BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE			0x00000001
125#define BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION		0x00000002
126#define BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE			0x00000004
127#define BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE			0x00000008
128#define BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH			0x00000010
129#define BTRFSIC_PRINT_MASK_END_IO_BIO_BH			0x00000020
130#define BTRFSIC_PRINT_MASK_VERBOSE				0x00000040
131#define BTRFSIC_PRINT_MASK_VERY_VERBOSE				0x00000080
132#define BTRFSIC_PRINT_MASK_INITIAL_TREE				0x00000100
133#define BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES			0x00000200
134#define BTRFSIC_PRINT_MASK_INITIAL_DATABASE			0x00000400
135#define BTRFSIC_PRINT_MASK_NUM_COPIES				0x00000800
136#define BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS		0x00001000
137#define BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE		0x00002000
138
139struct btrfsic_dev_state;
140struct btrfsic_state;
141
142struct btrfsic_block {
143	u32 magic_num;		/* only used for debug purposes */
144	unsigned int is_metadata:1;	/* if it is meta-data, not data-data */
145	unsigned int is_superblock:1;	/* if it is one of the superblocks */
146	unsigned int is_iodone:1;	/* if is done by lower subsystem */
147	unsigned int iodone_w_error:1;	/* error was indicated to endio */
148	unsigned int never_written:1;	/* block was added because it was
149					 * referenced, not because it was
150					 * written */
151	unsigned int mirror_num;	/* large enough to hold
152					 * BTRFS_SUPER_MIRROR_MAX */
153	struct btrfsic_dev_state *dev_state;
154	u64 dev_bytenr;		/* key, physical byte num on disk */
155	u64 logical_bytenr;	/* logical byte num on disk */
156	u64 generation;
157	struct btrfs_disk_key disk_key;	/* extra info to print in case of
158					 * issues, will not always be correct */
159	struct list_head collision_resolving_node;	/* list node */
160	struct list_head all_blocks_node;	/* list node */
161
162	/* the following two lists contain block_link items */
163	struct list_head ref_to_list;	/* list */
164	struct list_head ref_from_list;	/* list */
165	struct btrfsic_block *next_in_same_bio;
166	void *orig_bio_bh_private;
167	union {
168		bio_end_io_t *bio;
169		bh_end_io_t *bh;
170	} orig_bio_bh_end_io;
171	int submit_bio_bh_rw;
172	u64 flush_gen; /* only valid if !never_written */
173};
174
175/*
176 * Elements of this type are allocated dynamically and required because
177 * each block object can refer to and can be ref from multiple blocks.
178 * The key to lookup them in the hashtable is the dev_bytenr of
179 * the block ref to plus the one from the block refered from.
180 * The fact that they are searchable via a hashtable and that a
181 * ref_cnt is maintained is not required for the btrfs integrity
182 * check algorithm itself, it is only used to make the output more
183 * beautiful in case that an error is detected (an error is defined
184 * as a write operation to a block while that block is still referenced).
185 */
186struct btrfsic_block_link {
187	u32 magic_num;		/* only used for debug purposes */
188	u32 ref_cnt;
189	struct list_head node_ref_to;	/* list node */
190	struct list_head node_ref_from;	/* list node */
191	struct list_head collision_resolving_node;	/* list node */
192	struct btrfsic_block *block_ref_to;
193	struct btrfsic_block *block_ref_from;
194	u64 parent_generation;
195};
196
197struct btrfsic_dev_state {
198	u32 magic_num;		/* only used for debug purposes */
199	struct block_device *bdev;
200	struct btrfsic_state *state;
201	struct list_head collision_resolving_node;	/* list node */
202	struct btrfsic_block dummy_block_for_bio_bh_flush;
203	u64 last_flush_gen;
204	char name[BDEVNAME_SIZE];
205};
206
207struct btrfsic_block_hashtable {
208	struct list_head table[BTRFSIC_BLOCK_HASHTABLE_SIZE];
209};
210
211struct btrfsic_block_link_hashtable {
212	struct list_head table[BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE];
213};
214
215struct btrfsic_dev_state_hashtable {
216	struct list_head table[BTRFSIC_DEV2STATE_HASHTABLE_SIZE];
217};
218
219struct btrfsic_block_data_ctx {
220	u64 start;		/* virtual bytenr */
221	u64 dev_bytenr;		/* physical bytenr on device */
222	u32 len;
223	struct btrfsic_dev_state *dev;
224	char **datav;
225	struct page **pagev;
226	void *mem_to_free;
227};
228
229/* This structure is used to implement recursion without occupying
230 * any stack space, refer to btrfsic_process_metablock() */
231struct btrfsic_stack_frame {
232	u32 magic;
233	u32 nr;
234	int error;
235	int i;
236	int limit_nesting;
237	int num_copies;
238	int mirror_num;
239	struct btrfsic_block *block;
240	struct btrfsic_block_data_ctx *block_ctx;
241	struct btrfsic_block *next_block;
242	struct btrfsic_block_data_ctx next_block_ctx;
243	struct btrfs_header *hdr;
244	struct btrfsic_stack_frame *prev;
245};
246
247/* Some state per mounted filesystem */
248struct btrfsic_state {
249	u32 print_mask;
250	int include_extent_data;
251	int csum_size;
252	struct list_head all_blocks_list;
253	struct btrfsic_block_hashtable block_hashtable;
254	struct btrfsic_block_link_hashtable block_link_hashtable;
255	struct btrfs_root *root;
256	u64 max_superblock_generation;
257	struct btrfsic_block *latest_superblock;
258	u32 metablock_size;
259	u32 datablock_size;
260};
261
262static void btrfsic_block_init(struct btrfsic_block *b);
263static struct btrfsic_block *btrfsic_block_alloc(void);
264static void btrfsic_block_free(struct btrfsic_block *b);
265static void btrfsic_block_link_init(struct btrfsic_block_link *n);
266static struct btrfsic_block_link *btrfsic_block_link_alloc(void);
267static void btrfsic_block_link_free(struct btrfsic_block_link *n);
268static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds);
269static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void);
270static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds);
271static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h);
272static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
273					struct btrfsic_block_hashtable *h);
274static void btrfsic_block_hashtable_remove(struct btrfsic_block *b);
275static struct btrfsic_block *btrfsic_block_hashtable_lookup(
276		struct block_device *bdev,
277		u64 dev_bytenr,
278		struct btrfsic_block_hashtable *h);
279static void btrfsic_block_link_hashtable_init(
280		struct btrfsic_block_link_hashtable *h);
281static void btrfsic_block_link_hashtable_add(
282		struct btrfsic_block_link *l,
283		struct btrfsic_block_link_hashtable *h);
284static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l);
285static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
286		struct block_device *bdev_ref_to,
287		u64 dev_bytenr_ref_to,
288		struct block_device *bdev_ref_from,
289		u64 dev_bytenr_ref_from,
290		struct btrfsic_block_link_hashtable *h);
291static void btrfsic_dev_state_hashtable_init(
292		struct btrfsic_dev_state_hashtable *h);
293static void btrfsic_dev_state_hashtable_add(
294		struct btrfsic_dev_state *ds,
295		struct btrfsic_dev_state_hashtable *h);
296static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds);
297static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(
298		struct block_device *bdev,
299		struct btrfsic_dev_state_hashtable *h);
300static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void);
301static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf);
302static int btrfsic_process_superblock(struct btrfsic_state *state,
303				      struct btrfs_fs_devices *fs_devices);
304static int btrfsic_process_metablock(struct btrfsic_state *state,
305				     struct btrfsic_block *block,
306				     struct btrfsic_block_data_ctx *block_ctx,
307				     int limit_nesting, int force_iodone_flag);
308static void btrfsic_read_from_block_data(
309	struct btrfsic_block_data_ctx *block_ctx,
310	void *dst, u32 offset, size_t len);
311static int btrfsic_create_link_to_next_block(
312		struct btrfsic_state *state,
313		struct btrfsic_block *block,
314		struct btrfsic_block_data_ctx
315		*block_ctx, u64 next_bytenr,
316		int limit_nesting,
317		struct btrfsic_block_data_ctx *next_block_ctx,
318		struct btrfsic_block **next_blockp,
319		int force_iodone_flag,
320		int *num_copiesp, int *mirror_nump,
321		struct btrfs_disk_key *disk_key,
322		u64 parent_generation);
323static int btrfsic_handle_extent_data(struct btrfsic_state *state,
324				      struct btrfsic_block *block,
325				      struct btrfsic_block_data_ctx *block_ctx,
326				      u32 item_offset, int force_iodone_flag);
327static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
328			     struct btrfsic_block_data_ctx *block_ctx_out,
329			     int mirror_num);
330static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx);
331static int btrfsic_read_block(struct btrfsic_state *state,
332			      struct btrfsic_block_data_ctx *block_ctx);
333static void btrfsic_dump_database(struct btrfsic_state *state);
334static int btrfsic_test_for_metadata(struct btrfsic_state *state,
335				     char **datav, unsigned int num_pages);
336static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
337					  u64 dev_bytenr, char **mapped_datav,
338					  unsigned int num_pages,
339					  struct bio *bio, int *bio_is_patched,
340					  struct buffer_head *bh,
341					  int submit_bio_bh_rw);
342static int btrfsic_process_written_superblock(
343		struct btrfsic_state *state,
344		struct btrfsic_block *const block,
345		struct btrfs_super_block *const super_hdr);
346static void btrfsic_bio_end_io(struct bio *bp, int bio_error_status);
347static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate);
348static int btrfsic_is_block_ref_by_superblock(const struct btrfsic_state *state,
349					      const struct btrfsic_block *block,
350					      int recursion_level);
351static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
352					struct btrfsic_block *const block,
353					int recursion_level);
354static void btrfsic_print_add_link(const struct btrfsic_state *state,
355				   const struct btrfsic_block_link *l);
356static void btrfsic_print_rem_link(const struct btrfsic_state *state,
357				   const struct btrfsic_block_link *l);
358static char btrfsic_get_block_type(const struct btrfsic_state *state,
359				   const struct btrfsic_block *block);
360static void btrfsic_dump_tree(const struct btrfsic_state *state);
361static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
362				  const struct btrfsic_block *block,
363				  int indent_level);
364static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
365		struct btrfsic_state *state,
366		struct btrfsic_block_data_ctx *next_block_ctx,
367		struct btrfsic_block *next_block,
368		struct btrfsic_block *from_block,
369		u64 parent_generation);
370static struct btrfsic_block *btrfsic_block_lookup_or_add(
371		struct btrfsic_state *state,
372		struct btrfsic_block_data_ctx *block_ctx,
373		const char *additional_string,
374		int is_metadata,
375		int is_iodone,
376		int never_written,
377		int mirror_num,
378		int *was_created);
379static int btrfsic_process_superblock_dev_mirror(
380		struct btrfsic_state *state,
381		struct btrfsic_dev_state *dev_state,
382		struct btrfs_device *device,
383		int superblock_mirror_num,
384		struct btrfsic_dev_state **selected_dev_state,
385		struct btrfs_super_block *selected_super);
386static struct btrfsic_dev_state *btrfsic_dev_state_lookup(
387		struct block_device *bdev);
388static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
389					   u64 bytenr,
390					   struct btrfsic_dev_state *dev_state,
391					   u64 dev_bytenr);
392
393static struct mutex btrfsic_mutex;
394static int btrfsic_is_initialized;
395static struct btrfsic_dev_state_hashtable btrfsic_dev_state_hashtable;
396
397
398static void btrfsic_block_init(struct btrfsic_block *b)
399{
400	b->magic_num = BTRFSIC_BLOCK_MAGIC_NUMBER;
401	b->dev_state = NULL;
402	b->dev_bytenr = 0;
403	b->logical_bytenr = 0;
404	b->generation = BTRFSIC_GENERATION_UNKNOWN;
405	b->disk_key.objectid = 0;
406	b->disk_key.type = 0;
407	b->disk_key.offset = 0;
408	b->is_metadata = 0;
409	b->is_superblock = 0;
410	b->is_iodone = 0;
411	b->iodone_w_error = 0;
412	b->never_written = 0;
413	b->mirror_num = 0;
414	b->next_in_same_bio = NULL;
415	b->orig_bio_bh_private = NULL;
416	b->orig_bio_bh_end_io.bio = NULL;
417	INIT_LIST_HEAD(&b->collision_resolving_node);
418	INIT_LIST_HEAD(&b->all_blocks_node);
419	INIT_LIST_HEAD(&b->ref_to_list);
420	INIT_LIST_HEAD(&b->ref_from_list);
421	b->submit_bio_bh_rw = 0;
422	b->flush_gen = 0;
423}
424
425static struct btrfsic_block *btrfsic_block_alloc(void)
426{
427	struct btrfsic_block *b;
428
429	b = kzalloc(sizeof(*b), GFP_NOFS);
430	if (NULL != b)
431		btrfsic_block_init(b);
432
433	return b;
434}
435
436static void btrfsic_block_free(struct btrfsic_block *b)
437{
438	BUG_ON(!(NULL == b || BTRFSIC_BLOCK_MAGIC_NUMBER == b->magic_num));
439	kfree(b);
440}
441
442static void btrfsic_block_link_init(struct btrfsic_block_link *l)
443{
444	l->magic_num = BTRFSIC_BLOCK_LINK_MAGIC_NUMBER;
445	l->ref_cnt = 1;
446	INIT_LIST_HEAD(&l->node_ref_to);
447	INIT_LIST_HEAD(&l->node_ref_from);
448	INIT_LIST_HEAD(&l->collision_resolving_node);
449	l->block_ref_to = NULL;
450	l->block_ref_from = NULL;
451}
452
453static struct btrfsic_block_link *btrfsic_block_link_alloc(void)
454{
455	struct btrfsic_block_link *l;
456
457	l = kzalloc(sizeof(*l), GFP_NOFS);
458	if (NULL != l)
459		btrfsic_block_link_init(l);
460
461	return l;
462}
463
464static void btrfsic_block_link_free(struct btrfsic_block_link *l)
465{
466	BUG_ON(!(NULL == l || BTRFSIC_BLOCK_LINK_MAGIC_NUMBER == l->magic_num));
467	kfree(l);
468}
469
470static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds)
471{
472	ds->magic_num = BTRFSIC_DEV2STATE_MAGIC_NUMBER;
473	ds->bdev = NULL;
474	ds->state = NULL;
475	ds->name[0] = '\0';
476	INIT_LIST_HEAD(&ds->collision_resolving_node);
477	ds->last_flush_gen = 0;
478	btrfsic_block_init(&ds->dummy_block_for_bio_bh_flush);
479	ds->dummy_block_for_bio_bh_flush.is_iodone = 1;
480	ds->dummy_block_for_bio_bh_flush.dev_state = ds;
481}
482
483static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void)
484{
485	struct btrfsic_dev_state *ds;
486
487	ds = kzalloc(sizeof(*ds), GFP_NOFS);
488	if (NULL != ds)
489		btrfsic_dev_state_init(ds);
490
491	return ds;
492}
493
494static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds)
495{
496	BUG_ON(!(NULL == ds ||
497		 BTRFSIC_DEV2STATE_MAGIC_NUMBER == ds->magic_num));
498	kfree(ds);
499}
500
501static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h)
502{
503	int i;
504
505	for (i = 0; i < BTRFSIC_BLOCK_HASHTABLE_SIZE; i++)
506		INIT_LIST_HEAD(h->table + i);
507}
508
509static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
510					struct btrfsic_block_hashtable *h)
511{
512	const unsigned int hashval =
513	    (((unsigned int)(b->dev_bytenr >> 16)) ^
514	     ((unsigned int)((uintptr_t)b->dev_state->bdev))) &
515	     (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
516
517	list_add(&b->collision_resolving_node, h->table + hashval);
518}
519
520static void btrfsic_block_hashtable_remove(struct btrfsic_block *b)
521{
522	list_del(&b->collision_resolving_node);
523}
524
525static struct btrfsic_block *btrfsic_block_hashtable_lookup(
526		struct block_device *bdev,
527		u64 dev_bytenr,
528		struct btrfsic_block_hashtable *h)
529{
530	const unsigned int hashval =
531	    (((unsigned int)(dev_bytenr >> 16)) ^
532	     ((unsigned int)((uintptr_t)bdev))) &
533	     (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
534	struct list_head *elem;
535
536	list_for_each(elem, h->table + hashval) {
537		struct btrfsic_block *const b =
538		    list_entry(elem, struct btrfsic_block,
539			       collision_resolving_node);
540
541		if (b->dev_state->bdev == bdev && b->dev_bytenr == dev_bytenr)
542			return b;
543	}
544
545	return NULL;
546}
547
548static void btrfsic_block_link_hashtable_init(
549		struct btrfsic_block_link_hashtable *h)
550{
551	int i;
552
553	for (i = 0; i < BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE; i++)
554		INIT_LIST_HEAD(h->table + i);
555}
556
557static void btrfsic_block_link_hashtable_add(
558		struct btrfsic_block_link *l,
559		struct btrfsic_block_link_hashtable *h)
560{
561	const unsigned int hashval =
562	    (((unsigned int)(l->block_ref_to->dev_bytenr >> 16)) ^
563	     ((unsigned int)(l->block_ref_from->dev_bytenr >> 16)) ^
564	     ((unsigned int)((uintptr_t)l->block_ref_to->dev_state->bdev)) ^
565	     ((unsigned int)((uintptr_t)l->block_ref_from->dev_state->bdev)))
566	     & (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
567
568	BUG_ON(NULL == l->block_ref_to);
569	BUG_ON(NULL == l->block_ref_from);
570	list_add(&l->collision_resolving_node, h->table + hashval);
571}
572
573static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l)
574{
575	list_del(&l->collision_resolving_node);
576}
577
578static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
579		struct block_device *bdev_ref_to,
580		u64 dev_bytenr_ref_to,
581		struct block_device *bdev_ref_from,
582		u64 dev_bytenr_ref_from,
583		struct btrfsic_block_link_hashtable *h)
584{
585	const unsigned int hashval =
586	    (((unsigned int)(dev_bytenr_ref_to >> 16)) ^
587	     ((unsigned int)(dev_bytenr_ref_from >> 16)) ^
588	     ((unsigned int)((uintptr_t)bdev_ref_to)) ^
589	     ((unsigned int)((uintptr_t)bdev_ref_from))) &
590	     (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
591	struct list_head *elem;
592
593	list_for_each(elem, h->table + hashval) {
594		struct btrfsic_block_link *const l =
595		    list_entry(elem, struct btrfsic_block_link,
596			       collision_resolving_node);
597
598		BUG_ON(NULL == l->block_ref_to);
599		BUG_ON(NULL == l->block_ref_from);
600		if (l->block_ref_to->dev_state->bdev == bdev_ref_to &&
601		    l->block_ref_to->dev_bytenr == dev_bytenr_ref_to &&
602		    l->block_ref_from->dev_state->bdev == bdev_ref_from &&
603		    l->block_ref_from->dev_bytenr == dev_bytenr_ref_from)
604			return l;
605	}
606
607	return NULL;
608}
609
610static void btrfsic_dev_state_hashtable_init(
611		struct btrfsic_dev_state_hashtable *h)
612{
613	int i;
614
615	for (i = 0; i < BTRFSIC_DEV2STATE_HASHTABLE_SIZE; i++)
616		INIT_LIST_HEAD(h->table + i);
617}
618
619static void btrfsic_dev_state_hashtable_add(
620		struct btrfsic_dev_state *ds,
621		struct btrfsic_dev_state_hashtable *h)
622{
623	const unsigned int hashval =
624	    (((unsigned int)((uintptr_t)ds->bdev)) &
625	     (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1));
626
627	list_add(&ds->collision_resolving_node, h->table + hashval);
628}
629
630static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds)
631{
632	list_del(&ds->collision_resolving_node);
633}
634
635static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(
636		struct block_device *bdev,
637		struct btrfsic_dev_state_hashtable *h)
638{
639	const unsigned int hashval =
640	    (((unsigned int)((uintptr_t)bdev)) &
641	     (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1));
642	struct list_head *elem;
643
644	list_for_each(elem, h->table + hashval) {
645		struct btrfsic_dev_state *const ds =
646		    list_entry(elem, struct btrfsic_dev_state,
647			       collision_resolving_node);
648
649		if (ds->bdev == bdev)
650			return ds;
651	}
652
653	return NULL;
654}
655
656static int btrfsic_process_superblock(struct btrfsic_state *state,
657				      struct btrfs_fs_devices *fs_devices)
658{
659	int ret = 0;
660	struct btrfs_super_block *selected_super;
661	struct list_head *dev_head = &fs_devices->devices;
662	struct btrfs_device *device;
663	struct btrfsic_dev_state *selected_dev_state = NULL;
664	int pass;
665
666	BUG_ON(NULL == state);
667	selected_super = kzalloc(sizeof(*selected_super), GFP_NOFS);
668	if (NULL == selected_super) {
669		printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
670		return -1;
671	}
672
673	list_for_each_entry(device, dev_head, dev_list) {
674		int i;
675		struct btrfsic_dev_state *dev_state;
676
677		if (!device->bdev || !device->name)
678			continue;
679
680		dev_state = btrfsic_dev_state_lookup(device->bdev);
681		BUG_ON(NULL == dev_state);
682		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
683			ret = btrfsic_process_superblock_dev_mirror(
684					state, dev_state, device, i,
685					&selected_dev_state, selected_super);
686			if (0 != ret && 0 == i) {
687				kfree(selected_super);
688				return ret;
689			}
690		}
691	}
692
693	if (NULL == state->latest_superblock) {
694		printk(KERN_INFO "btrfsic: no superblock found!\n");
695		kfree(selected_super);
696		return -1;
697	}
698
699	state->csum_size = btrfs_super_csum_size(selected_super);
700
701	for (pass = 0; pass < 3; pass++) {
702		int num_copies;
703		int mirror_num;
704		u64 next_bytenr;
705
706		switch (pass) {
707		case 0:
708			next_bytenr = btrfs_super_root(selected_super);
709			if (state->print_mask &
710			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
711				printk(KERN_INFO "root@%llu\n", next_bytenr);
712			break;
713		case 1:
714			next_bytenr = btrfs_super_chunk_root(selected_super);
715			if (state->print_mask &
716			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
717				printk(KERN_INFO "chunk@%llu\n", next_bytenr);
718			break;
719		case 2:
720			next_bytenr = btrfs_super_log_root(selected_super);
721			if (0 == next_bytenr)
722				continue;
723			if (state->print_mask &
724			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
725				printk(KERN_INFO "log@%llu\n", next_bytenr);
726			break;
727		}
728
729		num_copies =
730		    btrfs_num_copies(state->root->fs_info,
731				     next_bytenr, state->metablock_size);
732		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
733			printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
734			       next_bytenr, num_copies);
735
736		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
737			struct btrfsic_block *next_block;
738			struct btrfsic_block_data_ctx tmp_next_block_ctx;
739			struct btrfsic_block_link *l;
740
741			ret = btrfsic_map_block(state, next_bytenr,
742						state->metablock_size,
743						&tmp_next_block_ctx,
744						mirror_num);
745			if (ret) {
746				printk(KERN_INFO "btrfsic:"
747				       " btrfsic_map_block(root @%llu,"
748				       " mirror %d) failed!\n",
749				       next_bytenr, mirror_num);
750				kfree(selected_super);
751				return -1;
752			}
753
754			next_block = btrfsic_block_hashtable_lookup(
755					tmp_next_block_ctx.dev->bdev,
756					tmp_next_block_ctx.dev_bytenr,
757					&state->block_hashtable);
758			BUG_ON(NULL == next_block);
759
760			l = btrfsic_block_link_hashtable_lookup(
761					tmp_next_block_ctx.dev->bdev,
762					tmp_next_block_ctx.dev_bytenr,
763					state->latest_superblock->dev_state->
764					bdev,
765					state->latest_superblock->dev_bytenr,
766					&state->block_link_hashtable);
767			BUG_ON(NULL == l);
768
769			ret = btrfsic_read_block(state, &tmp_next_block_ctx);
770			if (ret < (int)PAGE_CACHE_SIZE) {
771				printk(KERN_INFO
772				       "btrfsic: read @logical %llu failed!\n",
773				       tmp_next_block_ctx.start);
774				btrfsic_release_block_ctx(&tmp_next_block_ctx);
775				kfree(selected_super);
776				return -1;
777			}
778
779			ret = btrfsic_process_metablock(state,
780							next_block,
781							&tmp_next_block_ctx,
782							BTRFS_MAX_LEVEL + 3, 1);
783			btrfsic_release_block_ctx(&tmp_next_block_ctx);
784		}
785	}
786
787	kfree(selected_super);
788	return ret;
789}
790
791static int btrfsic_process_superblock_dev_mirror(
792		struct btrfsic_state *state,
793		struct btrfsic_dev_state *dev_state,
794		struct btrfs_device *device,
795		int superblock_mirror_num,
796		struct btrfsic_dev_state **selected_dev_state,
797		struct btrfs_super_block *selected_super)
798{
799	struct btrfs_super_block *super_tmp;
800	u64 dev_bytenr;
801	struct buffer_head *bh;
802	struct btrfsic_block *superblock_tmp;
803	int pass;
804	struct block_device *const superblock_bdev = device->bdev;
805
806	/* super block bytenr is always the unmapped device bytenr */
807	dev_bytenr = btrfs_sb_offset(superblock_mirror_num);
808	if (dev_bytenr + BTRFS_SUPER_INFO_SIZE > device->commit_total_bytes)
809		return -1;
810	bh = __bread(superblock_bdev, dev_bytenr / 4096,
811		     BTRFS_SUPER_INFO_SIZE);
812	if (NULL == bh)
813		return -1;
814	super_tmp = (struct btrfs_super_block *)
815	    (bh->b_data + (dev_bytenr & 4095));
816
817	if (btrfs_super_bytenr(super_tmp) != dev_bytenr ||
818	    btrfs_super_magic(super_tmp) != BTRFS_MAGIC ||
819	    memcmp(device->uuid, super_tmp->dev_item.uuid, BTRFS_UUID_SIZE) ||
820	    btrfs_super_nodesize(super_tmp) != state->metablock_size ||
821	    btrfs_super_sectorsize(super_tmp) != state->datablock_size) {
822		brelse(bh);
823		return 0;
824	}
825
826	superblock_tmp =
827	    btrfsic_block_hashtable_lookup(superblock_bdev,
828					   dev_bytenr,
829					   &state->block_hashtable);
830	if (NULL == superblock_tmp) {
831		superblock_tmp = btrfsic_block_alloc();
832		if (NULL == superblock_tmp) {
833			printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
834			brelse(bh);
835			return -1;
836		}
837		/* for superblock, only the dev_bytenr makes sense */
838		superblock_tmp->dev_bytenr = dev_bytenr;
839		superblock_tmp->dev_state = dev_state;
840		superblock_tmp->logical_bytenr = dev_bytenr;
841		superblock_tmp->generation = btrfs_super_generation(super_tmp);
842		superblock_tmp->is_metadata = 1;
843		superblock_tmp->is_superblock = 1;
844		superblock_tmp->is_iodone = 1;
845		superblock_tmp->never_written = 0;
846		superblock_tmp->mirror_num = 1 + superblock_mirror_num;
847		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
848			printk_in_rcu(KERN_INFO "New initial S-block (bdev %p, %s)"
849				     " @%llu (%s/%llu/%d)\n",
850				     superblock_bdev,
851				     rcu_str_deref(device->name), dev_bytenr,
852				     dev_state->name, dev_bytenr,
853				     superblock_mirror_num);
854		list_add(&superblock_tmp->all_blocks_node,
855			 &state->all_blocks_list);
856		btrfsic_block_hashtable_add(superblock_tmp,
857					    &state->block_hashtable);
858	}
859
860	/* select the one with the highest generation field */
861	if (btrfs_super_generation(super_tmp) >
862	    state->max_superblock_generation ||
863	    0 == state->max_superblock_generation) {
864		memcpy(selected_super, super_tmp, sizeof(*selected_super));
865		*selected_dev_state = dev_state;
866		state->max_superblock_generation =
867		    btrfs_super_generation(super_tmp);
868		state->latest_superblock = superblock_tmp;
869	}
870
871	for (pass = 0; pass < 3; pass++) {
872		u64 next_bytenr;
873		int num_copies;
874		int mirror_num;
875		const char *additional_string = NULL;
876		struct btrfs_disk_key tmp_disk_key;
877
878		tmp_disk_key.type = BTRFS_ROOT_ITEM_KEY;
879		tmp_disk_key.offset = 0;
880		switch (pass) {
881		case 0:
882			btrfs_set_disk_key_objectid(&tmp_disk_key,
883						    BTRFS_ROOT_TREE_OBJECTID);
884			additional_string = "initial root ";
885			next_bytenr = btrfs_super_root(super_tmp);
886			break;
887		case 1:
888			btrfs_set_disk_key_objectid(&tmp_disk_key,
889						    BTRFS_CHUNK_TREE_OBJECTID);
890			additional_string = "initial chunk ";
891			next_bytenr = btrfs_super_chunk_root(super_tmp);
892			break;
893		case 2:
894			btrfs_set_disk_key_objectid(&tmp_disk_key,
895						    BTRFS_TREE_LOG_OBJECTID);
896			additional_string = "initial log ";
897			next_bytenr = btrfs_super_log_root(super_tmp);
898			if (0 == next_bytenr)
899				continue;
900			break;
901		}
902
903		num_copies =
904		    btrfs_num_copies(state->root->fs_info,
905				     next_bytenr, state->metablock_size);
906		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
907			printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
908			       next_bytenr, num_copies);
909		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
910			struct btrfsic_block *next_block;
911			struct btrfsic_block_data_ctx tmp_next_block_ctx;
912			struct btrfsic_block_link *l;
913
914			if (btrfsic_map_block(state, next_bytenr,
915					      state->metablock_size,
916					      &tmp_next_block_ctx,
917					      mirror_num)) {
918				printk(KERN_INFO "btrfsic: btrfsic_map_block("
919				       "bytenr @%llu, mirror %d) failed!\n",
920				       next_bytenr, mirror_num);
921				brelse(bh);
922				return -1;
923			}
924
925			next_block = btrfsic_block_lookup_or_add(
926					state, &tmp_next_block_ctx,
927					additional_string, 1, 1, 0,
928					mirror_num, NULL);
929			if (NULL == next_block) {
930				btrfsic_release_block_ctx(&tmp_next_block_ctx);
931				brelse(bh);
932				return -1;
933			}
934
935			next_block->disk_key = tmp_disk_key;
936			next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
937			l = btrfsic_block_link_lookup_or_add(
938					state, &tmp_next_block_ctx,
939					next_block, superblock_tmp,
940					BTRFSIC_GENERATION_UNKNOWN);
941			btrfsic_release_block_ctx(&tmp_next_block_ctx);
942			if (NULL == l) {
943				brelse(bh);
944				return -1;
945			}
946		}
947	}
948	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES)
949		btrfsic_dump_tree_sub(state, superblock_tmp, 0);
950
951	brelse(bh);
952	return 0;
953}
954
955static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void)
956{
957	struct btrfsic_stack_frame *sf;
958
959	sf = kzalloc(sizeof(*sf), GFP_NOFS);
960	if (NULL == sf)
961		printk(KERN_INFO "btrfsic: alloc memory failed!\n");
962	else
963		sf->magic = BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER;
964	return sf;
965}
966
967static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf)
968{
969	BUG_ON(!(NULL == sf ||
970		 BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER == sf->magic));
971	kfree(sf);
972}
973
974static int btrfsic_process_metablock(
975		struct btrfsic_state *state,
976		struct btrfsic_block *const first_block,
977		struct btrfsic_block_data_ctx *const first_block_ctx,
978		int first_limit_nesting, int force_iodone_flag)
979{
980	struct btrfsic_stack_frame initial_stack_frame = { 0 };
981	struct btrfsic_stack_frame *sf;
982	struct btrfsic_stack_frame *next_stack;
983	struct btrfs_header *const first_hdr =
984		(struct btrfs_header *)first_block_ctx->datav[0];
985
986	BUG_ON(!first_hdr);
987	sf = &initial_stack_frame;
988	sf->error = 0;
989	sf->i = -1;
990	sf->limit_nesting = first_limit_nesting;
991	sf->block = first_block;
992	sf->block_ctx = first_block_ctx;
993	sf->next_block = NULL;
994	sf->hdr = first_hdr;
995	sf->prev = NULL;
996
997continue_with_new_stack_frame:
998	sf->block->generation = le64_to_cpu(sf->hdr->generation);
999	if (0 == sf->hdr->level) {
1000		struct btrfs_leaf *const leafhdr =
1001		    (struct btrfs_leaf *)sf->hdr;
1002
1003		if (-1 == sf->i) {
1004			sf->nr = btrfs_stack_header_nritems(&leafhdr->header);
1005
1006			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1007				printk(KERN_INFO
1008				       "leaf %llu items %d generation %llu"
1009				       " owner %llu\n",
1010				       sf->block_ctx->start, sf->nr,
1011				       btrfs_stack_header_generation(
1012					       &leafhdr->header),
1013				       btrfs_stack_header_owner(
1014					       &leafhdr->header));
1015		}
1016
1017continue_with_current_leaf_stack_frame:
1018		if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1019			sf->i++;
1020			sf->num_copies = 0;
1021		}
1022
1023		if (sf->i < sf->nr) {
1024			struct btrfs_item disk_item;
1025			u32 disk_item_offset =
1026				(uintptr_t)(leafhdr->items + sf->i) -
1027				(uintptr_t)leafhdr;
1028			struct btrfs_disk_key *disk_key;
1029			u8 type;
1030			u32 item_offset;
1031			u32 item_size;
1032
1033			if (disk_item_offset + sizeof(struct btrfs_item) >
1034			    sf->block_ctx->len) {
1035leaf_item_out_of_bounce_error:
1036				printk(KERN_INFO
1037				       "btrfsic: leaf item out of bounce at logical %llu, dev %s\n",
1038				       sf->block_ctx->start,
1039				       sf->block_ctx->dev->name);
1040				goto one_stack_frame_backwards;
1041			}
1042			btrfsic_read_from_block_data(sf->block_ctx,
1043						     &disk_item,
1044						     disk_item_offset,
1045						     sizeof(struct btrfs_item));
1046			item_offset = btrfs_stack_item_offset(&disk_item);
1047			item_size = btrfs_stack_item_size(&disk_item);
1048			disk_key = &disk_item.key;
1049			type = btrfs_disk_key_type(disk_key);
1050
1051			if (BTRFS_ROOT_ITEM_KEY == type) {
1052				struct btrfs_root_item root_item;
1053				u32 root_item_offset;
1054				u64 next_bytenr;
1055
1056				root_item_offset = item_offset +
1057					offsetof(struct btrfs_leaf, items);
1058				if (root_item_offset + item_size >
1059				    sf->block_ctx->len)
1060					goto leaf_item_out_of_bounce_error;
1061				btrfsic_read_from_block_data(
1062					sf->block_ctx, &root_item,
1063					root_item_offset,
1064					item_size);
1065				next_bytenr = btrfs_root_bytenr(&root_item);
1066
1067				sf->error =
1068				    btrfsic_create_link_to_next_block(
1069						state,
1070						sf->block,
1071						sf->block_ctx,
1072						next_bytenr,
1073						sf->limit_nesting,
1074						&sf->next_block_ctx,
1075						&sf->next_block,
1076						force_iodone_flag,
1077						&sf->num_copies,
1078						&sf->mirror_num,
1079						disk_key,
1080						btrfs_root_generation(
1081						&root_item));
1082				if (sf->error)
1083					goto one_stack_frame_backwards;
1084
1085				if (NULL != sf->next_block) {
1086					struct btrfs_header *const next_hdr =
1087					    (struct btrfs_header *)
1088					    sf->next_block_ctx.datav[0];
1089
1090					next_stack =
1091					    btrfsic_stack_frame_alloc();
1092					if (NULL == next_stack) {
1093						sf->error = -1;
1094						btrfsic_release_block_ctx(
1095								&sf->
1096								next_block_ctx);
1097						goto one_stack_frame_backwards;
1098					}
1099
1100					next_stack->i = -1;
1101					next_stack->block = sf->next_block;
1102					next_stack->block_ctx =
1103					    &sf->next_block_ctx;
1104					next_stack->next_block = NULL;
1105					next_stack->hdr = next_hdr;
1106					next_stack->limit_nesting =
1107					    sf->limit_nesting - 1;
1108					next_stack->prev = sf;
1109					sf = next_stack;
1110					goto continue_with_new_stack_frame;
1111				}
1112			} else if (BTRFS_EXTENT_DATA_KEY == type &&
1113				   state->include_extent_data) {
1114				sf->error = btrfsic_handle_extent_data(
1115						state,
1116						sf->block,
1117						sf->block_ctx,
1118						item_offset,
1119						force_iodone_flag);
1120				if (sf->error)
1121					goto one_stack_frame_backwards;
1122			}
1123
1124			goto continue_with_current_leaf_stack_frame;
1125		}
1126	} else {
1127		struct btrfs_node *const nodehdr = (struct btrfs_node *)sf->hdr;
1128
1129		if (-1 == sf->i) {
1130			sf->nr = btrfs_stack_header_nritems(&nodehdr->header);
1131
1132			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1133				printk(KERN_INFO "node %llu level %d items %d"
1134				       " generation %llu owner %llu\n",
1135				       sf->block_ctx->start,
1136				       nodehdr->header.level, sf->nr,
1137				       btrfs_stack_header_generation(
1138				       &nodehdr->header),
1139				       btrfs_stack_header_owner(
1140				       &nodehdr->header));
1141		}
1142
1143continue_with_current_node_stack_frame:
1144		if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1145			sf->i++;
1146			sf->num_copies = 0;
1147		}
1148
1149		if (sf->i < sf->nr) {
1150			struct btrfs_key_ptr key_ptr;
1151			u32 key_ptr_offset;
1152			u64 next_bytenr;
1153
1154			key_ptr_offset = (uintptr_t)(nodehdr->ptrs + sf->i) -
1155					  (uintptr_t)nodehdr;
1156			if (key_ptr_offset + sizeof(struct btrfs_key_ptr) >
1157			    sf->block_ctx->len) {
1158				printk(KERN_INFO
1159				       "btrfsic: node item out of bounce at logical %llu, dev %s\n",
1160				       sf->block_ctx->start,
1161				       sf->block_ctx->dev->name);
1162				goto one_stack_frame_backwards;
1163			}
1164			btrfsic_read_from_block_data(
1165				sf->block_ctx, &key_ptr, key_ptr_offset,
1166				sizeof(struct btrfs_key_ptr));
1167			next_bytenr = btrfs_stack_key_blockptr(&key_ptr);
1168
1169			sf->error = btrfsic_create_link_to_next_block(
1170					state,
1171					sf->block,
1172					sf->block_ctx,
1173					next_bytenr,
1174					sf->limit_nesting,
1175					&sf->next_block_ctx,
1176					&sf->next_block,
1177					force_iodone_flag,
1178					&sf->num_copies,
1179					&sf->mirror_num,
1180					&key_ptr.key,
1181					btrfs_stack_key_generation(&key_ptr));
1182			if (sf->error)
1183				goto one_stack_frame_backwards;
1184
1185			if (NULL != sf->next_block) {
1186				struct btrfs_header *const next_hdr =
1187				    (struct btrfs_header *)
1188				    sf->next_block_ctx.datav[0];
1189
1190				next_stack = btrfsic_stack_frame_alloc();
1191				if (NULL == next_stack) {
1192					sf->error = -1;
1193					goto one_stack_frame_backwards;
1194				}
1195
1196				next_stack->i = -1;
1197				next_stack->block = sf->next_block;
1198				next_stack->block_ctx = &sf->next_block_ctx;
1199				next_stack->next_block = NULL;
1200				next_stack->hdr = next_hdr;
1201				next_stack->limit_nesting =
1202				    sf->limit_nesting - 1;
1203				next_stack->prev = sf;
1204				sf = next_stack;
1205				goto continue_with_new_stack_frame;
1206			}
1207
1208			goto continue_with_current_node_stack_frame;
1209		}
1210	}
1211
1212one_stack_frame_backwards:
1213	if (NULL != sf->prev) {
1214		struct btrfsic_stack_frame *const prev = sf->prev;
1215
1216		/* the one for the initial block is freed in the caller */
1217		btrfsic_release_block_ctx(sf->block_ctx);
1218
1219		if (sf->error) {
1220			prev->error = sf->error;
1221			btrfsic_stack_frame_free(sf);
1222			sf = prev;
1223			goto one_stack_frame_backwards;
1224		}
1225
1226		btrfsic_stack_frame_free(sf);
1227		sf = prev;
1228		goto continue_with_new_stack_frame;
1229	} else {
1230		BUG_ON(&initial_stack_frame != sf);
1231	}
1232
1233	return sf->error;
1234}
1235
1236static void btrfsic_read_from_block_data(
1237	struct btrfsic_block_data_ctx *block_ctx,
1238	void *dstv, u32 offset, size_t len)
1239{
1240	size_t cur;
1241	size_t offset_in_page;
1242	char *kaddr;
1243	char *dst = (char *)dstv;
1244	size_t start_offset = block_ctx->start & ((u64)PAGE_CACHE_SIZE - 1);
1245	unsigned long i = (start_offset + offset) >> PAGE_CACHE_SHIFT;
1246
1247	WARN_ON(offset + len > block_ctx->len);
1248	offset_in_page = (start_offset + offset) & (PAGE_CACHE_SIZE - 1);
1249
1250	while (len > 0) {
1251		cur = min(len, ((size_t)PAGE_CACHE_SIZE - offset_in_page));
1252		BUG_ON(i >= DIV_ROUND_UP(block_ctx->len, PAGE_CACHE_SIZE));
1253		kaddr = block_ctx->datav[i];
1254		memcpy(dst, kaddr + offset_in_page, cur);
1255
1256		dst += cur;
1257		len -= cur;
1258		offset_in_page = 0;
1259		i++;
1260	}
1261}
1262
1263static int btrfsic_create_link_to_next_block(
1264		struct btrfsic_state *state,
1265		struct btrfsic_block *block,
1266		struct btrfsic_block_data_ctx *block_ctx,
1267		u64 next_bytenr,
1268		int limit_nesting,
1269		struct btrfsic_block_data_ctx *next_block_ctx,
1270		struct btrfsic_block **next_blockp,
1271		int force_iodone_flag,
1272		int *num_copiesp, int *mirror_nump,
1273		struct btrfs_disk_key *disk_key,
1274		u64 parent_generation)
1275{
1276	struct btrfsic_block *next_block = NULL;
1277	int ret;
1278	struct btrfsic_block_link *l;
1279	int did_alloc_block_link;
1280	int block_was_created;
1281
1282	*next_blockp = NULL;
1283	if (0 == *num_copiesp) {
1284		*num_copiesp =
1285		    btrfs_num_copies(state->root->fs_info,
1286				     next_bytenr, state->metablock_size);
1287		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1288			printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
1289			       next_bytenr, *num_copiesp);
1290		*mirror_nump = 1;
1291	}
1292
1293	if (*mirror_nump > *num_copiesp)
1294		return 0;
1295
1296	if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1297		printk(KERN_INFO
1298		       "btrfsic_create_link_to_next_block(mirror_num=%d)\n",
1299		       *mirror_nump);
1300	ret = btrfsic_map_block(state, next_bytenr,
1301				state->metablock_size,
1302				next_block_ctx, *mirror_nump);
1303	if (ret) {
1304		printk(KERN_INFO
1305		       "btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
1306		       next_bytenr, *mirror_nump);
1307		btrfsic_release_block_ctx(next_block_ctx);
1308		*next_blockp = NULL;
1309		return -1;
1310	}
1311
1312	next_block = btrfsic_block_lookup_or_add(state,
1313						 next_block_ctx, "referenced ",
1314						 1, force_iodone_flag,
1315						 !force_iodone_flag,
1316						 *mirror_nump,
1317						 &block_was_created);
1318	if (NULL == next_block) {
1319		btrfsic_release_block_ctx(next_block_ctx);
1320		*next_blockp = NULL;
1321		return -1;
1322	}
1323	if (block_was_created) {
1324		l = NULL;
1325		next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
1326	} else {
1327		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1328			if (next_block->logical_bytenr != next_bytenr &&
1329			    !(!next_block->is_metadata &&
1330			      0 == next_block->logical_bytenr))
1331				printk(KERN_INFO
1332				       "Referenced block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1333				       next_bytenr, next_block_ctx->dev->name,
1334				       next_block_ctx->dev_bytenr, *mirror_nump,
1335				       btrfsic_get_block_type(state,
1336							      next_block),
1337				       next_block->logical_bytenr);
1338			else
1339				printk(KERN_INFO
1340				       "Referenced block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1341				       next_bytenr, next_block_ctx->dev->name,
1342				       next_block_ctx->dev_bytenr, *mirror_nump,
1343				       btrfsic_get_block_type(state,
1344							      next_block));
1345		}
1346		next_block->logical_bytenr = next_bytenr;
1347
1348		next_block->mirror_num = *mirror_nump;
1349		l = btrfsic_block_link_hashtable_lookup(
1350				next_block_ctx->dev->bdev,
1351				next_block_ctx->dev_bytenr,
1352				block_ctx->dev->bdev,
1353				block_ctx->dev_bytenr,
1354				&state->block_link_hashtable);
1355	}
1356
1357	next_block->disk_key = *disk_key;
1358	if (NULL == l) {
1359		l = btrfsic_block_link_alloc();
1360		if (NULL == l) {
1361			printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
1362			btrfsic_release_block_ctx(next_block_ctx);
1363			*next_blockp = NULL;
1364			return -1;
1365		}
1366
1367		did_alloc_block_link = 1;
1368		l->block_ref_to = next_block;
1369		l->block_ref_from = block;
1370		l->ref_cnt = 1;
1371		l->parent_generation = parent_generation;
1372
1373		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1374			btrfsic_print_add_link(state, l);
1375
1376		list_add(&l->node_ref_to, &block->ref_to_list);
1377		list_add(&l->node_ref_from, &next_block->ref_from_list);
1378
1379		btrfsic_block_link_hashtable_add(l,
1380						 &state->block_link_hashtable);
1381	} else {
1382		did_alloc_block_link = 0;
1383		if (0 == limit_nesting) {
1384			l->ref_cnt++;
1385			l->parent_generation = parent_generation;
1386			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1387				btrfsic_print_add_link(state, l);
1388		}
1389	}
1390
1391	if (limit_nesting > 0 && did_alloc_block_link) {
1392		ret = btrfsic_read_block(state, next_block_ctx);
1393		if (ret < (int)next_block_ctx->len) {
1394			printk(KERN_INFO
1395			       "btrfsic: read block @logical %llu failed!\n",
1396			       next_bytenr);
1397			btrfsic_release_block_ctx(next_block_ctx);
1398			*next_blockp = NULL;
1399			return -1;
1400		}
1401
1402		*next_blockp = next_block;
1403	} else {
1404		*next_blockp = NULL;
1405	}
1406	(*mirror_nump)++;
1407
1408	return 0;
1409}
1410
1411static int btrfsic_handle_extent_data(
1412		struct btrfsic_state *state,
1413		struct btrfsic_block *block,
1414		struct btrfsic_block_data_ctx *block_ctx,
1415		u32 item_offset, int force_iodone_flag)
1416{
1417	int ret;
1418	struct btrfs_file_extent_item file_extent_item;
1419	u64 file_extent_item_offset;
1420	u64 next_bytenr;
1421	u64 num_bytes;
1422	u64 generation;
1423	struct btrfsic_block_link *l;
1424
1425	file_extent_item_offset = offsetof(struct btrfs_leaf, items) +
1426				  item_offset;
1427	if (file_extent_item_offset +
1428	    offsetof(struct btrfs_file_extent_item, disk_num_bytes) >
1429	    block_ctx->len) {
1430		printk(KERN_INFO
1431		       "btrfsic: file item out of bounce at logical %llu, dev %s\n",
1432		       block_ctx->start, block_ctx->dev->name);
1433		return -1;
1434	}
1435
1436	btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1437		file_extent_item_offset,
1438		offsetof(struct btrfs_file_extent_item, disk_num_bytes));
1439	if (BTRFS_FILE_EXTENT_REG != file_extent_item.type ||
1440	    btrfs_stack_file_extent_disk_bytenr(&file_extent_item) == 0) {
1441		if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1442			printk(KERN_INFO "extent_data: type %u, disk_bytenr = %llu\n",
1443			       file_extent_item.type,
1444			       btrfs_stack_file_extent_disk_bytenr(
1445			       &file_extent_item));
1446		return 0;
1447	}
1448
1449	if (file_extent_item_offset + sizeof(struct btrfs_file_extent_item) >
1450	    block_ctx->len) {
1451		printk(KERN_INFO
1452		       "btrfsic: file item out of bounce at logical %llu, dev %s\n",
1453		       block_ctx->start, block_ctx->dev->name);
1454		return -1;
1455	}
1456	btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1457				     file_extent_item_offset,
1458				     sizeof(struct btrfs_file_extent_item));
1459	next_bytenr = btrfs_stack_file_extent_disk_bytenr(&file_extent_item);
1460	if (btrfs_stack_file_extent_compression(&file_extent_item) ==
1461	    BTRFS_COMPRESS_NONE) {
1462		next_bytenr += btrfs_stack_file_extent_offset(&file_extent_item);
1463		num_bytes = btrfs_stack_file_extent_num_bytes(&file_extent_item);
1464	} else {
1465		num_bytes = btrfs_stack_file_extent_disk_num_bytes(&file_extent_item);
1466	}
1467	generation = btrfs_stack_file_extent_generation(&file_extent_item);
1468
1469	if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1470		printk(KERN_INFO "extent_data: type %u, disk_bytenr = %llu,"
1471		       " offset = %llu, num_bytes = %llu\n",
1472		       file_extent_item.type,
1473		       btrfs_stack_file_extent_disk_bytenr(&file_extent_item),
1474		       btrfs_stack_file_extent_offset(&file_extent_item),
1475		       num_bytes);
1476	while (num_bytes > 0) {
1477		u32 chunk_len;
1478		int num_copies;
1479		int mirror_num;
1480
1481		if (num_bytes > state->datablock_size)
1482			chunk_len = state->datablock_size;
1483		else
1484			chunk_len = num_bytes;
1485
1486		num_copies =
1487		    btrfs_num_copies(state->root->fs_info,
1488				     next_bytenr, state->datablock_size);
1489		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1490			printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
1491			       next_bytenr, num_copies);
1492		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
1493			struct btrfsic_block_data_ctx next_block_ctx;
1494			struct btrfsic_block *next_block;
1495			int block_was_created;
1496
1497			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1498				printk(KERN_INFO "btrfsic_handle_extent_data("
1499				       "mirror_num=%d)\n", mirror_num);
1500			if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1501				printk(KERN_INFO
1502				       "\tdisk_bytenr = %llu, num_bytes %u\n",
1503				       next_bytenr, chunk_len);
1504			ret = btrfsic_map_block(state, next_bytenr,
1505						chunk_len, &next_block_ctx,
1506						mirror_num);
1507			if (ret) {
1508				printk(KERN_INFO
1509				       "btrfsic: btrfsic_map_block(@%llu,"
1510				       " mirror=%d) failed!\n",
1511				       next_bytenr, mirror_num);
1512				return -1;
1513			}
1514
1515			next_block = btrfsic_block_lookup_or_add(
1516					state,
1517					&next_block_ctx,
1518					"referenced ",
1519					0,
1520					force_iodone_flag,
1521					!force_iodone_flag,
1522					mirror_num,
1523					&block_was_created);
1524			if (NULL == next_block) {
1525				printk(KERN_INFO
1526				       "btrfsic: error, kmalloc failed!\n");
1527				btrfsic_release_block_ctx(&next_block_ctx);
1528				return -1;
1529			}
1530			if (!block_was_created) {
1531				if ((state->print_mask &
1532				     BTRFSIC_PRINT_MASK_VERBOSE) &&
1533				    next_block->logical_bytenr != next_bytenr &&
1534				    !(!next_block->is_metadata &&
1535				      0 == next_block->logical_bytenr)) {
1536					printk(KERN_INFO
1537					       "Referenced block"
1538					       " @%llu (%s/%llu/%d)"
1539					       " found in hash table, D,"
1540					       " bytenr mismatch"
1541					       " (!= stored %llu).\n",
1542					       next_bytenr,
1543					       next_block_ctx.dev->name,
1544					       next_block_ctx.dev_bytenr,
1545					       mirror_num,
1546					       next_block->logical_bytenr);
1547				}
1548				next_block->logical_bytenr = next_bytenr;
1549				next_block->mirror_num = mirror_num;
1550			}
1551
1552			l = btrfsic_block_link_lookup_or_add(state,
1553							     &next_block_ctx,
1554							     next_block, block,
1555							     generation);
1556			btrfsic_release_block_ctx(&next_block_ctx);
1557			if (NULL == l)
1558				return -1;
1559		}
1560
1561		next_bytenr += chunk_len;
1562		num_bytes -= chunk_len;
1563	}
1564
1565	return 0;
1566}
1567
1568static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
1569			     struct btrfsic_block_data_ctx *block_ctx_out,
1570			     int mirror_num)
1571{
1572	int ret;
1573	u64 length;
1574	struct btrfs_bio *multi = NULL;
1575	struct btrfs_device *device;
1576
1577	length = len;
1578	ret = btrfs_map_block(state->root->fs_info, READ,
1579			      bytenr, &length, &multi, mirror_num);
1580
1581	if (ret) {
1582		block_ctx_out->start = 0;
1583		block_ctx_out->dev_bytenr = 0;
1584		block_ctx_out->len = 0;
1585		block_ctx_out->dev = NULL;
1586		block_ctx_out->datav = NULL;
1587		block_ctx_out->pagev = NULL;
1588		block_ctx_out->mem_to_free = NULL;
1589
1590		return ret;
1591	}
1592
1593	device = multi->stripes[0].dev;
1594	block_ctx_out->dev = btrfsic_dev_state_lookup(device->bdev);
1595	block_ctx_out->dev_bytenr = multi->stripes[0].physical;
1596	block_ctx_out->start = bytenr;
1597	block_ctx_out->len = len;
1598	block_ctx_out->datav = NULL;
1599	block_ctx_out->pagev = NULL;
1600	block_ctx_out->mem_to_free = NULL;
1601
1602	kfree(multi);
1603	if (NULL == block_ctx_out->dev) {
1604		ret = -ENXIO;
1605		printk(KERN_INFO "btrfsic: error, cannot lookup dev (#1)!\n");
1606	}
1607
1608	return ret;
1609}
1610
1611static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx)
1612{
1613	if (block_ctx->mem_to_free) {
1614		unsigned int num_pages;
1615
1616		BUG_ON(!block_ctx->datav);
1617		BUG_ON(!block_ctx->pagev);
1618		num_pages = (block_ctx->len + (u64)PAGE_CACHE_SIZE - 1) >>
1619			    PAGE_CACHE_SHIFT;
1620		while (num_pages > 0) {
1621			num_pages--;
1622			if (block_ctx->datav[num_pages]) {
1623				kunmap(block_ctx->pagev[num_pages]);
1624				block_ctx->datav[num_pages] = NULL;
1625			}
1626			if (block_ctx->pagev[num_pages]) {
1627				__free_page(block_ctx->pagev[num_pages]);
1628				block_ctx->pagev[num_pages] = NULL;
1629			}
1630		}
1631
1632		kfree(block_ctx->mem_to_free);
1633		block_ctx->mem_to_free = NULL;
1634		block_ctx->pagev = NULL;
1635		block_ctx->datav = NULL;
1636	}
1637}
1638
1639static int btrfsic_read_block(struct btrfsic_state *state,
1640			      struct btrfsic_block_data_ctx *block_ctx)
1641{
1642	unsigned int num_pages;
1643	unsigned int i;
1644	u64 dev_bytenr;
1645	int ret;
1646
1647	BUG_ON(block_ctx->datav);
1648	BUG_ON(block_ctx->pagev);
1649	BUG_ON(block_ctx->mem_to_free);
1650	if (block_ctx->dev_bytenr & ((u64)PAGE_CACHE_SIZE - 1)) {
1651		printk(KERN_INFO
1652		       "btrfsic: read_block() with unaligned bytenr %llu\n",
1653		       block_ctx->dev_bytenr);
1654		return -1;
1655	}
1656
1657	num_pages = (block_ctx->len + (u64)PAGE_CACHE_SIZE - 1) >>
1658		    PAGE_CACHE_SHIFT;
1659	block_ctx->mem_to_free = kzalloc((sizeof(*block_ctx->datav) +
1660					  sizeof(*block_ctx->pagev)) *
1661					 num_pages, GFP_NOFS);
1662	if (!block_ctx->mem_to_free)
1663		return -1;
1664	block_ctx->datav = block_ctx->mem_to_free;
1665	block_ctx->pagev = (struct page **)(block_ctx->datav + num_pages);
1666	for (i = 0; i < num_pages; i++) {
1667		block_ctx->pagev[i] = alloc_page(GFP_NOFS);
1668		if (!block_ctx->pagev[i])
1669			return -1;
1670	}
1671
1672	dev_bytenr = block_ctx->dev_bytenr;
1673	for (i = 0; i < num_pages;) {
1674		struct bio *bio;
1675		unsigned int j;
1676
1677		bio = btrfs_io_bio_alloc(GFP_NOFS, num_pages - i);
1678		if (!bio) {
1679			printk(KERN_INFO
1680			       "btrfsic: bio_alloc() for %u pages failed!\n",
1681			       num_pages - i);
1682			return -1;
1683		}
1684		bio->bi_bdev = block_ctx->dev->bdev;
1685		bio->bi_iter.bi_sector = dev_bytenr >> 9;
1686
1687		for (j = i; j < num_pages; j++) {
1688			ret = bio_add_page(bio, block_ctx->pagev[j],
1689					   PAGE_CACHE_SIZE, 0);
1690			if (PAGE_CACHE_SIZE != ret)
1691				break;
1692		}
1693		if (j == i) {
1694			printk(KERN_INFO
1695			       "btrfsic: error, failed to add a single page!\n");
1696			return -1;
1697		}
1698		if (submit_bio_wait(READ, bio)) {
1699			printk(KERN_INFO
1700			       "btrfsic: read error at logical %llu dev %s!\n",
1701			       block_ctx->start, block_ctx->dev->name);
1702			bio_put(bio);
1703			return -1;
1704		}
1705		bio_put(bio);
1706		dev_bytenr += (j - i) * PAGE_CACHE_SIZE;
1707		i = j;
1708	}
1709	for (i = 0; i < num_pages; i++) {
1710		block_ctx->datav[i] = kmap(block_ctx->pagev[i]);
1711		if (!block_ctx->datav[i]) {
1712			printk(KERN_INFO "btrfsic: kmap() failed (dev %s)!\n",
1713			       block_ctx->dev->name);
1714			return -1;
1715		}
1716	}
1717
1718	return block_ctx->len;
1719}
1720
1721static void btrfsic_dump_database(struct btrfsic_state *state)
1722{
1723	struct list_head *elem_all;
1724
1725	BUG_ON(NULL == state);
1726
1727	printk(KERN_INFO "all_blocks_list:\n");
1728	list_for_each(elem_all, &state->all_blocks_list) {
1729		const struct btrfsic_block *const b_all =
1730		    list_entry(elem_all, struct btrfsic_block,
1731			       all_blocks_node);
1732		struct list_head *elem_ref_to;
1733		struct list_head *elem_ref_from;
1734
1735		printk(KERN_INFO "%c-block @%llu (%s/%llu/%d)\n",
1736		       btrfsic_get_block_type(state, b_all),
1737		       b_all->logical_bytenr, b_all->dev_state->name,
1738		       b_all->dev_bytenr, b_all->mirror_num);
1739
1740		list_for_each(elem_ref_to, &b_all->ref_to_list) {
1741			const struct btrfsic_block_link *const l =
1742			    list_entry(elem_ref_to,
1743				       struct btrfsic_block_link,
1744				       node_ref_to);
1745
1746			printk(KERN_INFO " %c @%llu (%s/%llu/%d)"
1747			       " refers %u* to"
1748			       " %c @%llu (%s/%llu/%d)\n",
1749			       btrfsic_get_block_type(state, b_all),
1750			       b_all->logical_bytenr, b_all->dev_state->name,
1751			       b_all->dev_bytenr, b_all->mirror_num,
1752			       l->ref_cnt,
1753			       btrfsic_get_block_type(state, l->block_ref_to),
1754			       l->block_ref_to->logical_bytenr,
1755			       l->block_ref_to->dev_state->name,
1756			       l->block_ref_to->dev_bytenr,
1757			       l->block_ref_to->mirror_num);
1758		}
1759
1760		list_for_each(elem_ref_from, &b_all->ref_from_list) {
1761			const struct btrfsic_block_link *const l =
1762			    list_entry(elem_ref_from,
1763				       struct btrfsic_block_link,
1764				       node_ref_from);
1765
1766			printk(KERN_INFO " %c @%llu (%s/%llu/%d)"
1767			       " is ref %u* from"
1768			       " %c @%llu (%s/%llu/%d)\n",
1769			       btrfsic_get_block_type(state, b_all),
1770			       b_all->logical_bytenr, b_all->dev_state->name,
1771			       b_all->dev_bytenr, b_all->mirror_num,
1772			       l->ref_cnt,
1773			       btrfsic_get_block_type(state, l->block_ref_from),
1774			       l->block_ref_from->logical_bytenr,
1775			       l->block_ref_from->dev_state->name,
1776			       l->block_ref_from->dev_bytenr,
1777			       l->block_ref_from->mirror_num);
1778		}
1779
1780		printk(KERN_INFO "\n");
1781	}
1782}
1783
1784/*
1785 * Test whether the disk block contains a tree block (leaf or node)
1786 * (note that this test fails for the super block)
1787 */
1788static int btrfsic_test_for_metadata(struct btrfsic_state *state,
1789				     char **datav, unsigned int num_pages)
1790{
1791	struct btrfs_header *h;
1792	u8 csum[BTRFS_CSUM_SIZE];
1793	u32 crc = ~(u32)0;
1794	unsigned int i;
1795
1796	if (num_pages * PAGE_CACHE_SIZE < state->metablock_size)
1797		return 1; /* not metadata */
1798	num_pages = state->metablock_size >> PAGE_CACHE_SHIFT;
1799	h = (struct btrfs_header *)datav[0];
1800
1801	if (memcmp(h->fsid, state->root->fs_info->fsid, BTRFS_UUID_SIZE))
1802		return 1;
1803
1804	for (i = 0; i < num_pages; i++) {
1805		u8 *data = i ? datav[i] : (datav[i] + BTRFS_CSUM_SIZE);
1806		size_t sublen = i ? PAGE_CACHE_SIZE :
1807				    (PAGE_CACHE_SIZE - BTRFS_CSUM_SIZE);
1808
1809		crc = btrfs_crc32c(crc, data, sublen);
1810	}
1811	btrfs_csum_final(crc, csum);
1812	if (memcmp(csum, h->csum, state->csum_size))
1813		return 1;
1814
1815	return 0; /* is metadata */
1816}
1817
1818static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
1819					  u64 dev_bytenr, char **mapped_datav,
1820					  unsigned int num_pages,
1821					  struct bio *bio, int *bio_is_patched,
1822					  struct buffer_head *bh,
1823					  int submit_bio_bh_rw)
1824{
1825	int is_metadata;
1826	struct btrfsic_block *block;
1827	struct btrfsic_block_data_ctx block_ctx;
1828	int ret;
1829	struct btrfsic_state *state = dev_state->state;
1830	struct block_device *bdev = dev_state->bdev;
1831	unsigned int processed_len;
1832
1833	if (NULL != bio_is_patched)
1834		*bio_is_patched = 0;
1835
1836again:
1837	if (num_pages == 0)
1838		return;
1839
1840	processed_len = 0;
1841	is_metadata = (0 == btrfsic_test_for_metadata(state, mapped_datav,
1842						      num_pages));
1843
1844	block = btrfsic_block_hashtable_lookup(bdev, dev_bytenr,
1845					       &state->block_hashtable);
1846	if (NULL != block) {
1847		u64 bytenr = 0;
1848		struct list_head *elem_ref_to;
1849		struct list_head *tmp_ref_to;
1850
1851		if (block->is_superblock) {
1852			bytenr = btrfs_super_bytenr((struct btrfs_super_block *)
1853						    mapped_datav[0]);
1854			if (num_pages * PAGE_CACHE_SIZE <
1855			    BTRFS_SUPER_INFO_SIZE) {
1856				printk(KERN_INFO
1857				       "btrfsic: cannot work with too short bios!\n");
1858				return;
1859			}
1860			is_metadata = 1;
1861			BUG_ON(BTRFS_SUPER_INFO_SIZE & (PAGE_CACHE_SIZE - 1));
1862			processed_len = BTRFS_SUPER_INFO_SIZE;
1863			if (state->print_mask &
1864			    BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE) {
1865				printk(KERN_INFO
1866				       "[before new superblock is written]:\n");
1867				btrfsic_dump_tree_sub(state, block, 0);
1868			}
1869		}
1870		if (is_metadata) {
1871			if (!block->is_superblock) {
1872				if (num_pages * PAGE_CACHE_SIZE <
1873				    state->metablock_size) {
1874					printk(KERN_INFO
1875					       "btrfsic: cannot work with too short bios!\n");
1876					return;
1877				}
1878				processed_len = state->metablock_size;
1879				bytenr = btrfs_stack_header_bytenr(
1880						(struct btrfs_header *)
1881						mapped_datav[0]);
1882				btrfsic_cmp_log_and_dev_bytenr(state, bytenr,
1883							       dev_state,
1884							       dev_bytenr);
1885			}
1886			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1887				if (block->logical_bytenr != bytenr &&
1888				    !(!block->is_metadata &&
1889				      block->logical_bytenr == 0))
1890					printk(KERN_INFO
1891					       "Written block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1892					       bytenr, dev_state->name,
1893					       dev_bytenr,
1894					       block->mirror_num,
1895					       btrfsic_get_block_type(state,
1896								      block),
1897					       block->logical_bytenr);
1898				else
1899					printk(KERN_INFO
1900					       "Written block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1901					       bytenr, dev_state->name,
1902					       dev_bytenr, block->mirror_num,
1903					       btrfsic_get_block_type(state,
1904								      block));
1905			}
1906			block->logical_bytenr = bytenr;
1907		} else {
1908			if (num_pages * PAGE_CACHE_SIZE <
1909			    state->datablock_size) {
1910				printk(KERN_INFO
1911				       "btrfsic: cannot work with too short bios!\n");
1912				return;
1913			}
1914			processed_len = state->datablock_size;
1915			bytenr = block->logical_bytenr;
1916			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1917				printk(KERN_INFO
1918				       "Written block @%llu (%s/%llu/%d)"
1919				       " found in hash table, %c.\n",
1920				       bytenr, dev_state->name, dev_bytenr,
1921				       block->mirror_num,
1922				       btrfsic_get_block_type(state, block));
1923		}
1924
1925		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1926			printk(KERN_INFO
1927			       "ref_to_list: %cE, ref_from_list: %cE\n",
1928			       list_empty(&block->ref_to_list) ? ' ' : '!',
1929			       list_empty(&block->ref_from_list) ? ' ' : '!');
1930		if (btrfsic_is_block_ref_by_superblock(state, block, 0)) {
1931			printk(KERN_INFO "btrfs: attempt to overwrite %c-block"
1932			       " @%llu (%s/%llu/%d), old(gen=%llu,"
1933			       " objectid=%llu, type=%d, offset=%llu),"
1934			       " new(gen=%llu),"
1935			       " which is referenced by most recent superblock"
1936			       " (superblockgen=%llu)!\n",
1937			       btrfsic_get_block_type(state, block), bytenr,
1938			       dev_state->name, dev_bytenr, block->mirror_num,
1939			       block->generation,
1940			       btrfs_disk_key_objectid(&block->disk_key),
1941			       block->disk_key.type,
1942			       btrfs_disk_key_offset(&block->disk_key),
1943			       btrfs_stack_header_generation(
1944				       (struct btrfs_header *) mapped_datav[0]),
1945			       state->max_superblock_generation);
1946			btrfsic_dump_tree(state);
1947		}
1948
1949		if (!block->is_iodone && !block->never_written) {
1950			printk(KERN_INFO "btrfs: attempt to overwrite %c-block"
1951			       " @%llu (%s/%llu/%d), oldgen=%llu, newgen=%llu,"
1952			       " which is not yet iodone!\n",
1953			       btrfsic_get_block_type(state, block), bytenr,
1954			       dev_state->name, dev_bytenr, block->mirror_num,
1955			       block->generation,
1956			       btrfs_stack_header_generation(
1957				       (struct btrfs_header *)
1958				       mapped_datav[0]));
1959			/* it would not be safe to go on */
1960			btrfsic_dump_tree(state);
1961			goto continue_loop;
1962		}
1963
1964		/*
1965		 * Clear all references of this block. Do not free
1966		 * the block itself even if is not referenced anymore
1967		 * because it still carries valueable information
1968		 * like whether it was ever written and IO completed.
1969		 */
1970		list_for_each_safe(elem_ref_to, tmp_ref_to,
1971				   &block->ref_to_list) {
1972			struct btrfsic_block_link *const l =
1973			    list_entry(elem_ref_to,
1974				       struct btrfsic_block_link,
1975				       node_ref_to);
1976
1977			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1978				btrfsic_print_rem_link(state, l);
1979			l->ref_cnt--;
1980			if (0 == l->ref_cnt) {
1981				list_del(&l->node_ref_to);
1982				list_del(&l->node_ref_from);
1983				btrfsic_block_link_hashtable_remove(l);
1984				btrfsic_block_link_free(l);
1985			}
1986		}
1987
1988		block_ctx.dev = dev_state;
1989		block_ctx.dev_bytenr = dev_bytenr;
1990		block_ctx.start = bytenr;
1991		block_ctx.len = processed_len;
1992		block_ctx.pagev = NULL;
1993		block_ctx.mem_to_free = NULL;
1994		block_ctx.datav = mapped_datav;
1995
1996		if (is_metadata || state->include_extent_data) {
1997			block->never_written = 0;
1998			block->iodone_w_error = 0;
1999			if (NULL != bio) {
2000				block->is_iodone = 0;
2001				BUG_ON(NULL == bio_is_patched);
2002				if (!*bio_is_patched) {
2003					block->orig_bio_bh_private =
2004					    bio->bi_private;
2005					block->orig_bio_bh_end_io.bio =
2006					    bio->bi_end_io;
2007					block->next_in_same_bio = NULL;
2008					bio->bi_private = block;
2009					bio->bi_end_io = btrfsic_bio_end_io;
2010					*bio_is_patched = 1;
2011				} else {
2012					struct btrfsic_block *chained_block =
2013					    (struct btrfsic_block *)
2014					    bio->bi_private;
2015
2016					BUG_ON(NULL == chained_block);
2017					block->orig_bio_bh_private =
2018					    chained_block->orig_bio_bh_private;
2019					block->orig_bio_bh_end_io.bio =
2020					    chained_block->orig_bio_bh_end_io.
2021					    bio;
2022					block->next_in_same_bio = chained_block;
2023					bio->bi_private = block;
2024				}
2025			} else if (NULL != bh) {
2026				block->is_iodone = 0;
2027				block->orig_bio_bh_private = bh->b_private;
2028				block->orig_bio_bh_end_io.bh = bh->b_end_io;
2029				block->next_in_same_bio = NULL;
2030				bh->b_private = block;
2031				bh->b_end_io = btrfsic_bh_end_io;
2032			} else {
2033				block->is_iodone = 1;
2034				block->orig_bio_bh_private = NULL;
2035				block->orig_bio_bh_end_io.bio = NULL;
2036				block->next_in_same_bio = NULL;
2037			}
2038		}
2039
2040		block->flush_gen = dev_state->last_flush_gen + 1;
2041		block->submit_bio_bh_rw = submit_bio_bh_rw;
2042		if (is_metadata) {
2043			block->logical_bytenr = bytenr;
2044			block->is_metadata = 1;
2045			if (block->is_superblock) {
2046				BUG_ON(PAGE_CACHE_SIZE !=
2047				       BTRFS_SUPER_INFO_SIZE);
2048				ret = btrfsic_process_written_superblock(
2049						state,
2050						block,
2051						(struct btrfs_super_block *)
2052						mapped_datav[0]);
2053				if (state->print_mask &
2054				    BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE) {
2055					printk(KERN_INFO
2056					"[after new superblock is written]:\n");
2057					btrfsic_dump_tree_sub(state, block, 0);
2058				}
2059			} else {
2060				block->mirror_num = 0;	/* unknown */
2061				ret = btrfsic_process_metablock(
2062						state,
2063						block,
2064						&block_ctx,
2065						0, 0);
2066			}
2067			if (ret)
2068				printk(KERN_INFO
2069				       "btrfsic: btrfsic_process_metablock"
2070				       "(root @%llu) failed!\n",
2071				       dev_bytenr);
2072		} else {
2073			block->is_metadata = 0;
2074			block->mirror_num = 0;	/* unknown */
2075			block->generation = BTRFSIC_GENERATION_UNKNOWN;
2076			if (!state->include_extent_data
2077			    && list_empty(&block->ref_from_list)) {
2078				/*
2079				 * disk block is overwritten with extent
2080				 * data (not meta data) and we are configured
2081				 * to not include extent data: take the
2082				 * chance and free the block's memory
2083				 */
2084				btrfsic_block_hashtable_remove(block);
2085				list_del(&block->all_blocks_node);
2086				btrfsic_block_free(block);
2087			}
2088		}
2089		btrfsic_release_block_ctx(&block_ctx);
2090	} else {
2091		/* block has not been found in hash table */
2092		u64 bytenr;
2093
2094		if (!is_metadata) {
2095			processed_len = state->datablock_size;
2096			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2097				printk(KERN_INFO "Written block (%s/%llu/?)"
2098				       " !found in hash table, D.\n",
2099				       dev_state->name, dev_bytenr);
2100			if (!state->include_extent_data) {
2101				/* ignore that written D block */
2102				goto continue_loop;
2103			}
2104
2105			/* this is getting ugly for the
2106			 * include_extent_data case... */
2107			bytenr = 0;	/* unknown */
2108		} else {
2109			processed_len = state->metablock_size;
2110			bytenr = btrfs_stack_header_bytenr(
2111					(struct btrfs_header *)
2112					mapped_datav[0]);
2113			btrfsic_cmp_log_and_dev_bytenr(state, bytenr, dev_state,
2114						       dev_bytenr);
2115			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2116				printk(KERN_INFO
2117				       "Written block @%llu (%s/%llu/?)"
2118				       " !found in hash table, M.\n",
2119				       bytenr, dev_state->name, dev_bytenr);
2120		}
2121
2122		block_ctx.dev = dev_state;
2123		block_ctx.dev_bytenr = dev_bytenr;
2124		block_ctx.start = bytenr;
2125		block_ctx.len = processed_len;
2126		block_ctx.pagev = NULL;
2127		block_ctx.mem_to_free = NULL;
2128		block_ctx.datav = mapped_datav;
2129
2130		block = btrfsic_block_alloc();
2131		if (NULL == block) {
2132			printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
2133			btrfsic_release_block_ctx(&block_ctx);
2134			goto continue_loop;
2135		}
2136		block->dev_state = dev_state;
2137		block->dev_bytenr = dev_bytenr;
2138		block->logical_bytenr = bytenr;
2139		block->is_metadata = is_metadata;
2140		block->never_written = 0;
2141		block->iodone_w_error = 0;
2142		block->mirror_num = 0;	/* unknown */
2143		block->flush_gen = dev_state->last_flush_gen + 1;
2144		block->submit_bio_bh_rw = submit_bio_bh_rw;
2145		if (NULL != bio) {
2146			block->is_iodone = 0;
2147			BUG_ON(NULL == bio_is_patched);
2148			if (!*bio_is_patched) {
2149				block->orig_bio_bh_private = bio->bi_private;
2150				block->orig_bio_bh_end_io.bio = bio->bi_end_io;
2151				block->next_in_same_bio = NULL;
2152				bio->bi_private = block;
2153				bio->bi_end_io = btrfsic_bio_end_io;
2154				*bio_is_patched = 1;
2155			} else {
2156				struct btrfsic_block *chained_block =
2157				    (struct btrfsic_block *)
2158				    bio->bi_private;
2159
2160				BUG_ON(NULL == chained_block);
2161				block->orig_bio_bh_private =
2162				    chained_block->orig_bio_bh_private;
2163				block->orig_bio_bh_end_io.bio =
2164				    chained_block->orig_bio_bh_end_io.bio;
2165				block->next_in_same_bio = chained_block;
2166				bio->bi_private = block;
2167			}
2168		} else if (NULL != bh) {
2169			block->is_iodone = 0;
2170			block->orig_bio_bh_private = bh->b_private;
2171			block->orig_bio_bh_end_io.bh = bh->b_end_io;
2172			block->next_in_same_bio = NULL;
2173			bh->b_private = block;
2174			bh->b_end_io = btrfsic_bh_end_io;
2175		} else {
2176			block->is_iodone = 1;
2177			block->orig_bio_bh_private = NULL;
2178			block->orig_bio_bh_end_io.bio = NULL;
2179			block->next_in_same_bio = NULL;
2180		}
2181		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2182			printk(KERN_INFO
2183			       "New written %c-block @%llu (%s/%llu/%d)\n",
2184			       is_metadata ? 'M' : 'D',
2185			       block->logical_bytenr, block->dev_state->name,
2186			       block->dev_bytenr, block->mirror_num);
2187		list_add(&block->all_blocks_node, &state->all_blocks_list);
2188		btrfsic_block_hashtable_add(block, &state->block_hashtable);
2189
2190		if (is_metadata) {
2191			ret = btrfsic_process_metablock(state, block,
2192							&block_ctx, 0, 0);
2193			if (ret)
2194				printk(KERN_INFO
2195				       "btrfsic: process_metablock(root @%llu)"
2196				       " failed!\n",
2197				       dev_bytenr);
2198		}
2199		btrfsic_release_block_ctx(&block_ctx);
2200	}
2201
2202continue_loop:
2203	BUG_ON(!processed_len);
2204	dev_bytenr += processed_len;
2205	mapped_datav += processed_len >> PAGE_CACHE_SHIFT;
2206	num_pages -= processed_len >> PAGE_CACHE_SHIFT;
2207	goto again;
2208}
2209
2210static void btrfsic_bio_end_io(struct bio *bp, int bio_error_status)
2211{
2212	struct btrfsic_block *block = (struct btrfsic_block *)bp->bi_private;
2213	int iodone_w_error;
2214
2215	/* mutex is not held! This is not save if IO is not yet completed
2216	 * on umount */
2217	iodone_w_error = 0;
2218	if (bio_error_status)
2219		iodone_w_error = 1;
2220
2221	BUG_ON(NULL == block);
2222	bp->bi_private = block->orig_bio_bh_private;
2223	bp->bi_end_io = block->orig_bio_bh_end_io.bio;
2224
2225	do {
2226		struct btrfsic_block *next_block;
2227		struct btrfsic_dev_state *const dev_state = block->dev_state;
2228
2229		if ((dev_state->state->print_mask &
2230		     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2231			printk(KERN_INFO
2232			       "bio_end_io(err=%d) for %c @%llu (%s/%llu/%d)\n",
2233			       bio_error_status,
2234			       btrfsic_get_block_type(dev_state->state, block),
2235			       block->logical_bytenr, dev_state->name,
2236			       block->dev_bytenr, block->mirror_num);
2237		next_block = block->next_in_same_bio;
2238		block->iodone_w_error = iodone_w_error;
2239		if (block->submit_bio_bh_rw & REQ_FLUSH) {
2240			dev_state->last_flush_gen++;
2241			if ((dev_state->state->print_mask &
2242			     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2243				printk(KERN_INFO
2244				       "bio_end_io() new %s flush_gen=%llu\n",
2245				       dev_state->name,
2246				       dev_state->last_flush_gen);
2247		}
2248		if (block->submit_bio_bh_rw & REQ_FUA)
2249			block->flush_gen = 0; /* FUA completed means block is
2250					       * on disk */
2251		block->is_iodone = 1; /* for FLUSH, this releases the block */
2252		block = next_block;
2253	} while (NULL != block);
2254
2255	bp->bi_end_io(bp, bio_error_status);
2256}
2257
2258static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate)
2259{
2260	struct btrfsic_block *block = (struct btrfsic_block *)bh->b_private;
2261	int iodone_w_error = !uptodate;
2262	struct btrfsic_dev_state *dev_state;
2263
2264	BUG_ON(NULL == block);
2265	dev_state = block->dev_state;
2266	if ((dev_state->state->print_mask & BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2267		printk(KERN_INFO
2268		       "bh_end_io(error=%d) for %c @%llu (%s/%llu/%d)\n",
2269		       iodone_w_error,
2270		       btrfsic_get_block_type(dev_state->state, block),
2271		       block->logical_bytenr, block->dev_state->name,
2272		       block->dev_bytenr, block->mirror_num);
2273
2274	block->iodone_w_error = iodone_w_error;
2275	if (block->submit_bio_bh_rw & REQ_FLUSH) {
2276		dev_state->last_flush_gen++;
2277		if ((dev_state->state->print_mask &
2278		     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2279			printk(KERN_INFO
2280			       "bh_end_io() new %s flush_gen=%llu\n",
2281			       dev_state->name, dev_state->last_flush_gen);
2282	}
2283	if (block->submit_bio_bh_rw & REQ_FUA)
2284		block->flush_gen = 0; /* FUA completed means block is on disk */
2285
2286	bh->b_private = block->orig_bio_bh_private;
2287	bh->b_end_io = block->orig_bio_bh_end_io.bh;
2288	block->is_iodone = 1; /* for FLUSH, this releases the block */
2289	bh->b_end_io(bh, uptodate);
2290}
2291
2292static int btrfsic_process_written_superblock(
2293		struct btrfsic_state *state,
2294		struct btrfsic_block *const superblock,
2295		struct btrfs_super_block *const super_hdr)
2296{
2297	int pass;
2298
2299	superblock->generation = btrfs_super_generation(super_hdr);
2300	if (!(superblock->generation > state->max_superblock_generation ||
2301	      0 == state->max_superblock_generation)) {
2302		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2303			printk(KERN_INFO
2304			       "btrfsic: superblock @%llu (%s/%llu/%d)"
2305			       " with old gen %llu <= %llu\n",
2306			       superblock->logical_bytenr,
2307			       superblock->dev_state->name,
2308			       superblock->dev_bytenr, superblock->mirror_num,
2309			       btrfs_super_generation(super_hdr),
2310			       state->max_superblock_generation);
2311	} else {
2312		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2313			printk(KERN_INFO
2314			       "btrfsic: got new superblock @%llu (%s/%llu/%d)"
2315			       " with new gen %llu > %llu\n",
2316			       superblock->logical_bytenr,
2317			       superblock->dev_state->name,
2318			       superblock->dev_bytenr, superblock->mirror_num,
2319			       btrfs_super_generation(super_hdr),
2320			       state->max_superblock_generation);
2321
2322		state->max_superblock_generation =
2323		    btrfs_super_generation(super_hdr);
2324		state->latest_superblock = superblock;
2325	}
2326
2327	for (pass = 0; pass < 3; pass++) {
2328		int ret;
2329		u64 next_bytenr;
2330		struct btrfsic_block *next_block;
2331		struct btrfsic_block_data_ctx tmp_next_block_ctx;
2332		struct btrfsic_block_link *l;
2333		int num_copies;
2334		int mirror_num;
2335		const char *additional_string = NULL;
2336		struct btrfs_disk_key tmp_disk_key = {0};
2337
2338		btrfs_set_disk_key_objectid(&tmp_disk_key,
2339					    BTRFS_ROOT_ITEM_KEY);
2340		btrfs_set_disk_key_objectid(&tmp_disk_key, 0);
2341
2342		switch (pass) {
2343		case 0:
2344			btrfs_set_disk_key_objectid(&tmp_disk_key,
2345						    BTRFS_ROOT_TREE_OBJECTID);
2346			additional_string = "root ";
2347			next_bytenr = btrfs_super_root(super_hdr);
2348			if (state->print_mask &
2349			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2350				printk(KERN_INFO "root@%llu\n", next_bytenr);
2351			break;
2352		case 1:
2353			btrfs_set_disk_key_objectid(&tmp_disk_key,
2354						    BTRFS_CHUNK_TREE_OBJECTID);
2355			additional_string = "chunk ";
2356			next_bytenr = btrfs_super_chunk_root(super_hdr);
2357			if (state->print_mask &
2358			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2359				printk(KERN_INFO "chunk@%llu\n", next_bytenr);
2360			break;
2361		case 2:
2362			btrfs_set_disk_key_objectid(&tmp_disk_key,
2363						    BTRFS_TREE_LOG_OBJECTID);
2364			additional_string = "log ";
2365			next_bytenr = btrfs_super_log_root(super_hdr);
2366			if (0 == next_bytenr)
2367				continue;
2368			if (state->print_mask &
2369			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2370				printk(KERN_INFO "log@%llu\n", next_bytenr);
2371			break;
2372		}
2373
2374		num_copies =
2375		    btrfs_num_copies(state->root->fs_info,
2376				     next_bytenr, BTRFS_SUPER_INFO_SIZE);
2377		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
2378			printk(KERN_INFO "num_copies(log_bytenr=%llu) = %d\n",
2379			       next_bytenr, num_copies);
2380		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2381			int was_created;
2382
2383			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2384				printk(KERN_INFO
2385				       "btrfsic_process_written_superblock("
2386				       "mirror_num=%d)\n", mirror_num);
2387			ret = btrfsic_map_block(state, next_bytenr,
2388						BTRFS_SUPER_INFO_SIZE,
2389						&tmp_next_block_ctx,
2390						mirror_num);
2391			if (ret) {
2392				printk(KERN_INFO
2393				       "btrfsic: btrfsic_map_block(@%llu,"
2394				       " mirror=%d) failed!\n",
2395				       next_bytenr, mirror_num);
2396				return -1;
2397			}
2398
2399			next_block = btrfsic_block_lookup_or_add(
2400					state,
2401					&tmp_next_block_ctx,
2402					additional_string,
2403					1, 0, 1,
2404					mirror_num,
2405					&was_created);
2406			if (NULL == next_block) {
2407				printk(KERN_INFO
2408				       "btrfsic: error, kmalloc failed!\n");
2409				btrfsic_release_block_ctx(&tmp_next_block_ctx);
2410				return -1;
2411			}
2412
2413			next_block->disk_key = tmp_disk_key;
2414			if (was_created)
2415				next_block->generation =
2416				    BTRFSIC_GENERATION_UNKNOWN;
2417			l = btrfsic_block_link_lookup_or_add(
2418					state,
2419					&tmp_next_block_ctx,
2420					next_block,
2421					superblock,
2422					BTRFSIC_GENERATION_UNKNOWN);
2423			btrfsic_release_block_ctx(&tmp_next_block_ctx);
2424			if (NULL == l)
2425				return -1;
2426		}
2427	}
2428
2429	if (WARN_ON(-1 == btrfsic_check_all_ref_blocks(state, superblock, 0)))
2430		btrfsic_dump_tree(state);
2431
2432	return 0;
2433}
2434
2435static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
2436					struct btrfsic_block *const block,
2437					int recursion_level)
2438{
2439	struct list_head *elem_ref_to;
2440	int ret = 0;
2441
2442	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2443		/*
2444		 * Note that this situation can happen and does not
2445		 * indicate an error in regular cases. It happens
2446		 * when disk blocks are freed and later reused.
2447		 * The check-integrity module is not aware of any
2448		 * block free operations, it just recognizes block
2449		 * write operations. Therefore it keeps the linkage
2450		 * information for a block until a block is
2451		 * rewritten. This can temporarily cause incorrect
2452		 * and even circular linkage informations. This
2453		 * causes no harm unless such blocks are referenced
2454		 * by the most recent super block.
2455		 */
2456		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2457			printk(KERN_INFO
2458			       "btrfsic: abort cyclic linkage (case 1).\n");
2459
2460		return ret;
2461	}
2462
2463	/*
2464	 * This algorithm is recursive because the amount of used stack
2465	 * space is very small and the max recursion depth is limited.
2466	 */
2467	list_for_each(elem_ref_to, &block->ref_to_list) {
2468		const struct btrfsic_block_link *const l =
2469		    list_entry(elem_ref_to, struct btrfsic_block_link,
2470			       node_ref_to);
2471
2472		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2473			printk(KERN_INFO
2474			       "rl=%d, %c @%llu (%s/%llu/%d)"
2475			       " %u* refers to %c @%llu (%s/%llu/%d)\n",
2476			       recursion_level,
2477			       btrfsic_get_block_type(state, block),
2478			       block->logical_bytenr, block->dev_state->name,
2479			       block->dev_bytenr, block->mirror_num,
2480			       l->ref_cnt,
2481			       btrfsic_get_block_type(state, l->block_ref_to),
2482			       l->block_ref_to->logical_bytenr,
2483			       l->block_ref_to->dev_state->name,
2484			       l->block_ref_to->dev_bytenr,
2485			       l->block_ref_to->mirror_num);
2486		if (l->block_ref_to->never_written) {
2487			printk(KERN_INFO "btrfs: attempt to write superblock"
2488			       " which references block %c @%llu (%s/%llu/%d)"
2489			       " which is never written!\n",
2490			       btrfsic_get_block_type(state, l->block_ref_to),
2491			       l->block_ref_to->logical_bytenr,
2492			       l->block_ref_to->dev_state->name,
2493			       l->block_ref_to->dev_bytenr,
2494			       l->block_ref_to->mirror_num);
2495			ret = -1;
2496		} else if (!l->block_ref_to->is_iodone) {
2497			printk(KERN_INFO "btrfs: attempt to write superblock"
2498			       " which references block %c @%llu (%s/%llu/%d)"
2499			       " which is not yet iodone!\n",
2500			       btrfsic_get_block_type(state, l->block_ref_to),
2501			       l->block_ref_to->logical_bytenr,
2502			       l->block_ref_to->dev_state->name,
2503			       l->block_ref_to->dev_bytenr,
2504			       l->block_ref_to->mirror_num);
2505			ret = -1;
2506		} else if (l->block_ref_to->iodone_w_error) {
2507			printk(KERN_INFO "btrfs: attempt to write superblock"
2508			       " which references block %c @%llu (%s/%llu/%d)"
2509			       " which has write error!\n",
2510			       btrfsic_get_block_type(state, l->block_ref_to),
2511			       l->block_ref_to->logical_bytenr,
2512			       l->block_ref_to->dev_state->name,
2513			       l->block_ref_to->dev_bytenr,
2514			       l->block_ref_to->mirror_num);
2515			ret = -1;
2516		} else if (l->parent_generation !=
2517			   l->block_ref_to->generation &&
2518			   BTRFSIC_GENERATION_UNKNOWN !=
2519			   l->parent_generation &&
2520			   BTRFSIC_GENERATION_UNKNOWN !=
2521			   l->block_ref_to->generation) {
2522			printk(KERN_INFO "btrfs: attempt to write superblock"
2523			       " which references block %c @%llu (%s/%llu/%d)"
2524			       " with generation %llu !="
2525			       " parent generation %llu!\n",
2526			       btrfsic_get_block_type(state, l->block_ref_to),
2527			       l->block_ref_to->logical_bytenr,
2528			       l->block_ref_to->dev_state->name,
2529			       l->block_ref_to->dev_bytenr,
2530			       l->block_ref_to->mirror_num,
2531			       l->block_ref_to->generation,
2532			       l->parent_generation);
2533			ret = -1;
2534		} else if (l->block_ref_to->flush_gen >
2535			   l->block_ref_to->dev_state->last_flush_gen) {
2536			printk(KERN_INFO "btrfs: attempt to write superblock"
2537			       " which references block %c @%llu (%s/%llu/%d)"
2538			       " which is not flushed out of disk's write cache"
2539			       " (block flush_gen=%llu,"
2540			       " dev->flush_gen=%llu)!\n",
2541			       btrfsic_get_block_type(state, l->block_ref_to),
2542			       l->block_ref_to->logical_bytenr,
2543			       l->block_ref_to->dev_state->name,
2544			       l->block_ref_to->dev_bytenr,
2545			       l->block_ref_to->mirror_num, block->flush_gen,
2546			       l->block_ref_to->dev_state->last_flush_gen);
2547			ret = -1;
2548		} else if (-1 == btrfsic_check_all_ref_blocks(state,
2549							      l->block_ref_to,
2550							      recursion_level +
2551							      1)) {
2552			ret = -1;
2553		}
2554	}
2555
2556	return ret;
2557}
2558
2559static int btrfsic_is_block_ref_by_superblock(
2560		const struct btrfsic_state *state,
2561		const struct btrfsic_block *block,
2562		int recursion_level)
2563{
2564	struct list_head *elem_ref_from;
2565
2566	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2567		/* refer to comment at "abort cyclic linkage (case 1)" */
2568		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2569			printk(KERN_INFO
2570			       "btrfsic: abort cyclic linkage (case 2).\n");
2571
2572		return 0;
2573	}
2574
2575	/*
2576	 * This algorithm is recursive because the amount of used stack space
2577	 * is very small and the max recursion depth is limited.
2578	 */
2579	list_for_each(elem_ref_from, &block->ref_from_list) {
2580		const struct btrfsic_block_link *const l =
2581		    list_entry(elem_ref_from, struct btrfsic_block_link,
2582			       node_ref_from);
2583
2584		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2585			printk(KERN_INFO
2586			       "rl=%d, %c @%llu (%s/%llu/%d)"
2587			       " is ref %u* from %c @%llu (%s/%llu/%d)\n",
2588			       recursion_level,
2589			       btrfsic_get_block_type(state, block),
2590			       block->logical_bytenr, block->dev_state->name,
2591			       block->dev_bytenr, block->mirror_num,
2592			       l->ref_cnt,
2593			       btrfsic_get_block_type(state, l->block_ref_from),
2594			       l->block_ref_from->logical_bytenr,
2595			       l->block_ref_from->dev_state->name,
2596			       l->block_ref_from->dev_bytenr,
2597			       l->block_ref_from->mirror_num);
2598		if (l->block_ref_from->is_superblock &&
2599		    state->latest_superblock->dev_bytenr ==
2600		    l->block_ref_from->dev_bytenr &&
2601		    state->latest_superblock->dev_state->bdev ==
2602		    l->block_ref_from->dev_state->bdev)
2603			return 1;
2604		else if (btrfsic_is_block_ref_by_superblock(state,
2605							    l->block_ref_from,
2606							    recursion_level +
2607							    1))
2608			return 1;
2609	}
2610
2611	return 0;
2612}
2613
2614static void btrfsic_print_add_link(const struct btrfsic_state *state,
2615				   const struct btrfsic_block_link *l)
2616{
2617	printk(KERN_INFO
2618	       "Add %u* link from %c @%llu (%s/%llu/%d)"
2619	       " to %c @%llu (%s/%llu/%d).\n",
2620	       l->ref_cnt,
2621	       btrfsic_get_block_type(state, l->block_ref_from),
2622	       l->block_ref_from->logical_bytenr,
2623	       l->block_ref_from->dev_state->name,
2624	       l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2625	       btrfsic_get_block_type(state, l->block_ref_to),
2626	       l->block_ref_to->logical_bytenr,
2627	       l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2628	       l->block_ref_to->mirror_num);
2629}
2630
2631static void btrfsic_print_rem_link(const struct btrfsic_state *state,
2632				   const struct btrfsic_block_link *l)
2633{
2634	printk(KERN_INFO
2635	       "Rem %u* link from %c @%llu (%s/%llu/%d)"
2636	       " to %c @%llu (%s/%llu/%d).\n",
2637	       l->ref_cnt,
2638	       btrfsic_get_block_type(state, l->block_ref_from),
2639	       l->block_ref_from->logical_bytenr,
2640	       l->block_ref_from->dev_state->name,
2641	       l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2642	       btrfsic_get_block_type(state, l->block_ref_to),
2643	       l->block_ref_to->logical_bytenr,
2644	       l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2645	       l->block_ref_to->mirror_num);
2646}
2647
2648static char btrfsic_get_block_type(const struct btrfsic_state *state,
2649				   const struct btrfsic_block *block)
2650{
2651	if (block->is_superblock &&
2652	    state->latest_superblock->dev_bytenr == block->dev_bytenr &&
2653	    state->latest_superblock->dev_state->bdev == block->dev_state->bdev)
2654		return 'S';
2655	else if (block->is_superblock)
2656		return 's';
2657	else if (block->is_metadata)
2658		return 'M';
2659	else
2660		return 'D';
2661}
2662
2663static void btrfsic_dump_tree(const struct btrfsic_state *state)
2664{
2665	btrfsic_dump_tree_sub(state, state->latest_superblock, 0);
2666}
2667
2668static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
2669				  const struct btrfsic_block *block,
2670				  int indent_level)
2671{
2672	struct list_head *elem_ref_to;
2673	int indent_add;
2674	static char buf[80];
2675	int cursor_position;
2676
2677	/*
2678	 * Should better fill an on-stack buffer with a complete line and
2679	 * dump it at once when it is time to print a newline character.
2680	 */
2681
2682	/*
2683	 * This algorithm is recursive because the amount of used stack space
2684	 * is very small and the max recursion depth is limited.
2685	 */
2686	indent_add = sprintf(buf, "%c-%llu(%s/%llu/%d)",
2687			     btrfsic_get_block_type(state, block),
2688			     block->logical_bytenr, block->dev_state->name,
2689			     block->dev_bytenr, block->mirror_num);
2690	if (indent_level + indent_add > BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2691		printk("[...]\n");
2692		return;
2693	}
2694	printk(buf);
2695	indent_level += indent_add;
2696	if (list_empty(&block->ref_to_list)) {
2697		printk("\n");
2698		return;
2699	}
2700	if (block->mirror_num > 1 &&
2701	    !(state->print_mask & BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS)) {
2702		printk(" [...]\n");
2703		return;
2704	}
2705
2706	cursor_position = indent_level;
2707	list_for_each(elem_ref_to, &block->ref_to_list) {
2708		const struct btrfsic_block_link *const l =
2709		    list_entry(elem_ref_to, struct btrfsic_block_link,
2710			       node_ref_to);
2711
2712		while (cursor_position < indent_level) {
2713			printk(" ");
2714			cursor_position++;
2715		}
2716		if (l->ref_cnt > 1)
2717			indent_add = sprintf(buf, " %d*--> ", l->ref_cnt);
2718		else
2719			indent_add = sprintf(buf, " --> ");
2720		if (indent_level + indent_add >
2721		    BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2722			printk("[...]\n");
2723			cursor_position = 0;
2724			continue;
2725		}
2726
2727		printk(buf);
2728
2729		btrfsic_dump_tree_sub(state, l->block_ref_to,
2730				      indent_level + indent_add);
2731		cursor_position = 0;
2732	}
2733}
2734
2735static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
2736		struct btrfsic_state *state,
2737		struct btrfsic_block_data_ctx *next_block_ctx,
2738		struct btrfsic_block *next_block,
2739		struct btrfsic_block *from_block,
2740		u64 parent_generation)
2741{
2742	struct btrfsic_block_link *l;
2743
2744	l = btrfsic_block_link_hashtable_lookup(next_block_ctx->dev->bdev,
2745						next_block_ctx->dev_bytenr,
2746						from_block->dev_state->bdev,
2747						from_block->dev_bytenr,
2748						&state->block_link_hashtable);
2749	if (NULL == l) {
2750		l = btrfsic_block_link_alloc();
2751		if (NULL == l) {
2752			printk(KERN_INFO
2753			       "btrfsic: error, kmalloc" " failed!\n");
2754			return NULL;
2755		}
2756
2757		l->block_ref_to = next_block;
2758		l->block_ref_from = from_block;
2759		l->ref_cnt = 1;
2760		l->parent_generation = parent_generation;
2761
2762		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2763			btrfsic_print_add_link(state, l);
2764
2765		list_add(&l->node_ref_to, &from_block->ref_to_list);
2766		list_add(&l->node_ref_from, &next_block->ref_from_list);
2767
2768		btrfsic_block_link_hashtable_add(l,
2769						 &state->block_link_hashtable);
2770	} else {
2771		l->ref_cnt++;
2772		l->parent_generation = parent_generation;
2773		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2774			btrfsic_print_add_link(state, l);
2775	}
2776
2777	return l;
2778}
2779
2780static struct btrfsic_block *btrfsic_block_lookup_or_add(
2781		struct btrfsic_state *state,
2782		struct btrfsic_block_data_ctx *block_ctx,
2783		const char *additional_string,
2784		int is_metadata,
2785		int is_iodone,
2786		int never_written,
2787		int mirror_num,
2788		int *was_created)
2789{
2790	struct btrfsic_block *block;
2791
2792	block = btrfsic_block_hashtable_lookup(block_ctx->dev->bdev,
2793					       block_ctx->dev_bytenr,
2794					       &state->block_hashtable);
2795	if (NULL == block) {
2796		struct btrfsic_dev_state *dev_state;
2797
2798		block = btrfsic_block_alloc();
2799		if (NULL == block) {
2800			printk(KERN_INFO "btrfsic: error, kmalloc failed!\n");
2801			return NULL;
2802		}
2803		dev_state = btrfsic_dev_state_lookup(block_ctx->dev->bdev);
2804		if (NULL == dev_state) {
2805			printk(KERN_INFO
2806			       "btrfsic: error, lookup dev_state failed!\n");
2807			btrfsic_block_free(block);
2808			return NULL;
2809		}
2810		block->dev_state = dev_state;
2811		block->dev_bytenr = block_ctx->dev_bytenr;
2812		block->logical_bytenr = block_ctx->start;
2813		block->is_metadata = is_metadata;
2814		block->is_iodone = is_iodone;
2815		block->never_written = never_written;
2816		block->mirror_num = mirror_num;
2817		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2818			printk(KERN_INFO
2819			       "New %s%c-block @%llu (%s/%llu/%d)\n",
2820			       additional_string,
2821			       btrfsic_get_block_type(state, block),
2822			       block->logical_bytenr, dev_state->name,
2823			       block->dev_bytenr, mirror_num);
2824		list_add(&block->all_blocks_node, &state->all_blocks_list);
2825		btrfsic_block_hashtable_add(block, &state->block_hashtable);
2826		if (NULL != was_created)
2827			*was_created = 1;
2828	} else {
2829		if (NULL != was_created)
2830			*was_created = 0;
2831	}
2832
2833	return block;
2834}
2835
2836static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
2837					   u64 bytenr,
2838					   struct btrfsic_dev_state *dev_state,
2839					   u64 dev_bytenr)
2840{
2841	int num_copies;
2842	int mirror_num;
2843	int ret;
2844	struct btrfsic_block_data_ctx block_ctx;
2845	int match = 0;
2846
2847	num_copies = btrfs_num_copies(state->root->fs_info,
2848				      bytenr, state->metablock_size);
2849
2850	for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2851		ret = btrfsic_map_block(state, bytenr, state->metablock_size,
2852					&block_ctx, mirror_num);
2853		if (ret) {
2854			printk(KERN_INFO "btrfsic:"
2855			       " btrfsic_map_block(logical @%llu,"
2856			       " mirror %d) failed!\n",
2857			       bytenr, mirror_num);
2858			continue;
2859		}
2860
2861		if (dev_state->bdev == block_ctx.dev->bdev &&
2862		    dev_bytenr == block_ctx.dev_bytenr) {
2863			match++;
2864			btrfsic_release_block_ctx(&block_ctx);
2865			break;
2866		}
2867		btrfsic_release_block_ctx(&block_ctx);
2868	}
2869
2870	if (WARN_ON(!match)) {
2871		printk(KERN_INFO "btrfs: attempt to write M-block which contains logical bytenr that doesn't map to dev+physical bytenr of submit_bio,"
2872		       " buffer->log_bytenr=%llu, submit_bio(bdev=%s,"
2873		       " phys_bytenr=%llu)!\n",
2874		       bytenr, dev_state->name, dev_bytenr);
2875		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2876			ret = btrfsic_map_block(state, bytenr,
2877						state->metablock_size,
2878						&block_ctx, mirror_num);
2879			if (ret)
2880				continue;
2881
2882			printk(KERN_INFO "Read logical bytenr @%llu maps to"
2883			       " (%s/%llu/%d)\n",
2884			       bytenr, block_ctx.dev->name,
2885			       block_ctx.dev_bytenr, mirror_num);
2886		}
2887	}
2888}
2889
2890static struct btrfsic_dev_state *btrfsic_dev_state_lookup(
2891		struct block_device *bdev)
2892{
2893	struct btrfsic_dev_state *ds;
2894
2895	ds = btrfsic_dev_state_hashtable_lookup(bdev,
2896						&btrfsic_dev_state_hashtable);
2897	return ds;
2898}
2899
2900int btrfsic_submit_bh(int rw, struct buffer_head *bh)
2901{
2902	struct btrfsic_dev_state *dev_state;
2903
2904	if (!btrfsic_is_initialized)
2905		return submit_bh(rw, bh);
2906
2907	mutex_lock(&btrfsic_mutex);
2908	/* since btrfsic_submit_bh() might also be called before
2909	 * btrfsic_mount(), this might return NULL */
2910	dev_state = btrfsic_dev_state_lookup(bh->b_bdev);
2911
2912	/* Only called to write the superblock (incl. FLUSH/FUA) */
2913	if (NULL != dev_state &&
2914	    (rw & WRITE) && bh->b_size > 0) {
2915		u64 dev_bytenr;
2916
2917		dev_bytenr = 4096 * bh->b_blocknr;
2918		if (dev_state->state->print_mask &
2919		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2920			printk(KERN_INFO
2921			       "submit_bh(rw=0x%x, blocknr=%llu (bytenr %llu),"
2922			       " size=%zu, data=%p, bdev=%p)\n",
2923			       rw, (unsigned long long)bh->b_blocknr,
2924			       dev_bytenr, bh->b_size, bh->b_data, bh->b_bdev);
2925		btrfsic_process_written_block(dev_state, dev_bytenr,
2926					      &bh->b_data, 1, NULL,
2927					      NULL, bh, rw);
2928	} else if (NULL != dev_state && (rw & REQ_FLUSH)) {
2929		if (dev_state->state->print_mask &
2930		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2931			printk(KERN_INFO
2932			       "submit_bh(rw=0x%x FLUSH, bdev=%p)\n",
2933			       rw, bh->b_bdev);
2934		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
2935			if ((dev_state->state->print_mask &
2936			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
2937			      BTRFSIC_PRINT_MASK_VERBOSE)))
2938				printk(KERN_INFO
2939				       "btrfsic_submit_bh(%s) with FLUSH"
2940				       " but dummy block already in use"
2941				       " (ignored)!\n",
2942				       dev_state->name);
2943		} else {
2944			struct btrfsic_block *const block =
2945				&dev_state->dummy_block_for_bio_bh_flush;
2946
2947			block->is_iodone = 0;
2948			block->never_written = 0;
2949			block->iodone_w_error = 0;
2950			block->flush_gen = dev_state->last_flush_gen + 1;
2951			block->submit_bio_bh_rw = rw;
2952			block->orig_bio_bh_private = bh->b_private;
2953			block->orig_bio_bh_end_io.bh = bh->b_end_io;
2954			block->next_in_same_bio = NULL;
2955			bh->b_private = block;
2956			bh->b_end_io = btrfsic_bh_end_io;
2957		}
2958	}
2959	mutex_unlock(&btrfsic_mutex);
2960	return submit_bh(rw, bh);
2961}
2962
2963static void __btrfsic_submit_bio(int rw, struct bio *bio)
2964{
2965	struct btrfsic_dev_state *dev_state;
2966
2967	if (!btrfsic_is_initialized)
2968		return;
2969
2970	mutex_lock(&btrfsic_mutex);
2971	/* since btrfsic_submit_bio() is also called before
2972	 * btrfsic_mount(), this might return NULL */
2973	dev_state = btrfsic_dev_state_lookup(bio->bi_bdev);
2974	if (NULL != dev_state &&
2975	    (rw & WRITE) && NULL != bio->bi_io_vec) {
2976		unsigned int i;
2977		u64 dev_bytenr;
2978		u64 cur_bytenr;
2979		int bio_is_patched;
2980		char **mapped_datav;
2981
2982		dev_bytenr = 512 * bio->bi_iter.bi_sector;
2983		bio_is_patched = 0;
2984		if (dev_state->state->print_mask &
2985		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2986			printk(KERN_INFO
2987			       "submit_bio(rw=0x%x, bi_vcnt=%u,"
2988			       " bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
2989			       rw, bio->bi_vcnt,
2990			       (unsigned long long)bio->bi_iter.bi_sector,
2991			       dev_bytenr, bio->bi_bdev);
2992
2993		mapped_datav = kmalloc_array(bio->bi_vcnt,
2994					     sizeof(*mapped_datav), GFP_NOFS);
2995		if (!mapped_datav)
2996			goto leave;
2997		cur_bytenr = dev_bytenr;
2998		for (i = 0; i < bio->bi_vcnt; i++) {
2999			BUG_ON(bio->bi_io_vec[i].bv_len != PAGE_CACHE_SIZE);
3000			mapped_datav[i] = kmap(bio->bi_io_vec[i].bv_page);
3001			if (!mapped_datav[i]) {
3002				while (i > 0) {
3003					i--;
3004					kunmap(bio->bi_io_vec[i].bv_page);
3005				}
3006				kfree(mapped_datav);
3007				goto leave;
3008			}
3009			if (dev_state->state->print_mask &
3010			    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE)
3011				printk(KERN_INFO
3012				       "#%u: bytenr=%llu, len=%u, offset=%u\n",
3013				       i, cur_bytenr, bio->bi_io_vec[i].bv_len,
3014				       bio->bi_io_vec[i].bv_offset);
3015			cur_bytenr += bio->bi_io_vec[i].bv_len;
3016		}
3017		btrfsic_process_written_block(dev_state, dev_bytenr,
3018					      mapped_datav, bio->bi_vcnt,
3019					      bio, &bio_is_patched,
3020					      NULL, rw);
3021		while (i > 0) {
3022			i--;
3023			kunmap(bio->bi_io_vec[i].bv_page);
3024		}
3025		kfree(mapped_datav);
3026	} else if (NULL != dev_state && (rw & REQ_FLUSH)) {
3027		if (dev_state->state->print_mask &
3028		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
3029			printk(KERN_INFO
3030			       "submit_bio(rw=0x%x FLUSH, bdev=%p)\n",
3031			       rw, bio->bi_bdev);
3032		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
3033			if ((dev_state->state->print_mask &
3034			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
3035			      BTRFSIC_PRINT_MASK_VERBOSE)))
3036				printk(KERN_INFO
3037				       "btrfsic_submit_bio(%s) with FLUSH"
3038				       " but dummy block already in use"
3039				       " (ignored)!\n",
3040				       dev_state->name);
3041		} else {
3042			struct btrfsic_block *const block =
3043				&dev_state->dummy_block_for_bio_bh_flush;
3044
3045			block->is_iodone = 0;
3046			block->never_written = 0;
3047			block->iodone_w_error = 0;
3048			block->flush_gen = dev_state->last_flush_gen + 1;
3049			block->submit_bio_bh_rw = rw;
3050			block->orig_bio_bh_private = bio->bi_private;
3051			block->orig_bio_bh_end_io.bio = bio->bi_end_io;
3052			block->next_in_same_bio = NULL;
3053			bio->bi_private = block;
3054			bio->bi_end_io = btrfsic_bio_end_io;
3055		}
3056	}
3057leave:
3058	mutex_unlock(&btrfsic_mutex);
3059}
3060
3061void btrfsic_submit_bio(int rw, struct bio *bio)
3062{
3063	__btrfsic_submit_bio(rw, bio);
3064	submit_bio(rw, bio);
3065}
3066
3067int btrfsic_submit_bio_wait(int rw, struct bio *bio)
3068{
3069	__btrfsic_submit_bio(rw, bio);
3070	return submit_bio_wait(rw, bio);
3071}
3072
3073int btrfsic_mount(struct btrfs_root *root,
3074		  struct btrfs_fs_devices *fs_devices,
3075		  int including_extent_data, u32 print_mask)
3076{
3077	int ret;
3078	struct btrfsic_state *state;
3079	struct list_head *dev_head = &fs_devices->devices;
3080	struct btrfs_device *device;
3081
3082	if (root->nodesize & ((u64)PAGE_CACHE_SIZE - 1)) {
3083		printk(KERN_INFO
3084		       "btrfsic: cannot handle nodesize %d not being a multiple of PAGE_CACHE_SIZE %ld!\n",
3085		       root->nodesize, PAGE_CACHE_SIZE);
3086		return -1;
3087	}
3088	if (root->sectorsize & ((u64)PAGE_CACHE_SIZE - 1)) {
3089		printk(KERN_INFO
3090		       "btrfsic: cannot handle sectorsize %d not being a multiple of PAGE_CACHE_SIZE %ld!\n",
3091		       root->sectorsize, PAGE_CACHE_SIZE);
3092		return -1;
3093	}
3094	state = kzalloc(sizeof(*state), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
3095	if (!state) {
3096		state = vzalloc(sizeof(*state));
3097		if (!state) {
3098			printk(KERN_INFO "btrfs check-integrity: vzalloc() failed!\n");
3099			return -1;
3100		}
3101	}
3102
3103	if (!btrfsic_is_initialized) {
3104		mutex_init(&btrfsic_mutex);
3105		btrfsic_dev_state_hashtable_init(&btrfsic_dev_state_hashtable);
3106		btrfsic_is_initialized = 1;
3107	}
3108	mutex_lock(&btrfsic_mutex);
3109	state->root = root;
3110	state->print_mask = print_mask;
3111	state->include_extent_data = including_extent_data;
3112	state->csum_size = 0;
3113	state->metablock_size = root->nodesize;
3114	state->datablock_size = root->sectorsize;
3115	INIT_LIST_HEAD(&state->all_blocks_list);
3116	btrfsic_block_hashtable_init(&state->block_hashtable);
3117	btrfsic_block_link_hashtable_init(&state->block_link_hashtable);
3118	state->max_superblock_generation = 0;
3119	state->latest_superblock = NULL;
3120
3121	list_for_each_entry(device, dev_head, dev_list) {
3122		struct btrfsic_dev_state *ds;
3123		char *p;
3124
3125		if (!device->bdev || !device->name)
3126			continue;
3127
3128		ds = btrfsic_dev_state_alloc();
3129		if (NULL == ds) {
3130			printk(KERN_INFO
3131			       "btrfs check-integrity: kmalloc() failed!\n");
3132			mutex_unlock(&btrfsic_mutex);
3133			return -1;
3134		}
3135		ds->bdev = device->bdev;
3136		ds->state = state;
3137		bdevname(ds->bdev, ds->name);
3138		ds->name[BDEVNAME_SIZE - 1] = '\0';
3139		for (p = ds->name; *p != '\0'; p++);
3140		while (p > ds->name && *p != '/')
3141			p--;
3142		if (*p == '/')
3143			p++;
3144		strlcpy(ds->name, p, sizeof(ds->name));
3145		btrfsic_dev_state_hashtable_add(ds,
3146						&btrfsic_dev_state_hashtable);
3147	}
3148
3149	ret = btrfsic_process_superblock(state, fs_devices);
3150	if (0 != ret) {
3151		mutex_unlock(&btrfsic_mutex);
3152		btrfsic_unmount(root, fs_devices);
3153		return ret;
3154	}
3155
3156	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_DATABASE)
3157		btrfsic_dump_database(state);
3158	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_TREE)
3159		btrfsic_dump_tree(state);
3160
3161	mutex_unlock(&btrfsic_mutex);
3162	return 0;
3163}
3164
3165void btrfsic_unmount(struct btrfs_root *root,
3166		     struct btrfs_fs_devices *fs_devices)
3167{
3168	struct list_head *elem_all;
3169	struct list_head *tmp_all;
3170	struct btrfsic_state *state;
3171	struct list_head *dev_head = &fs_devices->devices;
3172	struct btrfs_device *device;
3173
3174	if (!btrfsic_is_initialized)
3175		return;
3176
3177	mutex_lock(&btrfsic_mutex);
3178
3179	state = NULL;
3180	list_for_each_entry(device, dev_head, dev_list) {
3181		struct btrfsic_dev_state *ds;
3182
3183		if (!device->bdev || !device->name)
3184			continue;
3185
3186		ds = btrfsic_dev_state_hashtable_lookup(
3187				device->bdev,
3188				&btrfsic_dev_state_hashtable);
3189		if (NULL != ds) {
3190			state = ds->state;
3191			btrfsic_dev_state_hashtable_remove(ds);
3192			btrfsic_dev_state_free(ds);
3193		}
3194	}
3195
3196	if (NULL == state) {
3197		printk(KERN_INFO
3198		       "btrfsic: error, cannot find state information"
3199		       " on umount!\n");
3200		mutex_unlock(&btrfsic_mutex);
3201		return;
3202	}
3203
3204	/*
3205	 * Don't care about keeping the lists' state up to date,
3206	 * just free all memory that was allocated dynamically.
3207	 * Free the blocks and the block_links.
3208	 */
3209	list_for_each_safe(elem_all, tmp_all, &state->all_blocks_list) {
3210		struct btrfsic_block *const b_all =
3211		    list_entry(elem_all, struct btrfsic_block,
3212			       all_blocks_node);
3213		struct list_head *elem_ref_to;
3214		struct list_head *tmp_ref_to;
3215
3216		list_for_each_safe(elem_ref_to, tmp_ref_to,
3217				   &b_all->ref_to_list) {
3218			struct btrfsic_block_link *const l =
3219			    list_entry(elem_ref_to,
3220				       struct btrfsic_block_link,
3221				       node_ref_to);
3222
3223			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
3224				btrfsic_print_rem_link(state, l);
3225
3226			l->ref_cnt--;
3227			if (0 == l->ref_cnt)
3228				btrfsic_block_link_free(l);
3229		}
3230
3231		if (b_all->is_iodone || b_all->never_written)
3232			btrfsic_block_free(b_all);
3233		else
3234			printk(KERN_INFO "btrfs: attempt to free %c-block"
3235			       " @%llu (%s/%llu/%d) on umount which is"
3236			       " not yet iodone!\n",
3237			       btrfsic_get_block_type(state, b_all),
3238			       b_all->logical_bytenr, b_all->dev_state->name,
3239			       b_all->dev_bytenr, b_all->mirror_num);
3240	}
3241
3242	mutex_unlock(&btrfsic_mutex);
3243
3244	kvfree(state);
3245}
3246