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