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/buffer_head.h>
81 #include <linux/mutex.h>
82 #include <linux/genhd.h>
83 #include <linux/blkdev.h>
84 #include <linux/mm.h>
85 #include <linux/string.h>
86 #include <linux/crc32c.h>
87 #include "ctree.h"
88 #include "disk-io.h"
89 #include "transaction.h"
90 #include "extent_io.h"
91 #include "volumes.h"
92 #include "print-tree.h"
93 #include "locking.h"
94 #include "check-integrity.h"
95 #include "rcu-string.h"
96 #include "compression.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_bh_private;
156 	union {
157 		bio_end_io_t *bio;
158 		bh_end_io_t *bh;
159 	} orig_bio_bh_end_io;
160 	int submit_bio_bh_rw;
161 	u64 flush_gen; /* only valid if !never_written */
162 };
163 
164 /*
165  * Elements of this type are allocated dynamically and required because
166  * each block object can refer to and can be ref from multiple blocks.
167  * The key to lookup them in the hashtable is the dev_bytenr of
168  * the block ref to plus the one from the block referred from.
169  * The fact that they are searchable via a hashtable and that a
170  * ref_cnt is maintained is not required for the btrfs integrity
171  * check algorithm itself, it is only used to make the output more
172  * beautiful in case that an error is detected (an error is defined
173  * as a write operation to a block while that block is still referenced).
174  */
175 struct btrfsic_block_link {
176 	u32 magic_num;		/* only used for debug purposes */
177 	u32 ref_cnt;
178 	struct list_head node_ref_to;	/* list node */
179 	struct list_head node_ref_from;	/* list node */
180 	struct list_head collision_resolving_node;	/* list node */
181 	struct btrfsic_block *block_ref_to;
182 	struct btrfsic_block *block_ref_from;
183 	u64 parent_generation;
184 };
185 
186 struct btrfsic_dev_state {
187 	u32 magic_num;		/* only used for debug purposes */
188 	struct block_device *bdev;
189 	struct btrfsic_state *state;
190 	struct list_head collision_resolving_node;	/* list node */
191 	struct btrfsic_block dummy_block_for_bio_bh_flush;
192 	u64 last_flush_gen;
193 	char name[BDEVNAME_SIZE];
194 };
195 
196 struct btrfsic_block_hashtable {
197 	struct list_head table[BTRFSIC_BLOCK_HASHTABLE_SIZE];
198 };
199 
200 struct btrfsic_block_link_hashtable {
201 	struct list_head table[BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE];
202 };
203 
204 struct btrfsic_dev_state_hashtable {
205 	struct list_head table[BTRFSIC_DEV2STATE_HASHTABLE_SIZE];
206 };
207 
208 struct btrfsic_block_data_ctx {
209 	u64 start;		/* virtual bytenr */
210 	u64 dev_bytenr;		/* physical bytenr on device */
211 	u32 len;
212 	struct btrfsic_dev_state *dev;
213 	char **datav;
214 	struct page **pagev;
215 	void *mem_to_free;
216 };
217 
218 /* This structure is used to implement recursion without occupying
219  * any stack space, refer to btrfsic_process_metablock() */
220 struct btrfsic_stack_frame {
221 	u32 magic;
222 	u32 nr;
223 	int error;
224 	int i;
225 	int limit_nesting;
226 	int num_copies;
227 	int mirror_num;
228 	struct btrfsic_block *block;
229 	struct btrfsic_block_data_ctx *block_ctx;
230 	struct btrfsic_block *next_block;
231 	struct btrfsic_block_data_ctx next_block_ctx;
232 	struct btrfs_header *hdr;
233 	struct btrfsic_stack_frame *prev;
234 };
235 
236 /* Some state per mounted filesystem */
237 struct btrfsic_state {
238 	u32 print_mask;
239 	int include_extent_data;
240 	int csum_size;
241 	struct list_head all_blocks_list;
242 	struct btrfsic_block_hashtable block_hashtable;
243 	struct btrfsic_block_link_hashtable block_link_hashtable;
244 	struct btrfs_fs_info *fs_info;
245 	u64 max_superblock_generation;
246 	struct btrfsic_block *latest_superblock;
247 	u32 metablock_size;
248 	u32 datablock_size;
249 };
250 
251 static void btrfsic_block_init(struct btrfsic_block *b);
252 static struct btrfsic_block *btrfsic_block_alloc(void);
253 static void btrfsic_block_free(struct btrfsic_block *b);
254 static void btrfsic_block_link_init(struct btrfsic_block_link *n);
255 static struct btrfsic_block_link *btrfsic_block_link_alloc(void);
256 static void btrfsic_block_link_free(struct btrfsic_block_link *n);
257 static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds);
258 static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void);
259 static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds);
260 static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h);
261 static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
262 					struct btrfsic_block_hashtable *h);
263 static void btrfsic_block_hashtable_remove(struct btrfsic_block *b);
264 static struct btrfsic_block *btrfsic_block_hashtable_lookup(
265 		struct block_device *bdev,
266 		u64 dev_bytenr,
267 		struct btrfsic_block_hashtable *h);
268 static void btrfsic_block_link_hashtable_init(
269 		struct btrfsic_block_link_hashtable *h);
270 static void btrfsic_block_link_hashtable_add(
271 		struct btrfsic_block_link *l,
272 		struct btrfsic_block_link_hashtable *h);
273 static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l);
274 static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
275 		struct block_device *bdev_ref_to,
276 		u64 dev_bytenr_ref_to,
277 		struct block_device *bdev_ref_from,
278 		u64 dev_bytenr_ref_from,
279 		struct btrfsic_block_link_hashtable *h);
280 static void btrfsic_dev_state_hashtable_init(
281 		struct btrfsic_dev_state_hashtable *h);
282 static void btrfsic_dev_state_hashtable_add(
283 		struct btrfsic_dev_state *ds,
284 		struct btrfsic_dev_state_hashtable *h);
285 static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds);
286 static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(dev_t dev,
287 		struct btrfsic_dev_state_hashtable *h);
288 static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void);
289 static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf);
290 static int btrfsic_process_superblock(struct btrfsic_state *state,
291 				      struct btrfs_fs_devices *fs_devices);
292 static int btrfsic_process_metablock(struct btrfsic_state *state,
293 				     struct btrfsic_block *block,
294 				     struct btrfsic_block_data_ctx *block_ctx,
295 				     int limit_nesting, int force_iodone_flag);
296 static void btrfsic_read_from_block_data(
297 	struct btrfsic_block_data_ctx *block_ctx,
298 	void *dst, u32 offset, size_t len);
299 static int btrfsic_create_link_to_next_block(
300 		struct btrfsic_state *state,
301 		struct btrfsic_block *block,
302 		struct btrfsic_block_data_ctx
303 		*block_ctx, u64 next_bytenr,
304 		int limit_nesting,
305 		struct btrfsic_block_data_ctx *next_block_ctx,
306 		struct btrfsic_block **next_blockp,
307 		int force_iodone_flag,
308 		int *num_copiesp, int *mirror_nump,
309 		struct btrfs_disk_key *disk_key,
310 		u64 parent_generation);
311 static int btrfsic_handle_extent_data(struct btrfsic_state *state,
312 				      struct btrfsic_block *block,
313 				      struct btrfsic_block_data_ctx *block_ctx,
314 				      u32 item_offset, int force_iodone_flag);
315 static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
316 			     struct btrfsic_block_data_ctx *block_ctx_out,
317 			     int mirror_num);
318 static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx);
319 static int btrfsic_read_block(struct btrfsic_state *state,
320 			      struct btrfsic_block_data_ctx *block_ctx);
321 static void btrfsic_dump_database(struct btrfsic_state *state);
322 static int btrfsic_test_for_metadata(struct btrfsic_state *state,
323 				     char **datav, unsigned int num_pages);
324 static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
325 					  u64 dev_bytenr, char **mapped_datav,
326 					  unsigned int num_pages,
327 					  struct bio *bio, int *bio_is_patched,
328 					  struct buffer_head *bh,
329 					  int submit_bio_bh_rw);
330 static int btrfsic_process_written_superblock(
331 		struct btrfsic_state *state,
332 		struct btrfsic_block *const block,
333 		struct btrfs_super_block *const super_hdr);
334 static void btrfsic_bio_end_io(struct bio *bp);
335 static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate);
336 static int btrfsic_is_block_ref_by_superblock(const struct btrfsic_state *state,
337 					      const struct btrfsic_block *block,
338 					      int recursion_level);
339 static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
340 					struct btrfsic_block *const block,
341 					int recursion_level);
342 static void btrfsic_print_add_link(const struct btrfsic_state *state,
343 				   const struct btrfsic_block_link *l);
344 static void btrfsic_print_rem_link(const struct btrfsic_state *state,
345 				   const struct btrfsic_block_link *l);
346 static char btrfsic_get_block_type(const struct btrfsic_state *state,
347 				   const struct btrfsic_block *block);
348 static void btrfsic_dump_tree(const struct btrfsic_state *state);
349 static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
350 				  const struct btrfsic_block *block,
351 				  int indent_level);
352 static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
353 		struct btrfsic_state *state,
354 		struct btrfsic_block_data_ctx *next_block_ctx,
355 		struct btrfsic_block *next_block,
356 		struct btrfsic_block *from_block,
357 		u64 parent_generation);
358 static struct btrfsic_block *btrfsic_block_lookup_or_add(
359 		struct btrfsic_state *state,
360 		struct btrfsic_block_data_ctx *block_ctx,
361 		const char *additional_string,
362 		int is_metadata,
363 		int is_iodone,
364 		int never_written,
365 		int mirror_num,
366 		int *was_created);
367 static int btrfsic_process_superblock_dev_mirror(
368 		struct btrfsic_state *state,
369 		struct btrfsic_dev_state *dev_state,
370 		struct btrfs_device *device,
371 		int superblock_mirror_num,
372 		struct btrfsic_dev_state **selected_dev_state,
373 		struct btrfs_super_block *selected_super);
374 static struct btrfsic_dev_state *btrfsic_dev_state_lookup(dev_t dev);
375 static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
376 					   u64 bytenr,
377 					   struct btrfsic_dev_state *dev_state,
378 					   u64 dev_bytenr);
379 
380 static struct mutex btrfsic_mutex;
381 static int btrfsic_is_initialized;
382 static struct btrfsic_dev_state_hashtable btrfsic_dev_state_hashtable;
383 
384 
btrfsic_block_init(struct btrfsic_block * b)385 static void btrfsic_block_init(struct btrfsic_block *b)
386 {
387 	b->magic_num = BTRFSIC_BLOCK_MAGIC_NUMBER;
388 	b->dev_state = NULL;
389 	b->dev_bytenr = 0;
390 	b->logical_bytenr = 0;
391 	b->generation = BTRFSIC_GENERATION_UNKNOWN;
392 	b->disk_key.objectid = 0;
393 	b->disk_key.type = 0;
394 	b->disk_key.offset = 0;
395 	b->is_metadata = 0;
396 	b->is_superblock = 0;
397 	b->is_iodone = 0;
398 	b->iodone_w_error = 0;
399 	b->never_written = 0;
400 	b->mirror_num = 0;
401 	b->next_in_same_bio = NULL;
402 	b->orig_bio_bh_private = NULL;
403 	b->orig_bio_bh_end_io.bio = NULL;
404 	INIT_LIST_HEAD(&b->collision_resolving_node);
405 	INIT_LIST_HEAD(&b->all_blocks_node);
406 	INIT_LIST_HEAD(&b->ref_to_list);
407 	INIT_LIST_HEAD(&b->ref_from_list);
408 	b->submit_bio_bh_rw = 0;
409 	b->flush_gen = 0;
410 }
411 
btrfsic_block_alloc(void)412 static struct btrfsic_block *btrfsic_block_alloc(void)
413 {
414 	struct btrfsic_block *b;
415 
416 	b = kzalloc(sizeof(*b), GFP_NOFS);
417 	if (NULL != b)
418 		btrfsic_block_init(b);
419 
420 	return b;
421 }
422 
btrfsic_block_free(struct btrfsic_block * b)423 static void btrfsic_block_free(struct btrfsic_block *b)
424 {
425 	BUG_ON(!(NULL == b || BTRFSIC_BLOCK_MAGIC_NUMBER == b->magic_num));
426 	kfree(b);
427 }
428 
btrfsic_block_link_init(struct btrfsic_block_link * l)429 static void btrfsic_block_link_init(struct btrfsic_block_link *l)
430 {
431 	l->magic_num = BTRFSIC_BLOCK_LINK_MAGIC_NUMBER;
432 	l->ref_cnt = 1;
433 	INIT_LIST_HEAD(&l->node_ref_to);
434 	INIT_LIST_HEAD(&l->node_ref_from);
435 	INIT_LIST_HEAD(&l->collision_resolving_node);
436 	l->block_ref_to = NULL;
437 	l->block_ref_from = NULL;
438 }
439 
btrfsic_block_link_alloc(void)440 static struct btrfsic_block_link *btrfsic_block_link_alloc(void)
441 {
442 	struct btrfsic_block_link *l;
443 
444 	l = kzalloc(sizeof(*l), GFP_NOFS);
445 	if (NULL != l)
446 		btrfsic_block_link_init(l);
447 
448 	return l;
449 }
450 
btrfsic_block_link_free(struct btrfsic_block_link * l)451 static void btrfsic_block_link_free(struct btrfsic_block_link *l)
452 {
453 	BUG_ON(!(NULL == l || BTRFSIC_BLOCK_LINK_MAGIC_NUMBER == l->magic_num));
454 	kfree(l);
455 }
456 
btrfsic_dev_state_init(struct btrfsic_dev_state * ds)457 static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds)
458 {
459 	ds->magic_num = BTRFSIC_DEV2STATE_MAGIC_NUMBER;
460 	ds->bdev = NULL;
461 	ds->state = NULL;
462 	ds->name[0] = '\0';
463 	INIT_LIST_HEAD(&ds->collision_resolving_node);
464 	ds->last_flush_gen = 0;
465 	btrfsic_block_init(&ds->dummy_block_for_bio_bh_flush);
466 	ds->dummy_block_for_bio_bh_flush.is_iodone = 1;
467 	ds->dummy_block_for_bio_bh_flush.dev_state = ds;
468 }
469 
btrfsic_dev_state_alloc(void)470 static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void)
471 {
472 	struct btrfsic_dev_state *ds;
473 
474 	ds = kzalloc(sizeof(*ds), GFP_NOFS);
475 	if (NULL != ds)
476 		btrfsic_dev_state_init(ds);
477 
478 	return ds;
479 }
480 
btrfsic_dev_state_free(struct btrfsic_dev_state * ds)481 static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds)
482 {
483 	BUG_ON(!(NULL == ds ||
484 		 BTRFSIC_DEV2STATE_MAGIC_NUMBER == ds->magic_num));
485 	kfree(ds);
486 }
487 
btrfsic_block_hashtable_init(struct btrfsic_block_hashtable * h)488 static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h)
489 {
490 	int i;
491 
492 	for (i = 0; i < BTRFSIC_BLOCK_HASHTABLE_SIZE; i++)
493 		INIT_LIST_HEAD(h->table + i);
494 }
495 
btrfsic_block_hashtable_add(struct btrfsic_block * b,struct btrfsic_block_hashtable * h)496 static void btrfsic_block_hashtable_add(struct btrfsic_block *b,
497 					struct btrfsic_block_hashtable *h)
498 {
499 	const unsigned int hashval =
500 	    (((unsigned int)(b->dev_bytenr >> 16)) ^
501 	     ((unsigned int)((uintptr_t)b->dev_state->bdev))) &
502 	     (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
503 
504 	list_add(&b->collision_resolving_node, h->table + hashval);
505 }
506 
btrfsic_block_hashtable_remove(struct btrfsic_block * b)507 static void btrfsic_block_hashtable_remove(struct btrfsic_block *b)
508 {
509 	list_del(&b->collision_resolving_node);
510 }
511 
btrfsic_block_hashtable_lookup(struct block_device * bdev,u64 dev_bytenr,struct btrfsic_block_hashtable * h)512 static struct btrfsic_block *btrfsic_block_hashtable_lookup(
513 		struct block_device *bdev,
514 		u64 dev_bytenr,
515 		struct btrfsic_block_hashtable *h)
516 {
517 	const unsigned int hashval =
518 	    (((unsigned int)(dev_bytenr >> 16)) ^
519 	     ((unsigned int)((uintptr_t)bdev))) &
520 	     (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1);
521 	struct btrfsic_block *b;
522 
523 	list_for_each_entry(b, h->table + hashval, collision_resolving_node) {
524 		if (b->dev_state->bdev == bdev && b->dev_bytenr == dev_bytenr)
525 			return b;
526 	}
527 
528 	return NULL;
529 }
530 
btrfsic_block_link_hashtable_init(struct btrfsic_block_link_hashtable * h)531 static void btrfsic_block_link_hashtable_init(
532 		struct btrfsic_block_link_hashtable *h)
533 {
534 	int i;
535 
536 	for (i = 0; i < BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE; i++)
537 		INIT_LIST_HEAD(h->table + i);
538 }
539 
btrfsic_block_link_hashtable_add(struct btrfsic_block_link * l,struct btrfsic_block_link_hashtable * h)540 static void btrfsic_block_link_hashtable_add(
541 		struct btrfsic_block_link *l,
542 		struct btrfsic_block_link_hashtable *h)
543 {
544 	const unsigned int hashval =
545 	    (((unsigned int)(l->block_ref_to->dev_bytenr >> 16)) ^
546 	     ((unsigned int)(l->block_ref_from->dev_bytenr >> 16)) ^
547 	     ((unsigned int)((uintptr_t)l->block_ref_to->dev_state->bdev)) ^
548 	     ((unsigned int)((uintptr_t)l->block_ref_from->dev_state->bdev)))
549 	     & (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
550 
551 	BUG_ON(NULL == l->block_ref_to);
552 	BUG_ON(NULL == l->block_ref_from);
553 	list_add(&l->collision_resolving_node, h->table + hashval);
554 }
555 
btrfsic_block_link_hashtable_remove(struct btrfsic_block_link * l)556 static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l)
557 {
558 	list_del(&l->collision_resolving_node);
559 }
560 
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)561 static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup(
562 		struct block_device *bdev_ref_to,
563 		u64 dev_bytenr_ref_to,
564 		struct block_device *bdev_ref_from,
565 		u64 dev_bytenr_ref_from,
566 		struct btrfsic_block_link_hashtable *h)
567 {
568 	const unsigned int hashval =
569 	    (((unsigned int)(dev_bytenr_ref_to >> 16)) ^
570 	     ((unsigned int)(dev_bytenr_ref_from >> 16)) ^
571 	     ((unsigned int)((uintptr_t)bdev_ref_to)) ^
572 	     ((unsigned int)((uintptr_t)bdev_ref_from))) &
573 	     (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1);
574 	struct btrfsic_block_link *l;
575 
576 	list_for_each_entry(l, h->table + hashval, collision_resolving_node) {
577 		BUG_ON(NULL == l->block_ref_to);
578 		BUG_ON(NULL == l->block_ref_from);
579 		if (l->block_ref_to->dev_state->bdev == bdev_ref_to &&
580 		    l->block_ref_to->dev_bytenr == dev_bytenr_ref_to &&
581 		    l->block_ref_from->dev_state->bdev == bdev_ref_from &&
582 		    l->block_ref_from->dev_bytenr == dev_bytenr_ref_from)
583 			return l;
584 	}
585 
586 	return NULL;
587 }
588 
btrfsic_dev_state_hashtable_init(struct btrfsic_dev_state_hashtable * h)589 static void btrfsic_dev_state_hashtable_init(
590 		struct btrfsic_dev_state_hashtable *h)
591 {
592 	int i;
593 
594 	for (i = 0; i < BTRFSIC_DEV2STATE_HASHTABLE_SIZE; i++)
595 		INIT_LIST_HEAD(h->table + i);
596 }
597 
btrfsic_dev_state_hashtable_add(struct btrfsic_dev_state * ds,struct btrfsic_dev_state_hashtable * h)598 static void btrfsic_dev_state_hashtable_add(
599 		struct btrfsic_dev_state *ds,
600 		struct btrfsic_dev_state_hashtable *h)
601 {
602 	const unsigned int hashval =
603 	    (((unsigned int)((uintptr_t)ds->bdev->bd_dev)) &
604 	     (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1));
605 
606 	list_add(&ds->collision_resolving_node, h->table + hashval);
607 }
608 
btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state * ds)609 static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds)
610 {
611 	list_del(&ds->collision_resolving_node);
612 }
613 
btrfsic_dev_state_hashtable_lookup(dev_t dev,struct btrfsic_dev_state_hashtable * h)614 static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(dev_t dev,
615 		struct btrfsic_dev_state_hashtable *h)
616 {
617 	const unsigned int hashval =
618 		dev & (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1);
619 	struct btrfsic_dev_state *ds;
620 
621 	list_for_each_entry(ds, h->table + hashval, collision_resolving_node) {
622 		if (ds->bdev->bd_dev == dev)
623 			return ds;
624 	}
625 
626 	return NULL;
627 }
628 
btrfsic_process_superblock(struct btrfsic_state * state,struct btrfs_fs_devices * fs_devices)629 static int btrfsic_process_superblock(struct btrfsic_state *state,
630 				      struct btrfs_fs_devices *fs_devices)
631 {
632 	struct btrfs_super_block *selected_super;
633 	struct list_head *dev_head = &fs_devices->devices;
634 	struct btrfs_device *device;
635 	struct btrfsic_dev_state *selected_dev_state = NULL;
636 	int ret = 0;
637 	int pass;
638 
639 	BUG_ON(NULL == state);
640 	selected_super = kzalloc(sizeof(*selected_super), GFP_NOFS);
641 	if (NULL == selected_super) {
642 		pr_info("btrfsic: error, kmalloc failed!\n");
643 		return -ENOMEM;
644 	}
645 
646 	list_for_each_entry(device, dev_head, dev_list) {
647 		int i;
648 		struct btrfsic_dev_state *dev_state;
649 
650 		if (!device->bdev || !device->name)
651 			continue;
652 
653 		dev_state = btrfsic_dev_state_lookup(device->bdev->bd_dev);
654 		BUG_ON(NULL == dev_state);
655 		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
656 			ret = btrfsic_process_superblock_dev_mirror(
657 					state, dev_state, device, i,
658 					&selected_dev_state, selected_super);
659 			if (0 != ret && 0 == i) {
660 				kfree(selected_super);
661 				return ret;
662 			}
663 		}
664 	}
665 
666 	if (NULL == state->latest_superblock) {
667 		pr_info("btrfsic: no superblock found!\n");
668 		kfree(selected_super);
669 		return -1;
670 	}
671 
672 	state->csum_size = btrfs_super_csum_size(selected_super);
673 
674 	for (pass = 0; pass < 3; pass++) {
675 		int num_copies;
676 		int mirror_num;
677 		u64 next_bytenr;
678 
679 		switch (pass) {
680 		case 0:
681 			next_bytenr = btrfs_super_root(selected_super);
682 			if (state->print_mask &
683 			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
684 				pr_info("root@%llu\n", next_bytenr);
685 			break;
686 		case 1:
687 			next_bytenr = btrfs_super_chunk_root(selected_super);
688 			if (state->print_mask &
689 			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
690 				pr_info("chunk@%llu\n", next_bytenr);
691 			break;
692 		case 2:
693 			next_bytenr = btrfs_super_log_root(selected_super);
694 			if (0 == next_bytenr)
695 				continue;
696 			if (state->print_mask &
697 			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
698 				pr_info("log@%llu\n", next_bytenr);
699 			break;
700 		}
701 
702 		num_copies = btrfs_num_copies(state->fs_info, next_bytenr,
703 					      state->metablock_size);
704 		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
705 			pr_info("num_copies(log_bytenr=%llu) = %d\n",
706 			       next_bytenr, num_copies);
707 
708 		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
709 			struct btrfsic_block *next_block;
710 			struct btrfsic_block_data_ctx tmp_next_block_ctx;
711 			struct btrfsic_block_link *l;
712 
713 			ret = btrfsic_map_block(state, next_bytenr,
714 						state->metablock_size,
715 						&tmp_next_block_ctx,
716 						mirror_num);
717 			if (ret) {
718 				pr_info("btrfsic: btrfsic_map_block(root @%llu, mirror %d) failed!\n",
719 				       next_bytenr, mirror_num);
720 				kfree(selected_super);
721 				return -1;
722 			}
723 
724 			next_block = btrfsic_block_hashtable_lookup(
725 					tmp_next_block_ctx.dev->bdev,
726 					tmp_next_block_ctx.dev_bytenr,
727 					&state->block_hashtable);
728 			BUG_ON(NULL == next_block);
729 
730 			l = btrfsic_block_link_hashtable_lookup(
731 					tmp_next_block_ctx.dev->bdev,
732 					tmp_next_block_ctx.dev_bytenr,
733 					state->latest_superblock->dev_state->
734 					bdev,
735 					state->latest_superblock->dev_bytenr,
736 					&state->block_link_hashtable);
737 			BUG_ON(NULL == l);
738 
739 			ret = btrfsic_read_block(state, &tmp_next_block_ctx);
740 			if (ret < (int)PAGE_SIZE) {
741 				pr_info("btrfsic: read @logical %llu failed!\n",
742 				       tmp_next_block_ctx.start);
743 				btrfsic_release_block_ctx(&tmp_next_block_ctx);
744 				kfree(selected_super);
745 				return -1;
746 			}
747 
748 			ret = btrfsic_process_metablock(state,
749 							next_block,
750 							&tmp_next_block_ctx,
751 							BTRFS_MAX_LEVEL + 3, 1);
752 			btrfsic_release_block_ctx(&tmp_next_block_ctx);
753 		}
754 	}
755 
756 	kfree(selected_super);
757 	return ret;
758 }
759 
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)760 static int btrfsic_process_superblock_dev_mirror(
761 		struct btrfsic_state *state,
762 		struct btrfsic_dev_state *dev_state,
763 		struct btrfs_device *device,
764 		int superblock_mirror_num,
765 		struct btrfsic_dev_state **selected_dev_state,
766 		struct btrfs_super_block *selected_super)
767 {
768 	struct btrfs_fs_info *fs_info = state->fs_info;
769 	struct btrfs_super_block *super_tmp;
770 	u64 dev_bytenr;
771 	struct buffer_head *bh;
772 	struct btrfsic_block *superblock_tmp;
773 	int pass;
774 	struct block_device *const superblock_bdev = device->bdev;
775 
776 	/* super block bytenr is always the unmapped device bytenr */
777 	dev_bytenr = btrfs_sb_offset(superblock_mirror_num);
778 	if (dev_bytenr + BTRFS_SUPER_INFO_SIZE > device->commit_total_bytes)
779 		return -1;
780 	bh = __bread(superblock_bdev, dev_bytenr / BTRFS_BDEV_BLOCKSIZE,
781 		     BTRFS_SUPER_INFO_SIZE);
782 	if (NULL == bh)
783 		return -1;
784 	super_tmp = (struct btrfs_super_block *)
785 	    (bh->b_data + (dev_bytenr & (BTRFS_BDEV_BLOCKSIZE - 1)));
786 
787 	if (btrfs_super_bytenr(super_tmp) != dev_bytenr ||
788 	    btrfs_super_magic(super_tmp) != BTRFS_MAGIC ||
789 	    memcmp(device->uuid, super_tmp->dev_item.uuid, BTRFS_UUID_SIZE) ||
790 	    btrfs_super_nodesize(super_tmp) != state->metablock_size ||
791 	    btrfs_super_sectorsize(super_tmp) != state->datablock_size) {
792 		brelse(bh);
793 		return 0;
794 	}
795 
796 	superblock_tmp =
797 	    btrfsic_block_hashtable_lookup(superblock_bdev,
798 					   dev_bytenr,
799 					   &state->block_hashtable);
800 	if (NULL == superblock_tmp) {
801 		superblock_tmp = btrfsic_block_alloc();
802 		if (NULL == superblock_tmp) {
803 			pr_info("btrfsic: error, kmalloc failed!\n");
804 			brelse(bh);
805 			return -1;
806 		}
807 		/* for superblock, only the dev_bytenr makes sense */
808 		superblock_tmp->dev_bytenr = dev_bytenr;
809 		superblock_tmp->dev_state = dev_state;
810 		superblock_tmp->logical_bytenr = dev_bytenr;
811 		superblock_tmp->generation = btrfs_super_generation(super_tmp);
812 		superblock_tmp->is_metadata = 1;
813 		superblock_tmp->is_superblock = 1;
814 		superblock_tmp->is_iodone = 1;
815 		superblock_tmp->never_written = 0;
816 		superblock_tmp->mirror_num = 1 + superblock_mirror_num;
817 		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
818 			btrfs_info_in_rcu(fs_info,
819 				"new initial S-block (bdev %p, %s) @%llu (%s/%llu/%d)",
820 				     superblock_bdev,
821 				     rcu_str_deref(device->name), dev_bytenr,
822 				     dev_state->name, dev_bytenr,
823 				     superblock_mirror_num);
824 		list_add(&superblock_tmp->all_blocks_node,
825 			 &state->all_blocks_list);
826 		btrfsic_block_hashtable_add(superblock_tmp,
827 					    &state->block_hashtable);
828 	}
829 
830 	/* select the one with the highest generation field */
831 	if (btrfs_super_generation(super_tmp) >
832 	    state->max_superblock_generation ||
833 	    0 == state->max_superblock_generation) {
834 		memcpy(selected_super, super_tmp, sizeof(*selected_super));
835 		*selected_dev_state = dev_state;
836 		state->max_superblock_generation =
837 		    btrfs_super_generation(super_tmp);
838 		state->latest_superblock = superblock_tmp;
839 	}
840 
841 	for (pass = 0; pass < 3; pass++) {
842 		u64 next_bytenr;
843 		int num_copies;
844 		int mirror_num;
845 		const char *additional_string = NULL;
846 		struct btrfs_disk_key tmp_disk_key;
847 
848 		tmp_disk_key.type = BTRFS_ROOT_ITEM_KEY;
849 		tmp_disk_key.offset = 0;
850 		switch (pass) {
851 		case 0:
852 			btrfs_set_disk_key_objectid(&tmp_disk_key,
853 						    BTRFS_ROOT_TREE_OBJECTID);
854 			additional_string = "initial root ";
855 			next_bytenr = btrfs_super_root(super_tmp);
856 			break;
857 		case 1:
858 			btrfs_set_disk_key_objectid(&tmp_disk_key,
859 						    BTRFS_CHUNK_TREE_OBJECTID);
860 			additional_string = "initial chunk ";
861 			next_bytenr = btrfs_super_chunk_root(super_tmp);
862 			break;
863 		case 2:
864 			btrfs_set_disk_key_objectid(&tmp_disk_key,
865 						    BTRFS_TREE_LOG_OBJECTID);
866 			additional_string = "initial log ";
867 			next_bytenr = btrfs_super_log_root(super_tmp);
868 			if (0 == next_bytenr)
869 				continue;
870 			break;
871 		}
872 
873 		num_copies = btrfs_num_copies(fs_info, next_bytenr,
874 					      state->metablock_size);
875 		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
876 			pr_info("num_copies(log_bytenr=%llu) = %d\n",
877 			       next_bytenr, num_copies);
878 		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
879 			struct btrfsic_block *next_block;
880 			struct btrfsic_block_data_ctx tmp_next_block_ctx;
881 			struct btrfsic_block_link *l;
882 
883 			if (btrfsic_map_block(state, next_bytenr,
884 					      state->metablock_size,
885 					      &tmp_next_block_ctx,
886 					      mirror_num)) {
887 				pr_info("btrfsic: btrfsic_map_block(bytenr @%llu, mirror %d) failed!\n",
888 				       next_bytenr, mirror_num);
889 				brelse(bh);
890 				return -1;
891 			}
892 
893 			next_block = btrfsic_block_lookup_or_add(
894 					state, &tmp_next_block_ctx,
895 					additional_string, 1, 1, 0,
896 					mirror_num, NULL);
897 			if (NULL == next_block) {
898 				btrfsic_release_block_ctx(&tmp_next_block_ctx);
899 				brelse(bh);
900 				return -1;
901 			}
902 
903 			next_block->disk_key = tmp_disk_key;
904 			next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
905 			l = btrfsic_block_link_lookup_or_add(
906 					state, &tmp_next_block_ctx,
907 					next_block, superblock_tmp,
908 					BTRFSIC_GENERATION_UNKNOWN);
909 			btrfsic_release_block_ctx(&tmp_next_block_ctx);
910 			if (NULL == l) {
911 				brelse(bh);
912 				return -1;
913 			}
914 		}
915 	}
916 	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES)
917 		btrfsic_dump_tree_sub(state, superblock_tmp, 0);
918 
919 	brelse(bh);
920 	return 0;
921 }
922 
btrfsic_stack_frame_alloc(void)923 static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void)
924 {
925 	struct btrfsic_stack_frame *sf;
926 
927 	sf = kzalloc(sizeof(*sf), GFP_NOFS);
928 	if (NULL == sf)
929 		pr_info("btrfsic: alloc memory failed!\n");
930 	else
931 		sf->magic = BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER;
932 	return sf;
933 }
934 
btrfsic_stack_frame_free(struct btrfsic_stack_frame * sf)935 static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf)
936 {
937 	BUG_ON(!(NULL == sf ||
938 		 BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER == sf->magic));
939 	kfree(sf);
940 }
941 
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)942 static int btrfsic_process_metablock(
943 		struct btrfsic_state *state,
944 		struct btrfsic_block *const first_block,
945 		struct btrfsic_block_data_ctx *const first_block_ctx,
946 		int first_limit_nesting, int force_iodone_flag)
947 {
948 	struct btrfsic_stack_frame initial_stack_frame = { 0 };
949 	struct btrfsic_stack_frame *sf;
950 	struct btrfsic_stack_frame *next_stack;
951 	struct btrfs_header *const first_hdr =
952 		(struct btrfs_header *)first_block_ctx->datav[0];
953 
954 	BUG_ON(!first_hdr);
955 	sf = &initial_stack_frame;
956 	sf->error = 0;
957 	sf->i = -1;
958 	sf->limit_nesting = first_limit_nesting;
959 	sf->block = first_block;
960 	sf->block_ctx = first_block_ctx;
961 	sf->next_block = NULL;
962 	sf->hdr = first_hdr;
963 	sf->prev = NULL;
964 
965 continue_with_new_stack_frame:
966 	sf->block->generation = le64_to_cpu(sf->hdr->generation);
967 	if (0 == sf->hdr->level) {
968 		struct btrfs_leaf *const leafhdr =
969 		    (struct btrfs_leaf *)sf->hdr;
970 
971 		if (-1 == sf->i) {
972 			sf->nr = btrfs_stack_header_nritems(&leafhdr->header);
973 
974 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
975 				pr_info("leaf %llu items %d generation %llu owner %llu\n",
976 				       sf->block_ctx->start, sf->nr,
977 				       btrfs_stack_header_generation(
978 					       &leafhdr->header),
979 				       btrfs_stack_header_owner(
980 					       &leafhdr->header));
981 		}
982 
983 continue_with_current_leaf_stack_frame:
984 		if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
985 			sf->i++;
986 			sf->num_copies = 0;
987 		}
988 
989 		if (sf->i < sf->nr) {
990 			struct btrfs_item disk_item;
991 			u32 disk_item_offset =
992 				(uintptr_t)(leafhdr->items + sf->i) -
993 				(uintptr_t)leafhdr;
994 			struct btrfs_disk_key *disk_key;
995 			u8 type;
996 			u32 item_offset;
997 			u32 item_size;
998 
999 			if (disk_item_offset + sizeof(struct btrfs_item) >
1000 			    sf->block_ctx->len) {
1001 leaf_item_out_of_bounce_error:
1002 				pr_info("btrfsic: leaf item out of bounce at logical %llu, dev %s\n",
1003 				       sf->block_ctx->start,
1004 				       sf->block_ctx->dev->name);
1005 				goto one_stack_frame_backwards;
1006 			}
1007 			btrfsic_read_from_block_data(sf->block_ctx,
1008 						     &disk_item,
1009 						     disk_item_offset,
1010 						     sizeof(struct btrfs_item));
1011 			item_offset = btrfs_stack_item_offset(&disk_item);
1012 			item_size = btrfs_stack_item_size(&disk_item);
1013 			disk_key = &disk_item.key;
1014 			type = btrfs_disk_key_type(disk_key);
1015 
1016 			if (BTRFS_ROOT_ITEM_KEY == type) {
1017 				struct btrfs_root_item root_item;
1018 				u32 root_item_offset;
1019 				u64 next_bytenr;
1020 
1021 				root_item_offset = item_offset +
1022 					offsetof(struct btrfs_leaf, items);
1023 				if (root_item_offset + item_size >
1024 				    sf->block_ctx->len)
1025 					goto leaf_item_out_of_bounce_error;
1026 				btrfsic_read_from_block_data(
1027 					sf->block_ctx, &root_item,
1028 					root_item_offset,
1029 					item_size);
1030 				next_bytenr = btrfs_root_bytenr(&root_item);
1031 
1032 				sf->error =
1033 				    btrfsic_create_link_to_next_block(
1034 						state,
1035 						sf->block,
1036 						sf->block_ctx,
1037 						next_bytenr,
1038 						sf->limit_nesting,
1039 						&sf->next_block_ctx,
1040 						&sf->next_block,
1041 						force_iodone_flag,
1042 						&sf->num_copies,
1043 						&sf->mirror_num,
1044 						disk_key,
1045 						btrfs_root_generation(
1046 						&root_item));
1047 				if (sf->error)
1048 					goto one_stack_frame_backwards;
1049 
1050 				if (NULL != sf->next_block) {
1051 					struct btrfs_header *const next_hdr =
1052 					    (struct btrfs_header *)
1053 					    sf->next_block_ctx.datav[0];
1054 
1055 					next_stack =
1056 					    btrfsic_stack_frame_alloc();
1057 					if (NULL == next_stack) {
1058 						sf->error = -1;
1059 						btrfsic_release_block_ctx(
1060 								&sf->
1061 								next_block_ctx);
1062 						goto one_stack_frame_backwards;
1063 					}
1064 
1065 					next_stack->i = -1;
1066 					next_stack->block = sf->next_block;
1067 					next_stack->block_ctx =
1068 					    &sf->next_block_ctx;
1069 					next_stack->next_block = NULL;
1070 					next_stack->hdr = next_hdr;
1071 					next_stack->limit_nesting =
1072 					    sf->limit_nesting - 1;
1073 					next_stack->prev = sf;
1074 					sf = next_stack;
1075 					goto continue_with_new_stack_frame;
1076 				}
1077 			} else if (BTRFS_EXTENT_DATA_KEY == type &&
1078 				   state->include_extent_data) {
1079 				sf->error = btrfsic_handle_extent_data(
1080 						state,
1081 						sf->block,
1082 						sf->block_ctx,
1083 						item_offset,
1084 						force_iodone_flag);
1085 				if (sf->error)
1086 					goto one_stack_frame_backwards;
1087 			}
1088 
1089 			goto continue_with_current_leaf_stack_frame;
1090 		}
1091 	} else {
1092 		struct btrfs_node *const nodehdr = (struct btrfs_node *)sf->hdr;
1093 
1094 		if (-1 == sf->i) {
1095 			sf->nr = btrfs_stack_header_nritems(&nodehdr->header);
1096 
1097 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1098 				pr_info("node %llu level %d items %d generation %llu owner %llu\n",
1099 				       sf->block_ctx->start,
1100 				       nodehdr->header.level, sf->nr,
1101 				       btrfs_stack_header_generation(
1102 				       &nodehdr->header),
1103 				       btrfs_stack_header_owner(
1104 				       &nodehdr->header));
1105 		}
1106 
1107 continue_with_current_node_stack_frame:
1108 		if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) {
1109 			sf->i++;
1110 			sf->num_copies = 0;
1111 		}
1112 
1113 		if (sf->i < sf->nr) {
1114 			struct btrfs_key_ptr key_ptr;
1115 			u32 key_ptr_offset;
1116 			u64 next_bytenr;
1117 
1118 			key_ptr_offset = (uintptr_t)(nodehdr->ptrs + sf->i) -
1119 					  (uintptr_t)nodehdr;
1120 			if (key_ptr_offset + sizeof(struct btrfs_key_ptr) >
1121 			    sf->block_ctx->len) {
1122 				pr_info("btrfsic: node item out of bounce at logical %llu, dev %s\n",
1123 				       sf->block_ctx->start,
1124 				       sf->block_ctx->dev->name);
1125 				goto one_stack_frame_backwards;
1126 			}
1127 			btrfsic_read_from_block_data(
1128 				sf->block_ctx, &key_ptr, key_ptr_offset,
1129 				sizeof(struct btrfs_key_ptr));
1130 			next_bytenr = btrfs_stack_key_blockptr(&key_ptr);
1131 
1132 			sf->error = btrfsic_create_link_to_next_block(
1133 					state,
1134 					sf->block,
1135 					sf->block_ctx,
1136 					next_bytenr,
1137 					sf->limit_nesting,
1138 					&sf->next_block_ctx,
1139 					&sf->next_block,
1140 					force_iodone_flag,
1141 					&sf->num_copies,
1142 					&sf->mirror_num,
1143 					&key_ptr.key,
1144 					btrfs_stack_key_generation(&key_ptr));
1145 			if (sf->error)
1146 				goto one_stack_frame_backwards;
1147 
1148 			if (NULL != sf->next_block) {
1149 				struct btrfs_header *const next_hdr =
1150 				    (struct btrfs_header *)
1151 				    sf->next_block_ctx.datav[0];
1152 
1153 				next_stack = btrfsic_stack_frame_alloc();
1154 				if (NULL == next_stack) {
1155 					sf->error = -1;
1156 					goto one_stack_frame_backwards;
1157 				}
1158 
1159 				next_stack->i = -1;
1160 				next_stack->block = sf->next_block;
1161 				next_stack->block_ctx = &sf->next_block_ctx;
1162 				next_stack->next_block = NULL;
1163 				next_stack->hdr = next_hdr;
1164 				next_stack->limit_nesting =
1165 				    sf->limit_nesting - 1;
1166 				next_stack->prev = sf;
1167 				sf = next_stack;
1168 				goto continue_with_new_stack_frame;
1169 			}
1170 
1171 			goto continue_with_current_node_stack_frame;
1172 		}
1173 	}
1174 
1175 one_stack_frame_backwards:
1176 	if (NULL != sf->prev) {
1177 		struct btrfsic_stack_frame *const prev = sf->prev;
1178 
1179 		/* the one for the initial block is freed in the caller */
1180 		btrfsic_release_block_ctx(sf->block_ctx);
1181 
1182 		if (sf->error) {
1183 			prev->error = sf->error;
1184 			btrfsic_stack_frame_free(sf);
1185 			sf = prev;
1186 			goto one_stack_frame_backwards;
1187 		}
1188 
1189 		btrfsic_stack_frame_free(sf);
1190 		sf = prev;
1191 		goto continue_with_new_stack_frame;
1192 	} else {
1193 		BUG_ON(&initial_stack_frame != sf);
1194 	}
1195 
1196 	return sf->error;
1197 }
1198 
btrfsic_read_from_block_data(struct btrfsic_block_data_ctx * block_ctx,void * dstv,u32 offset,size_t len)1199 static void btrfsic_read_from_block_data(
1200 	struct btrfsic_block_data_ctx *block_ctx,
1201 	void *dstv, u32 offset, size_t len)
1202 {
1203 	size_t cur;
1204 	size_t offset_in_page;
1205 	char *kaddr;
1206 	char *dst = (char *)dstv;
1207 	size_t start_offset = block_ctx->start & ((u64)PAGE_SIZE - 1);
1208 	unsigned long i = (start_offset + offset) >> PAGE_SHIFT;
1209 
1210 	WARN_ON(offset + len > block_ctx->len);
1211 	offset_in_page = (start_offset + offset) & (PAGE_SIZE - 1);
1212 
1213 	while (len > 0) {
1214 		cur = min(len, ((size_t)PAGE_SIZE - offset_in_page));
1215 		BUG_ON(i >= DIV_ROUND_UP(block_ctx->len, PAGE_SIZE));
1216 		kaddr = block_ctx->datav[i];
1217 		memcpy(dst, kaddr + offset_in_page, cur);
1218 
1219 		dst += cur;
1220 		len -= cur;
1221 		offset_in_page = 0;
1222 		i++;
1223 	}
1224 }
1225 
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)1226 static int btrfsic_create_link_to_next_block(
1227 		struct btrfsic_state *state,
1228 		struct btrfsic_block *block,
1229 		struct btrfsic_block_data_ctx *block_ctx,
1230 		u64 next_bytenr,
1231 		int limit_nesting,
1232 		struct btrfsic_block_data_ctx *next_block_ctx,
1233 		struct btrfsic_block **next_blockp,
1234 		int force_iodone_flag,
1235 		int *num_copiesp, int *mirror_nump,
1236 		struct btrfs_disk_key *disk_key,
1237 		u64 parent_generation)
1238 {
1239 	struct btrfs_fs_info *fs_info = state->fs_info;
1240 	struct btrfsic_block *next_block = NULL;
1241 	int ret;
1242 	struct btrfsic_block_link *l;
1243 	int did_alloc_block_link;
1244 	int block_was_created;
1245 
1246 	*next_blockp = NULL;
1247 	if (0 == *num_copiesp) {
1248 		*num_copiesp = btrfs_num_copies(fs_info, next_bytenr,
1249 						state->metablock_size);
1250 		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1251 			pr_info("num_copies(log_bytenr=%llu) = %d\n",
1252 			       next_bytenr, *num_copiesp);
1253 		*mirror_nump = 1;
1254 	}
1255 
1256 	if (*mirror_nump > *num_copiesp)
1257 		return 0;
1258 
1259 	if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1260 		pr_info("btrfsic_create_link_to_next_block(mirror_num=%d)\n",
1261 		       *mirror_nump);
1262 	ret = btrfsic_map_block(state, next_bytenr,
1263 				state->metablock_size,
1264 				next_block_ctx, *mirror_nump);
1265 	if (ret) {
1266 		pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
1267 		       next_bytenr, *mirror_nump);
1268 		btrfsic_release_block_ctx(next_block_ctx);
1269 		*next_blockp = NULL;
1270 		return -1;
1271 	}
1272 
1273 	next_block = btrfsic_block_lookup_or_add(state,
1274 						 next_block_ctx, "referenced ",
1275 						 1, force_iodone_flag,
1276 						 !force_iodone_flag,
1277 						 *mirror_nump,
1278 						 &block_was_created);
1279 	if (NULL == next_block) {
1280 		btrfsic_release_block_ctx(next_block_ctx);
1281 		*next_blockp = NULL;
1282 		return -1;
1283 	}
1284 	if (block_was_created) {
1285 		l = NULL;
1286 		next_block->generation = BTRFSIC_GENERATION_UNKNOWN;
1287 	} else {
1288 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1289 			if (next_block->logical_bytenr != next_bytenr &&
1290 			    !(!next_block->is_metadata &&
1291 			      0 == next_block->logical_bytenr))
1292 				pr_info("Referenced block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1293 				       next_bytenr, next_block_ctx->dev->name,
1294 				       next_block_ctx->dev_bytenr, *mirror_nump,
1295 				       btrfsic_get_block_type(state,
1296 							      next_block),
1297 				       next_block->logical_bytenr);
1298 			else
1299 				pr_info("Referenced block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1300 				       next_bytenr, next_block_ctx->dev->name,
1301 				       next_block_ctx->dev_bytenr, *mirror_nump,
1302 				       btrfsic_get_block_type(state,
1303 							      next_block));
1304 		}
1305 		next_block->logical_bytenr = next_bytenr;
1306 
1307 		next_block->mirror_num = *mirror_nump;
1308 		l = btrfsic_block_link_hashtable_lookup(
1309 				next_block_ctx->dev->bdev,
1310 				next_block_ctx->dev_bytenr,
1311 				block_ctx->dev->bdev,
1312 				block_ctx->dev_bytenr,
1313 				&state->block_link_hashtable);
1314 	}
1315 
1316 	next_block->disk_key = *disk_key;
1317 	if (NULL == l) {
1318 		l = btrfsic_block_link_alloc();
1319 		if (NULL == l) {
1320 			pr_info("btrfsic: error, kmalloc failed!\n");
1321 			btrfsic_release_block_ctx(next_block_ctx);
1322 			*next_blockp = NULL;
1323 			return -1;
1324 		}
1325 
1326 		did_alloc_block_link = 1;
1327 		l->block_ref_to = next_block;
1328 		l->block_ref_from = block;
1329 		l->ref_cnt = 1;
1330 		l->parent_generation = parent_generation;
1331 
1332 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1333 			btrfsic_print_add_link(state, l);
1334 
1335 		list_add(&l->node_ref_to, &block->ref_to_list);
1336 		list_add(&l->node_ref_from, &next_block->ref_from_list);
1337 
1338 		btrfsic_block_link_hashtable_add(l,
1339 						 &state->block_link_hashtable);
1340 	} else {
1341 		did_alloc_block_link = 0;
1342 		if (0 == limit_nesting) {
1343 			l->ref_cnt++;
1344 			l->parent_generation = parent_generation;
1345 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1346 				btrfsic_print_add_link(state, l);
1347 		}
1348 	}
1349 
1350 	if (limit_nesting > 0 && did_alloc_block_link) {
1351 		ret = btrfsic_read_block(state, next_block_ctx);
1352 		if (ret < (int)next_block_ctx->len) {
1353 			pr_info("btrfsic: read block @logical %llu failed!\n",
1354 			       next_bytenr);
1355 			btrfsic_release_block_ctx(next_block_ctx);
1356 			*next_blockp = NULL;
1357 			return -1;
1358 		}
1359 
1360 		*next_blockp = next_block;
1361 	} else {
1362 		*next_blockp = NULL;
1363 	}
1364 	(*mirror_nump)++;
1365 
1366 	return 0;
1367 }
1368 
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)1369 static int btrfsic_handle_extent_data(
1370 		struct btrfsic_state *state,
1371 		struct btrfsic_block *block,
1372 		struct btrfsic_block_data_ctx *block_ctx,
1373 		u32 item_offset, int force_iodone_flag)
1374 {
1375 	struct btrfs_fs_info *fs_info = state->fs_info;
1376 	struct btrfs_file_extent_item file_extent_item;
1377 	u64 file_extent_item_offset;
1378 	u64 next_bytenr;
1379 	u64 num_bytes;
1380 	u64 generation;
1381 	struct btrfsic_block_link *l;
1382 	int ret;
1383 
1384 	file_extent_item_offset = offsetof(struct btrfs_leaf, items) +
1385 				  item_offset;
1386 	if (file_extent_item_offset +
1387 	    offsetof(struct btrfs_file_extent_item, disk_num_bytes) >
1388 	    block_ctx->len) {
1389 		pr_info("btrfsic: file item out of bounce at logical %llu, dev %s\n",
1390 		       block_ctx->start, block_ctx->dev->name);
1391 		return -1;
1392 	}
1393 
1394 	btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1395 		file_extent_item_offset,
1396 		offsetof(struct btrfs_file_extent_item, disk_num_bytes));
1397 	if (BTRFS_FILE_EXTENT_REG != file_extent_item.type ||
1398 	    btrfs_stack_file_extent_disk_bytenr(&file_extent_item) == 0) {
1399 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1400 			pr_info("extent_data: type %u, disk_bytenr = %llu\n",
1401 			       file_extent_item.type,
1402 			       btrfs_stack_file_extent_disk_bytenr(
1403 			       &file_extent_item));
1404 		return 0;
1405 	}
1406 
1407 	if (file_extent_item_offset + sizeof(struct btrfs_file_extent_item) >
1408 	    block_ctx->len) {
1409 		pr_info("btrfsic: file item out of bounce at logical %llu, dev %s\n",
1410 		       block_ctx->start, block_ctx->dev->name);
1411 		return -1;
1412 	}
1413 	btrfsic_read_from_block_data(block_ctx, &file_extent_item,
1414 				     file_extent_item_offset,
1415 				     sizeof(struct btrfs_file_extent_item));
1416 	next_bytenr = btrfs_stack_file_extent_disk_bytenr(&file_extent_item);
1417 	if (btrfs_stack_file_extent_compression(&file_extent_item) ==
1418 	    BTRFS_COMPRESS_NONE) {
1419 		next_bytenr += btrfs_stack_file_extent_offset(&file_extent_item);
1420 		num_bytes = btrfs_stack_file_extent_num_bytes(&file_extent_item);
1421 	} else {
1422 		num_bytes = btrfs_stack_file_extent_disk_num_bytes(&file_extent_item);
1423 	}
1424 	generation = btrfs_stack_file_extent_generation(&file_extent_item);
1425 
1426 	if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1427 		pr_info("extent_data: type %u, disk_bytenr = %llu, offset = %llu, num_bytes = %llu\n",
1428 		       file_extent_item.type,
1429 		       btrfs_stack_file_extent_disk_bytenr(&file_extent_item),
1430 		       btrfs_stack_file_extent_offset(&file_extent_item),
1431 		       num_bytes);
1432 	while (num_bytes > 0) {
1433 		u32 chunk_len;
1434 		int num_copies;
1435 		int mirror_num;
1436 
1437 		if (num_bytes > state->datablock_size)
1438 			chunk_len = state->datablock_size;
1439 		else
1440 			chunk_len = num_bytes;
1441 
1442 		num_copies = btrfs_num_copies(fs_info, next_bytenr,
1443 					      state->datablock_size);
1444 		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
1445 			pr_info("num_copies(log_bytenr=%llu) = %d\n",
1446 			       next_bytenr, num_copies);
1447 		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
1448 			struct btrfsic_block_data_ctx next_block_ctx;
1449 			struct btrfsic_block *next_block;
1450 			int block_was_created;
1451 
1452 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1453 				pr_info("btrfsic_handle_extent_data(mirror_num=%d)\n",
1454 					mirror_num);
1455 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)
1456 				pr_info("\tdisk_bytenr = %llu, num_bytes %u\n",
1457 				       next_bytenr, chunk_len);
1458 			ret = btrfsic_map_block(state, next_bytenr,
1459 						chunk_len, &next_block_ctx,
1460 						mirror_num);
1461 			if (ret) {
1462 				pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
1463 				       next_bytenr, mirror_num);
1464 				return -1;
1465 			}
1466 
1467 			next_block = btrfsic_block_lookup_or_add(
1468 					state,
1469 					&next_block_ctx,
1470 					"referenced ",
1471 					0,
1472 					force_iodone_flag,
1473 					!force_iodone_flag,
1474 					mirror_num,
1475 					&block_was_created);
1476 			if (NULL == next_block) {
1477 				pr_info("btrfsic: error, kmalloc failed!\n");
1478 				btrfsic_release_block_ctx(&next_block_ctx);
1479 				return -1;
1480 			}
1481 			if (!block_was_created) {
1482 				if ((state->print_mask &
1483 				     BTRFSIC_PRINT_MASK_VERBOSE) &&
1484 				    next_block->logical_bytenr != next_bytenr &&
1485 				    !(!next_block->is_metadata &&
1486 				      0 == next_block->logical_bytenr)) {
1487 					pr_info("Referenced block @%llu (%s/%llu/%d) found in hash table, D, bytenr mismatch (!= stored %llu).\n",
1488 					       next_bytenr,
1489 					       next_block_ctx.dev->name,
1490 					       next_block_ctx.dev_bytenr,
1491 					       mirror_num,
1492 					       next_block->logical_bytenr);
1493 				}
1494 				next_block->logical_bytenr = next_bytenr;
1495 				next_block->mirror_num = mirror_num;
1496 			}
1497 
1498 			l = btrfsic_block_link_lookup_or_add(state,
1499 							     &next_block_ctx,
1500 							     next_block, block,
1501 							     generation);
1502 			btrfsic_release_block_ctx(&next_block_ctx);
1503 			if (NULL == l)
1504 				return -1;
1505 		}
1506 
1507 		next_bytenr += chunk_len;
1508 		num_bytes -= chunk_len;
1509 	}
1510 
1511 	return 0;
1512 }
1513 
btrfsic_map_block(struct btrfsic_state * state,u64 bytenr,u32 len,struct btrfsic_block_data_ctx * block_ctx_out,int mirror_num)1514 static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len,
1515 			     struct btrfsic_block_data_ctx *block_ctx_out,
1516 			     int mirror_num)
1517 {
1518 	struct btrfs_fs_info *fs_info = state->fs_info;
1519 	int ret;
1520 	u64 length;
1521 	struct btrfs_bio *multi = NULL;
1522 	struct btrfs_device *device;
1523 
1524 	length = len;
1525 	ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
1526 			      bytenr, &length, &multi, mirror_num);
1527 
1528 	if (ret) {
1529 		block_ctx_out->start = 0;
1530 		block_ctx_out->dev_bytenr = 0;
1531 		block_ctx_out->len = 0;
1532 		block_ctx_out->dev = NULL;
1533 		block_ctx_out->datav = NULL;
1534 		block_ctx_out->pagev = NULL;
1535 		block_ctx_out->mem_to_free = NULL;
1536 
1537 		return ret;
1538 	}
1539 
1540 	device = multi->stripes[0].dev;
1541 	if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state) ||
1542 	    !device->bdev || !device->name)
1543 		block_ctx_out->dev = NULL;
1544 	else
1545 		block_ctx_out->dev = btrfsic_dev_state_lookup(
1546 							device->bdev->bd_dev);
1547 	block_ctx_out->dev_bytenr = multi->stripes[0].physical;
1548 	block_ctx_out->start = bytenr;
1549 	block_ctx_out->len = len;
1550 	block_ctx_out->datav = NULL;
1551 	block_ctx_out->pagev = NULL;
1552 	block_ctx_out->mem_to_free = NULL;
1553 
1554 	kfree(multi);
1555 	if (NULL == block_ctx_out->dev) {
1556 		ret = -ENXIO;
1557 		pr_info("btrfsic: error, cannot lookup dev (#1)!\n");
1558 	}
1559 
1560 	return ret;
1561 }
1562 
btrfsic_release_block_ctx(struct btrfsic_block_data_ctx * block_ctx)1563 static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx)
1564 {
1565 	if (block_ctx->mem_to_free) {
1566 		unsigned int num_pages;
1567 
1568 		BUG_ON(!block_ctx->datav);
1569 		BUG_ON(!block_ctx->pagev);
1570 		num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
1571 			    PAGE_SHIFT;
1572 		while (num_pages > 0) {
1573 			num_pages--;
1574 			if (block_ctx->datav[num_pages]) {
1575 				kunmap(block_ctx->pagev[num_pages]);
1576 				block_ctx->datav[num_pages] = NULL;
1577 			}
1578 			if (block_ctx->pagev[num_pages]) {
1579 				__free_page(block_ctx->pagev[num_pages]);
1580 				block_ctx->pagev[num_pages] = NULL;
1581 			}
1582 		}
1583 
1584 		kfree(block_ctx->mem_to_free);
1585 		block_ctx->mem_to_free = NULL;
1586 		block_ctx->pagev = NULL;
1587 		block_ctx->datav = NULL;
1588 	}
1589 }
1590 
btrfsic_read_block(struct btrfsic_state * state,struct btrfsic_block_data_ctx * block_ctx)1591 static int btrfsic_read_block(struct btrfsic_state *state,
1592 			      struct btrfsic_block_data_ctx *block_ctx)
1593 {
1594 	unsigned int num_pages;
1595 	unsigned int i;
1596 	u64 dev_bytenr;
1597 	int ret;
1598 
1599 	BUG_ON(block_ctx->datav);
1600 	BUG_ON(block_ctx->pagev);
1601 	BUG_ON(block_ctx->mem_to_free);
1602 	if (block_ctx->dev_bytenr & ((u64)PAGE_SIZE - 1)) {
1603 		pr_info("btrfsic: read_block() with unaligned bytenr %llu\n",
1604 		       block_ctx->dev_bytenr);
1605 		return -1;
1606 	}
1607 
1608 	num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
1609 		    PAGE_SHIFT;
1610 	block_ctx->mem_to_free = kcalloc(sizeof(*block_ctx->datav) +
1611 						sizeof(*block_ctx->pagev),
1612 					 num_pages, GFP_NOFS);
1613 	if (!block_ctx->mem_to_free)
1614 		return -ENOMEM;
1615 	block_ctx->datav = block_ctx->mem_to_free;
1616 	block_ctx->pagev = (struct page **)(block_ctx->datav + num_pages);
1617 	for (i = 0; i < num_pages; i++) {
1618 		block_ctx->pagev[i] = alloc_page(GFP_NOFS);
1619 		if (!block_ctx->pagev[i])
1620 			return -1;
1621 	}
1622 
1623 	dev_bytenr = block_ctx->dev_bytenr;
1624 	for (i = 0; i < num_pages;) {
1625 		struct bio *bio;
1626 		unsigned int j;
1627 
1628 		bio = btrfs_io_bio_alloc(num_pages - i);
1629 		bio_set_dev(bio, block_ctx->dev->bdev);
1630 		bio->bi_iter.bi_sector = dev_bytenr >> 9;
1631 		bio->bi_opf = REQ_OP_READ;
1632 
1633 		for (j = i; j < num_pages; j++) {
1634 			ret = bio_add_page(bio, block_ctx->pagev[j],
1635 					   PAGE_SIZE, 0);
1636 			if (PAGE_SIZE != ret)
1637 				break;
1638 		}
1639 		if (j == i) {
1640 			pr_info("btrfsic: error, failed to add a single page!\n");
1641 			return -1;
1642 		}
1643 		if (submit_bio_wait(bio)) {
1644 			pr_info("btrfsic: read error at logical %llu dev %s!\n",
1645 			       block_ctx->start, block_ctx->dev->name);
1646 			bio_put(bio);
1647 			return -1;
1648 		}
1649 		bio_put(bio);
1650 		dev_bytenr += (j - i) * PAGE_SIZE;
1651 		i = j;
1652 	}
1653 	for (i = 0; i < num_pages; i++)
1654 		block_ctx->datav[i] = kmap(block_ctx->pagev[i]);
1655 
1656 	return block_ctx->len;
1657 }
1658 
btrfsic_dump_database(struct btrfsic_state * state)1659 static void btrfsic_dump_database(struct btrfsic_state *state)
1660 {
1661 	const struct btrfsic_block *b_all;
1662 
1663 	BUG_ON(NULL == state);
1664 
1665 	pr_info("all_blocks_list:\n");
1666 	list_for_each_entry(b_all, &state->all_blocks_list, all_blocks_node) {
1667 		const struct btrfsic_block_link *l;
1668 
1669 		pr_info("%c-block @%llu (%s/%llu/%d)\n",
1670 		       btrfsic_get_block_type(state, b_all),
1671 		       b_all->logical_bytenr, b_all->dev_state->name,
1672 		       b_all->dev_bytenr, b_all->mirror_num);
1673 
1674 		list_for_each_entry(l, &b_all->ref_to_list, node_ref_to) {
1675 			pr_info(" %c @%llu (%s/%llu/%d) refers %u* to %c @%llu (%s/%llu/%d)\n",
1676 			       btrfsic_get_block_type(state, b_all),
1677 			       b_all->logical_bytenr, b_all->dev_state->name,
1678 			       b_all->dev_bytenr, b_all->mirror_num,
1679 			       l->ref_cnt,
1680 			       btrfsic_get_block_type(state, l->block_ref_to),
1681 			       l->block_ref_to->logical_bytenr,
1682 			       l->block_ref_to->dev_state->name,
1683 			       l->block_ref_to->dev_bytenr,
1684 			       l->block_ref_to->mirror_num);
1685 		}
1686 
1687 		list_for_each_entry(l, &b_all->ref_from_list, node_ref_from) {
1688 			pr_info(" %c @%llu (%s/%llu/%d) is ref %u* from %c @%llu (%s/%llu/%d)\n",
1689 			       btrfsic_get_block_type(state, b_all),
1690 			       b_all->logical_bytenr, b_all->dev_state->name,
1691 			       b_all->dev_bytenr, b_all->mirror_num,
1692 			       l->ref_cnt,
1693 			       btrfsic_get_block_type(state, l->block_ref_from),
1694 			       l->block_ref_from->logical_bytenr,
1695 			       l->block_ref_from->dev_state->name,
1696 			       l->block_ref_from->dev_bytenr,
1697 			       l->block_ref_from->mirror_num);
1698 		}
1699 
1700 		pr_info("\n");
1701 	}
1702 }
1703 
1704 /*
1705  * Test whether the disk block contains a tree block (leaf or node)
1706  * (note that this test fails for the super block)
1707  */
btrfsic_test_for_metadata(struct btrfsic_state * state,char ** datav,unsigned int num_pages)1708 static int btrfsic_test_for_metadata(struct btrfsic_state *state,
1709 				     char **datav, unsigned int num_pages)
1710 {
1711 	struct btrfs_fs_info *fs_info = state->fs_info;
1712 	struct btrfs_header *h;
1713 	u8 csum[BTRFS_CSUM_SIZE];
1714 	u32 crc = ~(u32)0;
1715 	unsigned int i;
1716 
1717 	if (num_pages * PAGE_SIZE < state->metablock_size)
1718 		return 1; /* not metadata */
1719 	num_pages = state->metablock_size >> PAGE_SHIFT;
1720 	h = (struct btrfs_header *)datav[0];
1721 
1722 	if (memcmp(h->fsid, fs_info->fsid, BTRFS_FSID_SIZE))
1723 		return 1;
1724 
1725 	for (i = 0; i < num_pages; i++) {
1726 		u8 *data = i ? datav[i] : (datav[i] + BTRFS_CSUM_SIZE);
1727 		size_t sublen = i ? PAGE_SIZE :
1728 				    (PAGE_SIZE - BTRFS_CSUM_SIZE);
1729 
1730 		crc = crc32c(crc, data, sublen);
1731 	}
1732 	btrfs_csum_final(crc, csum);
1733 	if (memcmp(csum, h->csum, state->csum_size))
1734 		return 1;
1735 
1736 	return 0; /* is metadata */
1737 }
1738 
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,struct buffer_head * bh,int submit_bio_bh_rw)1739 static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state,
1740 					  u64 dev_bytenr, char **mapped_datav,
1741 					  unsigned int num_pages,
1742 					  struct bio *bio, int *bio_is_patched,
1743 					  struct buffer_head *bh,
1744 					  int submit_bio_bh_rw)
1745 {
1746 	int is_metadata;
1747 	struct btrfsic_block *block;
1748 	struct btrfsic_block_data_ctx block_ctx;
1749 	int ret;
1750 	struct btrfsic_state *state = dev_state->state;
1751 	struct block_device *bdev = dev_state->bdev;
1752 	unsigned int processed_len;
1753 
1754 	if (NULL != bio_is_patched)
1755 		*bio_is_patched = 0;
1756 
1757 again:
1758 	if (num_pages == 0)
1759 		return;
1760 
1761 	processed_len = 0;
1762 	is_metadata = (0 == btrfsic_test_for_metadata(state, mapped_datav,
1763 						      num_pages));
1764 
1765 	block = btrfsic_block_hashtable_lookup(bdev, dev_bytenr,
1766 					       &state->block_hashtable);
1767 	if (NULL != block) {
1768 		u64 bytenr = 0;
1769 		struct btrfsic_block_link *l, *tmp;
1770 
1771 		if (block->is_superblock) {
1772 			bytenr = btrfs_super_bytenr((struct btrfs_super_block *)
1773 						    mapped_datav[0]);
1774 			if (num_pages * PAGE_SIZE <
1775 			    BTRFS_SUPER_INFO_SIZE) {
1776 				pr_info("btrfsic: cannot work with too short bios!\n");
1777 				return;
1778 			}
1779 			is_metadata = 1;
1780 			BUG_ON(BTRFS_SUPER_INFO_SIZE & (PAGE_SIZE - 1));
1781 			processed_len = BTRFS_SUPER_INFO_SIZE;
1782 			if (state->print_mask &
1783 			    BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE) {
1784 				pr_info("[before new superblock is written]:\n");
1785 				btrfsic_dump_tree_sub(state, block, 0);
1786 			}
1787 		}
1788 		if (is_metadata) {
1789 			if (!block->is_superblock) {
1790 				if (num_pages * PAGE_SIZE <
1791 				    state->metablock_size) {
1792 					pr_info("btrfsic: cannot work with too short bios!\n");
1793 					return;
1794 				}
1795 				processed_len = state->metablock_size;
1796 				bytenr = btrfs_stack_header_bytenr(
1797 						(struct btrfs_header *)
1798 						mapped_datav[0]);
1799 				btrfsic_cmp_log_and_dev_bytenr(state, bytenr,
1800 							       dev_state,
1801 							       dev_bytenr);
1802 			}
1803 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) {
1804 				if (block->logical_bytenr != bytenr &&
1805 				    !(!block->is_metadata &&
1806 				      block->logical_bytenr == 0))
1807 					pr_info("Written block @%llu (%s/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu).\n",
1808 					       bytenr, dev_state->name,
1809 					       dev_bytenr,
1810 					       block->mirror_num,
1811 					       btrfsic_get_block_type(state,
1812 								      block),
1813 					       block->logical_bytenr);
1814 				else
1815 					pr_info("Written block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1816 					       bytenr, dev_state->name,
1817 					       dev_bytenr, block->mirror_num,
1818 					       btrfsic_get_block_type(state,
1819 								      block));
1820 			}
1821 			block->logical_bytenr = bytenr;
1822 		} else {
1823 			if (num_pages * PAGE_SIZE <
1824 			    state->datablock_size) {
1825 				pr_info("btrfsic: cannot work with too short bios!\n");
1826 				return;
1827 			}
1828 			processed_len = state->datablock_size;
1829 			bytenr = block->logical_bytenr;
1830 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1831 				pr_info("Written block @%llu (%s/%llu/%d) found in hash table, %c.\n",
1832 				       bytenr, dev_state->name, dev_bytenr,
1833 				       block->mirror_num,
1834 				       btrfsic_get_block_type(state, block));
1835 		}
1836 
1837 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1838 			pr_info("ref_to_list: %cE, ref_from_list: %cE\n",
1839 			       list_empty(&block->ref_to_list) ? ' ' : '!',
1840 			       list_empty(&block->ref_from_list) ? ' ' : '!');
1841 		if (btrfsic_is_block_ref_by_superblock(state, block, 0)) {
1842 			pr_info("btrfs: attempt to overwrite %c-block @%llu (%s/%llu/%d), old(gen=%llu, objectid=%llu, type=%d, offset=%llu), new(gen=%llu), which is referenced by most recent superblock (superblockgen=%llu)!\n",
1843 			       btrfsic_get_block_type(state, block), bytenr,
1844 			       dev_state->name, dev_bytenr, block->mirror_num,
1845 			       block->generation,
1846 			       btrfs_disk_key_objectid(&block->disk_key),
1847 			       block->disk_key.type,
1848 			       btrfs_disk_key_offset(&block->disk_key),
1849 			       btrfs_stack_header_generation(
1850 				       (struct btrfs_header *) mapped_datav[0]),
1851 			       state->max_superblock_generation);
1852 			btrfsic_dump_tree(state);
1853 		}
1854 
1855 		if (!block->is_iodone && !block->never_written) {
1856 			pr_info("btrfs: attempt to overwrite %c-block @%llu (%s/%llu/%d), oldgen=%llu, newgen=%llu, which is not yet iodone!\n",
1857 			       btrfsic_get_block_type(state, block), bytenr,
1858 			       dev_state->name, dev_bytenr, block->mirror_num,
1859 			       block->generation,
1860 			       btrfs_stack_header_generation(
1861 				       (struct btrfs_header *)
1862 				       mapped_datav[0]));
1863 			/* it would not be safe to go on */
1864 			btrfsic_dump_tree(state);
1865 			goto continue_loop;
1866 		}
1867 
1868 		/*
1869 		 * Clear all references of this block. Do not free
1870 		 * the block itself even if is not referenced anymore
1871 		 * because it still carries valuable information
1872 		 * like whether it was ever written and IO completed.
1873 		 */
1874 		list_for_each_entry_safe(l, tmp, &block->ref_to_list,
1875 					 node_ref_to) {
1876 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1877 				btrfsic_print_rem_link(state, l);
1878 			l->ref_cnt--;
1879 			if (0 == l->ref_cnt) {
1880 				list_del(&l->node_ref_to);
1881 				list_del(&l->node_ref_from);
1882 				btrfsic_block_link_hashtable_remove(l);
1883 				btrfsic_block_link_free(l);
1884 			}
1885 		}
1886 
1887 		block_ctx.dev = dev_state;
1888 		block_ctx.dev_bytenr = dev_bytenr;
1889 		block_ctx.start = bytenr;
1890 		block_ctx.len = processed_len;
1891 		block_ctx.pagev = NULL;
1892 		block_ctx.mem_to_free = NULL;
1893 		block_ctx.datav = mapped_datav;
1894 
1895 		if (is_metadata || state->include_extent_data) {
1896 			block->never_written = 0;
1897 			block->iodone_w_error = 0;
1898 			if (NULL != bio) {
1899 				block->is_iodone = 0;
1900 				BUG_ON(NULL == bio_is_patched);
1901 				if (!*bio_is_patched) {
1902 					block->orig_bio_bh_private =
1903 					    bio->bi_private;
1904 					block->orig_bio_bh_end_io.bio =
1905 					    bio->bi_end_io;
1906 					block->next_in_same_bio = NULL;
1907 					bio->bi_private = block;
1908 					bio->bi_end_io = btrfsic_bio_end_io;
1909 					*bio_is_patched = 1;
1910 				} else {
1911 					struct btrfsic_block *chained_block =
1912 					    (struct btrfsic_block *)
1913 					    bio->bi_private;
1914 
1915 					BUG_ON(NULL == chained_block);
1916 					block->orig_bio_bh_private =
1917 					    chained_block->orig_bio_bh_private;
1918 					block->orig_bio_bh_end_io.bio =
1919 					    chained_block->orig_bio_bh_end_io.
1920 					    bio;
1921 					block->next_in_same_bio = chained_block;
1922 					bio->bi_private = block;
1923 				}
1924 			} else if (NULL != bh) {
1925 				block->is_iodone = 0;
1926 				block->orig_bio_bh_private = bh->b_private;
1927 				block->orig_bio_bh_end_io.bh = bh->b_end_io;
1928 				block->next_in_same_bio = NULL;
1929 				bh->b_private = block;
1930 				bh->b_end_io = btrfsic_bh_end_io;
1931 			} else {
1932 				block->is_iodone = 1;
1933 				block->orig_bio_bh_private = NULL;
1934 				block->orig_bio_bh_end_io.bio = NULL;
1935 				block->next_in_same_bio = NULL;
1936 			}
1937 		}
1938 
1939 		block->flush_gen = dev_state->last_flush_gen + 1;
1940 		block->submit_bio_bh_rw = submit_bio_bh_rw;
1941 		if (is_metadata) {
1942 			block->logical_bytenr = bytenr;
1943 			block->is_metadata = 1;
1944 			if (block->is_superblock) {
1945 				BUG_ON(PAGE_SIZE !=
1946 				       BTRFS_SUPER_INFO_SIZE);
1947 				ret = btrfsic_process_written_superblock(
1948 						state,
1949 						block,
1950 						(struct btrfs_super_block *)
1951 						mapped_datav[0]);
1952 				if (state->print_mask &
1953 				    BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE) {
1954 					pr_info("[after new superblock is written]:\n");
1955 					btrfsic_dump_tree_sub(state, block, 0);
1956 				}
1957 			} else {
1958 				block->mirror_num = 0;	/* unknown */
1959 				ret = btrfsic_process_metablock(
1960 						state,
1961 						block,
1962 						&block_ctx,
1963 						0, 0);
1964 			}
1965 			if (ret)
1966 				pr_info("btrfsic: btrfsic_process_metablock(root @%llu) failed!\n",
1967 				       dev_bytenr);
1968 		} else {
1969 			block->is_metadata = 0;
1970 			block->mirror_num = 0;	/* unknown */
1971 			block->generation = BTRFSIC_GENERATION_UNKNOWN;
1972 			if (!state->include_extent_data
1973 			    && list_empty(&block->ref_from_list)) {
1974 				/*
1975 				 * disk block is overwritten with extent
1976 				 * data (not meta data) and we are configured
1977 				 * to not include extent data: take the
1978 				 * chance and free the block's memory
1979 				 */
1980 				btrfsic_block_hashtable_remove(block);
1981 				list_del(&block->all_blocks_node);
1982 				btrfsic_block_free(block);
1983 			}
1984 		}
1985 		btrfsic_release_block_ctx(&block_ctx);
1986 	} else {
1987 		/* block has not been found in hash table */
1988 		u64 bytenr;
1989 
1990 		if (!is_metadata) {
1991 			processed_len = state->datablock_size;
1992 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
1993 				pr_info("Written block (%s/%llu/?) !found in hash table, D.\n",
1994 				       dev_state->name, dev_bytenr);
1995 			if (!state->include_extent_data) {
1996 				/* ignore that written D block */
1997 				goto continue_loop;
1998 			}
1999 
2000 			/* this is getting ugly for the
2001 			 * include_extent_data case... */
2002 			bytenr = 0;	/* unknown */
2003 		} else {
2004 			processed_len = state->metablock_size;
2005 			bytenr = btrfs_stack_header_bytenr(
2006 					(struct btrfs_header *)
2007 					mapped_datav[0]);
2008 			btrfsic_cmp_log_and_dev_bytenr(state, bytenr, dev_state,
2009 						       dev_bytenr);
2010 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2011 				pr_info("Written block @%llu (%s/%llu/?) !found in hash table, M.\n",
2012 				       bytenr, dev_state->name, dev_bytenr);
2013 		}
2014 
2015 		block_ctx.dev = dev_state;
2016 		block_ctx.dev_bytenr = dev_bytenr;
2017 		block_ctx.start = bytenr;
2018 		block_ctx.len = processed_len;
2019 		block_ctx.pagev = NULL;
2020 		block_ctx.mem_to_free = NULL;
2021 		block_ctx.datav = mapped_datav;
2022 
2023 		block = btrfsic_block_alloc();
2024 		if (NULL == block) {
2025 			pr_info("btrfsic: error, kmalloc failed!\n");
2026 			btrfsic_release_block_ctx(&block_ctx);
2027 			goto continue_loop;
2028 		}
2029 		block->dev_state = dev_state;
2030 		block->dev_bytenr = dev_bytenr;
2031 		block->logical_bytenr = bytenr;
2032 		block->is_metadata = is_metadata;
2033 		block->never_written = 0;
2034 		block->iodone_w_error = 0;
2035 		block->mirror_num = 0;	/* unknown */
2036 		block->flush_gen = dev_state->last_flush_gen + 1;
2037 		block->submit_bio_bh_rw = submit_bio_bh_rw;
2038 		if (NULL != bio) {
2039 			block->is_iodone = 0;
2040 			BUG_ON(NULL == bio_is_patched);
2041 			if (!*bio_is_patched) {
2042 				block->orig_bio_bh_private = bio->bi_private;
2043 				block->orig_bio_bh_end_io.bio = bio->bi_end_io;
2044 				block->next_in_same_bio = NULL;
2045 				bio->bi_private = block;
2046 				bio->bi_end_io = btrfsic_bio_end_io;
2047 				*bio_is_patched = 1;
2048 			} else {
2049 				struct btrfsic_block *chained_block =
2050 				    (struct btrfsic_block *)
2051 				    bio->bi_private;
2052 
2053 				BUG_ON(NULL == chained_block);
2054 				block->orig_bio_bh_private =
2055 				    chained_block->orig_bio_bh_private;
2056 				block->orig_bio_bh_end_io.bio =
2057 				    chained_block->orig_bio_bh_end_io.bio;
2058 				block->next_in_same_bio = chained_block;
2059 				bio->bi_private = block;
2060 			}
2061 		} else if (NULL != bh) {
2062 			block->is_iodone = 0;
2063 			block->orig_bio_bh_private = bh->b_private;
2064 			block->orig_bio_bh_end_io.bh = bh->b_end_io;
2065 			block->next_in_same_bio = NULL;
2066 			bh->b_private = block;
2067 			bh->b_end_io = btrfsic_bh_end_io;
2068 		} else {
2069 			block->is_iodone = 1;
2070 			block->orig_bio_bh_private = NULL;
2071 			block->orig_bio_bh_end_io.bio = NULL;
2072 			block->next_in_same_bio = NULL;
2073 		}
2074 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2075 			pr_info("New written %c-block @%llu (%s/%llu/%d)\n",
2076 			       is_metadata ? 'M' : 'D',
2077 			       block->logical_bytenr, block->dev_state->name,
2078 			       block->dev_bytenr, block->mirror_num);
2079 		list_add(&block->all_blocks_node, &state->all_blocks_list);
2080 		btrfsic_block_hashtable_add(block, &state->block_hashtable);
2081 
2082 		if (is_metadata) {
2083 			ret = btrfsic_process_metablock(state, block,
2084 							&block_ctx, 0, 0);
2085 			if (ret)
2086 				pr_info("btrfsic: process_metablock(root @%llu) failed!\n",
2087 				       dev_bytenr);
2088 		}
2089 		btrfsic_release_block_ctx(&block_ctx);
2090 	}
2091 
2092 continue_loop:
2093 	BUG_ON(!processed_len);
2094 	dev_bytenr += processed_len;
2095 	mapped_datav += processed_len >> PAGE_SHIFT;
2096 	num_pages -= processed_len >> PAGE_SHIFT;
2097 	goto again;
2098 }
2099 
btrfsic_bio_end_io(struct bio * bp)2100 static void btrfsic_bio_end_io(struct bio *bp)
2101 {
2102 	struct btrfsic_block *block = (struct btrfsic_block *)bp->bi_private;
2103 	int iodone_w_error;
2104 
2105 	/* mutex is not held! This is not save if IO is not yet completed
2106 	 * on umount */
2107 	iodone_w_error = 0;
2108 	if (bp->bi_status)
2109 		iodone_w_error = 1;
2110 
2111 	BUG_ON(NULL == block);
2112 	bp->bi_private = block->orig_bio_bh_private;
2113 	bp->bi_end_io = block->orig_bio_bh_end_io.bio;
2114 
2115 	do {
2116 		struct btrfsic_block *next_block;
2117 		struct btrfsic_dev_state *const dev_state = block->dev_state;
2118 
2119 		if ((dev_state->state->print_mask &
2120 		     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2121 			pr_info("bio_end_io(err=%d) for %c @%llu (%s/%llu/%d)\n",
2122 			       bp->bi_status,
2123 			       btrfsic_get_block_type(dev_state->state, block),
2124 			       block->logical_bytenr, dev_state->name,
2125 			       block->dev_bytenr, block->mirror_num);
2126 		next_block = block->next_in_same_bio;
2127 		block->iodone_w_error = iodone_w_error;
2128 		if (block->submit_bio_bh_rw & REQ_PREFLUSH) {
2129 			dev_state->last_flush_gen++;
2130 			if ((dev_state->state->print_mask &
2131 			     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2132 				pr_info("bio_end_io() new %s flush_gen=%llu\n",
2133 				       dev_state->name,
2134 				       dev_state->last_flush_gen);
2135 		}
2136 		if (block->submit_bio_bh_rw & REQ_FUA)
2137 			block->flush_gen = 0; /* FUA completed means block is
2138 					       * on disk */
2139 		block->is_iodone = 1; /* for FLUSH, this releases the block */
2140 		block = next_block;
2141 	} while (NULL != block);
2142 
2143 	bp->bi_end_io(bp);
2144 }
2145 
btrfsic_bh_end_io(struct buffer_head * bh,int uptodate)2146 static void btrfsic_bh_end_io(struct buffer_head *bh, int uptodate)
2147 {
2148 	struct btrfsic_block *block = (struct btrfsic_block *)bh->b_private;
2149 	int iodone_w_error = !uptodate;
2150 	struct btrfsic_dev_state *dev_state;
2151 
2152 	BUG_ON(NULL == block);
2153 	dev_state = block->dev_state;
2154 	if ((dev_state->state->print_mask & BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2155 		pr_info("bh_end_io(error=%d) for %c @%llu (%s/%llu/%d)\n",
2156 		       iodone_w_error,
2157 		       btrfsic_get_block_type(dev_state->state, block),
2158 		       block->logical_bytenr, block->dev_state->name,
2159 		       block->dev_bytenr, block->mirror_num);
2160 
2161 	block->iodone_w_error = iodone_w_error;
2162 	if (block->submit_bio_bh_rw & REQ_PREFLUSH) {
2163 		dev_state->last_flush_gen++;
2164 		if ((dev_state->state->print_mask &
2165 		     BTRFSIC_PRINT_MASK_END_IO_BIO_BH))
2166 			pr_info("bh_end_io() new %s flush_gen=%llu\n",
2167 			       dev_state->name, dev_state->last_flush_gen);
2168 	}
2169 	if (block->submit_bio_bh_rw & REQ_FUA)
2170 		block->flush_gen = 0; /* FUA completed means block is on disk */
2171 
2172 	bh->b_private = block->orig_bio_bh_private;
2173 	bh->b_end_io = block->orig_bio_bh_end_io.bh;
2174 	block->is_iodone = 1; /* for FLUSH, this releases the block */
2175 	bh->b_end_io(bh, uptodate);
2176 }
2177 
btrfsic_process_written_superblock(struct btrfsic_state * state,struct btrfsic_block * const superblock,struct btrfs_super_block * const super_hdr)2178 static int btrfsic_process_written_superblock(
2179 		struct btrfsic_state *state,
2180 		struct btrfsic_block *const superblock,
2181 		struct btrfs_super_block *const super_hdr)
2182 {
2183 	struct btrfs_fs_info *fs_info = state->fs_info;
2184 	int pass;
2185 
2186 	superblock->generation = btrfs_super_generation(super_hdr);
2187 	if (!(superblock->generation > state->max_superblock_generation ||
2188 	      0 == state->max_superblock_generation)) {
2189 		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2190 			pr_info("btrfsic: superblock @%llu (%s/%llu/%d) with old gen %llu <= %llu\n",
2191 			       superblock->logical_bytenr,
2192 			       superblock->dev_state->name,
2193 			       superblock->dev_bytenr, superblock->mirror_num,
2194 			       btrfs_super_generation(super_hdr),
2195 			       state->max_superblock_generation);
2196 	} else {
2197 		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
2198 			pr_info("btrfsic: got new superblock @%llu (%s/%llu/%d) with new gen %llu > %llu\n",
2199 			       superblock->logical_bytenr,
2200 			       superblock->dev_state->name,
2201 			       superblock->dev_bytenr, superblock->mirror_num,
2202 			       btrfs_super_generation(super_hdr),
2203 			       state->max_superblock_generation);
2204 
2205 		state->max_superblock_generation =
2206 		    btrfs_super_generation(super_hdr);
2207 		state->latest_superblock = superblock;
2208 	}
2209 
2210 	for (pass = 0; pass < 3; pass++) {
2211 		int ret;
2212 		u64 next_bytenr;
2213 		struct btrfsic_block *next_block;
2214 		struct btrfsic_block_data_ctx tmp_next_block_ctx;
2215 		struct btrfsic_block_link *l;
2216 		int num_copies;
2217 		int mirror_num;
2218 		const char *additional_string = NULL;
2219 		struct btrfs_disk_key tmp_disk_key = {0};
2220 
2221 		btrfs_set_disk_key_objectid(&tmp_disk_key,
2222 					    BTRFS_ROOT_ITEM_KEY);
2223 		btrfs_set_disk_key_objectid(&tmp_disk_key, 0);
2224 
2225 		switch (pass) {
2226 		case 0:
2227 			btrfs_set_disk_key_objectid(&tmp_disk_key,
2228 						    BTRFS_ROOT_TREE_OBJECTID);
2229 			additional_string = "root ";
2230 			next_bytenr = btrfs_super_root(super_hdr);
2231 			if (state->print_mask &
2232 			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2233 				pr_info("root@%llu\n", next_bytenr);
2234 			break;
2235 		case 1:
2236 			btrfs_set_disk_key_objectid(&tmp_disk_key,
2237 						    BTRFS_CHUNK_TREE_OBJECTID);
2238 			additional_string = "chunk ";
2239 			next_bytenr = btrfs_super_chunk_root(super_hdr);
2240 			if (state->print_mask &
2241 			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2242 				pr_info("chunk@%llu\n", next_bytenr);
2243 			break;
2244 		case 2:
2245 			btrfs_set_disk_key_objectid(&tmp_disk_key,
2246 						    BTRFS_TREE_LOG_OBJECTID);
2247 			additional_string = "log ";
2248 			next_bytenr = btrfs_super_log_root(super_hdr);
2249 			if (0 == next_bytenr)
2250 				continue;
2251 			if (state->print_mask &
2252 			    BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION)
2253 				pr_info("log@%llu\n", next_bytenr);
2254 			break;
2255 		}
2256 
2257 		num_copies = btrfs_num_copies(fs_info, next_bytenr,
2258 					      BTRFS_SUPER_INFO_SIZE);
2259 		if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
2260 			pr_info("num_copies(log_bytenr=%llu) = %d\n",
2261 			       next_bytenr, num_copies);
2262 		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2263 			int was_created;
2264 
2265 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2266 				pr_info("btrfsic_process_written_superblock(mirror_num=%d)\n", mirror_num);
2267 			ret = btrfsic_map_block(state, next_bytenr,
2268 						BTRFS_SUPER_INFO_SIZE,
2269 						&tmp_next_block_ctx,
2270 						mirror_num);
2271 			if (ret) {
2272 				pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n",
2273 				       next_bytenr, mirror_num);
2274 				return -1;
2275 			}
2276 
2277 			next_block = btrfsic_block_lookup_or_add(
2278 					state,
2279 					&tmp_next_block_ctx,
2280 					additional_string,
2281 					1, 0, 1,
2282 					mirror_num,
2283 					&was_created);
2284 			if (NULL == next_block) {
2285 				pr_info("btrfsic: error, kmalloc failed!\n");
2286 				btrfsic_release_block_ctx(&tmp_next_block_ctx);
2287 				return -1;
2288 			}
2289 
2290 			next_block->disk_key = tmp_disk_key;
2291 			if (was_created)
2292 				next_block->generation =
2293 				    BTRFSIC_GENERATION_UNKNOWN;
2294 			l = btrfsic_block_link_lookup_or_add(
2295 					state,
2296 					&tmp_next_block_ctx,
2297 					next_block,
2298 					superblock,
2299 					BTRFSIC_GENERATION_UNKNOWN);
2300 			btrfsic_release_block_ctx(&tmp_next_block_ctx);
2301 			if (NULL == l)
2302 				return -1;
2303 		}
2304 	}
2305 
2306 	if (WARN_ON(-1 == btrfsic_check_all_ref_blocks(state, superblock, 0)))
2307 		btrfsic_dump_tree(state);
2308 
2309 	return 0;
2310 }
2311 
btrfsic_check_all_ref_blocks(struct btrfsic_state * state,struct btrfsic_block * const block,int recursion_level)2312 static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state,
2313 					struct btrfsic_block *const block,
2314 					int recursion_level)
2315 {
2316 	const struct btrfsic_block_link *l;
2317 	int ret = 0;
2318 
2319 	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2320 		/*
2321 		 * Note that this situation can happen and does not
2322 		 * indicate an error in regular cases. It happens
2323 		 * when disk blocks are freed and later reused.
2324 		 * The check-integrity module is not aware of any
2325 		 * block free operations, it just recognizes block
2326 		 * write operations. Therefore it keeps the linkage
2327 		 * information for a block until a block is
2328 		 * rewritten. This can temporarily cause incorrect
2329 		 * and even circular linkage informations. This
2330 		 * causes no harm unless such blocks are referenced
2331 		 * by the most recent super block.
2332 		 */
2333 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2334 			pr_info("btrfsic: abort cyclic linkage (case 1).\n");
2335 
2336 		return ret;
2337 	}
2338 
2339 	/*
2340 	 * This algorithm is recursive because the amount of used stack
2341 	 * space is very small and the max recursion depth is limited.
2342 	 */
2343 	list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
2344 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2345 			pr_info("rl=%d, %c @%llu (%s/%llu/%d) %u* refers to %c @%llu (%s/%llu/%d)\n",
2346 			       recursion_level,
2347 			       btrfsic_get_block_type(state, block),
2348 			       block->logical_bytenr, block->dev_state->name,
2349 			       block->dev_bytenr, block->mirror_num,
2350 			       l->ref_cnt,
2351 			       btrfsic_get_block_type(state, l->block_ref_to),
2352 			       l->block_ref_to->logical_bytenr,
2353 			       l->block_ref_to->dev_state->name,
2354 			       l->block_ref_to->dev_bytenr,
2355 			       l->block_ref_to->mirror_num);
2356 		if (l->block_ref_to->never_written) {
2357 			pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which is never written!\n",
2358 			       btrfsic_get_block_type(state, l->block_ref_to),
2359 			       l->block_ref_to->logical_bytenr,
2360 			       l->block_ref_to->dev_state->name,
2361 			       l->block_ref_to->dev_bytenr,
2362 			       l->block_ref_to->mirror_num);
2363 			ret = -1;
2364 		} else if (!l->block_ref_to->is_iodone) {
2365 			pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which is not yet iodone!\n",
2366 			       btrfsic_get_block_type(state, l->block_ref_to),
2367 			       l->block_ref_to->logical_bytenr,
2368 			       l->block_ref_to->dev_state->name,
2369 			       l->block_ref_to->dev_bytenr,
2370 			       l->block_ref_to->mirror_num);
2371 			ret = -1;
2372 		} else if (l->block_ref_to->iodone_w_error) {
2373 			pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which has write error!\n",
2374 			       btrfsic_get_block_type(state, l->block_ref_to),
2375 			       l->block_ref_to->logical_bytenr,
2376 			       l->block_ref_to->dev_state->name,
2377 			       l->block_ref_to->dev_bytenr,
2378 			       l->block_ref_to->mirror_num);
2379 			ret = -1;
2380 		} else if (l->parent_generation !=
2381 			   l->block_ref_to->generation &&
2382 			   BTRFSIC_GENERATION_UNKNOWN !=
2383 			   l->parent_generation &&
2384 			   BTRFSIC_GENERATION_UNKNOWN !=
2385 			   l->block_ref_to->generation) {
2386 			pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) with generation %llu != parent generation %llu!\n",
2387 			       btrfsic_get_block_type(state, l->block_ref_to),
2388 			       l->block_ref_to->logical_bytenr,
2389 			       l->block_ref_to->dev_state->name,
2390 			       l->block_ref_to->dev_bytenr,
2391 			       l->block_ref_to->mirror_num,
2392 			       l->block_ref_to->generation,
2393 			       l->parent_generation);
2394 			ret = -1;
2395 		} else if (l->block_ref_to->flush_gen >
2396 			   l->block_ref_to->dev_state->last_flush_gen) {
2397 			pr_info("btrfs: attempt to write superblock which references block %c @%llu (%s/%llu/%d) which is not flushed out of disk's write cache (block flush_gen=%llu, dev->flush_gen=%llu)!\n",
2398 			       btrfsic_get_block_type(state, l->block_ref_to),
2399 			       l->block_ref_to->logical_bytenr,
2400 			       l->block_ref_to->dev_state->name,
2401 			       l->block_ref_to->dev_bytenr,
2402 			       l->block_ref_to->mirror_num, block->flush_gen,
2403 			       l->block_ref_to->dev_state->last_flush_gen);
2404 			ret = -1;
2405 		} else if (-1 == btrfsic_check_all_ref_blocks(state,
2406 							      l->block_ref_to,
2407 							      recursion_level +
2408 							      1)) {
2409 			ret = -1;
2410 		}
2411 	}
2412 
2413 	return ret;
2414 }
2415 
btrfsic_is_block_ref_by_superblock(const struct btrfsic_state * state,const struct btrfsic_block * block,int recursion_level)2416 static int btrfsic_is_block_ref_by_superblock(
2417 		const struct btrfsic_state *state,
2418 		const struct btrfsic_block *block,
2419 		int recursion_level)
2420 {
2421 	const struct btrfsic_block_link *l;
2422 
2423 	if (recursion_level >= 3 + BTRFS_MAX_LEVEL) {
2424 		/* refer to comment at "abort cyclic linkage (case 1)" */
2425 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2426 			pr_info("btrfsic: abort cyclic linkage (case 2).\n");
2427 
2428 		return 0;
2429 	}
2430 
2431 	/*
2432 	 * This algorithm is recursive because the amount of used stack space
2433 	 * is very small and the max recursion depth is limited.
2434 	 */
2435 	list_for_each_entry(l, &block->ref_from_list, node_ref_from) {
2436 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2437 			pr_info("rl=%d, %c @%llu (%s/%llu/%d) is ref %u* from %c @%llu (%s/%llu/%d)\n",
2438 			       recursion_level,
2439 			       btrfsic_get_block_type(state, block),
2440 			       block->logical_bytenr, block->dev_state->name,
2441 			       block->dev_bytenr, block->mirror_num,
2442 			       l->ref_cnt,
2443 			       btrfsic_get_block_type(state, l->block_ref_from),
2444 			       l->block_ref_from->logical_bytenr,
2445 			       l->block_ref_from->dev_state->name,
2446 			       l->block_ref_from->dev_bytenr,
2447 			       l->block_ref_from->mirror_num);
2448 		if (l->block_ref_from->is_superblock &&
2449 		    state->latest_superblock->dev_bytenr ==
2450 		    l->block_ref_from->dev_bytenr &&
2451 		    state->latest_superblock->dev_state->bdev ==
2452 		    l->block_ref_from->dev_state->bdev)
2453 			return 1;
2454 		else if (btrfsic_is_block_ref_by_superblock(state,
2455 							    l->block_ref_from,
2456 							    recursion_level +
2457 							    1))
2458 			return 1;
2459 	}
2460 
2461 	return 0;
2462 }
2463 
btrfsic_print_add_link(const struct btrfsic_state * state,const struct btrfsic_block_link * l)2464 static void btrfsic_print_add_link(const struct btrfsic_state *state,
2465 				   const struct btrfsic_block_link *l)
2466 {
2467 	pr_info("Add %u* link from %c @%llu (%s/%llu/%d) to %c @%llu (%s/%llu/%d).\n",
2468 	       l->ref_cnt,
2469 	       btrfsic_get_block_type(state, l->block_ref_from),
2470 	       l->block_ref_from->logical_bytenr,
2471 	       l->block_ref_from->dev_state->name,
2472 	       l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2473 	       btrfsic_get_block_type(state, l->block_ref_to),
2474 	       l->block_ref_to->logical_bytenr,
2475 	       l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2476 	       l->block_ref_to->mirror_num);
2477 }
2478 
btrfsic_print_rem_link(const struct btrfsic_state * state,const struct btrfsic_block_link * l)2479 static void btrfsic_print_rem_link(const struct btrfsic_state *state,
2480 				   const struct btrfsic_block_link *l)
2481 {
2482 	pr_info("Rem %u* link from %c @%llu (%s/%llu/%d) to %c @%llu (%s/%llu/%d).\n",
2483 	       l->ref_cnt,
2484 	       btrfsic_get_block_type(state, l->block_ref_from),
2485 	       l->block_ref_from->logical_bytenr,
2486 	       l->block_ref_from->dev_state->name,
2487 	       l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num,
2488 	       btrfsic_get_block_type(state, l->block_ref_to),
2489 	       l->block_ref_to->logical_bytenr,
2490 	       l->block_ref_to->dev_state->name, l->block_ref_to->dev_bytenr,
2491 	       l->block_ref_to->mirror_num);
2492 }
2493 
btrfsic_get_block_type(const struct btrfsic_state * state,const struct btrfsic_block * block)2494 static char btrfsic_get_block_type(const struct btrfsic_state *state,
2495 				   const struct btrfsic_block *block)
2496 {
2497 	if (block->is_superblock &&
2498 	    state->latest_superblock->dev_bytenr == block->dev_bytenr &&
2499 	    state->latest_superblock->dev_state->bdev == block->dev_state->bdev)
2500 		return 'S';
2501 	else if (block->is_superblock)
2502 		return 's';
2503 	else if (block->is_metadata)
2504 		return 'M';
2505 	else
2506 		return 'D';
2507 }
2508 
btrfsic_dump_tree(const struct btrfsic_state * state)2509 static void btrfsic_dump_tree(const struct btrfsic_state *state)
2510 {
2511 	btrfsic_dump_tree_sub(state, state->latest_superblock, 0);
2512 }
2513 
btrfsic_dump_tree_sub(const struct btrfsic_state * state,const struct btrfsic_block * block,int indent_level)2514 static void btrfsic_dump_tree_sub(const struct btrfsic_state *state,
2515 				  const struct btrfsic_block *block,
2516 				  int indent_level)
2517 {
2518 	const struct btrfsic_block_link *l;
2519 	int indent_add;
2520 	static char buf[80];
2521 	int cursor_position;
2522 
2523 	/*
2524 	 * Should better fill an on-stack buffer with a complete line and
2525 	 * dump it at once when it is time to print a newline character.
2526 	 */
2527 
2528 	/*
2529 	 * This algorithm is recursive because the amount of used stack space
2530 	 * is very small and the max recursion depth is limited.
2531 	 */
2532 	indent_add = sprintf(buf, "%c-%llu(%s/%llu/%u)",
2533 			     btrfsic_get_block_type(state, block),
2534 			     block->logical_bytenr, block->dev_state->name,
2535 			     block->dev_bytenr, block->mirror_num);
2536 	if (indent_level + indent_add > BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2537 		printk("[...]\n");
2538 		return;
2539 	}
2540 	printk(buf);
2541 	indent_level += indent_add;
2542 	if (list_empty(&block->ref_to_list)) {
2543 		printk("\n");
2544 		return;
2545 	}
2546 	if (block->mirror_num > 1 &&
2547 	    !(state->print_mask & BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS)) {
2548 		printk(" [...]\n");
2549 		return;
2550 	}
2551 
2552 	cursor_position = indent_level;
2553 	list_for_each_entry(l, &block->ref_to_list, node_ref_to) {
2554 		while (cursor_position < indent_level) {
2555 			printk(" ");
2556 			cursor_position++;
2557 		}
2558 		if (l->ref_cnt > 1)
2559 			indent_add = sprintf(buf, " %d*--> ", l->ref_cnt);
2560 		else
2561 			indent_add = sprintf(buf, " --> ");
2562 		if (indent_level + indent_add >
2563 		    BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) {
2564 			printk("[...]\n");
2565 			cursor_position = 0;
2566 			continue;
2567 		}
2568 
2569 		printk(buf);
2570 
2571 		btrfsic_dump_tree_sub(state, l->block_ref_to,
2572 				      indent_level + indent_add);
2573 		cursor_position = 0;
2574 	}
2575 }
2576 
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)2577 static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add(
2578 		struct btrfsic_state *state,
2579 		struct btrfsic_block_data_ctx *next_block_ctx,
2580 		struct btrfsic_block *next_block,
2581 		struct btrfsic_block *from_block,
2582 		u64 parent_generation)
2583 {
2584 	struct btrfsic_block_link *l;
2585 
2586 	l = btrfsic_block_link_hashtable_lookup(next_block_ctx->dev->bdev,
2587 						next_block_ctx->dev_bytenr,
2588 						from_block->dev_state->bdev,
2589 						from_block->dev_bytenr,
2590 						&state->block_link_hashtable);
2591 	if (NULL == l) {
2592 		l = btrfsic_block_link_alloc();
2593 		if (NULL == l) {
2594 			pr_info("btrfsic: error, kmalloc failed!\n");
2595 			return NULL;
2596 		}
2597 
2598 		l->block_ref_to = next_block;
2599 		l->block_ref_from = from_block;
2600 		l->ref_cnt = 1;
2601 		l->parent_generation = parent_generation;
2602 
2603 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2604 			btrfsic_print_add_link(state, l);
2605 
2606 		list_add(&l->node_ref_to, &from_block->ref_to_list);
2607 		list_add(&l->node_ref_from, &next_block->ref_from_list);
2608 
2609 		btrfsic_block_link_hashtable_add(l,
2610 						 &state->block_link_hashtable);
2611 	} else {
2612 		l->ref_cnt++;
2613 		l->parent_generation = parent_generation;
2614 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2615 			btrfsic_print_add_link(state, l);
2616 	}
2617 
2618 	return l;
2619 }
2620 
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)2621 static struct btrfsic_block *btrfsic_block_lookup_or_add(
2622 		struct btrfsic_state *state,
2623 		struct btrfsic_block_data_ctx *block_ctx,
2624 		const char *additional_string,
2625 		int is_metadata,
2626 		int is_iodone,
2627 		int never_written,
2628 		int mirror_num,
2629 		int *was_created)
2630 {
2631 	struct btrfsic_block *block;
2632 
2633 	block = btrfsic_block_hashtable_lookup(block_ctx->dev->bdev,
2634 					       block_ctx->dev_bytenr,
2635 					       &state->block_hashtable);
2636 	if (NULL == block) {
2637 		struct btrfsic_dev_state *dev_state;
2638 
2639 		block = btrfsic_block_alloc();
2640 		if (NULL == block) {
2641 			pr_info("btrfsic: error, kmalloc failed!\n");
2642 			return NULL;
2643 		}
2644 		dev_state = btrfsic_dev_state_lookup(block_ctx->dev->bdev->bd_dev);
2645 		if (NULL == dev_state) {
2646 			pr_info("btrfsic: error, lookup dev_state failed!\n");
2647 			btrfsic_block_free(block);
2648 			return NULL;
2649 		}
2650 		block->dev_state = dev_state;
2651 		block->dev_bytenr = block_ctx->dev_bytenr;
2652 		block->logical_bytenr = block_ctx->start;
2653 		block->is_metadata = is_metadata;
2654 		block->is_iodone = is_iodone;
2655 		block->never_written = never_written;
2656 		block->mirror_num = mirror_num;
2657 		if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
2658 			pr_info("New %s%c-block @%llu (%s/%llu/%d)\n",
2659 			       additional_string,
2660 			       btrfsic_get_block_type(state, block),
2661 			       block->logical_bytenr, dev_state->name,
2662 			       block->dev_bytenr, mirror_num);
2663 		list_add(&block->all_blocks_node, &state->all_blocks_list);
2664 		btrfsic_block_hashtable_add(block, &state->block_hashtable);
2665 		if (NULL != was_created)
2666 			*was_created = 1;
2667 	} else {
2668 		if (NULL != was_created)
2669 			*was_created = 0;
2670 	}
2671 
2672 	return block;
2673 }
2674 
btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state * state,u64 bytenr,struct btrfsic_dev_state * dev_state,u64 dev_bytenr)2675 static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
2676 					   u64 bytenr,
2677 					   struct btrfsic_dev_state *dev_state,
2678 					   u64 dev_bytenr)
2679 {
2680 	struct btrfs_fs_info *fs_info = state->fs_info;
2681 	struct btrfsic_block_data_ctx block_ctx;
2682 	int num_copies;
2683 	int mirror_num;
2684 	int match = 0;
2685 	int ret;
2686 
2687 	num_copies = btrfs_num_copies(fs_info, bytenr, state->metablock_size);
2688 
2689 	for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2690 		ret = btrfsic_map_block(state, bytenr, state->metablock_size,
2691 					&block_ctx, mirror_num);
2692 		if (ret) {
2693 			pr_info("btrfsic: btrfsic_map_block(logical @%llu, mirror %d) failed!\n",
2694 			       bytenr, mirror_num);
2695 			continue;
2696 		}
2697 
2698 		if (dev_state->bdev == block_ctx.dev->bdev &&
2699 		    dev_bytenr == block_ctx.dev_bytenr) {
2700 			match++;
2701 			btrfsic_release_block_ctx(&block_ctx);
2702 			break;
2703 		}
2704 		btrfsic_release_block_ctx(&block_ctx);
2705 	}
2706 
2707 	if (WARN_ON(!match)) {
2708 		pr_info("btrfs: attempt to write M-block which contains logical bytenr that doesn't map to dev+physical bytenr of submit_bio, buffer->log_bytenr=%llu, submit_bio(bdev=%s, phys_bytenr=%llu)!\n",
2709 		       bytenr, dev_state->name, dev_bytenr);
2710 		for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
2711 			ret = btrfsic_map_block(state, bytenr,
2712 						state->metablock_size,
2713 						&block_ctx, mirror_num);
2714 			if (ret)
2715 				continue;
2716 
2717 			pr_info("Read logical bytenr @%llu maps to (%s/%llu/%d)\n",
2718 			       bytenr, block_ctx.dev->name,
2719 			       block_ctx.dev_bytenr, mirror_num);
2720 		}
2721 	}
2722 }
2723 
btrfsic_dev_state_lookup(dev_t dev)2724 static struct btrfsic_dev_state *btrfsic_dev_state_lookup(dev_t dev)
2725 {
2726 	return btrfsic_dev_state_hashtable_lookup(dev,
2727 						  &btrfsic_dev_state_hashtable);
2728 }
2729 
btrfsic_submit_bh(int op,int op_flags,struct buffer_head * bh)2730 int btrfsic_submit_bh(int op, int op_flags, struct buffer_head *bh)
2731 {
2732 	struct btrfsic_dev_state *dev_state;
2733 
2734 	if (!btrfsic_is_initialized)
2735 		return submit_bh(op, op_flags, bh);
2736 
2737 	mutex_lock(&btrfsic_mutex);
2738 	/* since btrfsic_submit_bh() might also be called before
2739 	 * btrfsic_mount(), this might return NULL */
2740 	dev_state = btrfsic_dev_state_lookup(bh->b_bdev->bd_dev);
2741 
2742 	/* Only called to write the superblock (incl. FLUSH/FUA) */
2743 	if (NULL != dev_state &&
2744 	    (op == REQ_OP_WRITE) && bh->b_size > 0) {
2745 		u64 dev_bytenr;
2746 
2747 		dev_bytenr = BTRFS_BDEV_BLOCKSIZE * bh->b_blocknr;
2748 		if (dev_state->state->print_mask &
2749 		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2750 			pr_info("submit_bh(op=0x%x,0x%x, blocknr=%llu (bytenr %llu), size=%zu, data=%p, bdev=%p)\n",
2751 			       op, op_flags, (unsigned long long)bh->b_blocknr,
2752 			       dev_bytenr, bh->b_size, bh->b_data, bh->b_bdev);
2753 		btrfsic_process_written_block(dev_state, dev_bytenr,
2754 					      &bh->b_data, 1, NULL,
2755 					      NULL, bh, op_flags);
2756 	} else if (NULL != dev_state && (op_flags & REQ_PREFLUSH)) {
2757 		if (dev_state->state->print_mask &
2758 		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2759 			pr_info("submit_bh(op=0x%x,0x%x FLUSH, bdev=%p)\n",
2760 			       op, op_flags, bh->b_bdev);
2761 		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
2762 			if ((dev_state->state->print_mask &
2763 			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
2764 			      BTRFSIC_PRINT_MASK_VERBOSE)))
2765 				pr_info("btrfsic_submit_bh(%s) with FLUSH but dummy block already in use (ignored)!\n",
2766 				       dev_state->name);
2767 		} else {
2768 			struct btrfsic_block *const block =
2769 				&dev_state->dummy_block_for_bio_bh_flush;
2770 
2771 			block->is_iodone = 0;
2772 			block->never_written = 0;
2773 			block->iodone_w_error = 0;
2774 			block->flush_gen = dev_state->last_flush_gen + 1;
2775 			block->submit_bio_bh_rw = op_flags;
2776 			block->orig_bio_bh_private = bh->b_private;
2777 			block->orig_bio_bh_end_io.bh = bh->b_end_io;
2778 			block->next_in_same_bio = NULL;
2779 			bh->b_private = block;
2780 			bh->b_end_io = btrfsic_bh_end_io;
2781 		}
2782 	}
2783 	mutex_unlock(&btrfsic_mutex);
2784 	return submit_bh(op, op_flags, bh);
2785 }
2786 
__btrfsic_submit_bio(struct bio * bio)2787 static void __btrfsic_submit_bio(struct bio *bio)
2788 {
2789 	struct btrfsic_dev_state *dev_state;
2790 
2791 	if (!btrfsic_is_initialized)
2792 		return;
2793 
2794 	mutex_lock(&btrfsic_mutex);
2795 	/* since btrfsic_submit_bio() is also called before
2796 	 * btrfsic_mount(), this might return NULL */
2797 	dev_state = btrfsic_dev_state_lookup(bio_dev(bio) + bio->bi_partno);
2798 	if (NULL != dev_state &&
2799 	    (bio_op(bio) == REQ_OP_WRITE) && bio_has_data(bio)) {
2800 		unsigned int i = 0;
2801 		u64 dev_bytenr;
2802 		u64 cur_bytenr;
2803 		struct bio_vec bvec;
2804 		struct bvec_iter iter;
2805 		int bio_is_patched;
2806 		char **mapped_datav;
2807 		unsigned int segs = bio_segments(bio);
2808 
2809 		dev_bytenr = 512 * bio->bi_iter.bi_sector;
2810 		bio_is_patched = 0;
2811 		if (dev_state->state->print_mask &
2812 		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2813 			pr_info("submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_disk=%p)\n",
2814 			       bio_op(bio), bio->bi_opf, segs,
2815 			       (unsigned long long)bio->bi_iter.bi_sector,
2816 			       dev_bytenr, bio->bi_disk);
2817 
2818 		mapped_datav = kmalloc_array(segs,
2819 					     sizeof(*mapped_datav), GFP_NOFS);
2820 		if (!mapped_datav)
2821 			goto leave;
2822 		cur_bytenr = dev_bytenr;
2823 
2824 		bio_for_each_segment(bvec, bio, iter) {
2825 			BUG_ON(bvec.bv_len != PAGE_SIZE);
2826 			mapped_datav[i] = kmap(bvec.bv_page);
2827 			i++;
2828 
2829 			if (dev_state->state->print_mask &
2830 			    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE)
2831 				pr_info("#%u: bytenr=%llu, len=%u, offset=%u\n",
2832 				       i, cur_bytenr, bvec.bv_len, bvec.bv_offset);
2833 			cur_bytenr += bvec.bv_len;
2834 		}
2835 		btrfsic_process_written_block(dev_state, dev_bytenr,
2836 					      mapped_datav, segs,
2837 					      bio, &bio_is_patched,
2838 					      NULL, bio->bi_opf);
2839 		bio_for_each_segment(bvec, bio, iter)
2840 			kunmap(bvec.bv_page);
2841 		kfree(mapped_datav);
2842 	} else if (NULL != dev_state && (bio->bi_opf & REQ_PREFLUSH)) {
2843 		if (dev_state->state->print_mask &
2844 		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
2845 			pr_info("submit_bio(rw=%d,0x%x FLUSH, disk=%p)\n",
2846 			       bio_op(bio), bio->bi_opf, bio->bi_disk);
2847 		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
2848 			if ((dev_state->state->print_mask &
2849 			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
2850 			      BTRFSIC_PRINT_MASK_VERBOSE)))
2851 				pr_info("btrfsic_submit_bio(%s) with FLUSH but dummy block already in use (ignored)!\n",
2852 				       dev_state->name);
2853 		} else {
2854 			struct btrfsic_block *const block =
2855 				&dev_state->dummy_block_for_bio_bh_flush;
2856 
2857 			block->is_iodone = 0;
2858 			block->never_written = 0;
2859 			block->iodone_w_error = 0;
2860 			block->flush_gen = dev_state->last_flush_gen + 1;
2861 			block->submit_bio_bh_rw = bio->bi_opf;
2862 			block->orig_bio_bh_private = bio->bi_private;
2863 			block->orig_bio_bh_end_io.bio = bio->bi_end_io;
2864 			block->next_in_same_bio = NULL;
2865 			bio->bi_private = block;
2866 			bio->bi_end_io = btrfsic_bio_end_io;
2867 		}
2868 	}
2869 leave:
2870 	mutex_unlock(&btrfsic_mutex);
2871 }
2872 
btrfsic_submit_bio(struct bio * bio)2873 void btrfsic_submit_bio(struct bio *bio)
2874 {
2875 	__btrfsic_submit_bio(bio);
2876 	submit_bio(bio);
2877 }
2878 
btrfsic_submit_bio_wait(struct bio * bio)2879 int btrfsic_submit_bio_wait(struct bio *bio)
2880 {
2881 	__btrfsic_submit_bio(bio);
2882 	return submit_bio_wait(bio);
2883 }
2884 
btrfsic_mount(struct btrfs_fs_info * fs_info,struct btrfs_fs_devices * fs_devices,int including_extent_data,u32 print_mask)2885 int btrfsic_mount(struct btrfs_fs_info *fs_info,
2886 		  struct btrfs_fs_devices *fs_devices,
2887 		  int including_extent_data, u32 print_mask)
2888 {
2889 	int ret;
2890 	struct btrfsic_state *state;
2891 	struct list_head *dev_head = &fs_devices->devices;
2892 	struct btrfs_device *device;
2893 
2894 	if (fs_info->nodesize & ((u64)PAGE_SIZE - 1)) {
2895 		pr_info("btrfsic: cannot handle nodesize %d not being a multiple of PAGE_SIZE %ld!\n",
2896 		       fs_info->nodesize, PAGE_SIZE);
2897 		return -1;
2898 	}
2899 	if (fs_info->sectorsize & ((u64)PAGE_SIZE - 1)) {
2900 		pr_info("btrfsic: cannot handle sectorsize %d not being a multiple of PAGE_SIZE %ld!\n",
2901 		       fs_info->sectorsize, PAGE_SIZE);
2902 		return -1;
2903 	}
2904 	state = kvzalloc(sizeof(*state), GFP_KERNEL);
2905 	if (!state) {
2906 		pr_info("btrfs check-integrity: allocation failed!\n");
2907 		return -ENOMEM;
2908 	}
2909 
2910 	if (!btrfsic_is_initialized) {
2911 		mutex_init(&btrfsic_mutex);
2912 		btrfsic_dev_state_hashtable_init(&btrfsic_dev_state_hashtable);
2913 		btrfsic_is_initialized = 1;
2914 	}
2915 	mutex_lock(&btrfsic_mutex);
2916 	state->fs_info = fs_info;
2917 	state->print_mask = print_mask;
2918 	state->include_extent_data = including_extent_data;
2919 	state->csum_size = 0;
2920 	state->metablock_size = fs_info->nodesize;
2921 	state->datablock_size = fs_info->sectorsize;
2922 	INIT_LIST_HEAD(&state->all_blocks_list);
2923 	btrfsic_block_hashtable_init(&state->block_hashtable);
2924 	btrfsic_block_link_hashtable_init(&state->block_link_hashtable);
2925 	state->max_superblock_generation = 0;
2926 	state->latest_superblock = NULL;
2927 
2928 	list_for_each_entry(device, dev_head, dev_list) {
2929 		struct btrfsic_dev_state *ds;
2930 		const char *p;
2931 
2932 		if (!device->bdev || !device->name)
2933 			continue;
2934 
2935 		ds = btrfsic_dev_state_alloc();
2936 		if (NULL == ds) {
2937 			pr_info("btrfs check-integrity: kmalloc() failed!\n");
2938 			mutex_unlock(&btrfsic_mutex);
2939 			return -ENOMEM;
2940 		}
2941 		ds->bdev = device->bdev;
2942 		ds->state = state;
2943 		bdevname(ds->bdev, ds->name);
2944 		ds->name[BDEVNAME_SIZE - 1] = '\0';
2945 		p = kbasename(ds->name);
2946 		strlcpy(ds->name, p, sizeof(ds->name));
2947 		btrfsic_dev_state_hashtable_add(ds,
2948 						&btrfsic_dev_state_hashtable);
2949 	}
2950 
2951 	ret = btrfsic_process_superblock(state, fs_devices);
2952 	if (0 != ret) {
2953 		mutex_unlock(&btrfsic_mutex);
2954 		btrfsic_unmount(fs_devices);
2955 		return ret;
2956 	}
2957 
2958 	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_DATABASE)
2959 		btrfsic_dump_database(state);
2960 	if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_TREE)
2961 		btrfsic_dump_tree(state);
2962 
2963 	mutex_unlock(&btrfsic_mutex);
2964 	return 0;
2965 }
2966 
btrfsic_unmount(struct btrfs_fs_devices * fs_devices)2967 void btrfsic_unmount(struct btrfs_fs_devices *fs_devices)
2968 {
2969 	struct btrfsic_block *b_all, *tmp_all;
2970 	struct btrfsic_state *state;
2971 	struct list_head *dev_head = &fs_devices->devices;
2972 	struct btrfs_device *device;
2973 
2974 	if (!btrfsic_is_initialized)
2975 		return;
2976 
2977 	mutex_lock(&btrfsic_mutex);
2978 
2979 	state = NULL;
2980 	list_for_each_entry(device, dev_head, dev_list) {
2981 		struct btrfsic_dev_state *ds;
2982 
2983 		if (!device->bdev || !device->name)
2984 			continue;
2985 
2986 		ds = btrfsic_dev_state_hashtable_lookup(
2987 				device->bdev->bd_dev,
2988 				&btrfsic_dev_state_hashtable);
2989 		if (NULL != ds) {
2990 			state = ds->state;
2991 			btrfsic_dev_state_hashtable_remove(ds);
2992 			btrfsic_dev_state_free(ds);
2993 		}
2994 	}
2995 
2996 	if (NULL == state) {
2997 		pr_info("btrfsic: error, cannot find state information on umount!\n");
2998 		mutex_unlock(&btrfsic_mutex);
2999 		return;
3000 	}
3001 
3002 	/*
3003 	 * Don't care about keeping the lists' state up to date,
3004 	 * just free all memory that was allocated dynamically.
3005 	 * Free the blocks and the block_links.
3006 	 */
3007 	list_for_each_entry_safe(b_all, tmp_all, &state->all_blocks_list,
3008 				 all_blocks_node) {
3009 		struct btrfsic_block_link *l, *tmp;
3010 
3011 		list_for_each_entry_safe(l, tmp, &b_all->ref_to_list,
3012 					 node_ref_to) {
3013 			if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE)
3014 				btrfsic_print_rem_link(state, l);
3015 
3016 			l->ref_cnt--;
3017 			if (0 == l->ref_cnt)
3018 				btrfsic_block_link_free(l);
3019 		}
3020 
3021 		if (b_all->is_iodone || b_all->never_written)
3022 			btrfsic_block_free(b_all);
3023 		else
3024 			pr_info("btrfs: attempt to free %c-block @%llu (%s/%llu/%d) on umount which is not yet iodone!\n",
3025 			       btrfsic_get_block_type(state, b_all),
3026 			       b_all->logical_bytenr, b_all->dev_state->name,
3027 			       b_all->dev_bytenr, b_all->mirror_num);
3028 	}
3029 
3030 	mutex_unlock(&btrfsic_mutex);
3031 
3032 	kvfree(state);
3033 }
3034