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0e9cebe7 JB |
1 | /* |
2 | * Copyright (C) 2014 Facebook. All rights reserved. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7 | #include <linux/device-mapper.h> | |
8 | ||
9 | #include <linux/module.h> | |
10 | #include <linux/init.h> | |
11 | #include <linux/blkdev.h> | |
12 | #include <linux/bio.h> | |
98d82f48 | 13 | #include <linux/dax.h> |
0e9cebe7 JB |
14 | #include <linux/slab.h> |
15 | #include <linux/kthread.h> | |
16 | #include <linux/freezer.h> | |
98d82f48 | 17 | #include <linux/uio.h> |
0e9cebe7 JB |
18 | |
19 | #define DM_MSG_PREFIX "log-writes" | |
20 | ||
21 | /* | |
22 | * This target will sequentially log all writes to the target device onto the | |
23 | * log device. This is helpful for replaying writes to check for fs consistency | |
24 | * at all times. This target provides a mechanism to mark specific events to | |
25 | * check data at a later time. So for example you would: | |
26 | * | |
27 | * write data | |
28 | * fsync | |
29 | * dmsetup message /dev/whatever mark mymark | |
30 | * unmount /mnt/test | |
31 | * | |
32 | * Then replay the log up to mymark and check the contents of the replay to | |
33 | * verify it matches what was written. | |
34 | * | |
35 | * We log writes only after they have been flushed, this makes the log describe | |
36 | * close to the order in which the data hits the actual disk, not its cache. So | |
37 | * for example the following sequence (W means write, C means complete) | |
38 | * | |
39 | * Wa,Wb,Wc,Cc,Ca,FLUSH,FUAd,Cb,CFLUSH,CFUAd | |
40 | * | |
41 | * Would result in the log looking like this: | |
42 | * | |
43 | * c,a,flush,fuad,b,<other writes>,<next flush> | |
44 | * | |
45 | * This is meant to help expose problems where file systems do not properly wait | |
46 | * on data being written before invoking a FLUSH. FUA bypasses cache so once it | |
47 | * completes it is added to the log as it should be on disk. | |
48 | * | |
49 | * We treat DISCARDs as if they don't bypass cache so that they are logged in | |
50 | * order of completion along with the normal writes. If we didn't do it this | |
51 | * way we would process all the discards first and then write all the data, when | |
52 | * in fact we want to do the data and the discard in the order that they | |
53 | * completed. | |
54 | */ | |
55 | #define LOG_FLUSH_FLAG (1 << 0) | |
56 | #define LOG_FUA_FLAG (1 << 1) | |
57 | #define LOG_DISCARD_FLAG (1 << 2) | |
58 | #define LOG_MARK_FLAG (1 << 3) | |
59 | ||
f4ad317a GU |
60 | #define WRITE_LOG_VERSION 1ULL |
61 | #define WRITE_LOG_MAGIC 0x6a736677736872ULL | |
0e9cebe7 JB |
62 | |
63 | /* | |
64 | * The disk format for this is braindead simple. | |
65 | * | |
66 | * At byte 0 we have our super, followed by the following sequence for | |
67 | * nr_entries: | |
68 | * | |
69 | * [ 1 sector ][ entry->nr_sectors ] | |
70 | * [log_write_entry][ data written ] | |
71 | * | |
72 | * The log_write_entry takes up a full sector so we can have arbitrary length | |
73 | * marks and it leaves us room for extra content in the future. | |
74 | */ | |
75 | ||
76 | /* | |
77 | * Basic info about the log for userspace. | |
78 | */ | |
79 | struct log_write_super { | |
80 | __le64 magic; | |
81 | __le64 version; | |
82 | __le64 nr_entries; | |
83 | __le32 sectorsize; | |
84 | }; | |
85 | ||
86 | /* | |
87 | * sector - the sector we wrote. | |
88 | * nr_sectors - the number of sectors we wrote. | |
89 | * flags - flags for this log entry. | |
90 | * data_len - the size of the data in this log entry, this is for private log | |
91 | * entry stuff, the MARK data provided by userspace for example. | |
92 | */ | |
93 | struct log_write_entry { | |
94 | __le64 sector; | |
95 | __le64 nr_sectors; | |
96 | __le64 flags; | |
97 | __le64 data_len; | |
98 | }; | |
99 | ||
100 | struct log_writes_c { | |
101 | struct dm_dev *dev; | |
102 | struct dm_dev *logdev; | |
103 | u64 logged_entries; | |
104 | u32 sectorsize; | |
228bb5b2 | 105 | u32 sectorshift; |
0e9cebe7 JB |
106 | atomic_t io_blocks; |
107 | atomic_t pending_blocks; | |
108 | sector_t next_sector; | |
109 | sector_t end_sector; | |
110 | bool logging_enabled; | |
111 | bool device_supports_discard; | |
112 | spinlock_t blocks_lock; | |
113 | struct list_head unflushed_blocks; | |
114 | struct list_head logging_blocks; | |
115 | wait_queue_head_t wait; | |
116 | struct task_struct *log_kthread; | |
117 | }; | |
118 | ||
119 | struct pending_block { | |
120 | int vec_cnt; | |
121 | u64 flags; | |
122 | sector_t sector; | |
123 | sector_t nr_sectors; | |
124 | char *data; | |
125 | u32 datalen; | |
126 | struct list_head list; | |
127 | struct bio_vec vecs[0]; | |
128 | }; | |
129 | ||
130 | struct per_bio_data { | |
131 | struct pending_block *block; | |
132 | }; | |
133 | ||
228bb5b2 JB |
134 | static inline sector_t bio_to_dev_sectors(struct log_writes_c *lc, |
135 | sector_t sectors) | |
136 | { | |
137 | return sectors >> (lc->sectorshift - SECTOR_SHIFT); | |
138 | } | |
139 | ||
140 | static inline sector_t dev_to_bio_sectors(struct log_writes_c *lc, | |
141 | sector_t sectors) | |
142 | { | |
143 | return sectors << (lc->sectorshift - SECTOR_SHIFT); | |
144 | } | |
145 | ||
0e9cebe7 JB |
146 | static void put_pending_block(struct log_writes_c *lc) |
147 | { | |
148 | if (atomic_dec_and_test(&lc->pending_blocks)) { | |
149 | smp_mb__after_atomic(); | |
150 | if (waitqueue_active(&lc->wait)) | |
151 | wake_up(&lc->wait); | |
152 | } | |
153 | } | |
154 | ||
155 | static void put_io_block(struct log_writes_c *lc) | |
156 | { | |
157 | if (atomic_dec_and_test(&lc->io_blocks)) { | |
158 | smp_mb__after_atomic(); | |
159 | if (waitqueue_active(&lc->wait)) | |
160 | wake_up(&lc->wait); | |
161 | } | |
162 | } | |
163 | ||
4246a0b6 | 164 | static void log_end_io(struct bio *bio) |
0e9cebe7 JB |
165 | { |
166 | struct log_writes_c *lc = bio->bi_private; | |
0e9cebe7 | 167 | |
4e4cbee9 | 168 | if (bio->bi_status) { |
0e9cebe7 JB |
169 | unsigned long flags; |
170 | ||
4e4cbee9 | 171 | DMERR("Error writing log block, error=%d", bio->bi_status); |
0e9cebe7 JB |
172 | spin_lock_irqsave(&lc->blocks_lock, flags); |
173 | lc->logging_enabled = false; | |
174 | spin_unlock_irqrestore(&lc->blocks_lock, flags); | |
175 | } | |
176 | ||
491221f8 | 177 | bio_free_pages(bio); |
0e9cebe7 JB |
178 | put_io_block(lc); |
179 | bio_put(bio); | |
180 | } | |
181 | ||
182 | /* | |
183 | * Meant to be called if there is an error, it will free all the pages | |
184 | * associated with the block. | |
185 | */ | |
186 | static void free_pending_block(struct log_writes_c *lc, | |
187 | struct pending_block *block) | |
188 | { | |
189 | int i; | |
190 | ||
191 | for (i = 0; i < block->vec_cnt; i++) { | |
192 | if (block->vecs[i].bv_page) | |
193 | __free_page(block->vecs[i].bv_page); | |
194 | } | |
195 | kfree(block->data); | |
196 | kfree(block); | |
197 | put_pending_block(lc); | |
198 | } | |
199 | ||
200 | static int write_metadata(struct log_writes_c *lc, void *entry, | |
201 | size_t entrylen, void *data, size_t datalen, | |
202 | sector_t sector) | |
203 | { | |
204 | struct bio *bio; | |
205 | struct page *page; | |
206 | void *ptr; | |
207 | size_t ret; | |
208 | ||
209 | bio = bio_alloc(GFP_KERNEL, 1); | |
210 | if (!bio) { | |
211 | DMERR("Couldn't alloc log bio"); | |
212 | goto error; | |
213 | } | |
214 | bio->bi_iter.bi_size = 0; | |
215 | bio->bi_iter.bi_sector = sector; | |
74d46992 | 216 | bio_set_dev(bio, lc->logdev->bdev); |
0e9cebe7 JB |
217 | bio->bi_end_io = log_end_io; |
218 | bio->bi_private = lc; | |
e6047149 | 219 | bio_set_op_attrs(bio, REQ_OP_WRITE, 0); |
0e9cebe7 JB |
220 | |
221 | page = alloc_page(GFP_KERNEL); | |
222 | if (!page) { | |
223 | DMERR("Couldn't alloc log page"); | |
224 | bio_put(bio); | |
225 | goto error; | |
226 | } | |
227 | ||
228 | ptr = kmap_atomic(page); | |
229 | memcpy(ptr, entry, entrylen); | |
230 | if (datalen) | |
231 | memcpy(ptr + entrylen, data, datalen); | |
232 | memset(ptr + entrylen + datalen, 0, | |
233 | lc->sectorsize - entrylen - datalen); | |
234 | kunmap_atomic(ptr); | |
235 | ||
236 | ret = bio_add_page(bio, page, lc->sectorsize, 0); | |
237 | if (ret != lc->sectorsize) { | |
238 | DMERR("Couldn't add page to the log block"); | |
239 | goto error_bio; | |
240 | } | |
4e49ea4a | 241 | submit_bio(bio); |
0e9cebe7 JB |
242 | return 0; |
243 | error_bio: | |
244 | bio_put(bio); | |
245 | __free_page(page); | |
246 | error: | |
247 | put_io_block(lc); | |
248 | return -1; | |
249 | } | |
250 | ||
e5a20660 RZ |
251 | static int write_inline_data(struct log_writes_c *lc, void *entry, |
252 | size_t entrylen, void *data, size_t datalen, | |
253 | sector_t sector) | |
254 | { | |
255 | int num_pages, bio_pages, pg_datalen, pg_sectorlen, i; | |
256 | struct page *page; | |
257 | struct bio *bio; | |
258 | size_t ret; | |
259 | void *ptr; | |
260 | ||
261 | while (datalen) { | |
262 | num_pages = ALIGN(datalen, PAGE_SIZE) >> PAGE_SHIFT; | |
263 | bio_pages = min(num_pages, BIO_MAX_PAGES); | |
264 | ||
265 | atomic_inc(&lc->io_blocks); | |
266 | ||
267 | bio = bio_alloc(GFP_KERNEL, bio_pages); | |
268 | if (!bio) { | |
269 | DMERR("Couldn't alloc inline data bio"); | |
270 | goto error; | |
271 | } | |
272 | ||
273 | bio->bi_iter.bi_size = 0; | |
274 | bio->bi_iter.bi_sector = sector; | |
275 | bio_set_dev(bio, lc->logdev->bdev); | |
276 | bio->bi_end_io = log_end_io; | |
277 | bio->bi_private = lc; | |
278 | bio_set_op_attrs(bio, REQ_OP_WRITE, 0); | |
279 | ||
280 | for (i = 0; i < bio_pages; i++) { | |
281 | pg_datalen = min_t(int, datalen, PAGE_SIZE); | |
282 | pg_sectorlen = ALIGN(pg_datalen, lc->sectorsize); | |
283 | ||
284 | page = alloc_page(GFP_KERNEL); | |
285 | if (!page) { | |
286 | DMERR("Couldn't alloc inline data page"); | |
287 | goto error_bio; | |
288 | } | |
289 | ||
290 | ptr = kmap_atomic(page); | |
291 | memcpy(ptr, data, pg_datalen); | |
292 | if (pg_sectorlen > pg_datalen) | |
293 | memset(ptr + pg_datalen, 0, pg_sectorlen - pg_datalen); | |
294 | kunmap_atomic(ptr); | |
295 | ||
296 | ret = bio_add_page(bio, page, pg_sectorlen, 0); | |
297 | if (ret != pg_sectorlen) { | |
298 | DMERR("Couldn't add page of inline data"); | |
299 | __free_page(page); | |
300 | goto error_bio; | |
301 | } | |
302 | ||
303 | datalen -= pg_datalen; | |
304 | data += pg_datalen; | |
305 | } | |
306 | submit_bio(bio); | |
307 | ||
308 | sector += bio_pages * PAGE_SECTORS; | |
309 | } | |
310 | return 0; | |
311 | error_bio: | |
312 | bio_free_pages(bio); | |
313 | bio_put(bio); | |
314 | error: | |
315 | put_io_block(lc); | |
316 | return -1; | |
317 | } | |
318 | ||
0e9cebe7 JB |
319 | static int log_one_block(struct log_writes_c *lc, |
320 | struct pending_block *block, sector_t sector) | |
321 | { | |
322 | struct bio *bio; | |
323 | struct log_write_entry entry; | |
e5a20660 | 324 | size_t metadatalen, ret; |
0e9cebe7 JB |
325 | int i; |
326 | ||
327 | entry.sector = cpu_to_le64(block->sector); | |
328 | entry.nr_sectors = cpu_to_le64(block->nr_sectors); | |
329 | entry.flags = cpu_to_le64(block->flags); | |
330 | entry.data_len = cpu_to_le64(block->datalen); | |
e5a20660 RZ |
331 | |
332 | metadatalen = (block->flags & LOG_MARK_FLAG) ? block->datalen : 0; | |
0e9cebe7 | 333 | if (write_metadata(lc, &entry, sizeof(entry), block->data, |
e5a20660 | 334 | metadatalen, sector)) { |
0e9cebe7 JB |
335 | free_pending_block(lc, block); |
336 | return -1; | |
337 | } | |
338 | ||
e5a20660 RZ |
339 | sector += dev_to_bio_sectors(lc, 1); |
340 | ||
341 | if (block->datalen && metadatalen == 0) { | |
342 | if (write_inline_data(lc, &entry, sizeof(entry), block->data, | |
343 | block->datalen, sector)) { | |
344 | free_pending_block(lc, block); | |
345 | return -1; | |
346 | } | |
347 | /* we don't support both inline data & bio data */ | |
348 | goto out; | |
349 | } | |
350 | ||
0e9cebe7 JB |
351 | if (!block->vec_cnt) |
352 | goto out; | |
0e9cebe7 | 353 | |
a5d60783 | 354 | atomic_inc(&lc->io_blocks); |
7efb3673 | 355 | bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt, BIO_MAX_PAGES)); |
0e9cebe7 JB |
356 | if (!bio) { |
357 | DMERR("Couldn't alloc log bio"); | |
358 | goto error; | |
359 | } | |
0e9cebe7 JB |
360 | bio->bi_iter.bi_size = 0; |
361 | bio->bi_iter.bi_sector = sector; | |
74d46992 | 362 | bio_set_dev(bio, lc->logdev->bdev); |
0e9cebe7 JB |
363 | bio->bi_end_io = log_end_io; |
364 | bio->bi_private = lc; | |
e6047149 | 365 | bio_set_op_attrs(bio, REQ_OP_WRITE, 0); |
0e9cebe7 JB |
366 | |
367 | for (i = 0; i < block->vec_cnt; i++) { | |
368 | /* | |
369 | * The page offset is always 0 because we allocate a new page | |
370 | * for every bvec in the original bio for simplicity sake. | |
371 | */ | |
372 | ret = bio_add_page(bio, block->vecs[i].bv_page, | |
373 | block->vecs[i].bv_len, 0); | |
374 | if (ret != block->vecs[i].bv_len) { | |
375 | atomic_inc(&lc->io_blocks); | |
4e49ea4a | 376 | submit_bio(bio); |
7efb3673 | 377 | bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt - i, BIO_MAX_PAGES)); |
0e9cebe7 JB |
378 | if (!bio) { |
379 | DMERR("Couldn't alloc log bio"); | |
380 | goto error; | |
381 | } | |
382 | bio->bi_iter.bi_size = 0; | |
383 | bio->bi_iter.bi_sector = sector; | |
74d46992 | 384 | bio_set_dev(bio, lc->logdev->bdev); |
0e9cebe7 JB |
385 | bio->bi_end_io = log_end_io; |
386 | bio->bi_private = lc; | |
e6047149 | 387 | bio_set_op_attrs(bio, REQ_OP_WRITE, 0); |
0e9cebe7 JB |
388 | |
389 | ret = bio_add_page(bio, block->vecs[i].bv_page, | |
390 | block->vecs[i].bv_len, 0); | |
391 | if (ret != block->vecs[i].bv_len) { | |
392 | DMERR("Couldn't add page on new bio?"); | |
393 | bio_put(bio); | |
394 | goto error; | |
395 | } | |
396 | } | |
397 | sector += block->vecs[i].bv_len >> SECTOR_SHIFT; | |
398 | } | |
4e49ea4a | 399 | submit_bio(bio); |
0e9cebe7 JB |
400 | out: |
401 | kfree(block->data); | |
402 | kfree(block); | |
403 | put_pending_block(lc); | |
404 | return 0; | |
405 | error: | |
406 | free_pending_block(lc, block); | |
407 | put_io_block(lc); | |
408 | return -1; | |
409 | } | |
410 | ||
411 | static int log_super(struct log_writes_c *lc) | |
412 | { | |
413 | struct log_write_super super; | |
414 | ||
415 | super.magic = cpu_to_le64(WRITE_LOG_MAGIC); | |
416 | super.version = cpu_to_le64(WRITE_LOG_VERSION); | |
417 | super.nr_entries = cpu_to_le64(lc->logged_entries); | |
418 | super.sectorsize = cpu_to_le32(lc->sectorsize); | |
419 | ||
420 | if (write_metadata(lc, &super, sizeof(super), NULL, 0, 0)) { | |
421 | DMERR("Couldn't write super"); | |
422 | return -1; | |
423 | } | |
424 | ||
425 | return 0; | |
426 | } | |
427 | ||
428 | static inline sector_t logdev_last_sector(struct log_writes_c *lc) | |
429 | { | |
430 | return i_size_read(lc->logdev->bdev->bd_inode) >> SECTOR_SHIFT; | |
431 | } | |
432 | ||
433 | static int log_writes_kthread(void *arg) | |
434 | { | |
435 | struct log_writes_c *lc = (struct log_writes_c *)arg; | |
436 | sector_t sector = 0; | |
437 | ||
438 | while (!kthread_should_stop()) { | |
439 | bool super = false; | |
440 | bool logging_enabled; | |
441 | struct pending_block *block = NULL; | |
442 | int ret; | |
443 | ||
444 | spin_lock_irq(&lc->blocks_lock); | |
445 | if (!list_empty(&lc->logging_blocks)) { | |
446 | block = list_first_entry(&lc->logging_blocks, | |
447 | struct pending_block, list); | |
448 | list_del_init(&block->list); | |
449 | if (!lc->logging_enabled) | |
450 | goto next; | |
451 | ||
452 | sector = lc->next_sector; | |
228bb5b2 JB |
453 | if (!(block->flags & LOG_DISCARD_FLAG)) |
454 | lc->next_sector += dev_to_bio_sectors(lc, block->nr_sectors); | |
455 | lc->next_sector += dev_to_bio_sectors(lc, 1); | |
0e9cebe7 JB |
456 | |
457 | /* | |
458 | * Apparently the size of the device may not be known | |
459 | * right away, so handle this properly. | |
460 | */ | |
461 | if (!lc->end_sector) | |
462 | lc->end_sector = logdev_last_sector(lc); | |
463 | if (lc->end_sector && | |
464 | lc->next_sector >= lc->end_sector) { | |
465 | DMERR("Ran out of space on the logdev"); | |
466 | lc->logging_enabled = false; | |
467 | goto next; | |
468 | } | |
469 | lc->logged_entries++; | |
470 | atomic_inc(&lc->io_blocks); | |
471 | ||
472 | super = (block->flags & (LOG_FUA_FLAG | LOG_MARK_FLAG)); | |
473 | if (super) | |
474 | atomic_inc(&lc->io_blocks); | |
475 | } | |
476 | next: | |
477 | logging_enabled = lc->logging_enabled; | |
478 | spin_unlock_irq(&lc->blocks_lock); | |
479 | if (block) { | |
480 | if (logging_enabled) { | |
481 | ret = log_one_block(lc, block, sector); | |
482 | if (!ret && super) | |
483 | ret = log_super(lc); | |
484 | if (ret) { | |
485 | spin_lock_irq(&lc->blocks_lock); | |
486 | lc->logging_enabled = false; | |
487 | spin_unlock_irq(&lc->blocks_lock); | |
488 | } | |
489 | } else | |
490 | free_pending_block(lc, block); | |
491 | continue; | |
492 | } | |
493 | ||
494 | if (!try_to_freeze()) { | |
495 | set_current_state(TASK_INTERRUPTIBLE); | |
496 | if (!kthread_should_stop() && | |
0c79c620 | 497 | list_empty(&lc->logging_blocks)) |
0e9cebe7 JB |
498 | schedule(); |
499 | __set_current_state(TASK_RUNNING); | |
500 | } | |
501 | } | |
502 | return 0; | |
503 | } | |
504 | ||
505 | /* | |
506 | * Construct a log-writes mapping: | |
507 | * log-writes <dev_path> <log_dev_path> | |
508 | */ | |
509 | static int log_writes_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
510 | { | |
511 | struct log_writes_c *lc; | |
512 | struct dm_arg_set as; | |
513 | const char *devname, *logdevname; | |
e80d1c80 | 514 | int ret; |
0e9cebe7 JB |
515 | |
516 | as.argc = argc; | |
517 | as.argv = argv; | |
518 | ||
519 | if (argc < 2) { | |
520 | ti->error = "Invalid argument count"; | |
521 | return -EINVAL; | |
522 | } | |
523 | ||
524 | lc = kzalloc(sizeof(struct log_writes_c), GFP_KERNEL); | |
525 | if (!lc) { | |
526 | ti->error = "Cannot allocate context"; | |
527 | return -ENOMEM; | |
528 | } | |
529 | spin_lock_init(&lc->blocks_lock); | |
530 | INIT_LIST_HEAD(&lc->unflushed_blocks); | |
531 | INIT_LIST_HEAD(&lc->logging_blocks); | |
532 | init_waitqueue_head(&lc->wait); | |
0e9cebe7 JB |
533 | atomic_set(&lc->io_blocks, 0); |
534 | atomic_set(&lc->pending_blocks, 0); | |
535 | ||
536 | devname = dm_shift_arg(&as); | |
e80d1c80 VG |
537 | ret = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &lc->dev); |
538 | if (ret) { | |
0e9cebe7 JB |
539 | ti->error = "Device lookup failed"; |
540 | goto bad; | |
541 | } | |
542 | ||
543 | logdevname = dm_shift_arg(&as); | |
e80d1c80 VG |
544 | ret = dm_get_device(ti, logdevname, dm_table_get_mode(ti->table), |
545 | &lc->logdev); | |
546 | if (ret) { | |
0e9cebe7 JB |
547 | ti->error = "Log device lookup failed"; |
548 | dm_put_device(ti, lc->dev); | |
549 | goto bad; | |
550 | } | |
551 | ||
228bb5b2 JB |
552 | lc->sectorsize = bdev_logical_block_size(lc->dev->bdev); |
553 | lc->sectorshift = ilog2(lc->sectorsize); | |
0e9cebe7 | 554 | lc->log_kthread = kthread_run(log_writes_kthread, lc, "log-write"); |
91e630d9 VZ |
555 | if (IS_ERR(lc->log_kthread)) { |
556 | ret = PTR_ERR(lc->log_kthread); | |
0e9cebe7 JB |
557 | ti->error = "Couldn't alloc kthread"; |
558 | dm_put_device(ti, lc->dev); | |
559 | dm_put_device(ti, lc->logdev); | |
560 | goto bad; | |
561 | } | |
562 | ||
228bb5b2 JB |
563 | /* |
564 | * next_sector is in 512b sectors to correspond to what bi_sector expects. | |
565 | * The super starts at sector 0, and the next_sector is the next logical | |
566 | * one based on the sectorsize of the device. | |
567 | */ | |
568 | lc->next_sector = lc->sectorsize >> SECTOR_SHIFT; | |
0e9cebe7 JB |
569 | lc->logging_enabled = true; |
570 | lc->end_sector = logdev_last_sector(lc); | |
571 | lc->device_supports_discard = true; | |
572 | ||
573 | ti->num_flush_bios = 1; | |
574 | ti->flush_supported = true; | |
575 | ti->num_discard_bios = 1; | |
576 | ti->discards_supported = true; | |
30187e1d | 577 | ti->per_io_data_size = sizeof(struct per_bio_data); |
0e9cebe7 JB |
578 | ti->private = lc; |
579 | return 0; | |
580 | ||
581 | bad: | |
582 | kfree(lc); | |
e80d1c80 | 583 | return ret; |
0e9cebe7 JB |
584 | } |
585 | ||
586 | static int log_mark(struct log_writes_c *lc, char *data) | |
587 | { | |
588 | struct pending_block *block; | |
589 | size_t maxsize = lc->sectorsize - sizeof(struct log_write_entry); | |
590 | ||
591 | block = kzalloc(sizeof(struct pending_block), GFP_KERNEL); | |
592 | if (!block) { | |
593 | DMERR("Error allocating pending block"); | |
594 | return -ENOMEM; | |
595 | } | |
596 | ||
597 | block->data = kstrndup(data, maxsize, GFP_KERNEL); | |
598 | if (!block->data) { | |
599 | DMERR("Error copying mark data"); | |
600 | kfree(block); | |
601 | return -ENOMEM; | |
602 | } | |
603 | atomic_inc(&lc->pending_blocks); | |
604 | block->datalen = strlen(block->data); | |
605 | block->flags |= LOG_MARK_FLAG; | |
606 | spin_lock_irq(&lc->blocks_lock); | |
607 | list_add_tail(&block->list, &lc->logging_blocks); | |
608 | spin_unlock_irq(&lc->blocks_lock); | |
609 | wake_up_process(lc->log_kthread); | |
610 | return 0; | |
611 | } | |
612 | ||
98d82f48 RZ |
613 | static int log_dax(struct log_writes_c *lc, sector_t sector, size_t bytes, |
614 | struct iov_iter *i) | |
615 | { | |
616 | struct pending_block *block; | |
617 | ||
618 | if (!bytes) | |
619 | return 0; | |
620 | ||
621 | block = kzalloc(sizeof(struct pending_block), GFP_KERNEL); | |
622 | if (!block) { | |
623 | DMERR("Error allocating dax pending block"); | |
624 | return -ENOMEM; | |
625 | } | |
626 | ||
627 | block->data = kzalloc(bytes, GFP_KERNEL); | |
628 | if (!block->data) { | |
629 | DMERR("Error allocating dax data space"); | |
630 | kfree(block); | |
631 | return -ENOMEM; | |
632 | } | |
633 | ||
634 | /* write data provided via the iterator */ | |
635 | if (!copy_from_iter(block->data, bytes, i)) { | |
636 | DMERR("Error copying dax data"); | |
637 | kfree(block->data); | |
638 | kfree(block); | |
639 | return -EIO; | |
640 | } | |
641 | ||
642 | /* rewind the iterator so that the block driver can use it */ | |
643 | iov_iter_revert(i, bytes); | |
644 | ||
645 | block->datalen = bytes; | |
646 | block->sector = bio_to_dev_sectors(lc, sector); | |
647 | block->nr_sectors = ALIGN(bytes, lc->sectorsize) >> lc->sectorshift; | |
648 | ||
649 | atomic_inc(&lc->pending_blocks); | |
650 | spin_lock_irq(&lc->blocks_lock); | |
651 | list_add_tail(&block->list, &lc->unflushed_blocks); | |
652 | spin_unlock_irq(&lc->blocks_lock); | |
653 | wake_up_process(lc->log_kthread); | |
654 | ||
655 | return 0; | |
656 | } | |
657 | ||
0e9cebe7 JB |
658 | static void log_writes_dtr(struct dm_target *ti) |
659 | { | |
660 | struct log_writes_c *lc = ti->private; | |
661 | ||
662 | spin_lock_irq(&lc->blocks_lock); | |
663 | list_splice_init(&lc->unflushed_blocks, &lc->logging_blocks); | |
664 | spin_unlock_irq(&lc->blocks_lock); | |
665 | ||
666 | /* | |
667 | * This is just nice to have since it'll update the super to include the | |
668 | * unflushed blocks, if it fails we don't really care. | |
669 | */ | |
670 | log_mark(lc, "dm-log-writes-end"); | |
671 | wake_up_process(lc->log_kthread); | |
672 | wait_event(lc->wait, !atomic_read(&lc->io_blocks) && | |
673 | !atomic_read(&lc->pending_blocks)); | |
674 | kthread_stop(lc->log_kthread); | |
675 | ||
676 | WARN_ON(!list_empty(&lc->logging_blocks)); | |
677 | WARN_ON(!list_empty(&lc->unflushed_blocks)); | |
678 | dm_put_device(ti, lc->dev); | |
679 | dm_put_device(ti, lc->logdev); | |
680 | kfree(lc); | |
681 | } | |
682 | ||
683 | static void normal_map_bio(struct dm_target *ti, struct bio *bio) | |
684 | { | |
685 | struct log_writes_c *lc = ti->private; | |
686 | ||
74d46992 | 687 | bio_set_dev(bio, lc->dev->bdev); |
0e9cebe7 JB |
688 | } |
689 | ||
690 | static int log_writes_map(struct dm_target *ti, struct bio *bio) | |
691 | { | |
692 | struct log_writes_c *lc = ti->private; | |
693 | struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data)); | |
694 | struct pending_block *block; | |
695 | struct bvec_iter iter; | |
696 | struct bio_vec bv; | |
697 | size_t alloc_size; | |
698 | int i = 0; | |
1eff9d32 JA |
699 | bool flush_bio = (bio->bi_opf & REQ_PREFLUSH); |
700 | bool fua_bio = (bio->bi_opf & REQ_FUA); | |
e6047149 | 701 | bool discard_bio = (bio_op(bio) == REQ_OP_DISCARD); |
0e9cebe7 JB |
702 | |
703 | pb->block = NULL; | |
704 | ||
705 | /* Don't bother doing anything if logging has been disabled */ | |
706 | if (!lc->logging_enabled) | |
707 | goto map_bio; | |
708 | ||
709 | /* | |
710 | * Map reads as normal. | |
711 | */ | |
712 | if (bio_data_dir(bio) == READ) | |
713 | goto map_bio; | |
714 | ||
715 | /* No sectors and not a flush? Don't care */ | |
716 | if (!bio_sectors(bio) && !flush_bio) | |
717 | goto map_bio; | |
718 | ||
719 | /* | |
720 | * Discards will have bi_size set but there's no actual data, so just | |
721 | * allocate the size of the pending block. | |
722 | */ | |
723 | if (discard_bio) | |
724 | alloc_size = sizeof(struct pending_block); | |
725 | else | |
726 | alloc_size = sizeof(struct pending_block) + sizeof(struct bio_vec) * bio_segments(bio); | |
727 | ||
728 | block = kzalloc(alloc_size, GFP_NOIO); | |
729 | if (!block) { | |
730 | DMERR("Error allocating pending block"); | |
731 | spin_lock_irq(&lc->blocks_lock); | |
732 | lc->logging_enabled = false; | |
733 | spin_unlock_irq(&lc->blocks_lock); | |
846785e6 | 734 | return DM_MAPIO_KILL; |
0e9cebe7 JB |
735 | } |
736 | INIT_LIST_HEAD(&block->list); | |
737 | pb->block = block; | |
738 | atomic_inc(&lc->pending_blocks); | |
739 | ||
740 | if (flush_bio) | |
741 | block->flags |= LOG_FLUSH_FLAG; | |
742 | if (fua_bio) | |
743 | block->flags |= LOG_FUA_FLAG; | |
744 | if (discard_bio) | |
745 | block->flags |= LOG_DISCARD_FLAG; | |
746 | ||
228bb5b2 JB |
747 | block->sector = bio_to_dev_sectors(lc, bio->bi_iter.bi_sector); |
748 | block->nr_sectors = bio_to_dev_sectors(lc, bio_sectors(bio)); | |
0e9cebe7 JB |
749 | |
750 | /* We don't need the data, just submit */ | |
751 | if (discard_bio) { | |
752 | WARN_ON(flush_bio || fua_bio); | |
753 | if (lc->device_supports_discard) | |
754 | goto map_bio; | |
4246a0b6 | 755 | bio_endio(bio); |
0e9cebe7 JB |
756 | return DM_MAPIO_SUBMITTED; |
757 | } | |
758 | ||
759 | /* Flush bio, splice the unflushed blocks onto this list and submit */ | |
760 | if (flush_bio && !bio_sectors(bio)) { | |
761 | spin_lock_irq(&lc->blocks_lock); | |
762 | list_splice_init(&lc->unflushed_blocks, &block->list); | |
763 | spin_unlock_irq(&lc->blocks_lock); | |
764 | goto map_bio; | |
765 | } | |
766 | ||
767 | /* | |
768 | * We will write this bio somewhere else way later so we need to copy | |
769 | * the actual contents into new pages so we know the data will always be | |
770 | * there. | |
771 | * | |
772 | * We do this because this could be a bio from O_DIRECT in which case we | |
773 | * can't just hold onto the page until some later point, we have to | |
774 | * manually copy the contents. | |
775 | */ | |
776 | bio_for_each_segment(bv, bio, iter) { | |
777 | struct page *page; | |
778 | void *src, *dst; | |
779 | ||
780 | page = alloc_page(GFP_NOIO); | |
781 | if (!page) { | |
782 | DMERR("Error allocing page"); | |
783 | free_pending_block(lc, block); | |
784 | spin_lock_irq(&lc->blocks_lock); | |
785 | lc->logging_enabled = false; | |
786 | spin_unlock_irq(&lc->blocks_lock); | |
846785e6 | 787 | return DM_MAPIO_KILL; |
0e9cebe7 JB |
788 | } |
789 | ||
790 | src = kmap_atomic(bv.bv_page); | |
791 | dst = kmap_atomic(page); | |
792 | memcpy(dst, src + bv.bv_offset, bv.bv_len); | |
793 | kunmap_atomic(dst); | |
794 | kunmap_atomic(src); | |
795 | block->vecs[i].bv_page = page; | |
796 | block->vecs[i].bv_len = bv.bv_len; | |
797 | block->vec_cnt++; | |
798 | i++; | |
799 | } | |
800 | ||
801 | /* Had a flush with data in it, weird */ | |
802 | if (flush_bio) { | |
803 | spin_lock_irq(&lc->blocks_lock); | |
804 | list_splice_init(&lc->unflushed_blocks, &block->list); | |
805 | spin_unlock_irq(&lc->blocks_lock); | |
806 | } | |
807 | map_bio: | |
808 | normal_map_bio(ti, bio); | |
809 | return DM_MAPIO_REMAPPED; | |
810 | } | |
811 | ||
4e4cbee9 CH |
812 | static int normal_end_io(struct dm_target *ti, struct bio *bio, |
813 | blk_status_t *error) | |
0e9cebe7 JB |
814 | { |
815 | struct log_writes_c *lc = ti->private; | |
816 | struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data)); | |
817 | ||
818 | if (bio_data_dir(bio) == WRITE && pb->block) { | |
819 | struct pending_block *block = pb->block; | |
820 | unsigned long flags; | |
821 | ||
822 | spin_lock_irqsave(&lc->blocks_lock, flags); | |
823 | if (block->flags & LOG_FLUSH_FLAG) { | |
824 | list_splice_tail_init(&block->list, &lc->logging_blocks); | |
825 | list_add_tail(&block->list, &lc->logging_blocks); | |
826 | wake_up_process(lc->log_kthread); | |
827 | } else if (block->flags & LOG_FUA_FLAG) { | |
828 | list_add_tail(&block->list, &lc->logging_blocks); | |
829 | wake_up_process(lc->log_kthread); | |
830 | } else | |
831 | list_add_tail(&block->list, &lc->unflushed_blocks); | |
832 | spin_unlock_irqrestore(&lc->blocks_lock, flags); | |
833 | } | |
834 | ||
1be56909 | 835 | return DM_ENDIO_DONE; |
0e9cebe7 JB |
836 | } |
837 | ||
838 | /* | |
839 | * INFO format: <logged entries> <highest allocated sector> | |
840 | */ | |
841 | static void log_writes_status(struct dm_target *ti, status_type_t type, | |
842 | unsigned status_flags, char *result, | |
843 | unsigned maxlen) | |
844 | { | |
845 | unsigned sz = 0; | |
846 | struct log_writes_c *lc = ti->private; | |
847 | ||
848 | switch (type) { | |
849 | case STATUSTYPE_INFO: | |
850 | DMEMIT("%llu %llu", lc->logged_entries, | |
851 | (unsigned long long)lc->next_sector - 1); | |
852 | if (!lc->logging_enabled) | |
853 | DMEMIT(" logging_disabled"); | |
854 | break; | |
855 | ||
856 | case STATUSTYPE_TABLE: | |
857 | DMEMIT("%s %s", lc->dev->name, lc->logdev->name); | |
858 | break; | |
859 | } | |
860 | } | |
861 | ||
e56f81e0 CH |
862 | static int log_writes_prepare_ioctl(struct dm_target *ti, |
863 | struct block_device **bdev, fmode_t *mode) | |
0e9cebe7 JB |
864 | { |
865 | struct log_writes_c *lc = ti->private; | |
866 | struct dm_dev *dev = lc->dev; | |
0e9cebe7 | 867 | |
e56f81e0 | 868 | *bdev = dev->bdev; |
0e9cebe7 JB |
869 | /* |
870 | * Only pass ioctls through if the device sizes match exactly. | |
871 | */ | |
872 | if (ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT) | |
e56f81e0 CH |
873 | return 1; |
874 | return 0; | |
0e9cebe7 JB |
875 | } |
876 | ||
0e9cebe7 JB |
877 | static int log_writes_iterate_devices(struct dm_target *ti, |
878 | iterate_devices_callout_fn fn, | |
879 | void *data) | |
880 | { | |
881 | struct log_writes_c *lc = ti->private; | |
882 | ||
883 | return fn(ti, lc->dev, 0, ti->len, data); | |
884 | } | |
885 | ||
886 | /* | |
887 | * Messages supported: | |
888 | * mark <mark data> - specify the marked data. | |
889 | */ | |
890 | static int log_writes_message(struct dm_target *ti, unsigned argc, char **argv) | |
891 | { | |
892 | int r = -EINVAL; | |
893 | struct log_writes_c *lc = ti->private; | |
894 | ||
895 | if (argc != 2) { | |
896 | DMWARN("Invalid log-writes message arguments, expect 2 arguments, got %d", argc); | |
897 | return r; | |
898 | } | |
899 | ||
900 | if (!strcasecmp(argv[0], "mark")) | |
901 | r = log_mark(lc, argv[1]); | |
902 | else | |
903 | DMWARN("Unrecognised log writes target message received: %s", argv[0]); | |
904 | ||
905 | return r; | |
906 | } | |
907 | ||
908 | static void log_writes_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
909 | { | |
910 | struct log_writes_c *lc = ti->private; | |
911 | struct request_queue *q = bdev_get_queue(lc->dev->bdev); | |
912 | ||
913 | if (!q || !blk_queue_discard(q)) { | |
914 | lc->device_supports_discard = false; | |
228bb5b2 | 915 | limits->discard_granularity = lc->sectorsize; |
0e9cebe7 JB |
916 | limits->max_discard_sectors = (UINT_MAX >> SECTOR_SHIFT); |
917 | } | |
228bb5b2 JB |
918 | limits->logical_block_size = bdev_logical_block_size(lc->dev->bdev); |
919 | limits->physical_block_size = bdev_physical_block_size(lc->dev->bdev); | |
920 | limits->io_min = limits->physical_block_size; | |
0e9cebe7 JB |
921 | } |
922 | ||
98d82f48 RZ |
923 | static long log_writes_dax_direct_access(struct dm_target *ti, pgoff_t pgoff, |
924 | long nr_pages, void **kaddr, pfn_t *pfn) | |
925 | { | |
926 | struct log_writes_c *lc = ti->private; | |
927 | sector_t sector = pgoff * PAGE_SECTORS; | |
928 | int ret; | |
929 | ||
930 | ret = bdev_dax_pgoff(lc->dev->bdev, sector, nr_pages * PAGE_SIZE, &pgoff); | |
931 | if (ret) | |
932 | return ret; | |
933 | return dax_direct_access(lc->dev->dax_dev, pgoff, nr_pages, kaddr, pfn); | |
934 | } | |
935 | ||
936 | static size_t log_writes_dax_copy_from_iter(struct dm_target *ti, | |
937 | pgoff_t pgoff, void *addr, size_t bytes, | |
938 | struct iov_iter *i) | |
939 | { | |
940 | struct log_writes_c *lc = ti->private; | |
941 | sector_t sector = pgoff * PAGE_SECTORS; | |
942 | int err; | |
943 | ||
944 | if (bdev_dax_pgoff(lc->dev->bdev, sector, ALIGN(bytes, PAGE_SIZE), &pgoff)) | |
945 | return 0; | |
946 | ||
947 | /* Don't bother doing anything if logging has been disabled */ | |
948 | if (!lc->logging_enabled) | |
949 | goto dax_copy; | |
950 | ||
951 | err = log_dax(lc, sector, bytes, i); | |
952 | if (err) { | |
953 | DMWARN("Error %d logging DAX write", err); | |
954 | return 0; | |
955 | } | |
956 | dax_copy: | |
957 | return dax_copy_from_iter(lc->dev->dax_dev, pgoff, addr, bytes, i); | |
958 | } | |
959 | ||
0e9cebe7 JB |
960 | static struct target_type log_writes_target = { |
961 | .name = "log-writes", | |
98d82f48 | 962 | .version = {1, 1, 0}, |
0e9cebe7 JB |
963 | .module = THIS_MODULE, |
964 | .ctr = log_writes_ctr, | |
965 | .dtr = log_writes_dtr, | |
966 | .map = log_writes_map, | |
967 | .end_io = normal_end_io, | |
968 | .status = log_writes_status, | |
e56f81e0 | 969 | .prepare_ioctl = log_writes_prepare_ioctl, |
0e9cebe7 JB |
970 | .message = log_writes_message, |
971 | .iterate_devices = log_writes_iterate_devices, | |
972 | .io_hints = log_writes_io_hints, | |
98d82f48 RZ |
973 | .direct_access = log_writes_dax_direct_access, |
974 | .dax_copy_from_iter = log_writes_dax_copy_from_iter, | |
0e9cebe7 JB |
975 | }; |
976 | ||
977 | static int __init dm_log_writes_init(void) | |
978 | { | |
979 | int r = dm_register_target(&log_writes_target); | |
980 | ||
981 | if (r < 0) | |
982 | DMERR("register failed %d", r); | |
983 | ||
984 | return r; | |
985 | } | |
986 | ||
987 | static void __exit dm_log_writes_exit(void) | |
988 | { | |
989 | dm_unregister_target(&log_writes_target); | |
990 | } | |
991 | ||
992 | module_init(dm_log_writes_init); | |
993 | module_exit(dm_log_writes_exit); | |
994 | ||
995 | MODULE_DESCRIPTION(DM_NAME " log writes target"); | |
996 | MODULE_AUTHOR("Josef Bacik <jbacik@fb.com>"); | |
997 | MODULE_LICENSE("GPL"); |