1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) STRATO AG 2012. All rights reserved.
4 */
5
6 #include <linux/sched.h>
7 #include <linux/bio.h>
8 #include <linux/slab.h>
9 #include <linux/blkdev.h>
10 #include <linux/kthread.h>
11 #include <linux/math64.h>
12 #include "misc.h"
13 #include "ctree.h"
14 #include "extent_map.h"
15 #include "disk-io.h"
16 #include "transaction.h"
17 #include "print-tree.h"
18 #include "volumes.h"
19 #include "async-thread.h"
20 #include "check-integrity.h"
21 #include "rcu-string.h"
22 #include "dev-replace.h"
23 #include "sysfs.h"
24 #include "zoned.h"
25 #include "block-group.h"
26
27 /*
28 * Device replace overview
29 *
30 * [Objective]
31 * To copy all extents (both new and on-disk) from source device to target
32 * device, while still keeping the filesystem read-write.
33 *
34 * [Method]
35 * There are two main methods involved:
36 *
37 * - Write duplication
38 *
39 * All new writes will be written to both target and source devices, so even
40 * if replace gets canceled, sources device still contains up-to-date data.
41 *
42 * Location: handle_ops_on_dev_replace() from __btrfs_map_block()
43 * Start: btrfs_dev_replace_start()
44 * End: btrfs_dev_replace_finishing()
45 * Content: Latest data/metadata
46 *
47 * - Copy existing extents
48 *
49 * This happens by re-using scrub facility, as scrub also iterates through
50 * existing extents from commit root.
51 *
52 * Location: scrub_write_block_to_dev_replace() from
53 * scrub_block_complete()
54 * Content: Data/meta from commit root.
55 *
56 * Due to the content difference, we need to avoid nocow write when dev-replace
57 * is happening. This is done by marking the block group read-only and waiting
58 * for NOCOW writes.
59 *
60 * After replace is done, the finishing part is done by swapping the target and
61 * source devices.
62 *
63 * Location: btrfs_dev_replace_update_device_in_mapping_tree() from
64 * btrfs_dev_replace_finishing()
65 */
66
67 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
68 int scrub_ret);
69 static int btrfs_dev_replace_kthread(void *data);
70
btrfs_init_dev_replace(struct btrfs_fs_info * fs_info)71 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info)
72 {
73 struct btrfs_dev_lookup_args args = { .devid = BTRFS_DEV_REPLACE_DEVID };
74 struct btrfs_key key;
75 struct btrfs_root *dev_root = fs_info->dev_root;
76 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
77 struct extent_buffer *eb;
78 int slot;
79 int ret = 0;
80 struct btrfs_path *path = NULL;
81 int item_size;
82 struct btrfs_dev_replace_item *ptr;
83 u64 src_devid;
84
85 if (!dev_root)
86 return 0;
87
88 path = btrfs_alloc_path();
89 if (!path) {
90 ret = -ENOMEM;
91 goto out;
92 }
93
94 key.objectid = 0;
95 key.type = BTRFS_DEV_REPLACE_KEY;
96 key.offset = 0;
97 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
98 if (ret) {
99 no_valid_dev_replace_entry_found:
100 /*
101 * We don't have a replace item or it's corrupted. If there is
102 * a replace target, fail the mount.
103 */
104 if (btrfs_find_device(fs_info->fs_devices, &args)) {
105 btrfs_err(fs_info,
106 "found replace target device without a valid replace item");
107 ret = -EUCLEAN;
108 goto out;
109 }
110 ret = 0;
111 dev_replace->replace_state =
112 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED;
113 dev_replace->cont_reading_from_srcdev_mode =
114 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS;
115 dev_replace->time_started = 0;
116 dev_replace->time_stopped = 0;
117 atomic64_set(&dev_replace->num_write_errors, 0);
118 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
119 dev_replace->cursor_left = 0;
120 dev_replace->committed_cursor_left = 0;
121 dev_replace->cursor_left_last_write_of_item = 0;
122 dev_replace->cursor_right = 0;
123 dev_replace->srcdev = NULL;
124 dev_replace->tgtdev = NULL;
125 dev_replace->is_valid = 0;
126 dev_replace->item_needs_writeback = 0;
127 goto out;
128 }
129 slot = path->slots[0];
130 eb = path->nodes[0];
131 item_size = btrfs_item_size_nr(eb, slot);
132 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item);
133
134 if (item_size != sizeof(struct btrfs_dev_replace_item)) {
135 btrfs_warn(fs_info,
136 "dev_replace entry found has unexpected size, ignore entry");
137 goto no_valid_dev_replace_entry_found;
138 }
139
140 src_devid = btrfs_dev_replace_src_devid(eb, ptr);
141 dev_replace->cont_reading_from_srcdev_mode =
142 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr);
143 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr);
144 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr);
145 dev_replace->time_stopped =
146 btrfs_dev_replace_time_stopped(eb, ptr);
147 atomic64_set(&dev_replace->num_write_errors,
148 btrfs_dev_replace_num_write_errors(eb, ptr));
149 atomic64_set(&dev_replace->num_uncorrectable_read_errors,
150 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr));
151 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr);
152 dev_replace->committed_cursor_left = dev_replace->cursor_left;
153 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left;
154 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr);
155 dev_replace->is_valid = 1;
156
157 dev_replace->item_needs_writeback = 0;
158 switch (dev_replace->replace_state) {
159 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
160 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
161 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
162 /*
163 * We don't have an active replace item but if there is a
164 * replace target, fail the mount.
165 */
166 if (btrfs_find_device(fs_info->fs_devices, &args)) {
167 btrfs_err(fs_info,
168 "replace devid present without an active replace item");
169 ret = -EUCLEAN;
170 } else {
171 dev_replace->srcdev = NULL;
172 dev_replace->tgtdev = NULL;
173 }
174 break;
175 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
176 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
177 dev_replace->tgtdev = btrfs_find_device(fs_info->fs_devices, &args);
178 args.devid = src_devid;
179 dev_replace->srcdev = btrfs_find_device(fs_info->fs_devices, &args);
180
181 /*
182 * allow 'btrfs dev replace_cancel' if src/tgt device is
183 * missing
184 */
185 if (!dev_replace->srcdev &&
186 !btrfs_test_opt(fs_info, DEGRADED)) {
187 ret = -EIO;
188 btrfs_warn(fs_info,
189 "cannot mount because device replace operation is ongoing and");
190 btrfs_warn(fs_info,
191 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
192 src_devid);
193 }
194 if (!dev_replace->tgtdev &&
195 !btrfs_test_opt(fs_info, DEGRADED)) {
196 ret = -EIO;
197 btrfs_warn(fs_info,
198 "cannot mount because device replace operation is ongoing and");
199 btrfs_warn(fs_info,
200 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
201 BTRFS_DEV_REPLACE_DEVID);
202 }
203 if (dev_replace->tgtdev) {
204 if (dev_replace->srcdev) {
205 dev_replace->tgtdev->total_bytes =
206 dev_replace->srcdev->total_bytes;
207 dev_replace->tgtdev->disk_total_bytes =
208 dev_replace->srcdev->disk_total_bytes;
209 dev_replace->tgtdev->commit_total_bytes =
210 dev_replace->srcdev->commit_total_bytes;
211 dev_replace->tgtdev->bytes_used =
212 dev_replace->srcdev->bytes_used;
213 dev_replace->tgtdev->commit_bytes_used =
214 dev_replace->srcdev->commit_bytes_used;
215 }
216 set_bit(BTRFS_DEV_STATE_REPLACE_TGT,
217 &dev_replace->tgtdev->dev_state);
218
219 WARN_ON(fs_info->fs_devices->rw_devices == 0);
220 dev_replace->tgtdev->io_width = fs_info->sectorsize;
221 dev_replace->tgtdev->io_align = fs_info->sectorsize;
222 dev_replace->tgtdev->sector_size = fs_info->sectorsize;
223 dev_replace->tgtdev->fs_info = fs_info;
224 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
225 &dev_replace->tgtdev->dev_state);
226 }
227 break;
228 }
229
230 out:
231 btrfs_free_path(path);
232 return ret;
233 }
234
235 /*
236 * Initialize a new device for device replace target from a given source dev
237 * and path.
238 *
239 * Return 0 and new device in @device_out, otherwise return < 0
240 */
btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info * fs_info,const char * device_path,struct btrfs_device * srcdev,struct btrfs_device ** device_out)241 static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
242 const char *device_path,
243 struct btrfs_device *srcdev,
244 struct btrfs_device **device_out)
245 {
246 struct btrfs_device *device;
247 struct block_device *bdev;
248 struct rcu_string *name;
249 u64 devid = BTRFS_DEV_REPLACE_DEVID;
250 int ret = 0;
251
252 *device_out = NULL;
253 if (srcdev->fs_devices->seeding) {
254 btrfs_err(fs_info, "the filesystem is a seed filesystem!");
255 return -EINVAL;
256 }
257
258 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
259 fs_info->bdev_holder);
260 if (IS_ERR(bdev)) {
261 btrfs_err(fs_info, "target device %s is invalid!", device_path);
262 return PTR_ERR(bdev);
263 }
264
265 if (!btrfs_check_device_zone_type(fs_info, bdev)) {
266 btrfs_err(fs_info,
267 "dev-replace: zoned type of target device mismatch with filesystem");
268 ret = -EINVAL;
269 goto error;
270 }
271
272 sync_blockdev(bdev);
273
274 list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
275 if (device->bdev == bdev) {
276 btrfs_err(fs_info,
277 "target device is in the filesystem!");
278 ret = -EEXIST;
279 goto error;
280 }
281 }
282
283
284 if (bdev_nr_bytes(bdev) < btrfs_device_get_total_bytes(srcdev)) {
285 btrfs_err(fs_info,
286 "target device is smaller than source device!");
287 ret = -EINVAL;
288 goto error;
289 }
290
291
292 device = btrfs_alloc_device(NULL, &devid, NULL);
293 if (IS_ERR(device)) {
294 ret = PTR_ERR(device);
295 goto error;
296 }
297
298 name = rcu_string_strdup(device_path, GFP_KERNEL);
299 if (!name) {
300 btrfs_free_device(device);
301 ret = -ENOMEM;
302 goto error;
303 }
304 rcu_assign_pointer(device->name, name);
305
306 set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
307 device->generation = 0;
308 device->io_width = fs_info->sectorsize;
309 device->io_align = fs_info->sectorsize;
310 device->sector_size = fs_info->sectorsize;
311 device->total_bytes = btrfs_device_get_total_bytes(srcdev);
312 device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev);
313 device->bytes_used = btrfs_device_get_bytes_used(srcdev);
314 device->commit_total_bytes = srcdev->commit_total_bytes;
315 device->commit_bytes_used = device->bytes_used;
316 device->fs_info = fs_info;
317 device->bdev = bdev;
318 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
319 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
320 device->mode = FMODE_EXCL;
321 device->dev_stats_valid = 1;
322 set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
323 device->fs_devices = fs_info->fs_devices;
324
325 ret = btrfs_get_dev_zone_info(device);
326 if (ret)
327 goto error;
328
329 mutex_lock(&fs_info->fs_devices->device_list_mutex);
330 list_add(&device->dev_list, &fs_info->fs_devices->devices);
331 fs_info->fs_devices->num_devices++;
332 fs_info->fs_devices->open_devices++;
333 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
334
335 *device_out = device;
336 return 0;
337
338 error:
339 blkdev_put(bdev, FMODE_EXCL);
340 return ret;
341 }
342
343 /*
344 * called from commit_transaction. Writes changed device replace state to
345 * disk.
346 */
btrfs_run_dev_replace(struct btrfs_trans_handle * trans)347 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans)
348 {
349 struct btrfs_fs_info *fs_info = trans->fs_info;
350 int ret;
351 struct btrfs_root *dev_root = fs_info->dev_root;
352 struct btrfs_path *path;
353 struct btrfs_key key;
354 struct extent_buffer *eb;
355 struct btrfs_dev_replace_item *ptr;
356 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
357
358 down_read(&dev_replace->rwsem);
359 if (!dev_replace->is_valid ||
360 !dev_replace->item_needs_writeback) {
361 up_read(&dev_replace->rwsem);
362 return 0;
363 }
364 up_read(&dev_replace->rwsem);
365
366 key.objectid = 0;
367 key.type = BTRFS_DEV_REPLACE_KEY;
368 key.offset = 0;
369
370 path = btrfs_alloc_path();
371 if (!path) {
372 ret = -ENOMEM;
373 goto out;
374 }
375 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
376 if (ret < 0) {
377 btrfs_warn(fs_info,
378 "error %d while searching for dev_replace item!",
379 ret);
380 goto out;
381 }
382
383 if (ret == 0 &&
384 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
385 /*
386 * need to delete old one and insert a new one.
387 * Since no attempt is made to recover any old state, if the
388 * dev_replace state is 'running', the data on the target
389 * drive is lost.
390 * It would be possible to recover the state: just make sure
391 * that the beginning of the item is never changed and always
392 * contains all the essential information. Then read this
393 * minimal set of information and use it as a base for the
394 * new state.
395 */
396 ret = btrfs_del_item(trans, dev_root, path);
397 if (ret != 0) {
398 btrfs_warn(fs_info,
399 "delete too small dev_replace item failed %d!",
400 ret);
401 goto out;
402 }
403 ret = 1;
404 }
405
406 if (ret == 1) {
407 /* need to insert a new item */
408 btrfs_release_path(path);
409 ret = btrfs_insert_empty_item(trans, dev_root, path,
410 &key, sizeof(*ptr));
411 if (ret < 0) {
412 btrfs_warn(fs_info,
413 "insert dev_replace item failed %d!", ret);
414 goto out;
415 }
416 }
417
418 eb = path->nodes[0];
419 ptr = btrfs_item_ptr(eb, path->slots[0],
420 struct btrfs_dev_replace_item);
421
422 down_write(&dev_replace->rwsem);
423 if (dev_replace->srcdev)
424 btrfs_set_dev_replace_src_devid(eb, ptr,
425 dev_replace->srcdev->devid);
426 else
427 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1);
428 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr,
429 dev_replace->cont_reading_from_srcdev_mode);
430 btrfs_set_dev_replace_replace_state(eb, ptr,
431 dev_replace->replace_state);
432 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started);
433 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped);
434 btrfs_set_dev_replace_num_write_errors(eb, ptr,
435 atomic64_read(&dev_replace->num_write_errors));
436 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr,
437 atomic64_read(&dev_replace->num_uncorrectable_read_errors));
438 dev_replace->cursor_left_last_write_of_item =
439 dev_replace->cursor_left;
440 btrfs_set_dev_replace_cursor_left(eb, ptr,
441 dev_replace->cursor_left_last_write_of_item);
442 btrfs_set_dev_replace_cursor_right(eb, ptr,
443 dev_replace->cursor_right);
444 dev_replace->item_needs_writeback = 0;
445 up_write(&dev_replace->rwsem);
446
447 btrfs_mark_buffer_dirty(eb);
448
449 out:
450 btrfs_free_path(path);
451
452 return ret;
453 }
454
btrfs_dev_name(struct btrfs_device * device)455 static char* btrfs_dev_name(struct btrfs_device *device)
456 {
457 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
458 return "<missing disk>";
459 else
460 return rcu_str_deref(device->name);
461 }
462
mark_block_group_to_copy(struct btrfs_fs_info * fs_info,struct btrfs_device * src_dev)463 static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info,
464 struct btrfs_device *src_dev)
465 {
466 struct btrfs_path *path;
467 struct btrfs_key key;
468 struct btrfs_key found_key;
469 struct btrfs_root *root = fs_info->dev_root;
470 struct btrfs_dev_extent *dev_extent = NULL;
471 struct btrfs_block_group *cache;
472 struct btrfs_trans_handle *trans;
473 int ret = 0;
474 u64 chunk_offset;
475
476 /* Do not use "to_copy" on non zoned filesystem for now */
477 if (!btrfs_is_zoned(fs_info))
478 return 0;
479
480 mutex_lock(&fs_info->chunk_mutex);
481
482 /* Ensure we don't have pending new block group */
483 spin_lock(&fs_info->trans_lock);
484 while (fs_info->running_transaction &&
485 !list_empty(&fs_info->running_transaction->dev_update_list)) {
486 spin_unlock(&fs_info->trans_lock);
487 mutex_unlock(&fs_info->chunk_mutex);
488 trans = btrfs_attach_transaction(root);
489 if (IS_ERR(trans)) {
490 ret = PTR_ERR(trans);
491 mutex_lock(&fs_info->chunk_mutex);
492 if (ret == -ENOENT) {
493 spin_lock(&fs_info->trans_lock);
494 continue;
495 } else {
496 goto unlock;
497 }
498 }
499
500 ret = btrfs_commit_transaction(trans);
501 mutex_lock(&fs_info->chunk_mutex);
502 if (ret)
503 goto unlock;
504
505 spin_lock(&fs_info->trans_lock);
506 }
507 spin_unlock(&fs_info->trans_lock);
508
509 path = btrfs_alloc_path();
510 if (!path) {
511 ret = -ENOMEM;
512 goto unlock;
513 }
514
515 path->reada = READA_FORWARD;
516 path->search_commit_root = 1;
517 path->skip_locking = 1;
518
519 key.objectid = src_dev->devid;
520 key.type = BTRFS_DEV_EXTENT_KEY;
521 key.offset = 0;
522
523 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
524 if (ret < 0)
525 goto free_path;
526 if (ret > 0) {
527 if (path->slots[0] >=
528 btrfs_header_nritems(path->nodes[0])) {
529 ret = btrfs_next_leaf(root, path);
530 if (ret < 0)
531 goto free_path;
532 if (ret > 0) {
533 ret = 0;
534 goto free_path;
535 }
536 } else {
537 ret = 0;
538 }
539 }
540
541 while (1) {
542 struct extent_buffer *leaf = path->nodes[0];
543 int slot = path->slots[0];
544
545 btrfs_item_key_to_cpu(leaf, &found_key, slot);
546
547 if (found_key.objectid != src_dev->devid)
548 break;
549
550 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
551 break;
552
553 if (found_key.offset < key.offset)
554 break;
555
556 dev_extent = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent);
557
558 chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dev_extent);
559
560 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
561 if (!cache)
562 goto skip;
563
564 spin_lock(&cache->lock);
565 cache->to_copy = 1;
566 spin_unlock(&cache->lock);
567
568 btrfs_put_block_group(cache);
569
570 skip:
571 ret = btrfs_next_item(root, path);
572 if (ret != 0) {
573 if (ret > 0)
574 ret = 0;
575 break;
576 }
577 }
578
579 free_path:
580 btrfs_free_path(path);
581 unlock:
582 mutex_unlock(&fs_info->chunk_mutex);
583
584 return ret;
585 }
586
btrfs_finish_block_group_to_copy(struct btrfs_device * srcdev,struct btrfs_block_group * cache,u64 physical)587 bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev,
588 struct btrfs_block_group *cache,
589 u64 physical)
590 {
591 struct btrfs_fs_info *fs_info = cache->fs_info;
592 struct extent_map *em;
593 struct map_lookup *map;
594 u64 chunk_offset = cache->start;
595 int num_extents, cur_extent;
596 int i;
597
598 /* Do not use "to_copy" on non zoned filesystem for now */
599 if (!btrfs_is_zoned(fs_info))
600 return true;
601
602 spin_lock(&cache->lock);
603 if (cache->removed) {
604 spin_unlock(&cache->lock);
605 return true;
606 }
607 spin_unlock(&cache->lock);
608
609 em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
610 ASSERT(!IS_ERR(em));
611 map = em->map_lookup;
612
613 num_extents = cur_extent = 0;
614 for (i = 0; i < map->num_stripes; i++) {
615 /* We have more device extent to copy */
616 if (srcdev != map->stripes[i].dev)
617 continue;
618
619 num_extents++;
620 if (physical == map->stripes[i].physical)
621 cur_extent = i;
622 }
623
624 free_extent_map(em);
625
626 if (num_extents > 1 && cur_extent < num_extents - 1) {
627 /*
628 * Has more stripes on this device. Keep this block group
629 * readonly until we finish all the stripes.
630 */
631 return false;
632 }
633
634 /* Last stripe on this device */
635 spin_lock(&cache->lock);
636 cache->to_copy = 0;
637 spin_unlock(&cache->lock);
638
639 return true;
640 }
641
btrfs_dev_replace_start(struct btrfs_fs_info * fs_info,const char * tgtdev_name,u64 srcdevid,const char * srcdev_name,int read_src)642 static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
643 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name,
644 int read_src)
645 {
646 struct btrfs_root *root = fs_info->dev_root;
647 struct btrfs_trans_handle *trans;
648 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
649 int ret;
650 struct btrfs_device *tgt_device = NULL;
651 struct btrfs_device *src_device = NULL;
652
653 src_device = btrfs_find_device_by_devspec(fs_info, srcdevid,
654 srcdev_name);
655 if (IS_ERR(src_device))
656 return PTR_ERR(src_device);
657
658 if (btrfs_pinned_by_swapfile(fs_info, src_device)) {
659 btrfs_warn_in_rcu(fs_info,
660 "cannot replace device %s (devid %llu) due to active swapfile",
661 btrfs_dev_name(src_device), src_device->devid);
662 return -ETXTBSY;
663 }
664
665 /*
666 * Here we commit the transaction to make sure commit_total_bytes
667 * of all the devices are updated.
668 */
669 trans = btrfs_attach_transaction(root);
670 if (!IS_ERR(trans)) {
671 ret = btrfs_commit_transaction(trans);
672 if (ret)
673 return ret;
674 } else if (PTR_ERR(trans) != -ENOENT) {
675 return PTR_ERR(trans);
676 }
677
678 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name,
679 src_device, &tgt_device);
680 if (ret)
681 return ret;
682
683 ret = mark_block_group_to_copy(fs_info, src_device);
684 if (ret)
685 return ret;
686
687 down_write(&dev_replace->rwsem);
688 switch (dev_replace->replace_state) {
689 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
690 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
691 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
692 break;
693 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
694 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
695 ASSERT(0);
696 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
697 up_write(&dev_replace->rwsem);
698 goto leave;
699 }
700
701 dev_replace->cont_reading_from_srcdev_mode = read_src;
702 dev_replace->srcdev = src_device;
703 dev_replace->tgtdev = tgt_device;
704
705 btrfs_info_in_rcu(fs_info,
706 "dev_replace from %s (devid %llu) to %s started",
707 btrfs_dev_name(src_device),
708 src_device->devid,
709 rcu_str_deref(tgt_device->name));
710
711 /*
712 * from now on, the writes to the srcdev are all duplicated to
713 * go to the tgtdev as well (refer to btrfs_map_block()).
714 */
715 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
716 dev_replace->time_started = ktime_get_real_seconds();
717 dev_replace->cursor_left = 0;
718 dev_replace->committed_cursor_left = 0;
719 dev_replace->cursor_left_last_write_of_item = 0;
720 dev_replace->cursor_right = 0;
721 dev_replace->is_valid = 1;
722 dev_replace->item_needs_writeback = 1;
723 atomic64_set(&dev_replace->num_write_errors, 0);
724 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
725 up_write(&dev_replace->rwsem);
726
727 ret = btrfs_sysfs_add_device(tgt_device);
728 if (ret)
729 btrfs_err(fs_info, "kobj add dev failed %d", ret);
730
731 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
732
733 /* Commit dev_replace state and reserve 1 item for it. */
734 trans = btrfs_start_transaction(root, 1);
735 if (IS_ERR(trans)) {
736 ret = PTR_ERR(trans);
737 down_write(&dev_replace->rwsem);
738 dev_replace->replace_state =
739 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED;
740 dev_replace->srcdev = NULL;
741 dev_replace->tgtdev = NULL;
742 up_write(&dev_replace->rwsem);
743 goto leave;
744 }
745
746 ret = btrfs_commit_transaction(trans);
747 WARN_ON(ret);
748
749 /* the disk copy procedure reuses the scrub code */
750 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
751 btrfs_device_get_total_bytes(src_device),
752 &dev_replace->scrub_progress, 0, 1);
753
754 ret = btrfs_dev_replace_finishing(fs_info, ret);
755 if (ret == -EINPROGRESS)
756 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
757
758 return ret;
759
760 leave:
761 btrfs_destroy_dev_replace_tgtdev(tgt_device);
762 return ret;
763 }
764
btrfs_dev_replace_by_ioctl(struct btrfs_fs_info * fs_info,struct btrfs_ioctl_dev_replace_args * args)765 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info,
766 struct btrfs_ioctl_dev_replace_args *args)
767 {
768 int ret;
769
770 switch (args->start.cont_reading_from_srcdev_mode) {
771 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
772 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
773 break;
774 default:
775 return -EINVAL;
776 }
777
778 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
779 args->start.tgtdev_name[0] == '\0')
780 return -EINVAL;
781
782 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name,
783 args->start.srcdevid,
784 args->start.srcdev_name,
785 args->start.cont_reading_from_srcdev_mode);
786 args->result = ret;
787 /* don't warn if EINPROGRESS, someone else might be running scrub */
788 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS ||
789 ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR)
790 return 0;
791
792 return ret;
793 }
794
795 /*
796 * blocked until all in-flight bios operations are finished.
797 */
btrfs_rm_dev_replace_blocked(struct btrfs_fs_info * fs_info)798 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
799 {
800 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
801 wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum(
802 &fs_info->dev_replace.bio_counter));
803 }
804
805 /*
806 * we have removed target device, it is safe to allow new bios request.
807 */
btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info * fs_info)808 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info)
809 {
810 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
811 wake_up(&fs_info->dev_replace.replace_wait);
812 }
813
814 /*
815 * When finishing the device replace, before swapping the source device with the
816 * target device we must update the chunk allocation state in the target device,
817 * as it is empty because replace works by directly copying the chunks and not
818 * through the normal chunk allocation path.
819 */
btrfs_set_target_alloc_state(struct btrfs_device * srcdev,struct btrfs_device * tgtdev)820 static int btrfs_set_target_alloc_state(struct btrfs_device *srcdev,
821 struct btrfs_device *tgtdev)
822 {
823 struct extent_state *cached_state = NULL;
824 u64 start = 0;
825 u64 found_start;
826 u64 found_end;
827 int ret = 0;
828
829 lockdep_assert_held(&srcdev->fs_info->chunk_mutex);
830
831 while (!find_first_extent_bit(&srcdev->alloc_state, start,
832 &found_start, &found_end,
833 CHUNK_ALLOCATED, &cached_state)) {
834 ret = set_extent_bits(&tgtdev->alloc_state, found_start,
835 found_end, CHUNK_ALLOCATED);
836 if (ret)
837 break;
838 start = found_end + 1;
839 }
840
841 free_extent_state(cached_state);
842 return ret;
843 }
844
btrfs_dev_replace_update_device_in_mapping_tree(struct btrfs_fs_info * fs_info,struct btrfs_device * srcdev,struct btrfs_device * tgtdev)845 static void btrfs_dev_replace_update_device_in_mapping_tree(
846 struct btrfs_fs_info *fs_info,
847 struct btrfs_device *srcdev,
848 struct btrfs_device *tgtdev)
849 {
850 struct extent_map_tree *em_tree = &fs_info->mapping_tree;
851 struct extent_map *em;
852 struct map_lookup *map;
853 u64 start = 0;
854 int i;
855
856 write_lock(&em_tree->lock);
857 do {
858 em = lookup_extent_mapping(em_tree, start, (u64)-1);
859 if (!em)
860 break;
861 map = em->map_lookup;
862 for (i = 0; i < map->num_stripes; i++)
863 if (srcdev == map->stripes[i].dev)
864 map->stripes[i].dev = tgtdev;
865 start = em->start + em->len;
866 free_extent_map(em);
867 } while (start);
868 write_unlock(&em_tree->lock);
869 }
870
btrfs_dev_replace_finishing(struct btrfs_fs_info * fs_info,int scrub_ret)871 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
872 int scrub_ret)
873 {
874 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
875 struct btrfs_device *tgt_device;
876 struct btrfs_device *src_device;
877 struct btrfs_root *root = fs_info->tree_root;
878 u8 uuid_tmp[BTRFS_UUID_SIZE];
879 struct btrfs_trans_handle *trans;
880 int ret = 0;
881
882 /* don't allow cancel or unmount to disturb the finishing procedure */
883 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
884
885 down_read(&dev_replace->rwsem);
886 /* was the operation canceled, or is it finished? */
887 if (dev_replace->replace_state !=
888 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
889 up_read(&dev_replace->rwsem);
890 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
891 return 0;
892 }
893
894 tgt_device = dev_replace->tgtdev;
895 src_device = dev_replace->srcdev;
896 up_read(&dev_replace->rwsem);
897
898 /*
899 * flush all outstanding I/O and inode extent mappings before the
900 * copy operation is declared as being finished
901 */
902 ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false);
903 if (ret) {
904 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
905 return ret;
906 }
907 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
908
909 if (!scrub_ret)
910 btrfs_reada_remove_dev(src_device);
911
912 /*
913 * We have to use this loop approach because at this point src_device
914 * has to be available for transaction commit to complete, yet new
915 * chunks shouldn't be allocated on the device.
916 */
917 while (1) {
918 trans = btrfs_start_transaction(root, 0);
919 if (IS_ERR(trans)) {
920 btrfs_reada_undo_remove_dev(src_device);
921 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
922 return PTR_ERR(trans);
923 }
924 ret = btrfs_commit_transaction(trans);
925 WARN_ON(ret);
926
927 /* Prevent write_all_supers() during the finishing procedure */
928 mutex_lock(&fs_info->fs_devices->device_list_mutex);
929 /* Prevent new chunks being allocated on the source device */
930 mutex_lock(&fs_info->chunk_mutex);
931
932 if (!list_empty(&src_device->post_commit_list)) {
933 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
934 mutex_unlock(&fs_info->chunk_mutex);
935 } else {
936 break;
937 }
938 }
939
940 down_write(&dev_replace->rwsem);
941 dev_replace->replace_state =
942 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
943 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
944 dev_replace->tgtdev = NULL;
945 dev_replace->srcdev = NULL;
946 dev_replace->time_stopped = ktime_get_real_seconds();
947 dev_replace->item_needs_writeback = 1;
948
949 /*
950 * Update allocation state in the new device and replace the old device
951 * with the new one in the mapping tree.
952 */
953 if (!scrub_ret) {
954 scrub_ret = btrfs_set_target_alloc_state(src_device, tgt_device);
955 if (scrub_ret)
956 goto error;
957 btrfs_dev_replace_update_device_in_mapping_tree(fs_info,
958 src_device,
959 tgt_device);
960 } else {
961 if (scrub_ret != -ECANCELED)
962 btrfs_err_in_rcu(fs_info,
963 "btrfs_scrub_dev(%s, %llu, %s) failed %d",
964 btrfs_dev_name(src_device),
965 src_device->devid,
966 rcu_str_deref(tgt_device->name), scrub_ret);
967 error:
968 up_write(&dev_replace->rwsem);
969 mutex_unlock(&fs_info->chunk_mutex);
970 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
971 btrfs_reada_undo_remove_dev(src_device);
972 btrfs_rm_dev_replace_blocked(fs_info);
973 if (tgt_device)
974 btrfs_destroy_dev_replace_tgtdev(tgt_device);
975 btrfs_rm_dev_replace_unblocked(fs_info);
976 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
977
978 return scrub_ret;
979 }
980
981 btrfs_info_in_rcu(fs_info,
982 "dev_replace from %s (devid %llu) to %s finished",
983 btrfs_dev_name(src_device),
984 src_device->devid,
985 rcu_str_deref(tgt_device->name));
986 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state);
987 tgt_device->devid = src_device->devid;
988 src_device->devid = BTRFS_DEV_REPLACE_DEVID;
989 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp));
990 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid));
991 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid));
992 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes);
993 btrfs_device_set_disk_total_bytes(tgt_device,
994 src_device->disk_total_bytes);
995 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used);
996 tgt_device->commit_bytes_used = src_device->bytes_used;
997
998 btrfs_assign_next_active_device(src_device, tgt_device);
999
1000 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
1001 fs_info->fs_devices->rw_devices++;
1002
1003 up_write(&dev_replace->rwsem);
1004 btrfs_rm_dev_replace_blocked(fs_info);
1005
1006 btrfs_rm_dev_replace_remove_srcdev(src_device);
1007
1008 btrfs_rm_dev_replace_unblocked(fs_info);
1009
1010 /*
1011 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will
1012 * update on-disk dev stats value during commit transaction
1013 */
1014 atomic_inc(&tgt_device->dev_stats_ccnt);
1015
1016 /*
1017 * this is again a consistent state where no dev_replace procedure
1018 * is running, the target device is part of the filesystem, the
1019 * source device is not part of the filesystem anymore and its 1st
1020 * superblock is scratched out so that it is no longer marked to
1021 * belong to this filesystem.
1022 */
1023 mutex_unlock(&fs_info->chunk_mutex);
1024 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1025
1026 /* replace the sysfs entry */
1027 btrfs_sysfs_remove_device(src_device);
1028 btrfs_sysfs_update_devid(tgt_device);
1029 if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &src_device->dev_state))
1030 btrfs_scratch_superblocks(fs_info, src_device->bdev,
1031 src_device->name->str);
1032
1033 /* write back the superblocks */
1034 trans = btrfs_start_transaction(root, 0);
1035 if (!IS_ERR(trans))
1036 btrfs_commit_transaction(trans);
1037
1038 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
1039
1040 btrfs_rm_dev_replace_free_srcdev(src_device);
1041
1042 return 0;
1043 }
1044
1045 /*
1046 * Read progress of device replace status according to the state and last
1047 * stored position. The value format is the same as for
1048 * btrfs_dev_replace::progress_1000
1049 */
btrfs_dev_replace_progress(struct btrfs_fs_info * fs_info)1050 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info)
1051 {
1052 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1053 u64 ret = 0;
1054
1055 switch (dev_replace->replace_state) {
1056 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
1057 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
1058 ret = 0;
1059 break;
1060 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
1061 ret = 1000;
1062 break;
1063 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
1064 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
1065 ret = div64_u64(dev_replace->cursor_left,
1066 div_u64(btrfs_device_get_total_bytes(
1067 dev_replace->srcdev), 1000));
1068 break;
1069 }
1070
1071 return ret;
1072 }
1073
btrfs_dev_replace_status(struct btrfs_fs_info * fs_info,struct btrfs_ioctl_dev_replace_args * args)1074 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
1075 struct btrfs_ioctl_dev_replace_args *args)
1076 {
1077 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1078
1079 down_read(&dev_replace->rwsem);
1080 /* even if !dev_replace_is_valid, the values are good enough for
1081 * the replace_status ioctl */
1082 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
1083 args->status.replace_state = dev_replace->replace_state;
1084 args->status.time_started = dev_replace->time_started;
1085 args->status.time_stopped = dev_replace->time_stopped;
1086 args->status.num_write_errors =
1087 atomic64_read(&dev_replace->num_write_errors);
1088 args->status.num_uncorrectable_read_errors =
1089 atomic64_read(&dev_replace->num_uncorrectable_read_errors);
1090 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info);
1091 up_read(&dev_replace->rwsem);
1092 }
1093
btrfs_dev_replace_cancel(struct btrfs_fs_info * fs_info)1094 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
1095 {
1096 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1097 struct btrfs_device *tgt_device = NULL;
1098 struct btrfs_device *src_device = NULL;
1099 struct btrfs_trans_handle *trans;
1100 struct btrfs_root *root = fs_info->tree_root;
1101 int result;
1102 int ret;
1103
1104 if (sb_rdonly(fs_info->sb))
1105 return -EROFS;
1106
1107 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
1108 down_write(&dev_replace->rwsem);
1109 switch (dev_replace->replace_state) {
1110 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
1111 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
1112 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
1113 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
1114 up_write(&dev_replace->rwsem);
1115 break;
1116 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
1117 tgt_device = dev_replace->tgtdev;
1118 src_device = dev_replace->srcdev;
1119 up_write(&dev_replace->rwsem);
1120 ret = btrfs_scrub_cancel(fs_info);
1121 if (ret < 0) {
1122 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
1123 } else {
1124 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
1125 /*
1126 * btrfs_dev_replace_finishing() will handle the
1127 * cleanup part
1128 */
1129 btrfs_info_in_rcu(fs_info,
1130 "dev_replace from %s (devid %llu) to %s canceled",
1131 btrfs_dev_name(src_device), src_device->devid,
1132 btrfs_dev_name(tgt_device));
1133 }
1134 break;
1135 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
1136 /*
1137 * Scrub doing the replace isn't running so we need to do the
1138 * cleanup step of btrfs_dev_replace_finishing() here
1139 */
1140 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
1141 tgt_device = dev_replace->tgtdev;
1142 src_device = dev_replace->srcdev;
1143 dev_replace->tgtdev = NULL;
1144 dev_replace->srcdev = NULL;
1145 dev_replace->replace_state =
1146 BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
1147 dev_replace->time_stopped = ktime_get_real_seconds();
1148 dev_replace->item_needs_writeback = 1;
1149
1150 up_write(&dev_replace->rwsem);
1151
1152 /* Scrub for replace must not be running in suspended state */
1153 ret = btrfs_scrub_cancel(fs_info);
1154 ASSERT(ret != -ENOTCONN);
1155
1156 trans = btrfs_start_transaction(root, 0);
1157 if (IS_ERR(trans)) {
1158 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
1159 return PTR_ERR(trans);
1160 }
1161 ret = btrfs_commit_transaction(trans);
1162 WARN_ON(ret);
1163
1164 btrfs_info_in_rcu(fs_info,
1165 "suspended dev_replace from %s (devid %llu) to %s canceled",
1166 btrfs_dev_name(src_device), src_device->devid,
1167 btrfs_dev_name(tgt_device));
1168
1169 if (tgt_device)
1170 btrfs_destroy_dev_replace_tgtdev(tgt_device);
1171 break;
1172 default:
1173 up_write(&dev_replace->rwsem);
1174 result = -EINVAL;
1175 }
1176
1177 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
1178 return result;
1179 }
1180
btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info * fs_info)1181 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info)
1182 {
1183 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1184
1185 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
1186 down_write(&dev_replace->rwsem);
1187
1188 switch (dev_replace->replace_state) {
1189 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
1190 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
1191 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
1192 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
1193 break;
1194 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
1195 dev_replace->replace_state =
1196 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
1197 dev_replace->time_stopped = ktime_get_real_seconds();
1198 dev_replace->item_needs_writeback = 1;
1199 btrfs_info(fs_info, "suspending dev_replace for unmount");
1200 break;
1201 }
1202
1203 up_write(&dev_replace->rwsem);
1204 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
1205 }
1206
1207 /* resume dev_replace procedure that was interrupted by unmount */
btrfs_resume_dev_replace_async(struct btrfs_fs_info * fs_info)1208 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
1209 {
1210 struct task_struct *task;
1211 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1212
1213 down_write(&dev_replace->rwsem);
1214
1215 switch (dev_replace->replace_state) {
1216 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
1217 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
1218 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
1219 up_write(&dev_replace->rwsem);
1220 return 0;
1221 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
1222 break;
1223 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
1224 dev_replace->replace_state =
1225 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
1226 break;
1227 }
1228 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) {
1229 btrfs_info(fs_info,
1230 "cannot continue dev_replace, tgtdev is missing");
1231 btrfs_info(fs_info,
1232 "you may cancel the operation after 'mount -o degraded'");
1233 dev_replace->replace_state =
1234 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
1235 up_write(&dev_replace->rwsem);
1236 return 0;
1237 }
1238 up_write(&dev_replace->rwsem);
1239
1240 /*
1241 * This could collide with a paused balance, but the exclusive op logic
1242 * should never allow both to start and pause. We don't want to allow
1243 * dev-replace to start anyway.
1244 */
1245 if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) {
1246 down_write(&dev_replace->rwsem);
1247 dev_replace->replace_state =
1248 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
1249 up_write(&dev_replace->rwsem);
1250 btrfs_info(fs_info,
1251 "cannot resume dev-replace, other exclusive operation running");
1252 return 0;
1253 }
1254
1255 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
1256 return PTR_ERR_OR_ZERO(task);
1257 }
1258
btrfs_dev_replace_kthread(void * data)1259 static int btrfs_dev_replace_kthread(void *data)
1260 {
1261 struct btrfs_fs_info *fs_info = data;
1262 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1263 u64 progress;
1264 int ret;
1265
1266 progress = btrfs_dev_replace_progress(fs_info);
1267 progress = div_u64(progress, 10);
1268 btrfs_info_in_rcu(fs_info,
1269 "continuing dev_replace from %s (devid %llu) to target %s @%u%%",
1270 btrfs_dev_name(dev_replace->srcdev),
1271 dev_replace->srcdev->devid,
1272 btrfs_dev_name(dev_replace->tgtdev),
1273 (unsigned int)progress);
1274
1275 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid,
1276 dev_replace->committed_cursor_left,
1277 btrfs_device_get_total_bytes(dev_replace->srcdev),
1278 &dev_replace->scrub_progress, 0, 1);
1279 ret = btrfs_dev_replace_finishing(fs_info, ret);
1280 WARN_ON(ret && ret != -ECANCELED);
1281
1282 btrfs_exclop_finish(fs_info);
1283 return 0;
1284 }
1285
btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace * dev_replace)1286 int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
1287 {
1288 if (!dev_replace->is_valid)
1289 return 0;
1290
1291 switch (dev_replace->replace_state) {
1292 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
1293 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
1294 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
1295 return 0;
1296 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
1297 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
1298 /*
1299 * return true even if tgtdev is missing (this is
1300 * something that can happen if the dev_replace
1301 * procedure is suspended by an umount and then
1302 * the tgtdev is missing (or "btrfs dev scan") was
1303 * not called and the filesystem is remounted
1304 * in degraded state. This does not stop the
1305 * dev_replace procedure. It needs to be canceled
1306 * manually if the cancellation is wanted.
1307 */
1308 break;
1309 }
1310 return 1;
1311 }
1312
btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info * fs_info)1313 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
1314 {
1315 percpu_counter_inc(&fs_info->dev_replace.bio_counter);
1316 }
1317
btrfs_bio_counter_sub(struct btrfs_fs_info * fs_info,s64 amount)1318 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount)
1319 {
1320 percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount);
1321 cond_wake_up_nomb(&fs_info->dev_replace.replace_wait);
1322 }
1323
btrfs_bio_counter_inc_blocked(struct btrfs_fs_info * fs_info)1324 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
1325 {
1326 while (1) {
1327 percpu_counter_inc(&fs_info->dev_replace.bio_counter);
1328 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING,
1329 &fs_info->fs_state)))
1330 break;
1331
1332 btrfs_bio_counter_dec(fs_info);
1333 wait_event(fs_info->dev_replace.replace_wait,
1334 !test_bit(BTRFS_FS_STATE_DEV_REPLACING,
1335 &fs_info->fs_state));
1336 }
1337 }
1338