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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/buffer_head.h>
10#include <linux/blkdev.h>
11#include <linux/random.h>
12#include <linux/iocontext.h>
13#include <linux/capability.h>
14#include <linux/kthread.h>
15#include <linux/math64.h>
16#include <asm/div64.h>
17#include "ctree.h"
18#include "extent_map.h"
19#include "disk-io.h"
20#include "transaction.h"
21#include "print-tree.h"
22#include "volumes.h"
23#include "async-thread.h"
24#include "check-integrity.h"
25#include "rcu-string.h"
26#include "dev-replace.h"
27#include "sysfs.h"
28
29static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
30 int scrub_ret);
31static void btrfs_dev_replace_update_device_in_mapping_tree(
32 struct btrfs_fs_info *fs_info,
33 struct btrfs_device *srcdev,
34 struct btrfs_device *tgtdev);
35static int btrfs_dev_replace_kthread(void *data);
36static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
37
38
39int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info)
40{
41 struct btrfs_key key;
42 struct btrfs_root *dev_root = fs_info->dev_root;
43 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
44 struct extent_buffer *eb;
45 int slot;
46 int ret = 0;
47 struct btrfs_path *path = NULL;
48 int item_size;
49 struct btrfs_dev_replace_item *ptr;
50 u64 src_devid;
51
52 path = btrfs_alloc_path();
53 if (!path) {
54 ret = -ENOMEM;
55 goto out;
56 }
57
58 key.objectid = 0;
59 key.type = BTRFS_DEV_REPLACE_KEY;
60 key.offset = 0;
61 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
62 if (ret) {
63no_valid_dev_replace_entry_found:
64 ret = 0;
65 dev_replace->replace_state =
66 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED;
67 dev_replace->cont_reading_from_srcdev_mode =
68 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS;
69 dev_replace->replace_state = 0;
70 dev_replace->time_started = 0;
71 dev_replace->time_stopped = 0;
72 atomic64_set(&dev_replace->num_write_errors, 0);
73 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
74 dev_replace->cursor_left = 0;
75 dev_replace->committed_cursor_left = 0;
76 dev_replace->cursor_left_last_write_of_item = 0;
77 dev_replace->cursor_right = 0;
78 dev_replace->srcdev = NULL;
79 dev_replace->tgtdev = NULL;
80 dev_replace->is_valid = 0;
81 dev_replace->item_needs_writeback = 0;
82 goto out;
83 }
84 slot = path->slots[0];
85 eb = path->nodes[0];
86 item_size = btrfs_item_size_nr(eb, slot);
87 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item);
88
89 if (item_size != sizeof(struct btrfs_dev_replace_item)) {
90 btrfs_warn(fs_info,
91 "dev_replace entry found has unexpected size, ignore entry");
92 goto no_valid_dev_replace_entry_found;
93 }
94
95 src_devid = btrfs_dev_replace_src_devid(eb, ptr);
96 dev_replace->cont_reading_from_srcdev_mode =
97 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr);
98 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr);
99 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr);
100 dev_replace->time_stopped =
101 btrfs_dev_replace_time_stopped(eb, ptr);
102 atomic64_set(&dev_replace->num_write_errors,
103 btrfs_dev_replace_num_write_errors(eb, ptr));
104 atomic64_set(&dev_replace->num_uncorrectable_read_errors,
105 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr));
106 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr);
107 dev_replace->committed_cursor_left = dev_replace->cursor_left;
108 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left;
109 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr);
110 dev_replace->is_valid = 1;
111
112 dev_replace->item_needs_writeback = 0;
113 switch (dev_replace->replace_state) {
114 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
115 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
116 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
117 dev_replace->srcdev = NULL;
118 dev_replace->tgtdev = NULL;
119 break;
120 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
121 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
122 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid,
123 NULL, NULL);
124 dev_replace->tgtdev = btrfs_find_device(fs_info,
125 BTRFS_DEV_REPLACE_DEVID,
126 NULL, NULL);
127 /*
128 * allow 'btrfs dev replace_cancel' if src/tgt device is
129 * missing
130 */
131 if (!dev_replace->srcdev &&
132 !btrfs_test_opt(fs_info, DEGRADED)) {
133 ret = -EIO;
134 btrfs_warn(fs_info,
135 "cannot mount because device replace operation is ongoing and");
136 btrfs_warn(fs_info,
137 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
138 src_devid);
139 }
140 if (!dev_replace->tgtdev &&
141 !btrfs_test_opt(fs_info, DEGRADED)) {
142 ret = -EIO;
143 btrfs_warn(fs_info,
144 "cannot mount because device replace operation is ongoing and");
145 btrfs_warn(fs_info,
146 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
147 BTRFS_DEV_REPLACE_DEVID);
148 }
149 if (dev_replace->tgtdev) {
150 if (dev_replace->srcdev) {
151 dev_replace->tgtdev->total_bytes =
152 dev_replace->srcdev->total_bytes;
153 dev_replace->tgtdev->disk_total_bytes =
154 dev_replace->srcdev->disk_total_bytes;
155 dev_replace->tgtdev->commit_total_bytes =
156 dev_replace->srcdev->commit_total_bytes;
157 dev_replace->tgtdev->bytes_used =
158 dev_replace->srcdev->bytes_used;
159 dev_replace->tgtdev->commit_bytes_used =
160 dev_replace->srcdev->commit_bytes_used;
161 }
162 set_bit(BTRFS_DEV_STATE_REPLACE_TGT,
163 &dev_replace->tgtdev->dev_state);
164
165 WARN_ON(fs_info->fs_devices->rw_devices == 0);
166 dev_replace->tgtdev->io_width = fs_info->sectorsize;
167 dev_replace->tgtdev->io_align = fs_info->sectorsize;
168 dev_replace->tgtdev->sector_size = fs_info->sectorsize;
169 dev_replace->tgtdev->fs_info = fs_info;
170 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
171 &dev_replace->tgtdev->dev_state);
172 }
173 break;
174 }
175
176out:
177 btrfs_free_path(path);
178 return ret;
179}
180
181/*
182 * called from commit_transaction. Writes changed device replace state to
183 * disk.
184 */
185int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
186 struct btrfs_fs_info *fs_info)
187{
188 int ret;
189 struct btrfs_root *dev_root = fs_info->dev_root;
190 struct btrfs_path *path;
191 struct btrfs_key key;
192 struct extent_buffer *eb;
193 struct btrfs_dev_replace_item *ptr;
194 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
195
196 btrfs_dev_replace_read_lock(dev_replace);
197 if (!dev_replace->is_valid ||
198 !dev_replace->item_needs_writeback) {
199 btrfs_dev_replace_read_unlock(dev_replace);
200 return 0;
201 }
202 btrfs_dev_replace_read_unlock(dev_replace);
203
204 key.objectid = 0;
205 key.type = BTRFS_DEV_REPLACE_KEY;
206 key.offset = 0;
207
208 path = btrfs_alloc_path();
209 if (!path) {
210 ret = -ENOMEM;
211 goto out;
212 }
213 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
214 if (ret < 0) {
215 btrfs_warn(fs_info,
216 "error %d while searching for dev_replace item!",
217 ret);
218 goto out;
219 }
220
221 if (ret == 0 &&
222 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
223 /*
224 * need to delete old one and insert a new one.
225 * Since no attempt is made to recover any old state, if the
226 * dev_replace state is 'running', the data on the target
227 * drive is lost.
228 * It would be possible to recover the state: just make sure
229 * that the beginning of the item is never changed and always
230 * contains all the essential information. Then read this
231 * minimal set of information and use it as a base for the
232 * new state.
233 */
234 ret = btrfs_del_item(trans, dev_root, path);
235 if (ret != 0) {
236 btrfs_warn(fs_info,
237 "delete too small dev_replace item failed %d!",
238 ret);
239 goto out;
240 }
241 ret = 1;
242 }
243
244 if (ret == 1) {
245 /* need to insert a new item */
246 btrfs_release_path(path);
247 ret = btrfs_insert_empty_item(trans, dev_root, path,
248 &key, sizeof(*ptr));
249 if (ret < 0) {
250 btrfs_warn(fs_info,
251 "insert dev_replace item failed %d!", ret);
252 goto out;
253 }
254 }
255
256 eb = path->nodes[0];
257 ptr = btrfs_item_ptr(eb, path->slots[0],
258 struct btrfs_dev_replace_item);
259
260 btrfs_dev_replace_write_lock(dev_replace);
261 if (dev_replace->srcdev)
262 btrfs_set_dev_replace_src_devid(eb, ptr,
263 dev_replace->srcdev->devid);
264 else
265 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1);
266 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr,
267 dev_replace->cont_reading_from_srcdev_mode);
268 btrfs_set_dev_replace_replace_state(eb, ptr,
269 dev_replace->replace_state);
270 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started);
271 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped);
272 btrfs_set_dev_replace_num_write_errors(eb, ptr,
273 atomic64_read(&dev_replace->num_write_errors));
274 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr,
275 atomic64_read(&dev_replace->num_uncorrectable_read_errors));
276 dev_replace->cursor_left_last_write_of_item =
277 dev_replace->cursor_left;
278 btrfs_set_dev_replace_cursor_left(eb, ptr,
279 dev_replace->cursor_left_last_write_of_item);
280 btrfs_set_dev_replace_cursor_right(eb, ptr,
281 dev_replace->cursor_right);
282 dev_replace->item_needs_writeback = 0;
283 btrfs_dev_replace_write_unlock(dev_replace);
284
285 btrfs_mark_buffer_dirty(eb);
286
287out:
288 btrfs_free_path(path);
289
290 return ret;
291}
292
293void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
294{
295 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
296
297 dev_replace->committed_cursor_left =
298 dev_replace->cursor_left_last_write_of_item;
299}
300
301static char* btrfs_dev_name(struct btrfs_device *device)
302{
303 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
304 return "<missing disk>";
305 else
306 return rcu_str_deref(device->name);
307}
308
309int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
310 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name,
311 int read_src)
312{
313 struct btrfs_root *root = fs_info->dev_root;
314 struct btrfs_trans_handle *trans;
315 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
316 int ret;
317 struct btrfs_device *tgt_device = NULL;
318 struct btrfs_device *src_device = NULL;
319
320 /* the disk copy procedure reuses the scrub code */
321 mutex_lock(&fs_info->volume_mutex);
322 ret = btrfs_find_device_by_devspec(fs_info, srcdevid,
323 srcdev_name, &src_device);
324 if (ret) {
325 mutex_unlock(&fs_info->volume_mutex);
326 return ret;
327 }
328
329 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name,
330 src_device, &tgt_device);
331 mutex_unlock(&fs_info->volume_mutex);
332 if (ret)
333 return ret;
334
335 /*
336 * Here we commit the transaction to make sure commit_total_bytes
337 * of all the devices are updated.
338 */
339 trans = btrfs_attach_transaction(root);
340 if (!IS_ERR(trans)) {
341 ret = btrfs_commit_transaction(trans);
342 if (ret)
343 return ret;
344 } else if (PTR_ERR(trans) != -ENOENT) {
345 return PTR_ERR(trans);
346 }
347
348 btrfs_dev_replace_write_lock(dev_replace);
349 switch (dev_replace->replace_state) {
350 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
351 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
352 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
353 break;
354 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
355 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
356 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
357 goto leave;
358 }
359
360 dev_replace->cont_reading_from_srcdev_mode = read_src;
361 WARN_ON(!src_device);
362 dev_replace->srcdev = src_device;
363 WARN_ON(!tgt_device);
364 dev_replace->tgtdev = tgt_device;
365
366 btrfs_info_in_rcu(fs_info,
367 "dev_replace from %s (devid %llu) to %s started",
368 btrfs_dev_name(src_device),
369 src_device->devid,
370 rcu_str_deref(tgt_device->name));
371
372 /*
373 * from now on, the writes to the srcdev are all duplicated to
374 * go to the tgtdev as well (refer to btrfs_map_block()).
375 */
376 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
377 dev_replace->time_started = get_seconds();
378 dev_replace->cursor_left = 0;
379 dev_replace->committed_cursor_left = 0;
380 dev_replace->cursor_left_last_write_of_item = 0;
381 dev_replace->cursor_right = 0;
382 dev_replace->is_valid = 1;
383 dev_replace->item_needs_writeback = 1;
384 atomic64_set(&dev_replace->num_write_errors, 0);
385 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
386 btrfs_dev_replace_write_unlock(dev_replace);
387
388 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device);
389 if (ret)
390 btrfs_err(fs_info, "kobj add dev failed %d", ret);
391
392 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
393
394 /* force writing the updated state information to disk */
395 trans = btrfs_start_transaction(root, 0);
396 if (IS_ERR(trans)) {
397 ret = PTR_ERR(trans);
398 btrfs_dev_replace_write_lock(dev_replace);
399 goto leave;
400 }
401
402 ret = btrfs_commit_transaction(trans);
403 WARN_ON(ret);
404
405 /* the disk copy procedure reuses the scrub code */
406 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
407 btrfs_device_get_total_bytes(src_device),
408 &dev_replace->scrub_progress, 0, 1);
409
410 ret = btrfs_dev_replace_finishing(fs_info, ret);
411 if (ret == -EINPROGRESS) {
412 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
413 } else {
414 WARN_ON(ret);
415 }
416
417 return ret;
418
419leave:
420 dev_replace->srcdev = NULL;
421 dev_replace->tgtdev = NULL;
422 btrfs_dev_replace_write_unlock(dev_replace);
423 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
424 return ret;
425}
426
427int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info,
428 struct btrfs_ioctl_dev_replace_args *args)
429{
430 int ret;
431
432 switch (args->start.cont_reading_from_srcdev_mode) {
433 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
434 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
435 break;
436 default:
437 return -EINVAL;
438 }
439
440 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
441 args->start.tgtdev_name[0] == '\0')
442 return -EINVAL;
443
444 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name,
445 args->start.srcdevid,
446 args->start.srcdev_name,
447 args->start.cont_reading_from_srcdev_mode);
448 args->result = ret;
449 /* don't warn if EINPROGRESS, someone else might be running scrub */
450 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS)
451 ret = 0;
452
453 return ret;
454}
455
456/*
457 * blocked until all in-flight bios operations are finished.
458 */
459static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
460{
461 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
462 wait_event(fs_info->replace_wait, !percpu_counter_sum(
463 &fs_info->bio_counter));
464}
465
466/*
467 * we have removed target device, it is safe to allow new bios request.
468 */
469static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info)
470{
471 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
472 wake_up(&fs_info->replace_wait);
473}
474
475static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
476 int scrub_ret)
477{
478 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
479 struct btrfs_device *tgt_device;
480 struct btrfs_device *src_device;
481 struct btrfs_root *root = fs_info->tree_root;
482 u8 uuid_tmp[BTRFS_UUID_SIZE];
483 struct btrfs_trans_handle *trans;
484 int ret = 0;
485
486 /* don't allow cancel or unmount to disturb the finishing procedure */
487 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
488
489 btrfs_dev_replace_read_lock(dev_replace);
490 /* was the operation canceled, or is it finished? */
491 if (dev_replace->replace_state !=
492 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
493 btrfs_dev_replace_read_unlock(dev_replace);
494 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
495 return 0;
496 }
497
498 tgt_device = dev_replace->tgtdev;
499 src_device = dev_replace->srcdev;
500 btrfs_dev_replace_read_unlock(dev_replace);
501
502 /*
503 * flush all outstanding I/O and inode extent mappings before the
504 * copy operation is declared as being finished
505 */
506 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
507 if (ret) {
508 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
509 return ret;
510 }
511 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
512
513 trans = btrfs_start_transaction(root, 0);
514 if (IS_ERR(trans)) {
515 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
516 return PTR_ERR(trans);
517 }
518 ret = btrfs_commit_transaction(trans);
519 WARN_ON(ret);
520
521 mutex_lock(&uuid_mutex);
522 /* keep away write_all_supers() during the finishing procedure */
523 mutex_lock(&fs_info->fs_devices->device_list_mutex);
524 mutex_lock(&fs_info->chunk_mutex);
525 btrfs_dev_replace_write_lock(dev_replace);
526 dev_replace->replace_state =
527 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
528 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
529 dev_replace->tgtdev = NULL;
530 dev_replace->srcdev = NULL;
531 dev_replace->time_stopped = get_seconds();
532 dev_replace->item_needs_writeback = 1;
533
534 /* replace old device with new one in mapping tree */
535 if (!scrub_ret) {
536 btrfs_dev_replace_update_device_in_mapping_tree(fs_info,
537 src_device,
538 tgt_device);
539 } else {
540 btrfs_err_in_rcu(fs_info,
541 "btrfs_scrub_dev(%s, %llu, %s) failed %d",
542 btrfs_dev_name(src_device),
543 src_device->devid,
544 rcu_str_deref(tgt_device->name), scrub_ret);
545 btrfs_dev_replace_write_unlock(dev_replace);
546 mutex_unlock(&fs_info->chunk_mutex);
547 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
548 mutex_unlock(&uuid_mutex);
549 btrfs_rm_dev_replace_blocked(fs_info);
550 if (tgt_device)
551 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
552 btrfs_rm_dev_replace_unblocked(fs_info);
553 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
554
555 return scrub_ret;
556 }
557
558 btrfs_info_in_rcu(fs_info,
559 "dev_replace from %s (devid %llu) to %s finished",
560 btrfs_dev_name(src_device),
561 src_device->devid,
562 rcu_str_deref(tgt_device->name));
563 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state);
564 tgt_device->devid = src_device->devid;
565 src_device->devid = BTRFS_DEV_REPLACE_DEVID;
566 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp));
567 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid));
568 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid));
569 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes);
570 btrfs_device_set_disk_total_bytes(tgt_device,
571 src_device->disk_total_bytes);
572 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used);
573 ASSERT(list_empty(&src_device->resized_list));
574 tgt_device->commit_total_bytes = src_device->commit_total_bytes;
575 tgt_device->commit_bytes_used = src_device->bytes_used;
576
577 btrfs_assign_next_active_device(fs_info, src_device, tgt_device);
578
579 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
580 fs_info->fs_devices->rw_devices++;
581
582 btrfs_dev_replace_write_unlock(dev_replace);
583
584 btrfs_rm_dev_replace_blocked(fs_info);
585
586 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device);
587
588 btrfs_rm_dev_replace_unblocked(fs_info);
589
590 /*
591 * this is again a consistent state where no dev_replace procedure
592 * is running, the target device is part of the filesystem, the
593 * source device is not part of the filesystem anymore and its 1st
594 * superblock is scratched out so that it is no longer marked to
595 * belong to this filesystem.
596 */
597 mutex_unlock(&fs_info->chunk_mutex);
598 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
599 mutex_unlock(&uuid_mutex);
600
601 /* replace the sysfs entry */
602 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device);
603 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device);
604
605 /* write back the superblocks */
606 trans = btrfs_start_transaction(root, 0);
607 if (!IS_ERR(trans))
608 btrfs_commit_transaction(trans);
609
610 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
611
612 return 0;
613}
614
615static void btrfs_dev_replace_update_device_in_mapping_tree(
616 struct btrfs_fs_info *fs_info,
617 struct btrfs_device *srcdev,
618 struct btrfs_device *tgtdev)
619{
620 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
621 struct extent_map *em;
622 struct map_lookup *map;
623 u64 start = 0;
624 int i;
625
626 write_lock(&em_tree->lock);
627 do {
628 em = lookup_extent_mapping(em_tree, start, (u64)-1);
629 if (!em)
630 break;
631 map = em->map_lookup;
632 for (i = 0; i < map->num_stripes; i++)
633 if (srcdev == map->stripes[i].dev)
634 map->stripes[i].dev = tgtdev;
635 start = em->start + em->len;
636 free_extent_map(em);
637 } while (start);
638 write_unlock(&em_tree->lock);
639}
640
641/*
642 * Read progress of device replace status according to the state and last
643 * stored position. The value format is the same as for
644 * btrfs_dev_replace::progress_1000
645 */
646static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info)
647{
648 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
649 u64 ret = 0;
650
651 switch (dev_replace->replace_state) {
652 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
653 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
654 ret = 0;
655 break;
656 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
657 ret = 1000;
658 break;
659 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
660 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
661 ret = div64_u64(dev_replace->cursor_left,
662 div_u64(btrfs_device_get_total_bytes(
663 dev_replace->srcdev), 1000));
664 break;
665 }
666
667 return ret;
668}
669
670void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
671 struct btrfs_ioctl_dev_replace_args *args)
672{
673 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
674
675 btrfs_dev_replace_read_lock(dev_replace);
676 /* even if !dev_replace_is_valid, the values are good enough for
677 * the replace_status ioctl */
678 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
679 args->status.replace_state = dev_replace->replace_state;
680 args->status.time_started = dev_replace->time_started;
681 args->status.time_stopped = dev_replace->time_stopped;
682 args->status.num_write_errors =
683 atomic64_read(&dev_replace->num_write_errors);
684 args->status.num_uncorrectable_read_errors =
685 atomic64_read(&dev_replace->num_uncorrectable_read_errors);
686 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info);
687 btrfs_dev_replace_read_unlock(dev_replace);
688}
689
690int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
691{
692 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
693 struct btrfs_device *tgt_device = NULL;
694 struct btrfs_device *src_device = NULL;
695 struct btrfs_trans_handle *trans;
696 struct btrfs_root *root = fs_info->tree_root;
697 int result;
698 int ret;
699
700 if (sb_rdonly(fs_info->sb))
701 return -EROFS;
702
703 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
704 btrfs_dev_replace_write_lock(dev_replace);
705 switch (dev_replace->replace_state) {
706 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
707 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
708 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
709 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
710 btrfs_dev_replace_write_unlock(dev_replace);
711 goto leave;
712 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
713 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
714 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
715 tgt_device = dev_replace->tgtdev;
716 src_device = dev_replace->srcdev;
717 dev_replace->tgtdev = NULL;
718 dev_replace->srcdev = NULL;
719 break;
720 }
721 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
722 dev_replace->time_stopped = get_seconds();
723 dev_replace->item_needs_writeback = 1;
724 btrfs_dev_replace_write_unlock(dev_replace);
725 btrfs_scrub_cancel(fs_info);
726
727 trans = btrfs_start_transaction(root, 0);
728 if (IS_ERR(trans)) {
729 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
730 return PTR_ERR(trans);
731 }
732 ret = btrfs_commit_transaction(trans);
733 WARN_ON(ret);
734
735 btrfs_info_in_rcu(fs_info,
736 "dev_replace from %s (devid %llu) to %s canceled",
737 btrfs_dev_name(src_device), src_device->devid,
738 btrfs_dev_name(tgt_device));
739
740 if (tgt_device)
741 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
742
743leave:
744 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
745 return result;
746}
747
748void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info)
749{
750 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
751
752 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
753 btrfs_dev_replace_write_lock(dev_replace);
754 switch (dev_replace->replace_state) {
755 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
756 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
757 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
758 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
759 break;
760 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
761 dev_replace->replace_state =
762 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
763 dev_replace->time_stopped = get_seconds();
764 dev_replace->item_needs_writeback = 1;
765 btrfs_info(fs_info, "suspending dev_replace for unmount");
766 break;
767 }
768
769 btrfs_dev_replace_write_unlock(dev_replace);
770 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
771}
772
773/* resume dev_replace procedure that was interrupted by unmount */
774int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
775{
776 struct task_struct *task;
777 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
778
779 btrfs_dev_replace_write_lock(dev_replace);
780 switch (dev_replace->replace_state) {
781 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
782 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
783 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
784 btrfs_dev_replace_write_unlock(dev_replace);
785 return 0;
786 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
787 break;
788 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
789 dev_replace->replace_state =
790 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
791 break;
792 }
793 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) {
794 btrfs_info(fs_info,
795 "cannot continue dev_replace, tgtdev is missing");
796 btrfs_info(fs_info,
797 "you may cancel the operation after 'mount -o degraded'");
798 btrfs_dev_replace_write_unlock(dev_replace);
799 return 0;
800 }
801 btrfs_dev_replace_write_unlock(dev_replace);
802
803 WARN_ON(test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
804 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
805 return PTR_ERR_OR_ZERO(task);
806}
807
808static int btrfs_dev_replace_kthread(void *data)
809{
810 struct btrfs_fs_info *fs_info = data;
811 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
812 u64 progress;
813
814 progress = btrfs_dev_replace_progress(fs_info);
815 progress = div_u64(progress, 10);
816 btrfs_info_in_rcu(fs_info,
817 "continuing dev_replace from %s (devid %llu) to target %s @%u%%",
818 btrfs_dev_name(dev_replace->srcdev),
819 dev_replace->srcdev->devid,
820 btrfs_dev_name(dev_replace->tgtdev),
821 (unsigned int)progress);
822
823 btrfs_dev_replace_continue_on_mount(fs_info);
824 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
825
826 return 0;
827}
828
829static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info)
830{
831 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
832 int ret;
833
834 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid,
835 dev_replace->committed_cursor_left,
836 btrfs_device_get_total_bytes(dev_replace->srcdev),
837 &dev_replace->scrub_progress, 0, 1);
838 ret = btrfs_dev_replace_finishing(fs_info, ret);
839 WARN_ON(ret);
840 return 0;
841}
842
843int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
844{
845 if (!dev_replace->is_valid)
846 return 0;
847
848 switch (dev_replace->replace_state) {
849 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
850 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
851 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
852 return 0;
853 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
854 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
855 /*
856 * return true even if tgtdev is missing (this is
857 * something that can happen if the dev_replace
858 * procedure is suspended by an umount and then
859 * the tgtdev is missing (or "btrfs dev scan") was
860 * not called and the the filesystem is remounted
861 * in degraded state. This does not stop the
862 * dev_replace procedure. It needs to be canceled
863 * manually if the cancellation is wanted.
864 */
865 break;
866 }
867 return 1;
868}
869
870void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace)
871{
872 read_lock(&dev_replace->lock);
873 atomic_inc(&dev_replace->read_locks);
874}
875
876void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace)
877{
878 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
879 atomic_dec(&dev_replace->read_locks);
880 read_unlock(&dev_replace->lock);
881}
882
883void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace)
884{
885again:
886 wait_event(dev_replace->read_lock_wq,
887 atomic_read(&dev_replace->blocking_readers) == 0);
888 write_lock(&dev_replace->lock);
889 if (atomic_read(&dev_replace->blocking_readers)) {
890 write_unlock(&dev_replace->lock);
891 goto again;
892 }
893}
894
895void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace)
896{
897 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0);
898 write_unlock(&dev_replace->lock);
899}
900
901/* inc blocking cnt and release read lock */
902void btrfs_dev_replace_set_lock_blocking(
903 struct btrfs_dev_replace *dev_replace)
904{
905 /* only set blocking for read lock */
906 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
907 atomic_inc(&dev_replace->blocking_readers);
908 read_unlock(&dev_replace->lock);
909}
910
911/* acquire read lock and dec blocking cnt */
912void btrfs_dev_replace_clear_lock_blocking(
913 struct btrfs_dev_replace *dev_replace)
914{
915 /* only set blocking for read lock */
916 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
917 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0);
918 read_lock(&dev_replace->lock);
919 if (atomic_dec_and_test(&dev_replace->blocking_readers) &&
920 waitqueue_active(&dev_replace->read_lock_wq))
921 wake_up(&dev_replace->read_lock_wq);
922}
923
924void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
925{
926 percpu_counter_inc(&fs_info->bio_counter);
927}
928
929void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount)
930{
931 percpu_counter_sub(&fs_info->bio_counter, amount);
932
933 if (waitqueue_active(&fs_info->replace_wait))
934 wake_up(&fs_info->replace_wait);
935}
936
937void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
938{
939 while (1) {
940 percpu_counter_inc(&fs_info->bio_counter);
941 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING,
942 &fs_info->fs_state)))
943 break;
944
945 btrfs_bio_counter_dec(fs_info);
946 wait_event(fs_info->replace_wait,
947 !test_bit(BTRFS_FS_STATE_DEV_REPLACING,
948 &fs_info->fs_state));
949 }
950}