1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) STRATO AG 2012. All rights reserved.
6 #include <linux/sched.h>
8 #include <linux/slab.h>
9 #include <linux/blkdev.h>
10 #include <linux/kthread.h>
11 #include <linux/math64.h>
14 #include "extent_map.h"
16 #include "transaction.h"
17 #include "print-tree.h"
19 #include "async-thread.h"
20 #include "dev-replace.h"
23 #include "block-group.h"
25 #include "accessors.h"
29 * Device replace overview
32 * To copy all extents (both new and on-disk) from source device to target
33 * device, while still keeping the filesystem read-write.
36 * There are two main methods involved:
40 * All new writes will be written to both target and source devices, so even
41 * if replace gets canceled, sources device still contains up-to-date data.
43 * Location: handle_ops_on_dev_replace() from btrfs_map_block()
44 * Start: btrfs_dev_replace_start()
45 * End: btrfs_dev_replace_finishing()
46 * Content: Latest data/metadata
48 * - Copy existing extents
50 * This happens by re-using scrub facility, as scrub also iterates through
51 * existing extents from commit root.
53 * Location: scrub_write_block_to_dev_replace() from
54 * scrub_block_complete()
55 * Content: Data/meta from commit root.
57 * Due to the content difference, we need to avoid nocow write when dev-replace
58 * is happening. This is done by marking the block group read-only and waiting
61 * After replace is done, the finishing part is done by swapping the target and
64 * Location: btrfs_dev_replace_update_device_in_mapping_tree() from
65 * btrfs_dev_replace_finishing()
68 static int btrfs_dev_replace_finishing(struct btrfs_fs_info
*fs_info
,
70 static int btrfs_dev_replace_kthread(void *data
);
72 int btrfs_init_dev_replace(struct btrfs_fs_info
*fs_info
)
74 struct btrfs_dev_lookup_args args
= { .devid
= BTRFS_DEV_REPLACE_DEVID
};
76 struct btrfs_root
*dev_root
= fs_info
->dev_root
;
77 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
78 struct extent_buffer
*eb
;
81 struct btrfs_path
*path
= NULL
;
83 struct btrfs_dev_replace_item
*ptr
;
89 path
= btrfs_alloc_path();
96 key
.type
= BTRFS_DEV_REPLACE_KEY
;
98 ret
= btrfs_search_slot(NULL
, dev_root
, &key
, path
, 0, 0);
100 no_valid_dev_replace_entry_found
:
102 * We don't have a replace item or it's corrupted. If there is
103 * a replace target, fail the mount.
105 if (btrfs_find_device(fs_info
->fs_devices
, &args
)) {
107 "found replace target device without a valid replace item");
112 dev_replace
->replace_state
=
113 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED
;
114 dev_replace
->cont_reading_from_srcdev_mode
=
115 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS
;
116 dev_replace
->time_started
= 0;
117 dev_replace
->time_stopped
= 0;
118 atomic64_set(&dev_replace
->num_write_errors
, 0);
119 atomic64_set(&dev_replace
->num_uncorrectable_read_errors
, 0);
120 dev_replace
->cursor_left
= 0;
121 dev_replace
->committed_cursor_left
= 0;
122 dev_replace
->cursor_left_last_write_of_item
= 0;
123 dev_replace
->cursor_right
= 0;
124 dev_replace
->srcdev
= NULL
;
125 dev_replace
->tgtdev
= NULL
;
126 dev_replace
->is_valid
= 0;
127 dev_replace
->item_needs_writeback
= 0;
130 slot
= path
->slots
[0];
132 item_size
= btrfs_item_size(eb
, slot
);
133 ptr
= btrfs_item_ptr(eb
, slot
, struct btrfs_dev_replace_item
);
135 if (item_size
!= sizeof(struct btrfs_dev_replace_item
)) {
137 "dev_replace entry found has unexpected size, ignore entry");
138 goto no_valid_dev_replace_entry_found
;
141 src_devid
= btrfs_dev_replace_src_devid(eb
, ptr
);
142 dev_replace
->cont_reading_from_srcdev_mode
=
143 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb
, ptr
);
144 dev_replace
->replace_state
= btrfs_dev_replace_replace_state(eb
, ptr
);
145 dev_replace
->time_started
= btrfs_dev_replace_time_started(eb
, ptr
);
146 dev_replace
->time_stopped
=
147 btrfs_dev_replace_time_stopped(eb
, ptr
);
148 atomic64_set(&dev_replace
->num_write_errors
,
149 btrfs_dev_replace_num_write_errors(eb
, ptr
));
150 atomic64_set(&dev_replace
->num_uncorrectable_read_errors
,
151 btrfs_dev_replace_num_uncorrectable_read_errors(eb
, ptr
));
152 dev_replace
->cursor_left
= btrfs_dev_replace_cursor_left(eb
, ptr
);
153 dev_replace
->committed_cursor_left
= dev_replace
->cursor_left
;
154 dev_replace
->cursor_left_last_write_of_item
= dev_replace
->cursor_left
;
155 dev_replace
->cursor_right
= btrfs_dev_replace_cursor_right(eb
, ptr
);
156 dev_replace
->is_valid
= 1;
158 dev_replace
->item_needs_writeback
= 0;
159 switch (dev_replace
->replace_state
) {
160 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED
:
161 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED
:
162 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
:
164 * We don't have an active replace item but if there is a
165 * replace target, fail the mount.
167 if (btrfs_find_device(fs_info
->fs_devices
, &args
)) {
169 "replace without active item, run 'device scan --forget' on the target device");
172 dev_replace
->srcdev
= NULL
;
173 dev_replace
->tgtdev
= NULL
;
176 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
:
177 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
:
178 dev_replace
->tgtdev
= btrfs_find_device(fs_info
->fs_devices
, &args
);
179 args
.devid
= src_devid
;
180 dev_replace
->srcdev
= btrfs_find_device(fs_info
->fs_devices
, &args
);
183 * allow 'btrfs dev replace_cancel' if src/tgt device is
186 if (!dev_replace
->srcdev
&&
187 !btrfs_test_opt(fs_info
, DEGRADED
)) {
190 "cannot mount because device replace operation is ongoing and");
192 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
195 if (!dev_replace
->tgtdev
&&
196 !btrfs_test_opt(fs_info
, DEGRADED
)) {
199 "cannot mount because device replace operation is ongoing and");
201 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
202 BTRFS_DEV_REPLACE_DEVID
);
204 if (dev_replace
->tgtdev
) {
205 if (dev_replace
->srcdev
) {
206 dev_replace
->tgtdev
->total_bytes
=
207 dev_replace
->srcdev
->total_bytes
;
208 dev_replace
->tgtdev
->disk_total_bytes
=
209 dev_replace
->srcdev
->disk_total_bytes
;
210 dev_replace
->tgtdev
->commit_total_bytes
=
211 dev_replace
->srcdev
->commit_total_bytes
;
212 dev_replace
->tgtdev
->bytes_used
=
213 dev_replace
->srcdev
->bytes_used
;
214 dev_replace
->tgtdev
->commit_bytes_used
=
215 dev_replace
->srcdev
->commit_bytes_used
;
217 set_bit(BTRFS_DEV_STATE_REPLACE_TGT
,
218 &dev_replace
->tgtdev
->dev_state
);
220 WARN_ON(fs_info
->fs_devices
->rw_devices
== 0);
221 dev_replace
->tgtdev
->io_width
= fs_info
->sectorsize
;
222 dev_replace
->tgtdev
->io_align
= fs_info
->sectorsize
;
223 dev_replace
->tgtdev
->sector_size
= fs_info
->sectorsize
;
224 dev_replace
->tgtdev
->fs_info
= fs_info
;
225 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA
,
226 &dev_replace
->tgtdev
->dev_state
);
232 btrfs_free_path(path
);
237 * Initialize a new device for device replace target from a given source dev
240 * Return 0 and new device in @device_out, otherwise return < 0
242 static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info
*fs_info
,
243 const char *device_path
,
244 struct btrfs_device
*srcdev
,
245 struct btrfs_device
**device_out
)
247 struct btrfs_fs_devices
*fs_devices
= fs_info
->fs_devices
;
248 struct btrfs_device
*device
;
249 struct bdev_handle
*bdev_handle
;
250 struct block_device
*bdev
;
251 u64 devid
= BTRFS_DEV_REPLACE_DEVID
;
255 if (srcdev
->fs_devices
->seeding
) {
256 btrfs_err(fs_info
, "the filesystem is a seed filesystem!");
260 bdev_handle
= bdev_open_by_path(device_path
, BLK_OPEN_WRITE
,
261 fs_info
->bdev_holder
, NULL
);
262 if (IS_ERR(bdev_handle
)) {
263 btrfs_err(fs_info
, "target device %s is invalid!", device_path
);
264 return PTR_ERR(bdev_handle
);
266 bdev
= bdev_handle
->bdev
;
268 if (!btrfs_check_device_zone_type(fs_info
, bdev
)) {
270 "dev-replace: zoned type of target device mismatch with filesystem");
277 list_for_each_entry(device
, &fs_devices
->devices
, dev_list
) {
278 if (device
->bdev
== bdev
) {
280 "target device is in the filesystem!");
287 if (bdev_nr_bytes(bdev
) < btrfs_device_get_total_bytes(srcdev
)) {
289 "target device is smaller than source device!");
295 device
= btrfs_alloc_device(NULL
, &devid
, NULL
, device_path
);
296 if (IS_ERR(device
)) {
297 ret
= PTR_ERR(device
);
301 ret
= lookup_bdev(device_path
, &device
->devt
);
305 set_bit(BTRFS_DEV_STATE_WRITEABLE
, &device
->dev_state
);
306 device
->generation
= 0;
307 device
->io_width
= fs_info
->sectorsize
;
308 device
->io_align
= fs_info
->sectorsize
;
309 device
->sector_size
= fs_info
->sectorsize
;
310 device
->total_bytes
= btrfs_device_get_total_bytes(srcdev
);
311 device
->disk_total_bytes
= btrfs_device_get_disk_total_bytes(srcdev
);
312 device
->bytes_used
= btrfs_device_get_bytes_used(srcdev
);
313 device
->commit_total_bytes
= srcdev
->commit_total_bytes
;
314 device
->commit_bytes_used
= device
->bytes_used
;
315 device
->fs_info
= fs_info
;
317 device
->bdev_handle
= bdev_handle
;
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
->dev_stats_valid
= 1;
321 set_blocksize(device
->bdev
, BTRFS_BDEV_BLOCKSIZE
);
322 device
->fs_devices
= fs_devices
;
324 ret
= btrfs_get_dev_zone_info(device
, false);
328 mutex_lock(&fs_devices
->device_list_mutex
);
329 list_add(&device
->dev_list
, &fs_devices
->devices
);
330 fs_devices
->num_devices
++;
331 fs_devices
->open_devices
++;
332 mutex_unlock(&fs_devices
->device_list_mutex
);
334 *device_out
= device
;
338 bdev_release(bdev_handle
);
343 * called from commit_transaction. Writes changed device replace state to
346 int btrfs_run_dev_replace(struct btrfs_trans_handle
*trans
)
348 struct btrfs_fs_info
*fs_info
= trans
->fs_info
;
350 struct btrfs_root
*dev_root
= fs_info
->dev_root
;
351 struct btrfs_path
*path
;
352 struct btrfs_key key
;
353 struct extent_buffer
*eb
;
354 struct btrfs_dev_replace_item
*ptr
;
355 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
357 down_read(&dev_replace
->rwsem
);
358 if (!dev_replace
->is_valid
||
359 !dev_replace
->item_needs_writeback
) {
360 up_read(&dev_replace
->rwsem
);
363 up_read(&dev_replace
->rwsem
);
366 key
.type
= BTRFS_DEV_REPLACE_KEY
;
369 path
= btrfs_alloc_path();
374 ret
= btrfs_search_slot(trans
, dev_root
, &key
, path
, -1, 1);
377 "error %d while searching for dev_replace item!",
383 btrfs_item_size(path
->nodes
[0], path
->slots
[0]) < sizeof(*ptr
)) {
385 * need to delete old one and insert a new one.
386 * Since no attempt is made to recover any old state, if the
387 * dev_replace state is 'running', the data on the target
389 * It would be possible to recover the state: just make sure
390 * that the beginning of the item is never changed and always
391 * contains all the essential information. Then read this
392 * minimal set of information and use it as a base for the
395 ret
= btrfs_del_item(trans
, dev_root
, path
);
398 "delete too small dev_replace item failed %d!",
406 /* need to insert a new item */
407 btrfs_release_path(path
);
408 ret
= btrfs_insert_empty_item(trans
, dev_root
, path
,
412 "insert dev_replace item failed %d!", ret
);
418 ptr
= btrfs_item_ptr(eb
, path
->slots
[0],
419 struct btrfs_dev_replace_item
);
421 down_write(&dev_replace
->rwsem
);
422 if (dev_replace
->srcdev
)
423 btrfs_set_dev_replace_src_devid(eb
, ptr
,
424 dev_replace
->srcdev
->devid
);
426 btrfs_set_dev_replace_src_devid(eb
, ptr
, (u64
)-1);
427 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb
, ptr
,
428 dev_replace
->cont_reading_from_srcdev_mode
);
429 btrfs_set_dev_replace_replace_state(eb
, ptr
,
430 dev_replace
->replace_state
);
431 btrfs_set_dev_replace_time_started(eb
, ptr
, dev_replace
->time_started
);
432 btrfs_set_dev_replace_time_stopped(eb
, ptr
, dev_replace
->time_stopped
);
433 btrfs_set_dev_replace_num_write_errors(eb
, ptr
,
434 atomic64_read(&dev_replace
->num_write_errors
));
435 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb
, ptr
,
436 atomic64_read(&dev_replace
->num_uncorrectable_read_errors
));
437 dev_replace
->cursor_left_last_write_of_item
=
438 dev_replace
->cursor_left
;
439 btrfs_set_dev_replace_cursor_left(eb
, ptr
,
440 dev_replace
->cursor_left_last_write_of_item
);
441 btrfs_set_dev_replace_cursor_right(eb
, ptr
,
442 dev_replace
->cursor_right
);
443 dev_replace
->item_needs_writeback
= 0;
444 up_write(&dev_replace
->rwsem
);
446 btrfs_mark_buffer_dirty(trans
, eb
);
449 btrfs_free_path(path
);
454 static int mark_block_group_to_copy(struct btrfs_fs_info
*fs_info
,
455 struct btrfs_device
*src_dev
)
457 struct btrfs_path
*path
;
458 struct btrfs_key key
;
459 struct btrfs_key found_key
;
460 struct btrfs_root
*root
= fs_info
->dev_root
;
461 struct btrfs_dev_extent
*dev_extent
= NULL
;
462 struct btrfs_block_group
*cache
;
463 struct btrfs_trans_handle
*trans
;
468 /* Do not use "to_copy" on non zoned filesystem for now */
469 if (!btrfs_is_zoned(fs_info
))
472 mutex_lock(&fs_info
->chunk_mutex
);
474 /* Ensure we don't have pending new block group */
475 spin_lock(&fs_info
->trans_lock
);
476 while (fs_info
->running_transaction
&&
477 !list_empty(&fs_info
->running_transaction
->dev_update_list
)) {
478 spin_unlock(&fs_info
->trans_lock
);
479 mutex_unlock(&fs_info
->chunk_mutex
);
480 trans
= btrfs_attach_transaction(root
);
482 ret
= PTR_ERR(trans
);
483 mutex_lock(&fs_info
->chunk_mutex
);
484 if (ret
== -ENOENT
) {
485 spin_lock(&fs_info
->trans_lock
);
492 ret
= btrfs_commit_transaction(trans
);
493 mutex_lock(&fs_info
->chunk_mutex
);
497 spin_lock(&fs_info
->trans_lock
);
499 spin_unlock(&fs_info
->trans_lock
);
501 path
= btrfs_alloc_path();
507 path
->reada
= READA_FORWARD
;
508 path
->search_commit_root
= 1;
509 path
->skip_locking
= 1;
511 key
.objectid
= src_dev
->devid
;
512 key
.type
= BTRFS_DEV_EXTENT_KEY
;
515 btrfs_for_each_slot(root
, &key
, &found_key
, path
, iter_ret
) {
516 struct extent_buffer
*leaf
= path
->nodes
[0];
518 if (found_key
.objectid
!= src_dev
->devid
)
521 if (found_key
.type
!= BTRFS_DEV_EXTENT_KEY
)
524 if (found_key
.offset
< key
.offset
)
527 dev_extent
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_dev_extent
);
529 chunk_offset
= btrfs_dev_extent_chunk_offset(leaf
, dev_extent
);
531 cache
= btrfs_lookup_block_group(fs_info
, chunk_offset
);
535 set_bit(BLOCK_GROUP_FLAG_TO_COPY
, &cache
->runtime_flags
);
536 btrfs_put_block_group(cache
);
541 btrfs_free_path(path
);
543 mutex_unlock(&fs_info
->chunk_mutex
);
548 bool btrfs_finish_block_group_to_copy(struct btrfs_device
*srcdev
,
549 struct btrfs_block_group
*cache
,
552 struct btrfs_fs_info
*fs_info
= cache
->fs_info
;
553 struct extent_map
*em
;
554 struct map_lookup
*map
;
555 u64 chunk_offset
= cache
->start
;
556 int num_extents
, cur_extent
;
559 /* Do not use "to_copy" on non zoned filesystem for now */
560 if (!btrfs_is_zoned(fs_info
))
563 spin_lock(&cache
->lock
);
564 if (test_bit(BLOCK_GROUP_FLAG_REMOVED
, &cache
->runtime_flags
)) {
565 spin_unlock(&cache
->lock
);
568 spin_unlock(&cache
->lock
);
570 em
= btrfs_get_chunk_map(fs_info
, chunk_offset
, 1);
572 map
= em
->map_lookup
;
576 for (i
= 0; i
< map
->num_stripes
; i
++) {
577 /* We have more device extent to copy */
578 if (srcdev
!= map
->stripes
[i
].dev
)
582 if (physical
== map
->stripes
[i
].physical
)
588 if (num_extents
> 1 && cur_extent
< num_extents
- 1) {
590 * Has more stripes on this device. Keep this block group
591 * readonly until we finish all the stripes.
596 /* Last stripe on this device */
597 clear_bit(BLOCK_GROUP_FLAG_TO_COPY
, &cache
->runtime_flags
);
602 static int btrfs_dev_replace_start(struct btrfs_fs_info
*fs_info
,
603 const char *tgtdev_name
, u64 srcdevid
, const char *srcdev_name
,
606 struct btrfs_root
*root
= fs_info
->dev_root
;
607 struct btrfs_trans_handle
*trans
;
608 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
610 struct btrfs_device
*tgt_device
= NULL
;
611 struct btrfs_device
*src_device
= NULL
;
613 src_device
= btrfs_find_device_by_devspec(fs_info
, srcdevid
,
615 if (IS_ERR(src_device
))
616 return PTR_ERR(src_device
);
618 if (btrfs_pinned_by_swapfile(fs_info
, src_device
)) {
619 btrfs_warn_in_rcu(fs_info
,
620 "cannot replace device %s (devid %llu) due to active swapfile",
621 btrfs_dev_name(src_device
), src_device
->devid
);
626 * Here we commit the transaction to make sure commit_total_bytes
627 * of all the devices are updated.
629 trans
= btrfs_attach_transaction(root
);
630 if (!IS_ERR(trans
)) {
631 ret
= btrfs_commit_transaction(trans
);
634 } else if (PTR_ERR(trans
) != -ENOENT
) {
635 return PTR_ERR(trans
);
638 ret
= btrfs_init_dev_replace_tgtdev(fs_info
, tgtdev_name
,
639 src_device
, &tgt_device
);
643 ret
= mark_block_group_to_copy(fs_info
, src_device
);
647 down_write(&dev_replace
->rwsem
);
648 switch (dev_replace
->replace_state
) {
649 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED
:
650 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED
:
651 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
:
653 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
:
654 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
:
656 ret
= BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED
;
657 up_write(&dev_replace
->rwsem
);
661 dev_replace
->cont_reading_from_srcdev_mode
= read_src
;
662 dev_replace
->srcdev
= src_device
;
663 dev_replace
->tgtdev
= tgt_device
;
665 btrfs_info_in_rcu(fs_info
,
666 "dev_replace from %s (devid %llu) to %s started",
667 btrfs_dev_name(src_device
),
669 btrfs_dev_name(tgt_device
));
672 * from now on, the writes to the srcdev are all duplicated to
673 * go to the tgtdev as well (refer to btrfs_map_block()).
675 dev_replace
->replace_state
= BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
;
676 dev_replace
->time_started
= ktime_get_real_seconds();
677 dev_replace
->cursor_left
= 0;
678 dev_replace
->committed_cursor_left
= 0;
679 dev_replace
->cursor_left_last_write_of_item
= 0;
680 dev_replace
->cursor_right
= 0;
681 dev_replace
->is_valid
= 1;
682 dev_replace
->item_needs_writeback
= 1;
683 atomic64_set(&dev_replace
->num_write_errors
, 0);
684 atomic64_set(&dev_replace
->num_uncorrectable_read_errors
, 0);
685 up_write(&dev_replace
->rwsem
);
687 ret
= btrfs_sysfs_add_device(tgt_device
);
689 btrfs_err(fs_info
, "kobj add dev failed %d", ret
);
691 btrfs_wait_ordered_roots(fs_info
, U64_MAX
, 0, (u64
)-1);
694 * Commit dev_replace state and reserve 1 item for it.
695 * This is crucial to ensure we won't miss copying extents for new block
696 * groups that are allocated after we started the device replace, and
697 * must be done after setting up the device replace state.
699 trans
= btrfs_start_transaction(root
, 1);
701 ret
= PTR_ERR(trans
);
702 down_write(&dev_replace
->rwsem
);
703 dev_replace
->replace_state
=
704 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED
;
705 dev_replace
->srcdev
= NULL
;
706 dev_replace
->tgtdev
= NULL
;
707 up_write(&dev_replace
->rwsem
);
711 ret
= btrfs_commit_transaction(trans
);
714 /* the disk copy procedure reuses the scrub code */
715 ret
= btrfs_scrub_dev(fs_info
, src_device
->devid
, 0,
716 btrfs_device_get_total_bytes(src_device
),
717 &dev_replace
->scrub_progress
, 0, 1);
719 ret
= btrfs_dev_replace_finishing(fs_info
, ret
);
720 if (ret
== -EINPROGRESS
)
721 ret
= BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS
;
726 btrfs_destroy_dev_replace_tgtdev(tgt_device
);
730 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info
*fs_info
,
731 struct btrfs_ioctl_dev_replace_args
*args
)
735 switch (args
->start
.cont_reading_from_srcdev_mode
) {
736 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS
:
737 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID
:
743 if ((args
->start
.srcdevid
== 0 && args
->start
.srcdev_name
[0] == '\0') ||
744 args
->start
.tgtdev_name
[0] == '\0')
747 ret
= btrfs_dev_replace_start(fs_info
, args
->start
.tgtdev_name
,
748 args
->start
.srcdevid
,
749 args
->start
.srcdev_name
,
750 args
->start
.cont_reading_from_srcdev_mode
);
752 /* don't warn if EINPROGRESS, someone else might be running scrub */
753 if (ret
== BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS
||
754 ret
== BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR
)
761 * blocked until all in-flight bios operations are finished.
763 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info
*fs_info
)
765 set_bit(BTRFS_FS_STATE_DEV_REPLACING
, &fs_info
->fs_state
);
766 wait_event(fs_info
->dev_replace
.replace_wait
, !percpu_counter_sum(
767 &fs_info
->dev_replace
.bio_counter
));
771 * we have removed target device, it is safe to allow new bios request.
773 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info
*fs_info
)
775 clear_bit(BTRFS_FS_STATE_DEV_REPLACING
, &fs_info
->fs_state
);
776 wake_up(&fs_info
->dev_replace
.replace_wait
);
780 * When finishing the device replace, before swapping the source device with the
781 * target device we must update the chunk allocation state in the target device,
782 * as it is empty because replace works by directly copying the chunks and not
783 * through the normal chunk allocation path.
785 static int btrfs_set_target_alloc_state(struct btrfs_device
*srcdev
,
786 struct btrfs_device
*tgtdev
)
788 struct extent_state
*cached_state
= NULL
;
794 lockdep_assert_held(&srcdev
->fs_info
->chunk_mutex
);
796 while (find_first_extent_bit(&srcdev
->alloc_state
, start
,
797 &found_start
, &found_end
,
798 CHUNK_ALLOCATED
, &cached_state
)) {
799 ret
= set_extent_bit(&tgtdev
->alloc_state
, found_start
,
800 found_end
, CHUNK_ALLOCATED
, NULL
);
803 start
= found_end
+ 1;
806 free_extent_state(cached_state
);
810 static void btrfs_dev_replace_update_device_in_mapping_tree(
811 struct btrfs_fs_info
*fs_info
,
812 struct btrfs_device
*srcdev
,
813 struct btrfs_device
*tgtdev
)
815 struct extent_map_tree
*em_tree
= &fs_info
->mapping_tree
;
816 struct extent_map
*em
;
817 struct map_lookup
*map
;
821 write_lock(&em_tree
->lock
);
823 em
= lookup_extent_mapping(em_tree
, start
, (u64
)-1);
826 map
= em
->map_lookup
;
827 for (i
= 0; i
< map
->num_stripes
; i
++)
828 if (srcdev
== map
->stripes
[i
].dev
)
829 map
->stripes
[i
].dev
= tgtdev
;
830 start
= em
->start
+ em
->len
;
833 write_unlock(&em_tree
->lock
);
836 static int btrfs_dev_replace_finishing(struct btrfs_fs_info
*fs_info
,
839 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
840 struct btrfs_fs_devices
*fs_devices
= fs_info
->fs_devices
;
841 struct btrfs_device
*tgt_device
;
842 struct btrfs_device
*src_device
;
843 struct btrfs_root
*root
= fs_info
->tree_root
;
844 u8 uuid_tmp
[BTRFS_UUID_SIZE
];
845 struct btrfs_trans_handle
*trans
;
848 /* don't allow cancel or unmount to disturb the finishing procedure */
849 mutex_lock(&dev_replace
->lock_finishing_cancel_unmount
);
851 down_read(&dev_replace
->rwsem
);
852 /* was the operation canceled, or is it finished? */
853 if (dev_replace
->replace_state
!=
854 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
) {
855 up_read(&dev_replace
->rwsem
);
856 mutex_unlock(&dev_replace
->lock_finishing_cancel_unmount
);
860 tgt_device
= dev_replace
->tgtdev
;
861 src_device
= dev_replace
->srcdev
;
862 up_read(&dev_replace
->rwsem
);
865 * flush all outstanding I/O and inode extent mappings before the
866 * copy operation is declared as being finished
868 ret
= btrfs_start_delalloc_roots(fs_info
, LONG_MAX
, false);
870 mutex_unlock(&dev_replace
->lock_finishing_cancel_unmount
);
873 btrfs_wait_ordered_roots(fs_info
, U64_MAX
, 0, (u64
)-1);
876 * We have to use this loop approach because at this point src_device
877 * has to be available for transaction commit to complete, yet new
878 * chunks shouldn't be allocated on the device.
881 trans
= btrfs_start_transaction(root
, 0);
883 mutex_unlock(&dev_replace
->lock_finishing_cancel_unmount
);
884 return PTR_ERR(trans
);
886 ret
= btrfs_commit_transaction(trans
);
889 /* Prevent write_all_supers() during the finishing procedure */
890 mutex_lock(&fs_devices
->device_list_mutex
);
891 /* Prevent new chunks being allocated on the source device */
892 mutex_lock(&fs_info
->chunk_mutex
);
894 if (!list_empty(&src_device
->post_commit_list
)) {
895 mutex_unlock(&fs_devices
->device_list_mutex
);
896 mutex_unlock(&fs_info
->chunk_mutex
);
902 down_write(&dev_replace
->rwsem
);
903 dev_replace
->replace_state
=
904 scrub_ret
? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
905 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED
;
906 dev_replace
->tgtdev
= NULL
;
907 dev_replace
->srcdev
= NULL
;
908 dev_replace
->time_stopped
= ktime_get_real_seconds();
909 dev_replace
->item_needs_writeback
= 1;
912 * Update allocation state in the new device and replace the old device
913 * with the new one in the mapping tree.
916 scrub_ret
= btrfs_set_target_alloc_state(src_device
, tgt_device
);
919 btrfs_dev_replace_update_device_in_mapping_tree(fs_info
,
923 if (scrub_ret
!= -ECANCELED
)
924 btrfs_err_in_rcu(fs_info
,
925 "btrfs_scrub_dev(%s, %llu, %s) failed %d",
926 btrfs_dev_name(src_device
),
928 btrfs_dev_name(tgt_device
), scrub_ret
);
930 up_write(&dev_replace
->rwsem
);
931 mutex_unlock(&fs_info
->chunk_mutex
);
932 mutex_unlock(&fs_devices
->device_list_mutex
);
933 btrfs_rm_dev_replace_blocked(fs_info
);
935 btrfs_destroy_dev_replace_tgtdev(tgt_device
);
936 btrfs_rm_dev_replace_unblocked(fs_info
);
937 mutex_unlock(&dev_replace
->lock_finishing_cancel_unmount
);
942 btrfs_info_in_rcu(fs_info
,
943 "dev_replace from %s (devid %llu) to %s finished",
944 btrfs_dev_name(src_device
),
946 btrfs_dev_name(tgt_device
));
947 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT
, &tgt_device
->dev_state
);
948 tgt_device
->devid
= src_device
->devid
;
949 src_device
->devid
= BTRFS_DEV_REPLACE_DEVID
;
950 memcpy(uuid_tmp
, tgt_device
->uuid
, sizeof(uuid_tmp
));
951 memcpy(tgt_device
->uuid
, src_device
->uuid
, sizeof(tgt_device
->uuid
));
952 memcpy(src_device
->uuid
, uuid_tmp
, sizeof(src_device
->uuid
));
953 btrfs_device_set_total_bytes(tgt_device
, src_device
->total_bytes
);
954 btrfs_device_set_disk_total_bytes(tgt_device
,
955 src_device
->disk_total_bytes
);
956 btrfs_device_set_bytes_used(tgt_device
, src_device
->bytes_used
);
957 tgt_device
->commit_bytes_used
= src_device
->bytes_used
;
959 btrfs_assign_next_active_device(src_device
, tgt_device
);
961 list_add(&tgt_device
->dev_alloc_list
, &fs_devices
->alloc_list
);
962 fs_devices
->rw_devices
++;
964 up_write(&dev_replace
->rwsem
);
965 btrfs_rm_dev_replace_blocked(fs_info
);
967 btrfs_rm_dev_replace_remove_srcdev(src_device
);
969 btrfs_rm_dev_replace_unblocked(fs_info
);
972 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will
973 * update on-disk dev stats value during commit transaction
975 atomic_inc(&tgt_device
->dev_stats_ccnt
);
978 * this is again a consistent state where no dev_replace procedure
979 * is running, the target device is part of the filesystem, the
980 * source device is not part of the filesystem anymore and its 1st
981 * superblock is scratched out so that it is no longer marked to
982 * belong to this filesystem.
984 mutex_unlock(&fs_info
->chunk_mutex
);
985 mutex_unlock(&fs_devices
->device_list_mutex
);
987 /* replace the sysfs entry */
988 btrfs_sysfs_remove_device(src_device
);
989 btrfs_sysfs_update_devid(tgt_device
);
990 if (test_bit(BTRFS_DEV_STATE_WRITEABLE
, &src_device
->dev_state
))
991 btrfs_scratch_superblocks(fs_info
, src_device
->bdev
,
992 src_device
->name
->str
);
994 /* write back the superblocks */
995 trans
= btrfs_start_transaction(root
, 0);
997 btrfs_commit_transaction(trans
);
999 mutex_unlock(&dev_replace
->lock_finishing_cancel_unmount
);
1001 btrfs_rm_dev_replace_free_srcdev(src_device
);
1007 * Read progress of device replace status according to the state and last
1008 * stored position. The value format is the same as for
1009 * btrfs_dev_replace::progress_1000
1011 static u64
btrfs_dev_replace_progress(struct btrfs_fs_info
*fs_info
)
1013 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
1016 switch (dev_replace
->replace_state
) {
1017 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED
:
1018 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
:
1021 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED
:
1024 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
:
1025 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
:
1026 ret
= div64_u64(dev_replace
->cursor_left
,
1027 div_u64(btrfs_device_get_total_bytes(
1028 dev_replace
->srcdev
), 1000));
1035 void btrfs_dev_replace_status(struct btrfs_fs_info
*fs_info
,
1036 struct btrfs_ioctl_dev_replace_args
*args
)
1038 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
1040 down_read(&dev_replace
->rwsem
);
1041 /* even if !dev_replace_is_valid, the values are good enough for
1042 * the replace_status ioctl */
1043 args
->result
= BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR
;
1044 args
->status
.replace_state
= dev_replace
->replace_state
;
1045 args
->status
.time_started
= dev_replace
->time_started
;
1046 args
->status
.time_stopped
= dev_replace
->time_stopped
;
1047 args
->status
.num_write_errors
=
1048 atomic64_read(&dev_replace
->num_write_errors
);
1049 args
->status
.num_uncorrectable_read_errors
=
1050 atomic64_read(&dev_replace
->num_uncorrectable_read_errors
);
1051 args
->status
.progress_1000
= btrfs_dev_replace_progress(fs_info
);
1052 up_read(&dev_replace
->rwsem
);
1055 int btrfs_dev_replace_cancel(struct btrfs_fs_info
*fs_info
)
1057 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
1058 struct btrfs_device
*tgt_device
= NULL
;
1059 struct btrfs_device
*src_device
= NULL
;
1060 struct btrfs_trans_handle
*trans
;
1061 struct btrfs_root
*root
= fs_info
->tree_root
;
1065 if (sb_rdonly(fs_info
->sb
))
1068 mutex_lock(&dev_replace
->lock_finishing_cancel_unmount
);
1069 down_write(&dev_replace
->rwsem
);
1070 switch (dev_replace
->replace_state
) {
1071 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED
:
1072 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED
:
1073 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
:
1074 result
= BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED
;
1075 up_write(&dev_replace
->rwsem
);
1077 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
:
1078 tgt_device
= dev_replace
->tgtdev
;
1079 src_device
= dev_replace
->srcdev
;
1080 up_write(&dev_replace
->rwsem
);
1081 ret
= btrfs_scrub_cancel(fs_info
);
1083 result
= BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED
;
1085 result
= BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR
;
1087 * btrfs_dev_replace_finishing() will handle the
1090 btrfs_info_in_rcu(fs_info
,
1091 "dev_replace from %s (devid %llu) to %s canceled",
1092 btrfs_dev_name(src_device
), src_device
->devid
,
1093 btrfs_dev_name(tgt_device
));
1096 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
:
1098 * Scrub doing the replace isn't running so we need to do the
1099 * cleanup step of btrfs_dev_replace_finishing() here
1101 result
= BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR
;
1102 tgt_device
= dev_replace
->tgtdev
;
1103 src_device
= dev_replace
->srcdev
;
1104 dev_replace
->tgtdev
= NULL
;
1105 dev_replace
->srcdev
= NULL
;
1106 dev_replace
->replace_state
=
1107 BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
;
1108 dev_replace
->time_stopped
= ktime_get_real_seconds();
1109 dev_replace
->item_needs_writeback
= 1;
1111 up_write(&dev_replace
->rwsem
);
1113 /* Scrub for replace must not be running in suspended state */
1114 btrfs_scrub_cancel(fs_info
);
1116 trans
= btrfs_start_transaction(root
, 0);
1117 if (IS_ERR(trans
)) {
1118 mutex_unlock(&dev_replace
->lock_finishing_cancel_unmount
);
1119 return PTR_ERR(trans
);
1121 ret
= btrfs_commit_transaction(trans
);
1124 btrfs_info_in_rcu(fs_info
,
1125 "suspended dev_replace from %s (devid %llu) to %s canceled",
1126 btrfs_dev_name(src_device
), src_device
->devid
,
1127 btrfs_dev_name(tgt_device
));
1130 btrfs_destroy_dev_replace_tgtdev(tgt_device
);
1133 up_write(&dev_replace
->rwsem
);
1137 mutex_unlock(&dev_replace
->lock_finishing_cancel_unmount
);
1141 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info
*fs_info
)
1143 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
1145 mutex_lock(&dev_replace
->lock_finishing_cancel_unmount
);
1146 down_write(&dev_replace
->rwsem
);
1148 switch (dev_replace
->replace_state
) {
1149 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED
:
1150 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED
:
1151 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
:
1152 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
:
1154 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
:
1155 dev_replace
->replace_state
=
1156 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
;
1157 dev_replace
->time_stopped
= ktime_get_real_seconds();
1158 dev_replace
->item_needs_writeback
= 1;
1159 btrfs_info(fs_info
, "suspending dev_replace for unmount");
1163 up_write(&dev_replace
->rwsem
);
1164 mutex_unlock(&dev_replace
->lock_finishing_cancel_unmount
);
1167 /* resume dev_replace procedure that was interrupted by unmount */
1168 int btrfs_resume_dev_replace_async(struct btrfs_fs_info
*fs_info
)
1170 struct task_struct
*task
;
1171 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
1173 down_write(&dev_replace
->rwsem
);
1175 switch (dev_replace
->replace_state
) {
1176 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED
:
1177 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED
:
1178 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
:
1179 up_write(&dev_replace
->rwsem
);
1181 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
:
1183 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
:
1184 dev_replace
->replace_state
=
1185 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
;
1188 if (!dev_replace
->tgtdev
|| !dev_replace
->tgtdev
->bdev
) {
1190 "cannot continue dev_replace, tgtdev is missing");
1192 "you may cancel the operation after 'mount -o degraded'");
1193 dev_replace
->replace_state
=
1194 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
;
1195 up_write(&dev_replace
->rwsem
);
1198 up_write(&dev_replace
->rwsem
);
1201 * This could collide with a paused balance, but the exclusive op logic
1202 * should never allow both to start and pause. We don't want to allow
1203 * dev-replace to start anyway.
1205 if (!btrfs_exclop_start(fs_info
, BTRFS_EXCLOP_DEV_REPLACE
)) {
1206 down_write(&dev_replace
->rwsem
);
1207 dev_replace
->replace_state
=
1208 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
;
1209 up_write(&dev_replace
->rwsem
);
1211 "cannot resume dev-replace, other exclusive operation running");
1215 task
= kthread_run(btrfs_dev_replace_kthread
, fs_info
, "btrfs-devrepl");
1216 return PTR_ERR_OR_ZERO(task
);
1219 static int btrfs_dev_replace_kthread(void *data
)
1221 struct btrfs_fs_info
*fs_info
= data
;
1222 struct btrfs_dev_replace
*dev_replace
= &fs_info
->dev_replace
;
1226 progress
= btrfs_dev_replace_progress(fs_info
);
1227 progress
= div_u64(progress
, 10);
1228 btrfs_info_in_rcu(fs_info
,
1229 "continuing dev_replace from %s (devid %llu) to target %s @%u%%",
1230 btrfs_dev_name(dev_replace
->srcdev
),
1231 dev_replace
->srcdev
->devid
,
1232 btrfs_dev_name(dev_replace
->tgtdev
),
1233 (unsigned int)progress
);
1235 ret
= btrfs_scrub_dev(fs_info
, dev_replace
->srcdev
->devid
,
1236 dev_replace
->committed_cursor_left
,
1237 btrfs_device_get_total_bytes(dev_replace
->srcdev
),
1238 &dev_replace
->scrub_progress
, 0, 1);
1239 ret
= btrfs_dev_replace_finishing(fs_info
, ret
);
1240 WARN_ON(ret
&& ret
!= -ECANCELED
);
1242 btrfs_exclop_finish(fs_info
);
1246 int __pure
btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace
*dev_replace
)
1248 if (!dev_replace
->is_valid
)
1251 switch (dev_replace
->replace_state
) {
1252 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED
:
1253 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED
:
1254 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
:
1256 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED
:
1257 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED
:
1259 * return true even if tgtdev is missing (this is
1260 * something that can happen if the dev_replace
1261 * procedure is suspended by an umount and then
1262 * the tgtdev is missing (or "btrfs dev scan") was
1263 * not called and the filesystem is remounted
1264 * in degraded state. This does not stop the
1265 * dev_replace procedure. It needs to be canceled
1266 * manually if the cancellation is wanted.
1273 void btrfs_bio_counter_sub(struct btrfs_fs_info
*fs_info
, s64 amount
)
1275 percpu_counter_sub(&fs_info
->dev_replace
.bio_counter
, amount
);
1276 cond_wake_up_nomb(&fs_info
->dev_replace
.replace_wait
);
1279 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info
*fs_info
)
1282 percpu_counter_inc(&fs_info
->dev_replace
.bio_counter
);
1283 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING
,
1284 &fs_info
->fs_state
)))
1287 btrfs_bio_counter_dec(fs_info
);
1288 wait_event(fs_info
->dev_replace
.replace_wait
,
1289 !test_bit(BTRFS_FS_STATE_DEV_REPLACING
,
1290 &fs_info
->fs_state
));