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1/*
2 * Copyright (C) STRATO AG 2012. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18#include <linux/sched.h>
19#include <linux/bio.h>
20#include <linux/slab.h>
21#include <linux/buffer_head.h>
22#include <linux/blkdev.h>
23#include <linux/random.h>
24#include <linux/iocontext.h>
25#include <linux/capability.h>
26#include <linux/kthread.h>
27#include <linux/math64.h>
28#include <asm/div64.h>
29#include "ctree.h"
30#include "extent_map.h"
31#include "disk-io.h"
32#include "transaction.h"
33#include "print-tree.h"
34#include "volumes.h"
35#include "async-thread.h"
36#include "check-integrity.h"
37#include "rcu-string.h"
38#include "dev-replace.h"
39#include "sysfs.h"
40
41static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
42 int scrub_ret);
43static void btrfs_dev_replace_update_device_in_mapping_tree(
44 struct btrfs_fs_info *fs_info,
45 struct btrfs_device *srcdev,
46 struct btrfs_device *tgtdev);
47static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
48static int btrfs_dev_replace_kthread(void *data);
49static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
50
51
52int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info)
53{
54 struct btrfs_key key;
55 struct btrfs_root *dev_root = fs_info->dev_root;
56 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
57 struct extent_buffer *eb;
58 int slot;
59 int ret = 0;
60 struct btrfs_path *path = NULL;
61 int item_size;
62 struct btrfs_dev_replace_item *ptr;
63 u64 src_devid;
64
65 path = btrfs_alloc_path();
66 if (!path) {
67 ret = -ENOMEM;
68 goto out;
69 }
70
71 key.objectid = 0;
72 key.type = BTRFS_DEV_REPLACE_KEY;
73 key.offset = 0;
74 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
75 if (ret) {
76no_valid_dev_replace_entry_found:
77 ret = 0;
78 dev_replace->replace_state =
79 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED;
80 dev_replace->cont_reading_from_srcdev_mode =
81 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS;
82 dev_replace->replace_state = 0;
83 dev_replace->time_started = 0;
84 dev_replace->time_stopped = 0;
85 atomic64_set(&dev_replace->num_write_errors, 0);
86 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
87 dev_replace->cursor_left = 0;
88 dev_replace->committed_cursor_left = 0;
89 dev_replace->cursor_left_last_write_of_item = 0;
90 dev_replace->cursor_right = 0;
91 dev_replace->srcdev = NULL;
92 dev_replace->tgtdev = NULL;
93 dev_replace->is_valid = 0;
94 dev_replace->item_needs_writeback = 0;
95 goto out;
96 }
97 slot = path->slots[0];
98 eb = path->nodes[0];
99 item_size = btrfs_item_size_nr(eb, slot);
100 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item);
101
102 if (item_size != sizeof(struct btrfs_dev_replace_item)) {
103 btrfs_warn(fs_info,
104 "dev_replace entry found has unexpected size, ignore entry");
105 goto no_valid_dev_replace_entry_found;
106 }
107
108 src_devid = btrfs_dev_replace_src_devid(eb, ptr);
109 dev_replace->cont_reading_from_srcdev_mode =
110 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr);
111 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr);
112 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr);
113 dev_replace->time_stopped =
114 btrfs_dev_replace_time_stopped(eb, ptr);
115 atomic64_set(&dev_replace->num_write_errors,
116 btrfs_dev_replace_num_write_errors(eb, ptr));
117 atomic64_set(&dev_replace->num_uncorrectable_read_errors,
118 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr));
119 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr);
120 dev_replace->committed_cursor_left = dev_replace->cursor_left;
121 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left;
122 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr);
123 dev_replace->is_valid = 1;
124
125 dev_replace->item_needs_writeback = 0;
126 switch (dev_replace->replace_state) {
127 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
128 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
129 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
130 dev_replace->srcdev = NULL;
131 dev_replace->tgtdev = NULL;
132 break;
133 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
134 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
135 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid,
136 NULL, NULL);
137 dev_replace->tgtdev = btrfs_find_device(fs_info,
138 BTRFS_DEV_REPLACE_DEVID,
139 NULL, NULL);
140 /*
141 * allow 'btrfs dev replace_cancel' if src/tgt device is
142 * missing
143 */
144 if (!dev_replace->srcdev &&
145 !btrfs_test_opt(fs_info, DEGRADED)) {
146 ret = -EIO;
147 btrfs_warn(fs_info,
148 "cannot mount because device replace operation is ongoing and");
149 btrfs_warn(fs_info,
150 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
151 src_devid);
152 }
153 if (!dev_replace->tgtdev &&
154 !btrfs_test_opt(fs_info, DEGRADED)) {
155 ret = -EIO;
156 btrfs_warn(fs_info,
157 "cannot mount because device replace operation is ongoing and");
158 btrfs_warn(fs_info,
159 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
160 BTRFS_DEV_REPLACE_DEVID);
161 }
162 if (dev_replace->tgtdev) {
163 if (dev_replace->srcdev) {
164 dev_replace->tgtdev->total_bytes =
165 dev_replace->srcdev->total_bytes;
166 dev_replace->tgtdev->disk_total_bytes =
167 dev_replace->srcdev->disk_total_bytes;
168 dev_replace->tgtdev->commit_total_bytes =
169 dev_replace->srcdev->commit_total_bytes;
170 dev_replace->tgtdev->bytes_used =
171 dev_replace->srcdev->bytes_used;
172 dev_replace->tgtdev->commit_bytes_used =
173 dev_replace->srcdev->commit_bytes_used;
174 }
175 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1;
176 btrfs_init_dev_replace_tgtdev_for_resume(fs_info,
177 dev_replace->tgtdev);
178 }
179 break;
180 }
181
182out:
183 btrfs_free_path(path);
184 return ret;
185}
186
187/*
188 * called from commit_transaction. Writes changed device replace state to
189 * disk.
190 */
191int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
192 struct btrfs_fs_info *fs_info)
193{
194 int ret;
195 struct btrfs_root *dev_root = fs_info->dev_root;
196 struct btrfs_path *path;
197 struct btrfs_key key;
198 struct extent_buffer *eb;
199 struct btrfs_dev_replace_item *ptr;
200 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
201
202 btrfs_dev_replace_lock(dev_replace, 0);
203 if (!dev_replace->is_valid ||
204 !dev_replace->item_needs_writeback) {
205 btrfs_dev_replace_unlock(dev_replace, 0);
206 return 0;
207 }
208 btrfs_dev_replace_unlock(dev_replace, 0);
209
210 key.objectid = 0;
211 key.type = BTRFS_DEV_REPLACE_KEY;
212 key.offset = 0;
213
214 path = btrfs_alloc_path();
215 if (!path) {
216 ret = -ENOMEM;
217 goto out;
218 }
219 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
220 if (ret < 0) {
221 btrfs_warn(fs_info,
222 "error %d while searching for dev_replace item!",
223 ret);
224 goto out;
225 }
226
227 if (ret == 0 &&
228 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
229 /*
230 * need to delete old one and insert a new one.
231 * Since no attempt is made to recover any old state, if the
232 * dev_replace state is 'running', the data on the target
233 * drive is lost.
234 * It would be possible to recover the state: just make sure
235 * that the beginning of the item is never changed and always
236 * contains all the essential information. Then read this
237 * minimal set of information and use it as a base for the
238 * new state.
239 */
240 ret = btrfs_del_item(trans, dev_root, path);
241 if (ret != 0) {
242 btrfs_warn(fs_info,
243 "delete too small dev_replace item failed %d!",
244 ret);
245 goto out;
246 }
247 ret = 1;
248 }
249
250 if (ret == 1) {
251 /* need to insert a new item */
252 btrfs_release_path(path);
253 ret = btrfs_insert_empty_item(trans, dev_root, path,
254 &key, sizeof(*ptr));
255 if (ret < 0) {
256 btrfs_warn(fs_info,
257 "insert dev_replace item failed %d!", ret);
258 goto out;
259 }
260 }
261
262 eb = path->nodes[0];
263 ptr = btrfs_item_ptr(eb, path->slots[0],
264 struct btrfs_dev_replace_item);
265
266 btrfs_dev_replace_lock(dev_replace, 1);
267 if (dev_replace->srcdev)
268 btrfs_set_dev_replace_src_devid(eb, ptr,
269 dev_replace->srcdev->devid);
270 else
271 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1);
272 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr,
273 dev_replace->cont_reading_from_srcdev_mode);
274 btrfs_set_dev_replace_replace_state(eb, ptr,
275 dev_replace->replace_state);
276 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started);
277 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped);
278 btrfs_set_dev_replace_num_write_errors(eb, ptr,
279 atomic64_read(&dev_replace->num_write_errors));
280 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr,
281 atomic64_read(&dev_replace->num_uncorrectable_read_errors));
282 dev_replace->cursor_left_last_write_of_item =
283 dev_replace->cursor_left;
284 btrfs_set_dev_replace_cursor_left(eb, ptr,
285 dev_replace->cursor_left_last_write_of_item);
286 btrfs_set_dev_replace_cursor_right(eb, ptr,
287 dev_replace->cursor_right);
288 dev_replace->item_needs_writeback = 0;
289 btrfs_dev_replace_unlock(dev_replace, 1);
290
291 btrfs_mark_buffer_dirty(eb);
292
293out:
294 btrfs_free_path(path);
295
296 return ret;
297}
298
299void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
300{
301 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
302
303 dev_replace->committed_cursor_left =
304 dev_replace->cursor_left_last_write_of_item;
305}
306
307int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, char *tgtdev_name,
308 u64 srcdevid, char *srcdev_name, int read_src)
309{
310 struct btrfs_root *root = fs_info->dev_root;
311 struct btrfs_trans_handle *trans;
312 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
313 int ret;
314 struct btrfs_device *tgt_device = NULL;
315 struct btrfs_device *src_device = NULL;
316
317 /* the disk copy procedure reuses the scrub code */
318 mutex_lock(&fs_info->volume_mutex);
319 ret = btrfs_find_device_by_devspec(fs_info, srcdevid,
320 srcdev_name, &src_device);
321 if (ret) {
322 mutex_unlock(&fs_info->volume_mutex);
323 return ret;
324 }
325
326 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name,
327 src_device, &tgt_device);
328 mutex_unlock(&fs_info->volume_mutex);
329 if (ret)
330 return ret;
331
332 /*
333 * Here we commit the transaction to make sure commit_total_bytes
334 * of all the devices are updated.
335 */
336 trans = btrfs_attach_transaction(root);
337 if (!IS_ERR(trans)) {
338 ret = btrfs_commit_transaction(trans);
339 if (ret)
340 return ret;
341 } else if (PTR_ERR(trans) != -ENOENT) {
342 return PTR_ERR(trans);
343 }
344
345 btrfs_dev_replace_lock(dev_replace, 1);
346 switch (dev_replace->replace_state) {
347 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
348 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
349 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
350 break;
351 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
352 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
353 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
354 goto leave;
355 }
356
357 dev_replace->cont_reading_from_srcdev_mode = read_src;
358 WARN_ON(!src_device);
359 dev_replace->srcdev = src_device;
360 WARN_ON(!tgt_device);
361 dev_replace->tgtdev = tgt_device;
362
363 btrfs_info_in_rcu(fs_info,
364 "dev_replace from %s (devid %llu) to %s started",
365 src_device->missing ? "<missing disk>" :
366 rcu_str_deref(src_device->name),
367 src_device->devid,
368 rcu_str_deref(tgt_device->name));
369
370 /*
371 * from now on, the writes to the srcdev are all duplicated to
372 * go to the tgtdev as well (refer to btrfs_map_block()).
373 */
374 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
375 dev_replace->time_started = get_seconds();
376 dev_replace->cursor_left = 0;
377 dev_replace->committed_cursor_left = 0;
378 dev_replace->cursor_left_last_write_of_item = 0;
379 dev_replace->cursor_right = 0;
380 dev_replace->is_valid = 1;
381 dev_replace->item_needs_writeback = 1;
382 atomic64_set(&dev_replace->num_write_errors, 0);
383 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
384 btrfs_dev_replace_unlock(dev_replace, 1);
385
386 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device);
387 if (ret)
388 btrfs_err(fs_info, "kobj add dev failed %d", ret);
389
390 btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1);
391
392 /* force writing the updated state information to disk */
393 trans = btrfs_start_transaction(root, 0);
394 if (IS_ERR(trans)) {
395 ret = PTR_ERR(trans);
396 btrfs_dev_replace_lock(dev_replace, 1);
397 goto leave;
398 }
399
400 ret = btrfs_commit_transaction(trans);
401 WARN_ON(ret);
402
403 /* the disk copy procedure reuses the scrub code */
404 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
405 btrfs_device_get_total_bytes(src_device),
406 &dev_replace->scrub_progress, 0, 1);
407
408 ret = btrfs_dev_replace_finishing(fs_info, ret);
409 if (ret == -EINPROGRESS) {
410 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
411 } else {
412 WARN_ON(ret);
413 }
414
415 return ret;
416
417leave:
418 dev_replace->srcdev = NULL;
419 dev_replace->tgtdev = NULL;
420 btrfs_dev_replace_unlock(dev_replace, 1);
421 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
422 return ret;
423}
424
425int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info,
426 struct btrfs_ioctl_dev_replace_args *args)
427{
428 int ret;
429
430 switch (args->start.cont_reading_from_srcdev_mode) {
431 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
432 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
433 break;
434 default:
435 return -EINVAL;
436 }
437
438 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
439 args->start.tgtdev_name[0] == '\0')
440 return -EINVAL;
441
442 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name,
443 args->start.srcdevid,
444 args->start.srcdev_name,
445 args->start.cont_reading_from_srcdev_mode);
446 args->result = ret;
447 /* don't warn if EINPROGRESS, someone else might be running scrub */
448 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS)
449 ret = 0;
450
451 return ret;
452}
453
454/*
455 * blocked until all in-flight bios operations are finished.
456 */
457static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
458{
459 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
460 wait_event(fs_info->replace_wait, !percpu_counter_sum(
461 &fs_info->bio_counter));
462}
463
464/*
465 * we have removed target device, it is safe to allow new bios request.
466 */
467static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info)
468{
469 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
470 wake_up(&fs_info->replace_wait);
471}
472
473static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
474 int scrub_ret)
475{
476 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
477 struct btrfs_device *tgt_device;
478 struct btrfs_device *src_device;
479 struct btrfs_root *root = fs_info->tree_root;
480 u8 uuid_tmp[BTRFS_UUID_SIZE];
481 struct btrfs_trans_handle *trans;
482 int ret = 0;
483
484 /* don't allow cancel or unmount to disturb the finishing procedure */
485 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
486
487 btrfs_dev_replace_lock(dev_replace, 0);
488 /* was the operation canceled, or is it finished? */
489 if (dev_replace->replace_state !=
490 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
491 btrfs_dev_replace_unlock(dev_replace, 0);
492 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
493 return 0;
494 }
495
496 tgt_device = dev_replace->tgtdev;
497 src_device = dev_replace->srcdev;
498 btrfs_dev_replace_unlock(dev_replace, 0);
499
500 /*
501 * flush all outstanding I/O and inode extent mappings before the
502 * copy operation is declared as being finished
503 */
504 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
505 if (ret) {
506 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
507 return ret;
508 }
509 btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1);
510
511 trans = btrfs_start_transaction(root, 0);
512 if (IS_ERR(trans)) {
513 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
514 return PTR_ERR(trans);
515 }
516 ret = btrfs_commit_transaction(trans);
517 WARN_ON(ret);
518
519 mutex_lock(&uuid_mutex);
520 /* keep away write_all_supers() during the finishing procedure */
521 mutex_lock(&fs_info->fs_devices->device_list_mutex);
522 mutex_lock(&fs_info->chunk_mutex);
523 btrfs_dev_replace_lock(dev_replace, 1);
524 dev_replace->replace_state =
525 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
526 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
527 dev_replace->tgtdev = NULL;
528 dev_replace->srcdev = NULL;
529 dev_replace->time_stopped = get_seconds();
530 dev_replace->item_needs_writeback = 1;
531
532 /* replace old device with new one in mapping tree */
533 if (!scrub_ret) {
534 btrfs_dev_replace_update_device_in_mapping_tree(fs_info,
535 src_device,
536 tgt_device);
537 } else {
538 btrfs_err_in_rcu(fs_info,
539 "btrfs_scrub_dev(%s, %llu, %s) failed %d",
540 src_device->missing ? "<missing disk>" :
541 rcu_str_deref(src_device->name),
542 src_device->devid,
543 rcu_str_deref(tgt_device->name), scrub_ret);
544 btrfs_dev_replace_unlock(dev_replace, 1);
545 mutex_unlock(&fs_info->chunk_mutex);
546 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
547 mutex_unlock(&uuid_mutex);
548 if (tgt_device)
549 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
550 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
551
552 return scrub_ret;
553 }
554
555 btrfs_info_in_rcu(fs_info,
556 "dev_replace from %s (devid %llu) to %s finished",
557 src_device->missing ? "<missing disk>" :
558 rcu_str_deref(src_device->name),
559 src_device->devid,
560 rcu_str_deref(tgt_device->name));
561 tgt_device->is_tgtdev_for_dev_replace = 0;
562 tgt_device->devid = src_device->devid;
563 src_device->devid = BTRFS_DEV_REPLACE_DEVID;
564 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp));
565 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid));
566 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid));
567 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes);
568 btrfs_device_set_disk_total_bytes(tgt_device,
569 src_device->disk_total_bytes);
570 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used);
571 ASSERT(list_empty(&src_device->resized_list));
572 tgt_device->commit_total_bytes = src_device->commit_total_bytes;
573 tgt_device->commit_bytes_used = src_device->bytes_used;
574
575 btrfs_assign_next_active_device(fs_info, src_device, tgt_device);
576
577 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
578 fs_info->fs_devices->rw_devices++;
579
580 btrfs_dev_replace_unlock(dev_replace, 1);
581
582 btrfs_rm_dev_replace_blocked(fs_info);
583
584 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device);
585
586 btrfs_rm_dev_replace_unblocked(fs_info);
587
588 /*
589 * this is again a consistent state where no dev_replace procedure
590 * is running, the target device is part of the filesystem, the
591 * source device is not part of the filesystem anymore and its 1st
592 * superblock is scratched out so that it is no longer marked to
593 * belong to this filesystem.
594 */
595 mutex_unlock(&fs_info->chunk_mutex);
596 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
597 mutex_unlock(&uuid_mutex);
598
599 /* replace the sysfs entry */
600 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device);
601 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device);
602
603 /* write back the superblocks */
604 trans = btrfs_start_transaction(root, 0);
605 if (!IS_ERR(trans))
606 btrfs_commit_transaction(trans);
607
608 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
609
610 return 0;
611}
612
613static void btrfs_dev_replace_update_device_in_mapping_tree(
614 struct btrfs_fs_info *fs_info,
615 struct btrfs_device *srcdev,
616 struct btrfs_device *tgtdev)
617{
618 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
619 struct extent_map *em;
620 struct map_lookup *map;
621 u64 start = 0;
622 int i;
623
624 write_lock(&em_tree->lock);
625 do {
626 em = lookup_extent_mapping(em_tree, start, (u64)-1);
627 if (!em)
628 break;
629 map = em->map_lookup;
630 for (i = 0; i < map->num_stripes; i++)
631 if (srcdev == map->stripes[i].dev)
632 map->stripes[i].dev = tgtdev;
633 start = em->start + em->len;
634 free_extent_map(em);
635 } while (start);
636 write_unlock(&em_tree->lock);
637}
638
639void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
640 struct btrfs_ioctl_dev_replace_args *args)
641{
642 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
643 struct btrfs_device *srcdev;
644
645 btrfs_dev_replace_lock(dev_replace, 0);
646 /* even if !dev_replace_is_valid, the values are good enough for
647 * the replace_status ioctl */
648 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
649 args->status.replace_state = dev_replace->replace_state;
650 args->status.time_started = dev_replace->time_started;
651 args->status.time_stopped = dev_replace->time_stopped;
652 args->status.num_write_errors =
653 atomic64_read(&dev_replace->num_write_errors);
654 args->status.num_uncorrectable_read_errors =
655 atomic64_read(&dev_replace->num_uncorrectable_read_errors);
656 switch (dev_replace->replace_state) {
657 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
658 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
659 args->status.progress_1000 = 0;
660 break;
661 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
662 args->status.progress_1000 = 1000;
663 break;
664 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
665 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
666 srcdev = dev_replace->srcdev;
667 args->status.progress_1000 = div_u64(dev_replace->cursor_left,
668 div_u64(btrfs_device_get_total_bytes(srcdev), 1000));
669 break;
670 }
671 btrfs_dev_replace_unlock(dev_replace, 0);
672}
673
674int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
675 struct btrfs_ioctl_dev_replace_args *args)
676{
677 args->result = __btrfs_dev_replace_cancel(fs_info);
678 return 0;
679}
680
681static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
682{
683 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
684 struct btrfs_device *tgt_device = NULL;
685 struct btrfs_trans_handle *trans;
686 struct btrfs_root *root = fs_info->tree_root;
687 u64 result;
688 int ret;
689
690 if (fs_info->sb->s_flags & MS_RDONLY)
691 return -EROFS;
692
693 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
694 btrfs_dev_replace_lock(dev_replace, 1);
695 switch (dev_replace->replace_state) {
696 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
697 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
698 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
699 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
700 btrfs_dev_replace_unlock(dev_replace, 1);
701 goto leave;
702 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
703 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
704 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
705 tgt_device = dev_replace->tgtdev;
706 dev_replace->tgtdev = NULL;
707 dev_replace->srcdev = NULL;
708 break;
709 }
710 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
711 dev_replace->time_stopped = get_seconds();
712 dev_replace->item_needs_writeback = 1;
713 btrfs_dev_replace_unlock(dev_replace, 1);
714 btrfs_scrub_cancel(fs_info);
715
716 trans = btrfs_start_transaction(root, 0);
717 if (IS_ERR(trans)) {
718 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
719 return PTR_ERR(trans);
720 }
721 ret = btrfs_commit_transaction(trans);
722 WARN_ON(ret);
723 if (tgt_device)
724 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
725
726leave:
727 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
728 return result;
729}
730
731void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info)
732{
733 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
734
735 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
736 btrfs_dev_replace_lock(dev_replace, 1);
737 switch (dev_replace->replace_state) {
738 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
739 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
740 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
741 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
742 break;
743 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
744 dev_replace->replace_state =
745 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
746 dev_replace->time_stopped = get_seconds();
747 dev_replace->item_needs_writeback = 1;
748 btrfs_info(fs_info, "suspending dev_replace for unmount");
749 break;
750 }
751
752 btrfs_dev_replace_unlock(dev_replace, 1);
753 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
754}
755
756/* resume dev_replace procedure that was interrupted by unmount */
757int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
758{
759 struct task_struct *task;
760 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
761
762 btrfs_dev_replace_lock(dev_replace, 1);
763 switch (dev_replace->replace_state) {
764 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
765 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
766 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
767 btrfs_dev_replace_unlock(dev_replace, 1);
768 return 0;
769 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
770 break;
771 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
772 dev_replace->replace_state =
773 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
774 break;
775 }
776 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) {
777 btrfs_info(fs_info,
778 "cannot continue dev_replace, tgtdev is missing");
779 btrfs_info(fs_info,
780 "you may cancel the operation after 'mount -o degraded'");
781 btrfs_dev_replace_unlock(dev_replace, 1);
782 return 0;
783 }
784 btrfs_dev_replace_unlock(dev_replace, 1);
785
786 WARN_ON(atomic_xchg(
787 &fs_info->mutually_exclusive_operation_running, 1));
788 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
789 return PTR_ERR_OR_ZERO(task);
790}
791
792static int btrfs_dev_replace_kthread(void *data)
793{
794 struct btrfs_fs_info *fs_info = data;
795 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
796 struct btrfs_ioctl_dev_replace_args *status_args;
797 u64 progress;
798
799 status_args = kzalloc(sizeof(*status_args), GFP_KERNEL);
800 if (status_args) {
801 btrfs_dev_replace_status(fs_info, status_args);
802 progress = status_args->status.progress_1000;
803 kfree(status_args);
804 progress = div_u64(progress, 10);
805 btrfs_info_in_rcu(fs_info,
806 "continuing dev_replace from %s (devid %llu) to %s @%u%%",
807 dev_replace->srcdev->missing ? "<missing disk>" :
808 rcu_str_deref(dev_replace->srcdev->name),
809 dev_replace->srcdev->devid,
810 dev_replace->tgtdev ?
811 rcu_str_deref(dev_replace->tgtdev->name) :
812 "<missing target disk>",
813 (unsigned int)progress);
814 }
815 btrfs_dev_replace_continue_on_mount(fs_info);
816 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
817
818 return 0;
819}
820
821static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info)
822{
823 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
824 int ret;
825
826 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid,
827 dev_replace->committed_cursor_left,
828 btrfs_device_get_total_bytes(dev_replace->srcdev),
829 &dev_replace->scrub_progress, 0, 1);
830 ret = btrfs_dev_replace_finishing(fs_info, ret);
831 WARN_ON(ret);
832 return 0;
833}
834
835int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
836{
837 if (!dev_replace->is_valid)
838 return 0;
839
840 switch (dev_replace->replace_state) {
841 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
842 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
843 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
844 return 0;
845 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
846 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
847 /*
848 * return true even if tgtdev is missing (this is
849 * something that can happen if the dev_replace
850 * procedure is suspended by an umount and then
851 * the tgtdev is missing (or "btrfs dev scan") was
852 * not called and the the filesystem is remounted
853 * in degraded state. This does not stop the
854 * dev_replace procedure. It needs to be canceled
855 * manually if the cancellation is wanted.
856 */
857 break;
858 }
859 return 1;
860}
861
862void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw)
863{
864 if (rw == 1) {
865 /* write */
866again:
867 wait_event(dev_replace->read_lock_wq,
868 atomic_read(&dev_replace->blocking_readers) == 0);
869 write_lock(&dev_replace->lock);
870 if (atomic_read(&dev_replace->blocking_readers)) {
871 write_unlock(&dev_replace->lock);
872 goto again;
873 }
874 } else {
875 read_lock(&dev_replace->lock);
876 atomic_inc(&dev_replace->read_locks);
877 }
878}
879
880void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw)
881{
882 if (rw == 1) {
883 /* write */
884 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0);
885 write_unlock(&dev_replace->lock);
886 } else {
887 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
888 atomic_dec(&dev_replace->read_locks);
889 read_unlock(&dev_replace->lock);
890 }
891}
892
893/* inc blocking cnt and release read lock */
894void btrfs_dev_replace_set_lock_blocking(
895 struct btrfs_dev_replace *dev_replace)
896{
897 /* only set blocking for read lock */
898 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
899 atomic_inc(&dev_replace->blocking_readers);
900 read_unlock(&dev_replace->lock);
901}
902
903/* acquire read lock and dec blocking cnt */
904void btrfs_dev_replace_clear_lock_blocking(
905 struct btrfs_dev_replace *dev_replace)
906{
907 /* only set blocking for read lock */
908 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
909 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0);
910 read_lock(&dev_replace->lock);
911 if (atomic_dec_and_test(&dev_replace->blocking_readers) &&
912 waitqueue_active(&dev_replace->read_lock_wq))
913 wake_up(&dev_replace->read_lock_wq);
914}
915
916void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
917{
918 percpu_counter_inc(&fs_info->bio_counter);
919}
920
921void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount)
922{
923 percpu_counter_sub(&fs_info->bio_counter, amount);
924
925 if (waitqueue_active(&fs_info->replace_wait))
926 wake_up(&fs_info->replace_wait);
927}
928
929void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
930{
931 while (1) {
932 percpu_counter_inc(&fs_info->bio_counter);
933 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING,
934 &fs_info->fs_state)))
935 break;
936
937 btrfs_bio_counter_dec(fs_info);
938 wait_event(fs_info->replace_wait,
939 !test_bit(BTRFS_FS_STATE_DEV_REPLACING,
940 &fs_info->fs_state));
941 }
942}
1/*
2 * Copyright (C) STRATO AG 2012. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18#include <linux/sched.h>
19#include <linux/bio.h>
20#include <linux/slab.h>
21#include <linux/buffer_head.h>
22#include <linux/blkdev.h>
23#include <linux/random.h>
24#include <linux/iocontext.h>
25#include <linux/capability.h>
26#include <linux/kthread.h>
27#include <linux/math64.h>
28#include <asm/div64.h>
29#include "ctree.h"
30#include "extent_map.h"
31#include "disk-io.h"
32#include "transaction.h"
33#include "print-tree.h"
34#include "volumes.h"
35#include "async-thread.h"
36#include "check-integrity.h"
37#include "rcu-string.h"
38#include "dev-replace.h"
39
40static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
41 int scrub_ret);
42static void btrfs_dev_replace_update_device_in_mapping_tree(
43 struct btrfs_fs_info *fs_info,
44 struct btrfs_device *srcdev,
45 struct btrfs_device *tgtdev);
46static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
47 char *srcdev_name,
48 struct btrfs_device **device);
49static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
50static int btrfs_dev_replace_kthread(void *data);
51static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
52
53
54int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info)
55{
56 struct btrfs_key key;
57 struct btrfs_root *dev_root = fs_info->dev_root;
58 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
59 struct extent_buffer *eb;
60 int slot;
61 int ret = 0;
62 struct btrfs_path *path = NULL;
63 int item_size;
64 struct btrfs_dev_replace_item *ptr;
65 u64 src_devid;
66
67 path = btrfs_alloc_path();
68 if (!path) {
69 ret = -ENOMEM;
70 goto out;
71 }
72
73 key.objectid = 0;
74 key.type = BTRFS_DEV_REPLACE_KEY;
75 key.offset = 0;
76 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
77 if (ret) {
78no_valid_dev_replace_entry_found:
79 ret = 0;
80 dev_replace->replace_state =
81 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED;
82 dev_replace->cont_reading_from_srcdev_mode =
83 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS;
84 dev_replace->replace_state = 0;
85 dev_replace->time_started = 0;
86 dev_replace->time_stopped = 0;
87 atomic64_set(&dev_replace->num_write_errors, 0);
88 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
89 dev_replace->cursor_left = 0;
90 dev_replace->committed_cursor_left = 0;
91 dev_replace->cursor_left_last_write_of_item = 0;
92 dev_replace->cursor_right = 0;
93 dev_replace->srcdev = NULL;
94 dev_replace->tgtdev = NULL;
95 dev_replace->is_valid = 0;
96 dev_replace->item_needs_writeback = 0;
97 goto out;
98 }
99 slot = path->slots[0];
100 eb = path->nodes[0];
101 item_size = btrfs_item_size_nr(eb, slot);
102 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item);
103
104 if (item_size != sizeof(struct btrfs_dev_replace_item)) {
105 btrfs_warn(fs_info,
106 "dev_replace entry found has unexpected size, ignore entry");
107 goto no_valid_dev_replace_entry_found;
108 }
109
110 src_devid = btrfs_dev_replace_src_devid(eb, ptr);
111 dev_replace->cont_reading_from_srcdev_mode =
112 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr);
113 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr);
114 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr);
115 dev_replace->time_stopped =
116 btrfs_dev_replace_time_stopped(eb, ptr);
117 atomic64_set(&dev_replace->num_write_errors,
118 btrfs_dev_replace_num_write_errors(eb, ptr));
119 atomic64_set(&dev_replace->num_uncorrectable_read_errors,
120 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr));
121 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr);
122 dev_replace->committed_cursor_left = dev_replace->cursor_left;
123 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left;
124 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr);
125 dev_replace->is_valid = 1;
126
127 dev_replace->item_needs_writeback = 0;
128 switch (dev_replace->replace_state) {
129 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
130 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
131 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
132 dev_replace->srcdev = NULL;
133 dev_replace->tgtdev = NULL;
134 break;
135 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
136 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
137 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid,
138 NULL, NULL);
139 dev_replace->tgtdev = btrfs_find_device(fs_info,
140 BTRFS_DEV_REPLACE_DEVID,
141 NULL, NULL);
142 /*
143 * allow 'btrfs dev replace_cancel' if src/tgt device is
144 * missing
145 */
146 if (!dev_replace->srcdev &&
147 !btrfs_test_opt(dev_root, DEGRADED)) {
148 ret = -EIO;
149 btrfs_warn(fs_info,
150 "cannot mount because device replace operation is ongoing and");
151 btrfs_warn(fs_info,
152 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
153 src_devid);
154 }
155 if (!dev_replace->tgtdev &&
156 !btrfs_test_opt(dev_root, DEGRADED)) {
157 ret = -EIO;
158 btrfs_warn(fs_info,
159 "cannot mount because device replace operation is ongoing and");
160 btrfs_warn(fs_info,
161 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
162 BTRFS_DEV_REPLACE_DEVID);
163 }
164 if (dev_replace->tgtdev) {
165 if (dev_replace->srcdev) {
166 dev_replace->tgtdev->total_bytes =
167 dev_replace->srcdev->total_bytes;
168 dev_replace->tgtdev->disk_total_bytes =
169 dev_replace->srcdev->disk_total_bytes;
170 dev_replace->tgtdev->bytes_used =
171 dev_replace->srcdev->bytes_used;
172 }
173 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1;
174 btrfs_init_dev_replace_tgtdev_for_resume(fs_info,
175 dev_replace->tgtdev);
176 }
177 break;
178 }
179
180out:
181 if (path)
182 btrfs_free_path(path);
183 return ret;
184}
185
186/*
187 * called from commit_transaction. Writes changed device replace state to
188 * disk.
189 */
190int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
191 struct btrfs_fs_info *fs_info)
192{
193 int ret;
194 struct btrfs_root *dev_root = fs_info->dev_root;
195 struct btrfs_path *path;
196 struct btrfs_key key;
197 struct extent_buffer *eb;
198 struct btrfs_dev_replace_item *ptr;
199 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
200
201 btrfs_dev_replace_lock(dev_replace);
202 if (!dev_replace->is_valid ||
203 !dev_replace->item_needs_writeback) {
204 btrfs_dev_replace_unlock(dev_replace);
205 return 0;
206 }
207 btrfs_dev_replace_unlock(dev_replace);
208
209 key.objectid = 0;
210 key.type = BTRFS_DEV_REPLACE_KEY;
211 key.offset = 0;
212
213 path = btrfs_alloc_path();
214 if (!path) {
215 ret = -ENOMEM;
216 goto out;
217 }
218 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
219 if (ret < 0) {
220 btrfs_warn(fs_info, "error %d while searching for dev_replace item!",
221 ret);
222 goto out;
223 }
224
225 if (ret == 0 &&
226 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
227 /*
228 * need to delete old one and insert a new one.
229 * Since no attempt is made to recover any old state, if the
230 * dev_replace state is 'running', the data on the target
231 * drive is lost.
232 * It would be possible to recover the state: just make sure
233 * that the beginning of the item is never changed and always
234 * contains all the essential information. Then read this
235 * minimal set of information and use it as a base for the
236 * new state.
237 */
238 ret = btrfs_del_item(trans, dev_root, path);
239 if (ret != 0) {
240 btrfs_warn(fs_info, "delete too small dev_replace item failed %d!",
241 ret);
242 goto out;
243 }
244 ret = 1;
245 }
246
247 if (ret == 1) {
248 /* need to insert a new item */
249 btrfs_release_path(path);
250 ret = btrfs_insert_empty_item(trans, dev_root, path,
251 &key, sizeof(*ptr));
252 if (ret < 0) {
253 btrfs_warn(fs_info, "insert dev_replace item failed %d!",
254 ret);
255 goto out;
256 }
257 }
258
259 eb = path->nodes[0];
260 ptr = btrfs_item_ptr(eb, path->slots[0],
261 struct btrfs_dev_replace_item);
262
263 btrfs_dev_replace_lock(dev_replace);
264 if (dev_replace->srcdev)
265 btrfs_set_dev_replace_src_devid(eb, ptr,
266 dev_replace->srcdev->devid);
267 else
268 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1);
269 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr,
270 dev_replace->cont_reading_from_srcdev_mode);
271 btrfs_set_dev_replace_replace_state(eb, ptr,
272 dev_replace->replace_state);
273 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started);
274 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped);
275 btrfs_set_dev_replace_num_write_errors(eb, ptr,
276 atomic64_read(&dev_replace->num_write_errors));
277 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr,
278 atomic64_read(&dev_replace->num_uncorrectable_read_errors));
279 dev_replace->cursor_left_last_write_of_item =
280 dev_replace->cursor_left;
281 btrfs_set_dev_replace_cursor_left(eb, ptr,
282 dev_replace->cursor_left_last_write_of_item);
283 btrfs_set_dev_replace_cursor_right(eb, ptr,
284 dev_replace->cursor_right);
285 dev_replace->item_needs_writeback = 0;
286 btrfs_dev_replace_unlock(dev_replace);
287
288 btrfs_mark_buffer_dirty(eb);
289
290out:
291 btrfs_free_path(path);
292
293 return ret;
294}
295
296void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
297{
298 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
299
300 dev_replace->committed_cursor_left =
301 dev_replace->cursor_left_last_write_of_item;
302}
303
304int btrfs_dev_replace_start(struct btrfs_root *root,
305 struct btrfs_ioctl_dev_replace_args *args)
306{
307 struct btrfs_trans_handle *trans;
308 struct btrfs_fs_info *fs_info = root->fs_info;
309 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
310 int ret;
311 struct btrfs_device *tgt_device = NULL;
312 struct btrfs_device *src_device = NULL;
313
314 if (btrfs_fs_incompat(fs_info, RAID56)) {
315 btrfs_warn(fs_info, "dev_replace cannot yet handle RAID5/RAID6");
316 return -EINVAL;
317 }
318
319 switch (args->start.cont_reading_from_srcdev_mode) {
320 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
321 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
322 break;
323 default:
324 return -EINVAL;
325 }
326
327 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
328 args->start.tgtdev_name[0] == '\0')
329 return -EINVAL;
330
331 mutex_lock(&fs_info->volume_mutex);
332 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name,
333 &tgt_device);
334 if (ret) {
335 btrfs_err(fs_info, "target device %s is invalid!",
336 args->start.tgtdev_name);
337 mutex_unlock(&fs_info->volume_mutex);
338 return -EINVAL;
339 }
340
341 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid,
342 args->start.srcdev_name,
343 &src_device);
344 mutex_unlock(&fs_info->volume_mutex);
345 if (ret) {
346 ret = -EINVAL;
347 goto leave_no_lock;
348 }
349
350 if (tgt_device->total_bytes < src_device->total_bytes) {
351 btrfs_err(fs_info, "target device is smaller than source device!");
352 ret = -EINVAL;
353 goto leave_no_lock;
354 }
355
356 btrfs_dev_replace_lock(dev_replace);
357 switch (dev_replace->replace_state) {
358 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
359 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
360 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
361 break;
362 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
363 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
364 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
365 goto leave;
366 }
367
368 dev_replace->cont_reading_from_srcdev_mode =
369 args->start.cont_reading_from_srcdev_mode;
370 WARN_ON(!src_device);
371 dev_replace->srcdev = src_device;
372 WARN_ON(!tgt_device);
373 dev_replace->tgtdev = tgt_device;
374
375 printk_in_rcu(KERN_INFO
376 "BTRFS: dev_replace from %s (devid %llu) to %s started\n",
377 src_device->missing ? "<missing disk>" :
378 rcu_str_deref(src_device->name),
379 src_device->devid,
380 rcu_str_deref(tgt_device->name));
381
382 tgt_device->total_bytes = src_device->total_bytes;
383 tgt_device->disk_total_bytes = src_device->disk_total_bytes;
384 tgt_device->bytes_used = src_device->bytes_used;
385
386 /*
387 * from now on, the writes to the srcdev are all duplicated to
388 * go to the tgtdev as well (refer to btrfs_map_block()).
389 */
390 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
391 dev_replace->time_started = get_seconds();
392 dev_replace->cursor_left = 0;
393 dev_replace->committed_cursor_left = 0;
394 dev_replace->cursor_left_last_write_of_item = 0;
395 dev_replace->cursor_right = 0;
396 dev_replace->is_valid = 1;
397 dev_replace->item_needs_writeback = 1;
398 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
399 btrfs_dev_replace_unlock(dev_replace);
400
401 btrfs_wait_ordered_roots(root->fs_info, -1);
402
403 /* force writing the updated state information to disk */
404 trans = btrfs_start_transaction(root, 0);
405 if (IS_ERR(trans)) {
406 ret = PTR_ERR(trans);
407 btrfs_dev_replace_lock(dev_replace);
408 goto leave;
409 }
410
411 ret = btrfs_commit_transaction(trans, root);
412 WARN_ON(ret);
413
414 /* the disk copy procedure reuses the scrub code */
415 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
416 src_device->total_bytes,
417 &dev_replace->scrub_progress, 0, 1);
418
419 ret = btrfs_dev_replace_finishing(root->fs_info, ret);
420 WARN_ON(ret);
421
422 return 0;
423
424leave:
425 dev_replace->srcdev = NULL;
426 dev_replace->tgtdev = NULL;
427 btrfs_dev_replace_unlock(dev_replace);
428leave_no_lock:
429 if (tgt_device)
430 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
431 return ret;
432}
433
434/*
435 * blocked until all flighting bios are finished.
436 */
437static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
438{
439 s64 writers;
440 DEFINE_WAIT(wait);
441
442 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
443 do {
444 prepare_to_wait(&fs_info->replace_wait, &wait,
445 TASK_UNINTERRUPTIBLE);
446 writers = percpu_counter_sum(&fs_info->bio_counter);
447 if (writers)
448 schedule();
449 finish_wait(&fs_info->replace_wait, &wait);
450 } while (writers);
451}
452
453/*
454 * we have removed target device, it is safe to allow new bios request.
455 */
456static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info)
457{
458 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
459 if (waitqueue_active(&fs_info->replace_wait))
460 wake_up(&fs_info->replace_wait);
461}
462
463static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
464 int scrub_ret)
465{
466 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
467 struct btrfs_device *tgt_device;
468 struct btrfs_device *src_device;
469 struct btrfs_root *root = fs_info->tree_root;
470 u8 uuid_tmp[BTRFS_UUID_SIZE];
471 struct btrfs_trans_handle *trans;
472 int ret = 0;
473
474 /* don't allow cancel or unmount to disturb the finishing procedure */
475 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
476
477 btrfs_dev_replace_lock(dev_replace);
478 /* was the operation canceled, or is it finished? */
479 if (dev_replace->replace_state !=
480 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
481 btrfs_dev_replace_unlock(dev_replace);
482 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
483 return 0;
484 }
485
486 tgt_device = dev_replace->tgtdev;
487 src_device = dev_replace->srcdev;
488 btrfs_dev_replace_unlock(dev_replace);
489
490 /*
491 * flush all outstanding I/O and inode extent mappings before the
492 * copy operation is declared as being finished
493 */
494 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1);
495 if (ret) {
496 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
497 return ret;
498 }
499 btrfs_wait_ordered_roots(root->fs_info, -1);
500
501 trans = btrfs_start_transaction(root, 0);
502 if (IS_ERR(trans)) {
503 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
504 return PTR_ERR(trans);
505 }
506 ret = btrfs_commit_transaction(trans, root);
507 WARN_ON(ret);
508
509 /* keep away write_all_supers() during the finishing procedure */
510 mutex_lock(&root->fs_info->chunk_mutex);
511 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
512 btrfs_dev_replace_lock(dev_replace);
513 dev_replace->replace_state =
514 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
515 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
516 dev_replace->tgtdev = NULL;
517 dev_replace->srcdev = NULL;
518 dev_replace->time_stopped = get_seconds();
519 dev_replace->item_needs_writeback = 1;
520
521 /* replace old device with new one in mapping tree */
522 if (!scrub_ret) {
523 btrfs_dev_replace_update_device_in_mapping_tree(fs_info,
524 src_device,
525 tgt_device);
526 } else {
527 printk_in_rcu(KERN_ERR
528 "BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n",
529 src_device->missing ? "<missing disk>" :
530 rcu_str_deref(src_device->name),
531 src_device->devid,
532 rcu_str_deref(tgt_device->name), scrub_ret);
533 btrfs_dev_replace_unlock(dev_replace);
534 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
535 mutex_unlock(&root->fs_info->chunk_mutex);
536 if (tgt_device)
537 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
538 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
539
540 return 0;
541 }
542
543 printk_in_rcu(KERN_INFO
544 "BTRFS: dev_replace from %s (devid %llu) to %s) finished\n",
545 src_device->missing ? "<missing disk>" :
546 rcu_str_deref(src_device->name),
547 src_device->devid,
548 rcu_str_deref(tgt_device->name));
549 tgt_device->is_tgtdev_for_dev_replace = 0;
550 tgt_device->devid = src_device->devid;
551 src_device->devid = BTRFS_DEV_REPLACE_DEVID;
552 tgt_device->bytes_used = src_device->bytes_used;
553 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp));
554 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid));
555 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid));
556 tgt_device->total_bytes = src_device->total_bytes;
557 tgt_device->disk_total_bytes = src_device->disk_total_bytes;
558 tgt_device->bytes_used = src_device->bytes_used;
559 if (fs_info->sb->s_bdev == src_device->bdev)
560 fs_info->sb->s_bdev = tgt_device->bdev;
561 if (fs_info->fs_devices->latest_bdev == src_device->bdev)
562 fs_info->fs_devices->latest_bdev = tgt_device->bdev;
563 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
564
565 btrfs_rm_dev_replace_blocked(fs_info);
566
567 btrfs_rm_dev_replace_srcdev(fs_info, src_device);
568
569 btrfs_rm_dev_replace_unblocked(fs_info);
570
571 /*
572 * this is again a consistent state where no dev_replace procedure
573 * is running, the target device is part of the filesystem, the
574 * source device is not part of the filesystem anymore and its 1st
575 * superblock is scratched out so that it is no longer marked to
576 * belong to this filesystem.
577 */
578 btrfs_dev_replace_unlock(dev_replace);
579 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
580 mutex_unlock(&root->fs_info->chunk_mutex);
581
582 /* write back the superblocks */
583 trans = btrfs_start_transaction(root, 0);
584 if (!IS_ERR(trans))
585 btrfs_commit_transaction(trans, root);
586
587 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
588
589 return 0;
590}
591
592static void btrfs_dev_replace_update_device_in_mapping_tree(
593 struct btrfs_fs_info *fs_info,
594 struct btrfs_device *srcdev,
595 struct btrfs_device *tgtdev)
596{
597 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
598 struct extent_map *em;
599 struct map_lookup *map;
600 u64 start = 0;
601 int i;
602
603 write_lock(&em_tree->lock);
604 do {
605 em = lookup_extent_mapping(em_tree, start, (u64)-1);
606 if (!em)
607 break;
608 map = (struct map_lookup *)em->bdev;
609 for (i = 0; i < map->num_stripes; i++)
610 if (srcdev == map->stripes[i].dev)
611 map->stripes[i].dev = tgtdev;
612 start = em->start + em->len;
613 free_extent_map(em);
614 } while (start);
615 write_unlock(&em_tree->lock);
616}
617
618static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
619 char *srcdev_name,
620 struct btrfs_device **device)
621{
622 int ret;
623
624 if (srcdevid) {
625 ret = 0;
626 *device = btrfs_find_device(root->fs_info, srcdevid, NULL,
627 NULL);
628 if (!*device)
629 ret = -ENOENT;
630 } else {
631 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name,
632 device);
633 }
634 return ret;
635}
636
637void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
638 struct btrfs_ioctl_dev_replace_args *args)
639{
640 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
641
642 btrfs_dev_replace_lock(dev_replace);
643 /* even if !dev_replace_is_valid, the values are good enough for
644 * the replace_status ioctl */
645 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
646 args->status.replace_state = dev_replace->replace_state;
647 args->status.time_started = dev_replace->time_started;
648 args->status.time_stopped = dev_replace->time_stopped;
649 args->status.num_write_errors =
650 atomic64_read(&dev_replace->num_write_errors);
651 args->status.num_uncorrectable_read_errors =
652 atomic64_read(&dev_replace->num_uncorrectable_read_errors);
653 switch (dev_replace->replace_state) {
654 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
655 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
656 args->status.progress_1000 = 0;
657 break;
658 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
659 args->status.progress_1000 = 1000;
660 break;
661 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
662 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
663 args->status.progress_1000 = div64_u64(dev_replace->cursor_left,
664 div64_u64(dev_replace->srcdev->total_bytes, 1000));
665 break;
666 }
667 btrfs_dev_replace_unlock(dev_replace);
668}
669
670int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
671 struct btrfs_ioctl_dev_replace_args *args)
672{
673 args->result = __btrfs_dev_replace_cancel(fs_info);
674 return 0;
675}
676
677static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
678{
679 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
680 struct btrfs_device *tgt_device = NULL;
681 struct btrfs_trans_handle *trans;
682 struct btrfs_root *root = fs_info->tree_root;
683 u64 result;
684 int ret;
685
686 if (fs_info->sb->s_flags & MS_RDONLY)
687 return -EROFS;
688
689 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
690 btrfs_dev_replace_lock(dev_replace);
691 switch (dev_replace->replace_state) {
692 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
693 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
694 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
695 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
696 btrfs_dev_replace_unlock(dev_replace);
697 goto leave;
698 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
699 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
700 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
701 tgt_device = dev_replace->tgtdev;
702 dev_replace->tgtdev = NULL;
703 dev_replace->srcdev = NULL;
704 break;
705 }
706 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
707 dev_replace->time_stopped = get_seconds();
708 dev_replace->item_needs_writeback = 1;
709 btrfs_dev_replace_unlock(dev_replace);
710 btrfs_scrub_cancel(fs_info);
711
712 trans = btrfs_start_transaction(root, 0);
713 if (IS_ERR(trans)) {
714 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
715 return PTR_ERR(trans);
716 }
717 ret = btrfs_commit_transaction(trans, root);
718 WARN_ON(ret);
719 if (tgt_device)
720 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
721
722leave:
723 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
724 return result;
725}
726
727void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info)
728{
729 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
730
731 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
732 btrfs_dev_replace_lock(dev_replace);
733 switch (dev_replace->replace_state) {
734 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
735 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
736 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
737 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
738 break;
739 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
740 dev_replace->replace_state =
741 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
742 dev_replace->time_stopped = get_seconds();
743 dev_replace->item_needs_writeback = 1;
744 btrfs_info(fs_info, "suspending dev_replace for unmount");
745 break;
746 }
747
748 btrfs_dev_replace_unlock(dev_replace);
749 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
750}
751
752/* resume dev_replace procedure that was interrupted by unmount */
753int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
754{
755 struct task_struct *task;
756 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
757
758 btrfs_dev_replace_lock(dev_replace);
759 switch (dev_replace->replace_state) {
760 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
761 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
762 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
763 btrfs_dev_replace_unlock(dev_replace);
764 return 0;
765 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
766 break;
767 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
768 dev_replace->replace_state =
769 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
770 break;
771 }
772 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) {
773 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing");
774 btrfs_info(fs_info,
775 "you may cancel the operation after 'mount -o degraded'");
776 btrfs_dev_replace_unlock(dev_replace);
777 return 0;
778 }
779 btrfs_dev_replace_unlock(dev_replace);
780
781 WARN_ON(atomic_xchg(
782 &fs_info->mutually_exclusive_operation_running, 1));
783 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
784 return PTR_ERR_OR_ZERO(task);
785}
786
787static int btrfs_dev_replace_kthread(void *data)
788{
789 struct btrfs_fs_info *fs_info = data;
790 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
791 struct btrfs_ioctl_dev_replace_args *status_args;
792 u64 progress;
793
794 status_args = kzalloc(sizeof(*status_args), GFP_NOFS);
795 if (status_args) {
796 btrfs_dev_replace_status(fs_info, status_args);
797 progress = status_args->status.progress_1000;
798 kfree(status_args);
799 do_div(progress, 10);
800 printk_in_rcu(KERN_INFO
801 "BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n",
802 dev_replace->srcdev->missing ? "<missing disk>" :
803 rcu_str_deref(dev_replace->srcdev->name),
804 dev_replace->srcdev->devid,
805 dev_replace->tgtdev ?
806 rcu_str_deref(dev_replace->tgtdev->name) :
807 "<missing target disk>",
808 (unsigned int)progress);
809 }
810 btrfs_dev_replace_continue_on_mount(fs_info);
811 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
812
813 return 0;
814}
815
816static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info)
817{
818 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
819 int ret;
820
821 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid,
822 dev_replace->committed_cursor_left,
823 dev_replace->srcdev->total_bytes,
824 &dev_replace->scrub_progress, 0, 1);
825 ret = btrfs_dev_replace_finishing(fs_info, ret);
826 WARN_ON(ret);
827 return 0;
828}
829
830int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
831{
832 if (!dev_replace->is_valid)
833 return 0;
834
835 switch (dev_replace->replace_state) {
836 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
837 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
838 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
839 return 0;
840 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
841 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
842 /*
843 * return true even if tgtdev is missing (this is
844 * something that can happen if the dev_replace
845 * procedure is suspended by an umount and then
846 * the tgtdev is missing (or "btrfs dev scan") was
847 * not called and the the filesystem is remounted
848 * in degraded state. This does not stop the
849 * dev_replace procedure. It needs to be canceled
850 * manually if the cancelation is wanted.
851 */
852 break;
853 }
854 return 1;
855}
856
857void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace)
858{
859 /* the beginning is just an optimization for the typical case */
860 if (atomic_read(&dev_replace->nesting_level) == 0) {
861acquire_lock:
862 /* this is not a nested case where the same thread
863 * is trying to acqurire the same lock twice */
864 mutex_lock(&dev_replace->lock);
865 mutex_lock(&dev_replace->lock_management_lock);
866 dev_replace->lock_owner = current->pid;
867 atomic_inc(&dev_replace->nesting_level);
868 mutex_unlock(&dev_replace->lock_management_lock);
869 return;
870 }
871
872 mutex_lock(&dev_replace->lock_management_lock);
873 if (atomic_read(&dev_replace->nesting_level) > 0 &&
874 dev_replace->lock_owner == current->pid) {
875 WARN_ON(!mutex_is_locked(&dev_replace->lock));
876 atomic_inc(&dev_replace->nesting_level);
877 mutex_unlock(&dev_replace->lock_management_lock);
878 return;
879 }
880
881 mutex_unlock(&dev_replace->lock_management_lock);
882 goto acquire_lock;
883}
884
885void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace)
886{
887 WARN_ON(!mutex_is_locked(&dev_replace->lock));
888 mutex_lock(&dev_replace->lock_management_lock);
889 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1);
890 WARN_ON(dev_replace->lock_owner != current->pid);
891 atomic_dec(&dev_replace->nesting_level);
892 if (atomic_read(&dev_replace->nesting_level) == 0) {
893 dev_replace->lock_owner = 0;
894 mutex_unlock(&dev_replace->lock_management_lock);
895 mutex_unlock(&dev_replace->lock);
896 } else {
897 mutex_unlock(&dev_replace->lock_management_lock);
898 }
899}
900
901void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
902{
903 percpu_counter_inc(&fs_info->bio_counter);
904}
905
906void btrfs_bio_counter_dec(struct btrfs_fs_info *fs_info)
907{
908 percpu_counter_dec(&fs_info->bio_counter);
909
910 if (waitqueue_active(&fs_info->replace_wait))
911 wake_up(&fs_info->replace_wait);
912}
913
914void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
915{
916 DEFINE_WAIT(wait);
917again:
918 percpu_counter_inc(&fs_info->bio_counter);
919 if (test_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state)) {
920 btrfs_bio_counter_dec(fs_info);
921 wait_event(fs_info->replace_wait,
922 !test_bit(BTRFS_FS_STATE_DEV_REPLACING,
923 &fs_info->fs_state));
924 goto again;
925 }
926
927}