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
41 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
42 int scrub_ret);
43 static 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);
47 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
48 char *srcdev_name,
49 struct btrfs_device **device);
50 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
51 static int btrfs_dev_replace_kthread(void *data);
52 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
53
54
btrfs_init_dev_replace(struct btrfs_fs_info * fs_info)55 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info)
56 {
57 struct btrfs_key key;
58 struct btrfs_root *dev_root = fs_info->dev_root;
59 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
60 struct extent_buffer *eb;
61 int slot;
62 int ret = 0;
63 struct btrfs_path *path = NULL;
64 int item_size;
65 struct btrfs_dev_replace_item *ptr;
66 u64 src_devid;
67
68 path = btrfs_alloc_path();
69 if (!path) {
70 ret = -ENOMEM;
71 goto out;
72 }
73
74 key.objectid = 0;
75 key.type = BTRFS_DEV_REPLACE_KEY;
76 key.offset = 0;
77 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
78 if (ret) {
79 no_valid_dev_replace_entry_found:
80 ret = 0;
81 dev_replace->replace_state =
82 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED;
83 dev_replace->cont_reading_from_srcdev_mode =
84 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS;
85 dev_replace->replace_state = 0;
86 dev_replace->time_started = 0;
87 dev_replace->time_stopped = 0;
88 atomic64_set(&dev_replace->num_write_errors, 0);
89 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
90 dev_replace->cursor_left = 0;
91 dev_replace->committed_cursor_left = 0;
92 dev_replace->cursor_left_last_write_of_item = 0;
93 dev_replace->cursor_right = 0;
94 dev_replace->srcdev = NULL;
95 dev_replace->tgtdev = NULL;
96 dev_replace->is_valid = 0;
97 dev_replace->item_needs_writeback = 0;
98 goto out;
99 }
100 slot = path->slots[0];
101 eb = path->nodes[0];
102 item_size = btrfs_item_size_nr(eb, slot);
103 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item);
104
105 if (item_size != sizeof(struct btrfs_dev_replace_item)) {
106 btrfs_warn(fs_info,
107 "dev_replace entry found has unexpected size, ignore entry");
108 goto no_valid_dev_replace_entry_found;
109 }
110
111 src_devid = btrfs_dev_replace_src_devid(eb, ptr);
112 dev_replace->cont_reading_from_srcdev_mode =
113 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr);
114 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr);
115 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr);
116 dev_replace->time_stopped =
117 btrfs_dev_replace_time_stopped(eb, ptr);
118 atomic64_set(&dev_replace->num_write_errors,
119 btrfs_dev_replace_num_write_errors(eb, ptr));
120 atomic64_set(&dev_replace->num_uncorrectable_read_errors,
121 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr));
122 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr);
123 dev_replace->committed_cursor_left = dev_replace->cursor_left;
124 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left;
125 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr);
126 dev_replace->is_valid = 1;
127
128 dev_replace->item_needs_writeback = 0;
129 switch (dev_replace->replace_state) {
130 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
131 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
132 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
133 dev_replace->srcdev = NULL;
134 dev_replace->tgtdev = NULL;
135 break;
136 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
137 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
138 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid,
139 NULL, NULL);
140 dev_replace->tgtdev = btrfs_find_device(fs_info,
141 BTRFS_DEV_REPLACE_DEVID,
142 NULL, NULL);
143 /*
144 * allow 'btrfs dev replace_cancel' if src/tgt device is
145 * missing
146 */
147 if (!dev_replace->srcdev &&
148 !btrfs_test_opt(dev_root, DEGRADED)) {
149 ret = -EIO;
150 btrfs_warn(fs_info,
151 "cannot mount because device replace operation is ongoing and");
152 btrfs_warn(fs_info,
153 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
154 src_devid);
155 }
156 if (!dev_replace->tgtdev &&
157 !btrfs_test_opt(dev_root, DEGRADED)) {
158 ret = -EIO;
159 btrfs_warn(fs_info,
160 "cannot mount because device replace operation is ongoing and");
161 btrfs_warn(fs_info,
162 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
163 BTRFS_DEV_REPLACE_DEVID);
164 }
165 if (dev_replace->tgtdev) {
166 if (dev_replace->srcdev) {
167 dev_replace->tgtdev->total_bytes =
168 dev_replace->srcdev->total_bytes;
169 dev_replace->tgtdev->disk_total_bytes =
170 dev_replace->srcdev->disk_total_bytes;
171 dev_replace->tgtdev->commit_total_bytes =
172 dev_replace->srcdev->commit_total_bytes;
173 dev_replace->tgtdev->bytes_used =
174 dev_replace->srcdev->bytes_used;
175 dev_replace->tgtdev->commit_bytes_used =
176 dev_replace->srcdev->commit_bytes_used;
177 }
178 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1;
179 btrfs_init_dev_replace_tgtdev_for_resume(fs_info,
180 dev_replace->tgtdev);
181 }
182 break;
183 }
184
185 out:
186 btrfs_free_path(path);
187 return ret;
188 }
189
190 /*
191 * called from commit_transaction. Writes changed device replace state to
192 * disk.
193 */
btrfs_run_dev_replace(struct btrfs_trans_handle * trans,struct btrfs_fs_info * fs_info)194 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
195 struct btrfs_fs_info *fs_info)
196 {
197 int ret;
198 struct btrfs_root *dev_root = fs_info->dev_root;
199 struct btrfs_path *path;
200 struct btrfs_key key;
201 struct extent_buffer *eb;
202 struct btrfs_dev_replace_item *ptr;
203 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
204
205 btrfs_dev_replace_lock(dev_replace);
206 if (!dev_replace->is_valid ||
207 !dev_replace->item_needs_writeback) {
208 btrfs_dev_replace_unlock(dev_replace);
209 return 0;
210 }
211 btrfs_dev_replace_unlock(dev_replace);
212
213 key.objectid = 0;
214 key.type = BTRFS_DEV_REPLACE_KEY;
215 key.offset = 0;
216
217 path = btrfs_alloc_path();
218 if (!path) {
219 ret = -ENOMEM;
220 goto out;
221 }
222 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
223 if (ret < 0) {
224 btrfs_warn(fs_info, "error %d while searching for dev_replace item!",
225 ret);
226 goto out;
227 }
228
229 if (ret == 0 &&
230 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
231 /*
232 * need to delete old one and insert a new one.
233 * Since no attempt is made to recover any old state, if the
234 * dev_replace state is 'running', the data on the target
235 * drive is lost.
236 * It would be possible to recover the state: just make sure
237 * that the beginning of the item is never changed and always
238 * contains all the essential information. Then read this
239 * minimal set of information and use it as a base for the
240 * new state.
241 */
242 ret = btrfs_del_item(trans, dev_root, path);
243 if (ret != 0) {
244 btrfs_warn(fs_info, "delete too small dev_replace item failed %d!",
245 ret);
246 goto out;
247 }
248 ret = 1;
249 }
250
251 if (ret == 1) {
252 /* need to insert a new item */
253 btrfs_release_path(path);
254 ret = btrfs_insert_empty_item(trans, dev_root, path,
255 &key, sizeof(*ptr));
256 if (ret < 0) {
257 btrfs_warn(fs_info, "insert dev_replace item failed %d!",
258 ret);
259 goto out;
260 }
261 }
262
263 eb = path->nodes[0];
264 ptr = btrfs_item_ptr(eb, path->slots[0],
265 struct btrfs_dev_replace_item);
266
267 btrfs_dev_replace_lock(dev_replace);
268 if (dev_replace->srcdev)
269 btrfs_set_dev_replace_src_devid(eb, ptr,
270 dev_replace->srcdev->devid);
271 else
272 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1);
273 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr,
274 dev_replace->cont_reading_from_srcdev_mode);
275 btrfs_set_dev_replace_replace_state(eb, ptr,
276 dev_replace->replace_state);
277 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started);
278 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped);
279 btrfs_set_dev_replace_num_write_errors(eb, ptr,
280 atomic64_read(&dev_replace->num_write_errors));
281 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr,
282 atomic64_read(&dev_replace->num_uncorrectable_read_errors));
283 dev_replace->cursor_left_last_write_of_item =
284 dev_replace->cursor_left;
285 btrfs_set_dev_replace_cursor_left(eb, ptr,
286 dev_replace->cursor_left_last_write_of_item);
287 btrfs_set_dev_replace_cursor_right(eb, ptr,
288 dev_replace->cursor_right);
289 dev_replace->item_needs_writeback = 0;
290 btrfs_dev_replace_unlock(dev_replace);
291
292 btrfs_mark_buffer_dirty(eb);
293
294 out:
295 btrfs_free_path(path);
296
297 return ret;
298 }
299
btrfs_after_dev_replace_commit(struct btrfs_fs_info * fs_info)300 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
301 {
302 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
303
304 dev_replace->committed_cursor_left =
305 dev_replace->cursor_left_last_write_of_item;
306 }
307
btrfs_dev_replace_start(struct btrfs_root * root,struct btrfs_ioctl_dev_replace_args * args)308 int btrfs_dev_replace_start(struct btrfs_root *root,
309 struct btrfs_ioctl_dev_replace_args *args)
310 {
311 struct btrfs_trans_handle *trans;
312 struct btrfs_fs_info *fs_info = root->fs_info;
313 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
314 int ret;
315 struct btrfs_device *tgt_device = NULL;
316 struct btrfs_device *src_device = NULL;
317
318 switch (args->start.cont_reading_from_srcdev_mode) {
319 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
320 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
321 break;
322 default:
323 return -EINVAL;
324 }
325
326 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
327 args->start.tgtdev_name[0] == '\0')
328 return -EINVAL;
329
330 /* the disk copy procedure reuses the scrub code */
331 mutex_lock(&fs_info->volume_mutex);
332 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid,
333 args->start.srcdev_name,
334 &src_device);
335 if (ret) {
336 mutex_unlock(&fs_info->volume_mutex);
337 return ret;
338 }
339
340 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name,
341 src_device, &tgt_device);
342 mutex_unlock(&fs_info->volume_mutex);
343 if (ret)
344 return ret;
345
346 /*
347 * Here we commit the transaction to make sure commit_total_bytes
348 * of all the devices are updated.
349 */
350 trans = btrfs_attach_transaction(root);
351 if (!IS_ERR(trans)) {
352 ret = btrfs_commit_transaction(trans, root);
353 if (ret)
354 return ret;
355 } else if (PTR_ERR(trans) != -ENOENT) {
356 return PTR_ERR(trans);
357 }
358
359 btrfs_dev_replace_lock(dev_replace);
360 switch (dev_replace->replace_state) {
361 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
362 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
363 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
364 break;
365 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
366 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
367 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
368 goto leave;
369 }
370
371 dev_replace->cont_reading_from_srcdev_mode =
372 args->start.cont_reading_from_srcdev_mode;
373 WARN_ON(!src_device);
374 dev_replace->srcdev = src_device;
375 WARN_ON(!tgt_device);
376 dev_replace->tgtdev = tgt_device;
377
378 btrfs_info_in_rcu(root->fs_info,
379 "dev_replace from %s (devid %llu) to %s started",
380 src_device->missing ? "<missing disk>" :
381 rcu_str_deref(src_device->name),
382 src_device->devid,
383 rcu_str_deref(tgt_device->name));
384
385 /*
386 * from now on, the writes to the srcdev are all duplicated to
387 * go to the tgtdev as well (refer to btrfs_map_block()).
388 */
389 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
390 dev_replace->time_started = get_seconds();
391 dev_replace->cursor_left = 0;
392 dev_replace->committed_cursor_left = 0;
393 dev_replace->cursor_left_last_write_of_item = 0;
394 dev_replace->cursor_right = 0;
395 dev_replace->is_valid = 1;
396 dev_replace->item_needs_writeback = 1;
397 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
398 btrfs_dev_replace_unlock(dev_replace);
399
400 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device);
401 if (ret)
402 btrfs_err(root->fs_info, "kobj add dev failed %d\n", ret);
403
404 btrfs_wait_ordered_roots(root->fs_info, -1);
405
406 /* force writing the updated state information to disk */
407 trans = btrfs_start_transaction(root, 0);
408 if (IS_ERR(trans)) {
409 ret = PTR_ERR(trans);
410 btrfs_dev_replace_lock(dev_replace);
411 goto leave;
412 }
413
414 ret = btrfs_commit_transaction(trans, root);
415 WARN_ON(ret);
416
417 /* the disk copy procedure reuses the scrub code */
418 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
419 btrfs_device_get_total_bytes(src_device),
420 &dev_replace->scrub_progress, 0, 1);
421
422 ret = btrfs_dev_replace_finishing(root->fs_info, ret);
423 /* don't warn if EINPROGRESS, someone else might be running scrub */
424 if (ret == -EINPROGRESS) {
425 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
426 ret = 0;
427 } else {
428 WARN_ON(ret);
429 }
430
431 return ret;
432
433 leave:
434 dev_replace->srcdev = NULL;
435 dev_replace->tgtdev = NULL;
436 btrfs_dev_replace_unlock(dev_replace);
437 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
438 return ret;
439 }
440
441 /*
442 * blocked until all flighting bios are finished.
443 */
btrfs_rm_dev_replace_blocked(struct btrfs_fs_info * fs_info)444 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
445 {
446 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
447 wait_event(fs_info->replace_wait, !percpu_counter_sum(
448 &fs_info->bio_counter));
449 }
450
451 /*
452 * we have removed target device, it is safe to allow new bios request.
453 */
btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info * fs_info)454 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info)
455 {
456 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
457 wake_up(&fs_info->replace_wait);
458 }
459
btrfs_dev_replace_finishing(struct btrfs_fs_info * fs_info,int scrub_ret)460 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
461 int scrub_ret)
462 {
463 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
464 struct btrfs_device *tgt_device;
465 struct btrfs_device *src_device;
466 struct btrfs_root *root = fs_info->tree_root;
467 u8 uuid_tmp[BTRFS_UUID_SIZE];
468 struct btrfs_trans_handle *trans;
469 int ret = 0;
470
471 /* don't allow cancel or unmount to disturb the finishing procedure */
472 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
473
474 btrfs_dev_replace_lock(dev_replace);
475 /* was the operation canceled, or is it finished? */
476 if (dev_replace->replace_state !=
477 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
478 btrfs_dev_replace_unlock(dev_replace);
479 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
480 return 0;
481 }
482
483 tgt_device = dev_replace->tgtdev;
484 src_device = dev_replace->srcdev;
485 btrfs_dev_replace_unlock(dev_replace);
486
487 /*
488 * flush all outstanding I/O and inode extent mappings before the
489 * copy operation is declared as being finished
490 */
491 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1);
492 if (ret) {
493 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
494 return ret;
495 }
496 btrfs_wait_ordered_roots(root->fs_info, -1);
497
498 while (1) {
499 trans = btrfs_start_transaction(root, 0);
500 if (IS_ERR(trans)) {
501 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
502 return PTR_ERR(trans);
503 }
504 ret = btrfs_commit_transaction(trans, root);
505 WARN_ON(ret);
506 mutex_lock(&uuid_mutex);
507 /* keep away write_all_supers() during the finishing procedure */
508 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
509 mutex_lock(&root->fs_info->chunk_mutex);
510 if (src_device->has_pending_chunks) {
511 mutex_unlock(&root->fs_info->chunk_mutex);
512 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
513 mutex_unlock(&uuid_mutex);
514 } else {
515 break;
516 }
517 }
518
519 btrfs_dev_replace_lock(dev_replace);
520 dev_replace->replace_state =
521 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
522 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
523 dev_replace->tgtdev = NULL;
524 dev_replace->srcdev = NULL;
525 dev_replace->time_stopped = get_seconds();
526 dev_replace->item_needs_writeback = 1;
527
528 /* replace old device with new one in mapping tree */
529 if (!scrub_ret) {
530 btrfs_dev_replace_update_device_in_mapping_tree(fs_info,
531 src_device,
532 tgt_device);
533 } else {
534 btrfs_err_in_rcu(root->fs_info,
535 "btrfs_scrub_dev(%s, %llu, %s) failed %d",
536 src_device->missing ? "<missing disk>" :
537 rcu_str_deref(src_device->name),
538 src_device->devid,
539 rcu_str_deref(tgt_device->name), scrub_ret);
540 btrfs_dev_replace_unlock(dev_replace);
541 mutex_unlock(&root->fs_info->chunk_mutex);
542 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
543 mutex_unlock(&uuid_mutex);
544 if (tgt_device)
545 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
546 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
547
548 return scrub_ret;
549 }
550
551 btrfs_info_in_rcu(root->fs_info,
552 "dev_replace from %s (devid %llu) to %s finished",
553 src_device->missing ? "<missing disk>" :
554 rcu_str_deref(src_device->name),
555 src_device->devid,
556 rcu_str_deref(tgt_device->name));
557 tgt_device->is_tgtdev_for_dev_replace = 0;
558 tgt_device->devid = src_device->devid;
559 src_device->devid = BTRFS_DEV_REPLACE_DEVID;
560 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp));
561 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid));
562 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid));
563 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes);
564 btrfs_device_set_disk_total_bytes(tgt_device,
565 src_device->disk_total_bytes);
566 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used);
567 ASSERT(list_empty(&src_device->resized_list));
568 tgt_device->commit_total_bytes = src_device->commit_total_bytes;
569 tgt_device->commit_bytes_used = src_device->bytes_used;
570 if (fs_info->sb->s_bdev == src_device->bdev)
571 fs_info->sb->s_bdev = tgt_device->bdev;
572 if (fs_info->fs_devices->latest_bdev == src_device->bdev)
573 fs_info->fs_devices->latest_bdev = tgt_device->bdev;
574 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
575 fs_info->fs_devices->rw_devices++;
576
577 btrfs_dev_replace_unlock(dev_replace);
578
579 btrfs_rm_dev_replace_blocked(fs_info);
580
581 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device);
582
583 btrfs_rm_dev_replace_unblocked(fs_info);
584
585 /*
586 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will
587 * update on-disk dev stats value during commit transaction
588 */
589 atomic_inc(&tgt_device->dev_stats_ccnt);
590
591 /*
592 * this is again a consistent state where no dev_replace procedure
593 * is running, the target device is part of the filesystem, the
594 * source device is not part of the filesystem anymore and its 1st
595 * superblock is scratched out so that it is no longer marked to
596 * belong to this filesystem.
597 */
598 mutex_unlock(&root->fs_info->chunk_mutex);
599 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
600 mutex_unlock(&uuid_mutex);
601
602 /* replace the sysfs entry */
603 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device);
604 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device);
605
606 /* write back the superblocks */
607 trans = btrfs_start_transaction(root, 0);
608 if (!IS_ERR(trans))
609 btrfs_commit_transaction(trans, root);
610
611 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
612
613 return 0;
614 }
615
btrfs_dev_replace_update_device_in_mapping_tree(struct btrfs_fs_info * fs_info,struct btrfs_device * srcdev,struct btrfs_device * tgtdev)616 static void btrfs_dev_replace_update_device_in_mapping_tree(
617 struct btrfs_fs_info *fs_info,
618 struct btrfs_device *srcdev,
619 struct btrfs_device *tgtdev)
620 {
621 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
622 struct extent_map *em;
623 struct map_lookup *map;
624 u64 start = 0;
625 int i;
626
627 write_lock(&em_tree->lock);
628 do {
629 em = lookup_extent_mapping(em_tree, start, (u64)-1);
630 if (!em)
631 break;
632 map = em->map_lookup;
633 for (i = 0; i < map->num_stripes; i++)
634 if (srcdev == map->stripes[i].dev)
635 map->stripes[i].dev = tgtdev;
636 start = em->start + em->len;
637 free_extent_map(em);
638 } while (start);
639 write_unlock(&em_tree->lock);
640 }
641
btrfs_dev_replace_find_srcdev(struct btrfs_root * root,u64 srcdevid,char * srcdev_name,struct btrfs_device ** device)642 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
643 char *srcdev_name,
644 struct btrfs_device **device)
645 {
646 int ret;
647
648 if (srcdevid) {
649 ret = 0;
650 *device = btrfs_find_device(root->fs_info, srcdevid, NULL,
651 NULL);
652 if (!*device)
653 ret = -ENOENT;
654 } else {
655 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name,
656 device);
657 }
658 return ret;
659 }
660
btrfs_dev_replace_status(struct btrfs_fs_info * fs_info,struct btrfs_ioctl_dev_replace_args * args)661 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
662 struct btrfs_ioctl_dev_replace_args *args)
663 {
664 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
665 struct btrfs_device *srcdev;
666
667 btrfs_dev_replace_lock(dev_replace);
668 /* even if !dev_replace_is_valid, the values are good enough for
669 * the replace_status ioctl */
670 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
671 args->status.replace_state = dev_replace->replace_state;
672 args->status.time_started = dev_replace->time_started;
673 args->status.time_stopped = dev_replace->time_stopped;
674 args->status.num_write_errors =
675 atomic64_read(&dev_replace->num_write_errors);
676 args->status.num_uncorrectable_read_errors =
677 atomic64_read(&dev_replace->num_uncorrectable_read_errors);
678 switch (dev_replace->replace_state) {
679 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
680 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
681 args->status.progress_1000 = 0;
682 break;
683 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
684 args->status.progress_1000 = 1000;
685 break;
686 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
687 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
688 srcdev = dev_replace->srcdev;
689 args->status.progress_1000 = div_u64(dev_replace->cursor_left,
690 div_u64(btrfs_device_get_total_bytes(srcdev), 1000));
691 break;
692 }
693 btrfs_dev_replace_unlock(dev_replace);
694 }
695
btrfs_dev_replace_cancel(struct btrfs_fs_info * fs_info,struct btrfs_ioctl_dev_replace_args * args)696 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
697 struct btrfs_ioctl_dev_replace_args *args)
698 {
699 args->result = __btrfs_dev_replace_cancel(fs_info);
700 return 0;
701 }
702
__btrfs_dev_replace_cancel(struct btrfs_fs_info * fs_info)703 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
704 {
705 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
706 struct btrfs_device *tgt_device = NULL;
707 struct btrfs_trans_handle *trans;
708 struct btrfs_root *root = fs_info->tree_root;
709 u64 result;
710 int ret;
711
712 if (fs_info->sb->s_flags & MS_RDONLY)
713 return -EROFS;
714
715 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
716 btrfs_dev_replace_lock(dev_replace);
717 switch (dev_replace->replace_state) {
718 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
719 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
720 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
721 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
722 btrfs_dev_replace_unlock(dev_replace);
723 goto leave;
724 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
725 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
726 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
727 tgt_device = dev_replace->tgtdev;
728 dev_replace->tgtdev = NULL;
729 dev_replace->srcdev = NULL;
730 break;
731 }
732 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
733 dev_replace->time_stopped = get_seconds();
734 dev_replace->item_needs_writeback = 1;
735 btrfs_dev_replace_unlock(dev_replace);
736 btrfs_scrub_cancel(fs_info);
737
738 trans = btrfs_start_transaction(root, 0);
739 if (IS_ERR(trans)) {
740 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
741 return PTR_ERR(trans);
742 }
743 ret = btrfs_commit_transaction(trans, root);
744 WARN_ON(ret);
745 if (tgt_device)
746 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
747
748 leave:
749 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
750 return result;
751 }
752
btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info * fs_info)753 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info)
754 {
755 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
756
757 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
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 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
764 break;
765 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
766 dev_replace->replace_state =
767 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
768 dev_replace->time_stopped = get_seconds();
769 dev_replace->item_needs_writeback = 1;
770 btrfs_info(fs_info, "suspending dev_replace for unmount");
771 break;
772 }
773
774 btrfs_dev_replace_unlock(dev_replace);
775 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
776 }
777
778 /* resume dev_replace procedure that was interrupted by unmount */
btrfs_resume_dev_replace_async(struct btrfs_fs_info * fs_info)779 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
780 {
781 struct task_struct *task;
782 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
783
784 btrfs_dev_replace_lock(dev_replace);
785 switch (dev_replace->replace_state) {
786 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
787 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
788 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
789 btrfs_dev_replace_unlock(dev_replace);
790 return 0;
791 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
792 break;
793 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
794 dev_replace->replace_state =
795 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
796 break;
797 }
798 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) {
799 btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing");
800 btrfs_info(fs_info,
801 "you may cancel the operation after 'mount -o degraded'");
802 btrfs_dev_replace_unlock(dev_replace);
803 return 0;
804 }
805 btrfs_dev_replace_unlock(dev_replace);
806
807 WARN_ON(atomic_xchg(
808 &fs_info->mutually_exclusive_operation_running, 1));
809 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
810 return PTR_ERR_OR_ZERO(task);
811 }
812
btrfs_dev_replace_kthread(void * data)813 static int btrfs_dev_replace_kthread(void *data)
814 {
815 struct btrfs_fs_info *fs_info = data;
816 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
817 struct btrfs_ioctl_dev_replace_args *status_args;
818 u64 progress;
819
820 status_args = kzalloc(sizeof(*status_args), GFP_NOFS);
821 if (status_args) {
822 btrfs_dev_replace_status(fs_info, status_args);
823 progress = status_args->status.progress_1000;
824 kfree(status_args);
825 progress = div_u64(progress, 10);
826 btrfs_info_in_rcu(fs_info,
827 "continuing dev_replace from %s (devid %llu) to %s @%u%%",
828 dev_replace->srcdev->missing ? "<missing disk>" :
829 rcu_str_deref(dev_replace->srcdev->name),
830 dev_replace->srcdev->devid,
831 dev_replace->tgtdev ?
832 rcu_str_deref(dev_replace->tgtdev->name) :
833 "<missing target disk>",
834 (unsigned int)progress);
835 }
836 btrfs_dev_replace_continue_on_mount(fs_info);
837 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
838
839 return 0;
840 }
841
btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info * fs_info)842 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info)
843 {
844 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
845 int ret;
846
847 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid,
848 dev_replace->committed_cursor_left,
849 btrfs_device_get_total_bytes(dev_replace->srcdev),
850 &dev_replace->scrub_progress, 0, 1);
851 ret = btrfs_dev_replace_finishing(fs_info, ret);
852 WARN_ON(ret);
853 return 0;
854 }
855
btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace * dev_replace)856 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
857 {
858 if (!dev_replace->is_valid)
859 return 0;
860
861 switch (dev_replace->replace_state) {
862 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
863 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
864 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
865 return 0;
866 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
867 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
868 /*
869 * return true even if tgtdev is missing (this is
870 * something that can happen if the dev_replace
871 * procedure is suspended by an umount and then
872 * the tgtdev is missing (or "btrfs dev scan") was
873 * not called and the the filesystem is remounted
874 * in degraded state. This does not stop the
875 * dev_replace procedure. It needs to be canceled
876 * manually if the cancelation is wanted.
877 */
878 break;
879 }
880 return 1;
881 }
882
btrfs_dev_replace_lock(struct btrfs_dev_replace * dev_replace)883 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace)
884 {
885 /* the beginning is just an optimization for the typical case */
886 if (atomic_read(&dev_replace->nesting_level) == 0) {
887 acquire_lock:
888 /* this is not a nested case where the same thread
889 * is trying to acqurire the same lock twice */
890 mutex_lock(&dev_replace->lock);
891 mutex_lock(&dev_replace->lock_management_lock);
892 dev_replace->lock_owner = current->pid;
893 atomic_inc(&dev_replace->nesting_level);
894 mutex_unlock(&dev_replace->lock_management_lock);
895 return;
896 }
897
898 mutex_lock(&dev_replace->lock_management_lock);
899 if (atomic_read(&dev_replace->nesting_level) > 0 &&
900 dev_replace->lock_owner == current->pid) {
901 WARN_ON(!mutex_is_locked(&dev_replace->lock));
902 atomic_inc(&dev_replace->nesting_level);
903 mutex_unlock(&dev_replace->lock_management_lock);
904 return;
905 }
906
907 mutex_unlock(&dev_replace->lock_management_lock);
908 goto acquire_lock;
909 }
910
btrfs_dev_replace_unlock(struct btrfs_dev_replace * dev_replace)911 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace)
912 {
913 WARN_ON(!mutex_is_locked(&dev_replace->lock));
914 mutex_lock(&dev_replace->lock_management_lock);
915 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1);
916 WARN_ON(dev_replace->lock_owner != current->pid);
917 atomic_dec(&dev_replace->nesting_level);
918 if (atomic_read(&dev_replace->nesting_level) == 0) {
919 dev_replace->lock_owner = 0;
920 mutex_unlock(&dev_replace->lock_management_lock);
921 mutex_unlock(&dev_replace->lock);
922 } else {
923 mutex_unlock(&dev_replace->lock_management_lock);
924 }
925 }
926
btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info * fs_info)927 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
928 {
929 percpu_counter_inc(&fs_info->bio_counter);
930 }
931
btrfs_bio_counter_sub(struct btrfs_fs_info * fs_info,s64 amount)932 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount)
933 {
934 percpu_counter_sub(&fs_info->bio_counter, amount);
935
936 if (waitqueue_active(&fs_info->replace_wait))
937 wake_up(&fs_info->replace_wait);
938 }
939
btrfs_bio_counter_inc_blocked(struct btrfs_fs_info * fs_info)940 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
941 {
942 while (1) {
943 percpu_counter_inc(&fs_info->bio_counter);
944 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING,
945 &fs_info->fs_state)))
946 break;
947
948 btrfs_bio_counter_dec(fs_info);
949 wait_event(fs_info->replace_wait,
950 !test_bit(BTRFS_FS_STATE_DEV_REPLACING,
951 &fs_info->fs_state));
952 }
953 }
954