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 u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
48 static int btrfs_dev_replace_kthread(void *data);
49 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
50
51
btrfs_init_dev_replace(struct btrfs_fs_info * fs_info)52 int 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) {
76 no_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
182 out:
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 */
btrfs_run_dev_replace(struct btrfs_trans_handle * trans,struct btrfs_fs_info * fs_info)191 int 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
293 out:
294 btrfs_free_path(path);
295
296 return ret;
297 }
298
btrfs_after_dev_replace_commit(struct btrfs_fs_info * fs_info)299 void 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
btrfs_dev_replace_start(struct btrfs_fs_info * fs_info,const char * tgtdev_name,u64 srcdevid,const char * srcdev_name,int read_src)307 int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
308 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name,
309 int read_src)
310 {
311 struct btrfs_root *root = fs_info->dev_root;
312 struct btrfs_trans_handle *trans;
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 /* the disk copy procedure reuses the scrub code */
319 mutex_lock(&fs_info->volume_mutex);
320 ret = btrfs_find_device_by_devspec(fs_info, srcdevid,
321 srcdev_name, &src_device);
322 if (ret) {
323 mutex_unlock(&fs_info->volume_mutex);
324 return ret;
325 }
326
327 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name,
328 src_device, &tgt_device);
329 mutex_unlock(&fs_info->volume_mutex);
330 if (ret)
331 return ret;
332
333 /*
334 * Here we commit the transaction to make sure commit_total_bytes
335 * of all the devices are updated.
336 */
337 trans = btrfs_attach_transaction(root);
338 if (!IS_ERR(trans)) {
339 ret = btrfs_commit_transaction(trans);
340 if (ret)
341 return ret;
342 } else if (PTR_ERR(trans) != -ENOENT) {
343 return PTR_ERR(trans);
344 }
345
346 btrfs_dev_replace_lock(dev_replace, 1);
347 switch (dev_replace->replace_state) {
348 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
349 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
350 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
351 break;
352 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
353 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
354 ASSERT(0);
355 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
356 goto leave;
357 }
358
359 dev_replace->cont_reading_from_srcdev_mode = read_src;
360 WARN_ON(!src_device);
361 dev_replace->srcdev = src_device;
362 WARN_ON(!tgt_device);
363 dev_replace->tgtdev = tgt_device;
364
365 btrfs_info_in_rcu(fs_info,
366 "dev_replace from %s (devid %llu) to %s started",
367 src_device->missing ? "<missing disk>" :
368 rcu_str_deref(src_device->name),
369 src_device->devid,
370 rcu_str_deref(tgt_device->name));
371
372 /*
373 * from now on, the writes to the srcdev are all duplicated to
374 * go to the tgtdev as well (refer to btrfs_map_block()).
375 */
376 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
377 dev_replace->time_started = get_seconds();
378 dev_replace->cursor_left = 0;
379 dev_replace->committed_cursor_left = 0;
380 dev_replace->cursor_left_last_write_of_item = 0;
381 dev_replace->cursor_right = 0;
382 dev_replace->is_valid = 1;
383 dev_replace->item_needs_writeback = 1;
384 atomic64_set(&dev_replace->num_write_errors, 0);
385 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
386 btrfs_dev_replace_unlock(dev_replace, 1);
387
388 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device);
389 if (ret)
390 btrfs_err(fs_info, "kobj add dev failed %d", ret);
391
392 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
393
394 /* force writing the updated state information to disk */
395 trans = btrfs_start_transaction(root, 0);
396 if (IS_ERR(trans)) {
397 ret = PTR_ERR(trans);
398 btrfs_dev_replace_lock(dev_replace, 1);
399 dev_replace->replace_state =
400 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED;
401 dev_replace->srcdev = NULL;
402 dev_replace->tgtdev = NULL;
403 goto leave;
404 }
405
406 ret = btrfs_commit_transaction(trans);
407 WARN_ON(ret);
408
409 /* the disk copy procedure reuses the scrub code */
410 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
411 btrfs_device_get_total_bytes(src_device),
412 &dev_replace->scrub_progress, 0, 1);
413
414 ret = btrfs_dev_replace_finishing(fs_info, ret);
415 if (ret == -EINPROGRESS) {
416 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
417 } else {
418 WARN_ON(ret);
419 }
420
421 return ret;
422
423 leave:
424 btrfs_dev_replace_unlock(dev_replace, 1);
425 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
426 return ret;
427 }
428
btrfs_dev_replace_by_ioctl(struct btrfs_fs_info * fs_info,struct btrfs_ioctl_dev_replace_args * args)429 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info,
430 struct btrfs_ioctl_dev_replace_args *args)
431 {
432 int ret;
433
434 switch (args->start.cont_reading_from_srcdev_mode) {
435 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
436 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
437 break;
438 default:
439 return -EINVAL;
440 }
441
442 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
443 args->start.tgtdev_name[0] == '\0')
444 return -EINVAL;
445
446 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name,
447 args->start.srcdevid,
448 args->start.srcdev_name,
449 args->start.cont_reading_from_srcdev_mode);
450 args->result = ret;
451 /* don't warn if EINPROGRESS, someone else might be running scrub */
452 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS)
453 ret = 0;
454
455 return ret;
456 }
457
458 /*
459 * blocked until all in-flight bios operations are finished.
460 */
btrfs_rm_dev_replace_blocked(struct btrfs_fs_info * fs_info)461 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
462 {
463 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
464 wait_event(fs_info->replace_wait, !percpu_counter_sum(
465 &fs_info->bio_counter));
466 }
467
468 /*
469 * we have removed target device, it is safe to allow new bios request.
470 */
btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info * fs_info)471 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info)
472 {
473 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
474 wake_up(&fs_info->replace_wait);
475 }
476
btrfs_dev_replace_finishing(struct btrfs_fs_info * fs_info,int scrub_ret)477 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
478 int scrub_ret)
479 {
480 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
481 struct btrfs_device *tgt_device;
482 struct btrfs_device *src_device;
483 struct btrfs_root *root = fs_info->tree_root;
484 u8 uuid_tmp[BTRFS_UUID_SIZE];
485 struct btrfs_trans_handle *trans;
486 int ret = 0;
487
488 /* don't allow cancel or unmount to disturb the finishing procedure */
489 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
490
491 btrfs_dev_replace_lock(dev_replace, 0);
492 /* was the operation canceled, or is it finished? */
493 if (dev_replace->replace_state !=
494 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
495 btrfs_dev_replace_unlock(dev_replace, 0);
496 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
497 return 0;
498 }
499
500 tgt_device = dev_replace->tgtdev;
501 src_device = dev_replace->srcdev;
502 btrfs_dev_replace_unlock(dev_replace, 0);
503
504 /*
505 * flush all outstanding I/O and inode extent mappings before the
506 * copy operation is declared as being finished
507 */
508 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
509 if (ret) {
510 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
511 return ret;
512 }
513 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
514
515 while (1) {
516 trans = btrfs_start_transaction(root, 0);
517 if (IS_ERR(trans)) {
518 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
519 return PTR_ERR(trans);
520 }
521 ret = btrfs_commit_transaction(trans);
522 WARN_ON(ret);
523 mutex_lock(&uuid_mutex);
524 /* keep away write_all_supers() during the finishing procedure */
525 mutex_lock(&fs_info->fs_devices->device_list_mutex);
526 mutex_lock(&fs_info->chunk_mutex);
527 if (src_device->has_pending_chunks) {
528 mutex_unlock(&root->fs_info->chunk_mutex);
529 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
530 mutex_unlock(&uuid_mutex);
531 } else {
532 break;
533 }
534 }
535
536 btrfs_dev_replace_lock(dev_replace, 1);
537 dev_replace->replace_state =
538 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
539 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
540 dev_replace->tgtdev = NULL;
541 dev_replace->srcdev = NULL;
542 dev_replace->time_stopped = get_seconds();
543 dev_replace->item_needs_writeback = 1;
544
545 /* replace old device with new one in mapping tree */
546 if (!scrub_ret) {
547 btrfs_dev_replace_update_device_in_mapping_tree(fs_info,
548 src_device,
549 tgt_device);
550 } else {
551 btrfs_err_in_rcu(fs_info,
552 "btrfs_scrub_dev(%s, %llu, %s) failed %d",
553 src_device->missing ? "<missing disk>" :
554 rcu_str_deref(src_device->name),
555 src_device->devid,
556 rcu_str_deref(tgt_device->name), scrub_ret);
557 btrfs_dev_replace_unlock(dev_replace, 1);
558 mutex_unlock(&fs_info->chunk_mutex);
559 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
560 mutex_unlock(&uuid_mutex);
561 btrfs_rm_dev_replace_blocked(fs_info);
562 if (tgt_device)
563 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
564 btrfs_rm_dev_replace_unblocked(fs_info);
565 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
566
567 return scrub_ret;
568 }
569
570 btrfs_info_in_rcu(fs_info,
571 "dev_replace from %s (devid %llu) to %s finished",
572 src_device->missing ? "<missing disk>" :
573 rcu_str_deref(src_device->name),
574 src_device->devid,
575 rcu_str_deref(tgt_device->name));
576 tgt_device->is_tgtdev_for_dev_replace = 0;
577 tgt_device->devid = src_device->devid;
578 src_device->devid = BTRFS_DEV_REPLACE_DEVID;
579 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp));
580 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid));
581 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid));
582 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes);
583 btrfs_device_set_disk_total_bytes(tgt_device,
584 src_device->disk_total_bytes);
585 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used);
586 ASSERT(list_empty(&src_device->resized_list));
587 tgt_device->commit_total_bytes = src_device->commit_total_bytes;
588 tgt_device->commit_bytes_used = src_device->bytes_used;
589
590 btrfs_assign_next_active_device(fs_info, src_device, tgt_device);
591
592 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
593 fs_info->fs_devices->rw_devices++;
594
595 btrfs_dev_replace_unlock(dev_replace, 1);
596
597 btrfs_rm_dev_replace_blocked(fs_info);
598
599 btrfs_rm_dev_replace_remove_srcdev(fs_info, src_device);
600
601 btrfs_rm_dev_replace_unblocked(fs_info);
602
603 /*
604 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will
605 * update on-disk dev stats value during commit transaction
606 */
607 atomic_inc(&tgt_device->dev_stats_ccnt);
608
609 /*
610 * this is again a consistent state where no dev_replace procedure
611 * is running, the target device is part of the filesystem, the
612 * source device is not part of the filesystem anymore and its 1st
613 * superblock is scratched out so that it is no longer marked to
614 * belong to this filesystem.
615 */
616 mutex_unlock(&fs_info->chunk_mutex);
617 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
618 mutex_unlock(&uuid_mutex);
619
620 /* replace the sysfs entry */
621 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device);
622 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device);
623
624 /* write back the superblocks */
625 trans = btrfs_start_transaction(root, 0);
626 if (!IS_ERR(trans))
627 btrfs_commit_transaction(trans);
628
629 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
630
631 return 0;
632 }
633
btrfs_dev_replace_update_device_in_mapping_tree(struct btrfs_fs_info * fs_info,struct btrfs_device * srcdev,struct btrfs_device * tgtdev)634 static void btrfs_dev_replace_update_device_in_mapping_tree(
635 struct btrfs_fs_info *fs_info,
636 struct btrfs_device *srcdev,
637 struct btrfs_device *tgtdev)
638 {
639 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
640 struct extent_map *em;
641 struct map_lookup *map;
642 u64 start = 0;
643 int i;
644
645 write_lock(&em_tree->lock);
646 do {
647 em = lookup_extent_mapping(em_tree, start, (u64)-1);
648 if (!em)
649 break;
650 map = em->map_lookup;
651 for (i = 0; i < map->num_stripes; i++)
652 if (srcdev == map->stripes[i].dev)
653 map->stripes[i].dev = tgtdev;
654 start = em->start + em->len;
655 free_extent_map(em);
656 } while (start);
657 write_unlock(&em_tree->lock);
658 }
659
660 /*
661 * Read progress of device replace status according to the state and last
662 * stored position. The value format is the same as for
663 * btrfs_dev_replace::progress_1000
664 */
btrfs_dev_replace_progress(struct btrfs_fs_info * fs_info)665 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info)
666 {
667 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
668 u64 ret = 0;
669
670 switch (dev_replace->replace_state) {
671 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
672 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
673 ret = 0;
674 break;
675 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
676 ret = 1000;
677 break;
678 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
679 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
680 ret = div64_u64(dev_replace->cursor_left,
681 div_u64(btrfs_device_get_total_bytes(
682 dev_replace->srcdev), 1000));
683 break;
684 }
685
686 return ret;
687 }
688
btrfs_dev_replace_status(struct btrfs_fs_info * fs_info,struct btrfs_ioctl_dev_replace_args * args)689 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
690 struct btrfs_ioctl_dev_replace_args *args)
691 {
692 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
693
694 btrfs_dev_replace_lock(dev_replace, 0);
695 /* even if !dev_replace_is_valid, the values are good enough for
696 * the replace_status ioctl */
697 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
698 args->status.replace_state = dev_replace->replace_state;
699 args->status.time_started = dev_replace->time_started;
700 args->status.time_stopped = dev_replace->time_stopped;
701 args->status.num_write_errors =
702 atomic64_read(&dev_replace->num_write_errors);
703 args->status.num_uncorrectable_read_errors =
704 atomic64_read(&dev_replace->num_uncorrectable_read_errors);
705 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info);
706 btrfs_dev_replace_unlock(dev_replace, 0);
707 }
708
btrfs_dev_replace_cancel(struct btrfs_fs_info * fs_info,struct btrfs_ioctl_dev_replace_args * args)709 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
710 struct btrfs_ioctl_dev_replace_args *args)
711 {
712 args->result = __btrfs_dev_replace_cancel(fs_info);
713 return 0;
714 }
715
__btrfs_dev_replace_cancel(struct btrfs_fs_info * fs_info)716 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
717 {
718 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
719 struct btrfs_device *tgt_device = NULL;
720 struct btrfs_trans_handle *trans;
721 struct btrfs_root *root = fs_info->tree_root;
722 u64 result;
723 int ret;
724
725 if (sb_rdonly(fs_info->sb))
726 return -EROFS;
727
728 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
729 btrfs_dev_replace_lock(dev_replace, 1);
730 switch (dev_replace->replace_state) {
731 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
732 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
733 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
734 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
735 btrfs_dev_replace_unlock(dev_replace, 1);
736 goto leave;
737 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
738 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
739 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
740 tgt_device = dev_replace->tgtdev;
741 dev_replace->tgtdev = NULL;
742 dev_replace->srcdev = NULL;
743 break;
744 }
745 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
746 dev_replace->time_stopped = get_seconds();
747 dev_replace->item_needs_writeback = 1;
748 btrfs_dev_replace_unlock(dev_replace, 1);
749 btrfs_scrub_cancel(fs_info);
750
751 trans = btrfs_start_transaction(root, 0);
752 if (IS_ERR(trans)) {
753 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
754 return PTR_ERR(trans);
755 }
756 ret = btrfs_commit_transaction(trans);
757 WARN_ON(ret);
758 if (tgt_device)
759 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
760
761 leave:
762 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
763 return result;
764 }
765
btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info * fs_info)766 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info)
767 {
768 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
769
770 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
771 btrfs_dev_replace_lock(dev_replace, 1);
772 switch (dev_replace->replace_state) {
773 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
774 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
775 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
776 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
777 break;
778 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
779 dev_replace->replace_state =
780 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
781 dev_replace->time_stopped = get_seconds();
782 dev_replace->item_needs_writeback = 1;
783 btrfs_info(fs_info, "suspending dev_replace for unmount");
784 break;
785 }
786
787 btrfs_dev_replace_unlock(dev_replace, 1);
788 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
789 }
790
791 /* resume dev_replace procedure that was interrupted by unmount */
btrfs_resume_dev_replace_async(struct btrfs_fs_info * fs_info)792 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
793 {
794 struct task_struct *task;
795 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
796
797 btrfs_dev_replace_lock(dev_replace, 1);
798 switch (dev_replace->replace_state) {
799 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
800 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
801 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
802 btrfs_dev_replace_unlock(dev_replace, 1);
803 return 0;
804 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
805 break;
806 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
807 dev_replace->replace_state =
808 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
809 break;
810 }
811 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) {
812 btrfs_info(fs_info,
813 "cannot continue dev_replace, tgtdev is missing");
814 btrfs_info(fs_info,
815 "you may cancel the operation after 'mount -o degraded'");
816 dev_replace->replace_state =
817 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
818 btrfs_dev_replace_unlock(dev_replace, 1);
819 return 0;
820 }
821 btrfs_dev_replace_unlock(dev_replace, 1);
822
823 WARN_ON(test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
824 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
825 return PTR_ERR_OR_ZERO(task);
826 }
827
btrfs_dev_replace_kthread(void * data)828 static int btrfs_dev_replace_kthread(void *data)
829 {
830 struct btrfs_fs_info *fs_info = data;
831 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
832 u64 progress;
833
834 progress = btrfs_dev_replace_progress(fs_info);
835 progress = div_u64(progress, 10);
836 btrfs_info_in_rcu(fs_info,
837 "continuing dev_replace from %s (devid %llu) to %s @%u%%",
838 dev_replace->srcdev->missing ? "<missing disk>"
839 : rcu_str_deref(dev_replace->srcdev->name),
840 dev_replace->srcdev->devid,
841 dev_replace->tgtdev ? rcu_str_deref(dev_replace->tgtdev->name)
842 : "<missing target disk>",
843 (unsigned int)progress);
844
845 btrfs_dev_replace_continue_on_mount(fs_info);
846 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
847
848 return 0;
849 }
850
btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info * fs_info)851 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info)
852 {
853 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
854 int ret;
855
856 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid,
857 dev_replace->committed_cursor_left,
858 btrfs_device_get_total_bytes(dev_replace->srcdev),
859 &dev_replace->scrub_progress, 0, 1);
860 ret = btrfs_dev_replace_finishing(fs_info, ret);
861 WARN_ON(ret);
862 return 0;
863 }
864
btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace * dev_replace)865 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
866 {
867 if (!dev_replace->is_valid)
868 return 0;
869
870 switch (dev_replace->replace_state) {
871 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
872 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
873 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
874 return 0;
875 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
876 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
877 /*
878 * return true even if tgtdev is missing (this is
879 * something that can happen if the dev_replace
880 * procedure is suspended by an umount and then
881 * the tgtdev is missing (or "btrfs dev scan") was
882 * not called and the the filesystem is remounted
883 * in degraded state. This does not stop the
884 * dev_replace procedure. It needs to be canceled
885 * manually if the cancellation is wanted.
886 */
887 break;
888 }
889 return 1;
890 }
891
btrfs_dev_replace_lock(struct btrfs_dev_replace * dev_replace,int rw)892 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw)
893 {
894 if (rw == 1) {
895 /* write */
896 again:
897 wait_event(dev_replace->read_lock_wq,
898 atomic_read(&dev_replace->blocking_readers) == 0);
899 write_lock(&dev_replace->lock);
900 if (atomic_read(&dev_replace->blocking_readers)) {
901 write_unlock(&dev_replace->lock);
902 goto again;
903 }
904 } else {
905 read_lock(&dev_replace->lock);
906 atomic_inc(&dev_replace->read_locks);
907 }
908 }
909
btrfs_dev_replace_unlock(struct btrfs_dev_replace * dev_replace,int rw)910 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw)
911 {
912 if (rw == 1) {
913 /* write */
914 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0);
915 write_unlock(&dev_replace->lock);
916 } else {
917 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
918 atomic_dec(&dev_replace->read_locks);
919 read_unlock(&dev_replace->lock);
920 }
921 }
922
923 /* inc blocking cnt and release read lock */
btrfs_dev_replace_set_lock_blocking(struct btrfs_dev_replace * dev_replace)924 void btrfs_dev_replace_set_lock_blocking(
925 struct btrfs_dev_replace *dev_replace)
926 {
927 /* only set blocking for read lock */
928 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
929 atomic_inc(&dev_replace->blocking_readers);
930 read_unlock(&dev_replace->lock);
931 }
932
933 /* acquire read lock and dec blocking cnt */
btrfs_dev_replace_clear_lock_blocking(struct btrfs_dev_replace * dev_replace)934 void btrfs_dev_replace_clear_lock_blocking(
935 struct btrfs_dev_replace *dev_replace)
936 {
937 /* only set blocking for read lock */
938 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
939 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0);
940 read_lock(&dev_replace->lock);
941 if (atomic_dec_and_test(&dev_replace->blocking_readers) &&
942 waitqueue_active(&dev_replace->read_lock_wq))
943 wake_up(&dev_replace->read_lock_wq);
944 }
945
btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info * fs_info)946 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
947 {
948 percpu_counter_inc(&fs_info->bio_counter);
949 }
950
btrfs_bio_counter_sub(struct btrfs_fs_info * fs_info,s64 amount)951 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount)
952 {
953 percpu_counter_sub(&fs_info->bio_counter, amount);
954
955 if (waitqueue_active(&fs_info->replace_wait))
956 wake_up(&fs_info->replace_wait);
957 }
958
btrfs_bio_counter_inc_blocked(struct btrfs_fs_info * fs_info)959 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
960 {
961 while (1) {
962 percpu_counter_inc(&fs_info->bio_counter);
963 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING,
964 &fs_info->fs_state)))
965 break;
966
967 btrfs_bio_counter_dec(fs_info);
968 wait_event(fs_info->replace_wait,
969 !test_bit(BTRFS_FS_STATE_DEV_REPLACING,
970 &fs_info->fs_state));
971 }
972 }
973