blob: 4253ad580e391489c71c671df92450f048d29aae [file] [log] [blame]
Stefan Behrense93c89c2012-11-05 17:33:06 +01001/*
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 "compat.h"
30#include "ctree.h"
31#include "extent_map.h"
32#include "disk-io.h"
33#include "transaction.h"
34#include "print-tree.h"
35#include "volumes.h"
36#include "async-thread.h"
37#include "check-integrity.h"
38#include "rcu-string.h"
39#include "dev-replace.h"
40
41static u64 btrfs_get_seconds_since_1970(void);
42static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
43 int scrub_ret);
44static void btrfs_dev_replace_update_device_in_mapping_tree(
45 struct btrfs_fs_info *fs_info,
46 struct btrfs_device *srcdev,
47 struct btrfs_device *tgtdev);
48static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
49 char *srcdev_name,
50 struct btrfs_device **device);
51static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
52static int btrfs_dev_replace_kthread(void *data);
53static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
54
55
56int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info)
57{
58 struct btrfs_key key;
59 struct btrfs_root *dev_root = fs_info->dev_root;
60 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
61 struct extent_buffer *eb;
62 int slot;
63 int ret = 0;
64 struct btrfs_path *path = NULL;
65 int item_size;
66 struct btrfs_dev_replace_item *ptr;
67 u64 src_devid;
68
69 path = btrfs_alloc_path();
70 if (!path) {
71 ret = -ENOMEM;
72 goto out;
73 }
74
75 key.objectid = 0;
76 key.type = BTRFS_DEV_REPLACE_KEY;
77 key.offset = 0;
78 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
79 if (ret) {
80no_valid_dev_replace_entry_found:
81 ret = 0;
82 dev_replace->replace_state =
83 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED;
84 dev_replace->cont_reading_from_srcdev_mode =
85 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS;
86 dev_replace->replace_state = 0;
87 dev_replace->time_started = 0;
88 dev_replace->time_stopped = 0;
89 atomic64_set(&dev_replace->num_write_errors, 0);
90 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
91 dev_replace->cursor_left = 0;
92 dev_replace->committed_cursor_left = 0;
93 dev_replace->cursor_left_last_write_of_item = 0;
94 dev_replace->cursor_right = 0;
95 dev_replace->srcdev = NULL;
96 dev_replace->tgtdev = NULL;
97 dev_replace->is_valid = 0;
98 dev_replace->item_needs_writeback = 0;
99 goto out;
100 }
101 slot = path->slots[0];
102 eb = path->nodes[0];
103 item_size = btrfs_item_size_nr(eb, slot);
104 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item);
105
106 if (item_size != sizeof(struct btrfs_dev_replace_item)) {
107 pr_warn("btrfs: dev_replace entry found has unexpected size, ignore entry\n");
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 pr_warn("btrfs: cannot mount because device replace operation is ongoing and\n" "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?\n",
151 (unsigned long long)src_devid);
152 }
153 if (!dev_replace->tgtdev &&
154 !btrfs_test_opt(dev_root, DEGRADED)) {
155 ret = -EIO;
156 pr_warn("btrfs: cannot mount because device replace operation is ongoing and\n" "tgtdev (devid %llu) is missing, need to run btrfs dev scan?\n",
157 (unsigned long long)BTRFS_DEV_REPLACE_DEVID);
158 }
159 if (dev_replace->tgtdev) {
160 if (dev_replace->srcdev) {
161 dev_replace->tgtdev->total_bytes =
162 dev_replace->srcdev->total_bytes;
163 dev_replace->tgtdev->disk_total_bytes =
164 dev_replace->srcdev->disk_total_bytes;
165 dev_replace->tgtdev->bytes_used =
166 dev_replace->srcdev->bytes_used;
167 }
168 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1;
169 btrfs_init_dev_replace_tgtdev_for_resume(fs_info,
170 dev_replace->tgtdev);
171 }
172 break;
173 }
174
175out:
176 if (path)
177 btrfs_free_path(path);
178 return ret;
179}
180
181/*
182 * called from commit_transaction. Writes changed device replace state to
183 * disk.
184 */
185int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
186 struct btrfs_fs_info *fs_info)
187{
188 int ret;
189 struct btrfs_root *dev_root = fs_info->dev_root;
190 struct btrfs_path *path;
191 struct btrfs_key key;
192 struct extent_buffer *eb;
193 struct btrfs_dev_replace_item *ptr;
194 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
195
196 btrfs_dev_replace_lock(dev_replace);
197 if (!dev_replace->is_valid ||
198 !dev_replace->item_needs_writeback) {
199 btrfs_dev_replace_unlock(dev_replace);
200 return 0;
201 }
202 btrfs_dev_replace_unlock(dev_replace);
203
204 key.objectid = 0;
205 key.type = BTRFS_DEV_REPLACE_KEY;
206 key.offset = 0;
207
208 path = btrfs_alloc_path();
209 if (!path) {
210 ret = -ENOMEM;
211 goto out;
212 }
213 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
214 if (ret < 0) {
215 pr_warn("btrfs: error %d while searching for dev_replace item!\n",
216 ret);
217 goto out;
218 }
219
220 if (ret == 0 &&
221 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
222 /*
223 * need to delete old one and insert a new one.
224 * Since no attempt is made to recover any old state, if the
225 * dev_replace state is 'running', the data on the target
226 * drive is lost.
227 * It would be possible to recover the state: just make sure
228 * that the beginning of the item is never changed and always
229 * contains all the essential information. Then read this
230 * minimal set of information and use it as a base for the
231 * new state.
232 */
233 ret = btrfs_del_item(trans, dev_root, path);
234 if (ret != 0) {
235 pr_warn("btrfs: delete too small dev_replace item failed %d!\n",
236 ret);
237 goto out;
238 }
239 ret = 1;
240 }
241
242 if (ret == 1) {
243 /* need to insert a new item */
244 btrfs_release_path(path);
245 ret = btrfs_insert_empty_item(trans, dev_root, path,
246 &key, sizeof(*ptr));
247 if (ret < 0) {
248 pr_warn("btrfs: insert dev_replace item failed %d!\n",
249 ret);
250 goto out;
251 }
252 }
253
254 eb = path->nodes[0];
255 ptr = btrfs_item_ptr(eb, path->slots[0],
256 struct btrfs_dev_replace_item);
257
258 btrfs_dev_replace_lock(dev_replace);
259 if (dev_replace->srcdev)
260 btrfs_set_dev_replace_src_devid(eb, ptr,
261 dev_replace->srcdev->devid);
262 else
263 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1);
264 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr,
265 dev_replace->cont_reading_from_srcdev_mode);
266 btrfs_set_dev_replace_replace_state(eb, ptr,
267 dev_replace->replace_state);
268 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started);
269 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped);
270 btrfs_set_dev_replace_num_write_errors(eb, ptr,
271 atomic64_read(&dev_replace->num_write_errors));
272 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr,
273 atomic64_read(&dev_replace->num_uncorrectable_read_errors));
274 dev_replace->cursor_left_last_write_of_item =
275 dev_replace->cursor_left;
276 btrfs_set_dev_replace_cursor_left(eb, ptr,
277 dev_replace->cursor_left_last_write_of_item);
278 btrfs_set_dev_replace_cursor_right(eb, ptr,
279 dev_replace->cursor_right);
280 dev_replace->item_needs_writeback = 0;
281 btrfs_dev_replace_unlock(dev_replace);
282
283 btrfs_mark_buffer_dirty(eb);
284
285out:
286 btrfs_free_path(path);
287
288 return ret;
289}
290
291void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
292{
293 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
294
295 dev_replace->committed_cursor_left =
296 dev_replace->cursor_left_last_write_of_item;
297}
298
299static u64 btrfs_get_seconds_since_1970(void)
300{
301 struct timespec t = CURRENT_TIME_SEC;
302
303 return t.tv_sec;
304}
305
306int btrfs_dev_replace_start(struct btrfs_root *root,
307 struct btrfs_ioctl_dev_replace_args *args)
308{
309 struct btrfs_trans_handle *trans;
310 struct btrfs_fs_info *fs_info = root->fs_info;
311 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
312 int ret;
313 struct btrfs_device *tgt_device = NULL;
314 struct btrfs_device *src_device = NULL;
315
Stefan Behrens49688102013-05-07 17:28:03 +0000316 if (btrfs_fs_incompat(fs_info, RAID56)) {
317 pr_warn("btrfs: dev_replace cannot yet handle RAID5/RAID6\n");
318 return -EINVAL;
319 }
320
Stefan Behrense93c89c2012-11-05 17:33:06 +0100321 switch (args->start.cont_reading_from_srcdev_mode) {
322 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
323 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
324 break;
325 default:
326 return -EINVAL;
327 }
328
329 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
330 args->start.tgtdev_name[0] == '\0')
331 return -EINVAL;
332
333 mutex_lock(&fs_info->volume_mutex);
334 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name,
335 &tgt_device);
336 if (ret) {
337 pr_err("btrfs: target device %s is invalid!\n",
338 args->start.tgtdev_name);
339 mutex_unlock(&fs_info->volume_mutex);
340 return -EINVAL;
341 }
342
343 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid,
344 args->start.srcdev_name,
345 &src_device);
346 mutex_unlock(&fs_info->volume_mutex);
347 if (ret) {
348 ret = -EINVAL;
349 goto leave_no_lock;
350 }
351
352 if (tgt_device->total_bytes < src_device->total_bytes) {
353 pr_err("btrfs: target device is smaller than source device!\n");
354 ret = -EINVAL;
355 goto leave_no_lock;
356 }
357
358 btrfs_dev_replace_lock(dev_replace);
359 switch (dev_replace->replace_state) {
360 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
361 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
362 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
363 break;
364 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
365 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
366 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
367 goto leave;
368 }
369
370 dev_replace->cont_reading_from_srcdev_mode =
371 args->start.cont_reading_from_srcdev_mode;
372 WARN_ON(!src_device);
373 dev_replace->srcdev = src_device;
374 WARN_ON(!tgt_device);
375 dev_replace->tgtdev = tgt_device;
376
377 printk_in_rcu(KERN_INFO
378 "btrfs: dev_replace from %s (devid %llu) to %s) started\n",
379 src_device->missing ? "<missing disk>" :
380 rcu_str_deref(src_device->name),
381 src_device->devid,
382 rcu_str_deref(tgt_device->name));
383
384 tgt_device->total_bytes = src_device->total_bytes;
385 tgt_device->disk_total_bytes = src_device->disk_total_bytes;
386 tgt_device->bytes_used = src_device->bytes_used;
387
388 /*
389 * from now on, the writes to the srcdev are all duplicated to
390 * go to the tgtdev as well (refer to btrfs_map_block()).
391 */
392 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
393 dev_replace->time_started = btrfs_get_seconds_since_1970();
394 dev_replace->cursor_left = 0;
395 dev_replace->committed_cursor_left = 0;
396 dev_replace->cursor_left_last_write_of_item = 0;
397 dev_replace->cursor_right = 0;
398 dev_replace->is_valid = 1;
399 dev_replace->item_needs_writeback = 1;
400 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
401 btrfs_dev_replace_unlock(dev_replace);
402
Miao Xie199c2a92013-05-15 07:48:23 +0000403 btrfs_wait_all_ordered_extents(root->fs_info, 0);
Stefan Behrense93c89c2012-11-05 17:33:06 +0100404
405 /* force writing the updated state information to disk */
406 trans = btrfs_start_transaction(root, 0);
407 if (IS_ERR(trans)) {
408 ret = PTR_ERR(trans);
409 btrfs_dev_replace_lock(dev_replace);
410 goto leave;
411 }
412
413 ret = btrfs_commit_transaction(trans, root);
414 WARN_ON(ret);
415
416 /* the disk copy procedure reuses the scrub code */
417 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
418 src_device->total_bytes,
419 &dev_replace->scrub_progress, 0, 1);
420
421 ret = btrfs_dev_replace_finishing(root->fs_info, ret);
422 WARN_ON(ret);
423
424 return 0;
425
426leave:
427 dev_replace->srcdev = NULL;
428 dev_replace->tgtdev = NULL;
429 btrfs_dev_replace_unlock(dev_replace);
430leave_no_lock:
431 if (tgt_device)
432 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
433 return ret;
434}
435
436static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
437 int scrub_ret)
438{
439 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
440 struct btrfs_device *tgt_device;
441 struct btrfs_device *src_device;
442 struct btrfs_root *root = fs_info->tree_root;
443 u8 uuid_tmp[BTRFS_UUID_SIZE];
444 struct btrfs_trans_handle *trans;
445 int ret = 0;
446
447 /* don't allow cancel or unmount to disturb the finishing procedure */
448 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
449
450 btrfs_dev_replace_lock(dev_replace);
451 /* was the operation canceled, or is it finished? */
452 if (dev_replace->replace_state !=
453 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
454 btrfs_dev_replace_unlock(dev_replace);
455 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
456 return 0;
457 }
458
459 tgt_device = dev_replace->tgtdev;
460 src_device = dev_replace->srcdev;
461 btrfs_dev_replace_unlock(dev_replace);
462
463 /* replace old device with new one in mapping tree */
464 if (!scrub_ret)
465 btrfs_dev_replace_update_device_in_mapping_tree(fs_info,
466 src_device,
467 tgt_device);
468
469 /*
470 * flush all outstanding I/O and inode extent mappings before the
471 * copy operation is declared as being finished
472 */
Miao Xieeb73c1b2013-05-15 07:48:22 +0000473 ret = btrfs_start_all_delalloc_inodes(root->fs_info, 0);
Miao Xie3edb2a62013-01-22 10:49:33 +0000474 if (ret) {
475 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
476 return ret;
477 }
Miao Xie199c2a92013-05-15 07:48:23 +0000478 btrfs_wait_all_ordered_extents(root->fs_info, 0);
Stefan Behrense93c89c2012-11-05 17:33:06 +0100479
480 trans = btrfs_start_transaction(root, 0);
481 if (IS_ERR(trans)) {
482 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
483 return PTR_ERR(trans);
484 }
485 ret = btrfs_commit_transaction(trans, root);
486 WARN_ON(ret);
487
488 /* keep away write_all_supers() during the finishing procedure */
489 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
490 btrfs_dev_replace_lock(dev_replace);
491 dev_replace->replace_state =
492 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
493 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
494 dev_replace->tgtdev = NULL;
495 dev_replace->srcdev = NULL;
496 dev_replace->time_stopped = btrfs_get_seconds_since_1970();
497 dev_replace->item_needs_writeback = 1;
498
499 if (scrub_ret) {
500 printk_in_rcu(KERN_ERR
501 "btrfs: btrfs_scrub_dev(%s, %llu, %s) failed %d\n",
502 src_device->missing ? "<missing disk>" :
503 rcu_str_deref(src_device->name),
504 src_device->devid,
505 rcu_str_deref(tgt_device->name), scrub_ret);
506 btrfs_dev_replace_unlock(dev_replace);
507 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
508 if (tgt_device)
509 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
510 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
511
512 return 0;
513 }
514
515 printk_in_rcu(KERN_INFO
516 "btrfs: dev_replace from %s (devid %llu) to %s) finished\n",
517 src_device->missing ? "<missing disk>" :
518 rcu_str_deref(src_device->name),
519 src_device->devid,
520 rcu_str_deref(tgt_device->name));
521 tgt_device->is_tgtdev_for_dev_replace = 0;
522 tgt_device->devid = src_device->devid;
523 src_device->devid = BTRFS_DEV_REPLACE_DEVID;
524 tgt_device->bytes_used = src_device->bytes_used;
525 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp));
526 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid));
527 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid));
528 tgt_device->total_bytes = src_device->total_bytes;
529 tgt_device->disk_total_bytes = src_device->disk_total_bytes;
530 tgt_device->bytes_used = src_device->bytes_used;
531 if (fs_info->sb->s_bdev == src_device->bdev)
532 fs_info->sb->s_bdev = tgt_device->bdev;
533 if (fs_info->fs_devices->latest_bdev == src_device->bdev)
534 fs_info->fs_devices->latest_bdev = tgt_device->bdev;
535 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
536
537 btrfs_rm_dev_replace_srcdev(fs_info, src_device);
538 if (src_device->bdev) {
539 /* zero out the old super */
540 btrfs_scratch_superblock(src_device);
541 }
542 /*
543 * this is again a consistent state where no dev_replace procedure
544 * is running, the target device is part of the filesystem, the
545 * source device is not part of the filesystem anymore and its 1st
546 * superblock is scratched out so that it is no longer marked to
547 * belong to this filesystem.
548 */
549 btrfs_dev_replace_unlock(dev_replace);
550 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
551
552 /* write back the superblocks */
553 trans = btrfs_start_transaction(root, 0);
554 if (!IS_ERR(trans))
555 btrfs_commit_transaction(trans, root);
556
557 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
558
559 return 0;
560}
561
562static void btrfs_dev_replace_update_device_in_mapping_tree(
563 struct btrfs_fs_info *fs_info,
564 struct btrfs_device *srcdev,
565 struct btrfs_device *tgtdev)
566{
567 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
568 struct extent_map *em;
569 struct map_lookup *map;
570 u64 start = 0;
571 int i;
572
573 write_lock(&em_tree->lock);
574 do {
575 em = lookup_extent_mapping(em_tree, start, (u64)-1);
576 if (!em)
577 break;
578 map = (struct map_lookup *)em->bdev;
579 for (i = 0; i < map->num_stripes; i++)
580 if (srcdev == map->stripes[i].dev)
581 map->stripes[i].dev = tgtdev;
582 start = em->start + em->len;
583 free_extent_map(em);
584 } while (start);
585 write_unlock(&em_tree->lock);
586}
587
588static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
589 char *srcdev_name,
590 struct btrfs_device **device)
591{
592 int ret;
593
594 if (srcdevid) {
595 ret = 0;
596 *device = btrfs_find_device(root->fs_info, srcdevid, NULL,
597 NULL);
598 if (!*device)
599 ret = -ENOENT;
600 } else {
601 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name,
602 device);
603 }
604 return ret;
605}
606
607void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
608 struct btrfs_ioctl_dev_replace_args *args)
609{
610 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
611
612 btrfs_dev_replace_lock(dev_replace);
613 /* even if !dev_replace_is_valid, the values are good enough for
614 * the replace_status ioctl */
615 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
616 args->status.replace_state = dev_replace->replace_state;
617 args->status.time_started = dev_replace->time_started;
618 args->status.time_stopped = dev_replace->time_stopped;
619 args->status.num_write_errors =
620 atomic64_read(&dev_replace->num_write_errors);
621 args->status.num_uncorrectable_read_errors =
622 atomic64_read(&dev_replace->num_uncorrectable_read_errors);
623 switch (dev_replace->replace_state) {
624 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
625 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
626 args->status.progress_1000 = 0;
627 break;
628 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
629 args->status.progress_1000 = 1000;
630 break;
631 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
632 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
633 args->status.progress_1000 = div64_u64(dev_replace->cursor_left,
634 div64_u64(dev_replace->srcdev->total_bytes, 1000));
635 break;
636 }
637 btrfs_dev_replace_unlock(dev_replace);
638}
639
640int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
641 struct btrfs_ioctl_dev_replace_args *args)
642{
643 args->result = __btrfs_dev_replace_cancel(fs_info);
644 return 0;
645}
646
647static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
648{
649 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
650 struct btrfs_device *tgt_device = NULL;
651 struct btrfs_trans_handle *trans;
652 struct btrfs_root *root = fs_info->tree_root;
653 u64 result;
654 int ret;
655
656 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
657 btrfs_dev_replace_lock(dev_replace);
658 switch (dev_replace->replace_state) {
659 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
660 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
661 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
662 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
663 btrfs_dev_replace_unlock(dev_replace);
664 goto leave;
665 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
666 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
667 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
668 tgt_device = dev_replace->tgtdev;
669 dev_replace->tgtdev = NULL;
670 dev_replace->srcdev = NULL;
671 break;
672 }
673 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
674 dev_replace->time_stopped = btrfs_get_seconds_since_1970();
675 dev_replace->item_needs_writeback = 1;
676 btrfs_dev_replace_unlock(dev_replace);
677 btrfs_scrub_cancel(fs_info);
678
679 trans = btrfs_start_transaction(root, 0);
680 if (IS_ERR(trans)) {
681 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
682 return PTR_ERR(trans);
683 }
684 ret = btrfs_commit_transaction(trans, root);
685 WARN_ON(ret);
686 if (tgt_device)
687 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
688
689leave:
690 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
691 return result;
692}
693
694void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info)
695{
696 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
697
698 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
699 btrfs_dev_replace_lock(dev_replace);
700 switch (dev_replace->replace_state) {
701 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
702 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
703 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
704 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
705 break;
706 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
707 dev_replace->replace_state =
708 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
709 dev_replace->time_stopped = btrfs_get_seconds_since_1970();
710 dev_replace->item_needs_writeback = 1;
711 pr_info("btrfs: suspending dev_replace for unmount\n");
712 break;
713 }
714
715 btrfs_dev_replace_unlock(dev_replace);
716 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
717}
718
719/* resume dev_replace procedure that was interrupted by unmount */
720int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
721{
722 struct task_struct *task;
723 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
724
725 btrfs_dev_replace_lock(dev_replace);
726 switch (dev_replace->replace_state) {
727 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
728 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
729 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
730 btrfs_dev_replace_unlock(dev_replace);
731 return 0;
732 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
733 break;
734 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
735 dev_replace->replace_state =
736 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
737 break;
738 }
739 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) {
740 pr_info("btrfs: cannot continue dev_replace, tgtdev is missing\n"
741 "btrfs: you may cancel the operation after 'mount -o degraded'\n");
742 btrfs_dev_replace_unlock(dev_replace);
743 return 0;
744 }
745 btrfs_dev_replace_unlock(dev_replace);
746
747 WARN_ON(atomic_xchg(
748 &fs_info->mutually_exclusive_operation_running, 1));
749 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
750 return PTR_RET(task);
751}
752
753static int btrfs_dev_replace_kthread(void *data)
754{
755 struct btrfs_fs_info *fs_info = data;
756 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
757 struct btrfs_ioctl_dev_replace_args *status_args;
758 u64 progress;
759
760 status_args = kzalloc(sizeof(*status_args), GFP_NOFS);
761 if (status_args) {
762 btrfs_dev_replace_status(fs_info, status_args);
763 progress = status_args->status.progress_1000;
764 kfree(status_args);
765 do_div(progress, 10);
766 printk_in_rcu(KERN_INFO
767 "btrfs: continuing dev_replace from %s (devid %llu) to %s @%u%%\n",
768 dev_replace->srcdev->missing ? "<missing disk>" :
769 rcu_str_deref(dev_replace->srcdev->name),
770 dev_replace->srcdev->devid,
771 dev_replace->tgtdev ?
772 rcu_str_deref(dev_replace->tgtdev->name) :
773 "<missing target disk>",
774 (unsigned int)progress);
775 }
776 btrfs_dev_replace_continue_on_mount(fs_info);
777 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
778
779 return 0;
780}
781
782static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info)
783{
784 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
785 int ret;
786
787 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid,
788 dev_replace->committed_cursor_left,
789 dev_replace->srcdev->total_bytes,
790 &dev_replace->scrub_progress, 0, 1);
791 ret = btrfs_dev_replace_finishing(fs_info, ret);
792 WARN_ON(ret);
793 return 0;
794}
795
796int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
797{
798 if (!dev_replace->is_valid)
799 return 0;
800
801 switch (dev_replace->replace_state) {
802 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
803 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
804 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
805 return 0;
806 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
807 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
808 /*
809 * return true even if tgtdev is missing (this is
810 * something that can happen if the dev_replace
811 * procedure is suspended by an umount and then
812 * the tgtdev is missing (or "btrfs dev scan") was
813 * not called and the the filesystem is remounted
814 * in degraded state. This does not stop the
815 * dev_replace procedure. It needs to be canceled
816 * manually if the cancelation is wanted.
817 */
818 break;
819 }
820 return 1;
821}
822
823void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace)
824{
825 /* the beginning is just an optimization for the typical case */
826 if (atomic_read(&dev_replace->nesting_level) == 0) {
827acquire_lock:
828 /* this is not a nested case where the same thread
829 * is trying to acqurire the same lock twice */
830 mutex_lock(&dev_replace->lock);
831 mutex_lock(&dev_replace->lock_management_lock);
832 dev_replace->lock_owner = current->pid;
833 atomic_inc(&dev_replace->nesting_level);
834 mutex_unlock(&dev_replace->lock_management_lock);
835 return;
836 }
837
838 mutex_lock(&dev_replace->lock_management_lock);
839 if (atomic_read(&dev_replace->nesting_level) > 0 &&
840 dev_replace->lock_owner == current->pid) {
841 WARN_ON(!mutex_is_locked(&dev_replace->lock));
842 atomic_inc(&dev_replace->nesting_level);
843 mutex_unlock(&dev_replace->lock_management_lock);
844 return;
845 }
846
847 mutex_unlock(&dev_replace->lock_management_lock);
848 goto acquire_lock;
849}
850
851void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace)
852{
853 WARN_ON(!mutex_is_locked(&dev_replace->lock));
854 mutex_lock(&dev_replace->lock_management_lock);
855 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1);
856 WARN_ON(dev_replace->lock_owner != current->pid);
857 atomic_dec(&dev_replace->nesting_level);
858 if (atomic_read(&dev_replace->nesting_level) == 0) {
859 dev_replace->lock_owner = 0;
860 mutex_unlock(&dev_replace->lock_management_lock);
861 mutex_unlock(&dev_replace->lock);
862 } else {
863 mutex_unlock(&dev_replace->lock_management_lock);
864 }
865}