arm: socfpga: Enable ARM_TWD for socfpga
[linux-2.6.git] / fs / btrfs / dev-replace.c
blob2cfc3dfff64f5708f71ec83af691b425b9f01b01
1 /*
2 * Copyright (C) STRATO AG 2012. All rights reserved.
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.
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.
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.
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"
40 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
41 int scrub_ret);
42 static void btrfs_dev_replace_update_device_in_mapping_tree(
43 struct btrfs_fs_info *fs_info,
44 struct btrfs_device *srcdev,
45 struct btrfs_device *tgtdev);
46 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
47 char *srcdev_name,
48 struct btrfs_device **device);
49 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
50 static int btrfs_dev_replace_kthread(void *data);
51 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
54 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info)
56 struct btrfs_key key;
57 struct btrfs_root *dev_root = fs_info->dev_root;
58 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
59 struct extent_buffer *eb;
60 int slot;
61 int ret = 0;
62 struct btrfs_path *path = NULL;
63 int item_size;
64 struct btrfs_dev_replace_item *ptr;
65 u64 src_devid;
67 path = btrfs_alloc_path();
68 if (!path) {
69 ret = -ENOMEM;
70 goto out;
73 key.objectid = 0;
74 key.type = BTRFS_DEV_REPLACE_KEY;
75 key.offset = 0;
76 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
77 if (ret) {
78 no_valid_dev_replace_entry_found:
79 ret = 0;
80 dev_replace->replace_state =
81 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED;
82 dev_replace->cont_reading_from_srcdev_mode =
83 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS;
84 dev_replace->replace_state = 0;
85 dev_replace->time_started = 0;
86 dev_replace->time_stopped = 0;
87 atomic64_set(&dev_replace->num_write_errors, 0);
88 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
89 dev_replace->cursor_left = 0;
90 dev_replace->committed_cursor_left = 0;
91 dev_replace->cursor_left_last_write_of_item = 0;
92 dev_replace->cursor_right = 0;
93 dev_replace->srcdev = NULL;
94 dev_replace->tgtdev = NULL;
95 dev_replace->is_valid = 0;
96 dev_replace->item_needs_writeback = 0;
97 goto out;
99 slot = path->slots[0];
100 eb = path->nodes[0];
101 item_size = btrfs_item_size_nr(eb, slot);
102 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item);
104 if (item_size != sizeof(struct btrfs_dev_replace_item)) {
105 pr_warn("btrfs: dev_replace entry found has unexpected size, ignore entry\n");
106 goto no_valid_dev_replace_entry_found;
109 src_devid = btrfs_dev_replace_src_devid(eb, ptr);
110 dev_replace->cont_reading_from_srcdev_mode =
111 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr);
112 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr);
113 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr);
114 dev_replace->time_stopped =
115 btrfs_dev_replace_time_stopped(eb, ptr);
116 atomic64_set(&dev_replace->num_write_errors,
117 btrfs_dev_replace_num_write_errors(eb, ptr));
118 atomic64_set(&dev_replace->num_uncorrectable_read_errors,
119 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr));
120 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr);
121 dev_replace->committed_cursor_left = dev_replace->cursor_left;
122 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left;
123 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr);
124 dev_replace->is_valid = 1;
126 dev_replace->item_needs_writeback = 0;
127 switch (dev_replace->replace_state) {
128 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
129 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
130 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
131 dev_replace->srcdev = NULL;
132 dev_replace->tgtdev = NULL;
133 break;
134 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
135 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
136 dev_replace->srcdev = btrfs_find_device(fs_info, src_devid,
137 NULL, NULL);
138 dev_replace->tgtdev = btrfs_find_device(fs_info,
139 BTRFS_DEV_REPLACE_DEVID,
140 NULL, NULL);
142 * allow 'btrfs dev replace_cancel' if src/tgt device is
143 * missing
145 if (!dev_replace->srcdev &&
146 !btrfs_test_opt(dev_root, DEGRADED)) {
147 ret = -EIO;
148 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",
149 src_devid);
151 if (!dev_replace->tgtdev &&
152 !btrfs_test_opt(dev_root, DEGRADED)) {
153 ret = -EIO;
154 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",
155 BTRFS_DEV_REPLACE_DEVID);
157 if (dev_replace->tgtdev) {
158 if (dev_replace->srcdev) {
159 dev_replace->tgtdev->total_bytes =
160 dev_replace->srcdev->total_bytes;
161 dev_replace->tgtdev->disk_total_bytes =
162 dev_replace->srcdev->disk_total_bytes;
163 dev_replace->tgtdev->bytes_used =
164 dev_replace->srcdev->bytes_used;
166 dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1;
167 btrfs_init_dev_replace_tgtdev_for_resume(fs_info,
168 dev_replace->tgtdev);
170 break;
173 out:
174 if (path)
175 btrfs_free_path(path);
176 return ret;
180 * called from commit_transaction. Writes changed device replace state to
181 * disk.
183 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
184 struct btrfs_fs_info *fs_info)
186 int ret;
187 struct btrfs_root *dev_root = fs_info->dev_root;
188 struct btrfs_path *path;
189 struct btrfs_key key;
190 struct extent_buffer *eb;
191 struct btrfs_dev_replace_item *ptr;
192 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
194 btrfs_dev_replace_lock(dev_replace);
195 if (!dev_replace->is_valid ||
196 !dev_replace->item_needs_writeback) {
197 btrfs_dev_replace_unlock(dev_replace);
198 return 0;
200 btrfs_dev_replace_unlock(dev_replace);
202 key.objectid = 0;
203 key.type = BTRFS_DEV_REPLACE_KEY;
204 key.offset = 0;
206 path = btrfs_alloc_path();
207 if (!path) {
208 ret = -ENOMEM;
209 goto out;
211 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
212 if (ret < 0) {
213 pr_warn("btrfs: error %d while searching for dev_replace item!\n",
214 ret);
215 goto out;
218 if (ret == 0 &&
219 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
221 * need to delete old one and insert a new one.
222 * Since no attempt is made to recover any old state, if the
223 * dev_replace state is 'running', the data on the target
224 * drive is lost.
225 * It would be possible to recover the state: just make sure
226 * that the beginning of the item is never changed and always
227 * contains all the essential information. Then read this
228 * minimal set of information and use it as a base for the
229 * new state.
231 ret = btrfs_del_item(trans, dev_root, path);
232 if (ret != 0) {
233 pr_warn("btrfs: delete too small dev_replace item failed %d!\n",
234 ret);
235 goto out;
237 ret = 1;
240 if (ret == 1) {
241 /* need to insert a new item */
242 btrfs_release_path(path);
243 ret = btrfs_insert_empty_item(trans, dev_root, path,
244 &key, sizeof(*ptr));
245 if (ret < 0) {
246 pr_warn("btrfs: insert dev_replace item failed %d!\n",
247 ret);
248 goto out;
252 eb = path->nodes[0];
253 ptr = btrfs_item_ptr(eb, path->slots[0],
254 struct btrfs_dev_replace_item);
256 btrfs_dev_replace_lock(dev_replace);
257 if (dev_replace->srcdev)
258 btrfs_set_dev_replace_src_devid(eb, ptr,
259 dev_replace->srcdev->devid);
260 else
261 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1);
262 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr,
263 dev_replace->cont_reading_from_srcdev_mode);
264 btrfs_set_dev_replace_replace_state(eb, ptr,
265 dev_replace->replace_state);
266 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started);
267 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped);
268 btrfs_set_dev_replace_num_write_errors(eb, ptr,
269 atomic64_read(&dev_replace->num_write_errors));
270 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr,
271 atomic64_read(&dev_replace->num_uncorrectable_read_errors));
272 dev_replace->cursor_left_last_write_of_item =
273 dev_replace->cursor_left;
274 btrfs_set_dev_replace_cursor_left(eb, ptr,
275 dev_replace->cursor_left_last_write_of_item);
276 btrfs_set_dev_replace_cursor_right(eb, ptr,
277 dev_replace->cursor_right);
278 dev_replace->item_needs_writeback = 0;
279 btrfs_dev_replace_unlock(dev_replace);
281 btrfs_mark_buffer_dirty(eb);
283 out:
284 btrfs_free_path(path);
286 return ret;
289 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
291 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
293 dev_replace->committed_cursor_left =
294 dev_replace->cursor_left_last_write_of_item;
297 int btrfs_dev_replace_start(struct btrfs_root *root,
298 struct btrfs_ioctl_dev_replace_args *args)
300 struct btrfs_trans_handle *trans;
301 struct btrfs_fs_info *fs_info = root->fs_info;
302 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
303 int ret;
304 struct btrfs_device *tgt_device = NULL;
305 struct btrfs_device *src_device = NULL;
307 if (btrfs_fs_incompat(fs_info, RAID56)) {
308 pr_warn("btrfs: dev_replace cannot yet handle RAID5/RAID6\n");
309 return -EINVAL;
312 switch (args->start.cont_reading_from_srcdev_mode) {
313 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
314 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
315 break;
316 default:
317 return -EINVAL;
320 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
321 args->start.tgtdev_name[0] == '\0')
322 return -EINVAL;
324 mutex_lock(&fs_info->volume_mutex);
325 ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name,
326 &tgt_device);
327 if (ret) {
328 pr_err("btrfs: target device %s is invalid!\n",
329 args->start.tgtdev_name);
330 mutex_unlock(&fs_info->volume_mutex);
331 return -EINVAL;
334 ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid,
335 args->start.srcdev_name,
336 &src_device);
337 mutex_unlock(&fs_info->volume_mutex);
338 if (ret) {
339 ret = -EINVAL;
340 goto leave_no_lock;
343 if (tgt_device->total_bytes < src_device->total_bytes) {
344 pr_err("btrfs: target device is smaller than source device!\n");
345 ret = -EINVAL;
346 goto leave_no_lock;
349 btrfs_dev_replace_lock(dev_replace);
350 switch (dev_replace->replace_state) {
351 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
352 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
353 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
354 break;
355 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
356 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
357 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
358 goto leave;
361 dev_replace->cont_reading_from_srcdev_mode =
362 args->start.cont_reading_from_srcdev_mode;
363 WARN_ON(!src_device);
364 dev_replace->srcdev = src_device;
365 WARN_ON(!tgt_device);
366 dev_replace->tgtdev = tgt_device;
368 printk_in_rcu(KERN_INFO
369 "btrfs: dev_replace from %s (devid %llu) to %s started\n",
370 src_device->missing ? "<missing disk>" :
371 rcu_str_deref(src_device->name),
372 src_device->devid,
373 rcu_str_deref(tgt_device->name));
375 tgt_device->total_bytes = src_device->total_bytes;
376 tgt_device->disk_total_bytes = src_device->disk_total_bytes;
377 tgt_device->bytes_used = src_device->bytes_used;
380 * from now on, the writes to the srcdev are all duplicated to
381 * go to the tgtdev as well (refer to btrfs_map_block()).
383 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
384 dev_replace->time_started = get_seconds();
385 dev_replace->cursor_left = 0;
386 dev_replace->committed_cursor_left = 0;
387 dev_replace->cursor_left_last_write_of_item = 0;
388 dev_replace->cursor_right = 0;
389 dev_replace->is_valid = 1;
390 dev_replace->item_needs_writeback = 1;
391 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
392 btrfs_dev_replace_unlock(dev_replace);
394 btrfs_wait_ordered_roots(root->fs_info, -1);
396 /* force writing the updated state information to disk */
397 trans = btrfs_start_transaction(root, 0);
398 if (IS_ERR(trans)) {
399 ret = PTR_ERR(trans);
400 btrfs_dev_replace_lock(dev_replace);
401 goto leave;
404 ret = btrfs_commit_transaction(trans, root);
405 WARN_ON(ret);
407 /* the disk copy procedure reuses the scrub code */
408 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
409 src_device->total_bytes,
410 &dev_replace->scrub_progress, 0, 1);
412 ret = btrfs_dev_replace_finishing(root->fs_info, ret);
413 WARN_ON(ret);
415 return 0;
417 leave:
418 dev_replace->srcdev = NULL;
419 dev_replace->tgtdev = NULL;
420 btrfs_dev_replace_unlock(dev_replace);
421 leave_no_lock:
422 if (tgt_device)
423 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
424 return ret;
427 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
428 int scrub_ret)
430 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
431 struct btrfs_device *tgt_device;
432 struct btrfs_device *src_device;
433 struct btrfs_root *root = fs_info->tree_root;
434 u8 uuid_tmp[BTRFS_UUID_SIZE];
435 struct btrfs_trans_handle *trans;
436 int ret = 0;
438 /* don't allow cancel or unmount to disturb the finishing procedure */
439 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
441 btrfs_dev_replace_lock(dev_replace);
442 /* was the operation canceled, or is it finished? */
443 if (dev_replace->replace_state !=
444 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
445 btrfs_dev_replace_unlock(dev_replace);
446 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
447 return 0;
450 tgt_device = dev_replace->tgtdev;
451 src_device = dev_replace->srcdev;
452 btrfs_dev_replace_unlock(dev_replace);
454 /* replace old device with new one in mapping tree */
455 if (!scrub_ret)
456 btrfs_dev_replace_update_device_in_mapping_tree(fs_info,
457 src_device,
458 tgt_device);
461 * flush all outstanding I/O and inode extent mappings before the
462 * copy operation is declared as being finished
464 ret = btrfs_start_delalloc_roots(root->fs_info, 0);
465 if (ret) {
466 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
467 return ret;
469 btrfs_wait_ordered_roots(root->fs_info, -1);
471 trans = btrfs_start_transaction(root, 0);
472 if (IS_ERR(trans)) {
473 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
474 return PTR_ERR(trans);
476 ret = btrfs_commit_transaction(trans, root);
477 WARN_ON(ret);
479 /* keep away write_all_supers() during the finishing procedure */
480 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
481 btrfs_dev_replace_lock(dev_replace);
482 dev_replace->replace_state =
483 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
484 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
485 dev_replace->tgtdev = NULL;
486 dev_replace->srcdev = NULL;
487 dev_replace->time_stopped = get_seconds();
488 dev_replace->item_needs_writeback = 1;
490 if (scrub_ret) {
491 printk_in_rcu(KERN_ERR
492 "btrfs: btrfs_scrub_dev(%s, %llu, %s) failed %d\n",
493 src_device->missing ? "<missing disk>" :
494 rcu_str_deref(src_device->name),
495 src_device->devid,
496 rcu_str_deref(tgt_device->name), scrub_ret);
497 btrfs_dev_replace_unlock(dev_replace);
498 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
499 if (tgt_device)
500 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
501 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
503 return 0;
506 printk_in_rcu(KERN_INFO
507 "btrfs: dev_replace from %s (devid %llu) to %s) finished\n",
508 src_device->missing ? "<missing disk>" :
509 rcu_str_deref(src_device->name),
510 src_device->devid,
511 rcu_str_deref(tgt_device->name));
512 tgt_device->is_tgtdev_for_dev_replace = 0;
513 tgt_device->devid = src_device->devid;
514 src_device->devid = BTRFS_DEV_REPLACE_DEVID;
515 tgt_device->bytes_used = src_device->bytes_used;
516 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp));
517 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid));
518 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid));
519 tgt_device->total_bytes = src_device->total_bytes;
520 tgt_device->disk_total_bytes = src_device->disk_total_bytes;
521 tgt_device->bytes_used = src_device->bytes_used;
522 if (fs_info->sb->s_bdev == src_device->bdev)
523 fs_info->sb->s_bdev = tgt_device->bdev;
524 if (fs_info->fs_devices->latest_bdev == src_device->bdev)
525 fs_info->fs_devices->latest_bdev = tgt_device->bdev;
526 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
528 btrfs_rm_dev_replace_srcdev(fs_info, src_device);
531 * this is again a consistent state where no dev_replace procedure
532 * is running, the target device is part of the filesystem, the
533 * source device is not part of the filesystem anymore and its 1st
534 * superblock is scratched out so that it is no longer marked to
535 * belong to this filesystem.
537 btrfs_dev_replace_unlock(dev_replace);
538 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
540 /* write back the superblocks */
541 trans = btrfs_start_transaction(root, 0);
542 if (!IS_ERR(trans))
543 btrfs_commit_transaction(trans, root);
545 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
547 return 0;
550 static void btrfs_dev_replace_update_device_in_mapping_tree(
551 struct btrfs_fs_info *fs_info,
552 struct btrfs_device *srcdev,
553 struct btrfs_device *tgtdev)
555 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
556 struct extent_map *em;
557 struct map_lookup *map;
558 u64 start = 0;
559 int i;
561 write_lock(&em_tree->lock);
562 do {
563 em = lookup_extent_mapping(em_tree, start, (u64)-1);
564 if (!em)
565 break;
566 map = (struct map_lookup *)em->bdev;
567 for (i = 0; i < map->num_stripes; i++)
568 if (srcdev == map->stripes[i].dev)
569 map->stripes[i].dev = tgtdev;
570 start = em->start + em->len;
571 free_extent_map(em);
572 } while (start);
573 write_unlock(&em_tree->lock);
576 static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid,
577 char *srcdev_name,
578 struct btrfs_device **device)
580 int ret;
582 if (srcdevid) {
583 ret = 0;
584 *device = btrfs_find_device(root->fs_info, srcdevid, NULL,
585 NULL);
586 if (!*device)
587 ret = -ENOENT;
588 } else {
589 ret = btrfs_find_device_missing_or_by_path(root, srcdev_name,
590 device);
592 return ret;
595 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
596 struct btrfs_ioctl_dev_replace_args *args)
598 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
600 btrfs_dev_replace_lock(dev_replace);
601 /* even if !dev_replace_is_valid, the values are good enough for
602 * the replace_status ioctl */
603 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
604 args->status.replace_state = dev_replace->replace_state;
605 args->status.time_started = dev_replace->time_started;
606 args->status.time_stopped = dev_replace->time_stopped;
607 args->status.num_write_errors =
608 atomic64_read(&dev_replace->num_write_errors);
609 args->status.num_uncorrectable_read_errors =
610 atomic64_read(&dev_replace->num_uncorrectable_read_errors);
611 switch (dev_replace->replace_state) {
612 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
613 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
614 args->status.progress_1000 = 0;
615 break;
616 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
617 args->status.progress_1000 = 1000;
618 break;
619 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
620 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
621 args->status.progress_1000 = div64_u64(dev_replace->cursor_left,
622 div64_u64(dev_replace->srcdev->total_bytes, 1000));
623 break;
625 btrfs_dev_replace_unlock(dev_replace);
628 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
629 struct btrfs_ioctl_dev_replace_args *args)
631 args->result = __btrfs_dev_replace_cancel(fs_info);
632 return 0;
635 static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
637 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
638 struct btrfs_device *tgt_device = NULL;
639 struct btrfs_trans_handle *trans;
640 struct btrfs_root *root = fs_info->tree_root;
641 u64 result;
642 int ret;
644 if (fs_info->sb->s_flags & MS_RDONLY)
645 return -EROFS;
647 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
648 btrfs_dev_replace_lock(dev_replace);
649 switch (dev_replace->replace_state) {
650 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
651 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
652 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
653 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
654 btrfs_dev_replace_unlock(dev_replace);
655 goto leave;
656 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
657 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
658 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
659 tgt_device = dev_replace->tgtdev;
660 dev_replace->tgtdev = NULL;
661 dev_replace->srcdev = NULL;
662 break;
664 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
665 dev_replace->time_stopped = get_seconds();
666 dev_replace->item_needs_writeback = 1;
667 btrfs_dev_replace_unlock(dev_replace);
668 btrfs_scrub_cancel(fs_info);
670 trans = btrfs_start_transaction(root, 0);
671 if (IS_ERR(trans)) {
672 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
673 return PTR_ERR(trans);
675 ret = btrfs_commit_transaction(trans, root);
676 WARN_ON(ret);
677 if (tgt_device)
678 btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
680 leave:
681 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
682 return result;
685 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info)
687 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
689 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
690 btrfs_dev_replace_lock(dev_replace);
691 switch (dev_replace->replace_state) {
692 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
693 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
694 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
695 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
696 break;
697 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
698 dev_replace->replace_state =
699 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
700 dev_replace->time_stopped = get_seconds();
701 dev_replace->item_needs_writeback = 1;
702 pr_info("btrfs: suspending dev_replace for unmount\n");
703 break;
706 btrfs_dev_replace_unlock(dev_replace);
707 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
710 /* resume dev_replace procedure that was interrupted by unmount */
711 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
713 struct task_struct *task;
714 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
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 btrfs_dev_replace_unlock(dev_replace);
722 return 0;
723 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
724 break;
725 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
726 dev_replace->replace_state =
727 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
728 break;
730 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) {
731 pr_info("btrfs: cannot continue dev_replace, tgtdev is missing\n"
732 "btrfs: you may cancel the operation after 'mount -o degraded'\n");
733 btrfs_dev_replace_unlock(dev_replace);
734 return 0;
736 btrfs_dev_replace_unlock(dev_replace);
738 WARN_ON(atomic_xchg(
739 &fs_info->mutually_exclusive_operation_running, 1));
740 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
741 return PTR_ERR_OR_ZERO(task);
744 static int btrfs_dev_replace_kthread(void *data)
746 struct btrfs_fs_info *fs_info = data;
747 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
748 struct btrfs_ioctl_dev_replace_args *status_args;
749 u64 progress;
751 status_args = kzalloc(sizeof(*status_args), GFP_NOFS);
752 if (status_args) {
753 btrfs_dev_replace_status(fs_info, status_args);
754 progress = status_args->status.progress_1000;
755 kfree(status_args);
756 do_div(progress, 10);
757 printk_in_rcu(KERN_INFO
758 "btrfs: continuing dev_replace from %s (devid %llu) to %s @%u%%\n",
759 dev_replace->srcdev->missing ? "<missing disk>" :
760 rcu_str_deref(dev_replace->srcdev->name),
761 dev_replace->srcdev->devid,
762 dev_replace->tgtdev ?
763 rcu_str_deref(dev_replace->tgtdev->name) :
764 "<missing target disk>",
765 (unsigned int)progress);
767 btrfs_dev_replace_continue_on_mount(fs_info);
768 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
770 return 0;
773 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info)
775 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
776 int ret;
778 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid,
779 dev_replace->committed_cursor_left,
780 dev_replace->srcdev->total_bytes,
781 &dev_replace->scrub_progress, 0, 1);
782 ret = btrfs_dev_replace_finishing(fs_info, ret);
783 WARN_ON(ret);
784 return 0;
787 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
789 if (!dev_replace->is_valid)
790 return 0;
792 switch (dev_replace->replace_state) {
793 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
794 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
795 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
796 return 0;
797 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
798 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
800 * return true even if tgtdev is missing (this is
801 * something that can happen if the dev_replace
802 * procedure is suspended by an umount and then
803 * the tgtdev is missing (or "btrfs dev scan") was
804 * not called and the the filesystem is remounted
805 * in degraded state. This does not stop the
806 * dev_replace procedure. It needs to be canceled
807 * manually if the cancelation is wanted.
809 break;
811 return 1;
814 void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace)
816 /* the beginning is just an optimization for the typical case */
817 if (atomic_read(&dev_replace->nesting_level) == 0) {
818 acquire_lock:
819 /* this is not a nested case where the same thread
820 * is trying to acqurire the same lock twice */
821 mutex_lock(&dev_replace->lock);
822 mutex_lock(&dev_replace->lock_management_lock);
823 dev_replace->lock_owner = current->pid;
824 atomic_inc(&dev_replace->nesting_level);
825 mutex_unlock(&dev_replace->lock_management_lock);
826 return;
829 mutex_lock(&dev_replace->lock_management_lock);
830 if (atomic_read(&dev_replace->nesting_level) > 0 &&
831 dev_replace->lock_owner == current->pid) {
832 WARN_ON(!mutex_is_locked(&dev_replace->lock));
833 atomic_inc(&dev_replace->nesting_level);
834 mutex_unlock(&dev_replace->lock_management_lock);
835 return;
838 mutex_unlock(&dev_replace->lock_management_lock);
839 goto acquire_lock;
842 void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace)
844 WARN_ON(!mutex_is_locked(&dev_replace->lock));
845 mutex_lock(&dev_replace->lock_management_lock);
846 WARN_ON(atomic_read(&dev_replace->nesting_level) < 1);
847 WARN_ON(dev_replace->lock_owner != current->pid);
848 atomic_dec(&dev_replace->nesting_level);
849 if (atomic_read(&dev_replace->nesting_level) == 0) {
850 dev_replace->lock_owner = 0;
851 mutex_unlock(&dev_replace->lock_management_lock);
852 mutex_unlock(&dev_replace->lock);
853 } else {
854 mutex_unlock(&dev_replace->lock_management_lock);