1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) STRATO AG 2012. All rights reserved.
4 */
5
6 #include <linux/sched.h>
7 #include <linux/bio.h>
8 #include <linux/slab.h>
9 #include <linux/blkdev.h>
10 #include <linux/kthread.h>
11 #include <linux/math64.h>
12 #include "ctree.h"
13 #include "extent_map.h"
14 #include "disk-io.h"
15 #include "transaction.h"
16 #include "print-tree.h"
17 #include "volumes.h"
18 #include "async-thread.h"
19 #include "check-integrity.h"
20 #include "rcu-string.h"
21 #include "dev-replace.h"
22 #include "sysfs.h"
23
24 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
25 int scrub_ret);
26 static void btrfs_dev_replace_update_device_in_mapping_tree(
27 struct btrfs_fs_info *fs_info,
28 struct btrfs_device *srcdev,
29 struct btrfs_device *tgtdev);
30 static int btrfs_dev_replace_kthread(void *data);
31
btrfs_init_dev_replace(struct btrfs_fs_info * fs_info)32 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info)
33 {
34 struct btrfs_key key;
35 struct btrfs_root *dev_root = fs_info->dev_root;
36 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
37 struct extent_buffer *eb;
38 int slot;
39 int ret = 0;
40 struct btrfs_path *path = NULL;
41 int item_size;
42 struct btrfs_dev_replace_item *ptr;
43 u64 src_devid;
44
45 path = btrfs_alloc_path();
46 if (!path) {
47 ret = -ENOMEM;
48 goto out;
49 }
50
51 key.objectid = 0;
52 key.type = BTRFS_DEV_REPLACE_KEY;
53 key.offset = 0;
54 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
55 if (ret) {
56 no_valid_dev_replace_entry_found:
57 ret = 0;
58 dev_replace->replace_state =
59 BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED;
60 dev_replace->cont_reading_from_srcdev_mode =
61 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS;
62 dev_replace->replace_state = 0;
63 dev_replace->time_started = 0;
64 dev_replace->time_stopped = 0;
65 atomic64_set(&dev_replace->num_write_errors, 0);
66 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
67 dev_replace->cursor_left = 0;
68 dev_replace->committed_cursor_left = 0;
69 dev_replace->cursor_left_last_write_of_item = 0;
70 dev_replace->cursor_right = 0;
71 dev_replace->srcdev = NULL;
72 dev_replace->tgtdev = NULL;
73 dev_replace->is_valid = 0;
74 dev_replace->item_needs_writeback = 0;
75 goto out;
76 }
77 slot = path->slots[0];
78 eb = path->nodes[0];
79 item_size = btrfs_item_size_nr(eb, slot);
80 ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item);
81
82 if (item_size != sizeof(struct btrfs_dev_replace_item)) {
83 btrfs_warn(fs_info,
84 "dev_replace entry found has unexpected size, ignore entry");
85 goto no_valid_dev_replace_entry_found;
86 }
87
88 src_devid = btrfs_dev_replace_src_devid(eb, ptr);
89 dev_replace->cont_reading_from_srcdev_mode =
90 btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr);
91 dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr);
92 dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr);
93 dev_replace->time_stopped =
94 btrfs_dev_replace_time_stopped(eb, ptr);
95 atomic64_set(&dev_replace->num_write_errors,
96 btrfs_dev_replace_num_write_errors(eb, ptr));
97 atomic64_set(&dev_replace->num_uncorrectable_read_errors,
98 btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr));
99 dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr);
100 dev_replace->committed_cursor_left = dev_replace->cursor_left;
101 dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left;
102 dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr);
103 dev_replace->is_valid = 1;
104
105 dev_replace->item_needs_writeback = 0;
106 switch (dev_replace->replace_state) {
107 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
108 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
109 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
110 dev_replace->srcdev = NULL;
111 dev_replace->tgtdev = NULL;
112 break;
113 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
114 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
115 dev_replace->srcdev = btrfs_find_device(fs_info->fs_devices,
116 src_devid, NULL, NULL, true);
117 dev_replace->tgtdev = btrfs_find_device(fs_info->fs_devices,
118 BTRFS_DEV_REPLACE_DEVID,
119 NULL, NULL, true);
120 /*
121 * allow 'btrfs dev replace_cancel' if src/tgt device is
122 * missing
123 */
124 if (!dev_replace->srcdev &&
125 !btrfs_test_opt(fs_info, DEGRADED)) {
126 ret = -EIO;
127 btrfs_warn(fs_info,
128 "cannot mount because device replace operation is ongoing and");
129 btrfs_warn(fs_info,
130 "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
131 src_devid);
132 }
133 if (!dev_replace->tgtdev &&
134 !btrfs_test_opt(fs_info, DEGRADED)) {
135 ret = -EIO;
136 btrfs_warn(fs_info,
137 "cannot mount because device replace operation is ongoing and");
138 btrfs_warn(fs_info,
139 "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?",
140 BTRFS_DEV_REPLACE_DEVID);
141 }
142 if (dev_replace->tgtdev) {
143 if (dev_replace->srcdev) {
144 dev_replace->tgtdev->total_bytes =
145 dev_replace->srcdev->total_bytes;
146 dev_replace->tgtdev->disk_total_bytes =
147 dev_replace->srcdev->disk_total_bytes;
148 dev_replace->tgtdev->commit_total_bytes =
149 dev_replace->srcdev->commit_total_bytes;
150 dev_replace->tgtdev->bytes_used =
151 dev_replace->srcdev->bytes_used;
152 dev_replace->tgtdev->commit_bytes_used =
153 dev_replace->srcdev->commit_bytes_used;
154 }
155 set_bit(BTRFS_DEV_STATE_REPLACE_TGT,
156 &dev_replace->tgtdev->dev_state);
157
158 WARN_ON(fs_info->fs_devices->rw_devices == 0);
159 dev_replace->tgtdev->io_width = fs_info->sectorsize;
160 dev_replace->tgtdev->io_align = fs_info->sectorsize;
161 dev_replace->tgtdev->sector_size = fs_info->sectorsize;
162 dev_replace->tgtdev->fs_info = fs_info;
163 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
164 &dev_replace->tgtdev->dev_state);
165 }
166 break;
167 }
168
169 out:
170 btrfs_free_path(path);
171 return ret;
172 }
173
174 /*
175 * Initialize a new device for device replace target from a given source dev
176 * and path.
177 *
178 * Return 0 and new device in @device_out, otherwise return < 0
179 */
btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info * fs_info,const char * device_path,struct btrfs_device * srcdev,struct btrfs_device ** device_out)180 static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
181 const char *device_path,
182 struct btrfs_device *srcdev,
183 struct btrfs_device **device_out)
184 {
185 struct btrfs_device *device;
186 struct block_device *bdev;
187 struct list_head *devices;
188 struct rcu_string *name;
189 u64 devid = BTRFS_DEV_REPLACE_DEVID;
190 int ret = 0;
191
192 *device_out = NULL;
193 if (srcdev->fs_devices->seeding) {
194 btrfs_err(fs_info, "the filesystem is a seed filesystem!");
195 return -EINVAL;
196 }
197
198 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
199 fs_info->bdev_holder);
200 if (IS_ERR(bdev)) {
201 btrfs_err(fs_info, "target device %s is invalid!", device_path);
202 return PTR_ERR(bdev);
203 }
204
205 filemap_write_and_wait(bdev->bd_inode->i_mapping);
206
207 devices = &fs_info->fs_devices->devices;
208 list_for_each_entry(device, devices, dev_list) {
209 if (device->bdev == bdev) {
210 btrfs_err(fs_info,
211 "target device is in the filesystem!");
212 ret = -EEXIST;
213 goto error;
214 }
215 }
216
217
218 if (i_size_read(bdev->bd_inode) <
219 btrfs_device_get_total_bytes(srcdev)) {
220 btrfs_err(fs_info,
221 "target device is smaller than source device!");
222 ret = -EINVAL;
223 goto error;
224 }
225
226
227 device = btrfs_alloc_device(NULL, &devid, NULL);
228 if (IS_ERR(device)) {
229 ret = PTR_ERR(device);
230 goto error;
231 }
232
233 name = rcu_string_strdup(device_path, GFP_KERNEL);
234 if (!name) {
235 btrfs_free_device(device);
236 ret = -ENOMEM;
237 goto error;
238 }
239 rcu_assign_pointer(device->name, name);
240
241 mutex_lock(&fs_info->fs_devices->device_list_mutex);
242 set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
243 device->generation = 0;
244 device->io_width = fs_info->sectorsize;
245 device->io_align = fs_info->sectorsize;
246 device->sector_size = fs_info->sectorsize;
247 device->total_bytes = btrfs_device_get_total_bytes(srcdev);
248 device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev);
249 device->bytes_used = btrfs_device_get_bytes_used(srcdev);
250 device->commit_total_bytes = srcdev->commit_total_bytes;
251 device->commit_bytes_used = device->bytes_used;
252 device->fs_info = fs_info;
253 device->bdev = bdev;
254 set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
255 set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
256 device->mode = FMODE_EXCL;
257 device->dev_stats_valid = 1;
258 set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
259 device->fs_devices = fs_info->fs_devices;
260 list_add(&device->dev_list, &fs_info->fs_devices->devices);
261 fs_info->fs_devices->num_devices++;
262 fs_info->fs_devices->open_devices++;
263 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
264
265 *device_out = device;
266 return 0;
267
268 error:
269 blkdev_put(bdev, FMODE_EXCL);
270 return ret;
271 }
272
273 /*
274 * called from commit_transaction. Writes changed device replace state to
275 * disk.
276 */
btrfs_run_dev_replace(struct btrfs_trans_handle * trans,struct btrfs_fs_info * fs_info)277 int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
278 struct btrfs_fs_info *fs_info)
279 {
280 int ret;
281 struct btrfs_root *dev_root = fs_info->dev_root;
282 struct btrfs_path *path;
283 struct btrfs_key key;
284 struct extent_buffer *eb;
285 struct btrfs_dev_replace_item *ptr;
286 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
287
288 btrfs_dev_replace_read_lock(dev_replace);
289 if (!dev_replace->is_valid ||
290 !dev_replace->item_needs_writeback) {
291 btrfs_dev_replace_read_unlock(dev_replace);
292 return 0;
293 }
294 btrfs_dev_replace_read_unlock(dev_replace);
295
296 key.objectid = 0;
297 key.type = BTRFS_DEV_REPLACE_KEY;
298 key.offset = 0;
299
300 path = btrfs_alloc_path();
301 if (!path) {
302 ret = -ENOMEM;
303 goto out;
304 }
305 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
306 if (ret < 0) {
307 btrfs_warn(fs_info,
308 "error %d while searching for dev_replace item!",
309 ret);
310 goto out;
311 }
312
313 if (ret == 0 &&
314 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
315 /*
316 * need to delete old one and insert a new one.
317 * Since no attempt is made to recover any old state, if the
318 * dev_replace state is 'running', the data on the target
319 * drive is lost.
320 * It would be possible to recover the state: just make sure
321 * that the beginning of the item is never changed and always
322 * contains all the essential information. Then read this
323 * minimal set of information and use it as a base for the
324 * new state.
325 */
326 ret = btrfs_del_item(trans, dev_root, path);
327 if (ret != 0) {
328 btrfs_warn(fs_info,
329 "delete too small dev_replace item failed %d!",
330 ret);
331 goto out;
332 }
333 ret = 1;
334 }
335
336 if (ret == 1) {
337 /* need to insert a new item */
338 btrfs_release_path(path);
339 ret = btrfs_insert_empty_item(trans, dev_root, path,
340 &key, sizeof(*ptr));
341 if (ret < 0) {
342 btrfs_warn(fs_info,
343 "insert dev_replace item failed %d!", ret);
344 goto out;
345 }
346 }
347
348 eb = path->nodes[0];
349 ptr = btrfs_item_ptr(eb, path->slots[0],
350 struct btrfs_dev_replace_item);
351
352 btrfs_dev_replace_write_lock(dev_replace);
353 if (dev_replace->srcdev)
354 btrfs_set_dev_replace_src_devid(eb, ptr,
355 dev_replace->srcdev->devid);
356 else
357 btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1);
358 btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr,
359 dev_replace->cont_reading_from_srcdev_mode);
360 btrfs_set_dev_replace_replace_state(eb, ptr,
361 dev_replace->replace_state);
362 btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started);
363 btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped);
364 btrfs_set_dev_replace_num_write_errors(eb, ptr,
365 atomic64_read(&dev_replace->num_write_errors));
366 btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr,
367 atomic64_read(&dev_replace->num_uncorrectable_read_errors));
368 dev_replace->cursor_left_last_write_of_item =
369 dev_replace->cursor_left;
370 btrfs_set_dev_replace_cursor_left(eb, ptr,
371 dev_replace->cursor_left_last_write_of_item);
372 btrfs_set_dev_replace_cursor_right(eb, ptr,
373 dev_replace->cursor_right);
374 dev_replace->item_needs_writeback = 0;
375 btrfs_dev_replace_write_unlock(dev_replace);
376
377 btrfs_mark_buffer_dirty(eb);
378
379 out:
380 btrfs_free_path(path);
381
382 return ret;
383 }
384
btrfs_after_dev_replace_commit(struct btrfs_fs_info * fs_info)385 void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
386 {
387 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
388
389 dev_replace->committed_cursor_left =
390 dev_replace->cursor_left_last_write_of_item;
391 }
392
btrfs_dev_name(struct btrfs_device * device)393 static char* btrfs_dev_name(struct btrfs_device *device)
394 {
395 if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
396 return "<missing disk>";
397 else
398 return rcu_str_deref(device->name);
399 }
400
btrfs_dev_replace_start(struct btrfs_fs_info * fs_info,const char * tgtdev_name,u64 srcdevid,const char * srcdev_name,int read_src)401 int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
402 const char *tgtdev_name, u64 srcdevid, const char *srcdev_name,
403 int read_src)
404 {
405 struct btrfs_root *root = fs_info->dev_root;
406 struct btrfs_trans_handle *trans;
407 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
408 int ret;
409 struct btrfs_device *tgt_device = NULL;
410 struct btrfs_device *src_device = NULL;
411
412 ret = btrfs_find_device_by_devspec(fs_info, srcdevid,
413 srcdev_name, &src_device);
414 if (ret)
415 return ret;
416
417 ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name,
418 src_device, &tgt_device);
419 if (ret)
420 return ret;
421
422 /*
423 * Here we commit the transaction to make sure commit_total_bytes
424 * of all the devices are updated.
425 */
426 trans = btrfs_attach_transaction(root);
427 if (!IS_ERR(trans)) {
428 ret = btrfs_commit_transaction(trans);
429 if (ret)
430 return ret;
431 } else if (PTR_ERR(trans) != -ENOENT) {
432 return PTR_ERR(trans);
433 }
434
435 btrfs_dev_replace_write_lock(dev_replace);
436 switch (dev_replace->replace_state) {
437 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
438 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
439 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
440 break;
441 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
442 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
443 ASSERT(0);
444 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
445 goto leave;
446 }
447
448 dev_replace->cont_reading_from_srcdev_mode = read_src;
449 WARN_ON(!src_device);
450 dev_replace->srcdev = src_device;
451 dev_replace->tgtdev = tgt_device;
452
453 btrfs_info_in_rcu(fs_info,
454 "dev_replace from %s (devid %llu) to %s started",
455 btrfs_dev_name(src_device),
456 src_device->devid,
457 rcu_str_deref(tgt_device->name));
458
459 /*
460 * from now on, the writes to the srcdev are all duplicated to
461 * go to the tgtdev as well (refer to btrfs_map_block()).
462 */
463 dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
464 dev_replace->time_started = ktime_get_real_seconds();
465 dev_replace->cursor_left = 0;
466 dev_replace->committed_cursor_left = 0;
467 dev_replace->cursor_left_last_write_of_item = 0;
468 dev_replace->cursor_right = 0;
469 dev_replace->is_valid = 1;
470 dev_replace->item_needs_writeback = 1;
471 atomic64_set(&dev_replace->num_write_errors, 0);
472 atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
473 btrfs_dev_replace_write_unlock(dev_replace);
474
475 ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device);
476 if (ret)
477 btrfs_err(fs_info, "kobj add dev failed %d", ret);
478
479 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
480
481 /* force writing the updated state information to disk */
482 trans = btrfs_start_transaction(root, 0);
483 if (IS_ERR(trans)) {
484 ret = PTR_ERR(trans);
485 btrfs_dev_replace_write_lock(dev_replace);
486 dev_replace->replace_state =
487 BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED;
488 dev_replace->srcdev = NULL;
489 dev_replace->tgtdev = NULL;
490 goto leave;
491 }
492
493 ret = btrfs_commit_transaction(trans);
494 WARN_ON(ret);
495
496 /* the disk copy procedure reuses the scrub code */
497 ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
498 btrfs_device_get_total_bytes(src_device),
499 &dev_replace->scrub_progress, 0, 1);
500
501 ret = btrfs_dev_replace_finishing(fs_info, ret);
502 if (ret == -EINPROGRESS) {
503 ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
504 } else {
505 WARN_ON(ret);
506 }
507
508 return ret;
509
510 leave:
511 btrfs_dev_replace_write_unlock(dev_replace);
512 btrfs_destroy_dev_replace_tgtdev(tgt_device);
513 return ret;
514 }
515
btrfs_dev_replace_by_ioctl(struct btrfs_fs_info * fs_info,struct btrfs_ioctl_dev_replace_args * args)516 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info,
517 struct btrfs_ioctl_dev_replace_args *args)
518 {
519 int ret;
520
521 switch (args->start.cont_reading_from_srcdev_mode) {
522 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
523 case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID:
524 break;
525 default:
526 return -EINVAL;
527 }
528
529 if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') ||
530 args->start.tgtdev_name[0] == '\0')
531 return -EINVAL;
532
533 ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name,
534 args->start.srcdevid,
535 args->start.srcdev_name,
536 args->start.cont_reading_from_srcdev_mode);
537 args->result = ret;
538 /* don't warn if EINPROGRESS, someone else might be running scrub */
539 if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS)
540 ret = 0;
541
542 return ret;
543 }
544
545 /*
546 * blocked until all in-flight bios operations are finished.
547 */
btrfs_rm_dev_replace_blocked(struct btrfs_fs_info * fs_info)548 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
549 {
550 set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
551 wait_event(fs_info->replace_wait, !percpu_counter_sum(
552 &fs_info->bio_counter));
553 }
554
555 /*
556 * we have removed target device, it is safe to allow new bios request.
557 */
btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info * fs_info)558 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info)
559 {
560 clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
561 wake_up(&fs_info->replace_wait);
562 }
563
btrfs_dev_replace_finishing(struct btrfs_fs_info * fs_info,int scrub_ret)564 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
565 int scrub_ret)
566 {
567 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
568 struct btrfs_device *tgt_device;
569 struct btrfs_device *src_device;
570 struct btrfs_root *root = fs_info->tree_root;
571 u8 uuid_tmp[BTRFS_UUID_SIZE];
572 struct btrfs_trans_handle *trans;
573 int ret = 0;
574
575 /* don't allow cancel or unmount to disturb the finishing procedure */
576 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
577
578 btrfs_dev_replace_read_lock(dev_replace);
579 /* was the operation canceled, or is it finished? */
580 if (dev_replace->replace_state !=
581 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
582 btrfs_dev_replace_read_unlock(dev_replace);
583 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
584 return 0;
585 }
586
587 tgt_device = dev_replace->tgtdev;
588 src_device = dev_replace->srcdev;
589 btrfs_dev_replace_read_unlock(dev_replace);
590
591 /*
592 * flush all outstanding I/O and inode extent mappings before the
593 * copy operation is declared as being finished
594 */
595 ret = btrfs_start_delalloc_roots(fs_info, -1);
596 if (ret) {
597 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
598 return ret;
599 }
600 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
601
602 while (1) {
603 trans = btrfs_start_transaction(root, 0);
604 if (IS_ERR(trans)) {
605 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
606 return PTR_ERR(trans);
607 }
608 ret = btrfs_commit_transaction(trans);
609 WARN_ON(ret);
610 /* keep away write_all_supers() during the finishing procedure */
611 mutex_lock(&fs_info->fs_devices->device_list_mutex);
612 mutex_lock(&fs_info->chunk_mutex);
613 if (src_device->has_pending_chunks) {
614 mutex_unlock(&root->fs_info->chunk_mutex);
615 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
616 } else {
617 break;
618 }
619 }
620
621 btrfs_dev_replace_write_lock(dev_replace);
622 dev_replace->replace_state =
623 scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
624 : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
625 dev_replace->tgtdev = NULL;
626 dev_replace->srcdev = NULL;
627 dev_replace->time_stopped = ktime_get_real_seconds();
628 dev_replace->item_needs_writeback = 1;
629
630 /* replace old device with new one in mapping tree */
631 if (!scrub_ret) {
632 btrfs_dev_replace_update_device_in_mapping_tree(fs_info,
633 src_device,
634 tgt_device);
635 } else {
636 btrfs_err_in_rcu(fs_info,
637 "btrfs_scrub_dev(%s, %llu, %s) failed %d",
638 btrfs_dev_name(src_device),
639 src_device->devid,
640 rcu_str_deref(tgt_device->name), scrub_ret);
641 btrfs_dev_replace_write_unlock(dev_replace);
642 mutex_unlock(&fs_info->chunk_mutex);
643 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
644 btrfs_rm_dev_replace_blocked(fs_info);
645 if (tgt_device)
646 btrfs_destroy_dev_replace_tgtdev(tgt_device);
647 btrfs_rm_dev_replace_unblocked(fs_info);
648 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
649
650 return scrub_ret;
651 }
652
653 btrfs_info_in_rcu(fs_info,
654 "dev_replace from %s (devid %llu) to %s finished",
655 btrfs_dev_name(src_device),
656 src_device->devid,
657 rcu_str_deref(tgt_device->name));
658 clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state);
659 tgt_device->devid = src_device->devid;
660 src_device->devid = BTRFS_DEV_REPLACE_DEVID;
661 memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp));
662 memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid));
663 memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid));
664 btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes);
665 btrfs_device_set_disk_total_bytes(tgt_device,
666 src_device->disk_total_bytes);
667 btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used);
668 ASSERT(list_empty(&src_device->resized_list));
669 tgt_device->commit_total_bytes = src_device->commit_total_bytes;
670 tgt_device->commit_bytes_used = src_device->bytes_used;
671
672 btrfs_assign_next_active_device(src_device, tgt_device);
673
674 list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
675 fs_info->fs_devices->rw_devices++;
676
677 btrfs_dev_replace_write_unlock(dev_replace);
678
679 btrfs_rm_dev_replace_blocked(fs_info);
680
681 btrfs_rm_dev_replace_remove_srcdev(src_device);
682
683 btrfs_rm_dev_replace_unblocked(fs_info);
684
685 /*
686 * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will
687 * update on-disk dev stats value during commit transaction
688 */
689 atomic_inc(&tgt_device->dev_stats_ccnt);
690
691 /*
692 * this is again a consistent state where no dev_replace procedure
693 * is running, the target device is part of the filesystem, the
694 * source device is not part of the filesystem anymore and its 1st
695 * superblock is scratched out so that it is no longer marked to
696 * belong to this filesystem.
697 */
698 mutex_unlock(&fs_info->chunk_mutex);
699 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
700
701 /* replace the sysfs entry */
702 btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device);
703 btrfs_rm_dev_replace_free_srcdev(fs_info, src_device);
704
705 /* write back the superblocks */
706 trans = btrfs_start_transaction(root, 0);
707 if (!IS_ERR(trans))
708 btrfs_commit_transaction(trans);
709
710 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
711
712 return 0;
713 }
714
btrfs_dev_replace_update_device_in_mapping_tree(struct btrfs_fs_info * fs_info,struct btrfs_device * srcdev,struct btrfs_device * tgtdev)715 static void btrfs_dev_replace_update_device_in_mapping_tree(
716 struct btrfs_fs_info *fs_info,
717 struct btrfs_device *srcdev,
718 struct btrfs_device *tgtdev)
719 {
720 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
721 struct extent_map *em;
722 struct map_lookup *map;
723 u64 start = 0;
724 int i;
725
726 write_lock(&em_tree->lock);
727 do {
728 em = lookup_extent_mapping(em_tree, start, (u64)-1);
729 if (!em)
730 break;
731 map = em->map_lookup;
732 for (i = 0; i < map->num_stripes; i++)
733 if (srcdev == map->stripes[i].dev)
734 map->stripes[i].dev = tgtdev;
735 start = em->start + em->len;
736 free_extent_map(em);
737 } while (start);
738 write_unlock(&em_tree->lock);
739 }
740
741 /*
742 * Read progress of device replace status according to the state and last
743 * stored position. The value format is the same as for
744 * btrfs_dev_replace::progress_1000
745 */
btrfs_dev_replace_progress(struct btrfs_fs_info * fs_info)746 static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info)
747 {
748 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
749 u64 ret = 0;
750
751 switch (dev_replace->replace_state) {
752 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
753 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
754 ret = 0;
755 break;
756 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
757 ret = 1000;
758 break;
759 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
760 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
761 ret = div64_u64(dev_replace->cursor_left,
762 div_u64(btrfs_device_get_total_bytes(
763 dev_replace->srcdev), 1000));
764 break;
765 }
766
767 return ret;
768 }
769
btrfs_dev_replace_status(struct btrfs_fs_info * fs_info,struct btrfs_ioctl_dev_replace_args * args)770 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
771 struct btrfs_ioctl_dev_replace_args *args)
772 {
773 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
774
775 btrfs_dev_replace_read_lock(dev_replace);
776 /* even if !dev_replace_is_valid, the values are good enough for
777 * the replace_status ioctl */
778 args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
779 args->status.replace_state = dev_replace->replace_state;
780 args->status.time_started = dev_replace->time_started;
781 args->status.time_stopped = dev_replace->time_stopped;
782 args->status.num_write_errors =
783 atomic64_read(&dev_replace->num_write_errors);
784 args->status.num_uncorrectable_read_errors =
785 atomic64_read(&dev_replace->num_uncorrectable_read_errors);
786 args->status.progress_1000 = btrfs_dev_replace_progress(fs_info);
787 btrfs_dev_replace_read_unlock(dev_replace);
788 }
789
btrfs_dev_replace_cancel(struct btrfs_fs_info * fs_info)790 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
791 {
792 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
793 struct btrfs_device *tgt_device = NULL;
794 struct btrfs_device *src_device = NULL;
795 struct btrfs_trans_handle *trans;
796 struct btrfs_root *root = fs_info->tree_root;
797 int result;
798 int ret;
799
800 if (sb_rdonly(fs_info->sb))
801 return -EROFS;
802
803 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
804 btrfs_dev_replace_write_lock(dev_replace);
805 switch (dev_replace->replace_state) {
806 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
807 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
808 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
809 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
810 btrfs_dev_replace_write_unlock(dev_replace);
811 break;
812 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
813 tgt_device = dev_replace->tgtdev;
814 src_device = dev_replace->srcdev;
815 btrfs_dev_replace_write_unlock(dev_replace);
816 ret = btrfs_scrub_cancel(fs_info);
817 if (ret < 0) {
818 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
819 } else {
820 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
821 /*
822 * btrfs_dev_replace_finishing() will handle the
823 * cleanup part
824 */
825 btrfs_info_in_rcu(fs_info,
826 "dev_replace from %s (devid %llu) to %s canceled",
827 btrfs_dev_name(src_device), src_device->devid,
828 btrfs_dev_name(tgt_device));
829 }
830 break;
831 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
832 /*
833 * Scrub doing the replace isn't running so we need to do the
834 * cleanup step of btrfs_dev_replace_finishing() here
835 */
836 result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
837 tgt_device = dev_replace->tgtdev;
838 src_device = dev_replace->srcdev;
839 dev_replace->tgtdev = NULL;
840 dev_replace->srcdev = NULL;
841 dev_replace->replace_state =
842 BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
843 dev_replace->time_stopped = ktime_get_real_seconds();
844 dev_replace->item_needs_writeback = 1;
845
846 btrfs_dev_replace_write_unlock(dev_replace);
847
848 btrfs_scrub_cancel(fs_info);
849
850 trans = btrfs_start_transaction(root, 0);
851 if (IS_ERR(trans)) {
852 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
853 return PTR_ERR(trans);
854 }
855 ret = btrfs_commit_transaction(trans);
856 WARN_ON(ret);
857
858 btrfs_info_in_rcu(fs_info,
859 "suspended dev_replace from %s (devid %llu) to %s canceled",
860 btrfs_dev_name(src_device), src_device->devid,
861 btrfs_dev_name(tgt_device));
862
863 if (tgt_device)
864 btrfs_destroy_dev_replace_tgtdev(tgt_device);
865 break;
866 default:
867 result = -EINVAL;
868 }
869
870 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
871 return result;
872 }
873
btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info * fs_info)874 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info)
875 {
876 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
877
878 mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
879 btrfs_dev_replace_write_lock(dev_replace);
880 switch (dev_replace->replace_state) {
881 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
882 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
883 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
884 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
885 break;
886 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
887 dev_replace->replace_state =
888 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
889 dev_replace->time_stopped = ktime_get_real_seconds();
890 dev_replace->item_needs_writeback = 1;
891 btrfs_info(fs_info, "suspending dev_replace for unmount");
892 break;
893 }
894
895 btrfs_dev_replace_write_unlock(dev_replace);
896 mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
897 }
898
899 /* resume dev_replace procedure that was interrupted by unmount */
btrfs_resume_dev_replace_async(struct btrfs_fs_info * fs_info)900 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
901 {
902 struct task_struct *task;
903 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
904
905 btrfs_dev_replace_write_lock(dev_replace);
906 switch (dev_replace->replace_state) {
907 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
908 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
909 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
910 btrfs_dev_replace_write_unlock(dev_replace);
911 return 0;
912 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
913 break;
914 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
915 dev_replace->replace_state =
916 BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
917 break;
918 }
919 if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) {
920 btrfs_info(fs_info,
921 "cannot continue dev_replace, tgtdev is missing");
922 btrfs_info(fs_info,
923 "you may cancel the operation after 'mount -o degraded'");
924 dev_replace->replace_state =
925 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
926 btrfs_dev_replace_write_unlock(dev_replace);
927 return 0;
928 }
929 btrfs_dev_replace_write_unlock(dev_replace);
930
931 /*
932 * This could collide with a paused balance, but the exclusive op logic
933 * should never allow both to start and pause. We don't want to allow
934 * dev-replace to start anyway.
935 */
936 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
937 btrfs_dev_replace_write_lock(dev_replace);
938 dev_replace->replace_state =
939 BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
940 btrfs_dev_replace_write_unlock(dev_replace);
941 btrfs_info(fs_info,
942 "cannot resume dev-replace, other exclusive operation running");
943 return 0;
944 }
945
946 task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
947 return PTR_ERR_OR_ZERO(task);
948 }
949
btrfs_dev_replace_kthread(void * data)950 static int btrfs_dev_replace_kthread(void *data)
951 {
952 struct btrfs_fs_info *fs_info = data;
953 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
954 u64 progress;
955 int ret;
956
957 progress = btrfs_dev_replace_progress(fs_info);
958 progress = div_u64(progress, 10);
959 btrfs_info_in_rcu(fs_info,
960 "continuing dev_replace from %s (devid %llu) to target %s @%u%%",
961 btrfs_dev_name(dev_replace->srcdev),
962 dev_replace->srcdev->devid,
963 btrfs_dev_name(dev_replace->tgtdev),
964 (unsigned int)progress);
965
966 ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid,
967 dev_replace->committed_cursor_left,
968 btrfs_device_get_total_bytes(dev_replace->srcdev),
969 &dev_replace->scrub_progress, 0, 1);
970 ret = btrfs_dev_replace_finishing(fs_info, ret);
971 WARN_ON(ret);
972
973 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
974 return 0;
975 }
976
btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace * dev_replace)977 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace)
978 {
979 if (!dev_replace->is_valid)
980 return 0;
981
982 switch (dev_replace->replace_state) {
983 case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
984 case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
985 case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
986 return 0;
987 case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
988 case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
989 /*
990 * return true even if tgtdev is missing (this is
991 * something that can happen if the dev_replace
992 * procedure is suspended by an umount and then
993 * the tgtdev is missing (or "btrfs dev scan") was
994 * not called and the the filesystem is remounted
995 * in degraded state. This does not stop the
996 * dev_replace procedure. It needs to be canceled
997 * manually if the cancellation is wanted.
998 */
999 break;
1000 }
1001 return 1;
1002 }
1003
btrfs_dev_replace_read_lock(struct btrfs_dev_replace * dev_replace)1004 void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace)
1005 {
1006 read_lock(&dev_replace->lock);
1007 atomic_inc(&dev_replace->read_locks);
1008 }
1009
btrfs_dev_replace_read_unlock(struct btrfs_dev_replace * dev_replace)1010 void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace)
1011 {
1012 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
1013 atomic_dec(&dev_replace->read_locks);
1014 read_unlock(&dev_replace->lock);
1015 }
1016
btrfs_dev_replace_write_lock(struct btrfs_dev_replace * dev_replace)1017 void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace)
1018 {
1019 again:
1020 wait_event(dev_replace->read_lock_wq,
1021 atomic_read(&dev_replace->blocking_readers) == 0);
1022 write_lock(&dev_replace->lock);
1023 if (atomic_read(&dev_replace->blocking_readers)) {
1024 write_unlock(&dev_replace->lock);
1025 goto again;
1026 }
1027 }
1028
btrfs_dev_replace_write_unlock(struct btrfs_dev_replace * dev_replace)1029 void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace)
1030 {
1031 ASSERT(atomic_read(&dev_replace->blocking_readers) == 0);
1032 write_unlock(&dev_replace->lock);
1033 }
1034
1035 /* inc blocking cnt and release read lock */
btrfs_dev_replace_set_lock_blocking(struct btrfs_dev_replace * dev_replace)1036 void btrfs_dev_replace_set_lock_blocking(
1037 struct btrfs_dev_replace *dev_replace)
1038 {
1039 /* only set blocking for read lock */
1040 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
1041 atomic_inc(&dev_replace->blocking_readers);
1042 read_unlock(&dev_replace->lock);
1043 }
1044
1045 /* acquire read lock and dec blocking cnt */
btrfs_dev_replace_clear_lock_blocking(struct btrfs_dev_replace * dev_replace)1046 void btrfs_dev_replace_clear_lock_blocking(
1047 struct btrfs_dev_replace *dev_replace)
1048 {
1049 /* only set blocking for read lock */
1050 ASSERT(atomic_read(&dev_replace->read_locks) > 0);
1051 ASSERT(atomic_read(&dev_replace->blocking_readers) > 0);
1052 read_lock(&dev_replace->lock);
1053 /* Barrier implied by atomic_dec_and_test */
1054 if (atomic_dec_and_test(&dev_replace->blocking_readers))
1055 cond_wake_up_nomb(&dev_replace->read_lock_wq);
1056 }
1057
btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info * fs_info)1058 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
1059 {
1060 percpu_counter_inc(&fs_info->bio_counter);
1061 }
1062
btrfs_bio_counter_sub(struct btrfs_fs_info * fs_info,s64 amount)1063 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount)
1064 {
1065 percpu_counter_sub(&fs_info->bio_counter, amount);
1066 cond_wake_up_nomb(&fs_info->replace_wait);
1067 }
1068
btrfs_bio_counter_inc_blocked(struct btrfs_fs_info * fs_info)1069 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
1070 {
1071 while (1) {
1072 percpu_counter_inc(&fs_info->bio_counter);
1073 if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING,
1074 &fs_info->fs_state)))
1075 break;
1076
1077 btrfs_bio_counter_dec(fs_info);
1078 wait_event(fs_info->replace_wait,
1079 !test_bit(BTRFS_FS_STATE_DEV_REPLACING,
1080 &fs_info->fs_state));
1081 }
1082 }
1083