2 * Copyright (C) 2007 Oracle. 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 <asm/div64.h>
29 #include "extent_map.h"
31 #include "transaction.h"
32 #include "print-tree.h"
34 #include "async-thread.h"
36 static int init_first_rw_device(struct btrfs_trans_handle *trans,
37 struct btrfs_root *root,
38 struct btrfs_device *device);
39 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
41 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
42 (sizeof(struct btrfs_bio_stripe) * (n)))
44 static DEFINE_MUTEX(uuid_mutex);
45 static LIST_HEAD(fs_uuids);
47 void btrfs_lock_volumes(void)
49 mutex_lock(&uuid_mutex);
52 void btrfs_unlock_volumes(void)
54 mutex_unlock(&uuid_mutex);
57 static void lock_chunks(struct btrfs_root *root)
59 mutex_lock(&root->fs_info->chunk_mutex);
62 static void unlock_chunks(struct btrfs_root *root)
64 mutex_unlock(&root->fs_info->chunk_mutex);
67 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
69 struct btrfs_device *device;
70 WARN_ON(fs_devices->opened);
71 while (!list_empty(&fs_devices->devices)) {
72 device = list_entry(fs_devices->devices.next,
73 struct btrfs_device, dev_list);
74 list_del(&device->dev_list);
81 int btrfs_cleanup_fs_uuids(void)
83 struct btrfs_fs_devices *fs_devices;
85 while (!list_empty(&fs_uuids)) {
86 fs_devices = list_entry(fs_uuids.next,
87 struct btrfs_fs_devices, list);
88 list_del(&fs_devices->list);
89 free_fs_devices(fs_devices);
94 static noinline struct btrfs_device *__find_device(struct list_head *head,
97 struct btrfs_device *dev;
99 list_for_each_entry(dev, head, dev_list) {
100 if (dev->devid == devid &&
101 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
108 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
110 struct btrfs_fs_devices *fs_devices;
112 list_for_each_entry(fs_devices, &fs_uuids, list) {
113 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
119 static void requeue_list(struct btrfs_pending_bios *pending_bios,
120 struct bio *head, struct bio *tail)
123 struct bio *old_head;
125 old_head = pending_bios->head;
126 pending_bios->head = head;
127 if (pending_bios->tail)
128 tail->bi_next = old_head;
130 pending_bios->tail = tail;
134 * we try to collect pending bios for a device so we don't get a large
135 * number of procs sending bios down to the same device. This greatly
136 * improves the schedulers ability to collect and merge the bios.
138 * But, it also turns into a long list of bios to process and that is sure
139 * to eventually make the worker thread block. The solution here is to
140 * make some progress and then put this work struct back at the end of
141 * the list if the block device is congested. This way, multiple devices
142 * can make progress from a single worker thread.
144 static noinline int run_scheduled_bios(struct btrfs_device *device)
147 struct backing_dev_info *bdi;
148 struct btrfs_fs_info *fs_info;
149 struct btrfs_pending_bios *pending_bios;
153 unsigned long num_run;
154 unsigned long num_sync_run;
155 unsigned long batch_run = 0;
157 unsigned long last_waited = 0;
160 bdi = blk_get_backing_dev_info(device->bdev);
161 fs_info = device->dev_root->fs_info;
162 limit = btrfs_async_submit_limit(fs_info);
163 limit = limit * 2 / 3;
165 /* we want to make sure that every time we switch from the sync
166 * list to the normal list, we unplug
171 spin_lock(&device->io_lock);
176 /* take all the bios off the list at once and process them
177 * later on (without the lock held). But, remember the
178 * tail and other pointers so the bios can be properly reinserted
179 * into the list if we hit congestion
181 if (!force_reg && device->pending_sync_bios.head) {
182 pending_bios = &device->pending_sync_bios;
185 pending_bios = &device->pending_bios;
189 pending = pending_bios->head;
190 tail = pending_bios->tail;
191 WARN_ON(pending && !tail);
194 * if pending was null this time around, no bios need processing
195 * at all and we can stop. Otherwise it'll loop back up again
196 * and do an additional check so no bios are missed.
198 * device->running_pending is used to synchronize with the
201 if (device->pending_sync_bios.head == NULL &&
202 device->pending_bios.head == NULL) {
204 device->running_pending = 0;
207 device->running_pending = 1;
210 pending_bios->head = NULL;
211 pending_bios->tail = NULL;
213 spin_unlock(&device->io_lock);
216 * if we're doing the regular priority list, make sure we unplug
217 * for any high prio bios we've sent down
219 if (pending_bios == &device->pending_bios && num_sync_run > 0) {
221 blk_run_backing_dev(bdi, NULL);
227 /* we want to work on both lists, but do more bios on the
228 * sync list than the regular list
231 pending_bios != &device->pending_sync_bios &&
232 device->pending_sync_bios.head) ||
233 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
234 device->pending_bios.head)) {
235 spin_lock(&device->io_lock);
236 requeue_list(pending_bios, pending, tail);
241 pending = pending->bi_next;
243 atomic_dec(&fs_info->nr_async_bios);
245 if (atomic_read(&fs_info->nr_async_bios) < limit &&
246 waitqueue_active(&fs_info->async_submit_wait))
247 wake_up(&fs_info->async_submit_wait);
249 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
251 if (cur->bi_rw & REQ_SYNC)
254 submit_bio(cur->bi_rw, cur);
257 if (need_resched()) {
259 blk_run_backing_dev(bdi, NULL);
266 * we made progress, there is more work to do and the bdi
267 * is now congested. Back off and let other work structs
270 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
271 fs_info->fs_devices->open_devices > 1) {
272 struct io_context *ioc;
274 ioc = current->io_context;
277 * the main goal here is that we don't want to
278 * block if we're going to be able to submit
279 * more requests without blocking.
281 * This code does two great things, it pokes into
282 * the elevator code from a filesystem _and_
283 * it makes assumptions about how batching works.
285 if (ioc && ioc->nr_batch_requests > 0 &&
286 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
288 ioc->last_waited == last_waited)) {
290 * we want to go through our batch of
291 * requests and stop. So, we copy out
292 * the ioc->last_waited time and test
293 * against it before looping
295 last_waited = ioc->last_waited;
296 if (need_resched()) {
298 blk_run_backing_dev(bdi, NULL);
305 spin_lock(&device->io_lock);
306 requeue_list(pending_bios, pending, tail);
307 device->running_pending = 1;
309 spin_unlock(&device->io_lock);
310 btrfs_requeue_work(&device->work);
317 blk_run_backing_dev(bdi, NULL);
320 * IO has already been through a long path to get here. Checksumming,
321 * async helper threads, perhaps compression. We've done a pretty
322 * good job of collecting a batch of IO and should just unplug
323 * the device right away.
325 * This will help anyone who is waiting on the IO, they might have
326 * already unplugged, but managed to do so before the bio they
327 * cared about found its way down here.
329 blk_run_backing_dev(bdi, NULL);
335 spin_lock(&device->io_lock);
336 if (device->pending_bios.head || device->pending_sync_bios.head)
338 spin_unlock(&device->io_lock);
344 static void pending_bios_fn(struct btrfs_work *work)
346 struct btrfs_device *device;
348 device = container_of(work, struct btrfs_device, work);
349 run_scheduled_bios(device);
352 static noinline int device_list_add(const char *path,
353 struct btrfs_super_block *disk_super,
354 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
356 struct btrfs_device *device;
357 struct btrfs_fs_devices *fs_devices;
358 u64 found_transid = btrfs_super_generation(disk_super);
361 fs_devices = find_fsid(disk_super->fsid);
363 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
366 INIT_LIST_HEAD(&fs_devices->devices);
367 INIT_LIST_HEAD(&fs_devices->alloc_list);
368 list_add(&fs_devices->list, &fs_uuids);
369 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
370 fs_devices->latest_devid = devid;
371 fs_devices->latest_trans = found_transid;
372 mutex_init(&fs_devices->device_list_mutex);
375 device = __find_device(&fs_devices->devices, devid,
376 disk_super->dev_item.uuid);
379 if (fs_devices->opened)
382 device = kzalloc(sizeof(*device), GFP_NOFS);
384 /* we can safely leave the fs_devices entry around */
387 device->devid = devid;
388 device->work.func = pending_bios_fn;
389 memcpy(device->uuid, disk_super->dev_item.uuid,
391 spin_lock_init(&device->io_lock);
392 device->name = kstrdup(path, GFP_NOFS);
397 INIT_LIST_HEAD(&device->dev_alloc_list);
399 mutex_lock(&fs_devices->device_list_mutex);
400 list_add(&device->dev_list, &fs_devices->devices);
401 mutex_unlock(&fs_devices->device_list_mutex);
403 device->fs_devices = fs_devices;
404 fs_devices->num_devices++;
405 } else if (!device->name || strcmp(device->name, path)) {
406 name = kstrdup(path, GFP_NOFS);
411 if (device->missing) {
412 fs_devices->missing_devices--;
417 if (found_transid > fs_devices->latest_trans) {
418 fs_devices->latest_devid = devid;
419 fs_devices->latest_trans = found_transid;
421 *fs_devices_ret = fs_devices;
425 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
427 struct btrfs_fs_devices *fs_devices;
428 struct btrfs_device *device;
429 struct btrfs_device *orig_dev;
431 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
433 return ERR_PTR(-ENOMEM);
435 INIT_LIST_HEAD(&fs_devices->devices);
436 INIT_LIST_HEAD(&fs_devices->alloc_list);
437 INIT_LIST_HEAD(&fs_devices->list);
438 mutex_init(&fs_devices->device_list_mutex);
439 fs_devices->latest_devid = orig->latest_devid;
440 fs_devices->latest_trans = orig->latest_trans;
441 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
443 mutex_lock(&orig->device_list_mutex);
444 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
445 device = kzalloc(sizeof(*device), GFP_NOFS);
449 device->name = kstrdup(orig_dev->name, GFP_NOFS);
455 device->devid = orig_dev->devid;
456 device->work.func = pending_bios_fn;
457 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
458 spin_lock_init(&device->io_lock);
459 INIT_LIST_HEAD(&device->dev_list);
460 INIT_LIST_HEAD(&device->dev_alloc_list);
462 list_add(&device->dev_list, &fs_devices->devices);
463 device->fs_devices = fs_devices;
464 fs_devices->num_devices++;
466 mutex_unlock(&orig->device_list_mutex);
469 mutex_unlock(&orig->device_list_mutex);
470 free_fs_devices(fs_devices);
471 return ERR_PTR(-ENOMEM);
474 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
476 struct btrfs_device *device, *next;
478 mutex_lock(&uuid_mutex);
480 mutex_lock(&fs_devices->device_list_mutex);
481 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
482 if (device->in_fs_metadata)
486 blkdev_put(device->bdev, device->mode);
488 fs_devices->open_devices--;
490 if (device->writeable) {
491 list_del_init(&device->dev_alloc_list);
492 device->writeable = 0;
493 fs_devices->rw_devices--;
495 list_del_init(&device->dev_list);
496 fs_devices->num_devices--;
500 mutex_unlock(&fs_devices->device_list_mutex);
502 if (fs_devices->seed) {
503 fs_devices = fs_devices->seed;
507 mutex_unlock(&uuid_mutex);
511 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
513 struct btrfs_device *device;
515 if (--fs_devices->opened > 0)
518 list_for_each_entry(device, &fs_devices->devices, dev_list) {
520 blkdev_put(device->bdev, device->mode);
521 fs_devices->open_devices--;
523 if (device->writeable) {
524 list_del_init(&device->dev_alloc_list);
525 fs_devices->rw_devices--;
529 device->writeable = 0;
530 device->in_fs_metadata = 0;
532 WARN_ON(fs_devices->open_devices);
533 WARN_ON(fs_devices->rw_devices);
534 fs_devices->opened = 0;
535 fs_devices->seeding = 0;
540 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
542 struct btrfs_fs_devices *seed_devices = NULL;
545 mutex_lock(&uuid_mutex);
546 ret = __btrfs_close_devices(fs_devices);
547 if (!fs_devices->opened) {
548 seed_devices = fs_devices->seed;
549 fs_devices->seed = NULL;
551 mutex_unlock(&uuid_mutex);
553 while (seed_devices) {
554 fs_devices = seed_devices;
555 seed_devices = fs_devices->seed;
556 __btrfs_close_devices(fs_devices);
557 free_fs_devices(fs_devices);
562 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
563 fmode_t flags, void *holder)
565 struct block_device *bdev;
566 struct list_head *head = &fs_devices->devices;
567 struct btrfs_device *device;
568 struct block_device *latest_bdev = NULL;
569 struct buffer_head *bh;
570 struct btrfs_super_block *disk_super;
571 u64 latest_devid = 0;
572 u64 latest_transid = 0;
579 list_for_each_entry(device, head, dev_list) {
585 bdev = blkdev_get_by_path(device->name, flags, holder);
587 printk(KERN_INFO "open %s failed\n", device->name);
590 set_blocksize(bdev, 4096);
592 bh = btrfs_read_dev_super(bdev);
598 disk_super = (struct btrfs_super_block *)bh->b_data;
599 devid = btrfs_stack_device_id(&disk_super->dev_item);
600 if (devid != device->devid)
603 if (memcmp(device->uuid, disk_super->dev_item.uuid,
607 device->generation = btrfs_super_generation(disk_super);
608 if (!latest_transid || device->generation > latest_transid) {
609 latest_devid = devid;
610 latest_transid = device->generation;
614 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
615 device->writeable = 0;
617 device->writeable = !bdev_read_only(bdev);
622 device->in_fs_metadata = 0;
623 device->mode = flags;
625 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
626 fs_devices->rotating = 1;
628 fs_devices->open_devices++;
629 if (device->writeable) {
630 fs_devices->rw_devices++;
631 list_add(&device->dev_alloc_list,
632 &fs_devices->alloc_list);
639 blkdev_put(bdev, flags);
643 if (fs_devices->open_devices == 0) {
647 fs_devices->seeding = seeding;
648 fs_devices->opened = 1;
649 fs_devices->latest_bdev = latest_bdev;
650 fs_devices->latest_devid = latest_devid;
651 fs_devices->latest_trans = latest_transid;
652 fs_devices->total_rw_bytes = 0;
657 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
658 fmode_t flags, void *holder)
662 mutex_lock(&uuid_mutex);
663 if (fs_devices->opened) {
664 fs_devices->opened++;
667 ret = __btrfs_open_devices(fs_devices, flags, holder);
669 mutex_unlock(&uuid_mutex);
673 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
674 struct btrfs_fs_devices **fs_devices_ret)
676 struct btrfs_super_block *disk_super;
677 struct block_device *bdev;
678 struct buffer_head *bh;
683 mutex_lock(&uuid_mutex);
686 bdev = blkdev_get_by_path(path, flags, holder);
693 ret = set_blocksize(bdev, 4096);
696 bh = btrfs_read_dev_super(bdev);
701 disk_super = (struct btrfs_super_block *)bh->b_data;
702 devid = btrfs_stack_device_id(&disk_super->dev_item);
703 transid = btrfs_super_generation(disk_super);
704 if (disk_super->label[0])
705 printk(KERN_INFO "device label %s ", disk_super->label);
707 /* FIXME, make a readl uuid parser */
708 printk(KERN_INFO "device fsid %llx-%llx ",
709 *(unsigned long long *)disk_super->fsid,
710 *(unsigned long long *)(disk_super->fsid + 8));
712 printk(KERN_CONT "devid %llu transid %llu %s\n",
713 (unsigned long long)devid, (unsigned long long)transid, path);
714 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
718 blkdev_put(bdev, flags);
720 mutex_unlock(&uuid_mutex);
724 /* helper to account the used device space in the range */
725 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
726 u64 end, u64 *length)
728 struct btrfs_key key;
729 struct btrfs_root *root = device->dev_root;
730 struct btrfs_dev_extent *dev_extent;
731 struct btrfs_path *path;
735 struct extent_buffer *l;
739 if (start >= device->total_bytes)
742 path = btrfs_alloc_path();
747 key.objectid = device->devid;
749 key.type = BTRFS_DEV_EXTENT_KEY;
751 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
755 ret = btrfs_previous_item(root, path, key.objectid, key.type);
762 slot = path->slots[0];
763 if (slot >= btrfs_header_nritems(l)) {
764 ret = btrfs_next_leaf(root, path);
772 btrfs_item_key_to_cpu(l, &key, slot);
774 if (key.objectid < device->devid)
777 if (key.objectid > device->devid)
780 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
783 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
784 extent_end = key.offset + btrfs_dev_extent_length(l,
786 if (key.offset <= start && extent_end > end) {
787 *length = end - start + 1;
789 } else if (key.offset <= start && extent_end > start)
790 *length += extent_end - start;
791 else if (key.offset > start && extent_end <= end)
792 *length += extent_end - key.offset;
793 else if (key.offset > start && key.offset <= end) {
794 *length += end - key.offset + 1;
796 } else if (key.offset > end)
804 btrfs_free_path(path);
809 * find_free_dev_extent - find free space in the specified device
810 * @trans: transaction handler
811 * @device: the device which we search the free space in
812 * @num_bytes: the size of the free space that we need
813 * @start: store the start of the free space.
814 * @len: the size of the free space. that we find, or the size of the max
815 * free space if we don't find suitable free space
817 * this uses a pretty simple search, the expectation is that it is
818 * called very infrequently and that a given device has a small number
821 * @start is used to store the start of the free space if we find. But if we
822 * don't find suitable free space, it will be used to store the start position
823 * of the max free space.
825 * @len is used to store the size of the free space that we find.
826 * But if we don't find suitable free space, it is used to store the size of
827 * the max free space.
829 int find_free_dev_extent(struct btrfs_trans_handle *trans,
830 struct btrfs_device *device, u64 num_bytes,
831 u64 *start, u64 *len)
833 struct btrfs_key key;
834 struct btrfs_root *root = device->dev_root;
835 struct btrfs_dev_extent *dev_extent;
836 struct btrfs_path *path;
842 u64 search_end = device->total_bytes;
845 struct extent_buffer *l;
847 /* FIXME use last free of some kind */
849 /* we don't want to overwrite the superblock on the drive,
850 * so we make sure to start at an offset of at least 1MB
852 search_start = 1024 * 1024;
854 if (root->fs_info->alloc_start + num_bytes <= search_end)
855 search_start = max(root->fs_info->alloc_start, search_start);
857 max_hole_start = search_start;
860 if (search_start >= search_end) {
865 path = btrfs_alloc_path();
872 key.objectid = device->devid;
873 key.offset = search_start;
874 key.type = BTRFS_DEV_EXTENT_KEY;
876 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
880 ret = btrfs_previous_item(root, path, key.objectid, key.type);
887 slot = path->slots[0];
888 if (slot >= btrfs_header_nritems(l)) {
889 ret = btrfs_next_leaf(root, path);
897 btrfs_item_key_to_cpu(l, &key, slot);
899 if (key.objectid < device->devid)
902 if (key.objectid > device->devid)
905 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
908 if (key.offset > search_start) {
909 hole_size = key.offset - search_start;
911 if (hole_size > max_hole_size) {
912 max_hole_start = search_start;
913 max_hole_size = hole_size;
917 * If this free space is greater than which we need,
918 * it must be the max free space that we have found
919 * until now, so max_hole_start must point to the start
920 * of this free space and the length of this free space
921 * is stored in max_hole_size. Thus, we return
922 * max_hole_start and max_hole_size and go back to the
925 if (hole_size >= num_bytes) {
931 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
932 extent_end = key.offset + btrfs_dev_extent_length(l,
934 if (extent_end > search_start)
935 search_start = extent_end;
941 hole_size = search_end- search_start;
942 if (hole_size > max_hole_size) {
943 max_hole_start = search_start;
944 max_hole_size = hole_size;
948 if (hole_size < num_bytes)
954 btrfs_free_path(path);
956 *start = max_hole_start;
958 *len = max_hole_size;
962 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
963 struct btrfs_device *device,
967 struct btrfs_path *path;
968 struct btrfs_root *root = device->dev_root;
969 struct btrfs_key key;
970 struct btrfs_key found_key;
971 struct extent_buffer *leaf = NULL;
972 struct btrfs_dev_extent *extent = NULL;
974 path = btrfs_alloc_path();
978 key.objectid = device->devid;
980 key.type = BTRFS_DEV_EXTENT_KEY;
982 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
984 ret = btrfs_previous_item(root, path, key.objectid,
985 BTRFS_DEV_EXTENT_KEY);
987 leaf = path->nodes[0];
988 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
989 extent = btrfs_item_ptr(leaf, path->slots[0],
990 struct btrfs_dev_extent);
991 BUG_ON(found_key.offset > start || found_key.offset +
992 btrfs_dev_extent_length(leaf, extent) < start);
994 } else if (ret == 0) {
995 leaf = path->nodes[0];
996 extent = btrfs_item_ptr(leaf, path->slots[0],
997 struct btrfs_dev_extent);
1001 if (device->bytes_used > 0)
1002 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
1003 ret = btrfs_del_item(trans, root, path);
1006 btrfs_free_path(path);
1010 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1011 struct btrfs_device *device,
1012 u64 chunk_tree, u64 chunk_objectid,
1013 u64 chunk_offset, u64 start, u64 num_bytes)
1016 struct btrfs_path *path;
1017 struct btrfs_root *root = device->dev_root;
1018 struct btrfs_dev_extent *extent;
1019 struct extent_buffer *leaf;
1020 struct btrfs_key key;
1022 WARN_ON(!device->in_fs_metadata);
1023 path = btrfs_alloc_path();
1027 key.objectid = device->devid;
1029 key.type = BTRFS_DEV_EXTENT_KEY;
1030 ret = btrfs_insert_empty_item(trans, root, path, &key,
1034 leaf = path->nodes[0];
1035 extent = btrfs_item_ptr(leaf, path->slots[0],
1036 struct btrfs_dev_extent);
1037 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1038 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1039 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1041 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1042 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1045 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1046 btrfs_mark_buffer_dirty(leaf);
1047 btrfs_free_path(path);
1051 static noinline int find_next_chunk(struct btrfs_root *root,
1052 u64 objectid, u64 *offset)
1054 struct btrfs_path *path;
1056 struct btrfs_key key;
1057 struct btrfs_chunk *chunk;
1058 struct btrfs_key found_key;
1060 path = btrfs_alloc_path();
1063 key.objectid = objectid;
1064 key.offset = (u64)-1;
1065 key.type = BTRFS_CHUNK_ITEM_KEY;
1067 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1073 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1077 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1079 if (found_key.objectid != objectid)
1082 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1083 struct btrfs_chunk);
1084 *offset = found_key.offset +
1085 btrfs_chunk_length(path->nodes[0], chunk);
1090 btrfs_free_path(path);
1094 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1097 struct btrfs_key key;
1098 struct btrfs_key found_key;
1099 struct btrfs_path *path;
1101 root = root->fs_info->chunk_root;
1103 path = btrfs_alloc_path();
1107 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1108 key.type = BTRFS_DEV_ITEM_KEY;
1109 key.offset = (u64)-1;
1111 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1117 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1118 BTRFS_DEV_ITEM_KEY);
1122 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1124 *objectid = found_key.offset + 1;
1128 btrfs_free_path(path);
1133 * the device information is stored in the chunk root
1134 * the btrfs_device struct should be fully filled in
1136 int btrfs_add_device(struct btrfs_trans_handle *trans,
1137 struct btrfs_root *root,
1138 struct btrfs_device *device)
1141 struct btrfs_path *path;
1142 struct btrfs_dev_item *dev_item;
1143 struct extent_buffer *leaf;
1144 struct btrfs_key key;
1147 root = root->fs_info->chunk_root;
1149 path = btrfs_alloc_path();
1153 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1154 key.type = BTRFS_DEV_ITEM_KEY;
1155 key.offset = device->devid;
1157 ret = btrfs_insert_empty_item(trans, root, path, &key,
1162 leaf = path->nodes[0];
1163 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1165 btrfs_set_device_id(leaf, dev_item, device->devid);
1166 btrfs_set_device_generation(leaf, dev_item, 0);
1167 btrfs_set_device_type(leaf, dev_item, device->type);
1168 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1169 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1170 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1171 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1172 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1173 btrfs_set_device_group(leaf, dev_item, 0);
1174 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1175 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1176 btrfs_set_device_start_offset(leaf, dev_item, 0);
1178 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1179 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1180 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1181 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1182 btrfs_mark_buffer_dirty(leaf);
1186 btrfs_free_path(path);
1190 static int btrfs_rm_dev_item(struct btrfs_root *root,
1191 struct btrfs_device *device)
1194 struct btrfs_path *path;
1195 struct btrfs_key key;
1196 struct btrfs_trans_handle *trans;
1198 root = root->fs_info->chunk_root;
1200 path = btrfs_alloc_path();
1204 trans = btrfs_start_transaction(root, 0);
1205 if (IS_ERR(trans)) {
1206 btrfs_free_path(path);
1207 return PTR_ERR(trans);
1209 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1210 key.type = BTRFS_DEV_ITEM_KEY;
1211 key.offset = device->devid;
1214 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1223 ret = btrfs_del_item(trans, root, path);
1227 btrfs_free_path(path);
1228 unlock_chunks(root);
1229 btrfs_commit_transaction(trans, root);
1233 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1235 struct btrfs_device *device;
1236 struct btrfs_device *next_device;
1237 struct block_device *bdev;
1238 struct buffer_head *bh = NULL;
1239 struct btrfs_super_block *disk_super;
1246 mutex_lock(&uuid_mutex);
1247 mutex_lock(&root->fs_info->volume_mutex);
1249 all_avail = root->fs_info->avail_data_alloc_bits |
1250 root->fs_info->avail_system_alloc_bits |
1251 root->fs_info->avail_metadata_alloc_bits;
1253 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1254 root->fs_info->fs_devices->num_devices <= 4) {
1255 printk(KERN_ERR "btrfs: unable to go below four devices "
1261 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1262 root->fs_info->fs_devices->num_devices <= 2) {
1263 printk(KERN_ERR "btrfs: unable to go below two "
1264 "devices on raid1\n");
1269 if (strcmp(device_path, "missing") == 0) {
1270 struct list_head *devices;
1271 struct btrfs_device *tmp;
1274 devices = &root->fs_info->fs_devices->devices;
1275 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1276 list_for_each_entry(tmp, devices, dev_list) {
1277 if (tmp->in_fs_metadata && !tmp->bdev) {
1282 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1287 printk(KERN_ERR "btrfs: no missing devices found to "
1292 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1293 root->fs_info->bdev_holder);
1295 ret = PTR_ERR(bdev);
1299 set_blocksize(bdev, 4096);
1300 bh = btrfs_read_dev_super(bdev);
1305 disk_super = (struct btrfs_super_block *)bh->b_data;
1306 devid = btrfs_stack_device_id(&disk_super->dev_item);
1307 dev_uuid = disk_super->dev_item.uuid;
1308 device = btrfs_find_device(root, devid, dev_uuid,
1316 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1317 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1323 if (device->writeable) {
1324 list_del_init(&device->dev_alloc_list);
1325 root->fs_info->fs_devices->rw_devices--;
1328 ret = btrfs_shrink_device(device, 0);
1332 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1336 device->in_fs_metadata = 0;
1339 * the device list mutex makes sure that we don't change
1340 * the device list while someone else is writing out all
1341 * the device supers.
1343 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1344 list_del_init(&device->dev_list);
1345 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1347 device->fs_devices->num_devices--;
1349 if (device->missing)
1350 root->fs_info->fs_devices->missing_devices--;
1352 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1353 struct btrfs_device, dev_list);
1354 if (device->bdev == root->fs_info->sb->s_bdev)
1355 root->fs_info->sb->s_bdev = next_device->bdev;
1356 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1357 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1360 blkdev_put(device->bdev, device->mode);
1361 device->bdev = NULL;
1362 device->fs_devices->open_devices--;
1365 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1366 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1368 if (device->fs_devices->open_devices == 0) {
1369 struct btrfs_fs_devices *fs_devices;
1370 fs_devices = root->fs_info->fs_devices;
1371 while (fs_devices) {
1372 if (fs_devices->seed == device->fs_devices)
1374 fs_devices = fs_devices->seed;
1376 fs_devices->seed = device->fs_devices->seed;
1377 device->fs_devices->seed = NULL;
1378 __btrfs_close_devices(device->fs_devices);
1379 free_fs_devices(device->fs_devices);
1383 * at this point, the device is zero sized. We want to
1384 * remove it from the devices list and zero out the old super
1386 if (device->writeable) {
1387 /* make sure this device isn't detected as part of
1390 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1391 set_buffer_dirty(bh);
1392 sync_dirty_buffer(bh);
1395 kfree(device->name);
1403 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1405 mutex_unlock(&root->fs_info->volume_mutex);
1406 mutex_unlock(&uuid_mutex);
1409 if (device->writeable) {
1410 list_add(&device->dev_alloc_list,
1411 &root->fs_info->fs_devices->alloc_list);
1412 root->fs_info->fs_devices->rw_devices++;
1418 * does all the dirty work required for changing file system's UUID.
1420 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1421 struct btrfs_root *root)
1423 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1424 struct btrfs_fs_devices *old_devices;
1425 struct btrfs_fs_devices *seed_devices;
1426 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1427 struct btrfs_device *device;
1430 BUG_ON(!mutex_is_locked(&uuid_mutex));
1431 if (!fs_devices->seeding)
1434 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1438 old_devices = clone_fs_devices(fs_devices);
1439 if (IS_ERR(old_devices)) {
1440 kfree(seed_devices);
1441 return PTR_ERR(old_devices);
1444 list_add(&old_devices->list, &fs_uuids);
1446 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1447 seed_devices->opened = 1;
1448 INIT_LIST_HEAD(&seed_devices->devices);
1449 INIT_LIST_HEAD(&seed_devices->alloc_list);
1450 mutex_init(&seed_devices->device_list_mutex);
1451 list_splice_init(&fs_devices->devices, &seed_devices->devices);
1452 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1453 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1454 device->fs_devices = seed_devices;
1457 fs_devices->seeding = 0;
1458 fs_devices->num_devices = 0;
1459 fs_devices->open_devices = 0;
1460 fs_devices->seed = seed_devices;
1462 generate_random_uuid(fs_devices->fsid);
1463 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1464 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1465 super_flags = btrfs_super_flags(disk_super) &
1466 ~BTRFS_SUPER_FLAG_SEEDING;
1467 btrfs_set_super_flags(disk_super, super_flags);
1473 * strore the expected generation for seed devices in device items.
1475 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1476 struct btrfs_root *root)
1478 struct btrfs_path *path;
1479 struct extent_buffer *leaf;
1480 struct btrfs_dev_item *dev_item;
1481 struct btrfs_device *device;
1482 struct btrfs_key key;
1483 u8 fs_uuid[BTRFS_UUID_SIZE];
1484 u8 dev_uuid[BTRFS_UUID_SIZE];
1488 path = btrfs_alloc_path();
1492 root = root->fs_info->chunk_root;
1493 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1495 key.type = BTRFS_DEV_ITEM_KEY;
1498 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1502 leaf = path->nodes[0];
1504 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1505 ret = btrfs_next_leaf(root, path);
1510 leaf = path->nodes[0];
1511 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1512 btrfs_release_path(root, path);
1516 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1517 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1518 key.type != BTRFS_DEV_ITEM_KEY)
1521 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1522 struct btrfs_dev_item);
1523 devid = btrfs_device_id(leaf, dev_item);
1524 read_extent_buffer(leaf, dev_uuid,
1525 (unsigned long)btrfs_device_uuid(dev_item),
1527 read_extent_buffer(leaf, fs_uuid,
1528 (unsigned long)btrfs_device_fsid(dev_item),
1530 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1533 if (device->fs_devices->seeding) {
1534 btrfs_set_device_generation(leaf, dev_item,
1535 device->generation);
1536 btrfs_mark_buffer_dirty(leaf);
1544 btrfs_free_path(path);
1548 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1550 struct btrfs_trans_handle *trans;
1551 struct btrfs_device *device;
1552 struct block_device *bdev;
1553 struct list_head *devices;
1554 struct super_block *sb = root->fs_info->sb;
1556 int seeding_dev = 0;
1559 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1562 bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
1563 root->fs_info->bdev_holder);
1565 return PTR_ERR(bdev);
1567 if (root->fs_info->fs_devices->seeding) {
1569 down_write(&sb->s_umount);
1570 mutex_lock(&uuid_mutex);
1573 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1574 mutex_lock(&root->fs_info->volume_mutex);
1576 devices = &root->fs_info->fs_devices->devices;
1578 * we have the volume lock, so we don't need the extra
1579 * device list mutex while reading the list here.
1581 list_for_each_entry(device, devices, dev_list) {
1582 if (device->bdev == bdev) {
1588 device = kzalloc(sizeof(*device), GFP_NOFS);
1590 /* we can safely leave the fs_devices entry around */
1595 device->name = kstrdup(device_path, GFP_NOFS);
1596 if (!device->name) {
1602 ret = find_next_devid(root, &device->devid);
1604 kfree(device->name);
1609 trans = btrfs_start_transaction(root, 0);
1610 if (IS_ERR(trans)) {
1611 kfree(device->name);
1613 ret = PTR_ERR(trans);
1619 device->writeable = 1;
1620 device->work.func = pending_bios_fn;
1621 generate_random_uuid(device->uuid);
1622 spin_lock_init(&device->io_lock);
1623 device->generation = trans->transid;
1624 device->io_width = root->sectorsize;
1625 device->io_align = root->sectorsize;
1626 device->sector_size = root->sectorsize;
1627 device->total_bytes = i_size_read(bdev->bd_inode);
1628 device->disk_total_bytes = device->total_bytes;
1629 device->dev_root = root->fs_info->dev_root;
1630 device->bdev = bdev;
1631 device->in_fs_metadata = 1;
1632 device->mode = FMODE_EXCL;
1633 set_blocksize(device->bdev, 4096);
1636 sb->s_flags &= ~MS_RDONLY;
1637 ret = btrfs_prepare_sprout(trans, root);
1641 device->fs_devices = root->fs_info->fs_devices;
1644 * we don't want write_supers to jump in here with our device
1647 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1648 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1649 list_add(&device->dev_alloc_list,
1650 &root->fs_info->fs_devices->alloc_list);
1651 root->fs_info->fs_devices->num_devices++;
1652 root->fs_info->fs_devices->open_devices++;
1653 root->fs_info->fs_devices->rw_devices++;
1654 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1656 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1657 root->fs_info->fs_devices->rotating = 1;
1659 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1660 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1661 total_bytes + device->total_bytes);
1663 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1664 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1666 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1669 ret = init_first_rw_device(trans, root, device);
1671 ret = btrfs_finish_sprout(trans, root);
1674 ret = btrfs_add_device(trans, root, device);
1678 * we've got more storage, clear any full flags on the space
1681 btrfs_clear_space_info_full(root->fs_info);
1683 unlock_chunks(root);
1684 btrfs_commit_transaction(trans, root);
1687 mutex_unlock(&uuid_mutex);
1688 up_write(&sb->s_umount);
1690 ret = btrfs_relocate_sys_chunks(root);
1694 mutex_unlock(&root->fs_info->volume_mutex);
1697 blkdev_put(bdev, FMODE_EXCL);
1699 mutex_unlock(&uuid_mutex);
1700 up_write(&sb->s_umount);
1705 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1706 struct btrfs_device *device)
1709 struct btrfs_path *path;
1710 struct btrfs_root *root;
1711 struct btrfs_dev_item *dev_item;
1712 struct extent_buffer *leaf;
1713 struct btrfs_key key;
1715 root = device->dev_root->fs_info->chunk_root;
1717 path = btrfs_alloc_path();
1721 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1722 key.type = BTRFS_DEV_ITEM_KEY;
1723 key.offset = device->devid;
1725 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1734 leaf = path->nodes[0];
1735 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1737 btrfs_set_device_id(leaf, dev_item, device->devid);
1738 btrfs_set_device_type(leaf, dev_item, device->type);
1739 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1740 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1741 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1742 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1743 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1744 btrfs_mark_buffer_dirty(leaf);
1747 btrfs_free_path(path);
1751 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1752 struct btrfs_device *device, u64 new_size)
1754 struct btrfs_super_block *super_copy =
1755 &device->dev_root->fs_info->super_copy;
1756 u64 old_total = btrfs_super_total_bytes(super_copy);
1757 u64 diff = new_size - device->total_bytes;
1759 if (!device->writeable)
1761 if (new_size <= device->total_bytes)
1764 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1765 device->fs_devices->total_rw_bytes += diff;
1767 device->total_bytes = new_size;
1768 device->disk_total_bytes = new_size;
1769 btrfs_clear_space_info_full(device->dev_root->fs_info);
1771 return btrfs_update_device(trans, device);
1774 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1775 struct btrfs_device *device, u64 new_size)
1778 lock_chunks(device->dev_root);
1779 ret = __btrfs_grow_device(trans, device, new_size);
1780 unlock_chunks(device->dev_root);
1784 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1785 struct btrfs_root *root,
1786 u64 chunk_tree, u64 chunk_objectid,
1790 struct btrfs_path *path;
1791 struct btrfs_key key;
1793 root = root->fs_info->chunk_root;
1794 path = btrfs_alloc_path();
1798 key.objectid = chunk_objectid;
1799 key.offset = chunk_offset;
1800 key.type = BTRFS_CHUNK_ITEM_KEY;
1802 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1805 ret = btrfs_del_item(trans, root, path);
1808 btrfs_free_path(path);
1812 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1815 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1816 struct btrfs_disk_key *disk_key;
1817 struct btrfs_chunk *chunk;
1824 struct btrfs_key key;
1826 array_size = btrfs_super_sys_array_size(super_copy);
1828 ptr = super_copy->sys_chunk_array;
1831 while (cur < array_size) {
1832 disk_key = (struct btrfs_disk_key *)ptr;
1833 btrfs_disk_key_to_cpu(&key, disk_key);
1835 len = sizeof(*disk_key);
1837 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1838 chunk = (struct btrfs_chunk *)(ptr + len);
1839 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1840 len += btrfs_chunk_item_size(num_stripes);
1845 if (key.objectid == chunk_objectid &&
1846 key.offset == chunk_offset) {
1847 memmove(ptr, ptr + len, array_size - (cur + len));
1849 btrfs_set_super_sys_array_size(super_copy, array_size);
1858 static int btrfs_relocate_chunk(struct btrfs_root *root,
1859 u64 chunk_tree, u64 chunk_objectid,
1862 struct extent_map_tree *em_tree;
1863 struct btrfs_root *extent_root;
1864 struct btrfs_trans_handle *trans;
1865 struct extent_map *em;
1866 struct map_lookup *map;
1870 root = root->fs_info->chunk_root;
1871 extent_root = root->fs_info->extent_root;
1872 em_tree = &root->fs_info->mapping_tree.map_tree;
1874 ret = btrfs_can_relocate(extent_root, chunk_offset);
1878 /* step one, relocate all the extents inside this chunk */
1879 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1883 trans = btrfs_start_transaction(root, 0);
1884 BUG_ON(IS_ERR(trans));
1889 * step two, delete the device extents and the
1890 * chunk tree entries
1892 read_lock(&em_tree->lock);
1893 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1894 read_unlock(&em_tree->lock);
1896 BUG_ON(em->start > chunk_offset ||
1897 em->start + em->len < chunk_offset);
1898 map = (struct map_lookup *)em->bdev;
1900 for (i = 0; i < map->num_stripes; i++) {
1901 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1902 map->stripes[i].physical);
1905 if (map->stripes[i].dev) {
1906 ret = btrfs_update_device(trans, map->stripes[i].dev);
1910 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1915 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
1917 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1918 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1922 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1925 write_lock(&em_tree->lock);
1926 remove_extent_mapping(em_tree, em);
1927 write_unlock(&em_tree->lock);
1932 /* once for the tree */
1933 free_extent_map(em);
1935 free_extent_map(em);
1937 unlock_chunks(root);
1938 btrfs_end_transaction(trans, root);
1942 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1944 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1945 struct btrfs_path *path;
1946 struct extent_buffer *leaf;
1947 struct btrfs_chunk *chunk;
1948 struct btrfs_key key;
1949 struct btrfs_key found_key;
1950 u64 chunk_tree = chunk_root->root_key.objectid;
1952 bool retried = false;
1956 path = btrfs_alloc_path();
1961 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1962 key.offset = (u64)-1;
1963 key.type = BTRFS_CHUNK_ITEM_KEY;
1966 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1971 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1978 leaf = path->nodes[0];
1979 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1981 chunk = btrfs_item_ptr(leaf, path->slots[0],
1982 struct btrfs_chunk);
1983 chunk_type = btrfs_chunk_type(leaf, chunk);
1984 btrfs_release_path(chunk_root, path);
1986 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1987 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1996 if (found_key.offset == 0)
1998 key.offset = found_key.offset - 1;
2001 if (failed && !retried) {
2005 } else if (failed && retried) {
2010 btrfs_free_path(path);
2014 static u64 div_factor(u64 num, int factor)
2023 int btrfs_balance(struct btrfs_root *dev_root)
2026 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
2027 struct btrfs_device *device;
2030 struct btrfs_path *path;
2031 struct btrfs_key key;
2032 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
2033 struct btrfs_trans_handle *trans;
2034 struct btrfs_key found_key;
2036 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
2039 if (!capable(CAP_SYS_ADMIN))
2042 mutex_lock(&dev_root->fs_info->volume_mutex);
2043 dev_root = dev_root->fs_info->dev_root;
2045 /* step one make some room on all the devices */
2046 list_for_each_entry(device, devices, dev_list) {
2047 old_size = device->total_bytes;
2048 size_to_free = div_factor(old_size, 1);
2049 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2050 if (!device->writeable ||
2051 device->total_bytes - device->bytes_used > size_to_free)
2054 ret = btrfs_shrink_device(device, old_size - size_to_free);
2059 trans = btrfs_start_transaction(dev_root, 0);
2060 BUG_ON(IS_ERR(trans));
2062 ret = btrfs_grow_device(trans, device, old_size);
2065 btrfs_end_transaction(trans, dev_root);
2068 /* step two, relocate all the chunks */
2069 path = btrfs_alloc_path();
2072 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2073 key.offset = (u64)-1;
2074 key.type = BTRFS_CHUNK_ITEM_KEY;
2077 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2082 * this shouldn't happen, it means the last relocate
2088 ret = btrfs_previous_item(chunk_root, path, 0,
2089 BTRFS_CHUNK_ITEM_KEY);
2093 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2095 if (found_key.objectid != key.objectid)
2098 /* chunk zero is special */
2099 if (found_key.offset == 0)
2102 btrfs_release_path(chunk_root, path);
2103 ret = btrfs_relocate_chunk(chunk_root,
2104 chunk_root->root_key.objectid,
2107 BUG_ON(ret && ret != -ENOSPC);
2108 key.offset = found_key.offset - 1;
2112 btrfs_free_path(path);
2113 mutex_unlock(&dev_root->fs_info->volume_mutex);
2118 * shrinking a device means finding all of the device extents past
2119 * the new size, and then following the back refs to the chunks.
2120 * The chunk relocation code actually frees the device extent
2122 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2124 struct btrfs_trans_handle *trans;
2125 struct btrfs_root *root = device->dev_root;
2126 struct btrfs_dev_extent *dev_extent = NULL;
2127 struct btrfs_path *path;
2135 bool retried = false;
2136 struct extent_buffer *l;
2137 struct btrfs_key key;
2138 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2139 u64 old_total = btrfs_super_total_bytes(super_copy);
2140 u64 old_size = device->total_bytes;
2141 u64 diff = device->total_bytes - new_size;
2143 if (new_size >= device->total_bytes)
2146 path = btrfs_alloc_path();
2154 device->total_bytes = new_size;
2155 if (device->writeable)
2156 device->fs_devices->total_rw_bytes -= diff;
2157 unlock_chunks(root);
2160 key.objectid = device->devid;
2161 key.offset = (u64)-1;
2162 key.type = BTRFS_DEV_EXTENT_KEY;
2165 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2169 ret = btrfs_previous_item(root, path, 0, key.type);
2174 btrfs_release_path(root, path);
2179 slot = path->slots[0];
2180 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2182 if (key.objectid != device->devid) {
2183 btrfs_release_path(root, path);
2187 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2188 length = btrfs_dev_extent_length(l, dev_extent);
2190 if (key.offset + length <= new_size) {
2191 btrfs_release_path(root, path);
2195 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2196 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2197 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2198 btrfs_release_path(root, path);
2200 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2202 if (ret && ret != -ENOSPC)
2209 if (failed && !retried) {
2213 } else if (failed && retried) {
2217 device->total_bytes = old_size;
2218 if (device->writeable)
2219 device->fs_devices->total_rw_bytes += diff;
2220 unlock_chunks(root);
2224 /* Shrinking succeeded, else we would be at "done". */
2225 trans = btrfs_start_transaction(root, 0);
2226 if (IS_ERR(trans)) {
2227 ret = PTR_ERR(trans);
2233 device->disk_total_bytes = new_size;
2234 /* Now btrfs_update_device() will change the on-disk size. */
2235 ret = btrfs_update_device(trans, device);
2237 unlock_chunks(root);
2238 btrfs_end_transaction(trans, root);
2241 WARN_ON(diff > old_total);
2242 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2243 unlock_chunks(root);
2244 btrfs_end_transaction(trans, root);
2246 btrfs_free_path(path);
2250 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2251 struct btrfs_root *root,
2252 struct btrfs_key *key,
2253 struct btrfs_chunk *chunk, int item_size)
2255 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2256 struct btrfs_disk_key disk_key;
2260 array_size = btrfs_super_sys_array_size(super_copy);
2261 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2264 ptr = super_copy->sys_chunk_array + array_size;
2265 btrfs_cpu_key_to_disk(&disk_key, key);
2266 memcpy(ptr, &disk_key, sizeof(disk_key));
2267 ptr += sizeof(disk_key);
2268 memcpy(ptr, chunk, item_size);
2269 item_size += sizeof(disk_key);
2270 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2274 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
2275 int num_stripes, int sub_stripes)
2277 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
2279 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2280 return calc_size * (num_stripes / sub_stripes);
2282 return calc_size * num_stripes;
2285 /* Used to sort the devices by max_avail(descending sort) */
2286 int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2)
2288 if (((struct btrfs_device_info *)dev_info1)->max_avail >
2289 ((struct btrfs_device_info *)dev_info2)->max_avail)
2291 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
2292 ((struct btrfs_device_info *)dev_info2)->max_avail)
2298 static int __btrfs_calc_nstripes(struct btrfs_fs_devices *fs_devices, u64 type,
2299 int *num_stripes, int *min_stripes,
2306 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2307 *num_stripes = fs_devices->rw_devices;
2310 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2314 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2315 if (fs_devices->rw_devices < 2)
2320 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2321 *num_stripes = fs_devices->rw_devices;
2322 if (*num_stripes < 4)
2324 *num_stripes &= ~(u32)1;
2332 static u64 __btrfs_calc_stripe_size(struct btrfs_fs_devices *fs_devices,
2333 u64 proposed_size, u64 type,
2334 int num_stripes, int small_stripe)
2336 int min_stripe_size = 1 * 1024 * 1024;
2337 u64 calc_size = proposed_size;
2338 u64 max_chunk_size = calc_size;
2341 if (type & (BTRFS_BLOCK_GROUP_RAID1 |
2342 BTRFS_BLOCK_GROUP_DUP |
2343 BTRFS_BLOCK_GROUP_RAID10))
2346 if (type & BTRFS_BLOCK_GROUP_DATA) {
2347 max_chunk_size = 10 * calc_size;
2348 min_stripe_size = 64 * 1024 * 1024;
2349 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2350 max_chunk_size = 256 * 1024 * 1024;
2351 min_stripe_size = 32 * 1024 * 1024;
2352 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2353 calc_size = 8 * 1024 * 1024;
2354 max_chunk_size = calc_size * 2;
2355 min_stripe_size = 1 * 1024 * 1024;
2358 /* we don't want a chunk larger than 10% of writeable space */
2359 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2362 if (calc_size * num_stripes > max_chunk_size * ncopies) {
2363 calc_size = max_chunk_size * ncopies;
2364 do_div(calc_size, num_stripes);
2365 do_div(calc_size, BTRFS_STRIPE_LEN);
2366 calc_size *= BTRFS_STRIPE_LEN;
2369 /* we don't want tiny stripes */
2371 calc_size = max_t(u64, min_stripe_size, calc_size);
2374 * we're about to do_div by the BTRFS_STRIPE_LEN so lets make sure
2375 * we end up with something bigger than a stripe
2377 calc_size = max_t(u64, calc_size, BTRFS_STRIPE_LEN);
2379 do_div(calc_size, BTRFS_STRIPE_LEN);
2380 calc_size *= BTRFS_STRIPE_LEN;
2385 static struct map_lookup *__shrink_map_lookup_stripes(struct map_lookup *map,
2388 struct map_lookup *new;
2389 size_t len = map_lookup_size(num_stripes);
2391 BUG_ON(map->num_stripes < num_stripes);
2393 if (map->num_stripes == num_stripes)
2396 new = kmalloc(len, GFP_NOFS);
2398 /* just change map->num_stripes */
2399 map->num_stripes = num_stripes;
2403 memcpy(new, map, len);
2404 new->num_stripes = num_stripes;
2410 * helper to allocate device space from btrfs_device_info, in which we stored
2411 * max free space information of every device. It is used when we can not
2412 * allocate chunks by default size.
2414 * By this helper, we can allocate a new chunk as larger as possible.
2416 static int __btrfs_alloc_tiny_space(struct btrfs_trans_handle *trans,
2417 struct btrfs_fs_devices *fs_devices,
2418 struct btrfs_device_info *devices,
2419 int nr_device, u64 type,
2420 struct map_lookup **map_lookup,
2421 int min_stripes, u64 *stripe_size)
2423 int i, index, sort_again = 0;
2424 int min_devices = min_stripes;
2425 u64 max_avail, min_free;
2426 struct map_lookup *map = *map_lookup;
2429 if (nr_device < min_stripes)
2432 btrfs_descending_sort_devices(devices, nr_device);
2434 max_avail = devices[0].max_avail;
2438 for (i = 0; i < nr_device; i++) {
2440 * if dev_offset = 0, it means the free space of this device
2441 * is less than what we need, and we didn't search max avail
2442 * extent on this device, so do it now.
2444 if (!devices[i].dev_offset) {
2445 ret = find_free_dev_extent(trans, devices[i].dev,
2447 &devices[i].dev_offset,
2448 &devices[i].max_avail);
2449 if (ret != 0 && ret != -ENOSPC)
2455 /* we update the max avail free extent of each devices, sort again */
2457 btrfs_descending_sort_devices(devices, nr_device);
2459 if (type & BTRFS_BLOCK_GROUP_DUP)
2462 if (!devices[min_devices - 1].max_avail)
2465 max_avail = devices[min_devices - 1].max_avail;
2466 if (type & BTRFS_BLOCK_GROUP_DUP)
2467 do_div(max_avail, 2);
2469 max_avail = __btrfs_calc_stripe_size(fs_devices, max_avail, type,
2471 if (type & BTRFS_BLOCK_GROUP_DUP)
2472 min_free = max_avail * 2;
2474 min_free = max_avail;
2476 if (min_free > devices[min_devices - 1].max_avail)
2479 map = __shrink_map_lookup_stripes(map, min_stripes);
2480 *stripe_size = max_avail;
2483 for (i = 0; i < min_stripes; i++) {
2484 map->stripes[i].dev = devices[index].dev;
2485 map->stripes[i].physical = devices[index].dev_offset;
2486 if (type & BTRFS_BLOCK_GROUP_DUP) {
2488 map->stripes[i].dev = devices[index].dev;
2489 map->stripes[i].physical = devices[index].dev_offset +
2499 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2500 struct btrfs_root *extent_root,
2501 struct map_lookup **map_ret,
2502 u64 *num_bytes, u64 *stripe_size,
2503 u64 start, u64 type)
2505 struct btrfs_fs_info *info = extent_root->fs_info;
2506 struct btrfs_device *device = NULL;
2507 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2508 struct list_head *cur;
2509 struct map_lookup *map;
2510 struct extent_map_tree *em_tree;
2511 struct extent_map *em;
2512 struct btrfs_device_info *devices_info;
2513 struct list_head private_devs;
2514 u64 calc_size = 1024 * 1024 * 1024;
2521 int min_devices; /* the min number of devices we need */
2526 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2527 (type & BTRFS_BLOCK_GROUP_DUP)) {
2529 type &= ~BTRFS_BLOCK_GROUP_DUP;
2531 if (list_empty(&fs_devices->alloc_list))
2534 ret = __btrfs_calc_nstripes(fs_devices, type, &num_stripes,
2535 &min_stripes, &sub_stripes);
2539 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
2544 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2549 map->num_stripes = num_stripes;
2551 cur = fs_devices->alloc_list.next;
2555 calc_size = __btrfs_calc_stripe_size(fs_devices, calc_size, type,
2558 if (type & BTRFS_BLOCK_GROUP_DUP) {
2559 min_free = calc_size * 2;
2562 min_free = calc_size;
2563 min_devices = min_stripes;
2566 INIT_LIST_HEAD(&private_devs);
2567 while (index < num_stripes) {
2568 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2569 BUG_ON(!device->writeable);
2570 if (device->total_bytes > device->bytes_used)
2571 avail = device->total_bytes - device->bytes_used;
2576 if (device->in_fs_metadata && avail >= min_free) {
2577 ret = find_free_dev_extent(trans, device, min_free,
2578 &devices_info[i].dev_offset,
2579 &devices_info[i].max_avail);
2581 list_move_tail(&device->dev_alloc_list,
2583 map->stripes[index].dev = device;
2584 map->stripes[index].physical =
2585 devices_info[i].dev_offset;
2587 if (type & BTRFS_BLOCK_GROUP_DUP) {
2588 map->stripes[index].dev = device;
2589 map->stripes[index].physical =
2590 devices_info[i].dev_offset +
2594 } else if (ret != -ENOSPC)
2597 devices_info[i].dev = device;
2599 } else if (device->in_fs_metadata &&
2600 avail >= BTRFS_STRIPE_LEN) {
2601 devices_info[i].dev = device;
2602 devices_info[i].max_avail = avail;
2606 if (cur == &fs_devices->alloc_list)
2610 list_splice(&private_devs, &fs_devices->alloc_list);
2611 if (index < num_stripes) {
2612 if (index >= min_stripes) {
2613 num_stripes = index;
2614 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2615 num_stripes /= sub_stripes;
2616 num_stripes *= sub_stripes;
2619 map = __shrink_map_lookup_stripes(map, num_stripes);
2620 } else if (i >= min_devices) {
2621 ret = __btrfs_alloc_tiny_space(trans, fs_devices,
2622 devices_info, i, type,
2632 map->sector_size = extent_root->sectorsize;
2633 map->stripe_len = BTRFS_STRIPE_LEN;
2634 map->io_align = BTRFS_STRIPE_LEN;
2635 map->io_width = BTRFS_STRIPE_LEN;
2637 map->sub_stripes = sub_stripes;
2640 *stripe_size = calc_size;
2641 *num_bytes = chunk_bytes_by_type(type, calc_size,
2642 map->num_stripes, sub_stripes);
2644 trace_btrfs_chunk_alloc(info->chunk_root, map, start, *num_bytes);
2646 em = alloc_extent_map(GFP_NOFS);
2651 em->bdev = (struct block_device *)map;
2653 em->len = *num_bytes;
2654 em->block_start = 0;
2655 em->block_len = em->len;
2657 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2658 write_lock(&em_tree->lock);
2659 ret = add_extent_mapping(em_tree, em);
2660 write_unlock(&em_tree->lock);
2662 free_extent_map(em);
2664 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2665 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2670 while (index < map->num_stripes) {
2671 device = map->stripes[index].dev;
2672 dev_offset = map->stripes[index].physical;
2674 ret = btrfs_alloc_dev_extent(trans, device,
2675 info->chunk_root->root_key.objectid,
2676 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2677 start, dev_offset, calc_size);
2682 kfree(devices_info);
2687 kfree(devices_info);
2691 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2692 struct btrfs_root *extent_root,
2693 struct map_lookup *map, u64 chunk_offset,
2694 u64 chunk_size, u64 stripe_size)
2697 struct btrfs_key key;
2698 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2699 struct btrfs_device *device;
2700 struct btrfs_chunk *chunk;
2701 struct btrfs_stripe *stripe;
2702 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2706 chunk = kzalloc(item_size, GFP_NOFS);
2711 while (index < map->num_stripes) {
2712 device = map->stripes[index].dev;
2713 device->bytes_used += stripe_size;
2714 ret = btrfs_update_device(trans, device);
2720 stripe = &chunk->stripe;
2721 while (index < map->num_stripes) {
2722 device = map->stripes[index].dev;
2723 dev_offset = map->stripes[index].physical;
2725 btrfs_set_stack_stripe_devid(stripe, device->devid);
2726 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2727 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2732 btrfs_set_stack_chunk_length(chunk, chunk_size);
2733 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2734 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2735 btrfs_set_stack_chunk_type(chunk, map->type);
2736 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2737 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2738 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2739 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2740 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2742 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2743 key.type = BTRFS_CHUNK_ITEM_KEY;
2744 key.offset = chunk_offset;
2746 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2749 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2750 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2760 * Chunk allocation falls into two parts. The first part does works
2761 * that make the new allocated chunk useable, but not do any operation
2762 * that modifies the chunk tree. The second part does the works that
2763 * require modifying the chunk tree. This division is important for the
2764 * bootstrap process of adding storage to a seed btrfs.
2766 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2767 struct btrfs_root *extent_root, u64 type)
2772 struct map_lookup *map;
2773 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2776 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2781 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2782 &stripe_size, chunk_offset, type);
2786 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2787 chunk_size, stripe_size);
2792 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2793 struct btrfs_root *root,
2794 struct btrfs_device *device)
2797 u64 sys_chunk_offset;
2801 u64 sys_stripe_size;
2803 struct map_lookup *map;
2804 struct map_lookup *sys_map;
2805 struct btrfs_fs_info *fs_info = root->fs_info;
2806 struct btrfs_root *extent_root = fs_info->extent_root;
2809 ret = find_next_chunk(fs_info->chunk_root,
2810 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2813 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2814 (fs_info->metadata_alloc_profile &
2815 fs_info->avail_metadata_alloc_bits);
2816 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2818 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2819 &stripe_size, chunk_offset, alloc_profile);
2822 sys_chunk_offset = chunk_offset + chunk_size;
2824 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2825 (fs_info->system_alloc_profile &
2826 fs_info->avail_system_alloc_bits);
2827 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2829 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2830 &sys_chunk_size, &sys_stripe_size,
2831 sys_chunk_offset, alloc_profile);
2834 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2838 * Modifying chunk tree needs allocating new blocks from both
2839 * system block group and metadata block group. So we only can
2840 * do operations require modifying the chunk tree after both
2841 * block groups were created.
2843 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2844 chunk_size, stripe_size);
2847 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2848 sys_chunk_offset, sys_chunk_size,
2854 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2856 struct extent_map *em;
2857 struct map_lookup *map;
2858 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2862 read_lock(&map_tree->map_tree.lock);
2863 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2864 read_unlock(&map_tree->map_tree.lock);
2868 if (btrfs_test_opt(root, DEGRADED)) {
2869 free_extent_map(em);
2873 map = (struct map_lookup *)em->bdev;
2874 for (i = 0; i < map->num_stripes; i++) {
2875 if (!map->stripes[i].dev->writeable) {
2880 free_extent_map(em);
2884 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2886 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2889 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2891 struct extent_map *em;
2894 write_lock(&tree->map_tree.lock);
2895 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2897 remove_extent_mapping(&tree->map_tree, em);
2898 write_unlock(&tree->map_tree.lock);
2903 free_extent_map(em);
2904 /* once for the tree */
2905 free_extent_map(em);
2909 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2911 struct extent_map *em;
2912 struct map_lookup *map;
2913 struct extent_map_tree *em_tree = &map_tree->map_tree;
2916 read_lock(&em_tree->lock);
2917 em = lookup_extent_mapping(em_tree, logical, len);
2918 read_unlock(&em_tree->lock);
2921 BUG_ON(em->start > logical || em->start + em->len < logical);
2922 map = (struct map_lookup *)em->bdev;
2923 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2924 ret = map->num_stripes;
2925 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2926 ret = map->sub_stripes;
2929 free_extent_map(em);
2933 static int find_live_mirror(struct map_lookup *map, int first, int num,
2937 if (map->stripes[optimal].dev->bdev)
2939 for (i = first; i < first + num; i++) {
2940 if (map->stripes[i].dev->bdev)
2943 /* we couldn't find one that doesn't fail. Just return something
2944 * and the io error handling code will clean up eventually
2949 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2950 u64 logical, u64 *length,
2951 struct btrfs_multi_bio **multi_ret,
2952 int mirror_num, struct page *unplug_page)
2954 struct extent_map *em;
2955 struct map_lookup *map;
2956 struct extent_map_tree *em_tree = &map_tree->map_tree;
2960 int stripes_allocated = 8;
2961 int stripes_required = 1;
2966 struct btrfs_multi_bio *multi = NULL;
2968 if (multi_ret && !(rw & REQ_WRITE))
2969 stripes_allocated = 1;
2972 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2977 atomic_set(&multi->error, 0);
2980 read_lock(&em_tree->lock);
2981 em = lookup_extent_mapping(em_tree, logical, *length);
2982 read_unlock(&em_tree->lock);
2984 if (!em && unplug_page) {
2990 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2991 (unsigned long long)logical,
2992 (unsigned long long)*length);
2996 BUG_ON(em->start > logical || em->start + em->len < logical);
2997 map = (struct map_lookup *)em->bdev;
2998 offset = logical - em->start;
3000 if (mirror_num > map->num_stripes)
3003 /* if our multi bio struct is too small, back off and try again */
3004 if (rw & REQ_WRITE) {
3005 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
3006 BTRFS_BLOCK_GROUP_DUP)) {
3007 stripes_required = map->num_stripes;
3009 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3010 stripes_required = map->sub_stripes;
3014 if (multi_ret && (rw & REQ_WRITE) &&
3015 stripes_allocated < stripes_required) {
3016 stripes_allocated = map->num_stripes;
3017 free_extent_map(em);
3023 * stripe_nr counts the total number of stripes we have to stride
3024 * to get to this block
3026 do_div(stripe_nr, map->stripe_len);
3028 stripe_offset = stripe_nr * map->stripe_len;
3029 BUG_ON(offset < stripe_offset);
3031 /* stripe_offset is the offset of this block in its stripe*/
3032 stripe_offset = offset - stripe_offset;
3034 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
3035 BTRFS_BLOCK_GROUP_RAID10 |
3036 BTRFS_BLOCK_GROUP_DUP)) {
3037 /* we limit the length of each bio to what fits in a stripe */
3038 *length = min_t(u64, em->len - offset,
3039 map->stripe_len - stripe_offset);
3041 *length = em->len - offset;
3044 if (!multi_ret && !unplug_page)
3049 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3050 if (unplug_page || (rw & REQ_WRITE))
3051 num_stripes = map->num_stripes;
3052 else if (mirror_num)
3053 stripe_index = mirror_num - 1;
3055 stripe_index = find_live_mirror(map, 0,
3057 current->pid % map->num_stripes);
3060 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3062 num_stripes = map->num_stripes;
3063 else if (mirror_num)
3064 stripe_index = mirror_num - 1;
3066 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3067 int factor = map->num_stripes / map->sub_stripes;
3069 stripe_index = do_div(stripe_nr, factor);
3070 stripe_index *= map->sub_stripes;
3072 if (unplug_page || (rw & REQ_WRITE))
3073 num_stripes = map->sub_stripes;
3074 else if (mirror_num)
3075 stripe_index += mirror_num - 1;
3077 stripe_index = find_live_mirror(map, stripe_index,
3078 map->sub_stripes, stripe_index +
3079 current->pid % map->sub_stripes);
3083 * after this do_div call, stripe_nr is the number of stripes
3084 * on this device we have to walk to find the data, and
3085 * stripe_index is the number of our device in the stripe array
3087 stripe_index = do_div(stripe_nr, map->num_stripes);
3089 BUG_ON(stripe_index >= map->num_stripes);
3091 for (i = 0; i < num_stripes; i++) {
3093 struct btrfs_device *device;
3094 struct backing_dev_info *bdi;
3096 device = map->stripes[stripe_index].dev;
3098 bdi = blk_get_backing_dev_info(device->bdev);
3099 if (bdi->unplug_io_fn)
3100 bdi->unplug_io_fn(bdi, unplug_page);
3103 multi->stripes[i].physical =
3104 map->stripes[stripe_index].physical +
3105 stripe_offset + stripe_nr * map->stripe_len;
3106 multi->stripes[i].dev = map->stripes[stripe_index].dev;
3112 multi->num_stripes = num_stripes;
3113 multi->max_errors = max_errors;
3116 free_extent_map(em);
3120 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3121 u64 logical, u64 *length,
3122 struct btrfs_multi_bio **multi_ret, int mirror_num)
3124 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
3128 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3129 u64 chunk_start, u64 physical, u64 devid,
3130 u64 **logical, int *naddrs, int *stripe_len)
3132 struct extent_map_tree *em_tree = &map_tree->map_tree;
3133 struct extent_map *em;
3134 struct map_lookup *map;
3141 read_lock(&em_tree->lock);
3142 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3143 read_unlock(&em_tree->lock);
3145 BUG_ON(!em || em->start != chunk_start);
3146 map = (struct map_lookup *)em->bdev;
3149 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3150 do_div(length, map->num_stripes / map->sub_stripes);
3151 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3152 do_div(length, map->num_stripes);
3154 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3157 for (i = 0; i < map->num_stripes; i++) {
3158 if (devid && map->stripes[i].dev->devid != devid)
3160 if (map->stripes[i].physical > physical ||
3161 map->stripes[i].physical + length <= physical)
3164 stripe_nr = physical - map->stripes[i].physical;
3165 do_div(stripe_nr, map->stripe_len);
3167 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3168 stripe_nr = stripe_nr * map->num_stripes + i;
3169 do_div(stripe_nr, map->sub_stripes);
3170 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3171 stripe_nr = stripe_nr * map->num_stripes + i;
3173 bytenr = chunk_start + stripe_nr * map->stripe_len;
3174 WARN_ON(nr >= map->num_stripes);
3175 for (j = 0; j < nr; j++) {
3176 if (buf[j] == bytenr)
3180 WARN_ON(nr >= map->num_stripes);
3187 *stripe_len = map->stripe_len;
3189 free_extent_map(em);
3193 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
3194 u64 logical, struct page *page)
3196 u64 length = PAGE_CACHE_SIZE;
3197 return __btrfs_map_block(map_tree, READ, logical, &length,
3201 static void end_bio_multi_stripe(struct bio *bio, int err)
3203 struct btrfs_multi_bio *multi = bio->bi_private;
3204 int is_orig_bio = 0;
3207 atomic_inc(&multi->error);
3209 if (bio == multi->orig_bio)
3212 if (atomic_dec_and_test(&multi->stripes_pending)) {
3215 bio = multi->orig_bio;
3217 bio->bi_private = multi->private;
3218 bio->bi_end_io = multi->end_io;
3219 /* only send an error to the higher layers if it is
3220 * beyond the tolerance of the multi-bio
3222 if (atomic_read(&multi->error) > multi->max_errors) {
3226 * this bio is actually up to date, we didn't
3227 * go over the max number of errors
3229 set_bit(BIO_UPTODATE, &bio->bi_flags);
3234 bio_endio(bio, err);
3235 } else if (!is_orig_bio) {
3240 struct async_sched {
3243 struct btrfs_fs_info *info;
3244 struct btrfs_work work;
3248 * see run_scheduled_bios for a description of why bios are collected for
3251 * This will add one bio to the pending list for a device and make sure
3252 * the work struct is scheduled.
3254 static noinline int schedule_bio(struct btrfs_root *root,
3255 struct btrfs_device *device,
3256 int rw, struct bio *bio)
3258 int should_queue = 1;
3259 struct btrfs_pending_bios *pending_bios;
3261 /* don't bother with additional async steps for reads, right now */
3262 if (!(rw & REQ_WRITE)) {
3264 submit_bio(rw, bio);
3270 * nr_async_bios allows us to reliably return congestion to the
3271 * higher layers. Otherwise, the async bio makes it appear we have
3272 * made progress against dirty pages when we've really just put it
3273 * on a queue for later
3275 atomic_inc(&root->fs_info->nr_async_bios);
3276 WARN_ON(bio->bi_next);
3277 bio->bi_next = NULL;
3280 spin_lock(&device->io_lock);
3281 if (bio->bi_rw & REQ_SYNC)
3282 pending_bios = &device->pending_sync_bios;
3284 pending_bios = &device->pending_bios;
3286 if (pending_bios->tail)
3287 pending_bios->tail->bi_next = bio;
3289 pending_bios->tail = bio;
3290 if (!pending_bios->head)
3291 pending_bios->head = bio;
3292 if (device->running_pending)
3295 spin_unlock(&device->io_lock);
3298 btrfs_queue_worker(&root->fs_info->submit_workers,
3303 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
3304 int mirror_num, int async_submit)
3306 struct btrfs_mapping_tree *map_tree;
3307 struct btrfs_device *dev;
3308 struct bio *first_bio = bio;
3309 u64 logical = (u64)bio->bi_sector << 9;
3312 struct btrfs_multi_bio *multi = NULL;
3317 length = bio->bi_size;
3318 map_tree = &root->fs_info->mapping_tree;
3319 map_length = length;
3321 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3325 total_devs = multi->num_stripes;
3326 if (map_length < length) {
3327 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3328 "len %llu\n", (unsigned long long)logical,
3329 (unsigned long long)length,
3330 (unsigned long long)map_length);
3333 multi->end_io = first_bio->bi_end_io;
3334 multi->private = first_bio->bi_private;
3335 multi->orig_bio = first_bio;
3336 atomic_set(&multi->stripes_pending, multi->num_stripes);
3338 while (dev_nr < total_devs) {
3339 if (total_devs > 1) {
3340 if (dev_nr < total_devs - 1) {
3341 bio = bio_clone(first_bio, GFP_NOFS);
3346 bio->bi_private = multi;
3347 bio->bi_end_io = end_bio_multi_stripe;
3349 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3350 dev = multi->stripes[dev_nr].dev;
3351 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3352 bio->bi_bdev = dev->bdev;
3354 schedule_bio(root, dev, rw, bio);
3356 submit_bio(rw, bio);
3358 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3359 bio->bi_sector = logical >> 9;
3360 bio_endio(bio, -EIO);
3364 if (total_devs == 1)
3369 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3372 struct btrfs_device *device;
3373 struct btrfs_fs_devices *cur_devices;
3375 cur_devices = root->fs_info->fs_devices;
3376 while (cur_devices) {
3378 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3379 device = __find_device(&cur_devices->devices,
3384 cur_devices = cur_devices->seed;
3389 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3390 u64 devid, u8 *dev_uuid)
3392 struct btrfs_device *device;
3393 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3395 device = kzalloc(sizeof(*device), GFP_NOFS);
3398 list_add(&device->dev_list,
3399 &fs_devices->devices);
3400 device->dev_root = root->fs_info->dev_root;
3401 device->devid = devid;
3402 device->work.func = pending_bios_fn;
3403 device->fs_devices = fs_devices;
3404 device->missing = 1;
3405 fs_devices->num_devices++;
3406 fs_devices->missing_devices++;
3407 spin_lock_init(&device->io_lock);
3408 INIT_LIST_HEAD(&device->dev_alloc_list);
3409 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3413 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3414 struct extent_buffer *leaf,
3415 struct btrfs_chunk *chunk)
3417 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3418 struct map_lookup *map;
3419 struct extent_map *em;
3423 u8 uuid[BTRFS_UUID_SIZE];
3428 logical = key->offset;
3429 length = btrfs_chunk_length(leaf, chunk);
3431 read_lock(&map_tree->map_tree.lock);
3432 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3433 read_unlock(&map_tree->map_tree.lock);
3435 /* already mapped? */
3436 if (em && em->start <= logical && em->start + em->len > logical) {
3437 free_extent_map(em);
3440 free_extent_map(em);
3443 em = alloc_extent_map(GFP_NOFS);
3446 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3447 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3449 free_extent_map(em);
3453 em->bdev = (struct block_device *)map;
3454 em->start = logical;
3456 em->block_start = 0;
3457 em->block_len = em->len;
3459 map->num_stripes = num_stripes;
3460 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3461 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3462 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3463 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3464 map->type = btrfs_chunk_type(leaf, chunk);
3465 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3466 for (i = 0; i < num_stripes; i++) {
3467 map->stripes[i].physical =
3468 btrfs_stripe_offset_nr(leaf, chunk, i);
3469 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3470 read_extent_buffer(leaf, uuid, (unsigned long)
3471 btrfs_stripe_dev_uuid_nr(chunk, i),
3473 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3475 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3477 free_extent_map(em);
3480 if (!map->stripes[i].dev) {
3481 map->stripes[i].dev =
3482 add_missing_dev(root, devid, uuid);
3483 if (!map->stripes[i].dev) {
3485 free_extent_map(em);
3489 map->stripes[i].dev->in_fs_metadata = 1;
3492 write_lock(&map_tree->map_tree.lock);
3493 ret = add_extent_mapping(&map_tree->map_tree, em);
3494 write_unlock(&map_tree->map_tree.lock);
3496 free_extent_map(em);
3501 static int fill_device_from_item(struct extent_buffer *leaf,
3502 struct btrfs_dev_item *dev_item,
3503 struct btrfs_device *device)
3507 device->devid = btrfs_device_id(leaf, dev_item);
3508 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3509 device->total_bytes = device->disk_total_bytes;
3510 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3511 device->type = btrfs_device_type(leaf, dev_item);
3512 device->io_align = btrfs_device_io_align(leaf, dev_item);
3513 device->io_width = btrfs_device_io_width(leaf, dev_item);
3514 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3516 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3517 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3522 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3524 struct btrfs_fs_devices *fs_devices;
3527 mutex_lock(&uuid_mutex);
3529 fs_devices = root->fs_info->fs_devices->seed;
3530 while (fs_devices) {
3531 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3535 fs_devices = fs_devices->seed;
3538 fs_devices = find_fsid(fsid);
3544 fs_devices = clone_fs_devices(fs_devices);
3545 if (IS_ERR(fs_devices)) {
3546 ret = PTR_ERR(fs_devices);
3550 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3551 root->fs_info->bdev_holder);
3555 if (!fs_devices->seeding) {
3556 __btrfs_close_devices(fs_devices);
3557 free_fs_devices(fs_devices);
3562 fs_devices->seed = root->fs_info->fs_devices->seed;
3563 root->fs_info->fs_devices->seed = fs_devices;
3565 mutex_unlock(&uuid_mutex);
3569 static int read_one_dev(struct btrfs_root *root,
3570 struct extent_buffer *leaf,
3571 struct btrfs_dev_item *dev_item)
3573 struct btrfs_device *device;
3576 u8 fs_uuid[BTRFS_UUID_SIZE];
3577 u8 dev_uuid[BTRFS_UUID_SIZE];
3579 devid = btrfs_device_id(leaf, dev_item);
3580 read_extent_buffer(leaf, dev_uuid,
3581 (unsigned long)btrfs_device_uuid(dev_item),
3583 read_extent_buffer(leaf, fs_uuid,
3584 (unsigned long)btrfs_device_fsid(dev_item),
3587 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3588 ret = open_seed_devices(root, fs_uuid);
3589 if (ret && !btrfs_test_opt(root, DEGRADED))
3593 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3594 if (!device || !device->bdev) {
3595 if (!btrfs_test_opt(root, DEGRADED))
3599 printk(KERN_WARNING "warning devid %llu missing\n",
3600 (unsigned long long)devid);
3601 device = add_missing_dev(root, devid, dev_uuid);
3604 } else if (!device->missing) {
3606 * this happens when a device that was properly setup
3607 * in the device info lists suddenly goes bad.
3608 * device->bdev is NULL, and so we have to set
3609 * device->missing to one here
3611 root->fs_info->fs_devices->missing_devices++;
3612 device->missing = 1;
3616 if (device->fs_devices != root->fs_info->fs_devices) {
3617 BUG_ON(device->writeable);
3618 if (device->generation !=
3619 btrfs_device_generation(leaf, dev_item))
3623 fill_device_from_item(leaf, dev_item, device);
3624 device->dev_root = root->fs_info->dev_root;
3625 device->in_fs_metadata = 1;
3626 if (device->writeable)
3627 device->fs_devices->total_rw_bytes += device->total_bytes;
3632 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3634 struct btrfs_dev_item *dev_item;
3636 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3638 return read_one_dev(root, buf, dev_item);
3641 int btrfs_read_sys_array(struct btrfs_root *root)
3643 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3644 struct extent_buffer *sb;
3645 struct btrfs_disk_key *disk_key;
3646 struct btrfs_chunk *chunk;
3648 unsigned long sb_ptr;
3654 struct btrfs_key key;
3656 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3657 BTRFS_SUPER_INFO_SIZE);
3660 btrfs_set_buffer_uptodate(sb);
3661 btrfs_set_buffer_lockdep_class(sb, 0);
3663 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3664 array_size = btrfs_super_sys_array_size(super_copy);
3666 ptr = super_copy->sys_chunk_array;
3667 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3670 while (cur < array_size) {
3671 disk_key = (struct btrfs_disk_key *)ptr;
3672 btrfs_disk_key_to_cpu(&key, disk_key);
3674 len = sizeof(*disk_key); ptr += len;
3678 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3679 chunk = (struct btrfs_chunk *)sb_ptr;
3680 ret = read_one_chunk(root, &key, sb, chunk);
3683 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3684 len = btrfs_chunk_item_size(num_stripes);
3693 free_extent_buffer(sb);
3697 int btrfs_read_chunk_tree(struct btrfs_root *root)
3699 struct btrfs_path *path;
3700 struct extent_buffer *leaf;
3701 struct btrfs_key key;
3702 struct btrfs_key found_key;
3706 root = root->fs_info->chunk_root;
3708 path = btrfs_alloc_path();
3712 /* first we search for all of the device items, and then we
3713 * read in all of the chunk items. This way we can create chunk
3714 * mappings that reference all of the devices that are afound
3716 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3720 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3724 leaf = path->nodes[0];
3725 slot = path->slots[0];
3726 if (slot >= btrfs_header_nritems(leaf)) {
3727 ret = btrfs_next_leaf(root, path);
3734 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3735 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3736 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3738 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3739 struct btrfs_dev_item *dev_item;
3740 dev_item = btrfs_item_ptr(leaf, slot,
3741 struct btrfs_dev_item);
3742 ret = read_one_dev(root, leaf, dev_item);
3746 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3747 struct btrfs_chunk *chunk;
3748 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3749 ret = read_one_chunk(root, &found_key, leaf, chunk);
3755 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3757 btrfs_release_path(root, path);
3762 btrfs_free_path(path);