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"
44 struct btrfs_bio_stripe stripes[];
47 static int init_first_rw_device(struct btrfs_trans_handle *trans,
48 struct btrfs_root *root,
49 struct btrfs_device *device);
50 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
52 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
53 (sizeof(struct btrfs_bio_stripe) * (n)))
55 static DEFINE_MUTEX(uuid_mutex);
56 static LIST_HEAD(fs_uuids);
58 void btrfs_lock_volumes(void)
60 mutex_lock(&uuid_mutex);
63 void btrfs_unlock_volumes(void)
65 mutex_unlock(&uuid_mutex);
68 static void lock_chunks(struct btrfs_root *root)
70 mutex_lock(&root->fs_info->chunk_mutex);
73 static void unlock_chunks(struct btrfs_root *root)
75 mutex_unlock(&root->fs_info->chunk_mutex);
78 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
80 struct btrfs_device *device;
81 WARN_ON(fs_devices->opened);
82 while (!list_empty(&fs_devices->devices)) {
83 device = list_entry(fs_devices->devices.next,
84 struct btrfs_device, dev_list);
85 list_del(&device->dev_list);
92 int btrfs_cleanup_fs_uuids(void)
94 struct btrfs_fs_devices *fs_devices;
96 while (!list_empty(&fs_uuids)) {
97 fs_devices = list_entry(fs_uuids.next,
98 struct btrfs_fs_devices, list);
99 list_del(&fs_devices->list);
100 free_fs_devices(fs_devices);
105 static noinline struct btrfs_device *__find_device(struct list_head *head,
108 struct btrfs_device *dev;
110 list_for_each_entry(dev, head, dev_list) {
111 if (dev->devid == devid &&
112 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
119 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
121 struct btrfs_fs_devices *fs_devices;
123 list_for_each_entry(fs_devices, &fs_uuids, list) {
124 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
130 static void requeue_list(struct btrfs_pending_bios *pending_bios,
131 struct bio *head, struct bio *tail)
134 struct bio *old_head;
136 old_head = pending_bios->head;
137 pending_bios->head = head;
138 if (pending_bios->tail)
139 tail->bi_next = old_head;
141 pending_bios->tail = tail;
145 * we try to collect pending bios for a device so we don't get a large
146 * number of procs sending bios down to the same device. This greatly
147 * improves the schedulers ability to collect and merge the bios.
149 * But, it also turns into a long list of bios to process and that is sure
150 * to eventually make the worker thread block. The solution here is to
151 * make some progress and then put this work struct back at the end of
152 * the list if the block device is congested. This way, multiple devices
153 * can make progress from a single worker thread.
155 static noinline int run_scheduled_bios(struct btrfs_device *device)
158 struct backing_dev_info *bdi;
159 struct btrfs_fs_info *fs_info;
160 struct btrfs_pending_bios *pending_bios;
164 unsigned long num_run;
165 unsigned long num_sync_run;
166 unsigned long batch_run = 0;
168 unsigned long last_waited = 0;
171 bdi = blk_get_backing_dev_info(device->bdev);
172 fs_info = device->dev_root->fs_info;
173 limit = btrfs_async_submit_limit(fs_info);
174 limit = limit * 2 / 3;
176 /* we want to make sure that every time we switch from the sync
177 * list to the normal list, we unplug
182 spin_lock(&device->io_lock);
187 /* take all the bios off the list at once and process them
188 * later on (without the lock held). But, remember the
189 * tail and other pointers so the bios can be properly reinserted
190 * into the list if we hit congestion
192 if (!force_reg && device->pending_sync_bios.head) {
193 pending_bios = &device->pending_sync_bios;
196 pending_bios = &device->pending_bios;
200 pending = pending_bios->head;
201 tail = pending_bios->tail;
202 WARN_ON(pending && !tail);
205 * if pending was null this time around, no bios need processing
206 * at all and we can stop. Otherwise it'll loop back up again
207 * and do an additional check so no bios are missed.
209 * device->running_pending is used to synchronize with the
212 if (device->pending_sync_bios.head == NULL &&
213 device->pending_bios.head == NULL) {
215 device->running_pending = 0;
218 device->running_pending = 1;
221 pending_bios->head = NULL;
222 pending_bios->tail = NULL;
224 spin_unlock(&device->io_lock);
227 * if we're doing the regular priority list, make sure we unplug
228 * for any high prio bios we've sent down
230 if (pending_bios == &device->pending_bios && num_sync_run > 0) {
232 blk_run_backing_dev(bdi, NULL);
238 /* we want to work on both lists, but do more bios on the
239 * sync list than the regular list
242 pending_bios != &device->pending_sync_bios &&
243 device->pending_sync_bios.head) ||
244 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
245 device->pending_bios.head)) {
246 spin_lock(&device->io_lock);
247 requeue_list(pending_bios, pending, tail);
252 pending = pending->bi_next;
254 atomic_dec(&fs_info->nr_async_bios);
256 if (atomic_read(&fs_info->nr_async_bios) < limit &&
257 waitqueue_active(&fs_info->async_submit_wait))
258 wake_up(&fs_info->async_submit_wait);
260 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
262 if (cur->bi_rw & REQ_SYNC)
265 submit_bio(cur->bi_rw, cur);
268 if (need_resched()) {
270 blk_run_backing_dev(bdi, NULL);
277 * we made progress, there is more work to do and the bdi
278 * is now congested. Back off and let other work structs
281 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
282 fs_info->fs_devices->open_devices > 1) {
283 struct io_context *ioc;
285 ioc = current->io_context;
288 * the main goal here is that we don't want to
289 * block if we're going to be able to submit
290 * more requests without blocking.
292 * This code does two great things, it pokes into
293 * the elevator code from a filesystem _and_
294 * it makes assumptions about how batching works.
296 if (ioc && ioc->nr_batch_requests > 0 &&
297 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
299 ioc->last_waited == last_waited)) {
301 * we want to go through our batch of
302 * requests and stop. So, we copy out
303 * the ioc->last_waited time and test
304 * against it before looping
306 last_waited = ioc->last_waited;
307 if (need_resched()) {
309 blk_run_backing_dev(bdi, NULL);
316 spin_lock(&device->io_lock);
317 requeue_list(pending_bios, pending, tail);
318 device->running_pending = 1;
320 spin_unlock(&device->io_lock);
321 btrfs_requeue_work(&device->work);
328 blk_run_backing_dev(bdi, NULL);
331 * IO has already been through a long path to get here. Checksumming,
332 * async helper threads, perhaps compression. We've done a pretty
333 * good job of collecting a batch of IO and should just unplug
334 * the device right away.
336 * This will help anyone who is waiting on the IO, they might have
337 * already unplugged, but managed to do so before the bio they
338 * cared about found its way down here.
340 blk_run_backing_dev(bdi, NULL);
346 spin_lock(&device->io_lock);
347 if (device->pending_bios.head || device->pending_sync_bios.head)
349 spin_unlock(&device->io_lock);
355 static void pending_bios_fn(struct btrfs_work *work)
357 struct btrfs_device *device;
359 device = container_of(work, struct btrfs_device, work);
360 run_scheduled_bios(device);
363 static noinline int device_list_add(const char *path,
364 struct btrfs_super_block *disk_super,
365 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
367 struct btrfs_device *device;
368 struct btrfs_fs_devices *fs_devices;
369 u64 found_transid = btrfs_super_generation(disk_super);
372 fs_devices = find_fsid(disk_super->fsid);
374 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
377 INIT_LIST_HEAD(&fs_devices->devices);
378 INIT_LIST_HEAD(&fs_devices->alloc_list);
379 list_add(&fs_devices->list, &fs_uuids);
380 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
381 fs_devices->latest_devid = devid;
382 fs_devices->latest_trans = found_transid;
383 mutex_init(&fs_devices->device_list_mutex);
386 device = __find_device(&fs_devices->devices, devid,
387 disk_super->dev_item.uuid);
390 if (fs_devices->opened)
393 device = kzalloc(sizeof(*device), GFP_NOFS);
395 /* we can safely leave the fs_devices entry around */
398 device->devid = devid;
399 device->work.func = pending_bios_fn;
400 memcpy(device->uuid, disk_super->dev_item.uuid,
402 spin_lock_init(&device->io_lock);
403 device->name = kstrdup(path, GFP_NOFS);
408 INIT_LIST_HEAD(&device->dev_alloc_list);
410 mutex_lock(&fs_devices->device_list_mutex);
411 list_add(&device->dev_list, &fs_devices->devices);
412 mutex_unlock(&fs_devices->device_list_mutex);
414 device->fs_devices = fs_devices;
415 fs_devices->num_devices++;
416 } else if (!device->name || strcmp(device->name, path)) {
417 name = kstrdup(path, GFP_NOFS);
422 if (device->missing) {
423 fs_devices->missing_devices--;
428 if (found_transid > fs_devices->latest_trans) {
429 fs_devices->latest_devid = devid;
430 fs_devices->latest_trans = found_transid;
432 *fs_devices_ret = fs_devices;
436 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
438 struct btrfs_fs_devices *fs_devices;
439 struct btrfs_device *device;
440 struct btrfs_device *orig_dev;
442 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
444 return ERR_PTR(-ENOMEM);
446 INIT_LIST_HEAD(&fs_devices->devices);
447 INIT_LIST_HEAD(&fs_devices->alloc_list);
448 INIT_LIST_HEAD(&fs_devices->list);
449 mutex_init(&fs_devices->device_list_mutex);
450 fs_devices->latest_devid = orig->latest_devid;
451 fs_devices->latest_trans = orig->latest_trans;
452 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
454 mutex_lock(&orig->device_list_mutex);
455 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
456 device = kzalloc(sizeof(*device), GFP_NOFS);
460 device->name = kstrdup(orig_dev->name, GFP_NOFS);
466 device->devid = orig_dev->devid;
467 device->work.func = pending_bios_fn;
468 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
469 spin_lock_init(&device->io_lock);
470 INIT_LIST_HEAD(&device->dev_list);
471 INIT_LIST_HEAD(&device->dev_alloc_list);
473 list_add(&device->dev_list, &fs_devices->devices);
474 device->fs_devices = fs_devices;
475 fs_devices->num_devices++;
477 mutex_unlock(&orig->device_list_mutex);
480 mutex_unlock(&orig->device_list_mutex);
481 free_fs_devices(fs_devices);
482 return ERR_PTR(-ENOMEM);
485 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
487 struct btrfs_device *device, *next;
489 mutex_lock(&uuid_mutex);
491 mutex_lock(&fs_devices->device_list_mutex);
492 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
493 if (device->in_fs_metadata)
497 blkdev_put(device->bdev, device->mode);
499 fs_devices->open_devices--;
501 if (device->writeable) {
502 list_del_init(&device->dev_alloc_list);
503 device->writeable = 0;
504 fs_devices->rw_devices--;
506 list_del_init(&device->dev_list);
507 fs_devices->num_devices--;
511 mutex_unlock(&fs_devices->device_list_mutex);
513 if (fs_devices->seed) {
514 fs_devices = fs_devices->seed;
518 mutex_unlock(&uuid_mutex);
522 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
524 struct btrfs_device *device;
526 if (--fs_devices->opened > 0)
529 list_for_each_entry(device, &fs_devices->devices, dev_list) {
531 blkdev_put(device->bdev, device->mode);
532 fs_devices->open_devices--;
534 if (device->writeable) {
535 list_del_init(&device->dev_alloc_list);
536 fs_devices->rw_devices--;
540 device->writeable = 0;
541 device->in_fs_metadata = 0;
543 WARN_ON(fs_devices->open_devices);
544 WARN_ON(fs_devices->rw_devices);
545 fs_devices->opened = 0;
546 fs_devices->seeding = 0;
551 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
553 struct btrfs_fs_devices *seed_devices = NULL;
556 mutex_lock(&uuid_mutex);
557 ret = __btrfs_close_devices(fs_devices);
558 if (!fs_devices->opened) {
559 seed_devices = fs_devices->seed;
560 fs_devices->seed = NULL;
562 mutex_unlock(&uuid_mutex);
564 while (seed_devices) {
565 fs_devices = seed_devices;
566 seed_devices = fs_devices->seed;
567 __btrfs_close_devices(fs_devices);
568 free_fs_devices(fs_devices);
573 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
574 fmode_t flags, void *holder)
576 struct block_device *bdev;
577 struct list_head *head = &fs_devices->devices;
578 struct btrfs_device *device;
579 struct block_device *latest_bdev = NULL;
580 struct buffer_head *bh;
581 struct btrfs_super_block *disk_super;
582 u64 latest_devid = 0;
583 u64 latest_transid = 0;
590 list_for_each_entry(device, head, dev_list) {
596 bdev = blkdev_get_by_path(device->name, flags, holder);
598 printk(KERN_INFO "open %s failed\n", device->name);
601 set_blocksize(bdev, 4096);
603 bh = btrfs_read_dev_super(bdev);
609 disk_super = (struct btrfs_super_block *)bh->b_data;
610 devid = btrfs_stack_device_id(&disk_super->dev_item);
611 if (devid != device->devid)
614 if (memcmp(device->uuid, disk_super->dev_item.uuid,
618 device->generation = btrfs_super_generation(disk_super);
619 if (!latest_transid || device->generation > latest_transid) {
620 latest_devid = devid;
621 latest_transid = device->generation;
625 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
626 device->writeable = 0;
628 device->writeable = !bdev_read_only(bdev);
633 device->in_fs_metadata = 0;
634 device->mode = flags;
636 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
637 fs_devices->rotating = 1;
639 fs_devices->open_devices++;
640 if (device->writeable) {
641 fs_devices->rw_devices++;
642 list_add(&device->dev_alloc_list,
643 &fs_devices->alloc_list);
650 blkdev_put(bdev, flags);
654 if (fs_devices->open_devices == 0) {
658 fs_devices->seeding = seeding;
659 fs_devices->opened = 1;
660 fs_devices->latest_bdev = latest_bdev;
661 fs_devices->latest_devid = latest_devid;
662 fs_devices->latest_trans = latest_transid;
663 fs_devices->total_rw_bytes = 0;
668 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
669 fmode_t flags, void *holder)
673 mutex_lock(&uuid_mutex);
674 if (fs_devices->opened) {
675 fs_devices->opened++;
678 ret = __btrfs_open_devices(fs_devices, flags, holder);
680 mutex_unlock(&uuid_mutex);
684 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
685 struct btrfs_fs_devices **fs_devices_ret)
687 struct btrfs_super_block *disk_super;
688 struct block_device *bdev;
689 struct buffer_head *bh;
694 mutex_lock(&uuid_mutex);
697 bdev = blkdev_get_by_path(path, flags, holder);
704 ret = set_blocksize(bdev, 4096);
707 bh = btrfs_read_dev_super(bdev);
712 disk_super = (struct btrfs_super_block *)bh->b_data;
713 devid = btrfs_stack_device_id(&disk_super->dev_item);
714 transid = btrfs_super_generation(disk_super);
715 if (disk_super->label[0])
716 printk(KERN_INFO "device label %s ", disk_super->label);
718 /* FIXME, make a readl uuid parser */
719 printk(KERN_INFO "device fsid %llx-%llx ",
720 *(unsigned long long *)disk_super->fsid,
721 *(unsigned long long *)(disk_super->fsid + 8));
723 printk(KERN_CONT "devid %llu transid %llu %s\n",
724 (unsigned long long)devid, (unsigned long long)transid, path);
725 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
729 blkdev_put(bdev, flags);
731 mutex_unlock(&uuid_mutex);
735 /* helper to account the used device space in the range */
736 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
737 u64 end, u64 *length)
739 struct btrfs_key key;
740 struct btrfs_root *root = device->dev_root;
741 struct btrfs_dev_extent *dev_extent;
742 struct btrfs_path *path;
746 struct extent_buffer *l;
750 if (start >= device->total_bytes)
753 path = btrfs_alloc_path();
758 key.objectid = device->devid;
760 key.type = BTRFS_DEV_EXTENT_KEY;
762 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
766 ret = btrfs_previous_item(root, path, key.objectid, key.type);
773 slot = path->slots[0];
774 if (slot >= btrfs_header_nritems(l)) {
775 ret = btrfs_next_leaf(root, path);
783 btrfs_item_key_to_cpu(l, &key, slot);
785 if (key.objectid < device->devid)
788 if (key.objectid > device->devid)
791 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
794 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
795 extent_end = key.offset + btrfs_dev_extent_length(l,
797 if (key.offset <= start && extent_end > end) {
798 *length = end - start + 1;
800 } else if (key.offset <= start && extent_end > start)
801 *length += extent_end - start;
802 else if (key.offset > start && extent_end <= end)
803 *length += extent_end - key.offset;
804 else if (key.offset > start && key.offset <= end) {
805 *length += end - key.offset + 1;
807 } else if (key.offset > end)
815 btrfs_free_path(path);
820 * find_free_dev_extent - find free space in the specified device
821 * @trans: transaction handler
822 * @device: the device which we search the free space in
823 * @num_bytes: the size of the free space that we need
824 * @start: store the start of the free space.
825 * @len: the size of the free space. that we find, or the size of the max
826 * free space if we don't find suitable free space
828 * this uses a pretty simple search, the expectation is that it is
829 * called very infrequently and that a given device has a small number
832 * @start is used to store the start of the free space if we find. But if we
833 * don't find suitable free space, it will be used to store the start position
834 * of the max free space.
836 * @len is used to store the size of the free space that we find.
837 * But if we don't find suitable free space, it is used to store the size of
838 * the max free space.
840 int find_free_dev_extent(struct btrfs_trans_handle *trans,
841 struct btrfs_device *device, u64 num_bytes,
842 u64 *start, u64 *len)
844 struct btrfs_key key;
845 struct btrfs_root *root = device->dev_root;
846 struct btrfs_dev_extent *dev_extent;
847 struct btrfs_path *path;
853 u64 search_end = device->total_bytes;
856 struct extent_buffer *l;
858 /* FIXME use last free of some kind */
860 /* we don't want to overwrite the superblock on the drive,
861 * so we make sure to start at an offset of at least 1MB
863 search_start = 1024 * 1024;
865 if (root->fs_info->alloc_start + num_bytes <= search_end)
866 search_start = max(root->fs_info->alloc_start, search_start);
868 max_hole_start = search_start;
871 if (search_start >= search_end) {
876 path = btrfs_alloc_path();
883 key.objectid = device->devid;
884 key.offset = search_start;
885 key.type = BTRFS_DEV_EXTENT_KEY;
887 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
891 ret = btrfs_previous_item(root, path, key.objectid, key.type);
898 slot = path->slots[0];
899 if (slot >= btrfs_header_nritems(l)) {
900 ret = btrfs_next_leaf(root, path);
908 btrfs_item_key_to_cpu(l, &key, slot);
910 if (key.objectid < device->devid)
913 if (key.objectid > device->devid)
916 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
919 if (key.offset > search_start) {
920 hole_size = key.offset - search_start;
922 if (hole_size > max_hole_size) {
923 max_hole_start = search_start;
924 max_hole_size = hole_size;
928 * If this free space is greater than which we need,
929 * it must be the max free space that we have found
930 * until now, so max_hole_start must point to the start
931 * of this free space and the length of this free space
932 * is stored in max_hole_size. Thus, we return
933 * max_hole_start and max_hole_size and go back to the
936 if (hole_size >= num_bytes) {
942 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
943 extent_end = key.offset + btrfs_dev_extent_length(l,
945 if (extent_end > search_start)
946 search_start = extent_end;
952 hole_size = search_end- search_start;
953 if (hole_size > max_hole_size) {
954 max_hole_start = search_start;
955 max_hole_size = hole_size;
959 if (hole_size < num_bytes)
965 btrfs_free_path(path);
967 *start = max_hole_start;
969 *len = max_hole_size;
973 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
974 struct btrfs_device *device,
978 struct btrfs_path *path;
979 struct btrfs_root *root = device->dev_root;
980 struct btrfs_key key;
981 struct btrfs_key found_key;
982 struct extent_buffer *leaf = NULL;
983 struct btrfs_dev_extent *extent = NULL;
985 path = btrfs_alloc_path();
989 key.objectid = device->devid;
991 key.type = BTRFS_DEV_EXTENT_KEY;
993 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
995 ret = btrfs_previous_item(root, path, key.objectid,
996 BTRFS_DEV_EXTENT_KEY);
998 leaf = path->nodes[0];
999 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1000 extent = btrfs_item_ptr(leaf, path->slots[0],
1001 struct btrfs_dev_extent);
1002 BUG_ON(found_key.offset > start || found_key.offset +
1003 btrfs_dev_extent_length(leaf, extent) < start);
1005 } else if (ret == 0) {
1006 leaf = path->nodes[0];
1007 extent = btrfs_item_ptr(leaf, path->slots[0],
1008 struct btrfs_dev_extent);
1012 if (device->bytes_used > 0)
1013 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
1014 ret = btrfs_del_item(trans, root, path);
1017 btrfs_free_path(path);
1021 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1022 struct btrfs_device *device,
1023 u64 chunk_tree, u64 chunk_objectid,
1024 u64 chunk_offset, u64 start, u64 num_bytes)
1027 struct btrfs_path *path;
1028 struct btrfs_root *root = device->dev_root;
1029 struct btrfs_dev_extent *extent;
1030 struct extent_buffer *leaf;
1031 struct btrfs_key key;
1033 WARN_ON(!device->in_fs_metadata);
1034 path = btrfs_alloc_path();
1038 key.objectid = device->devid;
1040 key.type = BTRFS_DEV_EXTENT_KEY;
1041 ret = btrfs_insert_empty_item(trans, root, path, &key,
1045 leaf = path->nodes[0];
1046 extent = btrfs_item_ptr(leaf, path->slots[0],
1047 struct btrfs_dev_extent);
1048 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1049 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1050 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1052 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1053 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1056 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1057 btrfs_mark_buffer_dirty(leaf);
1058 btrfs_free_path(path);
1062 static noinline int find_next_chunk(struct btrfs_root *root,
1063 u64 objectid, u64 *offset)
1065 struct btrfs_path *path;
1067 struct btrfs_key key;
1068 struct btrfs_chunk *chunk;
1069 struct btrfs_key found_key;
1071 path = btrfs_alloc_path();
1074 key.objectid = objectid;
1075 key.offset = (u64)-1;
1076 key.type = BTRFS_CHUNK_ITEM_KEY;
1078 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1084 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1088 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1090 if (found_key.objectid != objectid)
1093 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1094 struct btrfs_chunk);
1095 *offset = found_key.offset +
1096 btrfs_chunk_length(path->nodes[0], chunk);
1101 btrfs_free_path(path);
1105 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1108 struct btrfs_key key;
1109 struct btrfs_key found_key;
1110 struct btrfs_path *path;
1112 root = root->fs_info->chunk_root;
1114 path = btrfs_alloc_path();
1118 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1119 key.type = BTRFS_DEV_ITEM_KEY;
1120 key.offset = (u64)-1;
1122 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1128 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1129 BTRFS_DEV_ITEM_KEY);
1133 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1135 *objectid = found_key.offset + 1;
1139 btrfs_free_path(path);
1144 * the device information is stored in the chunk root
1145 * the btrfs_device struct should be fully filled in
1147 int btrfs_add_device(struct btrfs_trans_handle *trans,
1148 struct btrfs_root *root,
1149 struct btrfs_device *device)
1152 struct btrfs_path *path;
1153 struct btrfs_dev_item *dev_item;
1154 struct extent_buffer *leaf;
1155 struct btrfs_key key;
1158 root = root->fs_info->chunk_root;
1160 path = btrfs_alloc_path();
1164 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1165 key.type = BTRFS_DEV_ITEM_KEY;
1166 key.offset = device->devid;
1168 ret = btrfs_insert_empty_item(trans, root, path, &key,
1173 leaf = path->nodes[0];
1174 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1176 btrfs_set_device_id(leaf, dev_item, device->devid);
1177 btrfs_set_device_generation(leaf, dev_item, 0);
1178 btrfs_set_device_type(leaf, dev_item, device->type);
1179 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1180 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1181 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1182 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1183 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1184 btrfs_set_device_group(leaf, dev_item, 0);
1185 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1186 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1187 btrfs_set_device_start_offset(leaf, dev_item, 0);
1189 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1190 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1191 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1192 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1193 btrfs_mark_buffer_dirty(leaf);
1197 btrfs_free_path(path);
1201 static int btrfs_rm_dev_item(struct btrfs_root *root,
1202 struct btrfs_device *device)
1205 struct btrfs_path *path;
1206 struct btrfs_key key;
1207 struct btrfs_trans_handle *trans;
1209 root = root->fs_info->chunk_root;
1211 path = btrfs_alloc_path();
1215 trans = btrfs_start_transaction(root, 0);
1216 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1217 key.type = BTRFS_DEV_ITEM_KEY;
1218 key.offset = device->devid;
1221 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1230 ret = btrfs_del_item(trans, root, path);
1234 btrfs_free_path(path);
1235 unlock_chunks(root);
1236 btrfs_commit_transaction(trans, root);
1240 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1242 struct btrfs_device *device;
1243 struct btrfs_device *next_device;
1244 struct block_device *bdev;
1245 struct buffer_head *bh = NULL;
1246 struct btrfs_super_block *disk_super;
1253 mutex_lock(&uuid_mutex);
1254 mutex_lock(&root->fs_info->volume_mutex);
1256 all_avail = root->fs_info->avail_data_alloc_bits |
1257 root->fs_info->avail_system_alloc_bits |
1258 root->fs_info->avail_metadata_alloc_bits;
1260 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1261 root->fs_info->fs_devices->num_devices <= 4) {
1262 printk(KERN_ERR "btrfs: unable to go below four devices "
1268 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1269 root->fs_info->fs_devices->num_devices <= 2) {
1270 printk(KERN_ERR "btrfs: unable to go below two "
1271 "devices on raid1\n");
1276 if (strcmp(device_path, "missing") == 0) {
1277 struct list_head *devices;
1278 struct btrfs_device *tmp;
1281 devices = &root->fs_info->fs_devices->devices;
1282 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1283 list_for_each_entry(tmp, devices, dev_list) {
1284 if (tmp->in_fs_metadata && !tmp->bdev) {
1289 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1294 printk(KERN_ERR "btrfs: no missing devices found to "
1299 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1300 root->fs_info->bdev_holder);
1302 ret = PTR_ERR(bdev);
1306 set_blocksize(bdev, 4096);
1307 bh = btrfs_read_dev_super(bdev);
1312 disk_super = (struct btrfs_super_block *)bh->b_data;
1313 devid = btrfs_stack_device_id(&disk_super->dev_item);
1314 dev_uuid = disk_super->dev_item.uuid;
1315 device = btrfs_find_device(root, devid, dev_uuid,
1323 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1324 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1330 if (device->writeable) {
1331 list_del_init(&device->dev_alloc_list);
1332 root->fs_info->fs_devices->rw_devices--;
1335 ret = btrfs_shrink_device(device, 0);
1339 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1343 device->in_fs_metadata = 0;
1346 * the device list mutex makes sure that we don't change
1347 * the device list while someone else is writing out all
1348 * the device supers.
1350 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1351 list_del_init(&device->dev_list);
1352 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1354 device->fs_devices->num_devices--;
1356 if (device->missing)
1357 root->fs_info->fs_devices->missing_devices--;
1359 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1360 struct btrfs_device, dev_list);
1361 if (device->bdev == root->fs_info->sb->s_bdev)
1362 root->fs_info->sb->s_bdev = next_device->bdev;
1363 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1364 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1367 blkdev_put(device->bdev, device->mode);
1368 device->bdev = NULL;
1369 device->fs_devices->open_devices--;
1372 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1373 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1375 if (device->fs_devices->open_devices == 0) {
1376 struct btrfs_fs_devices *fs_devices;
1377 fs_devices = root->fs_info->fs_devices;
1378 while (fs_devices) {
1379 if (fs_devices->seed == device->fs_devices)
1381 fs_devices = fs_devices->seed;
1383 fs_devices->seed = device->fs_devices->seed;
1384 device->fs_devices->seed = NULL;
1385 __btrfs_close_devices(device->fs_devices);
1386 free_fs_devices(device->fs_devices);
1390 * at this point, the device is zero sized. We want to
1391 * remove it from the devices list and zero out the old super
1393 if (device->writeable) {
1394 /* make sure this device isn't detected as part of
1397 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1398 set_buffer_dirty(bh);
1399 sync_dirty_buffer(bh);
1402 kfree(device->name);
1410 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1412 mutex_unlock(&root->fs_info->volume_mutex);
1413 mutex_unlock(&uuid_mutex);
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);
1608 trans = btrfs_start_transaction(root, 0);
1611 device->writeable = 1;
1612 device->work.func = pending_bios_fn;
1613 generate_random_uuid(device->uuid);
1614 spin_lock_init(&device->io_lock);
1615 device->generation = trans->transid;
1616 device->io_width = root->sectorsize;
1617 device->io_align = root->sectorsize;
1618 device->sector_size = root->sectorsize;
1619 device->total_bytes = i_size_read(bdev->bd_inode);
1620 device->disk_total_bytes = device->total_bytes;
1621 device->dev_root = root->fs_info->dev_root;
1622 device->bdev = bdev;
1623 device->in_fs_metadata = 1;
1625 set_blocksize(device->bdev, 4096);
1628 sb->s_flags &= ~MS_RDONLY;
1629 ret = btrfs_prepare_sprout(trans, root);
1633 device->fs_devices = root->fs_info->fs_devices;
1636 * we don't want write_supers to jump in here with our device
1639 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1640 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1641 list_add(&device->dev_alloc_list,
1642 &root->fs_info->fs_devices->alloc_list);
1643 root->fs_info->fs_devices->num_devices++;
1644 root->fs_info->fs_devices->open_devices++;
1645 root->fs_info->fs_devices->rw_devices++;
1646 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1648 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1649 root->fs_info->fs_devices->rotating = 1;
1651 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1652 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1653 total_bytes + device->total_bytes);
1655 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1656 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1658 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1661 ret = init_first_rw_device(trans, root, device);
1663 ret = btrfs_finish_sprout(trans, root);
1666 ret = btrfs_add_device(trans, root, device);
1670 * we've got more storage, clear any full flags on the space
1673 btrfs_clear_space_info_full(root->fs_info);
1675 unlock_chunks(root);
1676 btrfs_commit_transaction(trans, root);
1679 mutex_unlock(&uuid_mutex);
1680 up_write(&sb->s_umount);
1682 ret = btrfs_relocate_sys_chunks(root);
1686 mutex_unlock(&root->fs_info->volume_mutex);
1689 blkdev_put(bdev, FMODE_EXCL);
1691 mutex_unlock(&uuid_mutex);
1692 up_write(&sb->s_umount);
1697 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1698 struct btrfs_device *device)
1701 struct btrfs_path *path;
1702 struct btrfs_root *root;
1703 struct btrfs_dev_item *dev_item;
1704 struct extent_buffer *leaf;
1705 struct btrfs_key key;
1707 root = device->dev_root->fs_info->chunk_root;
1709 path = btrfs_alloc_path();
1713 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1714 key.type = BTRFS_DEV_ITEM_KEY;
1715 key.offset = device->devid;
1717 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1726 leaf = path->nodes[0];
1727 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1729 btrfs_set_device_id(leaf, dev_item, device->devid);
1730 btrfs_set_device_type(leaf, dev_item, device->type);
1731 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1732 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1733 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1734 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1735 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1736 btrfs_mark_buffer_dirty(leaf);
1739 btrfs_free_path(path);
1743 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1744 struct btrfs_device *device, u64 new_size)
1746 struct btrfs_super_block *super_copy =
1747 &device->dev_root->fs_info->super_copy;
1748 u64 old_total = btrfs_super_total_bytes(super_copy);
1749 u64 diff = new_size - device->total_bytes;
1751 if (!device->writeable)
1753 if (new_size <= device->total_bytes)
1756 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1757 device->fs_devices->total_rw_bytes += diff;
1759 device->total_bytes = new_size;
1760 device->disk_total_bytes = new_size;
1761 btrfs_clear_space_info_full(device->dev_root->fs_info);
1763 return btrfs_update_device(trans, device);
1766 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1767 struct btrfs_device *device, u64 new_size)
1770 lock_chunks(device->dev_root);
1771 ret = __btrfs_grow_device(trans, device, new_size);
1772 unlock_chunks(device->dev_root);
1776 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1777 struct btrfs_root *root,
1778 u64 chunk_tree, u64 chunk_objectid,
1782 struct btrfs_path *path;
1783 struct btrfs_key key;
1785 root = root->fs_info->chunk_root;
1786 path = btrfs_alloc_path();
1790 key.objectid = chunk_objectid;
1791 key.offset = chunk_offset;
1792 key.type = BTRFS_CHUNK_ITEM_KEY;
1794 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1797 ret = btrfs_del_item(trans, root, path);
1800 btrfs_free_path(path);
1804 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1807 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1808 struct btrfs_disk_key *disk_key;
1809 struct btrfs_chunk *chunk;
1816 struct btrfs_key key;
1818 array_size = btrfs_super_sys_array_size(super_copy);
1820 ptr = super_copy->sys_chunk_array;
1823 while (cur < array_size) {
1824 disk_key = (struct btrfs_disk_key *)ptr;
1825 btrfs_disk_key_to_cpu(&key, disk_key);
1827 len = sizeof(*disk_key);
1829 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1830 chunk = (struct btrfs_chunk *)(ptr + len);
1831 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1832 len += btrfs_chunk_item_size(num_stripes);
1837 if (key.objectid == chunk_objectid &&
1838 key.offset == chunk_offset) {
1839 memmove(ptr, ptr + len, array_size - (cur + len));
1841 btrfs_set_super_sys_array_size(super_copy, array_size);
1850 static int btrfs_relocate_chunk(struct btrfs_root *root,
1851 u64 chunk_tree, u64 chunk_objectid,
1854 struct extent_map_tree *em_tree;
1855 struct btrfs_root *extent_root;
1856 struct btrfs_trans_handle *trans;
1857 struct extent_map *em;
1858 struct map_lookup *map;
1862 root = root->fs_info->chunk_root;
1863 extent_root = root->fs_info->extent_root;
1864 em_tree = &root->fs_info->mapping_tree.map_tree;
1866 ret = btrfs_can_relocate(extent_root, chunk_offset);
1870 /* step one, relocate all the extents inside this chunk */
1871 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1875 trans = btrfs_start_transaction(root, 0);
1881 * step two, delete the device extents and the
1882 * chunk tree entries
1884 read_lock(&em_tree->lock);
1885 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1886 read_unlock(&em_tree->lock);
1888 BUG_ON(em->start > chunk_offset ||
1889 em->start + em->len < chunk_offset);
1890 map = (struct map_lookup *)em->bdev;
1892 for (i = 0; i < map->num_stripes; i++) {
1893 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1894 map->stripes[i].physical);
1897 if (map->stripes[i].dev) {
1898 ret = btrfs_update_device(trans, map->stripes[i].dev);
1902 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1907 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1908 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1912 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1915 write_lock(&em_tree->lock);
1916 remove_extent_mapping(em_tree, em);
1917 write_unlock(&em_tree->lock);
1922 /* once for the tree */
1923 free_extent_map(em);
1925 free_extent_map(em);
1927 unlock_chunks(root);
1928 btrfs_end_transaction(trans, root);
1932 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1934 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1935 struct btrfs_path *path;
1936 struct extent_buffer *leaf;
1937 struct btrfs_chunk *chunk;
1938 struct btrfs_key key;
1939 struct btrfs_key found_key;
1940 u64 chunk_tree = chunk_root->root_key.objectid;
1942 bool retried = false;
1946 path = btrfs_alloc_path();
1951 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1952 key.offset = (u64)-1;
1953 key.type = BTRFS_CHUNK_ITEM_KEY;
1956 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1961 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1968 leaf = path->nodes[0];
1969 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1971 chunk = btrfs_item_ptr(leaf, path->slots[0],
1972 struct btrfs_chunk);
1973 chunk_type = btrfs_chunk_type(leaf, chunk);
1974 btrfs_release_path(chunk_root, path);
1976 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1977 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1986 if (found_key.offset == 0)
1988 key.offset = found_key.offset - 1;
1991 if (failed && !retried) {
1995 } else if (failed && retried) {
2000 btrfs_free_path(path);
2004 static u64 div_factor(u64 num, int factor)
2013 int btrfs_balance(struct btrfs_root *dev_root)
2016 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
2017 struct btrfs_device *device;
2020 struct btrfs_path *path;
2021 struct btrfs_key key;
2022 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
2023 struct btrfs_trans_handle *trans;
2024 struct btrfs_key found_key;
2026 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
2029 if (!capable(CAP_SYS_ADMIN))
2032 mutex_lock(&dev_root->fs_info->volume_mutex);
2033 dev_root = dev_root->fs_info->dev_root;
2035 /* step one make some room on all the devices */
2036 list_for_each_entry(device, devices, dev_list) {
2037 old_size = device->total_bytes;
2038 size_to_free = div_factor(old_size, 1);
2039 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2040 if (!device->writeable ||
2041 device->total_bytes - device->bytes_used > size_to_free)
2044 ret = btrfs_shrink_device(device, old_size - size_to_free);
2049 trans = btrfs_start_transaction(dev_root, 0);
2052 ret = btrfs_grow_device(trans, device, old_size);
2055 btrfs_end_transaction(trans, dev_root);
2058 /* step two, relocate all the chunks */
2059 path = btrfs_alloc_path();
2062 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2063 key.offset = (u64)-1;
2064 key.type = BTRFS_CHUNK_ITEM_KEY;
2067 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2072 * this shouldn't happen, it means the last relocate
2078 ret = btrfs_previous_item(chunk_root, path, 0,
2079 BTRFS_CHUNK_ITEM_KEY);
2083 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2085 if (found_key.objectid != key.objectid)
2088 /* chunk zero is special */
2089 if (found_key.offset == 0)
2092 btrfs_release_path(chunk_root, path);
2093 ret = btrfs_relocate_chunk(chunk_root,
2094 chunk_root->root_key.objectid,
2097 BUG_ON(ret && ret != -ENOSPC);
2098 key.offset = found_key.offset - 1;
2102 btrfs_free_path(path);
2103 mutex_unlock(&dev_root->fs_info->volume_mutex);
2108 * shrinking a device means finding all of the device extents past
2109 * the new size, and then following the back refs to the chunks.
2110 * The chunk relocation code actually frees the device extent
2112 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2114 struct btrfs_trans_handle *trans;
2115 struct btrfs_root *root = device->dev_root;
2116 struct btrfs_dev_extent *dev_extent = NULL;
2117 struct btrfs_path *path;
2125 bool retried = false;
2126 struct extent_buffer *l;
2127 struct btrfs_key key;
2128 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2129 u64 old_total = btrfs_super_total_bytes(super_copy);
2130 u64 old_size = device->total_bytes;
2131 u64 diff = device->total_bytes - new_size;
2133 if (new_size >= device->total_bytes)
2136 path = btrfs_alloc_path();
2144 device->total_bytes = new_size;
2145 if (device->writeable)
2146 device->fs_devices->total_rw_bytes -= diff;
2147 unlock_chunks(root);
2150 key.objectid = device->devid;
2151 key.offset = (u64)-1;
2152 key.type = BTRFS_DEV_EXTENT_KEY;
2155 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2159 ret = btrfs_previous_item(root, path, 0, key.type);
2164 btrfs_release_path(root, path);
2169 slot = path->slots[0];
2170 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2172 if (key.objectid != device->devid) {
2173 btrfs_release_path(root, path);
2177 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2178 length = btrfs_dev_extent_length(l, dev_extent);
2180 if (key.offset + length <= new_size) {
2181 btrfs_release_path(root, path);
2185 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2186 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2187 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2188 btrfs_release_path(root, path);
2190 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2192 if (ret && ret != -ENOSPC)
2199 if (failed && !retried) {
2203 } else if (failed && retried) {
2207 device->total_bytes = old_size;
2208 if (device->writeable)
2209 device->fs_devices->total_rw_bytes += diff;
2210 unlock_chunks(root);
2214 /* Shrinking succeeded, else we would be at "done". */
2215 trans = btrfs_start_transaction(root, 0);
2218 device->disk_total_bytes = new_size;
2219 /* Now btrfs_update_device() will change the on-disk size. */
2220 ret = btrfs_update_device(trans, device);
2222 unlock_chunks(root);
2223 btrfs_end_transaction(trans, root);
2226 WARN_ON(diff > old_total);
2227 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2228 unlock_chunks(root);
2229 btrfs_end_transaction(trans, root);
2231 btrfs_free_path(path);
2235 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2236 struct btrfs_root *root,
2237 struct btrfs_key *key,
2238 struct btrfs_chunk *chunk, int item_size)
2240 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2241 struct btrfs_disk_key disk_key;
2245 array_size = btrfs_super_sys_array_size(super_copy);
2246 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2249 ptr = super_copy->sys_chunk_array + array_size;
2250 btrfs_cpu_key_to_disk(&disk_key, key);
2251 memcpy(ptr, &disk_key, sizeof(disk_key));
2252 ptr += sizeof(disk_key);
2253 memcpy(ptr, chunk, item_size);
2254 item_size += sizeof(disk_key);
2255 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2259 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
2260 int num_stripes, int sub_stripes)
2262 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
2264 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2265 return calc_size * (num_stripes / sub_stripes);
2267 return calc_size * num_stripes;
2270 /* Used to sort the devices by max_avail(descending sort) */
2271 int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2)
2273 if (((struct btrfs_device_info *)dev_info1)->max_avail >
2274 ((struct btrfs_device_info *)dev_info2)->max_avail)
2276 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
2277 ((struct btrfs_device_info *)dev_info2)->max_avail)
2283 static int __btrfs_calc_nstripes(struct btrfs_fs_devices *fs_devices, u64 type,
2284 int *num_stripes, int *min_stripes,
2291 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2292 *num_stripes = fs_devices->rw_devices;
2295 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2299 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2300 if (fs_devices->rw_devices < 2)
2305 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2306 *num_stripes = fs_devices->rw_devices;
2307 if (*num_stripes < 4)
2309 *num_stripes &= ~(u32)1;
2317 static u64 __btrfs_calc_stripe_size(struct btrfs_fs_devices *fs_devices,
2318 u64 proposed_size, u64 type,
2319 int num_stripes, int small_stripe)
2321 int min_stripe_size = 1 * 1024 * 1024;
2322 u64 calc_size = proposed_size;
2323 u64 max_chunk_size = calc_size;
2326 if (type & (BTRFS_BLOCK_GROUP_RAID1 |
2327 BTRFS_BLOCK_GROUP_DUP |
2328 BTRFS_BLOCK_GROUP_RAID10))
2331 if (type & BTRFS_BLOCK_GROUP_DATA) {
2332 max_chunk_size = 10 * calc_size;
2333 min_stripe_size = 64 * 1024 * 1024;
2334 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2335 max_chunk_size = 256 * 1024 * 1024;
2336 min_stripe_size = 32 * 1024 * 1024;
2337 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2338 calc_size = 8 * 1024 * 1024;
2339 max_chunk_size = calc_size * 2;
2340 min_stripe_size = 1 * 1024 * 1024;
2343 /* we don't want a chunk larger than 10% of writeable space */
2344 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2347 if (calc_size * num_stripes > max_chunk_size * ncopies) {
2348 calc_size = max_chunk_size * ncopies;
2349 do_div(calc_size, num_stripes);
2350 do_div(calc_size, BTRFS_STRIPE_LEN);
2351 calc_size *= BTRFS_STRIPE_LEN;
2354 /* we don't want tiny stripes */
2356 calc_size = max_t(u64, min_stripe_size, calc_size);
2359 * we're about to do_div by the BTRFS_STRIPE_LEN so lets make sure
2360 * we end up with something bigger than a stripe
2362 calc_size = max_t(u64, calc_size, BTRFS_STRIPE_LEN);
2364 do_div(calc_size, BTRFS_STRIPE_LEN);
2365 calc_size *= BTRFS_STRIPE_LEN;
2370 static struct map_lookup *__shrink_map_lookup_stripes(struct map_lookup *map,
2373 struct map_lookup *new;
2374 size_t len = map_lookup_size(num_stripes);
2376 BUG_ON(map->num_stripes < num_stripes);
2378 if (map->num_stripes == num_stripes)
2381 new = kmalloc(len, GFP_NOFS);
2383 /* just change map->num_stripes */
2384 map->num_stripes = num_stripes;
2388 memcpy(new, map, len);
2389 new->num_stripes = num_stripes;
2395 * helper to allocate device space from btrfs_device_info, in which we stored
2396 * max free space information of every device. It is used when we can not
2397 * allocate chunks by default size.
2399 * By this helper, we can allocate a new chunk as larger as possible.
2401 static int __btrfs_alloc_tiny_space(struct btrfs_trans_handle *trans,
2402 struct btrfs_fs_devices *fs_devices,
2403 struct btrfs_device_info *devices,
2404 int nr_device, u64 type,
2405 struct map_lookup **map_lookup,
2406 int min_stripes, u64 *stripe_size)
2408 int i, index, sort_again = 0;
2409 int min_devices = min_stripes;
2410 u64 max_avail, min_free;
2411 struct map_lookup *map = *map_lookup;
2414 if (nr_device < min_stripes)
2417 btrfs_descending_sort_devices(devices, nr_device);
2419 max_avail = devices[0].max_avail;
2423 for (i = 0; i < nr_device; i++) {
2425 * if dev_offset = 0, it means the free space of this device
2426 * is less than what we need, and we didn't search max avail
2427 * extent on this device, so do it now.
2429 if (!devices[i].dev_offset) {
2430 ret = find_free_dev_extent(trans, devices[i].dev,
2432 &devices[i].dev_offset,
2433 &devices[i].max_avail);
2434 if (ret != 0 && ret != -ENOSPC)
2440 /* we update the max avail free extent of each devices, sort again */
2442 btrfs_descending_sort_devices(devices, nr_device);
2444 if (type & BTRFS_BLOCK_GROUP_DUP)
2447 if (!devices[min_devices - 1].max_avail)
2450 max_avail = devices[min_devices - 1].max_avail;
2451 if (type & BTRFS_BLOCK_GROUP_DUP)
2452 do_div(max_avail, 2);
2454 max_avail = __btrfs_calc_stripe_size(fs_devices, max_avail, type,
2456 if (type & BTRFS_BLOCK_GROUP_DUP)
2457 min_free = max_avail * 2;
2459 min_free = max_avail;
2461 if (min_free > devices[min_devices - 1].max_avail)
2464 map = __shrink_map_lookup_stripes(map, min_stripes);
2465 *stripe_size = max_avail;
2468 for (i = 0; i < min_stripes; i++) {
2469 map->stripes[i].dev = devices[index].dev;
2470 map->stripes[i].physical = devices[index].dev_offset;
2471 if (type & BTRFS_BLOCK_GROUP_DUP) {
2473 map->stripes[i].dev = devices[index].dev;
2474 map->stripes[i].physical = devices[index].dev_offset +
2484 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2485 struct btrfs_root *extent_root,
2486 struct map_lookup **map_ret,
2487 u64 *num_bytes, u64 *stripe_size,
2488 u64 start, u64 type)
2490 struct btrfs_fs_info *info = extent_root->fs_info;
2491 struct btrfs_device *device = NULL;
2492 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2493 struct list_head *cur;
2494 struct map_lookup *map;
2495 struct extent_map_tree *em_tree;
2496 struct extent_map *em;
2497 struct btrfs_device_info *devices_info;
2498 struct list_head private_devs;
2499 u64 calc_size = 1024 * 1024 * 1024;
2506 int min_devices; /* the min number of devices we need */
2511 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2512 (type & BTRFS_BLOCK_GROUP_DUP)) {
2514 type &= ~BTRFS_BLOCK_GROUP_DUP;
2516 if (list_empty(&fs_devices->alloc_list))
2519 ret = __btrfs_calc_nstripes(fs_devices, type, &num_stripes,
2520 &min_stripes, &sub_stripes);
2524 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
2529 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2534 map->num_stripes = num_stripes;
2536 cur = fs_devices->alloc_list.next;
2540 calc_size = __btrfs_calc_stripe_size(fs_devices, calc_size, type,
2543 if (type & BTRFS_BLOCK_GROUP_DUP) {
2544 min_free = calc_size * 2;
2547 min_free = calc_size;
2548 min_devices = min_stripes;
2551 INIT_LIST_HEAD(&private_devs);
2552 while (index < num_stripes) {
2553 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2554 BUG_ON(!device->writeable);
2555 if (device->total_bytes > device->bytes_used)
2556 avail = device->total_bytes - device->bytes_used;
2561 if (device->in_fs_metadata && avail >= min_free) {
2562 ret = find_free_dev_extent(trans, device, min_free,
2563 &devices_info[i].dev_offset,
2564 &devices_info[i].max_avail);
2566 list_move_tail(&device->dev_alloc_list,
2568 map->stripes[index].dev = device;
2569 map->stripes[index].physical =
2570 devices_info[i].dev_offset;
2572 if (type & BTRFS_BLOCK_GROUP_DUP) {
2573 map->stripes[index].dev = device;
2574 map->stripes[index].physical =
2575 devices_info[i].dev_offset +
2579 } else if (ret != -ENOSPC)
2582 devices_info[i].dev = device;
2584 } else if (device->in_fs_metadata &&
2585 avail >= BTRFS_STRIPE_LEN) {
2586 devices_info[i].dev = device;
2587 devices_info[i].max_avail = avail;
2591 if (cur == &fs_devices->alloc_list)
2595 list_splice(&private_devs, &fs_devices->alloc_list);
2596 if (index < num_stripes) {
2597 if (index >= min_stripes) {
2598 num_stripes = index;
2599 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2600 num_stripes /= sub_stripes;
2601 num_stripes *= sub_stripes;
2604 map = __shrink_map_lookup_stripes(map, num_stripes);
2605 } else if (i >= min_devices) {
2606 ret = __btrfs_alloc_tiny_space(trans, fs_devices,
2607 devices_info, i, type,
2617 map->sector_size = extent_root->sectorsize;
2618 map->stripe_len = BTRFS_STRIPE_LEN;
2619 map->io_align = BTRFS_STRIPE_LEN;
2620 map->io_width = BTRFS_STRIPE_LEN;
2622 map->sub_stripes = sub_stripes;
2625 *stripe_size = calc_size;
2626 *num_bytes = chunk_bytes_by_type(type, calc_size,
2627 map->num_stripes, sub_stripes);
2629 em = alloc_extent_map(GFP_NOFS);
2634 em->bdev = (struct block_device *)map;
2636 em->len = *num_bytes;
2637 em->block_start = 0;
2638 em->block_len = em->len;
2640 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2641 write_lock(&em_tree->lock);
2642 ret = add_extent_mapping(em_tree, em);
2643 write_unlock(&em_tree->lock);
2645 free_extent_map(em);
2647 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2648 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2653 while (index < map->num_stripes) {
2654 device = map->stripes[index].dev;
2655 dev_offset = map->stripes[index].physical;
2657 ret = btrfs_alloc_dev_extent(trans, device,
2658 info->chunk_root->root_key.objectid,
2659 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2660 start, dev_offset, calc_size);
2665 kfree(devices_info);
2670 kfree(devices_info);
2674 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2675 struct btrfs_root *extent_root,
2676 struct map_lookup *map, u64 chunk_offset,
2677 u64 chunk_size, u64 stripe_size)
2680 struct btrfs_key key;
2681 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2682 struct btrfs_device *device;
2683 struct btrfs_chunk *chunk;
2684 struct btrfs_stripe *stripe;
2685 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2689 chunk = kzalloc(item_size, GFP_NOFS);
2694 while (index < map->num_stripes) {
2695 device = map->stripes[index].dev;
2696 device->bytes_used += stripe_size;
2697 ret = btrfs_update_device(trans, device);
2703 stripe = &chunk->stripe;
2704 while (index < map->num_stripes) {
2705 device = map->stripes[index].dev;
2706 dev_offset = map->stripes[index].physical;
2708 btrfs_set_stack_stripe_devid(stripe, device->devid);
2709 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2710 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2715 btrfs_set_stack_chunk_length(chunk, chunk_size);
2716 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2717 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2718 btrfs_set_stack_chunk_type(chunk, map->type);
2719 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2720 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2721 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2722 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2723 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2725 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2726 key.type = BTRFS_CHUNK_ITEM_KEY;
2727 key.offset = chunk_offset;
2729 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2732 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2733 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2742 * Chunk allocation falls into two parts. The first part does works
2743 * that make the new allocated chunk useable, but not do any operation
2744 * that modifies the chunk tree. The second part does the works that
2745 * require modifying the chunk tree. This division is important for the
2746 * bootstrap process of adding storage to a seed btrfs.
2748 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2749 struct btrfs_root *extent_root, u64 type)
2754 struct map_lookup *map;
2755 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2758 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2763 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2764 &stripe_size, chunk_offset, type);
2768 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2769 chunk_size, stripe_size);
2774 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2775 struct btrfs_root *root,
2776 struct btrfs_device *device)
2779 u64 sys_chunk_offset;
2783 u64 sys_stripe_size;
2785 struct map_lookup *map;
2786 struct map_lookup *sys_map;
2787 struct btrfs_fs_info *fs_info = root->fs_info;
2788 struct btrfs_root *extent_root = fs_info->extent_root;
2791 ret = find_next_chunk(fs_info->chunk_root,
2792 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2795 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2796 (fs_info->metadata_alloc_profile &
2797 fs_info->avail_metadata_alloc_bits);
2798 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2800 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2801 &stripe_size, chunk_offset, alloc_profile);
2804 sys_chunk_offset = chunk_offset + chunk_size;
2806 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2807 (fs_info->system_alloc_profile &
2808 fs_info->avail_system_alloc_bits);
2809 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2811 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2812 &sys_chunk_size, &sys_stripe_size,
2813 sys_chunk_offset, alloc_profile);
2816 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2820 * Modifying chunk tree needs allocating new blocks from both
2821 * system block group and metadata block group. So we only can
2822 * do operations require modifying the chunk tree after both
2823 * block groups were created.
2825 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2826 chunk_size, stripe_size);
2829 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2830 sys_chunk_offset, sys_chunk_size,
2836 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2838 struct extent_map *em;
2839 struct map_lookup *map;
2840 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2844 read_lock(&map_tree->map_tree.lock);
2845 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2846 read_unlock(&map_tree->map_tree.lock);
2850 if (btrfs_test_opt(root, DEGRADED)) {
2851 free_extent_map(em);
2855 map = (struct map_lookup *)em->bdev;
2856 for (i = 0; i < map->num_stripes; i++) {
2857 if (!map->stripes[i].dev->writeable) {
2862 free_extent_map(em);
2866 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2868 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2871 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2873 struct extent_map *em;
2876 write_lock(&tree->map_tree.lock);
2877 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2879 remove_extent_mapping(&tree->map_tree, em);
2880 write_unlock(&tree->map_tree.lock);
2885 free_extent_map(em);
2886 /* once for the tree */
2887 free_extent_map(em);
2891 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2893 struct extent_map *em;
2894 struct map_lookup *map;
2895 struct extent_map_tree *em_tree = &map_tree->map_tree;
2898 read_lock(&em_tree->lock);
2899 em = lookup_extent_mapping(em_tree, logical, len);
2900 read_unlock(&em_tree->lock);
2903 BUG_ON(em->start > logical || em->start + em->len < logical);
2904 map = (struct map_lookup *)em->bdev;
2905 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2906 ret = map->num_stripes;
2907 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2908 ret = map->sub_stripes;
2911 free_extent_map(em);
2915 static int find_live_mirror(struct map_lookup *map, int first, int num,
2919 if (map->stripes[optimal].dev->bdev)
2921 for (i = first; i < first + num; i++) {
2922 if (map->stripes[i].dev->bdev)
2925 /* we couldn't find one that doesn't fail. Just return something
2926 * and the io error handling code will clean up eventually
2931 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2932 u64 logical, u64 *length,
2933 struct btrfs_multi_bio **multi_ret,
2934 int mirror_num, struct page *unplug_page)
2936 struct extent_map *em;
2937 struct map_lookup *map;
2938 struct extent_map_tree *em_tree = &map_tree->map_tree;
2942 int stripes_allocated = 8;
2943 int stripes_required = 1;
2948 struct btrfs_multi_bio *multi = NULL;
2950 if (multi_ret && !(rw & REQ_WRITE))
2951 stripes_allocated = 1;
2954 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2959 atomic_set(&multi->error, 0);
2962 read_lock(&em_tree->lock);
2963 em = lookup_extent_mapping(em_tree, logical, *length);
2964 read_unlock(&em_tree->lock);
2966 if (!em && unplug_page) {
2972 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2973 (unsigned long long)logical,
2974 (unsigned long long)*length);
2978 BUG_ON(em->start > logical || em->start + em->len < logical);
2979 map = (struct map_lookup *)em->bdev;
2980 offset = logical - em->start;
2982 if (mirror_num > map->num_stripes)
2985 /* if our multi bio struct is too small, back off and try again */
2986 if (rw & REQ_WRITE) {
2987 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2988 BTRFS_BLOCK_GROUP_DUP)) {
2989 stripes_required = map->num_stripes;
2991 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2992 stripes_required = map->sub_stripes;
2996 if (multi_ret && (rw & REQ_WRITE) &&
2997 stripes_allocated < stripes_required) {
2998 stripes_allocated = map->num_stripes;
2999 free_extent_map(em);
3005 * stripe_nr counts the total number of stripes we have to stride
3006 * to get to this block
3008 do_div(stripe_nr, map->stripe_len);
3010 stripe_offset = stripe_nr * map->stripe_len;
3011 BUG_ON(offset < stripe_offset);
3013 /* stripe_offset is the offset of this block in its stripe*/
3014 stripe_offset = offset - stripe_offset;
3016 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
3017 BTRFS_BLOCK_GROUP_RAID10 |
3018 BTRFS_BLOCK_GROUP_DUP)) {
3019 /* we limit the length of each bio to what fits in a stripe */
3020 *length = min_t(u64, em->len - offset,
3021 map->stripe_len - stripe_offset);
3023 *length = em->len - offset;
3026 if (!multi_ret && !unplug_page)
3031 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3032 if (unplug_page || (rw & REQ_WRITE))
3033 num_stripes = map->num_stripes;
3034 else if (mirror_num)
3035 stripe_index = mirror_num - 1;
3037 stripe_index = find_live_mirror(map, 0,
3039 current->pid % map->num_stripes);
3042 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3044 num_stripes = map->num_stripes;
3045 else if (mirror_num)
3046 stripe_index = mirror_num - 1;
3048 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3049 int factor = map->num_stripes / map->sub_stripes;
3051 stripe_index = do_div(stripe_nr, factor);
3052 stripe_index *= map->sub_stripes;
3054 if (unplug_page || (rw & REQ_WRITE))
3055 num_stripes = map->sub_stripes;
3056 else if (mirror_num)
3057 stripe_index += mirror_num - 1;
3059 stripe_index = find_live_mirror(map, stripe_index,
3060 map->sub_stripes, stripe_index +
3061 current->pid % map->sub_stripes);
3065 * after this do_div call, stripe_nr is the number of stripes
3066 * on this device we have to walk to find the data, and
3067 * stripe_index is the number of our device in the stripe array
3069 stripe_index = do_div(stripe_nr, map->num_stripes);
3071 BUG_ON(stripe_index >= map->num_stripes);
3073 for (i = 0; i < num_stripes; i++) {
3075 struct btrfs_device *device;
3076 struct backing_dev_info *bdi;
3078 device = map->stripes[stripe_index].dev;
3080 bdi = blk_get_backing_dev_info(device->bdev);
3081 if (bdi->unplug_io_fn)
3082 bdi->unplug_io_fn(bdi, unplug_page);
3085 multi->stripes[i].physical =
3086 map->stripes[stripe_index].physical +
3087 stripe_offset + stripe_nr * map->stripe_len;
3088 multi->stripes[i].dev = map->stripes[stripe_index].dev;
3094 multi->num_stripes = num_stripes;
3095 multi->max_errors = max_errors;
3098 free_extent_map(em);
3102 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3103 u64 logical, u64 *length,
3104 struct btrfs_multi_bio **multi_ret, int mirror_num)
3106 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
3110 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3111 u64 chunk_start, u64 physical, u64 devid,
3112 u64 **logical, int *naddrs, int *stripe_len)
3114 struct extent_map_tree *em_tree = &map_tree->map_tree;
3115 struct extent_map *em;
3116 struct map_lookup *map;
3123 read_lock(&em_tree->lock);
3124 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3125 read_unlock(&em_tree->lock);
3127 BUG_ON(!em || em->start != chunk_start);
3128 map = (struct map_lookup *)em->bdev;
3131 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3132 do_div(length, map->num_stripes / map->sub_stripes);
3133 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3134 do_div(length, map->num_stripes);
3136 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3139 for (i = 0; i < map->num_stripes; i++) {
3140 if (devid && map->stripes[i].dev->devid != devid)
3142 if (map->stripes[i].physical > physical ||
3143 map->stripes[i].physical + length <= physical)
3146 stripe_nr = physical - map->stripes[i].physical;
3147 do_div(stripe_nr, map->stripe_len);
3149 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3150 stripe_nr = stripe_nr * map->num_stripes + i;
3151 do_div(stripe_nr, map->sub_stripes);
3152 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3153 stripe_nr = stripe_nr * map->num_stripes + i;
3155 bytenr = chunk_start + stripe_nr * map->stripe_len;
3156 WARN_ON(nr >= map->num_stripes);
3157 for (j = 0; j < nr; j++) {
3158 if (buf[j] == bytenr)
3162 WARN_ON(nr >= map->num_stripes);
3169 *stripe_len = map->stripe_len;
3171 free_extent_map(em);
3175 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
3176 u64 logical, struct page *page)
3178 u64 length = PAGE_CACHE_SIZE;
3179 return __btrfs_map_block(map_tree, READ, logical, &length,
3183 static void end_bio_multi_stripe(struct bio *bio, int err)
3185 struct btrfs_multi_bio *multi = bio->bi_private;
3186 int is_orig_bio = 0;
3189 atomic_inc(&multi->error);
3191 if (bio == multi->orig_bio)
3194 if (atomic_dec_and_test(&multi->stripes_pending)) {
3197 bio = multi->orig_bio;
3199 bio->bi_private = multi->private;
3200 bio->bi_end_io = multi->end_io;
3201 /* only send an error to the higher layers if it is
3202 * beyond the tolerance of the multi-bio
3204 if (atomic_read(&multi->error) > multi->max_errors) {
3208 * this bio is actually up to date, we didn't
3209 * go over the max number of errors
3211 set_bit(BIO_UPTODATE, &bio->bi_flags);
3216 bio_endio(bio, err);
3217 } else if (!is_orig_bio) {
3222 struct async_sched {
3225 struct btrfs_fs_info *info;
3226 struct btrfs_work work;
3230 * see run_scheduled_bios for a description of why bios are collected for
3233 * This will add one bio to the pending list for a device and make sure
3234 * the work struct is scheduled.
3236 static noinline int schedule_bio(struct btrfs_root *root,
3237 struct btrfs_device *device,
3238 int rw, struct bio *bio)
3240 int should_queue = 1;
3241 struct btrfs_pending_bios *pending_bios;
3243 /* don't bother with additional async steps for reads, right now */
3244 if (!(rw & REQ_WRITE)) {
3246 submit_bio(rw, bio);
3252 * nr_async_bios allows us to reliably return congestion to the
3253 * higher layers. Otherwise, the async bio makes it appear we have
3254 * made progress against dirty pages when we've really just put it
3255 * on a queue for later
3257 atomic_inc(&root->fs_info->nr_async_bios);
3258 WARN_ON(bio->bi_next);
3259 bio->bi_next = NULL;
3262 spin_lock(&device->io_lock);
3263 if (bio->bi_rw & REQ_SYNC)
3264 pending_bios = &device->pending_sync_bios;
3266 pending_bios = &device->pending_bios;
3268 if (pending_bios->tail)
3269 pending_bios->tail->bi_next = bio;
3271 pending_bios->tail = bio;
3272 if (!pending_bios->head)
3273 pending_bios->head = bio;
3274 if (device->running_pending)
3277 spin_unlock(&device->io_lock);
3280 btrfs_queue_worker(&root->fs_info->submit_workers,
3285 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
3286 int mirror_num, int async_submit)
3288 struct btrfs_mapping_tree *map_tree;
3289 struct btrfs_device *dev;
3290 struct bio *first_bio = bio;
3291 u64 logical = (u64)bio->bi_sector << 9;
3294 struct btrfs_multi_bio *multi = NULL;
3299 length = bio->bi_size;
3300 map_tree = &root->fs_info->mapping_tree;
3301 map_length = length;
3303 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3307 total_devs = multi->num_stripes;
3308 if (map_length < length) {
3309 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3310 "len %llu\n", (unsigned long long)logical,
3311 (unsigned long long)length,
3312 (unsigned long long)map_length);
3315 multi->end_io = first_bio->bi_end_io;
3316 multi->private = first_bio->bi_private;
3317 multi->orig_bio = first_bio;
3318 atomic_set(&multi->stripes_pending, multi->num_stripes);
3320 while (dev_nr < total_devs) {
3321 if (total_devs > 1) {
3322 if (dev_nr < total_devs - 1) {
3323 bio = bio_clone(first_bio, GFP_NOFS);
3328 bio->bi_private = multi;
3329 bio->bi_end_io = end_bio_multi_stripe;
3331 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3332 dev = multi->stripes[dev_nr].dev;
3333 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3334 bio->bi_bdev = dev->bdev;
3336 schedule_bio(root, dev, rw, bio);
3338 submit_bio(rw, bio);
3340 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3341 bio->bi_sector = logical >> 9;
3342 bio_endio(bio, -EIO);
3346 if (total_devs == 1)
3351 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3354 struct btrfs_device *device;
3355 struct btrfs_fs_devices *cur_devices;
3357 cur_devices = root->fs_info->fs_devices;
3358 while (cur_devices) {
3360 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3361 device = __find_device(&cur_devices->devices,
3366 cur_devices = cur_devices->seed;
3371 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3372 u64 devid, u8 *dev_uuid)
3374 struct btrfs_device *device;
3375 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3377 device = kzalloc(sizeof(*device), GFP_NOFS);
3380 list_add(&device->dev_list,
3381 &fs_devices->devices);
3382 device->dev_root = root->fs_info->dev_root;
3383 device->devid = devid;
3384 device->work.func = pending_bios_fn;
3385 device->fs_devices = fs_devices;
3386 device->missing = 1;
3387 fs_devices->num_devices++;
3388 fs_devices->missing_devices++;
3389 spin_lock_init(&device->io_lock);
3390 INIT_LIST_HEAD(&device->dev_alloc_list);
3391 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3395 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3396 struct extent_buffer *leaf,
3397 struct btrfs_chunk *chunk)
3399 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3400 struct map_lookup *map;
3401 struct extent_map *em;
3405 u8 uuid[BTRFS_UUID_SIZE];
3410 logical = key->offset;
3411 length = btrfs_chunk_length(leaf, chunk);
3413 read_lock(&map_tree->map_tree.lock);
3414 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3415 read_unlock(&map_tree->map_tree.lock);
3417 /* already mapped? */
3418 if (em && em->start <= logical && em->start + em->len > logical) {
3419 free_extent_map(em);
3422 free_extent_map(em);
3425 em = alloc_extent_map(GFP_NOFS);
3428 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3429 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3431 free_extent_map(em);
3435 em->bdev = (struct block_device *)map;
3436 em->start = logical;
3438 em->block_start = 0;
3439 em->block_len = em->len;
3441 map->num_stripes = num_stripes;
3442 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3443 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3444 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3445 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3446 map->type = btrfs_chunk_type(leaf, chunk);
3447 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3448 for (i = 0; i < num_stripes; i++) {
3449 map->stripes[i].physical =
3450 btrfs_stripe_offset_nr(leaf, chunk, i);
3451 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3452 read_extent_buffer(leaf, uuid, (unsigned long)
3453 btrfs_stripe_dev_uuid_nr(chunk, i),
3455 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3457 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3459 free_extent_map(em);
3462 if (!map->stripes[i].dev) {
3463 map->stripes[i].dev =
3464 add_missing_dev(root, devid, uuid);
3465 if (!map->stripes[i].dev) {
3467 free_extent_map(em);
3471 map->stripes[i].dev->in_fs_metadata = 1;
3474 write_lock(&map_tree->map_tree.lock);
3475 ret = add_extent_mapping(&map_tree->map_tree, em);
3476 write_unlock(&map_tree->map_tree.lock);
3478 free_extent_map(em);
3483 static int fill_device_from_item(struct extent_buffer *leaf,
3484 struct btrfs_dev_item *dev_item,
3485 struct btrfs_device *device)
3489 device->devid = btrfs_device_id(leaf, dev_item);
3490 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3491 device->total_bytes = device->disk_total_bytes;
3492 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3493 device->type = btrfs_device_type(leaf, dev_item);
3494 device->io_align = btrfs_device_io_align(leaf, dev_item);
3495 device->io_width = btrfs_device_io_width(leaf, dev_item);
3496 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3498 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3499 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3504 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3506 struct btrfs_fs_devices *fs_devices;
3509 mutex_lock(&uuid_mutex);
3511 fs_devices = root->fs_info->fs_devices->seed;
3512 while (fs_devices) {
3513 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3517 fs_devices = fs_devices->seed;
3520 fs_devices = find_fsid(fsid);
3526 fs_devices = clone_fs_devices(fs_devices);
3527 if (IS_ERR(fs_devices)) {
3528 ret = PTR_ERR(fs_devices);
3532 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3533 root->fs_info->bdev_holder);
3537 if (!fs_devices->seeding) {
3538 __btrfs_close_devices(fs_devices);
3539 free_fs_devices(fs_devices);
3544 fs_devices->seed = root->fs_info->fs_devices->seed;
3545 root->fs_info->fs_devices->seed = fs_devices;
3547 mutex_unlock(&uuid_mutex);
3551 static int read_one_dev(struct btrfs_root *root,
3552 struct extent_buffer *leaf,
3553 struct btrfs_dev_item *dev_item)
3555 struct btrfs_device *device;
3558 u8 fs_uuid[BTRFS_UUID_SIZE];
3559 u8 dev_uuid[BTRFS_UUID_SIZE];
3561 devid = btrfs_device_id(leaf, dev_item);
3562 read_extent_buffer(leaf, dev_uuid,
3563 (unsigned long)btrfs_device_uuid(dev_item),
3565 read_extent_buffer(leaf, fs_uuid,
3566 (unsigned long)btrfs_device_fsid(dev_item),
3569 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3570 ret = open_seed_devices(root, fs_uuid);
3571 if (ret && !btrfs_test_opt(root, DEGRADED))
3575 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3576 if (!device || !device->bdev) {
3577 if (!btrfs_test_opt(root, DEGRADED))
3581 printk(KERN_WARNING "warning devid %llu missing\n",
3582 (unsigned long long)devid);
3583 device = add_missing_dev(root, devid, dev_uuid);
3586 } else if (!device->missing) {
3588 * this happens when a device that was properly setup
3589 * in the device info lists suddenly goes bad.
3590 * device->bdev is NULL, and so we have to set
3591 * device->missing to one here
3593 root->fs_info->fs_devices->missing_devices++;
3594 device->missing = 1;
3598 if (device->fs_devices != root->fs_info->fs_devices) {
3599 BUG_ON(device->writeable);
3600 if (device->generation !=
3601 btrfs_device_generation(leaf, dev_item))
3605 fill_device_from_item(leaf, dev_item, device);
3606 device->dev_root = root->fs_info->dev_root;
3607 device->in_fs_metadata = 1;
3608 if (device->writeable)
3609 device->fs_devices->total_rw_bytes += device->total_bytes;
3614 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3616 struct btrfs_dev_item *dev_item;
3618 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3620 return read_one_dev(root, buf, dev_item);
3623 int btrfs_read_sys_array(struct btrfs_root *root)
3625 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3626 struct extent_buffer *sb;
3627 struct btrfs_disk_key *disk_key;
3628 struct btrfs_chunk *chunk;
3630 unsigned long sb_ptr;
3636 struct btrfs_key key;
3638 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3639 BTRFS_SUPER_INFO_SIZE);
3642 btrfs_set_buffer_uptodate(sb);
3643 btrfs_set_buffer_lockdep_class(sb, 0);
3645 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3646 array_size = btrfs_super_sys_array_size(super_copy);
3648 ptr = super_copy->sys_chunk_array;
3649 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3652 while (cur < array_size) {
3653 disk_key = (struct btrfs_disk_key *)ptr;
3654 btrfs_disk_key_to_cpu(&key, disk_key);
3656 len = sizeof(*disk_key); ptr += len;
3660 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3661 chunk = (struct btrfs_chunk *)sb_ptr;
3662 ret = read_one_chunk(root, &key, sb, chunk);
3665 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3666 len = btrfs_chunk_item_size(num_stripes);
3675 free_extent_buffer(sb);
3679 int btrfs_read_chunk_tree(struct btrfs_root *root)
3681 struct btrfs_path *path;
3682 struct extent_buffer *leaf;
3683 struct btrfs_key key;
3684 struct btrfs_key found_key;
3688 root = root->fs_info->chunk_root;
3690 path = btrfs_alloc_path();
3694 /* first we search for all of the device items, and then we
3695 * read in all of the chunk items. This way we can create chunk
3696 * mappings that reference all of the devices that are afound
3698 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3702 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3706 leaf = path->nodes[0];
3707 slot = path->slots[0];
3708 if (slot >= btrfs_header_nritems(leaf)) {
3709 ret = btrfs_next_leaf(root, path);
3716 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3717 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3718 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3720 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3721 struct btrfs_dev_item *dev_item;
3722 dev_item = btrfs_item_ptr(leaf, slot,
3723 struct btrfs_dev_item);
3724 ret = read_one_dev(root, leaf, dev_item);
3728 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3729 struct btrfs_chunk *chunk;
3730 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3731 ret = read_one_chunk(root, &found_key, leaf, chunk);
3737 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3739 btrfs_release_path(root, path);
3744 btrfs_free_path(path);