diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/btrfs/volumes.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/btrfs/volumes.c | 4585 |
1 files changed, 4585 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/fs/btrfs/volumes.c b/ANDROID_3.4.5/fs/btrfs/volumes.c new file mode 100644 index 00000000..1411b995 --- /dev/null +++ b/ANDROID_3.4.5/fs/btrfs/volumes.c @@ -0,0 +1,4585 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ +#include <linux/sched.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/buffer_head.h> +#include <linux/blkdev.h> +#include <linux/random.h> +#include <linux/iocontext.h> +#include <linux/capability.h> +#include <linux/kthread.h> +#include <asm/div64.h> +#include "compat.h" +#include "ctree.h" +#include "extent_map.h" +#include "disk-io.h" +#include "transaction.h" +#include "print-tree.h" +#include "volumes.h" +#include "async-thread.h" +#include "check-integrity.h" + +static int init_first_rw_device(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_device *device); +static int btrfs_relocate_sys_chunks(struct btrfs_root *root); + +static DEFINE_MUTEX(uuid_mutex); +static LIST_HEAD(fs_uuids); + +static void lock_chunks(struct btrfs_root *root) +{ + mutex_lock(&root->fs_info->chunk_mutex); +} + +static void unlock_chunks(struct btrfs_root *root) +{ + mutex_unlock(&root->fs_info->chunk_mutex); +} + +static void free_fs_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_device *device; + WARN_ON(fs_devices->opened); + while (!list_empty(&fs_devices->devices)) { + device = list_entry(fs_devices->devices.next, + struct btrfs_device, dev_list); + list_del(&device->dev_list); + kfree(device->name); + kfree(device); + } + kfree(fs_devices); +} + +void btrfs_cleanup_fs_uuids(void) +{ + struct btrfs_fs_devices *fs_devices; + + while (!list_empty(&fs_uuids)) { + fs_devices = list_entry(fs_uuids.next, + struct btrfs_fs_devices, list); + list_del(&fs_devices->list); + free_fs_devices(fs_devices); + } +} + +static noinline struct btrfs_device *__find_device(struct list_head *head, + u64 devid, u8 *uuid) +{ + struct btrfs_device *dev; + + list_for_each_entry(dev, head, dev_list) { + if (dev->devid == devid && + (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) { + return dev; + } + } + return NULL; +} + +static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid) +{ + struct btrfs_fs_devices *fs_devices; + + list_for_each_entry(fs_devices, &fs_uuids, list) { + if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0) + return fs_devices; + } + return NULL; +} + +static void requeue_list(struct btrfs_pending_bios *pending_bios, + struct bio *head, struct bio *tail) +{ + + struct bio *old_head; + + old_head = pending_bios->head; + pending_bios->head = head; + if (pending_bios->tail) + tail->bi_next = old_head; + else + pending_bios->tail = tail; +} + +/* + * we try to collect pending bios for a device so we don't get a large + * number of procs sending bios down to the same device. This greatly + * improves the schedulers ability to collect and merge the bios. + * + * But, it also turns into a long list of bios to process and that is sure + * to eventually make the worker thread block. The solution here is to + * make some progress and then put this work struct back at the end of + * the list if the block device is congested. This way, multiple devices + * can make progress from a single worker thread. + */ +static noinline void run_scheduled_bios(struct btrfs_device *device) +{ + struct bio *pending; + struct backing_dev_info *bdi; + struct btrfs_fs_info *fs_info; + struct btrfs_pending_bios *pending_bios; + struct bio *tail; + struct bio *cur; + int again = 0; + unsigned long num_run; + unsigned long batch_run = 0; + unsigned long limit; + unsigned long last_waited = 0; + int force_reg = 0; + int sync_pending = 0; + struct blk_plug plug; + + /* + * this function runs all the bios we've collected for + * a particular device. We don't want to wander off to + * another device without first sending all of these down. + * So, setup a plug here and finish it off before we return + */ + blk_start_plug(&plug); + + bdi = blk_get_backing_dev_info(device->bdev); + fs_info = device->dev_root->fs_info; + limit = btrfs_async_submit_limit(fs_info); + limit = limit * 2 / 3; + +loop: + spin_lock(&device->io_lock); + +loop_lock: + num_run = 0; + + /* take all the bios off the list at once and process them + * later on (without the lock held). But, remember the + * tail and other pointers so the bios can be properly reinserted + * into the list if we hit congestion + */ + if (!force_reg && device->pending_sync_bios.head) { + pending_bios = &device->pending_sync_bios; + force_reg = 1; + } else { + pending_bios = &device->pending_bios; + force_reg = 0; + } + + pending = pending_bios->head; + tail = pending_bios->tail; + WARN_ON(pending && !tail); + + /* + * if pending was null this time around, no bios need processing + * at all and we can stop. Otherwise it'll loop back up again + * and do an additional check so no bios are missed. + * + * device->running_pending is used to synchronize with the + * schedule_bio code. + */ + if (device->pending_sync_bios.head == NULL && + device->pending_bios.head == NULL) { + again = 0; + device->running_pending = 0; + } else { + again = 1; + device->running_pending = 1; + } + + pending_bios->head = NULL; + pending_bios->tail = NULL; + + spin_unlock(&device->io_lock); + + while (pending) { + + rmb(); + /* we want to work on both lists, but do more bios on the + * sync list than the regular list + */ + if ((num_run > 32 && + pending_bios != &device->pending_sync_bios && + device->pending_sync_bios.head) || + (num_run > 64 && pending_bios == &device->pending_sync_bios && + device->pending_bios.head)) { + spin_lock(&device->io_lock); + requeue_list(pending_bios, pending, tail); + goto loop_lock; + } + + cur = pending; + pending = pending->bi_next; + cur->bi_next = NULL; + atomic_dec(&fs_info->nr_async_bios); + + if (atomic_read(&fs_info->nr_async_bios) < limit && + waitqueue_active(&fs_info->async_submit_wait)) + wake_up(&fs_info->async_submit_wait); + + BUG_ON(atomic_read(&cur->bi_cnt) == 0); + + /* + * if we're doing the sync list, record that our + * plug has some sync requests on it + * + * If we're doing the regular list and there are + * sync requests sitting around, unplug before + * we add more + */ + if (pending_bios == &device->pending_sync_bios) { + sync_pending = 1; + } else if (sync_pending) { + blk_finish_plug(&plug); + blk_start_plug(&plug); + sync_pending = 0; + } + + btrfsic_submit_bio(cur->bi_rw, cur); + num_run++; + batch_run++; + if (need_resched()) + cond_resched(); + + /* + * we made progress, there is more work to do and the bdi + * is now congested. Back off and let other work structs + * run instead + */ + if (pending && bdi_write_congested(bdi) && batch_run > 8 && + fs_info->fs_devices->open_devices > 1) { + struct io_context *ioc; + + ioc = current->io_context; + + /* + * the main goal here is that we don't want to + * block if we're going to be able to submit + * more requests without blocking. + * + * This code does two great things, it pokes into + * the elevator code from a filesystem _and_ + * it makes assumptions about how batching works. + */ + if (ioc && ioc->nr_batch_requests > 0 && + time_before(jiffies, ioc->last_waited + HZ/50UL) && + (last_waited == 0 || + ioc->last_waited == last_waited)) { + /* + * we want to go through our batch of + * requests and stop. So, we copy out + * the ioc->last_waited time and test + * against it before looping + */ + last_waited = ioc->last_waited; + if (need_resched()) + cond_resched(); + continue; + } + spin_lock(&device->io_lock); + requeue_list(pending_bios, pending, tail); + device->running_pending = 1; + + spin_unlock(&device->io_lock); + btrfs_requeue_work(&device->work); + goto done; + } + /* unplug every 64 requests just for good measure */ + if (batch_run % 64 == 0) { + blk_finish_plug(&plug); + blk_start_plug(&plug); + sync_pending = 0; + } + } + + cond_resched(); + if (again) + goto loop; + + spin_lock(&device->io_lock); + if (device->pending_bios.head || device->pending_sync_bios.head) + goto loop_lock; + spin_unlock(&device->io_lock); + +done: + blk_finish_plug(&plug); +} + +static void pending_bios_fn(struct btrfs_work *work) +{ + struct btrfs_device *device; + + device = container_of(work, struct btrfs_device, work); + run_scheduled_bios(device); +} + +static noinline int device_list_add(const char *path, + struct btrfs_super_block *disk_super, + u64 devid, struct btrfs_fs_devices **fs_devices_ret) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *fs_devices; + u64 found_transid = btrfs_super_generation(disk_super); + char *name; + + fs_devices = find_fsid(disk_super->fsid); + if (!fs_devices) { + fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); + if (!fs_devices) + return -ENOMEM; + INIT_LIST_HEAD(&fs_devices->devices); + INIT_LIST_HEAD(&fs_devices->alloc_list); + list_add(&fs_devices->list, &fs_uuids); + memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE); + fs_devices->latest_devid = devid; + fs_devices->latest_trans = found_transid; + mutex_init(&fs_devices->device_list_mutex); + device = NULL; + } else { + device = __find_device(&fs_devices->devices, devid, + disk_super->dev_item.uuid); + } + if (!device) { + if (fs_devices->opened) + return -EBUSY; + + device = kzalloc(sizeof(*device), GFP_NOFS); + if (!device) { + /* we can safely leave the fs_devices entry around */ + return -ENOMEM; + } + device->devid = devid; + device->work.func = pending_bios_fn; + memcpy(device->uuid, disk_super->dev_item.uuid, + BTRFS_UUID_SIZE); + spin_lock_init(&device->io_lock); + device->name = kstrdup(path, GFP_NOFS); + if (!device->name) { + kfree(device); + return -ENOMEM; + } + INIT_LIST_HEAD(&device->dev_alloc_list); + + /* init readahead state */ + spin_lock_init(&device->reada_lock); + device->reada_curr_zone = NULL; + atomic_set(&device->reada_in_flight, 0); + device->reada_next = 0; + INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT); + INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT); + + mutex_lock(&fs_devices->device_list_mutex); + list_add_rcu(&device->dev_list, &fs_devices->devices); + mutex_unlock(&fs_devices->device_list_mutex); + + device->fs_devices = fs_devices; + fs_devices->num_devices++; + } else if (!device->name || strcmp(device->name, path)) { + name = kstrdup(path, GFP_NOFS); + if (!name) + return -ENOMEM; + kfree(device->name); + device->name = name; + if (device->missing) { + fs_devices->missing_devices--; + device->missing = 0; + } + } + + if (found_transid > fs_devices->latest_trans) { + fs_devices->latest_devid = devid; + fs_devices->latest_trans = found_transid; + } + *fs_devices_ret = fs_devices; + return 0; +} + +static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig) +{ + struct btrfs_fs_devices *fs_devices; + struct btrfs_device *device; + struct btrfs_device *orig_dev; + + fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); + if (!fs_devices) + return ERR_PTR(-ENOMEM); + + INIT_LIST_HEAD(&fs_devices->devices); + INIT_LIST_HEAD(&fs_devices->alloc_list); + INIT_LIST_HEAD(&fs_devices->list); + mutex_init(&fs_devices->device_list_mutex); + fs_devices->latest_devid = orig->latest_devid; + fs_devices->latest_trans = orig->latest_trans; + memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid)); + + /* We have held the volume lock, it is safe to get the devices. */ + list_for_each_entry(orig_dev, &orig->devices, dev_list) { + device = kzalloc(sizeof(*device), GFP_NOFS); + if (!device) + goto error; + + device->name = kstrdup(orig_dev->name, GFP_NOFS); + if (!device->name) { + kfree(device); + goto error; + } + + device->devid = orig_dev->devid; + device->work.func = pending_bios_fn; + memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid)); + spin_lock_init(&device->io_lock); + INIT_LIST_HEAD(&device->dev_list); + INIT_LIST_HEAD(&device->dev_alloc_list); + + list_add(&device->dev_list, &fs_devices->devices); + device->fs_devices = fs_devices; + fs_devices->num_devices++; + } + return fs_devices; +error: + free_fs_devices(fs_devices); + return ERR_PTR(-ENOMEM); +} + +void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_device *device, *next; + + struct block_device *latest_bdev = NULL; + u64 latest_devid = 0; + u64 latest_transid = 0; + + mutex_lock(&uuid_mutex); +again: + /* This is the initialized path, it is safe to release the devices. */ + list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { + if (device->in_fs_metadata) { + if (!latest_transid || + device->generation > latest_transid) { + latest_devid = device->devid; + latest_transid = device->generation; + latest_bdev = device->bdev; + } + continue; + } + + if (device->bdev) { + blkdev_put(device->bdev, device->mode); + device->bdev = NULL; + fs_devices->open_devices--; + } + if (device->writeable) { + list_del_init(&device->dev_alloc_list); + device->writeable = 0; + fs_devices->rw_devices--; + } + list_del_init(&device->dev_list); + fs_devices->num_devices--; + kfree(device->name); + kfree(device); + } + + if (fs_devices->seed) { + fs_devices = fs_devices->seed; + goto again; + } + + fs_devices->latest_bdev = latest_bdev; + fs_devices->latest_devid = latest_devid; + fs_devices->latest_trans = latest_transid; + + mutex_unlock(&uuid_mutex); +} + +static void __free_device(struct work_struct *work) +{ + struct btrfs_device *device; + + device = container_of(work, struct btrfs_device, rcu_work); + + if (device->bdev) + blkdev_put(device->bdev, device->mode); + + kfree(device->name); + kfree(device); +} + +static void free_device(struct rcu_head *head) +{ + struct btrfs_device *device; + + device = container_of(head, struct btrfs_device, rcu); + + INIT_WORK(&device->rcu_work, __free_device); + schedule_work(&device->rcu_work); +} + +static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_device *device; + + if (--fs_devices->opened > 0) + return 0; + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry(device, &fs_devices->devices, dev_list) { + struct btrfs_device *new_device; + + if (device->bdev) + fs_devices->open_devices--; + + if (device->writeable) { + list_del_init(&device->dev_alloc_list); + fs_devices->rw_devices--; + } + + if (device->can_discard) + fs_devices->num_can_discard--; + + new_device = kmalloc(sizeof(*new_device), GFP_NOFS); + BUG_ON(!new_device); /* -ENOMEM */ + memcpy(new_device, device, sizeof(*new_device)); + new_device->name = kstrdup(device->name, GFP_NOFS); + BUG_ON(device->name && !new_device->name); /* -ENOMEM */ + new_device->bdev = NULL; + new_device->writeable = 0; + new_device->in_fs_metadata = 0; + new_device->can_discard = 0; + list_replace_rcu(&device->dev_list, &new_device->dev_list); + + call_rcu(&device->rcu, free_device); + } + mutex_unlock(&fs_devices->device_list_mutex); + + WARN_ON(fs_devices->open_devices); + WARN_ON(fs_devices->rw_devices); + fs_devices->opened = 0; + fs_devices->seeding = 0; + + return 0; +} + +int btrfs_close_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_fs_devices *seed_devices = NULL; + int ret; + + mutex_lock(&uuid_mutex); + ret = __btrfs_close_devices(fs_devices); + if (!fs_devices->opened) { + seed_devices = fs_devices->seed; + fs_devices->seed = NULL; + } + mutex_unlock(&uuid_mutex); + + while (seed_devices) { + fs_devices = seed_devices; + seed_devices = fs_devices->seed; + __btrfs_close_devices(fs_devices); + free_fs_devices(fs_devices); + } + return ret; +} + +static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, + fmode_t flags, void *holder) +{ + struct request_queue *q; + struct block_device *bdev; + struct list_head *head = &fs_devices->devices; + struct btrfs_device *device; + struct block_device *latest_bdev = NULL; + struct buffer_head *bh; + struct btrfs_super_block *disk_super; + u64 latest_devid = 0; + u64 latest_transid = 0; + u64 devid; + int seeding = 1; + int ret = 0; + + flags |= FMODE_EXCL; + + list_for_each_entry(device, head, dev_list) { + if (device->bdev) + continue; + if (!device->name) + continue; + + bdev = blkdev_get_by_path(device->name, flags, holder); + if (IS_ERR(bdev)) { + printk(KERN_INFO "open %s failed\n", device->name); + goto error; + } + filemap_write_and_wait(bdev->bd_inode->i_mapping); + invalidate_bdev(bdev); + set_blocksize(bdev, 4096); + + bh = btrfs_read_dev_super(bdev); + if (!bh) + goto error_close; + + disk_super = (struct btrfs_super_block *)bh->b_data; + devid = btrfs_stack_device_id(&disk_super->dev_item); + if (devid != device->devid) + goto error_brelse; + + if (memcmp(device->uuid, disk_super->dev_item.uuid, + BTRFS_UUID_SIZE)) + goto error_brelse; + + device->generation = btrfs_super_generation(disk_super); + if (!latest_transid || device->generation > latest_transid) { + latest_devid = devid; + latest_transid = device->generation; + latest_bdev = bdev; + } + + if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) { + device->writeable = 0; + } else { + device->writeable = !bdev_read_only(bdev); + seeding = 0; + } + + q = bdev_get_queue(bdev); + if (blk_queue_discard(q)) { + device->can_discard = 1; + fs_devices->num_can_discard++; + } + + device->bdev = bdev; + device->in_fs_metadata = 0; + device->mode = flags; + + if (!blk_queue_nonrot(bdev_get_queue(bdev))) + fs_devices->rotating = 1; + + fs_devices->open_devices++; + if (device->writeable) { + fs_devices->rw_devices++; + list_add(&device->dev_alloc_list, + &fs_devices->alloc_list); + } + brelse(bh); + continue; + +error_brelse: + brelse(bh); +error_close: + blkdev_put(bdev, flags); +error: + continue; + } + if (fs_devices->open_devices == 0) { + ret = -EINVAL; + goto out; + } + fs_devices->seeding = seeding; + fs_devices->opened = 1; + fs_devices->latest_bdev = latest_bdev; + fs_devices->latest_devid = latest_devid; + fs_devices->latest_trans = latest_transid; + fs_devices->total_rw_bytes = 0; +out: + return ret; +} + +int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, + fmode_t flags, void *holder) +{ + int ret; + + mutex_lock(&uuid_mutex); + if (fs_devices->opened) { + fs_devices->opened++; + ret = 0; + } else { + ret = __btrfs_open_devices(fs_devices, flags, holder); + } + mutex_unlock(&uuid_mutex); + return ret; +} + +int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, + struct btrfs_fs_devices **fs_devices_ret) +{ + struct btrfs_super_block *disk_super; + struct block_device *bdev; + struct buffer_head *bh; + int ret; + u64 devid; + u64 transid; + + flags |= FMODE_EXCL; + bdev = blkdev_get_by_path(path, flags, holder); + + if (IS_ERR(bdev)) { + ret = PTR_ERR(bdev); + goto error; + } + + mutex_lock(&uuid_mutex); + ret = set_blocksize(bdev, 4096); + if (ret) + goto error_close; + bh = btrfs_read_dev_super(bdev); + if (!bh) { + ret = -EINVAL; + goto error_close; + } + disk_super = (struct btrfs_super_block *)bh->b_data; + devid = btrfs_stack_device_id(&disk_super->dev_item); + transid = btrfs_super_generation(disk_super); + if (disk_super->label[0]) + printk(KERN_INFO "device label %s ", disk_super->label); + else + printk(KERN_INFO "device fsid %pU ", disk_super->fsid); + printk(KERN_CONT "devid %llu transid %llu %s\n", + (unsigned long long)devid, (unsigned long long)transid, path); + ret = device_list_add(path, disk_super, devid, fs_devices_ret); + + brelse(bh); +error_close: + mutex_unlock(&uuid_mutex); + blkdev_put(bdev, flags); +error: + return ret; +} + +/* helper to account the used device space in the range */ +int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start, + u64 end, u64 *length) +{ + struct btrfs_key key; + struct btrfs_root *root = device->dev_root; + struct btrfs_dev_extent *dev_extent; + struct btrfs_path *path; + u64 extent_end; + int ret; + int slot; + struct extent_buffer *l; + + *length = 0; + + if (start >= device->total_bytes) + return 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->reada = 2; + + key.objectid = device->devid; + key.offset = start; + key.type = BTRFS_DEV_EXTENT_KEY; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret > 0) { + ret = btrfs_previous_item(root, path, key.objectid, key.type); + if (ret < 0) + goto out; + } + + while (1) { + l = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(l)) { + ret = btrfs_next_leaf(root, path); + if (ret == 0) + continue; + if (ret < 0) + goto out; + + break; + } + btrfs_item_key_to_cpu(l, &key, slot); + + if (key.objectid < device->devid) + goto next; + + if (key.objectid > device->devid) + break; + + if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) + goto next; + + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + extent_end = key.offset + btrfs_dev_extent_length(l, + dev_extent); + if (key.offset <= start && extent_end > end) { + *length = end - start + 1; + break; + } else if (key.offset <= start && extent_end > start) + *length += extent_end - start; + else if (key.offset > start && extent_end <= end) + *length += extent_end - key.offset; + else if (key.offset > start && key.offset <= end) { + *length += end - key.offset + 1; + break; + } else if (key.offset > end) + break; + +next: + path->slots[0]++; + } + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + +/* + * find_free_dev_extent - find free space in the specified device + * @device: the device which we search the free space in + * @num_bytes: the size of the free space that we need + * @start: store the start of the free space. + * @len: the size of the free space. that we find, or the size of the max + * free space if we don't find suitable free space + * + * this uses a pretty simple search, the expectation is that it is + * called very infrequently and that a given device has a small number + * of extents + * + * @start is used to store the start of the free space if we find. But if we + * don't find suitable free space, it will be used to store the start position + * of the max free space. + * + * @len is used to store the size of the free space that we find. + * But if we don't find suitable free space, it is used to store the size of + * the max free space. + */ +int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes, + u64 *start, u64 *len) +{ + struct btrfs_key key; + struct btrfs_root *root = device->dev_root; + struct btrfs_dev_extent *dev_extent; + struct btrfs_path *path; + u64 hole_size; + u64 max_hole_start; + u64 max_hole_size; + u64 extent_end; + u64 search_start; + u64 search_end = device->total_bytes; + int ret; + int slot; + struct extent_buffer *l; + + /* FIXME use last free of some kind */ + + /* we don't want to overwrite the superblock on the drive, + * so we make sure to start at an offset of at least 1MB + */ + search_start = max(root->fs_info->alloc_start, 1024ull * 1024); + + max_hole_start = search_start; + max_hole_size = 0; + hole_size = 0; + + if (search_start >= search_end) { + ret = -ENOSPC; + goto error; + } + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto error; + } + path->reada = 2; + + key.objectid = device->devid; + key.offset = search_start; + key.type = BTRFS_DEV_EXTENT_KEY; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret > 0) { + ret = btrfs_previous_item(root, path, key.objectid, key.type); + if (ret < 0) + goto out; + } + + while (1) { + l = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(l)) { + ret = btrfs_next_leaf(root, path); + if (ret == 0) + continue; + if (ret < 0) + goto out; + + break; + } + btrfs_item_key_to_cpu(l, &key, slot); + + if (key.objectid < device->devid) + goto next; + + if (key.objectid > device->devid) + break; + + if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) + goto next; + + if (key.offset > search_start) { + hole_size = key.offset - search_start; + + if (hole_size > max_hole_size) { + max_hole_start = search_start; + max_hole_size = hole_size; + } + + /* + * If this free space is greater than which we need, + * it must be the max free space that we have found + * until now, so max_hole_start must point to the start + * of this free space and the length of this free space + * is stored in max_hole_size. Thus, we return + * max_hole_start and max_hole_size and go back to the + * caller. + */ + if (hole_size >= num_bytes) { + ret = 0; + goto out; + } + } + + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + extent_end = key.offset + btrfs_dev_extent_length(l, + dev_extent); + if (extent_end > search_start) + search_start = extent_end; +next: + path->slots[0]++; + cond_resched(); + } + + /* + * At this point, search_start should be the end of + * allocated dev extents, and when shrinking the device, + * search_end may be smaller than search_start. + */ + if (search_end > search_start) + hole_size = search_end - search_start; + + if (hole_size > max_hole_size) { + max_hole_start = search_start; + max_hole_size = hole_size; + } + + /* See above. */ + if (hole_size < num_bytes) + ret = -ENOSPC; + else + ret = 0; + +out: + btrfs_free_path(path); +error: + *start = max_hole_start; + if (len) + *len = max_hole_size; + return ret; +} + +static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans, + struct btrfs_device *device, + u64 start) +{ + int ret; + struct btrfs_path *path; + struct btrfs_root *root = device->dev_root; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *leaf = NULL; + struct btrfs_dev_extent *extent = NULL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = device->devid; + key.offset = start; + key.type = BTRFS_DEV_EXTENT_KEY; +again: + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret > 0) { + ret = btrfs_previous_item(root, path, key.objectid, + BTRFS_DEV_EXTENT_KEY); + if (ret) + goto out; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_extent); + BUG_ON(found_key.offset > start || found_key.offset + + btrfs_dev_extent_length(leaf, extent) < start); + key = found_key; + btrfs_release_path(path); + goto again; + } else if (ret == 0) { + leaf = path->nodes[0]; + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_extent); + } else { + btrfs_error(root->fs_info, ret, "Slot search failed"); + goto out; + } + + if (device->bytes_used > 0) { + u64 len = btrfs_dev_extent_length(leaf, extent); + device->bytes_used -= len; + spin_lock(&root->fs_info->free_chunk_lock); + root->fs_info->free_chunk_space += len; + spin_unlock(&root->fs_info->free_chunk_lock); + } + ret = btrfs_del_item(trans, root, path); + if (ret) { + btrfs_error(root->fs_info, ret, + "Failed to remove dev extent item"); + } +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans, + struct btrfs_device *device, + u64 chunk_tree, u64 chunk_objectid, + u64 chunk_offset, u64 start, u64 num_bytes) +{ + int ret; + struct btrfs_path *path; + struct btrfs_root *root = device->dev_root; + struct btrfs_dev_extent *extent; + struct extent_buffer *leaf; + struct btrfs_key key; + + WARN_ON(!device->in_fs_metadata); + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = device->devid; + key.offset = start; + key.type = BTRFS_DEV_EXTENT_KEY; + ret = btrfs_insert_empty_item(trans, root, path, &key, + sizeof(*extent)); + if (ret) + goto out; + + leaf = path->nodes[0]; + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_extent); + btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree); + btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid); + btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset); + + write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid, + (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent), + BTRFS_UUID_SIZE); + + btrfs_set_dev_extent_length(leaf, extent, num_bytes); + btrfs_mark_buffer_dirty(leaf); +out: + btrfs_free_path(path); + return ret; +} + +static noinline int find_next_chunk(struct btrfs_root *root, + u64 objectid, u64 *offset) +{ + struct btrfs_path *path; + int ret; + struct btrfs_key key; + struct btrfs_chunk *chunk; + struct btrfs_key found_key; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = objectid; + key.offset = (u64)-1; + key.type = BTRFS_CHUNK_ITEM_KEY; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto error; + + BUG_ON(ret == 0); /* Corruption */ + + ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY); + if (ret) { + *offset = 0; + } else { + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + if (found_key.objectid != objectid) + *offset = 0; + else { + chunk = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_chunk); + *offset = found_key.offset + + btrfs_chunk_length(path->nodes[0], chunk); + } + } + ret = 0; +error: + btrfs_free_path(path); + return ret; +} + +static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid) +{ + int ret; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_path *path; + + root = root->fs_info->chunk_root; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto error; + + BUG_ON(ret == 0); /* Corruption */ + + ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID, + BTRFS_DEV_ITEM_KEY); + if (ret) { + *objectid = 1; + } else { + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + *objectid = found_key.offset + 1; + } + ret = 0; +error: + btrfs_free_path(path); + return ret; +} + +/* + * the device information is stored in the chunk root + * the btrfs_device struct should be fully filled in + */ +int btrfs_add_device(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_device *device) +{ + int ret; + struct btrfs_path *path; + struct btrfs_dev_item *dev_item; + struct extent_buffer *leaf; + struct btrfs_key key; + unsigned long ptr; + + root = root->fs_info->chunk_root; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = device->devid; + + ret = btrfs_insert_empty_item(trans, root, path, &key, + sizeof(*dev_item)); + if (ret) + goto out; + + leaf = path->nodes[0]; + dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); + + btrfs_set_device_id(leaf, dev_item, device->devid); + btrfs_set_device_generation(leaf, dev_item, 0); + btrfs_set_device_type(leaf, dev_item, device->type); + btrfs_set_device_io_align(leaf, dev_item, device->io_align); + btrfs_set_device_io_width(leaf, dev_item, device->io_width); + btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); + btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes); + btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); + btrfs_set_device_group(leaf, dev_item, 0); + btrfs_set_device_seek_speed(leaf, dev_item, 0); + btrfs_set_device_bandwidth(leaf, dev_item, 0); + btrfs_set_device_start_offset(leaf, dev_item, 0); + + ptr = (unsigned long)btrfs_device_uuid(dev_item); + write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); + ptr = (unsigned long)btrfs_device_fsid(dev_item); + write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE); + btrfs_mark_buffer_dirty(leaf); + + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + +static int btrfs_rm_dev_item(struct btrfs_root *root, + struct btrfs_device *device) +{ + int ret; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_trans_handle *trans; + + root = root->fs_info->chunk_root; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = device->devid; + lock_chunks(root); + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto out; + + if (ret > 0) { + ret = -ENOENT; + goto out; + } + + ret = btrfs_del_item(trans, root, path); + if (ret) + goto out; +out: + btrfs_free_path(path); + unlock_chunks(root); + btrfs_commit_transaction(trans, root); + return ret; +} + +int btrfs_rm_device(struct btrfs_root *root, char *device_path) +{ + struct btrfs_device *device; + struct btrfs_device *next_device; + struct block_device *bdev; + struct buffer_head *bh = NULL; + struct btrfs_super_block *disk_super; + struct btrfs_fs_devices *cur_devices; + u64 all_avail; + u64 devid; + u64 num_devices; + u8 *dev_uuid; + int ret = 0; + bool clear_super = false; + + mutex_lock(&uuid_mutex); + + all_avail = root->fs_info->avail_data_alloc_bits | + root->fs_info->avail_system_alloc_bits | + root->fs_info->avail_metadata_alloc_bits; + + if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && + root->fs_info->fs_devices->num_devices <= 4) { + printk(KERN_ERR "btrfs: unable to go below four devices " + "on raid10\n"); + ret = -EINVAL; + goto out; + } + + if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && + root->fs_info->fs_devices->num_devices <= 2) { + printk(KERN_ERR "btrfs: unable to go below two " + "devices on raid1\n"); + ret = -EINVAL; + goto out; + } + + if (strcmp(device_path, "missing") == 0) { + struct list_head *devices; + struct btrfs_device *tmp; + + device = NULL; + devices = &root->fs_info->fs_devices->devices; + /* + * It is safe to read the devices since the volume_mutex + * is held. + */ + list_for_each_entry(tmp, devices, dev_list) { + if (tmp->in_fs_metadata && !tmp->bdev) { + device = tmp; + break; + } + } + bdev = NULL; + bh = NULL; + disk_super = NULL; + if (!device) { + printk(KERN_ERR "btrfs: no missing devices found to " + "remove\n"); + goto out; + } + } else { + bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL, + root->fs_info->bdev_holder); + if (IS_ERR(bdev)) { + ret = PTR_ERR(bdev); + goto out; + } + + set_blocksize(bdev, 4096); + invalidate_bdev(bdev); + bh = btrfs_read_dev_super(bdev); + if (!bh) { + ret = -EINVAL; + goto error_close; + } + disk_super = (struct btrfs_super_block *)bh->b_data; + devid = btrfs_stack_device_id(&disk_super->dev_item); + dev_uuid = disk_super->dev_item.uuid; + device = btrfs_find_device(root, devid, dev_uuid, + disk_super->fsid); + if (!device) { + ret = -ENOENT; + goto error_brelse; + } + } + + if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) { + printk(KERN_ERR "btrfs: unable to remove the only writeable " + "device\n"); + ret = -EINVAL; + goto error_brelse; + } + + if (device->writeable) { + lock_chunks(root); + list_del_init(&device->dev_alloc_list); + unlock_chunks(root); + root->fs_info->fs_devices->rw_devices--; + clear_super = true; + } + + ret = btrfs_shrink_device(device, 0); + if (ret) + goto error_undo; + + ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device); + if (ret) + goto error_undo; + + spin_lock(&root->fs_info->free_chunk_lock); + root->fs_info->free_chunk_space = device->total_bytes - + device->bytes_used; + spin_unlock(&root->fs_info->free_chunk_lock); + + device->in_fs_metadata = 0; + btrfs_scrub_cancel_dev(root, device); + + /* + * the device list mutex makes sure that we don't change + * the device list while someone else is writing out all + * the device supers. + */ + + cur_devices = device->fs_devices; + mutex_lock(&root->fs_info->fs_devices->device_list_mutex); + list_del_rcu(&device->dev_list); + + device->fs_devices->num_devices--; + + if (device->missing) + root->fs_info->fs_devices->missing_devices--; + + next_device = list_entry(root->fs_info->fs_devices->devices.next, + struct btrfs_device, dev_list); + if (device->bdev == root->fs_info->sb->s_bdev) + root->fs_info->sb->s_bdev = next_device->bdev; + if (device->bdev == root->fs_info->fs_devices->latest_bdev) + root->fs_info->fs_devices->latest_bdev = next_device->bdev; + + if (device->bdev) + device->fs_devices->open_devices--; + + call_rcu(&device->rcu, free_device); + mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); + + num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1; + btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices); + + if (cur_devices->open_devices == 0) { + struct btrfs_fs_devices *fs_devices; + fs_devices = root->fs_info->fs_devices; + while (fs_devices) { + if (fs_devices->seed == cur_devices) + break; + fs_devices = fs_devices->seed; + } + fs_devices->seed = cur_devices->seed; + cur_devices->seed = NULL; + lock_chunks(root); + __btrfs_close_devices(cur_devices); + unlock_chunks(root); + free_fs_devices(cur_devices); + } + + /* + * at this point, the device is zero sized. We want to + * remove it from the devices list and zero out the old super + */ + if (clear_super) { + /* make sure this device isn't detected as part of + * the FS anymore + */ + memset(&disk_super->magic, 0, sizeof(disk_super->magic)); + set_buffer_dirty(bh); + sync_dirty_buffer(bh); + } + + ret = 0; + +error_brelse: + brelse(bh); +error_close: + if (bdev) + blkdev_put(bdev, FMODE_READ | FMODE_EXCL); +out: + mutex_unlock(&uuid_mutex); + return ret; +error_undo: + if (device->writeable) { + lock_chunks(root); + list_add(&device->dev_alloc_list, + &root->fs_info->fs_devices->alloc_list); + unlock_chunks(root); + root->fs_info->fs_devices->rw_devices++; + } + goto error_brelse; +} + +/* + * does all the dirty work required for changing file system's UUID. + */ +static int btrfs_prepare_sprout(struct btrfs_root *root) +{ + struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; + struct btrfs_fs_devices *old_devices; + struct btrfs_fs_devices *seed_devices; + struct btrfs_super_block *disk_super = root->fs_info->super_copy; + struct btrfs_device *device; + u64 super_flags; + + BUG_ON(!mutex_is_locked(&uuid_mutex)); + if (!fs_devices->seeding) + return -EINVAL; + + seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); + if (!seed_devices) + return -ENOMEM; + + old_devices = clone_fs_devices(fs_devices); + if (IS_ERR(old_devices)) { + kfree(seed_devices); + return PTR_ERR(old_devices); + } + + list_add(&old_devices->list, &fs_uuids); + + memcpy(seed_devices, fs_devices, sizeof(*seed_devices)); + seed_devices->opened = 1; + INIT_LIST_HEAD(&seed_devices->devices); + INIT_LIST_HEAD(&seed_devices->alloc_list); + mutex_init(&seed_devices->device_list_mutex); + + mutex_lock(&root->fs_info->fs_devices->device_list_mutex); + list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices, + synchronize_rcu); + mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); + + list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list); + list_for_each_entry(device, &seed_devices->devices, dev_list) { + device->fs_devices = seed_devices; + } + + fs_devices->seeding = 0; + fs_devices->num_devices = 0; + fs_devices->open_devices = 0; + fs_devices->seed = seed_devices; + + generate_random_uuid(fs_devices->fsid); + memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE); + memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE); + super_flags = btrfs_super_flags(disk_super) & + ~BTRFS_SUPER_FLAG_SEEDING; + btrfs_set_super_flags(disk_super, super_flags); + + return 0; +} + +/* + * strore the expected generation for seed devices in device items. + */ +static int btrfs_finish_sprout(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_dev_item *dev_item; + struct btrfs_device *device; + struct btrfs_key key; + u8 fs_uuid[BTRFS_UUID_SIZE]; + u8 dev_uuid[BTRFS_UUID_SIZE]; + u64 devid; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + root = root->fs_info->chunk_root; + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.offset = 0; + key.type = BTRFS_DEV_ITEM_KEY; + + while (1) { + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); + if (ret < 0) + goto error; + + leaf = path->nodes[0]; +next_slot: + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret > 0) + break; + if (ret < 0) + goto error; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + btrfs_release_path(path); + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID || + key.type != BTRFS_DEV_ITEM_KEY) + break; + + dev_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_item); + devid = btrfs_device_id(leaf, dev_item); + read_extent_buffer(leaf, dev_uuid, + (unsigned long)btrfs_device_uuid(dev_item), + BTRFS_UUID_SIZE); + read_extent_buffer(leaf, fs_uuid, + (unsigned long)btrfs_device_fsid(dev_item), + BTRFS_UUID_SIZE); + device = btrfs_find_device(root, devid, dev_uuid, fs_uuid); + BUG_ON(!device); /* Logic error */ + + if (device->fs_devices->seeding) { + btrfs_set_device_generation(leaf, dev_item, + device->generation); + btrfs_mark_buffer_dirty(leaf); + } + + path->slots[0]++; + goto next_slot; + } + ret = 0; +error: + btrfs_free_path(path); + return ret; +} + +int btrfs_init_new_device(struct btrfs_root *root, char *device_path) +{ + struct request_queue *q; + struct btrfs_trans_handle *trans; + struct btrfs_device *device; + struct block_device *bdev; + struct list_head *devices; + struct super_block *sb = root->fs_info->sb; + u64 total_bytes; + int seeding_dev = 0; + int ret = 0; + + if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding) + return -EINVAL; + + bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, + root->fs_info->bdev_holder); + if (IS_ERR(bdev)) + return PTR_ERR(bdev); + + if (root->fs_info->fs_devices->seeding) { + seeding_dev = 1; + down_write(&sb->s_umount); + mutex_lock(&uuid_mutex); + } + + filemap_write_and_wait(bdev->bd_inode->i_mapping); + + devices = &root->fs_info->fs_devices->devices; + /* + * we have the volume lock, so we don't need the extra + * device list mutex while reading the list here. + */ + list_for_each_entry(device, devices, dev_list) { + if (device->bdev == bdev) { + ret = -EEXIST; + goto error; + } + } + + device = kzalloc(sizeof(*device), GFP_NOFS); + if (!device) { + /* we can safely leave the fs_devices entry around */ + ret = -ENOMEM; + goto error; + } + + device->name = kstrdup(device_path, GFP_NOFS); + if (!device->name) { + kfree(device); + ret = -ENOMEM; + goto error; + } + + ret = find_next_devid(root, &device->devid); + if (ret) { + kfree(device->name); + kfree(device); + goto error; + } + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + kfree(device->name); + kfree(device); + ret = PTR_ERR(trans); + goto error; + } + + lock_chunks(root); + + q = bdev_get_queue(bdev); + if (blk_queue_discard(q)) + device->can_discard = 1; + device->writeable = 1; + device->work.func = pending_bios_fn; + generate_random_uuid(device->uuid); + spin_lock_init(&device->io_lock); + device->generation = trans->transid; + device->io_width = root->sectorsize; + device->io_align = root->sectorsize; + device->sector_size = root->sectorsize; + device->total_bytes = i_size_read(bdev->bd_inode); + device->disk_total_bytes = device->total_bytes; + device->dev_root = root->fs_info->dev_root; + device->bdev = bdev; + device->in_fs_metadata = 1; + device->mode = FMODE_EXCL; + set_blocksize(device->bdev, 4096); + + if (seeding_dev) { + sb->s_flags &= ~MS_RDONLY; + ret = btrfs_prepare_sprout(root); + BUG_ON(ret); /* -ENOMEM */ + } + + device->fs_devices = root->fs_info->fs_devices; + + /* + * we don't want write_supers to jump in here with our device + * half setup + */ + mutex_lock(&root->fs_info->fs_devices->device_list_mutex); + list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices); + list_add(&device->dev_alloc_list, + &root->fs_info->fs_devices->alloc_list); + root->fs_info->fs_devices->num_devices++; + root->fs_info->fs_devices->open_devices++; + root->fs_info->fs_devices->rw_devices++; + if (device->can_discard) + root->fs_info->fs_devices->num_can_discard++; + root->fs_info->fs_devices->total_rw_bytes += device->total_bytes; + + spin_lock(&root->fs_info->free_chunk_lock); + root->fs_info->free_chunk_space += device->total_bytes; + spin_unlock(&root->fs_info->free_chunk_lock); + + if (!blk_queue_nonrot(bdev_get_queue(bdev))) + root->fs_info->fs_devices->rotating = 1; + + total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy); + btrfs_set_super_total_bytes(root->fs_info->super_copy, + total_bytes + device->total_bytes); + + total_bytes = btrfs_super_num_devices(root->fs_info->super_copy); + btrfs_set_super_num_devices(root->fs_info->super_copy, + total_bytes + 1); + mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); + + if (seeding_dev) { + ret = init_first_rw_device(trans, root, device); + if (ret) + goto error_trans; + ret = btrfs_finish_sprout(trans, root); + if (ret) + goto error_trans; + } else { + ret = btrfs_add_device(trans, root, device); + if (ret) + goto error_trans; + } + + /* + * we've got more storage, clear any full flags on the space + * infos + */ + btrfs_clear_space_info_full(root->fs_info); + + unlock_chunks(root); + ret = btrfs_commit_transaction(trans, root); + + if (seeding_dev) { + mutex_unlock(&uuid_mutex); + up_write(&sb->s_umount); + + if (ret) /* transaction commit */ + return ret; + + ret = btrfs_relocate_sys_chunks(root); + if (ret < 0) + btrfs_error(root->fs_info, ret, + "Failed to relocate sys chunks after " + "device initialization. This can be fixed " + "using the \"btrfs balance\" command."); + } + + return ret; + +error_trans: + unlock_chunks(root); + btrfs_abort_transaction(trans, root, ret); + btrfs_end_transaction(trans, root); + kfree(device->name); + kfree(device); +error: + blkdev_put(bdev, FMODE_EXCL); + if (seeding_dev) { + mutex_unlock(&uuid_mutex); + up_write(&sb->s_umount); + } + return ret; +} + +static noinline int btrfs_update_device(struct btrfs_trans_handle *trans, + struct btrfs_device *device) +{ + int ret; + struct btrfs_path *path; + struct btrfs_root *root; + struct btrfs_dev_item *dev_item; + struct extent_buffer *leaf; + struct btrfs_key key; + + root = device->dev_root->fs_info->chunk_root; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = device->devid; + + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); + if (ret < 0) + goto out; + + if (ret > 0) { + ret = -ENOENT; + goto out; + } + + leaf = path->nodes[0]; + dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); + + btrfs_set_device_id(leaf, dev_item, device->devid); + btrfs_set_device_type(leaf, dev_item, device->type); + btrfs_set_device_io_align(leaf, dev_item, device->io_align); + btrfs_set_device_io_width(leaf, dev_item, device->io_width); + btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); + btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes); + btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); + btrfs_mark_buffer_dirty(leaf); + +out: + btrfs_free_path(path); + return ret; +} + +static int __btrfs_grow_device(struct btrfs_trans_handle *trans, + struct btrfs_device *device, u64 new_size) +{ + struct btrfs_super_block *super_copy = + device->dev_root->fs_info->super_copy; + u64 old_total = btrfs_super_total_bytes(super_copy); + u64 diff = new_size - device->total_bytes; + + if (!device->writeable) + return -EACCES; + if (new_size <= device->total_bytes) + return -EINVAL; + + btrfs_set_super_total_bytes(super_copy, old_total + diff); + device->fs_devices->total_rw_bytes += diff; + + device->total_bytes = new_size; + device->disk_total_bytes = new_size; + btrfs_clear_space_info_full(device->dev_root->fs_info); + + return btrfs_update_device(trans, device); +} + +int btrfs_grow_device(struct btrfs_trans_handle *trans, + struct btrfs_device *device, u64 new_size) +{ + int ret; + lock_chunks(device->dev_root); + ret = __btrfs_grow_device(trans, device, new_size); + unlock_chunks(device->dev_root); + return ret; +} + +static int btrfs_free_chunk(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 chunk_tree, u64 chunk_objectid, + u64 chunk_offset) +{ + int ret; + struct btrfs_path *path; + struct btrfs_key key; + + root = root->fs_info->chunk_root; + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = chunk_objectid; + key.offset = chunk_offset; + key.type = BTRFS_CHUNK_ITEM_KEY; + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto out; + else if (ret > 0) { /* Logic error or corruption */ + btrfs_error(root->fs_info, -ENOENT, + "Failed lookup while freeing chunk."); + ret = -ENOENT; + goto out; + } + + ret = btrfs_del_item(trans, root, path); + if (ret < 0) + btrfs_error(root->fs_info, ret, + "Failed to delete chunk item."); +out: + btrfs_free_path(path); + return ret; +} + +static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64 + chunk_offset) +{ + struct btrfs_super_block *super_copy = root->fs_info->super_copy; + struct btrfs_disk_key *disk_key; + struct btrfs_chunk *chunk; + u8 *ptr; + int ret = 0; + u32 num_stripes; + u32 array_size; + u32 len = 0; + u32 cur; + struct btrfs_key key; + + array_size = btrfs_super_sys_array_size(super_copy); + + ptr = super_copy->sys_chunk_array; + cur = 0; + + while (cur < array_size) { + disk_key = (struct btrfs_disk_key *)ptr; + btrfs_disk_key_to_cpu(&key, disk_key); + + len = sizeof(*disk_key); + + if (key.type == BTRFS_CHUNK_ITEM_KEY) { + chunk = (struct btrfs_chunk *)(ptr + len); + num_stripes = btrfs_stack_chunk_num_stripes(chunk); + len += btrfs_chunk_item_size(num_stripes); + } else { + ret = -EIO; + break; + } + if (key.objectid == chunk_objectid && + key.offset == chunk_offset) { + memmove(ptr, ptr + len, array_size - (cur + len)); + array_size -= len; + btrfs_set_super_sys_array_size(super_copy, array_size); + } else { + ptr += len; + cur += len; + } + } + return ret; +} + +static int btrfs_relocate_chunk(struct btrfs_root *root, + u64 chunk_tree, u64 chunk_objectid, + u64 chunk_offset) +{ + struct extent_map_tree *em_tree; + struct btrfs_root *extent_root; + struct btrfs_trans_handle *trans; + struct extent_map *em; + struct map_lookup *map; + int ret; + int i; + + root = root->fs_info->chunk_root; + extent_root = root->fs_info->extent_root; + em_tree = &root->fs_info->mapping_tree.map_tree; + + ret = btrfs_can_relocate(extent_root, chunk_offset); + if (ret) + return -ENOSPC; + + /* step one, relocate all the extents inside this chunk */ + ret = btrfs_relocate_block_group(extent_root, chunk_offset); + if (ret) + return ret; + + trans = btrfs_start_transaction(root, 0); + BUG_ON(IS_ERR(trans)); + + lock_chunks(root); + + /* + * step two, delete the device extents and the + * chunk tree entries + */ + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, chunk_offset, 1); + read_unlock(&em_tree->lock); + + BUG_ON(!em || em->start > chunk_offset || + em->start + em->len < chunk_offset); + map = (struct map_lookup *)em->bdev; + + for (i = 0; i < map->num_stripes; i++) { + ret = btrfs_free_dev_extent(trans, map->stripes[i].dev, + map->stripes[i].physical); + BUG_ON(ret); + + if (map->stripes[i].dev) { + ret = btrfs_update_device(trans, map->stripes[i].dev); + BUG_ON(ret); + } + } + ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid, + chunk_offset); + + BUG_ON(ret); + + trace_btrfs_chunk_free(root, map, chunk_offset, em->len); + + if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) { + ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset); + BUG_ON(ret); + } + + ret = btrfs_remove_block_group(trans, extent_root, chunk_offset); + BUG_ON(ret); + + write_lock(&em_tree->lock); + remove_extent_mapping(em_tree, em); + write_unlock(&em_tree->lock); + + kfree(map); + em->bdev = NULL; + + /* once for the tree */ + free_extent_map(em); + /* once for us */ + free_extent_map(em); + + unlock_chunks(root); + btrfs_end_transaction(trans, root); + return 0; +} + +static int btrfs_relocate_sys_chunks(struct btrfs_root *root) +{ + struct btrfs_root *chunk_root = root->fs_info->chunk_root; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_chunk *chunk; + struct btrfs_key key; + struct btrfs_key found_key; + u64 chunk_tree = chunk_root->root_key.objectid; + u64 chunk_type; + bool retried = false; + int failed = 0; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + +again: + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.offset = (u64)-1; + key.type = BTRFS_CHUNK_ITEM_KEY; + + while (1) { + ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); + if (ret < 0) + goto error; + BUG_ON(ret == 0); /* Corruption */ + + ret = btrfs_previous_item(chunk_root, path, key.objectid, + key.type); + if (ret < 0) + goto error; + if (ret > 0) + break; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + chunk = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_chunk); + chunk_type = btrfs_chunk_type(leaf, chunk); + btrfs_release_path(path); + + if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) { + ret = btrfs_relocate_chunk(chunk_root, chunk_tree, + found_key.objectid, + found_key.offset); + if (ret == -ENOSPC) + failed++; + else if (ret) + BUG(); + } + + if (found_key.offset == 0) + break; + key.offset = found_key.offset - 1; + } + ret = 0; + if (failed && !retried) { + failed = 0; + retried = true; + goto again; + } else if (failed && retried) { + WARN_ON(1); + ret = -ENOSPC; + } +error: + btrfs_free_path(path); + return ret; +} + +static int insert_balance_item(struct btrfs_root *root, + struct btrfs_balance_control *bctl) +{ + struct btrfs_trans_handle *trans; + struct btrfs_balance_item *item; + struct btrfs_disk_balance_args disk_bargs; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key key; + int ret, err; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + + key.objectid = BTRFS_BALANCE_OBJECTID; + key.type = BTRFS_BALANCE_ITEM_KEY; + key.offset = 0; + + ret = btrfs_insert_empty_item(trans, root, path, &key, + sizeof(*item)); + if (ret) + goto out; + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item); + + memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item)); + + btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data); + btrfs_set_balance_data(leaf, item, &disk_bargs); + btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta); + btrfs_set_balance_meta(leaf, item, &disk_bargs); + btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys); + btrfs_set_balance_sys(leaf, item, &disk_bargs); + + btrfs_set_balance_flags(leaf, item, bctl->flags); + + btrfs_mark_buffer_dirty(leaf); +out: + btrfs_free_path(path); + err = btrfs_commit_transaction(trans, root); + if (err && !ret) + ret = err; + return ret; +} + +static int del_balance_item(struct btrfs_root *root) +{ + struct btrfs_trans_handle *trans; + struct btrfs_path *path; + struct btrfs_key key; + int ret, err; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + + key.objectid = BTRFS_BALANCE_OBJECTID; + key.type = BTRFS_BALANCE_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto out; + if (ret > 0) { + ret = -ENOENT; + goto out; + } + + ret = btrfs_del_item(trans, root, path); +out: + btrfs_free_path(path); + err = btrfs_commit_transaction(trans, root); + if (err && !ret) + ret = err; + return ret; +} + +/* + * This is a heuristic used to reduce the number of chunks balanced on + * resume after balance was interrupted. + */ +static void update_balance_args(struct btrfs_balance_control *bctl) +{ + /* + * Turn on soft mode for chunk types that were being converted. + */ + if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) + bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT; + if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) + bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT; + if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) + bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT; + + /* + * Turn on usage filter if is not already used. The idea is + * that chunks that we have already balanced should be + * reasonably full. Don't do it for chunks that are being + * converted - that will keep us from relocating unconverted + * (albeit full) chunks. + */ + if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) && + !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) { + bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE; + bctl->data.usage = 90; + } + if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) && + !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) { + bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE; + bctl->sys.usage = 90; + } + if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) && + !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) { + bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE; + bctl->meta.usage = 90; + } +} + +/* + * Should be called with both balance and volume mutexes held to + * serialize other volume operations (add_dev/rm_dev/resize) with + * restriper. Same goes for unset_balance_control. + */ +static void set_balance_control(struct btrfs_balance_control *bctl) +{ + struct btrfs_fs_info *fs_info = bctl->fs_info; + + BUG_ON(fs_info->balance_ctl); + + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl = bctl; + spin_unlock(&fs_info->balance_lock); +} + +static void unset_balance_control(struct btrfs_fs_info *fs_info) +{ + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + + BUG_ON(!fs_info->balance_ctl); + + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl = NULL; + spin_unlock(&fs_info->balance_lock); + + kfree(bctl); +} + +/* + * Balance filters. Return 1 if chunk should be filtered out + * (should not be balanced). + */ +static int chunk_profiles_filter(u64 chunk_type, + struct btrfs_balance_args *bargs) +{ + chunk_type = chunk_to_extended(chunk_type) & + BTRFS_EXTENDED_PROFILE_MASK; + + if (bargs->profiles & chunk_type) + return 0; + + return 1; +} + +static u64 div_factor_fine(u64 num, int factor) +{ + if (factor <= 0) + return 0; + if (factor >= 100) + return num; + + num *= factor; + do_div(num, 100); + return num; +} + +static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset, + struct btrfs_balance_args *bargs) +{ + struct btrfs_block_group_cache *cache; + u64 chunk_used, user_thresh; + int ret = 1; + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + chunk_used = btrfs_block_group_used(&cache->item); + + user_thresh = div_factor_fine(cache->key.offset, bargs->usage); + if (chunk_used < user_thresh) + ret = 0; + + btrfs_put_block_group(cache); + return ret; +} + +static int chunk_devid_filter(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + struct btrfs_balance_args *bargs) +{ + struct btrfs_stripe *stripe; + int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + int i; + + for (i = 0; i < num_stripes; i++) { + stripe = btrfs_stripe_nr(chunk, i); + if (btrfs_stripe_devid(leaf, stripe) == bargs->devid) + return 0; + } + + return 1; +} + +/* [pstart, pend) */ +static int chunk_drange_filter(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + u64 chunk_offset, + struct btrfs_balance_args *bargs) +{ + struct btrfs_stripe *stripe; + int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + u64 stripe_offset; + u64 stripe_length; + int factor; + int i; + + if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID)) + return 0; + + if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP | + BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) + factor = 2; + else + factor = 1; + factor = num_stripes / factor; + + for (i = 0; i < num_stripes; i++) { + stripe = btrfs_stripe_nr(chunk, i); + if (btrfs_stripe_devid(leaf, stripe) != bargs->devid) + continue; + + stripe_offset = btrfs_stripe_offset(leaf, stripe); + stripe_length = btrfs_chunk_length(leaf, chunk); + do_div(stripe_length, factor); + + if (stripe_offset < bargs->pend && + stripe_offset + stripe_length > bargs->pstart) + return 0; + } + + return 1; +} + +/* [vstart, vend) */ +static int chunk_vrange_filter(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + u64 chunk_offset, + struct btrfs_balance_args *bargs) +{ + if (chunk_offset < bargs->vend && + chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart) + /* at least part of the chunk is inside this vrange */ + return 0; + + return 1; +} + +static int chunk_soft_convert_filter(u64 chunk_type, + struct btrfs_balance_args *bargs) +{ + if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT)) + return 0; + + chunk_type = chunk_to_extended(chunk_type) & + BTRFS_EXTENDED_PROFILE_MASK; + + if (bargs->target == chunk_type) + return 1; + + return 0; +} + +static int should_balance_chunk(struct btrfs_root *root, + struct extent_buffer *leaf, + struct btrfs_chunk *chunk, u64 chunk_offset) +{ + struct btrfs_balance_control *bctl = root->fs_info->balance_ctl; + struct btrfs_balance_args *bargs = NULL; + u64 chunk_type = btrfs_chunk_type(leaf, chunk); + + /* type filter */ + if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) & + (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) { + return 0; + } + + if (chunk_type & BTRFS_BLOCK_GROUP_DATA) + bargs = &bctl->data; + else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) + bargs = &bctl->sys; + else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA) + bargs = &bctl->meta; + + /* profiles filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) && + chunk_profiles_filter(chunk_type, bargs)) { + return 0; + } + + /* usage filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) && + chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) { + return 0; + } + + /* devid filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) && + chunk_devid_filter(leaf, chunk, bargs)) { + return 0; + } + + /* drange filter, makes sense only with devid filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) && + chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) { + return 0; + } + + /* vrange filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) && + chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) { + return 0; + } + + /* soft profile changing mode */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) && + chunk_soft_convert_filter(chunk_type, bargs)) { + return 0; + } + + return 1; +} + +static u64 div_factor(u64 num, int factor) +{ + if (factor == 10) + return num; + num *= factor; + do_div(num, 10); + return num; +} + +static int __btrfs_balance(struct btrfs_fs_info *fs_info) +{ + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + struct btrfs_root *chunk_root = fs_info->chunk_root; + struct btrfs_root *dev_root = fs_info->dev_root; + struct list_head *devices; + struct btrfs_device *device; + u64 old_size; + u64 size_to_free; + struct btrfs_chunk *chunk; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_trans_handle *trans; + struct extent_buffer *leaf; + int slot; + int ret; + int enospc_errors = 0; + bool counting = true; + + /* step one make some room on all the devices */ + devices = &fs_info->fs_devices->devices; + list_for_each_entry(device, devices, dev_list) { + old_size = device->total_bytes; + size_to_free = div_factor(old_size, 1); + size_to_free = min(size_to_free, (u64)1 * 1024 * 1024); + if (!device->writeable || + device->total_bytes - device->bytes_used > size_to_free) + continue; + + ret = btrfs_shrink_device(device, old_size - size_to_free); + if (ret == -ENOSPC) + break; + BUG_ON(ret); + + trans = btrfs_start_transaction(dev_root, 0); + BUG_ON(IS_ERR(trans)); + + ret = btrfs_grow_device(trans, device, old_size); + BUG_ON(ret); + + btrfs_end_transaction(trans, dev_root); + } + + /* step two, relocate all the chunks */ + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto error; + } + + /* zero out stat counters */ + spin_lock(&fs_info->balance_lock); + memset(&bctl->stat, 0, sizeof(bctl->stat)); + spin_unlock(&fs_info->balance_lock); +again: + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.offset = (u64)-1; + key.type = BTRFS_CHUNK_ITEM_KEY; + + while (1) { + if ((!counting && atomic_read(&fs_info->balance_pause_req)) || + atomic_read(&fs_info->balance_cancel_req)) { + ret = -ECANCELED; + goto error; + } + + ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); + if (ret < 0) + goto error; + + /* + * this shouldn't happen, it means the last relocate + * failed + */ + if (ret == 0) + BUG(); /* FIXME break ? */ + + ret = btrfs_previous_item(chunk_root, path, 0, + BTRFS_CHUNK_ITEM_KEY); + if (ret) { + ret = 0; + break; + } + + leaf = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + if (found_key.objectid != key.objectid) + break; + + /* chunk zero is special */ + if (found_key.offset == 0) + break; + + chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); + + if (!counting) { + spin_lock(&fs_info->balance_lock); + bctl->stat.considered++; + spin_unlock(&fs_info->balance_lock); + } + + ret = should_balance_chunk(chunk_root, leaf, chunk, + found_key.offset); + btrfs_release_path(path); + if (!ret) + goto loop; + + if (counting) { + spin_lock(&fs_info->balance_lock); + bctl->stat.expected++; + spin_unlock(&fs_info->balance_lock); + goto loop; + } + + ret = btrfs_relocate_chunk(chunk_root, + chunk_root->root_key.objectid, + found_key.objectid, + found_key.offset); + if (ret && ret != -ENOSPC) + goto error; + if (ret == -ENOSPC) { + enospc_errors++; + } else { + spin_lock(&fs_info->balance_lock); + bctl->stat.completed++; + spin_unlock(&fs_info->balance_lock); + } +loop: + key.offset = found_key.offset - 1; + } + + if (counting) { + btrfs_release_path(path); + counting = false; + goto again; + } +error: + btrfs_free_path(path); + if (enospc_errors) { + printk(KERN_INFO "btrfs: %d enospc errors during balance\n", + enospc_errors); + if (!ret) + ret = -ENOSPC; + } + + return ret; +} + +/** + * alloc_profile_is_valid - see if a given profile is valid and reduced + * @flags: profile to validate + * @extended: if true @flags is treated as an extended profile + */ +static int alloc_profile_is_valid(u64 flags, int extended) +{ + u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK : + BTRFS_BLOCK_GROUP_PROFILE_MASK); + + flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK; + + /* 1) check that all other bits are zeroed */ + if (flags & ~mask) + return 0; + + /* 2) see if profile is reduced */ + if (flags == 0) + return !extended; /* "0" is valid for usual profiles */ + + /* true if exactly one bit set */ + return (flags & (flags - 1)) == 0; +} + +static inline int balance_need_close(struct btrfs_fs_info *fs_info) +{ + /* cancel requested || normal exit path */ + return atomic_read(&fs_info->balance_cancel_req) || + (atomic_read(&fs_info->balance_pause_req) == 0 && + atomic_read(&fs_info->balance_cancel_req) == 0); +} + +static void __cancel_balance(struct btrfs_fs_info *fs_info) +{ + int ret; + + unset_balance_control(fs_info); + ret = del_balance_item(fs_info->tree_root); + BUG_ON(ret); +} + +void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock, + struct btrfs_ioctl_balance_args *bargs); + +/* + * Should be called with both balance and volume mutexes held + */ +int btrfs_balance(struct btrfs_balance_control *bctl, + struct btrfs_ioctl_balance_args *bargs) +{ + struct btrfs_fs_info *fs_info = bctl->fs_info; + u64 allowed; + int mixed = 0; + int ret; + + if (btrfs_fs_closing(fs_info) || + atomic_read(&fs_info->balance_pause_req) || + atomic_read(&fs_info->balance_cancel_req)) { + ret = -EINVAL; + goto out; + } + + allowed = btrfs_super_incompat_flags(fs_info->super_copy); + if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) + mixed = 1; + + /* + * In case of mixed groups both data and meta should be picked, + * and identical options should be given for both of them. + */ + allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA; + if (mixed && (bctl->flags & allowed)) { + if (!(bctl->flags & BTRFS_BALANCE_DATA) || + !(bctl->flags & BTRFS_BALANCE_METADATA) || + memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) { + printk(KERN_ERR "btrfs: with mixed groups data and " + "metadata balance options must be the same\n"); + ret = -EINVAL; + goto out; + } + } + + allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE; + if (fs_info->fs_devices->num_devices == 1) + allowed |= BTRFS_BLOCK_GROUP_DUP; + else if (fs_info->fs_devices->num_devices < 4) + allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1); + else + allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10); + + if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (!alloc_profile_is_valid(bctl->data.target, 1) || + (bctl->data.target & ~allowed))) { + printk(KERN_ERR "btrfs: unable to start balance with target " + "data profile %llu\n", + (unsigned long long)bctl->data.target); + ret = -EINVAL; + goto out; + } + if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (!alloc_profile_is_valid(bctl->meta.target, 1) || + (bctl->meta.target & ~allowed))) { + printk(KERN_ERR "btrfs: unable to start balance with target " + "metadata profile %llu\n", + (unsigned long long)bctl->meta.target); + ret = -EINVAL; + goto out; + } + if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (!alloc_profile_is_valid(bctl->sys.target, 1) || + (bctl->sys.target & ~allowed))) { + printk(KERN_ERR "btrfs: unable to start balance with target " + "system profile %llu\n", + (unsigned long long)bctl->sys.target); + ret = -EINVAL; + goto out; + } + + /* allow dup'ed data chunks only in mixed mode */ + if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) { + printk(KERN_ERR "btrfs: dup for data is not allowed\n"); + ret = -EINVAL; + goto out; + } + + /* allow to reduce meta or sys integrity only if force set */ + allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10; + if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (fs_info->avail_system_alloc_bits & allowed) && + !(bctl->sys.target & allowed)) || + ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (fs_info->avail_metadata_alloc_bits & allowed) && + !(bctl->meta.target & allowed))) { + if (bctl->flags & BTRFS_BALANCE_FORCE) { + printk(KERN_INFO "btrfs: force reducing metadata " + "integrity\n"); + } else { + printk(KERN_ERR "btrfs: balance will reduce metadata " + "integrity, use force if you want this\n"); + ret = -EINVAL; + goto out; + } + } + + ret = insert_balance_item(fs_info->tree_root, bctl); + if (ret && ret != -EEXIST) + goto out; + + if (!(bctl->flags & BTRFS_BALANCE_RESUME)) { + BUG_ON(ret == -EEXIST); + set_balance_control(bctl); + } else { + BUG_ON(ret != -EEXIST); + spin_lock(&fs_info->balance_lock); + update_balance_args(bctl); + spin_unlock(&fs_info->balance_lock); + } + + atomic_inc(&fs_info->balance_running); + mutex_unlock(&fs_info->balance_mutex); + + ret = __btrfs_balance(fs_info); + + mutex_lock(&fs_info->balance_mutex); + atomic_dec(&fs_info->balance_running); + + if (bargs) { + memset(bargs, 0, sizeof(*bargs)); + update_ioctl_balance_args(fs_info, 0, bargs); + } + + if ((ret && ret != -ECANCELED && ret != -ENOSPC) || + balance_need_close(fs_info)) { + __cancel_balance(fs_info); + } + + wake_up(&fs_info->balance_wait_q); + + return ret; +out: + if (bctl->flags & BTRFS_BALANCE_RESUME) + __cancel_balance(fs_info); + else + kfree(bctl); + return ret; +} + +static int balance_kthread(void *data) +{ + struct btrfs_balance_control *bctl = + (struct btrfs_balance_control *)data; + struct btrfs_fs_info *fs_info = bctl->fs_info; + int ret = 0; + + mutex_lock(&fs_info->volume_mutex); + mutex_lock(&fs_info->balance_mutex); + + set_balance_control(bctl); + + if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) { + printk(KERN_INFO "btrfs: force skipping balance\n"); + } else { + printk(KERN_INFO "btrfs: continuing balance\n"); + ret = btrfs_balance(bctl, NULL); + } + + mutex_unlock(&fs_info->balance_mutex); + mutex_unlock(&fs_info->volume_mutex); + return ret; +} + +int btrfs_recover_balance(struct btrfs_root *tree_root) +{ + struct task_struct *tsk; + struct btrfs_balance_control *bctl; + struct btrfs_balance_item *item; + struct btrfs_disk_balance_args disk_bargs; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key key; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + bctl = kzalloc(sizeof(*bctl), GFP_NOFS); + if (!bctl) { + ret = -ENOMEM; + goto out; + } + + key.objectid = BTRFS_BALANCE_OBJECTID; + key.type = BTRFS_BALANCE_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); + if (ret < 0) + goto out_bctl; + if (ret > 0) { /* ret = -ENOENT; */ + ret = 0; + goto out_bctl; + } + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item); + + bctl->fs_info = tree_root->fs_info; + bctl->flags = btrfs_balance_flags(leaf, item) | BTRFS_BALANCE_RESUME; + + btrfs_balance_data(leaf, item, &disk_bargs); + btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs); + btrfs_balance_meta(leaf, item, &disk_bargs); + btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs); + btrfs_balance_sys(leaf, item, &disk_bargs); + btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs); + + tsk = kthread_run(balance_kthread, bctl, "btrfs-balance"); + if (IS_ERR(tsk)) + ret = PTR_ERR(tsk); + else + goto out; + +out_bctl: + kfree(bctl); +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_pause_balance(struct btrfs_fs_info *fs_info) +{ + int ret = 0; + + mutex_lock(&fs_info->balance_mutex); + if (!fs_info->balance_ctl) { + mutex_unlock(&fs_info->balance_mutex); + return -ENOTCONN; + } + + if (atomic_read(&fs_info->balance_running)) { + atomic_inc(&fs_info->balance_pause_req); + mutex_unlock(&fs_info->balance_mutex); + + wait_event(fs_info->balance_wait_q, + atomic_read(&fs_info->balance_running) == 0); + + mutex_lock(&fs_info->balance_mutex); + /* we are good with balance_ctl ripped off from under us */ + BUG_ON(atomic_read(&fs_info->balance_running)); + atomic_dec(&fs_info->balance_pause_req); + } else { + ret = -ENOTCONN; + } + + mutex_unlock(&fs_info->balance_mutex); + return ret; +} + +int btrfs_cancel_balance(struct btrfs_fs_info *fs_info) +{ + mutex_lock(&fs_info->balance_mutex); + if (!fs_info->balance_ctl) { + mutex_unlock(&fs_info->balance_mutex); + return -ENOTCONN; + } + + atomic_inc(&fs_info->balance_cancel_req); + /* + * if we are running just wait and return, balance item is + * deleted in btrfs_balance in this case + */ + if (atomic_read(&fs_info->balance_running)) { + mutex_unlock(&fs_info->balance_mutex); + wait_event(fs_info->balance_wait_q, + atomic_read(&fs_info->balance_running) == 0); + mutex_lock(&fs_info->balance_mutex); + } else { + /* __cancel_balance needs volume_mutex */ + mutex_unlock(&fs_info->balance_mutex); + mutex_lock(&fs_info->volume_mutex); + mutex_lock(&fs_info->balance_mutex); + + if (fs_info->balance_ctl) + __cancel_balance(fs_info); + + mutex_unlock(&fs_info->volume_mutex); + } + + BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running)); + atomic_dec(&fs_info->balance_cancel_req); + mutex_unlock(&fs_info->balance_mutex); + return 0; +} + +/* + * shrinking a device means finding all of the device extents past + * the new size, and then following the back refs to the chunks. + * The chunk relocation code actually frees the device extent + */ +int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = device->dev_root; + struct btrfs_dev_extent *dev_extent = NULL; + struct btrfs_path *path; + u64 length; + u64 chunk_tree; + u64 chunk_objectid; + u64 chunk_offset; + int ret; + int slot; + int failed = 0; + bool retried = false; + struct extent_buffer *l; + struct btrfs_key key; + struct btrfs_super_block *super_copy = root->fs_info->super_copy; + u64 old_total = btrfs_super_total_bytes(super_copy); + u64 old_size = device->total_bytes; + u64 diff = device->total_bytes - new_size; + + if (new_size >= device->total_bytes) + return -EINVAL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = 2; + + lock_chunks(root); + + device->total_bytes = new_size; + if (device->writeable) { + device->fs_devices->total_rw_bytes -= diff; + spin_lock(&root->fs_info->free_chunk_lock); + root->fs_info->free_chunk_space -= diff; + spin_unlock(&root->fs_info->free_chunk_lock); + } + unlock_chunks(root); + +again: + key.objectid = device->devid; + key.offset = (u64)-1; + key.type = BTRFS_DEV_EXTENT_KEY; + + do { + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto done; + + ret = btrfs_previous_item(root, path, 0, key.type); + if (ret < 0) + goto done; + if (ret) { + ret = 0; + btrfs_release_path(path); + break; + } + + l = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(l, &key, path->slots[0]); + + if (key.objectid != device->devid) { + btrfs_release_path(path); + break; + } + + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + length = btrfs_dev_extent_length(l, dev_extent); + + if (key.offset + length <= new_size) { + btrfs_release_path(path); + break; + } + + chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent); + chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent); + chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); + btrfs_release_path(path); + + ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid, + chunk_offset); + if (ret && ret != -ENOSPC) + goto done; + if (ret == -ENOSPC) + failed++; + } while (key.offset-- > 0); + + if (failed && !retried) { + failed = 0; + retried = true; + goto again; + } else if (failed && retried) { + ret = -ENOSPC; + lock_chunks(root); + + device->total_bytes = old_size; + if (device->writeable) + device->fs_devices->total_rw_bytes += diff; + spin_lock(&root->fs_info->free_chunk_lock); + root->fs_info->free_chunk_space += diff; + spin_unlock(&root->fs_info->free_chunk_lock); + unlock_chunks(root); + goto done; + } + + /* Shrinking succeeded, else we would be at "done". */ + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto done; + } + + lock_chunks(root); + + device->disk_total_bytes = new_size; + /* Now btrfs_update_device() will change the on-disk size. */ + ret = btrfs_update_device(trans, device); + if (ret) { + unlock_chunks(root); + btrfs_end_transaction(trans, root); + goto done; + } + WARN_ON(diff > old_total); + btrfs_set_super_total_bytes(super_copy, old_total - diff); + unlock_chunks(root); + btrfs_end_transaction(trans, root); +done: + btrfs_free_path(path); + return ret; +} + +static int btrfs_add_system_chunk(struct btrfs_root *root, + struct btrfs_key *key, + struct btrfs_chunk *chunk, int item_size) +{ + struct btrfs_super_block *super_copy = root->fs_info->super_copy; + struct btrfs_disk_key disk_key; + u32 array_size; + u8 *ptr; + + array_size = btrfs_super_sys_array_size(super_copy); + if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) + return -EFBIG; + + ptr = super_copy->sys_chunk_array + array_size; + btrfs_cpu_key_to_disk(&disk_key, key); + memcpy(ptr, &disk_key, sizeof(disk_key)); + ptr += sizeof(disk_key); + memcpy(ptr, chunk, item_size); + item_size += sizeof(disk_key); + btrfs_set_super_sys_array_size(super_copy, array_size + item_size); + return 0; +} + +/* + * sort the devices in descending order by max_avail, total_avail + */ +static int btrfs_cmp_device_info(const void *a, const void *b) +{ + const struct btrfs_device_info *di_a = a; + const struct btrfs_device_info *di_b = b; + + if (di_a->max_avail > di_b->max_avail) + return -1; + if (di_a->max_avail < di_b->max_avail) + return 1; + if (di_a->total_avail > di_b->total_avail) + return -1; + if (di_a->total_avail < di_b->total_avail) + return 1; + return 0; +} + +static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct map_lookup **map_ret, + u64 *num_bytes_out, u64 *stripe_size_out, + u64 start, u64 type) +{ + struct btrfs_fs_info *info = extent_root->fs_info; + struct btrfs_fs_devices *fs_devices = info->fs_devices; + struct list_head *cur; + struct map_lookup *map = NULL; + struct extent_map_tree *em_tree; + struct extent_map *em; + struct btrfs_device_info *devices_info = NULL; + u64 total_avail; + int num_stripes; /* total number of stripes to allocate */ + int sub_stripes; /* sub_stripes info for map */ + int dev_stripes; /* stripes per dev */ + int devs_max; /* max devs to use */ + int devs_min; /* min devs needed */ + int devs_increment; /* ndevs has to be a multiple of this */ + int ncopies; /* how many copies to data has */ + int ret; + u64 max_stripe_size; + u64 max_chunk_size; + u64 stripe_size; + u64 num_bytes; + int ndevs; + int i; + int j; + + BUG_ON(!alloc_profile_is_valid(type, 0)); + + if (list_empty(&fs_devices->alloc_list)) + return -ENOSPC; + + sub_stripes = 1; + dev_stripes = 1; + devs_increment = 1; + ncopies = 1; + devs_max = 0; /* 0 == as many as possible */ + devs_min = 1; + + /* + * define the properties of each RAID type. + * FIXME: move this to a global table and use it in all RAID + * calculation code + */ + if (type & (BTRFS_BLOCK_GROUP_DUP)) { + dev_stripes = 2; + ncopies = 2; + devs_max = 1; + } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) { + devs_min = 2; + } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) { + devs_increment = 2; + ncopies = 2; + devs_max = 2; + devs_min = 2; + } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) { + sub_stripes = 2; + devs_increment = 2; + ncopies = 2; + devs_min = 4; + } else { + devs_max = 1; + } + + if (type & BTRFS_BLOCK_GROUP_DATA) { + max_stripe_size = 1024 * 1024 * 1024; + max_chunk_size = 10 * max_stripe_size; + } else if (type & BTRFS_BLOCK_GROUP_METADATA) { + /* for larger filesystems, use larger metadata chunks */ + if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024) + max_stripe_size = 1024 * 1024 * 1024; + else + max_stripe_size = 256 * 1024 * 1024; + max_chunk_size = max_stripe_size; + } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) { + max_stripe_size = 32 * 1024 * 1024; + max_chunk_size = 2 * max_stripe_size; + } else { + printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n", + type); + BUG_ON(1); + } + + /* we don't want a chunk larger than 10% of writeable space */ + max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1), + max_chunk_size); + + devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices, + GFP_NOFS); + if (!devices_info) + return -ENOMEM; + + cur = fs_devices->alloc_list.next; + + /* + * in the first pass through the devices list, we gather information + * about the available holes on each device. + */ + ndevs = 0; + while (cur != &fs_devices->alloc_list) { + struct btrfs_device *device; + u64 max_avail; + u64 dev_offset; + + device = list_entry(cur, struct btrfs_device, dev_alloc_list); + + cur = cur->next; + + if (!device->writeable) { + printk(KERN_ERR + "btrfs: read-only device in alloc_list\n"); + WARN_ON(1); + continue; + } + + if (!device->in_fs_metadata) + continue; + + if (device->total_bytes > device->bytes_used) + total_avail = device->total_bytes - device->bytes_used; + else + total_avail = 0; + + /* If there is no space on this device, skip it. */ + if (total_avail == 0) + continue; + + ret = find_free_dev_extent(device, + max_stripe_size * dev_stripes, + &dev_offset, &max_avail); + if (ret && ret != -ENOSPC) + goto error; + + if (ret == 0) + max_avail = max_stripe_size * dev_stripes; + + if (max_avail < BTRFS_STRIPE_LEN * dev_stripes) + continue; + + devices_info[ndevs].dev_offset = dev_offset; + devices_info[ndevs].max_avail = max_avail; + devices_info[ndevs].total_avail = total_avail; + devices_info[ndevs].dev = device; + ++ndevs; + } + + /* + * now sort the devices by hole size / available space + */ + sort(devices_info, ndevs, sizeof(struct btrfs_device_info), + btrfs_cmp_device_info, NULL); + + /* round down to number of usable stripes */ + ndevs -= ndevs % devs_increment; + + if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) { + ret = -ENOSPC; + goto error; + } + + if (devs_max && ndevs > devs_max) + ndevs = devs_max; + /* + * the primary goal is to maximize the number of stripes, so use as many + * devices as possible, even if the stripes are not maximum sized. + */ + stripe_size = devices_info[ndevs-1].max_avail; + num_stripes = ndevs * dev_stripes; + + if (stripe_size * ndevs > max_chunk_size * ncopies) { + stripe_size = max_chunk_size * ncopies; + do_div(stripe_size, ndevs); + } + + do_div(stripe_size, dev_stripes); + + /* align to BTRFS_STRIPE_LEN */ + do_div(stripe_size, BTRFS_STRIPE_LEN); + stripe_size *= BTRFS_STRIPE_LEN; + + map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS); + if (!map) { + ret = -ENOMEM; + goto error; + } + map->num_stripes = num_stripes; + + for (i = 0; i < ndevs; ++i) { + for (j = 0; j < dev_stripes; ++j) { + int s = i * dev_stripes + j; + map->stripes[s].dev = devices_info[i].dev; + map->stripes[s].physical = devices_info[i].dev_offset + + j * stripe_size; + } + } + map->sector_size = extent_root->sectorsize; + map->stripe_len = BTRFS_STRIPE_LEN; + map->io_align = BTRFS_STRIPE_LEN; + map->io_width = BTRFS_STRIPE_LEN; + map->type = type; + map->sub_stripes = sub_stripes; + + *map_ret = map; + num_bytes = stripe_size * (num_stripes / ncopies); + + *stripe_size_out = stripe_size; + *num_bytes_out = num_bytes; + + trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes); + + em = alloc_extent_map(); + if (!em) { + ret = -ENOMEM; + goto error; + } + em->bdev = (struct block_device *)map; + em->start = start; + em->len = num_bytes; + em->block_start = 0; + em->block_len = em->len; + + em_tree = &extent_root->fs_info->mapping_tree.map_tree; + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em); + write_unlock(&em_tree->lock); + free_extent_map(em); + if (ret) + goto error; + + ret = btrfs_make_block_group(trans, extent_root, 0, type, + BTRFS_FIRST_CHUNK_TREE_OBJECTID, + start, num_bytes); + if (ret) + goto error; + + for (i = 0; i < map->num_stripes; ++i) { + struct btrfs_device *device; + u64 dev_offset; + + device = map->stripes[i].dev; + dev_offset = map->stripes[i].physical; + + ret = btrfs_alloc_dev_extent(trans, device, + info->chunk_root->root_key.objectid, + BTRFS_FIRST_CHUNK_TREE_OBJECTID, + start, dev_offset, stripe_size); + if (ret) { + btrfs_abort_transaction(trans, extent_root, ret); + goto error; + } + } + + kfree(devices_info); + return 0; + +error: + kfree(map); + kfree(devices_info); + return ret; +} + +static int __finish_chunk_alloc(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct map_lookup *map, u64 chunk_offset, + u64 chunk_size, u64 stripe_size) +{ + u64 dev_offset; + struct btrfs_key key; + struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; + struct btrfs_device *device; + struct btrfs_chunk *chunk; + struct btrfs_stripe *stripe; + size_t item_size = btrfs_chunk_item_size(map->num_stripes); + int index = 0; + int ret; + + chunk = kzalloc(item_size, GFP_NOFS); + if (!chunk) + return -ENOMEM; + + index = 0; + while (index < map->num_stripes) { + device = map->stripes[index].dev; + device->bytes_used += stripe_size; + ret = btrfs_update_device(trans, device); + if (ret) + goto out_free; + index++; + } + + spin_lock(&extent_root->fs_info->free_chunk_lock); + extent_root->fs_info->free_chunk_space -= (stripe_size * + map->num_stripes); + spin_unlock(&extent_root->fs_info->free_chunk_lock); + + index = 0; + stripe = &chunk->stripe; + while (index < map->num_stripes) { + device = map->stripes[index].dev; + dev_offset = map->stripes[index].physical; + + btrfs_set_stack_stripe_devid(stripe, device->devid); + btrfs_set_stack_stripe_offset(stripe, dev_offset); + memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE); + stripe++; + index++; + } + + btrfs_set_stack_chunk_length(chunk, chunk_size); + btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid); + btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len); + btrfs_set_stack_chunk_type(chunk, map->type); + btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes); + btrfs_set_stack_chunk_io_align(chunk, map->stripe_len); + btrfs_set_stack_chunk_io_width(chunk, map->stripe_len); + btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize); + btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes); + + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.type = BTRFS_CHUNK_ITEM_KEY; + key.offset = chunk_offset; + + ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size); + + if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) { + /* + * TODO: Cleanup of inserted chunk root in case of + * failure. + */ + ret = btrfs_add_system_chunk(chunk_root, &key, chunk, + item_size); + } + +out_free: + kfree(chunk); + return ret; +} + +/* + * Chunk allocation falls into two parts. The first part does works + * that make the new allocated chunk useable, but not do any operation + * that modifies the chunk tree. The second part does the works that + * require modifying the chunk tree. This division is important for the + * bootstrap process of adding storage to a seed btrfs. + */ +int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, u64 type) +{ + u64 chunk_offset; + u64 chunk_size; + u64 stripe_size; + struct map_lookup *map; + struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; + int ret; + + ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID, + &chunk_offset); + if (ret) + return ret; + + ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size, + &stripe_size, chunk_offset, type); + if (ret) + return ret; + + ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset, + chunk_size, stripe_size); + if (ret) + return ret; + return 0; +} + +static noinline int init_first_rw_device(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_device *device) +{ + u64 chunk_offset; + u64 sys_chunk_offset; + u64 chunk_size; + u64 sys_chunk_size; + u64 stripe_size; + u64 sys_stripe_size; + u64 alloc_profile; + struct map_lookup *map; + struct map_lookup *sys_map; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_root *extent_root = fs_info->extent_root; + int ret; + + ret = find_next_chunk(fs_info->chunk_root, + BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset); + if (ret) + return ret; + + alloc_profile = BTRFS_BLOCK_GROUP_METADATA | + fs_info->avail_metadata_alloc_bits; + alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile); + + ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size, + &stripe_size, chunk_offset, alloc_profile); + if (ret) + return ret; + + sys_chunk_offset = chunk_offset + chunk_size; + + alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM | + fs_info->avail_system_alloc_bits; + alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile); + + ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map, + &sys_chunk_size, &sys_stripe_size, + sys_chunk_offset, alloc_profile); + if (ret) + goto abort; + + ret = btrfs_add_device(trans, fs_info->chunk_root, device); + if (ret) + goto abort; + + /* + * Modifying chunk tree needs allocating new blocks from both + * system block group and metadata block group. So we only can + * do operations require modifying the chunk tree after both + * block groups were created. + */ + ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset, + chunk_size, stripe_size); + if (ret) + goto abort; + + ret = __finish_chunk_alloc(trans, extent_root, sys_map, + sys_chunk_offset, sys_chunk_size, + sys_stripe_size); + if (ret) + goto abort; + + return 0; + +abort: + btrfs_abort_transaction(trans, root, ret); + return ret; +} + +int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset) +{ + struct extent_map *em; + struct map_lookup *map; + struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; + int readonly = 0; + int i; + + read_lock(&map_tree->map_tree.lock); + em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); + read_unlock(&map_tree->map_tree.lock); + if (!em) + return 1; + + if (btrfs_test_opt(root, DEGRADED)) { + free_extent_map(em); + return 0; + } + + map = (struct map_lookup *)em->bdev; + for (i = 0; i < map->num_stripes; i++) { + if (!map->stripes[i].dev->writeable) { + readonly = 1; + break; + } + } + free_extent_map(em); + return readonly; +} + +void btrfs_mapping_init(struct btrfs_mapping_tree *tree) +{ + extent_map_tree_init(&tree->map_tree); +} + +void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree) +{ + struct extent_map *em; + + while (1) { + write_lock(&tree->map_tree.lock); + em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1); + if (em) + remove_extent_mapping(&tree->map_tree, em); + write_unlock(&tree->map_tree.lock); + if (!em) + break; + kfree(em->bdev); + /* once for us */ + free_extent_map(em); + /* once for the tree */ + free_extent_map(em); + } +} + +int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len) +{ + struct extent_map *em; + struct map_lookup *map; + struct extent_map_tree *em_tree = &map_tree->map_tree; + int ret; + + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, logical, len); + read_unlock(&em_tree->lock); + BUG_ON(!em); + + BUG_ON(em->start > logical || em->start + em->len < logical); + map = (struct map_lookup *)em->bdev; + if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1)) + ret = map->num_stripes; + else if (map->type & BTRFS_BLOCK_GROUP_RAID10) + ret = map->sub_stripes; + else + ret = 1; + free_extent_map(em); + return ret; +} + +static int find_live_mirror(struct map_lookup *map, int first, int num, + int optimal) +{ + int i; + if (map->stripes[optimal].dev->bdev) + return optimal; + for (i = first; i < first + num; i++) { + if (map->stripes[i].dev->bdev) + return i; + } + /* we couldn't find one that doesn't fail. Just return something + * and the io error handling code will clean up eventually + */ + return optimal; +} + +static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, + u64 logical, u64 *length, + struct btrfs_bio **bbio_ret, + int mirror_num) +{ + struct extent_map *em; + struct map_lookup *map; + struct extent_map_tree *em_tree = &map_tree->map_tree; + u64 offset; + u64 stripe_offset; + u64 stripe_end_offset; + u64 stripe_nr; + u64 stripe_nr_orig; + u64 stripe_nr_end; + int stripe_index; + int i; + int ret = 0; + int num_stripes; + int max_errors = 0; + struct btrfs_bio *bbio = NULL; + + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, logical, *length); + read_unlock(&em_tree->lock); + + if (!em) { + printk(KERN_CRIT "unable to find logical %llu len %llu\n", + (unsigned long long)logical, + (unsigned long long)*length); + BUG(); + } + + BUG_ON(em->start > logical || em->start + em->len < logical); + map = (struct map_lookup *)em->bdev; + offset = logical - em->start; + + if (mirror_num > map->num_stripes) + mirror_num = 0; + + stripe_nr = offset; + /* + * stripe_nr counts the total number of stripes we have to stride + * to get to this block + */ + do_div(stripe_nr, map->stripe_len); + + stripe_offset = stripe_nr * map->stripe_len; + BUG_ON(offset < stripe_offset); + + /* stripe_offset is the offset of this block in its stripe*/ + stripe_offset = offset - stripe_offset; + + if (rw & REQ_DISCARD) + *length = min_t(u64, em->len - offset, *length); + else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) { + /* we limit the length of each bio to what fits in a stripe */ + *length = min_t(u64, em->len - offset, + map->stripe_len - stripe_offset); + } else { + *length = em->len - offset; + } + + if (!bbio_ret) + goto out; + + num_stripes = 1; + stripe_index = 0; + stripe_nr_orig = stripe_nr; + stripe_nr_end = (offset + *length + map->stripe_len - 1) & + (~(map->stripe_len - 1)); + do_div(stripe_nr_end, map->stripe_len); + stripe_end_offset = stripe_nr_end * map->stripe_len - + (offset + *length); + if (map->type & BTRFS_BLOCK_GROUP_RAID0) { + if (rw & REQ_DISCARD) + num_stripes = min_t(u64, map->num_stripes, + stripe_nr_end - stripe_nr_orig); + stripe_index = do_div(stripe_nr, map->num_stripes); + } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) { + if (rw & (REQ_WRITE | REQ_DISCARD)) + num_stripes = map->num_stripes; + else if (mirror_num) + stripe_index = mirror_num - 1; + else { + stripe_index = find_live_mirror(map, 0, + map->num_stripes, + current->pid % map->num_stripes); + mirror_num = stripe_index + 1; + } + + } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { + if (rw & (REQ_WRITE | REQ_DISCARD)) { + num_stripes = map->num_stripes; + } else if (mirror_num) { + stripe_index = mirror_num - 1; + } else { + mirror_num = 1; + } + + } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { + int factor = map->num_stripes / map->sub_stripes; + + stripe_index = do_div(stripe_nr, factor); + stripe_index *= map->sub_stripes; + + if (rw & REQ_WRITE) + num_stripes = map->sub_stripes; + else if (rw & REQ_DISCARD) + num_stripes = min_t(u64, map->sub_stripes * + (stripe_nr_end - stripe_nr_orig), + map->num_stripes); + else if (mirror_num) + stripe_index += mirror_num - 1; + else { + int old_stripe_index = stripe_index; + stripe_index = find_live_mirror(map, stripe_index, + map->sub_stripes, stripe_index + + current->pid % map->sub_stripes); + mirror_num = stripe_index - old_stripe_index + 1; + } + } else { + /* + * after this do_div call, stripe_nr is the number of stripes + * on this device we have to walk to find the data, and + * stripe_index is the number of our device in the stripe array + */ + stripe_index = do_div(stripe_nr, map->num_stripes); + mirror_num = stripe_index + 1; + } + BUG_ON(stripe_index >= map->num_stripes); + + bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS); + if (!bbio) { + ret = -ENOMEM; + goto out; + } + atomic_set(&bbio->error, 0); + + if (rw & REQ_DISCARD) { + int factor = 0; + int sub_stripes = 0; + u64 stripes_per_dev = 0; + u32 remaining_stripes = 0; + u32 last_stripe = 0; + + if (map->type & + (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) { + if (map->type & BTRFS_BLOCK_GROUP_RAID0) + sub_stripes = 1; + else + sub_stripes = map->sub_stripes; + + factor = map->num_stripes / sub_stripes; + stripes_per_dev = div_u64_rem(stripe_nr_end - + stripe_nr_orig, + factor, + &remaining_stripes); + div_u64_rem(stripe_nr_end - 1, factor, &last_stripe); + last_stripe *= sub_stripes; + } + + for (i = 0; i < num_stripes; i++) { + bbio->stripes[i].physical = + map->stripes[stripe_index].physical + + stripe_offset + stripe_nr * map->stripe_len; + bbio->stripes[i].dev = map->stripes[stripe_index].dev; + + if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)) { + bbio->stripes[i].length = stripes_per_dev * + map->stripe_len; + + if (i / sub_stripes < remaining_stripes) + bbio->stripes[i].length += + map->stripe_len; + + /* + * Special for the first stripe and + * the last stripe: + * + * |-------|...|-------| + * |----------| + * off end_off + */ + if (i < sub_stripes) + bbio->stripes[i].length -= + stripe_offset; + + if (stripe_index >= last_stripe && + stripe_index <= (last_stripe + + sub_stripes - 1)) + bbio->stripes[i].length -= + stripe_end_offset; + + if (i == sub_stripes - 1) + stripe_offset = 0; + } else + bbio->stripes[i].length = *length; + + stripe_index++; + if (stripe_index == map->num_stripes) { + /* This could only happen for RAID0/10 */ + stripe_index = 0; + stripe_nr++; + } + } + } else { + for (i = 0; i < num_stripes; i++) { + bbio->stripes[i].physical = + map->stripes[stripe_index].physical + + stripe_offset + + stripe_nr * map->stripe_len; + bbio->stripes[i].dev = + map->stripes[stripe_index].dev; + stripe_index++; + } + } + + if (rw & REQ_WRITE) { + if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_DUP)) { + max_errors = 1; + } + } + + *bbio_ret = bbio; + bbio->num_stripes = num_stripes; + bbio->max_errors = max_errors; + bbio->mirror_num = mirror_num; +out: + free_extent_map(em); + return ret; +} + +int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, + u64 logical, u64 *length, + struct btrfs_bio **bbio_ret, int mirror_num) +{ + return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret, + mirror_num); +} + +int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree, + u64 chunk_start, u64 physical, u64 devid, + u64 **logical, int *naddrs, int *stripe_len) +{ + struct extent_map_tree *em_tree = &map_tree->map_tree; + struct extent_map *em; + struct map_lookup *map; + u64 *buf; + u64 bytenr; + u64 length; + u64 stripe_nr; + int i, j, nr = 0; + + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, chunk_start, 1); + read_unlock(&em_tree->lock); + + BUG_ON(!em || em->start != chunk_start); + map = (struct map_lookup *)em->bdev; + + length = em->len; + if (map->type & BTRFS_BLOCK_GROUP_RAID10) + do_div(length, map->num_stripes / map->sub_stripes); + else if (map->type & BTRFS_BLOCK_GROUP_RAID0) + do_div(length, map->num_stripes); + + buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS); + BUG_ON(!buf); /* -ENOMEM */ + + for (i = 0; i < map->num_stripes; i++) { + if (devid && map->stripes[i].dev->devid != devid) + continue; + if (map->stripes[i].physical > physical || + map->stripes[i].physical + length <= physical) + continue; + + stripe_nr = physical - map->stripes[i].physical; + do_div(stripe_nr, map->stripe_len); + + if (map->type & BTRFS_BLOCK_GROUP_RAID10) { + stripe_nr = stripe_nr * map->num_stripes + i; + do_div(stripe_nr, map->sub_stripes); + } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) { + stripe_nr = stripe_nr * map->num_stripes + i; + } + bytenr = chunk_start + stripe_nr * map->stripe_len; + WARN_ON(nr >= map->num_stripes); + for (j = 0; j < nr; j++) { + if (buf[j] == bytenr) + break; + } + if (j == nr) { + WARN_ON(nr >= map->num_stripes); + buf[nr++] = bytenr; + } + } + + *logical = buf; + *naddrs = nr; + *stripe_len = map->stripe_len; + + free_extent_map(em); + return 0; +} + +static void btrfs_end_bio(struct bio *bio, int err) +{ + struct btrfs_bio *bbio = bio->bi_private; + int is_orig_bio = 0; + + if (err) + atomic_inc(&bbio->error); + + if (bio == bbio->orig_bio) + is_orig_bio = 1; + + if (atomic_dec_and_test(&bbio->stripes_pending)) { + if (!is_orig_bio) { + bio_put(bio); + bio = bbio->orig_bio; + } + bio->bi_private = bbio->private; + bio->bi_end_io = bbio->end_io; + bio->bi_bdev = (struct block_device *) + (unsigned long)bbio->mirror_num; + /* only send an error to the higher layers if it is + * beyond the tolerance of the multi-bio + */ + if (atomic_read(&bbio->error) > bbio->max_errors) { + err = -EIO; + } else { + /* + * this bio is actually up to date, we didn't + * go over the max number of errors + */ + set_bit(BIO_UPTODATE, &bio->bi_flags); + err = 0; + } + kfree(bbio); + + bio_endio(bio, err); + } else if (!is_orig_bio) { + bio_put(bio); + } +} + +struct async_sched { + struct bio *bio; + int rw; + struct btrfs_fs_info *info; + struct btrfs_work work; +}; + +/* + * see run_scheduled_bios for a description of why bios are collected for + * async submit. + * + * This will add one bio to the pending list for a device and make sure + * the work struct is scheduled. + */ +static noinline void schedule_bio(struct btrfs_root *root, + struct btrfs_device *device, + int rw, struct bio *bio) +{ + int should_queue = 1; + struct btrfs_pending_bios *pending_bios; + + /* don't bother with additional async steps for reads, right now */ + if (!(rw & REQ_WRITE)) { + bio_get(bio); + btrfsic_submit_bio(rw, bio); + bio_put(bio); + return; + } + + /* + * nr_async_bios allows us to reliably return congestion to the + * higher layers. Otherwise, the async bio makes it appear we have + * made progress against dirty pages when we've really just put it + * on a queue for later + */ + atomic_inc(&root->fs_info->nr_async_bios); + WARN_ON(bio->bi_next); + bio->bi_next = NULL; + bio->bi_rw |= rw; + + spin_lock(&device->io_lock); + if (bio->bi_rw & REQ_SYNC) + pending_bios = &device->pending_sync_bios; + else + pending_bios = &device->pending_bios; + + if (pending_bios->tail) + pending_bios->tail->bi_next = bio; + + pending_bios->tail = bio; + if (!pending_bios->head) + pending_bios->head = bio; + if (device->running_pending) + should_queue = 0; + + spin_unlock(&device->io_lock); + + if (should_queue) + btrfs_queue_worker(&root->fs_info->submit_workers, + &device->work); +} + +int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio, + int mirror_num, int async_submit) +{ + struct btrfs_mapping_tree *map_tree; + struct btrfs_device *dev; + struct bio *first_bio = bio; + u64 logical = (u64)bio->bi_sector << 9; + u64 length = 0; + u64 map_length; + int ret; + int dev_nr = 0; + int total_devs = 1; + struct btrfs_bio *bbio = NULL; + + length = bio->bi_size; + map_tree = &root->fs_info->mapping_tree; + map_length = length; + + ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio, + mirror_num); + if (ret) /* -ENOMEM */ + return ret; + + total_devs = bbio->num_stripes; + if (map_length < length) { + printk(KERN_CRIT "mapping failed logical %llu bio len %llu " + "len %llu\n", (unsigned long long)logical, + (unsigned long long)length, + (unsigned long long)map_length); + BUG(); + } + + bbio->orig_bio = first_bio; + bbio->private = first_bio->bi_private; + bbio->end_io = first_bio->bi_end_io; + atomic_set(&bbio->stripes_pending, bbio->num_stripes); + + while (dev_nr < total_devs) { + if (dev_nr < total_devs - 1) { + bio = bio_clone(first_bio, GFP_NOFS); + BUG_ON(!bio); /* -ENOMEM */ + } else { + bio = first_bio; + } + bio->bi_private = bbio; + bio->bi_end_io = btrfs_end_bio; + bio->bi_sector = bbio->stripes[dev_nr].physical >> 9; + dev = bbio->stripes[dev_nr].dev; + if (dev && dev->bdev && (rw != WRITE || dev->writeable)) { + pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu " + "(%s id %llu), size=%u\n", rw, + (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev, + dev->name, dev->devid, bio->bi_size); + bio->bi_bdev = dev->bdev; + if (async_submit) + schedule_bio(root, dev, rw, bio); + else + btrfsic_submit_bio(rw, bio); + } else { + bio->bi_bdev = root->fs_info->fs_devices->latest_bdev; + bio->bi_sector = logical >> 9; + bio_endio(bio, -EIO); + } + dev_nr++; + } + return 0; +} + +struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid, + u8 *uuid, u8 *fsid) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *cur_devices; + + cur_devices = root->fs_info->fs_devices; + while (cur_devices) { + if (!fsid || + !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) { + device = __find_device(&cur_devices->devices, + devid, uuid); + if (device) + return device; + } + cur_devices = cur_devices->seed; + } + return NULL; +} + +static struct btrfs_device *add_missing_dev(struct btrfs_root *root, + u64 devid, u8 *dev_uuid) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; + + device = kzalloc(sizeof(*device), GFP_NOFS); + if (!device) + return NULL; + list_add(&device->dev_list, + &fs_devices->devices); + device->dev_root = root->fs_info->dev_root; + device->devid = devid; + device->work.func = pending_bios_fn; + device->fs_devices = fs_devices; + device->missing = 1; + fs_devices->num_devices++; + fs_devices->missing_devices++; + spin_lock_init(&device->io_lock); + INIT_LIST_HEAD(&device->dev_alloc_list); + memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE); + return device; +} + +static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key, + struct extent_buffer *leaf, + struct btrfs_chunk *chunk) +{ + struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; + struct map_lookup *map; + struct extent_map *em; + u64 logical; + u64 length; + u64 devid; + u8 uuid[BTRFS_UUID_SIZE]; + int num_stripes; + int ret; + int i; + + logical = key->offset; + length = btrfs_chunk_length(leaf, chunk); + + read_lock(&map_tree->map_tree.lock); + em = lookup_extent_mapping(&map_tree->map_tree, logical, 1); + read_unlock(&map_tree->map_tree.lock); + + /* already mapped? */ + if (em && em->start <= logical && em->start + em->len > logical) { + free_extent_map(em); + return 0; + } else if (em) { + free_extent_map(em); + } + + em = alloc_extent_map(); + if (!em) + return -ENOMEM; + num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS); + if (!map) { + free_extent_map(em); + return -ENOMEM; + } + + em->bdev = (struct block_device *)map; + em->start = logical; + em->len = length; + em->block_start = 0; + em->block_len = em->len; + + map->num_stripes = num_stripes; + map->io_width = btrfs_chunk_io_width(leaf, chunk); + map->io_align = btrfs_chunk_io_align(leaf, chunk); + map->sector_size = btrfs_chunk_sector_size(leaf, chunk); + map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk); + map->type = btrfs_chunk_type(leaf, chunk); + map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk); + for (i = 0; i < num_stripes; i++) { + map->stripes[i].physical = + btrfs_stripe_offset_nr(leaf, chunk, i); + devid = btrfs_stripe_devid_nr(leaf, chunk, i); + read_extent_buffer(leaf, uuid, (unsigned long) + btrfs_stripe_dev_uuid_nr(chunk, i), + BTRFS_UUID_SIZE); + map->stripes[i].dev = btrfs_find_device(root, devid, uuid, + NULL); + if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) { + kfree(map); + free_extent_map(em); + return -EIO; + } + if (!map->stripes[i].dev) { + map->stripes[i].dev = + add_missing_dev(root, devid, uuid); + if (!map->stripes[i].dev) { + kfree(map); + free_extent_map(em); + return -EIO; + } + } + map->stripes[i].dev->in_fs_metadata = 1; + } + + write_lock(&map_tree->map_tree.lock); + ret = add_extent_mapping(&map_tree->map_tree, em); + write_unlock(&map_tree->map_tree.lock); + BUG_ON(ret); /* Tree corruption */ + free_extent_map(em); + + return 0; +} + +static void fill_device_from_item(struct extent_buffer *leaf, + struct btrfs_dev_item *dev_item, + struct btrfs_device *device) +{ + unsigned long ptr; + + device->devid = btrfs_device_id(leaf, dev_item); + device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item); + device->total_bytes = device->disk_total_bytes; + device->bytes_used = btrfs_device_bytes_used(leaf, dev_item); + device->type = btrfs_device_type(leaf, dev_item); + device->io_align = btrfs_device_io_align(leaf, dev_item); + device->io_width = btrfs_device_io_width(leaf, dev_item); + device->sector_size = btrfs_device_sector_size(leaf, dev_item); + + ptr = (unsigned long)btrfs_device_uuid(dev_item); + read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); +} + +static int open_seed_devices(struct btrfs_root *root, u8 *fsid) +{ + struct btrfs_fs_devices *fs_devices; + int ret; + + BUG_ON(!mutex_is_locked(&uuid_mutex)); + + fs_devices = root->fs_info->fs_devices->seed; + while (fs_devices) { + if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) { + ret = 0; + goto out; + } + fs_devices = fs_devices->seed; + } + + fs_devices = find_fsid(fsid); + if (!fs_devices) { + ret = -ENOENT; + goto out; + } + + fs_devices = clone_fs_devices(fs_devices); + if (IS_ERR(fs_devices)) { + ret = PTR_ERR(fs_devices); + goto out; + } + + ret = __btrfs_open_devices(fs_devices, FMODE_READ, + root->fs_info->bdev_holder); + if (ret) { + free_fs_devices(fs_devices); + goto out; + } + + if (!fs_devices->seeding) { + __btrfs_close_devices(fs_devices); + free_fs_devices(fs_devices); + ret = -EINVAL; + goto out; + } + + fs_devices->seed = root->fs_info->fs_devices->seed; + root->fs_info->fs_devices->seed = fs_devices; +out: + return ret; +} + +static int read_one_dev(struct btrfs_root *root, + struct extent_buffer *leaf, + struct btrfs_dev_item *dev_item) +{ + struct btrfs_device *device; + u64 devid; + int ret; + u8 fs_uuid[BTRFS_UUID_SIZE]; + u8 dev_uuid[BTRFS_UUID_SIZE]; + + devid = btrfs_device_id(leaf, dev_item); + read_extent_buffer(leaf, dev_uuid, + (unsigned long)btrfs_device_uuid(dev_item), + BTRFS_UUID_SIZE); + read_extent_buffer(leaf, fs_uuid, + (unsigned long)btrfs_device_fsid(dev_item), + BTRFS_UUID_SIZE); + + if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) { + ret = open_seed_devices(root, fs_uuid); + if (ret && !btrfs_test_opt(root, DEGRADED)) + return ret; + } + + device = btrfs_find_device(root, devid, dev_uuid, fs_uuid); + if (!device || !device->bdev) { + if (!btrfs_test_opt(root, DEGRADED)) + return -EIO; + + if (!device) { + printk(KERN_WARNING "warning devid %llu missing\n", + (unsigned long long)devid); + device = add_missing_dev(root, devid, dev_uuid); + if (!device) + return -ENOMEM; + } else if (!device->missing) { + /* + * this happens when a device that was properly setup + * in the device info lists suddenly goes bad. + * device->bdev is NULL, and so we have to set + * device->missing to one here + */ + root->fs_info->fs_devices->missing_devices++; + device->missing = 1; + } + } + + if (device->fs_devices != root->fs_info->fs_devices) { + BUG_ON(device->writeable); + if (device->generation != + btrfs_device_generation(leaf, dev_item)) + return -EINVAL; + } + + fill_device_from_item(leaf, dev_item, device); + device->dev_root = root->fs_info->dev_root; + device->in_fs_metadata = 1; + if (device->writeable) { + device->fs_devices->total_rw_bytes += device->total_bytes; + spin_lock(&root->fs_info->free_chunk_lock); + root->fs_info->free_chunk_space += device->total_bytes - + device->bytes_used; + spin_unlock(&root->fs_info->free_chunk_lock); + } + ret = 0; + return ret; +} + +int btrfs_read_sys_array(struct btrfs_root *root) +{ + struct btrfs_super_block *super_copy = root->fs_info->super_copy; + struct extent_buffer *sb; + struct btrfs_disk_key *disk_key; + struct btrfs_chunk *chunk; + u8 *ptr; + unsigned long sb_ptr; + int ret = 0; + u32 num_stripes; + u32 array_size; + u32 len = 0; + u32 cur; + struct btrfs_key key; + + sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET, + BTRFS_SUPER_INFO_SIZE); + if (!sb) + return -ENOMEM; + btrfs_set_buffer_uptodate(sb); + btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0); + /* + * The sb extent buffer is artifical and just used to read the system array. + * btrfs_set_buffer_uptodate() call does not properly mark all it's + * pages up-to-date when the page is larger: extent does not cover the + * whole page and consequently check_page_uptodate does not find all + * the page's extents up-to-date (the hole beyond sb), + * write_extent_buffer then triggers a WARN_ON. + * + * Regular short extents go through mark_extent_buffer_dirty/writeback cycle, + * but sb spans only this function. Add an explicit SetPageUptodate call + * to silence the warning eg. on PowerPC 64. + */ + if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE) + SetPageUptodate(sb->pages[0]); + + write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE); + array_size = btrfs_super_sys_array_size(super_copy); + + ptr = super_copy->sys_chunk_array; + sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array); + cur = 0; + + while (cur < array_size) { + disk_key = (struct btrfs_disk_key *)ptr; + btrfs_disk_key_to_cpu(&key, disk_key); + + len = sizeof(*disk_key); ptr += len; + sb_ptr += len; + cur += len; + + if (key.type == BTRFS_CHUNK_ITEM_KEY) { + chunk = (struct btrfs_chunk *)sb_ptr; + ret = read_one_chunk(root, &key, sb, chunk); + if (ret) + break; + num_stripes = btrfs_chunk_num_stripes(sb, chunk); + len = btrfs_chunk_item_size(num_stripes); + } else { + ret = -EIO; + break; + } + ptr += len; + sb_ptr += len; + cur += len; + } + free_extent_buffer(sb); + return ret; +} + +int btrfs_read_chunk_tree(struct btrfs_root *root) +{ + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key key; + struct btrfs_key found_key; + int ret; + int slot; + + root = root->fs_info->chunk_root; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + mutex_lock(&uuid_mutex); + lock_chunks(root); + + /* first we search for all of the device items, and then we + * read in all of the chunk items. This way we can create chunk + * mappings that reference all of the devices that are afound + */ + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.offset = 0; + key.type = 0; +again: + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto error; + while (1) { + leaf = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret == 0) + continue; + if (ret < 0) + goto error; + break; + } + btrfs_item_key_to_cpu(leaf, &found_key, slot); + if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { + if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID) + break; + if (found_key.type == BTRFS_DEV_ITEM_KEY) { + struct btrfs_dev_item *dev_item; + dev_item = btrfs_item_ptr(leaf, slot, + struct btrfs_dev_item); + ret = read_one_dev(root, leaf, dev_item); + if (ret) + goto error; + } + } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) { + struct btrfs_chunk *chunk; + chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); + ret = read_one_chunk(root, &found_key, leaf, chunk); + if (ret) + goto error; + } + path->slots[0]++; + } + if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { + key.objectid = 0; + btrfs_release_path(path); + goto again; + } + ret = 0; +error: + unlock_chunks(root); + mutex_unlock(&uuid_mutex); + + btrfs_free_path(path); + return ret; +} |