diff options
Diffstat (limited to 'fs/btrfs/volumes.c')
| -rw-r--r-- | fs/btrfs/volumes.c | 3117 |
1 files changed, 3117 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c new file mode 100644 index 00000000000..ecf0633ab8c --- /dev/null +++ b/fs/btrfs/volumes.c @@ -0,0 +1,3117 @@ +/* + * 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/buffer_head.h> +#include <linux/blkdev.h> +#include <linux/random.h> +#include <asm/div64.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" + +struct map_lookup { + u64 type; + int io_align; + int io_width; + int stripe_len; + int sector_size; + int num_stripes; + int sub_stripes; + struct btrfs_bio_stripe stripes[]; +}; + +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); + + +#define map_lookup_size(n) (sizeof(struct map_lookup) + \ + (sizeof(struct btrfs_bio_stripe) * (n))) + +static DEFINE_MUTEX(uuid_mutex); +static LIST_HEAD(fs_uuids); + +void btrfs_lock_volumes(void) +{ + mutex_lock(&uuid_mutex); +} + +void btrfs_unlock_volumes(void) +{ + mutex_unlock(&uuid_mutex); +} + +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); +} + +int btrfs_cleanup_fs_uuids(void) +{ + struct btrfs_fs_devices *fs_devices; + struct btrfs_device *dev; + + while (!list_empty(&fs_uuids)) { + fs_devices = list_entry(fs_uuids.next, + struct btrfs_fs_devices, list); + list_del(&fs_devices->list); + while(!list_empty(&fs_devices->devices)) { + dev = list_entry(fs_devices->devices.next, + struct btrfs_device, dev_list); + if (dev->bdev) { + close_bdev_excl(dev->bdev); + fs_devices->open_devices--; + } + fs_devices->num_devices--; + if (dev->writeable) + fs_devices->rw_devices--; + list_del(&dev->dev_list); + list_del(&dev->dev_alloc_list); + kfree(dev->name); + kfree(dev); + } + WARN_ON(fs_devices->num_devices); + WARN_ON(fs_devices->open_devices); + WARN_ON(fs_devices->rw_devices); + kfree(fs_devices); + } + return 0; +} + +static noinline struct btrfs_device *__find_device(struct list_head *head, + u64 devid, u8 *uuid) +{ + struct btrfs_device *dev; + struct list_head *cur; + + list_for_each(cur, head) { + dev = list_entry(cur, struct btrfs_device, 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 list_head *cur; + struct btrfs_fs_devices *fs_devices; + + list_for_each(cur, &fs_uuids) { + fs_devices = list_entry(cur, struct btrfs_fs_devices, list); + if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0) + return fs_devices; + } + return NULL; +} + +/* + * 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 int noinline run_scheduled_bios(struct btrfs_device *device) +{ + struct bio *pending; + struct backing_dev_info *bdi; + struct btrfs_fs_info *fs_info; + struct bio *tail; + struct bio *cur; + int again = 0; + unsigned long num_run = 0; + unsigned long limit; + + bdi = device->bdev->bd_inode->i_mapping->backing_dev_info; + fs_info = device->dev_root->fs_info; + limit = btrfs_async_submit_limit(fs_info); + limit = limit * 2 / 3; + +loop: + spin_lock(&device->io_lock); + + /* 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 + */ + pending = device->pending_bios; + tail = device->pending_bio_tail; + WARN_ON(pending && !tail); + device->pending_bios = NULL; + device->pending_bio_tail = NULL; + + /* + * 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 (pending) { + again = 1; + device->running_pending = 1; + } else { + again = 0; + device->running_pending = 0; + } + spin_unlock(&device->io_lock); + + while(pending) { + 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); + bio_get(cur); + submit_bio(cur->bi_rw, cur); + bio_put(cur); + num_run++; + + /* + * 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) && + fs_info->fs_devices->open_devices > 1) { + struct bio *old_head; + + spin_lock(&device->io_lock); + + old_head = device->pending_bios; + device->pending_bios = pending; + if (device->pending_bio_tail) + tail->bi_next = old_head; + else + device->pending_bio_tail = tail; + + spin_unlock(&device->io_lock); + btrfs_requeue_work(&device->work); + goto done; + } + } + if (again) + goto loop; +done: + return 0; +} + +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); + + 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; + 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); + device->barriers = 1; + 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); + list_add(&device->dev_list, &fs_devices->devices); + device->fs_devices = fs_devices; + fs_devices->num_devices++; + } + + 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; +} + +int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices) +{ + struct list_head *tmp; + struct list_head *cur; + struct btrfs_device *device; + int seed_devices = 0; + + mutex_lock(&uuid_mutex); +again: + list_for_each_safe(cur, tmp, &fs_devices->devices) { + device = list_entry(cur, struct btrfs_device, dev_list); + if (device->in_fs_metadata) + continue; + + if (device->bdev) { + close_bdev_excl(device->bdev); + device->bdev = NULL; + fs_devices->open_devices--; + } + if (device->writeable) { + list_del_init(&device->dev_alloc_list); + device->writeable = 0; + fs_devices->rw_devices--; + } + if (!seed_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; + seed_devices = 1; + goto again; + } + + mutex_unlock(&uuid_mutex); + return 0; +} + +static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_fs_devices *seed_devices; + struct list_head *cur; + struct btrfs_device *device; +again: + if (--fs_devices->opened > 0) + return 0; + + list_for_each(cur, &fs_devices->devices) { + device = list_entry(cur, struct btrfs_device, dev_list); + if (device->bdev) { + close_bdev_excl(device->bdev); + fs_devices->open_devices--; + } + if (device->writeable) { + list_del_init(&device->dev_alloc_list); + fs_devices->rw_devices--; + } + + device->bdev = NULL; + device->writeable = 0; + device->in_fs_metadata = 0; + } + fs_devices->opened = 0; + fs_devices->seeding = 0; + fs_devices->sprouted = 0; + + seed_devices = fs_devices->seed; + fs_devices->seed = NULL; + if (seed_devices) { + fs_devices = seed_devices; + goto again; + } + return 0; +} + +int btrfs_close_devices(struct btrfs_fs_devices *fs_devices) +{ + int ret; + + mutex_lock(&uuid_mutex); + ret = __btrfs_close_devices(fs_devices); + mutex_unlock(&uuid_mutex); + return ret; +} + +int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, void *holder) +{ + struct block_device *bdev; + struct list_head *head = &fs_devices->devices; + struct list_head *cur; + 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; + + list_for_each(cur, head) { + device = list_entry(cur, struct btrfs_device, dev_list); + if (device->bdev) + continue; + if (!device->name) + continue; + + bdev = open_bdev_excl(device->name, MS_RDONLY, holder); + if (IS_ERR(bdev)) { + printk("open %s failed\n", device->name); + goto error; + } + set_blocksize(bdev, 4096); + + bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096); + if (!bh) + goto error_close; + + disk_super = (struct btrfs_super_block *)bh->b_data; + if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC, + sizeof(disk_super->magic))) + goto error_brelse; + + devid = le64_to_cpu(disk_super->dev_item.devid); + 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; + } + + device->bdev = bdev; + device->in_fs_metadata = 0; + fs_devices->open_devices++; + if (device->writeable) { + fs_devices->rw_devices++; + list_add(&device->dev_alloc_list, + &fs_devices->alloc_list); + } + continue; + +error_brelse: + brelse(bh); +error_close: + close_bdev_excl(bdev); +error: + continue; + } + if (fs_devices->open_devices == 0) { + ret = -EIO; + 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, + int flags, void *holder) +{ + int ret; + + mutex_lock(&uuid_mutex); + if (fs_devices->opened) { + if (fs_devices->sprouted) { + ret = -EBUSY; + } else { + fs_devices->opened++; + ret = 0; + } + } else { + ret = __btrfs_open_devices(fs_devices, holder); + } + mutex_unlock(&uuid_mutex); + return ret; +} + +int btrfs_scan_one_device(const char *path, int 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; + + mutex_lock(&uuid_mutex); + + bdev = open_bdev_excl(path, flags, holder); + + if (IS_ERR(bdev)) { + ret = PTR_ERR(bdev); + goto error; + } + + ret = set_blocksize(bdev, 4096); + if (ret) + goto error_close; + bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096); + if (!bh) { + ret = -EIO; + goto error_close; + } + disk_super = (struct btrfs_super_block *)bh->b_data; + if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC, + sizeof(disk_super->magic))) { + ret = -EINVAL; + goto error_brelse; + } + devid = le64_to_cpu(disk_super->dev_item.devid); + transid = btrfs_super_generation(disk_super); + if (disk_super->label[0]) + printk("device label %s ", disk_super->label); + else { + /* FIXME, make a readl uuid parser */ + printk("device fsid %llx-%llx ", + *(unsigned long long *)disk_super->fsid, + *(unsigned long long *)(disk_super->fsid + 8)); + } + printk("devid %Lu transid %Lu %s\n", devid, transid, path); + ret = device_list_add(path, disk_super, devid, fs_devices_ret); + +error_brelse: + brelse(bh); +error_close: + close_bdev_excl(bdev); +error: + mutex_unlock(&uuid_mutex); + return ret; +} + +/* + * 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 + */ +static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans, + struct btrfs_device *device, + u64 num_bytes, u64 *start) +{ + struct btrfs_key key; + struct btrfs_root *root = device->dev_root; + struct btrfs_dev_extent *dev_extent = NULL; + struct btrfs_path *path; + u64 hole_size = 0; + u64 last_byte = 0; + u64 search_start = 0; + u64 search_end = device->total_bytes; + int ret; + int slot = 0; + int start_found; + struct extent_buffer *l; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->reada = 2; + start_found = 0; + + /* 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((u64)1024 * 1024, search_start); + + if (root->fs_info->alloc_start + num_bytes <= device->total_bytes) + search_start = max(root->fs_info->alloc_start, search_start); + + key.objectid = device->devid; + key.offset = search_start; + key.type = BTRFS_DEV_EXTENT_KEY; + ret = btrfs_search_slot(trans, root, &key, path, 0, 0); + if (ret < 0) + goto error; + ret = btrfs_previous_item(root, path, 0, key.type); + if (ret < 0) + goto error; + l = path->nodes[0]; + btrfs_item_key_to_cpu(l, &key, path->slots[0]); + 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 error; +no_more_items: + if (!start_found) { + if (search_start >= search_end) { + ret = -ENOSPC; + goto error; + } + *start = search_start; + start_found = 1; + goto check_pending; + } + *start = last_byte > search_start ? + last_byte : search_start; + if (search_end <= *start) { + ret = -ENOSPC; + goto error; + } + goto check_pending; + } + btrfs_item_key_to_cpu(l, &key, slot); + + if (key.objectid < device->devid) + goto next; + + if (key.objectid > device->devid) + goto no_more_items; + + if (key.offset >= search_start && key.offset > last_byte && + start_found) { + if (last_byte < search_start) + last_byte = search_start; + hole_size = key.offset - last_byte; + if (key.offset > last_byte && + hole_size >= num_bytes) { + *start = last_byte; + goto check_pending; + } + } + if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) { + goto next; + } + + start_found = 1; + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent); +next: + path->slots[0]++; + cond_resched(); + } +check_pending: + /* we have to make sure we didn't find an extent that has already + * been allocated by the map tree or the original allocation + */ + BUG_ON(*start < search_start); + + if (*start + num_bytes > search_end) { + ret = -ENOSPC; + goto error; + } + /* check for pending inserts here */ + ret = 0; + +error: + btrfs_free_path(path); + return ret; +} + +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; + + 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); + BUG_ON(ret); + 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); + ret = 0; + } else if (ret == 0) { + leaf = path->nodes[0]; + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_extent); + } + BUG_ON(ret); + + if (device->bytes_used > 0) + device->bytes_used -= btrfs_dev_extent_length(leaf, extent); + ret = btrfs_del_item(trans, root, path); + BUG_ON(ret); + + 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)); + BUG_ON(ret); + + 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); + 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(); + BUG_ON(!path); + + 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); + + 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); + + 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); + + 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, 1); + 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; + u64 all_avail; + u64 devid; + u64 num_devices; + u8 *dev_uuid; + int ret = 0; + + mutex_lock(&uuid_mutex); + mutex_lock(&root->fs_info->volume_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->rw_devices <= 4) { + printk("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->rw_devices <= 2) { + printk("btrfs: unable to go below two devices on raid1\n"); + ret = -EINVAL; + goto out; + } + + if (strcmp(device_path, "missing") == 0) { + struct list_head *cur; + struct list_head *devices; + struct btrfs_device *tmp; + + device = NULL; + devices = &root->fs_info->fs_devices->devices; + list_for_each(cur, devices) { + tmp = list_entry(cur, struct btrfs_device, dev_list); + if (tmp->in_fs_metadata && !tmp->bdev) { + device = tmp; + break; + } + } + bdev = NULL; + bh = NULL; + disk_super = NULL; + if (!device) { + printk("btrfs: no missing devices found to remove\n"); + goto out; + } + } else { + bdev = open_bdev_excl(device_path, MS_RDONLY, + root->fs_info->bdev_holder); + if (IS_ERR(bdev)) { + ret = PTR_ERR(bdev); + goto out; + } + + set_blocksize(bdev, 4096); + bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096); + if (!bh) { + ret = -EIO; + goto error_close; + } + disk_super = (struct btrfs_super_block *)bh->b_data; + if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC, + sizeof(disk_super->magic))) { + ret = -ENOENT; + goto error_brelse; + } + devid = le64_to_cpu(disk_super->dev_item.devid); + 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("btrfs: unable to remove the only writeable device\n"); + ret = -EINVAL; + goto error_brelse; + } + + if (device->writeable) { + list_del_init(&device->dev_alloc_list); + root->fs_info->fs_devices->rw_devices--; + } + + ret = btrfs_shrink_device(device, 0); + if (ret) + goto error_brelse; + + ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device); + if (ret) + goto error_brelse; + + device->in_fs_metadata = 0; + if (device->fs_devices == root->fs_info->fs_devices) { + list_del_init(&device->dev_list); + root->fs_info->fs_devices->num_devices--; + if (device->bdev) + device->fs_devices->open_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; + + 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 (device->fs_devices != root->fs_info->fs_devices) { + BUG_ON(device->writeable); + brelse(bh); + if (bdev) + close_bdev_excl(bdev); + + if (device->bdev) { + close_bdev_excl(device->bdev); + device->bdev = NULL; + device->fs_devices->open_devices--; + } + if (device->fs_devices->open_devices == 0) { + struct btrfs_fs_devices *fs_devices; + fs_devices = root->fs_info->fs_devices; + while (fs_devices) { + if (fs_devices->seed == device->fs_devices) + break; + fs_devices = fs_devices->seed; + } + fs_devices->seed = device->fs_devices->seed; + device->fs_devices->seed = NULL; + __btrfs_close_devices(device->fs_devices); + } + ret = 0; + goto out; + } + + /* + * at this point, the device is zero sized. We want to + * remove it from the devices list and zero out the old super + */ + if (device->writeable) { + /* 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); + } + brelse(bh); + + if (device->bdev) { + /* one close for the device struct or super_block */ + close_bdev_excl(device->bdev); + } + if (bdev) { + /* one close for us */ + close_bdev_excl(bdev); + } + kfree(device->name); + kfree(device); + ret = 0; + goto out; + +error_brelse: + brelse(bh); +error_close: + if (bdev) + close_bdev_excl(bdev); +out: + mutex_unlock(&root->fs_info->volume_mutex); + mutex_unlock(&uuid_mutex); + return ret; +} + +/* + * does all the dirty work required for changing file system's UUID. + */ +static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; + struct btrfs_fs_devices *old_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 || fs_devices->opened != 1) + return -EINVAL; + + old_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); + if (!old_devices) + return -ENOMEM; + + memcpy(old_devices, fs_devices, sizeof(*old_devices)); + old_devices->opened = 1; + old_devices->sprouted = 1; + INIT_LIST_HEAD(&old_devices->devices); + INIT_LIST_HEAD(&old_devices->alloc_list); + list_splice_init(&fs_devices->devices, &old_devices->devices); + list_splice_init(&fs_devices->alloc_list, &old_devices->alloc_list); + list_for_each_entry(device, &old_devices->devices, dev_list) { + device->fs_devices = old_devices; + } + list_add(&old_devices->list, &fs_uuids); + + fs_devices->seeding = 0; + fs_devices->num_devices = 0; + fs_devices->open_devices = 0; + fs_devices->seed = old_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(root, 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); + + 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 btrfs_trans_handle *trans; + struct btrfs_device *device; + struct block_device *bdev; + struct list_head *cur; + 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 = open_bdev_excl(device_path, 0, root->fs_info->bdev_holder); + if (!bdev) { + return -EIO; + } + + 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); + mutex_lock(&root->fs_info->volume_mutex); + + devices = &root->fs_info->fs_devices->devices; + list_for_each(cur, devices) { + device = list_entry(cur, struct btrfs_device, 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); + goto error; + } + + trans = btrfs_start_transaction(root, 1); + lock_chunks(root); + + device->barriers = 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->dev_root = root->fs_info->dev_root; + device->bdev = bdev; + device->in_fs_metadata = 1; + set_blocksize(device->bdev, 4096); + + if (seeding_dev) { + sb->s_flags &= ~MS_RDONLY; + ret = btrfs_prepare_sprout(trans, root); + BUG_ON(ret); + } + + device->fs_devices = root->fs_info->fs_devices; + list_add(&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++; + root->fs_info->fs_devices->total_rw_bytes += device->total_bytes; + + 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); + + if (seeding_dev) { + ret = init_first_rw_device(trans, root, device); + BUG_ON(ret); + ret = btrfs_finish_sprout(trans, root); + BUG_ON(ret); + } else { + ret = btrfs_add_device(trans, root, device); + } + + unlock_chunks(root); + btrfs_commit_transaction(trans, root); + + if (seeding_dev) { + mutex_unlock(&uuid_mutex); + up_write(&sb->s_umount); + + ret = btrfs_relocate_sys_chunks(root); + BUG_ON(ret); + } +out: + mutex_unlock(&root->fs_info->volume_mutex); + return ret; +error: + close_bdev_excl(bdev); + if (seeding_dev) { + mutex_unlock(&uuid_mutex); + up_write(&sb->s_umount); + } + goto out; +} + +int noinline 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->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; + 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); + BUG_ON(ret); + + ret = btrfs_del_item(trans, root, path); + BUG_ON(ret); + + btrfs_free_path(path); + return 0; +} + +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; +} + +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; + + printk("btrfs relocating chunk %llu\n", + (unsigned long long)chunk_offset); + root = root->fs_info->chunk_root; + extent_root = root->fs_info->extent_root; + em_tree = &root->fs_info->mapping_tree.map_tree; + + /* step one, relocate all the extents inside this chunk */ + ret = btrfs_relocate_block_group(extent_root, chunk_offset); + BUG_ON(ret); + + trans = btrfs_start_transaction(root, 1); + BUG_ON(!trans); + + lock_chunks(root); + + /* + * step two, delete the device extents and the + * chunk tree entries + */ + spin_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, chunk_offset, 1); + spin_unlock(&em_tree->lock); + + BUG_ON(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); + + 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); + + spin_lock(&em_tree->lock); + remove_extent_mapping(em_tree, em); + spin_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; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + 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); + + 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(chunk_root, path); + + if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) { + ret = btrfs_relocate_chunk(chunk_root, chunk_tree, + found_key.objectid, + found_key.offset); + BUG_ON(ret); + } + + if (found_key.offset == 0) + break; + key.offset = found_key.offset - 1; + } + ret = 0; +error: + btrfs_free_path(path); + return ret; +} + +static u64 div_factor(u64 num, int factor) +{ + if (factor == 10) + return num; + num *= factor; + do_div(num, 10); + return num; +} + +int btrfs_balance(struct btrfs_root *dev_root) +{ + int ret; + struct list_head *cur; + struct list_head *devices = &dev_root->fs_info->fs_devices->devices; + struct btrfs_device *device; + u64 old_size; + u64 size_to_free; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_chunk *chunk; + struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root; + struct btrfs_trans_handle *trans; + struct btrfs_key found_key; + + if (dev_root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + + mutex_lock(&dev_root->fs_info->volume_mutex); + dev_root = dev_root->fs_info->dev_root; + + /* step one make some room on all the devices */ + list_for_each(cur, devices) { + device = list_entry(cur, struct btrfs_device, 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); + BUG_ON(ret); + + trans = btrfs_start_transaction(dev_root, 1); + BUG_ON(!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(); + BUG_ON(!path); + + 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; + + /* + * this shouldn't happen, it means the last relocate + * failed + */ + if (ret == 0) + break; + + ret = btrfs_previous_item(chunk_root, path, 0, + BTRFS_CHUNK_ITEM_KEY); + if (ret) + break; + + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + if (found_key.objectid != key.objectid) + break; + + chunk = btrfs_item_ptr(path->nodes[0], + path->slots[0], + struct btrfs_chunk); + key.offset = found_key.offset; + /* chunk zero is special */ + if (key.offset == 0) + break; + + btrfs_release_path(chunk_root, path); + ret = btrfs_relocate_chunk(chunk_root, + chunk_root->root_key.objectid, + found_key.objectid, + found_key.offset); + BUG_ON(ret); + } + ret = 0; +error: + btrfs_free_path(path); + mutex_unlock(&dev_root->fs_info->volume_mutex); + return ret; +} + +/* + * 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; + 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 diff = device->total_bytes - new_size; + + if (new_size >= device->total_bytes) + return -EINVAL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_start_transaction(root, 1); + if (!trans) { + ret = -ENOMEM; + goto done; + } + + path->reada = 2; + + lock_chunks(root); + + device->total_bytes = new_size; + if (device->writeable) + device->fs_devices->total_rw_bytes -= diff; + 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); + + key.objectid = device->devid; + key.offset = (u64)-1; + key.type = BTRFS_DEV_EXTENT_KEY; + + while (1) { + 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; + goto done; + } + + l = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(l, &key, path->slots[0]); + + if (key.objectid != device->devid) + goto done; + + 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) + goto done; + + 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(root, path); + + ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid, + chunk_offset); + if (ret) + goto done; + } + +done: + btrfs_free_path(path); + return ret; +} + +int btrfs_add_system_chunk(struct btrfs_trans_handle *trans, + 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; +} + +static u64 noinline chunk_bytes_by_type(u64 type, u64 calc_size, + int num_stripes, int sub_stripes) +{ + if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP)) + return calc_size; + else if (type & BTRFS_BLOCK_GROUP_RAID10) + return calc_size * (num_stripes / sub_stripes); + else + return calc_size * num_stripes; +} + +static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct map_lookup **map_ret, + u64 *num_bytes, u64 *stripe_size, + u64 start, u64 type) +{ + struct btrfs_fs_info *info = extent_root->fs_info; + struct btrfs_device *device = NULL; + 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 list_head private_devs; + int min_stripe_size = 1 * 1024 * 1024; + u64 calc_size = 1024 * 1024 * 1024; + u64 max_chunk_size = calc_size; + u64 min_free; + u64 avail; + u64 max_avail = 0; + u64 dev_offset; + int num_stripes = 1; + int min_stripes = 1; + int sub_stripes = 0; + int looped = 0; + int ret; + int index; + int stripe_len = 64 * 1024; + + if ((type & BTRFS_BLOCK_GROUP_RAID1) && + (type & BTRFS_BLOCK_GROUP_DUP)) { + WARN_ON(1); + type &= ~BTRFS_BLOCK_GROUP_DUP; + } + if (list_empty(&fs_devices->alloc_list)) + return -ENOSPC; + + if (type & (BTRFS_BLOCK_GROUP_RAID0)) { + num_stripes = fs_devices->rw_devices; + min_stripes = 2; + } + if (type & (BTRFS_BLOCK_GROUP_DUP)) { + num_stripes = 2; + min_stripes = 2; + } + if (type & (BTRFS_BLOCK_GROUP_RAID1)) { + num_stripes = min_t(u64, 2, fs_devices->rw_devices); + if (num_stripes < 2) + return -ENOSPC; + min_stripes = 2; + } + if (type & (BTRFS_BLOCK_GROUP_RAID10)) { + num_stripes = fs_devices->rw_devices; + if (num_stripes < 4) + return -ENOSPC; + num_stripes &= ~(u32)1; + sub_stripes = 2; + min_stripes = 4; + } + + if (type & BTRFS_BLOCK_GROUP_DATA) { + max_chunk_size = 10 * calc_size; + min_stripe_size = 64 * 1024 * 1024; + } else if (type & BTRFS_BLOCK_GROUP_METADATA) { + max_chunk_size = 4 * calc_size; + min_stripe_size = 32 * 1024 * 1024; + } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) { + calc_size = 8 * 1024 * 1024; + max_chunk_size = calc_size * 2; + min_stripe_size = 1 * 1024 * 1024; + } + + /* 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); + +again: + if (!map || map->num_stripes != num_stripes) { + kfree(map); + map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS); + if (!map) + return -ENOMEM; + map->num_stripes = num_stripes; + } + + if (calc_size * num_stripes > max_chunk_size) { + calc_size = max_chunk_size; + do_div(calc_size, num_stripes); + do_div(calc_size, stripe_len); + calc_size *= stripe_len; + } + /* we don't want tiny stripes */ + calc_size = max_t(u64, min_stripe_size, calc_size); + + do_div(calc_size, stripe_len); + calc_size *= stripe_len; + + cur = fs_devices->alloc_list.next; + index = 0; + + if (type & BTRFS_BLOCK_GROUP_DUP) + min_free = calc_size * 2; + else + min_free = calc_size; + + /* + * we add 1MB because we never use the first 1MB of the device, unless + * we've looped, then we are likely allocating the maximum amount of + * space left already + */ + if (!looped) + min_free += 1024 * 1024; + + INIT_LIST_HEAD(&private_devs); + while(index < num_stripes) { + device = list_entry(cur, struct btrfs_device, dev_alloc_list); + BUG_ON(!device->writeable); + if (device->total_bytes > device->bytes_used) + avail = device->total_bytes - device->bytes_used; + else + avail = 0; + cur = cur->next; + + if (device->in_fs_metadata && avail >= min_free) { + ret = find_free_dev_extent(trans, device, + min_free, &dev_offset); + if (ret == 0) { + list_move_tail(&device->dev_alloc_list, + &private_devs); + map->stripes[index].dev = device; + map->stripes[index].physical = dev_offset; + index++; + if (type & BTRFS_BLOCK_GROUP_DUP) { + map->stripes[index].dev = device; + map->stripes[index].physical = + dev_offset + calc_size; + index++; + } + } + } else if (device->in_fs_metadata && avail > max_avail) + max_avail = avail; + if (cur == &fs_devices->alloc_list) + break; + } + list_splice(&private_devs, &fs_devices->alloc_list); + if (index < num_stripes) { + if (index >= min_stripes) { + num_stripes = index; + if (type & (BTRFS_BLOCK_GROUP_RAID10)) { + num_stripes /= sub_stripes; + num_stripes *= sub_stripes; + } + looped = 1; + goto again; + } + if (!looped && max_avail > 0) { + looped = 1; + calc_size = max_avail; + goto again; + } + kfree(map); + return -ENOSPC; + } + map->sector_size = extent_root->sectorsize; + map->stripe_len = stripe_len; + map->io_align = stripe_len; + map->io_width = stripe_len; + map->type = type; + map->num_stripes = num_stripes; + map->sub_stripes = sub_stripes; + + *map_ret = map; + *stripe_size = calc_size; + *num_bytes = chunk_bytes_by_type(type, calc_size, + num_stripes, sub_stripes); + + em = alloc_extent_map(GFP_NOFS); + if (!em) { + kfree(map); + return -ENOMEM; + } + 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; + spin_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em); + spin_unlock(&em_tree->lock); + BUG_ON(ret); + free_extent_map(em); + + ret = btrfs_make_block_group(trans, extent_root, 0, type, + BTRFS_FIRST_CHUNK_TREE_OBJECTID, + start, *num_bytes); + BUG_ON(ret); + + index = 0; + while (index < map->num_stripes) { + device = map->stripes[index].dev; + dev_offset = map->stripes[index].physical; + + ret = btrfs_alloc_dev_extent(trans, device, + info->chunk_root->root_key.objectid, + BTRFS_FIRST_CHUNK_TREE_OBJECTID, + start, dev_offset, calc_size); + BUG_ON(ret); + index++; + } + + return 0; +} + +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); + BUG_ON(ret); + index++; + } + + 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); + BUG_ON(ret); + + if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) { + ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk, + item_size); + BUG_ON(ret); + } + kfree(chunk); + return 0; +} + +/* + * 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); + BUG_ON(ret); + return 0; +} + +static int noinline 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); + BUG_ON(ret); + + alloc_profile = BTRFS_BLOCK_GROUP_METADATA | + (fs_info->metadata_alloc_profile & + 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); + BUG_ON(ret); + + sys_chunk_offset = chunk_offset + chunk_size; + + alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM | + (fs_info->system_alloc_profile & + 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); + BUG_ON(ret); + + ret = btrfs_add_device(trans, fs_info->chunk_root, device); + BUG_ON(ret); + + /* + * 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); + BUG_ON(ret); + + ret = __finish_chunk_alloc(trans, extent_root, sys_map, + sys_chunk_offset, sys_chunk_size, + sys_stripe_size); + BUG_ON(ret); + return 0; +} + +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; + + spin_lock(&map_tree->map_tree.lock); + em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); + spin_unlock(&map_tree->map_tree.lock); + if (!em) + return 1; + + 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, GFP_NOFS); +} + +void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree) +{ + struct extent_map *em; + + while(1) { + spin_lock(&tree->map_tree.lock); + em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1); + if (em) + remove_extent_mapping(&tree->map_tree, em); + spin_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; + + spin_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, logical, len); + spin_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_multi_bio **multi_ret, + int mirror_num, struct page *unplug_page) +{ + 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_nr; + int stripes_allocated = 8; + int stripes_required = 1; + int stripe_index; + int i; + int num_stripes; + int max_errors = 0; + struct btrfs_multi_bio *multi = NULL; + + if (multi_ret && !(rw & (1 << BIO_RW))) { + stripes_allocated = 1; + } +again: + if (multi_ret) { + multi = kzalloc(btrfs_multi_bio_size(stripes_allocated), + GFP_NOFS); + if (!multi) + return -ENOMEM; + + atomic_set(&multi->error, 0); + } + + spin_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, logical, *length); + spin_unlock(&em_tree->lock); + + if (!em && unplug_page) + return 0; + + if (!em) { + printk("unable to find logical %Lu len %Lu\n", logical, *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; + + /* if our multi bio struct is too small, back off and try again */ + if (rw & (1 << BIO_RW)) { + if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_DUP)) { + stripes_required = map->num_stripes; + max_errors = 1; + } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { + stripes_required = map->sub_stripes; + max_errors = 1; + } + } + if (multi_ret && rw == WRITE && + stripes_allocated < stripes_required) { + stripes_allocated = map->num_stripes; + free_extent_map(em); + kfree(multi); + goto again; + } + 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 (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_DUP)) { + /* 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 (!multi_ret && !unplug_page) + goto out; + + num_stripes = 1; + stripe_index = 0; + if (map->type & BTRFS_BLOCK_GROUP_RAID1) { + if (unplug_page || (rw & (1 << BIO_RW))) + 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); + } + + } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { + if (rw & (1 << BIO_RW)) + num_stripes = map->num_stripes; + else if (mirror_num) + stripe_index = 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 (unplug_page || (rw & (1 << BIO_RW))) + num_stripes = map->sub_stripes; + else if (mirror_num) + stripe_index += mirror_num - 1; + else { + stripe_index = find_live_mirror(map, stripe_index, + map->sub_stripes, stripe_index + + current->pid % map->sub_stripes); + } + } 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); + } + BUG_ON(stripe_index >= map->num_stripes); + + for (i = 0; i < num_stripes; i++) { + if (unplug_page) { + struct btrfs_device *device; + struct backing_dev_info *bdi; + + device = map->stripes[stripe_index].dev; + if (device->bdev) { + bdi = blk_get_backing_dev_info(device->bdev); + if (bdi->unplug_io_fn) { + bdi->unplug_io_fn(bdi, unplug_page); + } + } + } else { + multi->stripes[i].physical = + map->stripes[stripe_index].physical + + stripe_offset + stripe_nr * map->stripe_len; + multi->stripes[i].dev = map->stripes[stripe_index].dev; + } + stripe_index++; + } + if (multi_ret) { + *multi_ret = multi; + multi->num_stripes = num_stripes; + multi->max_errors = max_errors; + } +out: + free_extent_map(em); + return 0; +} + +int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, + u64 logical, u64 *length, + struct btrfs_multi_bio **multi_ret, int mirror_num) +{ + return __btrfs_map_block(map_tree, rw, logical, length, multi_ret, + mirror_num, NULL); +} + +int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree, + u64 logical, struct page *page) +{ + u64 length = PAGE_CACHE_SIZE; + return __btrfs_map_block(map_tree, READ, logical, &length, + NULL, 0, page); +} + + +static void end_bio_multi_stripe(struct bio *bio, int err) +{ + struct btrfs_multi_bio *multi = bio->bi_private; + int is_orig_bio = 0; + + if (err) + atomic_inc(&multi->error); + + if (bio == multi->orig_bio) + is_orig_bio = 1; + + if (atomic_dec_and_test(&multi->stripes_pending)) { + if (!is_orig_bio) { + bio_put(bio); + bio = multi->orig_bio; + } + bio->bi_private = multi->private; + bio->bi_end_io = multi->end_io; + /* only send an error to the higher layers if it is + * beyond the tolerance of the multi-bio + */ + if (atomic_read(&multi->error) > multi->max_errors) { + err = -EIO; + } else if (err) { + /* + * 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(multi); + + 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 int noinline schedule_bio(struct btrfs_root *root, + struct btrfs_device *device, + int rw, struct bio *bio) +{ + int should_queue = 1; + + /* don't bother with additional async steps for reads, right now */ + if (!(rw & (1 << BIO_RW))) { + bio_get(bio); + submit_bio(rw, bio); + bio_put(bio); + return 0; + } + + /* + * 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 (device->pending_bio_tail) + device->pending_bio_tail->bi_next = bio; + + device->pending_bio_tail = bio; + if (!device->pending_bios) + device->pending_bios = 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); + return 0; +} + +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; + struct btrfs_multi_bio *multi = NULL; + int ret; + int dev_nr = 0; + int total_devs = 1; + + length = bio->bi_size; + map_tree = &root->fs_info->mapping_tree; + map_length = length; + + ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi, + mirror_num); + BUG_ON(ret); + + total_devs = multi->num_stripes; + if (map_length < length) { + printk("mapping failed logical %Lu bio len %Lu " + "len %Lu\n", logical, length, map_length); + BUG(); + } + multi->end_io = first_bio->bi_end_io; + multi->private = first_bio->bi_private; + multi->orig_bio = first_bio; + atomic_set(&multi->stripes_pending, multi->num_stripes); + + while(dev_nr < total_devs) { + if (total_devs > 1) { + if (dev_nr < total_devs - 1) { + bio = bio_clone(first_bio, GFP_NOFS); + BUG_ON(!bio); + } else { + bio = first_bio; + } + bio->bi_private = multi; + bio->bi_end_io = end_bio_multi_stripe; + } + bio->bi_sector = multi->stripes[dev_nr].physical >> 9; + dev = multi->stripes[dev_nr].dev; + BUG_ON(rw == WRITE && !dev->writeable); + if (dev && dev->bdev) { + bio->bi_bdev = dev->bdev; + if (async_submit) + schedule_bio(root, dev, rw, bio); + else + 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++; + } + if (total_devs == 1) + kfree(multi); + 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->barriers = 1; + device->dev_root = root->fs_info->dev_root; + device->devid = devid; + device->work.func = pending_bios_fn; + fs_devices->num_devices++; + spin_lock_init(&device->io_lock); + 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); + + spin_lock(&map_tree->map_tree.lock); + em = lookup_extent_mapping(&map_tree->map_tree, logical, 1); + spin_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); + } + + map = kzalloc(sizeof(*map), GFP_NOFS); + if (!map) + return -ENOMEM; + + em = alloc_extent_map(GFP_NOFS); + 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; + } + + spin_lock(&map_tree->map_tree.lock); + ret = add_extent_mapping(&map_tree->map_tree, em); + spin_unlock(&map_tree->map_tree.lock); + BUG_ON(ret); + free_extent_map(em); + + return 0; +} + +static int 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->total_bytes = btrfs_device_total_bytes(leaf, dev_item); + 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); + + return 0; +} + +static int open_seed_devices(struct btrfs_root *root, u8 *fsid) +{ + struct btrfs_fs_devices *fs_devices; + int ret; + + mutex_lock(&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; + } + if (fs_devices->opened) { + ret = -EBUSY; + goto out; + } + + ret = __btrfs_open_devices(fs_devices, root->fs_info->bdev_holder); + if (ret) + goto out; + + if (!fs_devices->seeding) { + __btrfs_close_devices(fs_devices); + ret = -EINVAL; + goto out; + } + + fs_devices->seed = root->fs_info->fs_devices->seed; + root->fs_info->fs_devices->seed = fs_devices; + fs_devices->sprouted = 1; +out: + mutex_unlock(&uuid_mutex); + 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; + int seed_devices = 0; + 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) + return ret; + seed_devices = 1; + } + + device = btrfs_find_device(root, devid, dev_uuid, fs_uuid); + if (!device || !device->bdev) { + if (!btrfs_test_opt(root, DEGRADED) || seed_devices) + return -EIO; + + if (!device) { + printk("warning devid %Lu missing\n", devid); + device = add_missing_dev(root, devid, dev_uuid); + if (!device) + return -ENOMEM; + } + } + + 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; + ret = 0; +#if 0 + ret = btrfs_open_device(device); + if (ret) { + kfree(device); + } +#endif + return ret; +} + +int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf) +{ + struct btrfs_dev_item *dev_item; + + dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block, + dev_item); + return read_one_dev(root, buf, dev_item); +} + +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); + 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; + + /* 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); + 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(root, path); + goto again; + } + ret = 0; +error: + btrfs_free_path(path); + return ret; +} |