diff options
Diffstat (limited to 'volumes.c')
| -rw-r--r-- | volumes.c | 771 |
1 files changed, 771 insertions, 0 deletions
diff --git a/volumes.c b/volumes.c new file mode 100644 index 00000000..2fb5a200 --- /dev/null +++ b/volumes.c @@ -0,0 +1,771 @@ +/* + * 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 "ctree.h" +#include "disk-io.h" +#include "transaction.h" +#include "print-tree.h" +#include "volumes.h" + +struct map_lookup { + struct cache_extent ce; + struct btrfs_device *dev; + u64 physical; +}; + +/* + * 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 int find_free_dev_extent(struct btrfs_trans_handle *trans, + struct btrfs_device *device, + struct btrfs_path *path, + u64 num_bytes, u64 *start) +{ + struct btrfs_key key; + struct btrfs_root *root = device->dev_root; + struct btrfs_dev_extent *dev_extent = NULL; + 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; + + start_found = 0; + path->reada = 2; + + /* FIXME use last free of some kind */ + + 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 + */ + btrfs_release_path(root, path); + BUG_ON(*start < search_start); + + if (*start + num_bytes >= search_end) { + ret = -ENOSPC; + goto error; + } + /* check for pending inserts here */ + return 0; + +error: + btrfs_release_path(root, path); + return ret; +} + +int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans, + struct btrfs_device *device, + u64 owner, u64 num_bytes, u64 *start) +{ + 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; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = find_free_dev_extent(trans, device, path, num_bytes, start); + if (ret) + goto err; + + 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_owner(leaf, extent, owner); + btrfs_set_dev_extent_length(leaf, extent, num_bytes); + btrfs_mark_buffer_dirty(leaf); +err: + btrfs_free_path(path); + return ret; +} + +static int find_next_chunk(struct btrfs_root *root, u64 *objectid) +{ + struct btrfs_path *path; + int ret; + struct btrfs_key key; + struct btrfs_key found_key; + + path = btrfs_alloc_path(); + BUG_ON(!path); + + key.objectid = (u64)-1; + 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) { + *objectid = 0; + } else { + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + *objectid = found_key.objectid + found_key.offset; + } + ret = 0; +error: + btrfs_free_path(path); + return ret; +} + +static struct btrfs_device *next_device(struct list_head *head, + struct list_head *last) +{ + struct list_head *next = last->next; + struct btrfs_device *dev; + + if (list_empty(head)) + return NULL; + + if (next == head) + next = next->next; + + dev = list_entry(next, struct btrfs_device, dev_list); + return dev; +} + +static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path, + u64 *objectid) +{ + int ret; + struct btrfs_key key; + struct btrfs_key found_key; + + 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_release_path(root, 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; + u64 free_devid; + + root = root->fs_info->chunk_root; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = find_next_devid(root, path, &free_devid); + if (ret) + goto out; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = free_devid; + + ret = btrfs_insert_empty_item(trans, root, path, &key, + sizeof(*dev_item) + device->name_len); + 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_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_rdev(leaf, dev_item, device->rdev); + btrfs_set_device_partition(leaf, dev_item, device->partition); + btrfs_set_device_name_len(leaf, dev_item, device->name_len); + btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes); + btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); + + ptr = (unsigned long)btrfs_device_name(dev_item); + write_extent_buffer(leaf, device->name, ptr, device->name_len); + + ptr = (unsigned long)btrfs_device_uuid(dev_item); + write_extent_buffer(leaf, device->uuid, ptr, BTRFS_DEV_UUID_SIZE); + btrfs_mark_buffer_dirty(leaf); + ret = 0; + +out: + btrfs_free_path(path); + return ret; +} +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_rdev(leaf, dev_item, device->rdev); + btrfs_set_device_partition(leaf, dev_item, device->partition); + 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; +} + +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; +} + +int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, u64 *start, + u64 *num_bytes, u32 type) +{ + u64 dev_offset; + struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; + struct btrfs_stripe *stripes; + struct btrfs_device *device = NULL; + struct btrfs_chunk *chunk; + struct list_head *dev_list = &extent_root->fs_info->devices; + struct list_head *last_dev = extent_root->fs_info->last_device; + struct map_lookup *map; + u64 physical; + u64 calc_size; + int num_stripes; + int ret; + int index = 0; + struct btrfs_key key; + + + ret = find_next_chunk(chunk_root, &key.objectid); + if (ret) + return ret; + + num_stripes = 1; + chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS); + if (!chunk) + return -ENOMEM; + + stripes = &chunk->stripe; + + while(index < num_stripes) { + device = next_device(dev_list, last_dev); + BUG_ON(!device); + last_dev = &device->dev_list; + extent_root->fs_info->last_device = last_dev; + + if (index == 0) { + int mask = device->io_align; + calc_size = (device->total_bytes * 95) / 100; + calc_size = device->total_bytes - calc_size; + calc_size = (calc_size / mask) * mask; + *num_bytes = calc_size; + } + + ret = btrfs_alloc_dev_extent(trans, device, + key.objectid, + calc_size, &dev_offset); + BUG_ON(ret); + + device->bytes_used += calc_size; + ret = btrfs_update_device(trans, device); + BUG_ON(ret); + + btrfs_set_stack_stripe_devid(stripes + index, device->devid); + btrfs_set_stack_stripe_offset(stripes + index, dev_offset); + physical = dev_offset; + index++; + } + + /* key.objectid was set above */ + key.offset = *num_bytes; + key.type = BTRFS_CHUNK_ITEM_KEY; + btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid); + btrfs_set_stack_chunk_stripe_len(chunk, 64 * 1024); + btrfs_set_stack_chunk_type(chunk, type); + btrfs_set_stack_chunk_num_stripes(chunk, num_stripes); + btrfs_set_stack_chunk_io_align(chunk, extent_root->sectorsize); + btrfs_set_stack_chunk_io_width(chunk, extent_root->sectorsize); + btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize); + + ret = btrfs_insert_item(trans, chunk_root, &key, chunk, + btrfs_chunk_item_size(num_stripes)); + BUG_ON(ret); + *start = key.objectid; + + map = kmalloc(sizeof(*map), GFP_NOFS); + if (!map) + return -ENOMEM; + + map->ce.start = key.objectid; + map->ce.size = key.offset; + + map->physical = physical; + map->dev = device; + + if (!map->dev) { + kfree(map); + return -EIO; + } + ret = insert_existing_cache_extent( + &extent_root->fs_info->mapping_tree.cache_tree, + &map->ce); + BUG_ON(ret); + + kfree(chunk); + return ret; +} + +void btrfs_mapping_init(struct btrfs_mapping_tree *tree) +{ + cache_tree_init(&tree->cache_tree); +} + +int btrfs_map_block(struct btrfs_mapping_tree *map_tree, + u64 logical, u64 *phys, u64 *length, + struct btrfs_device **dev) +{ + struct cache_extent *ce; + struct map_lookup *map; + u64 offset; + + ce = find_first_cache_extent(&map_tree->cache_tree, logical); + BUG_ON(!ce); + BUG_ON(ce->start > logical || ce->start + ce->size < logical); + map = container_of(ce, struct map_lookup, ce); + offset = logical - ce->start; + *phys = map->physical + offset; + *length = ce->size - offset; + *dev = map->dev; + return 0; +} + +struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid) +{ + struct btrfs_device *dev; + struct list_head *cur = root->fs_info->devices.next; + struct list_head *head = &root->fs_info->devices; + + while(cur != head) { + dev = list_entry(cur, struct btrfs_device, dev_list); + if (dev->devid == devid) + return dev; + cur = cur->next; + } + return NULL; +} + +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 cache_extent *ce; + u64 logical; + u64 length; + u64 devid; + int ret; + + logical = key->objectid; + length = key->offset; + ce = find_first_cache_extent(&map_tree->cache_tree, logical); + + /* already mapped? */ + if (ce && ce->start <= logical && ce->start + ce->size > logical) { + return 0; + } + + map = kmalloc(sizeof(*map), GFP_NOFS); + if (!map) + return -ENOMEM; + + map->ce.start = logical; + map->ce.size = length; + + map->physical = btrfs_stripe_offset_nr(leaf, chunk, 0); + devid = btrfs_stripe_devid_nr(leaf, chunk, 0); + map->dev = btrfs_find_device(root, devid); + + if (!map->dev) { + kfree(map); + return -EIO; + } + ret = insert_existing_cache_extent(&map_tree->cache_tree, &map->ce); + BUG_ON(ret); + + 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; + char *name; + + 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); + device->rdev = btrfs_device_rdev(leaf, dev_item); + device->partition = btrfs_device_partition(leaf, dev_item); + device->name_len = btrfs_device_name_len(leaf, dev_item); + + ptr = (unsigned long)btrfs_device_uuid(dev_item); + read_extent_buffer(leaf, device->uuid, ptr, BTRFS_DEV_UUID_SIZE); + + name = kmalloc(device->name_len + 1, GFP_NOFS); + if (!name) + return -ENOMEM; + device->name = name; + ptr = (unsigned long)btrfs_device_name(dev_item); + read_extent_buffer(leaf, name, ptr, device->name_len); + name[device->name_len] = '\0'; + return 0; +} + +static int read_one_dev(struct btrfs_root *root, struct btrfs_key *key, + struct extent_buffer *leaf, + struct btrfs_dev_item *dev_item) +{ + struct btrfs_device *device; + u64 devid; + int ret; + + devid = btrfs_device_id(leaf, dev_item); + if (btrfs_find_device(root, devid)) + return 0; + + device = kmalloc(sizeof(*device), GFP_NOFS); + if (!device) + return -ENOMEM; + + fill_device_from_item(leaf, dev_item, device); + device->dev_root = root->fs_info->dev_root; + device->fd = 0; + list_add(&device->dev_list, &root->fs_info->devices); + memcpy(&device->dev_key, key, sizeof(*key)); + + ret = btrfs_open_device(device); + if (ret) { + kfree(device); + } + 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 = root->fs_info->sb_buffer; + struct btrfs_disk_key *disk_key; + struct btrfs_dev_item *dev_item; + struct btrfs_chunk *chunk; + struct btrfs_key key; + u32 num_stripes; + u32 array_size; + u32 len = 0; + u8 *ptr; + unsigned long sb_ptr; + u32 cur; + int ret; + int dev_only = 1; + + array_size = btrfs_super_sys_array_size(super_copy); + + /* + * we do this loop twice, once for the device items and + * once for all of the chunks. This way there are device + * structs filled in for every chunk + */ +again: + 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.objectid == BTRFS_DEV_ITEMS_OBJECTID && + key.type == BTRFS_DEV_ITEM_KEY) { + dev_item = (struct btrfs_dev_item *)sb_ptr; + if (dev_only) { + ret = read_one_dev(root, &key, sb, dev_item); + BUG_ON(ret); + } + len = sizeof(*dev_item); + len += btrfs_device_name_len(sb, dev_item); + } else if (key.type == BTRFS_CHUNK_ITEM_KEY) { + + chunk = (struct btrfs_chunk *)sb_ptr; + if (!dev_only) { + ret = read_one_chunk(root, &key, sb, chunk); + BUG_ON(ret); + } + num_stripes = btrfs_chunk_num_stripes(sb, chunk); + len = btrfs_chunk_item_size(num_stripes); + } else { + BUG(); + } + ptr += len; + sb_ptr += len; + cur += len; + } + if (dev_only == 1) { + dev_only = 0; + goto again; + } + return 0; +} + +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, &found_key, leaf, + dev_item); + BUG_ON(ret); + } + } 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); + } + path->slots[0]++; + } + if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { + key.objectid = 0; + btrfs_release_path(root, path); + goto again; + } + + btrfs_free_path(path); + ret = 0; +error: + return ret; +} + |