diff options
Diffstat (limited to 'fs/btrfs/extent-tree.c')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 4034 |
1 files changed, 4034 insertions, 0 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c new file mode 100644 index 000000000000..5258923d621f --- /dev/null +++ b/fs/btrfs/extent-tree.c @@ -0,0 +1,4034 @@ +/* + * 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/pagemap.h> +#include <linux/writeback.h> +#include <linux/blkdev.h> +#include "hash.h" +#include "crc32c.h" +#include "ctree.h" +#include "disk-io.h" +#include "print-tree.h" +#include "transaction.h" +#include "volumes.h" +#include "locking.h" +#include "ref-cache.h" + +#define PENDING_EXTENT_INSERT 0 +#define PENDING_EXTENT_DELETE 1 +#define PENDING_BACKREF_UPDATE 2 + +struct pending_extent_op { + int type; + u64 bytenr; + u64 num_bytes; + u64 parent; + u64 orig_parent; + u64 generation; + u64 orig_generation; + int level; +}; + +static int finish_current_insert(struct btrfs_trans_handle *trans, struct + btrfs_root *extent_root); +static int del_pending_extents(struct btrfs_trans_handle *trans, struct + btrfs_root *extent_root); +static struct btrfs_block_group_cache * +__btrfs_find_block_group(struct btrfs_root *root, + struct btrfs_block_group_cache *hint, + u64 search_start, int data, int owner); + +void maybe_lock_mutex(struct btrfs_root *root) +{ + if (root != root->fs_info->extent_root && + root != root->fs_info->chunk_root && + root != root->fs_info->dev_root) { + mutex_lock(&root->fs_info->alloc_mutex); + } +} + +void maybe_unlock_mutex(struct btrfs_root *root) +{ + if (root != root->fs_info->extent_root && + root != root->fs_info->chunk_root && + root != root->fs_info->dev_root) { + mutex_unlock(&root->fs_info->alloc_mutex); + } +} + +static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) +{ + return (cache->flags & bits) == bits; +} + +/* + * this adds the block group to the fs_info rb tree for the block group + * cache + */ +int btrfs_add_block_group_cache(struct btrfs_fs_info *info, + struct btrfs_block_group_cache *block_group) +{ + struct rb_node **p; + struct rb_node *parent = NULL; + struct btrfs_block_group_cache *cache; + + spin_lock(&info->block_group_cache_lock); + p = &info->block_group_cache_tree.rb_node; + + while (*p) { + parent = *p; + cache = rb_entry(parent, struct btrfs_block_group_cache, + cache_node); + if (block_group->key.objectid < cache->key.objectid) { + p = &(*p)->rb_left; + } else if (block_group->key.objectid > cache->key.objectid) { + p = &(*p)->rb_right; + } else { + spin_unlock(&info->block_group_cache_lock); + return -EEXIST; + } + } + + rb_link_node(&block_group->cache_node, parent, p); + rb_insert_color(&block_group->cache_node, + &info->block_group_cache_tree); + spin_unlock(&info->block_group_cache_lock); + + return 0; +} + +/* + * This will return the block group at or after bytenr if contains is 0, else + * it will return the block group that contains the bytenr + */ +static struct btrfs_block_group_cache * +block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr, + int contains) +{ + struct btrfs_block_group_cache *cache, *ret = NULL; + struct rb_node *n; + u64 end, start; + + spin_lock(&info->block_group_cache_lock); + n = info->block_group_cache_tree.rb_node; + + while (n) { + cache = rb_entry(n, struct btrfs_block_group_cache, + cache_node); + end = cache->key.objectid + cache->key.offset - 1; + start = cache->key.objectid; + + if (bytenr < start) { + if (!contains && (!ret || start < ret->key.objectid)) + ret = cache; + n = n->rb_left; + } else if (bytenr > start) { + if (contains && bytenr <= end) { + ret = cache; + break; + } + n = n->rb_right; + } else { + ret = cache; + break; + } + } + spin_unlock(&info->block_group_cache_lock); + + return ret; +} + +/* + * this is only called by cache_block_group, since we could have freed extents + * we need to check the pinned_extents for any extents that can't be used yet + * since their free space will be released as soon as the transaction commits. + */ +static int add_new_free_space(struct btrfs_block_group_cache *block_group, + struct btrfs_fs_info *info, u64 start, u64 end) +{ + u64 extent_start, extent_end, size; + int ret; + + while (start < end) { + ret = find_first_extent_bit(&info->pinned_extents, start, + &extent_start, &extent_end, + EXTENT_DIRTY); + if (ret) + break; + + if (extent_start == start) { + start = extent_end + 1; + } else if (extent_start > start && extent_start < end) { + size = extent_start - start; + ret = btrfs_add_free_space(block_group, start, size); + BUG_ON(ret); + start = extent_end + 1; + } else { + break; + } + } + + if (start < end) { + size = end - start; + ret = btrfs_add_free_space(block_group, start, size); + BUG_ON(ret); + } + + return 0; +} + +static int cache_block_group(struct btrfs_root *root, + struct btrfs_block_group_cache *block_group) +{ + struct btrfs_path *path; + int ret = 0; + struct btrfs_key key; + struct extent_buffer *leaf; + int slot; + u64 last = 0; + u64 first_free; + int found = 0; + + if (!block_group) + return 0; + + root = root->fs_info->extent_root; + + if (block_group->cached) + return 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = 2; + /* + * we get into deadlocks with paths held by callers of this function. + * since the alloc_mutex is protecting things right now, just + * skip the locking here + */ + path->skip_locking = 1; + first_free = max_t(u64, block_group->key.objectid, + BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE); + key.objectid = block_group->key.objectid; + key.offset = 0; + btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto err; + ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY); + if (ret < 0) + goto err; + if (ret == 0) { + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.objectid + key.offset > first_free) + first_free = key.objectid + key.offset; + } + 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) + goto err; + if (ret == 0) + continue; + else + break; + } + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid < block_group->key.objectid) + goto next; + + if (key.objectid >= block_group->key.objectid + + block_group->key.offset) + break; + + if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) { + if (!found) { + last = first_free; + found = 1; + } + + add_new_free_space(block_group, root->fs_info, last, + key.objectid); + + last = key.objectid + key.offset; + } +next: + path->slots[0]++; + } + + if (!found) + last = first_free; + + add_new_free_space(block_group, root->fs_info, last, + block_group->key.objectid + + block_group->key.offset); + + block_group->cached = 1; + ret = 0; +err: + btrfs_free_path(path); + return ret; +} + +/* + * return the block group that starts at or after bytenr + */ +struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct + btrfs_fs_info *info, + u64 bytenr) +{ + struct btrfs_block_group_cache *cache; + + cache = block_group_cache_tree_search(info, bytenr, 0); + + return cache; +} + +/* + * return the block group that contains teh given bytenr + */ +struct btrfs_block_group_cache *btrfs_lookup_block_group(struct + btrfs_fs_info *info, + u64 bytenr) +{ + struct btrfs_block_group_cache *cache; + + cache = block_group_cache_tree_search(info, bytenr, 1); + + return cache; +} + +static int noinline find_free_space(struct btrfs_root *root, + struct btrfs_block_group_cache **cache_ret, + u64 *start_ret, u64 num, int data) +{ + int ret; + struct btrfs_block_group_cache *cache = *cache_ret; + struct btrfs_free_space *info = NULL; + u64 last; + u64 total_fs_bytes; + u64 search_start = *start_ret; + + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); + total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); + + if (!cache) + goto out; + + last = max(search_start, cache->key.objectid); + +again: + ret = cache_block_group(root, cache); + if (ret) + goto out; + + if (cache->ro || !block_group_bits(cache, data)) + goto new_group; + + info = btrfs_find_free_space(cache, last, num); + if (info) { + *start_ret = info->offset; + return 0; + } + +new_group: + last = cache->key.objectid + cache->key.offset; + + cache = btrfs_lookup_first_block_group(root->fs_info, last); + if (!cache || cache->key.objectid >= total_fs_bytes) + goto out; + + *cache_ret = cache; + goto again; + +out: + return -ENOSPC; +} + +static u64 div_factor(u64 num, int factor) +{ + if (factor == 10) + return num; + num *= factor; + do_div(num, 10); + return num; +} + +static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info, + u64 flags) +{ + struct list_head *head = &info->space_info; + struct list_head *cur; + struct btrfs_space_info *found; + list_for_each(cur, head) { + found = list_entry(cur, struct btrfs_space_info, list); + if (found->flags == flags) + return found; + } + return NULL; + +} + +static struct btrfs_block_group_cache * +__btrfs_find_block_group(struct btrfs_root *root, + struct btrfs_block_group_cache *hint, + u64 search_start, int data, int owner) +{ + struct btrfs_block_group_cache *cache; + struct btrfs_block_group_cache *found_group = NULL; + struct btrfs_fs_info *info = root->fs_info; + struct btrfs_space_info *sinfo; + u64 used; + u64 last = 0; + u64 free_check; + int full_search = 0; + int factor = 10; + int wrapped = 0; + + if (data & BTRFS_BLOCK_GROUP_METADATA) + factor = 9; + + if (search_start) { + struct btrfs_block_group_cache *shint; + shint = btrfs_lookup_first_block_group(info, search_start); + if (shint && block_group_bits(shint, data) && !shint->ro) { + spin_lock(&shint->lock); + used = btrfs_block_group_used(&shint->item); + if (used + shint->pinned < + div_factor(shint->key.offset, factor)) { + spin_unlock(&shint->lock); + return shint; + } + spin_unlock(&shint->lock); + } + } + if (hint && !hint->ro && block_group_bits(hint, data)) { + spin_lock(&hint->lock); + used = btrfs_block_group_used(&hint->item); + if (used + hint->pinned < + div_factor(hint->key.offset, factor)) { + spin_unlock(&hint->lock); + return hint; + } + spin_unlock(&hint->lock); + last = hint->key.objectid + hint->key.offset; + } else { + if (hint) + last = max(hint->key.objectid, search_start); + else + last = search_start; + } + sinfo = __find_space_info(root->fs_info, data); + if (!sinfo) + goto found; +again: + while(1) { + struct list_head *l; + + cache = NULL; + + spin_lock(&sinfo->lock); + list_for_each(l, &sinfo->block_groups) { + struct btrfs_block_group_cache *entry; + entry = list_entry(l, struct btrfs_block_group_cache, + list); + if ((entry->key.objectid >= last) && + (!cache || (entry->key.objectid < + cache->key.objectid))) + cache = entry; + } + spin_unlock(&sinfo->lock); + + if (!cache) + break; + + spin_lock(&cache->lock); + last = cache->key.objectid + cache->key.offset; + used = btrfs_block_group_used(&cache->item); + + if (!cache->ro && block_group_bits(cache, data)) { + free_check = div_factor(cache->key.offset, factor); + if (used + cache->pinned < free_check) { + found_group = cache; + spin_unlock(&cache->lock); + goto found; + } + } + spin_unlock(&cache->lock); + cond_resched(); + } + if (!wrapped) { + last = search_start; + wrapped = 1; + goto again; + } + if (!full_search && factor < 10) { + last = search_start; + full_search = 1; + factor = 10; + goto again; + } +found: + return found_group; +} + +struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root, + struct btrfs_block_group_cache + *hint, u64 search_start, + int data, int owner) +{ + + struct btrfs_block_group_cache *ret; + ret = __btrfs_find_block_group(root, hint, search_start, data, owner); + return ret; +} + +/* simple helper to search for an existing extent at a given offset */ +int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len) +{ + int ret; + struct btrfs_key key; + struct btrfs_path *path; + + path = btrfs_alloc_path(); + BUG_ON(!path); + maybe_lock_mutex(root); + key.objectid = start; + key.offset = len; + btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); + ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path, + 0, 0); + maybe_unlock_mutex(root); + btrfs_free_path(path); + return ret; +} + +/* + * Back reference rules. Back refs have three main goals: + * + * 1) differentiate between all holders of references to an extent so that + * when a reference is dropped we can make sure it was a valid reference + * before freeing the extent. + * + * 2) Provide enough information to quickly find the holders of an extent + * if we notice a given block is corrupted or bad. + * + * 3) Make it easy to migrate blocks for FS shrinking or storage pool + * maintenance. This is actually the same as #2, but with a slightly + * different use case. + * + * File extents can be referenced by: + * + * - multiple snapshots, subvolumes, or different generations in one subvol + * - different files inside a single subvolume + * - different offsets inside a file (bookend extents in file.c) + * + * The extent ref structure has fields for: + * + * - Objectid of the subvolume root + * - Generation number of the tree holding the reference + * - objectid of the file holding the reference + * - offset in the file corresponding to the key holding the reference + * - number of references holding by parent node (alway 1 for tree blocks) + * + * Btree leaf may hold multiple references to a file extent. In most cases, + * these references are from same file and the corresponding offsets inside + * the file are close together. So inode objectid and offset in file are + * just hints, they provide hints about where in the btree the references + * can be found and when we can stop searching. + * + * When a file extent is allocated the fields are filled in: + * (root_key.objectid, trans->transid, inode objectid, offset in file, 1) + * + * When a leaf is cow'd new references are added for every file extent found + * in the leaf. It looks similar to the create case, but trans->transid will + * be different when the block is cow'd. + * + * (root_key.objectid, trans->transid, inode objectid, offset in file, + * number of references in the leaf) + * + * Because inode objectid and offset in file are just hints, they are not + * used when backrefs are deleted. When a file extent is removed either + * during snapshot deletion or file truncation, we find the corresponding + * back back reference and check the following fields. + * + * (btrfs_header_owner(leaf), btrfs_header_generation(leaf)) + * + * Btree extents can be referenced by: + * + * - Different subvolumes + * - Different generations of the same subvolume + * + * When a tree block is created, back references are inserted: + * + * (root->root_key.objectid, trans->transid, level, 0, 1) + * + * When a tree block is cow'd, new back references are added for all the + * blocks it points to. If the tree block isn't in reference counted root, + * the old back references are removed. These new back references are of + * the form (trans->transid will have increased since creation): + * + * (root->root_key.objectid, trans->transid, level, 0, 1) + * + * When a backref is in deleting, the following fields are checked: + * + * if backref was for a tree root: + * (btrfs_header_owner(itself), btrfs_header_generation(itself)) + * else + * (btrfs_header_owner(parent), btrfs_header_generation(parent)) + * + * Back Reference Key composing: + * + * The key objectid corresponds to the first byte in the extent, the key + * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first + * byte of parent extent. If a extent is tree root, the key offset is set + * to the key objectid. + */ + +static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, u64 bytenr, + u64 parent, u64 ref_root, + u64 ref_generation, int del) +{ + struct btrfs_key key; + struct btrfs_extent_ref *ref; + struct extent_buffer *leaf; + int ret; + + key.objectid = bytenr; + key.type = BTRFS_EXTENT_REF_KEY; + key.offset = parent; + + ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1); + if (ret < 0) + goto out; + if (ret > 0) { + ret = -ENOENT; + goto out; + } + + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); + if (btrfs_ref_root(leaf, ref) != ref_root || + btrfs_ref_generation(leaf, ref) != ref_generation) { + ret = -EIO; + WARN_ON(1); + goto out; + } + ret = 0; +out: + return ret; +} + +static int noinline insert_extent_backref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + u64 bytenr, u64 parent, + u64 ref_root, u64 ref_generation, + u64 owner_objectid, u64 owner_offset) +{ + struct btrfs_key key; + struct extent_buffer *leaf; + struct btrfs_extent_ref *ref; + u32 num_refs; + int ret; + + key.objectid = bytenr; + key.type = BTRFS_EXTENT_REF_KEY; + key.offset = parent; + + ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref)); + if (ret == 0) { + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_ref); + btrfs_set_ref_root(leaf, ref, ref_root); + btrfs_set_ref_generation(leaf, ref, ref_generation); + btrfs_set_ref_objectid(leaf, ref, owner_objectid); + btrfs_set_ref_offset(leaf, ref, owner_offset); + btrfs_set_ref_num_refs(leaf, ref, 1); + } else if (ret == -EEXIST) { + u64 existing_owner; + BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID); + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_ref); + if (btrfs_ref_root(leaf, ref) != ref_root || + btrfs_ref_generation(leaf, ref) != ref_generation) { + ret = -EIO; + WARN_ON(1); + goto out; + } + + num_refs = btrfs_ref_num_refs(leaf, ref); + BUG_ON(num_refs == 0); + btrfs_set_ref_num_refs(leaf, ref, num_refs + 1); + + existing_owner = btrfs_ref_objectid(leaf, ref); + if (existing_owner == owner_objectid && + btrfs_ref_offset(leaf, ref) > owner_offset) { + btrfs_set_ref_offset(leaf, ref, owner_offset); + } else if (existing_owner != owner_objectid && + existing_owner != BTRFS_MULTIPLE_OBJECTIDS) { + btrfs_set_ref_objectid(leaf, ref, + BTRFS_MULTIPLE_OBJECTIDS); + btrfs_set_ref_offset(leaf, ref, 0); + } + ret = 0; + } else { + goto out; + } + btrfs_mark_buffer_dirty(path->nodes[0]); +out: + btrfs_release_path(root, path); + return ret; +} + +static int noinline remove_extent_backref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path) +{ + struct extent_buffer *leaf; + struct btrfs_extent_ref *ref; + u32 num_refs; + int ret = 0; + + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); + num_refs = btrfs_ref_num_refs(leaf, ref); + BUG_ON(num_refs == 0); + num_refs -= 1; + if (num_refs == 0) { + ret = btrfs_del_item(trans, root, path); + } else { + btrfs_set_ref_num_refs(leaf, ref, num_refs); + btrfs_mark_buffer_dirty(leaf); + } + btrfs_release_path(root, path); + return ret; +} + +static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 orig_parent, u64 parent, + u64 orig_root, u64 ref_root, + u64 orig_generation, u64 ref_generation, + u64 owner_objectid, u64 owner_offset) +{ + int ret; + struct btrfs_root *extent_root = root->fs_info->extent_root; + struct btrfs_path *path; + + if (root == root->fs_info->extent_root) { + struct pending_extent_op *extent_op; + u64 num_bytes; + + BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL); + num_bytes = btrfs_level_size(root, (int)owner_objectid); + if (test_range_bit(&root->fs_info->extent_ins, bytenr, + bytenr + num_bytes - 1, EXTENT_LOCKED, 0)) { + u64 priv; + ret = get_state_private(&root->fs_info->extent_ins, + bytenr, &priv); + BUG_ON(ret); + extent_op = (struct pending_extent_op *) + (unsigned long)priv; + BUG_ON(extent_op->parent != orig_parent); + BUG_ON(extent_op->generation != orig_generation); + extent_op->parent = parent; + extent_op->generation = ref_generation; + } else { + extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS); + BUG_ON(!extent_op); + + extent_op->type = PENDING_BACKREF_UPDATE; + extent_op->bytenr = bytenr; + extent_op->num_bytes = num_bytes; + extent_op->parent = parent; + extent_op->orig_parent = orig_parent; + extent_op->generation = ref_generation; + extent_op->orig_generation = orig_generation; + extent_op->level = (int)owner_objectid; + + set_extent_bits(&root->fs_info->extent_ins, + bytenr, bytenr + num_bytes - 1, + EXTENT_LOCKED, GFP_NOFS); + set_state_private(&root->fs_info->extent_ins, + bytenr, (unsigned long)extent_op); + } + return 0; + } + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + ret = lookup_extent_backref(trans, extent_root, path, + bytenr, orig_parent, orig_root, + orig_generation, 1); + if (ret) + goto out; + ret = remove_extent_backref(trans, extent_root, path); + if (ret) + goto out; + ret = insert_extent_backref(trans, extent_root, path, bytenr, + parent, ref_root, ref_generation, + owner_objectid, owner_offset); + BUG_ON(ret); + finish_current_insert(trans, extent_root); + del_pending_extents(trans, extent_root); +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_update_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 orig_parent, u64 parent, + u64 ref_root, u64 ref_generation, + u64 owner_objectid, u64 owner_offset) +{ + int ret; + if (ref_root == BTRFS_TREE_LOG_OBJECTID && + owner_objectid < BTRFS_FIRST_FREE_OBJECTID) + return 0; + maybe_lock_mutex(root); + ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent, + parent, ref_root, ref_root, + ref_generation, ref_generation, + owner_objectid, owner_offset); + maybe_unlock_mutex(root); + return ret; +} + +static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 orig_parent, u64 parent, + u64 orig_root, u64 ref_root, + u64 orig_generation, u64 ref_generation, + u64 owner_objectid, u64 owner_offset) +{ + struct btrfs_path *path; + int ret; + struct btrfs_key key; + struct extent_buffer *l; + struct btrfs_extent_item *item; + u32 refs; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = 1; + key.objectid = bytenr; + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, + 0, 1); + if (ret < 0) + return ret; + BUG_ON(ret == 0 || path->slots[0] == 0); + + path->slots[0]--; + l = path->nodes[0]; + + btrfs_item_key_to_cpu(l, &key, path->slots[0]); + BUG_ON(key.objectid != bytenr); + BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY); + + item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); + refs = btrfs_extent_refs(l, item); + btrfs_set_extent_refs(l, item, refs + 1); + btrfs_mark_buffer_dirty(path->nodes[0]); + + btrfs_release_path(root->fs_info->extent_root, path); + + path->reada = 1; + ret = insert_extent_backref(trans, root->fs_info->extent_root, + path, bytenr, parent, + ref_root, ref_generation, + owner_objectid, owner_offset); + BUG_ON(ret); + finish_current_insert(trans, root->fs_info->extent_root); + del_pending_extents(trans, root->fs_info->extent_root); + + btrfs_free_path(path); + return 0; +} + +int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, + u64 ref_root, u64 ref_generation, + u64 owner_objectid, u64 owner_offset) +{ + int ret; + if (ref_root == BTRFS_TREE_LOG_OBJECTID && + owner_objectid < BTRFS_FIRST_FREE_OBJECTID) + return 0; + maybe_lock_mutex(root); + ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent, + 0, ref_root, 0, ref_generation, + owner_objectid, owner_offset); + maybe_unlock_mutex(root); + return ret; +} + +int btrfs_extent_post_op(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + finish_current_insert(trans, root->fs_info->extent_root); + del_pending_extents(trans, root->fs_info->extent_root); + return 0; +} + +int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 num_bytes, u32 *refs) +{ + struct btrfs_path *path; + int ret; + struct btrfs_key key; + struct extent_buffer *l; + struct btrfs_extent_item *item; + + WARN_ON(num_bytes < root->sectorsize); + path = btrfs_alloc_path(); + path->reada = 1; + key.objectid = bytenr; + key.offset = num_bytes; + btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); + ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, + 0, 0); + if (ret < 0) + goto out; + if (ret != 0) { + btrfs_print_leaf(root, path->nodes[0]); + printk("failed to find block number %Lu\n", bytenr); + BUG(); + } + l = path->nodes[0]; + item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); + *refs = btrfs_extent_refs(l, item); +out: + btrfs_free_path(path); + return 0; +} + +static int get_reference_status(struct btrfs_root *root, u64 bytenr, + u64 parent_gen, u64 ref_objectid, + u64 *min_generation, u32 *ref_count) +{ + struct btrfs_root *extent_root = root->fs_info->extent_root; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_extent_ref *ref_item; + struct btrfs_key key; + struct btrfs_key found_key; + u64 root_objectid = root->root_key.objectid; + u64 ref_generation; + u32 nritems; + int ret; + + key.objectid = bytenr; + key.offset = (u64)-1; + key.type = BTRFS_EXTENT_ITEM_KEY; + + path = btrfs_alloc_path(); + mutex_lock(&root->fs_info->alloc_mutex); + ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); + if (ret < 0) + goto out; + BUG_ON(ret == 0); + if (ret < 0 || path->slots[0] == 0) + goto out; + + path->slots[0]--; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + if (found_key.objectid != bytenr || + found_key.type != BTRFS_EXTENT_ITEM_KEY) { + ret = 1; + goto out; + } + + *ref_count = 0; + *min_generation = (u64)-1; + + while (1) { + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(extent_root, path); + if (ret < 0) + goto out; + if (ret == 0) + continue; + break; + } + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid != bytenr) + break; + + if (found_key.type != BTRFS_EXTENT_REF_KEY) { + path->slots[0]++; + continue; + } + + ref_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_ref); + ref_generation = btrfs_ref_generation(leaf, ref_item); + /* + * For (parent_gen > 0 && parent_gen > ref_generation): + * + * we reach here through the oldest root, therefore + * all other reference from same snapshot should have + * a larger generation. + */ + if ((root_objectid != btrfs_ref_root(leaf, ref_item)) || + (parent_gen > 0 && parent_gen > ref_generation) || + (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID && + ref_objectid != btrfs_ref_objectid(leaf, ref_item))) { + *ref_count = 2; + break; + } + + *ref_count = 1; + if (*min_generation > ref_generation) + *min_generation = ref_generation; + + path->slots[0]++; + } + ret = 0; +out: + mutex_unlock(&root->fs_info->alloc_mutex); + btrfs_free_path(path); + return ret; +} + +int btrfs_cross_ref_exists(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_key *key, u64 bytenr) +{ + struct btrfs_root *old_root; + struct btrfs_path *path = NULL; + struct extent_buffer *eb; + struct btrfs_file_extent_item *item; + u64 ref_generation; + u64 min_generation; + u64 extent_start; + u32 ref_count; + int level; + int ret; + + BUG_ON(trans == NULL); + BUG_ON(key->type != BTRFS_EXTENT_DATA_KEY); + ret = get_reference_status(root, bytenr, 0, key->objectid, + &min_generation, &ref_count); + if (ret) + return ret; + + if (ref_count != 1) + return 1; + + old_root = root->dirty_root->root; + ref_generation = old_root->root_key.offset; + + /* all references are created in running transaction */ + if (min_generation > ref_generation) { + ret = 0; + goto out; + } + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + path->skip_locking = 1; + /* if no item found, the extent is referenced by other snapshot */ + ret = btrfs_search_slot(NULL, old_root, key, path, 0, 0); + if (ret) + goto out; + + eb = path->nodes[0]; + item = btrfs_item_ptr(eb, path->slots[0], + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(eb, item) != BTRFS_FILE_EXTENT_REG || + btrfs_file_extent_disk_bytenr(eb, item) != bytenr) { + ret = 1; + goto out; + } + + for (level = BTRFS_MAX_LEVEL - 1; level >= -1; level--) { + if (level >= 0) { + eb = path->nodes[level]; + if (!eb) + continue; + extent_start = eb->start; + } else + extent_start = bytenr; + + ret = get_reference_status(root, extent_start, ref_generation, + 0, &min_generation, &ref_count); + if (ret) + goto out; + + if (ref_count != 1) { + ret = 1; + goto out; + } + if (level >= 0) + ref_generation = btrfs_header_generation(eb); + } + ret = 0; +out: + if (path) + btrfs_free_path(path); + return ret; +} + +int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct extent_buffer *buf, u32 nr_extents) +{ + u32 nritems; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + int i; + int level; + int ret = 0; + + if (!root->ref_cows) + return 0; + + level = btrfs_header_level(buf); + nritems = btrfs_header_nritems(buf); + + if (level == 0) { + struct btrfs_leaf_ref *ref; + struct btrfs_extent_info *info; + + ref = btrfs_alloc_leaf_ref(root, nr_extents); + if (!ref) { + ret = -ENOMEM; + goto out; + } + + ref->root_gen = root->root_key.offset; + ref->bytenr = buf->start; + ref->owner = btrfs_header_owner(buf); + ref->generation = btrfs_header_generation(buf); + ref->nritems = nr_extents; + info = ref->extents; + + for (i = 0; nr_extents > 0 && i < nritems; i++) { + u64 disk_bytenr; + btrfs_item_key_to_cpu(buf, &key, i); + if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(buf, i, + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(buf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); + if (disk_bytenr == 0) + continue; + + info->bytenr = disk_bytenr; + info->num_bytes = + btrfs_file_extent_disk_num_bytes(buf, fi); + info->objectid = key.objectid; + info->offset = key.offset; + info++; + } + + BUG_ON(!root->ref_tree); + ret = btrfs_add_leaf_ref(root, ref); + WARN_ON(ret); + btrfs_free_leaf_ref(root, ref); + } +out: + return ret; +} + +int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct extent_buffer *orig_buf, struct extent_buffer *buf, + u32 *nr_extents) +{ + u64 bytenr; + u64 ref_root; + u64 orig_root; + u64 ref_generation; + u64 orig_generation; + u32 nritems; + u32 nr_file_extents = 0; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + int i; + int level; + int ret = 0; + int faili = 0; + int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *, + u64, u64, u64, u64, u64, u64, u64, u64, u64); + + ref_root = btrfs_header_owner(buf); + ref_generation = btrfs_header_generation(buf); + orig_root = btrfs_header_owner(orig_buf); + orig_generation = btrfs_header_generation(orig_buf); + + nritems = btrfs_header_nritems(buf); + level = btrfs_header_level(buf); + + if (root->ref_cows) { + process_func = __btrfs_inc_extent_ref; + } else { + if (level == 0 && + root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) + goto out; + if (level != 0 && + root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) + goto out; + process_func = __btrfs_update_extent_ref; + } + + for (i = 0; i < nritems; i++) { + cond_resched(); + if (level == 0) { + btrfs_item_key_to_cpu(buf, &key, i); + if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(buf, i, + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(buf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + bytenr = btrfs_file_extent_disk_bytenr(buf, fi); + if (bytenr == 0) + continue; + + nr_file_extents++; + + maybe_lock_mutex(root); + ret = process_func(trans, root, bytenr, + orig_buf->start, buf->start, + orig_root, ref_root, + orig_generation, ref_generation, + key.objectid, key.offset); + maybe_unlock_mutex(root); + + if (ret) { + faili = i; + WARN_ON(1); + goto fail; + } + } else { + bytenr = btrfs_node_blockptr(buf, i); + maybe_lock_mutex(root); + ret = process_func(trans, root, bytenr, + orig_buf->start, buf->start, + orig_root, ref_root, + orig_generation, ref_generation, + level - 1, 0); + maybe_unlock_mutex(root); + if (ret) { + faili = i; + WARN_ON(1); + goto fail; + } + } + } +out: + if (nr_extents) { + if (level == 0) + *nr_extents = nr_file_extents; + else + *nr_extents = nritems; + } + return 0; +fail: + WARN_ON(1); + return ret; +} + +int btrfs_update_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct extent_buffer *orig_buf, + struct extent_buffer *buf, int start_slot, int nr) + +{ + u64 bytenr; + u64 ref_root; + u64 orig_root; + u64 ref_generation; + u64 orig_generation; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + int i; + int ret; + int slot; + int level; + + BUG_ON(start_slot < 0); + BUG_ON(start_slot + nr > btrfs_header_nritems(buf)); + + ref_root = btrfs_header_owner(buf); + ref_generation = btrfs_header_generation(buf); + orig_root = btrfs_header_owner(orig_buf); + orig_generation = btrfs_header_generation(orig_buf); + level = btrfs_header_level(buf); + + if (!root->ref_cows) { + if (level == 0 && + root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) + return 0; + if (level != 0 && + root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) + return 0; + } + + for (i = 0, slot = start_slot; i < nr; i++, slot++) { + cond_resched(); + if (level == 0) { + btrfs_item_key_to_cpu(buf, &key, slot); + if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(buf, slot, + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(buf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + bytenr = btrfs_file_extent_disk_bytenr(buf, fi); + if (bytenr == 0) + continue; + maybe_lock_mutex(root); + ret = __btrfs_update_extent_ref(trans, root, bytenr, + orig_buf->start, buf->start, + orig_root, ref_root, + orig_generation, ref_generation, + key.objectid, key.offset); + maybe_unlock_mutex(root); + if (ret) + goto fail; + } else { + bytenr = btrfs_node_blockptr(buf, slot); + maybe_lock_mutex(root); + ret = __btrfs_update_extent_ref(trans, root, bytenr, + orig_buf->start, buf->start, + orig_root, ref_root, + orig_generation, ref_generation, + level - 1, 0); + maybe_unlock_mutex(root); + if (ret) + goto fail; + } + } + return 0; +fail: + WARN_ON(1); + return -1; +} + +static int write_one_cache_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_block_group_cache *cache) +{ + int ret; + int pending_ret; + struct btrfs_root *extent_root = root->fs_info->extent_root; + unsigned long bi; + struct extent_buffer *leaf; + + ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1); + if (ret < 0) + goto fail; + BUG_ON(ret); + + leaf = path->nodes[0]; + bi = btrfs_item_ptr_offset(leaf, path->slots[0]); + write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item)); + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(extent_root, path); +fail: + finish_current_insert(trans, extent_root); + pending_ret = del_pending_extents(trans, extent_root); + if (ret) + return ret; + if (pending_ret) + return pending_ret; + return 0; + +} + +int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_block_group_cache *cache, *entry; + struct rb_node *n; + int err = 0; + int werr = 0; + struct btrfs_path *path; + u64 last = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + mutex_lock(&root->fs_info->alloc_mutex); + while(1) { + cache = NULL; + spin_lock(&root->fs_info->block_group_cache_lock); + for (n = rb_first(&root->fs_info->block_group_cache_tree); + n; n = rb_next(n)) { + entry = rb_entry(n, struct btrfs_block_group_cache, + cache_node); + if (entry->dirty) { + cache = entry; + break; + } + } + spin_unlock(&root->fs_info->block_group_cache_lock); + + if (!cache) + break; + + last += cache->key.offset; + + err = write_one_cache_group(trans, root, + path, cache); + /* + * if we fail to write the cache group, we want + * to keep it marked dirty in hopes that a later + * write will work + */ + if (err) { + werr = err; + continue; + } + + cache->dirty = 0; + } + btrfs_free_path(path); + mutex_unlock(&root->fs_info->alloc_mutex); + return werr; +} + +static int update_space_info(struct btrfs_fs_info *info, u64 flags, + u64 total_bytes, u64 bytes_used, + struct btrfs_space_info **space_info) +{ + struct btrfs_space_info *found; + + found = __find_space_info(info, flags); + if (found) { + found->total_bytes += total_bytes; + found->bytes_used += bytes_used; + found->full = 0; + *space_info = found; + return 0; + } + found = kmalloc(sizeof(*found), GFP_NOFS); + if (!found) + return -ENOMEM; + + list_add(&found->list, &info->space_info); + INIT_LIST_HEAD(&found->block_groups); + spin_lock_init(&found->lock); + found->flags = flags; + found->total_bytes = total_bytes; + found->bytes_used = bytes_used; + found->bytes_pinned = 0; + found->full = 0; + found->force_alloc = 0; + *space_info = found; + return 0; +} + +static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) +{ + u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_DUP); + if (extra_flags) { + if (flags & BTRFS_BLOCK_GROUP_DATA) + fs_info->avail_data_alloc_bits |= extra_flags; + if (flags & BTRFS_BLOCK_GROUP_METADATA) + fs_info->avail_metadata_alloc_bits |= extra_flags; + if (flags & BTRFS_BLOCK_GROUP_SYSTEM) + fs_info->avail_system_alloc_bits |= extra_flags; + } +} + +static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags) +{ + u64 num_devices = root->fs_info->fs_devices->num_devices; + + if (num_devices == 1) + flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0); + if (num_devices < 4) + flags &= ~BTRFS_BLOCK_GROUP_RAID10; + + if ((flags & BTRFS_BLOCK_GROUP_DUP) && + (flags & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10))) { + flags &= ~BTRFS_BLOCK_GROUP_DUP; + } + + if ((flags & BTRFS_BLOCK_GROUP_RAID1) && + (flags & BTRFS_BLOCK_GROUP_RAID10)) { + flags &= ~BTRFS_BLOCK_GROUP_RAID1; + } + + if ((flags & BTRFS_BLOCK_GROUP_RAID0) && + ((flags & BTRFS_BLOCK_GROUP_RAID1) | + (flags & BTRFS_BLOCK_GROUP_RAID10) | + (flags & BTRFS_BLOCK_GROUP_DUP))) + flags &= ~BTRFS_BLOCK_GROUP_RAID0; + return flags; +} + +static int do_chunk_alloc(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, u64 alloc_bytes, + u64 flags, int force) +{ + struct btrfs_space_info *space_info; + u64 thresh; + u64 start; + u64 num_bytes; + int ret = 0; + + flags = reduce_alloc_profile(extent_root, flags); + + space_info = __find_space_info(extent_root->fs_info, flags); + if (!space_info) { + ret = update_space_info(extent_root->fs_info, flags, + 0, 0, &space_info); + BUG_ON(ret); + } + BUG_ON(!space_info); + + if (space_info->force_alloc) { + force = 1; + space_info->force_alloc = 0; + } + if (space_info->full) + goto out; + + thresh = div_factor(space_info->total_bytes, 6); + if (!force && + (space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) < + thresh) + goto out; + + mutex_lock(&extent_root->fs_info->chunk_mutex); + ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags); + if (ret == -ENOSPC) { +printk("space info full %Lu\n", flags); + space_info->full = 1; + goto out_unlock; + } + BUG_ON(ret); + + ret = btrfs_make_block_group(trans, extent_root, 0, flags, + BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes); + BUG_ON(ret); + +out_unlock: + mutex_unlock(&extent_root->fs_info->chunk_mutex); +out: + return ret; +} + +static int update_block_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, int alloc, + int mark_free) +{ + struct btrfs_block_group_cache *cache; + struct btrfs_fs_info *info = root->fs_info; + u64 total = num_bytes; + u64 old_val; + u64 byte_in_group; + + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); + while(total) { + cache = btrfs_lookup_block_group(info, bytenr); + if (!cache) { + return -1; + } + byte_in_group = bytenr - cache->key.objectid; + WARN_ON(byte_in_group > cache->key.offset); + + spin_lock(&cache->lock); + cache->dirty = 1; + old_val = btrfs_block_group_used(&cache->item); + num_bytes = min(total, cache->key.offset - byte_in_group); + if (alloc) { + old_val += num_bytes; + cache->space_info->bytes_used += num_bytes; + btrfs_set_block_group_used(&cache->item, old_val); + spin_unlock(&cache->lock); + } else { + old_val -= num_bytes; + cache->space_info->bytes_used -= num_bytes; + btrfs_set_block_group_used(&cache->item, old_val); + spin_unlock(&cache->lock); + if (mark_free) { + int ret; + ret = btrfs_add_free_space(cache, bytenr, + num_bytes); + if (ret) + return -1; + } + } + total -= num_bytes; + bytenr += num_bytes; + } + return 0; +} + +static u64 first_logical_byte(struct btrfs_root *root, u64 search_start) +{ + struct btrfs_block_group_cache *cache; + + cache = btrfs_lookup_first_block_group(root->fs_info, search_start); + if (!cache) + return 0; + + return cache->key.objectid; +} + + +int btrfs_update_pinned_extents(struct btrfs_root *root, + u64 bytenr, u64 num, int pin) +{ + u64 len; + struct btrfs_block_group_cache *cache; + struct btrfs_fs_info *fs_info = root->fs_info; + + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); + if (pin) { + set_extent_dirty(&fs_info->pinned_extents, + bytenr, bytenr + num - 1, GFP_NOFS); + } else { + clear_extent_dirty(&fs_info->pinned_extents, + bytenr, bytenr + num - 1, GFP_NOFS); + } + while (num > 0) { + cache = btrfs_lookup_block_group(fs_info, bytenr); + if (!cache) { + u64 first = first_logical_byte(root, bytenr); + WARN_ON(first < bytenr); + len = min(first - bytenr, num); + } else { + len = min(num, cache->key.offset - + (bytenr - cache->key.objectid)); + } + if (pin) { + if (cache) { + spin_lock(&cache->lock); + cache->pinned += len; + cache->space_info->bytes_pinned += len; + spin_unlock(&cache->lock); + } + fs_info->total_pinned += len; + } else { + if (cache) { + spin_lock(&cache->lock); + cache->pinned -= len; + cache->space_info->bytes_pinned -= len; + spin_unlock(&cache->lock); + } + fs_info->total_pinned -= len; + } + bytenr += len; + num -= len; + } + return 0; +} + +int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy) +{ + u64 last = 0; + u64 start; + u64 end; + struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents; + int ret; + + while(1) { + ret = find_first_extent_bit(pinned_extents, last, + &start, &end, EXTENT_DIRTY); + if (ret) + break; + set_extent_dirty(copy, start, end, GFP_NOFS); + last = end + 1; + } + return 0; +} + +int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_io_tree *unpin) +{ + u64 start; + u64 end; + int ret; + struct btrfs_block_group_cache *cache; + + mutex_lock(&root->fs_info->alloc_mutex); + while(1) { + ret = find_first_extent_bit(unpin, 0, &start, &end, + EXTENT_DIRTY); + if (ret) + break; + btrfs_update_pinned_extents(root, start, end + 1 - start, 0); + clear_extent_dirty(unpin, start, end, GFP_NOFS); + cache = btrfs_lookup_block_group(root->fs_info, start); + if (cache->cached) + btrfs_add_free_space(cache, start, end - start + 1); + if (need_resched()) { + mutex_unlock(&root->fs_info->alloc_mutex); + cond_resched(); + mutex_lock(&root->fs_info->alloc_mutex); + } + } + mutex_unlock(&root->fs_info->alloc_mutex); + return 0; +} + +static int finish_current_insert(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root) +{ + u64 start; + u64 end; + u64 priv; + struct btrfs_fs_info *info = extent_root->fs_info; + struct btrfs_path *path; + struct btrfs_extent_ref *ref; + struct pending_extent_op *extent_op; + struct btrfs_key key; + struct btrfs_extent_item extent_item; + int ret; + int err = 0; + + WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); + btrfs_set_stack_extent_refs(&extent_item, 1); + path = btrfs_alloc_path(); + + while(1) { + ret = find_first_extent_bit(&info->extent_ins, 0, &start, + &end, EXTENT_LOCKED); + if (ret) + break; + + ret = get_state_private(&info->extent_ins, start, &priv); + BUG_ON(ret); + extent_op = (struct pending_extent_op *)(unsigned long)priv; + + if (extent_op->type == PENDING_EXTENT_INSERT) { + key.objectid = start; + key.offset = end + 1 - start; + key.type = BTRFS_EXTENT_ITEM_KEY; + err = btrfs_insert_item(trans, extent_root, &key, + &extent_item, sizeof(extent_item)); + BUG_ON(err); + + clear_extent_bits(&info->extent_ins, start, end, + EXTENT_LOCKED, GFP_NOFS); + + err = insert_extent_backref(trans, extent_root, path, + start, extent_op->parent, + extent_root->root_key.objectid, + extent_op->generation, + extent_op->level, 0); + BUG_ON(err); + } else if (extent_op->type == PENDING_BACKREF_UPDATE) { + err = lookup_extent_backref(trans, extent_root, path, + start, extent_op->orig_parent, + extent_root->root_key.objectid, + extent_op->orig_generation, 0); + BUG_ON(err); + + clear_extent_bits(&info->extent_ins, start, end, + EXTENT_LOCKED, GFP_NOFS); + + key.objectid = start; + key.offset = extent_op->parent; + key.type = BTRFS_EXTENT_REF_KEY; + err = btrfs_set_item_key_safe(trans, extent_root, path, + &key); + BUG_ON(err); + ref = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_extent_ref); + btrfs_set_ref_generation(path->nodes[0], ref, + extent_op->generation); + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_release_path(extent_root, path); + } else { + BUG_ON(1); + } + kfree(extent_op); + + if (need_resched()) { + mutex_unlock(&extent_root->fs_info->alloc_mutex); + cond_resched(); + mutex_lock(&extent_root->fs_info->alloc_mutex); + } + } + btrfs_free_path(path); + return 0; +} + +static int pin_down_bytes(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, int is_data) +{ + int err = 0; + struct extent_buffer *buf; + + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); + if (is_data) + goto pinit; + + buf = btrfs_find_tree_block(root, bytenr, num_bytes); + if (!buf) + goto pinit; + + /* we can reuse a block if it hasn't been written + * and it is from this transaction. We can't + * reuse anything from the tree log root because + * it has tiny sub-transactions. + */ + if (btrfs_buffer_uptodate(buf, 0) && + btrfs_try_tree_lock(buf)) { + u64 header_owner = btrfs_header_owner(buf); + u64 header_transid = btrfs_header_generation(buf); + if (header_owner != BTRFS_TREE_LOG_OBJECTID && + header_transid == trans->transid && + !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { + clean_tree_block(NULL, root, buf); + btrfs_tree_unlock(buf); + free_extent_buffer(buf); + return 1; + } + btrfs_tree_unlock(buf); + } + free_extent_buffer(buf); +pinit: + btrfs_update_pinned_extents(root, bytenr, num_bytes, 1); + + BUG_ON(err < 0); + return 0; +} + +/* + * remove an extent from the root, returns 0 on success + */ +static int __free_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner_objectid, u64 owner_offset, + int pin, int mark_free) +{ + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_fs_info *info = root->fs_info; + struct btrfs_root *extent_root = info->extent_root; + struct extent_buffer *leaf; + int ret; + int extent_slot = 0; + int found_extent = 0; + int num_to_del = 1; + struct btrfs_extent_item *ei; + u32 refs; + + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); + key.objectid = bytenr; + btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); + key.offset = num_bytes; + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = 1; + ret = lookup_extent_backref(trans, extent_root, path, bytenr, parent, + root_objectid, ref_generation, 1); + if (ret == 0) { + struct btrfs_key found_key; + extent_slot = path->slots[0]; + while(extent_slot > 0) { + extent_slot--; + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + extent_slot); + if (found_key.objectid != bytenr) + break; + if (found_key.type == BTRFS_EXTENT_ITEM_KEY && + found_key.offset == num_bytes) { + found_extent = 1; + break; + } + if (path->slots[0] - extent_slot > 5) + break; + } + if (!found_extent) { + ret = remove_extent_backref(trans, extent_root, path); + BUG_ON(ret); + btrfs_release_path(extent_root, path); + ret = btrfs_search_slot(trans, extent_root, + &key, path, -1, 1); + BUG_ON(ret); + extent_slot = path->slots[0]; + } + } else { + btrfs_print_leaf(extent_root, path->nodes[0]); + WARN_ON(1); + printk("Unable to find ref byte nr %Lu root %Lu " + " gen %Lu owner %Lu offset %Lu\n", bytenr, + root_objectid, ref_generation, owner_objectid, + owner_offset); + } + + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, extent_slot, + struct btrfs_extent_item); + refs = btrfs_extent_refs(leaf, ei); + BUG_ON(refs == 0); + refs -= 1; + btrfs_set_extent_refs(leaf, ei, refs); + + btrfs_mark_buffer_dirty(leaf); + + if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) { + struct btrfs_extent_ref *ref; + ref = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_ref); + BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1); + /* if the back ref and the extent are next to each other + * they get deleted below in one shot + */ + path->slots[0] = extent_slot; + num_to_del = 2; + } else if (found_extent) { + /* otherwise delete the extent back ref */ + ret = remove_extent_backref(trans, extent_root, path); + BUG_ON(ret); + /* if refs are 0, we need to setup the path for deletion */ + if (refs == 0) { + btrfs_release_path(extent_root, path); + ret = btrfs_search_slot(trans, extent_root, &key, path, + -1, 1); + BUG_ON(ret); + } + } + + if (refs == 0) { + u64 super_used; + u64 root_used; +#ifdef BIO_RW_DISCARD + u64 map_length = num_bytes; + struct btrfs_multi_bio *multi = NULL; +#endif + + if (pin) { + ret = pin_down_bytes(trans, root, bytenr, num_bytes, + owner_objectid >= BTRFS_FIRST_FREE_OBJECTID); + if (ret > 0) + mark_free = 1; + BUG_ON(ret < 0); + } + + /* block accounting for super block */ + spin_lock_irq(&info->delalloc_lock); + super_used = btrfs_super_bytes_used(&info->super_copy); + btrfs_set_super_bytes_used(&info->super_copy, + super_used - num_bytes); + spin_unlock_irq(&info->delalloc_lock); + + /* block accounting for root item */ + root_used = btrfs_root_used(&root->root_item); + btrfs_set_root_used(&root->root_item, + root_used - num_bytes); + ret = btrfs_del_items(trans, extent_root, path, path->slots[0], + num_to_del); + BUG_ON(ret); + ret = update_block_group(trans, root, bytenr, num_bytes, 0, + mark_free); + BUG_ON(ret); + +#ifdef BIO_RW_DISCARD + /* Tell the block device(s) that the sectors can be discarded */ + ret = btrfs_map_block(&root->fs_info->mapping_tree, READ, + bytenr, &map_length, &multi, 0); + if (!ret) { + struct btrfs_bio_stripe *stripe = multi->stripes; + int i; + + if (map_length > num_bytes) + map_length = num_bytes; + + for (i = 0; i < multi->num_stripes; i++, stripe++) { + blkdev_issue_discard(stripe->dev->bdev, + stripe->physical >> 9, + map_length >> 9); + } + kfree(multi); + } +#endif + } + btrfs_free_path(path); + finish_current_insert(trans, extent_root); + return ret; +} + +/* + * find all the blocks marked as pending in the radix tree and remove + * them from the extent map + */ +static int del_pending_extents(struct btrfs_trans_handle *trans, struct + btrfs_root *extent_root) +{ + int ret; + int err = 0; + int mark_free = 0; + u64 start; + u64 end; + u64 priv; + struct extent_io_tree *pending_del; + struct extent_io_tree *extent_ins; + struct pending_extent_op *extent_op; + + WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); + extent_ins = &extent_root->fs_info->extent_ins; + pending_del = &extent_root->fs_info->pending_del; + + while(1) { + ret = find_first_extent_bit(pending_del, 0, &start, &end, + EXTENT_LOCKED); + if (ret) + break; + + ret = get_state_private(pending_del, start, &priv); + BUG_ON(ret); + extent_op = (struct pending_extent_op *)(unsigned long)priv; + + clear_extent_bits(pending_del, start, end, EXTENT_LOCKED, + GFP_NOFS); + + ret = pin_down_bytes(trans, extent_root, start, + end + 1 - start, 0); + mark_free = ret > 0; + if (!test_range_bit(extent_ins, start, end, + EXTENT_LOCKED, 0)) { +free_extent: + ret = __free_extent(trans, extent_root, + start, end + 1 - start, + extent_op->orig_parent, + extent_root->root_key.objectid, + extent_op->orig_generation, + extent_op->level, 0, 0, mark_free); + kfree(extent_op); + } else { + kfree(extent_op); + ret = get_state_private(extent_ins, start, &priv); + BUG_ON(ret); + extent_op = (struct pending_extent_op *) + (unsigned long)priv; + + clear_extent_bits(extent_ins, start, end, + EXTENT_LOCKED, GFP_NOFS); + + if (extent_op->type == PENDING_BACKREF_UPDATE) + goto free_extent; + + ret = update_block_group(trans, extent_root, start, + end + 1 - start, 0, mark_free); + BUG_ON(ret); + kfree(extent_op); + } + if (ret) + err = ret; + + if (need_resched()) { + mutex_unlock(&extent_root->fs_info->alloc_mutex); + cond_resched(); + mutex_lock(&extent_root->fs_info->alloc_mutex); + } + } + return err; +} + +/* + * remove an extent from the root, returns 0 on success + */ +static int __btrfs_free_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner_objectid, u64 owner_offset, int pin) +{ + struct btrfs_root *extent_root = root->fs_info->extent_root; + int pending_ret; + int ret; + + WARN_ON(num_bytes < root->sectorsize); + if (root == extent_root) { + struct pending_extent_op *extent_op; + + extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS); + BUG_ON(!extent_op); + + extent_op->type = PENDING_EXTENT_DELETE; + extent_op->bytenr = bytenr; + extent_op->num_bytes = num_bytes; + extent_op->parent = parent; + extent_op->orig_parent = parent; + extent_op->generation = ref_generation; + extent_op->orig_generation = ref_generation; + extent_op->level = (int)owner_objectid; + + set_extent_bits(&root->fs_info->pending_del, + bytenr, bytenr + num_bytes - 1, + EXTENT_LOCKED, GFP_NOFS); + set_state_private(&root->fs_info->pending_del, + bytenr, (unsigned long)extent_op); + return 0; + } + /* if metadata always pin */ + if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) { + if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { + struct btrfs_block_group_cache *cache; + + /* btrfs_free_reserved_extent */ + cache = btrfs_lookup_block_group(root->fs_info, bytenr); + BUG_ON(!cache); + btrfs_add_free_space(cache, bytenr, num_bytes); + return 0; + } + pin = 1; + } + + /* if data pin when any transaction has committed this */ + if (ref_generation != trans->transid) + pin = 1; + + ret = __free_extent(trans, root, bytenr, num_bytes, parent, + root_objectid, ref_generation, owner_objectid, + owner_offset, pin, pin == 0); + + finish_current_insert(trans, root->fs_info->extent_root); + pending_ret = del_pending_extents(trans, root->fs_info->extent_root); + return ret ? ret : pending_ret; +} + +int btrfs_free_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner_objectid, u64 owner_offset, int pin) +{ + int ret; + + maybe_lock_mutex(root); + ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent, + root_objectid, ref_generation, + owner_objectid, owner_offset, pin); + maybe_unlock_mutex(root); + return ret; +} + +static u64 stripe_align(struct btrfs_root *root, u64 val) +{ + u64 mask = ((u64)root->stripesize - 1); + u64 ret = (val + mask) & ~mask; + return ret; +} + +/* + * walks the btree of allocated extents and find a hole of a given size. + * The key ins is changed to record the hole: + * ins->objectid == block start + * ins->flags = BTRFS_EXTENT_ITEM_KEY + * ins->offset == number of blocks + * Any available blocks before search_start are skipped. + */ +static int noinline find_free_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *orig_root, + u64 num_bytes, u64 empty_size, + u64 search_start, u64 search_end, + u64 hint_byte, struct btrfs_key *ins, + u64 exclude_start, u64 exclude_nr, + int data) +{ + int ret; + u64 orig_search_start; + struct btrfs_root * root = orig_root->fs_info->extent_root; + struct btrfs_fs_info *info = root->fs_info; + u64 total_needed = num_bytes; + u64 *last_ptr = NULL; + struct btrfs_block_group_cache *block_group; + int chunk_alloc_done = 0; + int empty_cluster = 2 * 1024 * 1024; + int allowed_chunk_alloc = 0; + + WARN_ON(num_bytes < root->sectorsize); + btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); + + if (orig_root->ref_cows || empty_size) + allowed_chunk_alloc = 1; + + if (data & BTRFS_BLOCK_GROUP_METADATA) { + last_ptr = &root->fs_info->last_alloc; + empty_cluster = 256 * 1024; + } + + if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) + last_ptr = &root->fs_info->last_data_alloc; + + if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { + last_ptr = &root->fs_info->last_log_alloc; + if (!last_ptr == 0 && root->fs_info->last_alloc) { + *last_ptr = root->fs_info->last_alloc + empty_cluster; + } + } + + if (last_ptr) { + if (*last_ptr) + hint_byte = *last_ptr; + else + empty_size += empty_cluster; + } + + search_start = max(search_start, first_logical_byte(root, 0)); + orig_search_start = search_start; + + if (search_end == (u64)-1) + search_end = btrfs_super_total_bytes(&info->super_copy); + + search_start = max(search_start, hint_byte); + total_needed += empty_size; + +new_group: + block_group = btrfs_lookup_block_group(info, search_start); + + /* + * Ok this looks a little tricky, buts its really simple. First if we + * didn't find a block group obviously we want to start over. + * Secondly, if the block group we found does not match the type we + * need, and we have a last_ptr and its not 0, chances are the last + * allocation we made was at the end of the block group, so lets go + * ahead and skip the looking through the rest of the block groups and + * start at the beginning. This helps with metadata allocations, + * since you are likely to have a bunch of data block groups to search + * through first before you realize that you need to start over, so go + * ahead and start over and save the time. + */ + if (!block_group || (!block_group_bits(block_group, data) && + last_ptr && *last_ptr)) { + if (search_start != orig_search_start) { + if (last_ptr && *last_ptr) + *last_ptr = 0; + search_start = orig_search_start; + goto new_group; + } else if (!chunk_alloc_done && allowed_chunk_alloc) { + ret = do_chunk_alloc(trans, root, + num_bytes + 2 * 1024 * 1024, + data, 1); + if (ret < 0) { + struct btrfs_space_info *info; + + info = __find_space_info(root->fs_info, data); + goto error; + } + BUG_ON(ret); + chunk_alloc_done = 1; + search_start = orig_search_start; + goto new_group; + } else { + ret = -ENOSPC; + goto error; + } + } + + /* + * this is going to seach through all of the existing block groups it + * can find, so if we don't find something we need to see if we can + * allocate what we need. + */ + ret = find_free_space(root, &block_group, &search_start, + total_needed, data); + if (ret == -ENOSPC) { + /* + * instead of allocating, start at the original search start + * and see if there is something to be found, if not then we + * allocate + */ + if (search_start != orig_search_start) { + if (last_ptr && *last_ptr) { + *last_ptr = 0; + total_needed += empty_cluster; + } + search_start = orig_search_start; + goto new_group; + } + + /* + * we've already allocated, we're pretty screwed + */ + if (chunk_alloc_done) { + goto error; + } else if (!allowed_chunk_alloc && block_group && + block_group_bits(block_group, data)) { + block_group->space_info->force_alloc = 1; + goto error; + } else if (!allowed_chunk_alloc) { + goto error; + } + + ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024, + data, 1); + if (ret < 0) + goto error; + + BUG_ON(ret); + chunk_alloc_done = 1; + if (block_group) + search_start = block_group->key.objectid + + block_group->key.offset; + else + search_start = orig_search_start; + goto new_group; + } + + if (ret) + goto error; + + search_start = stripe_align(root, search_start); + ins->objectid = search_start; + ins->offset = num_bytes; + + if (ins->objectid + num_bytes >= search_end) { + search_start = orig_search_start; + if (chunk_alloc_done) { + ret = -ENOSPC; + goto error; + } + goto new_group; + } + + if (ins->objectid + num_bytes > + block_group->key.objectid + block_group->key.offset) { + if (search_start == orig_search_start && chunk_alloc_done) { + ret = -ENOSPC; + goto error; + } + search_start = block_group->key.objectid + + block_group->key.offset; + goto new_group; + } + + if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start && + ins->objectid < exclude_start + exclude_nr)) { + search_start = exclude_start + exclude_nr; + goto new_group; + } + + if (!(data & BTRFS_BLOCK_GROUP_DATA)) + trans->block_group = block_group; + + ins->offset = num_bytes; + if (last_ptr) { + *last_ptr = ins->objectid + ins->offset; + if (*last_ptr == + btrfs_super_total_bytes(&root->fs_info->super_copy)) + *last_ptr = 0; + } + + ret = 0; +error: + return ret; +} + +static void dump_space_info(struct btrfs_space_info *info, u64 bytes) +{ + struct btrfs_block_group_cache *cache; + struct list_head *l; + + printk(KERN_INFO "space_info has %Lu free, is %sfull\n", + info->total_bytes - info->bytes_used - info->bytes_pinned, + (info->full) ? "" : "not "); + + spin_lock(&info->lock); + list_for_each(l, &info->block_groups) { + cache = list_entry(l, struct btrfs_block_group_cache, list); + spin_lock(&cache->lock); + printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used " + "%Lu pinned\n", + cache->key.objectid, cache->key.offset, + btrfs_block_group_used(&cache->item), cache->pinned); + btrfs_dump_free_space(cache, bytes); + spin_unlock(&cache->lock); + } + spin_unlock(&info->lock); +} +static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 num_bytes, u64 min_alloc_size, + u64 empty_size, u64 hint_byte, + u64 search_end, struct btrfs_key *ins, + u64 data) +{ + int ret; + u64 search_start = 0; + u64 alloc_profile; + struct btrfs_fs_info *info = root->fs_info; + struct btrfs_block_group_cache *cache; + + if (data) { + alloc_profile = info->avail_data_alloc_bits & + info->data_alloc_profile; + data = BTRFS_BLOCK_GROUP_DATA | alloc_profile; + } else if (root == root->fs_info->chunk_root) { + alloc_profile = info->avail_system_alloc_bits & + info->system_alloc_profile; + data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile; + } else { + alloc_profile = info->avail_metadata_alloc_bits & + info->metadata_alloc_profile; + data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile; + } +again: + data = reduce_alloc_profile(root, data); + /* + * the only place that sets empty_size is btrfs_realloc_node, which + * is not called recursively on allocations + */ + if (empty_size || root->ref_cows) { + if (!(data & BTRFS_BLOCK_GROUP_METADATA)) { + ret = do_chunk_alloc(trans, root->fs_info->extent_root, + 2 * 1024 * 1024, + BTRFS_BLOCK_GROUP_METADATA | + (info->metadata_alloc_profile & + info->avail_metadata_alloc_bits), 0); + } + ret = do_chunk_alloc(trans, root->fs_info->extent_root, + num_bytes + 2 * 1024 * 1024, data, 0); + } + + WARN_ON(num_bytes < root->sectorsize); + ret = find_free_extent(trans, root, num_bytes, empty_size, + search_start, search_end, hint_byte, ins, + trans->alloc_exclude_start, + trans->alloc_exclude_nr, data); + + if (ret == -ENOSPC && num_bytes > min_alloc_size) { + num_bytes = num_bytes >> 1; + num_bytes = num_bytes & ~(root->sectorsize - 1); + num_bytes = max(num_bytes, min_alloc_size); + do_chunk_alloc(trans, root->fs_info->extent_root, + num_bytes, data, 1); + goto again; + } + if (ret) { + struct btrfs_space_info *sinfo; + + sinfo = __find_space_info(root->fs_info, data); + printk("allocation failed flags %Lu, wanted %Lu\n", + data, num_bytes); + dump_space_info(sinfo, num_bytes); + BUG(); + } + cache = btrfs_lookup_block_group(root->fs_info, ins->objectid); + if (!cache) { + printk(KERN_ERR "Unable to find block group for %Lu\n", ins->objectid); + return -ENOSPC; + } + + ret = btrfs_remove_free_space(cache, ins->objectid, ins->offset); + + return ret; +} + +int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len) +{ + struct btrfs_block_group_cache *cache; + + maybe_lock_mutex(root); + cache = btrfs_lookup_block_group(root->fs_info, start); + if (!cache) { + printk(KERN_ERR "Unable to find block group for %Lu\n", start); + maybe_unlock_mutex(root); + return -ENOSPC; + } + btrfs_add_free_space(cache, start, len); + maybe_unlock_mutex(root); + return 0; +} + +int btrfs_reserve_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 num_bytes, u64 min_alloc_size, + u64 empty_size, u64 hint_byte, + u64 search_end, struct btrfs_key *ins, + u64 data) +{ + int ret; + maybe_lock_mutex(root); + ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size, + empty_size, hint_byte, search_end, ins, + data); + maybe_unlock_mutex(root); + return ret; +} + +static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner, u64 owner_offset, + struct btrfs_key *ins) +{ + int ret; + int pending_ret; + u64 super_used; + u64 root_used; + u64 num_bytes = ins->offset; + u32 sizes[2]; + struct btrfs_fs_info *info = root->fs_info; + struct btrfs_root *extent_root = info->extent_root; + struct btrfs_extent_item *extent_item; + struct btrfs_extent_ref *ref; + struct btrfs_path *path; + struct btrfs_key keys[2]; + + if (parent == 0) + parent = ins->objectid; + + /* block accounting for super block */ + spin_lock_irq(&info->delalloc_lock); + super_used = btrfs_super_bytes_used(&info->super_copy); + btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes); + spin_unlock_irq(&info->delalloc_lock); + + /* block accounting for root item */ + root_used = btrfs_root_used(&root->root_item); + btrfs_set_root_used(&root->root_item, root_used + num_bytes); + + if (root == extent_root) { + struct pending_extent_op *extent_op; + + extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS); + BUG_ON(!extent_op); + + extent_op->type = PENDING_EXTENT_INSERT; + extent_op->bytenr = ins->objectid; + extent_op->num_bytes = ins->offset; + extent_op->parent = parent; + extent_op->orig_parent = 0; + extent_op->generation = ref_generation; + extent_op->orig_generation = 0; + extent_op->level = (int)owner; + + set_extent_bits(&root->fs_info->extent_ins, ins->objectid, + ins->objectid + ins->offset - 1, + EXTENT_LOCKED, GFP_NOFS); + set_state_private(&root->fs_info->extent_ins, + ins->objectid, (unsigned long)extent_op); + goto update_block; + } + + memcpy(&keys[0], ins, sizeof(*ins)); + keys[1].objectid = ins->objectid; + keys[1].type = BTRFS_EXTENT_REF_KEY; + keys[1].offset = parent; + sizes[0] = sizeof(*extent_item); + sizes[1] = sizeof(*ref); + + path = btrfs_alloc_path(); + BUG_ON(!path); + + ret = btrfs_insert_empty_items(trans, extent_root, path, keys, + sizes, 2); + BUG_ON(ret); + + extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_extent_item); + btrfs_set_extent_refs(path->nodes[0], extent_item, 1); + ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, + struct btrfs_extent_ref); + + btrfs_set_ref_root(path->nodes[0], ref, root_objectid); + btrfs_set_ref_generation(path->nodes[0], ref, ref_generation); + btrfs_set_ref_objectid(path->nodes[0], ref, owner); + btrfs_set_ref_offset(path->nodes[0], ref, owner_offset); + btrfs_set_ref_num_refs(path->nodes[0], ref, 1); + + btrfs_mark_buffer_dirty(path->nodes[0]); + + trans->alloc_exclude_start = 0; + trans->alloc_exclude_nr = 0; + btrfs_free_path(path); + finish_current_insert(trans, extent_root); + pending_ret = del_pending_extents(trans, extent_root); + + if (ret) + goto out; + if (pending_ret) { + ret = pending_ret; + goto out; + } + +update_block: + ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0); + if (ret) { + printk("update block group failed for %Lu %Lu\n", + ins->objectid, ins->offset); + BUG(); + } +out: + return ret; +} + +int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner, u64 owner_offset, + struct btrfs_key *ins) +{ + int ret; + + if (root_objectid == BTRFS_TREE_LOG_OBJECTID) + return 0; + maybe_lock_mutex(root); + ret = __btrfs_alloc_reserved_extent(trans, root, parent, + root_objectid, ref_generation, + owner, owner_offset, ins); + maybe_unlock_mutex(root); + return ret; +} + +/* + * this is used by the tree logging recovery code. It records that + * an extent has been allocated and makes sure to clear the free + * space cache bits as well + */ +int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner, u64 owner_offset, + struct btrfs_key *ins) +{ + int ret; + struct btrfs_block_group_cache *block_group; + + maybe_lock_mutex(root); + block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid); + cache_block_group(root, block_group); + + ret = btrfs_remove_free_space(block_group, ins->objectid, ins->offset); + BUG_ON(ret); + ret = __btrfs_alloc_reserved_extent(trans, root, parent, + root_objectid, ref_generation, + owner, owner_offset, ins); + maybe_unlock_mutex(root); + return ret; +} + +/* + * finds a free extent and does all the dirty work required for allocation + * returns the key for the extent through ins, and a tree buffer for + * the first block of the extent through buf. + * + * returns 0 if everything worked, non-zero otherwise. + */ +int btrfs_alloc_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 num_bytes, u64 parent, u64 min_alloc_size, + u64 root_objectid, u64 ref_generation, + u64 owner_objectid, u64 owner_offset, + u64 empty_size, u64 hint_byte, + u64 search_end, struct btrfs_key *ins, u64 data) +{ + int ret; + + maybe_lock_mutex(root); + + ret = __btrfs_reserve_extent(trans, root, num_bytes, + min_alloc_size, empty_size, hint_byte, + search_end, ins, data); + BUG_ON(ret); + if (root_objectid != BTRFS_TREE_LOG_OBJECTID) { + ret = __btrfs_alloc_reserved_extent(trans, root, parent, + root_objectid, ref_generation, + owner_objectid, owner_offset, ins); + BUG_ON(ret); + + } + maybe_unlock_mutex(root); + return ret; +} + +struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u32 blocksize) +{ + struct extent_buffer *buf; + + buf = btrfs_find_create_tree_block(root, bytenr, blocksize); + if (!buf) + return ERR_PTR(-ENOMEM); + btrfs_set_header_generation(buf, trans->transid); + btrfs_tree_lock(buf); + clean_tree_block(trans, root, buf); + btrfs_set_buffer_uptodate(buf); + if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { + set_extent_dirty(&root->dirty_log_pages, buf->start, + buf->start + buf->len - 1, GFP_NOFS); + } else { + set_extent_dirty(&trans->transaction->dirty_pages, buf->start, + buf->start + buf->len - 1, GFP_NOFS); + } + trans->blocks_used++; + return buf; +} + +/* + * helper function to allocate a block for a given tree + * returns the tree buffer or NULL. + */ +struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u32 blocksize, u64 parent, + u64 root_objectid, + u64 ref_generation, + int level, + u64 hint, + u64 empty_size) +{ + struct btrfs_key ins; + int ret; + struct extent_buffer *buf; + + ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize, + root_objectid, ref_generation, level, 0, + empty_size, hint, (u64)-1, &ins, 0); + if (ret) { + BUG_ON(ret > 0); + return ERR_PTR(ret); + } + + buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize); + return buf; +} + +int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct extent_buffer *leaf) +{ + u64 leaf_owner; + u64 leaf_generation; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + int i; + int nritems; + int ret; + + BUG_ON(!btrfs_is_leaf(leaf)); + nritems = btrfs_header_nritems(leaf); + leaf_owner = btrfs_header_owner(leaf); + leaf_generation = btrfs_header_generation(leaf); + + for (i = 0; i < nritems; i++) { + u64 disk_bytenr; + cond_resched(); + + btrfs_item_key_to_cpu(leaf, &key, i); + if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); + if (btrfs_file_extent_type(leaf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + /* + * FIXME make sure to insert a trans record that + * repeats the snapshot del on crash + */ + disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); + if (disk_bytenr == 0) + continue; + + mutex_lock(&root->fs_info->alloc_mutex); + ret = __btrfs_free_extent(trans, root, disk_bytenr, + btrfs_file_extent_disk_num_bytes(leaf, fi), + leaf->start, leaf_owner, leaf_generation, + key.objectid, key.offset, 0); + mutex_unlock(&root->fs_info->alloc_mutex); + BUG_ON(ret); + + atomic_inc(&root->fs_info->throttle_gen); + wake_up(&root->fs_info->transaction_throttle); + cond_resched(); + } + return 0; +} + +static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_leaf_ref *ref) +{ + int i; + int ret; + struct btrfs_extent_info *info = ref->extents; + + for (i = 0; i < ref->nritems; i++) { + mutex_lock(&root->fs_info->alloc_mutex); + ret = __btrfs_free_extent(trans, root, info->bytenr, + info->num_bytes, ref->bytenr, + ref->owner, ref->generation, + info->objectid, info->offset, 0); + mutex_unlock(&root->fs_info->alloc_mutex); + + atomic_inc(&root->fs_info->throttle_gen); + wake_up(&root->fs_info->transaction_throttle); + cond_resched(); + + BUG_ON(ret); + info++; + } + + return 0; +} + +int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len, + u32 *refs) +{ + int ret; + + ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs); + BUG_ON(ret); + +#if 0 // some debugging code in case we see problems here + /* if the refs count is one, it won't get increased again. But + * if the ref count is > 1, someone may be decreasing it at + * the same time we are. + */ + if (*refs != 1) { + struct extent_buffer *eb = NULL; + eb = btrfs_find_create_tree_block(root, start, len); + if (eb) + btrfs_tree_lock(eb); + + mutex_lock(&root->fs_info->alloc_mutex); + ret = lookup_extent_ref(NULL, root, start, len, refs); + BUG_ON(ret); + mutex_unlock(&root->fs_info->alloc_mutex); + + if (eb) { + btrfs_tree_unlock(eb); + free_extent_buffer(eb); + } + if (*refs == 1) { + printk("block %llu went down to one during drop_snap\n", + (unsigned long long)start); + } + + } +#endif + + cond_resched(); + return ret; +} + +/* + * helper function for drop_snapshot, this walks down the tree dropping ref + * counts as it goes. + */ +static int noinline walk_down_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int *level) +{ + u64 root_owner; + u64 root_gen; + u64 bytenr; + u64 ptr_gen; + struct extent_buffer *next; + struct extent_buffer *cur; + struct extent_buffer *parent; + struct btrfs_leaf_ref *ref; + u32 blocksize; + int ret; + u32 refs; + + WARN_ON(*level < 0); + WARN_ON(*level >= BTRFS_MAX_LEVEL); + ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start, + path->nodes[*level]->len, &refs); + BUG_ON(ret); + if (refs > 1) + goto out; + + /* + * walk down to the last node level and free all the leaves + */ + while(*level >= 0) { + WARN_ON(*level < 0); + WARN_ON(*level >= BTRFS_MAX_LEVEL); + cur = path->nodes[*level]; + + if (btrfs_header_level(cur) != *level) + WARN_ON(1); + + if (path->slots[*level] >= + btrfs_header_nritems(cur)) + break; + if (*level == 0) { + ret = btrfs_drop_leaf_ref(trans, root, cur); + BUG_ON(ret); + break; + } + bytenr = btrfs_node_blockptr(cur, path->slots[*level]); + ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); + blocksize = btrfs_level_size(root, *level - 1); + + ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs); + BUG_ON(ret); + if (refs != 1) { + parent = path->nodes[*level]; + root_owner = btrfs_header_owner(parent); + root_gen = btrfs_header_generation(parent); + path->slots[*level]++; + + mutex_lock(&root->fs_info->alloc_mutex); + ret = __btrfs_free_extent(trans, root, bytenr, + blocksize, parent->start, + root_owner, root_gen, 0, 0, 1); + BUG_ON(ret); + mutex_unlock(&root->fs_info->alloc_mutex); + + atomic_inc(&root->fs_info->throttle_gen); + wake_up(&root->fs_info->transaction_throttle); + cond_resched(); + + continue; + } + /* + * at this point, we have a single ref, and since the + * only place referencing this extent is a dead root + * the reference count should never go higher. + * So, we don't need to check it again + */ + if (*level == 1) { + ref = btrfs_lookup_leaf_ref(root, bytenr); + if (ref) { + ret = cache_drop_leaf_ref(trans, root, ref); + BUG_ON(ret); + btrfs_remove_leaf_ref(root, ref); + btrfs_free_leaf_ref(root, ref); + *level = 0; + break; + } + if (printk_ratelimit()) + printk("leaf ref miss for bytenr %llu\n", + (unsigned long long)bytenr); + } + next = btrfs_find_tree_block(root, bytenr, blocksize); + if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) { + free_extent_buffer(next); + + next = read_tree_block(root, bytenr, blocksize, + ptr_gen); + cond_resched(); +#if 0 + /* + * this is a debugging check and can go away + * the ref should never go all the way down to 1 + * at this point + */ + ret = lookup_extent_ref(NULL, root, bytenr, blocksize, + &refs); + BUG_ON(ret); + WARN_ON(refs != 1); +#endif + } + WARN_ON(*level <= 0); + if (path->nodes[*level-1]) + free_extent_buffer(path->nodes[*level-1]); + path->nodes[*level-1] = next; + *level = btrfs_header_level(next); + path->slots[*level] = 0; + cond_resched(); + } +out: + WARN_ON(*level < 0); + WARN_ON(*level >= BTRFS_MAX_LEVEL); + + if (path->nodes[*level] == root->node) { + parent = path->nodes[*level]; + bytenr = path->nodes[*level]->start; + } else { + parent = path->nodes[*level + 1]; + bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]); + } + + blocksize = btrfs_level_size(root, *level); + root_owner = btrfs_header_owner(parent); + root_gen = btrfs_header_generation(parent); + + mutex_lock(&root->fs_info->alloc_mutex); + ret = __btrfs_free_extent(trans, root, bytenr, blocksize, + parent->start, root_owner, root_gen, + 0, 0, 1); + mutex_unlock(&root->fs_info->alloc_mutex); + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + *level += 1; + BUG_ON(ret); + + cond_resched(); + return 0; +} + +/* + * helper for dropping snapshots. This walks back up the tree in the path + * to find the first node higher up where we haven't yet gone through + * all the slots + */ +static int noinline walk_up_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int *level) +{ + u64 root_owner; + u64 root_gen; + struct btrfs_root_item *root_item = &root->root_item; + int i; + int slot; + int ret; + + for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { + slot = path->slots[i]; + if (slot < btrfs_header_nritems(path->nodes[i]) - 1) { + struct extent_buffer *node; + struct btrfs_disk_key disk_key; + node = path->nodes[i]; + path->slots[i]++; + *level = i; + WARN_ON(*level == 0); + btrfs_node_key(node, &disk_key, path->slots[i]); + memcpy(&root_item->drop_progress, + &disk_key, sizeof(disk_key)); + root_item->drop_level = i; + return 0; + } else { + struct extent_buffer *parent; + if (path->nodes[*level] == root->node) + parent = path->nodes[*level]; + else + parent = path->nodes[*level + 1]; + + root_owner = btrfs_header_owner(parent); + root_gen = btrfs_header_generation(parent); + ret = btrfs_free_extent(trans, root, + path->nodes[*level]->start, + path->nodes[*level]->len, + parent->start, + root_owner, root_gen, 0, 0, 1); + BUG_ON(ret); + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + *level = i + 1; + } + } + return 1; +} + +/* + * drop the reference count on the tree rooted at 'snap'. This traverses + * the tree freeing any blocks that have a ref count of zero after being + * decremented. + */ +int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root + *root) +{ + int ret = 0; + int wret; + int level; + struct btrfs_path *path; + int i; + int orig_level; + struct btrfs_root_item *root_item = &root->root_item; + + WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex)); + path = btrfs_alloc_path(); + BUG_ON(!path); + + level = btrfs_header_level(root->node); + orig_level = level; + if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { + path->nodes[level] = root->node; + extent_buffer_get(root->node); + path->slots[level] = 0; + } else { + struct btrfs_key key; + struct btrfs_disk_key found_key; + struct extent_buffer *node; + + btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); + level = root_item->drop_level; + path->lowest_level = level; + wret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (wret < 0) { + ret = wret; + goto out; + } + node = path->nodes[level]; + btrfs_node_key(node, &found_key, path->slots[level]); + WARN_ON(memcmp(&found_key, &root_item->drop_progress, + sizeof(found_key))); + /* + * unlock our path, this is safe because only this + * function is allowed to delete this snapshot + */ + for (i = 0; i < BTRFS_MAX_LEVEL; i++) { + if (path->nodes[i] && path->locks[i]) { + path->locks[i] = 0; + btrfs_tree_unlock(path->nodes[i]); + } + } + } + while(1) { + wret = walk_down_tree(trans, root, path, &level); + if (wret > 0) + break; + if (wret < 0) + ret = wret; + + wret = walk_up_tree(trans, root, path, &level); + if (wret > 0) + break; + if (wret < 0) + ret = wret; + if (trans->transaction->in_commit) { + ret = -EAGAIN; + break; + } + atomic_inc(&root->fs_info->throttle_gen); + wake_up(&root->fs_info->transaction_throttle); + } + for (i = 0; i <= orig_level; i++) { + if (path->nodes[i]) { + free_extent_buffer(path->nodes[i]); + path->nodes[i] = NULL; + } + } +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_free_block_groups(struct btrfs_fs_info *info) +{ + struct btrfs_block_group_cache *block_group; + struct rb_node *n; + + mutex_lock(&info->alloc_mutex); + spin_lock(&info->block_group_cache_lock); + while ((n = rb_last(&info->block_group_cache_tree)) != NULL) { + block_group = rb_entry(n, struct btrfs_block_group_cache, + cache_node); + + btrfs_remove_free_space_cache(block_group); + rb_erase(&block_group->cache_node, + &info->block_group_cache_tree); + spin_lock(&block_group->space_info->lock); + list_del(&block_group->list); + spin_unlock(&block_group->space_info->lock); + kfree(block_group); + } + spin_unlock(&info->block_group_cache_lock); + mutex_unlock(&info->alloc_mutex); + return 0; +} + +static unsigned long calc_ra(unsigned long start, unsigned long last, + unsigned long nr) +{ + return min(last, start + nr - 1); +} + +static int noinline relocate_inode_pages(struct inode *inode, u64 start, + u64 len) +{ + u64 page_start; + u64 page_end; + unsigned long last_index; + unsigned long i; + struct page *page; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct file_ra_state *ra; + unsigned long total_read = 0; + unsigned long ra_pages; + struct btrfs_ordered_extent *ordered; + struct btrfs_trans_handle *trans; + + ra = kzalloc(sizeof(*ra), GFP_NOFS); + + mutex_lock(&inode->i_mutex); + i = start >> PAGE_CACHE_SHIFT; + last_index = (start + len - 1) >> PAGE_CACHE_SHIFT; + + ra_pages = BTRFS_I(inode)->root->fs_info->bdi.ra_pages; + + file_ra_state_init(ra, inode->i_mapping); + + for (; i <= last_index; i++) { + if (total_read % ra_pages == 0) { + btrfs_force_ra(inode->i_mapping, ra, NULL, i, + calc_ra(i, last_index, ra_pages)); + } + total_read++; +again: + if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode)) + goto truncate_racing; + page = grab_cache_page(inode->i_mapping, i); + if (!page) { + goto out_unlock; + } + if (!PageUptodate(page)) { + btrfs_readpage(NULL, page); + lock_page(page); + if (!PageUptodate(page)) { + unlock_page(page); + page_cache_release(page); + goto out_unlock; + } + } + wait_on_page_writeback(page); + + page_start = (u64)page->index << PAGE_CACHE_SHIFT; + page_end = page_start + PAGE_CACHE_SIZE - 1; + lock_extent(io_tree, page_start, page_end, GFP_NOFS); + + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + unlock_page(page); + page_cache_release(page); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + set_page_extent_mapped(page); + + /* + * make sure page_mkwrite is called for this page if userland + * wants to change it from mmap + */ + clear_page_dirty_for_io(page); + + btrfs_set_extent_delalloc(inode, page_start, page_end); + set_page_dirty(page); + + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + unlock_page(page); + page_cache_release(page); + } + +out_unlock: + /* we have to start the IO in order to get the ordered extents + * instantiated. This allows the relocation to code to wait + * for all the ordered extents to hit the disk. + * + * Otherwise, it would constantly loop over the same extents + * because the old ones don't get deleted until the IO is + * started + */ + btrfs_fdatawrite_range(inode->i_mapping, start, start + len - 1, + WB_SYNC_NONE); + kfree(ra); + trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1); + if (trans) { + btrfs_end_transaction(trans, BTRFS_I(inode)->root); + mark_inode_dirty(inode); + } + mutex_unlock(&inode->i_mutex); + return 0; + +truncate_racing: + vmtruncate(inode, inode->i_size); + balance_dirty_pages_ratelimited_nr(inode->i_mapping, + total_read); + goto out_unlock; +} + +/* + * The back references tell us which tree holds a ref on a block, + * but it is possible for the tree root field in the reference to + * reflect the original root before a snapshot was made. In this + * case we should search through all the children of a given root + * to find potential holders of references on a block. + * + * Instead, we do something a little less fancy and just search + * all the roots for a given key/block combination. + */ +static int find_root_for_ref(struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *key0, + int level, + int file_key, + struct btrfs_root **found_root, + u64 bytenr) +{ + struct btrfs_key root_location; + struct btrfs_root *cur_root = *found_root; + struct btrfs_file_extent_item *file_extent; + u64 root_search_start = BTRFS_FS_TREE_OBJECTID; + u64 found_bytenr; + int ret; + + root_location.offset = (u64)-1; + root_location.type = BTRFS_ROOT_ITEM_KEY; + path->lowest_level = level; + path->reada = 0; + while(1) { + ret = btrfs_search_slot(NULL, cur_root, key0, path, 0, 0); + found_bytenr = 0; + if (ret == 0 && file_key) { + struct extent_buffer *leaf = path->nodes[0]; + file_extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(leaf, file_extent) == + BTRFS_FILE_EXTENT_REG) { + found_bytenr = + btrfs_file_extent_disk_bytenr(leaf, + file_extent); + } + } else if (!file_key) { + if (path->nodes[level]) + found_bytenr = path->nodes[level]->start; + } + + btrfs_release_path(cur_root, path); + + if (found_bytenr == bytenr) { + *found_root = cur_root; + ret = 0; + goto out; + } + ret = btrfs_search_root(root->fs_info->tree_root, + root_search_start, &root_search_start); + if (ret) + break; + + root_location.objectid = root_search_start; + cur_root = btrfs_read_fs_root_no_name(root->fs_info, + &root_location); + if (!cur_root) { + ret = 1; + break; + } + } +out: + path->lowest_level = 0; + return ret; +} + +/* + * note, this releases the path + */ +static int noinline relocate_one_reference(struct btrfs_root *extent_root, + struct btrfs_path *path, + struct btrfs_key *extent_key, + u64 *last_file_objectid, + u64 *last_file_offset, + u64 *last_file_root, + u64 last_extent) +{ + struct inode *inode; + struct btrfs_root *found_root; + struct btrfs_key root_location; + struct btrfs_key found_key; + struct btrfs_extent_ref *ref; + u64 ref_root; + u64 ref_gen; + u64 ref_objectid; + u64 ref_offset; + int ret; + int level; + + WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); + + ref = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_extent_ref); + ref_root = btrfs_ref_root(path->nodes[0], ref); + ref_gen = btrfs_ref_generation(path->nodes[0], ref); + ref_objectid = btrfs_ref_objectid(path->nodes[0], ref); + ref_offset = btrfs_ref_offset(path->nodes[0], ref); + btrfs_release_path(extent_root, path); + + root_location.objectid = ref_root; + if (ref_gen == 0) + root_location.offset = 0; + else + root_location.offset = (u64)-1; + root_location.type = BTRFS_ROOT_ITEM_KEY; + + found_root = btrfs_read_fs_root_no_name(extent_root->fs_info, + &root_location); + BUG_ON(!found_root); + mutex_unlock(&extent_root->fs_info->alloc_mutex); + + if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) { + found_key.objectid = ref_objectid; + found_key.type = BTRFS_EXTENT_DATA_KEY; + found_key.offset = ref_offset; + level = 0; + + if (last_extent == extent_key->objectid && + *last_file_objectid == ref_objectid && + *last_file_offset == ref_offset && + *last_file_root == ref_root) + goto out; + + ret = find_root_for_ref(extent_root, path, &found_key, + level, 1, &found_root, + extent_key->objectid); + + if (ret) + goto out; + + if (last_extent == extent_key->objectid && + *last_file_objectid == ref_objectid && + *last_file_offset == ref_offset && + *last_file_root == ref_root) + goto out; + + inode = btrfs_iget_locked(extent_root->fs_info->sb, + ref_objectid, found_root); + if (inode->i_state & I_NEW) { + /* the inode and parent dir are two different roots */ + BTRFS_I(inode)->root = found_root; + BTRFS_I(inode)->location.objectid = ref_objectid; + BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; + BTRFS_I(inode)->location.offset = 0; + btrfs_read_locked_inode(inode); + unlock_new_inode(inode); + + } + /* this can happen if the reference is not against + * the latest version of the tree root + */ + if (is_bad_inode(inode)) + goto out; + + *last_file_objectid = inode->i_ino; + *last_file_root = found_root->root_key.objectid; + *last_file_offset = ref_offset; + + relocate_inode_pages(inode, ref_offset, extent_key->offset); + iput(inode); + } else { + struct btrfs_trans_handle *trans; + struct extent_buffer *eb; + int needs_lock = 0; + + eb = read_tree_block(found_root, extent_key->objectid, + extent_key->offset, 0); + btrfs_tree_lock(eb); + level = btrfs_header_level(eb); + + if (level == 0) + btrfs_item_key_to_cpu(eb, &found_key, 0); + else + btrfs_node_key_to_cpu(eb, &found_key, 0); + + btrfs_tree_unlock(eb); + free_extent_buffer(eb); + + ret = find_root_for_ref(extent_root, path, &found_key, + level, 0, &found_root, + extent_key->objectid); + + if (ret) + goto out; + + /* + * right here almost anything could happen to our key, + * but that's ok. The cow below will either relocate it + * or someone else will have relocated it. Either way, + * it is in a different spot than it was before and + * we're happy. + */ + + trans = btrfs_start_transaction(found_root, 1); + + if (found_root == extent_root->fs_info->extent_root || + found_root == extent_root->fs_info->chunk_root || + found_root == extent_root->fs_info->dev_root) { + needs_lock = 1; + mutex_lock(&extent_root->fs_info->alloc_mutex); + } + + path->lowest_level = level; + path->reada = 2; + ret = btrfs_search_slot(trans, found_root, &found_key, path, + 0, 1); + path->lowest_level = 0; + btrfs_release_path(found_root, path); + + if (found_root == found_root->fs_info->extent_root) + btrfs_extent_post_op(trans, found_root); + if (needs_lock) + mutex_unlock(&extent_root->fs_info->alloc_mutex); + + btrfs_end_transaction(trans, found_root); + + } +out: + mutex_lock(&extent_root->fs_info->alloc_mutex); + return 0; +} + +static int noinline del_extent_zero(struct btrfs_root *extent_root, + struct btrfs_path *path, + struct btrfs_key *extent_key) +{ + int ret; + struct btrfs_trans_handle *trans; + + trans = btrfs_start_transaction(extent_root, 1); + ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1); + if (ret > 0) { + ret = -EIO; + goto out; + } + if (ret < 0) + goto out; + ret = btrfs_del_item(trans, extent_root, path); +out: + btrfs_end_transaction(trans, extent_root); + return ret; +} + +static int noinline relocate_one_extent(struct btrfs_root *extent_root, + struct btrfs_path *path, + struct btrfs_key *extent_key) +{ + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *leaf; + u64 last_file_objectid = 0; + u64 last_file_root = 0; + u64 last_file_offset = (u64)-1; + u64 last_extent = 0; + u32 nritems; + u32 item_size; + int ret = 0; + + if (extent_key->objectid == 0) { + ret = del_extent_zero(extent_root, path, extent_key); + goto out; + } + key.objectid = extent_key->objectid; + key.type = BTRFS_EXTENT_REF_KEY; + key.offset = 0; + + while(1) { + ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); + + if (ret < 0) + goto out; + + ret = 0; + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (path->slots[0] == nritems) { + ret = btrfs_next_leaf(extent_root, path); + if (ret > 0) { + ret = 0; + goto out; + } + if (ret < 0) + goto out; + leaf = path->nodes[0]; + } + + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid != extent_key->objectid) { + break; + } + + if (found_key.type != BTRFS_EXTENT_REF_KEY) { + break; + } + + key.offset = found_key.offset + 1; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); + + ret = relocate_one_reference(extent_root, path, extent_key, + &last_file_objectid, + &last_file_offset, + &last_file_root, last_extent); + if (ret) + goto out; + last_extent = extent_key->objectid; + } + ret = 0; +out: + btrfs_release_path(extent_root, path); + return ret; +} + +static u64 update_block_group_flags(struct btrfs_root *root, u64 flags) +{ + u64 num_devices; + u64 stripped = BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10; + + num_devices = root->fs_info->fs_devices->num_devices; + if (num_devices == 1) { + stripped |= BTRFS_BLOCK_GROUP_DUP; + stripped = flags & ~stripped; + + /* turn raid0 into single device chunks */ + if (flags & BTRFS_BLOCK_GROUP_RAID0) + return stripped; + + /* turn mirroring into duplication */ + if (flags & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10)) + return stripped | BTRFS_BLOCK_GROUP_DUP; + return flags; + } else { + /* they already had raid on here, just return */ + if (flags & stripped) + return flags; + + stripped |= BTRFS_BLOCK_GROUP_DUP; + stripped = flags & ~stripped; + + /* switch duplicated blocks with raid1 */ + if (flags & BTRFS_BLOCK_GROUP_DUP) + return stripped | BTRFS_BLOCK_GROUP_RAID1; + + /* turn single device chunks into raid0 */ + return stripped | BTRFS_BLOCK_GROUP_RAID0; + } + return flags; +} + +int __alloc_chunk_for_shrink(struct btrfs_root *root, + struct btrfs_block_group_cache *shrink_block_group, + int force) +{ + struct btrfs_trans_handle *trans; + u64 new_alloc_flags; + u64 calc; + + spin_lock(&shrink_block_group->lock); + if (btrfs_block_group_used(&shrink_block_group->item) > 0) { + spin_unlock(&shrink_block_group->lock); + mutex_unlock(&root->fs_info->alloc_mutex); + + trans = btrfs_start_transaction(root, 1); + mutex_lock(&root->fs_info->alloc_mutex); + spin_lock(&shrink_block_group->lock); + + new_alloc_flags = update_block_group_flags(root, + shrink_block_group->flags); + if (new_alloc_flags != shrink_block_group->flags) { + calc = + btrfs_block_group_used(&shrink_block_group->item); + } else { + calc = shrink_block_group->key.offset; + } + spin_unlock(&shrink_block_group->lock); + + do_chunk_alloc(trans, root->fs_info->extent_root, + calc + 2 * 1024 * 1024, new_alloc_flags, force); + + mutex_unlock(&root->fs_info->alloc_mutex); + btrfs_end_transaction(trans, root); + mutex_lock(&root->fs_info->alloc_mutex); + } else + spin_unlock(&shrink_block_group->lock); + return 0; +} + +int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *tree_root = root->fs_info->tree_root; + struct btrfs_path *path; + u64 cur_byte; + u64 total_found; + u64 shrink_last_byte; + struct btrfs_block_group_cache *shrink_block_group; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *leaf; + u32 nritems; + int ret; + int progress; + + mutex_lock(&root->fs_info->alloc_mutex); + shrink_block_group = btrfs_lookup_block_group(root->fs_info, + shrink_start); + BUG_ON(!shrink_block_group); + + shrink_last_byte = shrink_block_group->key.objectid + + shrink_block_group->key.offset; + + shrink_block_group->space_info->total_bytes -= + shrink_block_group->key.offset; + path = btrfs_alloc_path(); + root = root->fs_info->extent_root; + path->reada = 2; + + printk("btrfs relocating block group %llu flags %llu\n", + (unsigned long long)shrink_start, + (unsigned long long)shrink_block_group->flags); + + __alloc_chunk_for_shrink(root, shrink_block_group, 1); + +again: + + shrink_block_group->ro = 1; + + total_found = 0; + progress = 0; + key.objectid = shrink_start; + key.offset = 0; + key.type = 0; + cur_byte = key.objectid; + + mutex_unlock(&root->fs_info->alloc_mutex); + + btrfs_start_delalloc_inodes(root); + btrfs_wait_ordered_extents(tree_root, 0); + + mutex_lock(&root->fs_info->alloc_mutex); + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY); + if (ret < 0) + goto out; + + if (ret == 0) { + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid + found_key.offset > shrink_start && + found_key.objectid < shrink_last_byte) { + cur_byte = found_key.objectid; + key.objectid = cur_byte; + } + } + btrfs_release_path(root, path); + + while(1) { + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + +next: + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret == 1) { + ret = 0; + break; + } + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + } + + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + if (found_key.objectid >= shrink_last_byte) + break; + + if (progress && need_resched()) { + memcpy(&key, &found_key, sizeof(key)); + cond_resched(); + btrfs_release_path(root, path); + btrfs_search_slot(NULL, root, &key, path, 0, 0); + progress = 0; + goto next; + } + progress = 1; + + if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY || + found_key.objectid + found_key.offset <= cur_byte) { + memcpy(&key, &found_key, sizeof(key)); + key.offset++; + path->slots[0]++; + goto next; + } + + total_found++; + cur_byte = found_key.objectid + found_key.offset; + key.objectid = cur_byte; + btrfs_release_path(root, path); + ret = relocate_one_extent(root, path, &found_key); + __alloc_chunk_for_shrink(root, shrink_block_group, 0); + } + + btrfs_release_path(root, path); + + if (total_found > 0) { + printk("btrfs relocate found %llu last extent was %llu\n", + (unsigned long long)total_found, + (unsigned long long)found_key.objectid); + mutex_unlock(&root->fs_info->alloc_mutex); + trans = btrfs_start_transaction(tree_root, 1); + btrfs_commit_transaction(trans, tree_root); + + btrfs_clean_old_snapshots(tree_root); + + btrfs_start_delalloc_inodes(root); + btrfs_wait_ordered_extents(tree_root, 0); + + trans = btrfs_start_transaction(tree_root, 1); + btrfs_commit_transaction(trans, tree_root); + mutex_lock(&root->fs_info->alloc_mutex); + goto again; + } + + /* + * we've freed all the extents, now remove the block + * group item from the tree + */ + mutex_unlock(&root->fs_info->alloc_mutex); + + trans = btrfs_start_transaction(root, 1); + + mutex_lock(&root->fs_info->alloc_mutex); + memcpy(&key, &shrink_block_group->key, sizeof(key)); + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret > 0) + ret = -EIO; + if (ret < 0) { + btrfs_end_transaction(trans, root); + goto out; + } + + spin_lock(&root->fs_info->block_group_cache_lock); + rb_erase(&shrink_block_group->cache_node, + &root->fs_info->block_group_cache_tree); + spin_unlock(&root->fs_info->block_group_cache_lock); + + ret = btrfs_remove_free_space(shrink_block_group, key.objectid, + key.offset); + if (ret) { + btrfs_end_transaction(trans, root); + goto out; + } + /* + memset(shrink_block_group, 0, sizeof(*shrink_block_group)); + kfree(shrink_block_group); + */ + + btrfs_del_item(trans, root, path); + btrfs_release_path(root, path); + mutex_unlock(&root->fs_info->alloc_mutex); + btrfs_commit_transaction(trans, root); + + mutex_lock(&root->fs_info->alloc_mutex); + + /* the code to unpin extents might set a few bits in the free + * space cache for this range again + */ + /* XXX? */ + ret = btrfs_remove_free_space(shrink_block_group, key.objectid, + key.offset); +out: + btrfs_free_path(path); + mutex_unlock(&root->fs_info->alloc_mutex); + return ret; +} + +int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path, + struct btrfs_key *key) +{ + int ret = 0; + struct btrfs_key found_key; + struct extent_buffer *leaf; + int slot; + + ret = btrfs_search_slot(NULL, root, key, path, 0, 0); + if (ret < 0) + goto out; + + while(1) { + slot = path->slots[0]; + leaf = path->nodes[0]; + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret == 0) + continue; + if (ret < 0) + goto out; + break; + } + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + if (found_key.objectid >= key->objectid && + found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { + ret = 0; + goto out; + } + path->slots[0]++; + } + ret = -ENOENT; +out: + return ret; +} + +int btrfs_read_block_groups(struct btrfs_root *root) +{ + struct btrfs_path *path; + int ret; + struct btrfs_block_group_cache *cache; + struct btrfs_fs_info *info = root->fs_info; + struct btrfs_space_info *space_info; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *leaf; + + root = info->extent_root; + key.objectid = 0; + key.offset = 0; + btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY); + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + mutex_lock(&root->fs_info->alloc_mutex); + while(1) { + ret = find_first_block_group(root, path, &key); + if (ret > 0) { + ret = 0; + goto error; + } + if (ret != 0) + goto error; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + cache = kzalloc(sizeof(*cache), GFP_NOFS); + if (!cache) { + ret = -ENOMEM; + break; + } + + spin_lock_init(&cache->lock); + INIT_LIST_HEAD(&cache->list); + read_extent_buffer(leaf, &cache->item, + btrfs_item_ptr_offset(leaf, path->slots[0]), + sizeof(cache->item)); + memcpy(&cache->key, &found_key, sizeof(found_key)); + + key.objectid = found_key.objectid + found_key.offset; + btrfs_release_path(root, path); + cache->flags = btrfs_block_group_flags(&cache->item); + + ret = update_space_info(info, cache->flags, found_key.offset, + btrfs_block_group_used(&cache->item), + &space_info); + BUG_ON(ret); + cache->space_info = space_info; + spin_lock(&space_info->lock); + list_add(&cache->list, &space_info->block_groups); + spin_unlock(&space_info->lock); + + ret = btrfs_add_block_group_cache(root->fs_info, cache); + BUG_ON(ret); + + if (key.objectid >= + btrfs_super_total_bytes(&info->super_copy)) + break; + } + ret = 0; +error: + btrfs_free_path(path); + mutex_unlock(&root->fs_info->alloc_mutex); + return ret; +} + +int btrfs_make_block_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytes_used, + u64 type, u64 chunk_objectid, u64 chunk_offset, + u64 size) +{ + int ret; + struct btrfs_root *extent_root; + struct btrfs_block_group_cache *cache; + + WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); + extent_root = root->fs_info->extent_root; + + root->fs_info->last_trans_new_blockgroup = trans->transid; + + cache = kzalloc(sizeof(*cache), GFP_NOFS); + if (!cache) + return -ENOMEM; + + cache->key.objectid = chunk_offset; + cache->key.offset = size; + spin_lock_init(&cache->lock); + INIT_LIST_HEAD(&cache->list); + btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY); + + btrfs_set_block_group_used(&cache->item, bytes_used); + btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid); + cache->flags = type; + btrfs_set_block_group_flags(&cache->item, type); + + ret = update_space_info(root->fs_info, cache->flags, size, bytes_used, + &cache->space_info); + BUG_ON(ret); + spin_lock(&cache->space_info->lock); + list_add(&cache->list, &cache->space_info->block_groups); + spin_unlock(&cache->space_info->lock); + + ret = btrfs_add_block_group_cache(root->fs_info, cache); + BUG_ON(ret); + + ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item, + sizeof(cache->item)); + BUG_ON(ret); + + finish_current_insert(trans, extent_root); + ret = del_pending_extents(trans, extent_root); + BUG_ON(ret); + set_avail_alloc_bits(extent_root->fs_info, type); + + return 0; +} |