/* * 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 #include #include #include #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); 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; mutex_lock(&info->pinned_mutex); 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_lock(block_group, start, size); BUG_ON(ret); start = extent_end + 1; } else { break; } } if (start < end) { size = end - start; ret = btrfs_add_free_space_lock(block_group, start, size); BUG_ON(ret); } mutex_unlock(&info->pinned_mutex); 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 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 u64 div_factor(u64 num, int factor) { if (factor == 10) return num; num *= factor; do_div(num, 10); return num; } 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; 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 + shint->reserved < 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 + hint->reserved < 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; } again: while (1) { cache = btrfs_lookup_first_block_group(root->fs_info, last); 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 + cache->reserved < 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); 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); 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 * - 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. * * When a file extent is allocated the fields are filled in: * (root_key.objectid, trans->transid, inode objectid, 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, * number of references in the leaf) * * When a file extent is removed either during snapshot deletion or * file truncation, we find the corresponding back reference and check * the following fields: * * (btrfs_header_owner(leaf), btrfs_header_generation(leaf), * inode objectid) * * 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, 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, 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), level) * else * (btrfs_header_owner(parent), btrfs_header_generation(parent), level) * * 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, u64 owner_objectid, int del) { struct btrfs_key key; struct btrfs_extent_ref *ref; struct extent_buffer *leaf; u64 ref_objectid; 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); ref_objectid = btrfs_ref_objectid(leaf, ref); if (btrfs_ref_root(leaf, ref) != ref_root || btrfs_ref_generation(leaf, ref) != ref_generation || (ref_objectid != owner_objectid && ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) { 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) { 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_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 && existing_owner != BTRFS_MULTIPLE_OBJECTIDS) { btrfs_set_ref_objectid(leaf, ref, BTRFS_MULTIPLE_OBJECTIDS); } 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) { 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); mutex_lock(&root->fs_info->extent_ins_mutex); if (test_range_bit(&root->fs_info->extent_ins, bytenr, bytenr + num_bytes - 1, EXTENT_WRITEBACK, 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_WRITEBACK, GFP_NOFS); set_state_private(&root->fs_info->extent_ins, bytenr, (unsigned long)extent_op); } mutex_unlock(&root->fs_info->extent_ins_mutex); 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, owner_objectid, 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); 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) { int ret; if (ref_root == BTRFS_TREE_LOG_OBJECTID && owner_objectid < BTRFS_FIRST_FREE_OBJECTID) return 0; ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent, parent, ref_root, ref_root, ref_generation, ref_generation, owner_objectid); 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) { 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); 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) { int ret; if (ref_root == BTRFS_TREE_LOG_OBJECTID && owner_objectid < BTRFS_FIRST_FREE_OBJECTID) return 0; ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent, 0, ref_root, 0, ref_generation, owner_objectid); 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(); 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: 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) { struct btrfs_key key; struct btrfs_file_extent_item *fi; u64 root_gen; u32 nritems; int i; int level; int ret = 0; int shared = 0; if (!root->ref_cows) return 0; if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { shared = 0; root_gen = root->root_key.offset; } else { shared = 1; root_gen = trans->transid - 1; } 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_gen; 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++; } ret = btrfs_add_leaf_ref(root, ref, shared); if (ret == -EEXIST && shared) { struct btrfs_leaf_ref *old; old = btrfs_lookup_leaf_ref(root, ref->bytenr); BUG_ON(!old); btrfs_remove_leaf_ref(root, old); btrfs_free_leaf_ref(root, old); ret = btrfs_add_leaf_ref(root, ref, shared); } 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); 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++; ret = process_func(trans, root, bytenr, orig_buf->start, buf->start, orig_root, ref_root, orig_generation, ref_generation, key.objectid); if (ret) { faili = i; WARN_ON(1); goto fail; } } else { bytenr = btrfs_node_blockptr(buf, i); ret = process_func(trans, root, bytenr, orig_buf->start, buf->start, orig_root, ref_root, orig_generation, ref_generation, level - 1); 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; ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_buf->start, buf->start, orig_root, ref_root, orig_generation, ref_generation, key.objectid); if (ret) goto fail; } else { bytenr = btrfs_node_blockptr(buf, slot); ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_buf->start, buf->start, orig_root, ref_root, orig_generation, ref_generation, level - 1); 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; 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; cache->dirty = 0; 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; } } btrfs_free_path(path); 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) { spin_lock(&found->lock); found->total_bytes += total_bytes; found->bytes_used += bytes_used; found->full = 0; spin_unlock(&found->lock); *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); init_rwsem(&found->groups_sem); spin_lock_init(&found->lock); found->flags = flags; found->total_bytes = total_bytes; found->bytes_used = bytes_used; found->bytes_pinned = 0; found->bytes_reserved = 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, waited = 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); spin_lock(&space_info->lock); if (space_info->force_alloc) { force = 1; space_info->force_alloc = 0; } if (space_info->full) { spin_unlock(&space_info->lock); goto out; } thresh = div_factor(space_info->total_bytes, 6); if (!force && (space_info->bytes_used + space_info->bytes_pinned + space_info->bytes_reserved + alloc_bytes) < thresh) { spin_unlock(&space_info->lock); goto out; } spin_unlock(&space_info->lock); ret = mutex_trylock(&extent_root->fs_info->chunk_mutex); if (!ret && !force) { goto out; } else if (!ret) { mutex_lock(&extent_root->fs_info->chunk_mutex); waited = 1; } if (waited) { spin_lock(&space_info->lock); if (space_info->full) { spin_unlock(&space_info->lock); goto out_unlock; } spin_unlock(&space_info->lock); } ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags); if (ret) { printk("space info full %Lu\n", flags); space_info->full = 1; goto out_unlock; } 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; 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->space_info->lock); 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); spin_unlock(&cache->space_info->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); spin_unlock(&cache->space_info->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->pinned_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); BUG_ON(!cache); len = min(num, cache->key.offset - (bytenr - cache->key.objectid)); if (pin) { spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); cache->pinned += len; cache->space_info->bytes_pinned += len; spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); fs_info->total_pinned += len; } else { spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); cache->pinned -= len; cache->space_info->bytes_pinned -= len; spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); fs_info->total_pinned -= len; } bytenr += len; num -= len; } return 0; } static int update_reserved_extents(struct btrfs_root *root, u64 bytenr, u64 num, int reserve) { u64 len; struct btrfs_block_group_cache *cache; struct btrfs_fs_info *fs_info = root->fs_info; while (num > 0) { cache = btrfs_lookup_block_group(fs_info, bytenr); BUG_ON(!cache); len = min(num, cache->key.offset - (bytenr - cache->key.objectid)); spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); if (reserve) { cache->reserved += len; cache->space_info->bytes_reserved += len; } else { cache->reserved -= len; cache->space_info->bytes_reserved -= len; } spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); 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; mutex_lock(&root->fs_info->pinned_mutex); 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; } mutex_unlock(&root->fs_info->pinned_mutex); 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->pinned_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->pinned_mutex); cond_resched(); mutex_lock(&root->fs_info->pinned_mutex); } } mutex_unlock(&root->fs_info->pinned_mutex); return 0; } static int finish_current_insert(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root) { u64 start; u64 end; u64 priv; u64 search = 0; 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; btrfs_set_stack_extent_refs(&extent_item, 1); path = btrfs_alloc_path(); while(1) { mutex_lock(&info->extent_ins_mutex); ret = find_first_extent_bit(&info->extent_ins, search, &start, &end, EXTENT_WRITEBACK); if (ret) { mutex_unlock(&info->extent_ins_mutex); if (search) { search = 0; continue; } break; } ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS); if (!ret) { search = end+1; mutex_unlock(&info->extent_ins_mutex); cond_resched(); continue; } BUG_ON(ret < 0); ret = get_state_private(&info->extent_ins, start, &priv); BUG_ON(ret); extent_op = (struct pending_extent_op *)(unsigned long)priv; mutex_unlock(&info->extent_ins_mutex); 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); mutex_lock(&info->extent_ins_mutex); clear_extent_bits(&info->extent_ins, start, end, EXTENT_WRITEBACK, GFP_NOFS); mutex_unlock(&info->extent_ins_mutex); err = insert_extent_backref(trans, extent_root, path, start, extent_op->parent, extent_root->root_key.objectid, extent_op->generation, extent_op->level); 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, extent_op->level, 0); BUG_ON(err); mutex_lock(&info->extent_ins_mutex); clear_extent_bits(&info->extent_ins, start, end, EXTENT_WRITEBACK, GFP_NOFS); mutex_unlock(&info->extent_ins_mutex); 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); unlock_extent(&info->extent_ins, start, end, GFP_NOFS); search = 0; cond_resched(); } 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; 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_owner != BTRFS_TREE_RELOC_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, 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; 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, owner_objectid, 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\n", bytenr, root_objectid, ref_generation, owner_objectid); } 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) { mutex_lock(&root->fs_info->pinned_mutex); ret = pin_down_bytes(trans, root, bytenr, num_bytes, owner_objectid >= BTRFS_FIRST_FREE_OBJECTID); mutex_unlock(&root->fs_info->pinned_mutex); 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); btrfs_release_path(extent_root, path); 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; u64 start; u64 end; u64 priv; u64 search = 0; struct extent_io_tree *pending_del; struct extent_io_tree *extent_ins; struct pending_extent_op *extent_op; struct btrfs_fs_info *info = extent_root->fs_info; extent_ins = &extent_root->fs_info->extent_ins; pending_del = &extent_root->fs_info->pending_del; while(1) { mutex_lock(&info->extent_ins_mutex); ret = find_first_extent_bit(pending_del, search, &start, &end, EXTENT_WRITEBACK); if (ret) { mutex_unlock(&info->extent_ins_mutex); if (search) { search = 0; continue; } break; } ret = try_lock_extent(extent_ins, start, end, GFP_NOFS); if (!ret) { search = end+1; mutex_unlock(&info->extent_ins_mutex); cond_resched(); continue; } BUG_ON(ret < 0); 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_WRITEBACK, GFP_NOFS); if (!test_range_bit(extent_ins, start, end, EXTENT_WRITEBACK, 0)) { mutex_unlock(&info->extent_ins_mutex); 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, 1, 0); kfree(extent_op); } else { kfree(extent_op); ret = get_state_private(&info->extent_ins, start, &priv); BUG_ON(ret); extent_op = (struct pending_extent_op *) (unsigned long)priv; clear_extent_bits(&info->extent_ins, start, end, EXTENT_WRITEBACK, GFP_NOFS); mutex_unlock(&info->extent_ins_mutex); if (extent_op->type == PENDING_BACKREF_UPDATE) goto free_extent; mutex_lock(&extent_root->fs_info->pinned_mutex); ret = pin_down_bytes(trans, extent_root, start, end + 1 - start, 0); mutex_unlock(&extent_root->fs_info->pinned_mutex); ret = update_block_group(trans, extent_root, start, end + 1 - start, 0, ret > 0); BUG_ON(ret); kfree(extent_op); } if (ret) err = ret; unlock_extent(extent_ins, start, end, GFP_NOFS); search = 0; cond_resched(); } 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, 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; mutex_lock(&root->fs_info->extent_ins_mutex); set_extent_bits(&root->fs_info->pending_del, bytenr, bytenr + num_bytes - 1, EXTENT_WRITEBACK, GFP_NOFS); set_state_private(&root->fs_info->pending_del, bytenr, (unsigned long)extent_op); mutex_unlock(&root->fs_info->extent_ins_mutex); 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); update_reserved_extents(root, bytenr, num_bytes, 0); 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, 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, int pin) { int ret; ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent, root_objectid, ref_generation, owner_objectid, pin); 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 = 0; struct btrfs_root * root = orig_root->fs_info->extent_root; u64 total_needed = num_bytes; u64 *last_ptr = NULL; struct btrfs_block_group_cache *block_group = NULL; int chunk_alloc_done = 0; int empty_cluster = 2 * 1024 * 1024; int allowed_chunk_alloc = 0; struct list_head *head = NULL, *cur = NULL; int loop = 0; struct btrfs_space_info *space_info; WARN_ON(num_bytes < root->sectorsize); btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); ins->objectid = 0; ins->offset = 0; 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 (last_ptr) { if (*last_ptr) hint_byte = *last_ptr; else empty_size += empty_cluster; } search_start = max(search_start, first_logical_byte(root, 0)); search_start = max(search_start, hint_byte); total_needed += empty_size; block_group = btrfs_lookup_block_group(root->fs_info, search_start); space_info = __find_space_info(root->fs_info, data); down_read(&space_info->groups_sem); while (1) { struct btrfs_free_space *free_space; /* * the only way this happens if our hint points to a block * group thats not of the proper type, while looping this * should never happen */ WARN_ON(!block_group); mutex_lock(&block_group->alloc_mutex); if (unlikely(!block_group_bits(block_group, data))) goto new_group; ret = cache_block_group(root, block_group); if (ret) { mutex_unlock(&block_group->alloc_mutex); break; } if (block_group->ro) goto new_group; free_space = btrfs_find_free_space(block_group, search_start, total_needed); if (free_space) { u64 start = block_group->key.objectid; u64 end = block_group->key.objectid + block_group->key.offset; search_start = stripe_align(root, free_space->offset); /* move on to the next group */ if (search_start + num_bytes >= search_end) goto new_group; /* move on to the next group */ if (search_start + num_bytes > end) goto new_group; if (exclude_nr > 0 && (search_start + num_bytes > exclude_start && search_start < exclude_start + exclude_nr)) { search_start = exclude_start + exclude_nr; /* * if search_start is still in this block group * then we just re-search this block group */ if (search_start >= start && search_start < end) { mutex_unlock(&block_group->alloc_mutex); continue; } /* else we go to the next block group */ goto new_group; } ins->objectid = search_start; ins->offset = num_bytes; btrfs_remove_free_space_lock(block_group, search_start, num_bytes); /* we are all good, lets return */ mutex_unlock(&block_group->alloc_mutex); break; } new_group: mutex_unlock(&block_group->alloc_mutex); /* * Here's how this works. * loop == 0: we were searching a block group via a hint * and didn't find anything, so we start at * the head of the block groups and keep searching * loop == 1: we're searching through all of the block groups * if we hit the head again we have searched * all of the block groups for this space and we * need to try and allocate, if we cant error out. * loop == 2: we allocated more space and are looping through * all of the block groups again. */ if (loop == 0) { head = &space_info->block_groups; cur = head->next; if (last_ptr && *last_ptr) { total_needed += empty_cluster; *last_ptr = 0; } loop++; } else if (loop == 1 && cur == head) { if (allowed_chunk_alloc && !chunk_alloc_done) { up_read(&space_info->groups_sem); ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024, data, 1); if (ret < 0) break; down_read(&space_info->groups_sem); loop++; head = &space_info->block_groups; cur = head->next; chunk_alloc_done = 1; } else if (!allowed_chunk_alloc) { space_info->force_alloc = 1; break; } else { break; } } else if (cur == head) { break; } block_group = list_entry(cur, struct btrfs_block_group_cache, list); search_start = block_group->key.objectid; cur = cur->next; } /* we found what we needed */ if (ins->objectid) { if (!(data & BTRFS_BLOCK_GROUP_DATA)) trans->block_group = block_group; if (last_ptr) *last_ptr = ins->objectid + ins->offset; ret = 0; } else if (!ret) { ret = -ENOSPC; } up_read(&space_info->groups_sem); 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->bytes_reserved, (info->full) ? "" : "not "); down_read(&info->groups_sem); 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 %Lu reserved\n", cache->key.objectid, cache->key.offset, btrfs_block_group_used(&cache->item), cache->pinned, cache->reserved); btrfs_dump_free_space(cache, bytes); spin_unlock(&cache->lock); } up_read(&info->groups_sem); } 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; 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(); } return ret; } int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len) { struct btrfs_block_group_cache *cache; cache = btrfs_lookup_block_group(root->fs_info, start); if (!cache) { printk(KERN_ERR "Unable to find block group for %Lu\n", start); return -ENOSPC; } btrfs_add_free_space(cache, start, len); update_reserved_extents(root, start, len, 0); 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; ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size, empty_size, hint_byte, search_end, ins, data); update_reserved_extents(root, ins->objectid, ins->offset, 1); 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, 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; mutex_lock(&root->fs_info->extent_ins_mutex); set_extent_bits(&root->fs_info->extent_ins, ins->objectid, ins->objectid + ins->offset - 1, EXTENT_WRITEBACK, GFP_NOFS); set_state_private(&root->fs_info->extent_ins, ins->objectid, (unsigned long)extent_op); mutex_unlock(&root->fs_info->extent_ins_mutex); 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_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, struct btrfs_key *ins) { int ret; if (root_objectid == BTRFS_TREE_LOG_OBJECTID) return 0; ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid, ref_generation, owner, ins); update_reserved_extents(root, ins->objectid, ins->offset, 0); 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, struct btrfs_key *ins) { int ret; struct btrfs_block_group_cache *block_group; block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid); mutex_lock(&block_group->alloc_mutex); cache_block_group(root, block_group); ret = btrfs_remove_free_space_lock(block_group, ins->objectid, ins->offset); mutex_unlock(&block_group->alloc_mutex); BUG_ON(ret); ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid, ref_generation, owner, ins); 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 empty_size, u64 hint_byte, u64 search_end, struct btrfs_key *ins, u64 data) { int ret; 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, ins); BUG_ON(ret); } else { update_reserved_extents(root, ins->objectid, ins->offset, 1); } 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, 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; ret = __btrfs_free_extent(trans, root, disk_bytenr, btrfs_file_extent_disk_num_bytes(leaf, fi), leaf->start, leaf_owner, leaf_generation, key.objectid, 0); 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++) { ret = __btrfs_free_extent(trans, root, info->bytenr, info->num_bytes, ref->bytenr, ref->owner, ref->generation, info->objectid, 0); 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]++; ret = __btrfs_free_extent(trans, root, bytenr, blocksize, parent->start, root_owner, root_gen, *level - 1, 1); BUG_ON(ret); 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 && ref->generation != ptr_gen) { btrfs_free_leaf_ref(root, ref); ref = NULL; } 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); ret = __btrfs_free_extent(trans, root, bytenr, blocksize, parent->start, root_owner, root_gen, *level, 1); free_extent_buffer(path->nodes[*level]); path->nodes[*level] = NULL; *level += 1; BUG_ON(ret); cond_resched(); return 0; } /* * helper function for drop_subtree, this function is similar to * walk_down_tree. The main difference is that it checks reference * counts while tree blocks are locked. */ static int noinline walk_down_subtree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int *level) { struct extent_buffer *next; struct extent_buffer *cur; struct extent_buffer *parent; u64 bytenr; u64 ptr_gen; u32 blocksize; u32 refs; int ret; cur = path->nodes[*level]; ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len, &refs); BUG_ON(ret); if (refs > 1) goto out; while (*level >= 0) { cur = path->nodes[*level]; if (*level == 0) { ret = btrfs_drop_leaf_ref(trans, root, cur); BUG_ON(ret); clean_tree_block(trans, root, cur); break; } if (path->slots[*level] >= btrfs_header_nritems(cur)) { clean_tree_block(trans, root, cur); break; } bytenr = btrfs_node_blockptr(cur, path->slots[*level]); blocksize = btrfs_level_size(root, *level - 1); ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); next = read_tree_block(root, bytenr, blocksize, ptr_gen); btrfs_tree_lock(next); ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize, &refs); BUG_ON(ret); if (refs > 1) { parent = path->nodes[*level]; ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent->start, btrfs_header_owner(parent), btrfs_header_generation(parent), *level - 1, 1); BUG_ON(ret); path->slots[*level]++; btrfs_tree_unlock(next); free_extent_buffer(next); continue; } *level = btrfs_header_level(next); path->nodes[*level] = next; path->slots[*level] = 0; path->locks[*level] = 1; cond_resched(); } out: parent = path->nodes[*level + 1]; bytenr = path->nodes[*level]->start; blocksize = path->nodes[*level]->len; ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent->start, btrfs_header_owner(parent), btrfs_header_generation(parent), *level, 1); BUG_ON(ret); if (path->locks[*level]) { btrfs_tree_unlock(path->nodes[*level]); path->locks[*level] = 0; } free_extent_buffer(path->nodes[*level]); path->nodes[*level] = NULL; *level += 1; 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, int max_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 < max_level && 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); clean_tree_block(trans, root, path->nodes[*level]); ret = btrfs_free_extent(trans, root, path->nodes[*level]->start, path->nodes[*level]->len, parent->start, root_owner, root_gen, *level, 1); BUG_ON(ret); if (path->locks[*level]) { btrfs_tree_unlock(path->nodes[*level]); path->locks[*level] = 0; } 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, BTRFS_MAX_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_drop_subtree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *node, struct extent_buffer *parent) { struct btrfs_path *path; int level; int parent_level; int ret = 0; int wret; path = btrfs_alloc_path(); BUG_ON(!path); BUG_ON(!btrfs_tree_locked(parent)); parent_level = btrfs_header_level(parent); extent_buffer_get(parent); path->nodes[parent_level] = parent; path->slots[parent_level] = btrfs_header_nritems(parent); BUG_ON(!btrfs_tree_locked(node)); level = btrfs_header_level(node); extent_buffer_get(node); path->nodes[level] = node; path->slots[level] = 0; while (1) { wret = walk_down_subtree(trans, root, path, &level); if (wret < 0) ret = wret; if (wret != 0) break; wret = walk_up_tree(trans, root, path, &level, parent_level); if (wret < 0) ret = wret; if (wret != 0) break; } btrfs_free_path(path); return ret; } 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 first_index; 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; struct btrfs_ordered_extent *ordered; unsigned int total_read = 0; unsigned int total_dirty = 0; int ret = 0; ra = kzalloc(sizeof(*ra), GFP_NOFS); mutex_lock(&inode->i_mutex); first_index = start >> PAGE_CACHE_SHIFT; last_index = (start + len - 1) >> PAGE_CACHE_SHIFT; /* make sure the dirty trick played by the caller work */ ret = invalidate_inode_pages2_range(inode->i_mapping, first_index, last_index); if (ret) goto out_unlock; file_ra_state_init(ra, inode->i_mapping); for (i = first_index ; i <= last_index; i++) { if (total_read % ra->ra_pages == 0) { btrfs_force_ra(inode->i_mapping, ra, NULL, i, calc_ra(i, last_index, ra->ra_pages)); } total_read++; again: if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode)) BUG_ON(1); page = grab_cache_page(inode->i_mapping, i); if (!page) { ret = -ENOMEM; goto out_unlock; } if (!PageUptodate(page)) { btrfs_readpage(NULL, page); lock_page(page); if (!PageUptodate(page)) { unlock_page(page); page_cache_release(page); ret = -EIO; 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); btrfs_set_extent_delalloc(inode, page_start, page_end); if (i == first_index) set_extent_bits(io_tree, page_start, page_end, EXTENT_BOUNDARY, GFP_NOFS); set_page_dirty(page); total_dirty++; unlock_extent(io_tree, page_start, page_end, GFP_NOFS); unlock_page(page); page_cache_release(page); } out_unlock: kfree(ra); mutex_unlock(&inode->i_mutex); balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty); return ret; } static int noinline relocate_data_extent(struct inode *reloc_inode, struct btrfs_key *extent_key, u64 offset) { struct btrfs_root *root = BTRFS_I(reloc_inode)->root; struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree; struct extent_map *em; em = alloc_extent_map(GFP_NOFS); BUG_ON(!em || IS_ERR(em)); em->start = extent_key->objectid - offset; em->len = extent_key->offset; em->block_len = extent_key->offset; em->block_start = extent_key->objectid; em->bdev = root->fs_info->fs_devices->latest_bdev; set_bit(EXTENT_FLAG_PINNED, &em->flags); /* setup extent map to cheat btrfs_readpage */ mutex_lock(&BTRFS_I(reloc_inode)->extent_mutex); while (1) { int ret; spin_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); spin_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(reloc_inode, em->start, em->start + em->len - 1, 0); } mutex_unlock(&BTRFS_I(reloc_inode)->extent_mutex); return relocate_inode_pages(reloc_inode, extent_key->objectid - offset, extent_key->offset); } struct btrfs_ref_path { u64 extent_start; u64 nodes[BTRFS_MAX_LEVEL]; u64 root_objectid; u64 root_generation; u64 owner_objectid; u32 num_refs; int lowest_level; int current_level; int shared_level; struct btrfs_key node_keys[BTRFS_MAX_LEVEL]; u64 new_nodes[BTRFS_MAX_LEVEL]; }; struct disk_extent { u64 ram_bytes; u64 disk_bytenr; u64 disk_num_bytes; u64 offset; u64 num_bytes; u8 compression; u8 encryption; u16 other_encoding; }; static int is_cowonly_root(u64 root_objectid) { if (root_objectid == BTRFS_ROOT_TREE_OBJECTID || root_objectid == BTRFS_EXTENT_TREE_OBJECTID || root_objectid == BTRFS_CHUNK_TREE_OBJECTID || root_objectid == BTRFS_DEV_TREE_OBJECTID || root_objectid == BTRFS_TREE_LOG_OBJECTID) return 1; return 0; } static int noinline __next_ref_path(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct btrfs_ref_path *ref_path, int first_time) { struct extent_buffer *leaf; struct btrfs_path *path; struct btrfs_extent_ref *ref; struct btrfs_key key; struct btrfs_key found_key; u64 bytenr; u32 nritems; int level; int ret = 1; path = btrfs_alloc_path(); if (!path) return -ENOMEM; if (first_time) { ref_path->lowest_level = -1; ref_path->current_level = -1; ref_path->shared_level = -1; goto walk_up; } walk_down: level = ref_path->current_level - 1; while (level >= -1) { u64 parent; if (level < ref_path->lowest_level) break; if (level >= 0) { bytenr = ref_path->nodes[level]; } else { bytenr = ref_path->extent_start; } BUG_ON(bytenr == 0); parent = ref_path->nodes[level + 1]; ref_path->nodes[level + 1] = 0; ref_path->current_level = level; BUG_ON(parent == 0); key.objectid = bytenr; key.offset = parent + 1; key.type = BTRFS_EXTENT_REF_KEY; ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0); if (ret < 0) goto out; BUG_ON(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) goto out; if (ret > 0) goto next; 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_REF_KEY) { if (level < ref_path->shared_level) ref_path->shared_level = level; goto found; } next: level--; btrfs_release_path(extent_root, path); if (need_resched()) { cond_resched(); } } /* reached lowest level */ ret = 1; goto out; walk_up: level = ref_path->current_level; while (level < BTRFS_MAX_LEVEL - 1) { u64 ref_objectid; if (level >= 0) { bytenr = ref_path->nodes[level]; } else { bytenr = ref_path->extent_start; } BUG_ON(bytenr == 0); key.objectid = bytenr; key.offset = 0; key.type = BTRFS_EXTENT_REF_KEY; ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0); if (ret < 0) goto out; 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) { /* the extent was freed by someone */ if (ref_path->lowest_level == level) goto out; btrfs_release_path(extent_root, path); goto walk_down; } 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_REF_KEY) { /* the extent was freed by someone */ if (ref_path->lowest_level == level) { ret = 1; goto out; } btrfs_release_path(extent_root, path); goto walk_down; } found: ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); ref_objectid = btrfs_ref_objectid(leaf, ref); if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) { if (first_time) { level = (int)ref_objectid; BUG_ON(level >= BTRFS_MAX_LEVEL); ref_path->lowest_level = level; ref_path->current_level = level; ref_path->nodes[level] = bytenr; } else { WARN_ON(ref_objectid != level); } } else { WARN_ON(level != -1); } first_time = 0; if (ref_path->lowest_level == level) { ref_path->owner_objectid = ref_objectid; ref_path->num_refs = btrfs_ref_num_refs(leaf, ref); } /* * the block is tree root or the block isn't in reference * counted tree. */ if (found_key.objectid == found_key.offset || is_cowonly_root(btrfs_ref_root(leaf, ref))) { ref_path->root_objectid = btrfs_ref_root(leaf, ref); ref_path->root_generation = btrfs_ref_generation(leaf, ref); if (level < 0) { /* special reference from the tree log */ ref_path->nodes[0] = found_key.offset; ref_path->current_level = 0; } ret = 0; goto out; } level++; BUG_ON(ref_path->nodes[level] != 0); ref_path->nodes[level] = found_key.offset; ref_path->current_level = level; /* * the reference was created in the running transaction, * no need to continue walking up. */ if (btrfs_ref_generation(leaf, ref) == trans->transid) { ref_path->root_objectid = btrfs_ref_root(leaf, ref); ref_path->root_generation = btrfs_ref_generation(leaf, ref); ret = 0; goto out; } btrfs_release_path(extent_root, path); if (need_resched()) { cond_resched(); } } /* reached max tree level, but no tree root found. */ BUG(); out: btrfs_free_path(path); return ret; } static int btrfs_first_ref_path(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct btrfs_ref_path *ref_path, u64 extent_start) { memset(ref_path, 0, sizeof(*ref_path)); ref_path->extent_start = extent_start; return __next_ref_path(trans, extent_root, ref_path, 1); } static int btrfs_next_ref_path(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct btrfs_ref_path *ref_path) { return __next_ref_path(trans, extent_root, ref_path, 0); } static int noinline get_new_locations(struct inode *reloc_inode, struct btrfs_key *extent_key, u64 offset, int no_fragment, struct disk_extent **extents, int *nr_extents) { struct btrfs_root *root = BTRFS_I(reloc_inode)->root; struct btrfs_path *path; struct btrfs_file_extent_item *fi; struct extent_buffer *leaf; struct disk_extent *exts = *extents; struct btrfs_key found_key; u64 cur_pos; u64 last_byte; u32 nritems; int nr = 0; int max = *nr_extents; int ret; WARN_ON(!no_fragment && *extents); if (!exts) { max = 1; exts = kmalloc(sizeof(*exts) * max, GFP_NOFS); if (!exts) return -ENOMEM; } path = btrfs_alloc_path(); BUG_ON(!path); cur_pos = extent_key->objectid - offset; last_byte = extent_key->objectid + extent_key->offset; ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino, cur_pos, 0); if (ret < 0) goto out; if (ret > 0) { ret = -ENOENT; goto out; } while (1) { 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 > 0) break; leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.offset != cur_pos || found_key.type != BTRFS_EXTENT_DATA_KEY || found_key.objectid != reloc_inode->i_ino) break; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG || btrfs_file_extent_disk_bytenr(leaf, fi) == 0) break; if (nr == max) { struct disk_extent *old = exts; max *= 2; exts = kzalloc(sizeof(*exts) * max, GFP_NOFS); memcpy(exts, old, sizeof(*exts) * nr); if (old != *extents) kfree(old); } exts[nr].disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); exts[nr].disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); exts[nr].offset = btrfs_file_extent_offset(leaf, fi); exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi); exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); exts[nr].compression = btrfs_file_extent_compression(leaf, fi); exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi); exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf, fi); WARN_ON(exts[nr].offset > 0); WARN_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes); cur_pos += exts[nr].num_bytes; nr++; if (cur_pos + offset >= last_byte) break; if (no_fragment) { ret = 1; goto out; } path->slots[0]++; } WARN_ON(cur_pos + offset > last_byte); if (cur_pos + offset < last_byte) { ret = -ENOENT; goto out; } ret = 0; out: btrfs_free_path(path); if (ret) { if (exts != *extents) kfree(exts); } else { *extents = exts; *nr_extents = nr; } return ret; } static int noinline replace_one_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *extent_key, struct btrfs_key *leaf_key, struct btrfs_ref_path *ref_path, struct disk_extent *new_extents, int nr_extents) { struct extent_buffer *leaf; struct btrfs_file_extent_item *fi; struct inode *inode = NULL; struct btrfs_key key; u64 lock_start = 0; u64 lock_end = 0; u64 num_bytes; u64 ext_offset; u64 first_pos; u32 nritems; int nr_scaned = 0; int extent_locked = 0; int ret; memcpy(&key, leaf_key, sizeof(key)); first_pos = INT_LIMIT(loff_t) - extent_key->offset; if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) { if (key.objectid < ref_path->owner_objectid || (key.objectid == ref_path->owner_objectid && key.type < BTRFS_EXTENT_DATA_KEY)) { key.objectid = ref_path->owner_objectid; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = 0; } } while (1) { ret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (ret < 0) goto out; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); next: if (extent_locked && ret > 0) { /* * the file extent item was modified by someone * before the extent got locked. */ mutex_unlock(&BTRFS_I(inode)->extent_mutex); unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); extent_locked = 0; } if (path->slots[0] >= nritems) { if (++nr_scaned > 2) break; BUG_ON(extent_locked); ret = btrfs_next_leaf(root, path); if (ret < 0) goto out; if (ret > 0) break; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) { if ((key.objectid > ref_path->owner_objectid) || (key.objectid == ref_path->owner_objectid && key.type > BTRFS_EXTENT_DATA_KEY) || (key.offset >= first_pos + extent_key->offset)) break; } if (inode && key.objectid != inode->i_ino) { BUG_ON(extent_locked); btrfs_release_path(root, path); mutex_unlock(&inode->i_mutex); iput(inode); inode = NULL; continue; } if (key.type != BTRFS_EXTENT_DATA_KEY) { path->slots[0]++; ret = 1; goto next; } fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); if ((btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) || (btrfs_file_extent_disk_bytenr(leaf, fi) != extent_key->objectid)) { path->slots[0]++; ret = 1; goto next; } num_bytes = btrfs_file_extent_num_bytes(leaf, fi); ext_offset = btrfs_file_extent_offset(leaf, fi); if (first_pos > key.offset - ext_offset) first_pos = key.offset - ext_offset; if (!extent_locked) { lock_start = key.offset; lock_end = lock_start + num_bytes - 1; } else { BUG_ON(lock_start != key.offset); BUG_ON(lock_end - lock_start + 1 < num_bytes); } if (!inode) { btrfs_release_path(root, path); inode = btrfs_iget_locked(root->fs_info->sb, key.objectid, root); if (inode->i_state & I_NEW) { BTRFS_I(inode)->root = root; BTRFS_I(inode)->location.objectid = key.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); } /* * some code call btrfs_commit_transaction while * holding the i_mutex, so we can't use mutex_lock * here. */ if (is_bad_inode(inode) || !mutex_trylock(&inode->i_mutex)) { iput(inode); inode = NULL; key.offset = (u64)-1; goto skip; } } if (!extent_locked) { struct btrfs_ordered_extent *ordered; btrfs_release_path(root, path); lock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); if (ordered && ordered->file_offset <= lock_end && ordered->file_offset + ordered->len > lock_start) { unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); key.offset += num_bytes; goto skip; } if (ordered) btrfs_put_ordered_extent(ordered); mutex_lock(&BTRFS_I(inode)->extent_mutex); extent_locked = 1; continue; } if (nr_extents == 1) { /* update extent pointer in place */ btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_disk_bytenr(leaf, fi, new_extents[0].disk_bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, fi, new_extents[0].disk_num_bytes); btrfs_set_file_extent_ram_bytes(leaf, fi, new_extents[0].ram_bytes); ext_offset += new_extents[0].offset; btrfs_set_file_extent_offset(leaf, fi, ext_offset); btrfs_mark_buffer_dirty(leaf); btrfs_drop_extent_cache(inode, key.offset, key.offset + num_bytes - 1, 0); ret = btrfs_inc_extent_ref(trans, root, new_extents[0].disk_bytenr, new_extents[0].disk_num_bytes, leaf->start, root->root_key.objectid, trans->transid, key.objectid); BUG_ON(ret); ret = btrfs_free_extent(trans, root, extent_key->objectid, extent_key->offset, leaf->start, btrfs_header_owner(leaf), btrfs_header_generation(leaf), key.objectid, 0); BUG_ON(ret); btrfs_release_path(root, path); key.offset += num_bytes; } else { u64 alloc_hint; u64 extent_len; int i; /* * drop old extent pointer at first, then insert the * new pointers one bye one */ btrfs_release_path(root, path); ret = btrfs_drop_extents(trans, root, inode, key.offset, key.offset + num_bytes, key.offset, &alloc_hint); BUG_ON(ret); for (i = 0; i < nr_extents; i++) { if (ext_offset >= new_extents[i].num_bytes) { ext_offset -= new_extents[i].num_bytes; continue; } extent_len = min(new_extents[i].num_bytes - ext_offset, num_bytes); ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*fi)); BUG_ON(ret); leaf = path->nodes[0]; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG); btrfs_set_file_extent_disk_bytenr(leaf, fi, new_extents[i].disk_bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, fi, new_extents[i].disk_num_bytes); btrfs_set_file_extent_ram_bytes(leaf, fi, new_extents[i].ram_bytes); btrfs_set_file_extent_compression(leaf, fi, new_extents[i].compression); btrfs_set_file_extent_encryption(leaf, fi, new_extents[i].encryption); btrfs_set_file_extent_other_encoding(leaf, fi, new_extents[i].other_encoding); btrfs_set_file_extent_num_bytes(leaf, fi, extent_len); ext_offset += new_extents[i].offset; btrfs_set_file_extent_offset(leaf, fi, ext_offset); btrfs_mark_buffer_dirty(leaf); btrfs_drop_extent_cache(inode, key.offset, key.offset + extent_len - 1, 0); ret = btrfs_inc_extent_ref(trans, root, new_extents[i].disk_bytenr, new_extents[i].disk_num_bytes, leaf->start, root->root_key.objectid, trans->transid, key.objectid); BUG_ON(ret); btrfs_release_path(root, path); inode_add_bytes(inode, extent_len); ext_offset = 0; num_bytes -= extent_len; key.offset += extent_len; if (num_bytes == 0) break; } BUG_ON(i >= nr_extents); } if (extent_locked) { mutex_unlock(&BTRFS_I(inode)->extent_mutex); unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); extent_locked = 0; } skip: if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS && key.offset >= first_pos + extent_key->offset) break; cond_resched(); } ret = 0; out: btrfs_release_path(root, path); if (inode) { mutex_unlock(&inode->i_mutex); if (extent_locked) { mutex_unlock(&BTRFS_I(inode)->extent_mutex); unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); } iput(inode); } return ret; } int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, u64 orig_start) { int level; int ret; BUG_ON(btrfs_header_generation(buf) != trans->transid); BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); level = btrfs_header_level(buf); if (level == 0) { struct btrfs_leaf_ref *ref; struct btrfs_leaf_ref *orig_ref; orig_ref = btrfs_lookup_leaf_ref(root, orig_start); if (!orig_ref) return -ENOENT; ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems); if (!ref) { btrfs_free_leaf_ref(root, orig_ref); return -ENOMEM; } ref->nritems = orig_ref->nritems; memcpy(ref->extents, orig_ref->extents, sizeof(ref->extents[0]) * ref->nritems); btrfs_free_leaf_ref(root, orig_ref); ref->root_gen = trans->transid; ref->bytenr = buf->start; ref->owner = btrfs_header_owner(buf); ref->generation = btrfs_header_generation(buf); ret = btrfs_add_leaf_ref(root, ref, 0); WARN_ON(ret); btrfs_free_leaf_ref(root, ref); } return 0; } static int noinline invalidate_extent_cache(struct btrfs_root *root, struct extent_buffer *leaf, struct btrfs_block_group_cache *group, struct btrfs_root *target_root) { struct btrfs_key key; struct inode *inode = NULL; struct btrfs_file_extent_item *fi; u64 num_bytes; u64 skip_objectid = 0; u32 nritems; u32 i; nritems = btrfs_header_nritems(leaf); for (i = 0; i < nritems; i++) { btrfs_item_key_to_cpu(leaf, &key, i); if (key.objectid == skip_objectid || key.type != 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; if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0) continue; if (!inode || inode->i_ino != key.objectid) { iput(inode); inode = btrfs_ilookup(target_root->fs_info->sb, key.objectid, target_root, 1); } if (!inode) { skip_objectid = key.objectid; continue; } num_bytes = btrfs_file_extent_num_bytes(leaf, fi); lock_extent(&BTRFS_I(inode)->io_tree, key.offset, key.offset + num_bytes - 1, GFP_NOFS); mutex_lock(&BTRFS_I(inode)->extent_mutex); btrfs_drop_extent_cache(inode, key.offset, key.offset + num_bytes - 1, 1); mutex_unlock(&BTRFS_I(inode)->extent_mutex); unlock_extent(&BTRFS_I(inode)->io_tree, key.offset, key.offset + num_bytes - 1, GFP_NOFS); cond_resched(); } iput(inode); return 0; } static int noinline replace_extents_in_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *leaf, struct btrfs_block_group_cache *group, struct inode *reloc_inode) { struct btrfs_key key; struct btrfs_key extent_key; struct btrfs_file_extent_item *fi; struct btrfs_leaf_ref *ref; struct disk_extent *new_extent; u64 bytenr; u64 num_bytes; u32 nritems; u32 i; int ext_index; int nr_extent; int ret; new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS); BUG_ON(!new_extent); ref = btrfs_lookup_leaf_ref(root, leaf->start); BUG_ON(!ref); ext_index = -1; nritems = btrfs_header_nritems(leaf); for (i = 0; i < nritems; i++) { 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; bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); if (bytenr == 0) continue; ext_index++; if (bytenr >= group->key.objectid + group->key.offset || bytenr + num_bytes <= group->key.objectid) continue; extent_key.objectid = bytenr; extent_key.offset = num_bytes; extent_key.type = BTRFS_EXTENT_ITEM_KEY; nr_extent = 1; ret = get_new_locations(reloc_inode, &extent_key, group->key.objectid, 1, &new_extent, &nr_extent); if (ret > 0) continue; BUG_ON(ret < 0); BUG_ON(ref->extents[ext_index].bytenr != bytenr); BUG_ON(ref->extents[ext_index].num_bytes != num_bytes); ref->extents[ext_index].bytenr = new_extent->disk_bytenr; ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes; btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_ram_bytes(leaf, fi, new_extent->ram_bytes); btrfs_set_file_extent_disk_bytenr(leaf, fi, new_extent->disk_bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, fi, new_extent->disk_num_bytes); new_extent->offset += btrfs_file_extent_offset(leaf, fi); btrfs_set_file_extent_offset(leaf, fi, new_extent->offset); btrfs_mark_buffer_dirty(leaf); ret = btrfs_inc_extent_ref(trans, root, new_extent->disk_bytenr, new_extent->disk_num_bytes, leaf->start, root->root_key.objectid, trans->transid, key.objectid); BUG_ON(ret); ret = btrfs_free_extent(trans, root, bytenr, num_bytes, leaf->start, btrfs_header_owner(leaf), btrfs_header_generation(leaf), key.objectid, 0); BUG_ON(ret); cond_resched(); } kfree(new_extent); BUG_ON(ext_index + 1 != ref->nritems); btrfs_free_leaf_ref(root, ref); return 0; } int btrfs_free_reloc_root(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_root *reloc_root; int ret; if (root->reloc_root) { reloc_root = root->reloc_root; root->reloc_root = NULL; list_add(&reloc_root->dead_list, &root->fs_info->dead_reloc_roots); btrfs_set_root_bytenr(&reloc_root->root_item, reloc_root->node->start); btrfs_set_root_level(&root->root_item, btrfs_header_level(reloc_root->node)); memset(&reloc_root->root_item.drop_progress, 0, sizeof(struct btrfs_disk_key)); reloc_root->root_item.drop_level = 0; ret = btrfs_update_root(trans, root->fs_info->tree_root, &reloc_root->root_key, &reloc_root->root_item); BUG_ON(ret); } return 0; } int btrfs_drop_dead_reloc_roots(struct btrfs_root *root) { struct btrfs_trans_handle *trans; struct btrfs_root *reloc_root; struct btrfs_root *prev_root = NULL; struct list_head dead_roots; int ret; unsigned long nr; INIT_LIST_HEAD(&dead_roots); list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots); while (!list_empty(&dead_roots)) { reloc_root = list_entry(dead_roots.prev, struct btrfs_root, dead_list); list_del_init(&reloc_root->dead_list); BUG_ON(reloc_root->commit_root != NULL); while (1) { trans = btrfs_join_transaction(root, 1); BUG_ON(!trans); mutex_lock(&root->fs_info->drop_mutex); ret = btrfs_drop_snapshot(trans, reloc_root); if (ret != -EAGAIN) break; mutex_unlock(&root->fs_info->drop_mutex); nr = trans->blocks_used; ret = btrfs_end_transaction(trans, root); BUG_ON(ret); btrfs_btree_balance_dirty(root, nr); } free_extent_buffer(reloc_root->node); ret = btrfs_del_root(trans, root->fs_info->tree_root, &reloc_root->root_key); BUG_ON(ret); mutex_unlock(&root->fs_info->drop_mutex); nr = trans->blocks_used; ret = btrfs_end_transaction(trans, root); BUG_ON(ret); btrfs_btree_balance_dirty(root, nr); kfree(prev_root); prev_root = reloc_root; } if (prev_root) { btrfs_remove_leaf_refs(prev_root, (u64)-1, 0); kfree(prev_root); } return 0; } int btrfs_add_dead_reloc_root(struct btrfs_root *root) { list_add(&root->dead_list, &root->fs_info->dead_reloc_roots); return 0; } int btrfs_cleanup_reloc_trees(struct btrfs_root *root) { struct btrfs_root *reloc_root; struct btrfs_trans_handle *trans; struct btrfs_key location; int found; int ret; mutex_lock(&root->fs_info->tree_reloc_mutex); ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL); BUG_ON(ret); found = !list_empty(&root->fs_info->dead_reloc_roots); mutex_unlock(&root->fs_info->tree_reloc_mutex); if (found) { trans = btrfs_start_transaction(root, 1); BUG_ON(!trans); ret = btrfs_commit_transaction(trans, root); BUG_ON(ret); } location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID; location.offset = (u64)-1; location.type = BTRFS_ROOT_ITEM_KEY; reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location); BUG_ON(!reloc_root); btrfs_orphan_cleanup(reloc_root); return 0; } static int noinline init_reloc_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_root *reloc_root; struct extent_buffer *eb; struct btrfs_root_item *root_item; struct btrfs_key root_key; int ret; BUG_ON(!root->ref_cows); if (root->reloc_root) return 0; root_item = kmalloc(sizeof(*root_item), GFP_NOFS); BUG_ON(!root_item); ret = btrfs_copy_root(trans, root, root->commit_root, &eb, BTRFS_TREE_RELOC_OBJECTID); BUG_ON(ret); root_key.objectid = BTRFS_TREE_RELOC_OBJECTID; root_key.offset = root->root_key.objectid; root_key.type = BTRFS_ROOT_ITEM_KEY; memcpy(root_item, &root->root_item, sizeof(root_item)); btrfs_set_root_refs(root_item, 0); btrfs_set_root_bytenr(root_item, eb->start); btrfs_set_root_level(root_item, btrfs_header_level(eb)); btrfs_set_root_generation(root_item, trans->transid); btrfs_tree_unlock(eb); free_extent_buffer(eb); ret = btrfs_insert_root(trans, root->fs_info->tree_root, &root_key, root_item); BUG_ON(ret); kfree(root_item); reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root, &root_key); BUG_ON(!reloc_root); reloc_root->last_trans = trans->transid; reloc_root->commit_root = NULL; reloc_root->ref_tree = &root->fs_info->reloc_ref_tree; root->reloc_root = reloc_root; return 0; } /* * Core function of space balance. * * The idea is using reloc trees to relocate tree blocks in reference * counted roots. There is one reloc tree for each subvol, and all * reloc trees share same root key objectid. Reloc trees are snapshots * of the latest committed roots of subvols (root->commit_root). * * To relocate a tree block referenced by a subvol, there are two steps. * COW the block through subvol's reloc tree, then update block pointer * in the subvol to point to the new block. Since all reloc trees share * same root key objectid, doing special handing for tree blocks owned * by them is easy. Once a tree block has been COWed in one reloc tree, * we can use the resulting new block directly when the same block is * required to COW again through other reloc trees. By this way, relocated * tree blocks are shared between reloc trees, so they are also shared * between subvols. */ static int noinline relocate_one_path(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *first_key, struct btrfs_ref_path *ref_path, struct btrfs_block_group_cache *group, struct inode *reloc_inode) { struct btrfs_root *reloc_root; struct extent_buffer *eb = NULL; struct btrfs_key *keys; u64 *nodes; int level; int shared_level; int lowest_level = 0; int ret; if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) lowest_level = ref_path->owner_objectid; if (!root->ref_cows) { path->lowest_level = lowest_level; ret = btrfs_search_slot(trans, root, first_key, path, 0, 1); BUG_ON(ret < 0); path->lowest_level = 0; btrfs_release_path(root, path); return 0; } mutex_lock(&root->fs_info->tree_reloc_mutex); ret = init_reloc_tree(trans, root); BUG_ON(ret); reloc_root = root->reloc_root; shared_level = ref_path->shared_level; ref_path->shared_level = BTRFS_MAX_LEVEL - 1; keys = ref_path->node_keys; nodes = ref_path->new_nodes; memset(&keys[shared_level + 1], 0, sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1)); memset(&nodes[shared_level + 1], 0, sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1)); if (nodes[lowest_level] == 0) { path->lowest_level = lowest_level; ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 1); BUG_ON(ret); for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) { eb = path->nodes[level]; if (!eb || eb == reloc_root->node) break; nodes[level] = eb->start; if (level == 0) btrfs_item_key_to_cpu(eb, &keys[level], 0); else btrfs_node_key_to_cpu(eb, &keys[level], 0); } if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { eb = path->nodes[0]; ret = replace_extents_in_leaf(trans, reloc_root, eb, group, reloc_inode); BUG_ON(ret); } btrfs_release_path(reloc_root, path); } else { ret = btrfs_merge_path(trans, reloc_root, keys, nodes, lowest_level); BUG_ON(ret); } /* * replace tree blocks in the fs tree with tree blocks in * the reloc tree. */ ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level); BUG_ON(ret < 0); if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 0); BUG_ON(ret); extent_buffer_get(path->nodes[0]); eb = path->nodes[0]; btrfs_release_path(reloc_root, path); ret = invalidate_extent_cache(reloc_root, eb, group, root); BUG_ON(ret); free_extent_buffer(eb); } mutex_unlock(&root->fs_info->tree_reloc_mutex); path->lowest_level = 0; return 0; } static int noinline relocate_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *first_key, struct btrfs_ref_path *ref_path) { int ret; ret = relocate_one_path(trans, root, path, first_key, ref_path, NULL, NULL); BUG_ON(ret); if (root == root->fs_info->extent_root) btrfs_extent_post_op(trans, root); return 0; } static int noinline del_extent_zero(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct btrfs_path *path, struct btrfs_key *extent_key) { int ret; ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1); if (ret) goto out; ret = btrfs_del_item(trans, extent_root, path); out: btrfs_release_path(extent_root, path); return ret; } static struct btrfs_root noinline *read_ref_root(struct btrfs_fs_info *fs_info, struct btrfs_ref_path *ref_path) { struct btrfs_key root_key; root_key.objectid = ref_path->root_objectid; root_key.type = BTRFS_ROOT_ITEM_KEY; if (is_cowonly_root(ref_path->root_objectid)) root_key.offset = 0; else root_key.offset = (u64)-1; return btrfs_read_fs_root_no_name(fs_info, &root_key); } static int noinline relocate_one_extent(struct btrfs_root *extent_root, struct btrfs_path *path, struct btrfs_key *extent_key, struct btrfs_block_group_cache *group, struct inode *reloc_inode, int pass) { struct btrfs_trans_handle *trans; struct btrfs_root *found_root; struct btrfs_ref_path *ref_path = NULL; struct disk_extent *new_extents = NULL; int nr_extents = 0; int loops; int ret; int level; struct btrfs_key first_key; u64 prev_block = 0; trans = btrfs_start_transaction(extent_root, 1); BUG_ON(!trans); if (extent_key->objectid == 0) { ret = del_extent_zero(trans, extent_root, path, extent_key); goto out; } ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS); if (!ref_path) { ret = -ENOMEM; goto out; } for (loops = 0; ; loops++) { if (loops == 0) { ret = btrfs_first_ref_path(trans, extent_root, ref_path, extent_key->objectid); } else { ret = btrfs_next_ref_path(trans, extent_root, ref_path); } if (ret < 0) goto out; if (ret > 0) break; if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID || ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID) continue; found_root = read_ref_root(extent_root->fs_info, ref_path); BUG_ON(!found_root); /* * for reference counted tree, only process reference paths * rooted at the latest committed root. */ if (found_root->ref_cows && ref_path->root_generation != found_root->root_key.offset) continue; if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { if (pass == 0) { /* * copy data extents to new locations */ u64 group_start = group->key.objectid; ret = relocate_data_extent(reloc_inode, extent_key, group_start); if (ret < 0) goto out; break; } level = 0; } else { level = ref_path->owner_objectid; } if (prev_block != ref_path->nodes[level]) { struct extent_buffer *eb; u64 block_start = ref_path->nodes[level]; u64 block_size = btrfs_level_size(found_root, level); eb = read_tree_block(found_root, block_start, block_size, 0); btrfs_tree_lock(eb); BUG_ON(level != btrfs_header_level(eb)); if (level == 0) btrfs_item_key_to_cpu(eb, &first_key, 0); else btrfs_node_key_to_cpu(eb, &first_key, 0); btrfs_tree_unlock(eb); free_extent_buffer(eb); prev_block = block_start; } if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID && pass >= 2) { /* * use fallback method to process the remaining * references. */ if (!new_extents) { u64 group_start = group->key.objectid; ret = get_new_locations(reloc_inode, extent_key, group_start, 0, &new_extents, &nr_extents); if (ret < 0) goto out; } btrfs_record_root_in_trans(found_root); ret = replace_one_extent(trans, found_root, path, extent_key, &first_key, ref_path, new_extents, nr_extents); if (ret < 0) goto out; continue; } btrfs_record_root_in_trans(found_root); if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) { ret = relocate_tree_block(trans, found_root, path, &first_key, ref_path); } else { /* * try to update data extent references while * keeping metadata shared between snapshots. */ ret = relocate_one_path(trans, found_root, path, &first_key, ref_path, group, reloc_inode); } if (ret < 0) goto out; } ret = 0; out: btrfs_end_transaction(trans, extent_root); kfree(new_extents); kfree(ref_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); trans = btrfs_start_transaction(root, 1); 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); btrfs_end_transaction(trans, root); } else spin_unlock(&shrink_block_group->lock); return 0; } static int __insert_orphan_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid, u64 size) { struct btrfs_path *path; struct btrfs_inode_item *item; struct extent_buffer *leaf; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = btrfs_insert_empty_inode(trans, root, path, objectid); if (ret) goto out; leaf = path->nodes[0]; item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item)); btrfs_set_inode_generation(leaf, item, 1); btrfs_set_inode_size(leaf, item, size); btrfs_set_inode_mode(leaf, item, S_IFREG | 0600); btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NODATASUM); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(root, path); out: btrfs_free_path(path); return ret; } static struct inode noinline *create_reloc_inode(struct btrfs_fs_info *fs_info, struct btrfs_block_group_cache *group) { struct inode *inode = NULL; struct btrfs_trans_handle *trans; struct btrfs_root *root; struct btrfs_key root_key; u64 objectid = BTRFS_FIRST_FREE_OBJECTID; int err = 0; root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID; root_key.type = BTRFS_ROOT_ITEM_KEY; root_key.offset = (u64)-1; root = btrfs_read_fs_root_no_name(fs_info, &root_key); if (IS_ERR(root)) return ERR_CAST(root); trans = btrfs_start_transaction(root, 1); BUG_ON(!trans); err = btrfs_find_free_objectid(trans, root, objectid, &objectid); if (err) goto out; err = __insert_orphan_inode(trans, root, objectid, group->key.offset); BUG_ON(err); err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0, group->key.offset, 0, group->key.offset, 0, 0, 0); BUG_ON(err); inode = btrfs_iget_locked(root->fs_info->sb, objectid, root); if (inode->i_state & I_NEW) { BTRFS_I(inode)->root = root; BTRFS_I(inode)->location.objectid = 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); BUG_ON(is_bad_inode(inode)); } else { BUG_ON(1); } err = btrfs_orphan_add(trans, inode); out: btrfs_end_transaction(trans, root); if (err) { if (inode) iput(inode); inode = ERR_PTR(err); } return inode; } int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start) { struct btrfs_trans_handle *trans; struct btrfs_path *path; struct btrfs_fs_info *info = root->fs_info; struct extent_buffer *leaf; struct inode *reloc_inode; struct btrfs_block_group_cache *block_group; struct btrfs_key key; u64 cur_byte; u64 total_found; u32 nritems; int ret; int progress; int pass = 0; root = root->fs_info->extent_root; block_group = btrfs_lookup_block_group(info, group_start); BUG_ON(!block_group); printk("btrfs relocating block group %llu flags %llu\n", (unsigned long long)block_group->key.objectid, (unsigned long long)block_group->flags); path = btrfs_alloc_path(); BUG_ON(!path); reloc_inode = create_reloc_inode(info, block_group); BUG_ON(IS_ERR(reloc_inode)); __alloc_chunk_for_shrink(root, block_group, 1); block_group->ro = 1; block_group->space_info->total_bytes -= block_group->key.offset; btrfs_start_delalloc_inodes(info->tree_root); btrfs_wait_ordered_extents(info->tree_root, 0); again: total_found = 0; progress = 0; key.objectid = block_group->key.objectid; key.offset = 0; key.type = 0; cur_byte = key.objectid; trans = btrfs_start_transaction(info->tree_root, 1); btrfs_commit_transaction(trans, info->tree_root); mutex_lock(&root->fs_info->cleaner_mutex); btrfs_clean_old_snapshots(info->tree_root); btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1); mutex_unlock(&root->fs_info->cleaner_mutex); 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, &key, path->slots[0]); if (key.objectid >= block_group->key.objectid + block_group->key.offset) break; if (progress && need_resched()) { btrfs_release_path(root, path); cond_resched(); progress = 0; continue; } progress = 1; if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY || key.objectid + key.offset <= cur_byte) { path->slots[0]++; goto next; } total_found++; cur_byte = key.objectid + key.offset; btrfs_release_path(root, path); __alloc_chunk_for_shrink(root, block_group, 0); ret = relocate_one_extent(root, path, &key, block_group, reloc_inode, pass); BUG_ON(ret < 0); key.objectid = cur_byte; key.type = 0; key.offset = 0; } btrfs_release_path(root, path); if (pass == 0) { btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1); invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1); WARN_ON(reloc_inode->i_mapping->nrpages); } if (total_found > 0) { printk("btrfs found %llu extents in pass %d\n", (unsigned long long)total_found, pass); pass++; goto again; } /* delete reloc_inode */ iput(reloc_inode); /* unpin extents in this range */ trans = btrfs_start_transaction(info->tree_root, 1); btrfs_commit_transaction(trans, info->tree_root); spin_lock(&block_group->lock); WARN_ON(block_group->pinned > 0); WARN_ON(block_group->reserved > 0); WARN_ON(btrfs_block_group_used(&block_group->item) > 0); spin_unlock(&block_group->lock); ret = 0; out: btrfs_free_path(path); 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_free_block_groups(struct btrfs_fs_info *info) { struct btrfs_block_group_cache *block_group; struct rb_node *n; 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); spin_unlock(&info->block_group_cache_lock); btrfs_remove_free_space_cache(block_group); spin_lock(&info->block_group_cache_lock); rb_erase(&block_group->cache_node, &info->block_group_cache_tree); down_write(&block_group->space_info->groups_sem); list_del(&block_group->list); up_write(&block_group->space_info->groups_sem); kfree(block_group); } spin_unlock(&info->block_group_cache_lock); return 0; } 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; 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); mutex_init(&cache->alloc_mutex); 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; down_write(&space_info->groups_sem); list_add_tail(&cache->list, &space_info->block_groups); up_write(&space_info->groups_sem); ret = btrfs_add_block_group_cache(root->fs_info, cache); BUG_ON(ret); set_avail_alloc_bits(root->fs_info, cache->flags); } ret = 0; error: btrfs_free_path(path); 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; 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); mutex_init(&cache->alloc_mutex); 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); down_write(&cache->space_info->groups_sem); list_add_tail(&cache->list, &cache->space_info->block_groups); up_write(&cache->space_info->groups_sem); 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; } int btrfs_remove_block_group(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 group_start) { struct btrfs_path *path; struct btrfs_block_group_cache *block_group; struct btrfs_key key; int ret; root = root->fs_info->extent_root; block_group = btrfs_lookup_block_group(root->fs_info, group_start); BUG_ON(!block_group); memcpy(&key, &block_group->key, sizeof(key)); path = btrfs_alloc_path(); BUG_ON(!path); btrfs_remove_free_space_cache(block_group); rb_erase(&block_group->cache_node, &root->fs_info->block_group_cache_tree); down_write(&block_group->space_info->groups_sem); list_del(&block_group->list); up_write(&block_group->space_info->groups_sem); /* memset(shrink_block_group, 0, sizeof(*shrink_block_group)); kfree(shrink_block_group); */ ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret > 0) ret = -EIO; if (ret < 0) goto out; ret = btrfs_del_item(trans, root, path); out: btrfs_free_path(path); return ret; }