| /* |
| * Copyright (C) 2009 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/pagemap.h> |
| #include <linux/writeback.h> |
| #include <linux/blkdev.h> |
| #include <linux/rbtree.h> |
| #include <linux/slab.h> |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "volumes.h" |
| #include "locking.h" |
| #include "btrfs_inode.h" |
| #include "async-thread.h" |
| #include "free-space-cache.h" |
| #include "inode-map.h" |
| |
| /* |
| * backref_node, mapping_node and tree_block start with this |
| */ |
| struct tree_entry { |
| struct rb_node rb_node; |
| u64 bytenr; |
| }; |
| |
| /* |
| * present a tree block in the backref cache |
| */ |
| struct backref_node { |
| struct rb_node rb_node; |
| u64 bytenr; |
| |
| u64 new_bytenr; |
| /* objectid of tree block owner, can be not uptodate */ |
| u64 owner; |
| /* link to pending, changed or detached list */ |
| struct list_head list; |
| /* list of upper level blocks reference this block */ |
| struct list_head upper; |
| /* list of child blocks in the cache */ |
| struct list_head lower; |
| /* NULL if this node is not tree root */ |
| struct btrfs_root *root; |
| /* extent buffer got by COW the block */ |
| struct extent_buffer *eb; |
| /* level of tree block */ |
| unsigned int level:8; |
| /* is the block in non-reference counted tree */ |
| unsigned int cowonly:1; |
| /* 1 if no child node in the cache */ |
| unsigned int lowest:1; |
| /* is the extent buffer locked */ |
| unsigned int locked:1; |
| /* has the block been processed */ |
| unsigned int processed:1; |
| /* have backrefs of this block been checked */ |
| unsigned int checked:1; |
| /* |
| * 1 if corresponding block has been cowed but some upper |
| * level block pointers may not point to the new location |
| */ |
| unsigned int pending:1; |
| /* |
| * 1 if the backref node isn't connected to any other |
| * backref node. |
| */ |
| unsigned int detached:1; |
| }; |
| |
| /* |
| * present a block pointer in the backref cache |
| */ |
| struct backref_edge { |
| struct list_head list[2]; |
| struct backref_node *node[2]; |
| }; |
| |
| #define LOWER 0 |
| #define UPPER 1 |
| |
| struct backref_cache { |
| /* red black tree of all backref nodes in the cache */ |
| struct rb_root rb_root; |
| /* for passing backref nodes to btrfs_reloc_cow_block */ |
| struct backref_node *path[BTRFS_MAX_LEVEL]; |
| /* |
| * list of blocks that have been cowed but some block |
| * pointers in upper level blocks may not reflect the |
| * new location |
| */ |
| struct list_head pending[BTRFS_MAX_LEVEL]; |
| /* list of backref nodes with no child node */ |
| struct list_head leaves; |
| /* list of blocks that have been cowed in current transaction */ |
| struct list_head changed; |
| /* list of detached backref node. */ |
| struct list_head detached; |
| |
| u64 last_trans; |
| |
| int nr_nodes; |
| int nr_edges; |
| }; |
| |
| /* |
| * map address of tree root to tree |
| */ |
| struct mapping_node { |
| struct rb_node rb_node; |
| u64 bytenr; |
| void *data; |
| }; |
| |
| struct mapping_tree { |
| struct rb_root rb_root; |
| spinlock_t lock; |
| }; |
| |
| /* |
| * present a tree block to process |
| */ |
| struct tree_block { |
| struct rb_node rb_node; |
| u64 bytenr; |
| struct btrfs_key key; |
| unsigned int level:8; |
| unsigned int key_ready:1; |
| }; |
| |
| #define MAX_EXTENTS 128 |
| |
| struct file_extent_cluster { |
| u64 start; |
| u64 end; |
| u64 boundary[MAX_EXTENTS]; |
| unsigned int nr; |
| }; |
| |
| struct reloc_control { |
| /* block group to relocate */ |
| struct btrfs_block_group_cache *block_group; |
| /* extent tree */ |
| struct btrfs_root *extent_root; |
| /* inode for moving data */ |
| struct inode *data_inode; |
| |
| struct btrfs_block_rsv *block_rsv; |
| |
| struct backref_cache backref_cache; |
| |
| struct file_extent_cluster cluster; |
| /* tree blocks have been processed */ |
| struct extent_io_tree processed_blocks; |
| /* map start of tree root to corresponding reloc tree */ |
| struct mapping_tree reloc_root_tree; |
| /* list of reloc trees */ |
| struct list_head reloc_roots; |
| /* size of metadata reservation for merging reloc trees */ |
| u64 merging_rsv_size; |
| /* size of relocated tree nodes */ |
| u64 nodes_relocated; |
| |
| u64 search_start; |
| u64 extents_found; |
| |
| unsigned int stage:8; |
| unsigned int create_reloc_tree:1; |
| unsigned int merge_reloc_tree:1; |
| unsigned int found_file_extent:1; |
| unsigned int commit_transaction:1; |
| }; |
| |
| /* stages of data relocation */ |
| #define MOVE_DATA_EXTENTS 0 |
| #define UPDATE_DATA_PTRS 1 |
| |
| static void remove_backref_node(struct backref_cache *cache, |
| struct backref_node *node); |
| static void __mark_block_processed(struct reloc_control *rc, |
| struct backref_node *node); |
| |
| static void mapping_tree_init(struct mapping_tree *tree) |
| { |
| tree->rb_root = RB_ROOT; |
| spin_lock_init(&tree->lock); |
| } |
| |
| static void backref_cache_init(struct backref_cache *cache) |
| { |
| int i; |
| cache->rb_root = RB_ROOT; |
| for (i = 0; i < BTRFS_MAX_LEVEL; i++) |
| INIT_LIST_HEAD(&cache->pending[i]); |
| INIT_LIST_HEAD(&cache->changed); |
| INIT_LIST_HEAD(&cache->detached); |
| INIT_LIST_HEAD(&cache->leaves); |
| } |
| |
| static void backref_cache_cleanup(struct backref_cache *cache) |
| { |
| struct backref_node *node; |
| int i; |
| |
| while (!list_empty(&cache->detached)) { |
| node = list_entry(cache->detached.next, |
| struct backref_node, list); |
| remove_backref_node(cache, node); |
| } |
| |
| while (!list_empty(&cache->leaves)) { |
| node = list_entry(cache->leaves.next, |
| struct backref_node, lower); |
| remove_backref_node(cache, node); |
| } |
| |
| cache->last_trans = 0; |
| |
| for (i = 0; i < BTRFS_MAX_LEVEL; i++) |
| BUG_ON(!list_empty(&cache->pending[i])); |
| BUG_ON(!list_empty(&cache->changed)); |
| BUG_ON(!list_empty(&cache->detached)); |
| BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root)); |
| BUG_ON(cache->nr_nodes); |
| BUG_ON(cache->nr_edges); |
| } |
| |
| static struct backref_node *alloc_backref_node(struct backref_cache *cache) |
| { |
| struct backref_node *node; |
| |
| node = kzalloc(sizeof(*node), GFP_NOFS); |
| if (node) { |
| INIT_LIST_HEAD(&node->list); |
| INIT_LIST_HEAD(&node->upper); |
| INIT_LIST_HEAD(&node->lower); |
| RB_CLEAR_NODE(&node->rb_node); |
| cache->nr_nodes++; |
| } |
| return node; |
| } |
| |
| static void free_backref_node(struct backref_cache *cache, |
| struct backref_node *node) |
| { |
| if (node) { |
| cache->nr_nodes--; |
| kfree(node); |
| } |
| } |
| |
| static struct backref_edge *alloc_backref_edge(struct backref_cache *cache) |
| { |
| struct backref_edge *edge; |
| |
| edge = kzalloc(sizeof(*edge), GFP_NOFS); |
| if (edge) |
| cache->nr_edges++; |
| return edge; |
| } |
| |
| static void free_backref_edge(struct backref_cache *cache, |
| struct backref_edge *edge) |
| { |
| if (edge) { |
| cache->nr_edges--; |
| kfree(edge); |
| } |
| } |
| |
| static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr, |
| struct rb_node *node) |
| { |
| struct rb_node **p = &root->rb_node; |
| struct rb_node *parent = NULL; |
| struct tree_entry *entry; |
| |
| while (*p) { |
| parent = *p; |
| entry = rb_entry(parent, struct tree_entry, rb_node); |
| |
| if (bytenr < entry->bytenr) |
| p = &(*p)->rb_left; |
| else if (bytenr > entry->bytenr) |
| p = &(*p)->rb_right; |
| else |
| return parent; |
| } |
| |
| rb_link_node(node, parent, p); |
| rb_insert_color(node, root); |
| return NULL; |
| } |
| |
| static struct rb_node *tree_search(struct rb_root *root, u64 bytenr) |
| { |
| struct rb_node *n = root->rb_node; |
| struct tree_entry *entry; |
| |
| while (n) { |
| entry = rb_entry(n, struct tree_entry, rb_node); |
| |
| if (bytenr < entry->bytenr) |
| n = n->rb_left; |
| else if (bytenr > entry->bytenr) |
| n = n->rb_right; |
| else |
| return n; |
| } |
| return NULL; |
| } |
| |
| static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr) |
| { |
| |
| struct btrfs_fs_info *fs_info = NULL; |
| struct backref_node *bnode = rb_entry(rb_node, struct backref_node, |
| rb_node); |
| if (bnode->root) |
| fs_info = bnode->root->fs_info; |
| btrfs_panic(fs_info, errno, "Inconsistency in backref cache " |
| "found at offset %llu\n", bytenr); |
| } |
| |
| /* |
| * walk up backref nodes until reach node presents tree root |
| */ |
| static struct backref_node *walk_up_backref(struct backref_node *node, |
| struct backref_edge *edges[], |
| int *index) |
| { |
| struct backref_edge *edge; |
| int idx = *index; |
| |
| while (!list_empty(&node->upper)) { |
| edge = list_entry(node->upper.next, |
| struct backref_edge, list[LOWER]); |
| edges[idx++] = edge; |
| node = edge->node[UPPER]; |
| } |
| BUG_ON(node->detached); |
| *index = idx; |
| return node; |
| } |
| |
| /* |
| * walk down backref nodes to find start of next reference path |
| */ |
| static struct backref_node *walk_down_backref(struct backref_edge *edges[], |
| int *index) |
| { |
| struct backref_edge *edge; |
| struct backref_node *lower; |
| int idx = *index; |
| |
| while (idx > 0) { |
| edge = edges[idx - 1]; |
| lower = edge->node[LOWER]; |
| if (list_is_last(&edge->list[LOWER], &lower->upper)) { |
| idx--; |
| continue; |
| } |
| edge = list_entry(edge->list[LOWER].next, |
| struct backref_edge, list[LOWER]); |
| edges[idx - 1] = edge; |
| *index = idx; |
| return edge->node[UPPER]; |
| } |
| *index = 0; |
| return NULL; |
| } |
| |
| static void unlock_node_buffer(struct backref_node *node) |
| { |
| if (node->locked) { |
| btrfs_tree_unlock(node->eb); |
| node->locked = 0; |
| } |
| } |
| |
| static void drop_node_buffer(struct backref_node *node) |
| { |
| if (node->eb) { |
| unlock_node_buffer(node); |
| free_extent_buffer(node->eb); |
| node->eb = NULL; |
| } |
| } |
| |
| static void drop_backref_node(struct backref_cache *tree, |
| struct backref_node *node) |
| { |
| BUG_ON(!list_empty(&node->upper)); |
| |
| drop_node_buffer(node); |
| list_del(&node->list); |
| list_del(&node->lower); |
| if (!RB_EMPTY_NODE(&node->rb_node)) |
| rb_erase(&node->rb_node, &tree->rb_root); |
| free_backref_node(tree, node); |
| } |
| |
| /* |
| * remove a backref node from the backref cache |
| */ |
| static void remove_backref_node(struct backref_cache *cache, |
| struct backref_node *node) |
| { |
| struct backref_node *upper; |
| struct backref_edge *edge; |
| |
| if (!node) |
| return; |
| |
| BUG_ON(!node->lowest && !node->detached); |
| while (!list_empty(&node->upper)) { |
| edge = list_entry(node->upper.next, struct backref_edge, |
| list[LOWER]); |
| upper = edge->node[UPPER]; |
| list_del(&edge->list[LOWER]); |
| list_del(&edge->list[UPPER]); |
| free_backref_edge(cache, edge); |
| |
| if (RB_EMPTY_NODE(&upper->rb_node)) { |
| BUG_ON(!list_empty(&node->upper)); |
| drop_backref_node(cache, node); |
| node = upper; |
| node->lowest = 1; |
| continue; |
| } |
| /* |
| * add the node to leaf node list if no other |
| * child block cached. |
| */ |
| if (list_empty(&upper->lower)) { |
| list_add_tail(&upper->lower, &cache->leaves); |
| upper->lowest = 1; |
| } |
| } |
| |
| drop_backref_node(cache, node); |
| } |
| |
| static void update_backref_node(struct backref_cache *cache, |
| struct backref_node *node, u64 bytenr) |
| { |
| struct rb_node *rb_node; |
| rb_erase(&node->rb_node, &cache->rb_root); |
| node->bytenr = bytenr; |
| rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node); |
| if (rb_node) |
| backref_tree_panic(rb_node, -EEXIST, bytenr); |
| } |
| |
| /* |
| * update backref cache after a transaction commit |
| */ |
| static int update_backref_cache(struct btrfs_trans_handle *trans, |
| struct backref_cache *cache) |
| { |
| struct backref_node *node; |
| int level = 0; |
| |
| if (cache->last_trans == 0) { |
| cache->last_trans = trans->transid; |
| return 0; |
| } |
| |
| if (cache->last_trans == trans->transid) |
| return 0; |
| |
| /* |
| * detached nodes are used to avoid unnecessary backref |
| * lookup. transaction commit changes the extent tree. |
| * so the detached nodes are no longer useful. |
| */ |
| while (!list_empty(&cache->detached)) { |
| node = list_entry(cache->detached.next, |
| struct backref_node, list); |
| remove_backref_node(cache, node); |
| } |
| |
| while (!list_empty(&cache->changed)) { |
| node = list_entry(cache->changed.next, |
| struct backref_node, list); |
| list_del_init(&node->list); |
| BUG_ON(node->pending); |
| update_backref_node(cache, node, node->new_bytenr); |
| } |
| |
| /* |
| * some nodes can be left in the pending list if there were |
| * errors during processing the pending nodes. |
| */ |
| for (level = 0; level < BTRFS_MAX_LEVEL; level++) { |
| list_for_each_entry(node, &cache->pending[level], list) { |
| BUG_ON(!node->pending); |
| if (node->bytenr == node->new_bytenr) |
| continue; |
| update_backref_node(cache, node, node->new_bytenr); |
| } |
| } |
| |
| cache->last_trans = 0; |
| return 1; |
| } |
| |
| |
| static int should_ignore_root(struct btrfs_root *root) |
| { |
| struct btrfs_root *reloc_root; |
| |
| if (!root->ref_cows) |
| return 0; |
| |
| reloc_root = root->reloc_root; |
| if (!reloc_root) |
| return 0; |
| |
| if (btrfs_root_last_snapshot(&reloc_root->root_item) == |
| root->fs_info->running_transaction->transid - 1) |
| return 0; |
| /* |
| * if there is reloc tree and it was created in previous |
| * transaction backref lookup can find the reloc tree, |
| * so backref node for the fs tree root is useless for |
| * relocation. |
| */ |
| return 1; |
| } |
| /* |
| * find reloc tree by address of tree root |
| */ |
| static struct btrfs_root *find_reloc_root(struct reloc_control *rc, |
| u64 bytenr) |
| { |
| struct rb_node *rb_node; |
| struct mapping_node *node; |
| struct btrfs_root *root = NULL; |
| |
| spin_lock(&rc->reloc_root_tree.lock); |
| rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr); |
| if (rb_node) { |
| node = rb_entry(rb_node, struct mapping_node, rb_node); |
| root = (struct btrfs_root *)node->data; |
| } |
| spin_unlock(&rc->reloc_root_tree.lock); |
| return root; |
| } |
| |
| 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 || |
| root_objectid == BTRFS_CSUM_TREE_OBJECTID) |
| return 1; |
| return 0; |
| } |
| |
| static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, |
| u64 root_objectid) |
| { |
| struct btrfs_key key; |
| |
| key.objectid = root_objectid; |
| key.type = BTRFS_ROOT_ITEM_KEY; |
| if (is_cowonly_root(root_objectid)) |
| key.offset = 0; |
| else |
| key.offset = (u64)-1; |
| |
| return btrfs_get_fs_root(fs_info, &key, false); |
| } |
| |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| static noinline_for_stack |
| struct btrfs_root *find_tree_root(struct reloc_control *rc, |
| struct extent_buffer *leaf, |
| struct btrfs_extent_ref_v0 *ref0) |
| { |
| struct btrfs_root *root; |
| u64 root_objectid = btrfs_ref_root_v0(leaf, ref0); |
| u64 generation = btrfs_ref_generation_v0(leaf, ref0); |
| |
| BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID); |
| |
| root = read_fs_root(rc->extent_root->fs_info, root_objectid); |
| BUG_ON(IS_ERR(root)); |
| |
| if (root->ref_cows && |
| generation != btrfs_root_generation(&root->root_item)) |
| return NULL; |
| |
| return root; |
| } |
| #endif |
| |
| static noinline_for_stack |
| int find_inline_backref(struct extent_buffer *leaf, int slot, |
| unsigned long *ptr, unsigned long *end) |
| { |
| struct btrfs_key key; |
| struct btrfs_extent_item *ei; |
| struct btrfs_tree_block_info *bi; |
| u32 item_size; |
| |
| btrfs_item_key_to_cpu(leaf, &key, slot); |
| |
| item_size = btrfs_item_size_nr(leaf, slot); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (item_size < sizeof(*ei)) { |
| WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0)); |
| return 1; |
| } |
| #endif |
| ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); |
| WARN_ON(!(btrfs_extent_flags(leaf, ei) & |
| BTRFS_EXTENT_FLAG_TREE_BLOCK)); |
| |
| if (key.type == BTRFS_EXTENT_ITEM_KEY && |
| item_size <= sizeof(*ei) + sizeof(*bi)) { |
| WARN_ON(item_size < sizeof(*ei) + sizeof(*bi)); |
| return 1; |
| } |
| if (key.type == BTRFS_METADATA_ITEM_KEY && |
| item_size <= sizeof(*ei)) { |
| WARN_ON(item_size < sizeof(*ei)); |
| return 1; |
| } |
| |
| if (key.type == BTRFS_EXTENT_ITEM_KEY) { |
| bi = (struct btrfs_tree_block_info *)(ei + 1); |
| *ptr = (unsigned long)(bi + 1); |
| } else { |
| *ptr = (unsigned long)(ei + 1); |
| } |
| *end = (unsigned long)ei + item_size; |
| return 0; |
| } |
| |
| /* |
| * build backref tree for a given tree block. root of the backref tree |
| * corresponds the tree block, leaves of the backref tree correspond |
| * roots of b-trees that reference the tree block. |
| * |
| * the basic idea of this function is check backrefs of a given block |
| * to find upper level blocks that refernece the block, and then check |
| * bakcrefs of these upper level blocks recursively. the recursion stop |
| * when tree root is reached or backrefs for the block is cached. |
| * |
| * NOTE: if we find backrefs for a block are cached, we know backrefs |
| * for all upper level blocks that directly/indirectly reference the |
| * block are also cached. |
| */ |
| static noinline_for_stack |
| struct backref_node *build_backref_tree(struct reloc_control *rc, |
| struct btrfs_key *node_key, |
| int level, u64 bytenr) |
| { |
| struct backref_cache *cache = &rc->backref_cache; |
| struct btrfs_path *path1; |
| struct btrfs_path *path2; |
| struct extent_buffer *eb; |
| struct btrfs_root *root; |
| struct backref_node *cur; |
| struct backref_node *upper; |
| struct backref_node *lower; |
| struct backref_node *node = NULL; |
| struct backref_node *exist = NULL; |
| struct backref_edge *edge; |
| struct rb_node *rb_node; |
| struct btrfs_key key; |
| unsigned long end; |
| unsigned long ptr; |
| LIST_HEAD(list); |
| LIST_HEAD(useless); |
| int cowonly; |
| int ret; |
| int err = 0; |
| bool need_check = true; |
| |
| path1 = btrfs_alloc_path(); |
| path2 = btrfs_alloc_path(); |
| if (!path1 || !path2) { |
| err = -ENOMEM; |
| goto out; |
| } |
| path1->reada = 1; |
| path2->reada = 2; |
| |
| node = alloc_backref_node(cache); |
| if (!node) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| node->bytenr = bytenr; |
| node->level = level; |
| node->lowest = 1; |
| cur = node; |
| again: |
| end = 0; |
| ptr = 0; |
| key.objectid = cur->bytenr; |
| key.type = BTRFS_METADATA_ITEM_KEY; |
| key.offset = (u64)-1; |
| |
| path1->search_commit_root = 1; |
| path1->skip_locking = 1; |
| ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1, |
| 0, 0); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| BUG_ON(!ret || !path1->slots[0]); |
| |
| path1->slots[0]--; |
| |
| WARN_ON(cur->checked); |
| if (!list_empty(&cur->upper)) { |
| /* |
| * the backref was added previously when processing |
| * backref of type BTRFS_TREE_BLOCK_REF_KEY |
| */ |
| BUG_ON(!list_is_singular(&cur->upper)); |
| edge = list_entry(cur->upper.next, struct backref_edge, |
| list[LOWER]); |
| BUG_ON(!list_empty(&edge->list[UPPER])); |
| exist = edge->node[UPPER]; |
| /* |
| * add the upper level block to pending list if we need |
| * check its backrefs |
| */ |
| if (!exist->checked) |
| list_add_tail(&edge->list[UPPER], &list); |
| } else { |
| exist = NULL; |
| } |
| |
| while (1) { |
| cond_resched(); |
| eb = path1->nodes[0]; |
| |
| if (ptr >= end) { |
| if (path1->slots[0] >= btrfs_header_nritems(eb)) { |
| ret = btrfs_next_leaf(rc->extent_root, path1); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| if (ret > 0) |
| break; |
| eb = path1->nodes[0]; |
| } |
| |
| btrfs_item_key_to_cpu(eb, &key, path1->slots[0]); |
| if (key.objectid != cur->bytenr) { |
| WARN_ON(exist); |
| break; |
| } |
| |
| if (key.type == BTRFS_EXTENT_ITEM_KEY || |
| key.type == BTRFS_METADATA_ITEM_KEY) { |
| ret = find_inline_backref(eb, path1->slots[0], |
| &ptr, &end); |
| if (ret) |
| goto next; |
| } |
| } |
| |
| if (ptr < end) { |
| /* update key for inline back ref */ |
| struct btrfs_extent_inline_ref *iref; |
| iref = (struct btrfs_extent_inline_ref *)ptr; |
| key.type = btrfs_extent_inline_ref_type(eb, iref); |
| key.offset = btrfs_extent_inline_ref_offset(eb, iref); |
| WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY && |
| key.type != BTRFS_SHARED_BLOCK_REF_KEY); |
| } |
| |
| if (exist && |
| ((key.type == BTRFS_TREE_BLOCK_REF_KEY && |
| exist->owner == key.offset) || |
| (key.type == BTRFS_SHARED_BLOCK_REF_KEY && |
| exist->bytenr == key.offset))) { |
| exist = NULL; |
| goto next; |
| } |
| |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (key.type == BTRFS_SHARED_BLOCK_REF_KEY || |
| key.type == BTRFS_EXTENT_REF_V0_KEY) { |
| if (key.type == BTRFS_EXTENT_REF_V0_KEY) { |
| struct btrfs_extent_ref_v0 *ref0; |
| ref0 = btrfs_item_ptr(eb, path1->slots[0], |
| struct btrfs_extent_ref_v0); |
| if (key.objectid == key.offset) { |
| root = find_tree_root(rc, eb, ref0); |
| if (root && !should_ignore_root(root)) |
| cur->root = root; |
| else |
| list_add(&cur->list, &useless); |
| break; |
| } |
| if (is_cowonly_root(btrfs_ref_root_v0(eb, |
| ref0))) |
| cur->cowonly = 1; |
| } |
| #else |
| BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); |
| if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) { |
| #endif |
| if (key.objectid == key.offset) { |
| /* |
| * only root blocks of reloc trees use |
| * backref of this type. |
| */ |
| root = find_reloc_root(rc, cur->bytenr); |
| BUG_ON(!root); |
| cur->root = root; |
| break; |
| } |
| |
| edge = alloc_backref_edge(cache); |
| if (!edge) { |
| err = -ENOMEM; |
| goto out; |
| } |
| rb_node = tree_search(&cache->rb_root, key.offset); |
| if (!rb_node) { |
| upper = alloc_backref_node(cache); |
| if (!upper) { |
| free_backref_edge(cache, edge); |
| err = -ENOMEM; |
| goto out; |
| } |
| upper->bytenr = key.offset; |
| upper->level = cur->level + 1; |
| /* |
| * backrefs for the upper level block isn't |
| * cached, add the block to pending list |
| */ |
| list_add_tail(&edge->list[UPPER], &list); |
| } else { |
| upper = rb_entry(rb_node, struct backref_node, |
| rb_node); |
| BUG_ON(!upper->checked); |
| INIT_LIST_HEAD(&edge->list[UPPER]); |
| } |
| list_add_tail(&edge->list[LOWER], &cur->upper); |
| edge->node[LOWER] = cur; |
| edge->node[UPPER] = upper; |
| |
| goto next; |
| } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { |
| goto next; |
| } |
| |
| /* key.type == BTRFS_TREE_BLOCK_REF_KEY */ |
| root = read_fs_root(rc->extent_root->fs_info, key.offset); |
| if (IS_ERR(root)) { |
| err = PTR_ERR(root); |
| goto out; |
| } |
| |
| if (!root->ref_cows) |
| cur->cowonly = 1; |
| |
| if (btrfs_root_level(&root->root_item) == cur->level) { |
| /* tree root */ |
| BUG_ON(btrfs_root_bytenr(&root->root_item) != |
| cur->bytenr); |
| if (should_ignore_root(root)) |
| list_add(&cur->list, &useless); |
| else |
| cur->root = root; |
| break; |
| } |
| |
| level = cur->level + 1; |
| |
| /* |
| * searching the tree to find upper level blocks |
| * reference the block. |
| */ |
| path2->search_commit_root = 1; |
| path2->skip_locking = 1; |
| path2->lowest_level = level; |
| ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0); |
| path2->lowest_level = 0; |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| if (ret > 0 && path2->slots[level] > 0) |
| path2->slots[level]--; |
| |
| eb = path2->nodes[level]; |
| WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) != |
| cur->bytenr); |
| |
| lower = cur; |
| need_check = true; |
| for (; level < BTRFS_MAX_LEVEL; level++) { |
| if (!path2->nodes[level]) { |
| BUG_ON(btrfs_root_bytenr(&root->root_item) != |
| lower->bytenr); |
| if (should_ignore_root(root)) |
| list_add(&lower->list, &useless); |
| else |
| lower->root = root; |
| break; |
| } |
| |
| edge = alloc_backref_edge(cache); |
| if (!edge) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| eb = path2->nodes[level]; |
| rb_node = tree_search(&cache->rb_root, eb->start); |
| if (!rb_node) { |
| upper = alloc_backref_node(cache); |
| if (!upper) { |
| free_backref_edge(cache, edge); |
| err = -ENOMEM; |
| goto out; |
| } |
| upper->bytenr = eb->start; |
| upper->owner = btrfs_header_owner(eb); |
| upper->level = lower->level + 1; |
| if (!root->ref_cows) |
| upper->cowonly = 1; |
| |
| /* |
| * if we know the block isn't shared |
| * we can void checking its backrefs. |
| */ |
| if (btrfs_block_can_be_shared(root, eb)) |
| upper->checked = 0; |
| else |
| upper->checked = 1; |
| |
| /* |
| * add the block to pending list if we |
| * need check its backrefs, we only do this once |
| * while walking up a tree as we will catch |
| * anything else later on. |
| */ |
| if (!upper->checked && need_check) { |
| need_check = false; |
| list_add_tail(&edge->list[UPPER], |
| &list); |
| } else |
| INIT_LIST_HEAD(&edge->list[UPPER]); |
| } else { |
| upper = rb_entry(rb_node, struct backref_node, |
| rb_node); |
| BUG_ON(!upper->checked); |
| INIT_LIST_HEAD(&edge->list[UPPER]); |
| if (!upper->owner) |
| upper->owner = btrfs_header_owner(eb); |
| } |
| list_add_tail(&edge->list[LOWER], &lower->upper); |
| edge->node[LOWER] = lower; |
| edge->node[UPPER] = upper; |
| |
| if (rb_node) |
| break; |
| lower = upper; |
| upper = NULL; |
| } |
| btrfs_release_path(path2); |
| next: |
| if (ptr < end) { |
| ptr += btrfs_extent_inline_ref_size(key.type); |
| if (ptr >= end) { |
| WARN_ON(ptr > end); |
| ptr = 0; |
| end = 0; |
| } |
| } |
| if (ptr >= end) |
| path1->slots[0]++; |
| } |
| btrfs_release_path(path1); |
| |
| cur->checked = 1; |
| WARN_ON(exist); |
| |
| /* the pending list isn't empty, take the first block to process */ |
| if (!list_empty(&list)) { |
| edge = list_entry(list.next, struct backref_edge, list[UPPER]); |
| list_del_init(&edge->list[UPPER]); |
| cur = edge->node[UPPER]; |
| goto again; |
| } |
| |
| /* |
| * everything goes well, connect backref nodes and insert backref nodes |
| * into the cache. |
| */ |
| BUG_ON(!node->checked); |
| cowonly = node->cowonly; |
| if (!cowonly) { |
| rb_node = tree_insert(&cache->rb_root, node->bytenr, |
| &node->rb_node); |
| if (rb_node) |
| backref_tree_panic(rb_node, -EEXIST, node->bytenr); |
| list_add_tail(&node->lower, &cache->leaves); |
| } |
| |
| list_for_each_entry(edge, &node->upper, list[LOWER]) |
| list_add_tail(&edge->list[UPPER], &list); |
| |
| while (!list_empty(&list)) { |
| edge = list_entry(list.next, struct backref_edge, list[UPPER]); |
| list_del_init(&edge->list[UPPER]); |
| upper = edge->node[UPPER]; |
| if (upper->detached) { |
| list_del(&edge->list[LOWER]); |
| lower = edge->node[LOWER]; |
| free_backref_edge(cache, edge); |
| if (list_empty(&lower->upper)) |
| list_add(&lower->list, &useless); |
| continue; |
| } |
| |
| if (!RB_EMPTY_NODE(&upper->rb_node)) { |
| if (upper->lowest) { |
| list_del_init(&upper->lower); |
| upper->lowest = 0; |
| } |
| |
| list_add_tail(&edge->list[UPPER], &upper->lower); |
| continue; |
| } |
| |
| BUG_ON(!upper->checked); |
| BUG_ON(cowonly != upper->cowonly); |
| if (!cowonly) { |
| rb_node = tree_insert(&cache->rb_root, upper->bytenr, |
| &upper->rb_node); |
| if (rb_node) |
| backref_tree_panic(rb_node, -EEXIST, |
| upper->bytenr); |
| } |
| |
| list_add_tail(&edge->list[UPPER], &upper->lower); |
| |
| list_for_each_entry(edge, &upper->upper, list[LOWER]) |
| list_add_tail(&edge->list[UPPER], &list); |
| } |
| /* |
| * process useless backref nodes. backref nodes for tree leaves |
| * are deleted from the cache. backref nodes for upper level |
| * tree blocks are left in the cache to avoid unnecessary backref |
| * lookup. |
| */ |
| while (!list_empty(&useless)) { |
| upper = list_entry(useless.next, struct backref_node, list); |
| list_del_init(&upper->list); |
| BUG_ON(!list_empty(&upper->upper)); |
| if (upper == node) |
| node = NULL; |
| if (upper->lowest) { |
| list_del_init(&upper->lower); |
| upper->lowest = 0; |
| } |
| while (!list_empty(&upper->lower)) { |
| edge = list_entry(upper->lower.next, |
| struct backref_edge, list[UPPER]); |
| list_del(&edge->list[UPPER]); |
| list_del(&edge->list[LOWER]); |
| lower = edge->node[LOWER]; |
| free_backref_edge(cache, edge); |
| |
| if (list_empty(&lower->upper)) |
| list_add(&lower->list, &useless); |
| } |
| __mark_block_processed(rc, upper); |
| if (upper->level > 0) { |
| list_add(&upper->list, &cache->detached); |
| upper->detached = 1; |
| } else { |
| rb_erase(&upper->rb_node, &cache->rb_root); |
| free_backref_node(cache, upper); |
| } |
| } |
| out: |
| btrfs_free_path(path1); |
| btrfs_free_path(path2); |
| if (err) { |
| while (!list_empty(&useless)) { |
| lower = list_entry(useless.next, |
| struct backref_node, upper); |
| list_del_init(&lower->upper); |
| } |
| upper = node; |
| INIT_LIST_HEAD(&list); |
| while (upper) { |
| if (RB_EMPTY_NODE(&upper->rb_node)) { |
| list_splice_tail(&upper->upper, &list); |
| free_backref_node(cache, upper); |
| } |
| |
| if (list_empty(&list)) |
| break; |
| |
| edge = list_entry(list.next, struct backref_edge, |
| list[LOWER]); |
| list_del(&edge->list[LOWER]); |
| upper = edge->node[UPPER]; |
| free_backref_edge(cache, edge); |
| } |
| return ERR_PTR(err); |
| } |
| BUG_ON(node && node->detached); |
| return node; |
| } |
| |
| /* |
| * helper to add backref node for the newly created snapshot. |
| * the backref node is created by cloning backref node that |
| * corresponds to root of source tree |
| */ |
| static int clone_backref_node(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct btrfs_root *src, |
| struct btrfs_root *dest) |
| { |
| struct btrfs_root *reloc_root = src->reloc_root; |
| struct backref_cache *cache = &rc->backref_cache; |
| struct backref_node *node = NULL; |
| struct backref_node *new_node; |
| struct backref_edge *edge; |
| struct backref_edge *new_edge; |
| struct rb_node *rb_node; |
| |
| if (cache->last_trans > 0) |
| update_backref_cache(trans, cache); |
| |
| rb_node = tree_search(&cache->rb_root, src->commit_root->start); |
| if (rb_node) { |
| node = rb_entry(rb_node, struct backref_node, rb_node); |
| if (node->detached) |
| node = NULL; |
| else |
| BUG_ON(node->new_bytenr != reloc_root->node->start); |
| } |
| |
| if (!node) { |
| rb_node = tree_search(&cache->rb_root, |
| reloc_root->commit_root->start); |
| if (rb_node) { |
| node = rb_entry(rb_node, struct backref_node, |
| rb_node); |
| BUG_ON(node->detached); |
| } |
| } |
| |
| if (!node) |
| return 0; |
| |
| new_node = alloc_backref_node(cache); |
| if (!new_node) |
| return -ENOMEM; |
| |
| new_node->bytenr = dest->node->start; |
| new_node->level = node->level; |
| new_node->lowest = node->lowest; |
| new_node->checked = 1; |
| new_node->root = dest; |
| |
| if (!node->lowest) { |
| list_for_each_entry(edge, &node->lower, list[UPPER]) { |
| new_edge = alloc_backref_edge(cache); |
| if (!new_edge) |
| goto fail; |
| |
| new_edge->node[UPPER] = new_node; |
| new_edge->node[LOWER] = edge->node[LOWER]; |
| list_add_tail(&new_edge->list[UPPER], |
| &new_node->lower); |
| } |
| } else { |
| list_add_tail(&new_node->lower, &cache->leaves); |
| } |
| |
| rb_node = tree_insert(&cache->rb_root, new_node->bytenr, |
| &new_node->rb_node); |
| if (rb_node) |
| backref_tree_panic(rb_node, -EEXIST, new_node->bytenr); |
| |
| if (!new_node->lowest) { |
| list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) { |
| list_add_tail(&new_edge->list[LOWER], |
| &new_edge->node[LOWER]->upper); |
| } |
| } |
| return 0; |
| fail: |
| while (!list_empty(&new_node->lower)) { |
| new_edge = list_entry(new_node->lower.next, |
| struct backref_edge, list[UPPER]); |
| list_del(&new_edge->list[UPPER]); |
| free_backref_edge(cache, new_edge); |
| } |
| free_backref_node(cache, new_node); |
| return -ENOMEM; |
| } |
| |
| /* |
| * helper to add 'address of tree root -> reloc tree' mapping |
| */ |
| static int __must_check __add_reloc_root(struct btrfs_root *root) |
| { |
| struct rb_node *rb_node; |
| struct mapping_node *node; |
| struct reloc_control *rc = root->fs_info->reloc_ctl; |
| |
| node = kmalloc(sizeof(*node), GFP_NOFS); |
| if (!node) |
| return -ENOMEM; |
| |
| node->bytenr = root->node->start; |
| node->data = root; |
| |
| spin_lock(&rc->reloc_root_tree.lock); |
| rb_node = tree_insert(&rc->reloc_root_tree.rb_root, |
| node->bytenr, &node->rb_node); |
| spin_unlock(&rc->reloc_root_tree.lock); |
| if (rb_node) { |
| btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found " |
| "for start=%llu while inserting into relocation " |
| "tree\n", node->bytenr); |
| kfree(node); |
| return -EEXIST; |
| } |
| |
| list_add_tail(&root->root_list, &rc->reloc_roots); |
| return 0; |
| } |
| |
| /* |
| * helper to update/delete the 'address of tree root -> reloc tree' |
| * mapping |
| */ |
| static int __update_reloc_root(struct btrfs_root *root, int del) |
| { |
| struct rb_node *rb_node; |
| struct mapping_node *node = NULL; |
| struct reloc_control *rc = root->fs_info->reloc_ctl; |
| |
| spin_lock(&rc->reloc_root_tree.lock); |
| rb_node = tree_search(&rc->reloc_root_tree.rb_root, |
| root->commit_root->start); |
| if (rb_node) { |
| node = rb_entry(rb_node, struct mapping_node, rb_node); |
| rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); |
| } |
| spin_unlock(&rc->reloc_root_tree.lock); |
| |
| if (!node) |
| return 0; |
| BUG_ON((struct btrfs_root *)node->data != root); |
| |
| if (!del) { |
| spin_lock(&rc->reloc_root_tree.lock); |
| node->bytenr = root->node->start; |
| rb_node = tree_insert(&rc->reloc_root_tree.rb_root, |
| node->bytenr, &node->rb_node); |
| spin_unlock(&rc->reloc_root_tree.lock); |
| if (rb_node) |
| backref_tree_panic(rb_node, -EEXIST, node->bytenr); |
| } else { |
| spin_lock(&root->fs_info->trans_lock); |
| list_del_init(&root->root_list); |
| spin_unlock(&root->fs_info->trans_lock); |
| kfree(node); |
| } |
| return 0; |
| } |
| |
| static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 objectid) |
| { |
| struct btrfs_root *reloc_root; |
| struct extent_buffer *eb; |
| struct btrfs_root_item *root_item; |
| struct btrfs_key root_key; |
| u64 last_snap = 0; |
| int ret; |
| |
| root_item = kmalloc(sizeof(*root_item), GFP_NOFS); |
| BUG_ON(!root_item); |
| |
| root_key.objectid = BTRFS_TREE_RELOC_OBJECTID; |
| root_key.type = BTRFS_ROOT_ITEM_KEY; |
| root_key.offset = objectid; |
| |
| if (root->root_key.objectid == objectid) { |
| /* called by btrfs_init_reloc_root */ |
| ret = btrfs_copy_root(trans, root, root->commit_root, &eb, |
| BTRFS_TREE_RELOC_OBJECTID); |
| BUG_ON(ret); |
| |
| last_snap = btrfs_root_last_snapshot(&root->root_item); |
| btrfs_set_root_last_snapshot(&root->root_item, |
| trans->transid - 1); |
| } else { |
| /* |
| * called by btrfs_reloc_post_snapshot_hook. |
| * the source tree is a reloc tree, all tree blocks |
| * modified after it was created have RELOC flag |
| * set in their headers. so it's OK to not update |
| * the 'last_snapshot'. |
| */ |
| ret = btrfs_copy_root(trans, root, root->node, &eb, |
| BTRFS_TREE_RELOC_OBJECTID); |
| BUG_ON(ret); |
| } |
| |
| memcpy(root_item, &root->root_item, sizeof(*root_item)); |
| 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); |
| |
| if (root->root_key.objectid == objectid) { |
| btrfs_set_root_refs(root_item, 0); |
| memset(&root_item->drop_progress, 0, |
| sizeof(struct btrfs_disk_key)); |
| root_item->drop_level = 0; |
| /* |
| * abuse rtransid, it is safe because it is impossible to |
| * receive data into a relocation tree. |
| */ |
| btrfs_set_root_rtransid(root_item, last_snap); |
| btrfs_set_root_otransid(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(root->fs_info->tree_root, &root_key); |
| BUG_ON(IS_ERR(reloc_root)); |
| reloc_root->last_trans = trans->transid; |
| return reloc_root; |
| } |
| |
| /* |
| * create reloc tree for a given fs tree. reloc tree is just a |
| * snapshot of the fs tree with special root objectid. |
| */ |
| int btrfs_init_reloc_root(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_root *reloc_root; |
| struct reloc_control *rc = root->fs_info->reloc_ctl; |
| struct btrfs_block_rsv *rsv; |
| int clear_rsv = 0; |
| int ret; |
| |
| if (root->reloc_root) { |
| reloc_root = root->reloc_root; |
| reloc_root->last_trans = trans->transid; |
| return 0; |
| } |
| |
| if (!rc || !rc->create_reloc_tree || |
| root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
| return 0; |
| |
| if (!trans->reloc_reserved) { |
| rsv = trans->block_rsv; |
| trans->block_rsv = rc->block_rsv; |
| clear_rsv = 1; |
| } |
| reloc_root = create_reloc_root(trans, root, root->root_key.objectid); |
| if (clear_rsv) |
| trans->block_rsv = rsv; |
| |
| ret = __add_reloc_root(reloc_root); |
| BUG_ON(ret < 0); |
| root->reloc_root = reloc_root; |
| return 0; |
| } |
| |
| /* |
| * update root item of reloc tree |
| */ |
| int btrfs_update_reloc_root(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_root *reloc_root; |
| struct btrfs_root_item *root_item; |
| int del = 0; |
| int ret; |
| |
| if (!root->reloc_root) |
| goto out; |
| |
| reloc_root = root->reloc_root; |
| root_item = &reloc_root->root_item; |
| |
| if (root->fs_info->reloc_ctl->merge_reloc_tree && |
| btrfs_root_refs(root_item) == 0) { |
| root->reloc_root = NULL; |
| del = 1; |
| } |
| |
| __update_reloc_root(reloc_root, del); |
| |
| if (reloc_root->commit_root != reloc_root->node) { |
| btrfs_set_root_node(root_item, reloc_root->node); |
| free_extent_buffer(reloc_root->commit_root); |
| reloc_root->commit_root = btrfs_root_node(reloc_root); |
| } |
| |
| ret = btrfs_update_root(trans, root->fs_info->tree_root, |
| &reloc_root->root_key, root_item); |
| BUG_ON(ret); |
| |
| out: |
| return 0; |
| } |
| |
| /* |
| * helper to find first cached inode with inode number >= objectid |
| * in a subvolume |
| */ |
| static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid) |
| { |
| struct rb_node *node; |
| struct rb_node *prev; |
| struct btrfs_inode *entry; |
| struct inode *inode; |
| |
| spin_lock(&root->inode_lock); |
| again: |
| node = root->inode_tree.rb_node; |
| prev = NULL; |
| while (node) { |
| prev = node; |
| entry = rb_entry(node, struct btrfs_inode, rb_node); |
| |
| if (objectid < btrfs_ino(&entry->vfs_inode)) |
| node = node->rb_left; |
| else if (objectid > btrfs_ino(&entry->vfs_inode)) |
| node = node->rb_right; |
| else |
| break; |
| } |
| if (!node) { |
| while (prev) { |
| entry = rb_entry(prev, struct btrfs_inode, rb_node); |
| if (objectid <= btrfs_ino(&entry->vfs_inode)) { |
| node = prev; |
| break; |
| } |
| prev = rb_next(prev); |
| } |
| } |
| while (node) { |
| entry = rb_entry(node, struct btrfs_inode, rb_node); |
| inode = igrab(&entry->vfs_inode); |
| if (inode) { |
| spin_unlock(&root->inode_lock); |
| return inode; |
| } |
| |
| objectid = btrfs_ino(&entry->vfs_inode) + 1; |
| if (cond_resched_lock(&root->inode_lock)) |
| goto again; |
| |
| node = rb_next(node); |
| } |
| spin_unlock(&root->inode_lock); |
| return NULL; |
| } |
| |
| static int in_block_group(u64 bytenr, |
| struct btrfs_block_group_cache *block_group) |
| { |
| if (bytenr >= block_group->key.objectid && |
| bytenr < block_group->key.objectid + block_group->key.offset) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * get new location of data |
| */ |
| static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr, |
| u64 bytenr, u64 num_bytes) |
| { |
| struct btrfs_root *root = BTRFS_I(reloc_inode)->root; |
| struct btrfs_path *path; |
| struct btrfs_file_extent_item *fi; |
| struct extent_buffer *leaf; |
| int ret; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| bytenr -= BTRFS_I(reloc_inode)->index_cnt; |
| ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode), |
| bytenr, 0); |
| if (ret < 0) |
| goto out; |
| if (ret > 0) { |
| ret = -ENOENT; |
| goto out; |
| } |
| |
| leaf = path->nodes[0]; |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| |
| BUG_ON(btrfs_file_extent_offset(leaf, fi) || |
| btrfs_file_extent_compression(leaf, fi) || |
| btrfs_file_extent_encryption(leaf, fi) || |
| btrfs_file_extent_other_encoding(leaf, fi)); |
| |
| if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| ret = 0; |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * update file extent items in the tree leaf to point to |
| * the new locations. |
| */ |
| static noinline_for_stack |
| int replace_file_extents(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct btrfs_root *root, |
| struct extent_buffer *leaf) |
| { |
| struct btrfs_key key; |
| struct btrfs_file_extent_item *fi; |
| struct inode *inode = NULL; |
| u64 parent; |
| u64 bytenr; |
| u64 new_bytenr = 0; |
| u64 num_bytes; |
| u64 end; |
| u32 nritems; |
| u32 i; |
| int ret = 0; |
| int first = 1; |
| int dirty = 0; |
| |
| if (rc->stage != UPDATE_DATA_PTRS) |
| return 0; |
| |
| /* reloc trees always use full backref */ |
| if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
| parent = leaf->start; |
| else |
| parent = 0; |
| |
| nritems = btrfs_header_nritems(leaf); |
| for (i = 0; i < nritems; i++) { |
| cond_resched(); |
| btrfs_item_key_to_cpu(leaf, &key, i); |
| if (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; |
| bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
| if (bytenr == 0) |
| continue; |
| if (!in_block_group(bytenr, rc->block_group)) |
| continue; |
| |
| /* |
| * if we are modifying block in fs tree, wait for readpage |
| * to complete and drop the extent cache |
| */ |
| if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { |
| if (first) { |
| inode = find_next_inode(root, key.objectid); |
| first = 0; |
| } else if (inode && btrfs_ino(inode) < key.objectid) { |
| btrfs_add_delayed_iput(inode); |
| inode = find_next_inode(root, key.objectid); |
| } |
| if (inode && btrfs_ino(inode) == key.objectid) { |
| end = key.offset + |
| btrfs_file_extent_num_bytes(leaf, fi); |
| WARN_ON(!IS_ALIGNED(key.offset, |
| root->sectorsize)); |
| WARN_ON(!IS_ALIGNED(end, root->sectorsize)); |
| end--; |
| ret = try_lock_extent(&BTRFS_I(inode)->io_tree, |
| key.offset, end); |
| if (!ret) |
| continue; |
| |
| btrfs_drop_extent_cache(inode, key.offset, end, |
| 1); |
| unlock_extent(&BTRFS_I(inode)->io_tree, |
| key.offset, end); |
| } |
| } |
| |
| ret = get_new_location(rc->data_inode, &new_bytenr, |
| bytenr, num_bytes); |
| if (ret) { |
| /* |
| * Don't have to abort since we've not changed anything |
| * in the file extent yet. |
| */ |
| break; |
| } |
| |
| btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr); |
| dirty = 1; |
| |
| key.offset -= btrfs_file_extent_offset(leaf, fi); |
| ret = btrfs_inc_extent_ref(trans, root, new_bytenr, |
| num_bytes, parent, |
| btrfs_header_owner(leaf), |
| key.objectid, key.offset, 1); |
| if (ret) { |
| btrfs_abort_transaction(trans, root, ret); |
| break; |
| } |
| |
| ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
| parent, btrfs_header_owner(leaf), |
| key.objectid, key.offset, 1); |
| if (ret) { |
| btrfs_abort_transaction(trans, root, ret); |
| break; |
| } |
| } |
| if (dirty) |
| btrfs_mark_buffer_dirty(leaf); |
| if (inode) |
| btrfs_add_delayed_iput(inode); |
| return ret; |
| } |
| |
| static noinline_for_stack |
| int memcmp_node_keys(struct extent_buffer *eb, int slot, |
| struct btrfs_path *path, int level) |
| { |
| struct btrfs_disk_key key1; |
| struct btrfs_disk_key key2; |
| btrfs_node_key(eb, &key1, slot); |
| btrfs_node_key(path->nodes[level], &key2, path->slots[level]); |
| return memcmp(&key1, &key2, sizeof(key1)); |
| } |
| |
| /* |
| * try to replace tree blocks in fs tree with the new blocks |
| * in reloc tree. tree blocks haven't been modified since the |
| * reloc tree was create can be replaced. |
| * |
| * if a block was replaced, level of the block + 1 is returned. |
| * if no block got replaced, 0 is returned. if there are other |
| * errors, a negative error number is returned. |
| */ |
| static noinline_for_stack |
| int replace_path(struct btrfs_trans_handle *trans, |
| struct btrfs_root *dest, struct btrfs_root *src, |
| struct btrfs_path *path, struct btrfs_key *next_key, |
| int lowest_level, int max_level) |
| { |
| struct extent_buffer *eb; |
| struct extent_buffer *parent; |
| struct btrfs_key key; |
| u64 old_bytenr; |
| u64 new_bytenr; |
| u64 old_ptr_gen; |
| u64 new_ptr_gen; |
| u64 last_snapshot; |
| u32 blocksize; |
| int cow = 0; |
| int level; |
| int ret; |
| int slot; |
| |
| BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); |
| BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID); |
| |
| last_snapshot = btrfs_root_last_snapshot(&src->root_item); |
| again: |
| slot = path->slots[lowest_level]; |
| btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot); |
| |
| eb = btrfs_lock_root_node(dest); |
| btrfs_set_lock_blocking(eb); |
| level = btrfs_header_level(eb); |
| |
| if (level < lowest_level) { |
| btrfs_tree_unlock(eb); |
| free_extent_buffer(eb); |
| return 0; |
| } |
| |
| if (cow) { |
| ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb); |
| BUG_ON(ret); |
| } |
| btrfs_set_lock_blocking(eb); |
| |
| if (next_key) { |
| next_key->objectid = (u64)-1; |
| next_key->type = (u8)-1; |
| next_key->offset = (u64)-1; |
| } |
| |
| parent = eb; |
| while (1) { |
| level = btrfs_header_level(parent); |
| BUG_ON(level < lowest_level); |
| |
| ret = btrfs_bin_search(parent, &key, level, &slot); |
| if (ret && slot > 0) |
| slot--; |
| |
| if (next_key && slot + 1 < btrfs_header_nritems(parent)) |
| btrfs_node_key_to_cpu(parent, next_key, slot + 1); |
| |
| old_bytenr = btrfs_node_blockptr(parent, slot); |
| blocksize = btrfs_level_size(dest, level - 1); |
| old_ptr_gen = btrfs_node_ptr_generation(parent, slot); |
| |
| if (level <= max_level) { |
| eb = path->nodes[level]; |
| new_bytenr = btrfs_node_blockptr(eb, |
| path->slots[level]); |
| new_ptr_gen = btrfs_node_ptr_generation(eb, |
| path->slots[level]); |
| } else { |
| new_bytenr = 0; |
| new_ptr_gen = 0; |
| } |
| |
| if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) { |
| ret = level; |
| break; |
| } |
| |
| if (new_bytenr == 0 || old_ptr_gen > last_snapshot || |
| memcmp_node_keys(parent, slot, path, level)) { |
| if (level <= lowest_level) { |
| ret = 0; |
| break; |
| } |
| |
| eb = read_tree_block(dest, old_bytenr, blocksize, |
| old_ptr_gen); |
| if (!eb || !extent_buffer_uptodate(eb)) { |
| ret = (!eb) ? -ENOMEM : -EIO; |
| free_extent_buffer(eb); |
| break; |
| } |
| btrfs_tree_lock(eb); |
| if (cow) { |
| ret = btrfs_cow_block(trans, dest, eb, parent, |
| slot, &eb); |
| BUG_ON(ret); |
| } |
| btrfs_set_lock_blocking(eb); |
| |
| btrfs_tree_unlock(parent); |
| free_extent_buffer(parent); |
| |
| parent = eb; |
| continue; |
| } |
| |
| if (!cow) { |
| btrfs_tree_unlock(parent); |
| free_extent_buffer(parent); |
| cow = 1; |
| goto again; |
| } |
| |
| btrfs_node_key_to_cpu(path->nodes[level], &key, |
| path->slots[level]); |
| btrfs_release_path(path); |
| |
| path->lowest_level = level; |
| ret = btrfs_search_slot(trans, src, &key, path, 0, 1); |
| path->lowest_level = 0; |
| BUG_ON(ret); |
| |
| /* |
| * swap blocks in fs tree and reloc tree. |
| */ |
| btrfs_set_node_blockptr(parent, slot, new_bytenr); |
| btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen); |
| btrfs_mark_buffer_dirty(parent); |
| |
| btrfs_set_node_blockptr(path->nodes[level], |
| path->slots[level], old_bytenr); |
| btrfs_set_node_ptr_generation(path->nodes[level], |
| path->slots[level], old_ptr_gen); |
| btrfs_mark_buffer_dirty(path->nodes[level]); |
| |
| ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize, |
| path->nodes[level]->start, |
| src->root_key.objectid, level - 1, 0, |
| 1); |
| BUG_ON(ret); |
| ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize, |
| 0, dest->root_key.objectid, level - 1, |
| 0, 1); |
| BUG_ON(ret); |
| |
| ret = btrfs_free_extent(trans, src, new_bytenr, blocksize, |
| path->nodes[level]->start, |
| src->root_key.objectid, level - 1, 0, |
| 1); |
| BUG_ON(ret); |
| |
| ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize, |
| 0, dest->root_key.objectid, level - 1, |
| 0, 1); |
| BUG_ON(ret); |
| |
| btrfs_unlock_up_safe(path, 0); |
| |
| ret = level; |
| break; |
| } |
| btrfs_tree_unlock(parent); |
| free_extent_buffer(parent); |
| return ret; |
| } |
| |
| /* |
| * helper to find next relocated block in reloc tree |
| */ |
| static noinline_for_stack |
| int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, |
| int *level) |
| { |
| struct extent_buffer *eb; |
| int i; |
| u64 last_snapshot; |
| u32 nritems; |
| |
| last_snapshot = btrfs_root_last_snapshot(&root->root_item); |
| |
| for (i = 0; i < *level; i++) { |
| free_extent_buffer(path->nodes[i]); |
| path->nodes[i] = NULL; |
| } |
| |
| for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) { |
| eb = path->nodes[i]; |
| nritems = btrfs_header_nritems(eb); |
| while (path->slots[i] + 1 < nritems) { |
| path->slots[i]++; |
| if (btrfs_node_ptr_generation(eb, path->slots[i]) <= |
| last_snapshot) |
| continue; |
| |
| *level = i; |
| return 0; |
| } |
| free_extent_buffer(path->nodes[i]); |
| path->nodes[i] = NULL; |
| } |
| return 1; |
| } |
| |
| /* |
| * walk down reloc tree to find relocated block of lowest level |
| */ |
| static noinline_for_stack |
| int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, |
| int *level) |
| { |
| struct extent_buffer *eb = NULL; |
| int i; |
| u64 bytenr; |
| u64 ptr_gen = 0; |
| u64 last_snapshot; |
| u32 blocksize; |
| u32 nritems; |
| |
| last_snapshot = btrfs_root_last_snapshot(&root->root_item); |
| |
| for (i = *level; i > 0; i--) { |
| eb = path->nodes[i]; |
| nritems = btrfs_header_nritems(eb); |
| while (path->slots[i] < nritems) { |
| ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]); |
| if (ptr_gen > last_snapshot) |
| break; |
| path->slots[i]++; |
| } |
| if (path->slots[i] >= nritems) { |
| if (i == *level) |
| break; |
| *level = i + 1; |
| return 0; |
| } |
| if (i == 1) { |
| *level = i; |
| return 0; |
| } |
| |
| bytenr = btrfs_node_blockptr(eb, path->slots[i]); |
| blocksize = btrfs_level_size(root, i - 1); |
| eb = read_tree_block(root, bytenr, blocksize, ptr_gen); |
| if (!eb || !extent_buffer_uptodate(eb)) { |
| free_extent_buffer(eb); |
| return -EIO; |
| } |
| BUG_ON(btrfs_header_level(eb) != i - 1); |
| path->nodes[i - 1] = eb; |
| path->slots[i - 1] = 0; |
| } |
| return 1; |
| } |
| |
| /* |
| * invalidate extent cache for file extents whose key in range of |
| * [min_key, max_key) |
| */ |
| static int invalidate_extent_cache(struct btrfs_root *root, |
| struct btrfs_key *min_key, |
| struct btrfs_key *max_key) |
| { |
| struct inode *inode = NULL; |
| u64 objectid; |
| u64 start, end; |
| u64 ino; |
| |
| objectid = min_key->objectid; |
| while (1) { |
| cond_resched(); |
| iput(inode); |
| |
| if (objectid > max_key->objectid) |
| break; |
| |
| inode = find_next_inode(root, objectid); |
| if (!inode) |
| break; |
| ino = btrfs_ino(inode); |
| |
| if (ino > max_key->objectid) { |
| iput(inode); |
| break; |
| } |
| |
| objectid = ino + 1; |
| if (!S_ISREG(inode->i_mode)) |
| continue; |
| |
| if (unlikely(min_key->objectid == ino)) { |
| if (min_key->type > BTRFS_EXTENT_DATA_KEY) |
| continue; |
| if (min_key->type < BTRFS_EXTENT_DATA_KEY) |
| start = 0; |
| else { |
| start = min_key->offset; |
| WARN_ON(!IS_ALIGNED(start, root->sectorsize)); |
| } |
| } else { |
| start = 0; |
| } |
| |
| if (unlikely(max_key->objectid == ino)) { |
| if (max_key->type < BTRFS_EXTENT_DATA_KEY) |
| continue; |
| if (max_key->type > BTRFS_EXTENT_DATA_KEY) { |
| end = (u64)-1; |
| } else { |
| if (max_key->offset == 0) |
| continue; |
| end = max_key->offset; |
| WARN_ON(!IS_ALIGNED(end, root->sectorsize)); |
| end--; |
| } |
| } else { |
| end = (u64)-1; |
| } |
| |
| /* the lock_extent waits for readpage to complete */ |
| lock_extent(&BTRFS_I(inode)->io_tree, start, end); |
| btrfs_drop_extent_cache(inode, start, end, 1); |
| unlock_extent(&BTRFS_I(inode)->io_tree, start, end); |
| } |
| return 0; |
| } |
| |
| static int find_next_key(struct btrfs_path *path, int level, |
| struct btrfs_key *key) |
| |
| { |
| while (level < BTRFS_MAX_LEVEL) { |
| if (!path->nodes[level]) |
| break; |
| if (path->slots[level] + 1 < |
| btrfs_header_nritems(path->nodes[level])) { |
| btrfs_node_key_to_cpu(path->nodes[level], key, |
| path->slots[level] + 1); |
| return 0; |
| } |
| level++; |
| } |
| return 1; |
| } |
| |
| /* |
| * merge the relocated tree blocks in reloc tree with corresponding |
| * fs tree. |
| */ |
| static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, |
| struct btrfs_root *root) |
| { |
| LIST_HEAD(inode_list); |
| struct btrfs_key key; |
| struct btrfs_key next_key; |
| struct btrfs_trans_handle *trans = NULL; |
| struct btrfs_root *reloc_root; |
| struct btrfs_root_item *root_item; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| int level; |
| int max_level; |
| int replaced = 0; |
| int ret; |
| int err = 0; |
| u32 min_reserved; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| path->reada = 1; |
| |
| reloc_root = root->reloc_root; |
| root_item = &reloc_root->root_item; |
| |
| if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { |
| level = btrfs_root_level(root_item); |
| extent_buffer_get(reloc_root->node); |
| path->nodes[level] = reloc_root->node; |
| path->slots[level] = 0; |
| } else { |
| btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); |
| |
| level = root_item->drop_level; |
| BUG_ON(level == 0); |
| path->lowest_level = level; |
| ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0); |
| path->lowest_level = 0; |
| if (ret < 0) { |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| btrfs_node_key_to_cpu(path->nodes[level], &next_key, |
| path->slots[level]); |
| WARN_ON(memcmp(&key, &next_key, sizeof(key))); |
| |
| btrfs_unlock_up_safe(path, 0); |
| } |
| |
| min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2; |
| memset(&next_key, 0, sizeof(next_key)); |
| |
| while (1) { |
| ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved, |
| BTRFS_RESERVE_FLUSH_ALL); |
| if (ret) { |
| err = ret; |
| goto out; |
| } |
| trans = btrfs_start_transaction(root, 0); |
| if (IS_ERR(trans)) { |
| err = PTR_ERR(trans); |
| trans = NULL; |
| goto out; |
| } |
| trans->block_rsv = rc->block_rsv; |
| |
| replaced = 0; |
| max_level = level; |
| |
| ret = walk_down_reloc_tree(reloc_root, path, &level); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| if (ret > 0) |
| break; |
| |
| if (!find_next_key(path, level, &key) && |
| btrfs_comp_cpu_keys(&next_key, &key) >= 0) { |
| ret = 0; |
| } else { |
| ret = replace_path(trans, root, reloc_root, path, |
| &next_key, level, max_level); |
| } |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| |
| if (ret > 0) { |
| level = ret; |
| btrfs_node_key_to_cpu(path->nodes[level], &key, |
| path->slots[level]); |
| replaced = 1; |
| } |
| |
| ret = walk_up_reloc_tree(reloc_root, path, &level); |
| if (ret > 0) |
| break; |
| |
| BUG_ON(level == 0); |
| /* |
| * save the merging progress in the drop_progress. |
| * this is OK since root refs == 1 in this case. |
| */ |
| btrfs_node_key(path->nodes[level], &root_item->drop_progress, |
| path->slots[level]); |
| root_item->drop_level = level; |
| |
| btrfs_end_transaction_throttle(trans, root); |
| trans = NULL; |
| |
| btrfs_btree_balance_dirty(root); |
| |
| if (replaced && rc->stage == UPDATE_DATA_PTRS) |
| invalidate_extent_cache(root, &key, &next_key); |
| } |
| |
| /* |
| * handle the case only one block in the fs tree need to be |
| * relocated and the block is tree root. |
| */ |
| leaf = btrfs_lock_root_node(root); |
| ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf); |
| btrfs_tree_unlock(leaf); |
| free_extent_buffer(leaf); |
| if (ret < 0) |
| err = ret; |
| out: |
| btrfs_free_path(path); |
| |
| if (err == 0) { |
| memset(&root_item->drop_progress, 0, |
| sizeof(root_item->drop_progress)); |
| root_item->drop_level = 0; |
| btrfs_set_root_refs(root_item, 0); |
| btrfs_update_reloc_root(trans, root); |
| } |
| |
| if (trans) |
| btrfs_end_transaction_throttle(trans, root); |
| |
| btrfs_btree_balance_dirty(root); |
| |
| if (replaced && rc->stage == UPDATE_DATA_PTRS) |
| invalidate_extent_cache(root, &key, &next_key); |
| |
| return err; |
| } |
| |
| static noinline_for_stack |
| int prepare_to_merge(struct reloc_control *rc, int err) |
| { |
| struct btrfs_root *root = rc->extent_root; |
| struct btrfs_root *reloc_root; |
| struct btrfs_trans_handle *trans; |
| LIST_HEAD(reloc_roots); |
| u64 num_bytes = 0; |
| int ret; |
| |
| mutex_lock(&root->fs_info->reloc_mutex); |
| rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2; |
| rc->merging_rsv_size += rc->nodes_relocated * 2; |
| mutex_unlock(&root->fs_info->reloc_mutex); |
| |
| again: |
| if (!err) { |
| num_bytes = rc->merging_rsv_size; |
| ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes, |
| BTRFS_RESERVE_FLUSH_ALL); |
| if (ret) |
| err = ret; |
| } |
| |
| trans = btrfs_join_transaction(rc->extent_root); |
| if (IS_ERR(trans)) { |
| if (!err) |
| btrfs_block_rsv_release(rc->extent_root, |
| rc->block_rsv, num_bytes); |
| return PTR_ERR(trans); |
| } |
| |
| if (!err) { |
| if (num_bytes != rc->merging_rsv_size) { |
| btrfs_end_transaction(trans, rc->extent_root); |
| btrfs_block_rsv_release(rc->extent_root, |
| rc->block_rsv, num_bytes); |
| goto again; |
| } |
| } |
| |
| rc->merge_reloc_tree = 1; |
| |
| while (!list_empty(&rc->reloc_roots)) { |
| reloc_root = list_entry(rc->reloc_roots.next, |
| struct btrfs_root, root_list); |
| list_del_init(&reloc_root->root_list); |
| |
| root = read_fs_root(reloc_root->fs_info, |
| reloc_root->root_key.offset); |
| BUG_ON(IS_ERR(root)); |
| BUG_ON(root->reloc_root != reloc_root); |
| |
| /* |
| * set reference count to 1, so btrfs_recover_relocation |
| * knows it should resumes merging |
| */ |
| if (!err) |
| btrfs_set_root_refs(&reloc_root->root_item, 1); |
| btrfs_update_reloc_root(trans, root); |
| |
| list_add(&reloc_root->root_list, &reloc_roots); |
| } |
| |
| list_splice(&reloc_roots, &rc->reloc_roots); |
| |
| if (!err) |
| btrfs_commit_transaction(trans, rc->extent_root); |
| else |
| btrfs_end_transaction(trans, rc->extent_root); |
| return err; |
| } |
| |
| static noinline_for_stack |
| void free_reloc_roots(struct list_head *list) |
| { |
| struct btrfs_root *reloc_root; |
| |
| while (!list_empty(list)) { |
| reloc_root = list_entry(list->next, struct btrfs_root, |
| root_list); |
| __update_reloc_root(reloc_root, 1); |
| free_extent_buffer(reloc_root->node); |
| free_extent_buffer(reloc_root->commit_root); |
| kfree(reloc_root); |
| } |
| } |
| |
| static noinline_for_stack |
| int merge_reloc_roots(struct reloc_control *rc) |
| { |
| struct btrfs_trans_handle *trans; |
| struct btrfs_root *root; |
| struct btrfs_root *reloc_root; |
| u64 last_snap; |
| u64 otransid; |
| u64 objectid; |
| LIST_HEAD(reloc_roots); |
| int found = 0; |
| int ret = 0; |
| again: |
| root = rc->extent_root; |
| |
| /* |
| * this serializes us with btrfs_record_root_in_transaction, |
| * we have to make sure nobody is in the middle of |
| * adding their roots to the list while we are |
| * doing this splice |
| */ |
| mutex_lock(&root->fs_info->reloc_mutex); |
| list_splice_init(&rc->reloc_roots, &reloc_roots); |
| mutex_unlock(&root->fs_info->reloc_mutex); |
| |
| while (!list_empty(&reloc_roots)) { |
| found = 1; |
| reloc_root = list_entry(reloc_roots.next, |
| struct btrfs_root, root_list); |
| |
| if (btrfs_root_refs(&reloc_root->root_item) > 0) { |
| root = read_fs_root(reloc_root->fs_info, |
| reloc_root->root_key.offset); |
| BUG_ON(IS_ERR(root)); |
| BUG_ON(root->reloc_root != reloc_root); |
| |
| ret = merge_reloc_root(rc, root); |
| if (ret) { |
| __update_reloc_root(reloc_root, 1); |
| free_extent_buffer(reloc_root->node); |
| free_extent_buffer(reloc_root->commit_root); |
| kfree(reloc_root); |
| goto out; |
| } |
| } else { |
| list_del_init(&reloc_root->root_list); |
| } |
| |
| /* |
| * we keep the old last snapshod transid in rtranid when we |
| * created the relocation tree. |
| */ |
| last_snap = btrfs_root_rtransid(&reloc_root->root_item); |
| otransid = btrfs_root_otransid(&reloc_root->root_item); |
| objectid = reloc_root->root_key.offset; |
| |
| ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1); |
| if (ret < 0) { |
| if (list_empty(&reloc_root->root_list)) |
| list_add_tail(&reloc_root->root_list, |
| &reloc_roots); |
| goto out; |
| } else if (!ret) { |
| /* |
| * recover the last snapshot tranid to avoid |
| * the space balance break NOCOW. |
| */ |
| root = read_fs_root(rc->extent_root->fs_info, |
| objectid); |
| if (IS_ERR(root)) |
| continue; |
| |
| trans = btrfs_join_transaction(root); |
| BUG_ON(IS_ERR(trans)); |
| |
| /* Check if the fs/file tree was snapshoted or not. */ |
| if (btrfs_root_last_snapshot(&root->root_item) == |
| otransid - 1) |
| btrfs_set_root_last_snapshot(&root->root_item, |
| last_snap); |
| |
| btrfs_end_transaction(trans, root); |
| } |
| } |
| |
| if (found) { |
| found = 0; |
| goto again; |
| } |
| out: |
| if (ret) { |
| btrfs_std_error(root->fs_info, ret); |
| if (!list_empty(&reloc_roots)) |
| free_reloc_roots(&reloc_roots); |
| } |
| |
| BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root)); |
| return ret; |
| } |
| |
| static void free_block_list(struct rb_root *blocks) |
| { |
| struct tree_block *block; |
| struct rb_node *rb_node; |
| while ((rb_node = rb_first(blocks))) { |
| block = rb_entry(rb_node, struct tree_block, rb_node); |
| rb_erase(rb_node, blocks); |
| kfree(block); |
| } |
| } |
| |
| static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans, |
| struct btrfs_root *reloc_root) |
| { |
| struct btrfs_root *root; |
| |
| if (reloc_root->last_trans == trans->transid) |
| return 0; |
| |
| root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset); |
| BUG_ON(IS_ERR(root)); |
| BUG_ON(root->reloc_root != reloc_root); |
| |
| return btrfs_record_root_in_trans(trans, root); |
| } |
| |
| static noinline_for_stack |
| struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct backref_node *node, |
| struct backref_edge *edges[], int *nr) |
| { |
| struct backref_node *next; |
| struct btrfs_root *root; |
| int index = 0; |
| |
| next = node; |
| while (1) { |
| cond_resched(); |
| next = walk_up_backref(next, edges, &index); |
| root = next->root; |
| BUG_ON(!root); |
| BUG_ON(!root->ref_cows); |
| |
| if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { |
| record_reloc_root_in_trans(trans, root); |
| break; |
| } |
| |
| btrfs_record_root_in_trans(trans, root); |
| root = root->reloc_root; |
| |
| if (next->new_bytenr != root->node->start) { |
| BUG_ON(next->new_bytenr); |
| BUG_ON(!list_empty(&next->list)); |
| next->new_bytenr = root->node->start; |
| next->root = root; |
| list_add_tail(&next->list, |
| &rc->backref_cache.changed); |
| __mark_block_processed(rc, next); |
| break; |
| } |
| |
| WARN_ON(1); |
| root = NULL; |
| next = walk_down_backref(edges, &index); |
| if (!next || next->level <= node->level) |
| break; |
| } |
| if (!root) |
| return NULL; |
| |
| *nr = index; |
| next = node; |
| /* setup backref node path for btrfs_reloc_cow_block */ |
| while (1) { |
| rc->backref_cache.path[next->level] = next; |
| if (--index < 0) |
| break; |
| next = edges[index]->node[UPPER]; |
| } |
| return root; |
| } |
| |
| /* |
| * select a tree root for relocation. return NULL if the block |
| * is reference counted. we should use do_relocation() in this |
| * case. return a tree root pointer if the block isn't reference |
| * counted. return -ENOENT if the block is root of reloc tree. |
| */ |
| static noinline_for_stack |
| struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans, |
| struct backref_node *node) |
| { |
| struct backref_node *next; |
| struct btrfs_root *root; |
| struct btrfs_root *fs_root = NULL; |
| struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; |
| int index = 0; |
| |
| next = node; |
| while (1) { |
| cond_resched(); |
| next = walk_up_backref(next, edges, &index); |
| root = next->root; |
| BUG_ON(!root); |
| |
| /* no other choice for non-references counted tree */ |
| if (!root->ref_cows) |
| return root; |
| |
| if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) |
| fs_root = root; |
| |
| if (next != node) |
| return NULL; |
| |
| next = walk_down_backref(edges, &index); |
| if (!next || next->level <= node->level) |
| break; |
| } |
| |
| if (!fs_root) |
| return ERR_PTR(-ENOENT); |
| return fs_root; |
| } |
| |
| static noinline_for_stack |
| u64 calcu_metadata_size(struct reloc_control *rc, |
| struct backref_node *node, int reserve) |
| { |
| struct backref_node *next = node; |
| struct backref_edge *edge; |
| struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; |
| u64 num_bytes = 0; |
| int index = 0; |
| |
| BUG_ON(reserve && node->processed); |
| |
| while (next) { |
| cond_resched(); |
| while (1) { |
| if (next->processed && (reserve || next != node)) |
| break; |
| |
| num_bytes += btrfs_level_size(rc->extent_root, |
| next->level); |
| |
| if (list_empty(&next->upper)) |
| break; |
| |
| edge = list_entry(next->upper.next, |
| struct backref_edge, list[LOWER]); |
| edges[index++] = edge; |
| next = edge->node[UPPER]; |
| } |
| next = walk_down_backref(edges, &index); |
| } |
| return num_bytes; |
| } |
| |
| static int reserve_metadata_space(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct backref_node *node) |
| { |
| struct btrfs_root *root = rc->extent_root; |
| u64 num_bytes; |
| int ret; |
| |
| num_bytes = calcu_metadata_size(rc, node, 1) * 2; |
| |
| trans->block_rsv = rc->block_rsv; |
| ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes, |
| BTRFS_RESERVE_FLUSH_ALL); |
| if (ret) { |
| if (ret == -EAGAIN) |
| rc->commit_transaction = 1; |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static void release_metadata_space(struct reloc_control *rc, |
| struct backref_node *node) |
| { |
| u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2; |
| btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes); |
| } |
| |
| /* |
| * relocate a block tree, and then update pointers in upper level |
| * blocks that reference the block to point to the new location. |
| * |
| * if called by link_to_upper, the block has already been relocated. |
| * in that case this function just updates pointers. |
| */ |
| static int do_relocation(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct backref_node *node, |
| struct btrfs_key *key, |
| struct btrfs_path *path, int lowest) |
| { |
| struct backref_node *upper; |
| struct backref_edge *edge; |
| struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; |
| struct btrfs_root *root; |
| struct extent_buffer *eb; |
| u32 blocksize; |
| u64 bytenr; |
| u64 generation; |
| int nr; |
| int slot; |
| int ret; |
| int err = 0; |
| |
| BUG_ON(lowest && node->eb); |
| |
| path->lowest_level = node->level + 1; |
| rc->backref_cache.path[node->level] = node; |
| list_for_each_entry(edge, &node->upper, list[LOWER]) { |
| cond_resched(); |
| |
| upper = edge->node[UPPER]; |
| root = select_reloc_root(trans, rc, upper, edges, &nr); |
| BUG_ON(!root); |
| |
| if (upper->eb && !upper->locked) { |
| if (!lowest) { |
| ret = btrfs_bin_search(upper->eb, key, |
| upper->level, &slot); |
| BUG_ON(ret); |
| bytenr = btrfs_node_blockptr(upper->eb, slot); |
| if (node->eb->start == bytenr) |
| goto next; |
| } |
| drop_node_buffer(upper); |
| } |
| |
| if (!upper->eb) { |
| ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| BUG_ON(ret > 0); |
| |
| if (!upper->eb) { |
| upper->eb = path->nodes[upper->level]; |
| path->nodes[upper->level] = NULL; |
| } else { |
| BUG_ON(upper->eb != path->nodes[upper->level]); |
| } |
| |
| upper->locked = 1; |
| path->locks[upper->level] = 0; |
| |
| slot = path->slots[upper->level]; |
| btrfs_release_path(path); |
| } else { |
| ret = btrfs_bin_search(upper->eb, key, upper->level, |
| &slot); |
| BUG_ON(ret); |
| } |
| |
| bytenr = btrfs_node_blockptr(upper->eb, slot); |
| if (lowest) { |
| BUG_ON(bytenr != node->bytenr); |
| } else { |
| if (node->eb->start == bytenr) |
| goto next; |
| } |
| |
| blocksize = btrfs_level_size(root, node->level); |
| generation = btrfs_node_ptr_generation(upper->eb, slot); |
| eb = read_tree_block(root, bytenr, blocksize, generation); |
| if (!eb || !extent_buffer_uptodate(eb)) { |
| free_extent_buffer(eb); |
| err = -EIO; |
| goto next; |
| } |
| btrfs_tree_lock(eb); |
| btrfs_set_lock_blocking(eb); |
| |
| if (!node->eb) { |
| ret = btrfs_cow_block(trans, root, eb, upper->eb, |
| slot, &eb); |
| btrfs_tree_unlock(eb); |
| free_extent_buffer(eb); |
| if (ret < 0) { |
| err = ret; |
| goto next; |
| } |
| BUG_ON(node->eb != eb); |
| } else { |
| btrfs_set_node_blockptr(upper->eb, slot, |
| node->eb->start); |
| btrfs_set_node_ptr_generation(upper->eb, slot, |
| trans->transid); |
| btrfs_mark_buffer_dirty(upper->eb); |
| |
| ret = btrfs_inc_extent_ref(trans, root, |
| node->eb->start, blocksize, |
| upper->eb->start, |
| btrfs_header_owner(upper->eb), |
| node->level, 0, 1); |
| BUG_ON(ret); |
| |
| ret = btrfs_drop_subtree(trans, root, eb, upper->eb); |
| BUG_ON(ret); |
| } |
| next: |
| if (!upper->pending) |
| drop_node_buffer(upper); |
| else |
| unlock_node_buffer(upper); |
| if (err) |
| break; |
| } |
| |
| if (!err && node->pending) { |
| drop_node_buffer(node); |
| list_move_tail(&node->list, &rc->backref_cache.changed); |
| node->pending = 0; |
| } |
| |
| path->lowest_level = 0; |
| BUG_ON(err == -ENOSPC); |
| return err; |
| } |
| |
| static int link_to_upper(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct backref_node *node, |
| struct btrfs_path *path) |
| { |
| struct btrfs_key key; |
| |
| btrfs_node_key_to_cpu(node->eb, &key, 0); |
| return do_relocation(trans, rc, node, &key, path, 0); |
| } |
| |
| static int finish_pending_nodes(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct btrfs_path *path, int err) |
| { |
| LIST_HEAD(list); |
| struct backref_cache *cache = &rc->backref_cache; |
| struct backref_node *node; |
| int level; |
| int ret; |
| |
| for (level = 0; level < BTRFS_MAX_LEVEL; level++) { |
| while (!list_empty(&cache->pending[level])) { |
| node = list_entry(cache->pending[level].next, |
| struct backref_node, list); |
| list_move_tail(&node->list, &list); |
| BUG_ON(!node->pending); |
| |
| if (!err) { |
| ret = link_to_upper(trans, rc, node, path); |
| if (ret < 0) |
| err = ret; |
| } |
| } |
| list_splice_init(&list, &cache->pending[level]); |
| } |
| return err; |
| } |
| |
| static void mark_block_processed(struct reloc_control *rc, |
| u64 bytenr, u32 blocksize) |
| { |
| set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1, |
| EXTENT_DIRTY, GFP_NOFS); |
| } |
| |
| static void __mark_block_processed(struct reloc_control *rc, |
| struct backref_node *node) |
| { |
| u32 blocksize; |
| if (node->level == 0 || |
| in_block_group(node->bytenr, rc->block_group)) { |
| blocksize = btrfs_level_size(rc->extent_root, node->level); |
| mark_block_processed(rc, node->bytenr, blocksize); |
| } |
| node->processed = 1; |
| } |
| |
| /* |
| * mark a block and all blocks directly/indirectly reference the block |
| * as processed. |
| */ |
| static void update_processed_blocks(struct reloc_control *rc, |
| struct backref_node *node) |
| { |
| struct backref_node *next = node; |
| struct backref_edge *edge; |
| struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; |
| int index = 0; |
| |
| while (next) { |
| cond_resched(); |
| while (1) { |
| if (next->processed) |
| break; |
| |
| __mark_block_processed(rc, next); |
| |
| if (list_empty(&next->upper)) |
| break; |
| |
| edge = list_entry(next->upper.next, |
| struct backref_edge, list[LOWER]); |
| edges[index++] = edge; |
| next = edge->node[UPPER]; |
| } |
| next = walk_down_backref(edges, &index); |
| } |
| } |
| |
| static int tree_block_processed(u64 bytenr, u32 blocksize, |
| struct reloc_control *rc) |
| { |
| if (test_range_bit(&rc->processed_blocks, bytenr, |
| bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL)) |
| return 1; |
| return 0; |
| } |
| |
| static int get_tree_block_key(struct reloc_control *rc, |
| struct tree_block *block) |
| { |
| struct extent_buffer *eb; |
| |
| BUG_ON(block->key_ready); |
| eb = read_tree_block(rc->extent_root, block->bytenr, |
| block->key.objectid, block->key.offset); |
| if (!eb || !extent_buffer_uptodate(eb)) { |
| free_extent_buffer(eb); |
| return -EIO; |
| } |
| WARN_ON(btrfs_header_level(eb) != block->level); |
| if (block->level == 0) |
| btrfs_item_key_to_cpu(eb, &block->key, 0); |
| else |
| btrfs_node_key_to_cpu(eb, &block->key, 0); |
| free_extent_buffer(eb); |
| block->key_ready = 1; |
| return 0; |
| } |
| |
| static int reada_tree_block(struct reloc_control *rc, |
| struct tree_block *block) |
| { |
| BUG_ON(block->key_ready); |
| if (block->key.type == BTRFS_METADATA_ITEM_KEY) |
| readahead_tree_block(rc->extent_root, block->bytenr, |
| block->key.objectid, |
| rc->extent_root->leafsize); |
| else |
| readahead_tree_block(rc->extent_root, block->bytenr, |
| block->key.objectid, block->key.offset); |
| return 0; |
| } |
| |
| /* |
| * helper function to relocate a tree block |
| */ |
| static int relocate_tree_block(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct backref_node *node, |
| struct btrfs_key *key, |
| struct btrfs_path *path) |
| { |
| struct btrfs_root *root; |
| int release = 0; |
| int ret = 0; |
| |
| if (!node) |
| return 0; |
| |
| BUG_ON(node->processed); |
| root = select_one_root(trans, node); |
| if (root == ERR_PTR(-ENOENT)) { |
| update_processed_blocks(rc, node); |
| goto out; |
| } |
| |
| if (!root || root->ref_cows) { |
| ret = reserve_metadata_space(trans, rc, node); |
| if (ret) |
| goto out; |
| release = 1; |
| } |
| |
| if (root) { |
| if (root->ref_cows) { |
| BUG_ON(node->new_bytenr); |
| BUG_ON(!list_empty(&node->list)); |
| btrfs_record_root_in_trans(trans, root); |
| root = root->reloc_root; |
| node->new_bytenr = root->node->start; |
| node->root = root; |
| list_add_tail(&node->list, &rc->backref_cache.changed); |
| } else { |
| path->lowest_level = node->level; |
| ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
| btrfs_release_path(path); |
| if (ret > 0) |
| ret = 0; |
| } |
| if (!ret) |
| update_processed_blocks(rc, node); |
| } else { |
| ret = do_relocation(trans, rc, node, key, path, 1); |
| } |
| out: |
| if (ret || node->level == 0 || node->cowonly) { |
| if (release) |
| release_metadata_space(rc, node); |
| remove_backref_node(&rc->backref_cache, node); |
| } |
| return ret; |
| } |
| |
| /* |
| * relocate a list of blocks |
| */ |
| static noinline_for_stack |
| int relocate_tree_blocks(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, struct rb_root *blocks) |
| { |
| struct backref_node *node; |
| struct btrfs_path *path; |
| struct tree_block *block; |
| struct rb_node *rb_node; |
| int ret; |
| int err = 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| err = -ENOMEM; |
| goto out_free_blocks; |
| } |
| |
| rb_node = rb_first(blocks); |
| while (rb_node) { |
| block = rb_entry(rb_node, struct tree_block, rb_node); |
| if (!block->key_ready) |
| reada_tree_block(rc, block); |
| rb_node = rb_next(rb_node); |
| } |
| |
| rb_node = rb_first(blocks); |
| while (rb_node) { |
| block = rb_entry(rb_node, struct tree_block, rb_node); |
| if (!block->key_ready) { |
| err = get_tree_block_key(rc, block); |
| if (err) |
| goto out_free_path; |
| } |
| rb_node = rb_next(rb_node); |
| } |
| |
| rb_node = rb_first(blocks); |
| while (rb_node) { |
| block = rb_entry(rb_node, struct tree_block, rb_node); |
| |
| node = build_backref_tree(rc, &block->key, |
| block->level, block->bytenr); |
| if (IS_ERR(node)) { |
| err = PTR_ERR(node); |
| goto out; |
| } |
| |
| ret = relocate_tree_block(trans, rc, node, &block->key, |
| path); |
| if (ret < 0) { |
| if (ret != -EAGAIN || rb_node == rb_first(blocks)) |
| err = ret; |
| goto out; |
| } |
| rb_node = rb_next(rb_node); |
| } |
| out: |
| err = finish_pending_nodes(trans, rc, path, err); |
| |
| out_free_path: |
| btrfs_free_path(path); |
| out_free_blocks: |
| free_block_list(blocks); |
| return err; |
| } |
| |
| static noinline_for_stack |
| int prealloc_file_extent_cluster(struct inode *inode, |
| struct file_extent_cluster *cluster) |
| { |
| u64 alloc_hint = 0; |
| u64 start; |
| u64 end; |
| u64 offset = BTRFS_I(inode)->index_cnt; |
| u64 num_bytes; |
| int nr = 0; |
| int ret = 0; |
| |
| BUG_ON(cluster->start != cluster->boundary[0]); |
| mutex_lock(&inode->i_mutex); |
| |
| ret = btrfs_check_data_free_space(inode, cluster->end + |
| 1 - cluster->start); |
| if (ret) |
| goto out; |
| |
| while (nr < cluster->nr) { |
| start = cluster->boundary[nr] - offset; |
| if (nr + 1 < cluster->nr) |
| end = cluster->boundary[nr + 1] - 1 - offset; |
| else |
| end = cluster->end - offset; |
| |
| lock_extent(&BTRFS_I(inode)->io_tree, start, end); |
| num_bytes = end + 1 - start; |
| ret = btrfs_prealloc_file_range(inode, 0, start, |
| num_bytes, num_bytes, |
| end + 1, &alloc_hint); |
| unlock_extent(&BTRFS_I(inode)->io_tree, start, end); |
| if (ret) |
| break; |
| nr++; |
| } |
| btrfs_free_reserved_data_space(inode, cluster->end + |
| 1 - cluster->start); |
| out: |
| mutex_unlock(&inode->i_mutex); |
| return ret; |
| } |
| |
| static noinline_for_stack |
| int setup_extent_mapping(struct inode *inode, u64 start, u64 end, |
| u64 block_start) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
| struct extent_map *em; |
| int ret = 0; |
| |
| em = alloc_extent_map(); |
| if (!em) |
| return -ENOMEM; |
| |
| em->start = start; |
| em->len = end + 1 - start; |
| em->block_len = em->len; |
| em->block_start = block_start; |
| em->bdev = root->fs_info->fs_devices->latest_bdev; |
| set_bit(EXTENT_FLAG_PINNED, &em->flags); |
| |
| lock_extent(&BTRFS_I(inode)->io_tree, start, end); |
| while (1) { |
| write_lock(&em_tree->lock); |
| ret = add_extent_mapping(em_tree, em, 0); |
| write_unlock(&em_tree->lock); |
| if (ret != -EEXIST) { |
| free_extent_map(em); |
| break; |
| } |
| btrfs_drop_extent_cache(inode, start, end, 0); |
| } |
| unlock_extent(&BTRFS_I(inode)->io_tree, start, end); |
| return ret; |
| } |
| |
| static int relocate_file_extent_cluster(struct inode *inode, |
| struct file_extent_cluster *cluster) |
| { |
| u64 page_start; |
| u64 page_end; |
| u64 offset = BTRFS_I(inode)->index_cnt; |
| unsigned long index; |
| unsigned long last_index; |
| struct page *page; |
| struct file_ra_state *ra; |
| gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); |
| int nr = 0; |
| int ret = 0; |
| |
| if (!cluster->nr) |
| return 0; |
| |
| ra = kzalloc(sizeof(*ra), GFP_NOFS); |
| if (!ra) |
| return -ENOMEM; |
| |
| ret = prealloc_file_extent_cluster(inode, cluster); |
| if (ret) |
| goto out; |
| |
| file_ra_state_init(ra, inode->i_mapping); |
| |
| ret = setup_extent_mapping(inode, cluster->start - offset, |
| cluster->end - offset, cluster->start); |
| if (ret) |
| goto out; |
| |
| index = (cluster->start - offset) >> PAGE_CACHE_SHIFT; |
| last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT; |
| while (index <= last_index) { |
| ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE); |
| if (ret) |
| goto out; |
| |
| page = find_lock_page(inode->i_mapping, index); |
| if (!page) { |
| page_cache_sync_readahead(inode->i_mapping, |
| ra, NULL, index, |
| last_index + 1 - index); |
| page = find_or_create_page(inode->i_mapping, index, |
| mask); |
| if (!page) { |
| btrfs_delalloc_release_metadata(inode, |
| PAGE_CACHE_SIZE); |
| ret = -ENOMEM; |
| goto out; |
| } |
| } |
| |
| if (PageReadahead(page)) { |
| page_cache_async_readahead(inode->i_mapping, |
| ra, NULL, page, index, |
| last_index + 1 - index); |
| } |
| |
| if (!PageUptodate(page)) { |
| btrfs_readpage(NULL, page); |
| lock_page(page); |
| if (!PageUptodate(page)) { |
| unlock_page(page); |
| page_cache_release(page); |
| btrfs_delalloc_release_metadata(inode, |
| PAGE_CACHE_SIZE); |
| ret = -EIO; |
| goto out; |
| } |
| } |
| |
| page_start = page_offset(page); |
| page_end = page_start + PAGE_CACHE_SIZE - 1; |
| |
| lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end); |
| |
| set_page_extent_mapped(page); |
| |
| if (nr < cluster->nr && |
| page_start + offset == cluster->boundary[nr]) { |
| set_extent_bits(&BTRFS_I(inode)->io_tree, |
| page_start, page_end, |
| EXTENT_BOUNDARY, GFP_NOFS); |
| nr++; |
| } |
| |
| btrfs_set_extent_delalloc(inode, page_start, page_end, NULL); |
| set_page_dirty(page); |
| |
| unlock_extent(&BTRFS_I(inode)->io_tree, |
| page_start, page_end); |
| unlock_page(page); |
| page_cache_release(page); |
| |
| index++; |
| balance_dirty_pages_ratelimited(inode->i_mapping); |
| btrfs_throttle(BTRFS_I(inode)->root); |
| } |
| WARN_ON(nr != cluster->nr); |
| out: |
| kfree(ra); |
| return ret; |
| } |
| |
| static noinline_for_stack |
| int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key, |
| struct file_extent_cluster *cluster) |
| { |
| int ret; |
| |
| if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) { |
| ret = relocate_file_extent_cluster(inode, cluster); |
| if (ret) |
| return ret; |
| cluster->nr = 0; |
| } |
| |
| if (!cluster->nr) |
| cluster->start = extent_key->objectid; |
| else |
| BUG_ON(cluster->nr >= MAX_EXTENTS); |
| cluster->end = extent_key->objectid + extent_key->offset - 1; |
| cluster->boundary[cluster->nr] = extent_key->objectid; |
| cluster->nr++; |
| |
| if (cluster->nr >= MAX_EXTENTS) { |
| ret = relocate_file_extent_cluster(inode, cluster); |
| if (ret) |
| return ret; |
| cluster->nr = 0; |
| } |
| return 0; |
| } |
| |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| static int get_ref_objectid_v0(struct reloc_control *rc, |
| struct btrfs_path *path, |
| struct btrfs_key *extent_key, |
| u64 *ref_objectid, int *path_change) |
| { |
| struct btrfs_key key; |
| struct extent_buffer *leaf; |
| struct btrfs_extent_ref_v0 *ref0; |
| int ret; |
| int slot; |
| |
| leaf = path->nodes[0]; |
| slot = path->slots[0]; |
| while (1) { |
| if (slot >= btrfs_header_nritems(leaf)) { |
| ret = btrfs_next_leaf(rc->extent_root, path); |
| if (ret < 0) |
| return ret; |
| BUG_ON(ret > 0); |
| leaf = path->nodes[0]; |
| slot = path->slots[0]; |
| if (path_change) |
| *path_change = 1; |
| } |
| btrfs_item_key_to_cpu(leaf, &key, slot); |
| if (key.objectid != extent_key->objectid) |
| return -ENOENT; |
| |
| if (key.type != BTRFS_EXTENT_REF_V0_KEY) { |
| slot++; |
| continue; |
| } |
| ref0 = btrfs_item_ptr(leaf, slot, |
| struct btrfs_extent_ref_v0); |
| *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0); |
| break; |
| } |
| return 0; |
| } |
| #endif |
| |
| /* |
| * helper to add a tree block to the list. |
| * the major work is getting the generation and level of the block |
| */ |
| static int add_tree_block(struct reloc_control *rc, |
| struct btrfs_key *extent_key, |
| struct btrfs_path *path, |
| struct rb_root *blocks) |
| { |
| struct extent_buffer *eb; |
| struct btrfs_extent_item *ei; |
| struct btrfs_tree_block_info *bi; |
| struct tree_block *block; |
| struct rb_node *rb_node; |
| u32 item_size; |
| int level = -1; |
| u64 generation; |
| |
| eb = path->nodes[0]; |
| item_size = btrfs_item_size_nr(eb, path->slots[0]); |
| |
| if (extent_key->type == BTRFS_METADATA_ITEM_KEY || |
| item_size >= sizeof(*ei) + sizeof(*bi)) { |
| ei = btrfs_item_ptr(eb, path->slots[0], |
| struct btrfs_extent_item); |
| if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) { |
| bi = (struct btrfs_tree_block_info *)(ei + 1); |
| level = btrfs_tree_block_level(eb, bi); |
| } else { |
| level = (int)extent_key->offset; |
| } |
| generation = btrfs_extent_generation(eb, ei); |
| } else { |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| u64 ref_owner; |
| int ret; |
| |
| BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0)); |
| ret = get_ref_objectid_v0(rc, path, extent_key, |
| &ref_owner, NULL); |
| if (ret < 0) |
| return ret; |
| BUG_ON(ref_owner >= BTRFS_MAX_LEVEL); |
| level = (int)ref_owner; |
| /* FIXME: get real generation */ |
| generation = 0; |
| #else |
| BUG(); |
| #endif |
| } |
| |
| btrfs_release_path(path); |
| |
| BUG_ON(level == -1); |
| |
| block = kmalloc(sizeof(*block), GFP_NOFS); |
| if (!block) |
| return -ENOMEM; |
| |
| block->bytenr = extent_key->objectid; |
| block->key.objectid = rc->extent_root->leafsize; |
| block->key.offset = generation; |
| block->level = level; |
| block->key_ready = 0; |
| |
| rb_node = tree_insert(blocks, block->bytenr, &block->rb_node); |
| if (rb_node) |
| backref_tree_panic(rb_node, -EEXIST, block->bytenr); |
| |
| return 0; |
| } |
| |
| /* |
| * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY |
| */ |
| static int __add_tree_block(struct reloc_control *rc, |
| u64 bytenr, u32 blocksize, |
| struct rb_root *blocks) |
| { |
| struct btrfs_path *path; |
| struct btrfs_key key; |
| int ret; |
| bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info, |
| SKINNY_METADATA); |
| |
| if (tree_block_processed(bytenr, blocksize, rc)) |
| return 0; |
| |
| if (tree_search(blocks, bytenr)) |
| return 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| again: |
| key.objectid = bytenr; |
| if (skinny) { |
| key.type = BTRFS_METADATA_ITEM_KEY; |
| key.offset = (u64)-1; |
| } else { |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = blocksize; |
| } |
| |
| path->search_commit_root = 1; |
| path->skip_locking = 1; |
| ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0); |
| if (ret < 0) |
| goto out; |
| |
| if (ret > 0 && skinny) { |
| if (path->slots[0]) { |
| path->slots[0]--; |
| btrfs_item_key_to_cpu(path->nodes[0], &key, |
| path->slots[0]); |
| if (key.objectid == bytenr && |
| (key.type == BTRFS_METADATA_ITEM_KEY || |
| (key.type == BTRFS_EXTENT_ITEM_KEY && |
| key.offset == blocksize))) |
| ret = 0; |
| } |
| |
| if (ret) { |
| skinny = false; |
| btrfs_release_path(path); |
| goto again; |
| } |
| } |
| BUG_ON(ret); |
| |
| ret = add_tree_block(rc, &key, path, blocks); |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * helper to check if the block use full backrefs for pointers in it |
| */ |
| static int block_use_full_backref(struct reloc_control *rc, |
| struct extent_buffer *eb) |
| { |
| u64 flags; |
| int ret; |
| |
| if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) || |
| btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV) |
| return 1; |
| |
| ret = btrfs_lookup_extent_info(NULL, rc->extent_root, |
| eb->start, btrfs_header_level(eb), 1, |
| NULL, &flags); |
| BUG_ON(ret); |
| |
| if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| ret = 1; |
| else |
| ret = 0; |
| return ret; |
| } |
| |
| static int delete_block_group_cache(struct btrfs_fs_info *fs_info, |
| struct inode *inode, u64 ino) |
| { |
| struct btrfs_key key; |
| struct btrfs_root *root = fs_info->tree_root; |
| struct btrfs_trans_handle *trans; |
| int ret = 0; |
| |
| if (inode) |
| goto truncate; |
| |
| key.objectid = ino; |
| key.type = BTRFS_INODE_ITEM_KEY; |
| key.offset = 0; |
| |
| inode = btrfs_iget(fs_info->sb, &key, root, NULL); |
| if (IS_ERR(inode) || is_bad_inode(inode)) { |
| if (!IS_ERR(inode)) |
| iput(inode); |
| return -ENOENT; |
| } |
| |
| truncate: |
| ret = btrfs_check_trunc_cache_free_space(root, |
| &fs_info->global_block_rsv); |
| if (ret) |
| goto out; |
| |
| trans = btrfs_join_transaction(root); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| goto out; |
| } |
| |
| ret = btrfs_truncate_free_space_cache(root, trans, inode); |
| |
| btrfs_end_transaction(trans, root); |
| btrfs_btree_balance_dirty(root); |
| out: |
| iput(inode); |
| return ret; |
| } |
| |
| /* |
| * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY |
| * this function scans fs tree to find blocks reference the data extent |
| */ |
| static int find_data_references(struct reloc_control *rc, |
| struct btrfs_key *extent_key, |
| struct extent_buffer *leaf, |
| struct btrfs_extent_data_ref *ref, |
| struct rb_root *blocks) |
| { |
| struct btrfs_path *path; |
| struct tree_block *block; |
| struct btrfs_root *root; |
| struct btrfs_file_extent_item *fi; |
| struct rb_node *rb_node; |
| struct btrfs_key key; |
| u64 ref_root; |
| u64 ref_objectid; |
| u64 ref_offset; |
| u32 ref_count; |
| u32 nritems; |
| int err = 0; |
| int added = 0; |
| int counted; |
| int ret; |
| |
| ref_root = btrfs_extent_data_ref_root(leaf, ref); |
| ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref); |
| ref_offset = btrfs_extent_data_ref_offset(leaf, ref); |
| ref_count = btrfs_extent_data_ref_count(leaf, ref); |
| |
| /* |
| * This is an extent belonging to the free space cache, lets just delete |
| * it and redo the search. |
| */ |
| if (ref_root == BTRFS_ROOT_TREE_OBJECTID) { |
| ret = delete_block_group_cache(rc->extent_root->fs_info, |
| NULL, ref_objectid); |
| if (ret != -ENOENT) |
| return ret; |
| ret = 0; |
| } |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| path->reada = 1; |
| |
| root = read_fs_root(rc->extent_root->fs_info, ref_root); |
| if (IS_ERR(root)) { |
| err = PTR_ERR(root); |
| goto out; |
| } |
| |
| key.objectid = ref_objectid; |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| if (ref_offset > ((u64)-1 << 32)) |
| key.offset = 0; |
| else |
| key.offset = ref_offset; |
| |
| path->search_commit_root = 1; |
| path->skip_locking = 1; |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| /* |
| * the references in tree blocks that use full backrefs |
| * are not counted in |
| */ |
| if (block_use_full_backref(rc, leaf)) |
| counted = 0; |
| else |
| counted = 1; |
| rb_node = tree_search(blocks, leaf->start); |
| if (rb_node) { |
| if (counted) |
| added = 1; |
| else |
| path->slots[0] = nritems; |
| } |
| |
| while (ref_count > 0) { |
| while (path->slots[0] >= nritems) { |
| ret = btrfs_next_leaf(root, path); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| if (WARN_ON(ret > 0)) |
| goto out; |
| |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| added = 0; |
| |
| if (block_use_full_backref(rc, leaf)) |
| counted = 0; |
| else |
| counted = 1; |
| rb_node = tree_search(blocks, leaf->start); |
| if (rb_node) { |
| if (counted) |
| added = 1; |
| else |
| path->slots[0] = nritems; |
| } |
| } |
| |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| if (WARN_ON(key.objectid != ref_objectid || |
| key.type != BTRFS_EXTENT_DATA_KEY)) |
| break; |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| |
| if (btrfs_file_extent_type(leaf, fi) == |
| BTRFS_FILE_EXTENT_INLINE) |
| goto next; |
| |
| if (btrfs_file_extent_disk_bytenr(leaf, fi) != |
| extent_key->objectid) |
| goto next; |
| |
| key.offset -= btrfs_file_extent_offset(leaf, fi); |
| if (key.offset != ref_offset) |
| goto next; |
| |
| if (counted) |
| ref_count--; |
| if (added) |
| goto next; |
| |
| if (!tree_block_processed(leaf->start, leaf->len, rc)) { |
| block = kmalloc(sizeof(*block), GFP_NOFS); |
| if (!block) { |
| err = -ENOMEM; |
| break; |
| } |
| block->bytenr = leaf->start; |
| btrfs_item_key_to_cpu(leaf, &block->key, 0); |
| block->level = 0; |
| block->key_ready = 1; |
| rb_node = tree_insert(blocks, block->bytenr, |
| &block->rb_node); |
| if (rb_node) |
| backref_tree_panic(rb_node, -EEXIST, |
| block->bytenr); |
| } |
| if (counted) |
| added = 1; |
| else |
| path->slots[0] = nritems; |
| next: |
| path->slots[0]++; |
| |
| } |
| out: |
| btrfs_free_path(path); |
| return err; |
| } |
| |
| /* |
| * helper to find all tree blocks that reference a given data extent |
| */ |
| static noinline_for_stack |
| int add_data_references(struct reloc_control *rc, |
| struct btrfs_key *extent_key, |
| struct btrfs_path *path, |
| struct rb_root *blocks) |
| { |
| struct btrfs_key key; |
| struct extent_buffer *eb; |
| struct btrfs_extent_data_ref *dref; |
| struct btrfs_extent_inline_ref *iref; |
| unsigned long ptr; |
| unsigned long end; |
| u32 blocksize = btrfs_level_size(rc->extent_root, 0); |
| int ret = 0; |
| int err = 0; |
| |
| eb = path->nodes[0]; |
| ptr = btrfs_item_ptr_offset(eb, path->slots[0]); |
| end = ptr + btrfs_item_size_nr(eb, path->slots[0]); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (ptr + sizeof(struct btrfs_extent_item_v0) == end) |
| ptr = end; |
| else |
| #endif |
| ptr += sizeof(struct btrfs_extent_item); |
| |
| while (ptr < end) { |
| iref = (struct btrfs_extent_inline_ref *)ptr; |
| key.type = btrfs_extent_inline_ref_type(eb, iref); |
| if (key.type == BTRFS_SHARED_DATA_REF_KEY) { |
| key.offset = btrfs_extent_inline_ref_offset(eb, iref); |
| ret = __add_tree_block(rc, key.offset, blocksize, |
| blocks); |
| } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { |
| dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| ret = find_data_references(rc, extent_key, |
| eb, dref, blocks); |
| } else { |
| BUG(); |
| } |
| if (ret) { |
| err = ret; |
| goto out; |
| } |
| ptr += btrfs_extent_inline_ref_size(key.type); |
| } |
| WARN_ON(ptr > end); |
| |
| while (1) { |
| cond_resched(); |
| eb = path->nodes[0]; |
| if (path->slots[0] >= btrfs_header_nritems(eb)) { |
| ret = btrfs_next_leaf(rc->extent_root, path); |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| if (ret > 0) |
| break; |
| eb = path->nodes[0]; |
| } |
| |
| btrfs_item_key_to_cpu(eb, &key, path->slots[0]); |
| if (key.objectid != extent_key->objectid) |
| break; |
| |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (key.type == BTRFS_SHARED_DATA_REF_KEY || |
| key.type == BTRFS_EXTENT_REF_V0_KEY) { |
| #else |
| BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); |
| if (key.type == BTRFS_SHARED_DATA_REF_KEY) { |
| #endif |
| ret = __add_tree_block(rc, key.offset, blocksize, |
| blocks); |
| } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { |
| dref = btrfs_item_ptr(eb, path->slots[0], |
| struct btrfs_extent_data_ref); |
| ret = find_data_references(rc, extent_key, |
| eb, dref, blocks); |
| } else { |
| ret = 0; |
| } |
| if (ret) { |
| err = ret; |
| break; |
| } |
| path->slots[0]++; |
| } |
| out: |
| btrfs_release_path(path); |
| if (err) |
| free_block_list(blocks); |
| return err; |
| } |
| |
| /* |
| * helper to find next unprocessed extent |
| */ |
| static noinline_for_stack |
| int find_next_extent(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, struct btrfs_path *path, |
| struct btrfs_key *extent_key) |
| { |
| struct btrfs_key key; |
| struct extent_buffer *leaf; |
| u64 start, end, last; |
| int ret; |
| |
| last = rc->block_group->key.objectid + rc->block_group->key.offset; |
| while (1) { |
| cond_resched(); |
| if (rc->search_start >= last) { |
| ret = 1; |
| break; |
| } |
| |
| key.objectid = rc->search_start; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = 0; |
| |
| path->search_commit_root = 1; |
| path->skip_locking = 1; |
| ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, |
| 0, 0); |
| if (ret < 0) |
| break; |
| next: |
| leaf = path->nodes[0]; |
| if (path->slots[0] >= btrfs_header_nritems(leaf)) { |
| ret = btrfs_next_leaf(rc->extent_root, path); |
| if (ret != 0) |
| break; |
| leaf = path->nodes[0]; |
| } |
| |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| if (key.objectid >= last) { |
| ret = 1; |
| break; |
| } |
| |
| if (key.type != BTRFS_EXTENT_ITEM_KEY && |
| key.type != BTRFS_METADATA_ITEM_KEY) { |
| path->slots[0]++; |
| goto next; |
| } |
| |
| if (key.type == BTRFS_EXTENT_ITEM_KEY && |
| key.objectid + key.offset <= rc->search_start) { |
| path->slots[0]++; |
| goto next; |
| } |
| |
| if (key.type == BTRFS_METADATA_ITEM_KEY && |
| key.objectid + rc->extent_root->leafsize <= |
| rc->search_start) { |
| path->slots[0]++; |
| goto next; |
| } |
| |
| ret = find_first_extent_bit(&rc->processed_blocks, |
| key.objectid, &start, &end, |
| EXTENT_DIRTY, NULL); |
| |
| if (ret == 0 && start <= key.objectid) { |
| btrfs_release_path(path); |
| rc->search_start = end + 1; |
| } else { |
| if (key.type == BTRFS_EXTENT_ITEM_KEY) |
| rc->search_start = key.objectid + key.offset; |
| else |
| rc->search_start = key.objectid + |
| rc->extent_root->leafsize; |
| memcpy(extent_key, &key, sizeof(key)); |
| return 0; |
| } |
| } |
| btrfs_release_path(path); |
| return ret; |
| } |
| |
| static void set_reloc_control(struct reloc_control *rc) |
| { |
| struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
| |
| mutex_lock(&fs_info->reloc_mutex); |
| fs_info->reloc_ctl = rc; |
| mutex_unlock(&fs_info->reloc_mutex); |
| } |
| |
| static void unset_reloc_control(struct reloc_control *rc) |
| { |
| struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
| |
| mutex_lock(&fs_info->reloc_mutex); |
| fs_info->reloc_ctl = NULL; |
| mutex_unlock(&fs_info->reloc_mutex); |
| } |
| |
| static int check_extent_flags(u64 flags) |
| { |
| if ((flags & BTRFS_EXTENT_FLAG_DATA) && |
| (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) |
| return 1; |
| if (!(flags & BTRFS_EXTENT_FLAG_DATA) && |
| !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) |
| return 1; |
| if ((flags & BTRFS_EXTENT_FLAG_DATA) && |
| (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) |
| return 1; |
| return 0; |
| } |
| |
| static noinline_for_stack |
| int prepare_to_relocate(struct reloc_control *rc) |
| { |
| struct btrfs_trans_handle *trans; |
| int ret; |
| |
| rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root, |
| BTRFS_BLOCK_RSV_TEMP); |
| if (!rc->block_rsv) |
| return -ENOMEM; |
| |
| /* |
| * reserve some space for creating reloc trees. |
| * btrfs_init_reloc_root will use them when there |
| * is no reservation in transaction handle. |
| */ |
| ret = btrfs_block_rsv_add(rc->extent_root, rc->block_rsv, |
| rc->extent_root->nodesize * 256, |
| BTRFS_RESERVE_FLUSH_ALL); |
| if (ret) |
| return ret; |
| |
| memset(&rc->cluster, 0, sizeof(rc->cluster)); |
| rc->search_start = rc->block_group->key.objectid; |
| rc->extents_found = 0; |
| rc->nodes_relocated = 0; |
| rc->merging_rsv_size = 0; |
| |
| rc->create_reloc_tree = 1; |
| set_reloc_control(rc); |
| |
| trans = btrfs_join_transaction(rc->extent_root); |
| if (IS_ERR(trans)) { |
| unset_reloc_control(rc); |
| /* |
| * extent tree is not a ref_cow tree and has no reloc_root to |
| * cleanup. And callers are responsible to free the above |
| * block rsv. |
| */ |
| return PTR_ERR(trans); |
| } |
| btrfs_commit_transaction(trans, rc->extent_root); |
| return 0; |
| } |
| |
| static noinline_for_stack int relocate_block_group(struct reloc_control *rc) |
| { |
| struct rb_root blocks = RB_ROOT; |
| struct btrfs_key key; |
| struct btrfs_trans_handle *trans = NULL; |
| struct btrfs_path *path; |
| struct btrfs_extent_item *ei; |
| u64 flags; |
| u32 item_size; |
| int ret; |
| int err = 0; |
| int progress = 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| path->reada = 1; |
| |
| ret = prepare_to_relocate(rc); |
| if (ret) { |
| err = ret; |
| goto out_free; |
| } |
| |
| while (1) { |
| progress++; |
| trans = btrfs_start_transaction(rc->extent_root, 0); |
| if (IS_ERR(trans)) { |
| err = PTR_ERR(trans); |
| trans = NULL; |
| break; |
| } |
| restart: |
| if (update_backref_cache(trans, &rc->backref_cache)) { |
| btrfs_end_transaction(trans, rc->extent_root); |
| continue; |
| } |
| |
| ret = find_next_extent(trans, rc, path, &key); |
| if (ret < 0) |
| err = ret; |
| if (ret != 0) |
| break; |
| |
| rc->extents_found++; |
| |
| ei = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_extent_item); |
| item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); |
| if (item_size >= sizeof(*ei)) { |
| flags = btrfs_extent_flags(path->nodes[0], ei); |
| ret = check_extent_flags(flags); |
| BUG_ON(ret); |
| |
| } else { |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| u64 ref_owner; |
| int path_change = 0; |
| |
| BUG_ON(item_size != |
| sizeof(struct btrfs_extent_item_v0)); |
| ret = get_ref_objectid_v0(rc, path, &key, &ref_owner, |
| &path_change); |
| if (ref_owner < BTRFS_FIRST_FREE_OBJECTID) |
| flags = BTRFS_EXTENT_FLAG_TREE_BLOCK; |
| else |
| flags = BTRFS_EXTENT_FLAG_DATA; |
| |
| if (path_change) { |
| btrfs_release_path(path); |
| |
| path->search_commit_root = 1; |
| path->skip_locking = 1; |
| ret = btrfs_search_slot(NULL, rc->extent_root, |
| &key, path, 0, 0); |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| BUG_ON(ret > 0); |
| } |
| #else |
| BUG(); |
| #endif |
| } |
| |
| if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
| ret = add_tree_block(rc, &key, path, &blocks); |
| } else if (rc->stage == UPDATE_DATA_PTRS && |
| (flags & BTRFS_EXTENT_FLAG_DATA)) { |
| ret = add_data_references(rc, &key, path, &blocks); |
| } else { |
| btrfs_release_path(path); |
| ret = 0; |
| } |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| |
| if (!RB_EMPTY_ROOT(&blocks)) { |
| ret = relocate_tree_blocks(trans, rc, &blocks); |
| if (ret < 0) { |
| if (ret != -EAGAIN) { |
| err = ret; |
| break; |
| } |
| rc->extents_found--; |
| rc->search_start = key.objectid; |
| } |
| } |
| |
| if (rc->commit_transaction) { |
| rc->commit_transaction = 0; |
| ret = btrfs_commit_transaction(trans, rc->extent_root); |
| BUG_ON(ret); |
| } else { |
| btrfs_end_transaction_throttle(trans, rc->extent_root); |
| btrfs_btree_balance_dirty(rc->extent_root); |
| } |
| trans = NULL; |
| |
| if (rc->stage == MOVE_DATA_EXTENTS && |
| (flags & BTRFS_EXTENT_FLAG_DATA)) { |
| rc->found_file_extent = 1; |
| ret = relocate_data_extent(rc->data_inode, |
| &key, &rc->cluster); |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| } |
| } |
| if (trans && progress && err == -ENOSPC) { |
| ret = btrfs_force_chunk_alloc(trans, rc->extent_root, |
| rc->block_group->flags); |
| if (ret == 0) { |
| err = 0; |
| progress = 0; |
| goto restart; |
| } |
| } |
| |
| btrfs_release_path(path); |
| clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY, |
| GFP_NOFS); |
| |
| if (trans) { |
| btrfs_end_transaction_throttle(trans, rc->extent_root); |
| btrfs_btree_balance_dirty(rc->extent_root); |
| } |
| |
| if (!err) { |
| ret = relocate_file_extent_cluster(rc->data_inode, |
| &rc->cluster); |
| if (ret < 0) |
| err = ret; |
| } |
| |
| rc->create_reloc_tree = 0; |
| set_reloc_control(rc); |
| |
| backref_cache_cleanup(&rc->backref_cache); |
| btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1); |
| |
| err = prepare_to_merge(rc, err); |
| |
| merge_reloc_roots(rc); |
| |
| rc->merge_reloc_tree = 0; |
| unset_reloc_control(rc); |
| btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1); |
| |
| /* get rid of pinned extents */ |
| trans = btrfs_join_transaction(rc->extent_root); |
| if (IS_ERR(trans)) |
| err = PTR_ERR(trans); |
| else |
| btrfs_commit_transaction(trans, rc->extent_root); |
| out_free: |
| btrfs_free_block_rsv(rc->extent_root, rc->block_rsv); |
| btrfs_free_path(path); |
| return err; |
| } |
| |
| static int __insert_orphan_inode(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 objectid) |
| { |
| 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, 0); |
| btrfs_set_inode_mode(leaf, item, S_IFREG | 0600); |
| btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS | |
| BTRFS_INODE_PREALLOC); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(path); |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * helper to create inode for data relocation. |
| * the inode is in data relocation tree and its link count is 0 |
| */ |
| static noinline_for_stack |
| struct inode *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 key; |
| u64 objectid = BTRFS_FIRST_FREE_OBJECTID; |
| int err = 0; |
| |
| root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID); |
| if (IS_ERR(root)) |
| return ERR_CAST(root); |
| |
| trans = btrfs_start_transaction(root, 6); |
| if (IS_ERR(trans)) |
| return ERR_CAST(trans); |
| |
| err = btrfs_find_free_objectid(root, &objectid); |
| if (err) |
| goto out; |
| |
| err = __insert_orphan_inode(trans, root, objectid); |
| BUG_ON(err); |
| |
| key.objectid = objectid; |
| key.type = BTRFS_INODE_ITEM_KEY; |
| key.offset = 0; |
| inode = btrfs_iget(root->fs_info->sb, &key, root, NULL); |
| BUG_ON(IS_ERR(inode) || is_bad_inode(inode)); |
| BTRFS_I(inode)->index_cnt = group->key.objectid; |
| |
| err = btrfs_orphan_add(trans, inode); |
| out: |
| btrfs_end_transaction(trans, root); |
| btrfs_btree_balance_dirty(root); |
| if (err) { |
| if (inode) |
| iput(inode); |
| inode = ERR_PTR(err); |
| } |
| return inode; |
| } |
| |
| static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info) |
| { |
| struct reloc_control *rc; |
| |
| rc = kzalloc(sizeof(*rc), GFP_NOFS); |
| if (!rc) |
| return NULL; |
| |
| INIT_LIST_HEAD(&rc->reloc_roots); |
| backref_cache_init(&rc->backref_cache); |
| mapping_tree_init(&rc->reloc_root_tree); |
| extent_io_tree_init(&rc->processed_blocks, |
| fs_info->btree_inode->i_mapping); |
| return rc; |
| } |
| |
| /* |
| * function to relocate all extents in a block group. |
| */ |
| int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start) |
| { |
| struct btrfs_fs_info *fs_info = extent_root->fs_info; |
| struct reloc_control *rc; |
| struct inode *inode; |
| struct btrfs_path *path; |
| int ret; |
| int rw = 0; |
| int err = 0; |
| |
| rc = alloc_reloc_control(fs_info); |
| if (!rc) |
| return -ENOMEM; |
| |
| rc->extent_root = extent_root; |
| |
| rc->block_group = btrfs_lookup_block_group(fs_info, group_start); |
| BUG_ON(!rc->block_group); |
| |
| if (!rc->block_group->ro) { |
| ret = btrfs_set_block_group_ro(extent_root, rc->block_group); |
| if (ret) { |
| err = ret; |
| goto out; |
| } |
| rw = 1; |
| } |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group, |
| path); |
| btrfs_free_path(path); |
| |
| if (!IS_ERR(inode)) |
| ret = delete_block_group_cache(fs_info, inode, 0); |
| else |
| ret = PTR_ERR(inode); |
| |
| if (ret && ret != -ENOENT) { |
| err = ret; |
| goto out; |
| } |
| |
| rc->data_inode = create_reloc_inode(fs_info, rc->block_group); |
| if (IS_ERR(rc->data_inode)) { |
| err = PTR_ERR(rc->data_inode); |
| rc->data_inode = NULL; |
| goto out; |
| } |
| |
| printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n", |
| rc->block_group->key.objectid, rc->block_group->flags); |
| |
| ret = btrfs_start_all_delalloc_inodes(fs_info, 0); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| btrfs_wait_all_ordered_extents(fs_info); |
| |
| while (1) { |
| mutex_lock(&fs_info->cleaner_mutex); |
| ret = relocate_block_group(rc); |
| mutex_unlock(&fs_info->cleaner_mutex); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| |
| if (rc->extents_found == 0) |
| break; |
| |
| printk(KERN_INFO "btrfs: found %llu extents\n", |
| rc->extents_found); |
| |
| if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) { |
| ret = btrfs_wait_ordered_range(rc->data_inode, 0, |
| (u64)-1); |
| if (ret) { |
| err = ret; |
| goto out; |
| } |
| invalidate_mapping_pages(rc->data_inode->i_mapping, |
| 0, -1); |
| rc->stage = UPDATE_DATA_PTRS; |
| } |
| } |
| |
| filemap_write_and_wait_range(fs_info->btree_inode->i_mapping, |
| rc->block_group->key.objectid, |
| rc->block_group->key.objectid + |
| rc->block_group->key.offset - 1); |
| |
| WARN_ON(rc->block_group->pinned > 0); |
| WARN_ON(rc->block_group->reserved > 0); |
| WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0); |
| out: |
| if (err && rw) |
| btrfs_set_block_group_rw(extent_root, rc->block_group); |
| iput(rc->data_inode); |
| btrfs_put_block_group(rc->block_group); |
| kfree(rc); |
| return err; |
| } |
| |
| static noinline_for_stack int mark_garbage_root(struct btrfs_root *root) |
| { |
| struct btrfs_trans_handle *trans; |
| int ret, err; |
| |
| trans = btrfs_start_transaction(root->fs_info->tree_root, 0); |
| if (IS_ERR(trans)) |
| return PTR_ERR(trans); |
| |
| memset(&root->root_item.drop_progress, 0, |
| sizeof(root->root_item.drop_progress)); |
| root->root_item.drop_level = 0; |
| btrfs_set_root_refs(&root->root_item, 0); |
| ret = btrfs_update_root(trans, root->fs_info->tree_root, |
| &root->root_key, &root->root_item); |
| |
| err = btrfs_end_transaction(trans, root->fs_info->tree_root); |
| if (err) |
| return err; |
| return ret; |
| } |
| |
| /* |
| * recover relocation interrupted by system crash. |
| * |
| * this function resumes merging reloc trees with corresponding fs trees. |
| * this is important for keeping the sharing of tree blocks |
| */ |
| int btrfs_recover_relocation(struct btrfs_root *root) |
| { |
| LIST_HEAD(reloc_roots); |
| struct btrfs_key key; |
| struct btrfs_root *fs_root; |
| struct btrfs_root *reloc_root; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| struct reloc_control *rc = NULL; |
| struct btrfs_trans_handle *trans; |
| int ret; |
| int err = 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| path->reada = -1; |
| |
| key.objectid = BTRFS_TREE_RELOC_OBJECTID; |
| key.type = BTRFS_ROOT_ITEM_KEY; |
| key.offset = (u64)-1; |
| |
| while (1) { |
| ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, |
| path, 0, 0); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| if (ret > 0) { |
| if (path->slots[0] == 0) |
| break; |
| path->slots[0]--; |
| } |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| btrfs_release_path(path); |
| |
| if (key.objectid != BTRFS_TREE_RELOC_OBJECTID || |
| key.type != BTRFS_ROOT_ITEM_KEY) |
| break; |
| |
| reloc_root = btrfs_read_fs_root(root, &key); |
| if (IS_ERR(reloc_root)) { |
| err = PTR_ERR(reloc_root); |
| goto out; |
| } |
| |
| list_add(&reloc_root->root_list, &reloc_roots); |
| |
| if (btrfs_root_refs(&reloc_root->root_item) > 0) { |
| fs_root = read_fs_root(root->fs_info, |
| reloc_root->root_key.offset); |
| if (IS_ERR(fs_root)) { |
| ret = PTR_ERR(fs_root); |
| if (ret != -ENOENT) { |
| err = ret; |
| goto out; |
| } |
| ret = mark_garbage_root(reloc_root); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| } |
| } |
| |
| if (key.offset == 0) |
| break; |
| |
| key.offset--; |
| } |
| btrfs_release_path(path); |
| |
| if (list_empty(&reloc_roots)) |
| goto out; |
| |
| rc = alloc_reloc_control(root->fs_info); |
| if (!rc) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| rc->extent_root = root->fs_info->extent_root; |
| |
| set_reloc_control(rc); |
| |
| trans = btrfs_join_transaction(rc->extent_root); |
| if (IS_ERR(trans)) { |
| unset_reloc_control(rc); |
| err = PTR_ERR(trans); |
| goto out_free; |
| } |
| |
| rc->merge_reloc_tree = 1; |
| |
| while (!list_empty(&reloc_roots)) { |
| reloc_root = list_entry(reloc_roots.next, |
| struct btrfs_root, root_list); |
| list_del(&reloc_root->root_list); |
| |
| if (btrfs_root_refs(&reloc_root->root_item) == 0) { |
| list_add_tail(&reloc_root->root_list, |
| &rc->reloc_roots); |
| continue; |
| } |
| |
| fs_root = read_fs_root(root->fs_info, |
| reloc_root->root_key.offset); |
| if (IS_ERR(fs_root)) { |
| err = PTR_ERR(fs_root); |
| goto out_free; |
| } |
| |
| err = __add_reloc_root(reloc_root); |
| BUG_ON(err < 0); /* -ENOMEM or logic error */ |
| fs_root->reloc_root = reloc_root; |
| } |
| |
| err = btrfs_commit_transaction(trans, rc->extent_root); |
| if (err) |
| goto out_free; |
| |
| merge_reloc_roots(rc); |
| |
| unset_reloc_control(rc); |
| |
| trans = btrfs_join_transaction(rc->extent_root); |
| if (IS_ERR(trans)) |
| err = PTR_ERR(trans); |
| else |
| err = btrfs_commit_transaction(trans, rc->extent_root); |
| out_free: |
| kfree(rc); |
| out: |
| if (!list_empty(&reloc_roots)) |
| free_reloc_roots(&reloc_roots); |
| |
| btrfs_free_path(path); |
| |
| if (err == 0) { |
| /* cleanup orphan inode in data relocation tree */ |
| fs_root = read_fs_root(root->fs_info, |
| BTRFS_DATA_RELOC_TREE_OBJECTID); |
| if (IS_ERR(fs_root)) |
| err = PTR_ERR(fs_root); |
| else |
| err = btrfs_orphan_cleanup(fs_root); |
| } |
| return err; |
| } |
| |
| /* |
| * helper to add ordered checksum for data relocation. |
| * |
| * cloning checksum properly handles the nodatasum extents. |
| * it also saves CPU time to re-calculate the checksum. |
| */ |
| int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len) |
| { |
| struct btrfs_ordered_sum *sums; |
| struct btrfs_ordered_extent *ordered; |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| int ret; |
| u64 disk_bytenr; |
| u64 new_bytenr; |
| LIST_HEAD(list); |
| |
| ordered = btrfs_lookup_ordered_extent(inode, file_pos); |
| BUG_ON(ordered->file_offset != file_pos || ordered->len != len); |
| |
| disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt; |
| ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr, |
| disk_bytenr + len - 1, &list, 0); |
| if (ret) |
| goto out; |
| |
| while (!list_empty(&list)) { |
| sums = list_entry(list.next, struct btrfs_ordered_sum, list); |
| list_del_init(&sums->list); |
| |
| /* |
| * We need to offset the new_bytenr based on where the csum is. |
| * We need to do this because we will read in entire prealloc |
| * extents but we may have written to say the middle of the |
| * prealloc extent, so we need to make sure the csum goes with |
| * the right disk offset. |
| * |
| * We can do this because the data reloc inode refers strictly |
| * to the on disk bytes, so we don't have to worry about |
| * disk_len vs real len like with real inodes since it's all |
| * disk length. |
| */ |
| new_bytenr = ordered->start + (sums->bytenr - disk_bytenr); |
| sums->bytenr = new_bytenr; |
| |
| btrfs_add_ordered_sum(inode, ordered, sums); |
| } |
| out: |
| btrfs_put_ordered_extent(ordered); |
| return ret; |
| } |
| |
| int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct extent_buffer *buf, |
| struct extent_buffer *cow) |
| { |
| struct reloc_control *rc; |
| struct backref_node *node; |
| int first_cow = 0; |
| int level; |
| int ret = 0; |
| |
| rc = root->fs_info->reloc_ctl; |
| if (!rc) |
| return 0; |
| |
| BUG_ON(rc->stage == UPDATE_DATA_PTRS && |
| root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID); |
| |
| level = btrfs_header_level(buf); |
| if (btrfs_header_generation(buf) <= |
| btrfs_root_last_snapshot(&root->root_item)) |
| first_cow = 1; |
| |
| if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID && |
| rc->create_reloc_tree) { |
| WARN_ON(!first_cow && level == 0); |
| |
| node = rc->backref_cache.path[level]; |
| BUG_ON(node->bytenr != buf->start && |
| node->new_bytenr != buf->start); |
| |
| drop_node_buffer(node); |
| extent_buffer_get(cow); |
| node->eb = cow; |
| node->new_bytenr = cow->start; |
| |
| if (!node->pending) { |
| list_move_tail(&node->list, |
| &rc->backref_cache.pending[level]); |
| node->pending = 1; |
| } |
| |
| if (first_cow) |
| __mark_block_processed(rc, node); |
| |
| if (first_cow && level > 0) |
| rc->nodes_relocated += buf->len; |
| } |
| |
| if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) |
| ret = replace_file_extents(trans, rc, root, cow); |
| return ret; |
| } |
| |
| /* |
| * called before creating snapshot. it calculates metadata reservation |
| * requried for relocating tree blocks in the snapshot |
| */ |
| void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans, |
| struct btrfs_pending_snapshot *pending, |
| u64 *bytes_to_reserve) |
| { |
| struct btrfs_root *root; |
| struct reloc_control *rc; |
| |
| root = pending->root; |
| if (!root->reloc_root) |
| return; |
| |
| rc = root->fs_info->reloc_ctl; |
| if (!rc->merge_reloc_tree) |
| return; |
| |
| root = root->reloc_root; |
| BUG_ON(btrfs_root_refs(&root->root_item) == 0); |
| /* |
| * relocation is in the stage of merging trees. the space |
| * used by merging a reloc tree is twice the size of |
| * relocated tree nodes in the worst case. half for cowing |
| * the reloc tree, half for cowing the fs tree. the space |
| * used by cowing the reloc tree will be freed after the |
| * tree is dropped. if we create snapshot, cowing the fs |
| * tree may use more space than it frees. so we need |
| * reserve extra space. |
| */ |
| *bytes_to_reserve += rc->nodes_relocated; |
| } |
| |
| /* |
| * called after snapshot is created. migrate block reservation |
| * and create reloc root for the newly created snapshot |
| */ |
| int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans, |
| struct btrfs_pending_snapshot *pending) |
| { |
| struct btrfs_root *root = pending->root; |
| struct btrfs_root *reloc_root; |
| struct btrfs_root *new_root; |
| struct reloc_control *rc; |
| int ret; |
| |
| if (!root->reloc_root) |
| return 0; |
| |
| rc = root->fs_info->reloc_ctl; |
| rc->merging_rsv_size += rc->nodes_relocated; |
| |
| if (rc->merge_reloc_tree) { |
| ret = btrfs_block_rsv_migrate(&pending->block_rsv, |
| rc->block_rsv, |
| rc->nodes_relocated); |
| if (ret) |
| return ret; |
| } |
| |
| new_root = pending->snap; |
| reloc_root = create_reloc_root(trans, root->reloc_root, |
| new_root->root_key.objectid); |
| if (IS_ERR(reloc_root)) |
| return PTR_ERR(reloc_root); |
| |
| ret = __add_reloc_root(reloc_root); |
| BUG_ON(ret < 0); |
| new_root->reloc_root = reloc_root; |
| |
| if (rc->create_reloc_tree) |
| ret = clone_backref_node(trans, rc, root, reloc_root); |
| return ret; |
| } |