diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/btrfs/ctree.h | 9 | ||||
-rw-r--r-- | fs/btrfs/extent-tree.c | 202 | ||||
-rw-r--r-- | fs/btrfs/inode.c | 6 | ||||
-rw-r--r-- | fs/btrfs/transaction.c | 16 | ||||
-rw-r--r-- | fs/btrfs/transaction.h | 5 |
5 files changed, 142 insertions, 96 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 5517dfc..8342208 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -617,7 +617,7 @@ struct btrfs_leaf_ref_tree { * in ram representation of the tree. extent_root is used for all allocations * and for the extent tree extent_root root. */ -struct dirty_root; +struct btrfs_dirty_root; struct btrfs_root { struct extent_buffer *node; @@ -627,7 +627,7 @@ struct btrfs_root { struct extent_buffer *commit_root; struct btrfs_leaf_ref_tree *ref_tree; struct btrfs_leaf_ref_tree ref_tree_struct; - struct dirty_root *dirty_root; + struct btrfs_dirty_root *dirty_root; struct btrfs_root_item root_item; struct btrfs_key root_key; @@ -1399,9 +1399,8 @@ static inline struct dentry *fdentry(struct file *file) { } /* extent-tree.c */ -u32 btrfs_count_snapshots_in_path(struct btrfs_root *root, - struct btrfs_path *count_path, - u64 expected_owner, u64 first_extent); +int btrfs_cross_ref_exists(struct btrfs_root *root, + struct btrfs_key *key, u64 bytenr); int btrfs_extent_post_op(struct btrfs_trans_handle *trans, struct btrfs_root *root); int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 6290cf4..fe1ddbd 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -802,70 +802,57 @@ out: return 0; } -u32 btrfs_count_snapshots_in_path(struct btrfs_root *root, - struct btrfs_path *count_path, - u64 expected_owner, - u64 first_extent) + +static int get_reference_status(struct btrfs_root *root, u64 bytenr, + u64 parent_gen, u64 ref_objectid, + u64 *min_generation, u32 *ref_count) { struct btrfs_root *extent_root = root->fs_info->extent_root; struct btrfs_path *path; - u64 bytenr; - u64 found_objectid; - u64 found_owner; + struct extent_buffer *leaf; + struct btrfs_extent_ref *ref_item; + struct btrfs_key key; + struct btrfs_key found_key; u64 root_objectid = root->root_key.objectid; - u32 total_count = 0; - u32 extent_refs; - u32 cur_count; + u64 ref_generation; u32 nritems; int ret; - struct btrfs_key key; - struct btrfs_key found_key; - struct extent_buffer *l; - struct btrfs_extent_item *item; - struct btrfs_extent_ref *ref_item; - int level = -1; - /* FIXME, needs locking */ - BUG(); - - mutex_lock(&root->fs_info->alloc_mutex); - path = btrfs_alloc_path(); -again: - if (level == -1) - bytenr = first_extent; - else - bytenr = count_path->nodes[level]->start; - - cur_count = 0; key.objectid = bytenr; key.offset = 0; + key.type = BTRFS_EXTENT_ITEM_KEY; - btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); + path = btrfs_alloc_path(); + mutex_lock(&root->fs_info->alloc_mutex); ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) goto out; BUG_ON(ret == 0); - l = path->nodes[0]; - btrfs_item_key_to_cpu(l, &found_key, path->slots[0]); + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != bytenr || found_key.type != BTRFS_EXTENT_ITEM_KEY) { + ret = 1; goto out; } - item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); - extent_refs = btrfs_extent_refs(l, item); + *ref_count = 0; + *min_generation = (u64)-1; + while (1) { - l = path->nodes[0]; - nritems = btrfs_header_nritems(l); + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(extent_root, path); + if (ret < 0) + goto out; if (ret == 0) continue; break; } - btrfs_item_key_to_cpu(l, &found_key, path->slots[0]); + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != bytenr) break; @@ -874,57 +861,120 @@ again: continue; } - cur_count++; - ref_item = btrfs_item_ptr(l, path->slots[0], + ref_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); - found_objectid = btrfs_ref_root(l, ref_item); - - if (found_objectid != root_objectid) { - total_count = 2; - goto out; - } - if (level == -1) { - found_owner = btrfs_ref_objectid(l, ref_item); - if (found_owner != expected_owner) { - total_count = 2; - goto out; - } - /* - * nasty. we don't count a reference held by - * the running transaction. This allows nodatacow - * to avoid cow most of the time - */ - if (found_owner >= BTRFS_FIRST_FREE_OBJECTID && - btrfs_ref_generation(l, ref_item) == - root->fs_info->generation) { - extent_refs--; - } + ref_generation = btrfs_ref_generation(leaf, ref_item); + /* + * For (parent_gen > 0 && parent_gen > ref_gen): + * + * we reach here through the oldest root, therefore + * all other reference from same snapshot should have + * a larger generation. + */ + if ((root_objectid != btrfs_ref_root(leaf, ref_item)) || + (parent_gen > 0 && parent_gen > ref_generation) || + (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID && + ref_objectid != btrfs_ref_objectid(leaf, ref_item))) { + if (ref_count) + *ref_count = 2; + break; } - total_count = 1; + + *ref_count = 1; + if (*min_generation > ref_generation) + *min_generation = ref_generation; + path->slots[0]++; } - /* - * if there is more than one reference against a data extent, - * we have to assume the other ref is another snapshot - */ - if (level == -1 && extent_refs > 1) { - total_count = 2; + ret = 0; +out: + mutex_unlock(&root->fs_info->alloc_mutex); + btrfs_free_path(path); + return ret; +} + +int btrfs_cross_ref_exists(struct btrfs_root *root, + struct btrfs_key *key, u64 bytenr) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *old_root; + struct btrfs_path *path = NULL; + struct extent_buffer *eb; + struct btrfs_file_extent_item *item; + u64 ref_generation; + u64 min_generation; + u64 extent_start; + u32 ref_count; + int level; + int ret; + + BUG_ON(key->type != BTRFS_EXTENT_DATA_KEY); + ret = get_reference_status(root, bytenr, 0, key->objectid, + &min_generation, &ref_count); + if (ret) + return ret; + + if (ref_count != 1) + return 1; + + trans = btrfs_start_transaction(root, 0); + old_root = root->dirty_root->root; + ref_generation = old_root->root_key.offset; + + /* all references are created in running transaction */ + if (min_generation > ref_generation) { + ret = 0; goto out; } - if (cur_count == 0) { - total_count = 0; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; goto out; } - if (level >= 0 && root->node == count_path->nodes[level]) + + path->skip_locking = 1; + /* if no item found, the extent is referenced by other snapshot */ + ret = btrfs_search_slot(NULL, old_root, key, path, 0, 0); + if (ret) goto out; - level++; - btrfs_release_path(root, path); - goto again; + eb = path->nodes[0]; + item = btrfs_item_ptr(eb, path->slots[0], + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(eb, item) != BTRFS_FILE_EXTENT_REG || + btrfs_file_extent_disk_bytenr(eb, item) != bytenr) { + ret = 1; + goto out; + } + + for (level = BTRFS_MAX_LEVEL - 1; level >= -1; level--) { + if (level >= 0) { + eb = path->nodes[level]; + if (!eb) + continue; + extent_start = eb->start; + } else + extent_start = bytenr; + + ret = get_reference_status(root, extent_start, ref_generation, + 0, &min_generation, &ref_count); + if (ret) + goto out; + + if (ref_count != 1) { + ret = 1; + goto out; + } + if (level >= 0) + ref_generation = btrfs_header_generation(eb); + } + ret = 0; out: - btrfs_free_path(path); - mutex_unlock(&root->fs_info->alloc_mutex); - return total_count; + if (path) + btrfs_free_path(path); + btrfs_end_transaction(trans, root); + return ret; } int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 7c87f86..3aa82ce 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -249,11 +249,8 @@ again: if (bytenr == 0) goto not_found; - if (btrfs_count_snapshots_in_path(root, path, inode->i_ino, - bytenr) != 1) { + if (btrfs_cross_ref_exists(root, &found_key, bytenr)) goto not_found; - } - /* * we may be called by the resizer, make sure we're inside * the limits of the FS @@ -277,6 +274,7 @@ loop: goto again; not_found: + btrfs_release_path(root, path); cow_file_range(inode, start, end); start = end + 1; goto loop; diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index b8be670..216f315 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -32,12 +32,6 @@ extern struct kmem_cache *btrfs_transaction_cachep; #define BTRFS_ROOT_TRANS_TAG 0 -struct dirty_root { - struct list_head list; - struct btrfs_root *root; - struct btrfs_root *latest_root; -}; - static noinline void put_transaction(struct btrfs_transaction *transaction) { WARN_ON(transaction->use_count == 0); @@ -91,7 +85,7 @@ static noinline int join_transaction(struct btrfs_root *root) static noinline int record_root_in_trans(struct btrfs_root *root) { - struct dirty_root *dirty; + struct btrfs_dirty_root *dirty; u64 running_trans_id = root->fs_info->running_transaction->transid; if (root->ref_cows && root->last_trans < running_trans_id) { WARN_ON(root == root->fs_info->extent_root); @@ -372,7 +366,7 @@ int btrfs_add_dead_root(struct btrfs_root *root, struct btrfs_root *latest, struct list_head *dead_list) { - struct dirty_root *dirty; + struct btrfs_dirty_root *dirty; dirty = kmalloc(sizeof(*dirty), GFP_NOFS); if (!dirty) @@ -387,7 +381,7 @@ static noinline int add_dirty_roots(struct btrfs_trans_handle *trans, struct radix_tree_root *radix, struct list_head *list) { - struct dirty_root *dirty; + struct btrfs_dirty_root *dirty; struct btrfs_root *gang[8]; struct btrfs_root *root; int i; @@ -498,7 +492,7 @@ int btrfs_defrag_root(struct btrfs_root *root, int cacheonly) static noinline int drop_dirty_roots(struct btrfs_root *tree_root, struct list_head *list) { - struct dirty_root *dirty; + struct btrfs_dirty_root *dirty; struct btrfs_trans_handle *trans; unsigned long nr; u64 num_bytes; @@ -509,7 +503,7 @@ static noinline int drop_dirty_roots(struct btrfs_root *tree_root, while(!list_empty(list)) { struct btrfs_root *root; - dirty = list_entry(list->prev, struct dirty_root, list); + dirty = list_entry(list->prev, struct btrfs_dirty_root, list); list_del_init(&dirty->list); num_bytes = btrfs_root_used(&dirty->root->root_item); diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index df2ca2a..f5adb23 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -52,6 +52,11 @@ struct btrfs_pending_snapshot { struct list_head list; }; +struct btrfs_dirty_root { + struct list_head list; + struct btrfs_root *root; + struct btrfs_root *latest_root; +}; static inline void btrfs_set_trans_block_group(struct btrfs_trans_handle *trans, struct inode *inode) |