diff options
Diffstat (limited to 'fs/btrfs/dir-item.c')
| -rw-r--r-- | fs/btrfs/dir-item.c | 122 |
1 files changed, 75 insertions, 47 deletions
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c index 863367c2c620..98c6faa8ce15 100644 --- a/fs/btrfs/dir-item.c +++ b/fs/btrfs/dir-item.c @@ -171,10 +171,40 @@ out_free: return 0; } +static struct btrfs_dir_item *btrfs_lookup_match_dir( + struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_path *path, + struct btrfs_key *key, const char *name, + int name_len, int mod) +{ + const int ins_len = (mod < 0 ? -1 : 0); + const int cow = (mod != 0); + int ret; + + ret = btrfs_search_slot(trans, root, key, path, ins_len, cow); + if (ret < 0) + return ERR_PTR(ret); + if (ret > 0) + return ERR_PTR(-ENOENT); + + return btrfs_match_dir_item_name(root->fs_info, path, name, name_len); +} + /* - * lookup a directory item based on name. 'dir' is the objectid - * we're searching in, and 'mod' tells us if you plan on deleting the - * item (use mod < 0) or changing the options (use mod > 0) + * Lookup for a directory item by name. + * + * @trans: The transaction handle to use. Can be NULL if @mod is 0. + * @root: The root of the target tree. + * @path: Path to use for the search. + * @dir: The inode number (objectid) of the directory. + * @name: The name associated to the directory entry we are looking for. + * @name_len: The length of the name. + * @mod: Used to indicate if the tree search is meant for a read only + * lookup, for a modification lookup or for a deletion lookup, so + * its value should be 0, 1 or -1, respectively. + * + * Returns: NULL if the dir item does not exists, an error pointer if an error + * happened, or a pointer to a dir item if a dir item exists for the given name. */ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, @@ -182,23 +212,18 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, const char *name, int name_len, int mod) { - int ret; struct btrfs_key key; - int ins_len = mod < 0 ? -1 : 0; - int cow = mod != 0; + struct btrfs_dir_item *di; key.objectid = dir; key.type = BTRFS_DIR_ITEM_KEY; - key.offset = btrfs_name_hash(name, name_len); - ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); - if (ret < 0) - return ERR_PTR(ret); - if (ret > 0) + di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod); + if (IS_ERR(di) && PTR_ERR(di) == -ENOENT) return NULL; - return btrfs_match_dir_item_name(root->fs_info, path, name, name_len); + return di; } int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir, @@ -212,7 +237,6 @@ int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir, int slot; struct btrfs_path *path; - path = btrfs_alloc_path(); if (!path) return -ENOMEM; @@ -221,20 +245,20 @@ int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir, key.type = BTRFS_DIR_ITEM_KEY; key.offset = btrfs_name_hash(name, name_len); - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); - - /* return back any errors */ - if (ret < 0) - goto out; + di = btrfs_lookup_match_dir(NULL, root, path, &key, name, name_len, 0); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + /* Nothing found, we're safe */ + if (ret == -ENOENT) { + ret = 0; + goto out; + } - /* nothing found, we're safe */ - if (ret > 0) { - ret = 0; - goto out; + if (ret < 0) + goto out; } /* we found an item, look for our name in the item */ - di = btrfs_match_dir_item_name(root->fs_info, path, name, name_len); if (di) { /* our exact name was found */ ret = -EEXIST; @@ -261,35 +285,42 @@ out: } /* - * lookup a directory item based on index. 'dir' is the objectid - * we're searching in, and 'mod' tells us if you plan on deleting the - * item (use mod < 0) or changing the options (use mod > 0) + * Lookup for a directory index item by name and index number. + * + * @trans: The transaction handle to use. Can be NULL if @mod is 0. + * @root: The root of the target tree. + * @path: Path to use for the search. + * @dir: The inode number (objectid) of the directory. + * @index: The index number. + * @name: The name associated to the directory entry we are looking for. + * @name_len: The length of the name. + * @mod: Used to indicate if the tree search is meant for a read only + * lookup, for a modification lookup or for a deletion lookup, so + * its value should be 0, 1 or -1, respectively. * - * The name is used to make sure the index really points to the name you were - * looking for. + * Returns: NULL if the dir index item does not exists, an error pointer if an + * error happened, or a pointer to a dir item if the dir index item exists and + * matches the criteria (name and index number). */ struct btrfs_dir_item * btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 dir, - u64 objectid, const char *name, int name_len, + u64 index, const char *name, int name_len, int mod) { - int ret; + struct btrfs_dir_item *di; struct btrfs_key key; - int ins_len = mod < 0 ? -1 : 0; - int cow = mod != 0; key.objectid = dir; key.type = BTRFS_DIR_INDEX_KEY; - key.offset = objectid; + key.offset = index; - ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); - if (ret < 0) - return ERR_PTR(ret); - if (ret > 0) - return ERR_PTR(-ENOENT); - return btrfs_match_dir_item_name(root->fs_info, path, name, name_len); + di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod); + if (di == ERR_PTR(-ENOENT)) + return NULL; + + return di; } struct btrfs_dir_item * @@ -346,21 +377,18 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans, const char *name, u16 name_len, int mod) { - int ret; struct btrfs_key key; - int ins_len = mod < 0 ? -1 : 0; - int cow = mod != 0; + struct btrfs_dir_item *di; key.objectid = dir; key.type = BTRFS_XATTR_ITEM_KEY; key.offset = btrfs_name_hash(name, name_len); - ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); - if (ret < 0) - return ERR_PTR(ret); - if (ret > 0) + + di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod); + if (IS_ERR(di) && PTR_ERR(di) == -ENOENT) return NULL; - return btrfs_match_dir_item_name(root->fs_info, path, name, name_len); + return di; } /* |