diff options
Diffstat (limited to 'fs/btrfs/dir-item.c')
| -rw-r--r-- | fs/btrfs/dir-item.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c index e4f30090d64..5040b71f190 100644 --- a/fs/btrfs/dir-item.c +++ b/fs/btrfs/dir-item.c @@ -21,6 +21,14 @@ #include "hash.h" #include "transaction.h" +/* + * insert a name into a directory, doing overflow properly if there is a hash + * collision. data_size indicates how big the item inserted should be. On + * success a struct btrfs_dir_item pointer is returned, otherwise it is + * an ERR_PTR. + * + * The name is not copied into the dir item, you have to do that yourself. + */ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle *trans, struct btrfs_root *root, @@ -55,6 +63,10 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle return (struct btrfs_dir_item *)ptr; } +/* + * xattrs work a lot like directories, this inserts an xattr item + * into the tree + */ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, u16 name_len, const void *data, u16 data_len, @@ -109,6 +121,13 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans, return ret; } +/* + * insert a directory item in the tree, doing all the magic for + * both indexes. 'dir' indicates which objectid to insert it into, + * 'location' is the key to stuff into the directory item, 'type' is the + * type of the inode we're pointing to, and 'index' is the sequence number + * to use for the second index (if one is created). + */ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, int name_len, u64 dir, struct btrfs_key *location, u8 type, u64 index) @@ -184,6 +203,11 @@ out: return 0; } +/* + * 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) + */ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 dir, @@ -222,6 +246,14 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, return btrfs_match_dir_item_name(root, path, name, name_len); } +/* + * 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) + * + * The name is used to make sure the index really points to the name you were + * looking for. + */ struct btrfs_dir_item * btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, @@ -282,6 +314,11 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans, return btrfs_match_dir_item_name(root, path, name, name_len); } +/* + * helper function to look at the directory item pointed to by 'path' + * this walks through all the entries in a dir item and finds one + * for a specific name. + */ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root, struct btrfs_path *path, const char *name, int name_len) @@ -313,6 +350,10 @@ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root, return NULL; } +/* + * given a pointer into a directory item, delete it. This + * handles items that have more than one entry in them. + */ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, |