diff options
| -rw-r--r-- | fs/btrfs/ctree.c | 37 | ||||
| -rw-r--r-- | fs/btrfs/ctree.h | 29 |
2 files changed, 66 insertions, 0 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index a795e89de3f1..6ae1bf7ab27f 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2298,6 +2298,43 @@ int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key, return ret; } +/** + * Search for a valid slot for the given path. + * + * @root: The root node of the tree. + * @key: Will contain a valid item if found. + * @path: The starting point to validate the slot. + * + * Return: 0 if the item is valid + * 1 if not found + * <0 if error. + */ +int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key, + struct btrfs_path *path) +{ + while (1) { + int ret; + const int slot = path->slots[0]; + const struct extent_buffer *leaf = path->nodes[0]; + + /* This is where we start walking the path. */ + if (slot >= btrfs_header_nritems(leaf)) { + /* + * If we've reached the last slot in this leaf we need + * to go to the next leaf and reset the path. + */ + ret = btrfs_next_leaf(root, path); + if (ret) + return ret; + continue; + } + /* Store the found, valid item in @key. */ + btrfs_item_key_to_cpu(leaf, key, slot); + break; + } + return 0; +} + /* * adjust the pointers going up the tree, starting at level * making sure the right key of each node is points to 'key'. diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 077c95e9baa5..1c50e051641d 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3039,6 +3039,35 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key, struct btrfs_path *path); +int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key, + struct btrfs_path *path); + +/* + * Search in @root for a given @key, and store the slot found in @found_key. + * + * @root: The root node of the tree. + * @key: The key we are looking for. + * @found_key: Will hold the found item. + * @path: Holds the current slot/leaf. + * @iter_ret: Contains the value returned from btrfs_search_slot or + * btrfs_get_next_valid_item, whichever was executed last. + * + * The @iter_ret is an output variable that will contain the return value of + * btrfs_search_slot, if it encountered an error, or the value returned from + * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid + * slot was found, 1 if there were no more leaves, and <0 if there was an error. + * + * It's recommended to use a separate variable for iter_ret and then use it to + * set the function return value so there's no confusion of the 0/1/errno + * values stemming from btrfs_search_slot. + */ +#define btrfs_for_each_slot(root, key, found_key, path, iter_ret) \ + for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0); \ + (iter_ret) >= 0 && \ + (iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \ + (path)->slots[0]++ \ + ) + static inline int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *p, u64 time_seq) { |