diff options
Diffstat (limited to 'fs/nilfs2/btree.c')
| -rw-r--r-- | fs/nilfs2/btree.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index ecdbae19a766..059f37137f9a 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -633,6 +633,44 @@ static int nilfs_btree_do_lookup_last(const struct nilfs_bmap *btree, return 0; } +/** + * nilfs_btree_get_next_key - get next valid key from btree path array + * @btree: bmap struct of btree + * @path: array of nilfs_btree_path struct + * @minlevel: start level + * @nextkey: place to store the next valid key + * + * Return Value: If a next key was found, 0 is returned. Otherwise, + * -ENOENT is returned. + */ +static int nilfs_btree_get_next_key(const struct nilfs_bmap *btree, + const struct nilfs_btree_path *path, + int minlevel, __u64 *nextkey) +{ + struct nilfs_btree_node *node; + int maxlevel = nilfs_btree_height(btree) - 1; + int index, next_adj, level; + + /* Next index is already set to bp_index for leaf nodes. */ + next_adj = 0; + for (level = minlevel; level <= maxlevel; level++) { + if (level == maxlevel) + node = nilfs_btree_get_root(btree); + else + node = nilfs_btree_get_nonroot_node(path, level); + + index = path[level].bp_index + next_adj; + if (index < nilfs_btree_node_get_nchildren(node)) { + /* Next key is in this node */ + *nextkey = nilfs_btree_node_get_key(node, index); + return 0; + } + /* For non-leaf nodes, next index is stored at bp_index + 1. */ + next_adj = 1; + } + return -ENOENT; +} + static int nilfs_btree_lookup(const struct nilfs_bmap *btree, __u64 key, int level, __u64 *ptrp) { @@ -1563,6 +1601,27 @@ out: return ret; } +static int nilfs_btree_seek_key(const struct nilfs_bmap *btree, __u64 start, + __u64 *keyp) +{ + struct nilfs_btree_path *path; + const int minlevel = NILFS_BTREE_LEVEL_NODE_MIN; + int ret; + + path = nilfs_btree_alloc_path(); + if (!path) + return -ENOMEM; + + ret = nilfs_btree_do_lookup(btree, path, start, NULL, minlevel, 0); + if (!ret) + *keyp = start; + else if (ret == -ENOENT) + ret = nilfs_btree_get_next_key(btree, path, minlevel, keyp); + + nilfs_btree_free_path(path); + return ret; +} + static int nilfs_btree_last_key(const struct nilfs_bmap *btree, __u64 *keyp) { struct nilfs_btree_path *path; @@ -2298,7 +2357,9 @@ static const struct nilfs_bmap_operations nilfs_btree_ops = { .bop_assign = nilfs_btree_assign, .bop_mark = nilfs_btree_mark, + .bop_seek_key = nilfs_btree_seek_key, .bop_last_key = nilfs_btree_last_key, + .bop_check_insert = NULL, .bop_check_delete = nilfs_btree_check_delete, .bop_gather_data = nilfs_btree_gather_data, @@ -2318,7 +2379,9 @@ static const struct nilfs_bmap_operations nilfs_btree_ops_gc = { .bop_assign = nilfs_btree_assign_gc, .bop_mark = NULL, + .bop_seek_key = NULL, .bop_last_key = NULL, + .bop_check_insert = NULL, .bop_check_delete = NULL, .bop_gather_data = NULL, |