nilfs2: add bmap function to seek a valid key
Add a new bmap function, nilfs_bmap_seek_key(), which seeks a valid
entry and returns its key starting from a given key. This function
can be used to skip hole blocks efficiently.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nilfs2/direct.c b/fs/nilfs2/direct.c
index 82f4865..ebf89fd 100644
--- a/fs/nilfs2/direct.c
+++ b/fs/nilfs2/direct.c
@@ -173,6 +173,21 @@
return ret;
}
+static int nilfs_direct_seek_key(const struct nilfs_bmap *direct, __u64 start,
+ __u64 *keyp)
+{
+ __u64 key;
+
+ for (key = start; key <= NILFS_DIRECT_KEY_MAX; key++) {
+ if (nilfs_direct_get_ptr(direct, key) !=
+ NILFS_BMAP_INVALID_PTR) {
+ *keyp = key;
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
static int nilfs_direct_last_key(const struct nilfs_bmap *direct, __u64 *keyp)
{
__u64 key, lastkey;
@@ -355,7 +370,9 @@
.bop_assign = nilfs_direct_assign,
.bop_mark = NULL,
+ .bop_seek_key = nilfs_direct_seek_key,
.bop_last_key = nilfs_direct_last_key,
+
.bop_check_insert = nilfs_direct_check_insert,
.bop_check_delete = NULL,
.bop_gather_data = nilfs_direct_gather_data,