ext4: let ext4_group_add_blocks() handle 0 blocks quickly

If ext4_group_add_blocks() is called with 0 block, make it return 0
without doing any extra work.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index dbe429567eb3..b6ef4da39ce3 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4691,6 +4691,9 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
 
         ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
 
+        if (count == 0)
+                return 0;
+
         ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
         /*
          * Check to see if we are freeing blocks across a group