Btrfs: fix extent map leak during fallocate error path

If the call to btrfs_qgroup_reserve_data() failed, we were leaking an
extent map structure. The failure can happen either due to an -ENOMEM
condition or, when quotas are enabled, due to -EDQUOT for example.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 48dfb8e4baf20276e8ac801ae84eb3a9e8583e4e..56304c400db57eb828730e5b99ed3f378b708331 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2856,8 +2856,10 @@ static long btrfs_fallocate(struct file *file, int mode,
                        }
                        ret = btrfs_qgroup_reserve_data(inode, cur_offset,
                                        last_byte - cur_offset);
-                       if (ret < 0)
+                       if (ret < 0) {
+                               free_extent_map(em);
                                break;
+                       }
                } else {
                        /*
                         * Do not need to reserve unwritten extent for this