Btrfs: don't compress for a small write

[cascardo/linux.git] / fs / btrfs / inode.c

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 251db68..fdb8f44 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -394,6 +394,14 @@ static noinline int compress_file_range(struct inode *inode,
            (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
                btrfs_add_inode_defrag(NULL, inode);
 
+       /*
+        * skip compression for a small file range(<=blocksize) that
+        * isn't an inline extent, since it dosen't save disk space at all.
+        */
+       if ((end - start + 1) <= blocksize &&
+           (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
+               goto cleanup_and_bail_uncompressed;
+
        actual_end = min_t(u64, isize, end + 1);
 again:
        will_compress = 0;