btrfs: add unlikely to critical error in btrfs_extend_item()

It's not expected to get a data size less than the leaf's free space,
which would lead to a leaf dump and BUG(), so tag the if statement's
expression as unlikely, hinting the compiler to potentially generate
better code.

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

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index e683f961742af2e832760deb46e6686fa74b183d..b5cf1b6f5adccfe1d2fb73126651e11b8c5baaab 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -4106,7 +4106,7 @@ void btrfs_extend_item(struct btrfs_trans_handle *trans,
        nritems = btrfs_header_nritems(leaf);
        data_end = leaf_data_end(leaf);
 
-       if (btrfs_leaf_free_space(leaf) < data_size) {
+       if (unlikely(btrfs_leaf_free_space(leaf) < data_size)) {
                btrfs_print_leaf(leaf);
                BUG();
        }