ext4: do not send discards as barriers

ext4 already uses synchronous discards, no need to add I/O barriers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index df44b345f6623a2cdc753ea32a1a3b8a6808b8f7..a22bfef3da95a644c4331950a8a97a3b979c3981 100644 (file)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2567,7 +2567,7 @@ static inline void ext4_issue_discard(struct super_block *sb,
        trace_ext4_discard_blocks(sb,
                        (unsigned long long) discard_block, count);
        ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS,
-                              BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+                              BLKDEV_IFL_WAIT);
        if (ret == EOPNOTSUPP) {
                ext4_warning(sb, "discard not supported, disabling");
                clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);