block: remove BLKDEV_IFL_WAIT

All the blkdev_issue_* helpers can only sanely be used for synchronous
caller.  To issue cache flushes or barriers asynchronously the caller needs
to set up a bio by itself with a completion callback to move the asynchronous
state machine ahead.  So drop the BLKDEV_IFL_WAIT flag that is always
specified when calling blkdev_issue_* and also remove the now unused flags
argument to blkdev_issue_flush and blkdev_issue_zeroout.  For
blkdev_issue_discard we need to keep it for the secure discard flag, which
gains a more descriptive name and loses the bitops vs flag confusion.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index a22bfef3da95..19aa0d44d822 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2566,8 +2566,7 @@ static inline void ext4_issue_discard(struct super_block *sb,
         discard_block = block + ext4_group_first_block_no(sb, block_group);
         trace_ext4_discard_blocks(sb,
                         (unsigned long long) discard_block, count);
-        ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS,
-                               BLKDEV_IFL_WAIT);
+        ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
         if (ret == EOPNOTSUPP) {
                 ext4_warning(sb, "discard not supported, disabling");
                 clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);