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>

2 files changed, 3 insertions, 5 deletions

diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 592adf2e546e..3f3ff5ee8f9d 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -128,10 +128,9 @@ int ext4_sync_file(struct file *file, int datasync)
                     (journal->j_fs_dev != journal->j_dev) &&
                     (journal->j_flags & JBD2_BARRIER))
                         blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL,
-                                        NULL, BLKDEV_IFL_WAIT);
+                                        NULL);
                 ret = jbd2_log_wait_commit(journal, commit_tid);
         } else if (journal->j_flags & JBD2_BARRIER)
-                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
-                        BLKDEV_IFL_WAIT);
+                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
         return ret;
 }
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);