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, 11 insertions, 14 deletions

diff --git a/block/blk-flush.c b/block/blk-flush.c
index 62b7df9bca9d..54b123d6563e 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -205,7 +205,6 @@ static void bio_end_flush(struct bio *bio, int err)
  * @bdev:       blockdev to issue flush for
  * @gfp_mask:   memory allocation flags (for bio_alloc)
  * @error_sector:       error sector
- * @flags:      BLKDEV_IFL_* flags to control behaviour
  *
  * Description:
  *    Issue a flush for the block device in question. Caller can supply
@@ -214,7 +213,7 @@ static void bio_end_flush(struct bio *bio, int err)
  *    request was pushed in some internal queue for later handling.
  */
 int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
-                sector_t *error_sector, unsigned long flags)
+                sector_t *error_sector)
 {
         DECLARE_COMPLETION_ONSTACK(wait);
         struct request_queue *q;
@@ -240,21 +239,19 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
         bio = bio_alloc(gfp_mask, 0);
         bio->bi_end_io = bio_end_flush;
         bio->bi_bdev = bdev;
-        if (test_bit(BLKDEV_WAIT, &flags))
-                bio->bi_private = &wait;
+        bio->bi_private = &wait;
 
         bio_get(bio);
         submit_bio(WRITE_FLUSH, bio);
-        if (test_bit(BLKDEV_WAIT, &flags)) {
-                wait_for_completion(&wait);
-                /*
-                 * The driver must store the error location in ->bi_sector, if
-                 * it supports it. For non-stacked drivers, this should be
-                 * copied from blk_rq_pos(rq).
-                 */
-                if (error_sector)
-                        *error_sector = bio->bi_sector;
-        }
+        wait_for_completion(&wait);
+
+        /*
+         * The driver must store the error location in ->bi_sector, if
+         * it supports it. For non-stacked drivers, this should be
+         * copied from blk_rq_pos(rq).
+         */
+        if (error_sector)
+               *error_sector = bio->bi_sector;
 
         if (!bio_flagged(bio, BIO_UPTODATE))
                 ret = -EIO;