Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits)
  xen-blkfront: disable barrier/flush write support
  Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c
  block: remove BLKDEV_IFL_WAIT
  aic7xxx_old: removed unused 'req' variable
  block: remove the BH_Eopnotsupp flag
  block: remove the BLKDEV_IFL_BARRIER flag
  block: remove the WRITE_BARRIER flag
  swap: do not send discards as barriers
  fat: do not send discards as barriers
  ext4: do not send discards as barriers
  jbd2: replace barriers with explicit flush / FUA usage
  jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
  jbd: replace barriers with explicit flush / FUA usage
  nilfs2: replace barriers with explicit flush / FUA usage
  reiserfs: replace barriers with explicit flush / FUA usage
  gfs2: replace barriers with explicit flush / FUA usage
  btrfs: replace barriers with explicit flush / FUA usage
  xfs: replace barriers with explicit flush / FUA usage
  block: pass gfp_mask and flags to sb_issue_discard
  dm: convey that all flushes are processed as empty
  ...

1 files changed, 21 insertions, 22 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 69b0a169e43d..31140d1259dc 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -506,9 +506,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 		int rw;
 		struct bio *bi;
 		mdk_rdev_t *rdev;
-		if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
-			rw = WRITE;
-		else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
+		if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
+			if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
+				rw = WRITE_FUA;
+			else
+				rw = WRITE;
+		} else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
 			rw = READ;
 		else
 			continue;
@@ -1031,6 +1034,8 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
 
 			while (wbi && wbi->bi_sector <
 				dev->sector + STRIPE_SECTORS) {
+				if (wbi->bi_rw & REQ_FUA)
+					set_bit(R5_WantFUA, &dev->flags);
 				tx = async_copy_data(1, wbi, dev->page,
 					dev->sector, tx);
 				wbi = r5_next_bio(wbi, dev->sector);
@@ -1048,15 +1053,22 @@ static void ops_complete_reconstruct(void *stripe_head_ref)
 	int pd_idx = sh->pd_idx;
 	int qd_idx = sh->qd_idx;
 	int i;
+	bool fua = false;
 
 	pr_debug("%s: stripe %llu\n", __func__,
 		(unsigned long long)sh->sector);
 
+	for (i = disks; i--; )
+		fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
+
 	for (i = disks; i--; ) {
 		struct r5dev *dev = &sh->dev[i];
 
-		if (dev->written || i == pd_idx || i == qd_idx)
+		if (dev->written || i == pd_idx || i == qd_idx) {
 			set_bit(R5_UPTODATE, &dev->flags);
+			if (fua)
+				set_bit(R5_WantFUA, &dev->flags);
+		}
 	}
 
 	if (sh->reconstruct_state == reconstruct_state_drain_run)
@@ -3281,7 +3293,7 @@ static void handle_stripe5(struct stripe_head *sh)
 
 	if (dec_preread_active) {
 		/* We delay this until after ops_run_io so that if make_request
-		 * is waiting on a barrier, it won't continue until the writes
+		 * is waiting on a flush, it won't continue until the writes
 		 * have actually been submitted.
 		 */
 		atomic_dec(&conf->preread_active_stripes);
@@ -3583,7 +3595,7 @@ static void handle_stripe6(struct stripe_head *sh)
 
 	if (dec_preread_active) {
 		/* We delay this until after ops_run_io so that if make_request
-		 * is waiting on a barrier, it won't continue until the writes
+		 * is waiting on a flush, it won't continue until the writes
 		 * have actually been submitted.
 		 */
 		atomic_dec(&conf->preread_active_stripes);
@@ -3978,14 +3990,8 @@ static int make_request(mddev_t *mddev, struct bio * bi)
 	const int rw = bio_data_dir(bi);
 	int remaining;
 
-	if (unlikely(bi->bi_rw & REQ_HARDBARRIER)) {
-		/* Drain all pending writes.  We only really need
-		 * to ensure they have been submitted, but this is
-		 * easier.
-		 */
-		mddev->pers->quiesce(mddev, 1);
-		mddev->pers->quiesce(mddev, 0);
-		md_barrier_request(mddev, bi);
+	if (unlikely(bi->bi_rw & REQ_FLUSH)) {
+		md_flush_request(mddev, bi);
 		return 0;
 	}
 
@@ -4103,7 +4109,7 @@ static int make_request(mddev_t *mddev, struct bio * bi)
 			finish_wait(&conf->wait_for_overlap, &w);
 			set_bit(STRIPE_HANDLE, &sh->state);
 			clear_bit(STRIPE_DELAYED, &sh->state);
-			if (mddev->barrier && 
+			if ((bi->bi_rw & REQ_SYNC) &&
 			    !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
 				atomic_inc(&conf->preread_active_stripes);
 			release_stripe(sh);
@@ -4126,13 +4132,6 @@ static int make_request(mddev_t *mddev, struct bio * bi)
 		bio_endio(bi, 0);
 	}
 
-	if (mddev->barrier) {
-		/* We need to wait for the stripes to all be handled.
-		 * So: wait for preread_active_stripes to drop to 0.
-		 */
-		wait_event(mddev->thread->wqueue,
-			   atomic_read(&conf->preread_active_stripes) == 0);
-	}
 	return 0;
 }