block: kill off REQ_UNPLUG

With the plugging now being explicitly controlled by the
submitter, callers need not pass down unplugging hints
to the block layer. If they want to unplug, it's because they
manually plugged on their own - in which case, they should just
unplug at will.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

8 files changed, 9 insertions, 21 deletions

diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index 2096628d6e6..aca302492ff 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -80,7 +80,7 @@ static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
 
 	if ((rw & WRITE) && !test_bit(MD_NO_FUA, &mdev->flags))
 		rw |= REQ_FUA;
-	rw |= REQ_UNPLUG | REQ_SYNC;
+	rw |= REQ_SYNC;
 
 	bio = bio_alloc(GFP_NOIO, 1);
 	bio->bi_bdev = bdev->md_bdev;
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 0b5718e1958..b0bd27dfc1e 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -377,7 +377,7 @@ union p_header {
 #define DP_HARDBARRIER	      1 /* depricated */
 #define DP_RW_SYNC	      2 /* equals REQ_SYNC    */
 #define DP_MAY_SET_IN_SYNC    4
-#define DP_UNPLUG             8 /* equals REQ_UNPLUG  */
+#define DP_UNPLUG             8 /* not used anymore   */
 #define DP_FUA               16 /* equals REQ_FUA     */
 #define DP_FLUSH             32 /* equals REQ_FLUSH   */
 #define DP_DISCARD           64 /* equals REQ_DISCARD */
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 6049cb85310..8a43ce0edee 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2477,12 +2477,11 @@ static u32 bio_flags_to_wire(struct drbd_conf *mdev, unsigned long bi_rw)
 {
 	if (mdev->agreed_pro_version >= 95)
 		return  (bi_rw & REQ_SYNC ? DP_RW_SYNC : 0) |
-			(bi_rw & REQ_UNPLUG ? DP_UNPLUG : 0) |
 			(bi_rw & REQ_FUA ? DP_FUA : 0) |
 			(bi_rw & REQ_FLUSH ? DP_FLUSH : 0) |
 			(bi_rw & REQ_DISCARD ? DP_DISCARD : 0);
 	else
-		return bi_rw & (REQ_SYNC | REQ_UNPLUG) ? DP_RW_SYNC : 0;
+		return bi_rw & REQ_SYNC ? DP_RW_SYNC : 0;
 }
 
 /* Used to send write requests
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 84132f8bf8a..8e68be939de 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1100,8 +1100,6 @@ next_bio:
 	/* > e->sector, unless this is the first bio */
 	bio->bi_sector = sector;
 	bio->bi_bdev = mdev->ldev->backing_bdev;
-	/* we special case some flags in the multi-bio case, see below
-	 * (REQ_UNPLUG) */
 	bio->bi_rw = rw;
 	bio->bi_private = e;
 	bio->bi_end_io = drbd_endio_sec;
@@ -1130,10 +1128,6 @@ next_bio:
 		bios = bios->bi_next;
 		bio->bi_next = NULL;
 
-		/* strip off REQ_UNPLUG unless it is the last bio */
-		if (bios)
-			bio->bi_rw &= ~REQ_UNPLUG;
-
 		drbd_generic_make_request(mdev, fault_type, bio);
 	} while (bios);
 	return 0;
@@ -1621,12 +1615,11 @@ static unsigned long write_flags_to_bio(struct drbd_conf *mdev, u32 dpf)
 {
 	if (mdev->agreed_pro_version >= 95)
 		return  (dpf & DP_RW_SYNC ? REQ_SYNC : 0) |
-			(dpf & DP_UNPLUG ? REQ_UNPLUG : 0) |
 			(dpf & DP_FUA ? REQ_FUA : 0) |
 			(dpf & DP_FLUSH ? REQ_FUA : 0) |
 			(dpf & DP_DISCARD ? REQ_DISCARD : 0);
 	else
-		return dpf & DP_RW_SYNC ? (REQ_SYNC | REQ_UNPLUG) : 0;
+		return dpf & DP_RW_SYNC ? REQ_SYNC : 0;
 }
 
 /* mirrored write */
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 54bfc274b39..ca203cb23f3 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -347,7 +347,7 @@ static void write_page(struct bitmap *bitmap, struct page *page, int wait)
 			atomic_inc(&bitmap->pending_writes);
 			set_buffer_locked(bh);
 			set_buffer_mapped(bh);
-			submit_bh(WRITE | REQ_UNPLUG | REQ_SYNC, bh);
+			submit_bh(WRITE | REQ_SYNC, bh);
 			bh = bh->b_this_page;
 		}
 
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 136d4f71a11..76a5af00a26 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -352,7 +352,7 @@ static void dispatch_io(int rw, unsigned int num_regions,
 	BUG_ON(num_regions > DM_IO_MAX_REGIONS);
 
 	if (sync)
-		rw |= REQ_SYNC | REQ_UNPLUG;
+		rw |= REQ_SYNC;
 
 	/*
 	 * For multiple regions we need to be careful to rewind
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index 400cf35094a..1bb73a13ca4 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -356,11 +356,8 @@ static int run_io_job(struct kcopyd_job *job)
 
 	if (job->rw == READ)
 		r = dm_io(&io_req, 1, &job->source, NULL);
-	else {
-		if (job->num_dests > 1)
-			io_req.bi_rw |= REQ_UNPLUG;
+	else
 		r = dm_io(&io_req, job->num_dests, job->dests, NULL);
-	}
 
 	return r;
 }
diff --git a/drivers/md/md.c b/drivers/md/md.c
index ca0d79c264b..28f9c1ee4e3 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -777,8 +777,7 @@ void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
 	bio->bi_end_io = super_written;
 
 	atomic_inc(&mddev->pending_writes);
-	submit_bio(REQ_WRITE | REQ_SYNC | REQ_UNPLUG | REQ_FLUSH | REQ_FUA,
-		   bio);
+	submit_bio(REQ_WRITE | REQ_SYNC | REQ_FLUSH | REQ_FUA, bio);
 }
 
 void md_super_wait(mddev_t *mddev)
@@ -806,7 +805,7 @@ int sync_page_io(mdk_rdev_t *rdev, sector_t sector, int size,
 	struct completion event;
 	int ret;
 
-	rw |= REQ_SYNC | REQ_UNPLUG;
+	rw |= REQ_SYNC;
 
 	bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
 		rdev->meta_bdev : rdev->bdev;