Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits)
  block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n
  xen-blkfront: fix missing out label
  blkdev: fix blkdev_issue_zeroout return value
  block: update request stacking methods to support discards
  block: fix missing export of blk_types.h
  writeback: fix bad _bh spinlock nesting
  drbd: revert "delay probes", feature is being re-implemented differently
  drbd: Initialize all members of sync_conf to their defaults [Bugz 315]
  drbd: Disable delay probes for the upcomming release
  writeback: cleanup bdi_register
  writeback: add new tracepoints
  writeback: remove unnecessary init_timer call
  writeback: optimize periodic bdi thread wakeups
  writeback: prevent unnecessary bdi threads wakeups
  writeback: move bdi threads exiting logic to the forker thread
  writeback: restructure bdi forker loop a little
  writeback: move last_active to bdi
  writeback: do not remove bdi from bdi_list
  writeback: simplify bdi code a little
  writeback: do not lose wake-ups in bdi threads
  ...

Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and
drivers/scsi/scsi_error.c as per Jens.

1 files changed, 18 insertions, 17 deletions

diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index 0d710c9d403b..f0faefca032f 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -13,7 +13,6 @@
  * blk_queue_ordered - does this queue support ordered writes
  * @q:        the request queue
  * @ordered:  one of QUEUE_ORDERED_*
- * @prepare_flush_fn: rq setup helper for cache flush ordered writes
  *
  * Description:
  *   For journalled file systems, doing ordered writes on a commit
@@ -22,15 +21,8 @@
  *   feature should call this function and indicate so.
  *
  **/
-int blk_queue_ordered(struct request_queue *q, unsigned ordered,
-		      prepare_flush_fn *prepare_flush_fn)
+int blk_queue_ordered(struct request_queue *q, unsigned ordered)
 {
-	if (!prepare_flush_fn && (ordered & (QUEUE_ORDERED_DO_PREFLUSH |
-					     QUEUE_ORDERED_DO_POSTFLUSH))) {
-		printk(KERN_ERR "%s: prepare_flush_fn required\n", __func__);
-		return -EINVAL;
-	}
-
 	if (ordered != QUEUE_ORDERED_NONE &&
 	    ordered != QUEUE_ORDERED_DRAIN &&
 	    ordered != QUEUE_ORDERED_DRAIN_FLUSH &&
@@ -44,7 +36,6 @@ int blk_queue_ordered(struct request_queue *q, unsigned ordered,
 
 	q->ordered = ordered;
 	q->next_ordered = ordered;
-	q->prepare_flush_fn = prepare_flush_fn;
 
 	return 0;
 }
@@ -79,7 +70,7 @@ unsigned blk_ordered_req_seq(struct request *rq)
 	 *
 	 * http://thread.gmane.org/gmane.linux.kernel/537473
 	 */
-	if (!blk_fs_request(rq))
+	if (rq->cmd_type != REQ_TYPE_FS)
 		return QUEUE_ORDSEQ_DRAIN;
 
 	if ((rq->cmd_flags & REQ_ORDERED_COLOR) ==
@@ -143,10 +134,10 @@ static void queue_flush(struct request_queue *q, unsigned which)
 	}
 
 	blk_rq_init(q, rq);
-	rq->cmd_flags = REQ_HARDBARRIER;
-	rq->rq_disk = q->bar_rq.rq_disk;
+	rq->cmd_type = REQ_TYPE_FS;
+	rq->cmd_flags = REQ_HARDBARRIER | REQ_FLUSH;
+	rq->rq_disk = q->orig_bar_rq->rq_disk;
 	rq->end_io = end_io;
-	q->prepare_flush_fn(q, rq);
 
 	elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
 }
@@ -203,7 +194,7 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
 		/* initialize proxy request and queue it */
 		blk_rq_init(q, rq);
 		if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
-			rq->cmd_flags |= REQ_RW;
+			rq->cmd_flags |= REQ_WRITE;
 		if (q->ordered & QUEUE_ORDERED_DO_FUA)
 			rq->cmd_flags |= REQ_FUA;
 		init_request_from_bio(rq, q->orig_bar_rq->bio);
@@ -236,7 +227,8 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
 bool blk_do_ordered(struct request_queue *q, struct request **rqp)
 {
 	struct request *rq = *rqp;
-	const int is_barrier = blk_fs_request(rq) && blk_barrier_rq(rq);
+	const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
+				(rq->cmd_flags & REQ_HARDBARRIER);
 
 	if (!q->ordseq) {
 		if (!is_barrier)
@@ -261,7 +253,7 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
 	 */
 
 	/* Special requests are not subject to ordering rules. */
-	if (!blk_fs_request(rq) &&
+	if (rq->cmd_type != REQ_TYPE_FS &&
 	    rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
 		return true;
 
@@ -319,6 +311,15 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
 	if (!q)
 		return -ENXIO;
 
+	/*
+	 * some block devices may not have their queue correctly set up here
+	 * (e.g. loop device without a backing file) and so issuing a flush
+	 * here will panic. Ensure there is a request function before issuing
+	 * the barrier.
+	 */
+	if (!q->make_request_fn)
+		return -ENXIO;
+
 	bio = bio_alloc(gfp_mask, 0);
 	bio->bi_end_io = bio_end_empty_barrier;
 	bio->bi_bdev = bdev;