Merge branch 'barrier' into for-linus

23 files changed, 240 insertions, 456 deletions

diff --git a/block/elevator.c b/block/elevator.c
index b9c518afe1f8..952aee04a68a 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -712,6 +712,14 @@ struct request *elv_next_request(struct request_queue *q)
 	int ret;
 
 	while ((rq = __elv_next_request(q)) != NULL) {
+		/*
+		 * Kill the empty barrier place holder, the driver must
+		 * not ever see it.
+		 */
+		if (blk_empty_barrier(rq)) {
+			end_queued_request(rq, 1);
+			continue;
+		}
 		if (!(rq->cmd_flags & REQ_STARTED)) {
 			/*
 			 * This is the first time the device driver
@@ -751,15 +759,8 @@ struct request *elv_next_request(struct request_queue *q)
 			rq = NULL;
 			break;
 		} else if (ret == BLKPREP_KILL) {
-			int nr_bytes = rq->hard_nr_sectors << 9;
-
-			if (!nr_bytes)
-				nr_bytes = rq->data_len;
-
-			blkdev_dequeue_request(rq);
 			rq->cmd_flags |= REQ_QUIET;
-			end_that_request_chunk(rq, 0, nr_bytes);
-			end_that_request_last(rq, 0);
+			end_queued_request(rq, 0);
 		} else {
 			printk(KERN_ERR "%s: bad return=%d\n", __FUNCTION__,
 								ret);
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index d875673e76cd..4df7d027eb06 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -304,23 +304,6 @@ int blk_queue_ordered(struct request_queue *q, unsigned ordered,
 
 EXPORT_SYMBOL(blk_queue_ordered);
 
-/**
- * blk_queue_issue_flush_fn - set function for issuing a flush
- * @q:     the request queue
- * @iff:   the function to be called issuing the flush
- *
- * Description:
- *   If a driver supports issuing a flush command, the support is notified
- *   to the block layer by defining it through this call.
- *
- **/
-void blk_queue_issue_flush_fn(struct request_queue *q, issue_flush_fn *iff)
-{
-	q->issue_flush_fn = iff;
-}
-
-EXPORT_SYMBOL(blk_queue_issue_flush_fn);
-
 /*
  * Cache flushing for ordered writes handling
  */
@@ -377,10 +360,12 @@ void blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
 	/*
 	 * Okay, sequence complete.
 	 */
-	rq = q->orig_bar_rq;
-	uptodate = q->orderr ? q->orderr : 1;
+	uptodate = 1;
+	if (q->orderr)
+		uptodate = q->orderr;
 
 	q->ordseq = 0;
+	rq = q->orig_bar_rq;
 
 	end_that_request_first(rq, uptodate, rq->hard_nr_sectors);
 	end_that_request_last(rq, uptodate);
@@ -445,7 +430,8 @@ static inline struct request *start_ordered(struct request_queue *q,
 	rq_init(q, rq);
 	if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
 		rq->cmd_flags |= REQ_RW;
-	rq->cmd_flags |= q->ordered & QUEUE_ORDERED_FUA ? REQ_FUA : 0;
+	if (q->ordered & QUEUE_ORDERED_FUA)
+		rq->cmd_flags |= REQ_FUA;
 	rq->elevator_private = NULL;
 	rq->elevator_private2 = NULL;
 	init_request_from_bio(rq, q->orig_bar_rq->bio);
@@ -455,9 +441,12 @@ static inline struct request *start_ordered(struct request_queue *q,
 	 * Queue ordered sequence.  As we stack them at the head, we
 	 * need to queue in reverse order.  Note that we rely on that
 	 * no fs request uses ELEVATOR_INSERT_FRONT and thus no fs
-	 * request gets inbetween ordered sequence.
+	 * request gets inbetween ordered sequence. If this request is
+	 * an empty barrier, we don't need to do a postflush ever since
+	 * there will be no data written between the pre and post flush.
+	 * Hence a single flush will suffice.
 	 */
-	if (q->ordered & QUEUE_ORDERED_POSTFLUSH)
+	if ((q->ordered & QUEUE_ORDERED_POSTFLUSH) && !blk_empty_barrier(rq))
 		queue_flush(q, QUEUE_ORDERED_POSTFLUSH);
 	else
 		q->ordseq |= QUEUE_ORDSEQ_POSTFLUSH;
@@ -481,7 +470,7 @@ static inline struct request *start_ordered(struct request_queue *q,
 int blk_do_ordered(struct request_queue *q, struct request **rqp)
 {
 	struct request *rq = *rqp;
-	int is_barrier = blk_fs_request(rq) && blk_barrier_rq(rq);
+	const int is_barrier = blk_fs_request(rq) && blk_barrier_rq(rq);
 
 	if (!q->ordseq) {
 		if (!is_barrier)
@@ -2660,6 +2649,14 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
 
 EXPORT_SYMBOL(blk_execute_rq);
 
+static void bio_end_empty_barrier(struct bio *bio, int err)
+{
+	if (err)
+		clear_bit(BIO_UPTODATE, &bio->bi_flags);
+
+	complete(bio->bi_private);
+}
+
 /**
  * blkdev_issue_flush - queue a flush
  * @bdev:	blockdev to issue flush for
@@ -2672,7 +2669,10 @@ EXPORT_SYMBOL(blk_execute_rq);
  */
 int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector)
 {
+	DECLARE_COMPLETION_ONSTACK(wait);
 	struct request_queue *q;
+	struct bio *bio;
+	int ret;
 
 	if (bdev->bd_disk == NULL)
 		return -ENXIO;
@@ -2680,10 +2680,32 @@ int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector)
 	q = bdev_get_queue(bdev);
 	if (!q)
 		return -ENXIO;
-	if (!q->issue_flush_fn)
-		return -EOPNOTSUPP;
 
-	return q->issue_flush_fn(q, bdev->bd_disk, error_sector);
+	bio = bio_alloc(GFP_KERNEL, 0);
+	if (!bio)
+		return -ENOMEM;
+
+	bio->bi_end_io = bio_end_empty_barrier;
+	bio->bi_private = &wait;
+	bio->bi_bdev = bdev;
+	submit_bio(1 << BIO_RW_BARRIER, bio);
+
+	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 rq->sector.
+	 */
+	if (error_sector)
+		*error_sector = bio->bi_sector;
+
+	ret = 0;
+	if (!bio_flagged(bio, BIO_UPTODATE))
+		ret = -EIO;
+
+	bio_put(bio);
+	return ret;
 }
 
 EXPORT_SYMBOL(blkdev_issue_flush);
@@ -3051,7 +3073,7 @@ static inline void blk_partition_remap(struct bio *bio)
 {
 	struct block_device *bdev = bio->bi_bdev;
 
-	if (bdev != bdev->bd_contains) {
+	if (bio_sectors(bio) && bdev != bdev->bd_contains) {
 		struct hd_struct *p = bdev->bd_part;
 		const int rw = bio_data_dir(bio);
 
@@ -3117,6 +3139,35 @@ static inline int should_fail_request(struct bio *bio)
 
 #endif /* CONFIG_FAIL_MAKE_REQUEST */
 
+/*
+ * Check whether this bio extends beyond the end of the device.
+ */
+static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)
+{
+	sector_t maxsector;
+
+	if (!nr_sectors)
+		return 0;
+
+	/* Test device or partition size, when known. */
+	maxsector = bio->bi_bdev->bd_inode->i_size >> 9;
+	if (maxsector) {
+		sector_t sector = bio->bi_sector;
+
+		if (maxsector < nr_sectors || maxsector - nr_sectors < sector) {
+			/*
+			 * This may well happen - the kernel calls bread()
+			 * without checking the size of the device, e.g., when
+			 * mounting a device.
+			 */
+			handle_bad_sector(bio);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 /**
  * generic_make_request: hand a buffer to its device driver for I/O
  * @bio:  The bio describing the location in memory and on the device.
@@ -3144,27 +3195,14 @@ static inline int should_fail_request(struct bio *bio)
 static inline void __generic_make_request(struct bio *bio)
 {
 	struct request_queue *q;
-	sector_t maxsector;
 	sector_t old_sector;
 	int ret, nr_sectors = bio_sectors(bio);
 	dev_t old_dev;
 
 	might_sleep();
-	/* Test device or partition size, when known. */
-	maxsector = bio->bi_bdev->bd_inode->i_size >> 9;
-	if (maxsector) {
-		sector_t sector = bio->bi_sector;
 
-		if (maxsector < nr_sectors || maxsector - nr_sectors < sector) {
-			/*
-			 * This may well happen - the kernel calls bread()
-			 * without checking the size of the device, e.g., when
-			 * mounting a device.
-			 */
-			handle_bad_sector(bio);
-			goto end_io;
-		}
-	}
+	if (bio_check_eod(bio, nr_sectors))
+		goto end_io;
 
 	/*
 	 * Resolve the mapping until finished. (drivers are
@@ -3191,7 +3229,7 @@ end_io:
 			break;
 		}
 
-		if (unlikely(bio_sectors(bio) > q->max_hw_sectors)) {
+		if (unlikely(nr_sectors > q->max_hw_sectors)) {
 			printk("bio too big device %s (%u > %u)\n", 
 				bdevname(bio->bi_bdev, b),
 				bio_sectors(bio),
@@ -3212,7 +3250,7 @@ end_io:
 		blk_partition_remap(bio);
 
 		if (old_sector != -1)
-			blk_add_trace_remap(q, bio, old_dev, bio->bi_sector, 
+			blk_add_trace_remap(q, bio, old_dev, bio->bi_sector,
 					    old_sector);
 
 		blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
@@ -3220,21 +3258,8 @@ end_io:
 		old_sector = bio->bi_sector;
 		old_dev = bio->bi_bdev->bd_dev;
 
-		maxsector = bio->bi_bdev->bd_inode->i_size >> 9;
-		if (maxsector) {
-			sector_t sector = bio->bi_sector;
-
-			if (maxsector < nr_sectors ||
-					maxsector - nr_sectors < sector) {
-				/*
-				 * This may well happen - partitions are not
-				 * checked to make sure they are within the size
-				 * of the whole device.
-				 */
-				handle_bad_sector(bio);
-				goto end_io;
-			}
-		}
+		if (bio_check_eod(bio, nr_sectors))
+			goto end_io;
 
 		ret = q->make_request_fn(q, bio);
 	} while (ret);
@@ -3307,23 +3332,32 @@ void submit_bio(int rw, struct bio *bio)
 {
 	int count = bio_sectors(bio);
 
-	BIO_BUG_ON(!bio->bi_size);
-	BIO_BUG_ON(!bio->bi_io_vec);
 	bio->bi_rw |= rw;
-	if (rw & WRITE) {
-		count_vm_events(PGPGOUT, count);
-	} else {
-		task_io_account_read(bio->bi_size);
-		count_vm_events(PGPGIN, count);
-	}
 
-	if (unlikely(block_dump)) {
-		char b[BDEVNAME_SIZE];
-		printk(KERN_DEBUG "%s(%d): %s block %Lu on %s\n",
-			current->comm, current->pid,
-			(rw & WRITE) ? "WRITE" : "READ",
-			(unsigned long long)bio->bi_sector,
-			bdevname(bio->bi_bdev,b));
+	/*
+	 * If it's a regular read/write or a barrier with data attached,
+	 * go through the normal accounting stuff before submission.
+	 */
+	if (!bio_empty_barrier(bio)) {
+
+		BIO_BUG_ON(!bio->bi_size);
+		BIO_BUG_ON(!bio->bi_io_vec);
+
+		if (rw & WRITE) {
+			count_vm_events(PGPGOUT, count);
+		} else {
+			task_io_account_read(bio->bi_size);
+			count_vm_events(PGPGIN, count);
+		}
+
+		if (unlikely(block_dump)) {
+			char b[BDEVNAME_SIZE];
+			printk(KERN_DEBUG "%s(%d): %s block %Lu on %s\n",
+				current->comm, current->pid,
+				(rw & WRITE) ? "WRITE" : "READ",
+				(unsigned long long)bio->bi_sector,
+				bdevname(bio->bi_bdev,b));
+		}
 	}
 
 	generic_make_request(bio);
@@ -3399,6 +3433,14 @@ static int __end_that_request_first(struct request *req, int uptodate,
 	while ((bio = req->bio) != NULL) {
 		int nbytes;
 
+		/*
+		 * For an empty barrier request, the low level driver must
+		 * store a potential error location in ->sector. We pass
+		 * that back up in ->bi_sector.
+		 */
+		if (blk_empty_barrier(req))
+			bio->bi_sector = req->sector;
+
 		if (nr_bytes >= bio->bi_size) {
 			req->bio = bio->bi_next;
 			nbytes = bio->bi_size;
@@ -3564,7 +3606,7 @@ static struct notifier_block blk_cpu_notifier __cpuinitdata = {
  * Description:
  *     Ends all I/O on a request. It does not handle partial completions,
  *     unless the driver actually implements this in its completion callback
- *     through requeueing. Theh actual completion happens out-of-order,
+ *     through requeueing. The actual completion happens out-of-order,
  *     through a softirq handler. The user must have registered a completion
  *     callback through blk_queue_softirq_done().
  **/
@@ -3627,15 +3669,83 @@ void end_that_request_last(struct request *req, int uptodate)
 
 EXPORT_SYMBOL(end_that_request_last);
 
-void end_request(struct request *req, int uptodate)
+static inline void __end_request(struct request *rq, int uptodate,
+				 unsigned int nr_bytes, int dequeue)
 {
-	if (!end_that_request_first(req, uptodate, req->hard_cur_sectors)) {
-		add_disk_randomness(req->rq_disk);
-		blkdev_dequeue_request(req);
-		end_that_request_last(req, uptodate);
+	if (!end_that_request_chunk(rq, uptodate, nr_bytes)) {
+		if (dequeue)
+			blkdev_dequeue_request(rq);
+		add_disk_randomness(rq->rq_disk);
+		end_that_request_last(rq, uptodate);
 	}
 }
 
+static unsigned int rq_byte_size(struct request *rq)
+{
+	if (blk_fs_request(rq))
+		return rq->hard_nr_sectors << 9;
+
+	return rq->data_len;
+}
+
+/**
+ * end_queued_request - end all I/O on a queued request
+ * @rq:		the request being processed
+ * @uptodate:	error value or 0/1 uptodate flag
+ *
+ * Description:
+ *     Ends all I/O on a request, and removes it from the block layer queues.
+ *     Not suitable for normal IO completion, unless the driver still has
+ *     the request attached to the block layer.
+ *
+ **/
+void end_queued_request(struct request *rq, int uptodate)
+{
+	__end_request(rq, uptodate, rq_byte_size(rq), 1);
+}
+EXPORT_SYMBOL(end_queued_request);
+
+/**
+ * end_dequeued_request - end all I/O on a dequeued request
+ * @rq:		the request being processed
+ * @uptodate:	error value or 0/1 uptodate flag
+ *
+ * Description:
+ *     Ends all I/O on a request. The request must already have been
+ *     dequeued using blkdev_dequeue_request(), as is normally the case
+ *     for most drivers.
+ *
+ **/
+void end_dequeued_request(struct request *rq, int uptodate)
+{
+	__end_request(rq, uptodate, rq_byte_size(rq), 0);
+}
+EXPORT_SYMBOL(end_dequeued_request);
+
+
+/**
+ * end_request - end I/O on the current segment of the request
+ * @rq:		the request being processed
+ * @uptodate:	error value or 0/1 uptodate flag
+ *
+ * Description:
+ *     Ends I/O on the current segment of a request. If that is the only
+ *     remaining segment, the request is also completed and freed.
+ *
+ *     This is a remnant of how older block drivers handled IO completions.
+ *     Modern drivers typically end IO on the full request in one go, unless
+ *     they have a residual value to account for. For that case this function
+ *     isn't really useful, unless the residual just happens to be the
+ *     full current segment. In other words, don't use this function in new
+ *     code. Either use end_request_completely(), or the
+ *     end_that_request_chunk() (along with end_that_request_last()) for
+ *     partial completions.
+ *
+ **/
+void end_request(struct request *req, int uptodate)
+{
+	__end_request(req, uptodate, req->hard_cur_sectors << 9, 1);
+}
 EXPORT_SYMBOL(end_request);
 
 static void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 540bf3676985..a8130a4ad6d4 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1133,16 +1133,21 @@ static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
 	 * Schedule reads for missing parts of the packet.
 	 */
 	for (f = 0; f < pkt->frames; f++) {
+		struct bio_vec *vec;
+
 		int p, offset;
 		if (written[f])
 			continue;
 		bio = pkt->r_bios[f];
+		vec = bio->bi_io_vec;
 		bio_init(bio);
 		bio->bi_max_vecs = 1;
 		bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
 		bio->bi_bdev = pd->bdev;
 		bio->bi_end_io = pkt_end_io_read;
 		bio->bi_private = pkt;
+		bio->bi_io_vec = vec;
+		bio->bi_destructor = pkt_bio_destructor;
 
 		p = (f * CD_FRAMESIZE) / PAGE_SIZE;
 		offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
@@ -1439,6 +1444,8 @@ static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
 	pkt->w_bio->bi_bdev = pd->bdev;
 	pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
 	pkt->w_bio->bi_private = pkt;
+	pkt->w_bio->bi_io_vec = bvec;
+	pkt->w_bio->bi_destructor = pkt_bio_destructor;
 	for (f = 0; f < pkt->frames; f++)
 		if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
 			BUG();
diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c
index 06d0552cf49c..e354bfc070e1 100644
--- a/drivers/block/ps3disk.c
+++ b/drivers/block/ps3disk.c
@@ -414,26 +414,6 @@ static void ps3disk_prepare_flush(struct request_queue *q, struct request *req)
 	req->cmd_type = REQ_TYPE_FLUSH;
 }
 
-static int ps3disk_issue_flush(struct request_queue *q, struct gendisk *gendisk,
-			       sector_t *sector)
-{
-	struct ps3_storage_device *dev = q->queuedata;
-	struct request *req;
-	int res;
-
-	dev_dbg(&dev->sbd.core, "%s:%u\n", __func__, __LINE__);
-
-	req = blk_get_request(q, WRITE, __GFP_WAIT);
-	ps3disk_prepare_flush(q, req);
-	res = blk_execute_rq(q, gendisk, req, 0);
-	if (res)
-		dev_err(&dev->sbd.core, "%s:%u: flush request failed %d\n",
-			__func__, __LINE__, res);
-	blk_put_request(req);
-	return res;
-}
-
-
 static unsigned long ps3disk_mask;
 
 static DEFINE_MUTEX(ps3disk_mask_mutex);
@@ -506,7 +486,6 @@ static int __devinit ps3disk_probe(struct ps3_system_bus_device *_dev)
 	blk_queue_dma_alignment(queue, dev->blk_size-1);
 	blk_queue_hardsect_size(queue, dev->blk_size);
 
-	blk_queue_issue_flush_fn(queue, ps3disk_issue_flush);
 	blk_queue_ordered(queue, QUEUE_ORDERED_DRAIN_FLUSH,
 			  ps3disk_prepare_flush);
 
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 4754769eda97..92177ca48b4d 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -716,32 +716,6 @@ static void idedisk_prepare_flush(struct request_queue *q, struct request *rq)
 	rq->buffer = rq->cmd;
 }
 
-static int idedisk_issue_flush(struct request_queue *q, struct gendisk *disk,
-			       sector_t *error_sector)
-{
-	ide_drive_t *drive = q->queuedata;
-	struct request *rq;
-	int ret;
-
-	if (!drive->wcache)
-		return 0;
-
-	rq = blk_get_request(q, WRITE, __GFP_WAIT);
-
-	idedisk_prepare_flush(q, rq);
-
-	ret = blk_execute_rq(q, disk, rq, 0);
-
-	/*
-	 * if we failed and caller wants error offset, get it
-	 */
-	if (ret && error_sector)
-		*error_sector = ide_get_error_location(drive, rq->cmd);
-
-	blk_put_request(rq);
-	return ret;
-}
-
 /*
  * This is tightly woven into the driver->do_special can not touch.
  * DON'T do it again until a total personality rewrite is committed.
@@ -781,7 +755,6 @@ static void update_ordered(ide_drive_t *drive)
 	struct hd_driveid *id = drive->id;
 	unsigned ordered = QUEUE_ORDERED_NONE;
 	prepare_flush_fn *prep_fn = NULL;
-	issue_flush_fn *issue_fn = NULL;
 
 	if (drive->wcache) {
 		unsigned long long capacity;
@@ -805,13 +778,11 @@ static void update_ordered(ide_drive_t *drive)
 		if (barrier) {
 			ordered = QUEUE_ORDERED_DRAIN_FLUSH;
 			prep_fn = idedisk_prepare_flush;
-			issue_fn = idedisk_issue_flush;
 		}
 	} else
 		ordered = QUEUE_ORDERED_DRAIN;
 
 	blk_queue_ordered(drive->queue, ordered, prep_fn);
-	blk_queue_issue_flush_fn(drive->queue, issue_fn);
 }
 
 static int write_cache(ide_drive_t *drive, int arg)
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 4cece930114c..f36ff5962af6 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -322,41 +322,6 @@ static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
 	spin_unlock_irqrestore(&ide_lock, flags);
 }
 
-/*
- * FIXME: probably move this somewhere else, name is bad too :)
- */
-u64 ide_get_error_location(ide_drive_t *drive, char *args)
-{
-	u32 high, low;
-	u8 hcyl, lcyl, sect;
-	u64 sector;
-
-	high = 0;
-	hcyl = args[5];
-	lcyl = args[4];
-	sect = args[3];
-
-	if (ide_id_has_flush_cache_ext(drive->id)) {
-		low = (hcyl << 16) | (lcyl << 8) | sect;
-		HWIF(drive)->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
-		high = ide_read_24(drive);
-	} else {
-		u8 cur = HWIF(drive)->INB(IDE_SELECT_REG);
-		if (cur & 0x40) {
-			high = cur & 0xf;
-			low = (hcyl << 16) | (lcyl << 8) | sect;
-		} else {
-			low = hcyl * drive->head * drive->sect;
-			low += lcyl * drive->sect;
-			low += sect - 1;
-		}
-	}
-
-	sector = ((u64) high << 24) | low;
-	return sector;
-}
-EXPORT_SYMBOL(ide_get_error_location);
-
 /**
  *	ide_end_drive_cmd	-	end an explicit drive command
  *	@drive: command 
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 2bcde5798b5a..fbe477bb2c68 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -999,33 +999,6 @@ void dm_table_unplug_all(struct dm_table *t)
 	}
 }
 
-int dm_table_flush_all(struct dm_table *t)
-{
-	struct list_head *d, *devices = dm_table_get_devices(t);
-	int ret = 0;
-	unsigned i;
-
-	for (i = 0; i < t->num_targets; i++)
-		if (t->targets[i].type->flush)
-			t->targets[i].type->flush(&t->targets[i]);
-
-	for (d = devices->next; d != devices; d = d->next) {
-		struct dm_dev *dd = list_entry(d, struct dm_dev, list);
-		struct request_queue *q = bdev_get_queue(dd->bdev);
-		int err;
-
-		if (!q->issue_flush_fn)
-			err = -EOPNOTSUPP;
-		else
-			err = q->issue_flush_fn(q, dd->bdev->bd_disk, NULL);
-
-		if (!ret)
-			ret = err;
-	}
-
-	return ret;
-}
-
 struct mapped_device *dm_table_get_md(struct dm_table *t)
 {
 	dm_get(t->md);
@@ -1043,4 +1016,3 @@ EXPORT_SYMBOL(dm_table_get_md);
 EXPORT_SYMBOL(dm_table_put);
 EXPORT_SYMBOL(dm_table_get);
 EXPORT_SYMBOL(dm_table_unplug_all);
-EXPORT_SYMBOL(dm_table_flush_all);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 167765c47747..d837d37f6209 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -840,21 +840,6 @@ static int dm_request(struct request_queue *q, struct bio *bio)
 	return 0;
 }
 
-static int dm_flush_all(struct request_queue *q, struct gendisk *disk,
-			sector_t *error_sector)
-{
-	struct mapped_device *md = q->queuedata;
-	struct dm_table *map = dm_get_table(md);
-	int ret = -ENXIO;
-
-	if (map) {
-		ret = dm_table_flush_all(map);
-		dm_table_put(map);
-	}
-
-	return ret;
-}
-
 static void dm_unplug_all(struct request_queue *q)
 {
 	struct mapped_device *md = q->queuedata;
@@ -1003,7 +988,6 @@ static struct mapped_device *alloc_dev(int minor)
 	blk_queue_make_request(md->queue, dm_request);
 	blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
 	md->queue->unplug_fn = dm_unplug_all;
-	md->queue->issue_flush_fn = dm_flush_all;
 
 	md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache);
 	if (!md->io_pool)
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 462ee652a890..4b3faa45277e 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -111,7 +111,6 @@ void dm_table_postsuspend_targets(struct dm_table *t);
 int dm_table_resume_targets(struct dm_table *t);
 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
 void dm_table_unplug_all(struct dm_table *t);
-int dm_table_flush_all(struct dm_table *t);
 
 /*-----------------------------------------------------------------
  * A registry of target types.
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 550148770bb2..56a11f6c127b 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -92,25 +92,6 @@ static void linear_unplug(struct request_queue *q)
 	}
 }
 
-static int linear_issue_flush(struct request_queue *q, struct gendisk *disk,
-			      sector_t *error_sector)
-{
-	mddev_t *mddev = q->queuedata;
-	linear_conf_t *conf = mddev_to_conf(mddev);
-	int i, ret = 0;
-
-	for (i=0; i < mddev->raid_disks && ret == 0; i++) {
-		struct block_device *bdev = conf->disks[i].rdev->bdev;
-		struct request_queue *r_queue = bdev_get_queue(bdev);
-
-		if (!r_queue->issue_flush_fn)
-			ret = -EOPNOTSUPP;
-		else
-			ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, error_sector);
-	}
-	return ret;
-}
-
 static int linear_congested(void *data, int bits)
 {
 	mddev_t *mddev = data;
@@ -279,7 +260,6 @@ static int linear_run (mddev_t *mddev)
 
 	blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec);
 	mddev->queue->unplug_fn = linear_unplug;
-	mddev->queue->issue_flush_fn = linear_issue_flush;
 	mddev->queue->backing_dev_info.congested_fn = linear_congested;
 	mddev->queue->backing_dev_info.congested_data = mddev;
 	return 0;
diff --git a/drivers/md/md.c b/drivers/md/md.c
index acf1b81b47cb..0dc563d76b39 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3463,7 +3463,6 @@ static int do_md_stop(mddev_t * mddev, int mode)
 			mddev->pers->stop(mddev);
 			mddev->queue->merge_bvec_fn = NULL;
 			mddev->queue->unplug_fn = NULL;
-			mddev->queue->issue_flush_fn = NULL;
 			mddev->queue->backing_dev_info.congested_fn = NULL;
 			if (mddev->pers->sync_request)
 				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index f2a63f394ad9..b35731cceac6 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -194,35 +194,6 @@ static void multipath_status (struct seq_file *seq, mddev_t *mddev)
 	seq_printf (seq, "]");
 }
 
-static int multipath_issue_flush(struct request_queue *q, struct gendisk *disk,
-				 sector_t *error_sector)
-{
-	mddev_t *mddev = q->queuedata;
-	multipath_conf_t *conf = mddev_to_conf(mddev);
-	int i, ret = 0;
-
-	rcu_read_lock();
-	for (i=0; i<mddev->raid_disks && ret == 0; i++) {
-		mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev);
-		if (rdev && !test_bit(Faulty, &rdev->flags)) {
-			struct block_device *bdev = rdev->bdev;
-			struct request_queue *r_queue = bdev_get_queue(bdev);
-
-			if (!r_queue->issue_flush_fn)
-				ret = -EOPNOTSUPP;
-			else {
-				atomic_inc(&rdev->nr_pending);
-				rcu_read_unlock();
-				ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
-							      error_sector);
-				rdev_dec_pending(rdev, mddev);
-				rcu_read_lock();
-			}
-		}
-	}
-	rcu_read_unlock();
-	return ret;
-}
 static int multipath_congested(void *data, int bits)
 {
 	mddev_t *mddev = data;
@@ -527,7 +498,6 @@ static int multipath_run (mddev_t *mddev)
 	mddev->array_size = mddev->size;
 
 	mddev->queue->unplug_fn = multipath_unplug;
-	mddev->queue->issue_flush_fn = multipath_issue_flush;
 	mddev->queue->backing_dev_info.congested_fn = multipath_congested;
 	mddev->queue->backing_dev_info.congested_data = mddev;
 
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index ef0da2d84959..e79e1a538d44 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -40,26 +40,6 @@ static void raid0_unplug(struct request_queue *q)
 	}
 }
 
-static int raid0_issue_flush(struct request_queue *q, struct gendisk *disk,
-			     sector_t *error_sector)
-{
-	mddev_t *mddev = q->queuedata;
-	raid0_conf_t *conf = mddev_to_conf(mddev);
-	mdk_rdev_t **devlist = conf->strip_zone[0].dev;
-	int i, ret = 0;
-
-	for (i=0; i<mddev->raid_disks && ret == 0; i++) {
-		struct block_device *bdev = devlist[i]->bdev;
-		struct request_queue *r_queue = bdev_get_queue(bdev);
-
-		if (!r_queue->issue_flush_fn)
-			ret = -EOPNOTSUPP;
-		else
-			ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, error_sector);
-	}
-	return ret;
-}
-
 static int raid0_congested(void *data, int bits)
 {
 	mddev_t *mddev = data;
@@ -250,7 +230,6 @@ static int create_strip_zones (mddev_t *mddev)
 
 	mddev->queue->unplug_fn = raid0_unplug;
 
-	mddev->queue->issue_flush_fn = raid0_issue_flush;
 	mddev->queue->backing_dev_info.congested_fn = raid0_congested;
 	mddev->queue->backing_dev_info.congested_data = mddev;
 
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 6d03bea6fa58..0bcefad82413 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -567,36 +567,6 @@ static void raid1_unplug(struct request_queue *q)
 	md_wakeup_thread(mddev->thread);
 }
 
-static int raid1_issue_flush(struct request_queue *q, struct gendisk *disk,
-			     sector_t *error_sector)
-{
-	mddev_t *mddev = q->queuedata;
-	conf_t *conf = mddev_to_conf(mddev);
-	int i, ret = 0;
-
-	rcu_read_lock();
-	for (i=0; i<mddev->raid_disks && ret == 0; i++) {
-		mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
-		if (rdev && !test_bit(Faulty, &rdev->flags)) {
-			struct block_device *bdev = rdev->bdev;
-			struct request_queue *r_queue = bdev_get_queue(bdev);
-
-			if (!r_queue->issue_flush_fn)
-				ret = -EOPNOTSUPP;
-			else {
-				atomic_inc(&rdev->nr_pending);
-				rcu_read_unlock();
-				ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
-							      error_sector);
-				rdev_dec_pending(rdev, mddev);
-				rcu_read_lock();
-			}
-		}
-	}
-	rcu_read_unlock();
-	return ret;
-}
-
 static int raid1_congested(void *data, int bits)
 {
 	mddev_t *mddev = data;
@@ -1997,7 +1967,6 @@ static int run(mddev_t *mddev)
 	mddev->array_size = mddev->size;
 
 	mddev->queue->unplug_fn = raid1_unplug;
-	mddev->queue->issue_flush_fn = raid1_issue_flush;
 	mddev->queue->backing_dev_info.congested_fn = raid1_congested;
 	mddev->queue->backing_dev_info.congested_data = mddev;
 
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 25a96c42bdb0..fc6607acb6e4 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -611,36 +611,6 @@ static void raid10_unplug(struct request_queue *q)
 	md_wakeup_thread(mddev->thread);
 }
 
-static int raid10_issue_flush(struct request_queue *q, struct gendisk *disk,
-			     sector_t *error_sector)
-{
-	mddev_t *mddev = q->queuedata;
-	conf_t *conf = mddev_to_conf(mddev);
-	int i, ret = 0;
-
-	rcu_read_lock();
-	for (i=0; i<mddev->raid_disks && ret == 0; i++) {
-		mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
-		if (rdev && !test_bit(Faulty, &rdev->flags)) {
-			struct block_device *bdev = rdev->bdev;
-			struct request_queue *r_queue = bdev_get_queue(bdev);
-
-			if (!r_queue->issue_flush_fn)
-				ret = -EOPNOTSUPP;
-			else {
-				atomic_inc(&rdev->nr_pending);
-				rcu_read_unlock();
-				ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
-							      error_sector);
-				rdev_dec_pending(rdev, mddev);
-				rcu_read_lock();
-			}
-		}
-	}
-	rcu_read_unlock();
-	return ret;
-}
-
 static int raid10_congested(void *data, int bits)
 {
 	mddev_t *mddev = data;
@@ -2118,7 +2088,6 @@ static int run(mddev_t *mddev)
 	mddev->resync_max_sectors = size << conf->chunk_shift;
 
 	mddev->queue->unplug_fn = raid10_unplug;
-	mddev->queue->issue_flush_fn = raid10_issue_flush;
 	mddev->queue->backing_dev_info.congested_fn = raid10_congested;
 	mddev->queue->backing_dev_info.congested_data = mddev;
 
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index caaca9e178bc..8ee181a01f52 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3204,36 +3204,6 @@ static void raid5_unplug_device(struct request_queue *q)
 	unplug_slaves(mddev);
 }
 
-static int raid5_issue_flush(struct request_queue *q, struct gendisk *disk,
-			     sector_t *error_sector)
-{
-	mddev_t *mddev = q->queuedata;
-	raid5_conf_t *conf = mddev_to_conf(mddev);
-	int i, ret = 0;
-
-	rcu_read_lock();
-	for (i=0; i<mddev->raid_disks && ret == 0; i++) {
-		mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
-		if (rdev && !test_bit(Faulty, &rdev->flags)) {
-			struct block_device *bdev = rdev->bdev;
-			struct request_queue *r_queue = bdev_get_queue(bdev);
-
-			if (!r_queue->issue_flush_fn)
-				ret = -EOPNOTSUPP;
-			else {
-				atomic_inc(&rdev->nr_pending);
-				rcu_read_unlock();
-				ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
-							      error_sector);
-				rdev_dec_pending(rdev, mddev);
-				rcu_read_lock();
-			}
-		}
-	}
-	rcu_read_unlock();
-	return ret;
-}
-
 static int raid5_congested(void *data, int bits)
 {
 	mddev_t *mddev = data;
@@ -4263,7 +4233,6 @@ static int run(mddev_t *mddev)
 		       mdname(mddev));
 
 	mddev->queue->unplug_fn = raid5_unplug_device;
-	mddev->queue->issue_flush_fn = raid5_issue_flush;
 	mddev->queue->backing_dev_info.congested_data = mddev;
 	mddev->queue->backing_dev_info.congested_fn = raid5_congested;
 
diff --git a/drivers/message/i2o/i2o_block.c b/drivers/message/i2o/i2o_block.c
index 50b2c7334410..d602ba6d5417 100644
--- a/drivers/message/i2o/i2o_block.c
+++ b/drivers/message/i2o/i2o_block.c
@@ -149,29 +149,6 @@ static int i2o_block_device_flush(struct i2o_device *dev)
 };
 
 /**
- *	i2o_block_issue_flush - device-flush interface for block-layer
- *	@queue: the request queue of the device which should be flushed
- *	@disk: gendisk
- *	@error_sector: error offset
- *
- *	Helper function to provide flush functionality to block-layer.
- *
- *	Returns 0 on success or negative error code on failure.
- */
-
-static int i2o_block_issue_flush(struct request_queue * queue, struct gendisk *disk,
-				 sector_t * error_sector)
-{
-	struct i2o_block_device *i2o_blk_dev = queue->queuedata;
-	int rc = -ENODEV;
-
-	if (likely(i2o_blk_dev))
-		rc = i2o_block_device_flush(i2o_blk_dev->i2o_dev);
-
-	return rc;
-}
-
-/**
  *	i2o_block_device_mount - Mount (load) the media of device dev
  *	@dev: I2O device which should receive the mount request
  *	@media_id: Media Identifier
@@ -1009,7 +986,6 @@ static struct i2o_block_device *i2o_block_device_alloc(void)
 	}
 
 	blk_queue_prep_rq(queue, i2o_block_prep_req_fn);
-	blk_queue_issue_flush_fn(queue, i2o_block_issue_flush);
 
 	gd->major = I2O_MAJOR;
 	gd->queue = queue;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 0a3a528212c2..69f542c4923c 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -826,27 +826,6 @@ static int sd_sync_cache(struct scsi_disk *sdkp)
 	return 0;
 }
 
-static int sd_issue_flush(struct request_queue *q, struct gendisk *disk,
-			  sector_t *error_sector)
-{
-	int ret = 0;
-	struct scsi_device *sdp = q->queuedata;
-	struct scsi_disk *sdkp;
-
-	if (sdp->sdev_state != SDEV_RUNNING)
-		return -ENXIO;
-
-	sdkp = scsi_disk_get_from_dev(&sdp->sdev_gendev);
-
-	if (!sdkp)
-               return -ENODEV;
-
-	if (sdkp->WCE)
-		ret = sd_sync_cache(sdkp);
-	scsi_disk_put(sdkp);
-	return ret;
-}
-
 static void sd_prepare_flush(struct request_queue *q, struct request *rq)
 {
 	memset(rq->cmd, 0, sizeof(rq->cmd));
@@ -1697,7 +1676,6 @@ static int sd_probe(struct device *dev)
 	sd_revalidate_disk(gd);
 
 	blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
-	blk_queue_issue_flush_fn(sdp->request_queue, sd_issue_flush);
 
 	gd->driverfs_dev = &sdp->sdev_gendev;
 	gd->flags = GENHD_FL_DRIVERFS;
diff --git a/fs/bio.c b/fs/bio.c
index 5f604f269dfa..d59ddbf79626 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -109,11 +109,14 @@ static inline struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned lon
 
 void bio_free(struct bio *bio, struct bio_set *bio_set)
 {
-	const int pool_idx = BIO_POOL_IDX(bio);
+	if (bio->bi_io_vec) {
+		const int pool_idx = BIO_POOL_IDX(bio);
 
-	BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS);
+		BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS);
+
+		mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]);
+	}
 
-	mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]);
 	mempool_free(bio, bio_set->bio_pool);
 }
 
@@ -127,21 +130,9 @@ static void bio_fs_destructor(struct bio *bio)
 
 void bio_init(struct bio *bio)
 {
-	bio->bi_next = NULL;
-	bio->bi_bdev = NULL;
+	memset(bio, 0, sizeof(*bio));
 	bio->bi_flags = 1 << BIO_UPTODATE;
-	bio->bi_rw = 0;
-	bio->bi_vcnt = 0;
-	bio->bi_idx = 0;
-	bio->bi_phys_segments = 0;
-	bio->bi_hw_segments = 0;
-	bio->bi_hw_front_size = 0;
-	bio->bi_hw_back_size = 0;
-	bio->bi_size = 0;
-	bio->bi_max_vecs = 0;
-	bio->bi_end_io = NULL;
 	atomic_set(&bio->bi_cnt, 1);
-	bio->bi_private = NULL;
 }
 
 /**
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 089a8bc55dd4..4da441337d6e 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -176,13 +176,28 @@ struct bio {
 #define bio_offset(bio)		bio_iovec((bio))->bv_offset
 #define bio_segments(bio)	((bio)->bi_vcnt - (bio)->bi_idx)
 #define bio_sectors(bio)	((bio)->bi_size >> 9)
-#define bio_cur_sectors(bio)	(bio_iovec(bio)->bv_len >> 9)
-#define bio_data(bio)		(page_address(bio_page((bio))) + bio_offset((bio)))
 #define bio_barrier(bio)	((bio)->bi_rw & (1 << BIO_RW_BARRIER))
 #define bio_sync(bio)		((bio)->bi_rw & (1 << BIO_RW_SYNC))
 #define bio_failfast(bio)	((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
 #define bio_rw_ahead(bio)	((bio)->bi_rw & (1 << BIO_RW_AHEAD))
 #define bio_rw_meta(bio)	((bio)->bi_rw & (1 << BIO_RW_META))
+#define bio_empty_barrier(bio)	(bio_barrier(bio) && !(bio)->bi_size)
+
+static inline unsigned int bio_cur_sectors(struct bio *bio)
+{
+	if (bio->bi_vcnt)
+		return bio_iovec(bio)->bv_len >> 9;
+
+	return 0;
+}
+
+static inline void *bio_data(struct bio *bio)
+{
+	if (bio->bi_vcnt)
+		return page_address(bio_page(bio)) + bio_offset(bio);
+
+	return NULL;
+}
 
 /*
  * will die
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5ed888b04b29..bbf906a0b419 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -330,7 +330,6 @@ typedef void (unplug_fn) (struct request_queue *);
 
 struct bio_vec;
 typedef int (merge_bvec_fn) (struct request_queue *, struct bio *, struct bio_vec *);
-typedef int (issue_flush_fn) (struct request_queue *, struct gendisk *, sector_t *);
 typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
 typedef void (softirq_done_fn)(struct request *);
 
@@ -368,7 +367,6 @@ struct request_queue
 	prep_rq_fn		*prep_rq_fn;
 	unplug_fn		*unplug_fn;
 	merge_bvec_fn		*merge_bvec_fn;
-	issue_flush_fn		*issue_flush_fn;
 	prepare_flush_fn	*prepare_flush_fn;
 	softirq_done_fn		*softirq_done_fn;
 
@@ -540,6 +538,7 @@ enum {
 #define blk_barrier_rq(rq)	((rq)->cmd_flags & REQ_HARDBARRIER)
 #define blk_fua_rq(rq)		((rq)->cmd_flags & REQ_FUA)
 #define blk_bidi_rq(rq)		((rq)->next_rq != NULL)
+#define blk_empty_barrier(rq)	(blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
 
 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
 
@@ -729,7 +728,9 @@ static inline void blk_run_address_space(struct address_space *mapping)
 extern int end_that_request_first(struct request *, int, int);
 extern int end_that_request_chunk(struct request *, int, int);
 extern void end_that_request_last(struct request *, int);
-extern void end_request(struct request *req, int uptodate);
+extern void end_request(struct request *, int);
+extern void end_queued_request(struct request *, int);
+extern void end_dequeued_request(struct request *, int);
 extern void blk_complete_request(struct request *);
 
 /*
@@ -767,7 +768,6 @@ extern void blk_queue_dma_alignment(struct request_queue *, int);
 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
-extern void blk_queue_issue_flush_fn(struct request_queue *, issue_flush_fn *);
 extern int blk_do_ordered(struct request_queue *, struct request **);
 extern unsigned blk_ordered_cur_seq(struct request_queue *);
 extern unsigned blk_ordered_req_seq(struct request *);
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 02a27e8cbad2..234fa3df24f6 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1093,11 +1093,6 @@ extern ide_startstop_t ide_do_reset (ide_drive_t *);
 extern void ide_init_drive_cmd (struct request *rq);
 
 /*
- * this function returns error location sector offset in case of a write error
- */
-extern u64 ide_get_error_location(ide_drive_t *, char *);
-
-/*
  * "action" parameter type for ide_do_drive_cmd() below.
  */
 typedef enum {
diff --git a/mm/bounce.c b/mm/bounce.c
index 3b549bf31f7d..b6d2d0f1019b 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -265,6 +265,12 @@ void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
 	mempool_t *pool;
 
 	/*
+	 * Data-less bio, nothing to bounce
+	 */
+	if (bio_empty_barrier(*bio_orig))
+		return;
+
+	/*
 	 * for non-isa bounce case, just check if the bounce pfn is equal
 	 * to or bigger than the highest pfn in the system -- in that case,
 	 * don't waste time iterating over bio segments