1 files changed, 171 insertions, 149 deletions

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 5eeb9e0d256..f1a1795a568 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -8,7 +8,9 @@
 #include <linux/blkdev.h>
 #include <linux/bootmem.h>	/* for max_pfn/max_low_pfn */
 #include <linux/gcd.h>
+#include <linux/lcm.h>
 #include <linux/jiffies.h>
+#include <linux/gfp.h>
 
 #include "blk.h"
 
@@ -35,6 +37,23 @@ void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn)
 EXPORT_SYMBOL(blk_queue_prep_rq);
 
 /**
+ * blk_queue_unprep_rq - set an unprepare_request function for queue
+ * @q:		queue
+ * @ufn:	unprepare_request function
+ *
+ * It's possible for a queue to register an unprepare_request callback
+ * which is invoked before the request is finally completed. The goal
+ * of the function is to deallocate any data that was allocated in the
+ * prepare_request callback.
+ *
+ */
+void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *ufn)
+{
+	q->unprep_rq_fn = ufn;
+}
+EXPORT_SYMBOL(blk_queue_unprep_rq);
+
+/**
  * blk_queue_merge_bvec - set a merge_bvec function for queue
  * @q:		queue
  * @mbfn:	merge_bvec_fn
@@ -85,33 +104,54 @@ EXPORT_SYMBOL_GPL(blk_queue_lld_busy);
  * @lim:  the queue_limits structure to reset
  *
  * Description:
- *   Returns a queue_limit struct to its default state.  Can be used by
- *   stacking drivers like DM that stage table swaps and reuse an
- *   existing device queue.
+ *   Returns a queue_limit struct to its default state.
  */
 void blk_set_default_limits(struct queue_limits *lim)
 {
-	lim->max_phys_segments = MAX_PHYS_SEGMENTS;
-	lim->max_hw_segments = MAX_HW_SEGMENTS;
+	lim->max_segments = BLK_MAX_SEGMENTS;
+	lim->max_integrity_segments = 0;
 	lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
-	lim->max_segment_size = MAX_SEGMENT_SIZE;
-	lim->max_sectors = BLK_DEF_MAX_SECTORS;
-	lim->max_hw_sectors = INT_MAX;
+	lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
+	lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
+	lim->chunk_sectors = 0;
+	lim->max_write_same_sectors = 0;
 	lim->max_discard_sectors = 0;
 	lim->discard_granularity = 0;
 	lim->discard_alignment = 0;
 	lim->discard_misaligned = 0;
-	lim->discard_zeroes_data = -1;
+	lim->discard_zeroes_data = 0;
 	lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
 	lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
 	lim->alignment_offset = 0;
 	lim->io_opt = 0;
 	lim->misaligned = 0;
-	lim->no_cluster = 0;
+	lim->cluster = 1;
 }
 EXPORT_SYMBOL(blk_set_default_limits);
 
 /**
+ * blk_set_stacking_limits - set default limits for stacking devices
+ * @lim:  the queue_limits structure to reset
+ *
+ * Description:
+ *   Returns a queue_limit struct to its default state. Should be used
+ *   by stacking drivers like DM that have no internal limits.
+ */
+void blk_set_stacking_limits(struct queue_limits *lim)
+{
+	blk_set_default_limits(lim);
+
+	/* Inherit limits from component devices */
+	lim->discard_zeroes_data = 1;
+	lim->max_segments = USHRT_MAX;
+	lim->max_hw_sectors = UINT_MAX;
+	lim->max_segment_size = UINT_MAX;
+	lim->max_sectors = UINT_MAX;
+	lim->max_write_same_sectors = UINT_MAX;
+}
+EXPORT_SYMBOL(blk_set_stacking_limits);
+
+/**
  * blk_queue_make_request - define an alternate make_request function for a device
  * @q:  the request queue for the device to be affected
  * @mfn: the alternate make_request function
@@ -145,23 +185,7 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
 	blk_queue_congestion_threshold(q);
 	q->nr_batching = BLK_BATCH_REQ;
 
-	q->unplug_thresh = 4;		/* hmm */
-	q->unplug_delay = msecs_to_jiffies(3);	/* 3 milliseconds */
-	if (q->unplug_delay == 0)
-		q->unplug_delay = 1;
-
-	q->unplug_timer.function = blk_unplug_timeout;
-	q->unplug_timer.data = (unsigned long)q;
-
 	blk_set_default_limits(&q->limits);
-	blk_queue_max_sectors(q, SAFE_MAX_SECTORS);
-
-	/*
-	 * If the caller didn't supply a lock, fall back to our embedded
-	 * per-queue locks
-	 */
-	if (!q->queue_lock)
-		q->queue_lock = &q->__queue_lock;
 
 	/*
 	 * by default assume old behaviour and bounce for any highmem page
@@ -173,17 +197,17 @@ EXPORT_SYMBOL(blk_queue_make_request);
 /**
  * blk_queue_bounce_limit - set bounce buffer limit for queue
  * @q: the request queue for the device
- * @dma_mask: the maximum address the device can handle
+ * @max_addr: the maximum address the device can handle
  *
  * Description:
  *    Different hardware can have different requirements as to what pages
  *    it can do I/O directly to. A low level driver can call
  *    blk_queue_bounce_limit to have lower memory pages allocated as bounce
- *    buffers for doing I/O to pages residing above @dma_mask.
+ *    buffers for doing I/O to pages residing above @max_addr.
  **/
-void blk_queue_bounce_limit(struct request_queue *q, u64 dma_mask)
+void blk_queue_bounce_limit(struct request_queue *q, u64 max_addr)
 {
-	unsigned long b_pfn = dma_mask >> PAGE_SHIFT;
+	unsigned long b_pfn = max_addr >> PAGE_SHIFT;
 	int dma = 0;
 
 	q->bounce_gfp = GFP_NOIO;
@@ -195,7 +219,7 @@ void blk_queue_bounce_limit(struct request_queue *q, u64 dma_mask)
 	 */
 	if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
 		dma = 1;
-	q->limits.bounce_pfn = max_low_pfn;
+	q->limits.bounce_pfn = max(max_low_pfn, b_pfn);
 #else
 	if (b_pfn < blk_max_low_pfn)
 		dma = 1;
@@ -210,41 +234,70 @@ void blk_queue_bounce_limit(struct request_queue *q, u64 dma_mask)
 EXPORT_SYMBOL(blk_queue_bounce_limit);
 
 /**
- * blk_queue_max_sectors - set max sectors for a request for this queue
- * @q:  the request queue for the device
- * @max_sectors:  max sectors in the usual 512b unit
+ * blk_limits_max_hw_sectors - set hard and soft limit of max sectors for request
+ * @limits: the queue limits
+ * @max_hw_sectors:  max hardware sectors in the usual 512b unit
  *
  * Description:
- *    Enables a low level driver to set an upper limit on the size of
- *    received requests.
+ *    Enables a low level driver to set a hard upper limit,
+ *    max_hw_sectors, on the size of requests.  max_hw_sectors is set by
+ *    the device driver based upon the combined capabilities of I/O
+ *    controller and storage device.
+ *
+ *    max_sectors is a soft limit imposed by the block layer for
+ *    filesystem type requests.  This value can be overridden on a
+ *    per-device basis in /sys/block/<device>/queue/max_sectors_kb.
+ *    The soft limit can not exceed max_hw_sectors.
  **/
-void blk_queue_max_sectors(struct request_queue *q, unsigned int max_sectors)
+void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_sectors)
 {
-	if ((max_sectors << 9) < PAGE_CACHE_SIZE) {
-		max_sectors = 1 << (PAGE_CACHE_SHIFT - 9);
+	if ((max_hw_sectors << 9) < PAGE_CACHE_SIZE) {
+		max_hw_sectors = 1 << (PAGE_CACHE_SHIFT - 9);
 		printk(KERN_INFO "%s: set to minimum %d\n",
-		       __func__, max_sectors);
+		       __func__, max_hw_sectors);
 	}
 
-	if (BLK_DEF_MAX_SECTORS > max_sectors)
-		q->limits.max_hw_sectors = q->limits.max_sectors = max_sectors;
-	else {
-		q->limits.max_sectors = BLK_DEF_MAX_SECTORS;
-		q->limits.max_hw_sectors = max_sectors;
-	}
+	limits->max_hw_sectors = max_hw_sectors;
+	limits->max_sectors = min_t(unsigned int, max_hw_sectors,
+				    BLK_DEF_MAX_SECTORS);
 }
-EXPORT_SYMBOL(blk_queue_max_sectors);
+EXPORT_SYMBOL(blk_limits_max_hw_sectors);
 
-void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_sectors)
+/**
+ * blk_queue_max_hw_sectors - set max sectors for a request for this queue
+ * @q:  the request queue for the device
+ * @max_hw_sectors:  max hardware sectors in the usual 512b unit
+ *
+ * Description:
+ *    See description for blk_limits_max_hw_sectors().
+ **/
+void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
 {
-	if (BLK_DEF_MAX_SECTORS > max_sectors)
-		q->limits.max_hw_sectors = BLK_DEF_MAX_SECTORS;
-	else
-		q->limits.max_hw_sectors = max_sectors;
+	blk_limits_max_hw_sectors(&q->limits, max_hw_sectors);
 }
 EXPORT_SYMBOL(blk_queue_max_hw_sectors);
 
 /**
+ * blk_queue_chunk_sectors - set size of the chunk for this queue
+ * @q:  the request queue for the device
+ * @chunk_sectors:  chunk sectors in the usual 512b unit
+ *
+ * Description:
+ *    If a driver doesn't want IOs to cross a given chunk size, it can set
+ *    this limit and prevent merging across chunks. Note that the chunk size
+ *    must currently be a power-of-2 in sectors. Also note that the block
+ *    layer must accept a page worth of data at any offset. So if the
+ *    crossing of chunks is a hard limitation in the driver, it must still be
+ *    prepared to split single page bios.
+ **/
+void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
+{
+	BUG_ON(!is_power_of_2(chunk_sectors));
+	q->limits.chunk_sectors = chunk_sectors;
+}
+EXPORT_SYMBOL(blk_queue_chunk_sectors);
+
+/**
  * blk_queue_max_discard_sectors - set max sectors for a single discard
  * @q:  the request queue for the device
  * @max_discard_sectors: maximum number of sectors to discard
@@ -257,41 +310,27 @@ void blk_queue_max_discard_sectors(struct request_queue *q,
 EXPORT_SYMBOL(blk_queue_max_discard_sectors);
 
 /**
- * blk_queue_max_phys_segments - set max phys segments for a request for this queue
+ * blk_queue_max_write_same_sectors - set max sectors for a single write same
  * @q:  the request queue for the device
- * @max_segments:  max number of segments
- *
- * Description:
- *    Enables a low level driver to set an upper limit on the number of
- *    physical data segments in a request.  This would be the largest sized
- *    scatter list the driver could handle.
+ * @max_write_same_sectors: maximum number of sectors to write per command
  **/
-void blk_queue_max_phys_segments(struct request_queue *q,
-				 unsigned short max_segments)
+void blk_queue_max_write_same_sectors(struct request_queue *q,
+				      unsigned int max_write_same_sectors)
 {
-	if (!max_segments) {
-		max_segments = 1;
-		printk(KERN_INFO "%s: set to minimum %d\n",
-		       __func__, max_segments);
-	}
-
-	q->limits.max_phys_segments = max_segments;
+	q->limits.max_write_same_sectors = max_write_same_sectors;
 }
-EXPORT_SYMBOL(blk_queue_max_phys_segments);
+EXPORT_SYMBOL(blk_queue_max_write_same_sectors);
 
 /**
- * blk_queue_max_hw_segments - set max hw segments for a request for this queue
+ * blk_queue_max_segments - set max hw segments for a request for this queue
  * @q:  the request queue for the device
  * @max_segments:  max number of segments
  *
  * Description:
  *    Enables a low level driver to set an upper limit on the number of
- *    hw data segments in a request.  This would be the largest number of
- *    address/length pairs the host adapter can actually give at once
- *    to the device.
+ *    hw data segments in a request.
  **/
-void blk_queue_max_hw_segments(struct request_queue *q,
-			       unsigned short max_segments)
+void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
 {
 	if (!max_segments) {
 		max_segments = 1;
@@ -299,9 +338,9 @@ void blk_queue_max_hw_segments(struct request_queue *q,
 		       __func__, max_segments);
 	}
 
-	q->limits.max_hw_segments = max_segments;
+	q->limits.max_segments = max_segments;
 }
-EXPORT_SYMBOL(blk_queue_max_hw_segments);
+EXPORT_SYMBOL(blk_queue_max_segments);
 
 /**
  * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
@@ -356,7 +395,7 @@ EXPORT_SYMBOL(blk_queue_logical_block_size);
  *   hardware can operate on without reverting to read-modify-write
  *   operations.
  */
-void blk_queue_physical_block_size(struct request_queue *q, unsigned short size)
+void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
 {
 	q->limits.physical_block_size = size;
 
@@ -468,11 +507,6 @@ void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
 }
 EXPORT_SYMBOL(blk_queue_io_opt);
 
-/*
- * Returns the minimum that is _not_ zero, unless both are zero.
- */
-#define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r))
-
 /**
  * blk_queue_stack_limits - inherit underlying queue limits for stacked drivers
  * @t:	the stacking driver (top)
@@ -481,33 +515,14 @@ EXPORT_SYMBOL(blk_queue_io_opt);
 void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
 {
 	blk_stack_limits(&t->limits, &b->limits, 0);
-
-	if (!t->queue_lock)
-		WARN_ON_ONCE(1);
-	else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) {
-		unsigned long flags;
-		spin_lock_irqsave(t->queue_lock, flags);
-		queue_flag_clear(QUEUE_FLAG_CLUSTER, t);
-		spin_unlock_irqrestore(t->queue_lock, flags);
-	}
 }
 EXPORT_SYMBOL(blk_queue_stack_limits);
 
-static unsigned int lcm(unsigned int a, unsigned int b)
-{
-	if (a && b)
-		return (a * b) / gcd(a, b);
-	else if (b)
-		return b;
-
-	return a;
-}
-
 /**
  * blk_stack_limits - adjust queue_limits for stacked devices
  * @t:	the stacking driver limits (top device)
  * @b:  the underlying queue limits (bottom, component device)
- * @offset:  offset to beginning of data within component device
+ * @start:  first data sector within component device
  *
  * Description:
  *    This function is used by stacking drivers like MD and DM to ensure
@@ -525,30 +540,29 @@ static unsigned int lcm(unsigned int a, unsigned int b)
  *    the alignment_offset is undefined.
  */
 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
-		     sector_t offset)
+		     sector_t start)
 {
-	sector_t alignment;
-	unsigned int top, bottom, ret = 0;
+	unsigned int top, bottom, alignment, ret = 0;
 
 	t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
 	t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
+	t->max_write_same_sectors = min(t->max_write_same_sectors,
+					b->max_write_same_sectors);
 	t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn);
 
 	t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
 					    b->seg_boundary_mask);
 
-	t->max_phys_segments = min_not_zero(t->max_phys_segments,
-					    b->max_phys_segments);
-
-	t->max_hw_segments = min_not_zero(t->max_hw_segments,
-					  b->max_hw_segments);
+	t->max_segments = min_not_zero(t->max_segments, b->max_segments);
+	t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
+						 b->max_integrity_segments);
 
 	t->max_segment_size = min_not_zero(t->max_segment_size,
 					   b->max_segment_size);
 
 	t->misaligned |= b->misaligned;
 
-	alignment = queue_limit_alignment_offset(b, offset);
+	alignment = queue_limit_alignment_offset(b, start);
 
 	/* Bottom device has different alignment.  Check that it is
 	 * compatible with the current top alignment.
@@ -575,7 +589,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 	t->io_min = max(t->io_min, b->io_min);
 	t->io_opt = lcm(t->io_opt, b->io_opt);
 
-	t->no_cluster |= b->no_cluster;
+	t->cluster &= b->cluster;
 	t->discard_zeroes_data &= b->discard_zeroes_data;
 
 	/* Physical block size a multiple of the logical block size? */
@@ -599,6 +613,10 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 		ret = -1;
 	}
 
+	t->raid_partial_stripes_expensive =
+		max(t->raid_partial_stripes_expensive,
+		    b->raid_partial_stripes_expensive);
+
 	/* Find lowest common alignment_offset */
 	t->alignment_offset = lcm(t->alignment_offset, alignment)
 		& (max(t->physical_block_size, t->io_min) - 1);
@@ -611,11 +629,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 
 	/* Discard alignment and granularity */
 	if (b->discard_granularity) {
-		unsigned int granularity = b->discard_granularity;
-		offset &= granularity - 1;
-
-		alignment = (granularity + b->discard_alignment - offset)
-			& (granularity - 1);
+		alignment = queue_limit_discard_alignment(b, start);
 
 		if (t->discard_granularity != 0 &&
 		    t->discard_alignment != alignment) {
@@ -623,7 +637,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 			bottom = b->discard_granularity + alignment;
 
 			/* Verify that top and bottom intervals line up */
-			if (max(top, bottom) & (min(top, bottom) - 1))
+			if ((max(top, bottom) % min(top, bottom)) != 0)
 				t->discard_misaligned = 1;
 		}
 
@@ -631,8 +645,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 						      b->max_discard_sectors);
 		t->discard_granularity = max(t->discard_granularity,
 					     b->discard_granularity);
-		t->discard_alignment = lcm(t->discard_alignment, alignment) &
-			(t->discard_granularity - 1);
+		t->discard_alignment = lcm(t->discard_alignment, alignment) %
+			t->discard_granularity;
 	}
 
 	return ret;
@@ -657,7 +671,7 @@ int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
 
 	start += get_start_sect(bdev);
 
-	return blk_stack_limits(t, &bq->limits, start << 9);
+	return blk_stack_limits(t, &bq->limits, start);
 }
 EXPORT_SYMBOL(bdev_stack_limits);
 
@@ -668,19 +682,15 @@ EXPORT_SYMBOL(bdev_stack_limits);
  * @offset:  offset to beginning of data within component device
  *
  * Description:
- *    Merges the limits for two queues.  Returns 0 if alignment
- *    didn't change.  Returns -1 if adding the bottom device caused
- *    misalignment.
+ *    Merges the limits for a top level gendisk and a bottom level
+ *    block_device.
  */
 void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
 		       sector_t offset)
 {
 	struct request_queue *t = disk->queue;
-	struct request_queue *b = bdev_get_queue(bdev);
-
-	offset += get_start_sect(bdev) << 9;
 
-	if (blk_stack_limits(&t->limits, &b->limits, offset) < 0) {
+	if (bdev_stack_limits(&t->limits, bdev, offset >> 9) < 0) {
 		char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE];
 
 		disk_name(disk, 0, top);
@@ -689,17 +699,6 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
 		printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
 		       top, bottom);
 	}
-
-	if (!t->queue_lock)
-		WARN_ON_ONCE(1);
-	else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) {
-		unsigned long flags;
-
-		spin_lock_irqsave(t->queue_lock, flags);
-		if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags))
-			queue_flag_clear(QUEUE_FLAG_CLUSTER, t);
-		spin_unlock_irqrestore(t->queue_lock, flags);
-	}
 }
 EXPORT_SYMBOL(disk_stack_limits);
 
@@ -752,22 +751,19 @@ EXPORT_SYMBOL(blk_queue_update_dma_pad);
  * does is adjust the queue so that the buf is always appended
  * silently to the scatterlist.
  *
- * Note: This routine adjusts max_hw_segments to make room for
- * appending the drain buffer.  If you call
- * blk_queue_max_hw_segments() or blk_queue_max_phys_segments() after
- * calling this routine, you must set the limit to one fewer than your
- * device can support otherwise there won't be room for the drain
- * buffer.
+ * Note: This routine adjusts max_hw_segments to make room for appending
+ * the drain buffer.  If you call blk_queue_max_segments() after calling
+ * this routine, you must set the limit to one fewer than your device
+ * can support otherwise there won't be room for the drain buffer.
  */
 int blk_queue_dma_drain(struct request_queue *q,
 			       dma_drain_needed_fn *dma_drain_needed,
 			       void *buf, unsigned int size)
 {
-	if (queue_max_hw_segments(q) < 2 || queue_max_phys_segments(q) < 2)
+	if (queue_max_segments(q) < 2)
 		return -EINVAL;
 	/* make room for appending the drain */
-	blk_queue_max_hw_segments(q, queue_max_hw_segments(q) - 1);
-	blk_queue_max_phys_segments(q, queue_max_phys_segments(q) - 1);
+	blk_queue_max_segments(q, queue_max_segments(q) - 1);
 	q->dma_drain_needed = dma_drain_needed;
 	q->dma_drain_buffer = buf;
 	q->dma_drain_size = size;
@@ -832,6 +828,32 @@ void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
 }
 EXPORT_SYMBOL(blk_queue_update_dma_alignment);
 
+/**
+ * blk_queue_flush - configure queue's cache flush capability
+ * @q:		the request queue for the device
+ * @flush:	0, REQ_FLUSH or REQ_FLUSH | REQ_FUA
+ *
+ * Tell block layer cache flush capability of @q.  If it supports
+ * flushing, REQ_FLUSH should be set.  If it supports bypassing
+ * write cache for individual writes, REQ_FUA should be set.
+ */
+void blk_queue_flush(struct request_queue *q, unsigned int flush)
+{
+	WARN_ON_ONCE(flush & ~(REQ_FLUSH | REQ_FUA));
+
+	if (WARN_ON_ONCE(!(flush & REQ_FLUSH) && (flush & REQ_FUA)))
+		flush &= ~REQ_FUA;
+
+	q->flush_flags = flush & (REQ_FLUSH | REQ_FUA);
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush);
+
+void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
+{
+	q->flush_not_queueable = !queueable;
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);
+
 static int __init blk_settings_init(void)
 {
 	blk_max_low_pfn = max_low_pfn - 1;