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

Pull block IO fixes from Jens Axboe:
 "Second round of updates and fixes for 3.14-rc2.  Most of this stuff
  has been queued up for a while.  The notable exception is the blk-mq
  changes, which are naturally a bit more in flux still.

  The pull request contains:

   - Two bug fixes for the new immutable vecs, causing crashes with raid
     or swap.  From Kent.

   - Various blk-mq tweaks and fixes from Christoph.  A fix for
     integrity bio's from Nic.

   - A few bcache fixes from Kent and Darrick Wong.

   - xen-blk{front,back} fixes from David Vrabel, Matt Rushton, Nicolas
     Swenson, and Roger Pau Monne.

   - Fix for a vec miscount with integrity vectors from Martin.

   - Minor annotations or fixes from Masanari Iida and Rashika Kheria.

   - Tweak to null_blk to do more normal FIFO processing of requests
     from Shlomo Pongratz.

   - Elevator switching bypass fix from Tejun.

   - Softlockup in blkdev_issue_discard() fix when !CONFIG_PREEMPT from
     me"

* 'for-linus' of git://git.kernel.dk/linux-block: (31 commits)
  block: add cond_resched() to potentially long running ioctl discard loop
  xen-blkback: init persistent_purge_work work_struct
  blk-mq: pair blk_mq_start_request / blk_mq_requeue_request
  blk-mq: dont assume rq->errors is set when returning an error from ->queue_rq
  block: Fix cloning of discard/write same bios
  block: Fix type mismatch in ssize_t_blk_mq_tag_sysfs_show
  blk-mq: rework flush sequencing logic
  null_blk: use blk_complete_request and blk_mq_complete_request
  virtio_blk: use blk_mq_complete_request
  blk-mq: rework I/O completions
  fs: Add prototype declaration to appropriate header file include/linux/bio.h
  fs: Mark function as static in fs/bio-integrity.c
  block/null_blk: Fix completion processing from LIFO to FIFO
  block: Explicitly handle discard/write same segments
  block: Fix nr_vecs for inline integrity vectors
  blk-mq: Add bio_integrity setup to blk_mq_make_request
  blk-mq: initialize sg_reserved_size
  blk-mq: handle dma_drain_size
  blk-mq: divert __blk_put_request for MQ ops
  blk-mq: support at_head inserations for blk_execute_rq
  ...

4 files changed, 36 insertions, 30 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 70654521dab6..5a4d39b4686b 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -250,6 +250,17 @@ static inline unsigned bio_segments(struct bio *bio)
 	struct bio_vec bv;
 	struct bvec_iter iter;
 
+	/*
+	 * We special case discard/write same, because they interpret bi_size
+	 * differently:
+	 */
+
+	if (bio->bi_rw & REQ_DISCARD)
+		return 1;
+
+	if (bio->bi_rw & REQ_WRITE_SAME)
+		return 1;
+
 	bio_for_each_segment(bv, bio, iter)
 		segs++;
 
@@ -332,6 +343,7 @@ extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
 
 extern struct bio_set *fs_bio_set;
+unsigned int bio_integrity_tag_size(struct bio *bio);
 
 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 {
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 161b23105b1e..18ba8a627f46 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -83,6 +83,8 @@ struct blk_mq_ops {
 	 */
 	rq_timed_out_fn		*timeout;
 
+	softirq_done_fn		*complete;
+
 	/*
 	 * Override for hctx allocations (should probably go)
 	 */
@@ -119,11 +121,12 @@ void blk_mq_init_commands(struct request_queue *, void (*init)(void *data, struc
 
 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 
-void blk_mq_insert_request(struct request_queue *, struct request *, bool);
+void blk_mq_insert_request(struct request_queue *, struct request *,
+		bool, bool);
 void blk_mq_run_queues(struct request_queue *q, bool async);
 void blk_mq_free_request(struct request *rq);
 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
-struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp, bool reserved);
+struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp);
 struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, gfp_t gfp);
 struct request *blk_mq_rq_from_tag(struct request_queue *q, unsigned int tag);
 
@@ -133,6 +136,8 @@ void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
 
 void blk_mq_end_io(struct request *rq, int error);
 
+void blk_mq_complete_request(struct request *rq);
+
 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
 void blk_mq_stop_hw_queues(struct request_queue *q);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 8678c4322b44..4afa4f8f6090 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -98,7 +98,7 @@ struct request {
 	struct list_head queuelist;
 	union {
 		struct call_single_data csd;
-		struct work_struct mq_flush_data;
+		struct work_struct mq_flush_work;
 	};
 
 	struct request_queue *q;
@@ -448,13 +448,8 @@ struct request_queue {
 	unsigned long		flush_pending_since;
 	struct list_head	flush_queue[2];
 	struct list_head	flush_data_in_flight;
-	union {
-		struct request	flush_rq;
-		struct {
-			spinlock_t mq_flush_lock;
-			struct work_struct mq_flush_work;
-		};
-	};
+	struct request		*flush_rq;
+	spinlock_t		mq_flush_lock;
 
 	struct mutex		sysfs_lock;
 
diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h
index ae665ac59c36..32ec05a6572f 100644
--- a/include/xen/interface/io/blkif.h
+++ b/include/xen/interface/io/blkif.h
@@ -113,13 +113,13 @@ typedef uint64_t blkif_sector_t;
  * it's less than the number provided by the backend. The indirect_grefs field
  * in blkif_request_indirect should be filled by the frontend with the
  * grant references of the pages that are holding the indirect segments.
- * This pages are filled with an array of blkif_request_segment_aligned
- * that hold the information about the segments. The number of indirect
- * pages to use is determined by the maximum number of segments
- * a indirect request contains. Every indirect page can contain a maximum
- * of 512 segments (PAGE_SIZE/sizeof(blkif_request_segment_aligned)),
- * so to calculate the number of indirect pages to use we have to do
- * ceil(indirect_segments/512).
+ * These pages are filled with an array of blkif_request_segment that hold the
+ * information about the segments. The number of indirect pages to use is
+ * determined by the number of segments an indirect request contains. Every
+ * indirect page can contain a maximum of
+ * (PAGE_SIZE / sizeof(struct blkif_request_segment)) segments, so to
+ * calculate the number of indirect pages to use we have to do
+ * ceil(indirect_segments / (PAGE_SIZE / sizeof(struct blkif_request_segment))).
  *
  * If a backend does not recognize BLKIF_OP_INDIRECT, it should *not*
  * create the "feature-max-indirect-segments" node!
@@ -135,13 +135,12 @@ typedef uint64_t blkif_sector_t;
 
 #define BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST 8
 
-struct blkif_request_segment_aligned {
-	grant_ref_t gref;        /* reference to I/O buffer frame        */
-	/* @first_sect: first sector in frame to transfer (inclusive).   */
-	/* @last_sect: last sector in frame to transfer (inclusive).     */
-	uint8_t     first_sect, last_sect;
-	uint16_t    _pad; /* padding to make it 8 bytes, so it's cache-aligned */
-} __attribute__((__packed__));
+struct blkif_request_segment {
+		grant_ref_t gref;        /* reference to I/O buffer frame        */
+		/* @first_sect: first sector in frame to transfer (inclusive).   */
+		/* @last_sect: last sector in frame to transfer (inclusive).     */
+		uint8_t     first_sect, last_sect;
+};
 
 struct blkif_request_rw {
 	uint8_t        nr_segments;  /* number of segments                   */
@@ -151,12 +150,7 @@ struct blkif_request_rw {
 #endif
 	uint64_t       id;           /* private guest value, echoed in resp  */
 	blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
-	struct blkif_request_segment {
-		grant_ref_t gref;        /* reference to I/O buffer frame        */
-		/* @first_sect: first sector in frame to transfer (inclusive).   */
-		/* @last_sect: last sector in frame to transfer (inclusive).     */
-		uint8_t     first_sect, last_sect;
-	} seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
 } __attribute__((__packed__));
 
 struct blkif_request_discard {