Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block

Pull block IO core updates from Jens Axboe:
 "This is the pull request for the core changes in the block layer for
  3.13.  It contains:

   - The new blk-mq request interface.

     This is a new and more scalable queueing model that marries the
     best part of the request based interface we currently have (which
     is fully featured, but scales poorly) and the bio based "interface"
     which the new drivers for high IOPS devices end up using because
     it's much faster than the request based one.

     The bio interface has no block layer support, since it taps into
     the stack much earlier.  This means that drivers end up having to
     implement a lot of functionality on their own, like tagging,
     timeout handling, requeue, etc.  The blk-mq interface provides all
     these.  Some drivers even provide a switch to select bio or rq and
     has code to handle both, since things like merging only works in
     the rq model and hence is faster for some workloads.  This is a
     huge mess.  Conversion of these drivers nets us a substantial code
     reduction.  Initial results on converting SCSI to this model even
     shows an 8x improvement on single queue devices.  So while the
     model was intended to work on the newer multiqueue devices, it has
     substantial improvements for "classic" hardware as well.  This code
     has gone through extensive testing and development, it's now ready
     to go.  A pull request is coming to convert virtio-blk to this
     model will be will be coming as well, with more drivers scheduled
     for 3.14 conversion.

   - Two blktrace fixes from Jan and Chen Gang.

   - A plug merge fix from Alireza Haghdoost.

   - Conversion of __get_cpu_var() from Christoph Lameter.

   - Fix for sector_div() with 64-bit divider from Geert Uytterhoeven.

   - A fix for a race between request completion and the timeout
     handling from Jeff Moyer.  This is what caused the merge conflict
     with blk-mq/core, in case you are looking at that.

   - A dm stacking fix from Mike Snitzer.

   - A code consolidation fix and duplicated code removal from Kent
     Overstreet.

   - A handful of block bug fixes from Mikulas Patocka, fixing a loop
     crash and memory corruption on blk cg.

   - Elevator switch bug fix from Tomoki Sekiyama.

  A heads-up that I had to rebase this branch.  Initially the immutable
  bio_vecs had been queued up for inclusion, but a week later, it became
  clear that it wasn't fully cooked yet.  So the decision was made to
  pull this out and postpone it until 3.14.  It was a straight forward
  rebase, just pruning out the immutable series and the later fixes of
  problems with it.  The rest of the patches applied directly and no
  further changes were made"

* 'for-3.13/core' of git://git.kernel.dk/linux-block: (31 commits)
  block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  block: Do not call sector_div() with a 64-bit divisor
  kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup()
  block: Consolidate duplicated bio_trim() implementations
  block: Use rw_copy_check_uvector()
  block: Enable sysfs nomerge control for I/O requests in the plug list
  block: properly stack underlying max_segment_size to DM device
  elevator: acquire q->sysfs_lock in elevator_change()
  elevator: Fix a race in elevator switching and md device initialization
  block: Replace __get_cpu_var uses
  bdi: test bdi_init failure
  block: fix a probe argument to blk_register_region
  loop: fix crash if blk_alloc_queue fails
  blk-core: Fix memory corruption if blkcg_init_queue fails
  block: fix race between request completion and timeout handling
  blktrace: Send BLK_TN_PROCESS events to all running traces
  blk-mq: don't disallow request merges for req->special being set
  blk-mq: mq plug list breakage
  blk-mq: fix for flush deadlock
  ...

1 files changed, 49 insertions, 11 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0e6f765aa1f5..f26ec20f6354 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -8,6 +8,7 @@
 #include <linux/major.h>
 #include <linux/genhd.h>
 #include <linux/list.h>
+#include <linux/llist.h>
 #include <linux/timer.h>
 #include <linux/workqueue.h>
 #include <linux/pagemap.h>
@@ -94,12 +95,19 @@ enum rq_cmd_type_bits {
  * as well!
  */
 struct request {
-	struct list_head queuelist;
-	struct call_single_data csd;
+	union {
+		struct list_head queuelist;
+		struct llist_node ll_list;
+	};
+	union {
+		struct call_single_data csd;
+		struct work_struct mq_flush_data;
+	};
 
 	struct request_queue *q;
+	struct blk_mq_ctx *mq_ctx;
 
-	unsigned int cmd_flags;
+	u64 cmd_flags;
 	enum rq_cmd_type_bits cmd_type;
 	unsigned long atomic_flags;
 
@@ -160,8 +168,6 @@ struct request {
 
 	unsigned short ioprio;
 
-	int ref_count;
-
 	void *special;		/* opaque pointer available for LLD use */
 	char *buffer;		/* kaddr of the current segment if available */
 
@@ -215,6 +221,8 @@ struct request_pm_state
 
 #include <linux/elevator.h>
 
+struct blk_queue_ctx;
+
 typedef void (request_fn_proc) (struct request_queue *q);
 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
@@ -313,6 +321,18 @@ struct request_queue {
 	dma_drain_needed_fn	*dma_drain_needed;
 	lld_busy_fn		*lld_busy_fn;
 
+	struct blk_mq_ops	*mq_ops;
+
+	unsigned int		*mq_map;
+
+	/* sw queues */
+	struct blk_mq_ctx	*queue_ctx;
+	unsigned int		nr_queues;
+
+	/* hw dispatch queues */
+	struct blk_mq_hw_ctx	**queue_hw_ctx;
+	unsigned int		nr_hw_queues;
+
 	/*
 	 * Dispatch queue sorting
 	 */
@@ -361,6 +381,11 @@ struct request_queue {
 	 */
 	struct kobject kobj;
 
+	/*
+	 * mq queue kobject
+	 */
+	struct kobject mq_kobj;
+
 #ifdef CONFIG_PM_RUNTIME
 	struct device		*dev;
 	int			rpm_status;
@@ -425,7 +450,13 @@ struct request_queue {
 	unsigned long		flush_pending_since;
 	struct list_head	flush_queue[2];
 	struct list_head	flush_data_in_flight;
-	struct request		flush_rq;
+	union {
+		struct request	flush_rq;
+		struct {
+			spinlock_t mq_flush_lock;
+			struct work_struct mq_flush_work;
+		};
+	};
 
 	struct mutex		sysfs_lock;
 
@@ -437,14 +468,14 @@ struct request_queue {
 	struct bsg_class_device bsg_dev;
 #endif
 
-#ifdef CONFIG_BLK_CGROUP
-	struct list_head	all_q_node;
-#endif
 #ifdef CONFIG_BLK_DEV_THROTTLING
 	/* Throttle data */
 	struct throtl_data *td;
 #endif
 	struct rcu_head		rcu_head;
+	wait_queue_head_t	mq_freeze_wq;
+	struct percpu_counter	mq_usage_counter;
+	struct list_head	all_q_node;
 };
 
 #define QUEUE_FLAG_QUEUED	1	/* uses generic tag queueing */
@@ -467,6 +498,7 @@ struct request_queue {
 #define QUEUE_FLAG_SECDISCARD  17	/* supports SECDISCARD */
 #define QUEUE_FLAG_SAME_FORCE  18	/* force complete on same CPU */
 #define QUEUE_FLAG_DEAD        19	/* queue tear-down finished */
+#define QUEUE_FLAG_INIT_DONE   20	/* queue is initialized */
 
 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
 				 (1 << QUEUE_FLAG_STACKABLE)	|	\
@@ -539,6 +571,7 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 #define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
 #define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
 #define blk_queue_bypass(q)	test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
+#define blk_queue_init_done(q)	test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 #define blk_queue_noxmerges(q)	\
 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
@@ -570,7 +603,7 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 
 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
 
-#define rq_data_dir(rq)		((rq)->cmd_flags & 1)
+#define rq_data_dir(rq)		(((rq)->cmd_flags & 1) != 0)
 
 static inline unsigned int blk_queue_cluster(struct request_queue *q)
 {
@@ -1013,6 +1046,7 @@ static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
 struct blk_plug {
 	unsigned long magic; /* detect uninitialized use-cases */
 	struct list_head list; /* requests */
+	struct list_head mq_list; /* blk-mq requests */
 	struct list_head cb_list; /* md requires an unplug callback */
 };
 #define BLK_MAX_REQUEST_COUNT 16
@@ -1050,7 +1084,10 @@ static inline bool blk_needs_flush_plug(struct task_struct *tsk)
 {
 	struct blk_plug *plug = tsk->plug;
 
-	return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list));
+	return plug &&
+		(!list_empty(&plug->list) ||
+		 !list_empty(&plug->mq_list) ||
+		 !list_empty(&plug->cb_list));
 }
 
 /*
@@ -1325,6 +1362,7 @@ static inline void put_dev_sector(Sector p)
 
 struct work_struct;
 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
+int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
 
 #ifdef CONFIG_BLK_CGROUP
 /*