1 files changed, 116 insertions, 103 deletions

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 4fecf46ef681..de8c85a03bb7 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -9,6 +9,7 @@
 #include <linux/prefetch.h>
 #include <linux/srcu.h>
 #include <linux/rw_hint.h>
+#include <linux/rwsem.h>
 
 struct blk_mq_tags;
 struct blk_flush_queue;
@@ -28,7 +29,7 @@ typedef enum rq_end_io_ret (rq_end_io_fn)(struct request *, blk_status_t);
 typedef __u32 __bitwise req_flags_t;
 
 /* Keep rqf_name[] in sync with the definitions below */
-enum {
+enum rqf_flags {
 	/* drive already may have started this one */
 	__RQF_STARTED,
 	/* request for flush sequence */
@@ -156,9 +157,6 @@ struct request {
 	struct blk_crypto_keyslot *crypt_keyslot;
 #endif
 
-	enum rw_hint write_hint;
-	unsigned short ioprio;
-
 	enum mq_rq_state state;
 	atomic_t ref;
 
@@ -222,7 +220,9 @@ static inline bool blk_rq_is_passthrough(struct request *rq)
 
 static inline unsigned short req_get_ioprio(struct request *req)
 {
-	return req->ioprio;
+	if (req->bio)
+		return req->bio->bi_ioprio;
+	return 0;
 }
 
 #define rq_data_dir(rq)		(op_is_write(req_op(rq)) ? WRITE : READ)
@@ -230,62 +230,61 @@ static inline unsigned short req_get_ioprio(struct request *req)
 #define rq_dma_dir(rq) \
 	(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
 
-#define rq_list_add(listptr, rq)	do {		\
-	(rq)->rq_next = *(listptr);			\
-	*(listptr) = rq;				\
-} while (0)
-
-#define rq_list_add_tail(lastpptr, rq)	do {		\
-	(rq)->rq_next = NULL;				\
-	**(lastpptr) = rq;				\
-	*(lastpptr) = &rq->rq_next;			\
-} while (0)
-
-#define rq_list_pop(listptr)				\
-({							\
-	struct request *__req = NULL;			\
-	if ((listptr) && *(listptr))	{		\
-		__req = *(listptr);			\
-		*(listptr) = __req->rq_next;		\
-	}						\
-	__req;						\
-})
+static inline int rq_list_empty(const struct rq_list *rl)
+{
+	return rl->head == NULL;
+}
 
-#define rq_list_peek(listptr)				\
-({							\
-	struct request *__req = NULL;			\
-	if ((listptr) && *(listptr))			\
-		__req = *(listptr);			\
-	__req;						\
-})
+static inline void rq_list_init(struct rq_list *rl)
+{
+	rl->head = NULL;
+	rl->tail = NULL;
+}
+
+static inline void rq_list_add_tail(struct rq_list *rl, struct request *rq)
+{
+	rq->rq_next = NULL;
+	if (rl->tail)
+		rl->tail->rq_next = rq;
+	else
+		rl->head = rq;
+	rl->tail = rq;
+}
 
-#define rq_list_for_each(listptr, pos)			\
-	for (pos = rq_list_peek((listptr)); pos; pos = rq_list_next(pos))
+static inline void rq_list_add_head(struct rq_list *rl, struct request *rq)
+{
+	rq->rq_next = rl->head;
+	rl->head = rq;
+	if (!rl->tail)
+		rl->tail = rq;
+}
 
-#define rq_list_for_each_safe(listptr, pos, nxt)			\
-	for (pos = rq_list_peek((listptr)), nxt = rq_list_next(pos);	\
-		pos; pos = nxt, nxt = pos ? rq_list_next(pos) : NULL)
+static inline struct request *rq_list_pop(struct rq_list *rl)
+{
+	struct request *rq = rl->head;
 
-#define rq_list_next(rq)	(rq)->rq_next
-#define rq_list_empty(list)	((list) == (struct request *) NULL)
+	if (rq) {
+		rl->head = rl->head->rq_next;
+		if (!rl->head)
+			rl->tail = NULL;
+		rq->rq_next = NULL;
+	}
 
-/**
- * rq_list_move() - move a struct request from one list to another
- * @src: The source list @rq is currently in
- * @dst: The destination list that @rq will be appended to
- * @rq: The request to move
- * @prev: The request preceding @rq in @src (NULL if @rq is the head)
- */
-static inline void rq_list_move(struct request **src, struct request **dst,
-				struct request *rq, struct request *prev)
+	return rq;
+}
+
+static inline struct request *rq_list_peek(struct rq_list *rl)
 {
-	if (prev)
-		prev->rq_next = rq->rq_next;
-	else
-		*src = rq->rq_next;
-	rq_list_add(dst, rq);
+	return rl->head;
 }
 
+#define rq_list_for_each(rl, pos)					\
+	for (pos = rq_list_peek((rl)); (pos); pos = pos->rq_next)
+
+#define rq_list_for_each_safe(rl, pos, nxt)				\
+	for (pos = rq_list_peek((rl)), nxt = pos->rq_next;		\
+		pos; pos = nxt, nxt = pos ? pos->rq_next : NULL)
+
 /**
  * enum blk_eh_timer_return - How the timeout handler should proceed
  * @BLK_EH_DONE: The block driver completed the command or will complete it at
@@ -298,13 +297,6 @@ enum blk_eh_timer_return {
 	BLK_EH_RESET_TIMER,
 };
 
-/* Keep alloc_policy_name[] in sync with the definitions below */
-enum {
-	BLK_TAG_ALLOC_FIFO,	/* allocate starting from 0 */
-	BLK_TAG_ALLOC_RR,	/* allocate starting from last allocated tag */
-	BLK_TAG_ALLOC_MAX
-};
-
 /**
  * struct blk_mq_hw_ctx - State for a hardware queue facing the hardware
  * block device
@@ -515,6 +507,9 @@ enum hctx_type {
  *		   request_queue.tag_set_list.
  * @srcu:	   Use as lock when type of the request queue is blocking
  *		   (BLK_MQ_F_BLOCKING).
+ * @update_nr_hwq_lock:
+ * 		   Synchronize updating nr_hw_queues with add/del disk &
+ * 		   switching elevator.
  */
 struct blk_mq_tag_set {
 	const struct blk_mq_ops	*ops;
@@ -536,6 +531,8 @@ struct blk_mq_tag_set {
 	struct mutex		tag_list_lock;
 	struct list_head	tag_list;
 	struct srcu_struct	*srcu;
+
+	struct rw_semaphore	update_nr_hwq_lock;
 };
 
 /**
@@ -577,7 +574,7 @@ struct blk_mq_ops {
 	 * empty the @rqlist completely, then the rest will be queued
 	 * individually by the block layer upon return.
 	 */
-	void (*queue_rqs)(struct request **rqlist);
+	void (*queue_rqs)(struct rq_list *rqlist);
 
 	/**
 	 * @get_budget: Reserve budget before queue request, once .queue_rq is
@@ -670,7 +667,6 @@ struct blk_mq_ops {
 
 /* Keep hctx_flag_name[] in sync with the definitions below */
 enum {
-	BLK_MQ_F_SHOULD_MERGE	= 1 << 0,
 	BLK_MQ_F_TAG_QUEUE_SHARED = 1 << 1,
 	/*
 	 * Set when this device requires underlying blk-mq device for
@@ -679,23 +675,20 @@ enum {
 	BLK_MQ_F_STACKING	= 1 << 2,
 	BLK_MQ_F_TAG_HCTX_SHARED = 1 << 3,
 	BLK_MQ_F_BLOCKING	= 1 << 4,
-	/* Do not allow an I/O scheduler to be configured. */
-	BLK_MQ_F_NO_SCHED	= 1 << 5,
+
+	/*
+	 * Alloc tags on a round-robin base instead of the first available one.
+	 */
+	BLK_MQ_F_TAG_RR		= 1 << 5,
 
 	/*
 	 * Select 'none' during queue registration in case of a single hwq
 	 * or shared hwqs instead of 'mq-deadline'.
 	 */
 	BLK_MQ_F_NO_SCHED_BY_DEFAULT	= 1 << 6,
-	BLK_MQ_F_ALLOC_POLICY_START_BIT = 7,
-	BLK_MQ_F_ALLOC_POLICY_BITS = 1,
+
+	BLK_MQ_F_MAX = 1 << 7,
 };
-#define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
-	((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
-		((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
-#define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
-	((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
-		<< BLK_MQ_F_ALLOC_POLICY_START_BIT)
 
 #define BLK_MQ_MAX_DEPTH	(10240)
 #define BLK_MQ_NO_HCTX_IDX	(-1U)
@@ -857,12 +850,6 @@ void blk_mq_end_request_batch(struct io_comp_batch *ib);
  */
 static inline bool blk_mq_need_time_stamp(struct request *rq)
 {
-	/*
-	 * passthrough io doesn't use iostat accounting, cgroup stats
-	 * and io scheduler functionalities.
-	 */
-	if (blk_rq_is_passthrough(rq))
-		return false;
 	return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS | RQF_USE_SCHED));
 }
 
@@ -871,28 +858,46 @@ static inline bool blk_mq_is_reserved_rq(struct request *rq)
 	return rq->rq_flags & RQF_RESV;
 }
 
-/*
+/**
+ * blk_mq_add_to_batch() - add a request to the completion batch
+ * @req: The request to add to batch
+ * @iob: The batch to add the request
+ * @is_error: Specify true if the request failed with an error
+ * @complete: The completaion handler for the request
+ *
  * Batched completions only work when there is no I/O error and no special
  * ->end_io handler.
+ *
+ * Return: true when the request was added to the batch, otherwise false
  */
 static inline bool blk_mq_add_to_batch(struct request *req,
-				       struct io_comp_batch *iob, int ioerror,
+				       struct io_comp_batch *iob, bool is_error,
 				       void (*complete)(struct io_comp_batch *))
 {
 	/*
-	 * blk_mq_end_request_batch() can't end request allocated from
-	 * sched tags
+	 * Check various conditions that exclude batch processing:
+	 * 1) No batch container
+	 * 2) Has scheduler data attached
+	 * 3) Not a passthrough request and end_io set
+	 * 4) Not a passthrough request and failed with an error
 	 */
-	if (!iob || (req->rq_flags & RQF_SCHED_TAGS) || ioerror ||
-			(req->end_io && !blk_rq_is_passthrough(req)))
+	if (!iob)
+		return false;
+	if (req->rq_flags & RQF_SCHED_TAGS)
 		return false;
+	if (!blk_rq_is_passthrough(req)) {
+		if (req->end_io)
+			return false;
+		if (is_error)
+			return false;
+	}
 
 	if (!iob->complete)
 		iob->complete = complete;
 	else if (iob->complete != complete)
 		return false;
 	iob->need_ts |= blk_mq_need_time_stamp(req);
-	rq_list_add(&iob->req_list, req);
+	rq_list_add_tail(&iob->req_list, req);
 	return true;
 }
 
@@ -919,14 +924,32 @@ void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs);
 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 		busy_tag_iter_fn *fn, void *priv);
 void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset);
-void blk_mq_freeze_queue(struct request_queue *q);
-void blk_mq_unfreeze_queue(struct request_queue *q);
+void blk_mq_freeze_queue_nomemsave(struct request_queue *q);
+void blk_mq_unfreeze_queue_nomemrestore(struct request_queue *q);
+static inline unsigned int __must_check
+blk_mq_freeze_queue(struct request_queue *q)
+{
+	unsigned int memflags = memalloc_noio_save();
+
+	blk_mq_freeze_queue_nomemsave(q);
+	return memflags;
+}
+static inline void
+blk_mq_unfreeze_queue(struct request_queue *q, unsigned int memflags)
+{
+	blk_mq_unfreeze_queue_nomemrestore(q);
+	memalloc_noio_restore(memflags);
+}
 void blk_freeze_queue_start(struct request_queue *q);
 void blk_mq_freeze_queue_wait(struct request_queue *q);
 int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
 				     unsigned long timeout);
+void blk_mq_unfreeze_queue_non_owner(struct request_queue *q);
+void blk_freeze_queue_start_non_owner(struct request_queue *q);
 
 void blk_mq_map_queues(struct blk_mq_queue_map *qmap);
+void blk_mq_map_hw_queues(struct blk_mq_queue_map *qmap,
+			  struct device *dev, unsigned int offset);
 void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
 
 void blk_mq_quiesce_queue_nowait(struct request_queue *q);
@@ -983,15 +1006,6 @@ static inline void blk_mq_cleanup_rq(struct request *rq)
 		rq->q->mq_ops->cleanup_rq(rq);
 }
 
-static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
-		unsigned int nr_segs)
-{
-	rq->nr_phys_segments = nr_segs;
-	rq->__data_len = bio->bi_iter.bi_size;
-	rq->bio = rq->biotail = bio;
-	rq->ioprio = bio_prio(bio);
-}
-
 void blk_mq_hctx_set_fq_lock_class(struct blk_mq_hw_ctx *hctx,
 		struct lock_class_key *key);
 
@@ -1023,8 +1037,8 @@ int blk_rq_map_user_io(struct request *, struct rq_map_data *,
 int blk_rq_map_user_iov(struct request_queue *, struct request *,
 		struct rq_map_data *, const struct iov_iter *, gfp_t);
 int blk_rq_unmap_user(struct bio *);
-int blk_rq_map_kern(struct request_queue *, struct request *, void *,
-		unsigned int, gfp_t);
+int blk_rq_map_kern(struct request *rq, void *kbuf, unsigned int len,
+		gfp_t gfp);
 int blk_rq_append_bio(struct request *rq, struct bio *bio);
 void blk_execute_rq_nowait(struct request *rq, bool at_head);
 blk_status_t blk_execute_rq(struct request *rq, bool at_head);
@@ -1165,14 +1179,13 @@ static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
 	return max_t(unsigned short, rq->nr_phys_segments, 1);
 }
 
-int __blk_rq_map_sg(struct request_queue *q, struct request *rq,
-		struct scatterlist *sglist, struct scatterlist **last_sg);
-static inline int blk_rq_map_sg(struct request_queue *q, struct request *rq,
-		struct scatterlist *sglist)
+int __blk_rq_map_sg(struct request *rq, struct scatterlist *sglist,
+		struct scatterlist **last_sg);
+static inline int blk_rq_map_sg(struct request *rq, struct scatterlist *sglist)
 {
 	struct scatterlist *last_sg = NULL;
 
-	return __blk_rq_map_sg(q, rq, sglist, &last_sg);
+	return __blk_rq_map_sg(rq, sglist, &last_sg);
 }
 void blk_dump_rq_flags(struct request *, char *);