block: move struct request to blk-mq.h

struct request is only used by blk-mq drivers, so move it and all
related declarations to blk-mq.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 465 insertions, 0 deletions

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 13ba1861e688..bd4086a6f28e 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -6,10 +6,218 @@
 #include <linux/sbitmap.h>
 #include <linux/srcu.h>
 #include <linux/lockdep.h>
+#include <linux/scatterlist.h>
 
 struct blk_mq_tags;
 struct blk_flush_queue;
 
+#define BLKDEV_MIN_RQ	4
+#define BLKDEV_MAX_RQ	128	/* Default maximum */
+
+typedef void (rq_end_io_fn)(struct request *, blk_status_t);
+
+/*
+ * request flags */
+typedef __u32 __bitwise req_flags_t;
+
+/* drive already may have started this one */
+#define RQF_STARTED		((__force req_flags_t)(1 << 1))
+/* may not be passed by ioscheduler */
+#define RQF_SOFTBARRIER		((__force req_flags_t)(1 << 3))
+/* request for flush sequence */
+#define RQF_FLUSH_SEQ		((__force req_flags_t)(1 << 4))
+/* merge of different types, fail separately */
+#define RQF_MIXED_MERGE		((__force req_flags_t)(1 << 5))
+/* track inflight for MQ */
+#define RQF_MQ_INFLIGHT		((__force req_flags_t)(1 << 6))
+/* don't call prep for this one */
+#define RQF_DONTPREP		((__force req_flags_t)(1 << 7))
+/* vaguely specified driver internal error.  Ignored by the block layer */
+#define RQF_FAILED		((__force req_flags_t)(1 << 10))
+/* don't warn about errors */
+#define RQF_QUIET		((__force req_flags_t)(1 << 11))
+/* elevator private data attached */
+#define RQF_ELVPRIV		((__force req_flags_t)(1 << 12))
+/* account into disk and partition IO statistics */
+#define RQF_IO_STAT		((__force req_flags_t)(1 << 13))
+/* runtime pm request */
+#define RQF_PM			((__force req_flags_t)(1 << 15))
+/* on IO scheduler merge hash */
+#define RQF_HASHED		((__force req_flags_t)(1 << 16))
+/* track IO completion time */
+#define RQF_STATS		((__force req_flags_t)(1 << 17))
+/* Look at ->special_vec for the actual data payload instead of the
+   bio chain. */
+#define RQF_SPECIAL_PAYLOAD	((__force req_flags_t)(1 << 18))
+/* The per-zone write lock is held for this request */
+#define RQF_ZONE_WRITE_LOCKED	((__force req_flags_t)(1 << 19))
+/* already slept for hybrid poll */
+#define RQF_MQ_POLL_SLEPT	((__force req_flags_t)(1 << 20))
+/* ->timeout has been called, don't expire again */
+#define RQF_TIMED_OUT		((__force req_flags_t)(1 << 21))
+
+/* flags that prevent us from merging requests: */
+#define RQF_NOMERGE_FLAGS \
+	(RQF_STARTED | RQF_SOFTBARRIER | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD)
+
+enum mq_rq_state {
+	MQ_RQ_IDLE		= 0,
+	MQ_RQ_IN_FLIGHT		= 1,
+	MQ_RQ_COMPLETE		= 2,
+};
+
+/*
+ * Try to put the fields that are referenced together in the same cacheline.
+ *
+ * If you modify this structure, make sure to update blk_rq_init() and
+ * especially blk_mq_rq_ctx_init() to take care of the added fields.
+ */
+struct request {
+	struct request_queue *q;
+	struct blk_mq_ctx *mq_ctx;
+	struct blk_mq_hw_ctx *mq_hctx;
+
+	unsigned int cmd_flags;		/* op and common flags */
+	req_flags_t rq_flags;
+
+	int tag;
+	int internal_tag;
+
+	/* the following two fields are internal, NEVER access directly */
+	unsigned int __data_len;	/* total data len */
+	sector_t __sector;		/* sector cursor */
+
+	struct bio *bio;
+	struct bio *biotail;
+
+	struct list_head queuelist;
+
+	/*
+	 * The hash is used inside the scheduler, and killed once the
+	 * request reaches the dispatch list. The ipi_list is only used
+	 * to queue the request for softirq completion, which is long
+	 * after the request has been unhashed (and even removed from
+	 * the dispatch list).
+	 */
+	union {
+		struct hlist_node hash;	/* merge hash */
+		struct llist_node ipi_list;
+	};
+
+	/*
+	 * The rb_node is only used inside the io scheduler, requests
+	 * are pruned when moved to the dispatch queue. So let the
+	 * completion_data share space with the rb_node.
+	 */
+	union {
+		struct rb_node rb_node;	/* sort/lookup */
+		struct bio_vec special_vec;
+		void *completion_data;
+		int error_count; /* for legacy drivers, don't use */
+	};
+
+	/*
+	 * Three pointers are available for the IO schedulers, if they need
+	 * more they have to dynamically allocate it.  Flush requests are
+	 * never put on the IO scheduler. So let the flush fields share
+	 * space with the elevator data.
+	 */
+	union {
+		struct {
+			struct io_cq		*icq;
+			void			*priv[2];
+		} elv;
+
+		struct {
+			unsigned int		seq;
+			struct list_head	list;
+			rq_end_io_fn		*saved_end_io;
+		} flush;
+	};
+
+	struct gendisk *rq_disk;
+	struct block_device *part;
+#ifdef CONFIG_BLK_RQ_ALLOC_TIME
+	/* Time that the first bio started allocating this request. */
+	u64 alloc_time_ns;
+#endif
+	/* Time that this request was allocated for this IO. */
+	u64 start_time_ns;
+	/* Time that I/O was submitted to the device. */
+	u64 io_start_time_ns;
+
+#ifdef CONFIG_BLK_WBT
+	unsigned short wbt_flags;
+#endif
+	/*
+	 * rq sectors used for blk stats. It has the same value
+	 * with blk_rq_sectors(rq), except that it never be zeroed
+	 * by completion.
+	 */
+	unsigned short stats_sectors;
+
+	/*
+	 * Number of scatter-gather DMA addr+len pairs after
+	 * physical address coalescing is performed.
+	 */
+	unsigned short nr_phys_segments;
+
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+	unsigned short nr_integrity_segments;
+#endif
+
+#ifdef CONFIG_BLK_INLINE_ENCRYPTION
+	struct bio_crypt_ctx *crypt_ctx;
+	struct blk_ksm_keyslot *crypt_keyslot;
+#endif
+
+	unsigned short write_hint;
+	unsigned short ioprio;
+
+	enum mq_rq_state state;
+	refcount_t ref;
+
+	unsigned int timeout;
+	unsigned long deadline;
+
+	union {
+		struct __call_single_data csd;
+		u64 fifo_time;
+	};
+
+	/*
+	 * completion callback.
+	 */
+	rq_end_io_fn *end_io;
+	void *end_io_data;
+};
+
+#define req_op(req) \
+	((req)->cmd_flags & REQ_OP_MASK)
+
+static inline bool blk_rq_is_passthrough(struct request *rq)
+{
+	return blk_op_is_passthrough(req_op(rq));
+}
+
+static inline unsigned short req_get_ioprio(struct request *req)
+{
+	return req->ioprio;
+}
+
+#define rq_data_dir(rq)		(op_is_write(req_op(rq)) ? WRITE : READ)
+
+#define rq_dma_dir(rq) \
+	(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
+
+enum blk_eh_timer_return {
+	BLK_EH_DONE,		/* drivers has completed the command */
+	BLK_EH_RESET_TIMER,	/* reset timer and try again */
+};
+
+#define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
+#define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
+
 /**
  * struct blk_mq_hw_ctx - State for a hardware queue facing the hardware
  * block device
@@ -637,4 +845,261 @@ blk_qc_t blk_mq_submit_bio(struct bio *bio);
 void blk_mq_hctx_set_fq_lock_class(struct blk_mq_hw_ctx *hctx,
 		struct lock_class_key *key);
 
+static inline bool rq_is_sync(struct request *rq)
+{
+	return op_is_sync(rq->cmd_flags);
+}
+
+void blk_rq_init(struct request_queue *q, struct request *rq);
+void blk_put_request(struct request *rq);
+struct request *blk_get_request(struct request_queue *q, unsigned int op,
+		blk_mq_req_flags_t flags);
+int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
+		struct bio_set *bs, gfp_t gfp_mask,
+		int (*bio_ctr)(struct bio *, struct bio *, void *), void *data);
+void blk_rq_unprep_clone(struct request *rq);
+blk_status_t blk_insert_cloned_request(struct request_queue *q,
+		struct request *rq);
+
+struct rq_map_data {
+	struct page **pages;
+	int page_order;
+	int nr_entries;
+	unsigned long offset;
+	int null_mapped;
+	int from_user;
+};
+
+int blk_rq_map_user(struct request_queue *, struct request *,
+		struct rq_map_data *, void __user *, unsigned long, gfp_t);
+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_append_bio(struct request *rq, struct bio *bio);
+void blk_execute_rq_nowait(struct gendisk *, struct request *, int,
+		rq_end_io_fn *);
+blk_status_t blk_execute_rq(struct gendisk *bd_disk, struct request *rq,
+		int at_head);
+
+struct req_iterator {
+	struct bvec_iter iter;
+	struct bio *bio;
+};
+
+#define __rq_for_each_bio(_bio, rq)	\
+	if ((rq->bio))			\
+		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
+
+#define rq_for_each_segment(bvl, _rq, _iter)			\
+	__rq_for_each_bio(_iter.bio, _rq)			\
+		bio_for_each_segment(bvl, _iter.bio, _iter.iter)
+
+#define rq_for_each_bvec(bvl, _rq, _iter)			\
+	__rq_for_each_bio(_iter.bio, _rq)			\
+		bio_for_each_bvec(bvl, _iter.bio, _iter.iter)
+
+#define rq_iter_last(bvec, _iter)				\
+		(_iter.bio->bi_next == NULL &&			\
+		 bio_iter_last(bvec, _iter.iter))
+
+/*
+ * blk_rq_pos()			: the current sector
+ * blk_rq_bytes()		: bytes left in the entire request
+ * blk_rq_cur_bytes()		: bytes left in the current segment
+ * blk_rq_err_bytes()		: bytes left till the next error boundary
+ * blk_rq_sectors()		: sectors left in the entire request
+ * blk_rq_cur_sectors()		: sectors left in the current segment
+ * blk_rq_stats_sectors()	: sectors of the entire request used for stats
+ */
+static inline sector_t blk_rq_pos(const struct request *rq)
+{
+	return rq->__sector;
+}
+
+static inline unsigned int blk_rq_bytes(const struct request *rq)
+{
+	return rq->__data_len;
+}
+
+static inline int blk_rq_cur_bytes(const struct request *rq)
+{
+	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
+}
+
+unsigned int blk_rq_err_bytes(const struct request *rq);
+
+static inline unsigned int blk_rq_sectors(const struct request *rq)
+{
+	return blk_rq_bytes(rq) >> SECTOR_SHIFT;
+}
+
+static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
+{
+	return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
+}
+
+static inline unsigned int blk_rq_stats_sectors(const struct request *rq)
+{
+	return rq->stats_sectors;
+}
+
+/*
+ * Some commands like WRITE SAME have a payload or data transfer size which
+ * is different from the size of the request.  Any driver that supports such
+ * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
+ * calculate the data transfer size.
+ */
+static inline unsigned int blk_rq_payload_bytes(struct request *rq)
+{
+	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+		return rq->special_vec.bv_len;
+	return blk_rq_bytes(rq);
+}
+
+/*
+ * Return the first full biovec in the request.  The caller needs to check that
+ * there are any bvecs before calling this helper.
+ */
+static inline struct bio_vec req_bvec(struct request *rq)
+{
+	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+		return rq->special_vec;
+	return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter);
+}
+
+static inline unsigned int blk_rq_count_bios(struct request *rq)
+{
+	unsigned int nr_bios = 0;
+	struct bio *bio;
+
+	__rq_for_each_bio(bio, rq)
+		nr_bios++;
+
+	return nr_bios;
+}
+
+void blk_steal_bios(struct bio_list *list, struct request *rq);
+
+/*
+ * Request completion related functions.
+ *
+ * blk_update_request() completes given number of bytes and updates
+ * the request without completing it.
+ */
+bool blk_update_request(struct request *rq, blk_status_t error,
+			       unsigned int nr_bytes);
+void blk_abort_request(struct request *);
+
+/*
+ * Number of physical segments as sent to the device.
+ *
+ * Normally this is the number of discontiguous data segments sent by the
+ * submitter.  But for data-less command like discard we might have no
+ * actual data segments submitted, but the driver might have to add it's
+ * own special payload.  In that case we still return 1 here so that this
+ * special payload will be mapped.
+ */
+static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
+{
+	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+		return 1;
+	return rq->nr_phys_segments;
+}
+
+/*
+ * Number of discard segments (or ranges) the driver needs to fill in.
+ * Each discard bio merged into a request is counted as one segment.
+ */
+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)
+{
+	struct scatterlist *last_sg = NULL;
+
+	return __blk_rq_map_sg(q, rq, sglist, &last_sg);
+}
+void blk_dump_rq_flags(struct request *, char *);
+
+#ifdef CONFIG_BLK_DEV_ZONED
+static inline unsigned int blk_rq_zone_no(struct request *rq)
+{
+	return blk_queue_zone_no(rq->q, blk_rq_pos(rq));
+}
+
+static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
+{
+	return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
+}
+
+bool blk_req_needs_zone_write_lock(struct request *rq);
+bool blk_req_zone_write_trylock(struct request *rq);
+void __blk_req_zone_write_lock(struct request *rq);
+void __blk_req_zone_write_unlock(struct request *rq);
+
+static inline void blk_req_zone_write_lock(struct request *rq)
+{
+	if (blk_req_needs_zone_write_lock(rq))
+		__blk_req_zone_write_lock(rq);
+}
+
+static inline void blk_req_zone_write_unlock(struct request *rq)
+{
+	if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED)
+		__blk_req_zone_write_unlock(rq);
+}
+
+static inline bool blk_req_zone_is_write_locked(struct request *rq)
+{
+	return rq->q->seq_zones_wlock &&
+		test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock);
+}
+
+static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
+{
+	if (!blk_req_needs_zone_write_lock(rq))
+		return true;
+	return !blk_req_zone_is_write_locked(rq);
+}
+#else /* CONFIG_BLK_DEV_ZONED */
+static inline bool blk_req_needs_zone_write_lock(struct request *rq)
+{
+	return false;
+}
+
+static inline void blk_req_zone_write_lock(struct request *rq)
+{
+}
+
+static inline void blk_req_zone_write_unlock(struct request *rq)
+{
+}
+static inline bool blk_req_zone_is_write_locked(struct request *rq)
+{
+	return false;
+}
+
+static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
+{
+	return true;
+}
+#endif /* CONFIG_BLK_DEV_ZONED */
+
+#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+# error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 #endif
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+void rq_flush_dcache_pages(struct request *rq);
+#else
+static inline void rq_flush_dcache_pages(struct request *rq)
+{
+}
+#endif /* ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE */
+#endif /* BLK_MQ_H */