move all struct request releated code out of blk-core.c (rebased)

move all struct request releated code out of blk-core.c (rebased)

[Christoph Hellwig]

Hi Jens,

this series (against the for-5.16/passthrough-flag branch) removes the
remaining struct request related code from blk-core.c and cleans up a
few related bits around that.

Diffstat:
 b/block/Makefile            |    2 
 b/block/blk-core.c          |  341 --------------------------
 b/block/blk-mq.c            |  573 ++++++++++++++++++++++++++++++++++++--------
 b/block/blk-mq.h            |    3 
 b/block/blk.h               |   33 --
 b/drivers/mtd/mtd_blkdevs.c |   10 
 b/drivers/mtd/ubi/block.c   |    6 
 b/drivers/scsi/scsi_lib.c   |   42 +++
 b/include/linux/blk-mq.h    |   13 
 block/blk-exec.c            |  116 --------
 10 files changed, 552 insertions(+), 587 deletions(-)

[PATCH 01/11] block: move blk_rq_err_bytes to scsi

[Christoph Hellwig]

blk_rq_err_bytes is only used by the scsi midlayer, so move it there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c        | 41 ----------------------------------------
 drivers/scsi/scsi_lib.c | 42 ++++++++++++++++++++++++++++++++++++++++-
 include/linux/blk-mq.h  |  3 ---
 3 files changed, 41 insertions(+), 45 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 9ee32f85d74e1..e27a659973965 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1173,47 +1173,6 @@ blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *
 }
 EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
 
-/**
- * blk_rq_err_bytes - determine number of bytes till the next failure boundary
- * @rq: request to examine
- *
- * Description:
- *     A request could be merge of IOs which require different failure
- *     handling.  This function determines the number of bytes which
- *     can be failed from the beginning of the request without
- *     crossing into area which need to be retried further.
- *
- * Return:
- *     The number of bytes to fail.
- */
-unsigned int blk_rq_err_bytes(const struct request *rq)
-{
-	unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK;
-	unsigned int bytes = 0;
-	struct bio *bio;
-
-	if (!(rq->rq_flags & RQF_MIXED_MERGE))
-		return blk_rq_bytes(rq);
-
-	/*
-	 * Currently the only 'mixing' which can happen is between
-	 * different fastfail types.  We can safely fail portions
-	 * which have all the failfast bits that the first one has -
-	 * the ones which are at least as eager to fail as the first
-	 * one.
-	 */
-	for (bio = rq->bio; bio; bio = bio->bi_next) {
-		if ((bio->bi_opf & ff) != ff)
-			break;
-		bytes += bio->bi_iter.bi_size;
-	}
-
-	/* this could lead to infinite loop */
-	BUG_ON(blk_rq_bytes(rq) && !bytes);
-	return bytes;
-}
-EXPORT_SYMBOL_GPL(blk_rq_err_bytes);
-
 static void update_io_ticks(struct block_device *part, unsigned long now,
 		bool end)
 {
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 621d841d819a3..5e8b5ecb3245a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -617,6 +617,46 @@ static blk_status_t scsi_result_to_blk_status(struct scsi_cmnd *cmd, int result)
 	}
 }
 
+/**
+ * scsi_rq_err_bytes - determine number of bytes till the next failure boundary
+ * @rq: request to examine
+ *
+ * Description:
+ *     A request could be merge of IOs which require different failure
+ *     handling.  This function determines the number of bytes which
+ *     can be failed from the beginning of the request without
+ *     crossing into area which need to be retried further.
+ *
+ * Return:
+ *     The number of bytes to fail.
+ */
+static unsigned int scsi_rq_err_bytes(const struct request *rq)
+{
+	unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK;
+	unsigned int bytes = 0;
+	struct bio *bio;
+
+	if (!(rq->rq_flags & RQF_MIXED_MERGE))
+		return blk_rq_bytes(rq);
+
+	/*
+	 * Currently the only 'mixing' which can happen is between
+	 * different fastfail types.  We can safely fail portions
+	 * which have all the failfast bits that the first one has -
+	 * the ones which are at least as eager to fail as the first
+	 * one.
+	 */
+	for (bio = rq->bio; bio; bio = bio->bi_next) {
+		if ((bio->bi_opf & ff) != ff)
+			break;
+		bytes += bio->bi_iter.bi_size;
+	}
+
+	/* this could lead to infinite loop */
+	BUG_ON(blk_rq_bytes(rq) && !bytes);
+	return bytes;
+}
+
 /* Helper for scsi_io_completion() when "reprep" action required. */
 static void scsi_io_completion_reprep(struct scsi_cmnd *cmd,
 				      struct request_queue *q)
@@ -794,7 +834,7 @@ static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
 				scsi_print_command(cmd);
 			}
 		}
-		if (!scsi_end_request(req, blk_stat, blk_rq_err_bytes(req)))
+		if (!scsi_end_request(req, blk_stat, scsi_rq_err_bytes(req)))
 			return;
 		fallthrough;
 	case ACTION_REPREP:
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 2949d9ac74849..a78d9a0f2a1be 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -947,7 +947,6 @@ struct req_iterator {
  * 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
@@ -971,8 +970,6 @@ static inline int blk_rq_cur_bytes(const struct request *rq)
 	return bio_iovec(rq->bio).bv_len;
 }
 
-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;
-- 
2.30.2

[PATCH 02/11] block: remove rq_flush_dcache_pages

[Christoph Hellwig]

This function is trivial, and flush_dcache_page is always defined, so
just open code it in the 2.5 callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c          | 19 -------------------
 drivers/mtd/mtd_blkdevs.c | 10 ++++++++--
 drivers/mtd/ubi/block.c   |  6 +++++-
 include/linux/blk-mq.h    | 10 ----------
 4 files changed, 13 insertions(+), 32 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index e27a659973965..f1ca31a89493a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1297,25 +1297,6 @@ void blk_steal_bios(struct bio_list *list, struct request *rq)
 }
 EXPORT_SYMBOL_GPL(blk_steal_bios);
 
-#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
-/**
- * rq_flush_dcache_pages - Helper function to flush all pages in a request
- * @rq: the request to be flushed
- *
- * Description:
- *     Flush all pages in @rq.
- */
-void rq_flush_dcache_pages(struct request *rq)
-{
-	struct req_iterator iter;
-	struct bio_vec bvec;
-
-	rq_for_each_segment(bvec, rq, iter)
-		flush_dcache_page(bvec.bv_page);
-}
-EXPORT_SYMBOL_GPL(rq_flush_dcache_pages);
-#endif
-
 /**
  * blk_lld_busy - Check if underlying low-level drivers of a device are busy
  * @q : the queue of the device being checked
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 4eaba6f4ec680..66f81d42fe778 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -46,6 +46,8 @@ static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr,
 			       struct mtd_blktrans_dev *dev,
 			       struct request *req)
 {
+	struct req_iterator iter;
+	struct bio_vec bvec;
 	unsigned long block, nsect;
 	char *buf;
 
@@ -76,13 +78,17 @@ static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr,
 			}
 		}
 		kunmap(bio_page(req->bio));
-		rq_flush_dcache_pages(req);
+
+		rq_for_each_segment(bvec, req, iter)
+			flush_dcache_page(bvec.bv_page);
 		return BLK_STS_OK;
 	case REQ_OP_WRITE:
 		if (!tr->writesect)
 			return BLK_STS_IOERR;
 
-		rq_flush_dcache_pages(req);
+		rq_for_each_segment(bvec, req, iter)
+			flush_dcache_page(bvec.bv_page);
+
 		buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
 		for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
 			if (tr->writesect(dev, block, buf)) {
diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index 062e6c2c45f5f..302426ab30f8d 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -294,6 +294,8 @@ static void ubiblock_do_work(struct work_struct *work)
 	int ret;
 	struct ubiblock_pdu *pdu = container_of(work, struct ubiblock_pdu, work);
 	struct request *req = blk_mq_rq_from_pdu(pdu);
+	struct req_iterator iter;
+	struct bio_vec bvec;
 
 	blk_mq_start_request(req);
 
@@ -305,7 +307,9 @@ static void ubiblock_do_work(struct work_struct *work)
 	blk_rq_map_sg(req->q, req, pdu->usgl.sg);
 
 	ret = ubiblock_read(pdu);
-	rq_flush_dcache_pages(req);
+
+	rq_for_each_segment(bvec, req, iter)
+		flush_dcache_page(bvec.bv_page);
 
 	blk_mq_end_request(req, errno_to_blk_status(ret));
 }
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index a78d9a0f2a1be..308edc2a4925b 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -1132,14 +1132,4 @@ static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
 }
 #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 */
-- 
2.30.2

[PATCH 03/11] block: remove blk-exec.c

[Christoph Hellwig]

All this code is tightly coupled to the blk-mq core, so move it
there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/Makefile   |   2 +-
 block/blk-exec.c | 116 -----------------------------------------------
 block/blk-mq.c   | 107 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 108 insertions(+), 117 deletions(-)
 delete mode 100644 block/blk-exec.c

diff --git a/block/Makefile b/block/Makefile
index 44df57e562bf0..f38eaa6129296 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -5,7 +5,7 @@
 
 obj-y		:= bdev.o fops.o bio.o elevator.o blk-core.o blk-sysfs.o \
 			blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
-			blk-exec.o blk-merge.o blk-timeout.o \
+			blk-merge.o blk-timeout.o \
 			blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \
 			blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \
 			genhd.o ioprio.o badblocks.o partitions/ blk-rq-qos.o \
diff --git a/block/blk-exec.c b/block/blk-exec.c
deleted file mode 100644
index 1b8b47f6e79bb..0000000000000
--- a/block/blk-exec.c
+++ /dev/null
@@ -1,116 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Functions related to setting various queue properties from drivers
- */
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/blk-mq.h>
-#include <linux/sched/sysctl.h>
-
-#include "blk.h"
-#include "blk-mq-sched.h"
-
-/**
- * blk_end_sync_rq - executes a completion event on a request
- * @rq: request to complete
- * @error: end I/O status of the request
- */
-static void blk_end_sync_rq(struct request *rq, blk_status_t error)
-{
-	struct completion *waiting = rq->end_io_data;
-
-	rq->end_io_data = (void *)(uintptr_t)error;
-
-	/*
-	 * complete last, if this is a stack request the process (and thus
-	 * the rq pointer) could be invalid right after this complete()
-	 */
-	complete(waiting);
-}
-
-/**
- * blk_execute_rq_nowait - insert a request to I/O scheduler for execution
- * @bd_disk:	matching gendisk
- * @rq:		request to insert
- * @at_head:    insert request at head or tail of queue
- * @done:	I/O completion handler
- *
- * Description:
- *    Insert a fully prepared request at the back of the I/O scheduler queue
- *    for execution.  Don't wait for completion.
- *
- * Note:
- *    This function will invoke @done directly if the queue is dead.
- */
-void blk_execute_rq_nowait(struct gendisk *bd_disk, struct request *rq,
-			   int at_head, rq_end_io_fn *done)
-{
-	WARN_ON(irqs_disabled());
-	WARN_ON(!blk_rq_is_passthrough(rq));
-
-	rq->rq_disk = bd_disk;
-	rq->end_io = done;
-
-	blk_account_io_start(rq);
-
-	/*
-	 * don't check dying flag for MQ because the request won't
-	 * be reused after dying flag is set
-	 */
-	blk_mq_sched_insert_request(rq, at_head, true, false);
-}
-EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
-
-static bool blk_rq_is_poll(struct request *rq)
-{
-	if (!rq->mq_hctx)
-		return false;
-	if (rq->mq_hctx->type != HCTX_TYPE_POLL)
-		return false;
-	if (WARN_ON_ONCE(!rq->bio))
-		return false;
-	return true;
-}
-
-static void blk_rq_poll_completion(struct request *rq, struct completion *wait)
-{
-	do {
-		bio_poll(rq->bio, NULL, 0);
-		cond_resched();
-	} while (!completion_done(wait));
-}
-
-/**
- * blk_execute_rq - insert a request into queue for execution
- * @bd_disk:	matching gendisk
- * @rq:		request to insert
- * @at_head:    insert request at head or tail of queue
- *
- * Description:
- *    Insert a fully prepared request at the back of the I/O scheduler queue
- *    for execution and wait for completion.
- * Return: The blk_status_t result provided to blk_mq_end_request().
- */
-blk_status_t blk_execute_rq(struct gendisk *bd_disk, struct request *rq, int at_head)
-{
-	DECLARE_COMPLETION_ONSTACK(wait);
-	unsigned long hang_check;
-
-	rq->end_io_data = &wait;
-	blk_execute_rq_nowait(bd_disk, rq, at_head, blk_end_sync_rq);
-
-	/* Prevent hang_check timer from firing at us during very long I/O */
-	hang_check = sysctl_hung_task_timeout_secs;
-
-	if (blk_rq_is_poll(rq))
-		blk_rq_poll_completion(rq, &wait);
-	else if (hang_check)
-		while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2)));
-	else
-		wait_for_completion_io(&wait);
-
-	return (blk_status_t)(uintptr_t)rq->end_io_data;
-}
-EXPORT_SYMBOL(blk_execute_rq);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3ab34c4f20daf..c33411f9ce898 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -28,6 +28,7 @@
 #include <linux/crash_dump.h>
 #include <linux/prefetch.h>
 #include <linux/blk-crypto.h>
+#include <linux/sched/sysctl.h>
 
 #include <trace/events/block.h>
 
@@ -1057,6 +1058,112 @@ void blk_mq_start_request(struct request *rq)
 }
 EXPORT_SYMBOL(blk_mq_start_request);
 
+/**
+ * blk_end_sync_rq - executes a completion event on a request
+ * @rq: request to complete
+ * @error: end I/O status of the request
+ */
+static void blk_end_sync_rq(struct request *rq, blk_status_t error)
+{
+	struct completion *waiting = rq->end_io_data;
+
+	rq->end_io_data = (void *)(uintptr_t)error;
+
+	/*
+	 * complete last, if this is a stack request the process (and thus
+	 * the rq pointer) could be invalid right after this complete()
+	 */
+	complete(waiting);
+}
+
+/**
+ * blk_execute_rq_nowait - insert a request to I/O scheduler for execution
+ * @bd_disk:	matching gendisk
+ * @rq:		request to insert
+ * @at_head:    insert request at head or tail of queue
+ * @done:	I/O completion handler
+ *
+ * Description:
+ *    Insert a fully prepared request at the back of the I/O scheduler queue
+ *    for execution.  Don't wait for completion.
+ *
+ * Note:
+ *    This function will invoke @done directly if the queue is dead.
+ */
+void blk_execute_rq_nowait(struct gendisk *bd_disk, struct request *rq,
+			   int at_head, rq_end_io_fn *done)
+{
+	WARN_ON(irqs_disabled());
+	WARN_ON(!blk_rq_is_passthrough(rq));
+
+	rq->rq_disk = bd_disk;
+	rq->end_io = done;
+
+	blk_account_io_start(rq);
+
+	/*
+	 * don't check dying flag for MQ because the request won't
+	 * be reused after dying flag is set
+	 */
+	blk_mq_sched_insert_request(rq, at_head, true, false);
+}
+EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
+
+static bool blk_rq_is_poll(struct request *rq)
+{
+	if (!rq->mq_hctx)
+		return false;
+	if (rq->mq_hctx->type != HCTX_TYPE_POLL)
+		return false;
+	if (WARN_ON_ONCE(!rq->bio))
+		return false;
+	return true;
+}
+
+static void blk_rq_poll_completion(struct request *rq, struct completion *wait)
+{
+	do {
+		bio_poll(rq->bio, NULL, 0);
+		cond_resched();
+	} while (!completion_done(wait));
+}
+
+/**
+ * blk_execute_rq - insert a request into queue for execution
+ * @bd_disk:	matching gendisk
+ * @rq:		request to insert
+ * @at_head:    insert request at head or tail of queue
+ *
+ * Description:
+ *    Insert a fully prepared request at the back of the I/O scheduler queue
+ *    for execution and wait for completion.
+ * Return: The blk_status_t result provided to blk_mq_end_request().
+ */
+blk_status_t blk_execute_rq(struct gendisk *bd_disk, struct request *rq,
+		int at_head)
+{
+	DECLARE_COMPLETION_ONSTACK(wait);
+	unsigned long hang_check;
+
+	rq->end_io_data = &wait;
+	blk_execute_rq_nowait(bd_disk, rq, at_head, blk_end_sync_rq);
+
+	/* Prevent hang_check timer from firing at us during very long I/O */
+	hang_check = sysctl_hung_task_timeout_secs;
+
+	if (blk_rq_is_poll(rq))
+		blk_rq_poll_completion(rq, &wait);
+	else if (hang_check)
+		while (!wait_for_completion_io_timeout(&wait,
+				hang_check * (HZ/2)))
+			;
+	else
+		wait_for_completion_io(&wait);
+
+	return (blk_status_t)(uintptr_t)rq->end_io_data;
+}
+EXPORT_SYMBOL(blk_execute_rq);
+
 static void __blk_mq_requeue_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
-- 
2.30.2

[PATCH 04/11] blk-mq: move blk_mq_flush_plug_list

[Christoph Hellwig]

Move blk_mq_flush_plug_list and blk_mq_plug_issue_direct down in blk-mq.c
to prepare for marking blk_mq_request_issue_directly static without the
need of a forward declaration.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-mq.c | 184 ++++++++++++++++++++++++-------------------------
 1 file changed, 92 insertions(+), 92 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index c33411f9ce898..d70a470c9c1f1 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2308,98 +2308,6 @@ static void blk_mq_commit_rqs(struct blk_mq_hw_ctx *hctx, int *queued,
 	*queued = 0;
 }
 
-static void blk_mq_plug_issue_direct(struct blk_plug *plug, bool from_schedule)
-{
-	struct blk_mq_hw_ctx *hctx = NULL;
-	struct request *rq;
-	int queued = 0;
-	int errors = 0;
-
-	while ((rq = rq_list_pop(&plug->mq_list))) {
-		bool last = rq_list_empty(plug->mq_list);
-		blk_status_t ret;
-
-		if (hctx != rq->mq_hctx) {
-			if (hctx)
-				blk_mq_commit_rqs(hctx, &queued, from_schedule);
-			hctx = rq->mq_hctx;
-		}
-
-		ret = blk_mq_request_issue_directly(rq, last);
-		switch (ret) {
-		case BLK_STS_OK:
-			queued++;
-			break;
-		case BLK_STS_RESOURCE:
-		case BLK_STS_DEV_RESOURCE:
-			blk_mq_request_bypass_insert(rq, false, last);
-			blk_mq_commit_rqs(hctx, &queued, from_schedule);
-			return;
-		default:
-			blk_mq_end_request(rq, ret);
-			errors++;
-			break;
-		}
-	}
-
-	/*
-	 * If we didn't flush the entire list, we could have told the driver
-	 * there was more coming, but that turned out to be a lie.
-	 */
-	if (errors)
-		blk_mq_commit_rqs(hctx, &queued, from_schedule);
-}
-
-void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
-{
-	struct blk_mq_hw_ctx *this_hctx;
-	struct blk_mq_ctx *this_ctx;
-	unsigned int depth;
-	LIST_HEAD(list);
-
-	if (rq_list_empty(plug->mq_list))
-		return;
-	plug->rq_count = 0;
-
-	if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) {
-		blk_mq_plug_issue_direct(plug, false);
-		if (rq_list_empty(plug->mq_list))
-			return;
-	}
-
-	this_hctx = NULL;
-	this_ctx = NULL;
-	depth = 0;
-	do {
-		struct request *rq;
-
-		rq = rq_list_pop(&plug->mq_list);
-
-		if (!this_hctx) {
-			this_hctx = rq->mq_hctx;
-			this_ctx = rq->mq_ctx;
-		} else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx) {
-			trace_block_unplug(this_hctx->queue, depth,
-						!from_schedule);
-			blk_mq_sched_insert_requests(this_hctx, this_ctx,
-						&list, from_schedule);
-			depth = 0;
-			this_hctx = rq->mq_hctx;
-			this_ctx = rq->mq_ctx;
-
-		}
-
-		list_add(&rq->queuelist, &list);
-		depth++;
-	} while (!rq_list_empty(plug->mq_list));
-
-	if (!list_empty(&list)) {
-		trace_block_unplug(this_hctx->queue, depth, !from_schedule);
-		blk_mq_sched_insert_requests(this_hctx, this_ctx, &list,
-						from_schedule);
-	}
-}
-
 static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
 		unsigned int nr_segs)
 {
@@ -2539,6 +2447,98 @@ blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last)
 	return ret;
 }
 
+static void blk_mq_plug_issue_direct(struct blk_plug *plug, bool from_schedule)
+{
+	struct blk_mq_hw_ctx *hctx = NULL;
+	struct request *rq;
+	int queued = 0;
+	int errors = 0;
+
+	while ((rq = rq_list_pop(&plug->mq_list))) {
+		bool last = rq_list_empty(plug->mq_list);
+		blk_status_t ret;
+
+		if (hctx != rq->mq_hctx) {
+			if (hctx)
+				blk_mq_commit_rqs(hctx, &queued, from_schedule);
+			hctx = rq->mq_hctx;
+		}
+
+		ret = blk_mq_request_issue_directly(rq, last);
+		switch (ret) {
+		case BLK_STS_OK:
+			queued++;
+			break;
+		case BLK_STS_RESOURCE:
+		case BLK_STS_DEV_RESOURCE:
+			blk_mq_request_bypass_insert(rq, false, last);
+			blk_mq_commit_rqs(hctx, &queued, from_schedule);
+			return;
+		default:
+			blk_mq_end_request(rq, ret);
+			errors++;
+			break;
+		}
+	}
+
+	/*
+	 * If we didn't flush the entire list, we could have told the driver
+	 * there was more coming, but that turned out to be a lie.
+	 */
+	if (errors)
+		blk_mq_commit_rqs(hctx, &queued, from_schedule);
+}
+
+void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
+{
+	struct blk_mq_hw_ctx *this_hctx;
+	struct blk_mq_ctx *this_ctx;
+	unsigned int depth;
+	LIST_HEAD(list);
+
+	if (rq_list_empty(plug->mq_list))
+		return;
+	plug->rq_count = 0;
+
+	if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) {
+		blk_mq_plug_issue_direct(plug, false);
+		if (rq_list_empty(plug->mq_list))
+			return;
+	}
+
+	this_hctx = NULL;
+	this_ctx = NULL;
+	depth = 0;
+	do {
+		struct request *rq;
+
+		rq = rq_list_pop(&plug->mq_list);
+
+		if (!this_hctx) {
+			this_hctx = rq->mq_hctx;
+			this_ctx = rq->mq_ctx;
+		} else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx) {
+			trace_block_unplug(this_hctx->queue, depth,
+						!from_schedule);
+			blk_mq_sched_insert_requests(this_hctx, this_ctx,
+						&list, from_schedule);
+			depth = 0;
+			this_hctx = rq->mq_hctx;
+			this_ctx = rq->mq_ctx;
+
+		}
+
+		list_add(&rq->queuelist, &list);
+		depth++;
+	} while (!rq_list_empty(plug->mq_list));
+
+	if (!list_empty(&list)) {
+		trace_block_unplug(this_hctx->queue, depth, !from_schedule);
+		blk_mq_sched_insert_requests(this_hctx, this_ctx, &list,
+						from_schedule);
+	}
+}
+
 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
 		struct list_head *list)
 {
-- 
2.30.2

[PATCH 05/11] block: move request based cloning helpers to blk-mq.c

[Christoph Hellwig]

Keep all the request based code together.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c | 184 +----------------------------------------------
 block/blk-mq.c   | 175 +++++++++++++++++++++++++++++++++++++++++++-
 block/blk-mq.h   |   3 -
 block/blk.h      |  10 +++
 4 files changed, 185 insertions(+), 187 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index f1ca31a89493a..e1c928ec92946 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -592,7 +592,7 @@ static int __init setup_fail_make_request(char *str)
 }
 __setup("fail_make_request=", setup_fail_make_request);
 
-static bool should_fail_request(struct block_device *part, unsigned int bytes)
+bool should_fail_request(struct block_device *part, unsigned int bytes)
 {
 	return part->bd_make_it_fail && should_fail(&fail_make_request, bytes);
 }
@@ -606,15 +606,6 @@ static int __init fail_make_request_debugfs(void)
 }
 
 late_initcall(fail_make_request_debugfs);
-
-#else /* CONFIG_FAIL_MAKE_REQUEST */
-
-static inline bool should_fail_request(struct block_device *part,
-					unsigned int bytes)
-{
-	return false;
-}
-
 #endif /* CONFIG_FAIL_MAKE_REQUEST */
 
 static inline bool bio_check_ro(struct bio *bio)
@@ -1087,92 +1078,6 @@ int iocb_bio_iopoll(struct kiocb *kiocb, struct io_comp_batch *iob,
 }
 EXPORT_SYMBOL_GPL(iocb_bio_iopoll);
 
-/**
- * blk_cloned_rq_check_limits - Helper function to check a cloned request
- *                              for the new queue limits
- * @q:  the queue
- * @rq: the request being checked
- *
- * Description:
- *    @rq may have been made based on weaker limitations of upper-level queues
- *    in request stacking drivers, and it may violate the limitation of @q.
- *    Since the block layer and the underlying device driver trust @rq
- *    after it is inserted to @q, it should be checked against @q before
- *    the insertion using this generic function.
- *
- *    Request stacking drivers like request-based dm may change the queue
- *    limits when retrying requests on other queues. Those requests need
- *    to be checked against the new queue limits again during dispatch.
- */
-static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q,
-				      struct request *rq)
-{
-	unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq));
-
-	if (blk_rq_sectors(rq) > max_sectors) {
-		/*
-		 * SCSI device does not have a good way to return if
-		 * Write Same/Zero is actually supported. If a device rejects
-		 * a non-read/write command (discard, write same,etc.) the
-		 * low-level device driver will set the relevant queue limit to
-		 * 0 to prevent blk-lib from issuing more of the offending
-		 * operations. Commands queued prior to the queue limit being
-		 * reset need to be completed with BLK_STS_NOTSUPP to avoid I/O
-		 * errors being propagated to upper layers.
-		 */
-		if (max_sectors == 0)
-			return BLK_STS_NOTSUPP;
-
-		printk(KERN_ERR "%s: over max size limit. (%u > %u)\n",
-			__func__, blk_rq_sectors(rq), max_sectors);
-		return BLK_STS_IOERR;
-	}
-
-	/*
-	 * The queue settings related to segment counting may differ from the
-	 * original queue.
-	 */
-	rq->nr_phys_segments = blk_recalc_rq_segments(rq);
-	if (rq->nr_phys_segments > queue_max_segments(q)) {
-		printk(KERN_ERR "%s: over max segments limit. (%hu > %hu)\n",
-			__func__, rq->nr_phys_segments, queue_max_segments(q));
-		return BLK_STS_IOERR;
-	}
-
-	return BLK_STS_OK;
-}
-
-/**
- * blk_insert_cloned_request - Helper for stacking drivers to submit a request
- * @q:  the queue to submit the request
- * @rq: the request being queued
- */
-blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq)
-{
-	blk_status_t ret;
-
-	ret = blk_cloned_rq_check_limits(q, rq);
-	if (ret != BLK_STS_OK)
-		return ret;
-
-	if (rq->rq_disk &&
-	    should_fail_request(rq->rq_disk->part0, blk_rq_bytes(rq)))
-		return BLK_STS_IOERR;
-
-	if (blk_crypto_insert_cloned_request(rq))
-		return BLK_STS_IOERR;
-
-	blk_account_io_start(rq);
-
-	/*
-	 * Since we have a scheduler attached on the top device,
-	 * bypass a potential scheduler on the bottom device for
-	 * insert.
-	 */
-	return blk_mq_request_issue_directly(rq, true);
-}
-EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
-
 static void update_io_ticks(struct block_device *part, unsigned long now,
 		bool end)
 {
@@ -1325,93 +1230,6 @@ int blk_lld_busy(struct request_queue *q)
 }
 EXPORT_SYMBOL_GPL(blk_lld_busy);
 
-/**
- * blk_rq_unprep_clone - Helper function to free all bios in a cloned request
- * @rq: the clone request to be cleaned up
- *
- * Description:
- *     Free all bios in @rq for a cloned request.
- */
-void blk_rq_unprep_clone(struct request *rq)
-{
-	struct bio *bio;
-
-	while ((bio = rq->bio) != NULL) {
-		rq->bio = bio->bi_next;
-
-		bio_put(bio);
-	}
-}
-EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
-
-/**
- * blk_rq_prep_clone - Helper function to setup clone request
- * @rq: the request to be setup
- * @rq_src: original request to be cloned
- * @bs: bio_set that bios for clone are allocated from
- * @gfp_mask: memory allocation mask for bio
- * @bio_ctr: setup function to be called for each clone bio.
- *           Returns %0 for success, non %0 for failure.
- * @data: private data to be passed to @bio_ctr
- *
- * Description:
- *     Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq.
- *     Also, pages which the original bios are pointing to are not copied
- *     and the cloned bios just point same pages.
- *     So cloned bios must be completed before original bios, which means
- *     the caller must complete @rq before @rq_src.
- */
-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)
-{
-	struct bio *bio, *bio_src;
-
-	if (!bs)
-		bs = &fs_bio_set;
-
-	__rq_for_each_bio(bio_src, rq_src) {
-		bio = bio_clone_fast(bio_src, gfp_mask, bs);
-		if (!bio)
-			goto free_and_out;
-
-		if (bio_ctr && bio_ctr(bio, bio_src, data))
-			goto free_and_out;
-
-		if (rq->bio) {
-			rq->biotail->bi_next = bio;
-			rq->biotail = bio;
-		} else {
-			rq->bio = rq->biotail = bio;
-		}
-		bio = NULL;
-	}
-
-	/* Copy attributes of the original request to the clone request. */
-	rq->__sector = blk_rq_pos(rq_src);
-	rq->__data_len = blk_rq_bytes(rq_src);
-	if (rq_src->rq_flags & RQF_SPECIAL_PAYLOAD) {
-		rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
-		rq->special_vec = rq_src->special_vec;
-	}
-	rq->nr_phys_segments = rq_src->nr_phys_segments;
-	rq->ioprio = rq_src->ioprio;
-
-	if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0)
-		goto free_and_out;
-
-	return 0;
-
-free_and_out:
-	if (bio)
-		bio_put(bio);
-	blk_rq_unprep_clone(rq);
-
-	return -ENOMEM;
-}
-EXPORT_SYMBOL_GPL(blk_rq_prep_clone);
-
 int kblockd_schedule_work(struct work_struct *work)
 {
 	return queue_work(kblockd_workqueue, work);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index d70a470c9c1f1..0362ec9ad4d14 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2434,7 +2434,7 @@ static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
 	hctx_unlock(hctx, srcu_idx);
 }
 
-blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last)
+static blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last)
 {
 	blk_status_t ret;
 	int srcu_idx;
@@ -2821,6 +2821,179 @@ void blk_mq_submit_bio(struct bio *bio)
 	}
 }
 
+/**
+ * blk_cloned_rq_check_limits - Helper function to check a cloned request
+ *                              for the new queue limits
+ * @q:  the queue
+ * @rq: the request being checked
+ *
+ * Description:
+ *    @rq may have been made based on weaker limitations of upper-level queues
+ *    in request stacking drivers, and it may violate the limitation of @q.
+ *    Since the block layer and the underlying device driver trust @rq
+ *    after it is inserted to @q, it should be checked against @q before
+ *    the insertion using this generic function.
+ *
+ *    Request stacking drivers like request-based dm may change the queue
+ *    limits when retrying requests on other queues. Those requests need
+ *    to be checked against the new queue limits again during dispatch.
+ */
+static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q,
+				      struct request *rq)
+{
+	unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq));
+
+	if (blk_rq_sectors(rq) > max_sectors) {
+		/*
+		 * SCSI device does not have a good way to return if
+		 * Write Same/Zero is actually supported. If a device rejects
+		 * a non-read/write command (discard, write same,etc.) the
+		 * low-level device driver will set the relevant queue limit to
+		 * 0 to prevent blk-lib from issuing more of the offending
+		 * operations. Commands queued prior to the queue limit being
+		 * reset need to be completed with BLK_STS_NOTSUPP to avoid I/O
+		 * errors being propagated to upper layers.
+		 */
+		if (max_sectors == 0)
+			return BLK_STS_NOTSUPP;
+
+		printk(KERN_ERR "%s: over max size limit. (%u > %u)\n",
+			__func__, blk_rq_sectors(rq), max_sectors);
+		return BLK_STS_IOERR;
+	}
+
+	/*
+	 * The queue settings related to segment counting may differ from the
+	 * original queue.
+	 */
+	rq->nr_phys_segments = blk_recalc_rq_segments(rq);
+	if (rq->nr_phys_segments > queue_max_segments(q)) {
+		printk(KERN_ERR "%s: over max segments limit. (%hu > %hu)\n",
+			__func__, rq->nr_phys_segments, queue_max_segments(q));
+		return BLK_STS_IOERR;
+	}
+
+	return BLK_STS_OK;
+}
+
+/**
+ * blk_insert_cloned_request - Helper for stacking drivers to submit a request
+ * @q:  the queue to submit the request
+ * @rq: the request being queued
+ */
+blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq)
+{
+	blk_status_t ret;
+
+	ret = blk_cloned_rq_check_limits(q, rq);
+	if (ret != BLK_STS_OK)
+		return ret;
+
+	if (rq->rq_disk &&
+	    should_fail_request(rq->rq_disk->part0, blk_rq_bytes(rq)))
+		return BLK_STS_IOERR;
+
+	if (blk_crypto_insert_cloned_request(rq))
+		return BLK_STS_IOERR;
+
+	blk_account_io_start(rq);
+
+	/*
+	 * Since we have a scheduler attached on the top device,
+	 * bypass a potential scheduler on the bottom device for
+	 * insert.
+	 */
+	return blk_mq_request_issue_directly(rq, true);
+}
+EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
+
+/**
+ * blk_rq_unprep_clone - Helper function to free all bios in a cloned request
+ * @rq: the clone request to be cleaned up
+ *
+ * Description:
+ *     Free all bios in @rq for a cloned request.
+ */
+void blk_rq_unprep_clone(struct request *rq)
+{
+	struct bio *bio;
+
+	while ((bio = rq->bio) != NULL) {
+		rq->bio = bio->bi_next;
+
+		bio_put(bio);
+	}
+}
+EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
+
+/**
+ * blk_rq_prep_clone - Helper function to setup clone request
+ * @rq: the request to be setup
+ * @rq_src: original request to be cloned
+ * @bs: bio_set that bios for clone are allocated from
+ * @gfp_mask: memory allocation mask for bio
+ * @bio_ctr: setup function to be called for each clone bio.
+ *           Returns %0 for success, non %0 for failure.
+ * @data: private data to be passed to @bio_ctr
+ *
+ * Description:
+ *     Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq.
+ *     Also, pages which the original bios are pointing to are not copied
+ *     and the cloned bios just point same pages.
+ *     So cloned bios must be completed before original bios, which means
+ *     the caller must complete @rq before @rq_src.
+ */
+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)
+{
+	struct bio *bio, *bio_src;
+
+	if (!bs)
+		bs = &fs_bio_set;
+
+	__rq_for_each_bio(bio_src, rq_src) {
+		bio = bio_clone_fast(bio_src, gfp_mask, bs);
+		if (!bio)
+			goto free_and_out;
+
+		if (bio_ctr && bio_ctr(bio, bio_src, data))
+			goto free_and_out;
+
+		if (rq->bio) {
+			rq->biotail->bi_next = bio;
+			rq->biotail = bio;
+		} else {
+			rq->bio = rq->biotail = bio;
+		}
+		bio = NULL;
+	}
+
+	/* Copy attributes of the original request to the clone request. */
+	rq->__sector = blk_rq_pos(rq_src);
+	rq->__data_len = blk_rq_bytes(rq_src);
+	if (rq_src->rq_flags & RQF_SPECIAL_PAYLOAD) {
+		rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
+		rq->special_vec = rq_src->special_vec;
+	}
+	rq->nr_phys_segments = rq_src->nr_phys_segments;
+	rq->ioprio = rq_src->ioprio;
+
+	if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0)
+		goto free_and_out;
+
+	return 0;
+
+free_and_out:
+	if (bio)
+		bio_put(bio);
+	blk_rq_unprep_clone(rq);
+
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(blk_rq_prep_clone);
+
 static size_t order_to_size(unsigned int order)
 {
 	return (size_t)PAGE_SIZE << order;
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 8acfa650f5751..f39454456c064 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -65,9 +65,6 @@ void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
 				  bool run_queue);
 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
 				struct list_head *list);
-
-/* Used by blk_insert_cloned_request() to issue request directly */
-blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last);
 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
 				    struct list_head *list);
 
diff --git a/block/blk.h b/block/blk.h
index b4fed2033e48f..1bac4063afffb 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -493,4 +493,14 @@ int disk_register_independent_access_ranges(struct gendisk *disk,
 				struct blk_independent_access_ranges *new_iars);
 void disk_unregister_independent_access_ranges(struct gendisk *disk);
 
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+bool should_fail_request(struct block_device *part, unsigned int bytes);
+#else /* CONFIG_FAIL_MAKE_REQUEST */
+static inline bool should_fail_request(struct block_device *part,
+					unsigned int bytes)
+{
+	return false;
+}
+#endif /* CONFIG_FAIL_MAKE_REQUEST */
+
 #endif /* BLK_INTERNAL_H */
-- 
2.30.2

[PATCH 06/11] block: move blk_rq_init to blk-mq.c

[Christoph Hellwig]

blk_rq_init deals with a request structure, so move it to blk-mq.c

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c | 17 -----------------
 block/blk-mq.c   | 17 +++++++++++++++++
 2 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index e1c928ec92946..a3384c85074e3 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -109,23 +109,6 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q)
 }
 EXPORT_SYMBOL_GPL(blk_queue_flag_test_and_set);
 
-void blk_rq_init(struct request_queue *q, struct request *rq)
-{
-	memset(rq, 0, sizeof(*rq));
-
-	INIT_LIST_HEAD(&rq->queuelist);
-	rq->q = q;
-	rq->__sector = (sector_t) -1;
-	INIT_HLIST_NODE(&rq->hash);
-	RB_CLEAR_NODE(&rq->rb_node);
-	rq->tag = BLK_MQ_NO_TAG;
-	rq->internal_tag = BLK_MQ_NO_TAG;
-	rq->start_time_ns = ktime_get_ns();
-	rq->part = NULL;
-	blk_crypto_rq_set_defaults(rq);
-}
-EXPORT_SYMBOL(blk_rq_init);
-
 #define REQ_OP_NAME(name) [REQ_OP_##name] = #name
 static const char *const blk_op_name[] = {
 	REQ_OP_NAME(READ),
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0362ec9ad4d14..8d0d18ef07d09 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -328,6 +328,23 @@ void blk_mq_wake_waiters(struct request_queue *q)
 			blk_mq_tag_wakeup_all(hctx->tags, true);
 }
 
+void blk_rq_init(struct request_queue *q, struct request *rq)
+{
+	memset(rq, 0, sizeof(*rq));
+
+	INIT_LIST_HEAD(&rq->queuelist);
+	rq->q = q;
+	rq->__sector = (sector_t) -1;
+	INIT_HLIST_NODE(&rq->hash);
+	RB_CLEAR_NODE(&rq->rb_node);
+	rq->tag = BLK_MQ_NO_TAG;
+	rq->internal_tag = BLK_MQ_NO_TAG;
+	rq->start_time_ns = ktime_get_ns();
+	rq->part = NULL;
+	blk_crypto_rq_set_defaults(rq);
+}
+EXPORT_SYMBOL(blk_rq_init);
+
 static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 		struct blk_mq_tags *tags, unsigned int tag, u64 alloc_time_ns)
 {
-- 
2.30.2

[PATCH 07/11] block: move blk_steal_bios to blk-mq.c

[Christoph Hellwig]

Keep all the request based code together.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c | 21 ---------------------
 block/blk-mq.c   | 21 +++++++++++++++++++++
 2 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index a3384c85074e3..723a8c84aef12 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1164,27 +1164,6 @@ void disk_end_io_acct(struct gendisk *disk, unsigned int op,
 }
 EXPORT_SYMBOL(disk_end_io_acct);
 
-/*
- * Steal bios from a request and add them to a bio list.
- * The request must not have been partially completed before.
- */
-void blk_steal_bios(struct bio_list *list, struct request *rq)
-{
-	if (rq->bio) {
-		if (list->tail)
-			list->tail->bi_next = rq->bio;
-		else
-			list->head = rq->bio;
-		list->tail = rq->biotail;
-
-		rq->bio = NULL;
-		rq->biotail = NULL;
-	}
-
-	rq->__data_len = 0;
-}
-EXPORT_SYMBOL_GPL(blk_steal_bios);
-
 /**
  * blk_lld_busy - Check if underlying low-level drivers of a device are busy
  * @q : the queue of the device being checked
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 8d0d18ef07d09..300fa393e6445 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3011,6 +3011,27 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 }
 EXPORT_SYMBOL_GPL(blk_rq_prep_clone);
 
+/*
+ * Steal bios from a request and add them to a bio list.
+ * The request must not have been partially completed before.
+ */
+void blk_steal_bios(struct bio_list *list, struct request *rq)
+{
+	if (rq->bio) {
+		if (list->tail)
+			list->tail->bi_next = rq->bio;
+		else
+			list->head = rq->bio;
+		list->tail = rq->biotail;
+
+		rq->bio = NULL;
+		rq->biotail = NULL;
+	}
+
+	rq->__data_len = 0;
+}
+EXPORT_SYMBOL_GPL(blk_steal_bios);
+
 static size_t order_to_size(unsigned int order)
 {
 	return (size_t)PAGE_SIZE << order;
-- 
2.30.2

[PATCH 08/11] block: move blk_account_io_{start,done} to blk-mq.c

[Christoph Hellwig]

These are only used for request based I/O, so move them where they are
used.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c | 27 +--------------------------
 block/blk-mq.c   | 42 ++++++++++++++++++++++++++++++++++++++++++
 block/blk.h      | 21 +--------------------
 3 files changed, 44 insertions(+), 46 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 723a8c84aef12..60cc44418ce79 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1061,8 +1061,7 @@ int iocb_bio_iopoll(struct kiocb *kiocb, struct io_comp_batch *iob,
 }
 EXPORT_SYMBOL_GPL(iocb_bio_iopoll);
 
-static void update_io_ticks(struct block_device *part, unsigned long now,
-		bool end)
+void update_io_ticks(struct block_device *part, unsigned long now, bool end)
 {
 	unsigned long stamp;
 again:
@@ -1077,30 +1076,6 @@ static void update_io_ticks(struct block_device *part, unsigned long now,
 	}
 }
 
-void __blk_account_io_done(struct request *req, u64 now)
-{
-	const int sgrp = op_stat_group(req_op(req));
-
-	part_stat_lock();
-	update_io_ticks(req->part, jiffies, true);
-	part_stat_inc(req->part, ios[sgrp]);
-	part_stat_add(req->part, nsecs[sgrp], now - req->start_time_ns);
-	part_stat_unlock();
-}
-
-void __blk_account_io_start(struct request *rq)
-{
-	/* passthrough requests can hold bios that do not have ->bi_bdev set */
-	if (rq->bio && rq->bio->bi_bdev)
-		rq->part = rq->bio->bi_bdev;
-	else
-		rq->part = rq->rq_disk->part0;
-
-	part_stat_lock();
-	update_io_ticks(rq->part, jiffies, false);
-	part_stat_unlock();
-}
-
 static unsigned long __part_start_io_acct(struct block_device *part,
 					  unsigned int sectors, unsigned int op)
 {
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 300fa393e6445..8b7edfc9623dd 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -809,6 +809,48 @@ bool blk_update_request(struct request *req, blk_status_t error,
 }
 EXPORT_SYMBOL_GPL(blk_update_request);
 
+static void __blk_account_io_done(struct request *req, u64 now)
+{
+	const int sgrp = op_stat_group(req_op(req));
+
+	part_stat_lock();
+	update_io_ticks(req->part, jiffies, true);
+	part_stat_inc(req->part, ios[sgrp]);
+	part_stat_add(req->part, nsecs[sgrp], now - req->start_time_ns);
+	part_stat_unlock();
+}
+
+static inline void blk_account_io_done(struct request *req, u64 now)
+{
+	/*
+	 * Account IO completion.  flush_rq isn't accounted as a
+	 * normal IO on queueing nor completion.  Accounting the
+	 * containing request is enough.
+	 */
+	if (blk_do_io_stat(req) && req->part &&
+	    !(req->rq_flags & RQF_FLUSH_SEQ))
+		__blk_account_io_done(req, now);
+}
+
+static void __blk_account_io_start(struct request *rq)
+{
+	/* passthrough requests can hold bios that do not have ->bi_bdev set */
+	if (rq->bio && rq->bio->bi_bdev)
+		rq->part = rq->bio->bi_bdev;
+	else
+		rq->part = rq->rq_disk->part0;
+
+	part_stat_lock();
+	update_io_ticks(rq->part, jiffies, false);
+	part_stat_unlock();
+}
+
+static inline void blk_account_io_start(struct request *req)
+{
+	if (blk_do_io_stat(req))
+		__blk_account_io_start(req);
+}
+
 static inline void __blk_mq_end_request_acct(struct request *rq, u64 now)
 {
 	if (rq->rq_flags & RQF_STATS) {
diff --git a/block/blk.h b/block/blk.h
index 1bac4063afffb..a1cbf17d18b98 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -257,9 +257,6 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
 			struct bio *bio, unsigned int nr_segs);
 
-void __blk_account_io_start(struct request *req);
-void __blk_account_io_done(struct request *req, u64 now);
-
 /*
  * Plug flush limits
  */
@@ -350,23 +347,7 @@ static inline bool blk_do_io_stat(struct request *rq)
 	return (rq->rq_flags & RQF_IO_STAT) && rq->rq_disk;
 }
 
-static inline void blk_account_io_done(struct request *req, u64 now)
-{
-	/*
-	 * Account IO completion.  flush_rq isn't accounted as a
-	 * normal IO on queueing nor completion.  Accounting the
-	 * containing request is enough.
-	 */
-	if (blk_do_io_stat(req) && req->part &&
-	    !(req->rq_flags & RQF_FLUSH_SEQ))
-		__blk_account_io_done(req, now);
-}
-
-static inline void blk_account_io_start(struct request *req)
-{
-	if (blk_do_io_stat(req))
-		__blk_account_io_start(req);
-}
+void update_io_ticks(struct block_device *part, unsigned long now, bool end);
 
 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
 {
-- 
2.30.2

[PATCH 09/11] block: move blk_dump_rq_flags to blk-mq.c

[Christoph Hellwig]

blk_dump_rq_flags deals with a request, so move it to blk-mq.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c | 14 --------------
 block/blk-mq.c   | 14 ++++++++++++++
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 60cc44418ce79..89971630f092f 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -217,20 +217,6 @@ void blk_print_req_error(struct request *req, blk_status_t status)
 		IOPRIO_PRIO_CLASS(req->ioprio));
 }
 
-void blk_dump_rq_flags(struct request *rq, char *msg)
-{
-	printk(KERN_INFO "%s: dev %s: flags=%llx\n", msg,
-		rq->rq_disk ? rq->rq_disk->disk_name : "?",
-		(unsigned long long) rq->cmd_flags);
-
-	printk(KERN_INFO "  sector %llu, nr/cnr %u/%u\n",
-	       (unsigned long long)blk_rq_pos(rq),
-	       blk_rq_sectors(rq), blk_rq_cur_sectors(rq));
-	printk(KERN_INFO "  bio %p, biotail %p, len %u\n",
-	       rq->bio, rq->biotail, blk_rq_bytes(rq));
-}
-EXPORT_SYMBOL(blk_dump_rq_flags);
-
 /**
  * blk_sync_queue - cancel any pending callbacks on a queue
  * @q: the queue
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 8b7edfc9623dd..f8a39f4fce01e 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -667,6 +667,20 @@ void blk_mq_free_plug_rqs(struct blk_plug *plug)
 		blk_mq_free_request(rq);
 }
 
+void blk_dump_rq_flags(struct request *rq, char *msg)
+{
+	printk(KERN_INFO "%s: dev %s: flags=%llx\n", msg,
+		rq->rq_disk ? rq->rq_disk->disk_name : "?",
+		(unsigned long long) rq->cmd_flags);
+
+	printk(KERN_INFO "  sector %llu, nr/cnr %u/%u\n",
+	       (unsigned long long)blk_rq_pos(rq),
+	       blk_rq_sectors(rq), blk_rq_cur_sectors(rq));
+	printk(KERN_INFO "  bio %p, biotail %p, len %u\n",
+	       rq->bio, rq->biotail, blk_rq_bytes(rq));
+}
+EXPORT_SYMBOL(blk_dump_rq_flags);
+
 static void req_bio_endio(struct request *rq, struct bio *bio,
 			  unsigned int nbytes, blk_status_t error)
 {
-- 
2.30.2

[PATCH 10/11] block: move blk_print_req_error to blk-mq.c

[Christoph Hellwig]

This function is only used by the request completion path.  Factor out
a blk_status_to_str to keep blk_errors private in blk-core.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c | 15 +++------------
 block/blk-mq.c   | 13 +++++++++++++
 block/blk.h      |  2 +-
 3 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 89971630f092f..5722c1d9da09c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -199,22 +199,13 @@ int blk_status_to_errno(blk_status_t status)
 }
 EXPORT_SYMBOL_GPL(blk_status_to_errno);
 
-void blk_print_req_error(struct request *req, blk_status_t status)
+const char *blk_status_to_str(blk_status_t status)
 {
 	int idx = (__force int)status;
 
 	if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors)))
-		return;
-
-	printk_ratelimited(KERN_ERR
-		"%s error, dev %s, sector %llu op 0x%x:(%s) flags 0x%x "
-		"phys_seg %u prio class %u\n",
-		blk_errors[idx].name,
-		req->rq_disk ? req->rq_disk->disk_name : "?",
-		blk_rq_pos(req), req_op(req), blk_op_str(req_op(req)),
-		req->cmd_flags & ~REQ_OP_MASK,
-		req->nr_phys_segments,
-		IOPRIO_PRIO_CLASS(req->ioprio));
+		return "<null>";
+	return blk_errors[idx].name;
 }
 
 /**
diff --git a/block/blk-mq.c b/block/blk-mq.c
index f8a39f4fce01e..1feb9ab65f28a 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -717,6 +717,19 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
 	}
 }
 
+static void blk_print_req_error(struct request *req, blk_status_t status)
+{
+	printk_ratelimited(KERN_ERR
+		"%s error, dev %s, sector %llu op 0x%x:(%s) flags 0x%x "
+		"phys_seg %u prio class %u\n",
+		blk_status_to_str(status),
+		req->rq_disk ? req->rq_disk->disk_name : "?",
+		blk_rq_pos(req), req_op(req), blk_op_str(req_op(req)),
+		req->cmd_flags & ~REQ_OP_MASK,
+		req->nr_phys_segments,
+		IOPRIO_PRIO_CLASS(req->ioprio));
+}
+
 /**
  * blk_update_request - Complete multiple bytes without completing the request
  * @req:      the request being processed
diff --git a/block/blk.h b/block/blk.h
index a1cbf17d18b98..296e3010f8d65 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -250,7 +250,7 @@ static inline void blk_integrity_del(struct gendisk *disk)
 
 unsigned long blk_rq_timeout(unsigned long timeout);
 void blk_add_timer(struct request *req);
-void blk_print_req_error(struct request *req, blk_status_t status);
+const char *blk_status_to_str(blk_status_t status);
 
 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 		unsigned int nr_segs, bool *same_queue_rq);
-- 
2.30.2

Re: [PATCH 10/11] block: move blk_print_req_error to blk-mq.c

[Chaitanya Kulkarni]

On 11/16/2021 10:14 PM, Christoph Hellwig wrote:
> This function is only used by the request completion path.  Factor out
> a blk_status_to_str to keep blk_errors private in blk-core.c.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>

for the whole series:-

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

[PATCH 11/11] block: don't include blk-mq headers in blk-core.c

[Christoph Hellwig]

All request based code is in the blk-mq files now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 5722c1d9da09c..ee54b34d5e99c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -16,7 +16,6 @@
 #include <linux/module.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
-#include <linux/blk-mq.h>
 #include <linux/blk-pm.h>
 #include <linux/blk-integrity.h>
 #include <linux/highmem.h>
@@ -47,8 +46,6 @@
 #include <trace/events/block.h>
 
 #include "blk.h"
-#include "blk-mq.h"
-#include "blk-mq-sched.h"
 #include "blk-pm.h"
 #include "blk-throttle.h"
 
-- 
2.30.2

Re: move all struct request releated code out of blk-core.c (rebased)

[Johannes Thumshirn]

On 17/11/2021 07:14, Christoph Hellwig wrote:
> Hi Jens,
> 
> this series (against the for-5.16/passthrough-flag branch) removes the
> remaining struct request related code from blk-core.c and cleans up a
> few related bits around that.
> 
> Diffstat:
>  b/block/Makefile            |    2 
>  b/block/blk-core.c          |  341 --------------------------
>  b/block/blk-mq.c            |  573 ++++++++++++++++++++++++++++++++++++--------
>  b/block/blk-mq.h            |    3 
>  b/block/blk.h               |   33 --
>  b/drivers/mtd/mtd_blkdevs.c |   10 
>  b/drivers/mtd/ubi/block.c   |    6 
>  b/drivers/scsi/scsi_lib.c   |   42 +++
>  b/include/linux/blk-mq.h    |   13 
>  block/blk-exec.c            |  116 --------
>  10 files changed, 552 insertions(+), 587 deletions(-)
> 

Looks good, for the whole series:
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Re: move all struct request releated code out of blk-core.c (rebased)

[Jens Axboe]

On Wed, 17 Nov 2021 07:13:53 +0100, Christoph Hellwig wrote:
> this series (against the for-5.16/passthrough-flag branch) removes the
> remaining struct request related code from blk-core.c and cleans up a
> few related bits around that.
> 
> Diffstat:
>  b/block/Makefile            |    2
>  b/block/blk-core.c          |  341 --------------------------
>  b/block/blk-mq.c            |  573 ++++++++++++++++++++++++++++++++++++--------
>  b/block/blk-mq.h            |    3
>  b/block/blk.h               |   33 --
>  b/drivers/mtd/mtd_blkdevs.c |   10
>  b/drivers/mtd/ubi/block.c   |    6
>  b/drivers/scsi/scsi_lib.c   |   42 +++
>  b/include/linux/blk-mq.h    |   13
>  block/blk-exec.c            |  116 --------
>  10 files changed, 552 insertions(+), 587 deletions(-)
> 
> [...]

Applied, thanks!

[01/11] block: move blk_rq_err_bytes to scsi
        commit: 6ace6442a37e17d56a1c54f55bea48ac796f869d
[02/11] block: remove rq_flush_dcache_pages
        commit: 01ed1e78789a2e3d7a895ca38706a4fb1a6146d0
[03/11] block: remove blk-exec.c
        commit: 9048707b1d8f8aebcf23e5b5b143ad1de2a93b34
[04/11] blk-mq: move blk_mq_flush_plug_list
        commit: 33af852518417ed7a90703c572e58cc99bef4770
[05/11] block: move request based cloning helpers to blk-mq.c
        commit: 432f3b8863dc44ac224e231dbe1b0038b5aa4239
[06/11] block: move blk_rq_init to blk-mq.c
        commit: 8586ee1a36a8f690492a7b7ee8f31c514d65957d
[07/11] block: move blk_steal_bios to blk-mq.c
        commit: 4ef40a1dc9ebeaa87cb53f16641d439d4ebcfdd0
[08/11] block: move blk_account_io_{start,done} to blk-mq.c
        commit: 1bdc7c540b455837af9d736e5f0abb77cfce3e62
[09/11] block: move blk_dump_rq_flags to blk-mq.c
        commit: 8a77648954e63f6654042567e31794bfd5ea02a5
[10/11] block: move blk_print_req_error to blk-mq.c
        commit: 065c87d65d74ac24bfc3bbc43de068ba99188b1c
[11/11] block: don't include blk-mq headers in blk-core.c
        commit: d94d230a3711ac85af1c3cd484419a4a81193387

Best regards,
-- 
Jens Axboe