diff mbox series

[16/26] block: move the io_stat flag setting to queue_limits

Message ID 20240611051929.513387-17-hch@lst.de (mailing list archive)
State New
Headers show
Series [01/26] sd: fix sd_is_zoned | expand

Commit Message

Christoph Hellwig June 11, 2024, 5:19 a.m. UTC
Move the io_stat flag into the queue_limits feature field so that it
can be set atomically and all I/O is frozen when changing the flag.

Simplify md and dm to set the flag unconditionally instead of avoiding
setting a simple flag for cases where it already is set by other means,
which is a bit pointless.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-mq-debugfs.c        |  1 -
 block/blk-mq.c                |  6 +++++-
 block/blk-sysfs.c             |  2 +-
 drivers/md/dm-table.c         | 12 +++++++++---
 drivers/md/dm.c               | 13 +++----------
 drivers/md/md.c               |  5 ++---
 drivers/nvme/host/multipath.c |  2 +-
 include/linux/blkdev.h        |  9 +++++----
 8 files changed, 26 insertions(+), 24 deletions(-)

Comments

Damien Le Moal June 11, 2024, 8:09 a.m. UTC | #1
On 6/11/24 2:19 PM, Christoph Hellwig wrote:
> Move the io_stat flag into the queue_limits feature field so that it
> can be set atomically and all I/O is frozen when changing the flag.

Why a feature ? It seems more appropriate for io_stat to be a flag rather than
a feature as that is a block layer thing rather than a device characteristic, no ?

> 
> Simplify md and dm to set the flag unconditionally instead of avoiding
> setting a simple flag for cases where it already is set by other means,
> which is a bit pointless.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
Christoph Hellwig June 12, 2024, 4:58 a.m. UTC | #2
On Tue, Jun 11, 2024 at 05:09:45PM +0900, Damien Le Moal wrote:
> On 6/11/24 2:19 PM, Christoph Hellwig wrote:
> > Move the io_stat flag into the queue_limits feature field so that it
> > can be set atomically and all I/O is frozen when changing the flag.
> 
> Why a feature ? It seems more appropriate for io_stat to be a flag rather than
> a feature as that is a block layer thing rather than a device characteristic, no ?

Because it must actually be supported by the driver for bio based
drivers.  Then again we also support chaning it through sysfs, so
we might actually need both.  At least unlike say the cache it's
not actively harmful when enabled despite not being supported.

I can look into that, but I'll do it in another series after getting
all the driver changes out.
diff mbox series

Patch

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 6b7edb50bfd3fa..cbe99444ed1a54 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -84,7 +84,6 @@  static const char *const blk_queue_flag_name[] = {
 	QUEUE_FLAG_NAME(NOMERGES),
 	QUEUE_FLAG_NAME(SAME_COMP),
 	QUEUE_FLAG_NAME(FAIL_IO),
-	QUEUE_FLAG_NAME(IO_STAT),
 	QUEUE_FLAG_NAME(NOXMERGES),
 	QUEUE_FLAG_NAME(SYNCHRONOUS),
 	QUEUE_FLAG_NAME(SAME_FORCE),
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 58b0d6c7cc34d6..cf67dc13f7dd4c 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -4116,7 +4116,11 @@  struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set,
 	struct request_queue *q;
 	int ret;
 
-	q = blk_alloc_queue(lim ? lim : &default_lim, set->numa_node);
+	if (!lim)
+		lim = &default_lim;
+	lim->features |= BLK_FEAT_IO_STAT;
+
+	q = blk_alloc_queue(lim, set->numa_node);
 	if (IS_ERR(q))
 		return q;
 	q->queuedata = queuedata;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 9174aca3b85526..6f58530fb3c08e 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -324,7 +324,7 @@  queue_##name##_store(struct request_queue *q, const char *page, size_t count) \
 
 QUEUE_SYSFS_FEATURE(rotational, BLK_FEAT_ROTATIONAL)
 QUEUE_SYSFS_FEATURE(add_random, BLK_FEAT_ADD_RANDOM)
-QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
+QUEUE_SYSFS_FEATURE(iostats, BLK_FEAT_IO_STAT)
 QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0);
 #undef QUEUE_SYSFS_BIT_FNS
 
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 7654babc2775c1..3e3b713502f61e 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -579,6 +579,12 @@  int dm_split_args(int *argc, char ***argvp, char *input)
 	return 0;
 }
 
+static void dm_set_stacking_limits(struct queue_limits *limits)
+{
+	blk_set_stacking_limits(limits);
+	limits->features |= BLK_FEAT_IO_STAT;
+}
+
 /*
  * Impose necessary and sufficient conditions on a devices's table such
  * that any incoming bio which respects its logical_block_size can be
@@ -617,7 +623,7 @@  static int validate_hardware_logical_block_alignment(struct dm_table *t,
 	for (i = 0; i < t->num_targets; i++) {
 		ti = dm_table_get_target(t, i);
 
-		blk_set_stacking_limits(&ti_limits);
+		dm_set_stacking_limits(&ti_limits);
 
 		/* combine all target devices' limits */
 		if (ti->type->iterate_devices)
@@ -1591,7 +1597,7 @@  int dm_calculate_queue_limits(struct dm_table *t,
 	unsigned int zone_sectors = 0;
 	bool zoned = false;
 
-	blk_set_stacking_limits(limits);
+	dm_set_stacking_limits(limits);
 
 	t->integrity_supported = true;
 	for (unsigned int i = 0; i < t->num_targets; i++) {
@@ -1604,7 +1610,7 @@  int dm_calculate_queue_limits(struct dm_table *t,
 	for (unsigned int i = 0; i < t->num_targets; i++) {
 		struct dm_target *ti = dm_table_get_target(t, i);
 
-		blk_set_stacking_limits(&ti_limits);
+		dm_set_stacking_limits(&ti_limits);
 
 		if (!ti->type->iterate_devices) {
 			/* Set I/O hints portion of queue limits */
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 13037d6a6f62a2..8a976cee448bed 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2386,22 +2386,15 @@  int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
 	struct table_device *td;
 	int r;
 
-	switch (type) {
-	case DM_TYPE_REQUEST_BASED:
+	WARN_ON_ONCE(type == DM_TYPE_NONE);
+
+	if (type == DM_TYPE_REQUEST_BASED) {
 		md->disk->fops = &dm_rq_blk_dops;
 		r = dm_mq_init_request_queue(md, t);
 		if (r) {
 			DMERR("Cannot initialize queue for request-based dm mapped device");
 			return r;
 		}
-		break;
-	case DM_TYPE_BIO_BASED:
-	case DM_TYPE_DAX_BIO_BASED:
-		blk_queue_flag_set(QUEUE_FLAG_IO_STAT, md->queue);
-		break;
-	case DM_TYPE_NONE:
-		WARN_ON_ONCE(true);
-		break;
 	}
 
 	r = dm_calculate_queue_limits(t, &limits);
diff --git a/drivers/md/md.c b/drivers/md/md.c
index c23423c51fb7c2..8db0db8d5a27ac 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5787,7 +5787,8 @@  struct mddev *md_alloc(dev_t dev, char *name)
 	int unit;
 	int error;
 	struct queue_limits lim = {
-		.features		= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA,
+		.features		= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA |
+					  BLK_FEAT_IO_STAT,
 	};
 
 	/*
@@ -6152,8 +6153,6 @@  int md_run(struct mddev *mddev)
 	if (!mddev_is_dm(mddev)) {
 		struct request_queue *q = mddev->gendisk->queue;
 
-		blk_queue_flag_set(QUEUE_FLAG_IO_STAT, q);
-
 		/* Set the NOWAIT flags if all underlying devices support it */
 		if (nowait)
 			blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 58c13304e558e0..eea727cfa9e67d 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -538,6 +538,7 @@  int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
 
 	blk_set_stacking_limits(&lim);
 	lim.dma_alignment = 3;
+	lim.features |= BLK_FEAT_IO_STAT;
 	if (head->ids.csi != NVME_CSI_ZNS)
 		lim.max_zone_append_sectors = 0;
 
@@ -550,7 +551,6 @@  int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
 			ctrl->subsys->instance, head->instance);
 
 	blk_queue_flag_set(QUEUE_FLAG_NOWAIT, head->disk->queue);
-	blk_queue_flag_set(QUEUE_FLAG_IO_STAT, head->disk->queue);
 	/*
 	 * This assumes all controllers that refer to a namespace either
 	 * support poll queues or not.  That is not a strict guarantee,
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e6a2382e21c4fe..f8e38f94fd8c9a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -295,6 +295,9 @@  enum {
 
 	/* contributes to the random number pool */
 	BLK_FEAT_ADD_RANDOM			= (1u << 3),
+
+	/* do disk/partitions IO accounting */
+	BLK_FEAT_IO_STAT			= (1u << 4),
 };
 
 /*
@@ -558,7 +561,6 @@  struct request_queue {
 #define QUEUE_FLAG_NOMERGES     3	/* disable merge attempts */
 #define QUEUE_FLAG_SAME_COMP	4	/* complete on same CPU-group */
 #define QUEUE_FLAG_FAIL_IO	5	/* fake timeout */
-#define QUEUE_FLAG_IO_STAT	7	/* do disk/partitions IO accounting */
 #define QUEUE_FLAG_NOXMERGES	9	/* No extended merges */
 #define QUEUE_FLAG_SYNCHRONOUS	11	/* always completes in submit context */
 #define QUEUE_FLAG_SAME_FORCE	12	/* force complete on same CPU */
@@ -577,8 +579,7 @@  struct request_queue {
 #define QUEUE_FLAG_SQ_SCHED     30	/* single queue style io dispatch */
 #define QUEUE_FLAG_SKIP_TAGSET_QUIESCE	31 /* quiesce_tagset skip the queue*/
 
-#define QUEUE_FLAG_MQ_DEFAULT	((1UL << QUEUE_FLAG_IO_STAT) |		\
-				 (1UL << QUEUE_FLAG_SAME_COMP) |	\
+#define QUEUE_FLAG_MQ_DEFAULT	((1UL << QUEUE_FLAG_SAME_COMP) |	\
 				 (1UL << QUEUE_FLAG_NOWAIT))
 
 void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
@@ -592,7 +593,7 @@  bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
 #define blk_queue_noxmerges(q)	\
 	test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
 #define blk_queue_nonrot(q)	((q)->limits.features & BLK_FEAT_ROTATIONAL)
-#define blk_queue_io_stat(q)	test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
+#define blk_queue_io_stat(q)	((q)->limits.features & BLK_FEAT_IO_STAT)
 #define blk_queue_zone_resetall(q)	\
 	test_bit(QUEUE_FLAG_ZONE_RESETALL, &(q)->queue_flags)
 #define blk_queue_dax(q)	test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)