[PATCH 0/5] Five small zoned block device patches

[PATCH 0/5] Five small zoned block device patches

[Bart Van Assche]

Hello Jens,

In this patch series there are five patches with small improvements for the
zoned block device code. Please consider these patches for the upstream kernel.

Thanks,

Bart.

Bart Van Assche (5):
  block: Remove a superfluous cast from blkdev_report_zones()
  include/uapi/linux/blkzoned.h: Remove a superfluous __packed directive
  block: Remove bdev_nr_zones()
  block: Inline blk_queue_nr_zones()
  block: Make struct request_queue smaller for CONFIG_BLK_DEV_ZONED=n

 block/Kconfig                 |  4 ++++
 block/Makefile                |  1 +
 block/blk-mq-debugfs-zoned.c  | 24 ++++++++++++++++++++++++
 block/blk-mq-debugfs.c        | 15 ---------------
 block/blk-mq-debugfs.h        |  9 +++++++++
 block/blk-zoned.c             |  2 +-
 include/linux/blkdev.h        | 20 ++++++--------------
 include/uapi/linux/blkzoned.h |  2 +-
 8 files changed, 46 insertions(+), 31 deletions(-)
 create mode 100644 block/blk-mq-debugfs-zoned.c

-- 
2.17.0

[PATCH 1/5] block: Remove a superfluous cast from blkdev_report_zones()

[Bart Van Assche]

No cast is necessary when assigning a non-void pointer to a void
pointer.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Matias Bjorling <mb@lightnvm.io>
Cc: Christoph Hellwig <hch@lst.de>
---
 block/blk-zoned.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 3d08dc84db16..92e6108487c4 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -200,7 +200,7 @@ int blkdev_report_zones(struct block_device *bdev,
 		/* Get header in the first page */
 		ofst = 0;
 		if (!nr_rep) {
-			hdr = (struct blk_zone_report_hdr *) addr;
+			hdr = addr;
 			nr_rep = hdr->nr_zones;
 			ofst = sizeof(struct blk_zone_report_hdr);
 		}
-- 
2.17.0

[PATCH 2/5] include/uapi/linux/blkzoned.h: Remove a superfluous __packed directive

[Bart Van Assche]

Using the __packed directive for a structure that does not need
it is wrong because it makes gcc generate suboptimal code on some
architectures. Hence remove the __packed directive from the
blk_zone_report structure definition. See also
http://digitalvampire.org/blog/index.php/2006/07/31/why-you-shouldnt-use-__attribute__packed/.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Matias Bjorling <mb@lightnvm.io>
Cc: Christoph Hellwig <hch@lst.de>
---
 include/uapi/linux/blkzoned.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/uapi/linux/blkzoned.h b/include/uapi/linux/blkzoned.h
index e3c70fe6bf0f..ff5a5db8906a 100644
--- a/include/uapi/linux/blkzoned.h
+++ b/include/uapi/linux/blkzoned.h
@@ -117,7 +117,7 @@ struct blk_zone_report {
 	__u32		nr_zones;
 	__u8		reserved[4];
 	struct blk_zone zones[0];
-} __packed;
+};
 
 /**
  * struct blk_zone_range - BLKRESETZONE ioctl request
-- 
2.17.0

[PATCH 3/5] block: Remove bdev_nr_zones()

[Bart Van Assche]

Remove this function since it has no callers. This function was
introduced in commit 6cc77e9cb080 ("block: introduce zoned block
devices zone write locking").

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matias Bjorling <mb@lightnvm.io>
---
 include/linux/blkdev.h | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index a8b98eadebb2..05cd0c8e5735 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1648,15 +1648,6 @@ static inline unsigned int bdev_zone_sectors(struct block_device *bdev)
 	return 0;
 }
 
-static inline unsigned int bdev_nr_zones(struct block_device *bdev)
-{
-	struct request_queue *q = bdev_get_queue(bdev);
-
-	if (q)
-		return blk_queue_nr_zones(q);
-	return 0;
-}
-
 static inline int queue_dma_alignment(struct request_queue *q)
 {
 	return q ? q->dma_alignment : 511;
-- 
2.17.0

[PATCH 4/5] block: Inline blk_queue_nr_zones()

[Bart Van Assche]

Since the implementation of blk_queue_nr_zones() is trivial and since
it only has a single caller, inline this function.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Matias Bjorling <mb@lightnvm.io>
Cc: Christoph Hellwig <hch@lst.de>
---
 block/blk-mq-debugfs.c | 2 +-
 include/linux/blkdev.h | 5 -----
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 67aa2d4e2e89..b92ef4c3038e 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -214,7 +214,7 @@ static int queue_zone_wlock_show(void *data, struct seq_file *m)
 	if (!q->seq_zones_wlock)
 		return 0;
 
-	for (i = 0; i < blk_queue_nr_zones(q); i++)
+	for (i = 0; i < q->nr_zones; i++)
 		if (test_bit(i, q->seq_zones_wlock))
 			seq_printf(m, "%u\n", i);
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 05cd0c8e5735..96640bcd5e78 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -800,11 +800,6 @@ static inline unsigned int blk_queue_zone_sectors(struct request_queue *q)
 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
 }
 
-static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
-{
-	return q->nr_zones;
-}
-
 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
 					     sector_t sector)
 {
-- 
2.17.0

[PATCH 5/5] block: Make struct request_queue smaller for CONFIG_BLK_DEV_ZONED=n

[Bart Van Assche]

Exclude zoned block device members from struct request_queue for
CONFIG_BLK_DEV_ZONED == n. Avoid breaking the build by only building
the code that uses these struct request_queue members if
CONFIG_BLK_DEV_ZONED != n.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Matias Bjorling <mb@lightnvm.io>
Cc: Christoph Hellwig <hch@lst.de>
---
 block/Kconfig                |  4 ++++
 block/Makefile               |  1 +
 block/blk-mq-debugfs-zoned.c | 24 ++++++++++++++++++++++++
 block/blk-mq-debugfs.c       | 15 ---------------
 block/blk-mq-debugfs.h       |  9 +++++++++
 include/linux/blkdev.h       |  6 ++++++
 6 files changed, 44 insertions(+), 15 deletions(-)
 create mode 100644 block/blk-mq-debugfs-zoned.c

diff --git a/block/Kconfig b/block/Kconfig
index 28ec55752b68..0514f0b61226 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -177,6 +177,10 @@ config BLK_DEBUG_FS
 	Unless you are building a kernel for a tiny system, you should
 	say Y here.
 
+config BLK_DEBUG_FS_ZONED
+       bool
+       default BLK_DEBUG_FS && BLK_DEV_ZONED
+
 config BLK_SED_OPAL
 	bool "Logic for interfacing with Opal enabled SEDs"
 	---help---
diff --git a/block/Makefile b/block/Makefile
index 6a56303b9925..a8f94cdb75c3 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -34,4 +34,5 @@ obj-$(CONFIG_BLK_MQ_RDMA)	+= blk-mq-rdma.o
 obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
 obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
 obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
+obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
 obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
diff --git a/block/blk-mq-debugfs-zoned.c b/block/blk-mq-debugfs-zoned.c
new file mode 100644
index 000000000000..fb2c82c351e4
--- /dev/null
+++ b/block/blk-mq-debugfs-zoned.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 Western Digital Corporation or its affiliates.
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/blkdev.h>
+#include "blk-mq-debugfs.h"
+
+int queue_zone_wlock_show(void *data, struct seq_file *m)
+{
+	struct request_queue *q = data;
+	unsigned int i;
+
+	if (!q->seq_zones_wlock)
+		return 0;
+
+	for (i = 0; i < q->nr_zones; i++)
+		if (test_bit(i, q->seq_zones_wlock))
+			seq_printf(m, "%u\n", i);
+
+	return 0;
+}
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index b92ef4c3038e..9907e6610656 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -206,21 +206,6 @@ static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 	return count;
 }
 
-static int queue_zone_wlock_show(void *data, struct seq_file *m)
-{
-	struct request_queue *q = data;
-	unsigned int i;
-
-	if (!q->seq_zones_wlock)
-		return 0;
-
-	for (i = 0; i < q->nr_zones; i++)
-		if (test_bit(i, q->seq_zones_wlock))
-			seq_printf(m, "%u\n", i);
-
-	return 0;
-}
-
 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 	{ "poll_stat", 0400, queue_poll_stat_show },
 	{ "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
diff --git a/block/blk-mq-debugfs.h b/block/blk-mq-debugfs.h
index b3342d8dc934..d287638b2c6a 100644
--- a/block/blk-mq-debugfs.h
+++ b/block/blk-mq-debugfs.h
@@ -81,4 +81,13 @@ static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hc
 }
 #endif
 
+#ifdef CONFIG_BLK_DEBUG_FS_ZONED
+int queue_zone_wlock_show(void *data, struct seq_file *m);
+#else
+static inline int queue_zone_wlock_show(void *data, struct seq_file *m)
+{
+	return 0;
+}
+#endif
+
 #endif
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 96640bcd5e78..f7c8dcd3127c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -589,6 +589,7 @@ struct request_queue {
 
 	struct queue_limits	limits;
 
+#ifdef CONFIG_BLK_DEV_ZONED
 	/*
 	 * Zoned block device information for request dispatch control.
 	 * nr_zones is the total number of zones of the device. This is always
@@ -609,6 +610,7 @@ struct request_queue {
 	unsigned int		nr_zones;
 	unsigned long		*seq_zones_bitmap;
 	unsigned long		*seq_zones_wlock;
+#endif /* CONFIG_BLK_DEV_ZONED */
 
 	/*
 	 * sg stuff
@@ -800,6 +802,7 @@ static inline unsigned int blk_queue_zone_sectors(struct request_queue *q)
 	return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
 }
 
+#ifdef CONFIG_BLK_DEV_ZONED
 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
 					     sector_t sector)
 {
@@ -815,6 +818,7 @@ static inline bool blk_queue_zone_is_seq(struct request_queue *q,
 		return false;
 	return test_bit(blk_queue_zone_no(q, sector), q->seq_zones_bitmap);
 }
+#endif /* CONFIG_BLK_DEV_ZONED */
 
 static inline bool rq_is_sync(struct request *rq)
 {
@@ -1073,6 +1077,7 @@ static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
 	return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
 }
 
+#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));
@@ -1082,6 +1087,7 @@ static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
 {
 	return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
 }
+#endif /* CONFIG_BLK_DEV_ZONED */
 
 /*
  * Some commands like WRITE SAME have a payload or data transfer size which
-- 
2.17.0

Re: [PATCH 0/5] Five small zoned block device patches

[Jens Axboe]

On 6/15/18 3:55 PM, Bart Van Assche wrote:
> Hello Jens,
> 
> In this patch series there are five patches with small improvements for the
> zoned block device code. Please consider these patches for the upstream kernel.

Looks fine to me. Are you thinking 4.18 or 4.19?

-- 
Jens Axboe

Re: [PATCH 0/5] Five small zoned block device patches

[Bart Van Assche]

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DQoNClRoYW5rcywNCg0KQmFydC4NCg0KDQoNCg==

Re: [PATCH 0/5] Five small zoned block device patches

[Jens Axboe]

On 6/16/18 2:58 PM, Bart Van Assche wrote:
> On Sat, 2018-06-16 at 12:27 -0600, Jens Axboe wrote:
>> On 6/15/18 3:55 PM, Bart Van Assche wrote:
>>> Hello Jens,
>>>
>>> In this patch series there are five patches with small improvements for the
>>> zoned block device code. Please consider these patches for the upstream kernel.
>>
>> Looks fine to me. Are you thinking 4.18 or 4.19?
> 
> Hello Jens,
> 
> I'm fine with either kernel version. These patches do not change any
> functionality so queuing these patches is not urgent. However, the sooner
> these get upstream the lower the change that any bug fixes that touch the
> same code conflict with this patch series ...

I like them all as cleanups, but as cleanups I think we should queue them
up for 4.19. I'll do that.

-- 
Jens Axboe

[PATCH 0/5] Five small zoned block device patches

[Bart Van Assche]

Hello Jens,

In this patch series there are five patches with small improvements for the
zoned block device code. Please consider these patches for the upstream kernel.

Thanks,

Bart.

Bart Van Assche (5):
  block: Remove a superfluous cast from blkdev_report_zones()
  include/uapi/linux/blkzoned.h: Remove a superfluous __packed directive
  block: Remove bdev_nr_zones()
  block: Inline blk_queue_nr_zones()
  block: Make struct request_queue smaller for CONFIG_BLK_DEV_ZONED=n

 block/Kconfig                 |  4 ++++
 block/Makefile                |  1 +
 block/blk-mq-debugfs-zoned.c  | 24 ++++++++++++++++++++++++
 block/blk-mq-debugfs.c        | 15 ---------------
 block/blk-mq-debugfs.h        |  9 +++++++++
 block/blk-zoned.c             |  2 +-
 include/linux/blkdev.h        | 20 ++++++--------------
 include/uapi/linux/blkzoned.h |  2 +-
 8 files changed, 46 insertions(+), 31 deletions(-)
 create mode 100644 block/blk-mq-debugfs-zoned.c

-- 
2.17.0