[PATCH V4 0/4] ublk_drv: add generic mechanism to get/set parameters

[PATCH V4 0/4] ublk_drv: add generic mechanism to get/set parameters

[Ming Lei]

Hello Jens,

The 1st two patches fixes ublk device leak or hang issue in case of some
failure path, such as, failing to start device.

The 3rd patch adds two control commands for setting/getting device
parameters in generic way, and easy to extend to add new parameter
type.

The 4th patch cleans UAPI of ublksrv_ctrl_dev_info, and userspace needs
to be updated for this driver change, so please consider this patchset
for v5.20.

Verified by all targets in the following branch, and pass all built-in
tests.

https://github.com/ming1/ubdsrv/tree/parameter_out

Also all device data including parameters is exported as json in
above tree.

V4:
- take Christoph's suggestion to put all parameters into one single
  structure.
- move reserved fields of ublksrv_ctrl_dev_info into end

V3:
- drop device reference after add_disk fails, as suggested by Christoph, 1/5
- simplify the 3rd patch: replace xarray with plain array, remove
  function table and avoid indirect call, then reduce boiler plate for
  addressing Christoph's comment

V2:
- re-organize patches
- limit parameter max length
- take Christoph's approach to replace bitfields with flags, and use
char type to define block size shift
- add two fixes, which is triggered when testing set/get parameter
  commands
- cleanup uapi header


Ming Lei (4):
  ublk_drv: cancel device even though disk isn't up
  ublk_drv: fix ublk device leak in case that add_disk fails
  ublk_drv: add SET_PARAMS/GET_PARAMS control command
  ublk_drv: cleanup ublksrv_ctrl_dev_info

 drivers/block/ublk_drv.c      | 242 +++++++++++++++++++++++++++++-----
 include/uapi/linux/ublk_cmd.h |  62 ++++++++-
 2 files changed, 264 insertions(+), 40 deletions(-)

-- 
2.31.1

[PATCH V4 1/4] ublk_drv: cancel device even though disk isn't up

[Ming Lei]

Each ublk queue is started before adding disk, we have to cancel queues in
ublk_stop_dev() so that ubq daemon can be exited, otherwise DEL_DEV command
may hang forever.

Also avoid to cancel queues two times by checking if queue is ready,
otherwise use-after-free on io_uring may be triggered because ublk_stop_dev
is called by ublk_remove() too.

Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 3f1906965ac8..7ece4c2ef062 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -788,16 +788,27 @@ static void ublk_daemon_monitor_work(struct work_struct *work)
 				UBLK_DAEMON_MONITOR_PERIOD);
 }
 
+static inline bool ublk_queue_ready(struct ublk_queue *ubq)
+{
+	return ubq->nr_io_ready == ubq->q_depth;
+}
+
 static void ublk_cancel_queue(struct ublk_queue *ubq)
 {
 	int i;
 
+	if (!ublk_queue_ready(ubq))
+		return;
+
 	for (i = 0; i < ubq->q_depth; i++) {
 		struct ublk_io *io = &ubq->ios[i];
 
 		if (io->flags & UBLK_IO_FLAG_ACTIVE)
 			io_uring_cmd_done(io->cmd, UBLK_IO_RES_ABORT, 0);
 	}
+
+	/* all io commands are canceled */
+	ubq->nr_io_ready = 0;
 }
 
 /* Cancel all pending commands, must be called after del_gendisk() returns */
@@ -818,19 +829,14 @@ static void ublk_stop_dev(struct ublk_device *ub)
 	del_gendisk(ub->ub_disk);
 	ub->dev_info.state = UBLK_S_DEV_DEAD;
 	ub->dev_info.ublksrv_pid = -1;
-	ublk_cancel_dev(ub);
 	put_disk(ub->ub_disk);
 	ub->ub_disk = NULL;
  unlock:
+	ublk_cancel_dev(ub);
 	mutex_unlock(&ub->mutex);
 	cancel_delayed_work_sync(&ub->monitor_work);
 }
 
-static inline bool ublk_queue_ready(struct ublk_queue *ubq)
-{
-	return ubq->nr_io_ready == ubq->q_depth;
-}
-
 /* device can only be started after all IOs are ready */
 static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq)
 {
-- 
2.31.1

[PATCH V4 2/4] ublk_drv: fix ublk device leak in case that add_disk fails

[Ming Lei]

->free_disk is only called after disk is added successfully, so
drop ublk device reference in case of add_disk() failure.

Fixes: 6d9e6dfdf3b2 ("ublk: defer disk allocation")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 7ece4c2ef062..ae98e81b21ce 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1190,6 +1190,11 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
 	get_device(&ub->cdev_dev);
 	ret = add_disk(disk);
 	if (ret) {
+		/*
+		 * Has to drop the reference since ->free_disk won't be
+		 * called in case of add_disk failure.
+		 */
+		ublk_put_device(ub);
 		put_disk(disk);
 		goto out_unlock;
 	}
-- 
2.31.1

[PATCH V4 3/4] ublk_drv: add SET_PARAMS/GET_PARAMS control command

[Ming Lei]

Add two commands to set/get parameters generically.

One important goal of ublk is to provide generic framework for making
block device by userspace flexibly.

As one generic block device, there are still lots of block parameters,
such as max_sectors, write_cache/fua, discard related limits,
zoned parameters, ...., so this patch starts to add generic mechanism
for set/get device parameters.

Both generic block parameters(all kinds of queue settings) and ublk
feature parameters can be covered with this way, then it becomes quite
easy to extend in future.

Add two parameter types are used so far: basic(covers basic queue setting
and misc settings which can't be grouped easily) and discard, basic type
must be set, and discard type becomes optional now

This way provides mechanism to simulate any kind of generic block device
from userspace easily, from both block queue setting viewpoint or ublk
feature viewpoint.

The style of putting all parameters together is suggested by Christoph.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c      | 205 +++++++++++++++++++++++++++++++---
 include/uapi/linux/ublk_cmd.h |  47 ++++++++
 2 files changed, 234 insertions(+), 18 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index ae98e81b21ce..20ad83b25318 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -49,6 +49,9 @@
 /* All UBLK_F_* have to be included into UBLK_F_ALL */
 #define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY | UBLK_F_URING_CMD_COMP_IN_TASK)
 
+/* All UBLK_PARAM_TYPE_* should be included here */
+#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD)
+
 struct ublk_rq_data {
 	struct callback_head work;
 };
@@ -137,6 +140,8 @@ struct ublk_device {
 	spinlock_t		mm_lock;
 	struct mm_struct	*mm;
 
+	struct ublk_params	params;
+
 	struct completion	completion;
 	unsigned int		nr_queues_ready;
 	atomic_t		nr_aborted_queues;
@@ -149,6 +154,12 @@ struct ublk_device {
 	struct work_struct	stop_work;
 };
 
+/* header of ublk_params */
+struct ublk_params_header {
+	__u32	len;
+	__u32	types;
+};
+
 static dev_t ublk_chr_devt;
 static struct class *ublk_chr_class;
 
@@ -160,6 +171,91 @@ static DEFINE_MUTEX(ublk_ctl_mutex);
 
 static struct miscdevice ublk_misc;
 
+static void ublk_dev_param_basic_apply(struct ublk_device *ub)
+{
+	struct request_queue *q = ub->ub_disk->queue;
+	const struct ublk_param_basic *p = &ub->params.basic;
+
+	blk_queue_logical_block_size(q, 1 << p->logical_bs_shift);
+	blk_queue_physical_block_size(q, 1 << p->physical_bs_shift);
+	blk_queue_io_min(q, 1 << p->io_min_shift);
+	blk_queue_io_opt(q, 1 << p->io_opt_shift);
+
+	blk_queue_write_cache(q, p->attrs & UBLK_ATTR_VOLATILE_CACHE,
+			p->attrs & UBLK_ATTR_FUA);
+	if (p->attrs & UBLK_ATTR_ROTATIONAL)
+		blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
+	else
+		blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
+
+	blk_queue_max_hw_sectors(q, p->max_sectors);
+	blk_queue_chunk_sectors(q, p->chunk_sectors);
+	blk_queue_virt_boundary(q, p->virt_boundary_mask);
+
+	if (p->attrs & UBLK_ATTR_READ_ONLY)
+		set_disk_ro(ub->ub_disk, true);
+
+	set_capacity(ub->ub_disk, p->dev_sectors);
+}
+
+static void ublk_dev_param_discard_apply(struct ublk_device *ub)
+{
+	struct request_queue *q = ub->ub_disk->queue;
+	const struct ublk_param_discard *p = &ub->params.discard;
+
+	q->limits.discard_alignment = p->discard_alignment;
+	q->limits.discard_granularity = p->discard_granularity;
+	blk_queue_max_discard_sectors(q, p->max_discard_sectors);
+	blk_queue_max_write_zeroes_sectors(q,
+			p->max_write_zeroes_sectors);
+	blk_queue_max_discard_segments(q, p->max_discard_segments);
+}
+
+static int ublk_validate_params(const struct ublk_device *ub)
+{
+	/* basic param is the only one which must be set */
+	if (ub->params.types & UBLK_PARAM_TYPE_BASIC) {
+		const struct ublk_param_basic *p = &ub->params.basic;
+
+		if (p->logical_bs_shift > PAGE_SHIFT)
+			return -EINVAL;
+
+		if (p->logical_bs_shift > p->physical_bs_shift)
+			return -EINVAL;
+
+		if (p->max_sectors > (ub->dev_info.rq_max_blocks <<
+					(ub->bs_shift - 9)))
+			return -EINVAL;
+	} else
+		return -EINVAL;
+
+	if (ub->params.types & UBLK_PARAM_TYPE_DISCARD) {
+		const struct ublk_param_discard *p = &ub->params.discard;
+
+		/* So far, only support single segment discard */
+		if (p->max_discard_sectors && p->max_discard_segments != 1)
+			return -EINVAL;
+
+		if (!p->discard_granularity)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ublk_apply_params(struct ublk_device *ub)
+{
+	if (!(ub->params.types & UBLK_PARAM_TYPE_BASIC))
+		return -EINVAL;
+
+	ublk_dev_param_basic_apply(ub);
+
+	if (ub->params.types & UBLK_PARAM_TYPE_DISCARD)
+		ublk_dev_param_discard_apply(ub);
+
+	return 0;
+}
+
 static inline bool ublk_can_use_task_work(const struct ublk_queue *ubq)
 {
 	if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK) &&
@@ -1138,7 +1234,6 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
 {
 	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
 	int ublksrv_pid = (int)header->data[0];
-	unsigned long dev_blocks = header->data[1];
 	struct ublk_device *ub;
 	struct gendisk *disk;
 	int ret = -EINVAL;
@@ -1161,10 +1256,6 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
 		goto out_unlock;
 	}
 
-	/* We may get disk size updated */
-	if (dev_blocks)
-		ub->dev_info.dev_blocks = dev_blocks;
-
 	disk = blk_mq_alloc_disk(&ub->tag_set, ub);
 	if (IS_ERR(disk)) {
 		ret = PTR_ERR(disk);
@@ -1174,19 +1265,13 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
 	disk->fops = &ub_fops;
 	disk->private_data = ub;
 
-	blk_queue_logical_block_size(disk->queue, ub->dev_info.block_size);
-	blk_queue_physical_block_size(disk->queue, ub->dev_info.block_size);
-	blk_queue_io_min(disk->queue, ub->dev_info.block_size);
-	blk_queue_max_hw_sectors(disk->queue,
-		ub->dev_info.rq_max_blocks << (ub->bs_shift - 9));
-	disk->queue->limits.discard_granularity = PAGE_SIZE;
-	blk_queue_max_discard_sectors(disk->queue, UINT_MAX >> 9);
-	blk_queue_max_write_zeroes_sectors(disk->queue, UINT_MAX >> 9);
-
-	set_capacity(disk, ub->dev_info.dev_blocks << (ub->bs_shift - 9));
-
 	ub->dev_info.ublksrv_pid = ublksrv_pid;
 	ub->ub_disk = disk;
+
+	ret = ublk_apply_params(ub);
+	if (ret)
+		goto out_put_disk;
+
 	get_device(&ub->cdev_dev);
 	ret = add_disk(disk);
 	if (ret) {
@@ -1195,11 +1280,13 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
 		 * called in case of add_disk failure.
 		 */
 		ublk_put_device(ub);
-		put_disk(disk);
-		goto out_unlock;
+		goto out_put_disk;
 	}
 	set_bit(UB_STATE_USED, &ub->state);
 	ub->dev_info.state = UBLK_S_DEV_LIVE;
+out_put_disk:
+	if (ret)
+		put_disk(disk);
 out_unlock:
 	mutex_unlock(&ub->mutex);
 	ublk_put_device(ub);
@@ -1447,6 +1534,82 @@ static int ublk_ctrl_get_dev_info(struct io_uring_cmd *cmd)
 	return ret;
 }
 
+static int ublk_ctrl_get_params(struct io_uring_cmd *cmd)
+{
+	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
+	void __user *argp = (void __user *)(unsigned long)header->addr;
+	struct ublk_params_header ph;
+	struct ublk_device *ub;
+	int ret;
+
+	if (header->len <= sizeof(ph) || !header->addr)
+		return -EINVAL;
+
+	if (copy_from_user(&ph, argp, sizeof(ph)))
+		return -EFAULT;
+
+	if (ph.len > header->len || !ph.len)
+		return -EINVAL;
+
+	if (ph.len > sizeof(struct ublk_params))
+		ph.len = sizeof(struct ublk_params);
+
+	ub = ublk_get_device_from_id(header->dev_id);
+	if (!ub)
+		return -EINVAL;
+
+	mutex_lock(&ub->mutex);
+	if (copy_to_user(argp, &ub->params, ph.len))
+		ret = -EFAULT;
+	else
+		ret = 0;
+	mutex_unlock(&ub->mutex);
+
+	ublk_put_device(ub);
+	return ret;
+}
+
+static int ublk_ctrl_set_params(struct io_uring_cmd *cmd)
+{
+	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
+	void __user *argp = (void __user *)(unsigned long)header->addr;
+	struct ublk_params_header ph;
+	struct ublk_device *ub;
+	int ret = -EFAULT;
+
+	if (header->len <= sizeof(ph) || !header->addr)
+		return -EINVAL;
+
+	if (copy_from_user(&ph, argp, sizeof(ph)))
+		return -EFAULT;
+
+	if (ph.len > header->len || !ph.len || !ph.types)
+		return -EINVAL;
+
+	if (ph.len > sizeof(struct ublk_params))
+		ph.len = sizeof(struct ublk_params);
+
+	ub = ublk_get_device_from_id(header->dev_id);
+	if (!ub)
+		return -EINVAL;
+
+	/* parameters can only be changed when device isn't live */
+	mutex_lock(&ub->mutex);
+	if (ub->dev_info.state == UBLK_S_DEV_LIVE) {
+		ret = -EACCES;
+	} else if (copy_from_user(&ub->params, argp, ph.len)) {
+		ret = -EFAULT;
+	} else {
+		/* clear all we don't support yet */
+		ub->params.types &= UBLK_PARAM_TYPE_ALL;
+		ret = ublk_validate_params(ub);
+	}
+	mutex_unlock(&ub->mutex);
+	ublk_put_device(ub);
+
+	return ret;
+}
+
 static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
 		unsigned int issue_flags)
 {
@@ -1482,6 +1645,12 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
 	case UBLK_CMD_GET_QUEUE_AFFINITY:
 		ret = ublk_ctrl_get_queue_affinity(cmd);
 		break;
+	case UBLK_CMD_GET_PARAMS:
+		ret = ublk_ctrl_get_params(cmd);
+		break;
+	case UBLK_CMD_SET_PARAMS:
+		ret = ublk_ctrl_set_params(cmd);
+		break;
 	default:
 		break;
 	}
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index ca33092354ab..54d065426f06 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -15,6 +15,8 @@
 #define	UBLK_CMD_DEL_DEV		0x05
 #define	UBLK_CMD_START_DEV	0x06
 #define	UBLK_CMD_STOP_DEV	0x07
+#define	UBLK_CMD_SET_PARAMS	0x08
+#define	UBLK_CMD_GET_PARAMS	0x09
 
 /*
  * IO commands, issued by ublk server, and handled by ublk driver.
@@ -158,4 +160,49 @@ struct ublksrv_io_cmd {
 	__u64	addr;
 };
 
+struct ublk_param_basic {
+#define UBLK_ATTR_READ_ONLY            (1 << 0)
+#define UBLK_ATTR_ROTATIONAL           (1 << 1)
+#define UBLK_ATTR_VOLATILE_CACHE       (1 << 2)
+#define UBLK_ATTR_FUA                  (1 << 3)
+	__u32	attrs;
+	__u8	logical_bs_shift;
+	__u8	physical_bs_shift;
+	__u8	io_opt_shift;
+	__u8	io_min_shift;
+
+	__u32	max_sectors;
+	__u32	chunk_sectors;
+
+	__u64   dev_sectors;
+	__u64   virt_boundary_mask;
+};
+
+struct ublk_param_discard {
+	__u32	discard_alignment;
+
+	__u32	discard_granularity;
+	__u32	max_discard_sectors;
+
+	__u32	max_write_zeroes_sectors;
+	__u16	max_discard_segments;
+	__u16	reserved0;
+};
+
+struct ublk_params {
+	/*
+	 * Total length of parameters, userspace has to set 'len' for both
+	 * SET_PARAMS and GET_PARAMS command, and driver may update len
+	 * if two sides use different version of 'ublk_params', same with
+	 * 'types' fields.
+	 */
+	__u32	len;
+#define UBLK_PARAM_TYPE_BASIC           (1 << 0)
+#define UBLK_PARAM_TYPE_DISCARD         (1 << 1)
+	__u32	types;			/* types of parameter included */
+
+	struct ublk_param_basic		basic;
+	struct ublk_param_discard	discard;
+};
+
 #endif
-- 
2.31.1

[PATCH V4 4/4] ublk_drv: cleanup ublksrv_ctrl_dev_info

[Ming Lei]

Remove all block device related info from ublksrv_ctrl_dev_info,
meantime reduce its size into 64 bytes because:

1) ublksrv_ctrl_dev_info becomes cleaner without including any
block related info

2) generic set/get parameter command can be used to set block
related setting easily and cleanly

3) generic set/get parameter command can be used for extending
ublk without needing more info in ublksrv_ctrl_dev_info

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c      | 18 +++++++-----------
 include/uapi/linux/ublk_cmd.h | 15 ++++++++-------
 2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 20ad83b25318..2b3cd671a653 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -122,7 +122,6 @@ struct ublk_device {
 	char	*__queues;
 
 	unsigned short  queue_size;
-	unsigned short  bs_shift;
 	struct ublksrv_ctrl_dev_info	dev_info;
 
 	struct blk_mq_tag_set	tag_set;
@@ -223,8 +222,7 @@ static int ublk_validate_params(const struct ublk_device *ub)
 		if (p->logical_bs_shift > p->physical_bs_shift)
 			return -EINVAL;
 
-		if (p->max_sectors > (ub->dev_info.rq_max_blocks <<
-					(ub->bs_shift - 9)))
+		if (p->max_sectors > (ub->dev_info.max_io_buf_bytes >> 9))
 			return -EINVAL;
 	} else
 		return -EINVAL;
@@ -1185,13 +1183,13 @@ static void ublk_stop_work_fn(struct work_struct *work)
 	ublk_stop_dev(ub);
 }
 
-/* align maximum I/O size to PAGE_SIZE */
+/* align max io buffer size with PAGE_SIZE */
 static void ublk_align_max_io_size(struct ublk_device *ub)
 {
-	unsigned int max_rq_bytes = ub->dev_info.rq_max_blocks << ub->bs_shift;
+	unsigned int max_io_bytes = ub->dev_info.max_io_buf_bytes;
 
-	ub->dev_info.rq_max_blocks =
-		round_down(max_rq_bytes, PAGE_SIZE) >> ub->bs_shift;
+	ub->dev_info.max_io_buf_bytes =
+		round_down(max_io_bytes, PAGE_SIZE);
 }
 
 static int ublk_add_tag_set(struct ublk_device *ub)
@@ -1348,9 +1346,8 @@ static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info)
 {
 	pr_devel("%s: dev id %d flags %llx\n", __func__,
 			info->dev_id, info->flags);
-	pr_devel("\t nr_hw_queues %d queue_depth %d block size %d dev_capacity %lld\n",
-			info->nr_hw_queues, info->queue_depth,
-			info->block_size, info->dev_blocks);
+	pr_devel("\t nr_hw_queues %d queue_depth %d\n",
+			info->nr_hw_queues, info->queue_depth);
 }
 
 static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
@@ -1410,7 +1407,6 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
 	/* We are not ready to support zero copy */
 	ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY;
 
-	ub->bs_shift = ilog2(ub->dev_info.block_size);
 	ub->dev_info.nr_hw_queues = min_t(unsigned int,
 			ub->dev_info.nr_hw_queues, nr_cpu_ids);
 	ublk_align_max_io_size(ub);
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index 54d065426f06..57d86d0e8c5b 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -80,22 +80,23 @@ struct ublksrv_ctrl_cmd {
 struct ublksrv_ctrl_dev_info {
 	__u16	nr_hw_queues;
 	__u16	queue_depth;
-	__u16	block_size;
 	__u16	state;
+	__u16	pad0;
 
-	__u32	rq_max_blocks;
+	__u32	max_io_buf_bytes;
 	__u32	dev_id;
 
-	__u64   dev_blocks;
-
 	__s32	ublksrv_pid;
-	__s32	reserved0;
+	__u32	pad1;
+
 	__u64	flags;
-	__u64	flags_reserved;
 
 	/* For ublksrv internal use, invisible to ublk driver */
 	__u64	ublksrv_flags;
-	__u64	reserved1[9];
+
+	__u64	reserved0;
+	__u64	reserved1;
+	__u64   reserved2;
 };
 
 #define		UBLK_IO_OP_READ		0
-- 
2.31.1

Re: [PATCH V4 0/4] ublk_drv: add generic mechanism to get/set parameters

[Jens Axboe]

On 7/30/22 3:27 AM, Ming Lei wrote:
> Hello Jens,
> 
> The 1st two patches fixes ublk device leak or hang issue in case of some
> failure path, such as, failing to start device.
> 
> The 3rd patch adds two control commands for setting/getting device
> parameters in generic way, and easy to extend to add new parameter
> type.
> 
> The 4th patch cleans UAPI of ublksrv_ctrl_dev_info, and userspace needs
> to be updated for this driver change, so please consider this patchset
> for v5.20.
> 
> Verified by all targets in the following branch, and pass all built-in
> tests.

This will miss the first pull request, but I've queued it up for this
merge window.

-- 
Jens Axboe

Re: [PATCH V4 0/4] ublk_drv: add generic mechanism to get/set parameters

[Jens Axboe]

On Sat, 30 Jul 2022 17:27:46 +0800, Ming Lei wrote:
> The 1st two patches fixes ublk device leak or hang issue in case of some
> failure path, such as, failing to start device.
> 
> The 3rd patch adds two control commands for setting/getting device
> parameters in generic way, and easy to extend to add new parameter
> type.
> 
> [...]

Applied, thanks!

[1/4] ublk_drv: cancel device even though disk isn't up
      commit: 90828a5e0d656f83f67929ece0a50ff0fb6ab7a3
[2/4] ublk_drv: fix ublk device leak in case that add_disk fails
      commit: ed772fe30a04e07e25313b62c0659b2bcf41195c
[3/4] ublk_drv: add SET_PARAMS/GET_PARAMS control command
      commit: 134ec0b02374bb85451ef90ab0d0bac233c945f1
[4/4] ublk_drv: cleanup ublksrv_ctrl_dev_info
      commit: 099d9b8d637b88a7718fe51129db4dc686ce9cea

Best regards,
-- 
Jens Axboe

Re: [PATCH V4 0/4] ublk_drv: add generic mechanism to get/set parameters

[Ming Lei]

On Sat, Jul 30, 2022 at 09:04:24AM -0600, Jens Axboe wrote:
> On 7/30/22 3:27 AM, Ming Lei wrote:
> > Hello Jens,
> > 
> > The 1st two patches fixes ublk device leak or hang issue in case of some
> > failure path, such as, failing to start device.
> > 
> > The 3rd patch adds two control commands for setting/getting device
> > parameters in generic way, and easy to extend to add new parameter
> > type.
> > 
> > The 4th patch cleans UAPI of ublksrv_ctrl_dev_info, and userspace needs
> > to be updated for this driver change, so please consider this patchset
> > for v5.20.
> > 
> > Verified by all targets in the following branch, and pass all built-in
> > tests.
> 
> This will miss the first pull request, but I've queued it up for this
> merge window.

That is great, thanks for queuing it up!

-- 
Ming