[PATCH v10 0/3] ublk: enable zoned storage support

[PATCH v10 0/3] ublk: enable zoned storage support

[Andreas Hindborg (Samsung)]

From: Andreas Hindborg <a.hindborg@samsung.com>

Hi All,

This patch set adds zoned storage support to `ublk`. The first two patches do
some house cleaning in preparation for the last patch. The last patch adds
support for report_zones and the following operations:

 - REQ_OP_ZONE_OPEN
 - REQ_OP_ZONE_CLOSE
 - REQ_OP_ZONE_FINISH
 - REQ_OP_ZONE_RESET
 - REQ_OP_ZONE_APPEND

A user space component based on ubdsrv is available for testing [1] with the
"loop" target.

Read/write and zone operations are tested with zenfs [2].

The zone append path is tested with fio -> zonefs -> ublk -> null_blk.

The series is based on v6.5-rc4.

Changes for v10
 - Remove IO flag UBLK_IO_FLAG_ZONE_APPEND
 - Rename ublk_rq_data.nr_sectors to nr_zones
 - Change UAPI by adding field `nr_zones` in union with
   `ublksrv_io_desc.nr_sectors` and use zone count instead of sector count when
   applicable
 - Add documentation suggested Ming to UAPI `UBLK_IO_OP_REPORT_ZONES` and
   `ublksrv_io_cmd`
 - Updated user space component [1]

[1] https://github.com/metaspace/ubdsrv/tree/2966e5f9637b5856d4a4273ae113e31b1c53ff98
[2] https://github.com/westerndigitalcorporation/zenfs
[3] https://git.kernel.dk/linux.git

Andreas Hindborg (3):
  ublk: add helper to check if device supports user copy
  ublk: move check for empty address field on command submission
  ublk: enable zoned storage support

 drivers/block/ublk_drv.c      | 353 ++++++++++++++++++++++++++++++++--
 include/uapi/linux/ublk_cmd.h |  63 +++++-
 2 files changed, 388 insertions(+), 28 deletions(-)


base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
-- 
2.41.0

[PATCH v10 1/3] ublk: add helper to check if device supports user copy

[Andreas Hindborg (Samsung)]

From: Andreas Hindborg <a.hindborg@samsung.com>

This will be used by ublk zoned storage support.

Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
---
 drivers/block/ublk_drv.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 21d2e71c5514..db3523e281a6 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -185,6 +185,11 @@ struct ublk_params_header {
 	__u32	types;
 };
 
+static inline bool ublk_dev_is_user_copy(const struct ublk_device *ub)
+{
+	return ub->dev_info.flags & UBLK_F_USER_COPY;
+}
+
 static inline void __ublk_complete_rq(struct request *req);
 static void ublk_complete_rq(struct kref *ref);
 
@@ -2038,7 +2043,7 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
 		UBLK_F_URING_CMD_COMP_IN_TASK;
 
 	/* GET_DATA isn't needed any more with USER_COPY */
-	if (ub->dev_info.flags & UBLK_F_USER_COPY)
+	if (ublk_dev_is_user_copy(ub))
 		ub->dev_info.flags &= ~UBLK_F_NEED_GET_DATA;
 
 	/* We are not ready to support zero copy */
-- 
2.41.0

[PATCH v10 2/3] ublk: move check for empty address field on command submission

[Andreas Hindborg (Samsung)]

From: Andreas Hindborg <a.hindborg@samsung.com>

In preparation for zoned storage support, move the check for empty `addr`
field into the command handler case statement. Note that the check makes no
sense for `UBLK_IO_NEED_GET_DATA` because the `addr` field must always be
set for this command.

Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
---
 drivers/block/ublk_drv.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index db3523e281a6..5a1ee17636ac 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1419,11 +1419,6 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
 			^ (_IOC_NR(cmd_op) == UBLK_IO_NEED_GET_DATA))
 		goto out;
 
-	if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
-		ret = -EINVAL;
-		goto out;
-	}
-
 	ret = ublk_check_cmd_op(cmd_op);
 	if (ret)
 		goto out;
@@ -1452,6 +1447,12 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
 				goto out;
 		}
 
+		/* User copy requires addr to be unset */
+		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
+			ret = -EINVAL;
+			goto out;
+		}
+
 		ublk_fill_io_cmd(io, cmd, ub_cmd->addr);
 		ublk_mark_io_ready(ub, ubq);
 		break;
@@ -1470,6 +1471,13 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
 						req_op(req) == REQ_OP_READ))
 				goto out;
 		}
+
+		/* User copy requires addr to be unset */
+		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
+			ret = -EINVAL;
+			goto out;
+		}
+
 		ublk_fill_io_cmd(io, cmd, ub_cmd->addr);
 		ublk_commit_completion(ub, ub_cmd);
 		break;
-- 
2.41.0

[PATCH v10 3/3] ublk: enable zoned storage support

[Andreas Hindborg (Samsung)]

From: Andreas Hindborg <a.hindborg@samsung.com>

Add zoned storage support to ublk: report_zones and operations:
 - REQ_OP_ZONE_OPEN
 - REQ_OP_ZONE_CLOSE
 - REQ_OP_ZONE_FINISH
 - REQ_OP_ZONE_RESET
 - REQ_OP_ZONE_APPEND

The zone append feature uses the `addr` field of `struct ublksrv_io_cmd` to
communicate ALBA back to the kernel. Therefore ublk must be used with the
user copy feature (UBLK_F_USER_COPY) for zoned storage support to be
available. Without this feature, ublk will not allow zoned storage support.

Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
---
 drivers/block/ublk_drv.c      | 332 ++++++++++++++++++++++++++++++++--
 include/uapi/linux/ublk_cmd.h |  63 ++++++-
 2 files changed, 371 insertions(+), 24 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 5a1ee17636ac..b8f704b84b61 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -56,16 +56,21 @@
 		| UBLK_F_USER_RECOVERY_REISSUE \
 		| UBLK_F_UNPRIVILEGED_DEV \
 		| UBLK_F_CMD_IOCTL_ENCODE \
-		| UBLK_F_USER_COPY)
+		| UBLK_F_USER_COPY \
+		| UBLK_F_ZONED)
 
 /* All UBLK_PARAM_TYPE_* should be included here */
-#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | \
-		UBLK_PARAM_TYPE_DISCARD | UBLK_PARAM_TYPE_DEVT)
+#define UBLK_PARAM_TYPE_ALL                                \
+	(UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD | \
+	 UBLK_PARAM_TYPE_DEVT | UBLK_PARAM_TYPE_ZONED)
 
 struct ublk_rq_data {
 	struct llist_node node;
 
 	struct kref ref;
+	__u64 sector;
+	__u32 operation;
+	__u32 nr_zones;
 };
 
 struct ublk_uring_cmd_pdu {
@@ -185,11 +190,263 @@ struct ublk_params_header {
 	__u32	types;
 };
 
+static inline unsigned int ublk_req_build_flags(struct request *req);
+static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq,
+						   int tag);
+
 static inline bool ublk_dev_is_user_copy(const struct ublk_device *ub)
 {
 	return ub->dev_info.flags & UBLK_F_USER_COPY;
 }
 
+static inline bool ublk_dev_is_zoned(const struct ublk_device *ub)
+{
+	return ub->dev_info.flags & UBLK_F_ZONED;
+}
+
+static inline bool ublk_queue_is_zoned(struct ublk_queue *ubq)
+{
+	return ubq->flags & UBLK_F_ZONED;
+}
+
+#ifdef CONFIG_BLK_DEV_ZONED
+
+static int ublk_get_nr_zones(const struct ublk_device *ub)
+{
+	const struct ublk_param_basic *p = &ub->params.basic;
+
+	/* Zone size is a power of 2 */
+	return p->dev_sectors >> ilog2(p->chunk_sectors);
+}
+
+static int ublk_revalidate_disk_zones(struct ublk_device *ub)
+{
+	return blk_revalidate_disk_zones(ub->ub_disk, NULL);
+}
+
+static int ublk_dev_param_zoned_validate(const struct ublk_device *ub)
+{
+	const struct ublk_param_zoned *p = &ub->params.zoned;
+	int nr_zones;
+
+	if (!ublk_dev_is_zoned(ub))
+		return -EINVAL;
+
+	if (!p->max_zone_append_sectors)
+		return -EINVAL;
+
+	nr_zones = ublk_get_nr_zones(ub);
+
+	if (p->max_active_zones > nr_zones)
+		return -EINVAL;
+
+	if (p->max_open_zones > nr_zones)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ublk_dev_param_zoned_apply(struct ublk_device *ub)
+{
+	const struct ublk_param_zoned *p = &ub->params.zoned;
+
+	disk_set_zoned(ub->ub_disk, BLK_ZONED_HM);
+	blk_queue_required_elevator_features(ub->ub_disk->queue,
+					     ELEVATOR_F_ZBD_SEQ_WRITE);
+	disk_set_max_active_zones(ub->ub_disk, p->max_active_zones);
+	disk_set_max_open_zones(ub->ub_disk, p->max_open_zones);
+	blk_queue_max_zone_append_sectors(ub->ub_disk->queue, p->max_zone_append_sectors);
+
+	ub->ub_disk->nr_zones = ublk_get_nr_zones(ub);
+
+	return 0;
+}
+
+/* Based on virtblk_alloc_report_buffer */
+static void *ublk_alloc_report_buffer(struct ublk_device *ublk,
+				      unsigned int nr_zones, size_t *buflen)
+{
+	struct request_queue *q = ublk->ub_disk->queue;
+	size_t bufsize;
+	void *buf;
+
+	nr_zones = min_t(unsigned int, nr_zones,
+			 ublk->ub_disk->nr_zones);
+
+	bufsize = nr_zones * sizeof(struct blk_zone);
+	bufsize =
+		min_t(size_t, bufsize, queue_max_hw_sectors(q) << SECTOR_SHIFT);
+
+	while (bufsize >= sizeof(struct blk_zone)) {
+		buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
+		if (buf) {
+			*buflen = bufsize;
+			return buf;
+		}
+		bufsize >>= 1;
+	}
+
+	*buflen = 0;
+	return NULL;
+}
+
+static int ublk_report_zones(struct gendisk *disk, sector_t sector,
+		      unsigned int nr_zones, report_zones_cb cb, void *data)
+{
+	struct ublk_device *ub = disk->private_data;
+	unsigned int zone_size_sectors = disk->queue->limits.chunk_sectors;
+	unsigned int first_zone = sector >> ilog2(zone_size_sectors);
+	unsigned int done_zones = 0;
+	unsigned int max_zones_per_request;
+	int ret;
+	struct blk_zone *buffer;
+	size_t buffer_length;
+
+	nr_zones = min_t(unsigned int, ub->ub_disk->nr_zones - first_zone,
+			 nr_zones);
+
+	buffer = ublk_alloc_report_buffer(ub, nr_zones, &buffer_length);
+	if (!buffer)
+		return -ENOMEM;
+
+	max_zones_per_request = buffer_length / sizeof(struct blk_zone);
+
+	while (done_zones < nr_zones) {
+		unsigned int remaining_zones = nr_zones - done_zones;
+		unsigned int zones_in_request =
+			min_t(unsigned int, remaining_zones, max_zones_per_request);
+		struct request *req;
+		struct ublk_rq_data *pdu;
+		blk_status_t status;
+
+		memset(buffer, 0, buffer_length);
+
+		req = blk_mq_alloc_request(disk->queue, REQ_OP_DRV_IN, 0);
+		if (IS_ERR(req)) {
+			ret = PTR_ERR(req);
+			goto out;
+		}
+
+		pdu = blk_mq_rq_to_pdu(req);
+		pdu->operation = UBLK_IO_OP_REPORT_ZONES;
+		pdu->sector = sector;
+		pdu->nr_zones = zones_in_request;
+
+		ret = blk_rq_map_kern(disk->queue, req, buffer, buffer_length,
+					GFP_KERNEL);
+		if (ret) {
+			blk_mq_free_request(req);
+			goto out;
+		}
+
+		status = blk_execute_rq(req, 0);
+		ret = blk_status_to_errno(status);
+		blk_mq_free_request(req);
+		if (ret)
+			goto out;
+
+		for (unsigned int i = 0; i < zones_in_request; i++) {
+			struct blk_zone *zone = buffer + i;
+
+			/* A zero length zone means no more zones in this response */
+			if (!zone->len)
+				break;
+
+			ret = cb(zone, i, data);
+			if (ret)
+				goto out;
+
+			done_zones++;
+			sector += zone_size_sectors;
+
+		}
+	}
+
+	ret = done_zones;
+
+out:
+	kvfree(buffer);
+	return ret;
+}
+
+static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq,
+					 struct request *req)
+{
+	struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag);
+	struct ublk_io *io = &ubq->ios[req->tag];
+	struct ublk_rq_data *pdu = blk_mq_rq_to_pdu(req);
+	u32 ublk_op;
+
+	switch (req_op(req)) {
+	case REQ_OP_ZONE_OPEN:
+		ublk_op = UBLK_IO_OP_ZONE_OPEN;
+		break;
+	case REQ_OP_ZONE_CLOSE:
+		ublk_op = UBLK_IO_OP_ZONE_CLOSE;
+		break;
+	case REQ_OP_ZONE_FINISH:
+		ublk_op = UBLK_IO_OP_ZONE_FINISH;
+		break;
+	case REQ_OP_ZONE_RESET:
+		ublk_op = UBLK_IO_OP_ZONE_RESET;
+		break;
+	case REQ_OP_ZONE_APPEND:
+		ublk_op = UBLK_IO_OP_ZONE_APPEND;
+		break;
+	case REQ_OP_DRV_IN:
+		ublk_op = pdu->operation;
+		switch (ublk_op) {
+		case UBLK_IO_OP_REPORT_ZONES:
+			iod->op_flags = ublk_op | ublk_req_build_flags(req);
+			iod->nr_zones = pdu->nr_zones;
+			iod->start_sector = pdu->sector;
+			return BLK_STS_OK;
+		default:
+			return BLK_STS_IOERR;
+		}
+	case REQ_OP_ZONE_RESET_ALL:
+	case REQ_OP_DRV_OUT:
+		/* We do not support reset_all and drv_out */
+		return BLK_STS_NOTSUPP;
+	default:
+		return BLK_STS_IOERR;
+	}
+
+	iod->op_flags = ublk_op | ublk_req_build_flags(req);
+	iod->nr_sectors = blk_rq_sectors(req);
+	iod->start_sector = blk_rq_pos(req);
+	iod->addr = io->addr;
+
+	return BLK_STS_OK;
+}
+
+#else
+
+#define ublk_report_zones (NULL)
+
+static int ublk_dev_param_zoned_validate(const struct ublk_device *ub)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ublk_dev_param_zoned_apply(struct ublk_device *ub)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ublk_revalidate_disk_zones(struct ublk_device *ub)
+{
+	return 0;
+}
+
+static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq,
+					 struct request *req)
+{
+	return -EOPNOTSUPP;
+}
+
+#endif
+
 static inline void __ublk_complete_rq(struct request *req);
 static void ublk_complete_rq(struct kref *ref);
 
@@ -286,6 +543,9 @@ static int ublk_validate_params(const struct ublk_device *ub)
 
 		if (p->max_sectors > (ub->dev_info.max_io_buf_bytes >> 9))
 			return -EINVAL;
+
+		if (ublk_dev_is_zoned(ub) && !p->chunk_sectors)
+			return -EINVAL;
 	} else
 		return -EINVAL;
 
@@ -304,6 +564,11 @@ static int ublk_validate_params(const struct ublk_device *ub)
 	if (ub->params.types & UBLK_PARAM_TYPE_DEVT)
 		return -EINVAL;
 
+	if (ub->params.types & UBLK_PARAM_TYPE_ZONED)
+		return ublk_dev_param_zoned_validate(ub);
+	else if (ublk_dev_is_zoned(ub))
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -317,6 +582,9 @@ static int ublk_apply_params(struct ublk_device *ub)
 	if (ub->params.types & UBLK_PARAM_TYPE_DISCARD)
 		ublk_dev_param_discard_apply(ub);
 
+	if (ub->params.types & UBLK_PARAM_TYPE_ZONED)
+		return ublk_dev_param_zoned_apply(ub);
+
 	return 0;
 }
 
@@ -487,6 +755,7 @@ static const struct block_device_operations ub_fops = {
 	.owner =	THIS_MODULE,
 	.open =		ublk_open,
 	.free_disk =	ublk_free_disk,
+	.report_zones =	ublk_report_zones,
 };
 
 #define UBLK_MAX_PIN_PAGES	32
@@ -601,7 +870,8 @@ static inline bool ublk_need_map_req(const struct request *req)
 
 static inline bool ublk_need_unmap_req(const struct request *req)
 {
-	return ublk_rq_has_data(req) && req_op(req) == REQ_OP_READ;
+	return ublk_rq_has_data(req) &&
+	       (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_DRV_IN);
 }
 
 static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req,
@@ -685,8 +955,13 @@ static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req)
 {
 	struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag);
 	struct ublk_io *io = &ubq->ios[req->tag];
+	enum req_op op = req_op(req);
 	u32 ublk_op;
 
+	if (!ublk_queue_is_zoned(ubq) &&
+	    (op_is_zone_mgmt(op) || op == REQ_OP_ZONE_APPEND))
+		return -EIO;
+
 	switch (req_op(req)) {
 	case REQ_OP_READ:
 		ublk_op = UBLK_IO_OP_READ;
@@ -704,6 +979,8 @@ static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req)
 		ublk_op = UBLK_IO_OP_WRITE_ZEROES;
 		break;
 	default:
+		if (ublk_queue_is_zoned(ubq))
+			return ublk_setup_iod_zoned(ubq, req);
 		return BLK_STS_IOERR;
 	}
 
@@ -756,7 +1033,8 @@ static inline void __ublk_complete_rq(struct request *req)
 	 *
 	 * Both the two needn't unmap.
 	 */
-	if (req_op(req) != REQ_OP_READ && req_op(req) != REQ_OP_WRITE)
+	if (req_op(req) != REQ_OP_READ && req_op(req) != REQ_OP_WRITE &&
+	    req_op(req) != REQ_OP_DRV_IN)
 		goto exit;
 
 	/* for READ request, writing data in iod->addr to rq buffers */
@@ -1120,6 +1398,9 @@ static void ublk_commit_completion(struct ublk_device *ub,
 	/* find the io request and complete */
 	req = blk_mq_tag_to_rq(ub->tag_set.tags[qid], tag);
 
+	if (req_op(req) == REQ_OP_ZONE_APPEND)
+		req->__sector = ub_cmd->zone_append_lba;
+
 	if (req && likely(!blk_should_fake_timeout(req->q)))
 		ublk_put_req_ref(ubq, req);
 }
@@ -1472,8 +1753,12 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
 				goto out;
 		}
 
-		/* User copy requires addr to be unset */
-		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
+		/*
+		 * User copy requires addr to be unset when command is not zone
+		 * append
+		 */
+		if (ublk_support_user_copy(ubq) &&
+		    req_op(req) != REQ_OP_ZONE_APPEND && ub_cmd->addr) {
 			ret = -EINVAL;
 			goto out;
 		}
@@ -1550,11 +1835,14 @@ static inline bool ublk_check_ubuf_dir(const struct request *req,
 		int ubuf_dir)
 {
 	/* copy ubuf to request pages */
-	if (req_op(req) == REQ_OP_READ && ubuf_dir == ITER_SOURCE)
+	if ((req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_DRV_IN) &&
+	    ubuf_dir == ITER_SOURCE)
 		return true;
 
 	/* copy request pages to ubuf */
-	if (req_op(req) == REQ_OP_WRITE && ubuf_dir == ITER_DEST)
+	if ((req_op(req) == REQ_OP_WRITE ||
+	     req_op(req) == REQ_OP_ZONE_APPEND) &&
+	    ubuf_dir == ITER_DEST)
 		return true;
 
 	return false;
@@ -1894,17 +2182,24 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd)
 
 	get_device(&ub->cdev_dev);
 	ub->dev_info.state = UBLK_S_DEV_LIVE;
+
+	if (ublk_dev_is_zoned(ub)) {
+		ret = ublk_revalidate_disk_zones(ub);
+		if (ret)
+			goto out_put_cdev;
+	}
+
 	ret = add_disk(disk);
+	if (ret)
+		goto out_put_cdev;
+
+	set_bit(UB_STATE_USED, &ub->state);
+
+out_put_cdev:
 	if (ret) {
-		/*
-		 * Has to drop the reference since ->free_disk won't be
-		 * called in case of add_disk failure.
-		 */
 		ub->dev_info.state = UBLK_S_DEV_DEAD;
 		ublk_put_device(ub);
-		goto out_put_disk;
 	}
-	set_bit(UB_STATE_USED, &ub->state);
 out_put_disk:
 	if (ret)
 		put_disk(disk);
@@ -2054,6 +2349,13 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
 	if (ublk_dev_is_user_copy(ub))
 		ub->dev_info.flags &= ~UBLK_F_NEED_GET_DATA;
 
+	/* Zoned storage support requires user copy feature */
+	if (ublk_dev_is_zoned(ub) &&
+	    (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) || !ublk_dev_is_user_copy(ub))) {
+		ret = -EINVAL;
+		goto out_free_dev_number;
+	}
+
 	/* We are not ready to support zero copy */
 	ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY;
 
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index 4b8558db90e1..2685e53e4752 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -176,6 +176,12 @@
 /* Copy between request and user buffer by pread()/pwrite() */
 #define UBLK_F_USER_COPY	(1UL << 7)
 
+/*
+ * User space sets this flag when setting up the device to request zoned storage support. Kernel may
+ * deny the request by returning an error.
+ */
+#define UBLK_F_ZONED (1ULL << 8)
+
 /* device state */
 #define UBLK_S_DEV_DEAD	0
 #define UBLK_S_DEV_LIVE	1
@@ -232,9 +238,26 @@ struct ublksrv_ctrl_dev_info {
 #define		UBLK_IO_OP_READ		0
 #define		UBLK_IO_OP_WRITE		1
 #define		UBLK_IO_OP_FLUSH		2
-#define		UBLK_IO_OP_DISCARD	3
-#define		UBLK_IO_OP_WRITE_SAME	4
-#define		UBLK_IO_OP_WRITE_ZEROES	5
+#define		UBLK_IO_OP_DISCARD		3
+#define		UBLK_IO_OP_WRITE_SAME		4
+#define		UBLK_IO_OP_WRITE_ZEROES		5
+#define		UBLK_IO_OP_ZONE_OPEN		10
+#define		UBLK_IO_OP_ZONE_CLOSE		11
+#define		UBLK_IO_OP_ZONE_FINISH		12
+#define		UBLK_IO_OP_ZONE_APPEND		13
+#define		UBLK_IO_OP_ZONE_RESET		15
+/*
+ * Construct a zone report. The report request is carried in `struct
+ * ublksrv_io_desc`. The `start_sector` field must be the first sector of a zone
+ * and shall indicate the first zone of the report. The `nr_zones` shall
+ * indicate how many zones should be reported at most. The report shall be
+ * delivered as a `struct blk_zone` array. To report fewer zones than requested,
+ * zero the last entry of the returned array.
+ *
+ * Related definitions(blk_zone, blk_zone_cond, blk_zone_type, ...) in
+ * include/uapi/linux/blkzoned.h are part of ublk UAPI.
+ */
+#define		UBLK_IO_OP_REPORT_ZONES		18
 
 #define		UBLK_IO_F_FAILFAST_DEV		(1U << 8)
 #define		UBLK_IO_F_FAILFAST_TRANSPORT	(1U << 9)
@@ -255,7 +278,10 @@ struct ublksrv_io_desc {
 	/* op: bit 0-7, flags: bit 8-31 */
 	__u32		op_flags;
 
-	__u32		nr_sectors;
+	union {
+		__u32		nr_sectors;
+		__u32		nr_zones; /* for UBLK_IO_OP_REPORT_ZONES */
+	};
 
 	/* start sector for this io */
 	__u64		start_sector;
@@ -284,11 +310,21 @@ struct ublksrv_io_cmd {
 	/* io result, it is valid for COMMIT* command only */
 	__s32	result;
 
-	/*
-	 * userspace buffer address in ublksrv daemon process, valid for
-	 * FETCH* command only
-	 */
-	__u64	addr;
+	union {
+		/*
+		 * userspace buffer address in ublksrv daemon process, valid for
+		 * FETCH* command only
+		 *
+		 * `addr` should not be used when UBLK_F_USER_COPY is enabled,
+		 * because userspace handles data copy by pread()/pwrite() over
+		 * /dev/ublkcN. But in case of UBLK_F_ZONED, this union is
+		 * re-used to pass back the allocated LBA for
+		 * UBLK_IO_OP_ZONE_APPEND which actually depends on
+		 * UBLK_F_USER_COPY
+		 */
+		__u64	addr;
+		__u64	zone_append_lba;
+	};
 };
 
 struct ublk_param_basic {
@@ -331,6 +367,13 @@ struct ublk_param_devt {
 	__u32   disk_minor;
 };
 
+struct ublk_param_zoned {
+	__u32	max_open_zones;
+	__u32	max_active_zones;
+	__u32	max_zone_append_sectors;
+	__u8	reserved[20];
+};
+
 struct ublk_params {
 	/*
 	 * Total length of parameters, userspace has to set 'len' for both
@@ -342,11 +385,13 @@ struct ublk_params {
 #define UBLK_PARAM_TYPE_BASIC           (1 << 0)
 #define UBLK_PARAM_TYPE_DISCARD         (1 << 1)
 #define UBLK_PARAM_TYPE_DEVT            (1 << 2)
+#define UBLK_PARAM_TYPE_ZONED           (1 << 3)
 	__u32	types;			/* types of parameter included */
 
 	struct ublk_param_basic		basic;
 	struct ublk_param_discard	discard;
 	struct ublk_param_devt		devt;
+	struct ublk_param_zoned	zoned;
 };
 
 #endif
-- 
2.41.0

Re: [PATCH v10 3/3] ublk: enable zoned storage support

[kernel test robot]

Hi Andreas,

kernel test robot noticed the following build errors:

[auto build test ERROR on 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4]

url:    https://github.com/intel-lab-lkp/linux/commits/Andreas-Hindborg-Samsung/ublk-add-helper-to-check-if-device-supports-user-copy/20230803-224003
base:   5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
patch link:    https://lore.kernel.org/r/20230803140701.18515-4-nmi%40metaspace.dk
patch subject: [PATCH v10 3/3] ublk: enable zoned storage support
config: sh-randconfig-r024-20230731 (https://download.01.org/0day-ci/archive/20230804/202308040229.pFTUh2cG-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230804/202308040229.pFTUh2cG-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308040229.pFTUh2cG-lkp@intel.com/

All error/warnings (new ones prefixed by >>):

   drivers/block/ublk_drv.c: In function 'ublk_alloc_report_buffer':
>> drivers/block/ublk_drv.c:281:23: error: implicit declaration of function '__vmalloc'; did you mean '__kmalloc'? [-Werror=implicit-function-declaration]
     281 |                 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
         |                       ^~~~~~~~~
         |                       __kmalloc
>> drivers/block/ublk_drv.c:281:21: warning: assignment to 'void *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
     281 |                 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
         |                     ^
   cc1: some warnings being treated as errors


vim +281 drivers/block/ublk_drv.c

   264	
   265	/* Based on virtblk_alloc_report_buffer */
   266	static void *ublk_alloc_report_buffer(struct ublk_device *ublk,
   267					      unsigned int nr_zones, size_t *buflen)
   268	{
   269		struct request_queue *q = ublk->ub_disk->queue;
   270		size_t bufsize;
   271		void *buf;
   272	
   273		nr_zones = min_t(unsigned int, nr_zones,
   274				 ublk->ub_disk->nr_zones);
   275	
   276		bufsize = nr_zones * sizeof(struct blk_zone);
   277		bufsize =
   278			min_t(size_t, bufsize, queue_max_hw_sectors(q) << SECTOR_SHIFT);
   279	
   280		while (bufsize >= sizeof(struct blk_zone)) {
 > 281			buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
   282			if (buf) {
   283				*buflen = bufsize;
   284				return buf;
   285			}
   286			bufsize >>= 1;
   287		}
   288	
   289		*buflen = 0;
   290		return NULL;
   291	}
   292	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v10 1/3] ublk: add helper to check if device supports user copy

[Johannes Thumshirn]

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

Re: [PATCH v10 3/3] ublk: enable zoned storage support

[Johannes Thumshirn]

On 03.08.23 16:09, Andreas Hindborg (Samsung) wrote:
> + buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);

Missing #include <linux/vmalloc.h> so the bot doesn't complain.
But while we're at it, why can't you just use kvmalloc() here?

Re: [PATCH v10 3/3] ublk: enable zoned storage support

[Andreas Hindborg (Samsung)]

Johannes Thumshirn <Johannes.Thumshirn@wdc.com> writes:

> On 03.08.23 16:09, Andreas Hindborg (Samsung) wrote:
>> + buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
>
> Missing #include <linux/vmalloc.h> so the bot doesn't complain.

Thanks, gotta add that so code compiles for Sega Dreamcast!

> But while we're at it, why can't you just use kvmalloc() here?

I don't see why not. It should be better for small reports I guess. I will change it.

BR Andreas

Re: [PATCH v10 2/3] ublk: move check for empty address field on command submission

[Ming Lei]

Hi Andreas,

On Thu, Aug 03, 2023 at 04:07:00PM +0200, Andreas Hindborg (Samsung) wrote:
> From: Andreas Hindborg <a.hindborg@samsung.com>
> 
> In preparation for zoned storage support, move the check for empty `addr`
> field into the command handler case statement. Note that the check makes no
> sense for `UBLK_IO_NEED_GET_DATA` because the `addr` field must always be
> set for this command.
> 
> Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
> ---
>  drivers/block/ublk_drv.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index db3523e281a6..5a1ee17636ac 100644
> --- a/drivers/block/ublk_drv.c
> +++ b/drivers/block/ublk_drv.c
> @@ -1419,11 +1419,6 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>  			^ (_IOC_NR(cmd_op) == UBLK_IO_NEED_GET_DATA))
>  		goto out;
>  
> -	if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
> -		ret = -EINVAL;
> -		goto out;
> -	}
> -
>  	ret = ublk_check_cmd_op(cmd_op);
>  	if (ret)
>  		goto out;
> @@ -1452,6 +1447,12 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>  				goto out;
>  		}
>  
> +		/* User copy requires addr to be unset */
> +		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +

Given you have to post v11 for fixing build issue, please convert the
above two 'if' into one 'if else':

		if (!ublk_support_user_copy(ubq)) {
			/*
			 * FETCH_RQ has to provide IO buffer if NEED GET
			 * DATA is not enabled
			 */
			if (!ub_cmd->addr && !ublk_need_get_data(ubq))
				goto out;
		} else {
			if (ub_cmd->addr) {
				ret = -EINVAL;
				goto out;
			}
		}

>  		ublk_fill_io_cmd(io, cmd, ub_cmd->addr);
>  		ublk_mark_io_ready(ub, ubq);
>  		break;
> @@ -1470,6 +1471,13 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>  						req_op(req) == REQ_OP_READ))
>  				goto out;
>  		}
> +
> +		/* User copy requires addr to be unset */
> +		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +

Same with above.

BTW, I have verified this patchset with ublk-zoned example in
libublk-rs:

https://github.com/ming1/libublk-rs/tree/zoned.v2

cargo run --example zoned -- add -1 10240
mkfs.btrfs -O zoned /dev/ublkb0
mount & git clone linux-kernel &umount

Hope V11 can be merged.


Thanks,
Ming

Re: [PATCH v10 2/3] ublk: move check for empty address field on command submission

[Andreas Hindborg (Samsung)]

Ming Lei <tom.leiming@gmail.com> writes:

> Hi Andreas,
>
> On Thu, Aug 03, 2023 at 04:07:00PM +0200, Andreas Hindborg (Samsung) wrote:
>> From: Andreas Hindborg <a.hindborg@samsung.com>
>> 
>> In preparation for zoned storage support, move the check for empty `addr`
>> field into the command handler case statement. Note that the check makes no
>> sense for `UBLK_IO_NEED_GET_DATA` because the `addr` field must always be
>> set for this command.
>> 
>> Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
>> ---
>>  drivers/block/ublk_drv.c | 18 +++++++++++++-----
>>  1 file changed, 13 insertions(+), 5 deletions(-)
>> 
>> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
>> index db3523e281a6..5a1ee17636ac 100644
>> --- a/drivers/block/ublk_drv.c
>> +++ b/drivers/block/ublk_drv.c
>> @@ -1419,11 +1419,6 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>>  			^ (_IOC_NR(cmd_op) == UBLK_IO_NEED_GET_DATA))
>>  		goto out;
>>  
>> -	if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
>> -		ret = -EINVAL;
>> -		goto out;
>> -	}
>> -
>>  	ret = ublk_check_cmd_op(cmd_op);
>>  	if (ret)
>>  		goto out;
>> @@ -1452,6 +1447,12 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>>  				goto out;
>>  		}
>>  
>> +		/* User copy requires addr to be unset */
>> +		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
>> +			ret = -EINVAL;
>> +			goto out;
>> +		}
>> +
>
> Given you have to post v11 for fixing build issue, please convert the
> above two 'if' into one 'if else':
>
> 		if (!ublk_support_user_copy(ubq)) {
> 			/*
> 			 * FETCH_RQ has to provide IO buffer if NEED GET
> 			 * DATA is not enabled
> 			 */
> 			if (!ub_cmd->addr && !ublk_need_get_data(ubq))
> 				goto out;
> 		} else {
> 			if (ub_cmd->addr) {
> 				ret = -EINVAL;
> 				goto out;
> 			}
> 		}

Alright. I was debating with myself one over the other 😅

>
>>  		ublk_fill_io_cmd(io, cmd, ub_cmd->addr);
>>  		ublk_mark_io_ready(ub, ubq);
>>  		break;
>> @@ -1470,6 +1471,13 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>>  						req_op(req) == REQ_OP_READ))
>>  				goto out;
>>  		}
>> +
>> +		/* User copy requires addr to be unset */
>> +		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
>> +			ret = -EINVAL;
>> +			goto out;
>> +		}
>> +
>
> Same with above.
>
> BTW, I have verified this patchset with ublk-zoned example in
> libublk-rs:
>
> https://github.com/ming1/libublk-rs/tree/zoned.v2
>
> cargo run --example zoned -- add -1 10240
> mkfs.btrfs -O zoned /dev/ublkb0
> mount & git clone linux-kernel &umount

Thanks!

BR Andreas

Re: [PATCH v10 3/3] ublk: enable zoned storage support

[Johannes Thumshirn]

On 04.08.23 12:12, Andreas Hindborg (Samsung) wrote:
> 
> Johannes Thumshirn <Johannes.Thumshirn@wdc.com> writes:
> 
>> On 03.08.23 16:09, Andreas Hindborg (Samsung) wrote:
>>> + buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
>>
>> Missing #include <linux/vmalloc.h> so the bot doesn't complain.
> 
> Thanks, gotta add that so code compiles for Sega Dreamcast!
> 
>> But while we're at it, why can't you just use kvmalloc() here?
> 
> I don't see why not. It should be better for small reports I guess. I will change it.

Yep, that way you won't need vmalloc.h either. The double underscore 
versions of a function are always a red flag when reviewing code to me.