[PATCH v2] block: ublk: enable zoned storage support

From: Andreas Hindborg
Date: Fri Feb 24 2023 - 15:06:57 EST

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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

This allows implementation of zoned storage devices in user space. An
example user space implementation based on ubdsrv is available [1].

[1] https://github.com/metaspace/ubdsrv/commit/14a2b708f74f70cfecb076d92e680dc718cc1f6d

Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
---
Changes since v1:
- Fixed conditional compilation bug
- Refactored to collect conditional code additions together
- Fixed style errors
- Zero stack allocated value used for zone report

Reported-by: Niklas Cassel <Niklas.Cassel@xxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Link: https://lore.kernel.org/oe-kbuild-all/202302250222.XOrw9j6z-lkp@xxxxxxxxx/
v1: https://lore.kernel.org/linux-block/20230224125950.214779-1-nmi@xxxxxxxxxxxx/

drivers/block/ublk_drv.c | 150 ++++++++++++++++++++++++++++++++--
include/uapi/linux/ublk_cmd.h | 18 ++++
2 files changed, 162 insertions(+), 6 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 6368b56eacf1..37e516903867 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -20,6 +20,7 @@
#include <linux/major.h>
#include <linux/wait.h>
#include <linux/blkdev.h>
+#include <linux/blkzoned.h>
#include <linux/init.h>
#include <linux/swap.h>
#include <linux/slab.h>
@@ -51,10 +52,12 @@
| UBLK_F_URING_CMD_COMP_IN_TASK \
| UBLK_F_NEED_GET_DATA \
| UBLK_F_USER_RECOVERY \
- | UBLK_F_USER_RECOVERY_REISSUE)
+ | UBLK_F_USER_RECOVERY_REISSUE \
+ | UBLK_F_ZONED)

/* All UBLK_PARAM_TYPE_* should be included here */
-#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD)
+#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD \
+ | UBLK_PARAM_TYPE_ZONED)

struct ublk_rq_data {
struct llist_node node;
@@ -187,6 +190,98 @@ static DEFINE_MUTEX(ublk_ctl_mutex);

static struct miscdevice ublk_misc;

+#ifdef CONFIG_BLK_DEV_ZONED
+static void ublk_set_nr_zones(struct ublk_device *ub)
+{
+ const struct ublk_param_basic *p = &ub->params.basic;
+
+ if (ub->dev_info.flags & UBLK_F_ZONED && p->chunk_sectors)
+ ub->ub_disk->nr_zones = p->dev_sectors / p->chunk_sectors;
+}
+
+static void ublk_dev_param_zoned_apply(struct ublk_device *ub)
+{
+ const struct ublk_param_zoned *p = &ub->params.zoned;
+
+ if (ub->dev_info.flags & UBLK_F_ZONED) {
+ disk_set_max_active_zones(ub->ub_disk, p->max_active_zones);
+ disk_set_max_open_zones(ub->ub_disk, p->max_open_zones);
+ }
+}
+
+static int ublk_revalidate_disk_zones(struct gendisk *disk)
+{
+ return blk_revalidate_disk_zones(disk, 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;
+ unsigned int zone_size;
+ unsigned int first_zone;
+ int ret = 0;
+
+ ub = disk->private_data;
+
+ if (!(ub->dev_info.flags & UBLK_F_ZONED))
+ return -EINVAL;
+
+ zone_size = disk->queue->limits.chunk_sectors;
+ first_zone = sector >> ilog2(zone_size);
+ nr_zones = min(ub->ub_disk->nr_zones - first_zone, nr_zones);
+
+ for (unsigned int i = 0; i < nr_zones; i++) {
+ struct request *req;
+ blk_status_t status;
+ struct blk_zone info = {0};
+
+ req = blk_mq_alloc_request(disk->queue, REQ_OP_DRV_IN, 0);
+
+ if (IS_ERR(req)) {
+ ret = PTR_ERR(req);
+ goto out;
+ }
+
+ req->__sector = sector;
+
+ ret = blk_rq_map_kern(disk->queue, req, &info, sizeof(info),
+ GFP_KERNEL);
+
+ if (ret)
+ goto out;
+
+ status = blk_execute_rq(req, 0);
+ ret = blk_status_to_errno(status);
+ if (ret)
+ goto out;
+
+ blk_mq_free_request(req);
+
+ ret = cb(&info, i, data);
+ if (ret)
+ goto out;
+
+ /* A zero length zone means don't ask for more zones */
+ if (!info.len) {
+ nr_zones = i;
+ break;
+ }
+
+ sector += zone_size;
+ }
+ ret = nr_zones;
+
+ out:
+ return ret;
+}
+#else
+void ublk_set_nr_zones(struct ublk_device *ub);
+void ublk_dev_param_zoned_apply(struct ublk_device *ub);
+int ublk_revalidate_disk_zones(struct gendisk *disk);
+#endif
+
static void ublk_dev_param_basic_apply(struct ublk_device *ub)
{
struct request_queue *q = ub->ub_disk->queue;
@@ -212,6 +307,9 @@ static void ublk_dev_param_basic_apply(struct ublk_device *ub)
set_disk_ro(ub->ub_disk, true);

set_capacity(ub->ub_disk, p->dev_sectors);
+
+ if (IS_ENABLED(CONFIG_BLK_DEV_ZONED))
+ ublk_set_nr_zones(ub);
}

static void ublk_dev_param_discard_apply(struct ublk_device *ub)
@@ -268,6 +366,9 @@ static int ublk_apply_params(struct ublk_device *ub)
if (ub->params.types & UBLK_PARAM_TYPE_DISCARD)
ublk_dev_param_discard_apply(ub);

+ if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && (ub->params.types & UBLK_PARAM_TYPE_ZONED))
+ ublk_dev_param_zoned_apply(ub);
+
return 0;
}

@@ -361,9 +462,13 @@ static void ublk_free_disk(struct gendisk *disk)
put_device(&ub->cdev_dev);
}

+
static const struct block_device_operations ub_fops = {
- .owner = THIS_MODULE,
- .free_disk = ublk_free_disk,
+ .owner = THIS_MODULE,
+ .free_disk = ublk_free_disk,
+#ifdef CONFIG_BLK_DEV_ZONED
+ .report_zones = ublk_report_zones,
+#endif
};

#define UBLK_MAX_PIN_PAGES 32
@@ -499,7 +604,7 @@ static int ublk_unmap_io(const struct ublk_queue *ubq,
{
const unsigned int rq_bytes = blk_rq_bytes(req);

- if (req_op(req) == REQ_OP_READ && ublk_rq_has_data(req)) {
+ if ((req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_DRV_IN) && ublk_rq_has_data(req)) {
struct ublk_map_data data = {
.ubq = ubq,
.rq = req,
@@ -566,6 +671,26 @@ static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req)
case REQ_OP_WRITE_ZEROES:
ublk_op = UBLK_IO_OP_WRITE_ZEROES;
break;
+#ifdef CONFIG_BLK_DEV_ZONED
+ 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_DRV_IN:
+ ublk_op = UBLK_IO_OP_DRV_IN;
+ break;
+ case REQ_OP_ZONE_APPEND:
+ /* We do not support zone append yet */
+ fallthrough;
+#endif
default:
return BLK_STS_IOERR;
}
@@ -612,7 +737,8 @@ static 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) {
blk_mq_end_request(req, BLK_STS_OK);
return;
}
@@ -1535,6 +1661,15 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
if (ret)
goto out_put_disk;

+ if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
+ ub->dev_info.flags & UBLK_F_ZONED) {
+ disk_set_zoned(disk, BLK_ZONED_HM);
+ blk_queue_required_elevator_features(disk->queue, ELEVATOR_F_ZBD_SEQ_WRITE);
+ ret = ublk_revalidate_disk_zones(disk);
+ if (ret)
+ goto out_put_disk;
+ }
+
get_device(&ub->cdev_dev);
ret = add_disk(disk);
if (ret) {
@@ -1673,6 +1808,9 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
if (!IS_BUILTIN(CONFIG_BLK_DEV_UBLK))
ub->dev_info.flags |= UBLK_F_URING_CMD_COMP_IN_TASK;

+ if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED))
+ ub->dev_info.flags &= ~UBLK_F_ZONED;
+
/* 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 8f88e3a29998..074b97821575 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -78,6 +78,10 @@
#define UBLK_F_USER_RECOVERY (1UL << 3)

#define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4)
+/*
+ * Enable zoned device support
+ */
+#define UBLK_F_ZONED (1ULL << 5)

/* device state */
#define UBLK_S_DEV_DEAD 0
@@ -129,6 +133,12 @@ struct ublksrv_ctrl_dev_info {
#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
+#define UBLK_IO_OP_DRV_IN 34

#define UBLK_IO_F_FAILFAST_DEV (1U << 8)
#define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9)
@@ -214,6 +224,12 @@ struct ublk_param_discard {
__u16 reserved0;
};

+struct ublk_param_zoned {
+ __u64 max_open_zones;
+ __u64 max_active_zones;
+ __u64 max_append_size;
+};
+
struct ublk_params {
/*
* Total length of parameters, userspace has to set 'len' for both
@@ -224,10 +240,12 @@ struct ublk_params {
__u32 len;
#define UBLK_PARAM_TYPE_BASIC (1 << 0)
#define UBLK_PARAM_TYPE_DISCARD (1 << 1)
+#define UBLK_PARAM_TYPE_ZONED (1 << 2)
__u32 types; /* types of parameter included */

struct ublk_param_basic basic;
struct ublk_param_discard discard;
+ struct ublk_param_zoned zoned;
};

#endif

base-commit: c9c3395d5e3dcc6daee66c6908354d47bf98cb0c
--
2.39.2

Next message: Andy Shevchenko: "[PATCH v1 1/1] devres: Pass unique name of the resource to devm_add_action()"
Previous message: kernel test robot: "Re: [PATCH] block: ublk: enable zoned storage support"
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