[PATCH v4 3/4] ublk: enable zoned storage support

From: Andreas Hindborg
Date: Wed Jun 28 2023 - 15:07:33 EST


From: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>

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

Note: This commit changes the ublk kernel module name from `ublk_drv.ko` to
`ublk.ko` in order to link multiple translation units into the module.

Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/block/Kconfig | 4 +
drivers/block/Makefile | 4 +-
drivers/block/ublk_drv-zoned.c | 144 +++++++++++++++++++++++++++++++++
drivers/block/ublk_drv.c | 64 +++++++++++++--
drivers/block/ublk_drv.h | 15 ++++
include/uapi/linux/ublk_cmd.h | 14 ++++
7 files changed, 239 insertions(+), 7 deletions(-)
create mode 100644 drivers/block/ublk_drv-zoned.c

diff --git a/MAINTAINERS b/MAINTAINERS
index ace71c90751c..db8a8deb5926 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21555,6 +21555,7 @@ S: Maintained
F: Documentation/block/ublk.rst
F: drivers/block/ublk_drv.c
F: drivers/block/ublk_drv.h
+F: drivers/block/ublk_drv-zoned.c
F: include/uapi/linux/ublk_cmd.h

UCLINUX (M68KNOMMU AND COLDFIRE)
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 5b9d4aaebb81..c58dfd035557 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -402,6 +402,10 @@ config BLKDEV_UBLK_LEGACY_OPCODES
suggested to enable N if your application(ublk server) switches to
ioctl command encoding.

+config BLK_DEV_UBLK_ZONED
+ def_bool y
+ depends on BLK_DEV_UBLK && BLK_DEV_ZONED
+
source "drivers/block/rnbd/Kconfig"

endif # BLK_DEV
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index 101612cba303..bc1649e20ec2 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -37,6 +37,8 @@ obj-$(CONFIG_BLK_DEV_RNBD) += rnbd/

obj-$(CONFIG_BLK_DEV_NULL_BLK) += null_blk/

-obj-$(CONFIG_BLK_DEV_UBLK) += ublk_drv.o
+obj-$(CONFIG_BLK_DEV_UBLK) += ublk.o
+ublk-$(CONFIG_BLK_DEV_UBLK) += ublk_drv.o
+ublk-$(CONFIG_BLK_DEV_UBLK_ZONED) += ublk_drv-zoned.o

swim_mod-y := swim.o swim_asm.o
diff --git a/drivers/block/ublk_drv-zoned.c b/drivers/block/ublk_drv-zoned.c
new file mode 100644
index 000000000000..ea86bf4b3681
--- /dev/null
+++ b/drivers/block/ublk_drv-zoned.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2023 Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
+ */
+#include <linux/blkzoned.h>
+#include <linux/ublk_cmd.h>
+#include <linux/vmalloc.h>
+
+#include "ublk_drv.h"
+
+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;
+}
+
+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);
+ }
+}
+
+int ublk_revalidate_disk_zones(struct gendisk *disk)
+{
+ return blk_revalidate_disk_zones(disk, NULL);
+}
+
+/* Based on virtblk_alloc_report_buffer */
+static void *ublk_alloc_report_buffer(struct ublk_device *ublk,
+ unsigned int nr_zones,
+ unsigned int zone_sectors, size_t *buflen)
+{
+ struct request_queue *q = ublk->ub_disk->queue;
+ size_t bufsize;
+ void *buf;
+
+ nr_zones = min_t(unsigned int, nr_zones,
+ get_capacity(ublk->ub_disk) >> ilog2(zone_sectors));
+
+ bufsize = nr_zones * sizeof(struct blk_zone);
+ bufsize =
+ min_t(size_t, bufsize, queue_max_hw_sectors(q) << SECTOR_SHIFT);
+ bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
+
+ while (bufsize >= sizeof(struct blk_zone)) {
+ buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
+ if (buf) {
+ *buflen = bufsize;
+ return buf;
+ }
+ bufsize >>= 1;
+ }
+
+ bufsize = 0;
+ return NULL;
+}
+
+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;
+ struct blk_zone *buffer;
+ size_t buffer_length;
+
+ if (!(ub->dev_info.flags & UBLK_F_ZONED))
+ return -EOPNOTSUPP;
+
+ nr_zones = min_t(unsigned int, ub->ub_disk->nr_zones - first_zone,
+ nr_zones);
+
+ buffer = ublk_alloc_report_buffer(ub, nr_zones, zone_size_sectors,
+ &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);
+ int err = 0;
+ 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))
+ return PTR_ERR(req);
+
+ pdu = blk_mq_rq_to_pdu(req);
+ pdu->operation = UBLK_IO_OP_REPORT_ZONES;
+ pdu->sector = sector;
+ pdu->nr_sectors = remaining_zones * zone_size_sectors;
+
+ err = blk_rq_map_kern(disk->queue, req, buffer, buffer_length,
+ GFP_KERNEL);
+ if (err) {
+ blk_mq_free_request(req);
+ kvfree(buffer);
+ return err;
+ }
+
+ status = blk_execute_rq(req, 0);
+ err = blk_status_to_errno(status);
+ blk_mq_free_request(req);
+ if (err) {
+ kvfree(buffer);
+ return err;
+ }
+
+ for (unsigned int i = 0; i < zones_in_request; i++) {
+ struct blk_zone *zone = buffer + i;
+
+ err = cb(zone, i, data);
+ if (err)
+ return err;
+
+ done_zones++;
+ sector += zone_size_sectors;
+
+ /* A zero length zone means don't ask for more zones */
+ if (!zone->len) {
+ kvfree(buffer);
+ return done_zones;
+ }
+ }
+ }
+
+ kvfree(buffer);
+ return done_zones;
+}
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index e519dc0d9fe7..88fa39853c61 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -57,12 +57,13 @@
| 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_uring_cmd_pdu {
struct ublk_queue *ubq;
@@ -209,6 +210,9 @@ 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)
@@ -269,6 +273,9 @@ 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;
}

@@ -439,6 +446,7 @@ 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
@@ -553,7 +561,8 @@ 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,
@@ -637,6 +646,7 @@ 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];
+ struct ublk_rq_data *pdu = blk_mq_rq_to_pdu(req);
u32 ublk_op;

switch (req_op(req)) {
@@ -655,6 +665,35 @@ 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;
+ 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 = pdu->operation;
+ switch (ublk_op) {
+ case UBLK_IO_OP_REPORT_ZONES:
+ iod->op_flags = ublk_op | ublk_req_build_flags(req);
+ iod->nr_sectors = pdu->nr_sectors;
+ iod->start_sector = pdu->sector;
+ iod->addr = io->addr;
+ return BLK_STS_OK;
+ default:
+ return BLK_STS_IOERR;
+ }
+ case REQ_OP_ZONE_APPEND:
+ case REQ_OP_ZONE_RESET_ALL:
+ case REQ_OP_DRV_OUT:
+ /* We do not support zone append or reset_all yet */
+ fallthrough;
default:
return BLK_STS_IOERR;
}
@@ -708,7 +747,8 @@ 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 */
@@ -1835,6 +1875,15 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd)
if (ub->nr_privileged_daemon != ub->nr_queues_ready)
set_bit(GD_SUPPRESS_PART_SCAN, &disk->state);

+ 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);
ub->dev_info.state = UBLK_S_DEV_LIVE;
ret = add_disk(disk);
@@ -1997,6 +2046,9 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
if (ub->dev_info.flags & UBLK_F_USER_COPY)
ub->dev_info.flags &= ~UBLK_F_NEED_GET_DATA;

+ 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/drivers/block/ublk_drv.h b/drivers/block/ublk_drv.h
index f81e62256456..7242430fd6b9 100644
--- a/drivers/block/ublk_drv.h
+++ b/drivers/block/ublk_drv.h
@@ -50,6 +50,21 @@ struct ublk_rq_data {
struct llist_node node;

struct kref ref;
+ enum ublk_op operation;
+ __u64 sector;
+ __u32 nr_sectors;
};

+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);
+
+#ifdef CONFIG_BLK_DEV_UBLK_ZONED
+int ublk_report_zones(struct gendisk *disk, sector_t sector,
+ unsigned int nr_zones, report_zones_cb cb,
+ void *data);
+#else
+#define ublk_report_zones NULL
+#endif
+
#endif
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index 471b3b983045..436525afffe8 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -176,6 +176,11 @@
/* Copy between request and user buffer by pread()/pwrite() */
#define UBLK_F_USER_COPY (1UL << 7)

+/*
+ * Enable zoned device support
+ */
+#define UBLK_F_ZONED (1ULL << 8)
+
/* device state */
#define UBLK_S_DEV_DEAD 0
#define UBLK_S_DEV_LIVE 1
@@ -242,6 +247,7 @@ enum ublk_op {
UBLK_IO_OP_ZONE_APPEND = 13,
UBLK_IO_OP_ZONE_RESET = 15,
__UBLK_IO_OP_DRV_IN_START = 32,
+ UBLK_IO_OP_REPORT_ZONES = __UBLK_IO_OP_DRV_IN_START,
__UBLK_IO_OP_DRV_IN_END = 96,
__UBLK_IO_OP_DRV_OUT_START = __UBLK_IO_OP_DRV_IN_END,
__UBLK_IO_OP_DRV_OUT_END = 160,
@@ -342,6 +348,12 @@ struct ublk_param_devt {
__u32 disk_minor;
};

+struct ublk_param_zoned {
+ __u32 max_open_zones;
+ __u32 max_active_zones;
+ __u8 reserved[24];
+};
+
struct ublk_params {
/*
* Total length of parameters, userspace has to set 'len' for both
@@ -353,11 +365,13 @@ 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