[PATCH v3] block: ublk: enable zoned storage support
From: Andreas Hindborg
Date: Thu Mar 16 2023 - 10:55:53 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
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/2c60b9ffdfb7cb44c5cce0272bb52229ea6c95d4
Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
---
Changes since v2:
- Allow reporting of multiple zones in a single request
- Move zoned functions to separate translation unit
- Do not overload REQ_OP_DRV_IN for zone report
- Reserve space in ublk_param_zoned for future parameters
- Do not overload (struct request).__sector and .__data_len
- Remove unnecessary conditional compilation
- Remove goto statements in ublk_report_zones
v1: https://lore.kernel.org/linux-block/20230224125950.214779-1-nmi@xxxxxxxxxxxx/
v2: https://lore.kernel.org/all/20230224200502.391570-1-nmi@xxxxxxxxxxxx/
drivers/block/Kconfig | 4 +
drivers/block/Makefile | 1 +
drivers/block/ublk_drv-zoned.c | 142 +++++++++++++++++++++++++++++++++
drivers/block/ublk_drv.c | 113 ++++++++++++++------------
drivers/block/ublk_drv.h | 69 ++++++++++++++++
include/uapi/linux/ublk_cmd.h | 37 +++++++--
6 files changed, 308 insertions(+), 58 deletions(-)
create mode 100644 drivers/block/ublk_drv-zoned.c
create mode 100644 drivers/block/ublk_drv.h
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index f79f20430ef7..311e401eece5 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -385,6 +385,10 @@ config BLK_DEV_UBLK
can handle batch more effectively, but task_work_add() isn't exported
for module, so ublk has to be built to kernel.
+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..0de9379ba9df 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -38,5 +38,6 @@ 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_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..fbcbe1bbf653
--- /dev/null
+++ b/drivers/block/ublk_drv-zoned.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2023 Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
+ */
+#include <linux/blkzoned.h>
+#include <linux/ublk_cmd.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)
+{
+ unsigned int done_zones = 0;
+ 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);
+ struct blk_zone *buffer;
+ size_t buffer_length;
+ unsigned int max_zones_per_request;
+
+ 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 d1d1c8d606c8..69a3e7dedfc0 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -44,6 +44,7 @@
#include <linux/task_work.h>
#include <linux/namei.h>
#include <uapi/linux/ublk_cmd.h>
+#include "ublk_drv.h"
#define UBLK_MINORS (1U << MINORBITS)
@@ -53,16 +54,13 @@
| UBLK_F_NEED_GET_DATA \
| UBLK_F_USER_RECOVERY \
| UBLK_F_USER_RECOVERY_REISSUE \
- | UBLK_F_UNPRIVILEGED_DEV)
+ | UBLK_F_UNPRIVILEGED_DEV \
+ | 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)
-
-struct ublk_rq_data {
- struct llist_node node;
- struct callback_head work;
-};
+#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;
@@ -135,45 +133,6 @@ struct ublk_queue {
#define UBLK_DAEMON_MONITOR_PERIOD (5 * HZ)
-struct ublk_device {
- struct gendisk *ub_disk;
-
- char *__queues;
-
- unsigned int queue_size;
- struct ublksrv_ctrl_dev_info dev_info;
-
- struct blk_mq_tag_set tag_set;
-
- struct cdev cdev;
- struct device cdev_dev;
-
-#define UB_STATE_OPEN 0
-#define UB_STATE_USED 1
-#define UB_STATE_DELETED 2
- unsigned long state;
- int ub_number;
-
- struct mutex mutex;
-
- spinlock_t mm_lock;
- struct mm_struct *mm;
-
- struct ublk_params params;
-
- struct completion completion;
- unsigned int nr_queues_ready;
- unsigned int nr_privileged_daemon;
-
- /*
- * Our ubq->daemon may be killed without any notification, so
- * monitor each queue's daemon periodically
- */
- struct delayed_work monitor_work;
- struct work_struct quiesce_work;
- struct work_struct stop_work;
-};
-
/* header of ublk_params */
struct ublk_params_header {
__u32 len;
@@ -225,6 +184,9 @@ 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)
@@ -285,6 +247,9 @@ 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;
}
@@ -420,9 +385,10 @@ static int ublk_open(struct block_device *bdev, fmode_t mode)
}
static const struct block_device_operations ub_fops = {
- .owner = THIS_MODULE,
- .open = ublk_open,
- .free_disk = ublk_free_disk,
+ .owner = THIS_MODULE,
+ .open = ublk_open,
+ .free_disk = ublk_free_disk,
+ .report_zones = ublk_report_zones,
};
#define UBLK_MAX_PIN_PAGES 32
@@ -558,7 +524,7 @@ 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,
@@ -607,6 +573,7 @@ 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)) {
@@ -625,6 +592,35 @@ 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:
+ case REQ_OP_DRV_OUT:
+ 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:
+ /* We do not support zone append or reset_all yet */
+ fallthrough;
default:
return BLK_STS_IOERR;
}
@@ -671,7 +667,8 @@ 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;
}
@@ -1601,6 +1598,15 @@ 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);
ret = add_disk(disk);
if (ret) {
@@ -1746,6 +1752,9 @@ 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/drivers/block/ublk_drv.h b/drivers/block/ublk_drv.h
new file mode 100644
index 000000000000..7b21235d7673
--- /dev/null
+++ b/drivers/block/ublk_drv.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _UBLK_DRV_H
+#define _UBLK_DRV_H
+
+#include <uapi/linux/ublk_cmd.h>
+#include <linux/blk-mq.h>
+#include <linux/cdev.h>
+
+struct ublk_device {
+ struct gendisk *ub_disk;
+
+ char *__queues;
+
+ unsigned int queue_size;
+ struct ublksrv_ctrl_dev_info dev_info;
+
+ struct blk_mq_tag_set tag_set;
+
+ struct cdev cdev;
+ struct device cdev_dev;
+
+#define UB_STATE_OPEN 0
+#define UB_STATE_USED 1
+#define UB_STATE_DELETED 2
+ unsigned long state;
+ int ub_number;
+
+ struct mutex mutex;
+
+ spinlock_t mm_lock;
+ struct mm_struct *mm;
+
+ struct ublk_params params;
+
+ struct completion completion;
+ unsigned int nr_queues_ready;
+ unsigned int nr_privileged_daemon;
+
+ /*
+ * Our ubq->daemon may be killed without any notification, so
+ * monitor each queue's daemon periodically
+ */
+ struct delayed_work monitor_work;
+ struct work_struct quiesce_work;
+ struct work_struct stop_work;
+};
+
+struct ublk_rq_data {
+ struct llist_node node;
+ struct callback_head work;
+ 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 f6238ccc7800..a9c3e71b0756 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -102,6 +102,11 @@
*/
#define UBLK_F_UNPRIVILEGED_DEV (1UL << 5)
+/*
+ * Enable zoned device support
+ */
+#define UBLK_F_ZONED (1ULL << 6)
+
/* device state */
#define UBLK_S_DEV_DEAD 0
#define UBLK_S_DEV_LIVE 1
@@ -155,12 +160,24 @@ struct ublksrv_ctrl_dev_info {
__u64 reserved2;
};
-#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
+enum ublk_op {
+ UBLK_IO_OP_READ = 0,
+ UBLK_IO_OP_WRITE = 1,
+ UBLK_IO_OP_FLUSH = 2,
+ UBLK_IO_OP_DISCARD = 3,
+ UBLK_IO_OP_WRITE_SAME = 4,
+ UBLK_IO_OP_WRITE_ZEROES = 5,
+ UBLK_IO_OP_ZONE_OPEN = 10,
+ UBLK_IO_OP_ZONE_CLOSE = 11,
+ UBLK_IO_OP_ZONE_FINISH = 12,
+ 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,
+};
#define UBLK_IO_F_FAILFAST_DEV (1U << 8)
#define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9)
@@ -257,6 +274,12 @@ 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
@@ -268,11 +291,13 @@ 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
base-commit: eeac8ede17557680855031c6f305ece2378af326
--
2.39.2