Hello Andreas, On Fri, Feb 24, 2023 at 01:59:50PM +0100, Andreas Hindborg wrote: > 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> > --- Did you try to build this patch with CONFIG_BLK_DEV_ZONED disabled? I got the following build errors when building it on top of vanilla v6.2 when CONFIG_BLK_DEV_ZONED is disabled: drivers/block/ublk_drv.c: In function ‘ublk_dev_param_basic_apply’: drivers/block/ublk_drv.c:221:28: error: ‘struct gendisk’ has no member named ‘nr_zones’ 221 | ub->ub_disk->nr_zones = p->dev_sectors / p->chunk_sectors; | ^~ drivers/block/ublk_drv.c: In function ‘ublk_dev_param_zoned_apply’: drivers/block/ublk_drv.c:244:17: error: implicit declaration of function ‘disk_set_max_active_zones’; did you mean ‘bdev_max_active_zones’? [-Werror=implicit-function-declaration] 244 | disk_set_max_active_zones(ub->ub_disk, p->max_active_zones); | ^~~~~~~~~~~~~~~~~~~~~~~~~ | bdev_max_active_zones drivers/block/ublk_drv.c:245:17: error: implicit declaration of function ‘disk_set_max_open_zones’; did you mean ‘bdev_max_open_zones’? [-Werror=implicit-function-declaration] 245 | disk_set_max_open_zones(ub->ub_disk, p->max_open_zones); > drivers/block/ublk_drv.c | 145 ++++++++++++++++++++++++++++++++-- > include/uapi/linux/ublk_cmd.h | 18 +++++ > 2 files changed, 157 insertions(+), 6 deletions(-) > > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c > index 6368b56eacf1..9741b4b1647b 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; > @@ -212,6 +215,11 @@ 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) && > + ub->dev_info.flags & UBLK_F_ZONED && p->chunk_sectors) { > + ub->ub_disk->nr_zones = p->dev_sectors / p->chunk_sectors; > + } Kernel coding style says to not unnecessarily use braces where a single statement will do: https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces > } > > static void ublk_dev_param_discard_apply(struct ublk_device *ub) > @@ -227,6 +235,19 @@ static void ublk_dev_param_discard_apply(struct ublk_device *ub) > blk_queue_max_discard_segments(q, p->max_discard_segments); > } > > +static void ublk_dev_param_zoned_apply(struct ublk_device *ub) > +{ > + const struct ublk_param_zoned *p = &ub->params.zoned; > + > + if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && > + 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); > + /* We do not support zone append yet */ > + //blk_queue_max_zone_append_sectors(q, zone_size); Remove commented out code. It can be added once that feature is added. > + } > +} > + > static int ublk_validate_params(const struct ublk_device *ub) > { > /* basic param is the only one which must be set */ > @@ -268,6 +289,9 @@ 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) > + ublk_dev_param_zoned_apply(ub); > + > return 0; > } > > @@ -361,9 +385,18 @@ static void ublk_free_disk(struct gendisk *disk) > put_device(&ub->cdev_dev); > } > > +#if IS_ENABLED(CONFIG_BLK_DEV_ZONED) Here you use "#if IS_ENABLED(CONFIG_BLK_DEV_ZONED)" yet further down you use "#ifdef CONFIG_BLK_DEV_ZONED". IS_ENABLED() is usually used when testing for a Kconfig within a normal C conditional, e.g. if (IS_ENABLED()), where possible, in order to avoid ugly C preprocessor conditionals completely. However, if you have to use C preprocessor conditionals, then #ifdef CONFIG_SOMETHING is the most common way to conditionally include something. > +static int ublk_report_zones(struct gendisk *disk, sector_t sector, > + unsigned int nr_zones, report_zones_cb cb, > + void *data); > +#endif > + > static const struct block_device_operations ub_fops = { > - .owner = THIS_MODULE, > - .free_disk = ublk_free_disk, > + .owner = THIS_MODULE, > + .free_disk = ublk_free_disk, > +#if IS_ENABLED(CONFIG_BLK_DEV_ZONED) > + .report_zones = ublk_report_zones, > +#endif > }; > > #define UBLK_MAX_PIN_PAGES 32 > @@ -499,7 +532,7 @@ 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 +599,26 @@ 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 +665,8 @@ 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; > } > @@ -1493,6 +1547,73 @@ static struct ublk_device *ublk_get_device_from_id(int idx) > return ub; > } > > +#ifdef CONFIG_BLK_DEV_ZONED > +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++) { > + No need for empty line here. > + struct request *req; > + blk_status_t status; > + struct blk_zone info; Since this is allocated on the stack, does it need memset()? null_blk seems to memset blk_zone before the loop, but not inside the loop: https://github.com/torvalds/linux/blob/v6.2/drivers/block/null_blk/zoned.c#L206 So I'm a bit confused... If e.g. cb() is blkdev_copy_zone_to_user() https://github.com/torvalds/linux/blob/v6.2/block/blk-zoned.c#L318 It will copy whatever the kernel allocated. So I guess that since you can't guarantee that the ublk user space driver will fill in all fields in the zone when receiving a REQ_OP_DRV_IN, I assume that you do need to do a memset() in order to not potentially leak kernel space data. > + > + 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; > +} > +#endif > + > static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd) > { > struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; > @@ -1535,6 +1656,15 @@ 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 = blk_revalidate_disk_zones(disk, NULL); > + if (ret) > + goto out_put_disk; > + } > + > get_device(&ub->cdev_dev); > ret = add_disk(disk); > if (ret) { > @@ -1673,6 +1803,9 @@ 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 > -- > 2.39.2 >
