On Fri, Feb 24, 2023 at 09:05:01PM +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 As I suggested, please write one simple & clean zoned target for verifying the interface, and better to not add to tgt_null.c. > > 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++) { The local variable 'i' needs to be declared in the front part of this function body. > + 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; Why is req->__sector set? > + > + 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; > + } I'd suggest to report as many as possible zones in one command, and the dev_info.max_io_buf_bytes is the max allowed buffer size for one command, please refer to nvme_ns_report_zones(). Also we are going to extend ublk in the multiple LUN/NS style, and I guess that won't be one issue since ->report_zones() is always done on disk level, right? > + 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 one null ublk_report_zones in #else branch of the above #ifdef, then we can save one #ifdef. > }; > > #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 The above '#ifdef' is needn't, since OP_ZONE should be defined no matter if CONFIG_BLK_DEV_ZONED is enabled or not. > 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; > +}; Is the above zoned parameter enough for future extension? Does ZNS need extra parameter? Or some zoned new(important) features? I highly suggest to reserve some fields for extension, given it is one ABI interface, which is supposed to be defined well enough from the beginning. Thanks, Ming
