On Fri, Jul 07, 2023 at 05:04:41PM +0200, Andreas Hindborg (Samsung) wrote: > > Ming Lei <ming.lei@xxxxxxxxxx> writes: > > > On Thu, Jul 06, 2023 at 03:09:30PM +0200, Andreas Hindborg wrote: > >> 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 > >> - REQ_OP_ZONE_APPEND > >> > >> The zone append feature uses the `addr` field of `struct ublksrv_io_cmd` to > >> communicate ALBA back to the kernel. Therefore ublk must be used with the > >> user copy feature (UBLK_F_USER_COPY) for zoned storage support to be > >> available. Without this feature, ublk will not allow zoned storage support. > >> > >> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx> > >> --- > >> drivers/block/Kconfig | 4 + > >> drivers/block/ublk_drv.c | 341 ++++++++++++++++++++++++++++++++-- > >> include/uapi/linux/ublk_cmd.h | 30 +++ > >> 3 files changed, 363 insertions(+), 12 deletions(-) > >> > >> diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig > >> index 5b9d4aaebb81..3f7bedae8511 100644 > >> --- a/drivers/block/Kconfig > >> +++ b/drivers/block/Kconfig > >> @@ -373,6 +373,7 @@ config BLK_DEV_RBD > >> config BLK_DEV_UBLK > >> tristate "Userspace block driver (Experimental)" > >> select IO_URING > >> + select BLK_DEV_UBLK_ZONED if BLK_DEV_ZONED > >> help > >> io_uring based userspace block driver. Together with ublk server, ublk > >> has been working well, but interface with userspace or command data > >> @@ -402,6 +403,9 @@ config BLKDEV_UBLK_LEGACY_OPCODES > >> suggested to enable N if your application(ublk server) switches to > >> ioctl command encoding. > >> > >> +config BLK_DEV_UBLK_ZONED > >> + bool > >> + > >> source "drivers/block/rnbd/Kconfig" > >> > >> endif # BLK_DEV > >> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c > >> index 8d271901efac..a5adcfc976a5 100644 > >> --- a/drivers/block/ublk_drv.c > >> +++ b/drivers/block/ublk_drv.c > >> @@ -56,22 +56,28 @@ > >> | 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_rq_data { > >> struct llist_node node; > >> > >> struct kref ref; > >> + __u32 operation; > >> + __u64 sector; > >> + __u32 nr_sectors; > >> }; > > > > Please put "operation" and "nr_sectors" together, then holes > > can be avoided. > > Got it 👍 > > > > >> > >> struct ublk_uring_cmd_pdu { > >> struct ublk_queue *ubq; > >> }; > >> > >> + > > > > ? > > Sorry. > > > > >> /* > >> * io command is active: sqe cmd is received, and its cqe isn't done > >> * > >> @@ -110,6 +116,11 @@ struct ublk_uring_cmd_pdu { > >> */ > >> #define UBLK_IO_FLAG_NEED_GET_DATA 0x08 > >> > >> +/* > >> + * Set when IO is Zone Append > >> + */ > >> +#define UBLK_IO_FLAG_ZONE_APPEND 0x10 > >> + > >> struct ublk_io { > >> /* userspace buffer address from io cmd */ > >> __u64 addr; > >> @@ -184,6 +195,31 @@ struct ublk_params_header { > >> __u32 len; > >> __u32 types; > >> }; > >> +static inline int ublk_dev_params_zoned(const struct ublk_device *ub) > >> +{ > >> + return ub->params.types & UBLK_PARAM_TYPE_ZONED; > >> +} > >> + > >> +static inline bool ublk_dev_is_zoned(const struct ublk_device *ub) > >> +{ > >> + return ub->dev_info.flags & UBLK_F_ZONED; > >> +} > >> + > >> +static int ublk_set_nr_zones(struct ublk_device *ub); > >> +static int ublk_dev_param_zoned_validate(const struct ublk_device *ub); > >> +static int ublk_dev_param_zoned_apply(struct ublk_device *ub); > >> +static int ublk_revalidate_disk_zones(struct ublk_device *ub); > >> + > >> +#ifndef CONFIG_BLK_DEV_UBLK_ZONED > >> + > >> +#define ublk_report_zones (NULL) > >> + > >> +#else > >> + > >> +static int ublk_report_zones(struct gendisk *disk, sector_t sector, > >> + unsigned int nr_zones, report_zones_cb cb, void *data); > >> + > >> +#endif > > > > Please merge the following "#ifdef CONFIG_BLK_DEV_UBLK_ZONED" with the > > above one, then you can avoid the above declarations. Meantime, we don't > > add code after MODULE_LICENSE(). > > Ok 👍 > > > > >> > >> static inline bool ublk_dev_is_user_copy(const struct ublk_device *ub) > >> { > >> @@ -232,7 +268,7 @@ static inline unsigned ublk_pos_to_tag(loff_t pos) > >> UBLK_TAG_BITS_MASK; > >> } > >> > >> -static void ublk_dev_param_basic_apply(struct ublk_device *ub) > >> +static int ublk_dev_param_basic_apply(struct ublk_device *ub) > >> { > >> struct request_queue *q = ub->ub_disk->queue; > >> const struct ublk_param_basic *p = &ub->params.basic; > >> @@ -257,6 +293,11 @@ 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 (ublk_dev_is_zoned(ub)) > >> + return ublk_set_nr_zones(ub); > >> + > > > > The above change can be moved into ublk_dev_param_zoned_apply() which > > is always done after ublk_dev_param_basic_apply(). > > Ok > > > > >> + return 0; > >> } > >> > >> static void ublk_dev_param_discard_apply(struct ublk_device *ub) > >> @@ -286,6 +327,9 @@ static int ublk_validate_params(const struct ublk_device *ub) > >> > >> if (p->max_sectors > (ub->dev_info.max_io_buf_bytes >> 9)) > >> return -EINVAL; > >> + > >> + if (ublk_dev_is_zoned(ub) && !p->chunk_sectors) > >> + return -EINVAL; > >> } else > >> return -EINVAL; > >> > >> @@ -304,19 +348,26 @@ static int ublk_validate_params(const struct ublk_device *ub) > >> if (ub->params.types & UBLK_PARAM_TYPE_DEVT) > >> return -EINVAL; > >> > >> - return 0; > >> + return ublk_dev_param_zoned_validate(ub); > > > > Please follow current style of: > > > > if (ub->params.types & UBLK_PARAM_TYPE_ZONED) > > return ublk_dev_param_zoned_validate(ub); > > > > Then you can avoid lots of check on ublk_dev_params_zoned(). > > Ok, but then I need > > > if (ublk_dev_is_zoned(ub) && !ublk_dev_params_zoned(ub)) > return -EINVAL; > > here to check if user is forgetting zoned parameters for zoned ublk dev. > Or do you want to drop this check? OK, zoned is a bit special, then you still can do it: if (ub->params.types & UBLK_PARAM_TYPE_ZONED) return ublk_dev_param_zoned_validate(ub); else if (ublk_dev_is_zoned(ub)) return -EINVAL; which is more readable. > > > > >> } > >> > >> static int ublk_apply_params(struct ublk_device *ub) > >> { > >> + int ret; > >> + > >> if (!(ub->params.types & UBLK_PARAM_TYPE_BASIC)) > >> return -EINVAL; > >> > >> - ublk_dev_param_basic_apply(ub); > >> + ret = ublk_dev_param_basic_apply(ub); > >> + if (ret) > >> + return ret; > >> > >> if (ub->params.types & UBLK_PARAM_TYPE_DISCARD) > >> ublk_dev_param_discard_apply(ub); > >> > >> + if (ublk_dev_params_zoned(ub)) > >> + return ublk_dev_param_zoned_apply(ub); > >> + > >> return 0; > >> } > >> > >> @@ -487,6 +538,7 @@ 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 > >> @@ -601,7 +653,8 @@ 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, > >> @@ -685,6 +738,7 @@ 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)) { > >> @@ -703,6 +757,37 @@ 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; > >> + return BLK_STS_OK; > >> + default: > >> + return BLK_STS_IOERR; > >> + } > >> + case REQ_OP_ZONE_APPEND: > >> + ublk_op = UBLK_IO_OP_ZONE_APPEND; > >> + io->flags |= UBLK_IO_FLAG_ZONE_APPEND; > >> + break; > >> + case REQ_OP_ZONE_RESET_ALL: > > > > BLK_STS_NOTSUPP should be returned, since in future we may support it, > > and userspace need to know what is wrong. > > Ok > > > > >> + case REQ_OP_DRV_OUT: > >> + /* We do not support reset_all and drv_out */ > >> + fallthrough; > >> default: > >> return BLK_STS_IOERR; > >> } > >> @@ -756,7 +841,8 @@ 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 */ > >> @@ -1120,6 +1206,11 @@ static void ublk_commit_completion(struct ublk_device *ub, > >> /* find the io request and complete */ > >> req = blk_mq_tag_to_rq(ub->tag_set.tags[qid], tag); > >> > >> + if (io->flags & UBLK_IO_FLAG_ZONE_APPEND) { > >> + req->__sector = ub_cmd->addr; > >> + io->flags &= ~UBLK_IO_FLAG_ZONE_APPEND; > >> + } > >> + > >> if (req && likely(!blk_should_fake_timeout(req->q))) > >> ublk_put_req_ref(ubq, req); > >> } > >> @@ -1419,7 +1510,8 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd, > >> ^ (_IOC_NR(cmd_op) == UBLK_IO_NEED_GET_DATA)) > >> goto out; > >> > >> - if (ublk_support_user_copy(ubq) && ub_cmd->addr) { > >> + if (ublk_support_user_copy(ubq) && > >> + !(io->flags & UBLK_IO_FLAG_ZONE_APPEND) && ub_cmd->addr) { > >> ret = -EINVAL; > >> goto out; > >> } > >> @@ -1542,11 +1634,14 @@ static inline bool ublk_check_ubuf_dir(const struct request *req, > >> int ubuf_dir) > >> { > >> /* copy ubuf to request pages */ > >> - if (req_op(req) == REQ_OP_READ && ubuf_dir == ITER_SOURCE) > >> + if ((req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_DRV_IN) && > >> + ubuf_dir == ITER_SOURCE) > >> return true; > >> > >> /* copy request pages to ubuf */ > >> - if (req_op(req) == REQ_OP_WRITE && ubuf_dir == ITER_DEST) > >> + if ((req_op(req) == REQ_OP_WRITE || > >> + req_op(req) == REQ_OP_ZONE_APPEND) && > >> + ubuf_dir == ITER_DEST) > >> return true; > >> > >> return false; > >> @@ -1883,8 +1978,12 @@ 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); > >> > >> - get_device(&ub->cdev_dev); > >> ub->dev_info.state = UBLK_S_DEV_LIVE; > >> + ret = ublk_revalidate_disk_zones(ub); > >> + if (ret) > >> + goto out_put_disk; > >> + > >> + get_device(&ub->cdev_dev); > >> ret = add_disk(disk); > >> if (ret) { > >> /* > >> @@ -2045,6 +2144,13 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) > >> if (ublk_dev_is_user_copy(ub)) > >> ub->dev_info.flags &= ~UBLK_F_NEED_GET_DATA; > >> > >> + /* Zoned storage support requires user copy feature */ > >> + if (ublk_dev_is_zoned(ub) && > >> + (!IS_ENABLED(CONFIG_BLK_DEV_UBLK_ZONED) || !ublk_dev_is_user_copy(ub))) { > >> + ret = -EINVAL; > >> + goto out_free_dev_number; > >> + } > >> + > >> /* We are not ready to support zero copy */ > >> ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY; > >> > >> @@ -2629,3 +2735,214 @@ MODULE_PARM_DESC(ublks_max, "max number of ublk devices allowed to add(default: > >> > >> MODULE_AUTHOR("Ming Lei <ming.lei@xxxxxxxxxx>"); > >> MODULE_LICENSE("GPL"); > >> + > >> +#ifdef CONFIG_BLK_DEV_UBLK_ZONED > >> + > >> +static int get_nr_zones(const struct ublk_device *ub) > >> +{ > >> + const struct ublk_param_basic *p = &ub->params.basic; > >> + > >> + if (!p->chunk_sectors) > >> + return 0; > > > > There isn't zoned device if the above check fails, so no > > need to check it. > > Ok, but this is called from `ublk_dev_param_zoned_validate()` to > validate user sets params correct. Should we not report error to user > space during parameter validation if user space sets chunk_sectors to > zero for zoned device? That has been covered in UBLK_PARAM_TYPE_BASIC branch of ublk_validate_params(). > > > > >> + > >> + /* Zone size is a power of 2 */ > >> + return p->dev_sectors >> ilog2(p->chunk_sectors); > >> +} > >> + > >> +static int ublk_set_nr_zones(struct ublk_device *ub) > >> +{ > >> + ub->ub_disk->nr_zones = get_nr_zones(ub); > >> + if (!ub->ub_disk->nr_zones) > >> + return -EINVAL; > > > > Is nr_zones one must for zoned? > > Zero zones for a zoned storage device is not allowed, as far as I am > aware. Am I mistaken? OK, never mind, I just didn't see such check in null zoned and virtio-blk. > > > > >> + > >> + return 0; > >> +} > >> + > >> +static int ublk_revalidate_disk_zones(struct ublk_device *ub) > >> +{ > >> + if (ublk_dev_is_zoned(ub)) > >> + return blk_revalidate_disk_zones(ub->ub_disk, NULL); > >> + > >> + return 0; > >> +} > >> + > >> +static int ublk_dev_param_zoned_validate(const struct ublk_device *ub) > >> +{ > >> + const struct ublk_param_zoned *p = &ub->params.zoned; > >> + int nr_zones; > >> + > >> + if (ublk_dev_is_zoned(ub) && !ublk_dev_params_zoned(ub)) > >> + return -EINVAL; > >> + > >> + if (!ublk_dev_is_zoned(ub) && ublk_dev_params_zoned(ub)) > >> + return -EINVAL; > >> + > >> + if (!ublk_dev_params_zoned(ub)) > >> + return 0; > > > > The above can be simplified as single check if we follow current > > validate/apply code style: > > > > if (!ublk_dev_is_zoned(ub)) > > return -EINVAL; > > If we do that we will not be able to check if user space sets the > `UBLK_F_ZONED` flag without setting zoned parameters. Should I validate > that at call site or drop the check? Please see above comment, which can be covered as: if (ub->params.types & UBLK_PARAM_TYPE_ZONED) return ublk_dev_param_zoned_validate(ub); else if (ublk_dev_is_zoned(ub)) return -EINVAL; > > >> + > >> + if (!p->max_zone_append_sectors) > >> + return -EINVAL; > >> + > >> + nr_zones = get_nr_zones(ub); > >> + > >> + if (p->max_active_zones > nr_zones) > >> + return -EINVAL; > >> + > >> + if (p->max_open_zones > nr_zones) > >> + return -EINVAL; > >> + > >> + return 0; > >> +} > >> + > >> +static int ublk_dev_param_zoned_apply(struct ublk_device *ub) > >> +{ > >> + const struct ublk_param_zoned *p = &ub->params.zoned; > >> + > >> + disk_set_zoned(ub->ub_disk, BLK_ZONED_HM); > >> + blk_queue_required_elevator_features(ub->ub_disk->queue, > >> + ELEVATOR_F_ZBD_SEQ_WRITE); > >> + disk_set_max_active_zones(ub->ub_disk, p->max_active_zones); > >> + disk_set_max_open_zones(ub->ub_disk, p->max_open_zones); > >> + blk_queue_max_zone_append_sectors(ub->ub_disk->queue, p->max_zone_append_sectors); > >> + > >> + return 0; > >> +} > >> + > >> +/* Based on virtblk_alloc_report_buffer */ > >> +static void *ublk_alloc_report_buffer(struct ublk_device *ublk, > >> + unsigned int nr_zones, size_t *buflen) > >> +{ > >> + struct request_queue *q = ublk->ub_disk->queue; > >> + size_t bufsize; > >> + void *buf; > >> + > >> + nr_zones = min_t(unsigned int, nr_zones, > >> + ublk->ub_disk->nr_zones); > >> + > >> + 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; > >> + } > >> + > >> + *buflen = 0; > >> + return 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 = 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; > >> + int ret; > >> + struct blk_zone *buffer; > >> + size_t buffer_length; > >> + > >> + if (!ublk_dev_is_zoned(ub)) > >> + 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, &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); > >> + 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)) { > >> + ret = PTR_ERR(req); > >> + goto out; > >> + } > >> + > >> + 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; > >> + > >> + ret = blk_rq_map_kern(disk->queue, req, buffer, buffer_length, > >> + GFP_KERNEL); > >> + if (ret) { > >> + blk_mq_free_request(req); > >> + goto out; > >> + } > >> + > >> + status = blk_execute_rq(req, 0); > >> + ret = blk_status_to_errno(status); > >> + blk_mq_free_request(req); > >> + if (ret) > >> + goto out; > >> + > >> + for (unsigned int i = 0; i < zones_in_request; i++) { > >> + struct blk_zone *zone = buffer + i; > >> + > >> + /* A zero length zone means no more zones in this response */ > >> + if (!zone->len) > >> + break; > >> + > >> + ret = cb(zone, i, data); > >> + if (ret) > >> + goto out; > >> + > >> + done_zones++; > >> + sector += zone_size_sectors; > >> + > >> + } > >> + } > >> + > >> + ret = done_zones; > >> + > >> +out: > >> + kvfree(buffer); > >> + return ret; > >> +} > >> + > >> +#else > >> + > >> +static int ublk_set_nr_zones(struct ublk_device *ub) > >> +{ > >> + return 0; > >> +} > >> + > >> +static int ublk_dev_param_zoned_validate(const struct ublk_device *ub) > >> +{ > >> + if (ublk_dev_params_zoned(ub)) > >> + return -EINVAL; > >> + return 0; > > > > Please move the check outside by following current code style, then: > > > > return -EINVAL; > > > > Ok, but then we move the check for user applying zoned params to > non-zoned device when CONFIG_BLK_DEV_ZONED to call site? Yes, the point is to move check in common code, then not only reduce repeated check, but also cleaner. Thanks, Ming