On Tue, Jul 11, 2023 at 09:23:53AM +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. Without one userspace implementation, it is hard to verify the kernel change, so I write one zoned target example based on libublk-rs by taking one day. https://github.com/ming1/libublk-rs.git [1] It is one zoned-ramdisk example, and should be easy to add persistence zoned. All zoned commands are covered, except for REQ_OP_ZONE_RESET_ALL. How to create ublk-zoned: cargo run --example zoned -- add -1 1024 #1024MB So far it passes all blktests/zbd tests for external zoned device. 'mkfs.btrfs -O zoned' & mount & git clone linux_kernel in this btrfs works. So this patchset gets verified now, so far so good. [1] not publish to crates.io yet, still need some cleanup > > Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx> > --- > drivers/block/ublk_drv.c | 314 ++++++++++++++++++++++++++++++++-- > include/uapi/linux/ublk_cmd.h | 36 +++- > 2 files changed, 331 insertions(+), 19 deletions(-) > > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c > index 8d271901efac..a57be961b708 100644 > --- a/drivers/block/ublk_drv.c > +++ b/drivers/block/ublk_drv.c > @@ -56,16 +56,21 @@ > | 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; > + __u64 sector; > + __u32 operation; > + __u32 nr_sectors; > }; > > struct ublk_uring_cmd_pdu { > @@ -110,6 +115,11 @@ 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; > @@ -190,6 +200,198 @@ static inline bool ublk_dev_is_user_copy(const struct ublk_device *ub) > return ub->dev_info.flags & UBLK_F_USER_COPY; > } > > +static inline bool ublk_dev_is_zoned(const struct ublk_device *ub) > +{ > + return ub->dev_info.flags & UBLK_F_ZONED; > +} > + > +static inline bool ublk_queue_is_zoned(struct ublk_queue *ubq) > +{ > + return ubq->flags & UBLK_F_ZONED; > +} > + > +#ifdef CONFIG_BLK_DEV_ZONED > + > +static int ublk_get_nr_zones(const struct ublk_device *ub) > +{ > + const struct ublk_param_basic *p = &ub->params.basic; > + > + /* Zone size is a power of 2 */ > + return p->dev_sectors >> ilog2(p->chunk_sectors); > +} > + > +static int ublk_revalidate_disk_zones(struct ublk_device *ub) > +{ > + return blk_revalidate_disk_zones(ub->ub_disk, NULL); > +} > + > +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)) > + return -EINVAL; > + > + if (!p->max_zone_append_sectors) > + return -EINVAL; > + > + nr_zones = ublk_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); > + > + ub->ub_disk->nr_zones = ublk_get_nr_zones(ub); > + > + 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); 'bufsize' shouldn't related with queue_max_segments() given we don't enable segment limit yet. > + > + 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; > + > + 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; pdu->nr_sectors will be set to ublksrv_io_desc->nr_sectors as part of UAPI, I feel it is hard to understand to pass 'remaining_zones * zone_size_sectors', probably it is fine to re-define as buffer size or requested nr_blk_zone, or other ideas? > + > + 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 > + > +#define ublk_report_zones (NULL) > + > +static int ublk_dev_param_zoned_validate(const struct ublk_device *ub) > +{ > + return -EOPNOTSUPP; > +} > + > +static int ublk_dev_param_zoned_apply(struct ublk_device *ub) > +{ > + return -EOPNOTSUPP; > +} > + > +static int ublk_revalidate_disk_zones(struct ublk_device *ub) > +{ > + return 0; > +} > + > +#endif > + > static inline void __ublk_complete_rq(struct request *req); > static void ublk_complete_rq(struct kref *ref); > > @@ -232,7 +434,7 @@ 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 +459,8 @@ 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); > + > + return 0; > } > > static void ublk_dev_param_discard_apply(struct ublk_device *ub) > @@ -286,6 +490,9 @@ 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 +511,31 @@ static int ublk_validate_params(const struct ublk_device *ub) > if (ub->params.types & UBLK_PARAM_TYPE_DEVT) > return -EINVAL; > > + if (ub->params.types & UBLK_PARAM_TYPE_ZONED) > + return ublk_dev_param_zoned_validate(ub); > + else if (ublk_dev_is_zoned(ub)) > + return -EINVAL; > + > return 0; > } > > 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 (ub->params.types & UBLK_PARAM_TYPE_ZONED) > + return ublk_dev_param_zoned_apply(ub); > + > return 0; > } > > @@ -487,6 +706,7 @@ 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 +821,8 @@ 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, > @@ -685,8 +906,14 @@ 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); > + enum req_op op = req_op(req); > u32 ublk_op; > > + if (!ublk_queue_is_zoned(ubq) && > + (op_is_zone_mgmt(op) || op == REQ_OP_ZONE_APPEND)) > + return -EIO; > + > switch (req_op(req)) { > case REQ_OP_READ: > ublk_op = UBLK_IO_OP_READ; > @@ -703,6 +930,37 @@ 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: > + case REQ_OP_DRV_OUT: > + /* We do not support reset_all and drv_out */ > + return BLK_STS_NOTSUPP; I'd suggest to move all zoned handling & the above check into one helper, such as: default: if (ublk_queue_is_zoned()) return ublk_zoned_setup_iod(); Then zoned check can be avoided for other generic OPs, and zoned patch conflict could be avoided usually. Anyway, this version looks much better, and I think we are close to go. Thanks, Ming
