On Fri, Jul 14, 2023 at 09:25:10AM +0200, Andreas Hindborg wrote:
> From: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
Hello Andreas!
>
> 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/ublk_drv.c | 335 ++++++++++++++++++++++++++++++++--
> include/uapi/linux/ublk_cmd.h | 36 +++-
> 2 files changed, 354 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index 8d271901efac..5698f4575e05 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;
> @@ -185,11 +195,264 @@ struct ublk_params_header {
> __u32 types;
> };
>
> +static inline unsigned int ublk_req_build_flags(struct request *req);
> +static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq,
> + int tag);
> +
> 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);
> +
> + 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 = zones_in_request * 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;
> +}
> +
> +static blk_status_t ublk_setup_iod_zoned(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)) {
> + 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_ZONE_APPEND:
> + ublk_op = UBLK_IO_OP_ZONE_APPEND;
> + io->flags |= UBLK_IO_FLAG_ZONE_APPEND;
> + 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_RESET_ALL:
> + case REQ_OP_DRV_OUT:
> + /* We do not support reset_all and drv_out */
> + return BLK_STS_NOTSUPP;
> + default:
> + return BLK_STS_IOERR;
> + }
> +
> + iod->op_flags = ublk_op | ublk_req_build_flags(req);
> + iod->nr_sectors = blk_rq_sectors(req);
> + iod->start_sector = blk_rq_pos(req);
> + iod->addr = io->addr;
> +
> + return BLK_STS_OK;
> +}
> +
> +#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;
> +}
> +
> +static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq,
> + struct request *req)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +#endif
> +
> static inline void __ublk_complete_rq(struct request *req);
> static void ublk_complete_rq(struct kref *ref);
>
> @@ -286,6 +549,9 @@ 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;
>
> @@ -304,6 +570,11 @@ 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;
> }
>
> @@ -317,6 +588,9 @@ 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)
> + return ublk_dev_param_zoned_apply(ub);
> +
> return 0;
> }
>
> @@ -487,6 +761,7 @@ 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 +876,8 @@ 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 +961,13 @@ 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];
> + 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;
> @@ -704,6 +985,8 @@ static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req)
> ublk_op = UBLK_IO_OP_WRITE_ZEROES;
> break;
> default:
> + if (ublk_queue_is_zoned(ubq))
> + return ublk_setup_iod_zoned(ubq, req);
> return BLK_STS_IOERR;
> }
>
> @@ -756,7 +1039,8 @@ 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 +1404,11 @@ 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) {
Do we really need to introduce a completely new flag just for this?
if (req_op(req) == REQ_OP_ZONE_APPEND)
should work just as well, no?
Kind regards,
Niklas
