diff options
| -rw-r--r-- | drivers/block/ublk_drv.c | 124 | ||||
| -rw-r--r-- | include/uapi/linux/ublk_cmd.h | 19 |
2 files changed, 142 insertions, 1 deletions
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 33fadca3ee90..1b47341962d0 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -51,6 +51,7 @@ /* private ioctl command mirror */ #define UBLK_CMD_DEL_DEV_ASYNC _IOC_NR(UBLK_U_CMD_DEL_DEV_ASYNC) #define UBLK_CMD_UPDATE_SIZE _IOC_NR(UBLK_U_CMD_UPDATE_SIZE) +#define UBLK_CMD_QUIESCE_DEV _IOC_NR(UBLK_U_CMD_QUIESCE_DEV) #define UBLK_IO_REGISTER_IO_BUF _IOC_NR(UBLK_U_IO_REGISTER_IO_BUF) #define UBLK_IO_UNREGISTER_IO_BUF _IOC_NR(UBLK_U_IO_UNREGISTER_IO_BUF) @@ -67,7 +68,8 @@ | UBLK_F_ZONED \ | UBLK_F_USER_RECOVERY_FAIL_IO \ | UBLK_F_UPDATE_SIZE \ - | UBLK_F_AUTO_BUF_REG) + | UBLK_F_AUTO_BUF_REG \ + | UBLK_F_QUIESCE) #define UBLK_F_ALL_RECOVERY_FLAGS (UBLK_F_USER_RECOVERY \ | UBLK_F_USER_RECOVERY_REISSUE \ @@ -2841,6 +2843,11 @@ static int ublk_ctrl_add_dev(const struct ublksrv_ctrl_cmd *header) return -EINVAL; } + if ((info.flags & UBLK_F_QUIESCE) && !(info.flags & UBLK_F_USER_RECOVERY)) { + pr_warn("UBLK_F_QUIESCE requires UBLK_F_USER_RECOVERY\n"); + return -EINVAL; + } + /* * unprivileged device can't be trusted, but RECOVERY and * RECOVERY_REISSUE still may hang error handling, so can't @@ -3233,6 +3240,117 @@ static void ublk_ctrl_set_size(struct ublk_device *ub, const struct ublksrv_ctrl set_capacity_and_notify(ub->ub_disk, p->dev_sectors); mutex_unlock(&ub->mutex); } + +struct count_busy { + const struct ublk_queue *ubq; + unsigned int nr_busy; +}; + +static bool ublk_count_busy_req(struct request *rq, void *data) +{ + struct count_busy *idle = data; + + if (!blk_mq_request_started(rq) && rq->mq_hctx->driver_data == idle->ubq) + idle->nr_busy += 1; + return true; +} + +/* uring_cmd is guaranteed to be active if the associated request is idle */ +static bool ubq_has_idle_io(const struct ublk_queue *ubq) +{ + struct count_busy data = { + .ubq = ubq, + }; + + blk_mq_tagset_busy_iter(&ubq->dev->tag_set, ublk_count_busy_req, &data); + return data.nr_busy < ubq->q_depth; +} + +/* Wait until each hw queue has at least one idle IO */ +static int ublk_wait_for_idle_io(struct ublk_device *ub, + unsigned int timeout_ms) +{ + unsigned int elapsed = 0; + int ret; + + while (elapsed < timeout_ms && !signal_pending(current)) { + unsigned int queues_cancelable = 0; + int i; + + for (i = 0; i < ub->dev_info.nr_hw_queues; i++) { + struct ublk_queue *ubq = ublk_get_queue(ub, i); + + queues_cancelable += !!ubq_has_idle_io(ubq); + } + + /* + * Each queue needs at least one active command for + * notifying ublk server + */ + if (queues_cancelable == ub->dev_info.nr_hw_queues) + break; + + msleep(UBLK_REQUEUE_DELAY_MS); + elapsed += UBLK_REQUEUE_DELAY_MS; + } + + if (signal_pending(current)) + ret = -EINTR; + else if (elapsed >= timeout_ms) + ret = -EBUSY; + else + ret = 0; + + return ret; +} + +static int ublk_ctrl_quiesce_dev(struct ublk_device *ub, + const struct ublksrv_ctrl_cmd *header) +{ + /* zero means wait forever */ + u64 timeout_ms = header->data[0]; + struct gendisk *disk; + int i, ret = -ENODEV; + + if (!(ub->dev_info.flags & UBLK_F_QUIESCE)) + return -EOPNOTSUPP; + + mutex_lock(&ub->mutex); + disk = ublk_get_disk(ub); + if (!disk) + goto unlock; + if (ub->dev_info.state == UBLK_S_DEV_DEAD) + goto put_disk; + + ret = 0; + /* already in expected state */ + if (ub->dev_info.state != UBLK_S_DEV_LIVE) + goto put_disk; + + /* Mark all queues as canceling */ + blk_mq_quiesce_queue(disk->queue); + for (i = 0; i < ub->dev_info.nr_hw_queues; i++) { + struct ublk_queue *ubq = ublk_get_queue(ub, i); + + ubq->canceling = true; + } + blk_mq_unquiesce_queue(disk->queue); + + if (!timeout_ms) + timeout_ms = UINT_MAX; + ret = ublk_wait_for_idle_io(ub, timeout_ms); + +put_disk: + ublk_put_disk(disk); +unlock: + mutex_unlock(&ub->mutex); + + /* Cancel pending uring_cmd */ + if (!ret) + ublk_cancel_dev(ub); + return ret; +} + /* * All control commands are sent via /dev/ublk-control, so we have to check * the destination device's permission @@ -3319,6 +3437,7 @@ static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub, case UBLK_CMD_START_USER_RECOVERY: case UBLK_CMD_END_USER_RECOVERY: case UBLK_CMD_UPDATE_SIZE: + case UBLK_CMD_QUIESCE_DEV: mask = MAY_READ | MAY_WRITE; break; default: @@ -3414,6 +3533,9 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, ublk_ctrl_set_size(ub, header); ret = 0; break; + case UBLK_CMD_QUIESCE_DEV: + ret = ublk_ctrl_quiesce_dev(ub, header); + break; default: ret = -EOPNOTSUPP; break; diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index 1c40632cb164..56c7e3fc666f 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -53,6 +53,8 @@ _IOR('u', 0x14, struct ublksrv_ctrl_cmd) #define UBLK_U_CMD_UPDATE_SIZE \ _IOWR('u', 0x15, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_QUIESCE_DEV \ + _IOWR('u', 0x16, struct ublksrv_ctrl_cmd) /* * 64bits are enough now, and it should be easy to extend in case of @@ -253,6 +255,23 @@ */ #define UBLK_F_AUTO_BUF_REG (1ULL << 11) +/* + * Control command `UBLK_U_CMD_QUIESCE_DEV` is added for quiescing device, + * which state can be transitioned to `UBLK_S_DEV_QUIESCED` or + * `UBLK_S_DEV_FAIL_IO` finally, and it needs ublk server cooperation for + * handling `UBLK_IO_RES_ABORT` correctly. + * + * Typical use case is for supporting to upgrade ublk server application, + * meantime keep ublk block device persistent during the period. + * + * This feature is only available when UBLK_F_USER_RECOVERY is enabled. + * + * Note, this command returns -EBUSY in case that all IO commands are being + * handled by ublk server and not completed in specified time period which + * is passed from the control command parameter. + */ +#define UBLK_F_QUIESCE (1ULL << 12) + /* device state */ #define UBLK_S_DEV_DEAD 0 #define UBLK_S_DEV_LIVE 1 |