diff options
Diffstat (limited to 'include/uapi/linux/ublk_cmd.h')
| -rw-r--r-- | include/uapi/linux/ublk_cmd.h | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index 583b86681c93..56c7e3fc666f 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -51,6 +51,10 @@ _IOR('u', 0x13, struct ublksrv_ctrl_cmd) #define UBLK_U_CMD_DEL_DEV_ASYNC \ _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 @@ -211,6 +215,63 @@ */ #define UBLK_F_USER_RECOVERY_FAIL_IO (1ULL << 9) +/* + * Resizing a block device is possible with UBLK_U_CMD_UPDATE_SIZE + * New size is passed in cmd->data[0] and is in units of sectors + */ +#define UBLK_F_UPDATE_SIZE (1ULL << 10) + +/* + * request buffer is registered automatically to uring_cmd's io_uring + * context before delivering this io command to ublk server, meantime + * it is un-registered automatically when completing this io command. + * + * For using this feature: + * + * - ublk server has to create sparse buffer table on the same `io_ring_ctx` + * for issuing `UBLK_IO_FETCH_REQ` and `UBLK_IO_COMMIT_AND_FETCH_REQ`. + * If uring_cmd isn't issued on same `io_ring_ctx`, it is ublk server's + * responsibility to unregister the buffer by issuing `IO_UNREGISTER_IO_BUF` + * manually, otherwise this ublk request won't complete. + * + * - ublk server passes auto buf register data via uring_cmd's sqe->addr, + * `struct ublk_auto_buf_reg` is populated from sqe->addr, please see + * the definition of ublk_sqe_addr_to_auto_buf_reg() + * + * - pass buffer index from `ublk_auto_buf_reg.index` + * + * - all reserved fields in `ublk_auto_buf_reg` need to be zeroed + * + * - pass flags from `ublk_auto_buf_reg.flags` if needed + * + * This way avoids extra cost from two uring_cmd, but also simplifies backend + * implementation, such as, the dependency on IO_REGISTER_IO_BUF and + * IO_UNREGISTER_IO_BUF becomes not necessary. + * + * If wrong data or flags are provided, both IO_FETCH_REQ and + * IO_COMMIT_AND_FETCH_REQ are failed, for the latter, the ublk IO request + * won't be completed until new IO_COMMIT_AND_FETCH_REQ command is issued + * successfully + */ +#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 @@ -297,6 +358,17 @@ struct ublksrv_ctrl_dev_info { #define UBLK_IO_F_FUA (1U << 13) #define UBLK_IO_F_NOUNMAP (1U << 15) #define UBLK_IO_F_SWAP (1U << 16) +/* + * For UBLK_F_AUTO_BUF_REG & UBLK_AUTO_BUF_REG_FALLBACK only. + * + * This flag is set if auto buffer register is failed & ublk server passes + * UBLK_AUTO_BUF_REG_FALLBACK, and ublk server need to register buffer + * manually for handling the delivered IO command if this flag is observed + * + * ublk server has to check this flag if UBLK_AUTO_BUF_REG_FALLBACK is + * passed in. + */ +#define UBLK_IO_F_NEED_REG_BUF (1U << 17) /* * io cmd is described by this structure, and stored in share memory, indexed @@ -331,6 +403,62 @@ static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod) return iod->op_flags >> 8; } +/* + * If this flag is set, fallback by completing the uring_cmd and setting + * `UBLK_IO_F_NEED_REG_BUF` in case of auto-buf-register failure; + * otherwise the client ublk request is failed silently + * + * If ublk server passes this flag, it has to check if UBLK_IO_F_NEED_REG_BUF + * is set in `ublksrv_io_desc.op_flags`. If UBLK_IO_F_NEED_REG_BUF is set, + * ublk server needs to register io buffer manually for handling IO command. + */ +#define UBLK_AUTO_BUF_REG_FALLBACK (1 << 0) +#define UBLK_AUTO_BUF_REG_F_MASK UBLK_AUTO_BUF_REG_FALLBACK + +struct ublk_auto_buf_reg { + /* index for registering the delivered request buffer */ + __u16 index; + __u8 flags; + __u8 reserved0; + + /* + * io_ring FD can be passed via the reserve field in future for + * supporting to register io buffer to external io_uring + */ + __u32 reserved1; +}; + +/* + * For UBLK_F_AUTO_BUF_REG, auto buffer register data is carried via + * uring_cmd's sqe->addr: + * + * - bit0 ~ bit15: buffer index + * - bit16 ~ bit23: flags + * - bit24 ~ bit31: reserved0 + * - bit32 ~ bit63: reserved1 + */ +static inline struct ublk_auto_buf_reg ublk_sqe_addr_to_auto_buf_reg( + __u64 sqe_addr) +{ + struct ublk_auto_buf_reg reg = { + .index = sqe_addr & 0xffff, + .flags = (sqe_addr >> 16) & 0xff, + .reserved0 = (sqe_addr >> 24) & 0xff, + .reserved1 = sqe_addr >> 32, + }; + + return reg; +} + +static inline __u64 +ublk_auto_buf_reg_to_sqe_addr(const struct ublk_auto_buf_reg *buf) +{ + __u64 addr = buf->index | (__u64)buf->flags << 16 | (__u64)buf->reserved0 << 24 | + (__u64)buf->reserved1 << 32; + + return addr; +} + /* issued to ublk driver via /dev/ublkcN */ struct ublksrv_io_cmd { __u16 q_id; |