/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * RDMA Network Block Driver * * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved. * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved. * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved. */ #ifndef RNBD_PROTO_H #define RNBD_PROTO_H #include #include #include #include #include #include #include #define RNBD_PROTO_VER_MAJOR 2 #define RNBD_PROTO_VER_MINOR 0 /* The default port number the RTRS server is listening on. */ #define RTRS_PORT 1234 /** * enum rnbd_msg_types - RNBD message types * @RNBD_MSG_SESS_INFO: initial session info from client to server * @RNBD_MSG_SESS_INFO_RSP: initial session info from server to client * @RNBD_MSG_OPEN: open (map) device request * @RNBD_MSG_OPEN_RSP: response to an @RNBD_MSG_OPEN * @RNBD_MSG_IO: block IO request operation * @RNBD_MSG_CLOSE: close (unmap) device request */ enum rnbd_msg_type { RNBD_MSG_SESS_INFO, RNBD_MSG_SESS_INFO_RSP, RNBD_MSG_OPEN, RNBD_MSG_OPEN_RSP, RNBD_MSG_IO, RNBD_MSG_CLOSE, }; /** * struct rnbd_msg_hdr - header of RNBD messages * @type: Message type, valid values see: enum rnbd_msg_types */ struct rnbd_msg_hdr { __le16 type; __le16 __padding; }; /** * We allow to map RO many times and RW only once. We allow to map yet another * time RW, if MIGRATION is provided (second RW export can be required for * example for VM migration) */ enum rnbd_access_mode { RNBD_ACCESS_RO, RNBD_ACCESS_RW, RNBD_ACCESS_MIGRATION, }; /** * struct rnbd_msg_sess_info - initial session info from client to server * @hdr: message header * @ver: RNBD protocol version */ struct rnbd_msg_sess_info { struct rnbd_msg_hdr hdr; u8 ver; u8 reserved[31]; }; /** * struct rnbd_msg_sess_info_rsp - initial session info from server to client * @hdr: message header * @ver: RNBD protocol version */ struct rnbd_msg_sess_info_rsp { struct rnbd_msg_hdr hdr; u8 ver; u8 reserved[31]; }; /** * struct rnbd_msg_open - request to open a remote device. * @hdr: message header * @access_mode: the mode to open remote device, valid values see: * enum rnbd_access_mode * @device_name: device path on remote side */ struct rnbd_msg_open { struct rnbd_msg_hdr hdr; u8 access_mode; u8 resv1; s8 dev_name[NAME_MAX]; u8 reserved[3]; }; /** * struct rnbd_msg_close - request to close a remote device. * @hdr: message header * @device_id: device_id on server side to identify the device */ struct rnbd_msg_close { struct rnbd_msg_hdr hdr; __le32 device_id; }; enum rnbd_cache_policy { RNBD_FUA = 1 << 0, RNBD_WRITEBACK = 1 << 1, }; /** * struct rnbd_msg_open_rsp - response message to RNBD_MSG_OPEN * @hdr: message header * @device_id: device_id on server side to identify the device * @nsectors: number of sectors in the usual 512b unit * @max_hw_sectors: max hardware sectors in the usual 512b unit * @max_write_same_sectors: max sectors for WRITE SAME in the 512b unit * @max_discard_sectors: max. sectors that can be discarded at once in 512b * unit. * @discard_granularity: size of the internal discard allocation unit in bytes * @discard_alignment: offset from internal allocation assignment in bytes * @physical_block_size: physical block size device supports in bytes * @logical_block_size: logical block size device supports in bytes * @max_segments: max segments hardware support in one transfer * @secure_discard: supports secure discard * @rotation: is a rotational disc? * @cache_policy: support write-back caching or FUA? */ struct rnbd_msg_open_rsp { struct rnbd_msg_hdr hdr; __le32 device_id; __le64 nsectors; __le32 max_hw_sectors; __le32 max_write_same_sectors; __le32 max_discard_sectors; __le32 discard_granularity; __le32 discard_alignment; __le16 physical_block_size; __le16 logical_block_size; __le16 max_segments; __le16 secure_discard; u8 rotational; u8 cache_policy; u8 reserved[10]; }; /** * struct rnbd_msg_io - message for I/O read/write * @hdr: message header * @device_id: device_id on server side to find the right device * @sector: bi_sector attribute from struct bio * @rw: valid values are defined in enum rnbd_io_flags * @bi_size: number of bytes for I/O read/write * @prio: priority */ struct rnbd_msg_io { struct rnbd_msg_hdr hdr; __le32 device_id; __le64 sector; __le32 rw; __le32 bi_size; __le16 prio; }; #define RNBD_OP_BITS 8 #define RNBD_OP_MASK ((1 << RNBD_OP_BITS) - 1) /** * enum rnbd_io_flags - RNBD request types from rq_flag_bits * @RNBD_OP_READ: read sectors from the device * @RNBD_OP_WRITE: write sectors to the device * @RNBD_OP_FLUSH: flush the volatile write cache * @RNBD_OP_DISCARD: discard sectors * @RNBD_OP_SECURE_ERASE: securely erase sectors * @RNBD_OP_WRITE_SAME: write the same sectors many times * @RNBD_F_SYNC: request is sync (sync write or read) * @RNBD_F_FUA: forced unit access */ enum rnbd_io_flags { /* Operations */ RNBD_OP_READ = 0, RNBD_OP_WRITE = 1, RNBD_OP_FLUSH = 2, RNBD_OP_DISCARD = 3, RNBD_OP_SECURE_ERASE = 4, RNBD_OP_WRITE_SAME = 5, RNBD_OP_LAST, /* Flags */ RNBD_F_SYNC = 1<<(RNBD_OP_BITS + 0), RNBD_F_FUA = 1<<(RNBD_OP_BITS + 1), RNBD_F_ALL = (RNBD_F_SYNC | RNBD_F_FUA) }; static inline u32 rnbd_op(u32 flags) { return flags & RNBD_OP_MASK; } static inline u32 rnbd_flags(u32 flags) { return flags & ~RNBD_OP_MASK; } static inline bool rnbd_flags_supported(u32 flags) { u32 op; op = rnbd_op(flags); flags = rnbd_flags(flags); if (op >= RNBD_OP_LAST) return false; if (flags & ~RNBD_F_ALL) return false; return true; } static inline u32 rnbd_to_bio_flags(u32 rnbd_opf) { u32 bio_opf; switch (rnbd_op(rnbd_opf)) { case RNBD_OP_READ: bio_opf = REQ_OP_READ; break; case RNBD_OP_WRITE: bio_opf = REQ_OP_WRITE; break; case RNBD_OP_FLUSH: bio_opf = REQ_OP_WRITE | REQ_PREFLUSH; break; case RNBD_OP_DISCARD: bio_opf = REQ_OP_DISCARD; break; case RNBD_OP_SECURE_ERASE: bio_opf = REQ_OP_SECURE_ERASE; break; case RNBD_OP_WRITE_SAME: bio_opf = REQ_OP_WRITE_SAME; break; default: WARN(1, "Unknown RNBD type: %d (flags %d)\n", rnbd_op(rnbd_opf), rnbd_opf); bio_opf = 0; } if (rnbd_opf & RNBD_F_SYNC) bio_opf |= REQ_SYNC; if (rnbd_opf & RNBD_F_FUA) bio_opf |= REQ_FUA; return bio_opf; } static inline u32 rq_to_rnbd_flags(struct request *rq) { u32 rnbd_opf; switch (req_op(rq)) { case REQ_OP_READ: rnbd_opf = RNBD_OP_READ; break; case REQ_OP_WRITE: rnbd_opf = RNBD_OP_WRITE; break; case REQ_OP_DISCARD: rnbd_opf = RNBD_OP_DISCARD; break; case REQ_OP_SECURE_ERASE: rnbd_opf = RNBD_OP_SECURE_ERASE; break; case REQ_OP_WRITE_SAME: rnbd_opf = RNBD_OP_WRITE_SAME; break; case REQ_OP_FLUSH: rnbd_opf = RNBD_OP_FLUSH; break; default: WARN(1, "Unknown request type %d (flags %llu)\n", req_op(rq), (unsigned long long)rq->cmd_flags); rnbd_opf = 0; } if (op_is_sync(rq->cmd_flags)) rnbd_opf |= RNBD_F_SYNC; if (op_is_flush(rq->cmd_flags)) rnbd_opf |= RNBD_F_FUA; return rnbd_opf; } const char *rnbd_access_mode_str(enum rnbd_access_mode mode); #endif /* RNBD_PROTO_H */