diff options
Diffstat (limited to 'drivers/block/rnbd/rnbd-proto.h')
| -rw-r--r-- | drivers/block/rnbd/rnbd-proto.h | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/block/rnbd/rnbd-proto.h b/drivers/block/rnbd/rnbd-proto.h new file mode 100644 index 0000000000..e32f8f2c86 --- /dev/null +++ b/drivers/block/rnbd/rnbd-proto.h @@ -0,0 +1,292 @@ +/* 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 <linux/types.h> +#include <linux/blk-mq.h> +#include <linux/limits.h> +#include <linux/inet.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <rdma/ib.h> + +#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, +}; + +static const __maybe_unused struct { + enum rnbd_access_mode mode; + const char *str; +} rnbd_access_modes[] = { + [RNBD_ACCESS_RO] = {RNBD_ACCESS_RO, "ro"}, + [RNBD_ACCESS_RW] = {RNBD_ACCESS_RW, "rw"}, + [RNBD_ACCESS_MIGRATION] = {RNBD_ACCESS_MIGRATION, "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 + * @obsolete_rotational: obsolete, not in used. + * @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 obsolete_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, + + /* Flags */ + RNBD_F_SYNC = 1<<(RNBD_OP_BITS + 0), + RNBD_F_FUA = 1<<(RNBD_OP_BITS + 1), +}; + +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 blk_opf_t rnbd_to_bio_flags(u32 rnbd_opf) +{ + blk_opf_t 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; + 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_FLUSH: + rnbd_opf = RNBD_OP_FLUSH; + break; + default: + WARN(1, "Unknown request type %d (flags %llu)\n", + (__force u32)req_op(rq), + (__force 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 */ |