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The C and C++ Include Header Files
/usr/include/linux/ublk_cmd.h
$ cat -n /usr/include/linux/ublk_cmd.h 1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef USER_BLK_DRV_CMD_INC_H 3 #define USER_BLK_DRV_CMD_INC_H 4 5 #include <linux/types.h> 6 7 /* ublk server command definition */ 8 9 /* 10 * Admin commands, issued by ublk server, and handled by ublk driver. 11 * 12 * Legacy command definition, don't use in new application, and don't 13 * add new such definition any more 14 */ 15 #define UBLK_CMD_GET_QUEUE_AFFINITY 0x01 16 #define UBLK_CMD_GET_DEV_INFO 0x02 17 #define UBLK_CMD_ADD_DEV 0x04 18 #define UBLK_CMD_DEL_DEV 0x05 19 #define UBLK_CMD_START_DEV 0x06 20 #define UBLK_CMD_STOP_DEV 0x07 21 #define UBLK_CMD_SET_PARAMS 0x08 22 #define UBLK_CMD_GET_PARAMS 0x09 23 #define UBLK_CMD_START_USER_RECOVERY 0x10 24 #define UBLK_CMD_END_USER_RECOVERY 0x11 25 #define UBLK_CMD_GET_DEV_INFO2 0x12 26 27 /* Any new ctrl command should encode by __IO*() */ 28 #define UBLK_U_CMD_GET_QUEUE_AFFINITY \ 29 _IOR('u', UBLK_CMD_GET_QUEUE_AFFINITY, struct ublksrv_ctrl_cmd) 30 #define UBLK_U_CMD_GET_DEV_INFO \ 31 _IOR('u', UBLK_CMD_GET_DEV_INFO, struct ublksrv_ctrl_cmd) 32 #define UBLK_U_CMD_ADD_DEV \ 33 _IOWR('u', UBLK_CMD_ADD_DEV, struct ublksrv_ctrl_cmd) 34 #define UBLK_U_CMD_DEL_DEV \ 35 _IOWR('u', UBLK_CMD_DEL_DEV, struct ublksrv_ctrl_cmd) 36 #define UBLK_U_CMD_START_DEV \ 37 _IOWR('u', UBLK_CMD_START_DEV, struct ublksrv_ctrl_cmd) 38 #define UBLK_U_CMD_STOP_DEV \ 39 _IOWR('u', UBLK_CMD_STOP_DEV, struct ublksrv_ctrl_cmd) 40 #define UBLK_U_CMD_SET_PARAMS \ 41 _IOWR('u', UBLK_CMD_SET_PARAMS, struct ublksrv_ctrl_cmd) 42 #define UBLK_U_CMD_GET_PARAMS \ 43 _IOR('u', UBLK_CMD_GET_PARAMS, struct ublksrv_ctrl_cmd) 44 #define UBLK_U_CMD_START_USER_RECOVERY \ 45 _IOWR('u', UBLK_CMD_START_USER_RECOVERY, struct ublksrv_ctrl_cmd) 46 #define UBLK_U_CMD_END_USER_RECOVERY \ 47 _IOWR('u', UBLK_CMD_END_USER_RECOVERY, struct ublksrv_ctrl_cmd) 48 #define UBLK_U_CMD_GET_DEV_INFO2 \ 49 _IOR('u', UBLK_CMD_GET_DEV_INFO2, struct ublksrv_ctrl_cmd) 50 #define UBLK_U_CMD_GET_FEATURES \ 51 _IOR('u', 0x13, struct ublksrv_ctrl_cmd) 52 53 /* 54 * 64bits are enough now, and it should be easy to extend in case of 55 * running out of feature flags 56 */ 57 #define UBLK_FEATURES_LEN 8 58 59 /* 60 * IO commands, issued by ublk server, and handled by ublk driver. 61 * 62 * FETCH_REQ: issued via sqe(URING_CMD) beforehand for fetching IO request 63 * from ublk driver, should be issued only when starting device. After 64 * the associated cqe is returned, request's tag can be retrieved via 65 * cqe->userdata. 66 * 67 * COMMIT_AND_FETCH_REQ: issued via sqe(URING_CMD) after ublkserver handled 68 * this IO request, request's handling result is committed to ublk 69 * driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be 70 * handled before completing io request. 71 * 72 * NEED_GET_DATA: only used for write requests to set io addr and copy data 73 * When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA 74 * command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA. 75 * 76 * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag 77 * while starting a ublk device. 78 */ 79 80 /* 81 * Legacy IO command definition, don't use in new application, and don't 82 * add new such definition any more 83 */ 84 #define UBLK_IO_FETCH_REQ 0x20 85 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21 86 #define UBLK_IO_NEED_GET_DATA 0x22 87 88 /* Any new IO command should encode by __IOWR() */ 89 #define UBLK_U_IO_FETCH_REQ \ 90 _IOWR('u', UBLK_IO_FETCH_REQ, struct ublksrv_io_cmd) 91 #define UBLK_U_IO_COMMIT_AND_FETCH_REQ \ 92 _IOWR('u', UBLK_IO_COMMIT_AND_FETCH_REQ, struct ublksrv_io_cmd) 93 #define UBLK_U_IO_NEED_GET_DATA \ 94 _IOWR('u', UBLK_IO_NEED_GET_DATA, struct ublksrv_io_cmd) 95 96 /* only ABORT means that no re-fetch */ 97 #define UBLK_IO_RES_OK 0 98 #define UBLK_IO_RES_NEED_GET_DATA 1 99 #define UBLK_IO_RES_ABORT (-ENODEV) 100 101 #define UBLKSRV_CMD_BUF_OFFSET 0 102 #define UBLKSRV_IO_BUF_OFFSET 0x80000000 103 104 /* tag bit is 16bit, so far limit at most 4096 IOs for each queue */ 105 #define UBLK_MAX_QUEUE_DEPTH 4096 106 107 /* single IO buffer max size is 32MB */ 108 #define UBLK_IO_BUF_OFF 0 109 #define UBLK_IO_BUF_BITS 25 110 #define UBLK_IO_BUF_BITS_MASK ((1ULL << UBLK_IO_BUF_BITS) - 1) 111 112 /* so at most 64K IOs for each queue */ 113 #define UBLK_TAG_OFF UBLK_IO_BUF_BITS 114 #define UBLK_TAG_BITS 16 115 #define UBLK_TAG_BITS_MASK ((1ULL << UBLK_TAG_BITS) - 1) 116 117 /* max 4096 queues */ 118 #define UBLK_QID_OFF (UBLK_TAG_OFF + UBLK_TAG_BITS) 119 #define UBLK_QID_BITS 12 120 #define UBLK_QID_BITS_MASK ((1ULL << UBLK_QID_BITS) - 1) 121 122 #define UBLK_MAX_NR_QUEUES (1U << UBLK_QID_BITS) 123 124 #define UBLKSRV_IO_BUF_TOTAL_BITS (UBLK_QID_OFF + UBLK_QID_BITS) 125 #define UBLKSRV_IO_BUF_TOTAL_SIZE (1ULL << UBLKSRV_IO_BUF_TOTAL_BITS) 126 127 /* 128 * zero copy requires 4k block size, and can remap ublk driver's io 129 * request into ublksrv's vm space 130 */ 131 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0) 132 133 /* 134 * Force to complete io cmd via io_uring_cmd_complete_in_task so that 135 * performance comparison is done easily with using task_work_add 136 */ 137 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1) 138 139 /* 140 * User should issue io cmd again for write requests to 141 * set io buffer address and copy data from bio vectors 142 * to the userspace io buffer. 143 * 144 * In this mode, task_work is not used. 145 */ 146 #define UBLK_F_NEED_GET_DATA (1UL << 2) 147 148 #define UBLK_F_USER_RECOVERY (1UL << 3) 149 150 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4) 151 152 /* 153 * Unprivileged user can create /dev/ublkcN and /dev/ublkbN. 154 * 155 * /dev/ublk-control needs to be available for unprivileged user, and it 156 * can be done via udev rule to make all control commands available to 157 * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all 158 * other commands are only allowed for the owner of the specified device. 159 * 160 * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and 161 * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only 162 * the current user's uid/gid is stored, that said owner of the created 163 * device is always the current user. 164 * 165 * We still need udev rule to apply OWNER/GROUP with the stored owner_uid 166 * and owner_gid. 167 * 168 * Then ublk server can be run as unprivileged user, and /dev/ublkbN can 169 * be accessed and managed by its owner represented by owner_uid/owner_gid. 170 */ 171 #define UBLK_F_UNPRIVILEGED_DEV (1UL << 5) 172 173 /* use ioctl encoding for uring command */ 174 #define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6) 175 176 /* 177 * Copy between request and user buffer by pread()/pwrite() 178 * 179 * Not available for UBLK_F_UNPRIVILEGED_DEV, otherwise userspace may 180 * deceive us by not filling request buffer, then kernel uninitialized 181 * data may be leaked. 182 */ 183 #define UBLK_F_USER_COPY (1UL << 7) 184 185 /* 186 * User space sets this flag when setting up the device to request zoned storage support. Kernel may 187 * deny the request by returning an error. 188 */ 189 #define UBLK_F_ZONED (1ULL << 8) 190 191 /* device state */ 192 #define UBLK_S_DEV_DEAD 0 193 #define UBLK_S_DEV_LIVE 1 194 #define UBLK_S_DEV_QUIESCED 2 195 196 /* shipped via sqe->cmd of io_uring command */ 197 struct ublksrv_ctrl_cmd { 198 /* sent to which device, must be valid */ 199 __u32 dev_id; 200 201 /* sent to which queue, must be -1 if the cmd isn't for queue */ 202 __u16 queue_id; 203 /* 204 * cmd specific buffer, can be IN or OUT. 205 */ 206 __u16 len; 207 __u64 addr; 208 209 /* __inline__ data */ 210 __u64 data[1]; 211 212 /* 213 * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2 214 * only, include null char 215 */ 216 __u16 dev_path_len; 217 __u16 pad; 218 __u32 reserved; 219 }; 220 221 struct ublksrv_ctrl_dev_info { 222 __u16 nr_hw_queues; 223 __u16 queue_depth; 224 __u16 state; 225 __u16 pad0; 226 227 __u32 max_io_buf_bytes; 228 __u32 dev_id; 229 230 __s32 ublksrv_pid; 231 __u32 pad1; 232 233 __u64 flags; 234 235 /* For ublksrv internal use, invisible to ublk driver */ 236 __u64 ublksrv_flags; 237 238 __u32 owner_uid; /* store by kernel */ 239 __u32 owner_gid; /* store by kernel */ 240 __u64 reserved1; 241 __u64 reserved2; 242 }; 243 244 #define UBLK_IO_OP_READ 0 245 #define UBLK_IO_OP_WRITE 1 246 #define UBLK_IO_OP_FLUSH 2 247 #define UBLK_IO_OP_DISCARD 3 248 #define UBLK_IO_OP_WRITE_SAME 4 249 #define UBLK_IO_OP_WRITE_ZEROES 5 250 #define UBLK_IO_OP_ZONE_OPEN 10 251 #define UBLK_IO_OP_ZONE_CLOSE 11 252 #define UBLK_IO_OP_ZONE_FINISH 12 253 #define UBLK_IO_OP_ZONE_APPEND 13 254 #define UBLK_IO_OP_ZONE_RESET_ALL 14 255 #define UBLK_IO_OP_ZONE_RESET 15 256 /* 257 * Construct a zone report. The report request is carried in `struct 258 * ublksrv_io_desc`. The `start_sector` field must be the first sector of a zone 259 * and shall indicate the first zone of the report. The `nr_zones` shall 260 * indicate how many zones should be reported at most. The report shall be 261 * delivered as a `struct blk_zone` array. To report fewer zones than requested, 262 * zero the last entry of the returned array. 263 * 264 * Related definitions(blk_zone, blk_zone_cond, blk_zone_type, ...) in 265 * include/uapi/linux/blkzoned.h are part of ublk UAPI. 266 */ 267 #define UBLK_IO_OP_REPORT_ZONES 18 268 269 #define UBLK_IO_F_FAILFAST_DEV (1U << 8) 270 #define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9) 271 #define UBLK_IO_F_FAILFAST_DRIVER (1U << 10) 272 #define UBLK_IO_F_META (1U << 11) 273 #define UBLK_IO_F_FUA (1U << 13) 274 #define UBLK_IO_F_NOUNMAP (1U << 15) 275 #define UBLK_IO_F_SWAP (1U << 16) 276 277 /* 278 * io cmd is described by this structure, and stored in share memory, indexed 279 * by request tag. 280 * 281 * The data is stored by ublk driver, and read by ublksrv after one fetch command 282 * returns. 283 */ 284 struct ublksrv_io_desc { 285 /* op: bit 0-7, flags: bit 8-31 */ 286 __u32 op_flags; 287 288 union { 289 __u32 nr_sectors; 290 __u32 nr_zones; /* for UBLK_IO_OP_REPORT_ZONES */ 291 }; 292 293 /* start sector for this io */ 294 __u64 start_sector; 295 296 /* buffer address in ublksrv daemon vm space, from ublk driver */ 297 __u64 addr; 298 }; 299 300 static __inline__ __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod) 301 { 302 return iod->op_flags & 0xff; 303 } 304 305 static __inline__ __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod) 306 { 307 return iod->op_flags >> 8; 308 } 309 310 /* issued to ublk driver via /dev/ublkcN */ 311 struct ublksrv_io_cmd { 312 __u16 q_id; 313 314 /* for fetch/commit which result */ 315 __u16 tag; 316 317 /* io result, it is valid for COMMIT* command only */ 318 __s32 result; 319 320 union { 321 /* 322 * userspace buffer address in ublksrv daemon process, valid for 323 * FETCH* command only 324 * 325 * `addr` should not be used when UBLK_F_USER_COPY is enabled, 326 * because userspace handles data copy by pread()/pwrite() over 327 * /dev/ublkcN. But in case of UBLK_F_ZONED, this union is 328 * re-used to pass back the allocated LBA for 329 * UBLK_IO_OP_ZONE_APPEND which actually depends on 330 * UBLK_F_USER_COPY 331 */ 332 __u64 addr; 333 __u64 zone_append_lba; 334 }; 335 }; 336 337 struct ublk_param_basic { 338 #define UBLK_ATTR_READ_ONLY (1 << 0) 339 #define UBLK_ATTR_ROTATIONAL (1 << 1) 340 #define UBLK_ATTR_VOLATILE_CACHE (1 << 2) 341 #define UBLK_ATTR_FUA (1 << 3) 342 __u32 attrs; 343 __u8 logical_bs_shift; 344 __u8 physical_bs_shift; 345 __u8 io_opt_shift; 346 __u8 io_min_shift; 347 348 __u32 max_sectors; 349 __u32 chunk_sectors; 350 351 __u64 dev_sectors; 352 __u64 virt_boundary_mask; 353 }; 354 355 struct ublk_param_discard { 356 __u32 discard_alignment; 357 358 __u32 discard_granularity; 359 __u32 max_discard_sectors; 360 361 __u32 max_write_zeroes_sectors; 362 __u16 max_discard_segments; 363 __u16 reserved0; 364 }; 365 366 /* 367 * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available 368 * after device is started 369 */ 370 struct ublk_param_devt { 371 __u32 char_major; 372 __u32 char_minor; 373 __u32 disk_major; 374 __u32 disk_minor; 375 }; 376 377 struct ublk_param_zoned { 378 __u32 max_open_zones; 379 __u32 max_active_zones; 380 __u32 max_zone_append_sectors; 381 __u8 reserved[20]; 382 }; 383 384 struct ublk_params { 385 /* 386 * Total length of parameters, userspace has to set 'len' for both 387 * SET_PARAMS and GET_PARAMS command, and driver may update len 388 * if two sides use different version of 'ublk_params', same with 389 * 'types' fields. 390 */ 391 __u32 len; 392 #define UBLK_PARAM_TYPE_BASIC (1 << 0) 393 #define UBLK_PARAM_TYPE_DISCARD (1 << 1) 394 #define UBLK_PARAM_TYPE_DEVT (1 << 2) 395 #define UBLK_PARAM_TYPE_ZONED (1 << 3) 396 __u32 types; /* types of parameter included */ 397 398 struct ublk_param_basic basic; 399 struct ublk_param_discard discard; 400 struct ublk_param_devt devt; 401 struct ublk_param_zoned zoned; 402 }; 403 404 #endif
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