design.txt revision 1.2.4.2
1 1.2.4.2 skrll Device-mapper to libdevmapper protocol 2 1.2.4.2 skrll 3 1.2.4.2 skrll 4 1.2.4.2 skrll 5 1.2.4.2 skrll 1) Device mapper device in a POV of LVM it is an Logical Volume. 6 1.2.4.2 skrll Logical Volume is virtual block device is made from logical blocks. 7 1.2.4.2 skrll These blocks are mapped to real device blocks with algorithm called 8 1.2.4.2 skrll target. 9 1.2.4.2 skrll 10 1.2.4.2 skrll Functions available to dm device: 11 1.2.4.2 skrll create, remove, list, status of device. 12 1.2.4.2 skrll 13 1.2.4.2 skrll 2) device mapper target is function which defines how are Logical blocks 14 1.2.4.2 skrll mapped to physical. There are many targets linear, stripe, mirror etc. 15 1.2.4.2 skrll 16 1.2.4.2 skrll Functions available to dm device: 17 1.2.4.2 skrll list available targets. They can be added with module in linux. 18 1.2.4.2 skrll 19 1.2.4.2 skrll 3) dm table. 20 1.2.4.2 skrll Every device-mapper device consits from one or more tables. Table specify 21 1.2.4.2 skrll Start, length of logical blocks and target which is used to map them to 22 1.2.4.2 skrll physical blocks. 23 1.2.4.2 skrll 24 1.2.4.2 skrll {start} {length} {target} | {device} {target parameters} 25 1.2.4.2 skrll 26 1.2.4.2 skrll after | are target specific parameters listed. 27 1.2.4.2 skrll 28 1.2.4.2 skrll Functions available to dm device: 29 1.2.4.2 skrll load, unload, table_status. 30 1.2.4.2 skrll 31 1.2.4.2 skrll 32 1.2.4.2 skrll List of available ioct calls 33 1.2.4.2 skrll 34 1.2.4.2 skrll DM_VERSION 35 1.2.4.2 skrll DM_REMOVE_ALL 36 1.2.4.2 skrll DM_LIST_DEVICES 37 1.2.4.2 skrll DM_DEV_CREATE 38 1.2.4.2 skrll DM_DEV_REMOVE 39 1.2.4.2 skrll DM_DEV_RENAME 40 1.2.4.2 skrll DM_DEV_SUSPEND 41 1.2.4.2 skrll DM_DEV_STATUS 42 1.2.4.2 skrll DM_DEV_WAIT 43 1.2.4.2 skrll DM_TABLE_LOAD 44 1.2.4.2 skrll DM_TABLE_CLEAR 45 1.2.4.2 skrll DM_TABLE_DEPS 46 1.2.4.2 skrll DM_TABLE_STATUS 47 1.2.4.2 skrll DM_LIST_VERSIONS 48 1.2.4.2 skrll DM_TARGET_MSG 49 1.2.4.2 skrll DM_DEV_SET_GEOMETRY 50 1.2.4.2 skrll 51 1.2.4.2 skrll 1) DM_VERSION 52 1.2.4.2 skrll 53 1.2.4.2 skrll in: struct dm-ioctl 54 1.2.4.2 skrll 55 1.2.4.2 skrll out: struct dm-ioctl 56 1.2.4.2 skrll 57 1.2.4.2 skrll Fuction: 58 1.2.4.2 skrll sends libdevmapper ioctl protocol version to kernel and ask for kernel version. 59 1.2.4.2 skrll If major and minor numbers are good we can continue. 60 1.2.4.2 skrll 61 1.2.4.2 skrll 2) DM_REMOVE_ALL 62 1.2.4.2 skrll 63 1.2.4.2 skrll in: none 64 1.2.4.2 skrll 65 1.2.4.2 skrll out: none 66 1.2.4.2 skrll 67 1.2.4.2 skrll Function: 68 1.2.4.2 skrll This ioctl will remove all DM devices/tables from DM driver. 69 1.2.4.2 skrll 70 1.2.4.2 skrll 3) DM_LIST_DEVICES 71 1.2.4.2 skrll 72 1.2.4.2 skrll in: none 73 1.2.4.2 skrll 74 1.2.4.2 skrll out: List of structures describing all devices created in driver. 75 1.2.4.2 skrll 76 1.2.4.2 skrll Function: 77 1.2.4.2 skrll List all devices created in driver. (linux use struct dm_name_list) 78 1.2.4.2 skrll 79 1.2.4.2 skrll Implementation: 80 1.2.4.2 skrll Kernel driver will place list of struct dm_name_list behind 81 1.2.4.2 skrll struct dm_ioctl in userspace. Kernel driver will list through 82 1.2.4.2 skrll the all devices and copyout info about them. 83 1.2.4.2 skrll 84 1.2.4.2 skrll 4) DM_DEV_CREATE 85 1.2.4.2 skrll 86 1.2.4.2 skrll in: struct dm-ioctl(name/uuid) 87 1.2.4.2 skrll 88 1.2.4.2 skrll out: none 89 1.2.4.2 skrll 90 1.2.4.2 skrll Function: 91 1.2.4.2 skrll Create device in dm driver, with specified name/uuid(uuid is prefered). 92 1.2.4.2 skrll (linux use struct dm_name_list) 93 1.2.4.2 skrll 94 1.2.4.2 skrll 5) DM_DEV_REMOVE 95 1.2.4.2 skrll 96 1.2.4.2 skrll in: struct dm-ioctl(name/uuid) 97 1.2.4.2 skrll 98 1.2.4.2 skrll out: none 99 1.2.4.2 skrll 100 1.2.4.2 skrll Function: 101 1.2.4.2 skrll Remove device from dm driver list, also remove device tables. 102 1.2.4.2 skrll 103 1.2.4.2 skrll 6) DM_DEV_RENAME 104 1.2.4.2 skrll 105 1.2.4.2 skrll in: struct dm-ioctl(name/uuid) and string found after dm-ioctl struct in buffer 106 1.2.4.2 skrll 107 1.2.4.2 skrll out: none 108 1.2.4.2 skrll 109 1.2.4.2 skrll Function: 110 1.2.4.2 skrll Rename device from name to string. 111 1.2.4.2 skrll 112 1.2.4.2 skrll Implementation: 113 1.2.4.2 skrll Kernel driver will find device with name from struct dm_ioctl-name/uuid. 114 1.2.4.2 skrll Change name of selected device to string foun behind struc dm_ioctl header 115 1.2.4.2 skrll in userspace buffer. 116 1.2.4.2 skrll 117 1.2.4.2 skrll 7) DM_DEV_SUSPEND 118 1.2.4.2 skrll 119 1.2.4.2 skrll in: dm-ioctl(name/uuid) 120 1.2.4.2 skrll 121 1.2.4.2 skrll out: none 122 1.2.4.2 skrll 123 1.2.4.2 skrll Function: 124 1.2.4.2 skrll Suspend all io's on device, after this ioctl. Already started io's will be done. 125 1.2.4.2 skrll Newer can't be started. 126 1.2.4.2 skrll 127 1.2.4.2 skrll 8) DM_DEV_STATUS 128 1.2.4.2 skrll 129 1.2.4.2 skrll in: dm-ioctl(name/uuid) 130 1.2.4.2 skrll 131 1.2.4.2 skrll out: dm-ioctl (minor,open_count,target_count) 132 1.2.4.2 skrll 133 1.2.4.2 skrll Function: 134 1.2.4.2 skrll Return status info about selected device 135 1.2.4.2 skrll 136 1.2.4.2 skrll Implementation: 137 1.2.4.2 skrll Kernel driver will find device with name from struct dm_ioctl-name/uuid. 138 1.2.4.2 skrll Change values minor,open_count,target_count in dm_ioctl struct for 139 1.2.4.2 skrll selected device. 140 1.2.4.2 skrll 141 1.2.4.2 skrll 9) DM_DEV_WAIT 142 1.2.4.2 skrll 143 1.2.4.2 skrll in: dm-ioctl(name/uuid) 144 1.2.4.2 skrll 145 1.2.4.2 skrll out: none 146 1.2.4.2 skrll 147 1.2.4.2 skrll Function: 148 1.2.4.2 skrll Wait for device event to happen. 149 1.2.4.2 skrll 150 1.2.4.2 skrll 10) DM_TABLE_LOAD 151 1.2.4.2 skrll 152 1.2.4.2 skrll in: dm-ioctl(name/uuid),table specification 153 1.2.4.2 skrll 154 1.2.4.2 skrll out: none 155 1.2.4.2 skrll 156 1.2.4.2 skrll Function: 157 1.2.4.2 skrll Load table to selected device. Table is loaded to unused slot and than switched. 158 1.2.4.2 skrll (linux use struct dm_target_spec) 159 1.2.4.2 skrll 160 1.2.4.2 skrll Implementation: 161 1.2.4.2 skrll Kernel driver will find device with name from struct dm_ioctl-name/uuid. 162 1.2.4.2 skrll Table is added to the inactive slot. Every device can have more than one 163 1.2.4.2 skrll table loaded. Tables are stored in SLIST. This ioctl also open physical 164 1.2.4.2 skrll device spedcified in table and add it to dm_device specific pdev list. 165 1.2.4.2 skrll 166 1.2.4.2 skrll 11) DM_TABLE_CLEAR 167 1.2.4.2 skrll 168 1.2.4.2 skrll in: dm-ioctl(name/uuid) 169 1.2.4.2 skrll 170 1.2.4.2 skrll out: none 171 1.2.4.2 skrll 172 1.2.4.2 skrll Function: 173 1.2.4.2 skrll Remove table from unused slot. 174 1.2.4.2 skrll 175 1.2.4.2 skrll 12) DM_TABLE_DEPS 176 1.2.4.2 skrll 177 1.2.4.2 skrll in: dm-ioctl(name/uuid) 178 1.2.4.2 skrll 179 1.2.4.2 skrll out: list of dependiences devices 180 1.2.4.2 skrll 181 1.2.4.2 skrll Function: 182 1.2.4.2 skrll Return set of device dependiences e.g. mirror device for mirror target etc.. 183 1.2.4.2 skrll 184 1.2.4.2 skrll 13) DM_TABLE_STATUS 185 1.2.4.2 skrll 186 1.2.4.2 skrll in: dm-ioctl(name/uuid) 187 1.2.4.2 skrll 188 1.2.4.2 skrll out: list of used tables from selected devices (linux use struct dm_target_spec) 189 1.2.4.2 skrll 190 1.2.4.2 skrll Function: 191 1.2.4.2 skrll List all tables in active slot in device with name name/uuid. 192 1.2.4.2 skrll 193 1.2.4.2 skrll Implementation: 194 1.2.4.2 skrll Kernel driver will find device with name from struct dm_ioctl-name/uuid. 195 1.2.4.2 skrll DM driver will copyout dm_target_spec structures behidn struct dm_ioctl. 196 1.2.4.2 skrll 197 1.2.4.2 skrll 14) DM_LIST_VERSIONS 198 1.2.4.2 skrll 199 1.2.4.2 skrll in: none 200 1.2.4.2 skrll 201 1.2.4.2 skrll out: list of all targets in device-mapper driver (linux use struct dm_target_versions) 202 1.2.4.2 skrll 203 1.2.4.2 skrll Function: 204 1.2.4.2 skrll List all available targets to libdevmapper. 205 1.2.4.2 skrll 206 1.2.4.2 skrll Implementation: 207 1.2.4.2 skrll Kernel driver will copy out known target versions. 208 1.2.4.2 skrll 209 1.2.4.2 skrll 15) DM_TARGET_MSG 210 1.2.4.2 skrll 211 1.2.4.2 skrll in: message to driver (linux use struct dm_target_msg) 212 1.2.4.2 skrll 213 1.2.4.2 skrll out: none 214 1.2.4.2 skrll 215 1.2.4.2 skrll Function: 216 1.2.4.2 skrll Send message to kernel driver target. 217 1.2.4.2 skrll 218 1.2.4.2 skrll 219 1.2.4.2 skrll 16) DM_DEV_SET_GEOMETRY 220 1.2.4.2 skrll 221 1.2.4.2 skrll Function: 222 1.2.4.2 skrll Set geometry of device-mapper driver. 223 1.2.4.2 skrll 224 1.2.4.2 skrll 225 1.2.4.2 skrll NetBSD device-mapper driver implementation 226 1.2.4.2 skrll 227 1.2.4.2 skrll device-mapper devices -> devs dm_dev.c 228 1.2.4.2 skrll 229 1.2.4.2 skrll This entity is created with DM_DEV_CREATE ioctl, and stores info 230 1.2.4.2 skrll about every device in device mapper driver. It has two slots for 231 1.2.4.2 skrll active and inactive table, list of active physical devices added 232 1.2.4.2 skrll to this device and list of upcalled devices (for targets which use 233 1.2.4.2 skrll more than one physical device e.g. mirror, snapshot etc..). 234 1.2.4.2 skrll 235 1.2.4.2 skrll device-mapper physical devices -> pdevs dm_pdev.c 236 1.2.4.2 skrll 237 1.2.4.2 skrll This structure contains opened device VNODES. Because I physical 238 1.2.4.2 skrll device can be found in more than one table loaded to different 239 1.2.4.2 skrll dm devices. When device is destroyed I decrement all reference 240 1.2.4.2 skrll counters for all added pdevs (I remove pdevs with ref_cnt == 0). 241 1.2.4.2 skrll 242 1.2.4.2 skrll device-mapper tables -> table dm_table.c, dm_ioctl.c 243 1.2.4.2 skrll 244 1.2.4.2 skrll Table describe how is dm device made. What blocks are mapped with 245 1.2.4.2 skrll what target. In our implementation every table contains pointer to 246 1.2.4.2 skrll target specific config data. These config_data are allocated in 247 1.2.4.2 skrll DM_TABLE_LOAD function with target_init routine. Every table 248 1.2.4.2 skrll contains pointer to used target. 249 1.2.4.2 skrll 250 1.2.4.2 skrll device-mapper targets -> target dm_target.c 251 1.2.4.2 skrll 252 1.2.4.2 skrll Target describes mapping of logical blocks to physical. It has 253 1.2.4.2 skrll function pointers to function which does init, strategy, destroy, 254 1.2.4.2 skrll upcall functions. 255 1.2.4.2 skrll 256 1.2.4.2 skrll P.S I want to thank reinod@ for great help and guidance :). 257 1.2.4.2 skrll 258 1.2.4.2 skrll 259 1.2.4.2 skrll 260 1.2.4.2 skrll Desing of new device-mapper ioctl interface 261 1.2.4.2 skrll 262 1.2.4.2 skrll Basic architecture of device-mapper -> libdevmapper ioctl interface is this. 263 1.2.4.2 skrll Libdevmapper allocate buffer with size of data_size. At the start of this buffer 264 1.2.4.2 skrll dm-ioctl structure is placed. any aditional information from/to kernel are placed 265 1.2.4.2 skrll behind end (start of data part is pointed with data_start var.) of dm-ioctl struct. 266 1.2.4.2 skrll 267 1.2.4.2 skrll Kernel driver then after ioctl call have to copyin data from userspace to kernel. 268 1.2.4.2 skrll When kernel driver want to send data back to user space library it must copyout 269 1.2.4.2 skrll data from kernel. 270 1.2.4.2 skrll 271 1.2.4.2 skrll 1) In Linux device-mapper ioctl interface implementation there are these ioctls. 272 1.2.4.2 skrll 273 1.2.4.2 skrll DM_VERSION * 274 1.2.4.2 skrll DM_REMOVE_ALL 275 1.2.4.2 skrll DM_LIST_DEVICES * 276 1.2.4.2 skrll DM_DEV_CREATE * 277 1.2.4.2 skrll DM_DEV_REMOVE * 278 1.2.4.2 skrll DM_DEV_RENAME * 279 1.2.4.2 skrll DM_DEV_SUSPEND 280 1.2.4.2 skrll DM_DEV_STATUS * 281 1.2.4.2 skrll DM_DEV_WAIT 282 1.2.4.2 skrll DM_TABLE_LOAD * 283 1.2.4.2 skrll DM_TABLE_CLEAR * 284 1.2.4.2 skrll DM_TABLE_DEPS 285 1.2.4.2 skrll DM_TABLE_STATUS * 286 1.2.4.2 skrll DM_LIST_VERSIONS * 287 1.2.4.2 skrll DM_TARGET_MSG 288 1.2.4.2 skrll DM_DEV_SET_GEOMETRY 289 1.2.4.2 skrll 290 1.2.4.2 skrll * means implemented in current version of NetBSD device-mapper. 291 1.2.4.2 skrll 292 1.2.4.2 skrll 1a) struct dm_ioctl based ioctl calls 293 1.2.4.2 skrll These ioctl calls communicate only with basic dm_ioctl structure. 294 1.2.4.2 skrll 295 1.2.4.2 skrll DM_VERSION 296 1.2.4.2 skrll DM_DEV_STATUS 297 1.2.4.2 skrll DM_DEV_CREATE 298 1.2.4.2 skrll 299 1.2.4.2 skrll Protocol structure: 300 1.2.4.2 skrll 301 1.2.4.2 skrll struct dm_ioctl { 302 1.2.4.2 skrll uint32_t version[3]; /* device-mapper kernel/userspace version */ 303 1.2.4.2 skrll uint32_t data_size; /* total size of data passed in 304 1.2.4.2 skrll * including this struct */ 305 1.2.4.2 skrll 306 1.2.4.2 skrll uint32_t data_start; /* offset to start of data 307 1.2.4.2 skrll * relative to start of this struct */ 308 1.2.4.2 skrll 309 1.2.4.2 skrll uint32_t target_count; /* in/out */ /* This should be set when DM_TABLE_STATUS is called */ 310 1.2.4.2 skrll int32_t open_count; /* device open count */ 311 1.2.4.2 skrll uint32_t flags; /* information flags */ 312 1.2.4.2 skrll uint32_t event_nr; /* event counters not implemented */ 313 1.2.4.2 skrll uint32_t padding; 314 1.2.4.2 skrll 315 1.2.4.2 skrll uint64_t dev; /* dev_t */ 316 1.2.4.2 skrll 317 1.2.4.2 skrll char name[DM_NAME_LEN]; /* device name */ 318 1.2.4.2 skrll char uuid[DM_UUID_LEN]; /* unique identifier for 319 1.2.4.2 skrll * the block device */ 320 1.2.4.2 skrll 321 1.2.4.2 skrll void *user_space_addr; /*this is needed for netbsd 322 1.2.4.2 skrll because they differently 323 1.2.4.2 skrll implement ioctl syscall*/ 324 1.2.4.2 skrll }; 325 1.2.4.2 skrll 326 1.2.4.2 skrll As SOC task I want to replace this structure with proplib dict. Proplib dict 327 1.2.4.2 skrll basic structure should be: 328 1.2.4.2 skrll 329 1.2.4.2 skrll Note: I don't need data_star, data_size and use_space_addr. They are needed 330 1.2.4.2 skrll for current implementation. 331 1.2.4.2 skrll 332 1.2.4.2 skrll <dict> 333 1.2.4.2 skrll <key>version</key> 334 1.2.4.2 skrll <string>...</string> 335 1.2.4.2 skrll 336 1.2.4.2 skrll <key>target_count</key> 337 1.2.4.2 skrll <integer></integer> 338 1.2.4.2 skrll 339 1.2.4.2 skrll <key>open_count</key> 340 1.2.4.2 skrll <integer></integer> 341 1.2.4.2 skrll 342 1.2.4.2 skrll <key>flags</key> 343 1.2.4.2 skrll <integer></integer> 344 1.2.4.2 skrll 345 1.2.4.2 skrll <key>event_nr</key> 346 1.2.4.2 skrll <integer></integer> 347 1.2.4.2 skrll 348 1.2.4.2 skrll <key>dev</key> 349 1.2.4.2 skrll <integer></integer> 350 1.2.4.2 skrll 351 1.2.4.2 skrll <key>name</key> 352 1.2.4.2 skrll <string>...</string> 353 1.2.4.2 skrll 354 1.2.4.2 skrll <key>uuid</key> 355 1.2.4.2 skrll <string>...</string> 356 1.2.4.2 skrll 357 1.2.4.2 skrll 358 1.2.4.2 skrll <dict> 359 1.2.4.2 skrll <!-- ioctl specific data --> 360 1.2.4.2 skrll </dict> 361 1.2.4.2 skrll </dict> 362 1.2.4.2 skrll 363 1.2.4.2 skrll 1b) DM_LIST_VERSIONS ioctl 364 1.2.4.2 skrll 365 1.2.4.2 skrll This ioctl is used to get list of supported targets from kernel. Target 366 1.2.4.2 skrll define mapping of Logical blocks to physical blocks on real device. 367 1.2.4.2 skrll There are linear, zero, error, mirror, snapshot, multipath etc... targets. 368 1.2.4.2 skrll 369 1.2.4.2 skrll For every target kernel driver should copyout this structure to userspace. 370 1.2.4.2 skrll 371 1.2.4.2 skrll Protocol structure: 372 1.2.4.2 skrll 373 1.2.4.2 skrll struct dm_target_versions { 374 1.2.4.2 skrll uint32_t next; 375 1.2.4.2 skrll uint32_t version[3]; 376 1.2.4.2 skrll 377 1.2.4.2 skrll char name[0]; 378 1.2.4.2 skrll }; 379 1.2.4.2 skrll 380 1.2.4.2 skrll Because I need more then on dm_target_version I will need one major proplib 381 1.2.4.2 skrll dictionary to store children dictionaries with target data. 382 1.2.4.2 skrll 383 1.2.4.2 skrll <dict> 384 1.2.4.2 skrll <dict ID="id"> 385 1.2.4.2 skrll <key>version</key> 386 1.2.4.2 skrll <string>...</string> 387 1.2.4.2 skrll 388 1.2.4.2 skrll <key>name</key> 389 1.2.4.2 skrll <string>...</string> 390 1.2.4.2 skrll </dict> 391 1.2.4.2 skrll </dict> 392 1.2.4.2 skrll 393 1.2.4.2 skrll 2a) DM_LIST_DEVICES 394 1.2.4.2 skrll 395 1.2.4.2 skrll This ioctl is used to list all devices defined in kernel driver. 396 1.2.4.2 skrll 397 1.2.4.2 skrll Protocol structure: 398 1.2.4.2 skrll 399 1.2.4.2 skrll struct dm_name_list { 400 1.2.4.2 skrll uint64_t dev; 401 1.2.4.2 skrll uint32_t next; /* offset to the next record from 402 1.2.4.2 skrll the _start_ of this */ 403 1.2.4.2 skrll char name[0]; 404 1.2.4.2 skrll }; 405 1.2.4.2 skrll 406 1.2.4.2 skrll Again because I can have more than one device in kernel driver I need one parent 407 1.2.4.2 skrll dictionary and more children dictionaries. 408 1.2.4.2 skrll 409 1.2.4.2 skrll <dict> 410 1.2.4.2 skrll <dict ID="id"> 411 1.2.4.2 skrll <key>dev</key> 412 1.2.4.2 skrll <integer>...</integer> 413 1.2.4.2 skrll 414 1.2.4.2 skrll <key>name</key> 415 1.2.4.2 skrll <string>...</string> 416 1.2.4.2 skrll </dict> 417 1.2.4.2 skrll </dict> 418 1.2.4.2 skrll 419 1.2.4.2 skrll 2b) DM_DEV_RENAME 420 1.2.4.2 skrll This ioctl is called when libdevmapper want to rename device-mapper device. 421 1.2.4.2 skrll Libdevmapper library appends null terminated string to dm_ioctl struct in 422 1.2.4.2 skrll userspace.. 423 1.2.4.2 skrll 424 1.2.4.2 skrll <dict> 425 1.2.4.2 skrll <key>name</key> 426 1.2.4.2 skrll <string>...</string> 427 1.2.4.2 skrll </dict> 428 1.2.4.2 skrll 429 1.2.4.2 skrll 2c) DM_DEV_CREATE, DM_DEV_REMOVE, DM_DEV_STATUS 430 1.2.4.2 skrll Modify only dm_ioctl structure so I don't need to specify new structures. 431 1.2.4.2 skrll 432 1.2.4.2 skrll 433 1.2.4.2 skrll 3a) DM_TABLE_LOAD, DM_TABLE_STATUS 434 1.2.4.2 skrll DM_TABLE_LOAD ioctl loads table to device. DM_TABLE_STATUS send info about 435 1.2.4.2 skrll every table for selected device to userspace. Table is different for every 436 1.2.4.2 skrll target basic table structure is this 437 1.2.4.2 skrll 438 1.2.4.2 skrll {start} {length} {target} {additional information} 439 1.2.4.2 skrll 440 1.2.4.2 skrll e.g. 441 1.2.4.2 skrll 0 100 zero 442 1.2.4.2 skrll 443 1.2.4.2 skrll 0 100 linear /dev/wdba 384 444 1.2.4.2 skrll 445 1.2.4.2 skrll Protocol structure: 446 1.2.4.2 skrll 447 1.2.4.2 skrll struct dm_target_spec { 448 1.2.4.2 skrll uint64_t sector_start; 449 1.2.4.2 skrll uint64_t length; 450 1.2.4.2 skrll int32_t status; /* used when reading from kernel only */ 451 1.2.4.2 skrll 452 1.2.4.2 skrll uint32_t next; 453 1.2.4.2 skrll 454 1.2.4.2 skrll char target_type[DM_MAX_TYPE_NAME]; 455 1.2.4.2 skrll 456 1.2.4.2 skrll /* 457 1.2.4.2 skrll * Parameter string starts immediately after this object. 458 1.2.4.2 skrll * Be careful to add padding after string to ensure correct 459 1.2.4.2 skrll * alignment of subsequent dm_target_spec. 460 1.2.4.2 skrll */ 461 1.2.4.2 skrll }; 462 1.2.4.2 skrll 463 1.2.4.2 skrll <dict> 464 1.2.4.2 skrll <key>sector_start</key> 465 1.2.4.2 skrll <integer>...</integer> 466 1.2.4.2 skrll 467 1.2.4.2 skrll <key>length</key> 468 1.2.4.2 skrll <integer>...</integer> 469 1.2.4.2 skrll 470 1.2.4.2 skrll <key>target_type</key> 471 1.2.4.2 skrll <string>...</string> 472 1.2.4.2 skrll 473 1.2.4.2 skrll <key>aditional info</key> 474 1.2.4.2 skrll <string>...</string> 475 1.2.4.2 skrll </dict> 476
Indexes created Sun Oct 12 09:09:55 GMT 2025