design.txt revision 1.2.2.2
1 1.2.2.2 mjf Device-mapper to libdevmapper protocol 2 1.2.2.2 mjf 3 1.2.2.2 mjf 4 1.2.2.2 mjf 5 1.2.2.2 mjf 1) Device mapper device in a POV of LVM it is an Logical Volume. 6 1.2.2.2 mjf Logical Volume is virtual block device is made from logical blocks. 7 1.2.2.2 mjf These blocks are mapped to real device blocks with algorithm called 8 1.2.2.2 mjf target. 9 1.2.2.2 mjf 10 1.2.2.2 mjf Functions available to dm device: 11 1.2.2.2 mjf create, remove, list, status of device. 12 1.2.2.2 mjf 13 1.2.2.2 mjf 2) device mapper target is function which defines how are Logical blocks 14 1.2.2.2 mjf mapped to physical. There are many targets linear, stripe, mirror etc. 15 1.2.2.2 mjf 16 1.2.2.2 mjf Functions available to dm device: 17 1.2.2.2 mjf list available targets. They can be added with module in linux. 18 1.2.2.2 mjf 19 1.2.2.2 mjf 3) dm table. 20 1.2.2.2 mjf Every device-mapper device consits from one or more tables. Table specify 21 1.2.2.2 mjf Start, length of logical blocks and target which is used to map them to 22 1.2.2.2 mjf physical blocks. 23 1.2.2.2 mjf 24 1.2.2.2 mjf {start} {length} {target} | {device} {target parameters} 25 1.2.2.2 mjf 26 1.2.2.2 mjf after | are target specific parameters listed. 27 1.2.2.2 mjf 28 1.2.2.2 mjf Functions available to dm device: 29 1.2.2.2 mjf load, unload, table_status. 30 1.2.2.2 mjf 31 1.2.2.2 mjf 32 1.2.2.2 mjf List of available ioct calls 33 1.2.2.2 mjf 34 1.2.2.2 mjf DM_VERSION 35 1.2.2.2 mjf DM_REMOVE_ALL 36 1.2.2.2 mjf DM_LIST_DEVICES 37 1.2.2.2 mjf DM_DEV_CREATE 38 1.2.2.2 mjf DM_DEV_REMOVE 39 1.2.2.2 mjf DM_DEV_RENAME 40 1.2.2.2 mjf DM_DEV_SUSPEND 41 1.2.2.2 mjf DM_DEV_STATUS 42 1.2.2.2 mjf DM_DEV_WAIT 43 1.2.2.2 mjf DM_TABLE_LOAD 44 1.2.2.2 mjf DM_TABLE_CLEAR 45 1.2.2.2 mjf DM_TABLE_DEPS 46 1.2.2.2 mjf DM_TABLE_STATUS 47 1.2.2.2 mjf DM_LIST_VERSIONS 48 1.2.2.2 mjf DM_TARGET_MSG 49 1.2.2.2 mjf DM_DEV_SET_GEOMETRY 50 1.2.2.2 mjf 51 1.2.2.2 mjf 1) DM_VERSION 52 1.2.2.2 mjf 53 1.2.2.2 mjf in: struct dm-ioctl 54 1.2.2.2 mjf 55 1.2.2.2 mjf out: struct dm-ioctl 56 1.2.2.2 mjf 57 1.2.2.2 mjf Fuction: 58 1.2.2.2 mjf sends libdevmapper ioctl protocol version to kernel and ask for kernel version. 59 1.2.2.2 mjf If major and minor numbers are good we can continue. 60 1.2.2.2 mjf 61 1.2.2.2 mjf 2) DM_REMOVE_ALL 62 1.2.2.2 mjf 63 1.2.2.2 mjf in: none 64 1.2.2.2 mjf 65 1.2.2.2 mjf out: none 66 1.2.2.2 mjf 67 1.2.2.2 mjf Function: 68 1.2.2.2 mjf This ioctl will remove all DM devices/tables from DM driver. 69 1.2.2.2 mjf 70 1.2.2.2 mjf 3) DM_LIST_DEVICES 71 1.2.2.2 mjf 72 1.2.2.2 mjf in: none 73 1.2.2.2 mjf 74 1.2.2.2 mjf out: List of structures describing all devices created in driver. 75 1.2.2.2 mjf 76 1.2.2.2 mjf Function: 77 1.2.2.2 mjf List all devices created in driver. (linux use struct dm_name_list) 78 1.2.2.2 mjf 79 1.2.2.2 mjf Implementation: 80 1.2.2.2 mjf Kernel driver will place list of struct dm_name_list behind 81 1.2.2.2 mjf struct dm_ioctl in userspace. Kernel driver will list through 82 1.2.2.2 mjf the all devices and copyout info about them. 83 1.2.2.2 mjf 84 1.2.2.2 mjf 4) DM_DEV_CREATE 85 1.2.2.2 mjf 86 1.2.2.2 mjf in: struct dm-ioctl(name/uuid) 87 1.2.2.2 mjf 88 1.2.2.2 mjf out: none 89 1.2.2.2 mjf 90 1.2.2.2 mjf Function: 91 1.2.2.2 mjf Create device in dm driver, with specified name/uuid(uuid is prefered). 92 1.2.2.2 mjf (linux use struct dm_name_list) 93 1.2.2.2 mjf 94 1.2.2.2 mjf 5) DM_DEV_REMOVE 95 1.2.2.2 mjf 96 1.2.2.2 mjf in: struct dm-ioctl(name/uuid) 97 1.2.2.2 mjf 98 1.2.2.2 mjf out: none 99 1.2.2.2 mjf 100 1.2.2.2 mjf Function: 101 1.2.2.2 mjf Remove device from dm driver list, also remove device tables. 102 1.2.2.2 mjf 103 1.2.2.2 mjf 6) DM_DEV_RENAME 104 1.2.2.2 mjf 105 1.2.2.2 mjf in: struct dm-ioctl(name/uuid) and string found after dm-ioctl struct in buffer 106 1.2.2.2 mjf 107 1.2.2.2 mjf out: none 108 1.2.2.2 mjf 109 1.2.2.2 mjf Function: 110 1.2.2.2 mjf Rename device from name to string. 111 1.2.2.2 mjf 112 1.2.2.2 mjf Implementation: 113 1.2.2.2 mjf Kernel driver will find device with name from struct dm_ioctl-name/uuid. 114 1.2.2.2 mjf Change name of selected device to string foun behind struc dm_ioctl header 115 1.2.2.2 mjf in userspace buffer. 116 1.2.2.2 mjf 117 1.2.2.2 mjf 7) DM_DEV_SUSPEND 118 1.2.2.2 mjf 119 1.2.2.2 mjf in: dm-ioctl(name/uuid) 120 1.2.2.2 mjf 121 1.2.2.2 mjf out: none 122 1.2.2.2 mjf 123 1.2.2.2 mjf Function: 124 1.2.2.2 mjf Suspend all io's on device, after this ioctl. Already started io's will be done. 125 1.2.2.2 mjf Newer can't be started. 126 1.2.2.2 mjf 127 1.2.2.2 mjf 8) DM_DEV_STATUS 128 1.2.2.2 mjf 129 1.2.2.2 mjf in: dm-ioctl(name/uuid) 130 1.2.2.2 mjf 131 1.2.2.2 mjf out: dm-ioctl (minor,open_count,target_count) 132 1.2.2.2 mjf 133 1.2.2.2 mjf Function: 134 1.2.2.2 mjf Return status info about selected device 135 1.2.2.2 mjf 136 1.2.2.2 mjf Implementation: 137 1.2.2.2 mjf Kernel driver will find device with name from struct dm_ioctl-name/uuid. 138 1.2.2.2 mjf Change values minor,open_count,target_count in dm_ioctl struct for 139 1.2.2.2 mjf selected device. 140 1.2.2.2 mjf 141 1.2.2.2 mjf 9) DM_DEV_WAIT 142 1.2.2.2 mjf 143 1.2.2.2 mjf in: dm-ioctl(name/uuid) 144 1.2.2.2 mjf 145 1.2.2.2 mjf out: none 146 1.2.2.2 mjf 147 1.2.2.2 mjf Function: 148 1.2.2.2 mjf Wait for device event to happen. 149 1.2.2.2 mjf 150 1.2.2.2 mjf 10) DM_TABLE_LOAD 151 1.2.2.2 mjf 152 1.2.2.2 mjf in: dm-ioctl(name/uuid),table specification 153 1.2.2.2 mjf 154 1.2.2.2 mjf out: none 155 1.2.2.2 mjf 156 1.2.2.2 mjf Function: 157 1.2.2.2 mjf Load table to selected device. Table is loaded to unused slot and than switched. 158 1.2.2.2 mjf (linux use struct dm_target_spec) 159 1.2.2.2 mjf 160 1.2.2.2 mjf Implementation: 161 1.2.2.2 mjf Kernel driver will find device with name from struct dm_ioctl-name/uuid. 162 1.2.2.2 mjf Table is added to the inactive slot. Every device can have more than one 163 1.2.2.2 mjf table loaded. Tables are stored in SLIST. This ioctl also open physical 164 1.2.2.2 mjf device spedcified in table and add it to dm_device specific pdev list. 165 1.2.2.2 mjf 166 1.2.2.2 mjf 11) DM_TABLE_CLEAR 167 1.2.2.2 mjf 168 1.2.2.2 mjf in: dm-ioctl(name/uuid) 169 1.2.2.2 mjf 170 1.2.2.2 mjf out: none 171 1.2.2.2 mjf 172 1.2.2.2 mjf Function: 173 1.2.2.2 mjf Remove table from unused slot. 174 1.2.2.2 mjf 175 1.2.2.2 mjf 12) DM_TABLE_DEPS 176 1.2.2.2 mjf 177 1.2.2.2 mjf in: dm-ioctl(name/uuid) 178 1.2.2.2 mjf 179 1.2.2.2 mjf out: list of dependiences devices 180 1.2.2.2 mjf 181 1.2.2.2 mjf Function: 182 1.2.2.2 mjf Return set of device dependiences e.g. mirror device for mirror target etc.. 183 1.2.2.2 mjf 184 1.2.2.2 mjf 13) DM_TABLE_STATUS 185 1.2.2.2 mjf 186 1.2.2.2 mjf in: dm-ioctl(name/uuid) 187 1.2.2.2 mjf 188 1.2.2.2 mjf out: list of used tables from selected devices (linux use struct dm_target_spec) 189 1.2.2.2 mjf 190 1.2.2.2 mjf Function: 191 1.2.2.2 mjf List all tables in active slot in device with name name/uuid. 192 1.2.2.2 mjf 193 1.2.2.2 mjf Implementation: 194 1.2.2.2 mjf Kernel driver will find device with name from struct dm_ioctl-name/uuid. 195 1.2.2.2 mjf DM driver will copyout dm_target_spec structures behidn struct dm_ioctl. 196 1.2.2.2 mjf 197 1.2.2.2 mjf 14) DM_LIST_VERSIONS 198 1.2.2.2 mjf 199 1.2.2.2 mjf in: none 200 1.2.2.2 mjf 201 1.2.2.2 mjf out: list of all targets in device-mapper driver (linux use struct dm_target_versions) 202 1.2.2.2 mjf 203 1.2.2.2 mjf Function: 204 1.2.2.2 mjf List all available targets to libdevmapper. 205 1.2.2.2 mjf 206 1.2.2.2 mjf Implementation: 207 1.2.2.2 mjf Kernel driver will copy out known target versions. 208 1.2.2.2 mjf 209 1.2.2.2 mjf 15) DM_TARGET_MSG 210 1.2.2.2 mjf 211 1.2.2.2 mjf in: message to driver (linux use struct dm_target_msg) 212 1.2.2.2 mjf 213 1.2.2.2 mjf out: none 214 1.2.2.2 mjf 215 1.2.2.2 mjf Function: 216 1.2.2.2 mjf Send message to kernel driver target. 217 1.2.2.2 mjf 218 1.2.2.2 mjf 219 1.2.2.2 mjf 16) DM_DEV_SET_GEOMETRY 220 1.2.2.2 mjf 221 1.2.2.2 mjf Function: 222 1.2.2.2 mjf Set geometry of device-mapper driver. 223 1.2.2.2 mjf 224 1.2.2.2 mjf 225 1.2.2.2 mjf NetBSD device-mapper driver implementation 226 1.2.2.2 mjf 227 1.2.2.2 mjf device-mapper devices -> devs dm_dev.c 228 1.2.2.2 mjf 229 1.2.2.2 mjf This entity is created with DM_DEV_CREATE ioctl, and stores info 230 1.2.2.2 mjf about every device in device mapper driver. It has two slots for 231 1.2.2.2 mjf active and inactive table, list of active physical devices added 232 1.2.2.2 mjf to this device and list of upcalled devices (for targets which use 233 1.2.2.2 mjf more than one physical device e.g. mirror, snapshot etc..). 234 1.2.2.2 mjf 235 1.2.2.2 mjf device-mapper physical devices -> pdevs dm_pdev.c 236 1.2.2.2 mjf 237 1.2.2.2 mjf This structure contains opened device VNODES. Because I physical 238 1.2.2.2 mjf device can be found in more than one table loaded to different 239 1.2.2.2 mjf dm devices. When device is destroyed I decrement all reference 240 1.2.2.2 mjf counters for all added pdevs (I remove pdevs with ref_cnt == 0). 241 1.2.2.2 mjf 242 1.2.2.2 mjf device-mapper tables -> table dm_table.c, dm_ioctl.c 243 1.2.2.2 mjf 244 1.2.2.2 mjf Table describe how is dm device made. What blocks are mapped with 245 1.2.2.2 mjf what target. In our implementation every table contains pointer to 246 1.2.2.2 mjf target specific config data. These config_data are allocated in 247 1.2.2.2 mjf DM_TABLE_LOAD function with target_init routine. Every table 248 1.2.2.2 mjf contains pointer to used target. 249 1.2.2.2 mjf 250 1.2.2.2 mjf device-mapper targets -> target dm_target.c 251 1.2.2.2 mjf 252 1.2.2.2 mjf Target describes mapping of logical blocks to physical. It has 253 1.2.2.2 mjf function pointers to function which does init, strategy, destroy, 254 1.2.2.2 mjf upcall functions. 255 1.2.2.2 mjf 256 1.2.2.2 mjf P.S I want to thank reinod@ for great help and guidance :). 257 1.2.2.2 mjf 258 1.2.2.2 mjf 259 1.2.2.2 mjf 260 1.2.2.2 mjf Desing of new device-mapper ioctl interface 261 1.2.2.2 mjf 262 1.2.2.2 mjf Basic architecture of device-mapper -> libdevmapper ioctl interface is this. 263 1.2.2.2 mjf Libdevmapper allocate buffer with size of data_size. At the start of this buffer 264 1.2.2.2 mjf dm-ioctl structure is placed. any aditional information from/to kernel are placed 265 1.2.2.2 mjf behind end (start of data part is pointed with data_start var.) of dm-ioctl struct. 266 1.2.2.2 mjf 267 1.2.2.2 mjf Kernel driver then after ioctl call have to copyin data from userspace to kernel. 268 1.2.2.2 mjf When kernel driver want to send data back to user space library it must copyout 269 1.2.2.2 mjf data from kernel. 270 1.2.2.2 mjf 271 1.2.2.2 mjf 1) In Linux device-mapper ioctl interface implementation there are these ioctls. 272 1.2.2.2 mjf 273 1.2.2.2 mjf DM_VERSION * 274 1.2.2.2 mjf DM_REMOVE_ALL 275 1.2.2.2 mjf DM_LIST_DEVICES * 276 1.2.2.2 mjf DM_DEV_CREATE * 277 1.2.2.2 mjf DM_DEV_REMOVE * 278 1.2.2.2 mjf DM_DEV_RENAME * 279 1.2.2.2 mjf DM_DEV_SUSPEND 280 1.2.2.2 mjf DM_DEV_STATUS * 281 1.2.2.2 mjf DM_DEV_WAIT 282 1.2.2.2 mjf DM_TABLE_LOAD * 283 1.2.2.2 mjf DM_TABLE_CLEAR * 284 1.2.2.2 mjf DM_TABLE_DEPS 285 1.2.2.2 mjf DM_TABLE_STATUS * 286 1.2.2.2 mjf DM_LIST_VERSIONS * 287 1.2.2.2 mjf DM_TARGET_MSG 288 1.2.2.2 mjf DM_DEV_SET_GEOMETRY 289 1.2.2.2 mjf 290 1.2.2.2 mjf * means implemented in current version of NetBSD device-mapper. 291 1.2.2.2 mjf 292 1.2.2.2 mjf 1a) struct dm_ioctl based ioctl calls 293 1.2.2.2 mjf These ioctl calls communicate only with basic dm_ioctl structure. 294 1.2.2.2 mjf 295 1.2.2.2 mjf DM_VERSION 296 1.2.2.2 mjf DM_DEV_STATUS 297 1.2.2.2 mjf DM_DEV_CREATE 298 1.2.2.2 mjf 299 1.2.2.2 mjf Protocol structure: 300 1.2.2.2 mjf 301 1.2.2.2 mjf struct dm_ioctl { 302 1.2.2.2 mjf uint32_t version[3]; /* device-mapper kernel/userspace version */ 303 1.2.2.2 mjf uint32_t data_size; /* total size of data passed in 304 1.2.2.2 mjf * including this struct */ 305 1.2.2.2 mjf 306 1.2.2.2 mjf uint32_t data_start; /* offset to start of data 307 1.2.2.2 mjf * relative to start of this struct */ 308 1.2.2.2 mjf 309 1.2.2.2 mjf uint32_t target_count; /* in/out */ /* This should be set when DM_TABLE_STATUS is called */ 310 1.2.2.2 mjf int32_t open_count; /* device open count */ 311 1.2.2.2 mjf uint32_t flags; /* information flags */ 312 1.2.2.2 mjf uint32_t event_nr; /* event counters not implemented */ 313 1.2.2.2 mjf uint32_t padding; 314 1.2.2.2 mjf 315 1.2.2.2 mjf uint64_t dev; /* dev_t */ 316 1.2.2.2 mjf 317 1.2.2.2 mjf char name[DM_NAME_LEN]; /* device name */ 318 1.2.2.2 mjf char uuid[DM_UUID_LEN]; /* unique identifier for 319 1.2.2.2 mjf * the block device */ 320 1.2.2.2 mjf 321 1.2.2.2 mjf void *user_space_addr; /*this is needed for netbsd 322 1.2.2.2 mjf because they differently 323 1.2.2.2 mjf implement ioctl syscall*/ 324 1.2.2.2 mjf }; 325 1.2.2.2 mjf 326 1.2.2.2 mjf As SOC task I want to replace this structure with proplib dict. Proplib dict 327 1.2.2.2 mjf basic structure should be: 328 1.2.2.2 mjf 329 1.2.2.2 mjf Note: I don't need data_star, data_size and use_space_addr. They are needed 330 1.2.2.2 mjf for current implementation. 331 1.2.2.2 mjf 332 1.2.2.2 mjf <dict> 333 1.2.2.2 mjf <key>version</key> 334 1.2.2.2 mjf <string>...</string> 335 1.2.2.2 mjf 336 1.2.2.2 mjf <key>target_count</key> 337 1.2.2.2 mjf <integer></integer> 338 1.2.2.2 mjf 339 1.2.2.2 mjf <key>open_count</key> 340 1.2.2.2 mjf <integer></integer> 341 1.2.2.2 mjf 342 1.2.2.2 mjf <key>flags</key> 343 1.2.2.2 mjf <integer></integer> 344 1.2.2.2 mjf 345 1.2.2.2 mjf <key>event_nr</key> 346 1.2.2.2 mjf <integer></integer> 347 1.2.2.2 mjf 348 1.2.2.2 mjf <key>dev</key> 349 1.2.2.2 mjf <integer></integer> 350 1.2.2.2 mjf 351 1.2.2.2 mjf <key>name</key> 352 1.2.2.2 mjf <string>...</string> 353 1.2.2.2 mjf 354 1.2.2.2 mjf <key>uuid</key> 355 1.2.2.2 mjf <string>...</string> 356 1.2.2.2 mjf 357 1.2.2.2 mjf 358 1.2.2.2 mjf <dict> 359 1.2.2.2 mjf <!-- ioctl specific data --> 360 1.2.2.2 mjf </dict> 361 1.2.2.2 mjf </dict> 362 1.2.2.2 mjf 363 1.2.2.2 mjf 1b) DM_LIST_VERSIONS ioctl 364 1.2.2.2 mjf 365 1.2.2.2 mjf This ioctl is used to get list of supported targets from kernel. Target 366 1.2.2.2 mjf define mapping of Logical blocks to physical blocks on real device. 367 1.2.2.2 mjf There are linear, zero, error, mirror, snapshot, multipath etc... targets. 368 1.2.2.2 mjf 369 1.2.2.2 mjf For every target kernel driver should copyout this structure to userspace. 370 1.2.2.2 mjf 371 1.2.2.2 mjf Protocol structure: 372 1.2.2.2 mjf 373 1.2.2.2 mjf struct dm_target_versions { 374 1.2.2.2 mjf uint32_t next; 375 1.2.2.2 mjf uint32_t version[3]; 376 1.2.2.2 mjf 377 1.2.2.2 mjf char name[0]; 378 1.2.2.2 mjf }; 379 1.2.2.2 mjf 380 1.2.2.2 mjf Because I need more then on dm_target_version I will need one major proplib 381 1.2.2.2 mjf dictionary to store children dictionaries with target data. 382 1.2.2.2 mjf 383 1.2.2.2 mjf <dict> 384 1.2.2.2 mjf <dict ID="id"> 385 1.2.2.2 mjf <key>version</key> 386 1.2.2.2 mjf <string>...</string> 387 1.2.2.2 mjf 388 1.2.2.2 mjf <key>name</key> 389 1.2.2.2 mjf <string>...</string> 390 1.2.2.2 mjf </dict> 391 1.2.2.2 mjf </dict> 392 1.2.2.2 mjf 393 1.2.2.2 mjf 2a) DM_LIST_DEVICES 394 1.2.2.2 mjf 395 1.2.2.2 mjf This ioctl is used to list all devices defined in kernel driver. 396 1.2.2.2 mjf 397 1.2.2.2 mjf Protocol structure: 398 1.2.2.2 mjf 399 1.2.2.2 mjf struct dm_name_list { 400 1.2.2.2 mjf uint64_t dev; 401 1.2.2.2 mjf uint32_t next; /* offset to the next record from 402 1.2.2.2 mjf the _start_ of this */ 403 1.2.2.2 mjf char name[0]; 404 1.2.2.2 mjf }; 405 1.2.2.2 mjf 406 1.2.2.2 mjf Again because I can have more than one device in kernel driver I need one parent 407 1.2.2.2 mjf dictionary and more children dictionaries. 408 1.2.2.2 mjf 409 1.2.2.2 mjf <dict> 410 1.2.2.2 mjf <dict ID="id"> 411 1.2.2.2 mjf <key>dev</key> 412 1.2.2.2 mjf <integer>...</integer> 413 1.2.2.2 mjf 414 1.2.2.2 mjf <key>name</key> 415 1.2.2.2 mjf <string>...</string> 416 1.2.2.2 mjf </dict> 417 1.2.2.2 mjf </dict> 418 1.2.2.2 mjf 419 1.2.2.2 mjf 2b) DM_DEV_RENAME 420 1.2.2.2 mjf This ioctl is called when libdevmapper want to rename device-mapper device. 421 1.2.2.2 mjf Libdevmapper library appends null terminated string to dm_ioctl struct in 422 1.2.2.2 mjf userspace.. 423 1.2.2.2 mjf 424 1.2.2.2 mjf <dict> 425 1.2.2.2 mjf <key>name</key> 426 1.2.2.2 mjf <string>...</string> 427 1.2.2.2 mjf </dict> 428 1.2.2.2 mjf 429 1.2.2.2 mjf 2c) DM_DEV_CREATE, DM_DEV_REMOVE, DM_DEV_STATUS 430 1.2.2.2 mjf Modify only dm_ioctl structure so I don't need to specify new structures. 431 1.2.2.2 mjf 432 1.2.2.2 mjf 433 1.2.2.2 mjf 3a) DM_TABLE_LOAD, DM_TABLE_STATUS 434 1.2.2.2 mjf DM_TABLE_LOAD ioctl loads table to device. DM_TABLE_STATUS send info about 435 1.2.2.2 mjf every table for selected device to userspace. Table is different for every 436 1.2.2.2 mjf target basic table structure is this 437 1.2.2.2 mjf 438 1.2.2.2 mjf {start} {length} {target} {additional information} 439 1.2.2.2 mjf 440 1.2.2.2 mjf e.g. 441 1.2.2.2 mjf 0 100 zero 442 1.2.2.2 mjf 443 1.2.2.2 mjf 0 100 linear /dev/wdba 384 444 1.2.2.2 mjf 445 1.2.2.2 mjf Protocol structure: 446 1.2.2.2 mjf 447 1.2.2.2 mjf struct dm_target_spec { 448 1.2.2.2 mjf uint64_t sector_start; 449 1.2.2.2 mjf uint64_t length; 450 1.2.2.2 mjf int32_t status; /* used when reading from kernel only */ 451 1.2.2.2 mjf 452 1.2.2.2 mjf uint32_t next; 453 1.2.2.2 mjf 454 1.2.2.2 mjf char target_type[DM_MAX_TYPE_NAME]; 455 1.2.2.2 mjf 456 1.2.2.2 mjf /* 457 1.2.2.2 mjf * Parameter string starts immediately after this object. 458 1.2.2.2 mjf * Be careful to add padding after string to ensure correct 459 1.2.2.2 mjf * alignment of subsequent dm_target_spec. 460 1.2.2.2 mjf */ 461 1.2.2.2 mjf }; 462 1.2.2.2 mjf 463 1.2.2.2 mjf <dict> 464 1.2.2.2 mjf <key>sector_start</key> 465 1.2.2.2 mjf <integer>...</integer> 466 1.2.2.2 mjf 467 1.2.2.2 mjf <key>length</key> 468 1.2.2.2 mjf <integer>...</integer> 469 1.2.2.2 mjf 470 1.2.2.2 mjf <key>target_type</key> 471 1.2.2.2 mjf <string>...</string> 472 1.2.2.2 mjf 473 1.2.2.2 mjf <key>aditional info</key> 474 1.2.2.2 mjf <string>...</string> 475 1.2.2.2 mjf </dict> 476
Indexes created Sat Oct 11 19:10:01 GMT 2025