| 1 | /* |
| 2 | * 9p backend |
| 3 | * |
| 4 | * Copyright IBM, Corp. 2011 |
| 5 | * |
| 6 | * Authors: |
| 7 | * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> |
| 8 | * |
| 9 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 10 | * the COPYING file in the top-level directory. |
| 11 | * |
| 12 | */ |
| 13 | |
| 14 | /* |
| 15 | * Not so fast! You might want to read the 9p developer docs first: |
| 16 | * https://wiki.qemu.org/Documentation/9p |
| 17 | */ |
| 18 | |
| 19 | #include "qemu/osdep.h" |
| 20 | #include "fsdev/qemu-fsdev.h" |
| 21 | #include "qemu/thread.h" |
| 22 | #include "qemu/main-loop.h" |
| 23 | #include "coth.h" |
| 24 | |
| 25 | static ssize_t __readlink(V9fsState *s, V9fsPath *path, V9fsString *buf) |
| 26 | { |
| 27 | ssize_t len, maxlen = PATH_MAX; |
| 28 | |
| 29 | buf->data = g_malloc(PATH_MAX); |
| 30 | for (;;) { |
| 31 | len = s->ops->readlink(&s->ctx, path, buf->data, maxlen); |
| 32 | if (len < 0) { |
| 33 | g_free(buf->data); |
| 34 | buf->data = NULL; |
| 35 | buf->size = 0; |
| 36 | break; |
| 37 | } else if (len == maxlen) { |
| 38 | /* |
| 39 | * We dodn't have space to put the NULL or we have more |
| 40 | * to read. Increase the size and try again |
| 41 | */ |
| 42 | maxlen *= 2; |
| 43 | g_free(buf->data); |
| 44 | buf->data = g_malloc(maxlen); |
| 45 | continue; |
| 46 | } |
| 47 | /* |
| 48 | * Null terminate the readlink output |
| 49 | */ |
| 50 | buf->data[len] = '\0'; |
| 51 | buf->size = len; |
| 52 | break; |
| 53 | } |
| 54 | return len; |
| 55 | } |
| 56 | |
| 57 | int coroutine_fn v9fs_co_readlink(V9fsPDU *pdu, V9fsPath *path, V9fsString *buf) |
| 58 | { |
| 59 | int err; |
| 60 | V9fsState *s = pdu->s; |
| 61 | |
| 62 | if (v9fs_request_cancelled(pdu)) { |
| 63 | return -EINTR; |
| 64 | } |
| 65 | v9fs_path_read_lock(s); |
| 66 | v9fs_co_run_in_worker( |
| 67 | { |
| 68 | err = __readlink(s, path, buf); |
| 69 | if (err < 0) { |
| 70 | err = -errno; |
| 71 | } |
| 72 | }); |
| 73 | v9fs_path_unlock(s); |
| 74 | return err; |
| 75 | } |
| 76 | |
| 77 | int coroutine_fn v9fs_co_statfs(V9fsPDU *pdu, V9fsPath *path, |
| 78 | struct statfs *stbuf) |
| 79 | { |
| 80 | int err; |
| 81 | V9fsState *s = pdu->s; |
| 82 | |
| 83 | if (v9fs_request_cancelled(pdu)) { |
| 84 | return -EINTR; |
| 85 | } |
| 86 | v9fs_path_read_lock(s); |
| 87 | v9fs_co_run_in_worker( |
| 88 | { |
| 89 | err = s->ops->statfs(&s->ctx, path, stbuf); |
| 90 | if (err < 0) { |
| 91 | err = -errno; |
| 92 | } |
| 93 | }); |
| 94 | v9fs_path_unlock(s); |
| 95 | return err; |
| 96 | } |
| 97 | |
| 98 | int coroutine_fn v9fs_co_chmod(V9fsPDU *pdu, V9fsPath *path, mode_t mode) |
| 99 | { |
| 100 | int err; |
| 101 | FsCred cred; |
| 102 | V9fsState *s = pdu->s; |
| 103 | |
| 104 | if (v9fs_request_cancelled(pdu)) { |
| 105 | return -EINTR; |
| 106 | } |
| 107 | cred_init(&cred); |
| 108 | cred.fc_mode = mode; |
| 109 | v9fs_path_read_lock(s); |
| 110 | v9fs_co_run_in_worker( |
| 111 | { |
| 112 | err = s->ops->chmod(&s->ctx, path, &cred); |
| 113 | if (err < 0) { |
| 114 | err = -errno; |
| 115 | } |
| 116 | }); |
| 117 | v9fs_path_unlock(s); |
| 118 | return err; |
| 119 | } |
| 120 | |
| 121 | int coroutine_fn v9fs_co_utimensat(V9fsPDU *pdu, V9fsPath *path, |
| 122 | struct timespec times[2]) |
| 123 | { |
| 124 | int err; |
| 125 | V9fsState *s = pdu->s; |
| 126 | |
| 127 | if (v9fs_request_cancelled(pdu)) { |
| 128 | return -EINTR; |
| 129 | } |
| 130 | v9fs_path_read_lock(s); |
| 131 | v9fs_co_run_in_worker( |
| 132 | { |
| 133 | err = s->ops->utimensat(&s->ctx, path, times); |
| 134 | if (err < 0) { |
| 135 | err = -errno; |
| 136 | } |
| 137 | }); |
| 138 | v9fs_path_unlock(s); |
| 139 | return err; |
| 140 | } |
| 141 | |
| 142 | int coroutine_fn v9fs_co_futimens(V9fsPDU *pdu, V9fsFidState *fidp, |
| 143 | struct timespec times[2]) |
| 144 | { |
| 145 | int err; |
| 146 | V9fsState *s = pdu->s; |
| 147 | |
| 148 | if (v9fs_request_cancelled(pdu)) { |
| 149 | return -EINTR; |
| 150 | } |
| 151 | v9fs_co_run_in_worker( |
| 152 | { |
| 153 | err = s->ops->futimens(&s->ctx, fidp->fid_type, &fidp->fs, times); |
| 154 | if (err < 0) { |
| 155 | err = -errno; |
| 156 | } |
| 157 | }); |
| 158 | return err; |
| 159 | } |
| 160 | |
| 161 | int coroutine_fn v9fs_co_chown(V9fsPDU *pdu, V9fsPath *path, uid_t uid, |
| 162 | gid_t gid) |
| 163 | { |
| 164 | int err; |
| 165 | FsCred cred; |
| 166 | V9fsState *s = pdu->s; |
| 167 | |
| 168 | if (v9fs_request_cancelled(pdu)) { |
| 169 | return -EINTR; |
| 170 | } |
| 171 | cred_init(&cred); |
| 172 | cred.fc_uid = uid; |
| 173 | cred.fc_gid = gid; |
| 174 | v9fs_path_read_lock(s); |
| 175 | v9fs_co_run_in_worker( |
| 176 | { |
| 177 | err = s->ops->chown(&s->ctx, path, &cred); |
| 178 | if (err < 0) { |
| 179 | err = -errno; |
| 180 | } |
| 181 | }); |
| 182 | v9fs_path_unlock(s); |
| 183 | return err; |
| 184 | } |
| 185 | |
| 186 | int coroutine_fn v9fs_co_truncate(V9fsPDU *pdu, V9fsPath *path, off_t size) |
| 187 | { |
| 188 | int err; |
| 189 | V9fsState *s = pdu->s; |
| 190 | |
| 191 | if (v9fs_request_cancelled(pdu)) { |
| 192 | return -EINTR; |
| 193 | } |
| 194 | v9fs_path_read_lock(s); |
| 195 | v9fs_co_run_in_worker( |
| 196 | { |
| 197 | err = s->ops->truncate(&s->ctx, path, size); |
| 198 | if (err < 0) { |
| 199 | err = -errno; |
| 200 | } |
| 201 | }); |
| 202 | v9fs_path_unlock(s); |
| 203 | return err; |
| 204 | } |
| 205 | |
| 206 | int coroutine_fn v9fs_co_ftruncate(V9fsPDU *pdu, V9fsFidState *fidp, off_t size) |
| 207 | { |
| 208 | int err; |
| 209 | V9fsState *s = pdu->s; |
| 210 | |
| 211 | if (v9fs_request_cancelled(pdu)) { |
| 212 | return -EINTR; |
| 213 | } |
| 214 | v9fs_co_run_in_worker( |
| 215 | { |
| 216 | err = s->ops->ftruncate(&s->ctx, fidp->fid_type, &fidp->fs, size); |
| 217 | if (err < 0) { |
| 218 | err = -errno; |
| 219 | } |
| 220 | }); |
| 221 | return err; |
| 222 | } |
| 223 | |
| 224 | int coroutine_fn v9fs_co_mknod(V9fsPDU *pdu, V9fsFidState *fidp, |
| 225 | V9fsString *name, uid_t uid, gid_t gid, |
| 226 | dev_t dev, mode_t mode, struct stat *stbuf) |
| 227 | { |
| 228 | int err; |
| 229 | V9fsPath path; |
| 230 | FsCred cred; |
| 231 | V9fsState *s = pdu->s; |
| 232 | |
| 233 | if (v9fs_request_cancelled(pdu)) { |
| 234 | return -EINTR; |
| 235 | } |
| 236 | cred_init(&cred); |
| 237 | cred.fc_uid = uid; |
| 238 | cred.fc_gid = gid; |
| 239 | cred.fc_mode = mode; |
| 240 | cred.fc_rdev = dev; |
| 241 | v9fs_path_read_lock(s); |
| 242 | v9fs_co_run_in_worker( |
| 243 | { |
| 244 | err = s->ops->mknod(&s->ctx, &fidp->path, name->data, &cred); |
| 245 | if (err < 0) { |
| 246 | err = -errno; |
| 247 | } else { |
| 248 | v9fs_path_init(&path); |
| 249 | err = v9fs_name_to_path(s, &fidp->path, name->data, &path); |
| 250 | if (!err) { |
| 251 | err = s->ops->lstat(&s->ctx, &path, stbuf); |
| 252 | if (err < 0) { |
| 253 | err = -errno; |
| 254 | } |
| 255 | } |
| 256 | v9fs_path_free(&path); |
| 257 | } |
| 258 | }); |
| 259 | v9fs_path_unlock(s); |
| 260 | return err; |
| 261 | } |
| 262 | |
| 263 | /* Only works with path name based fid */ |
| 264 | int coroutine_fn v9fs_co_remove(V9fsPDU *pdu, V9fsPath *path) |
| 265 | { |
| 266 | int err; |
| 267 | V9fsState *s = pdu->s; |
| 268 | |
| 269 | if (v9fs_request_cancelled(pdu)) { |
| 270 | return -EINTR; |
| 271 | } |
| 272 | v9fs_path_read_lock(s); |
| 273 | v9fs_co_run_in_worker( |
| 274 | { |
| 275 | err = s->ops->remove(&s->ctx, path->data); |
| 276 | if (err < 0) { |
| 277 | err = -errno; |
| 278 | } |
| 279 | }); |
| 280 | v9fs_path_unlock(s); |
| 281 | return err; |
| 282 | } |
| 283 | |
| 284 | int coroutine_fn v9fs_co_unlinkat(V9fsPDU *pdu, V9fsPath *path, |
| 285 | V9fsString *name, int flags) |
| 286 | { |
| 287 | int err; |
| 288 | V9fsState *s = pdu->s; |
| 289 | |
| 290 | if (v9fs_request_cancelled(pdu)) { |
| 291 | return -EINTR; |
| 292 | } |
| 293 | v9fs_path_read_lock(s); |
| 294 | v9fs_co_run_in_worker( |
| 295 | { |
| 296 | err = s->ops->unlinkat(&s->ctx, path, name->data, flags); |
| 297 | if (err < 0) { |
| 298 | err = -errno; |
| 299 | } |
| 300 | }); |
| 301 | v9fs_path_unlock(s); |
| 302 | return err; |
| 303 | } |
| 304 | |
| 305 | /* Only work with path name based fid */ |
| 306 | int coroutine_fn v9fs_co_rename(V9fsPDU *pdu, V9fsPath *oldpath, |
| 307 | V9fsPath *newpath) |
| 308 | { |
| 309 | int err; |
| 310 | V9fsState *s = pdu->s; |
| 311 | |
| 312 | if (v9fs_request_cancelled(pdu)) { |
| 313 | return -EINTR; |
| 314 | } |
| 315 | v9fs_co_run_in_worker( |
| 316 | { |
| 317 | err = s->ops->rename(&s->ctx, oldpath->data, newpath->data); |
| 318 | if (err < 0) { |
| 319 | err = -errno; |
| 320 | } |
| 321 | }); |
| 322 | return err; |
| 323 | } |
| 324 | |
| 325 | int coroutine_fn v9fs_co_renameat(V9fsPDU *pdu, V9fsPath *olddirpath, |
| 326 | V9fsString *oldname, V9fsPath *newdirpath, |
| 327 | V9fsString *newname) |
| 328 | { |
| 329 | int err; |
| 330 | V9fsState *s = pdu->s; |
| 331 | |
| 332 | if (v9fs_request_cancelled(pdu)) { |
| 333 | return -EINTR; |
| 334 | } |
| 335 | v9fs_co_run_in_worker( |
| 336 | { |
| 337 | err = s->ops->renameat(&s->ctx, olddirpath, oldname->data, |
| 338 | newdirpath, newname->data); |
| 339 | if (err < 0) { |
| 340 | err = -errno; |
| 341 | } |
| 342 | }); |
| 343 | return err; |
| 344 | } |
| 345 | |
| 346 | int coroutine_fn v9fs_co_symlink(V9fsPDU *pdu, V9fsFidState *dfidp, |
| 347 | V9fsString *name, const char *oldpath, |
| 348 | gid_t gid, struct stat *stbuf) |
| 349 | { |
| 350 | int err; |
| 351 | FsCred cred; |
| 352 | V9fsPath path; |
| 353 | V9fsState *s = pdu->s; |
| 354 | |
| 355 | if (v9fs_request_cancelled(pdu)) { |
| 356 | return -EINTR; |
| 357 | } |
| 358 | cred_init(&cred); |
| 359 | cred.fc_uid = dfidp->uid; |
| 360 | cred.fc_gid = gid; |
| 361 | cred.fc_mode = 0777; |
| 362 | v9fs_path_read_lock(s); |
| 363 | v9fs_co_run_in_worker( |
| 364 | { |
| 365 | err = s->ops->symlink(&s->ctx, oldpath, &dfidp->path, |
| 366 | name->data, &cred); |
| 367 | if (err < 0) { |
| 368 | err = -errno; |
| 369 | } else { |
| 370 | v9fs_path_init(&path); |
| 371 | err = v9fs_name_to_path(s, &dfidp->path, name->data, &path); |
| 372 | if (!err) { |
| 373 | err = s->ops->lstat(&s->ctx, &path, stbuf); |
| 374 | if (err < 0) { |
| 375 | err = -errno; |
| 376 | } |
| 377 | } |
| 378 | v9fs_path_free(&path); |
| 379 | } |
| 380 | }); |
| 381 | v9fs_path_unlock(s); |
| 382 | return err; |
| 383 | } |
| 384 | |
| 385 | /* |
| 386 | * For path name based fid we don't block. So we can |
| 387 | * directly call the fs driver ops. |
| 388 | */ |
| 389 | int coroutine_fn v9fs_co_name_to_path(V9fsPDU *pdu, V9fsPath *dirpath, |
| 390 | const char *name, V9fsPath *path) |
| 391 | { |
| 392 | int err; |
| 393 | V9fsState *s = pdu->s; |
| 394 | |
| 395 | if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) { |
| 396 | err = s->ops->name_to_path(&s->ctx, dirpath, name, path); |
| 397 | if (err < 0) { |
| 398 | err = -errno; |
| 399 | } |
| 400 | } else { |
| 401 | if (v9fs_request_cancelled(pdu)) { |
| 402 | return -EINTR; |
| 403 | } |
| 404 | v9fs_co_run_in_worker( |
| 405 | { |
| 406 | err = s->ops->name_to_path(&s->ctx, dirpath, name, path); |
| 407 | if (err < 0) { |
| 408 | err = -errno; |
| 409 | } |
| 410 | }); |
| 411 | } |
| 412 | return err; |
| 413 | } |