1 /* 2 FUSE: Filesystem in Userspace 3 Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu> 4 5 This program can be distributed under the terms of the GNU GPL. 6 See the file COPYING. 7 */ 8 9 #include "fuse_i.h" 10 11 #include <linux/pagemap.h> 12 #include <linux/file.h> 13 #include <linux/gfp.h> 14 #include <linux/sched.h> 15 #include <linux/namei.h> 16 #include <linux/mount.h> 17 18 static inline unsigned long time_to_jiffies(unsigned long sec, 19 unsigned long nsec) 20 { 21 struct timespec ts = {sec, nsec}; 22 return jiffies + timespec_to_jiffies(&ts); 23 } 24 25 static void fuse_lookup_init(struct fuse_req *req, struct inode *dir, 26 struct dentry *entry, 27 struct fuse_entry_out *outarg) 28 { 29 req->in.h.opcode = FUSE_LOOKUP; 30 req->in.h.nodeid = get_node_id(dir); 31 req->inode = dir; 32 req->in.numargs = 1; 33 req->in.args[0].size = entry->d_name.len + 1; 34 req->in.args[0].value = entry->d_name.name; 35 req->out.numargs = 1; 36 req->out.args[0].size = sizeof(struct fuse_entry_out); 37 req->out.args[0].value = outarg; 38 } 39 40 static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) 41 { 42 if (!entry->d_inode || is_bad_inode(entry->d_inode)) 43 return 0; 44 else if (time_after(jiffies, entry->d_time)) { 45 int err; 46 struct fuse_entry_out outarg; 47 struct inode *inode = entry->d_inode; 48 struct fuse_inode *fi = get_fuse_inode(inode); 49 struct fuse_conn *fc = get_fuse_conn(inode); 50 struct fuse_req *req = fuse_get_request(fc); 51 if (!req) 52 return 0; 53 54 fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg); 55 request_send(fc, req); 56 err = req->out.h.error; 57 if (!err) { 58 if (outarg.nodeid != get_node_id(inode)) { 59 fuse_send_forget(fc, req, outarg.nodeid, 1); 60 return 0; 61 } 62 fi->nlookup ++; 63 } 64 fuse_put_request(fc, req); 65 if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) 66 return 0; 67 68 fuse_change_attributes(inode, &outarg.attr); 69 entry->d_time = time_to_jiffies(outarg.entry_valid, 70 outarg.entry_valid_nsec); 71 fi->i_time = time_to_jiffies(outarg.attr_valid, 72 outarg.attr_valid_nsec); 73 } 74 return 1; 75 } 76 77 static int dir_alias(struct inode *inode) 78 { 79 if (S_ISDIR(inode->i_mode)) { 80 /* Don't allow creating an alias to a directory */ 81 struct dentry *alias = d_find_alias(inode); 82 if (alias) { 83 dput(alias); 84 return 1; 85 } 86 } 87 return 0; 88 } 89 90 static inline int invalid_nodeid(u64 nodeid) 91 { 92 return !nodeid || nodeid == FUSE_ROOT_ID; 93 } 94 95 static struct dentry_operations fuse_dentry_operations = { 96 .d_revalidate = fuse_dentry_revalidate, 97 }; 98 99 static int fuse_lookup_iget(struct inode *dir, struct dentry *entry, 100 struct inode **inodep) 101 { 102 int err; 103 struct fuse_entry_out outarg; 104 struct inode *inode = NULL; 105 struct fuse_conn *fc = get_fuse_conn(dir); 106 struct fuse_req *req; 107 108 if (entry->d_name.len > FUSE_NAME_MAX) 109 return -ENAMETOOLONG; 110 111 req = fuse_get_request(fc); 112 if (!req) 113 return -EINTR; 114 115 fuse_lookup_init(req, dir, entry, &outarg); 116 request_send(fc, req); 117 err = req->out.h.error; 118 if (!err && invalid_nodeid(outarg.nodeid)) 119 err = -EIO; 120 if (!err) { 121 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, 122 &outarg.attr); 123 if (!inode) { 124 fuse_send_forget(fc, req, outarg.nodeid, 1); 125 return -ENOMEM; 126 } 127 } 128 fuse_put_request(fc, req); 129 if (err && err != -ENOENT) 130 return err; 131 132 if (inode) { 133 struct fuse_inode *fi = get_fuse_inode(inode); 134 entry->d_time = time_to_jiffies(outarg.entry_valid, 135 outarg.entry_valid_nsec); 136 fi->i_time = time_to_jiffies(outarg.attr_valid, 137 outarg.attr_valid_nsec); 138 } 139 140 entry->d_op = &fuse_dentry_operations; 141 *inodep = inode; 142 return 0; 143 } 144 145 void fuse_invalidate_attr(struct inode *inode) 146 { 147 get_fuse_inode(inode)->i_time = jiffies - 1; 148 } 149 150 static void fuse_invalidate_entry(struct dentry *entry) 151 { 152 d_invalidate(entry); 153 entry->d_time = jiffies - 1; 154 } 155 156 static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, 157 struct nameidata *nd) 158 { 159 int err; 160 struct inode *inode; 161 struct fuse_conn *fc = get_fuse_conn(dir); 162 struct fuse_req *req; 163 struct fuse_open_in inarg; 164 struct fuse_open_out outopen; 165 struct fuse_entry_out outentry; 166 struct fuse_inode *fi; 167 struct fuse_file *ff; 168 struct file *file; 169 int flags = nd->intent.open.flags - 1; 170 171 err = -ENOSYS; 172 if (fc->no_create) 173 goto out; 174 175 err = -ENAMETOOLONG; 176 if (entry->d_name.len > FUSE_NAME_MAX) 177 goto out; 178 179 err = -EINTR; 180 req = fuse_get_request(fc); 181 if (!req) 182 goto out; 183 184 ff = fuse_file_alloc(); 185 if (!ff) 186 goto out_put_request; 187 188 flags &= ~O_NOCTTY; 189 memset(&inarg, 0, sizeof(inarg)); 190 inarg.flags = flags; 191 inarg.mode = mode; 192 req->in.h.opcode = FUSE_CREATE; 193 req->in.h.nodeid = get_node_id(dir); 194 req->inode = dir; 195 req->in.numargs = 2; 196 req->in.args[0].size = sizeof(inarg); 197 req->in.args[0].value = &inarg; 198 req->in.args[1].size = entry->d_name.len + 1; 199 req->in.args[1].value = entry->d_name.name; 200 req->out.numargs = 2; 201 req->out.args[0].size = sizeof(outentry); 202 req->out.args[0].value = &outentry; 203 req->out.args[1].size = sizeof(outopen); 204 req->out.args[1].value = &outopen; 205 request_send(fc, req); 206 err = req->out.h.error; 207 if (err) { 208 if (err == -ENOSYS) 209 fc->no_create = 1; 210 goto out_free_ff; 211 } 212 213 err = -EIO; 214 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid)) 215 goto out_free_ff; 216 217 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, 218 &outentry.attr); 219 err = -ENOMEM; 220 if (!inode) { 221 flags &= ~(O_CREAT | O_EXCL | O_TRUNC); 222 ff->fh = outopen.fh; 223 fuse_send_release(fc, ff, outentry.nodeid, NULL, flags, 0); 224 goto out_put_request; 225 } 226 fuse_put_request(fc, req); 227 entry->d_time = time_to_jiffies(outentry.entry_valid, 228 outentry.entry_valid_nsec); 229 fi = get_fuse_inode(inode); 230 fi->i_time = time_to_jiffies(outentry.attr_valid, 231 outentry.attr_valid_nsec); 232 233 d_instantiate(entry, inode); 234 file = lookup_instantiate_filp(nd, entry, generic_file_open); 235 if (IS_ERR(file)) { 236 ff->fh = outopen.fh; 237 fuse_send_release(fc, ff, outentry.nodeid, inode, flags, 0); 238 return PTR_ERR(file); 239 } 240 fuse_finish_open(inode, file, ff, &outopen); 241 return 0; 242 243 out_free_ff: 244 fuse_file_free(ff); 245 out_put_request: 246 fuse_put_request(fc, req); 247 out: 248 return err; 249 } 250 251 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req, 252 struct inode *dir, struct dentry *entry, 253 int mode) 254 { 255 struct fuse_entry_out outarg; 256 struct inode *inode; 257 struct fuse_inode *fi; 258 int err; 259 260 req->in.h.nodeid = get_node_id(dir); 261 req->inode = dir; 262 req->out.numargs = 1; 263 req->out.args[0].size = sizeof(outarg); 264 req->out.args[0].value = &outarg; 265 request_send(fc, req); 266 err = req->out.h.error; 267 if (err) { 268 fuse_put_request(fc, req); 269 return err; 270 } 271 if (invalid_nodeid(outarg.nodeid)) { 272 fuse_put_request(fc, req); 273 return -EIO; 274 } 275 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, 276 &outarg.attr); 277 if (!inode) { 278 fuse_send_forget(fc, req, outarg.nodeid, 1); 279 return -ENOMEM; 280 } 281 fuse_put_request(fc, req); 282 283 /* Don't allow userspace to do really stupid things... */ 284 if (((inode->i_mode ^ mode) & S_IFMT) || dir_alias(inode)) { 285 iput(inode); 286 return -EIO; 287 } 288 289 entry->d_time = time_to_jiffies(outarg.entry_valid, 290 outarg.entry_valid_nsec); 291 292 fi = get_fuse_inode(inode); 293 fi->i_time = time_to_jiffies(outarg.attr_valid, 294 outarg.attr_valid_nsec); 295 296 d_instantiate(entry, inode); 297 fuse_invalidate_attr(dir); 298 return 0; 299 } 300 301 static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode, 302 dev_t rdev) 303 { 304 struct fuse_mknod_in inarg; 305 struct fuse_conn *fc = get_fuse_conn(dir); 306 struct fuse_req *req = fuse_get_request(fc); 307 if (!req) 308 return -EINTR; 309 310 memset(&inarg, 0, sizeof(inarg)); 311 inarg.mode = mode; 312 inarg.rdev = new_encode_dev(rdev); 313 req->in.h.opcode = FUSE_MKNOD; 314 req->in.numargs = 2; 315 req->in.args[0].size = sizeof(inarg); 316 req->in.args[0].value = &inarg; 317 req->in.args[1].size = entry->d_name.len + 1; 318 req->in.args[1].value = entry->d_name.name; 319 return create_new_entry(fc, req, dir, entry, mode); 320 } 321 322 static int fuse_create(struct inode *dir, struct dentry *entry, int mode, 323 struct nameidata *nd) 324 { 325 if (nd && (nd->flags & LOOKUP_CREATE)) { 326 int err = fuse_create_open(dir, entry, mode, nd); 327 if (err != -ENOSYS) 328 return err; 329 /* Fall back on mknod */ 330 } 331 return fuse_mknod(dir, entry, mode, 0); 332 } 333 334 static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode) 335 { 336 struct fuse_mkdir_in inarg; 337 struct fuse_conn *fc = get_fuse_conn(dir); 338 struct fuse_req *req = fuse_get_request(fc); 339 if (!req) 340 return -EINTR; 341 342 memset(&inarg, 0, sizeof(inarg)); 343 inarg.mode = mode; 344 req->in.h.opcode = FUSE_MKDIR; 345 req->in.numargs = 2; 346 req->in.args[0].size = sizeof(inarg); 347 req->in.args[0].value = &inarg; 348 req->in.args[1].size = entry->d_name.len + 1; 349 req->in.args[1].value = entry->d_name.name; 350 return create_new_entry(fc, req, dir, entry, S_IFDIR); 351 } 352 353 static int fuse_symlink(struct inode *dir, struct dentry *entry, 354 const char *link) 355 { 356 struct fuse_conn *fc = get_fuse_conn(dir); 357 unsigned len = strlen(link) + 1; 358 struct fuse_req *req; 359 360 if (len > FUSE_SYMLINK_MAX) 361 return -ENAMETOOLONG; 362 363 req = fuse_get_request(fc); 364 if (!req) 365 return -EINTR; 366 367 req->in.h.opcode = FUSE_SYMLINK; 368 req->in.numargs = 2; 369 req->in.args[0].size = entry->d_name.len + 1; 370 req->in.args[0].value = entry->d_name.name; 371 req->in.args[1].size = len; 372 req->in.args[1].value = link; 373 return create_new_entry(fc, req, dir, entry, S_IFLNK); 374 } 375 376 static int fuse_unlink(struct inode *dir, struct dentry *entry) 377 { 378 int err; 379 struct fuse_conn *fc = get_fuse_conn(dir); 380 struct fuse_req *req = fuse_get_request(fc); 381 if (!req) 382 return -EINTR; 383 384 req->in.h.opcode = FUSE_UNLINK; 385 req->in.h.nodeid = get_node_id(dir); 386 req->inode = dir; 387 req->in.numargs = 1; 388 req->in.args[0].size = entry->d_name.len + 1; 389 req->in.args[0].value = entry->d_name.name; 390 request_send(fc, req); 391 err = req->out.h.error; 392 fuse_put_request(fc, req); 393 if (!err) { 394 struct inode *inode = entry->d_inode; 395 396 /* Set nlink to zero so the inode can be cleared, if 397 the inode does have more links this will be 398 discovered at the next lookup/getattr */ 399 inode->i_nlink = 0; 400 fuse_invalidate_attr(inode); 401 fuse_invalidate_attr(dir); 402 } else if (err == -EINTR) 403 fuse_invalidate_entry(entry); 404 return err; 405 } 406 407 static int fuse_rmdir(struct inode *dir, struct dentry *entry) 408 { 409 int err; 410 struct fuse_conn *fc = get_fuse_conn(dir); 411 struct fuse_req *req = fuse_get_request(fc); 412 if (!req) 413 return -EINTR; 414 415 req->in.h.opcode = FUSE_RMDIR; 416 req->in.h.nodeid = get_node_id(dir); 417 req->inode = dir; 418 req->in.numargs = 1; 419 req->in.args[0].size = entry->d_name.len + 1; 420 req->in.args[0].value = entry->d_name.name; 421 request_send(fc, req); 422 err = req->out.h.error; 423 fuse_put_request(fc, req); 424 if (!err) { 425 entry->d_inode->i_nlink = 0; 426 fuse_invalidate_attr(dir); 427 } else if (err == -EINTR) 428 fuse_invalidate_entry(entry); 429 return err; 430 } 431 432 static int fuse_rename(struct inode *olddir, struct dentry *oldent, 433 struct inode *newdir, struct dentry *newent) 434 { 435 int err; 436 struct fuse_rename_in inarg; 437 struct fuse_conn *fc = get_fuse_conn(olddir); 438 struct fuse_req *req = fuse_get_request(fc); 439 if (!req) 440 return -EINTR; 441 442 memset(&inarg, 0, sizeof(inarg)); 443 inarg.newdir = get_node_id(newdir); 444 req->in.h.opcode = FUSE_RENAME; 445 req->in.h.nodeid = get_node_id(olddir); 446 req->inode = olddir; 447 req->inode2 = newdir; 448 req->in.numargs = 3; 449 req->in.args[0].size = sizeof(inarg); 450 req->in.args[0].value = &inarg; 451 req->in.args[1].size = oldent->d_name.len + 1; 452 req->in.args[1].value = oldent->d_name.name; 453 req->in.args[2].size = newent->d_name.len + 1; 454 req->in.args[2].value = newent->d_name.name; 455 request_send(fc, req); 456 err = req->out.h.error; 457 fuse_put_request(fc, req); 458 if (!err) { 459 fuse_invalidate_attr(olddir); 460 if (olddir != newdir) 461 fuse_invalidate_attr(newdir); 462 } else if (err == -EINTR) { 463 /* If request was interrupted, DEITY only knows if the 464 rename actually took place. If the invalidation 465 fails (e.g. some process has CWD under the renamed 466 directory), then there can be inconsistency between 467 the dcache and the real filesystem. Tough luck. */ 468 fuse_invalidate_entry(oldent); 469 if (newent->d_inode) 470 fuse_invalidate_entry(newent); 471 } 472 473 return err; 474 } 475 476 static int fuse_link(struct dentry *entry, struct inode *newdir, 477 struct dentry *newent) 478 { 479 int err; 480 struct fuse_link_in inarg; 481 struct inode *inode = entry->d_inode; 482 struct fuse_conn *fc = get_fuse_conn(inode); 483 struct fuse_req *req = fuse_get_request(fc); 484 if (!req) 485 return -EINTR; 486 487 memset(&inarg, 0, sizeof(inarg)); 488 inarg.oldnodeid = get_node_id(inode); 489 req->in.h.opcode = FUSE_LINK; 490 req->inode2 = inode; 491 req->in.numargs = 2; 492 req->in.args[0].size = sizeof(inarg); 493 req->in.args[0].value = &inarg; 494 req->in.args[1].size = newent->d_name.len + 1; 495 req->in.args[1].value = newent->d_name.name; 496 err = create_new_entry(fc, req, newdir, newent, inode->i_mode); 497 /* Contrary to "normal" filesystems it can happen that link 498 makes two "logical" inodes point to the same "physical" 499 inode. We invalidate the attributes of the old one, so it 500 will reflect changes in the backing inode (link count, 501 etc.) 502 */ 503 if (!err || err == -EINTR) 504 fuse_invalidate_attr(inode); 505 return err; 506 } 507 508 int fuse_do_getattr(struct inode *inode) 509 { 510 int err; 511 struct fuse_attr_out arg; 512 struct fuse_conn *fc = get_fuse_conn(inode); 513 struct fuse_req *req = fuse_get_request(fc); 514 if (!req) 515 return -EINTR; 516 517 req->in.h.opcode = FUSE_GETATTR; 518 req->in.h.nodeid = get_node_id(inode); 519 req->inode = inode; 520 req->out.numargs = 1; 521 req->out.args[0].size = sizeof(arg); 522 req->out.args[0].value = &arg; 523 request_send(fc, req); 524 err = req->out.h.error; 525 fuse_put_request(fc, req); 526 if (!err) { 527 if ((inode->i_mode ^ arg.attr.mode) & S_IFMT) { 528 make_bad_inode(inode); 529 err = -EIO; 530 } else { 531 struct fuse_inode *fi = get_fuse_inode(inode); 532 fuse_change_attributes(inode, &arg.attr); 533 fi->i_time = time_to_jiffies(arg.attr_valid, 534 arg.attr_valid_nsec); 535 } 536 } 537 return err; 538 } 539 540 /* 541 * Calling into a user-controlled filesystem gives the filesystem 542 * daemon ptrace-like capabilities over the requester process. This 543 * means, that the filesystem daemon is able to record the exact 544 * filesystem operations performed, and can also control the behavior 545 * of the requester process in otherwise impossible ways. For example 546 * it can delay the operation for arbitrary length of time allowing 547 * DoS against the requester. 548 * 549 * For this reason only those processes can call into the filesystem, 550 * for which the owner of the mount has ptrace privilege. This 551 * excludes processes started by other users, suid or sgid processes. 552 */ 553 static int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task) 554 { 555 if (fc->flags & FUSE_ALLOW_OTHER) 556 return 1; 557 558 if (task->euid == fc->user_id && 559 task->suid == fc->user_id && 560 task->uid == fc->user_id && 561 task->egid == fc->group_id && 562 task->sgid == fc->group_id && 563 task->gid == fc->group_id) 564 return 1; 565 566 return 0; 567 } 568 569 static int fuse_revalidate(struct dentry *entry) 570 { 571 struct inode *inode = entry->d_inode; 572 struct fuse_inode *fi = get_fuse_inode(inode); 573 struct fuse_conn *fc = get_fuse_conn(inode); 574 575 if (!fuse_allow_task(fc, current)) 576 return -EACCES; 577 if (get_node_id(inode) != FUSE_ROOT_ID && 578 time_before_eq(jiffies, fi->i_time)) 579 return 0; 580 581 return fuse_do_getattr(inode); 582 } 583 584 static int fuse_access(struct inode *inode, int mask) 585 { 586 struct fuse_conn *fc = get_fuse_conn(inode); 587 struct fuse_req *req; 588 struct fuse_access_in inarg; 589 int err; 590 591 if (fc->no_access) 592 return 0; 593 594 req = fuse_get_request(fc); 595 if (!req) 596 return -EINTR; 597 598 memset(&inarg, 0, sizeof(inarg)); 599 inarg.mask = mask; 600 req->in.h.opcode = FUSE_ACCESS; 601 req->in.h.nodeid = get_node_id(inode); 602 req->inode = inode; 603 req->in.numargs = 1; 604 req->in.args[0].size = sizeof(inarg); 605 req->in.args[0].value = &inarg; 606 request_send(fc, req); 607 err = req->out.h.error; 608 fuse_put_request(fc, req); 609 if (err == -ENOSYS) { 610 fc->no_access = 1; 611 err = 0; 612 } 613 return err; 614 } 615 616 static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd) 617 { 618 struct fuse_conn *fc = get_fuse_conn(inode); 619 620 if (!fuse_allow_task(fc, current)) 621 return -EACCES; 622 else if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { 623 int err = generic_permission(inode, mask, NULL); 624 625 /* If permission is denied, try to refresh file 626 attributes. This is also needed, because the root 627 node will at first have no permissions */ 628 if (err == -EACCES) { 629 err = fuse_do_getattr(inode); 630 if (!err) 631 err = generic_permission(inode, mask, NULL); 632 } 633 634 /* FIXME: Need some mechanism to revoke permissions: 635 currently if the filesystem suddenly changes the 636 file mode, we will not be informed about it, and 637 continue to allow access to the file/directory. 638 639 This is actually not so grave, since the user can 640 simply keep access to the file/directory anyway by 641 keeping it open... */ 642 643 return err; 644 } else { 645 int mode = inode->i_mode; 646 if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO)) 647 return -EACCES; 648 649 if (nd && (nd->flags & LOOKUP_ACCESS)) 650 return fuse_access(inode, mask); 651 return 0; 652 } 653 } 654 655 static int parse_dirfile(char *buf, size_t nbytes, struct file *file, 656 void *dstbuf, filldir_t filldir) 657 { 658 while (nbytes >= FUSE_NAME_OFFSET) { 659 struct fuse_dirent *dirent = (struct fuse_dirent *) buf; 660 size_t reclen = FUSE_DIRENT_SIZE(dirent); 661 int over; 662 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) 663 return -EIO; 664 if (reclen > nbytes) 665 break; 666 667 over = filldir(dstbuf, dirent->name, dirent->namelen, 668 file->f_pos, dirent->ino, dirent->type); 669 if (over) 670 break; 671 672 buf += reclen; 673 nbytes -= reclen; 674 file->f_pos = dirent->off; 675 } 676 677 return 0; 678 } 679 680 static inline size_t fuse_send_readdir(struct fuse_req *req, struct file *file, 681 struct inode *inode, loff_t pos, 682 size_t count) 683 { 684 return fuse_send_read_common(req, file, inode, pos, count, 1); 685 } 686 687 static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir) 688 { 689 int err; 690 size_t nbytes; 691 struct page *page; 692 struct inode *inode = file->f_dentry->d_inode; 693 struct fuse_conn *fc = get_fuse_conn(inode); 694 struct fuse_req *req = fuse_get_request(fc); 695 if (!req) 696 return -EINTR; 697 698 page = alloc_page(GFP_KERNEL); 699 if (!page) { 700 fuse_put_request(fc, req); 701 return -ENOMEM; 702 } 703 req->num_pages = 1; 704 req->pages[0] = page; 705 nbytes = fuse_send_readdir(req, file, inode, file->f_pos, PAGE_SIZE); 706 err = req->out.h.error; 707 fuse_put_request(fc, req); 708 if (!err) 709 err = parse_dirfile(page_address(page), nbytes, file, dstbuf, 710 filldir); 711 712 __free_page(page); 713 fuse_invalidate_attr(inode); /* atime changed */ 714 return err; 715 } 716 717 static char *read_link(struct dentry *dentry) 718 { 719 struct inode *inode = dentry->d_inode; 720 struct fuse_conn *fc = get_fuse_conn(inode); 721 struct fuse_req *req = fuse_get_request(fc); 722 char *link; 723 724 if (!req) 725 return ERR_PTR(-EINTR); 726 727 link = (char *) __get_free_page(GFP_KERNEL); 728 if (!link) { 729 link = ERR_PTR(-ENOMEM); 730 goto out; 731 } 732 req->in.h.opcode = FUSE_READLINK; 733 req->in.h.nodeid = get_node_id(inode); 734 req->inode = inode; 735 req->out.argvar = 1; 736 req->out.numargs = 1; 737 req->out.args[0].size = PAGE_SIZE - 1; 738 req->out.args[0].value = link; 739 request_send(fc, req); 740 if (req->out.h.error) { 741 free_page((unsigned long) link); 742 link = ERR_PTR(req->out.h.error); 743 } else 744 link[req->out.args[0].size] = '\0'; 745 out: 746 fuse_put_request(fc, req); 747 fuse_invalidate_attr(inode); /* atime changed */ 748 return link; 749 } 750 751 static void free_link(char *link) 752 { 753 if (!IS_ERR(link)) 754 free_page((unsigned long) link); 755 } 756 757 static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd) 758 { 759 nd_set_link(nd, read_link(dentry)); 760 return NULL; 761 } 762 763 static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c) 764 { 765 free_link(nd_get_link(nd)); 766 } 767 768 static int fuse_dir_open(struct inode *inode, struct file *file) 769 { 770 return fuse_open_common(inode, file, 1); 771 } 772 773 static int fuse_dir_release(struct inode *inode, struct file *file) 774 { 775 return fuse_release_common(inode, file, 1); 776 } 777 778 static int fuse_dir_fsync(struct file *file, struct dentry *de, int datasync) 779 { 780 /* nfsd can call this with no file */ 781 return file ? fuse_fsync_common(file, de, datasync, 1) : 0; 782 } 783 784 static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg) 785 { 786 unsigned ivalid = iattr->ia_valid; 787 788 if (ivalid & ATTR_MODE) 789 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode; 790 if (ivalid & ATTR_UID) 791 arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid; 792 if (ivalid & ATTR_GID) 793 arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid; 794 if (ivalid & ATTR_SIZE) 795 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size; 796 /* You can only _set_ these together (they may change by themselves) */ 797 if ((ivalid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) { 798 arg->valid |= FATTR_ATIME | FATTR_MTIME; 799 arg->atime = iattr->ia_atime.tv_sec; 800 arg->mtime = iattr->ia_mtime.tv_sec; 801 } 802 if (ivalid & ATTR_FILE) { 803 struct fuse_file *ff = iattr->ia_file->private_data; 804 arg->valid |= FATTR_FH; 805 arg->fh = ff->fh; 806 } 807 } 808 809 static int fuse_setattr(struct dentry *entry, struct iattr *attr) 810 { 811 struct inode *inode = entry->d_inode; 812 struct fuse_conn *fc = get_fuse_conn(inode); 813 struct fuse_inode *fi = get_fuse_inode(inode); 814 struct fuse_req *req; 815 struct fuse_setattr_in inarg; 816 struct fuse_attr_out outarg; 817 int err; 818 int is_truncate = 0; 819 820 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { 821 err = inode_change_ok(inode, attr); 822 if (err) 823 return err; 824 } 825 826 if (attr->ia_valid & ATTR_SIZE) { 827 unsigned long limit; 828 is_truncate = 1; 829 limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; 830 if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) { 831 send_sig(SIGXFSZ, current, 0); 832 return -EFBIG; 833 } 834 } 835 836 req = fuse_get_request(fc); 837 if (!req) 838 return -EINTR; 839 840 memset(&inarg, 0, sizeof(inarg)); 841 iattr_to_fattr(attr, &inarg); 842 req->in.h.opcode = FUSE_SETATTR; 843 req->in.h.nodeid = get_node_id(inode); 844 req->inode = inode; 845 req->in.numargs = 1; 846 req->in.args[0].size = sizeof(inarg); 847 req->in.args[0].value = &inarg; 848 req->out.numargs = 1; 849 req->out.args[0].size = sizeof(outarg); 850 req->out.args[0].value = &outarg; 851 request_send(fc, req); 852 err = req->out.h.error; 853 fuse_put_request(fc, req); 854 if (!err) { 855 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { 856 make_bad_inode(inode); 857 err = -EIO; 858 } else { 859 if (is_truncate) { 860 loff_t origsize = i_size_read(inode); 861 i_size_write(inode, outarg.attr.size); 862 if (origsize > outarg.attr.size) 863 vmtruncate(inode, outarg.attr.size); 864 } 865 fuse_change_attributes(inode, &outarg.attr); 866 fi->i_time = time_to_jiffies(outarg.attr_valid, 867 outarg.attr_valid_nsec); 868 } 869 } else if (err == -EINTR) 870 fuse_invalidate_attr(inode); 871 872 return err; 873 } 874 875 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, 876 struct kstat *stat) 877 { 878 struct inode *inode = entry->d_inode; 879 int err = fuse_revalidate(entry); 880 if (!err) 881 generic_fillattr(inode, stat); 882 883 return err; 884 } 885 886 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, 887 struct nameidata *nd) 888 { 889 struct inode *inode; 890 int err; 891 892 err = fuse_lookup_iget(dir, entry, &inode); 893 if (err) 894 return ERR_PTR(err); 895 if (inode && dir_alias(inode)) { 896 iput(inode); 897 return ERR_PTR(-EIO); 898 } 899 d_add(entry, inode); 900 return NULL; 901 } 902 903 static int fuse_setxattr(struct dentry *entry, const char *name, 904 const void *value, size_t size, int flags) 905 { 906 struct inode *inode = entry->d_inode; 907 struct fuse_conn *fc = get_fuse_conn(inode); 908 struct fuse_req *req; 909 struct fuse_setxattr_in inarg; 910 int err; 911 912 if (size > FUSE_XATTR_SIZE_MAX) 913 return -E2BIG; 914 915 if (fc->no_setxattr) 916 return -EOPNOTSUPP; 917 918 req = fuse_get_request(fc); 919 if (!req) 920 return -EINTR; 921 922 memset(&inarg, 0, sizeof(inarg)); 923 inarg.size = size; 924 inarg.flags = flags; 925 req->in.h.opcode = FUSE_SETXATTR; 926 req->in.h.nodeid = get_node_id(inode); 927 req->inode = inode; 928 req->in.numargs = 3; 929 req->in.args[0].size = sizeof(inarg); 930 req->in.args[0].value = &inarg; 931 req->in.args[1].size = strlen(name) + 1; 932 req->in.args[1].value = name; 933 req->in.args[2].size = size; 934 req->in.args[2].value = value; 935 request_send(fc, req); 936 err = req->out.h.error; 937 fuse_put_request(fc, req); 938 if (err == -ENOSYS) { 939 fc->no_setxattr = 1; 940 err = -EOPNOTSUPP; 941 } 942 return err; 943 } 944 945 static ssize_t fuse_getxattr(struct dentry *entry, const char *name, 946 void *value, size_t size) 947 { 948 struct inode *inode = entry->d_inode; 949 struct fuse_conn *fc = get_fuse_conn(inode); 950 struct fuse_req *req; 951 struct fuse_getxattr_in inarg; 952 struct fuse_getxattr_out outarg; 953 ssize_t ret; 954 955 if (fc->no_getxattr) 956 return -EOPNOTSUPP; 957 958 req = fuse_get_request(fc); 959 if (!req) 960 return -EINTR; 961 962 memset(&inarg, 0, sizeof(inarg)); 963 inarg.size = size; 964 req->in.h.opcode = FUSE_GETXATTR; 965 req->in.h.nodeid = get_node_id(inode); 966 req->inode = inode; 967 req->in.numargs = 2; 968 req->in.args[0].size = sizeof(inarg); 969 req->in.args[0].value = &inarg; 970 req->in.args[1].size = strlen(name) + 1; 971 req->in.args[1].value = name; 972 /* This is really two different operations rolled into one */ 973 req->out.numargs = 1; 974 if (size) { 975 req->out.argvar = 1; 976 req->out.args[0].size = size; 977 req->out.args[0].value = value; 978 } else { 979 req->out.args[0].size = sizeof(outarg); 980 req->out.args[0].value = &outarg; 981 } 982 request_send(fc, req); 983 ret = req->out.h.error; 984 if (!ret) 985 ret = size ? req->out.args[0].size : outarg.size; 986 else { 987 if (ret == -ENOSYS) { 988 fc->no_getxattr = 1; 989 ret = -EOPNOTSUPP; 990 } 991 } 992 fuse_put_request(fc, req); 993 return ret; 994 } 995 996 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) 997 { 998 struct inode *inode = entry->d_inode; 999 struct fuse_conn *fc = get_fuse_conn(inode); 1000 struct fuse_req *req; 1001 struct fuse_getxattr_in inarg; 1002 struct fuse_getxattr_out outarg; 1003 ssize_t ret; 1004 1005 if (fc->no_listxattr) 1006 return -EOPNOTSUPP; 1007 1008 req = fuse_get_request(fc); 1009 if (!req) 1010 return -EINTR; 1011 1012 memset(&inarg, 0, sizeof(inarg)); 1013 inarg.size = size; 1014 req->in.h.opcode = FUSE_LISTXATTR; 1015 req->in.h.nodeid = get_node_id(inode); 1016 req->inode = inode; 1017 req->in.numargs = 1; 1018 req->in.args[0].size = sizeof(inarg); 1019 req->in.args[0].value = &inarg; 1020 /* This is really two different operations rolled into one */ 1021 req->out.numargs = 1; 1022 if (size) { 1023 req->out.argvar = 1; 1024 req->out.args[0].size = size; 1025 req->out.args[0].value = list; 1026 } else { 1027 req->out.args[0].size = sizeof(outarg); 1028 req->out.args[0].value = &outarg; 1029 } 1030 request_send(fc, req); 1031 ret = req->out.h.error; 1032 if (!ret) 1033 ret = size ? req->out.args[0].size : outarg.size; 1034 else { 1035 if (ret == -ENOSYS) { 1036 fc->no_listxattr = 1; 1037 ret = -EOPNOTSUPP; 1038 } 1039 } 1040 fuse_put_request(fc, req); 1041 return ret; 1042 } 1043 1044 static int fuse_removexattr(struct dentry *entry, const char *name) 1045 { 1046 struct inode *inode = entry->d_inode; 1047 struct fuse_conn *fc = get_fuse_conn(inode); 1048 struct fuse_req *req; 1049 int err; 1050 1051 if (fc->no_removexattr) 1052 return -EOPNOTSUPP; 1053 1054 req = fuse_get_request(fc); 1055 if (!req) 1056 return -EINTR; 1057 1058 req->in.h.opcode = FUSE_REMOVEXATTR; 1059 req->in.h.nodeid = get_node_id(inode); 1060 req->inode = inode; 1061 req->in.numargs = 1; 1062 req->in.args[0].size = strlen(name) + 1; 1063 req->in.args[0].value = name; 1064 request_send(fc, req); 1065 err = req->out.h.error; 1066 fuse_put_request(fc, req); 1067 if (err == -ENOSYS) { 1068 fc->no_removexattr = 1; 1069 err = -EOPNOTSUPP; 1070 } 1071 return err; 1072 } 1073 1074 static struct inode_operations fuse_dir_inode_operations = { 1075 .lookup = fuse_lookup, 1076 .mkdir = fuse_mkdir, 1077 .symlink = fuse_symlink, 1078 .unlink = fuse_unlink, 1079 .rmdir = fuse_rmdir, 1080 .rename = fuse_rename, 1081 .link = fuse_link, 1082 .setattr = fuse_setattr, 1083 .create = fuse_create, 1084 .mknod = fuse_mknod, 1085 .permission = fuse_permission, 1086 .getattr = fuse_getattr, 1087 .setxattr = fuse_setxattr, 1088 .getxattr = fuse_getxattr, 1089 .listxattr = fuse_listxattr, 1090 .removexattr = fuse_removexattr, 1091 }; 1092 1093 static struct file_operations fuse_dir_operations = { 1094 .llseek = generic_file_llseek, 1095 .read = generic_read_dir, 1096 .readdir = fuse_readdir, 1097 .open = fuse_dir_open, 1098 .release = fuse_dir_release, 1099 .fsync = fuse_dir_fsync, 1100 }; 1101 1102 static struct inode_operations fuse_common_inode_operations = { 1103 .setattr = fuse_setattr, 1104 .permission = fuse_permission, 1105 .getattr = fuse_getattr, 1106 .setxattr = fuse_setxattr, 1107 .getxattr = fuse_getxattr, 1108 .listxattr = fuse_listxattr, 1109 .removexattr = fuse_removexattr, 1110 }; 1111 1112 static struct inode_operations fuse_symlink_inode_operations = { 1113 .setattr = fuse_setattr, 1114 .follow_link = fuse_follow_link, 1115 .put_link = fuse_put_link, 1116 .readlink = generic_readlink, 1117 .getattr = fuse_getattr, 1118 .setxattr = fuse_setxattr, 1119 .getxattr = fuse_getxattr, 1120 .listxattr = fuse_listxattr, 1121 .removexattr = fuse_removexattr, 1122 }; 1123 1124 void fuse_init_common(struct inode *inode) 1125 { 1126 inode->i_op = &fuse_common_inode_operations; 1127 } 1128 1129 void fuse_init_dir(struct inode *inode) 1130 { 1131 inode->i_op = &fuse_dir_inode_operations; 1132 inode->i_fop = &fuse_dir_operations; 1133 } 1134 1135 void fuse_init_symlink(struct inode *inode) 1136 { 1137 inode->i_op = &fuse_symlink_inode_operations; 1138 } 1139