1 /* 2 FUSE: Filesystem in Userspace 3 Copyright (C) 2001-2008 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/sched.h> 14 #include <linux/namei.h> 15 #include <linux/slab.h> 16 17 static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx) 18 { 19 struct fuse_conn *fc = get_fuse_conn(dir); 20 struct fuse_inode *fi = get_fuse_inode(dir); 21 22 if (!fc->do_readdirplus) 23 return false; 24 if (!fc->readdirplus_auto) 25 return true; 26 if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state)) 27 return true; 28 if (ctx->pos == 0) 29 return true; 30 return false; 31 } 32 33 static void fuse_advise_use_readdirplus(struct inode *dir) 34 { 35 struct fuse_inode *fi = get_fuse_inode(dir); 36 37 set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state); 38 } 39 40 #if BITS_PER_LONG >= 64 41 static inline void fuse_dentry_settime(struct dentry *entry, u64 time) 42 { 43 entry->d_time = time; 44 } 45 46 static inline u64 fuse_dentry_time(struct dentry *entry) 47 { 48 return entry->d_time; 49 } 50 #else 51 /* 52 * On 32 bit archs store the high 32 bits of time in d_fsdata 53 */ 54 static void fuse_dentry_settime(struct dentry *entry, u64 time) 55 { 56 entry->d_time = time; 57 entry->d_fsdata = (void *) (unsigned long) (time >> 32); 58 } 59 60 static u64 fuse_dentry_time(struct dentry *entry) 61 { 62 return (u64) entry->d_time + 63 ((u64) (unsigned long) entry->d_fsdata << 32); 64 } 65 #endif 66 67 /* 68 * FUSE caches dentries and attributes with separate timeout. The 69 * time in jiffies until the dentry/attributes are valid is stored in 70 * dentry->d_time and fuse_inode->i_time respectively. 71 */ 72 73 /* 74 * Calculate the time in jiffies until a dentry/attributes are valid 75 */ 76 static u64 time_to_jiffies(unsigned long sec, unsigned long nsec) 77 { 78 if (sec || nsec) { 79 struct timespec ts = {sec, nsec}; 80 return get_jiffies_64() + timespec_to_jiffies(&ts); 81 } else 82 return 0; 83 } 84 85 /* 86 * Set dentry and possibly attribute timeouts from the lookup/mk* 87 * replies 88 */ 89 static void fuse_change_entry_timeout(struct dentry *entry, 90 struct fuse_entry_out *o) 91 { 92 fuse_dentry_settime(entry, 93 time_to_jiffies(o->entry_valid, o->entry_valid_nsec)); 94 } 95 96 static u64 attr_timeout(struct fuse_attr_out *o) 97 { 98 return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); 99 } 100 101 static u64 entry_attr_timeout(struct fuse_entry_out *o) 102 { 103 return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); 104 } 105 106 /* 107 * Mark the attributes as stale, so that at the next call to 108 * ->getattr() they will be fetched from userspace 109 */ 110 void fuse_invalidate_attr(struct inode *inode) 111 { 112 get_fuse_inode(inode)->i_time = 0; 113 } 114 115 /* 116 * Just mark the entry as stale, so that a next attempt to look it up 117 * will result in a new lookup call to userspace 118 * 119 * This is called when a dentry is about to become negative and the 120 * timeout is unknown (unlink, rmdir, rename and in some cases 121 * lookup) 122 */ 123 void fuse_invalidate_entry_cache(struct dentry *entry) 124 { 125 fuse_dentry_settime(entry, 0); 126 } 127 128 /* 129 * Same as fuse_invalidate_entry_cache(), but also try to remove the 130 * dentry from the hash 131 */ 132 static void fuse_invalidate_entry(struct dentry *entry) 133 { 134 d_invalidate(entry); 135 fuse_invalidate_entry_cache(entry); 136 } 137 138 static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_req *req, 139 u64 nodeid, struct qstr *name, 140 struct fuse_entry_out *outarg) 141 { 142 memset(outarg, 0, sizeof(struct fuse_entry_out)); 143 req->in.h.opcode = FUSE_LOOKUP; 144 req->in.h.nodeid = nodeid; 145 req->in.numargs = 1; 146 req->in.args[0].size = name->len + 1; 147 req->in.args[0].value = name->name; 148 req->out.numargs = 1; 149 if (fc->minor < 9) 150 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; 151 else 152 req->out.args[0].size = sizeof(struct fuse_entry_out); 153 req->out.args[0].value = outarg; 154 } 155 156 u64 fuse_get_attr_version(struct fuse_conn *fc) 157 { 158 u64 curr_version; 159 160 /* 161 * The spin lock isn't actually needed on 64bit archs, but we 162 * don't yet care too much about such optimizations. 163 */ 164 spin_lock(&fc->lock); 165 curr_version = fc->attr_version; 166 spin_unlock(&fc->lock); 167 168 return curr_version; 169 } 170 171 /* 172 * Check whether the dentry is still valid 173 * 174 * If the entry validity timeout has expired and the dentry is 175 * positive, try to redo the lookup. If the lookup results in a 176 * different inode, then let the VFS invalidate the dentry and redo 177 * the lookup once more. If the lookup results in the same inode, 178 * then refresh the attributes, timeouts and mark the dentry valid. 179 */ 180 static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags) 181 { 182 struct inode *inode; 183 struct dentry *parent; 184 struct fuse_conn *fc; 185 186 inode = ACCESS_ONCE(entry->d_inode); 187 if (inode && is_bad_inode(inode)) 188 return 0; 189 else if (fuse_dentry_time(entry) < get_jiffies_64()) { 190 int err; 191 struct fuse_entry_out outarg; 192 struct fuse_req *req; 193 struct fuse_forget_link *forget; 194 u64 attr_version; 195 196 /* For negative dentries, always do a fresh lookup */ 197 if (!inode) 198 return 0; 199 200 if (flags & LOOKUP_RCU) 201 return -ECHILD; 202 203 fc = get_fuse_conn(inode); 204 req = fuse_get_req_nopages(fc); 205 if (IS_ERR(req)) 206 return 0; 207 208 forget = fuse_alloc_forget(); 209 if (!forget) { 210 fuse_put_request(fc, req); 211 return 0; 212 } 213 214 attr_version = fuse_get_attr_version(fc); 215 216 parent = dget_parent(entry); 217 fuse_lookup_init(fc, req, get_node_id(parent->d_inode), 218 &entry->d_name, &outarg); 219 fuse_request_send(fc, req); 220 dput(parent); 221 err = req->out.h.error; 222 fuse_put_request(fc, req); 223 /* Zero nodeid is same as -ENOENT */ 224 if (!err && !outarg.nodeid) 225 err = -ENOENT; 226 if (!err) { 227 struct fuse_inode *fi = get_fuse_inode(inode); 228 if (outarg.nodeid != get_node_id(inode)) { 229 fuse_queue_forget(fc, forget, outarg.nodeid, 1); 230 return 0; 231 } 232 spin_lock(&fc->lock); 233 fi->nlookup++; 234 spin_unlock(&fc->lock); 235 } 236 kfree(forget); 237 if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) 238 return 0; 239 240 fuse_change_attributes(inode, &outarg.attr, 241 entry_attr_timeout(&outarg), 242 attr_version); 243 fuse_change_entry_timeout(entry, &outarg); 244 } else if (inode) { 245 fc = get_fuse_conn(inode); 246 if (fc->readdirplus_auto) { 247 parent = dget_parent(entry); 248 fuse_advise_use_readdirplus(parent->d_inode); 249 dput(parent); 250 } 251 } 252 return 1; 253 } 254 255 static int invalid_nodeid(u64 nodeid) 256 { 257 return !nodeid || nodeid == FUSE_ROOT_ID; 258 } 259 260 const struct dentry_operations fuse_dentry_operations = { 261 .d_revalidate = fuse_dentry_revalidate, 262 }; 263 264 int fuse_valid_type(int m) 265 { 266 return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) || 267 S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m); 268 } 269 270 /* 271 * Add a directory inode to a dentry, ensuring that no other dentry 272 * refers to this inode. Called with fc->inst_mutex. 273 */ 274 static struct dentry *fuse_d_add_directory(struct dentry *entry, 275 struct inode *inode) 276 { 277 struct dentry *alias = d_find_alias(inode); 278 if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) { 279 /* This tries to shrink the subtree below alias */ 280 fuse_invalidate_entry(alias); 281 dput(alias); 282 if (!hlist_empty(&inode->i_dentry)) 283 return ERR_PTR(-EBUSY); 284 } else { 285 dput(alias); 286 } 287 return d_splice_alias(inode, entry); 288 } 289 290 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name, 291 struct fuse_entry_out *outarg, struct inode **inode) 292 { 293 struct fuse_conn *fc = get_fuse_conn_super(sb); 294 struct fuse_req *req; 295 struct fuse_forget_link *forget; 296 u64 attr_version; 297 int err; 298 299 *inode = NULL; 300 err = -ENAMETOOLONG; 301 if (name->len > FUSE_NAME_MAX) 302 goto out; 303 304 req = fuse_get_req_nopages(fc); 305 err = PTR_ERR(req); 306 if (IS_ERR(req)) 307 goto out; 308 309 forget = fuse_alloc_forget(); 310 err = -ENOMEM; 311 if (!forget) { 312 fuse_put_request(fc, req); 313 goto out; 314 } 315 316 attr_version = fuse_get_attr_version(fc); 317 318 fuse_lookup_init(fc, req, nodeid, name, outarg); 319 fuse_request_send(fc, req); 320 err = req->out.h.error; 321 fuse_put_request(fc, req); 322 /* Zero nodeid is same as -ENOENT, but with valid timeout */ 323 if (err || !outarg->nodeid) 324 goto out_put_forget; 325 326 err = -EIO; 327 if (!outarg->nodeid) 328 goto out_put_forget; 329 if (!fuse_valid_type(outarg->attr.mode)) 330 goto out_put_forget; 331 332 *inode = fuse_iget(sb, outarg->nodeid, outarg->generation, 333 &outarg->attr, entry_attr_timeout(outarg), 334 attr_version); 335 err = -ENOMEM; 336 if (!*inode) { 337 fuse_queue_forget(fc, forget, outarg->nodeid, 1); 338 goto out; 339 } 340 err = 0; 341 342 out_put_forget: 343 kfree(forget); 344 out: 345 return err; 346 } 347 348 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, 349 unsigned int flags) 350 { 351 int err; 352 struct fuse_entry_out outarg; 353 struct inode *inode; 354 struct dentry *newent; 355 struct fuse_conn *fc = get_fuse_conn(dir); 356 bool outarg_valid = true; 357 358 err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, 359 &outarg, &inode); 360 if (err == -ENOENT) { 361 outarg_valid = false; 362 err = 0; 363 } 364 if (err) 365 goto out_err; 366 367 err = -EIO; 368 if (inode && get_node_id(inode) == FUSE_ROOT_ID) 369 goto out_iput; 370 371 if (inode && S_ISDIR(inode->i_mode)) { 372 mutex_lock(&fc->inst_mutex); 373 newent = fuse_d_add_directory(entry, inode); 374 mutex_unlock(&fc->inst_mutex); 375 err = PTR_ERR(newent); 376 if (IS_ERR(newent)) 377 goto out_iput; 378 } else { 379 newent = d_splice_alias(inode, entry); 380 } 381 382 entry = newent ? newent : entry; 383 if (outarg_valid) 384 fuse_change_entry_timeout(entry, &outarg); 385 else 386 fuse_invalidate_entry_cache(entry); 387 388 fuse_advise_use_readdirplus(dir); 389 return newent; 390 391 out_iput: 392 iput(inode); 393 out_err: 394 return ERR_PTR(err); 395 } 396 397 /* 398 * Atomic create+open operation 399 * 400 * If the filesystem doesn't support this, then fall back to separate 401 * 'mknod' + 'open' requests. 402 */ 403 static int fuse_create_open(struct inode *dir, struct dentry *entry, 404 struct file *file, unsigned flags, 405 umode_t mode, int *opened) 406 { 407 int err; 408 struct inode *inode; 409 struct fuse_conn *fc = get_fuse_conn(dir); 410 struct fuse_req *req; 411 struct fuse_forget_link *forget; 412 struct fuse_create_in inarg; 413 struct fuse_open_out outopen; 414 struct fuse_entry_out outentry; 415 struct fuse_file *ff; 416 417 /* Userspace expects S_IFREG in create mode */ 418 BUG_ON((mode & S_IFMT) != S_IFREG); 419 420 forget = fuse_alloc_forget(); 421 err = -ENOMEM; 422 if (!forget) 423 goto out_err; 424 425 req = fuse_get_req_nopages(fc); 426 err = PTR_ERR(req); 427 if (IS_ERR(req)) 428 goto out_put_forget_req; 429 430 err = -ENOMEM; 431 ff = fuse_file_alloc(fc); 432 if (!ff) 433 goto out_put_request; 434 435 if (!fc->dont_mask) 436 mode &= ~current_umask(); 437 438 flags &= ~O_NOCTTY; 439 memset(&inarg, 0, sizeof(inarg)); 440 memset(&outentry, 0, sizeof(outentry)); 441 inarg.flags = flags; 442 inarg.mode = mode; 443 inarg.umask = current_umask(); 444 req->in.h.opcode = FUSE_CREATE; 445 req->in.h.nodeid = get_node_id(dir); 446 req->in.numargs = 2; 447 req->in.args[0].size = fc->minor < 12 ? sizeof(struct fuse_open_in) : 448 sizeof(inarg); 449 req->in.args[0].value = &inarg; 450 req->in.args[1].size = entry->d_name.len + 1; 451 req->in.args[1].value = entry->d_name.name; 452 req->out.numargs = 2; 453 if (fc->minor < 9) 454 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; 455 else 456 req->out.args[0].size = sizeof(outentry); 457 req->out.args[0].value = &outentry; 458 req->out.args[1].size = sizeof(outopen); 459 req->out.args[1].value = &outopen; 460 fuse_request_send(fc, req); 461 err = req->out.h.error; 462 if (err) 463 goto out_free_ff; 464 465 err = -EIO; 466 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid)) 467 goto out_free_ff; 468 469 fuse_put_request(fc, req); 470 ff->fh = outopen.fh; 471 ff->nodeid = outentry.nodeid; 472 ff->open_flags = outopen.open_flags; 473 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, 474 &outentry.attr, entry_attr_timeout(&outentry), 0); 475 if (!inode) { 476 flags &= ~(O_CREAT | O_EXCL | O_TRUNC); 477 fuse_sync_release(ff, flags); 478 fuse_queue_forget(fc, forget, outentry.nodeid, 1); 479 err = -ENOMEM; 480 goto out_err; 481 } 482 kfree(forget); 483 d_instantiate(entry, inode); 484 fuse_change_entry_timeout(entry, &outentry); 485 fuse_invalidate_attr(dir); 486 err = finish_open(file, entry, generic_file_open, opened); 487 if (err) { 488 fuse_sync_release(ff, flags); 489 } else { 490 file->private_data = fuse_file_get(ff); 491 fuse_finish_open(inode, file); 492 } 493 return err; 494 495 out_free_ff: 496 fuse_file_free(ff); 497 out_put_request: 498 fuse_put_request(fc, req); 499 out_put_forget_req: 500 kfree(forget); 501 out_err: 502 return err; 503 } 504 505 static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t); 506 static int fuse_atomic_open(struct inode *dir, struct dentry *entry, 507 struct file *file, unsigned flags, 508 umode_t mode, int *opened) 509 { 510 int err; 511 struct fuse_conn *fc = get_fuse_conn(dir); 512 struct dentry *res = NULL; 513 514 if (d_unhashed(entry)) { 515 res = fuse_lookup(dir, entry, 0); 516 if (IS_ERR(res)) 517 return PTR_ERR(res); 518 519 if (res) 520 entry = res; 521 } 522 523 if (!(flags & O_CREAT) || entry->d_inode) 524 goto no_open; 525 526 /* Only creates */ 527 *opened |= FILE_CREATED; 528 529 if (fc->no_create) 530 goto mknod; 531 532 err = fuse_create_open(dir, entry, file, flags, mode, opened); 533 if (err == -ENOSYS) { 534 fc->no_create = 1; 535 goto mknod; 536 } 537 out_dput: 538 dput(res); 539 return err; 540 541 mknod: 542 err = fuse_mknod(dir, entry, mode, 0); 543 if (err) 544 goto out_dput; 545 no_open: 546 return finish_no_open(file, res); 547 } 548 549 /* 550 * Code shared between mknod, mkdir, symlink and link 551 */ 552 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req, 553 struct inode *dir, struct dentry *entry, 554 umode_t mode) 555 { 556 struct fuse_entry_out outarg; 557 struct inode *inode; 558 int err; 559 struct fuse_forget_link *forget; 560 561 forget = fuse_alloc_forget(); 562 if (!forget) { 563 fuse_put_request(fc, req); 564 return -ENOMEM; 565 } 566 567 memset(&outarg, 0, sizeof(outarg)); 568 req->in.h.nodeid = get_node_id(dir); 569 req->out.numargs = 1; 570 if (fc->minor < 9) 571 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; 572 else 573 req->out.args[0].size = sizeof(outarg); 574 req->out.args[0].value = &outarg; 575 fuse_request_send(fc, req); 576 err = req->out.h.error; 577 fuse_put_request(fc, req); 578 if (err) 579 goto out_put_forget_req; 580 581 err = -EIO; 582 if (invalid_nodeid(outarg.nodeid)) 583 goto out_put_forget_req; 584 585 if ((outarg.attr.mode ^ mode) & S_IFMT) 586 goto out_put_forget_req; 587 588 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, 589 &outarg.attr, entry_attr_timeout(&outarg), 0); 590 if (!inode) { 591 fuse_queue_forget(fc, forget, outarg.nodeid, 1); 592 return -ENOMEM; 593 } 594 kfree(forget); 595 596 if (S_ISDIR(inode->i_mode)) { 597 struct dentry *alias; 598 mutex_lock(&fc->inst_mutex); 599 alias = d_find_alias(inode); 600 if (alias) { 601 /* New directory must have moved since mkdir */ 602 mutex_unlock(&fc->inst_mutex); 603 dput(alias); 604 iput(inode); 605 return -EBUSY; 606 } 607 d_instantiate(entry, inode); 608 mutex_unlock(&fc->inst_mutex); 609 } else 610 d_instantiate(entry, inode); 611 612 fuse_change_entry_timeout(entry, &outarg); 613 fuse_invalidate_attr(dir); 614 return 0; 615 616 out_put_forget_req: 617 kfree(forget); 618 return err; 619 } 620 621 static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode, 622 dev_t rdev) 623 { 624 struct fuse_mknod_in inarg; 625 struct fuse_conn *fc = get_fuse_conn(dir); 626 struct fuse_req *req = fuse_get_req_nopages(fc); 627 if (IS_ERR(req)) 628 return PTR_ERR(req); 629 630 if (!fc->dont_mask) 631 mode &= ~current_umask(); 632 633 memset(&inarg, 0, sizeof(inarg)); 634 inarg.mode = mode; 635 inarg.rdev = new_encode_dev(rdev); 636 inarg.umask = current_umask(); 637 req->in.h.opcode = FUSE_MKNOD; 638 req->in.numargs = 2; 639 req->in.args[0].size = fc->minor < 12 ? FUSE_COMPAT_MKNOD_IN_SIZE : 640 sizeof(inarg); 641 req->in.args[0].value = &inarg; 642 req->in.args[1].size = entry->d_name.len + 1; 643 req->in.args[1].value = entry->d_name.name; 644 return create_new_entry(fc, req, dir, entry, mode); 645 } 646 647 static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode, 648 bool excl) 649 { 650 return fuse_mknod(dir, entry, mode, 0); 651 } 652 653 static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode) 654 { 655 struct fuse_mkdir_in inarg; 656 struct fuse_conn *fc = get_fuse_conn(dir); 657 struct fuse_req *req = fuse_get_req_nopages(fc); 658 if (IS_ERR(req)) 659 return PTR_ERR(req); 660 661 if (!fc->dont_mask) 662 mode &= ~current_umask(); 663 664 memset(&inarg, 0, sizeof(inarg)); 665 inarg.mode = mode; 666 inarg.umask = current_umask(); 667 req->in.h.opcode = FUSE_MKDIR; 668 req->in.numargs = 2; 669 req->in.args[0].size = sizeof(inarg); 670 req->in.args[0].value = &inarg; 671 req->in.args[1].size = entry->d_name.len + 1; 672 req->in.args[1].value = entry->d_name.name; 673 return create_new_entry(fc, req, dir, entry, S_IFDIR); 674 } 675 676 static int fuse_symlink(struct inode *dir, struct dentry *entry, 677 const char *link) 678 { 679 struct fuse_conn *fc = get_fuse_conn(dir); 680 unsigned len = strlen(link) + 1; 681 struct fuse_req *req = fuse_get_req_nopages(fc); 682 if (IS_ERR(req)) 683 return PTR_ERR(req); 684 685 req->in.h.opcode = FUSE_SYMLINK; 686 req->in.numargs = 2; 687 req->in.args[0].size = entry->d_name.len + 1; 688 req->in.args[0].value = entry->d_name.name; 689 req->in.args[1].size = len; 690 req->in.args[1].value = link; 691 return create_new_entry(fc, req, dir, entry, S_IFLNK); 692 } 693 694 static int fuse_unlink(struct inode *dir, struct dentry *entry) 695 { 696 int err; 697 struct fuse_conn *fc = get_fuse_conn(dir); 698 struct fuse_req *req = fuse_get_req_nopages(fc); 699 if (IS_ERR(req)) 700 return PTR_ERR(req); 701 702 req->in.h.opcode = FUSE_UNLINK; 703 req->in.h.nodeid = get_node_id(dir); 704 req->in.numargs = 1; 705 req->in.args[0].size = entry->d_name.len + 1; 706 req->in.args[0].value = entry->d_name.name; 707 fuse_request_send(fc, req); 708 err = req->out.h.error; 709 fuse_put_request(fc, req); 710 if (!err) { 711 struct inode *inode = entry->d_inode; 712 struct fuse_inode *fi = get_fuse_inode(inode); 713 714 spin_lock(&fc->lock); 715 fi->attr_version = ++fc->attr_version; 716 /* 717 * If i_nlink == 0 then unlink doesn't make sense, yet this can 718 * happen if userspace filesystem is careless. It would be 719 * difficult to enforce correct nlink usage so just ignore this 720 * condition here 721 */ 722 if (inode->i_nlink > 0) 723 drop_nlink(inode); 724 spin_unlock(&fc->lock); 725 fuse_invalidate_attr(inode); 726 fuse_invalidate_attr(dir); 727 fuse_invalidate_entry_cache(entry); 728 } else if (err == -EINTR) 729 fuse_invalidate_entry(entry); 730 return err; 731 } 732 733 static int fuse_rmdir(struct inode *dir, struct dentry *entry) 734 { 735 int err; 736 struct fuse_conn *fc = get_fuse_conn(dir); 737 struct fuse_req *req = fuse_get_req_nopages(fc); 738 if (IS_ERR(req)) 739 return PTR_ERR(req); 740 741 req->in.h.opcode = FUSE_RMDIR; 742 req->in.h.nodeid = get_node_id(dir); 743 req->in.numargs = 1; 744 req->in.args[0].size = entry->d_name.len + 1; 745 req->in.args[0].value = entry->d_name.name; 746 fuse_request_send(fc, req); 747 err = req->out.h.error; 748 fuse_put_request(fc, req); 749 if (!err) { 750 clear_nlink(entry->d_inode); 751 fuse_invalidate_attr(dir); 752 fuse_invalidate_entry_cache(entry); 753 } else if (err == -EINTR) 754 fuse_invalidate_entry(entry); 755 return err; 756 } 757 758 static int fuse_rename(struct inode *olddir, struct dentry *oldent, 759 struct inode *newdir, struct dentry *newent) 760 { 761 int err; 762 struct fuse_rename_in inarg; 763 struct fuse_conn *fc = get_fuse_conn(olddir); 764 struct fuse_req *req = fuse_get_req_nopages(fc); 765 766 if (IS_ERR(req)) 767 return PTR_ERR(req); 768 769 memset(&inarg, 0, sizeof(inarg)); 770 inarg.newdir = get_node_id(newdir); 771 req->in.h.opcode = FUSE_RENAME; 772 req->in.h.nodeid = get_node_id(olddir); 773 req->in.numargs = 3; 774 req->in.args[0].size = sizeof(inarg); 775 req->in.args[0].value = &inarg; 776 req->in.args[1].size = oldent->d_name.len + 1; 777 req->in.args[1].value = oldent->d_name.name; 778 req->in.args[2].size = newent->d_name.len + 1; 779 req->in.args[2].value = newent->d_name.name; 780 fuse_request_send(fc, req); 781 err = req->out.h.error; 782 fuse_put_request(fc, req); 783 if (!err) { 784 /* ctime changes */ 785 fuse_invalidate_attr(oldent->d_inode); 786 787 fuse_invalidate_attr(olddir); 788 if (olddir != newdir) 789 fuse_invalidate_attr(newdir); 790 791 /* newent will end up negative */ 792 if (newent->d_inode) { 793 fuse_invalidate_attr(newent->d_inode); 794 fuse_invalidate_entry_cache(newent); 795 } 796 } else if (err == -EINTR) { 797 /* If request was interrupted, DEITY only knows if the 798 rename actually took place. If the invalidation 799 fails (e.g. some process has CWD under the renamed 800 directory), then there can be inconsistency between 801 the dcache and the real filesystem. Tough luck. */ 802 fuse_invalidate_entry(oldent); 803 if (newent->d_inode) 804 fuse_invalidate_entry(newent); 805 } 806 807 return err; 808 } 809 810 static int fuse_link(struct dentry *entry, struct inode *newdir, 811 struct dentry *newent) 812 { 813 int err; 814 struct fuse_link_in inarg; 815 struct inode *inode = entry->d_inode; 816 struct fuse_conn *fc = get_fuse_conn(inode); 817 struct fuse_req *req = fuse_get_req_nopages(fc); 818 if (IS_ERR(req)) 819 return PTR_ERR(req); 820 821 memset(&inarg, 0, sizeof(inarg)); 822 inarg.oldnodeid = get_node_id(inode); 823 req->in.h.opcode = FUSE_LINK; 824 req->in.numargs = 2; 825 req->in.args[0].size = sizeof(inarg); 826 req->in.args[0].value = &inarg; 827 req->in.args[1].size = newent->d_name.len + 1; 828 req->in.args[1].value = newent->d_name.name; 829 err = create_new_entry(fc, req, newdir, newent, inode->i_mode); 830 /* Contrary to "normal" filesystems it can happen that link 831 makes two "logical" inodes point to the same "physical" 832 inode. We invalidate the attributes of the old one, so it 833 will reflect changes in the backing inode (link count, 834 etc.) 835 */ 836 if (!err) { 837 struct fuse_inode *fi = get_fuse_inode(inode); 838 839 spin_lock(&fc->lock); 840 fi->attr_version = ++fc->attr_version; 841 inc_nlink(inode); 842 spin_unlock(&fc->lock); 843 fuse_invalidate_attr(inode); 844 } else if (err == -EINTR) { 845 fuse_invalidate_attr(inode); 846 } 847 return err; 848 } 849 850 static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, 851 struct kstat *stat) 852 { 853 unsigned int blkbits; 854 855 stat->dev = inode->i_sb->s_dev; 856 stat->ino = attr->ino; 857 stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 858 stat->nlink = attr->nlink; 859 stat->uid = make_kuid(&init_user_ns, attr->uid); 860 stat->gid = make_kgid(&init_user_ns, attr->gid); 861 stat->rdev = inode->i_rdev; 862 stat->atime.tv_sec = attr->atime; 863 stat->atime.tv_nsec = attr->atimensec; 864 stat->mtime.tv_sec = attr->mtime; 865 stat->mtime.tv_nsec = attr->mtimensec; 866 stat->ctime.tv_sec = attr->ctime; 867 stat->ctime.tv_nsec = attr->ctimensec; 868 stat->size = attr->size; 869 stat->blocks = attr->blocks; 870 871 if (attr->blksize != 0) 872 blkbits = ilog2(attr->blksize); 873 else 874 blkbits = inode->i_sb->s_blocksize_bits; 875 876 stat->blksize = 1 << blkbits; 877 } 878 879 static int fuse_do_getattr(struct inode *inode, struct kstat *stat, 880 struct file *file) 881 { 882 int err; 883 struct fuse_getattr_in inarg; 884 struct fuse_attr_out outarg; 885 struct fuse_conn *fc = get_fuse_conn(inode); 886 struct fuse_req *req; 887 u64 attr_version; 888 889 req = fuse_get_req_nopages(fc); 890 if (IS_ERR(req)) 891 return PTR_ERR(req); 892 893 attr_version = fuse_get_attr_version(fc); 894 895 memset(&inarg, 0, sizeof(inarg)); 896 memset(&outarg, 0, sizeof(outarg)); 897 /* Directories have separate file-handle space */ 898 if (file && S_ISREG(inode->i_mode)) { 899 struct fuse_file *ff = file->private_data; 900 901 inarg.getattr_flags |= FUSE_GETATTR_FH; 902 inarg.fh = ff->fh; 903 } 904 req->in.h.opcode = FUSE_GETATTR; 905 req->in.h.nodeid = get_node_id(inode); 906 req->in.numargs = 1; 907 req->in.args[0].size = sizeof(inarg); 908 req->in.args[0].value = &inarg; 909 req->out.numargs = 1; 910 if (fc->minor < 9) 911 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; 912 else 913 req->out.args[0].size = sizeof(outarg); 914 req->out.args[0].value = &outarg; 915 fuse_request_send(fc, req); 916 err = req->out.h.error; 917 fuse_put_request(fc, req); 918 if (!err) { 919 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { 920 make_bad_inode(inode); 921 err = -EIO; 922 } else { 923 fuse_change_attributes(inode, &outarg.attr, 924 attr_timeout(&outarg), 925 attr_version); 926 if (stat) 927 fuse_fillattr(inode, &outarg.attr, stat); 928 } 929 } 930 return err; 931 } 932 933 int fuse_update_attributes(struct inode *inode, struct kstat *stat, 934 struct file *file, bool *refreshed) 935 { 936 struct fuse_inode *fi = get_fuse_inode(inode); 937 int err; 938 bool r; 939 940 if (fi->i_time < get_jiffies_64()) { 941 r = true; 942 err = fuse_do_getattr(inode, stat, file); 943 } else { 944 r = false; 945 err = 0; 946 if (stat) { 947 generic_fillattr(inode, stat); 948 stat->mode = fi->orig_i_mode; 949 stat->ino = fi->orig_ino; 950 } 951 } 952 953 if (refreshed != NULL) 954 *refreshed = r; 955 956 return err; 957 } 958 959 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid, 960 u64 child_nodeid, struct qstr *name) 961 { 962 int err = -ENOTDIR; 963 struct inode *parent; 964 struct dentry *dir; 965 struct dentry *entry; 966 967 parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid); 968 if (!parent) 969 return -ENOENT; 970 971 mutex_lock(&parent->i_mutex); 972 if (!S_ISDIR(parent->i_mode)) 973 goto unlock; 974 975 err = -ENOENT; 976 dir = d_find_alias(parent); 977 if (!dir) 978 goto unlock; 979 980 entry = d_lookup(dir, name); 981 dput(dir); 982 if (!entry) 983 goto unlock; 984 985 fuse_invalidate_attr(parent); 986 fuse_invalidate_entry(entry); 987 988 if (child_nodeid != 0 && entry->d_inode) { 989 mutex_lock(&entry->d_inode->i_mutex); 990 if (get_node_id(entry->d_inode) != child_nodeid) { 991 err = -ENOENT; 992 goto badentry; 993 } 994 if (d_mountpoint(entry)) { 995 err = -EBUSY; 996 goto badentry; 997 } 998 if (S_ISDIR(entry->d_inode->i_mode)) { 999 shrink_dcache_parent(entry); 1000 if (!simple_empty(entry)) { 1001 err = -ENOTEMPTY; 1002 goto badentry; 1003 } 1004 entry->d_inode->i_flags |= S_DEAD; 1005 } 1006 dont_mount(entry); 1007 clear_nlink(entry->d_inode); 1008 err = 0; 1009 badentry: 1010 mutex_unlock(&entry->d_inode->i_mutex); 1011 if (!err) 1012 d_delete(entry); 1013 } else { 1014 err = 0; 1015 } 1016 dput(entry); 1017 1018 unlock: 1019 mutex_unlock(&parent->i_mutex); 1020 iput(parent); 1021 return err; 1022 } 1023 1024 /* 1025 * Calling into a user-controlled filesystem gives the filesystem 1026 * daemon ptrace-like capabilities over the current process. This 1027 * means, that the filesystem daemon is able to record the exact 1028 * filesystem operations performed, and can also control the behavior 1029 * of the requester process in otherwise impossible ways. For example 1030 * it can delay the operation for arbitrary length of time allowing 1031 * DoS against the requester. 1032 * 1033 * For this reason only those processes can call into the filesystem, 1034 * for which the owner of the mount has ptrace privilege. This 1035 * excludes processes started by other users, suid or sgid processes. 1036 */ 1037 int fuse_allow_current_process(struct fuse_conn *fc) 1038 { 1039 const struct cred *cred; 1040 1041 if (fc->flags & FUSE_ALLOW_OTHER) 1042 return 1; 1043 1044 cred = current_cred(); 1045 if (uid_eq(cred->euid, fc->user_id) && 1046 uid_eq(cred->suid, fc->user_id) && 1047 uid_eq(cred->uid, fc->user_id) && 1048 gid_eq(cred->egid, fc->group_id) && 1049 gid_eq(cred->sgid, fc->group_id) && 1050 gid_eq(cred->gid, fc->group_id)) 1051 return 1; 1052 1053 return 0; 1054 } 1055 1056 static int fuse_access(struct inode *inode, int mask) 1057 { 1058 struct fuse_conn *fc = get_fuse_conn(inode); 1059 struct fuse_req *req; 1060 struct fuse_access_in inarg; 1061 int err; 1062 1063 if (fc->no_access) 1064 return 0; 1065 1066 req = fuse_get_req_nopages(fc); 1067 if (IS_ERR(req)) 1068 return PTR_ERR(req); 1069 1070 memset(&inarg, 0, sizeof(inarg)); 1071 inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC); 1072 req->in.h.opcode = FUSE_ACCESS; 1073 req->in.h.nodeid = get_node_id(inode); 1074 req->in.numargs = 1; 1075 req->in.args[0].size = sizeof(inarg); 1076 req->in.args[0].value = &inarg; 1077 fuse_request_send(fc, req); 1078 err = req->out.h.error; 1079 fuse_put_request(fc, req); 1080 if (err == -ENOSYS) { 1081 fc->no_access = 1; 1082 err = 0; 1083 } 1084 return err; 1085 } 1086 1087 static int fuse_perm_getattr(struct inode *inode, int mask) 1088 { 1089 if (mask & MAY_NOT_BLOCK) 1090 return -ECHILD; 1091 1092 return fuse_do_getattr(inode, NULL, NULL); 1093 } 1094 1095 /* 1096 * Check permission. The two basic access models of FUSE are: 1097 * 1098 * 1) Local access checking ('default_permissions' mount option) based 1099 * on file mode. This is the plain old disk filesystem permission 1100 * modell. 1101 * 1102 * 2) "Remote" access checking, where server is responsible for 1103 * checking permission in each inode operation. An exception to this 1104 * is if ->permission() was invoked from sys_access() in which case an 1105 * access request is sent. Execute permission is still checked 1106 * locally based on file mode. 1107 */ 1108 static int fuse_permission(struct inode *inode, int mask) 1109 { 1110 struct fuse_conn *fc = get_fuse_conn(inode); 1111 bool refreshed = false; 1112 int err = 0; 1113 1114 if (!fuse_allow_current_process(fc)) 1115 return -EACCES; 1116 1117 /* 1118 * If attributes are needed, refresh them before proceeding 1119 */ 1120 if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) || 1121 ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) { 1122 struct fuse_inode *fi = get_fuse_inode(inode); 1123 1124 if (fi->i_time < get_jiffies_64()) { 1125 refreshed = true; 1126 1127 err = fuse_perm_getattr(inode, mask); 1128 if (err) 1129 return err; 1130 } 1131 } 1132 1133 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { 1134 err = generic_permission(inode, mask); 1135 1136 /* If permission is denied, try to refresh file 1137 attributes. This is also needed, because the root 1138 node will at first have no permissions */ 1139 if (err == -EACCES && !refreshed) { 1140 err = fuse_perm_getattr(inode, mask); 1141 if (!err) 1142 err = generic_permission(inode, mask); 1143 } 1144 1145 /* Note: the opposite of the above test does not 1146 exist. So if permissions are revoked this won't be 1147 noticed immediately, only after the attribute 1148 timeout has expired */ 1149 } else if (mask & (MAY_ACCESS | MAY_CHDIR)) { 1150 if (mask & MAY_NOT_BLOCK) 1151 return -ECHILD; 1152 1153 err = fuse_access(inode, mask); 1154 } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { 1155 if (!(inode->i_mode & S_IXUGO)) { 1156 if (refreshed) 1157 return -EACCES; 1158 1159 err = fuse_perm_getattr(inode, mask); 1160 if (!err && !(inode->i_mode & S_IXUGO)) 1161 return -EACCES; 1162 } 1163 } 1164 return err; 1165 } 1166 1167 static int parse_dirfile(char *buf, size_t nbytes, struct file *file, 1168 struct dir_context *ctx) 1169 { 1170 while (nbytes >= FUSE_NAME_OFFSET) { 1171 struct fuse_dirent *dirent = (struct fuse_dirent *) buf; 1172 size_t reclen = FUSE_DIRENT_SIZE(dirent); 1173 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) 1174 return -EIO; 1175 if (reclen > nbytes) 1176 break; 1177 1178 if (!dir_emit(ctx, dirent->name, dirent->namelen, 1179 dirent->ino, dirent->type)) 1180 break; 1181 1182 buf += reclen; 1183 nbytes -= reclen; 1184 ctx->pos = dirent->off; 1185 } 1186 1187 return 0; 1188 } 1189 1190 static int fuse_direntplus_link(struct file *file, 1191 struct fuse_direntplus *direntplus, 1192 u64 attr_version) 1193 { 1194 int err; 1195 struct fuse_entry_out *o = &direntplus->entry_out; 1196 struct fuse_dirent *dirent = &direntplus->dirent; 1197 struct dentry *parent = file->f_path.dentry; 1198 struct qstr name = QSTR_INIT(dirent->name, dirent->namelen); 1199 struct dentry *dentry; 1200 struct dentry *alias; 1201 struct inode *dir = parent->d_inode; 1202 struct fuse_conn *fc; 1203 struct inode *inode; 1204 1205 if (!o->nodeid) { 1206 /* 1207 * Unlike in the case of fuse_lookup, zero nodeid does not mean 1208 * ENOENT. Instead, it only means the userspace filesystem did 1209 * not want to return attributes/handle for this entry. 1210 * 1211 * So do nothing. 1212 */ 1213 return 0; 1214 } 1215 1216 if (name.name[0] == '.') { 1217 /* 1218 * We could potentially refresh the attributes of the directory 1219 * and its parent? 1220 */ 1221 if (name.len == 1) 1222 return 0; 1223 if (name.name[1] == '.' && name.len == 2) 1224 return 0; 1225 } 1226 fc = get_fuse_conn(dir); 1227 1228 name.hash = full_name_hash(name.name, name.len); 1229 dentry = d_lookup(parent, &name); 1230 if (dentry && dentry->d_inode) { 1231 inode = dentry->d_inode; 1232 if (get_node_id(inode) == o->nodeid) { 1233 struct fuse_inode *fi; 1234 fi = get_fuse_inode(inode); 1235 spin_lock(&fc->lock); 1236 fi->nlookup++; 1237 spin_unlock(&fc->lock); 1238 1239 /* 1240 * The other branch to 'found' comes via fuse_iget() 1241 * which bumps nlookup inside 1242 */ 1243 goto found; 1244 } 1245 err = d_invalidate(dentry); 1246 if (err) 1247 goto out; 1248 dput(dentry); 1249 dentry = NULL; 1250 } 1251 1252 dentry = d_alloc(parent, &name); 1253 err = -ENOMEM; 1254 if (!dentry) 1255 goto out; 1256 1257 inode = fuse_iget(dir->i_sb, o->nodeid, o->generation, 1258 &o->attr, entry_attr_timeout(o), attr_version); 1259 if (!inode) 1260 goto out; 1261 1262 alias = d_materialise_unique(dentry, inode); 1263 err = PTR_ERR(alias); 1264 if (IS_ERR(alias)) 1265 goto out; 1266 if (alias) { 1267 dput(dentry); 1268 dentry = alias; 1269 } 1270 1271 found: 1272 fuse_change_attributes(inode, &o->attr, entry_attr_timeout(o), 1273 attr_version); 1274 1275 fuse_change_entry_timeout(dentry, o); 1276 1277 err = 0; 1278 out: 1279 if (dentry) 1280 dput(dentry); 1281 return err; 1282 } 1283 1284 static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file, 1285 struct dir_context *ctx, u64 attr_version) 1286 { 1287 struct fuse_direntplus *direntplus; 1288 struct fuse_dirent *dirent; 1289 size_t reclen; 1290 int over = 0; 1291 int ret; 1292 1293 while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) { 1294 direntplus = (struct fuse_direntplus *) buf; 1295 dirent = &direntplus->dirent; 1296 reclen = FUSE_DIRENTPLUS_SIZE(direntplus); 1297 1298 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) 1299 return -EIO; 1300 if (reclen > nbytes) 1301 break; 1302 1303 if (!over) { 1304 /* We fill entries into dstbuf only as much as 1305 it can hold. But we still continue iterating 1306 over remaining entries to link them. If not, 1307 we need to send a FORGET for each of those 1308 which we did not link. 1309 */ 1310 over = !dir_emit(ctx, dirent->name, dirent->namelen, 1311 dirent->ino, dirent->type); 1312 ctx->pos = dirent->off; 1313 } 1314 1315 buf += reclen; 1316 nbytes -= reclen; 1317 1318 ret = fuse_direntplus_link(file, direntplus, attr_version); 1319 if (ret) 1320 fuse_force_forget(file, direntplus->entry_out.nodeid); 1321 } 1322 1323 return 0; 1324 } 1325 1326 static int fuse_readdir(struct file *file, struct dir_context *ctx) 1327 { 1328 int plus, err; 1329 size_t nbytes; 1330 struct page *page; 1331 struct inode *inode = file_inode(file); 1332 struct fuse_conn *fc = get_fuse_conn(inode); 1333 struct fuse_req *req; 1334 u64 attr_version = 0; 1335 1336 if (is_bad_inode(inode)) 1337 return -EIO; 1338 1339 req = fuse_get_req(fc, 1); 1340 if (IS_ERR(req)) 1341 return PTR_ERR(req); 1342 1343 page = alloc_page(GFP_KERNEL); 1344 if (!page) { 1345 fuse_put_request(fc, req); 1346 return -ENOMEM; 1347 } 1348 1349 plus = fuse_use_readdirplus(inode, ctx); 1350 req->out.argpages = 1; 1351 req->num_pages = 1; 1352 req->pages[0] = page; 1353 req->page_descs[0].length = PAGE_SIZE; 1354 if (plus) { 1355 attr_version = fuse_get_attr_version(fc); 1356 fuse_read_fill(req, file, ctx->pos, PAGE_SIZE, 1357 FUSE_READDIRPLUS); 1358 } else { 1359 fuse_read_fill(req, file, ctx->pos, PAGE_SIZE, 1360 FUSE_READDIR); 1361 } 1362 fuse_request_send(fc, req); 1363 nbytes = req->out.args[0].size; 1364 err = req->out.h.error; 1365 fuse_put_request(fc, req); 1366 if (!err) { 1367 if (plus) { 1368 err = parse_dirplusfile(page_address(page), nbytes, 1369 file, ctx, 1370 attr_version); 1371 } else { 1372 err = parse_dirfile(page_address(page), nbytes, file, 1373 ctx); 1374 } 1375 } 1376 1377 __free_page(page); 1378 fuse_invalidate_attr(inode); /* atime changed */ 1379 return err; 1380 } 1381 1382 static char *read_link(struct dentry *dentry) 1383 { 1384 struct inode *inode = dentry->d_inode; 1385 struct fuse_conn *fc = get_fuse_conn(inode); 1386 struct fuse_req *req = fuse_get_req_nopages(fc); 1387 char *link; 1388 1389 if (IS_ERR(req)) 1390 return ERR_CAST(req); 1391 1392 link = (char *) __get_free_page(GFP_KERNEL); 1393 if (!link) { 1394 link = ERR_PTR(-ENOMEM); 1395 goto out; 1396 } 1397 req->in.h.opcode = FUSE_READLINK; 1398 req->in.h.nodeid = get_node_id(inode); 1399 req->out.argvar = 1; 1400 req->out.numargs = 1; 1401 req->out.args[0].size = PAGE_SIZE - 1; 1402 req->out.args[0].value = link; 1403 fuse_request_send(fc, req); 1404 if (req->out.h.error) { 1405 free_page((unsigned long) link); 1406 link = ERR_PTR(req->out.h.error); 1407 } else 1408 link[req->out.args[0].size] = '\0'; 1409 out: 1410 fuse_put_request(fc, req); 1411 fuse_invalidate_attr(inode); /* atime changed */ 1412 return link; 1413 } 1414 1415 static void free_link(char *link) 1416 { 1417 if (!IS_ERR(link)) 1418 free_page((unsigned long) link); 1419 } 1420 1421 static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd) 1422 { 1423 nd_set_link(nd, read_link(dentry)); 1424 return NULL; 1425 } 1426 1427 static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c) 1428 { 1429 free_link(nd_get_link(nd)); 1430 } 1431 1432 static int fuse_dir_open(struct inode *inode, struct file *file) 1433 { 1434 return fuse_open_common(inode, file, true); 1435 } 1436 1437 static int fuse_dir_release(struct inode *inode, struct file *file) 1438 { 1439 fuse_release_common(file, FUSE_RELEASEDIR); 1440 1441 return 0; 1442 } 1443 1444 static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end, 1445 int datasync) 1446 { 1447 return fuse_fsync_common(file, start, end, datasync, 1); 1448 } 1449 1450 static long fuse_dir_ioctl(struct file *file, unsigned int cmd, 1451 unsigned long arg) 1452 { 1453 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); 1454 1455 /* FUSE_IOCTL_DIR only supported for API version >= 7.18 */ 1456 if (fc->minor < 18) 1457 return -ENOTTY; 1458 1459 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR); 1460 } 1461 1462 static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd, 1463 unsigned long arg) 1464 { 1465 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); 1466 1467 if (fc->minor < 18) 1468 return -ENOTTY; 1469 1470 return fuse_ioctl_common(file, cmd, arg, 1471 FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR); 1472 } 1473 1474 static bool update_mtime(unsigned ivalid) 1475 { 1476 /* Always update if mtime is explicitly set */ 1477 if (ivalid & ATTR_MTIME_SET) 1478 return true; 1479 1480 /* If it's an open(O_TRUNC) or an ftruncate(), don't update */ 1481 if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE))) 1482 return false; 1483 1484 /* In all other cases update */ 1485 return true; 1486 } 1487 1488 static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg) 1489 { 1490 unsigned ivalid = iattr->ia_valid; 1491 1492 if (ivalid & ATTR_MODE) 1493 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode; 1494 if (ivalid & ATTR_UID) 1495 arg->valid |= FATTR_UID, arg->uid = from_kuid(&init_user_ns, iattr->ia_uid); 1496 if (ivalid & ATTR_GID) 1497 arg->valid |= FATTR_GID, arg->gid = from_kgid(&init_user_ns, iattr->ia_gid); 1498 if (ivalid & ATTR_SIZE) 1499 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size; 1500 if (ivalid & ATTR_ATIME) { 1501 arg->valid |= FATTR_ATIME; 1502 arg->atime = iattr->ia_atime.tv_sec; 1503 arg->atimensec = iattr->ia_atime.tv_nsec; 1504 if (!(ivalid & ATTR_ATIME_SET)) 1505 arg->valid |= FATTR_ATIME_NOW; 1506 } 1507 if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) { 1508 arg->valid |= FATTR_MTIME; 1509 arg->mtime = iattr->ia_mtime.tv_sec; 1510 arg->mtimensec = iattr->ia_mtime.tv_nsec; 1511 if (!(ivalid & ATTR_MTIME_SET)) 1512 arg->valid |= FATTR_MTIME_NOW; 1513 } 1514 } 1515 1516 /* 1517 * Prevent concurrent writepages on inode 1518 * 1519 * This is done by adding a negative bias to the inode write counter 1520 * and waiting for all pending writes to finish. 1521 */ 1522 void fuse_set_nowrite(struct inode *inode) 1523 { 1524 struct fuse_conn *fc = get_fuse_conn(inode); 1525 struct fuse_inode *fi = get_fuse_inode(inode); 1526 1527 BUG_ON(!mutex_is_locked(&inode->i_mutex)); 1528 1529 spin_lock(&fc->lock); 1530 BUG_ON(fi->writectr < 0); 1531 fi->writectr += FUSE_NOWRITE; 1532 spin_unlock(&fc->lock); 1533 wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE); 1534 } 1535 1536 /* 1537 * Allow writepages on inode 1538 * 1539 * Remove the bias from the writecounter and send any queued 1540 * writepages. 1541 */ 1542 static void __fuse_release_nowrite(struct inode *inode) 1543 { 1544 struct fuse_inode *fi = get_fuse_inode(inode); 1545 1546 BUG_ON(fi->writectr != FUSE_NOWRITE); 1547 fi->writectr = 0; 1548 fuse_flush_writepages(inode); 1549 } 1550 1551 void fuse_release_nowrite(struct inode *inode) 1552 { 1553 struct fuse_conn *fc = get_fuse_conn(inode); 1554 1555 spin_lock(&fc->lock); 1556 __fuse_release_nowrite(inode); 1557 spin_unlock(&fc->lock); 1558 } 1559 1560 /* 1561 * Set attributes, and at the same time refresh them. 1562 * 1563 * Truncation is slightly complicated, because the 'truncate' request 1564 * may fail, in which case we don't want to touch the mapping. 1565 * vmtruncate() doesn't allow for this case, so do the rlimit checking 1566 * and the actual truncation by hand. 1567 */ 1568 int fuse_do_setattr(struct inode *inode, struct iattr *attr, 1569 struct file *file) 1570 { 1571 struct fuse_conn *fc = get_fuse_conn(inode); 1572 struct fuse_req *req; 1573 struct fuse_setattr_in inarg; 1574 struct fuse_attr_out outarg; 1575 bool is_truncate = false; 1576 loff_t oldsize; 1577 int err; 1578 1579 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS)) 1580 attr->ia_valid |= ATTR_FORCE; 1581 1582 err = inode_change_ok(inode, attr); 1583 if (err) 1584 return err; 1585 1586 if (attr->ia_valid & ATTR_OPEN) { 1587 if (fc->atomic_o_trunc) 1588 return 0; 1589 file = NULL; 1590 } 1591 1592 if (attr->ia_valid & ATTR_SIZE) 1593 is_truncate = true; 1594 1595 req = fuse_get_req_nopages(fc); 1596 if (IS_ERR(req)) 1597 return PTR_ERR(req); 1598 1599 if (is_truncate) 1600 fuse_set_nowrite(inode); 1601 1602 memset(&inarg, 0, sizeof(inarg)); 1603 memset(&outarg, 0, sizeof(outarg)); 1604 iattr_to_fattr(attr, &inarg); 1605 if (file) { 1606 struct fuse_file *ff = file->private_data; 1607 inarg.valid |= FATTR_FH; 1608 inarg.fh = ff->fh; 1609 } 1610 if (attr->ia_valid & ATTR_SIZE) { 1611 /* For mandatory locking in truncate */ 1612 inarg.valid |= FATTR_LOCKOWNER; 1613 inarg.lock_owner = fuse_lock_owner_id(fc, current->files); 1614 } 1615 req->in.h.opcode = FUSE_SETATTR; 1616 req->in.h.nodeid = get_node_id(inode); 1617 req->in.numargs = 1; 1618 req->in.args[0].size = sizeof(inarg); 1619 req->in.args[0].value = &inarg; 1620 req->out.numargs = 1; 1621 if (fc->minor < 9) 1622 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; 1623 else 1624 req->out.args[0].size = sizeof(outarg); 1625 req->out.args[0].value = &outarg; 1626 fuse_request_send(fc, req); 1627 err = req->out.h.error; 1628 fuse_put_request(fc, req); 1629 if (err) { 1630 if (err == -EINTR) 1631 fuse_invalidate_attr(inode); 1632 goto error; 1633 } 1634 1635 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { 1636 make_bad_inode(inode); 1637 err = -EIO; 1638 goto error; 1639 } 1640 1641 spin_lock(&fc->lock); 1642 fuse_change_attributes_common(inode, &outarg.attr, 1643 attr_timeout(&outarg)); 1644 oldsize = inode->i_size; 1645 i_size_write(inode, outarg.attr.size); 1646 1647 if (is_truncate) { 1648 /* NOTE: this may release/reacquire fc->lock */ 1649 __fuse_release_nowrite(inode); 1650 } 1651 spin_unlock(&fc->lock); 1652 1653 /* 1654 * Only call invalidate_inode_pages2() after removing 1655 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. 1656 */ 1657 if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { 1658 truncate_pagecache(inode, oldsize, outarg.attr.size); 1659 invalidate_inode_pages2(inode->i_mapping); 1660 } 1661 1662 return 0; 1663 1664 error: 1665 if (is_truncate) 1666 fuse_release_nowrite(inode); 1667 1668 return err; 1669 } 1670 1671 static int fuse_setattr(struct dentry *entry, struct iattr *attr) 1672 { 1673 struct inode *inode = entry->d_inode; 1674 1675 if (!fuse_allow_current_process(get_fuse_conn(inode))) 1676 return -EACCES; 1677 1678 if (attr->ia_valid & ATTR_FILE) 1679 return fuse_do_setattr(inode, attr, attr->ia_file); 1680 else 1681 return fuse_do_setattr(inode, attr, NULL); 1682 } 1683 1684 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, 1685 struct kstat *stat) 1686 { 1687 struct inode *inode = entry->d_inode; 1688 struct fuse_conn *fc = get_fuse_conn(inode); 1689 1690 if (!fuse_allow_current_process(fc)) 1691 return -EACCES; 1692 1693 return fuse_update_attributes(inode, stat, NULL, NULL); 1694 } 1695 1696 static int fuse_setxattr(struct dentry *entry, const char *name, 1697 const void *value, size_t size, int flags) 1698 { 1699 struct inode *inode = entry->d_inode; 1700 struct fuse_conn *fc = get_fuse_conn(inode); 1701 struct fuse_req *req; 1702 struct fuse_setxattr_in inarg; 1703 int err; 1704 1705 if (fc->no_setxattr) 1706 return -EOPNOTSUPP; 1707 1708 req = fuse_get_req_nopages(fc); 1709 if (IS_ERR(req)) 1710 return PTR_ERR(req); 1711 1712 memset(&inarg, 0, sizeof(inarg)); 1713 inarg.size = size; 1714 inarg.flags = flags; 1715 req->in.h.opcode = FUSE_SETXATTR; 1716 req->in.h.nodeid = get_node_id(inode); 1717 req->in.numargs = 3; 1718 req->in.args[0].size = sizeof(inarg); 1719 req->in.args[0].value = &inarg; 1720 req->in.args[1].size = strlen(name) + 1; 1721 req->in.args[1].value = name; 1722 req->in.args[2].size = size; 1723 req->in.args[2].value = value; 1724 fuse_request_send(fc, req); 1725 err = req->out.h.error; 1726 fuse_put_request(fc, req); 1727 if (err == -ENOSYS) { 1728 fc->no_setxattr = 1; 1729 err = -EOPNOTSUPP; 1730 } 1731 return err; 1732 } 1733 1734 static ssize_t fuse_getxattr(struct dentry *entry, const char *name, 1735 void *value, size_t size) 1736 { 1737 struct inode *inode = entry->d_inode; 1738 struct fuse_conn *fc = get_fuse_conn(inode); 1739 struct fuse_req *req; 1740 struct fuse_getxattr_in inarg; 1741 struct fuse_getxattr_out outarg; 1742 ssize_t ret; 1743 1744 if (fc->no_getxattr) 1745 return -EOPNOTSUPP; 1746 1747 req = fuse_get_req_nopages(fc); 1748 if (IS_ERR(req)) 1749 return PTR_ERR(req); 1750 1751 memset(&inarg, 0, sizeof(inarg)); 1752 inarg.size = size; 1753 req->in.h.opcode = FUSE_GETXATTR; 1754 req->in.h.nodeid = get_node_id(inode); 1755 req->in.numargs = 2; 1756 req->in.args[0].size = sizeof(inarg); 1757 req->in.args[0].value = &inarg; 1758 req->in.args[1].size = strlen(name) + 1; 1759 req->in.args[1].value = name; 1760 /* This is really two different operations rolled into one */ 1761 req->out.numargs = 1; 1762 if (size) { 1763 req->out.argvar = 1; 1764 req->out.args[0].size = size; 1765 req->out.args[0].value = value; 1766 } else { 1767 req->out.args[0].size = sizeof(outarg); 1768 req->out.args[0].value = &outarg; 1769 } 1770 fuse_request_send(fc, req); 1771 ret = req->out.h.error; 1772 if (!ret) 1773 ret = size ? req->out.args[0].size : outarg.size; 1774 else { 1775 if (ret == -ENOSYS) { 1776 fc->no_getxattr = 1; 1777 ret = -EOPNOTSUPP; 1778 } 1779 } 1780 fuse_put_request(fc, req); 1781 return ret; 1782 } 1783 1784 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) 1785 { 1786 struct inode *inode = entry->d_inode; 1787 struct fuse_conn *fc = get_fuse_conn(inode); 1788 struct fuse_req *req; 1789 struct fuse_getxattr_in inarg; 1790 struct fuse_getxattr_out outarg; 1791 ssize_t ret; 1792 1793 if (!fuse_allow_current_process(fc)) 1794 return -EACCES; 1795 1796 if (fc->no_listxattr) 1797 return -EOPNOTSUPP; 1798 1799 req = fuse_get_req_nopages(fc); 1800 if (IS_ERR(req)) 1801 return PTR_ERR(req); 1802 1803 memset(&inarg, 0, sizeof(inarg)); 1804 inarg.size = size; 1805 req->in.h.opcode = FUSE_LISTXATTR; 1806 req->in.h.nodeid = get_node_id(inode); 1807 req->in.numargs = 1; 1808 req->in.args[0].size = sizeof(inarg); 1809 req->in.args[0].value = &inarg; 1810 /* This is really two different operations rolled into one */ 1811 req->out.numargs = 1; 1812 if (size) { 1813 req->out.argvar = 1; 1814 req->out.args[0].size = size; 1815 req->out.args[0].value = list; 1816 } else { 1817 req->out.args[0].size = sizeof(outarg); 1818 req->out.args[0].value = &outarg; 1819 } 1820 fuse_request_send(fc, req); 1821 ret = req->out.h.error; 1822 if (!ret) 1823 ret = size ? req->out.args[0].size : outarg.size; 1824 else { 1825 if (ret == -ENOSYS) { 1826 fc->no_listxattr = 1; 1827 ret = -EOPNOTSUPP; 1828 } 1829 } 1830 fuse_put_request(fc, req); 1831 return ret; 1832 } 1833 1834 static int fuse_removexattr(struct dentry *entry, const char *name) 1835 { 1836 struct inode *inode = entry->d_inode; 1837 struct fuse_conn *fc = get_fuse_conn(inode); 1838 struct fuse_req *req; 1839 int err; 1840 1841 if (fc->no_removexattr) 1842 return -EOPNOTSUPP; 1843 1844 req = fuse_get_req_nopages(fc); 1845 if (IS_ERR(req)) 1846 return PTR_ERR(req); 1847 1848 req->in.h.opcode = FUSE_REMOVEXATTR; 1849 req->in.h.nodeid = get_node_id(inode); 1850 req->in.numargs = 1; 1851 req->in.args[0].size = strlen(name) + 1; 1852 req->in.args[0].value = name; 1853 fuse_request_send(fc, req); 1854 err = req->out.h.error; 1855 fuse_put_request(fc, req); 1856 if (err == -ENOSYS) { 1857 fc->no_removexattr = 1; 1858 err = -EOPNOTSUPP; 1859 } 1860 return err; 1861 } 1862 1863 static const struct inode_operations fuse_dir_inode_operations = { 1864 .lookup = fuse_lookup, 1865 .mkdir = fuse_mkdir, 1866 .symlink = fuse_symlink, 1867 .unlink = fuse_unlink, 1868 .rmdir = fuse_rmdir, 1869 .rename = fuse_rename, 1870 .link = fuse_link, 1871 .setattr = fuse_setattr, 1872 .create = fuse_create, 1873 .atomic_open = fuse_atomic_open, 1874 .mknod = fuse_mknod, 1875 .permission = fuse_permission, 1876 .getattr = fuse_getattr, 1877 .setxattr = fuse_setxattr, 1878 .getxattr = fuse_getxattr, 1879 .listxattr = fuse_listxattr, 1880 .removexattr = fuse_removexattr, 1881 }; 1882 1883 static const struct file_operations fuse_dir_operations = { 1884 .llseek = generic_file_llseek, 1885 .read = generic_read_dir, 1886 .iterate = fuse_readdir, 1887 .open = fuse_dir_open, 1888 .release = fuse_dir_release, 1889 .fsync = fuse_dir_fsync, 1890 .unlocked_ioctl = fuse_dir_ioctl, 1891 .compat_ioctl = fuse_dir_compat_ioctl, 1892 }; 1893 1894 static const struct inode_operations fuse_common_inode_operations = { 1895 .setattr = fuse_setattr, 1896 .permission = fuse_permission, 1897 .getattr = fuse_getattr, 1898 .setxattr = fuse_setxattr, 1899 .getxattr = fuse_getxattr, 1900 .listxattr = fuse_listxattr, 1901 .removexattr = fuse_removexattr, 1902 }; 1903 1904 static const struct inode_operations fuse_symlink_inode_operations = { 1905 .setattr = fuse_setattr, 1906 .follow_link = fuse_follow_link, 1907 .put_link = fuse_put_link, 1908 .readlink = generic_readlink, 1909 .getattr = fuse_getattr, 1910 .setxattr = fuse_setxattr, 1911 .getxattr = fuse_getxattr, 1912 .listxattr = fuse_listxattr, 1913 .removexattr = fuse_removexattr, 1914 }; 1915 1916 void fuse_init_common(struct inode *inode) 1917 { 1918 inode->i_op = &fuse_common_inode_operations; 1919 } 1920 1921 void fuse_init_dir(struct inode *inode) 1922 { 1923 inode->i_op = &fuse_dir_inode_operations; 1924 inode->i_fop = &fuse_dir_operations; 1925 } 1926 1927 void fuse_init_symlink(struct inode *inode) 1928 { 1929 inode->i_op = &fuse_symlink_inode_operations; 1930 } 1931