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