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 17static 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 33static 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 41static inline void fuse_dentry_settime(struct dentry *entry, u64 time) 42{ 43 entry->d_time = time; 44} 45 46static 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 */ 54static 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 60static 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 */ 76static 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 */ 89static 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 96static u64 attr_timeout(struct fuse_attr_out *o) 97{ 98 return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); 99} 100 101static 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 */ 110void fuse_invalidate_attr(struct inode *inode) 111{ 112 get_fuse_inode(inode)->i_time = 0; 113} 114 115/** 116 * Mark the attributes as stale due to an atime change. Avoid the invalidate if 117 * atime is not used. 118 */ 119void fuse_invalidate_atime(struct inode *inode) 120{ 121 if (!IS_RDONLY(inode)) 122 fuse_invalidate_attr(inode); 123} 124 125/* 126 * Just mark the entry as stale, so that a next attempt to look it up 127 * will result in a new lookup call to userspace 128 * 129 * This is called when a dentry is about to become negative and the 130 * timeout is unknown (unlink, rmdir, rename and in some cases 131 * lookup) 132 */ 133void fuse_invalidate_entry_cache(struct dentry *entry) 134{ 135 fuse_dentry_settime(entry, 0); 136} 137 138/* 139 * Same as fuse_invalidate_entry_cache(), but also try to remove the 140 * dentry from the hash 141 */ 142static void fuse_invalidate_entry(struct dentry *entry) 143{ 144 d_invalidate(entry); 145 fuse_invalidate_entry_cache(entry); 146} 147 148static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_args *args, 149 u64 nodeid, struct qstr *name, 150 struct fuse_entry_out *outarg) 151{ 152 memset(outarg, 0, sizeof(struct fuse_entry_out)); 153 args->in.h.opcode = FUSE_LOOKUP; 154 args->in.h.nodeid = nodeid; 155 args->in.numargs = 1; 156 args->in.args[0].size = name->len + 1; 157 args->in.args[0].value = name->name; 158 args->out.numargs = 1; 159 args->out.args[0].size = sizeof(struct fuse_entry_out); 160 args->out.args[0].value = outarg; 161} 162 163u64 fuse_get_attr_version(struct fuse_conn *fc) 164{ 165 u64 curr_version; 166 167 /* 168 * The spin lock isn't actually needed on 64bit archs, but we 169 * don't yet care too much about such optimizations. 170 */ 171 spin_lock(&fc->lock); 172 curr_version = fc->attr_version; 173 spin_unlock(&fc->lock); 174 175 return curr_version; 176} 177 178/* 179 * Check whether the dentry is still valid 180 * 181 * If the entry validity timeout has expired and the dentry is 182 * positive, try to redo the lookup. If the lookup results in a 183 * different inode, then let the VFS invalidate the dentry and redo 184 * the lookup once more. If the lookup results in the same inode, 185 * then refresh the attributes, timeouts and mark the dentry valid. 186 */ 187static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags) 188{ 189 struct inode *inode; 190 struct dentry *parent; 191 struct fuse_conn *fc; 192 struct fuse_inode *fi; 193 int ret; 194 195 inode = d_inode_rcu(entry); 196 if (inode && is_bad_inode(inode)) 197 goto invalid; 198 else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) || 199 (flags & LOOKUP_REVAL)) { 200 struct fuse_entry_out outarg; 201 FUSE_ARGS(args); 202 struct fuse_forget_link *forget; 203 u64 attr_version; 204 205 /* For negative dentries, always do a fresh lookup */ 206 if (!inode) 207 goto invalid; 208 209 ret = -ECHILD; 210 if (flags & LOOKUP_RCU) 211 goto out; 212 213 fc = get_fuse_conn(inode); 214 215 forget = fuse_alloc_forget(); 216 ret = -ENOMEM; 217 if (!forget) 218 goto out; 219 220 attr_version = fuse_get_attr_version(fc); 221 222 parent = dget_parent(entry); 223 fuse_lookup_init(fc, &args, get_node_id(d_inode(parent)), 224 &entry->d_name, &outarg); 225 ret = fuse_simple_request(fc, &args); 226 dput(parent); 227 /* Zero nodeid is same as -ENOENT */ 228 if (!ret && !outarg.nodeid) 229 ret = -ENOENT; 230 if (!ret) { 231 fi = get_fuse_inode(inode); 232 if (outarg.nodeid != get_node_id(inode)) { 233 fuse_queue_forget(fc, forget, outarg.nodeid, 1); 234 goto invalid; 235 } 236 spin_lock(&fc->lock); 237 fi->nlookup++; 238 spin_unlock(&fc->lock); 239 } 240 kfree(forget); 241 if (ret == -ENOMEM) 242 goto out; 243 if (ret || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) 244 goto invalid; 245 246 fuse_change_attributes(inode, &outarg.attr, 247 entry_attr_timeout(&outarg), 248 attr_version); 249 fuse_change_entry_timeout(entry, &outarg); 250 } else if (inode) { 251 fi = get_fuse_inode(inode); 252 if (flags & LOOKUP_RCU) { 253 if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state)) 254 return -ECHILD; 255 } else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) { 256 parent = dget_parent(entry); 257 fuse_advise_use_readdirplus(d_inode(parent)); 258 dput(parent); 259 } 260 } 261 ret = 1; 262out: 263 return ret; 264 265invalid: 266 ret = 0; 267 goto out; 268} 269 270static int invalid_nodeid(u64 nodeid) 271{ 272 return !nodeid || nodeid == FUSE_ROOT_ID; 273} 274 275const struct dentry_operations fuse_dentry_operations = { 276 .d_revalidate = fuse_dentry_revalidate, 277}; 278 279int fuse_valid_type(int m) 280{ 281 return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) || 282 S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m); 283} 284 285int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name, 286 struct fuse_entry_out *outarg, struct inode **inode) 287{ 288 struct fuse_conn *fc = get_fuse_conn_super(sb); 289 FUSE_ARGS(args); 290 struct fuse_forget_link *forget; 291 u64 attr_version; 292 int err; 293 294 *inode = NULL; 295 err = -ENAMETOOLONG; 296 if (name->len > FUSE_NAME_MAX) 297 goto out; 298 299 300 forget = fuse_alloc_forget(); 301 err = -ENOMEM; 302 if (!forget) 303 goto out; 304 305 attr_version = fuse_get_attr_version(fc); 306 307 fuse_lookup_init(fc, &args, nodeid, name, outarg); 308 err = fuse_simple_request(fc, &args); 309 /* Zero nodeid is same as -ENOENT, but with valid timeout */ 310 if (err || !outarg->nodeid) 311 goto out_put_forget; 312 313 err = -EIO; 314 if (!outarg->nodeid) 315 goto out_put_forget; 316 if (!fuse_valid_type(outarg->attr.mode)) 317 goto out_put_forget; 318 319 *inode = fuse_iget(sb, outarg->nodeid, outarg->generation, 320 &outarg->attr, entry_attr_timeout(outarg), 321 attr_version); 322 err = -ENOMEM; 323 if (!*inode) { 324 fuse_queue_forget(fc, forget, outarg->nodeid, 1); 325 goto out; 326 } 327 err = 0; 328 329 out_put_forget: 330 kfree(forget); 331 out: 332 return err; 333} 334 335static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, 336 unsigned int flags) 337{ 338 int err; 339 struct fuse_entry_out outarg; 340 struct inode *inode; 341 struct dentry *newent; 342 bool outarg_valid = true; 343 344 err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, 345 &outarg, &inode); 346 if (err == -ENOENT) { 347 outarg_valid = false; 348 err = 0; 349 } 350 if (err) 351 goto out_err; 352 353 err = -EIO; 354 if (inode && get_node_id(inode) == FUSE_ROOT_ID) 355 goto out_iput; 356 357 newent = d_splice_alias(inode, entry); 358 err = PTR_ERR(newent); 359 if (IS_ERR(newent)) 360 goto out_err; 361 362 entry = newent ? newent : entry; 363 if (outarg_valid) 364 fuse_change_entry_timeout(entry, &outarg); 365 else 366 fuse_invalidate_entry_cache(entry); 367 368 fuse_advise_use_readdirplus(dir); 369 return newent; 370 371 out_iput: 372 iput(inode); 373 out_err: 374 return ERR_PTR(err); 375} 376 377/* 378 * Atomic create+open operation 379 * 380 * If the filesystem doesn't support this, then fall back to separate 381 * 'mknod' + 'open' requests. 382 */ 383static int fuse_create_open(struct inode *dir, struct dentry *entry, 384 struct file *file, unsigned flags, 385 umode_t mode, int *opened) 386{ 387 int err; 388 struct inode *inode; 389 struct fuse_conn *fc = get_fuse_conn(dir); 390 FUSE_ARGS(args); 391 struct fuse_forget_link *forget; 392 struct fuse_create_in inarg; 393 struct fuse_open_out outopen; 394 struct fuse_entry_out outentry; 395 struct fuse_file *ff; 396 397 /* Userspace expects S_IFREG in create mode */ 398 BUG_ON((mode & S_IFMT) != S_IFREG); 399 400 forget = fuse_alloc_forget(); 401 err = -ENOMEM; 402 if (!forget) 403 goto out_err; 404 405 err = -ENOMEM; 406 ff = fuse_file_alloc(fc); 407 if (!ff) 408 goto out_put_forget_req; 409 410 if (!fc->dont_mask) 411 mode &= ~current_umask(); 412 413 flags &= ~O_NOCTTY; 414 memset(&inarg, 0, sizeof(inarg)); 415 memset(&outentry, 0, sizeof(outentry)); 416 inarg.flags = flags; 417 inarg.mode = mode; 418 inarg.umask = current_umask(); 419 args.in.h.opcode = FUSE_CREATE; 420 args.in.h.nodeid = get_node_id(dir); 421 args.in.numargs = 2; 422 args.in.args[0].size = sizeof(inarg); 423 args.in.args[0].value = &inarg; 424 args.in.args[1].size = entry->d_name.len + 1; 425 args.in.args[1].value = entry->d_name.name; 426 args.out.numargs = 2; 427 args.out.args[0].size = sizeof(outentry); 428 args.out.args[0].value = &outentry; 429 args.out.args[1].size = sizeof(outopen); 430 args.out.args[1].value = &outopen; 431 err = fuse_simple_request(fc, &args); 432 if (err) 433 goto out_free_ff; 434 435 err = -EIO; 436 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid)) 437 goto out_free_ff; 438 439 ff->fh = outopen.fh; 440 ff->nodeid = outentry.nodeid; 441 ff->open_flags = outopen.open_flags; 442 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, 443 &outentry.attr, entry_attr_timeout(&outentry), 0); 444 if (!inode) { 445 flags &= ~(O_CREAT | O_EXCL | O_TRUNC); 446 fuse_sync_release(ff, flags); 447 fuse_queue_forget(fc, forget, outentry.nodeid, 1); 448 err = -ENOMEM; 449 goto out_err; 450 } 451 kfree(forget); 452 d_instantiate(entry, inode); 453 fuse_change_entry_timeout(entry, &outentry); 454 fuse_invalidate_attr(dir); 455 err = finish_open(file, entry, generic_file_open, opened); 456 if (err) { 457 fuse_sync_release(ff, flags); 458 } else { 459 file->private_data = fuse_file_get(ff); 460 fuse_finish_open(inode, file); 461 } 462 return err; 463 464out_free_ff: 465 fuse_file_free(ff); 466out_put_forget_req: 467 kfree(forget); 468out_err: 469 return err; 470} 471 472static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t); 473static int fuse_atomic_open(struct inode *dir, struct dentry *entry, 474 struct file *file, unsigned flags, 475 umode_t mode, int *opened) 476{ 477 int err; 478 struct fuse_conn *fc = get_fuse_conn(dir); 479 struct dentry *res = NULL; 480 481 if (d_unhashed(entry)) { 482 res = fuse_lookup(dir, entry, 0); 483 if (IS_ERR(res)) 484 return PTR_ERR(res); 485 486 if (res) 487 entry = res; 488 } 489 490 if (!(flags & O_CREAT) || d_really_is_positive(entry)) 491 goto no_open; 492 493 /* Only creates */ 494 *opened |= FILE_CREATED; 495 496 if (fc->no_create) 497 goto mknod; 498 499 err = fuse_create_open(dir, entry, file, flags, mode, opened); 500 if (err == -ENOSYS) { 501 fc->no_create = 1; 502 goto mknod; 503 } 504out_dput: 505 dput(res); 506 return err; 507 508mknod: 509 err = fuse_mknod(dir, entry, mode, 0); 510 if (err) 511 goto out_dput; 512no_open: 513 return finish_no_open(file, res); 514} 515 516/* 517 * Code shared between mknod, mkdir, symlink and link 518 */ 519static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args, 520 struct inode *dir, struct dentry *entry, 521 umode_t mode) 522{ 523 struct fuse_entry_out outarg; 524 struct inode *inode; 525 int err; 526 struct fuse_forget_link *forget; 527 528 forget = fuse_alloc_forget(); 529 if (!forget) 530 return -ENOMEM; 531 532 memset(&outarg, 0, sizeof(outarg)); 533 args->in.h.nodeid = get_node_id(dir); 534 args->out.numargs = 1; 535 args->out.args[0].size = sizeof(outarg); 536 args->out.args[0].value = &outarg; 537 err = fuse_simple_request(fc, args); 538 if (err) 539 goto out_put_forget_req; 540 541 err = -EIO; 542 if (invalid_nodeid(outarg.nodeid)) 543 goto out_put_forget_req; 544 545 if ((outarg.attr.mode ^ mode) & S_IFMT) 546 goto out_put_forget_req; 547 548 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, 549 &outarg.attr, entry_attr_timeout(&outarg), 0); 550 if (!inode) { 551 fuse_queue_forget(fc, forget, outarg.nodeid, 1); 552 return -ENOMEM; 553 } 554 kfree(forget); 555 556 err = d_instantiate_no_diralias(entry, inode); 557 if (err) 558 return err; 559 560 fuse_change_entry_timeout(entry, &outarg); 561 fuse_invalidate_attr(dir); 562 return 0; 563 564 out_put_forget_req: 565 kfree(forget); 566 return err; 567} 568 569static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode, 570 dev_t rdev) 571{ 572 struct fuse_mknod_in inarg; 573 struct fuse_conn *fc = get_fuse_conn(dir); 574 FUSE_ARGS(args); 575 576 if (!fc->dont_mask) 577 mode &= ~current_umask(); 578 579 memset(&inarg, 0, sizeof(inarg)); 580 inarg.mode = mode; 581 inarg.rdev = new_encode_dev(rdev); 582 inarg.umask = current_umask(); 583 args.in.h.opcode = FUSE_MKNOD; 584 args.in.numargs = 2; 585 args.in.args[0].size = sizeof(inarg); 586 args.in.args[0].value = &inarg; 587 args.in.args[1].size = entry->d_name.len + 1; 588 args.in.args[1].value = entry->d_name.name; 589 return create_new_entry(fc, &args, dir, entry, mode); 590} 591 592static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode, 593 bool excl) 594{ 595 return fuse_mknod(dir, entry, mode, 0); 596} 597 598static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode) 599{ 600 struct fuse_mkdir_in inarg; 601 struct fuse_conn *fc = get_fuse_conn(dir); 602 FUSE_ARGS(args); 603 604 if (!fc->dont_mask) 605 mode &= ~current_umask(); 606 607 memset(&inarg, 0, sizeof(inarg)); 608 inarg.mode = mode; 609 inarg.umask = current_umask(); 610 args.in.h.opcode = FUSE_MKDIR; 611 args.in.numargs = 2; 612 args.in.args[0].size = sizeof(inarg); 613 args.in.args[0].value = &inarg; 614 args.in.args[1].size = entry->d_name.len + 1; 615 args.in.args[1].value = entry->d_name.name; 616 return create_new_entry(fc, &args, dir, entry, S_IFDIR); 617} 618 619static int fuse_symlink(struct inode *dir, struct dentry *entry, 620 const char *link) 621{ 622 struct fuse_conn *fc = get_fuse_conn(dir); 623 unsigned len = strlen(link) + 1; 624 FUSE_ARGS(args); 625 626 args.in.h.opcode = FUSE_SYMLINK; 627 args.in.numargs = 2; 628 args.in.args[0].size = entry->d_name.len + 1; 629 args.in.args[0].value = entry->d_name.name; 630 args.in.args[1].size = len; 631 args.in.args[1].value = link; 632 return create_new_entry(fc, &args, dir, entry, S_IFLNK); 633} 634 635static inline void fuse_update_ctime(struct inode *inode) 636{ 637 if (!IS_NOCMTIME(inode)) { 638 inode->i_ctime = current_fs_time(inode->i_sb); 639 mark_inode_dirty_sync(inode); 640 } 641} 642 643static int fuse_unlink(struct inode *dir, struct dentry *entry) 644{ 645 int err; 646 struct fuse_conn *fc = get_fuse_conn(dir); 647 FUSE_ARGS(args); 648 649 args.in.h.opcode = FUSE_UNLINK; 650 args.in.h.nodeid = get_node_id(dir); 651 args.in.numargs = 1; 652 args.in.args[0].size = entry->d_name.len + 1; 653 args.in.args[0].value = entry->d_name.name; 654 err = fuse_simple_request(fc, &args); 655 if (!err) { 656 struct inode *inode = d_inode(entry); 657 struct fuse_inode *fi = get_fuse_inode(inode); 658 659 spin_lock(&fc->lock); 660 fi->attr_version = ++fc->attr_version; 661 /* 662 * If i_nlink == 0 then unlink doesn't make sense, yet this can 663 * happen if userspace filesystem is careless. It would be 664 * difficult to enforce correct nlink usage so just ignore this 665 * condition here 666 */ 667 if (inode->i_nlink > 0) 668 drop_nlink(inode); 669 spin_unlock(&fc->lock); 670 fuse_invalidate_attr(inode); 671 fuse_invalidate_attr(dir); 672 fuse_invalidate_entry_cache(entry); 673 fuse_update_ctime(inode); 674 } else if (err == -EINTR) 675 fuse_invalidate_entry(entry); 676 return err; 677} 678 679static int fuse_rmdir(struct inode *dir, struct dentry *entry) 680{ 681 int err; 682 struct fuse_conn *fc = get_fuse_conn(dir); 683 FUSE_ARGS(args); 684 685 args.in.h.opcode = FUSE_RMDIR; 686 args.in.h.nodeid = get_node_id(dir); 687 args.in.numargs = 1; 688 args.in.args[0].size = entry->d_name.len + 1; 689 args.in.args[0].value = entry->d_name.name; 690 err = fuse_simple_request(fc, &args); 691 if (!err) { 692 clear_nlink(d_inode(entry)); 693 fuse_invalidate_attr(dir); 694 fuse_invalidate_entry_cache(entry); 695 } else if (err == -EINTR) 696 fuse_invalidate_entry(entry); 697 return err; 698} 699 700static int fuse_rename_common(struct inode *olddir, struct dentry *oldent, 701 struct inode *newdir, struct dentry *newent, 702 unsigned int flags, int opcode, size_t argsize) 703{ 704 int err; 705 struct fuse_rename2_in inarg; 706 struct fuse_conn *fc = get_fuse_conn(olddir); 707 FUSE_ARGS(args); 708 709 memset(&inarg, 0, argsize); 710 inarg.newdir = get_node_id(newdir); 711 inarg.flags = flags; 712 args.in.h.opcode = opcode; 713 args.in.h.nodeid = get_node_id(olddir); 714 args.in.numargs = 3; 715 args.in.args[0].size = argsize; 716 args.in.args[0].value = &inarg; 717 args.in.args[1].size = oldent->d_name.len + 1; 718 args.in.args[1].value = oldent->d_name.name; 719 args.in.args[2].size = newent->d_name.len + 1; 720 args.in.args[2].value = newent->d_name.name; 721 err = fuse_simple_request(fc, &args); 722 if (!err) { 723 /* ctime changes */ 724 fuse_invalidate_attr(d_inode(oldent)); 725 fuse_update_ctime(d_inode(oldent)); 726 727 if (flags & RENAME_EXCHANGE) { 728 fuse_invalidate_attr(d_inode(newent)); 729 fuse_update_ctime(d_inode(newent)); 730 } 731 732 fuse_invalidate_attr(olddir); 733 if (olddir != newdir) 734 fuse_invalidate_attr(newdir); 735 736 /* newent will end up negative */ 737 if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent)) { 738 fuse_invalidate_attr(d_inode(newent)); 739 fuse_invalidate_entry_cache(newent); 740 fuse_update_ctime(d_inode(newent)); 741 } 742 } else if (err == -EINTR) { 743 /* If request was interrupted, DEITY only knows if the 744 rename actually took place. If the invalidation 745 fails (e.g. some process has CWD under the renamed 746 directory), then there can be inconsistency between 747 the dcache and the real filesystem. Tough luck. */ 748 fuse_invalidate_entry(oldent); 749 if (d_really_is_positive(newent)) 750 fuse_invalidate_entry(newent); 751 } 752 753 return err; 754} 755 756static int fuse_rename2(struct inode *olddir, struct dentry *oldent, 757 struct inode *newdir, struct dentry *newent, 758 unsigned int flags) 759{ 760 struct fuse_conn *fc = get_fuse_conn(olddir); 761 int err; 762 763 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) 764 return -EINVAL; 765 766 if (flags) { 767 if (fc->no_rename2 || fc->minor < 23) 768 return -EINVAL; 769 770 err = fuse_rename_common(olddir, oldent, newdir, newent, flags, 771 FUSE_RENAME2, 772 sizeof(struct fuse_rename2_in)); 773 if (err == -ENOSYS) { 774 fc->no_rename2 = 1; 775 err = -EINVAL; 776 } 777 } else { 778 err = fuse_rename_common(olddir, oldent, newdir, newent, 0, 779 FUSE_RENAME, 780 sizeof(struct fuse_rename_in)); 781 } 782 783 return err; 784} 785 786static int fuse_link(struct dentry *entry, struct inode *newdir, 787 struct dentry *newent) 788{ 789 int err; 790 struct fuse_link_in inarg; 791 struct inode *inode = d_inode(entry); 792 struct fuse_conn *fc = get_fuse_conn(inode); 793 FUSE_ARGS(args); 794 795 memset(&inarg, 0, sizeof(inarg)); 796 inarg.oldnodeid = get_node_id(inode); 797 args.in.h.opcode = FUSE_LINK; 798 args.in.numargs = 2; 799 args.in.args[0].size = sizeof(inarg); 800 args.in.args[0].value = &inarg; 801 args.in.args[1].size = newent->d_name.len + 1; 802 args.in.args[1].value = newent->d_name.name; 803 err = create_new_entry(fc, &args, newdir, newent, inode->i_mode); 804 /* Contrary to "normal" filesystems it can happen that link 805 makes two "logical" inodes point to the same "physical" 806 inode. We invalidate the attributes of the old one, so it 807 will reflect changes in the backing inode (link count, 808 etc.) 809 */ 810 if (!err) { 811 struct fuse_inode *fi = get_fuse_inode(inode); 812 813 spin_lock(&fc->lock); 814 fi->attr_version = ++fc->attr_version; 815 inc_nlink(inode); 816 spin_unlock(&fc->lock); 817 fuse_invalidate_attr(inode); 818 fuse_update_ctime(inode); 819 } else if (err == -EINTR) { 820 fuse_invalidate_attr(inode); 821 } 822 return err; 823} 824 825static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, 826 struct kstat *stat) 827{ 828 unsigned int blkbits; 829 struct fuse_conn *fc = get_fuse_conn(inode); 830 831 /* see the comment in fuse_change_attributes() */ 832 if (fc->writeback_cache && S_ISREG(inode->i_mode)) { 833 attr->size = i_size_read(inode); 834 attr->mtime = inode->i_mtime.tv_sec; 835 attr->mtimensec = inode->i_mtime.tv_nsec; 836 attr->ctime = inode->i_ctime.tv_sec; 837 attr->ctimensec = inode->i_ctime.tv_nsec; 838 } 839 840 stat->dev = inode->i_sb->s_dev; 841 stat->ino = attr->ino; 842 stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 843 stat->nlink = attr->nlink; 844 stat->uid = make_kuid(&init_user_ns, attr->uid); 845 stat->gid = make_kgid(&init_user_ns, attr->gid); 846 stat->rdev = inode->i_rdev; 847 stat->atime.tv_sec = attr->atime; 848 stat->atime.tv_nsec = attr->atimensec; 849 stat->mtime.tv_sec = attr->mtime; 850 stat->mtime.tv_nsec = attr->mtimensec; 851 stat->ctime.tv_sec = attr->ctime; 852 stat->ctime.tv_nsec = attr->ctimensec; 853 stat->size = attr->size; 854 stat->blocks = attr->blocks; 855 856 if (attr->blksize != 0) 857 blkbits = ilog2(attr->blksize); 858 else 859 blkbits = inode->i_sb->s_blocksize_bits; 860 861 stat->blksize = 1 << blkbits; 862} 863 864static int fuse_do_getattr(struct inode *inode, struct kstat *stat, 865 struct file *file) 866{ 867 int err; 868 struct fuse_getattr_in inarg; 869 struct fuse_attr_out outarg; 870 struct fuse_conn *fc = get_fuse_conn(inode); 871 FUSE_ARGS(args); 872 u64 attr_version; 873 874 attr_version = fuse_get_attr_version(fc); 875 876 memset(&inarg, 0, sizeof(inarg)); 877 memset(&outarg, 0, sizeof(outarg)); 878 /* Directories have separate file-handle space */ 879 if (file && S_ISREG(inode->i_mode)) { 880 struct fuse_file *ff = file->private_data; 881 882 inarg.getattr_flags |= FUSE_GETATTR_FH; 883 inarg.fh = ff->fh; 884 } 885 args.in.h.opcode = FUSE_GETATTR; 886 args.in.h.nodeid = get_node_id(inode); 887 args.in.numargs = 1; 888 args.in.args[0].size = sizeof(inarg); 889 args.in.args[0].value = &inarg; 890 args.out.numargs = 1; 891 args.out.args[0].size = sizeof(outarg); 892 args.out.args[0].value = &outarg; 893 err = fuse_simple_request(fc, &args); 894 if (!err) { 895 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { 896 make_bad_inode(inode); 897 err = -EIO; 898 } else { 899 fuse_change_attributes(inode, &outarg.attr, 900 attr_timeout(&outarg), 901 attr_version); 902 if (stat) 903 fuse_fillattr(inode, &outarg.attr, stat); 904 } 905 } 906 return err; 907} 908 909int fuse_update_attributes(struct inode *inode, struct kstat *stat, 910 struct file *file, bool *refreshed) 911{ 912 struct fuse_inode *fi = get_fuse_inode(inode); 913 int err; 914 bool r; 915 916 if (time_before64(fi->i_time, get_jiffies_64())) { 917 r = true; 918 err = fuse_do_getattr(inode, stat, file); 919 } else { 920 r = false; 921 err = 0; 922 if (stat) { 923 generic_fillattr(inode, stat); 924 stat->mode = fi->orig_i_mode; 925 stat->ino = fi->orig_ino; 926 } 927 } 928 929 if (refreshed != NULL) 930 *refreshed = r; 931 932 return err; 933} 934 935int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid, 936 u64 child_nodeid, struct qstr *name) 937{ 938 int err = -ENOTDIR; 939 struct inode *parent; 940 struct dentry *dir; 941 struct dentry *entry; 942 943 parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid); 944 if (!parent) 945 return -ENOENT; 946 947 mutex_lock(&parent->i_mutex); 948 if (!S_ISDIR(parent->i_mode)) 949 goto unlock; 950 951 err = -ENOENT; 952 dir = d_find_alias(parent); 953 if (!dir) 954 goto unlock; 955 956 entry = d_lookup(dir, name); 957 dput(dir); 958 if (!entry) 959 goto unlock; 960 961 fuse_invalidate_attr(parent); 962 fuse_invalidate_entry(entry); 963 964 if (child_nodeid != 0 && d_really_is_positive(entry)) { 965 mutex_lock(&d_inode(entry)->i_mutex); 966 if (get_node_id(d_inode(entry)) != child_nodeid) { 967 err = -ENOENT; 968 goto badentry; 969 } 970 if (d_mountpoint(entry)) { 971 err = -EBUSY; 972 goto badentry; 973 } 974 if (d_is_dir(entry)) { 975 shrink_dcache_parent(entry); 976 if (!simple_empty(entry)) { 977 err = -ENOTEMPTY; 978 goto badentry; 979 } 980 d_inode(entry)->i_flags |= S_DEAD; 981 } 982 dont_mount(entry); 983 clear_nlink(d_inode(entry)); 984 err = 0; 985 badentry: 986 mutex_unlock(&d_inode(entry)->i_mutex); 987 if (!err) 988 d_delete(entry); 989 } else { 990 err = 0; 991 } 992 dput(entry); 993 994 unlock: 995 mutex_unlock(&parent->i_mutex); 996 iput(parent); 997 return err; 998} 999 1000/* 1001 * Calling into a user-controlled filesystem gives the filesystem 1002 * daemon ptrace-like capabilities over the current process. This 1003 * means, that the filesystem daemon is able to record the exact 1004 * filesystem operations performed, and can also control the behavior 1005 * of the requester process in otherwise impossible ways. For example 1006 * it can delay the operation for arbitrary length of time allowing 1007 * DoS against the requester. 1008 * 1009 * For this reason only those processes can call into the filesystem, 1010 * for which the owner of the mount has ptrace privilege. This 1011 * excludes processes started by other users, suid or sgid processes. 1012 */ 1013int fuse_allow_current_process(struct fuse_conn *fc) 1014{ 1015 const struct cred *cred; 1016 1017 if (fc->flags & FUSE_ALLOW_OTHER) 1018 return 1; 1019 1020 cred = current_cred(); 1021 if (uid_eq(cred->euid, fc->user_id) && 1022 uid_eq(cred->suid, fc->user_id) && 1023 uid_eq(cred->uid, fc->user_id) && 1024 gid_eq(cred->egid, fc->group_id) && 1025 gid_eq(cred->sgid, fc->group_id) && 1026 gid_eq(cred->gid, fc->group_id)) 1027 return 1; 1028 1029 return 0; 1030} 1031 1032static int fuse_access(struct inode *inode, int mask) 1033{ 1034 struct fuse_conn *fc = get_fuse_conn(inode); 1035 FUSE_ARGS(args); 1036 struct fuse_access_in inarg; 1037 int err; 1038 1039 BUG_ON(mask & MAY_NOT_BLOCK); 1040 1041 if (fc->no_access) 1042 return 0; 1043 1044 memset(&inarg, 0, sizeof(inarg)); 1045 inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC); 1046 args.in.h.opcode = FUSE_ACCESS; 1047 args.in.h.nodeid = get_node_id(inode); 1048 args.in.numargs = 1; 1049 args.in.args[0].size = sizeof(inarg); 1050 args.in.args[0].value = &inarg; 1051 err = fuse_simple_request(fc, &args); 1052 if (err == -ENOSYS) { 1053 fc->no_access = 1; 1054 err = 0; 1055 } 1056 return err; 1057} 1058 1059static int fuse_perm_getattr(struct inode *inode, int mask) 1060{ 1061 if (mask & MAY_NOT_BLOCK) 1062 return -ECHILD; 1063 1064 return fuse_do_getattr(inode, NULL, NULL); 1065} 1066 1067/* 1068 * Check permission. The two basic access models of FUSE are: 1069 * 1070 * 1) Local access checking ('default_permissions' mount option) based 1071 * on file mode. This is the plain old disk filesystem permission 1072 * modell. 1073 * 1074 * 2) "Remote" access checking, where server is responsible for 1075 * checking permission in each inode operation. An exception to this 1076 * is if ->permission() was invoked from sys_access() in which case an 1077 * access request is sent. Execute permission is still checked 1078 * locally based on file mode. 1079 */ 1080static int fuse_permission(struct inode *inode, int mask) 1081{ 1082 struct fuse_conn *fc = get_fuse_conn(inode); 1083 bool refreshed = false; 1084 int err = 0; 1085 1086 if (!fuse_allow_current_process(fc)) 1087 return -EACCES; 1088 1089 /* 1090 * If attributes are needed, refresh them before proceeding 1091 */ 1092 if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) || 1093 ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) { 1094 struct fuse_inode *fi = get_fuse_inode(inode); 1095 1096 if (time_before64(fi->i_time, get_jiffies_64())) { 1097 refreshed = true; 1098 1099 err = fuse_perm_getattr(inode, mask); 1100 if (err) 1101 return err; 1102 } 1103 } 1104 1105 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { 1106 err = generic_permission(inode, mask); 1107 1108 /* If permission is denied, try to refresh file 1109 attributes. This is also needed, because the root 1110 node will at first have no permissions */ 1111 if (err == -EACCES && !refreshed) { 1112 err = fuse_perm_getattr(inode, mask); 1113 if (!err) 1114 err = generic_permission(inode, mask); 1115 } 1116 1117 /* Note: the opposite of the above test does not 1118 exist. So if permissions are revoked this won't be 1119 noticed immediately, only after the attribute 1120 timeout has expired */ 1121 } else if (mask & (MAY_ACCESS | MAY_CHDIR)) { 1122 err = fuse_access(inode, mask); 1123 } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { 1124 if (!(inode->i_mode & S_IXUGO)) { 1125 if (refreshed) 1126 return -EACCES; 1127 1128 err = fuse_perm_getattr(inode, mask); 1129 if (!err && !(inode->i_mode & S_IXUGO)) 1130 return -EACCES; 1131 } 1132 } 1133 return err; 1134} 1135 1136static int parse_dirfile(char *buf, size_t nbytes, struct file *file, 1137 struct dir_context *ctx) 1138{ 1139 while (nbytes >= FUSE_NAME_OFFSET) { 1140 struct fuse_dirent *dirent = (struct fuse_dirent *) buf; 1141 size_t reclen = FUSE_DIRENT_SIZE(dirent); 1142 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) 1143 return -EIO; 1144 if (reclen > nbytes) 1145 break; 1146 if (memchr(dirent->name, '/', dirent->namelen) != NULL) 1147 return -EIO; 1148 1149 if (!dir_emit(ctx, dirent->name, dirent->namelen, 1150 dirent->ino, dirent->type)) 1151 break; 1152 1153 buf += reclen; 1154 nbytes -= reclen; 1155 ctx->pos = dirent->off; 1156 } 1157 1158 return 0; 1159} 1160 1161static int fuse_direntplus_link(struct file *file, 1162 struct fuse_direntplus *direntplus, 1163 u64 attr_version) 1164{ 1165 int err; 1166 struct fuse_entry_out *o = &direntplus->entry_out; 1167 struct fuse_dirent *dirent = &direntplus->dirent; 1168 struct dentry *parent = file->f_path.dentry; 1169 struct qstr name = QSTR_INIT(dirent->name, dirent->namelen); 1170 struct dentry *dentry; 1171 struct dentry *alias; 1172 struct inode *dir = d_inode(parent); 1173 struct fuse_conn *fc; 1174 struct inode *inode; 1175 1176 if (!o->nodeid) { 1177 /* 1178 * Unlike in the case of fuse_lookup, zero nodeid does not mean 1179 * ENOENT. Instead, it only means the userspace filesystem did 1180 * not want to return attributes/handle for this entry. 1181 * 1182 * So do nothing. 1183 */ 1184 return 0; 1185 } 1186 1187 if (name.name[0] == '.') { 1188 /* 1189 * We could potentially refresh the attributes of the directory 1190 * and its parent? 1191 */ 1192 if (name.len == 1) 1193 return 0; 1194 if (name.name[1] == '.' && name.len == 2) 1195 return 0; 1196 } 1197 1198 if (invalid_nodeid(o->nodeid)) 1199 return -EIO; 1200 if (!fuse_valid_type(o->attr.mode)) 1201 return -EIO; 1202 1203 fc = get_fuse_conn(dir); 1204 1205 name.hash = full_name_hash(name.name, name.len); 1206 dentry = d_lookup(parent, &name); 1207 if (dentry) { 1208 inode = d_inode(dentry); 1209 if (!inode) { 1210 d_drop(dentry); 1211 } else if (get_node_id(inode) != o->nodeid || 1212 ((o->attr.mode ^ inode->i_mode) & S_IFMT)) { 1213 d_invalidate(dentry); 1214 } else if (is_bad_inode(inode)) { 1215 err = -EIO; 1216 goto out; 1217 } else { 1218 struct fuse_inode *fi; 1219 fi = get_fuse_inode(inode); 1220 spin_lock(&fc->lock); 1221 fi->nlookup++; 1222 spin_unlock(&fc->lock); 1223 1224 fuse_change_attributes(inode, &o->attr, 1225 entry_attr_timeout(o), 1226 attr_version); 1227 1228 /* 1229 * The other branch to 'found' comes via fuse_iget() 1230 * which bumps nlookup inside 1231 */ 1232 goto found; 1233 } 1234 dput(dentry); 1235 } 1236 1237 dentry = d_alloc(parent, &name); 1238 err = -ENOMEM; 1239 if (!dentry) 1240 goto out; 1241 1242 inode = fuse_iget(dir->i_sb, o->nodeid, o->generation, 1243 &o->attr, entry_attr_timeout(o), attr_version); 1244 if (!inode) 1245 goto out; 1246 1247 alias = d_splice_alias(inode, dentry); 1248 err = PTR_ERR(alias); 1249 if (IS_ERR(alias)) 1250 goto out; 1251 1252 if (alias) { 1253 dput(dentry); 1254 dentry = alias; 1255 } 1256 1257found: 1258 if (fc->readdirplus_auto) 1259 set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state); 1260 fuse_change_entry_timeout(dentry, o); 1261 1262 err = 0; 1263out: 1264 dput(dentry); 1265 return err; 1266} 1267 1268static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file, 1269 struct dir_context *ctx, u64 attr_version) 1270{ 1271 struct fuse_direntplus *direntplus; 1272 struct fuse_dirent *dirent; 1273 size_t reclen; 1274 int over = 0; 1275 int ret; 1276 1277 while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) { 1278 direntplus = (struct fuse_direntplus *) buf; 1279 dirent = &direntplus->dirent; 1280 reclen = FUSE_DIRENTPLUS_SIZE(direntplus); 1281 1282 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) 1283 return -EIO; 1284 if (reclen > nbytes) 1285 break; 1286 if (memchr(dirent->name, '/', dirent->namelen) != NULL) 1287 return -EIO; 1288 1289 if (!over) { 1290 /* We fill entries into dstbuf only as much as 1291 it can hold. But we still continue iterating 1292 over remaining entries to link them. If not, 1293 we need to send a FORGET for each of those 1294 which we did not link. 1295 */ 1296 over = !dir_emit(ctx, dirent->name, dirent->namelen, 1297 dirent->ino, dirent->type); 1298 ctx->pos = dirent->off; 1299 } 1300 1301 buf += reclen; 1302 nbytes -= reclen; 1303 1304 ret = fuse_direntplus_link(file, direntplus, attr_version); 1305 if (ret) 1306 fuse_force_forget(file, direntplus->entry_out.nodeid); 1307 } 1308 1309 return 0; 1310} 1311 1312static int fuse_readdir(struct file *file, struct dir_context *ctx) 1313{ 1314 int plus, err; 1315 size_t nbytes; 1316 struct page *page; 1317 struct inode *inode = file_inode(file); 1318 struct fuse_conn *fc = get_fuse_conn(inode); 1319 struct fuse_req *req; 1320 u64 attr_version = 0; 1321 1322 if (is_bad_inode(inode)) 1323 return -EIO; 1324 1325 req = fuse_get_req(fc, 1); 1326 if (IS_ERR(req)) 1327 return PTR_ERR(req); 1328 1329 page = alloc_page(GFP_KERNEL); 1330 if (!page) { 1331 fuse_put_request(fc, req); 1332 return -ENOMEM; 1333 } 1334 1335 plus = fuse_use_readdirplus(inode, ctx); 1336 req->out.argpages = 1; 1337 req->num_pages = 1; 1338 req->pages[0] = page; 1339 req->page_descs[0].length = PAGE_SIZE; 1340 if (plus) { 1341 attr_version = fuse_get_attr_version(fc); 1342 fuse_read_fill(req, file, ctx->pos, PAGE_SIZE, 1343 FUSE_READDIRPLUS); 1344 } else { 1345 fuse_read_fill(req, file, ctx->pos, PAGE_SIZE, 1346 FUSE_READDIR); 1347 } 1348 fuse_request_send(fc, req); 1349 nbytes = req->out.args[0].size; 1350 err = req->out.h.error; 1351 fuse_put_request(fc, req); 1352 if (!err) { 1353 if (plus) { 1354 err = parse_dirplusfile(page_address(page), nbytes, 1355 file, ctx, 1356 attr_version); 1357 } else { 1358 err = parse_dirfile(page_address(page), nbytes, file, 1359 ctx); 1360 } 1361 } 1362 1363 __free_page(page); 1364 fuse_invalidate_atime(inode); 1365 return err; 1366} 1367 1368static char *read_link(struct dentry *dentry) 1369{ 1370 struct inode *inode = d_inode(dentry); 1371 struct fuse_conn *fc = get_fuse_conn(inode); 1372 FUSE_ARGS(args); 1373 char *link; 1374 ssize_t ret; 1375 1376 link = (char *) __get_free_page(GFP_KERNEL); 1377 if (!link) 1378 return ERR_PTR(-ENOMEM); 1379 1380 args.in.h.opcode = FUSE_READLINK; 1381 args.in.h.nodeid = get_node_id(inode); 1382 args.out.argvar = 1; 1383 args.out.numargs = 1; 1384 args.out.args[0].size = PAGE_SIZE - 1; 1385 args.out.args[0].value = link; 1386 ret = fuse_simple_request(fc, &args); 1387 if (ret < 0) { 1388 free_page((unsigned long) link); 1389 link = ERR_PTR(ret); 1390 } else { 1391 link[ret] = '\0'; 1392 } 1393 fuse_invalidate_atime(inode); 1394 return link; 1395} 1396 1397static void free_link(char *link) 1398{ 1399 if (!IS_ERR(link)) 1400 free_page((unsigned long) link); 1401} 1402 1403static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd) 1404{ 1405 nd_set_link(nd, read_link(dentry)); 1406 return NULL; 1407} 1408 1409static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c) 1410{ 1411 free_link(nd_get_link(nd)); 1412} 1413 1414static int fuse_dir_open(struct inode *inode, struct file *file) 1415{ 1416 return fuse_open_common(inode, file, true); 1417} 1418 1419static int fuse_dir_release(struct inode *inode, struct file *file) 1420{ 1421 fuse_release_common(file, FUSE_RELEASEDIR); 1422 1423 return 0; 1424} 1425 1426static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end, 1427 int datasync) 1428{ 1429 return fuse_fsync_common(file, start, end, datasync, 1); 1430} 1431 1432static long fuse_dir_ioctl(struct file *file, unsigned int cmd, 1433 unsigned long arg) 1434{ 1435 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); 1436 1437 /* FUSE_IOCTL_DIR only supported for API version >= 7.18 */ 1438 if (fc->minor < 18) 1439 return -ENOTTY; 1440 1441 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR); 1442} 1443 1444static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd, 1445 unsigned long arg) 1446{ 1447 struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); 1448 1449 if (fc->minor < 18) 1450 return -ENOTTY; 1451 1452 return fuse_ioctl_common(file, cmd, arg, 1453 FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR); 1454} 1455 1456static bool update_mtime(unsigned ivalid, bool trust_local_mtime) 1457{ 1458 /* Always update if mtime is explicitly set */ 1459 if (ivalid & ATTR_MTIME_SET) 1460 return true; 1461 1462 /* Or if kernel i_mtime is the official one */ 1463 if (trust_local_mtime) 1464 return true; 1465 1466 /* If it's an open(O_TRUNC) or an ftruncate(), don't update */ 1467 if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE))) 1468 return false; 1469 1470 /* In all other cases update */ 1471 return true; 1472} 1473 1474static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg, 1475 bool trust_local_cmtime) 1476{ 1477 unsigned ivalid = iattr->ia_valid; 1478 1479 if (ivalid & ATTR_MODE) 1480 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode; 1481 if (ivalid & ATTR_UID) 1482 arg->valid |= FATTR_UID, arg->uid = from_kuid(&init_user_ns, iattr->ia_uid); 1483 if (ivalid & ATTR_GID) 1484 arg->valid |= FATTR_GID, arg->gid = from_kgid(&init_user_ns, iattr->ia_gid); 1485 if (ivalid & ATTR_SIZE) 1486 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size; 1487 if (ivalid & ATTR_ATIME) { 1488 arg->valid |= FATTR_ATIME; 1489 arg->atime = iattr->ia_atime.tv_sec; 1490 arg->atimensec = iattr->ia_atime.tv_nsec; 1491 if (!(ivalid & ATTR_ATIME_SET)) 1492 arg->valid |= FATTR_ATIME_NOW; 1493 } 1494 if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_cmtime)) { 1495 arg->valid |= FATTR_MTIME; 1496 arg->mtime = iattr->ia_mtime.tv_sec; 1497 arg->mtimensec = iattr->ia_mtime.tv_nsec; 1498 if (!(ivalid & ATTR_MTIME_SET) && !trust_local_cmtime) 1499 arg->valid |= FATTR_MTIME_NOW; 1500 } 1501 if ((ivalid & ATTR_CTIME) && trust_local_cmtime) { 1502 arg->valid |= FATTR_CTIME; 1503 arg->ctime = iattr->ia_ctime.tv_sec; 1504 arg->ctimensec = iattr->ia_ctime.tv_nsec; 1505 } 1506} 1507 1508/* 1509 * Prevent concurrent writepages on inode 1510 * 1511 * This is done by adding a negative bias to the inode write counter 1512 * and waiting for all pending writes to finish. 1513 */ 1514void fuse_set_nowrite(struct inode *inode) 1515{ 1516 struct fuse_conn *fc = get_fuse_conn(inode); 1517 struct fuse_inode *fi = get_fuse_inode(inode); 1518 1519 BUG_ON(!mutex_is_locked(&inode->i_mutex)); 1520 1521 spin_lock(&fc->lock); 1522 BUG_ON(fi->writectr < 0); 1523 fi->writectr += FUSE_NOWRITE; 1524 spin_unlock(&fc->lock); 1525 wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE); 1526} 1527 1528/* 1529 * Allow writepages on inode 1530 * 1531 * Remove the bias from the writecounter and send any queued 1532 * writepages. 1533 */ 1534static void __fuse_release_nowrite(struct inode *inode) 1535{ 1536 struct fuse_inode *fi = get_fuse_inode(inode); 1537 1538 BUG_ON(fi->writectr != FUSE_NOWRITE); 1539 fi->writectr = 0; 1540 fuse_flush_writepages(inode); 1541} 1542 1543void fuse_release_nowrite(struct inode *inode) 1544{ 1545 struct fuse_conn *fc = get_fuse_conn(inode); 1546 1547 spin_lock(&fc->lock); 1548 __fuse_release_nowrite(inode); 1549 spin_unlock(&fc->lock); 1550} 1551 1552static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_args *args, 1553 struct inode *inode, 1554 struct fuse_setattr_in *inarg_p, 1555 struct fuse_attr_out *outarg_p) 1556{ 1557 args->in.h.opcode = FUSE_SETATTR; 1558 args->in.h.nodeid = get_node_id(inode); 1559 args->in.numargs = 1; 1560 args->in.args[0].size = sizeof(*inarg_p); 1561 args->in.args[0].value = inarg_p; 1562 args->out.numargs = 1; 1563 args->out.args[0].size = sizeof(*outarg_p); 1564 args->out.args[0].value = outarg_p; 1565} 1566 1567/* 1568 * Flush inode->i_mtime to the server 1569 */ 1570int fuse_flush_times(struct inode *inode, struct fuse_file *ff) 1571{ 1572 struct fuse_conn *fc = get_fuse_conn(inode); 1573 FUSE_ARGS(args); 1574 struct fuse_setattr_in inarg; 1575 struct fuse_attr_out outarg; 1576 1577 memset(&inarg, 0, sizeof(inarg)); 1578 memset(&outarg, 0, sizeof(outarg)); 1579 1580 inarg.valid = FATTR_MTIME; 1581 inarg.mtime = inode->i_mtime.tv_sec; 1582 inarg.mtimensec = inode->i_mtime.tv_nsec; 1583 if (fc->minor >= 23) { 1584 inarg.valid |= FATTR_CTIME; 1585 inarg.ctime = inode->i_ctime.tv_sec; 1586 inarg.ctimensec = inode->i_ctime.tv_nsec; 1587 } 1588 if (ff) { 1589 inarg.valid |= FATTR_FH; 1590 inarg.fh = ff->fh; 1591 } 1592 fuse_setattr_fill(fc, &args, inode, &inarg, &outarg); 1593 1594 return fuse_simple_request(fc, &args); 1595} 1596 1597/* 1598 * Set attributes, and at the same time refresh them. 1599 * 1600 * Truncation is slightly complicated, because the 'truncate' request 1601 * may fail, in which case we don't want to touch the mapping. 1602 * vmtruncate() doesn't allow for this case, so do the rlimit checking 1603 * and the actual truncation by hand. 1604 */ 1605int fuse_do_setattr(struct inode *inode, struct iattr *attr, 1606 struct file *file) 1607{ 1608 struct fuse_conn *fc = get_fuse_conn(inode); 1609 struct fuse_inode *fi = get_fuse_inode(inode); 1610 FUSE_ARGS(args); 1611 struct fuse_setattr_in inarg; 1612 struct fuse_attr_out outarg; 1613 bool is_truncate = false; 1614 bool is_wb = fc->writeback_cache; 1615 loff_t oldsize; 1616 int err; 1617 bool trust_local_cmtime = is_wb && S_ISREG(inode->i_mode); 1618 1619 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS)) 1620 attr->ia_valid |= ATTR_FORCE; 1621 1622 err = inode_change_ok(inode, attr); 1623 if (err) 1624 return err; 1625 1626 if (attr->ia_valid & ATTR_OPEN) { 1627 if (fc->atomic_o_trunc) 1628 return 0; 1629 file = NULL; 1630 } 1631 1632 if (attr->ia_valid & ATTR_SIZE) 1633 is_truncate = true; 1634 1635 if (is_truncate) { 1636 fuse_set_nowrite(inode); 1637 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); 1638 if (trust_local_cmtime && attr->ia_size != inode->i_size) 1639 attr->ia_valid |= ATTR_MTIME | ATTR_CTIME; 1640 } 1641 1642 memset(&inarg, 0, sizeof(inarg)); 1643 memset(&outarg, 0, sizeof(outarg)); 1644 iattr_to_fattr(attr, &inarg, trust_local_cmtime); 1645 if (file) { 1646 struct fuse_file *ff = file->private_data; 1647 inarg.valid |= FATTR_FH; 1648 inarg.fh = ff->fh; 1649 } 1650 if (attr->ia_valid & ATTR_SIZE) { 1651 /* For mandatory locking in truncate */ 1652 inarg.valid |= FATTR_LOCKOWNER; 1653 inarg.lock_owner = fuse_lock_owner_id(fc, current->files); 1654 } 1655 fuse_setattr_fill(fc, &args, inode, &inarg, &outarg); 1656 err = fuse_simple_request(fc, &args); 1657 if (err) { 1658 if (err == -EINTR) 1659 fuse_invalidate_attr(inode); 1660 goto error; 1661 } 1662 1663 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { 1664 make_bad_inode(inode); 1665 err = -EIO; 1666 goto error; 1667 } 1668 1669 spin_lock(&fc->lock); 1670 /* the kernel maintains i_mtime locally */ 1671 if (trust_local_cmtime) { 1672 if (attr->ia_valid & ATTR_MTIME) 1673 inode->i_mtime = attr->ia_mtime; 1674 if (attr->ia_valid & ATTR_CTIME) 1675 inode->i_ctime = attr->ia_ctime; 1676 /* FIXME: clear I_DIRTY_SYNC? */ 1677 } 1678 1679 fuse_change_attributes_common(inode, &outarg.attr, 1680 attr_timeout(&outarg)); 1681 oldsize = inode->i_size; 1682 /* see the comment in fuse_change_attributes() */ 1683 if (!is_wb || is_truncate || !S_ISREG(inode->i_mode)) 1684 i_size_write(inode, outarg.attr.size); 1685 1686 if (is_truncate) { 1687 /* NOTE: this may release/reacquire fc->lock */ 1688 __fuse_release_nowrite(inode); 1689 } 1690 spin_unlock(&fc->lock); 1691 1692 /* 1693 * Only call invalidate_inode_pages2() after removing 1694 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. 1695 */ 1696 if ((is_truncate || !is_wb) && 1697 S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { 1698 truncate_pagecache(inode, outarg.attr.size); 1699 invalidate_inode_pages2(inode->i_mapping); 1700 } 1701 1702 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); 1703 return 0; 1704 1705error: 1706 if (is_truncate) 1707 fuse_release_nowrite(inode); 1708 1709 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); 1710 return err; 1711} 1712 1713static int fuse_setattr(struct dentry *entry, struct iattr *attr) 1714{ 1715 struct inode *inode = d_inode(entry); 1716 1717 if (!fuse_allow_current_process(get_fuse_conn(inode))) 1718 return -EACCES; 1719 1720 if (attr->ia_valid & ATTR_FILE) 1721 return fuse_do_setattr(inode, attr, attr->ia_file); 1722 else 1723 return fuse_do_setattr(inode, attr, NULL); 1724} 1725 1726static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, 1727 struct kstat *stat) 1728{ 1729 struct inode *inode = d_inode(entry); 1730 struct fuse_conn *fc = get_fuse_conn(inode); 1731 1732 if (!fuse_allow_current_process(fc)) 1733 return -EACCES; 1734 1735 return fuse_update_attributes(inode, stat, NULL, NULL); 1736} 1737 1738static int fuse_setxattr(struct dentry *entry, const char *name, 1739 const void *value, size_t size, int flags) 1740{ 1741 struct inode *inode = d_inode(entry); 1742 struct fuse_conn *fc = get_fuse_conn(inode); 1743 FUSE_ARGS(args); 1744 struct fuse_setxattr_in inarg; 1745 int err; 1746 1747 if (fc->no_setxattr) 1748 return -EOPNOTSUPP; 1749 1750 memset(&inarg, 0, sizeof(inarg)); 1751 inarg.size = size; 1752 inarg.flags = flags; 1753 args.in.h.opcode = FUSE_SETXATTR; 1754 args.in.h.nodeid = get_node_id(inode); 1755 args.in.numargs = 3; 1756 args.in.args[0].size = sizeof(inarg); 1757 args.in.args[0].value = &inarg; 1758 args.in.args[1].size = strlen(name) + 1; 1759 args.in.args[1].value = name; 1760 args.in.args[2].size = size; 1761 args.in.args[2].value = value; 1762 err = fuse_simple_request(fc, &args); 1763 if (err == -ENOSYS) { 1764 fc->no_setxattr = 1; 1765 err = -EOPNOTSUPP; 1766 } 1767 if (!err) { 1768 fuse_invalidate_attr(inode); 1769 fuse_update_ctime(inode); 1770 } 1771 return err; 1772} 1773 1774static ssize_t fuse_getxattr(struct dentry *entry, const char *name, 1775 void *value, size_t size) 1776{ 1777 struct inode *inode = d_inode(entry); 1778 struct fuse_conn *fc = get_fuse_conn(inode); 1779 FUSE_ARGS(args); 1780 struct fuse_getxattr_in inarg; 1781 struct fuse_getxattr_out outarg; 1782 ssize_t ret; 1783 1784 if (fc->no_getxattr) 1785 return -EOPNOTSUPP; 1786 1787 memset(&inarg, 0, sizeof(inarg)); 1788 inarg.size = size; 1789 args.in.h.opcode = FUSE_GETXATTR; 1790 args.in.h.nodeid = get_node_id(inode); 1791 args.in.numargs = 2; 1792 args.in.args[0].size = sizeof(inarg); 1793 args.in.args[0].value = &inarg; 1794 args.in.args[1].size = strlen(name) + 1; 1795 args.in.args[1].value = name; 1796 /* This is really two different operations rolled into one */ 1797 args.out.numargs = 1; 1798 if (size) { 1799 args.out.argvar = 1; 1800 args.out.args[0].size = size; 1801 args.out.args[0].value = value; 1802 } else { 1803 args.out.args[0].size = sizeof(outarg); 1804 args.out.args[0].value = &outarg; 1805 } 1806 ret = fuse_simple_request(fc, &args); 1807 if (!ret && !size) 1808 ret = outarg.size; 1809 if (ret == -ENOSYS) { 1810 fc->no_getxattr = 1; 1811 ret = -EOPNOTSUPP; 1812 } 1813 return ret; 1814} 1815 1816static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) 1817{ 1818 struct inode *inode = d_inode(entry); 1819 struct fuse_conn *fc = get_fuse_conn(inode); 1820 FUSE_ARGS(args); 1821 struct fuse_getxattr_in inarg; 1822 struct fuse_getxattr_out outarg; 1823 ssize_t ret; 1824 1825 if (!fuse_allow_current_process(fc)) 1826 return -EACCES; 1827 1828 if (fc->no_listxattr) 1829 return -EOPNOTSUPP; 1830 1831 memset(&inarg, 0, sizeof(inarg)); 1832 inarg.size = size; 1833 args.in.h.opcode = FUSE_LISTXATTR; 1834 args.in.h.nodeid = get_node_id(inode); 1835 args.in.numargs = 1; 1836 args.in.args[0].size = sizeof(inarg); 1837 args.in.args[0].value = &inarg; 1838 /* This is really two different operations rolled into one */ 1839 args.out.numargs = 1; 1840 if (size) { 1841 args.out.argvar = 1; 1842 args.out.args[0].size = size; 1843 args.out.args[0].value = list; 1844 } else { 1845 args.out.args[0].size = sizeof(outarg); 1846 args.out.args[0].value = &outarg; 1847 } 1848 ret = fuse_simple_request(fc, &args); 1849 if (!ret && !size) 1850 ret = outarg.size; 1851 if (ret == -ENOSYS) { 1852 fc->no_listxattr = 1; 1853 ret = -EOPNOTSUPP; 1854 } 1855 return ret; 1856} 1857 1858static int fuse_removexattr(struct dentry *entry, const char *name) 1859{ 1860 struct inode *inode = d_inode(entry); 1861 struct fuse_conn *fc = get_fuse_conn(inode); 1862 FUSE_ARGS(args); 1863 int err; 1864 1865 if (fc->no_removexattr) 1866 return -EOPNOTSUPP; 1867 1868 args.in.h.opcode = FUSE_REMOVEXATTR; 1869 args.in.h.nodeid = get_node_id(inode); 1870 args.in.numargs = 1; 1871 args.in.args[0].size = strlen(name) + 1; 1872 args.in.args[0].value = name; 1873 err = fuse_simple_request(fc, &args); 1874 if (err == -ENOSYS) { 1875 fc->no_removexattr = 1; 1876 err = -EOPNOTSUPP; 1877 } 1878 if (!err) { 1879 fuse_invalidate_attr(inode); 1880 fuse_update_ctime(inode); 1881 } 1882 return err; 1883} 1884 1885static const struct inode_operations fuse_dir_inode_operations = { 1886 .lookup = fuse_lookup, 1887 .mkdir = fuse_mkdir, 1888 .symlink = fuse_symlink, 1889 .unlink = fuse_unlink, 1890 .rmdir = fuse_rmdir, 1891 .rename2 = fuse_rename2, 1892 .link = fuse_link, 1893 .setattr = fuse_setattr, 1894 .create = fuse_create, 1895 .atomic_open = fuse_atomic_open, 1896 .mknod = fuse_mknod, 1897 .permission = fuse_permission, 1898 .getattr = fuse_getattr, 1899 .setxattr = fuse_setxattr, 1900 .getxattr = fuse_getxattr, 1901 .listxattr = fuse_listxattr, 1902 .removexattr = fuse_removexattr, 1903}; 1904 1905static const struct file_operations fuse_dir_operations = { 1906 .llseek = generic_file_llseek, 1907 .read = generic_read_dir, 1908 .iterate = fuse_readdir, 1909 .open = fuse_dir_open, 1910 .release = fuse_dir_release, 1911 .fsync = fuse_dir_fsync, 1912 .unlocked_ioctl = fuse_dir_ioctl, 1913 .compat_ioctl = fuse_dir_compat_ioctl, 1914}; 1915 1916static const struct inode_operations fuse_common_inode_operations = { 1917 .setattr = fuse_setattr, 1918 .permission = fuse_permission, 1919 .getattr = fuse_getattr, 1920 .setxattr = fuse_setxattr, 1921 .getxattr = fuse_getxattr, 1922 .listxattr = fuse_listxattr, 1923 .removexattr = fuse_removexattr, 1924}; 1925 1926static const struct inode_operations fuse_symlink_inode_operations = { 1927 .setattr = fuse_setattr, 1928 .follow_link = fuse_follow_link, 1929 .put_link = fuse_put_link, 1930 .readlink = generic_readlink, 1931 .getattr = fuse_getattr, 1932 .setxattr = fuse_setxattr, 1933 .getxattr = fuse_getxattr, 1934 .listxattr = fuse_listxattr, 1935 .removexattr = fuse_removexattr, 1936}; 1937 1938void fuse_init_common(struct inode *inode) 1939{ 1940 inode->i_op = &fuse_common_inode_operations; 1941} 1942 1943void fuse_init_dir(struct inode *inode) 1944{ 1945 inode->i_op = &fuse_dir_inode_operations; 1946 inode->i_fop = &fuse_dir_operations; 1947} 1948 1949void fuse_init_symlink(struct inode *inode) 1950{ 1951 inode->i_op = &fuse_symlink_inode_operations; 1952} 1953