1 /* 2 FUSE: Filesystem in Userspace 3 Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu> 4 5 This program can be distributed under the terms of the GNU GPL. 6 See the file COPYING. 7 */ 8 9 #include "fuse_i.h" 10 11 #include <linux/pagemap.h> 12 #include <linux/file.h> 13 #include <linux/gfp.h> 14 #include <linux/sched.h> 15 #include <linux/namei.h> 16 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 = entry->d_inode; 160 161 if (inode && is_bad_inode(inode)) 162 return 0; 163 else if (fuse_dentry_time(entry) < get_jiffies_64()) { 164 int err; 165 struct fuse_entry_out outarg; 166 struct fuse_conn *fc; 167 struct fuse_req *req; 168 struct fuse_req *forget_req; 169 struct dentry *parent; 170 u64 attr_version; 171 172 /* For negative dentries, always do a fresh lookup */ 173 if (!inode) 174 return 0; 175 176 fc = get_fuse_conn(inode); 177 req = fuse_get_req(fc); 178 if (IS_ERR(req)) 179 return 0; 180 181 forget_req = fuse_get_req(fc); 182 if (IS_ERR(forget_req)) { 183 fuse_put_request(fc, req); 184 return 0; 185 } 186 187 attr_version = fuse_get_attr_version(fc); 188 189 parent = dget_parent(entry); 190 fuse_lookup_init(fc, req, get_node_id(parent->d_inode), 191 &entry->d_name, &outarg); 192 request_send(fc, req); 193 dput(parent); 194 err = req->out.h.error; 195 fuse_put_request(fc, req); 196 /* Zero nodeid is same as -ENOENT */ 197 if (!err && !outarg.nodeid) 198 err = -ENOENT; 199 if (!err) { 200 struct fuse_inode *fi = get_fuse_inode(inode); 201 if (outarg.nodeid != get_node_id(inode)) { 202 fuse_send_forget(fc, forget_req, 203 outarg.nodeid, 1); 204 return 0; 205 } 206 spin_lock(&fc->lock); 207 fi->nlookup ++; 208 spin_unlock(&fc->lock); 209 } 210 fuse_put_request(fc, forget_req); 211 if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) 212 return 0; 213 214 fuse_change_attributes(inode, &outarg.attr, 215 entry_attr_timeout(&outarg), 216 attr_version); 217 fuse_change_entry_timeout(entry, &outarg); 218 } 219 return 1; 220 } 221 222 static int invalid_nodeid(u64 nodeid) 223 { 224 return !nodeid || nodeid == FUSE_ROOT_ID; 225 } 226 227 struct dentry_operations fuse_dentry_operations = { 228 .d_revalidate = fuse_dentry_revalidate, 229 }; 230 231 int fuse_valid_type(int m) 232 { 233 return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) || 234 S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m); 235 } 236 237 /* 238 * Add a directory inode to a dentry, ensuring that no other dentry 239 * refers to this inode. Called with fc->inst_mutex. 240 */ 241 static struct dentry *fuse_d_add_directory(struct dentry *entry, 242 struct inode *inode) 243 { 244 struct dentry *alias = d_find_alias(inode); 245 if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) { 246 /* This tries to shrink the subtree below alias */ 247 fuse_invalidate_entry(alias); 248 dput(alias); 249 if (!list_empty(&inode->i_dentry)) 250 return ERR_PTR(-EBUSY); 251 } else { 252 dput(alias); 253 } 254 return d_splice_alias(inode, entry); 255 } 256 257 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name, 258 struct fuse_entry_out *outarg, struct inode **inode) 259 { 260 struct fuse_conn *fc = get_fuse_conn_super(sb); 261 struct fuse_req *req; 262 struct fuse_req *forget_req; 263 u64 attr_version; 264 int err; 265 266 *inode = NULL; 267 err = -ENAMETOOLONG; 268 if (name->len > FUSE_NAME_MAX) 269 goto out; 270 271 req = fuse_get_req(fc); 272 err = PTR_ERR(req); 273 if (IS_ERR(req)) 274 goto out; 275 276 forget_req = fuse_get_req(fc); 277 err = PTR_ERR(forget_req); 278 if (IS_ERR(forget_req)) { 279 fuse_put_request(fc, req); 280 goto out; 281 } 282 283 attr_version = fuse_get_attr_version(fc); 284 285 fuse_lookup_init(fc, req, nodeid, name, outarg); 286 request_send(fc, req); 287 err = req->out.h.error; 288 fuse_put_request(fc, req); 289 /* Zero nodeid is same as -ENOENT, but with valid timeout */ 290 if (err || !outarg->nodeid) 291 goto out_put_forget; 292 293 err = -EIO; 294 if (!outarg->nodeid) 295 goto out_put_forget; 296 if (!fuse_valid_type(outarg->attr.mode)) 297 goto out_put_forget; 298 299 *inode = fuse_iget(sb, outarg->nodeid, outarg->generation, 300 &outarg->attr, entry_attr_timeout(outarg), 301 attr_version); 302 err = -ENOMEM; 303 if (!*inode) { 304 fuse_send_forget(fc, forget_req, outarg->nodeid, 1); 305 goto out; 306 } 307 err = 0; 308 309 out_put_forget: 310 fuse_put_request(fc, forget_req); 311 out: 312 return err; 313 } 314 315 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, 316 struct nameidata *nd) 317 { 318 int err; 319 struct fuse_entry_out outarg; 320 struct inode *inode; 321 struct dentry *newent; 322 struct fuse_conn *fc = get_fuse_conn(dir); 323 bool outarg_valid = true; 324 325 err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, 326 &outarg, &inode); 327 if (err == -ENOENT) { 328 outarg_valid = false; 329 err = 0; 330 } 331 if (err) 332 goto out_err; 333 334 err = -EIO; 335 if (inode && get_node_id(inode) == FUSE_ROOT_ID) 336 goto out_iput; 337 338 if (inode && S_ISDIR(inode->i_mode)) { 339 mutex_lock(&fc->inst_mutex); 340 newent = fuse_d_add_directory(entry, inode); 341 mutex_unlock(&fc->inst_mutex); 342 err = PTR_ERR(newent); 343 if (IS_ERR(newent)) 344 goto out_iput; 345 } else { 346 newent = d_splice_alias(inode, entry); 347 } 348 349 entry = newent ? newent : entry; 350 entry->d_op = &fuse_dentry_operations; 351 if (outarg_valid) 352 fuse_change_entry_timeout(entry, &outarg); 353 else 354 fuse_invalidate_entry_cache(entry); 355 356 return newent; 357 358 out_iput: 359 iput(inode); 360 out_err: 361 return ERR_PTR(err); 362 } 363 364 /* 365 * Synchronous release for the case when something goes wrong in CREATE_OPEN 366 */ 367 static void fuse_sync_release(struct fuse_conn *fc, struct fuse_file *ff, 368 u64 nodeid, int flags) 369 { 370 fuse_release_fill(ff, nodeid, flags, FUSE_RELEASE); 371 ff->reserved_req->force = 1; 372 request_send(fc, ff->reserved_req); 373 fuse_put_request(fc, ff->reserved_req); 374 kfree(ff); 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 */ 383 static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, 384 struct nameidata *nd) 385 { 386 int err; 387 struct inode *inode; 388 struct fuse_conn *fc = get_fuse_conn(dir); 389 struct fuse_req *req; 390 struct fuse_req *forget_req; 391 struct fuse_open_in inarg; 392 struct fuse_open_out outopen; 393 struct fuse_entry_out outentry; 394 struct fuse_file *ff; 395 struct file *file; 396 int flags = nd->intent.open.flags - 1; 397 398 if (fc->no_create) 399 return -ENOSYS; 400 401 forget_req = fuse_get_req(fc); 402 if (IS_ERR(forget_req)) 403 return PTR_ERR(forget_req); 404 405 req = fuse_get_req(fc); 406 err = PTR_ERR(req); 407 if (IS_ERR(req)) 408 goto out_put_forget_req; 409 410 err = -ENOMEM; 411 ff = fuse_file_alloc(); 412 if (!ff) 413 goto out_put_request; 414 415 flags &= ~O_NOCTTY; 416 memset(&inarg, 0, sizeof(inarg)); 417 memset(&outentry, 0, sizeof(outentry)); 418 inarg.flags = flags; 419 inarg.mode = mode; 420 req->in.h.opcode = FUSE_CREATE; 421 req->in.h.nodeid = get_node_id(dir); 422 req->in.numargs = 2; 423 req->in.args[0].size = sizeof(inarg); 424 req->in.args[0].value = &inarg; 425 req->in.args[1].size = entry->d_name.len + 1; 426 req->in.args[1].value = entry->d_name.name; 427 req->out.numargs = 2; 428 if (fc->minor < 9) 429 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; 430 else 431 req->out.args[0].size = sizeof(outentry); 432 req->out.args[0].value = &outentry; 433 req->out.args[1].size = sizeof(outopen); 434 req->out.args[1].value = &outopen; 435 request_send(fc, req); 436 err = req->out.h.error; 437 if (err) { 438 if (err == -ENOSYS) 439 fc->no_create = 1; 440 goto out_free_ff; 441 } 442 443 err = -EIO; 444 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid)) 445 goto out_free_ff; 446 447 fuse_put_request(fc, req); 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 ff->fh = outopen.fh; 453 fuse_sync_release(fc, ff, outentry.nodeid, flags); 454 fuse_send_forget(fc, forget_req, outentry.nodeid, 1); 455 return -ENOMEM; 456 } 457 fuse_put_request(fc, forget_req); 458 d_instantiate(entry, inode); 459 fuse_change_entry_timeout(entry, &outentry); 460 fuse_invalidate_attr(dir); 461 file = lookup_instantiate_filp(nd, entry, generic_file_open); 462 if (IS_ERR(file)) { 463 ff->fh = outopen.fh; 464 fuse_sync_release(fc, ff, outentry.nodeid, flags); 465 return PTR_ERR(file); 466 } 467 fuse_finish_open(inode, file, ff, &outopen); 468 return 0; 469 470 out_free_ff: 471 fuse_file_free(ff); 472 out_put_request: 473 fuse_put_request(fc, req); 474 out_put_forget_req: 475 fuse_put_request(fc, forget_req); 476 return err; 477 } 478 479 /* 480 * Code shared between mknod, mkdir, symlink and link 481 */ 482 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req, 483 struct inode *dir, struct dentry *entry, 484 int mode) 485 { 486 struct fuse_entry_out outarg; 487 struct inode *inode; 488 int err; 489 struct fuse_req *forget_req; 490 491 forget_req = fuse_get_req(fc); 492 if (IS_ERR(forget_req)) { 493 fuse_put_request(fc, req); 494 return PTR_ERR(forget_req); 495 } 496 497 memset(&outarg, 0, sizeof(outarg)); 498 req->in.h.nodeid = get_node_id(dir); 499 req->out.numargs = 1; 500 if (fc->minor < 9) 501 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; 502 else 503 req->out.args[0].size = sizeof(outarg); 504 req->out.args[0].value = &outarg; 505 request_send(fc, req); 506 err = req->out.h.error; 507 fuse_put_request(fc, req); 508 if (err) 509 goto out_put_forget_req; 510 511 err = -EIO; 512 if (invalid_nodeid(outarg.nodeid)) 513 goto out_put_forget_req; 514 515 if ((outarg.attr.mode ^ mode) & S_IFMT) 516 goto out_put_forget_req; 517 518 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, 519 &outarg.attr, entry_attr_timeout(&outarg), 0); 520 if (!inode) { 521 fuse_send_forget(fc, forget_req, outarg.nodeid, 1); 522 return -ENOMEM; 523 } 524 fuse_put_request(fc, forget_req); 525 526 if (S_ISDIR(inode->i_mode)) { 527 struct dentry *alias; 528 mutex_lock(&fc->inst_mutex); 529 alias = d_find_alias(inode); 530 if (alias) { 531 /* New directory must have moved since mkdir */ 532 mutex_unlock(&fc->inst_mutex); 533 dput(alias); 534 iput(inode); 535 return -EBUSY; 536 } 537 d_instantiate(entry, inode); 538 mutex_unlock(&fc->inst_mutex); 539 } else 540 d_instantiate(entry, inode); 541 542 fuse_change_entry_timeout(entry, &outarg); 543 fuse_invalidate_attr(dir); 544 return 0; 545 546 out_put_forget_req: 547 fuse_put_request(fc, forget_req); 548 return err; 549 } 550 551 static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode, 552 dev_t rdev) 553 { 554 struct fuse_mknod_in inarg; 555 struct fuse_conn *fc = get_fuse_conn(dir); 556 struct fuse_req *req = fuse_get_req(fc); 557 if (IS_ERR(req)) 558 return PTR_ERR(req); 559 560 memset(&inarg, 0, sizeof(inarg)); 561 inarg.mode = mode; 562 inarg.rdev = new_encode_dev(rdev); 563 req->in.h.opcode = FUSE_MKNOD; 564 req->in.numargs = 2; 565 req->in.args[0].size = sizeof(inarg); 566 req->in.args[0].value = &inarg; 567 req->in.args[1].size = entry->d_name.len + 1; 568 req->in.args[1].value = entry->d_name.name; 569 return create_new_entry(fc, req, dir, entry, mode); 570 } 571 572 static int fuse_create(struct inode *dir, struct dentry *entry, int mode, 573 struct nameidata *nd) 574 { 575 if (nd && (nd->flags & LOOKUP_OPEN)) { 576 int err = fuse_create_open(dir, entry, mode, nd); 577 if (err != -ENOSYS) 578 return err; 579 /* Fall back on mknod */ 580 } 581 return fuse_mknod(dir, entry, mode, 0); 582 } 583 584 static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode) 585 { 586 struct fuse_mkdir_in inarg; 587 struct fuse_conn *fc = get_fuse_conn(dir); 588 struct fuse_req *req = fuse_get_req(fc); 589 if (IS_ERR(req)) 590 return PTR_ERR(req); 591 592 memset(&inarg, 0, sizeof(inarg)); 593 inarg.mode = mode; 594 req->in.h.opcode = FUSE_MKDIR; 595 req->in.numargs = 2; 596 req->in.args[0].size = sizeof(inarg); 597 req->in.args[0].value = &inarg; 598 req->in.args[1].size = entry->d_name.len + 1; 599 req->in.args[1].value = entry->d_name.name; 600 return create_new_entry(fc, req, dir, entry, S_IFDIR); 601 } 602 603 static int fuse_symlink(struct inode *dir, struct dentry *entry, 604 const char *link) 605 { 606 struct fuse_conn *fc = get_fuse_conn(dir); 607 unsigned len = strlen(link) + 1; 608 struct fuse_req *req = fuse_get_req(fc); 609 if (IS_ERR(req)) 610 return PTR_ERR(req); 611 612 req->in.h.opcode = FUSE_SYMLINK; 613 req->in.numargs = 2; 614 req->in.args[0].size = entry->d_name.len + 1; 615 req->in.args[0].value = entry->d_name.name; 616 req->in.args[1].size = len; 617 req->in.args[1].value = link; 618 return create_new_entry(fc, req, dir, entry, S_IFLNK); 619 } 620 621 static int fuse_unlink(struct inode *dir, struct dentry *entry) 622 { 623 int err; 624 struct fuse_conn *fc = get_fuse_conn(dir); 625 struct fuse_req *req = fuse_get_req(fc); 626 if (IS_ERR(req)) 627 return PTR_ERR(req); 628 629 req->in.h.opcode = FUSE_UNLINK; 630 req->in.h.nodeid = get_node_id(dir); 631 req->in.numargs = 1; 632 req->in.args[0].size = entry->d_name.len + 1; 633 req->in.args[0].value = entry->d_name.name; 634 request_send(fc, req); 635 err = req->out.h.error; 636 fuse_put_request(fc, req); 637 if (!err) { 638 struct inode *inode = entry->d_inode; 639 640 /* Set nlink to zero so the inode can be cleared, if 641 the inode does have more links this will be 642 discovered at the next lookup/getattr */ 643 clear_nlink(inode); 644 fuse_invalidate_attr(inode); 645 fuse_invalidate_attr(dir); 646 fuse_invalidate_entry_cache(entry); 647 } else if (err == -EINTR) 648 fuse_invalidate_entry(entry); 649 return err; 650 } 651 652 static int fuse_rmdir(struct inode *dir, struct dentry *entry) 653 { 654 int err; 655 struct fuse_conn *fc = get_fuse_conn(dir); 656 struct fuse_req *req = fuse_get_req(fc); 657 if (IS_ERR(req)) 658 return PTR_ERR(req); 659 660 req->in.h.opcode = FUSE_RMDIR; 661 req->in.h.nodeid = get_node_id(dir); 662 req->in.numargs = 1; 663 req->in.args[0].size = entry->d_name.len + 1; 664 req->in.args[0].value = entry->d_name.name; 665 request_send(fc, req); 666 err = req->out.h.error; 667 fuse_put_request(fc, req); 668 if (!err) { 669 clear_nlink(entry->d_inode); 670 fuse_invalidate_attr(dir); 671 fuse_invalidate_entry_cache(entry); 672 } else if (err == -EINTR) 673 fuse_invalidate_entry(entry); 674 return err; 675 } 676 677 static int fuse_rename(struct inode *olddir, struct dentry *oldent, 678 struct inode *newdir, struct dentry *newent) 679 { 680 int err; 681 struct fuse_rename_in inarg; 682 struct fuse_conn *fc = get_fuse_conn(olddir); 683 struct fuse_req *req = fuse_get_req(fc); 684 if (IS_ERR(req)) 685 return PTR_ERR(req); 686 687 memset(&inarg, 0, sizeof(inarg)); 688 inarg.newdir = get_node_id(newdir); 689 req->in.h.opcode = FUSE_RENAME; 690 req->in.h.nodeid = get_node_id(olddir); 691 req->in.numargs = 3; 692 req->in.args[0].size = sizeof(inarg); 693 req->in.args[0].value = &inarg; 694 req->in.args[1].size = oldent->d_name.len + 1; 695 req->in.args[1].value = oldent->d_name.name; 696 req->in.args[2].size = newent->d_name.len + 1; 697 req->in.args[2].value = newent->d_name.name; 698 request_send(fc, req); 699 err = req->out.h.error; 700 fuse_put_request(fc, req); 701 if (!err) { 702 /* ctime changes */ 703 fuse_invalidate_attr(oldent->d_inode); 704 705 fuse_invalidate_attr(olddir); 706 if (olddir != newdir) 707 fuse_invalidate_attr(newdir); 708 709 /* newent will end up negative */ 710 if (newent->d_inode) 711 fuse_invalidate_entry_cache(newent); 712 } else if (err == -EINTR) { 713 /* If request was interrupted, DEITY only knows if the 714 rename actually took place. If the invalidation 715 fails (e.g. some process has CWD under the renamed 716 directory), then there can be inconsistency between 717 the dcache and the real filesystem. Tough luck. */ 718 fuse_invalidate_entry(oldent); 719 if (newent->d_inode) 720 fuse_invalidate_entry(newent); 721 } 722 723 return err; 724 } 725 726 static int fuse_link(struct dentry *entry, struct inode *newdir, 727 struct dentry *newent) 728 { 729 int err; 730 struct fuse_link_in inarg; 731 struct inode *inode = entry->d_inode; 732 struct fuse_conn *fc = get_fuse_conn(inode); 733 struct fuse_req *req = fuse_get_req(fc); 734 if (IS_ERR(req)) 735 return PTR_ERR(req); 736 737 memset(&inarg, 0, sizeof(inarg)); 738 inarg.oldnodeid = get_node_id(inode); 739 req->in.h.opcode = FUSE_LINK; 740 req->in.numargs = 2; 741 req->in.args[0].size = sizeof(inarg); 742 req->in.args[0].value = &inarg; 743 req->in.args[1].size = newent->d_name.len + 1; 744 req->in.args[1].value = newent->d_name.name; 745 err = create_new_entry(fc, req, newdir, newent, inode->i_mode); 746 /* Contrary to "normal" filesystems it can happen that link 747 makes two "logical" inodes point to the same "physical" 748 inode. We invalidate the attributes of the old one, so it 749 will reflect changes in the backing inode (link count, 750 etc.) 751 */ 752 if (!err || err == -EINTR) 753 fuse_invalidate_attr(inode); 754 return err; 755 } 756 757 static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, 758 struct kstat *stat) 759 { 760 stat->dev = inode->i_sb->s_dev; 761 stat->ino = attr->ino; 762 stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 763 stat->nlink = attr->nlink; 764 stat->uid = attr->uid; 765 stat->gid = attr->gid; 766 stat->rdev = inode->i_rdev; 767 stat->atime.tv_sec = attr->atime; 768 stat->atime.tv_nsec = attr->atimensec; 769 stat->mtime.tv_sec = attr->mtime; 770 stat->mtime.tv_nsec = attr->mtimensec; 771 stat->ctime.tv_sec = attr->ctime; 772 stat->ctime.tv_nsec = attr->ctimensec; 773 stat->size = attr->size; 774 stat->blocks = attr->blocks; 775 stat->blksize = (1 << inode->i_blkbits); 776 } 777 778 static int fuse_do_getattr(struct inode *inode, struct kstat *stat, 779 struct file *file) 780 { 781 int err; 782 struct fuse_getattr_in inarg; 783 struct fuse_attr_out outarg; 784 struct fuse_conn *fc = get_fuse_conn(inode); 785 struct fuse_req *req; 786 u64 attr_version; 787 788 req = fuse_get_req(fc); 789 if (IS_ERR(req)) 790 return PTR_ERR(req); 791 792 attr_version = fuse_get_attr_version(fc); 793 794 memset(&inarg, 0, sizeof(inarg)); 795 memset(&outarg, 0, sizeof(outarg)); 796 /* Directories have separate file-handle space */ 797 if (file && S_ISREG(inode->i_mode)) { 798 struct fuse_file *ff = file->private_data; 799 800 inarg.getattr_flags |= FUSE_GETATTR_FH; 801 inarg.fh = ff->fh; 802 } 803 req->in.h.opcode = FUSE_GETATTR; 804 req->in.h.nodeid = get_node_id(inode); 805 req->in.numargs = 1; 806 req->in.args[0].size = sizeof(inarg); 807 req->in.args[0].value = &inarg; 808 req->out.numargs = 1; 809 if (fc->minor < 9) 810 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; 811 else 812 req->out.args[0].size = sizeof(outarg); 813 req->out.args[0].value = &outarg; 814 request_send(fc, req); 815 err = req->out.h.error; 816 fuse_put_request(fc, req); 817 if (!err) { 818 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { 819 make_bad_inode(inode); 820 err = -EIO; 821 } else { 822 fuse_change_attributes(inode, &outarg.attr, 823 attr_timeout(&outarg), 824 attr_version); 825 if (stat) 826 fuse_fillattr(inode, &outarg.attr, stat); 827 } 828 } 829 return err; 830 } 831 832 int fuse_update_attributes(struct inode *inode, struct kstat *stat, 833 struct file *file, bool *refreshed) 834 { 835 struct fuse_inode *fi = get_fuse_inode(inode); 836 int err; 837 bool r; 838 839 if (fi->i_time < get_jiffies_64()) { 840 r = true; 841 err = fuse_do_getattr(inode, stat, file); 842 } else { 843 r = false; 844 err = 0; 845 if (stat) { 846 generic_fillattr(inode, stat); 847 stat->mode = fi->orig_i_mode; 848 } 849 } 850 851 if (refreshed != NULL) 852 *refreshed = r; 853 854 return err; 855 } 856 857 /* 858 * Calling into a user-controlled filesystem gives the filesystem 859 * daemon ptrace-like capabilities over the requester process. This 860 * means, that the filesystem daemon is able to record the exact 861 * filesystem operations performed, and can also control the behavior 862 * of the requester process in otherwise impossible ways. For example 863 * it can delay the operation for arbitrary length of time allowing 864 * DoS against the requester. 865 * 866 * For this reason only those processes can call into the filesystem, 867 * for which the owner of the mount has ptrace privilege. This 868 * excludes processes started by other users, suid or sgid processes. 869 */ 870 int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task) 871 { 872 if (fc->flags & FUSE_ALLOW_OTHER) 873 return 1; 874 875 if (task->euid == fc->user_id && 876 task->suid == fc->user_id && 877 task->uid == fc->user_id && 878 task->egid == fc->group_id && 879 task->sgid == fc->group_id && 880 task->gid == fc->group_id) 881 return 1; 882 883 return 0; 884 } 885 886 static int fuse_access(struct inode *inode, int mask) 887 { 888 struct fuse_conn *fc = get_fuse_conn(inode); 889 struct fuse_req *req; 890 struct fuse_access_in inarg; 891 int err; 892 893 if (fc->no_access) 894 return 0; 895 896 req = fuse_get_req(fc); 897 if (IS_ERR(req)) 898 return PTR_ERR(req); 899 900 memset(&inarg, 0, sizeof(inarg)); 901 inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC); 902 req->in.h.opcode = FUSE_ACCESS; 903 req->in.h.nodeid = get_node_id(inode); 904 req->in.numargs = 1; 905 req->in.args[0].size = sizeof(inarg); 906 req->in.args[0].value = &inarg; 907 request_send(fc, req); 908 err = req->out.h.error; 909 fuse_put_request(fc, req); 910 if (err == -ENOSYS) { 911 fc->no_access = 1; 912 err = 0; 913 } 914 return err; 915 } 916 917 /* 918 * Check permission. The two basic access models of FUSE are: 919 * 920 * 1) Local access checking ('default_permissions' mount option) based 921 * on file mode. This is the plain old disk filesystem permission 922 * modell. 923 * 924 * 2) "Remote" access checking, where server is responsible for 925 * checking permission in each inode operation. An exception to this 926 * is if ->permission() was invoked from sys_access() in which case an 927 * access request is sent. Execute permission is still checked 928 * locally based on file mode. 929 */ 930 static int fuse_permission(struct inode *inode, int mask) 931 { 932 struct fuse_conn *fc = get_fuse_conn(inode); 933 bool refreshed = false; 934 int err = 0; 935 936 if (!fuse_allow_task(fc, current)) 937 return -EACCES; 938 939 /* 940 * If attributes are needed, refresh them before proceeding 941 */ 942 if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) || 943 ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) { 944 err = fuse_update_attributes(inode, NULL, NULL, &refreshed); 945 if (err) 946 return err; 947 } 948 949 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { 950 err = generic_permission(inode, mask, NULL); 951 952 /* If permission is denied, try to refresh file 953 attributes. This is also needed, because the root 954 node will at first have no permissions */ 955 if (err == -EACCES && !refreshed) { 956 err = fuse_do_getattr(inode, NULL, NULL); 957 if (!err) 958 err = generic_permission(inode, mask, NULL); 959 } 960 961 /* Note: the opposite of the above test does not 962 exist. So if permissions are revoked this won't be 963 noticed immediately, only after the attribute 964 timeout has expired */ 965 } else if (mask & MAY_ACCESS) { 966 err = fuse_access(inode, mask); 967 } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { 968 if (!(inode->i_mode & S_IXUGO)) { 969 if (refreshed) 970 return -EACCES; 971 972 err = fuse_do_getattr(inode, NULL, NULL); 973 if (!err && !(inode->i_mode & S_IXUGO)) 974 return -EACCES; 975 } 976 } 977 return err; 978 } 979 980 static int parse_dirfile(char *buf, size_t nbytes, struct file *file, 981 void *dstbuf, filldir_t filldir) 982 { 983 while (nbytes >= FUSE_NAME_OFFSET) { 984 struct fuse_dirent *dirent = (struct fuse_dirent *) buf; 985 size_t reclen = FUSE_DIRENT_SIZE(dirent); 986 int over; 987 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) 988 return -EIO; 989 if (reclen > nbytes) 990 break; 991 992 over = filldir(dstbuf, dirent->name, dirent->namelen, 993 file->f_pos, dirent->ino, dirent->type); 994 if (over) 995 break; 996 997 buf += reclen; 998 nbytes -= reclen; 999 file->f_pos = dirent->off; 1000 } 1001 1002 return 0; 1003 } 1004 1005 static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir) 1006 { 1007 int err; 1008 size_t nbytes; 1009 struct page *page; 1010 struct inode *inode = file->f_path.dentry->d_inode; 1011 struct fuse_conn *fc = get_fuse_conn(inode); 1012 struct fuse_req *req; 1013 1014 if (is_bad_inode(inode)) 1015 return -EIO; 1016 1017 req = fuse_get_req(fc); 1018 if (IS_ERR(req)) 1019 return PTR_ERR(req); 1020 1021 page = alloc_page(GFP_KERNEL); 1022 if (!page) { 1023 fuse_put_request(fc, req); 1024 return -ENOMEM; 1025 } 1026 req->num_pages = 1; 1027 req->pages[0] = page; 1028 fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR); 1029 request_send(fc, req); 1030 nbytes = req->out.args[0].size; 1031 err = req->out.h.error; 1032 fuse_put_request(fc, req); 1033 if (!err) 1034 err = parse_dirfile(page_address(page), nbytes, file, dstbuf, 1035 filldir); 1036 1037 __free_page(page); 1038 fuse_invalidate_attr(inode); /* atime changed */ 1039 return err; 1040 } 1041 1042 static char *read_link(struct dentry *dentry) 1043 { 1044 struct inode *inode = dentry->d_inode; 1045 struct fuse_conn *fc = get_fuse_conn(inode); 1046 struct fuse_req *req = fuse_get_req(fc); 1047 char *link; 1048 1049 if (IS_ERR(req)) 1050 return ERR_CAST(req); 1051 1052 link = (char *) __get_free_page(GFP_KERNEL); 1053 if (!link) { 1054 link = ERR_PTR(-ENOMEM); 1055 goto out; 1056 } 1057 req->in.h.opcode = FUSE_READLINK; 1058 req->in.h.nodeid = get_node_id(inode); 1059 req->out.argvar = 1; 1060 req->out.numargs = 1; 1061 req->out.args[0].size = PAGE_SIZE - 1; 1062 req->out.args[0].value = link; 1063 request_send(fc, req); 1064 if (req->out.h.error) { 1065 free_page((unsigned long) link); 1066 link = ERR_PTR(req->out.h.error); 1067 } else 1068 link[req->out.args[0].size] = '\0'; 1069 out: 1070 fuse_put_request(fc, req); 1071 fuse_invalidate_attr(inode); /* atime changed */ 1072 return link; 1073 } 1074 1075 static void free_link(char *link) 1076 { 1077 if (!IS_ERR(link)) 1078 free_page((unsigned long) link); 1079 } 1080 1081 static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd) 1082 { 1083 nd_set_link(nd, read_link(dentry)); 1084 return NULL; 1085 } 1086 1087 static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c) 1088 { 1089 free_link(nd_get_link(nd)); 1090 } 1091 1092 static int fuse_dir_open(struct inode *inode, struct file *file) 1093 { 1094 return fuse_open_common(inode, file, 1); 1095 } 1096 1097 static int fuse_dir_release(struct inode *inode, struct file *file) 1098 { 1099 return fuse_release_common(inode, file, 1); 1100 } 1101 1102 static int fuse_dir_fsync(struct file *file, struct dentry *de, int datasync) 1103 { 1104 /* nfsd can call this with no file */ 1105 return file ? fuse_fsync_common(file, de, datasync, 1) : 0; 1106 } 1107 1108 static bool update_mtime(unsigned ivalid) 1109 { 1110 /* Always update if mtime is explicitly set */ 1111 if (ivalid & ATTR_MTIME_SET) 1112 return true; 1113 1114 /* If it's an open(O_TRUNC) or an ftruncate(), don't update */ 1115 if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE))) 1116 return false; 1117 1118 /* In all other cases update */ 1119 return true; 1120 } 1121 1122 static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg) 1123 { 1124 unsigned ivalid = iattr->ia_valid; 1125 1126 if (ivalid & ATTR_MODE) 1127 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode; 1128 if (ivalid & ATTR_UID) 1129 arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid; 1130 if (ivalid & ATTR_GID) 1131 arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid; 1132 if (ivalid & ATTR_SIZE) 1133 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size; 1134 if (ivalid & ATTR_ATIME) { 1135 arg->valid |= FATTR_ATIME; 1136 arg->atime = iattr->ia_atime.tv_sec; 1137 arg->atimensec = iattr->ia_atime.tv_nsec; 1138 if (!(ivalid & ATTR_ATIME_SET)) 1139 arg->valid |= FATTR_ATIME_NOW; 1140 } 1141 if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) { 1142 arg->valid |= FATTR_MTIME; 1143 arg->mtime = iattr->ia_mtime.tv_sec; 1144 arg->mtimensec = iattr->ia_mtime.tv_nsec; 1145 if (!(ivalid & ATTR_MTIME_SET)) 1146 arg->valid |= FATTR_MTIME_NOW; 1147 } 1148 } 1149 1150 /* 1151 * Prevent concurrent writepages on inode 1152 * 1153 * This is done by adding a negative bias to the inode write counter 1154 * and waiting for all pending writes to finish. 1155 */ 1156 void fuse_set_nowrite(struct inode *inode) 1157 { 1158 struct fuse_conn *fc = get_fuse_conn(inode); 1159 struct fuse_inode *fi = get_fuse_inode(inode); 1160 1161 BUG_ON(!mutex_is_locked(&inode->i_mutex)); 1162 1163 spin_lock(&fc->lock); 1164 BUG_ON(fi->writectr < 0); 1165 fi->writectr += FUSE_NOWRITE; 1166 spin_unlock(&fc->lock); 1167 wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE); 1168 } 1169 1170 /* 1171 * Allow writepages on inode 1172 * 1173 * Remove the bias from the writecounter and send any queued 1174 * writepages. 1175 */ 1176 static void __fuse_release_nowrite(struct inode *inode) 1177 { 1178 struct fuse_inode *fi = get_fuse_inode(inode); 1179 1180 BUG_ON(fi->writectr != FUSE_NOWRITE); 1181 fi->writectr = 0; 1182 fuse_flush_writepages(inode); 1183 } 1184 1185 void fuse_release_nowrite(struct inode *inode) 1186 { 1187 struct fuse_conn *fc = get_fuse_conn(inode); 1188 1189 spin_lock(&fc->lock); 1190 __fuse_release_nowrite(inode); 1191 spin_unlock(&fc->lock); 1192 } 1193 1194 /* 1195 * Set attributes, and at the same time refresh them. 1196 * 1197 * Truncation is slightly complicated, because the 'truncate' request 1198 * may fail, in which case we don't want to touch the mapping. 1199 * vmtruncate() doesn't allow for this case, so do the rlimit checking 1200 * and the actual truncation by hand. 1201 */ 1202 static int fuse_do_setattr(struct dentry *entry, struct iattr *attr, 1203 struct file *file) 1204 { 1205 struct inode *inode = entry->d_inode; 1206 struct fuse_conn *fc = get_fuse_conn(inode); 1207 struct fuse_req *req; 1208 struct fuse_setattr_in inarg; 1209 struct fuse_attr_out outarg; 1210 bool is_truncate = false; 1211 loff_t oldsize; 1212 int err; 1213 1214 if (!fuse_allow_task(fc, current)) 1215 return -EACCES; 1216 1217 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { 1218 err = inode_change_ok(inode, attr); 1219 if (err) 1220 return err; 1221 } 1222 1223 if ((attr->ia_valid & ATTR_OPEN) && fc->atomic_o_trunc) 1224 return 0; 1225 1226 if (attr->ia_valid & ATTR_SIZE) { 1227 unsigned long limit; 1228 if (IS_SWAPFILE(inode)) 1229 return -ETXTBSY; 1230 limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; 1231 if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) { 1232 send_sig(SIGXFSZ, current, 0); 1233 return -EFBIG; 1234 } 1235 is_truncate = true; 1236 } 1237 1238 req = fuse_get_req(fc); 1239 if (IS_ERR(req)) 1240 return PTR_ERR(req); 1241 1242 if (is_truncate) 1243 fuse_set_nowrite(inode); 1244 1245 memset(&inarg, 0, sizeof(inarg)); 1246 memset(&outarg, 0, sizeof(outarg)); 1247 iattr_to_fattr(attr, &inarg); 1248 if (file) { 1249 struct fuse_file *ff = file->private_data; 1250 inarg.valid |= FATTR_FH; 1251 inarg.fh = ff->fh; 1252 } 1253 if (attr->ia_valid & ATTR_SIZE) { 1254 /* For mandatory locking in truncate */ 1255 inarg.valid |= FATTR_LOCKOWNER; 1256 inarg.lock_owner = fuse_lock_owner_id(fc, current->files); 1257 } 1258 req->in.h.opcode = FUSE_SETATTR; 1259 req->in.h.nodeid = get_node_id(inode); 1260 req->in.numargs = 1; 1261 req->in.args[0].size = sizeof(inarg); 1262 req->in.args[0].value = &inarg; 1263 req->out.numargs = 1; 1264 if (fc->minor < 9) 1265 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; 1266 else 1267 req->out.args[0].size = sizeof(outarg); 1268 req->out.args[0].value = &outarg; 1269 request_send(fc, req); 1270 err = req->out.h.error; 1271 fuse_put_request(fc, req); 1272 if (err) { 1273 if (err == -EINTR) 1274 fuse_invalidate_attr(inode); 1275 goto error; 1276 } 1277 1278 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { 1279 make_bad_inode(inode); 1280 err = -EIO; 1281 goto error; 1282 } 1283 1284 spin_lock(&fc->lock); 1285 fuse_change_attributes_common(inode, &outarg.attr, 1286 attr_timeout(&outarg)); 1287 oldsize = inode->i_size; 1288 i_size_write(inode, outarg.attr.size); 1289 1290 if (is_truncate) { 1291 /* NOTE: this may release/reacquire fc->lock */ 1292 __fuse_release_nowrite(inode); 1293 } 1294 spin_unlock(&fc->lock); 1295 1296 /* 1297 * Only call invalidate_inode_pages2() after removing 1298 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. 1299 */ 1300 if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { 1301 if (outarg.attr.size < oldsize) 1302 fuse_truncate(inode->i_mapping, outarg.attr.size); 1303 invalidate_inode_pages2(inode->i_mapping); 1304 } 1305 1306 return 0; 1307 1308 error: 1309 if (is_truncate) 1310 fuse_release_nowrite(inode); 1311 1312 return err; 1313 } 1314 1315 static int fuse_setattr(struct dentry *entry, struct iattr *attr) 1316 { 1317 if (attr->ia_valid & ATTR_FILE) 1318 return fuse_do_setattr(entry, attr, attr->ia_file); 1319 else 1320 return fuse_do_setattr(entry, attr, NULL); 1321 } 1322 1323 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, 1324 struct kstat *stat) 1325 { 1326 struct inode *inode = entry->d_inode; 1327 struct fuse_conn *fc = get_fuse_conn(inode); 1328 1329 if (!fuse_allow_task(fc, current)) 1330 return -EACCES; 1331 1332 return fuse_update_attributes(inode, stat, NULL, NULL); 1333 } 1334 1335 static int fuse_setxattr(struct dentry *entry, const char *name, 1336 const void *value, size_t size, int flags) 1337 { 1338 struct inode *inode = entry->d_inode; 1339 struct fuse_conn *fc = get_fuse_conn(inode); 1340 struct fuse_req *req; 1341 struct fuse_setxattr_in inarg; 1342 int err; 1343 1344 if (fc->no_setxattr) 1345 return -EOPNOTSUPP; 1346 1347 req = fuse_get_req(fc); 1348 if (IS_ERR(req)) 1349 return PTR_ERR(req); 1350 1351 memset(&inarg, 0, sizeof(inarg)); 1352 inarg.size = size; 1353 inarg.flags = flags; 1354 req->in.h.opcode = FUSE_SETXATTR; 1355 req->in.h.nodeid = get_node_id(inode); 1356 req->in.numargs = 3; 1357 req->in.args[0].size = sizeof(inarg); 1358 req->in.args[0].value = &inarg; 1359 req->in.args[1].size = strlen(name) + 1; 1360 req->in.args[1].value = name; 1361 req->in.args[2].size = size; 1362 req->in.args[2].value = value; 1363 request_send(fc, req); 1364 err = req->out.h.error; 1365 fuse_put_request(fc, req); 1366 if (err == -ENOSYS) { 1367 fc->no_setxattr = 1; 1368 err = -EOPNOTSUPP; 1369 } 1370 return err; 1371 } 1372 1373 static ssize_t fuse_getxattr(struct dentry *entry, const char *name, 1374 void *value, size_t size) 1375 { 1376 struct inode *inode = entry->d_inode; 1377 struct fuse_conn *fc = get_fuse_conn(inode); 1378 struct fuse_req *req; 1379 struct fuse_getxattr_in inarg; 1380 struct fuse_getxattr_out outarg; 1381 ssize_t ret; 1382 1383 if (fc->no_getxattr) 1384 return -EOPNOTSUPP; 1385 1386 req = fuse_get_req(fc); 1387 if (IS_ERR(req)) 1388 return PTR_ERR(req); 1389 1390 memset(&inarg, 0, sizeof(inarg)); 1391 inarg.size = size; 1392 req->in.h.opcode = FUSE_GETXATTR; 1393 req->in.h.nodeid = get_node_id(inode); 1394 req->in.numargs = 2; 1395 req->in.args[0].size = sizeof(inarg); 1396 req->in.args[0].value = &inarg; 1397 req->in.args[1].size = strlen(name) + 1; 1398 req->in.args[1].value = name; 1399 /* This is really two different operations rolled into one */ 1400 req->out.numargs = 1; 1401 if (size) { 1402 req->out.argvar = 1; 1403 req->out.args[0].size = size; 1404 req->out.args[0].value = value; 1405 } else { 1406 req->out.args[0].size = sizeof(outarg); 1407 req->out.args[0].value = &outarg; 1408 } 1409 request_send(fc, req); 1410 ret = req->out.h.error; 1411 if (!ret) 1412 ret = size ? req->out.args[0].size : outarg.size; 1413 else { 1414 if (ret == -ENOSYS) { 1415 fc->no_getxattr = 1; 1416 ret = -EOPNOTSUPP; 1417 } 1418 } 1419 fuse_put_request(fc, req); 1420 return ret; 1421 } 1422 1423 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) 1424 { 1425 struct inode *inode = entry->d_inode; 1426 struct fuse_conn *fc = get_fuse_conn(inode); 1427 struct fuse_req *req; 1428 struct fuse_getxattr_in inarg; 1429 struct fuse_getxattr_out outarg; 1430 ssize_t ret; 1431 1432 if (!fuse_allow_task(fc, current)) 1433 return -EACCES; 1434 1435 if (fc->no_listxattr) 1436 return -EOPNOTSUPP; 1437 1438 req = fuse_get_req(fc); 1439 if (IS_ERR(req)) 1440 return PTR_ERR(req); 1441 1442 memset(&inarg, 0, sizeof(inarg)); 1443 inarg.size = size; 1444 req->in.h.opcode = FUSE_LISTXATTR; 1445 req->in.h.nodeid = get_node_id(inode); 1446 req->in.numargs = 1; 1447 req->in.args[0].size = sizeof(inarg); 1448 req->in.args[0].value = &inarg; 1449 /* This is really two different operations rolled into one */ 1450 req->out.numargs = 1; 1451 if (size) { 1452 req->out.argvar = 1; 1453 req->out.args[0].size = size; 1454 req->out.args[0].value = list; 1455 } else { 1456 req->out.args[0].size = sizeof(outarg); 1457 req->out.args[0].value = &outarg; 1458 } 1459 request_send(fc, req); 1460 ret = req->out.h.error; 1461 if (!ret) 1462 ret = size ? req->out.args[0].size : outarg.size; 1463 else { 1464 if (ret == -ENOSYS) { 1465 fc->no_listxattr = 1; 1466 ret = -EOPNOTSUPP; 1467 } 1468 } 1469 fuse_put_request(fc, req); 1470 return ret; 1471 } 1472 1473 static int fuse_removexattr(struct dentry *entry, const char *name) 1474 { 1475 struct inode *inode = entry->d_inode; 1476 struct fuse_conn *fc = get_fuse_conn(inode); 1477 struct fuse_req *req; 1478 int err; 1479 1480 if (fc->no_removexattr) 1481 return -EOPNOTSUPP; 1482 1483 req = fuse_get_req(fc); 1484 if (IS_ERR(req)) 1485 return PTR_ERR(req); 1486 1487 req->in.h.opcode = FUSE_REMOVEXATTR; 1488 req->in.h.nodeid = get_node_id(inode); 1489 req->in.numargs = 1; 1490 req->in.args[0].size = strlen(name) + 1; 1491 req->in.args[0].value = name; 1492 request_send(fc, req); 1493 err = req->out.h.error; 1494 fuse_put_request(fc, req); 1495 if (err == -ENOSYS) { 1496 fc->no_removexattr = 1; 1497 err = -EOPNOTSUPP; 1498 } 1499 return err; 1500 } 1501 1502 static const struct inode_operations fuse_dir_inode_operations = { 1503 .lookup = fuse_lookup, 1504 .mkdir = fuse_mkdir, 1505 .symlink = fuse_symlink, 1506 .unlink = fuse_unlink, 1507 .rmdir = fuse_rmdir, 1508 .rename = fuse_rename, 1509 .link = fuse_link, 1510 .setattr = fuse_setattr, 1511 .create = fuse_create, 1512 .mknod = fuse_mknod, 1513 .permission = fuse_permission, 1514 .getattr = fuse_getattr, 1515 .setxattr = fuse_setxattr, 1516 .getxattr = fuse_getxattr, 1517 .listxattr = fuse_listxattr, 1518 .removexattr = fuse_removexattr, 1519 }; 1520 1521 static const struct file_operations fuse_dir_operations = { 1522 .llseek = generic_file_llseek, 1523 .read = generic_read_dir, 1524 .readdir = fuse_readdir, 1525 .open = fuse_dir_open, 1526 .release = fuse_dir_release, 1527 .fsync = fuse_dir_fsync, 1528 }; 1529 1530 static const struct inode_operations fuse_common_inode_operations = { 1531 .setattr = fuse_setattr, 1532 .permission = fuse_permission, 1533 .getattr = fuse_getattr, 1534 .setxattr = fuse_setxattr, 1535 .getxattr = fuse_getxattr, 1536 .listxattr = fuse_listxattr, 1537 .removexattr = fuse_removexattr, 1538 }; 1539 1540 static const struct inode_operations fuse_symlink_inode_operations = { 1541 .setattr = fuse_setattr, 1542 .follow_link = fuse_follow_link, 1543 .put_link = fuse_put_link, 1544 .readlink = generic_readlink, 1545 .getattr = fuse_getattr, 1546 .setxattr = fuse_setxattr, 1547 .getxattr = fuse_getxattr, 1548 .listxattr = fuse_listxattr, 1549 .removexattr = fuse_removexattr, 1550 }; 1551 1552 void fuse_init_common(struct inode *inode) 1553 { 1554 inode->i_op = &fuse_common_inode_operations; 1555 } 1556 1557 void fuse_init_dir(struct inode *inode) 1558 { 1559 inode->i_op = &fuse_dir_inode_operations; 1560 inode->i_fop = &fuse_dir_operations; 1561 } 1562 1563 void fuse_init_symlink(struct inode *inode) 1564 { 1565 inode->i_op = &fuse_symlink_inode_operations; 1566 } 1567