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/slab.h> 13 #include <linux/file.h> 14 #include <linux/seq_file.h> 15 #include <linux/init.h> 16 #include <linux/module.h> 17 #include <linux/moduleparam.h> 18 #include <linux/fs_context.h> 19 #include <linux/fs_parser.h> 20 #include <linux/statfs.h> 21 #include <linux/random.h> 22 #include <linux/sched.h> 23 #include <linux/exportfs.h> 24 #include <linux/posix_acl.h> 25 #include <linux/pid_namespace.h> 26 #include <uapi/linux/magic.h> 27 28 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); 29 MODULE_DESCRIPTION("Filesystem in Userspace"); 30 MODULE_LICENSE("GPL"); 31 32 static struct kmem_cache *fuse_inode_cachep; 33 struct list_head fuse_conn_list; 34 DEFINE_MUTEX(fuse_mutex); 35 36 static int set_global_limit(const char *val, const struct kernel_param *kp); 37 38 unsigned max_user_bgreq; 39 module_param_call(max_user_bgreq, set_global_limit, param_get_uint, 40 &max_user_bgreq, 0644); 41 __MODULE_PARM_TYPE(max_user_bgreq, "uint"); 42 MODULE_PARM_DESC(max_user_bgreq, 43 "Global limit for the maximum number of backgrounded requests an " 44 "unprivileged user can set"); 45 46 unsigned max_user_congthresh; 47 module_param_call(max_user_congthresh, set_global_limit, param_get_uint, 48 &max_user_congthresh, 0644); 49 __MODULE_PARM_TYPE(max_user_congthresh, "uint"); 50 MODULE_PARM_DESC(max_user_congthresh, 51 "Global limit for the maximum congestion threshold an " 52 "unprivileged user can set"); 53 54 #define FUSE_DEFAULT_BLKSIZE 512 55 56 /** Maximum number of outstanding background requests */ 57 #define FUSE_DEFAULT_MAX_BACKGROUND 12 58 59 /** Congestion starts at 75% of maximum */ 60 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4) 61 62 #ifdef CONFIG_BLOCK 63 static struct file_system_type fuseblk_fs_type; 64 #endif 65 66 struct fuse_forget_link *fuse_alloc_forget(void) 67 { 68 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL_ACCOUNT); 69 } 70 71 static struct fuse_submount_lookup *fuse_alloc_submount_lookup(void) 72 { 73 struct fuse_submount_lookup *sl; 74 75 sl = kzalloc(sizeof(struct fuse_submount_lookup), GFP_KERNEL_ACCOUNT); 76 if (!sl) 77 return NULL; 78 sl->forget = fuse_alloc_forget(); 79 if (!sl->forget) 80 goto out_free; 81 82 return sl; 83 84 out_free: 85 kfree(sl); 86 return NULL; 87 } 88 89 static struct inode *fuse_alloc_inode(struct super_block *sb) 90 { 91 struct fuse_inode *fi; 92 93 fi = alloc_inode_sb(sb, fuse_inode_cachep, GFP_KERNEL); 94 if (!fi) 95 return NULL; 96 97 fi->i_time = 0; 98 fi->inval_mask = ~0; 99 fi->nodeid = 0; 100 fi->nlookup = 0; 101 fi->attr_version = 0; 102 fi->orig_ino = 0; 103 fi->state = 0; 104 fi->submount_lookup = NULL; 105 mutex_init(&fi->mutex); 106 spin_lock_init(&fi->lock); 107 fi->forget = fuse_alloc_forget(); 108 if (!fi->forget) 109 goto out_free; 110 111 if (IS_ENABLED(CONFIG_FUSE_DAX) && !fuse_dax_inode_alloc(sb, fi)) 112 goto out_free_forget; 113 114 return &fi->inode; 115 116 out_free_forget: 117 kfree(fi->forget); 118 out_free: 119 kmem_cache_free(fuse_inode_cachep, fi); 120 return NULL; 121 } 122 123 static void fuse_free_inode(struct inode *inode) 124 { 125 struct fuse_inode *fi = get_fuse_inode(inode); 126 127 mutex_destroy(&fi->mutex); 128 kfree(fi->forget); 129 #ifdef CONFIG_FUSE_DAX 130 kfree(fi->dax); 131 #endif 132 kmem_cache_free(fuse_inode_cachep, fi); 133 } 134 135 static void fuse_cleanup_submount_lookup(struct fuse_conn *fc, 136 struct fuse_submount_lookup *sl) 137 { 138 if (!refcount_dec_and_test(&sl->count)) 139 return; 140 141 fuse_queue_forget(fc, sl->forget, sl->nodeid, 1); 142 sl->forget = NULL; 143 kfree(sl); 144 } 145 146 static void fuse_evict_inode(struct inode *inode) 147 { 148 struct fuse_inode *fi = get_fuse_inode(inode); 149 150 /* Will write inode on close/munmap and in all other dirtiers */ 151 WARN_ON(inode->i_state & I_DIRTY_INODE); 152 153 truncate_inode_pages_final(&inode->i_data); 154 clear_inode(inode); 155 if (inode->i_sb->s_flags & SB_ACTIVE) { 156 struct fuse_conn *fc = get_fuse_conn(inode); 157 158 if (FUSE_IS_DAX(inode)) 159 fuse_dax_inode_cleanup(inode); 160 if (fi->nlookup) { 161 fuse_queue_forget(fc, fi->forget, fi->nodeid, 162 fi->nlookup); 163 fi->forget = NULL; 164 } 165 166 if (fi->submount_lookup) { 167 fuse_cleanup_submount_lookup(fc, fi->submount_lookup); 168 fi->submount_lookup = NULL; 169 } 170 } 171 if (S_ISREG(inode->i_mode) && !fuse_is_bad(inode)) { 172 WARN_ON(!list_empty(&fi->write_files)); 173 WARN_ON(!list_empty(&fi->queued_writes)); 174 } 175 } 176 177 static int fuse_reconfigure(struct fs_context *fsc) 178 { 179 struct super_block *sb = fsc->root->d_sb; 180 181 sync_filesystem(sb); 182 if (fsc->sb_flags & SB_MANDLOCK) 183 return -EINVAL; 184 185 return 0; 186 } 187 188 /* 189 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down 190 * so that it will fit. 191 */ 192 static ino_t fuse_squash_ino(u64 ino64) 193 { 194 ino_t ino = (ino_t) ino64; 195 if (sizeof(ino_t) < sizeof(u64)) 196 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8; 197 return ino; 198 } 199 200 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, 201 struct fuse_statx *sx, 202 u64 attr_valid, u32 cache_mask) 203 { 204 struct fuse_conn *fc = get_fuse_conn(inode); 205 struct fuse_inode *fi = get_fuse_inode(inode); 206 207 lockdep_assert_held(&fi->lock); 208 209 fi->attr_version = atomic64_inc_return(&fc->attr_version); 210 fi->i_time = attr_valid; 211 /* Clear basic stats from invalid mask */ 212 set_mask_bits(&fi->inval_mask, STATX_BASIC_STATS, 0); 213 214 inode->i_ino = fuse_squash_ino(attr->ino); 215 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 216 set_nlink(inode, attr->nlink); 217 inode->i_uid = make_kuid(fc->user_ns, attr->uid); 218 inode->i_gid = make_kgid(fc->user_ns, attr->gid); 219 inode->i_blocks = attr->blocks; 220 221 /* Sanitize nsecs */ 222 attr->atimensec = min_t(u32, attr->atimensec, NSEC_PER_SEC - 1); 223 attr->mtimensec = min_t(u32, attr->mtimensec, NSEC_PER_SEC - 1); 224 attr->ctimensec = min_t(u32, attr->ctimensec, NSEC_PER_SEC - 1); 225 226 inode_set_atime(inode, attr->atime, attr->atimensec); 227 /* mtime from server may be stale due to local buffered write */ 228 if (!(cache_mask & STATX_MTIME)) { 229 inode_set_mtime(inode, attr->mtime, attr->mtimensec); 230 } 231 if (!(cache_mask & STATX_CTIME)) { 232 inode_set_ctime(inode, attr->ctime, attr->ctimensec); 233 } 234 if (sx) { 235 /* Sanitize nsecs */ 236 sx->btime.tv_nsec = 237 min_t(u32, sx->btime.tv_nsec, NSEC_PER_SEC - 1); 238 239 /* 240 * Btime has been queried, cache is valid (whether or not btime 241 * is available or not) so clear STATX_BTIME from inval_mask. 242 * 243 * Availability of the btime attribute is indicated in 244 * FUSE_I_BTIME 245 */ 246 set_mask_bits(&fi->inval_mask, STATX_BTIME, 0); 247 if (sx->mask & STATX_BTIME) { 248 set_bit(FUSE_I_BTIME, &fi->state); 249 fi->i_btime.tv_sec = sx->btime.tv_sec; 250 fi->i_btime.tv_nsec = sx->btime.tv_nsec; 251 } 252 } 253 254 if (attr->blksize != 0) 255 inode->i_blkbits = ilog2(attr->blksize); 256 else 257 inode->i_blkbits = inode->i_sb->s_blocksize_bits; 258 259 /* 260 * Don't set the sticky bit in i_mode, unless we want the VFS 261 * to check permissions. This prevents failures due to the 262 * check in may_delete(). 263 */ 264 fi->orig_i_mode = inode->i_mode; 265 if (!fc->default_permissions) 266 inode->i_mode &= ~S_ISVTX; 267 268 fi->orig_ino = attr->ino; 269 270 /* 271 * We are refreshing inode data and it is possible that another 272 * client set suid/sgid or security.capability xattr. So clear 273 * S_NOSEC. Ideally, we could have cleared it only if suid/sgid 274 * was set or if security.capability xattr was set. But we don't 275 * know if security.capability has been set or not. So clear it 276 * anyway. Its less efficient but should be safe. 277 */ 278 inode->i_flags &= ~S_NOSEC; 279 } 280 281 u32 fuse_get_cache_mask(struct inode *inode) 282 { 283 struct fuse_conn *fc = get_fuse_conn(inode); 284 285 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) 286 return 0; 287 288 return STATX_MTIME | STATX_CTIME | STATX_SIZE; 289 } 290 291 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, 292 struct fuse_statx *sx, 293 u64 attr_valid, u64 attr_version) 294 { 295 struct fuse_conn *fc = get_fuse_conn(inode); 296 struct fuse_inode *fi = get_fuse_inode(inode); 297 u32 cache_mask; 298 loff_t oldsize; 299 struct timespec64 old_mtime; 300 301 spin_lock(&fi->lock); 302 /* 303 * In case of writeback_cache enabled, writes update mtime, ctime and 304 * may update i_size. In these cases trust the cached value in the 305 * inode. 306 */ 307 cache_mask = fuse_get_cache_mask(inode); 308 if (cache_mask & STATX_SIZE) 309 attr->size = i_size_read(inode); 310 311 if (cache_mask & STATX_MTIME) { 312 attr->mtime = inode_get_mtime_sec(inode); 313 attr->mtimensec = inode_get_mtime_nsec(inode); 314 } 315 if (cache_mask & STATX_CTIME) { 316 attr->ctime = inode_get_ctime_sec(inode); 317 attr->ctimensec = inode_get_ctime_nsec(inode); 318 } 319 320 if ((attr_version != 0 && fi->attr_version > attr_version) || 321 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { 322 spin_unlock(&fi->lock); 323 return; 324 } 325 326 old_mtime = inode_get_mtime(inode); 327 fuse_change_attributes_common(inode, attr, sx, attr_valid, cache_mask); 328 329 oldsize = inode->i_size; 330 /* 331 * In case of writeback_cache enabled, the cached writes beyond EOF 332 * extend local i_size without keeping userspace server in sync. So, 333 * attr->size coming from server can be stale. We cannot trust it. 334 */ 335 if (!(cache_mask & STATX_SIZE)) 336 i_size_write(inode, attr->size); 337 spin_unlock(&fi->lock); 338 339 if (!cache_mask && S_ISREG(inode->i_mode)) { 340 bool inval = false; 341 342 if (oldsize != attr->size) { 343 truncate_pagecache(inode, attr->size); 344 if (!fc->explicit_inval_data) 345 inval = true; 346 } else if (fc->auto_inval_data) { 347 struct timespec64 new_mtime = { 348 .tv_sec = attr->mtime, 349 .tv_nsec = attr->mtimensec, 350 }; 351 352 /* 353 * Auto inval mode also checks and invalidates if mtime 354 * has changed. 355 */ 356 if (!timespec64_equal(&old_mtime, &new_mtime)) 357 inval = true; 358 } 359 360 if (inval) 361 invalidate_inode_pages2(inode->i_mapping); 362 } 363 364 if (IS_ENABLED(CONFIG_FUSE_DAX)) 365 fuse_dax_dontcache(inode, attr->flags); 366 } 367 368 static void fuse_init_submount_lookup(struct fuse_submount_lookup *sl, 369 u64 nodeid) 370 { 371 sl->nodeid = nodeid; 372 refcount_set(&sl->count, 1); 373 } 374 375 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr, 376 struct fuse_conn *fc) 377 { 378 inode->i_mode = attr->mode & S_IFMT; 379 inode->i_size = attr->size; 380 inode_set_mtime(inode, attr->mtime, attr->mtimensec); 381 inode_set_ctime(inode, attr->ctime, attr->ctimensec); 382 if (S_ISREG(inode->i_mode)) { 383 fuse_init_common(inode); 384 fuse_init_file_inode(inode, attr->flags); 385 } else if (S_ISDIR(inode->i_mode)) 386 fuse_init_dir(inode); 387 else if (S_ISLNK(inode->i_mode)) 388 fuse_init_symlink(inode); 389 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || 390 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { 391 fuse_init_common(inode); 392 init_special_inode(inode, inode->i_mode, 393 new_decode_dev(attr->rdev)); 394 } else 395 BUG(); 396 /* 397 * Ensure that we don't cache acls for daemons without FUSE_POSIX_ACL 398 * so they see the exact same behavior as before. 399 */ 400 if (!fc->posix_acl) 401 inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE; 402 } 403 404 static int fuse_inode_eq(struct inode *inode, void *_nodeidp) 405 { 406 u64 nodeid = *(u64 *) _nodeidp; 407 if (get_node_id(inode) == nodeid) 408 return 1; 409 else 410 return 0; 411 } 412 413 static int fuse_inode_set(struct inode *inode, void *_nodeidp) 414 { 415 u64 nodeid = *(u64 *) _nodeidp; 416 get_fuse_inode(inode)->nodeid = nodeid; 417 return 0; 418 } 419 420 struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 421 int generation, struct fuse_attr *attr, 422 u64 attr_valid, u64 attr_version) 423 { 424 struct inode *inode; 425 struct fuse_inode *fi; 426 struct fuse_conn *fc = get_fuse_conn_super(sb); 427 428 /* 429 * Auto mount points get their node id from the submount root, which is 430 * not a unique identifier within this filesystem. 431 * 432 * To avoid conflicts, do not place submount points into the inode hash 433 * table. 434 */ 435 if (fc->auto_submounts && (attr->flags & FUSE_ATTR_SUBMOUNT) && 436 S_ISDIR(attr->mode)) { 437 struct fuse_inode *fi; 438 439 inode = new_inode(sb); 440 if (!inode) 441 return NULL; 442 443 fuse_init_inode(inode, attr, fc); 444 fi = get_fuse_inode(inode); 445 fi->nodeid = nodeid; 446 fi->submount_lookup = fuse_alloc_submount_lookup(); 447 if (!fi->submount_lookup) { 448 iput(inode); 449 return NULL; 450 } 451 /* Sets nlookup = 1 on fi->submount_lookup->nlookup */ 452 fuse_init_submount_lookup(fi->submount_lookup, nodeid); 453 inode->i_flags |= S_AUTOMOUNT; 454 goto done; 455 } 456 457 retry: 458 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); 459 if (!inode) 460 return NULL; 461 462 if ((inode->i_state & I_NEW)) { 463 inode->i_flags |= S_NOATIME; 464 if (!fc->writeback_cache || !S_ISREG(attr->mode)) 465 inode->i_flags |= S_NOCMTIME; 466 inode->i_generation = generation; 467 fuse_init_inode(inode, attr, fc); 468 unlock_new_inode(inode); 469 } else if (fuse_stale_inode(inode, generation, attr)) { 470 /* nodeid was reused, any I/O on the old inode should fail */ 471 fuse_make_bad(inode); 472 iput(inode); 473 goto retry; 474 } 475 fi = get_fuse_inode(inode); 476 spin_lock(&fi->lock); 477 fi->nlookup++; 478 spin_unlock(&fi->lock); 479 done: 480 fuse_change_attributes(inode, attr, NULL, attr_valid, attr_version); 481 482 return inode; 483 } 484 485 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid, 486 struct fuse_mount **fm) 487 { 488 struct fuse_mount *fm_iter; 489 struct inode *inode; 490 491 WARN_ON(!rwsem_is_locked(&fc->killsb)); 492 list_for_each_entry(fm_iter, &fc->mounts, fc_entry) { 493 if (!fm_iter->sb) 494 continue; 495 496 inode = ilookup5(fm_iter->sb, nodeid, fuse_inode_eq, &nodeid); 497 if (inode) { 498 if (fm) 499 *fm = fm_iter; 500 return inode; 501 } 502 } 503 504 return NULL; 505 } 506 507 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid, 508 loff_t offset, loff_t len) 509 { 510 struct fuse_inode *fi; 511 struct inode *inode; 512 pgoff_t pg_start; 513 pgoff_t pg_end; 514 515 inode = fuse_ilookup(fc, nodeid, NULL); 516 if (!inode) 517 return -ENOENT; 518 519 fi = get_fuse_inode(inode); 520 spin_lock(&fi->lock); 521 fi->attr_version = atomic64_inc_return(&fc->attr_version); 522 spin_unlock(&fi->lock); 523 524 fuse_invalidate_attr(inode); 525 forget_all_cached_acls(inode); 526 if (offset >= 0) { 527 pg_start = offset >> PAGE_SHIFT; 528 if (len <= 0) 529 pg_end = -1; 530 else 531 pg_end = (offset + len - 1) >> PAGE_SHIFT; 532 invalidate_inode_pages2_range(inode->i_mapping, 533 pg_start, pg_end); 534 } 535 iput(inode); 536 return 0; 537 } 538 539 bool fuse_lock_inode(struct inode *inode) 540 { 541 bool locked = false; 542 543 if (!get_fuse_conn(inode)->parallel_dirops) { 544 mutex_lock(&get_fuse_inode(inode)->mutex); 545 locked = true; 546 } 547 548 return locked; 549 } 550 551 void fuse_unlock_inode(struct inode *inode, bool locked) 552 { 553 if (locked) 554 mutex_unlock(&get_fuse_inode(inode)->mutex); 555 } 556 557 static void fuse_umount_begin(struct super_block *sb) 558 { 559 struct fuse_conn *fc = get_fuse_conn_super(sb); 560 561 if (fc->no_force_umount) 562 return; 563 564 fuse_abort_conn(fc); 565 566 // Only retire block-device-based superblocks. 567 if (sb->s_bdev != NULL) 568 retire_super(sb); 569 } 570 571 static void fuse_send_destroy(struct fuse_mount *fm) 572 { 573 if (fm->fc->conn_init) { 574 FUSE_ARGS(args); 575 576 args.opcode = FUSE_DESTROY; 577 args.force = true; 578 args.nocreds = true; 579 fuse_simple_request(fm, &args); 580 } 581 } 582 583 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 584 { 585 stbuf->f_type = FUSE_SUPER_MAGIC; 586 stbuf->f_bsize = attr->bsize; 587 stbuf->f_frsize = attr->frsize; 588 stbuf->f_blocks = attr->blocks; 589 stbuf->f_bfree = attr->bfree; 590 stbuf->f_bavail = attr->bavail; 591 stbuf->f_files = attr->files; 592 stbuf->f_ffree = attr->ffree; 593 stbuf->f_namelen = attr->namelen; 594 /* fsid is left zero */ 595 } 596 597 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 598 { 599 struct super_block *sb = dentry->d_sb; 600 struct fuse_mount *fm = get_fuse_mount_super(sb); 601 FUSE_ARGS(args); 602 struct fuse_statfs_out outarg; 603 int err; 604 605 if (!fuse_allow_current_process(fm->fc)) { 606 buf->f_type = FUSE_SUPER_MAGIC; 607 return 0; 608 } 609 610 memset(&outarg, 0, sizeof(outarg)); 611 args.in_numargs = 0; 612 args.opcode = FUSE_STATFS; 613 args.nodeid = get_node_id(d_inode(dentry)); 614 args.out_numargs = 1; 615 args.out_args[0].size = sizeof(outarg); 616 args.out_args[0].value = &outarg; 617 err = fuse_simple_request(fm, &args); 618 if (!err) 619 convert_fuse_statfs(buf, &outarg.st); 620 return err; 621 } 622 623 static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void) 624 { 625 struct fuse_sync_bucket *bucket; 626 627 bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL); 628 if (bucket) { 629 init_waitqueue_head(&bucket->waitq); 630 /* Initial active count */ 631 atomic_set(&bucket->count, 1); 632 } 633 return bucket; 634 } 635 636 static void fuse_sync_fs_writes(struct fuse_conn *fc) 637 { 638 struct fuse_sync_bucket *bucket, *new_bucket; 639 int count; 640 641 new_bucket = fuse_sync_bucket_alloc(); 642 spin_lock(&fc->lock); 643 bucket = rcu_dereference_protected(fc->curr_bucket, 1); 644 count = atomic_read(&bucket->count); 645 WARN_ON(count < 1); 646 /* No outstanding writes? */ 647 if (count == 1) { 648 spin_unlock(&fc->lock); 649 kfree(new_bucket); 650 return; 651 } 652 653 /* 654 * Completion of new bucket depends on completion of this bucket, so add 655 * one more count. 656 */ 657 atomic_inc(&new_bucket->count); 658 rcu_assign_pointer(fc->curr_bucket, new_bucket); 659 spin_unlock(&fc->lock); 660 /* 661 * Drop initial active count. At this point if all writes in this and 662 * ancestor buckets complete, the count will go to zero and this task 663 * will be woken up. 664 */ 665 atomic_dec(&bucket->count); 666 667 wait_event(bucket->waitq, atomic_read(&bucket->count) == 0); 668 669 /* Drop temp count on descendant bucket */ 670 fuse_sync_bucket_dec(new_bucket); 671 kfree_rcu(bucket, rcu); 672 } 673 674 static int fuse_sync_fs(struct super_block *sb, int wait) 675 { 676 struct fuse_mount *fm = get_fuse_mount_super(sb); 677 struct fuse_conn *fc = fm->fc; 678 struct fuse_syncfs_in inarg; 679 FUSE_ARGS(args); 680 int err; 681 682 /* 683 * Userspace cannot handle the wait == 0 case. Avoid a 684 * gratuitous roundtrip. 685 */ 686 if (!wait) 687 return 0; 688 689 /* The filesystem is being unmounted. Nothing to do. */ 690 if (!sb->s_root) 691 return 0; 692 693 if (!fc->sync_fs) 694 return 0; 695 696 fuse_sync_fs_writes(fc); 697 698 memset(&inarg, 0, sizeof(inarg)); 699 args.in_numargs = 1; 700 args.in_args[0].size = sizeof(inarg); 701 args.in_args[0].value = &inarg; 702 args.opcode = FUSE_SYNCFS; 703 args.nodeid = get_node_id(sb->s_root->d_inode); 704 args.out_numargs = 0; 705 706 err = fuse_simple_request(fm, &args); 707 if (err == -ENOSYS) { 708 fc->sync_fs = 0; 709 err = 0; 710 } 711 712 return err; 713 } 714 715 enum { 716 OPT_SOURCE, 717 OPT_SUBTYPE, 718 OPT_FD, 719 OPT_ROOTMODE, 720 OPT_USER_ID, 721 OPT_GROUP_ID, 722 OPT_DEFAULT_PERMISSIONS, 723 OPT_ALLOW_OTHER, 724 OPT_MAX_READ, 725 OPT_BLKSIZE, 726 OPT_ERR 727 }; 728 729 static const struct fs_parameter_spec fuse_fs_parameters[] = { 730 fsparam_string ("source", OPT_SOURCE), 731 fsparam_u32 ("fd", OPT_FD), 732 fsparam_u32oct ("rootmode", OPT_ROOTMODE), 733 fsparam_u32 ("user_id", OPT_USER_ID), 734 fsparam_u32 ("group_id", OPT_GROUP_ID), 735 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS), 736 fsparam_flag ("allow_other", OPT_ALLOW_OTHER), 737 fsparam_u32 ("max_read", OPT_MAX_READ), 738 fsparam_u32 ("blksize", OPT_BLKSIZE), 739 fsparam_string ("subtype", OPT_SUBTYPE), 740 {} 741 }; 742 743 static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param) 744 { 745 struct fs_parse_result result; 746 struct fuse_fs_context *ctx = fsc->fs_private; 747 int opt; 748 749 if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { 750 /* 751 * Ignore options coming from mount(MS_REMOUNT) for backward 752 * compatibility. 753 */ 754 if (fsc->oldapi) 755 return 0; 756 757 return invalfc(fsc, "No changes allowed in reconfigure"); 758 } 759 760 opt = fs_parse(fsc, fuse_fs_parameters, param, &result); 761 if (opt < 0) 762 return opt; 763 764 switch (opt) { 765 case OPT_SOURCE: 766 if (fsc->source) 767 return invalfc(fsc, "Multiple sources specified"); 768 fsc->source = param->string; 769 param->string = NULL; 770 break; 771 772 case OPT_SUBTYPE: 773 if (ctx->subtype) 774 return invalfc(fsc, "Multiple subtypes specified"); 775 ctx->subtype = param->string; 776 param->string = NULL; 777 return 0; 778 779 case OPT_FD: 780 ctx->fd = result.uint_32; 781 ctx->fd_present = true; 782 break; 783 784 case OPT_ROOTMODE: 785 if (!fuse_valid_type(result.uint_32)) 786 return invalfc(fsc, "Invalid rootmode"); 787 ctx->rootmode = result.uint_32; 788 ctx->rootmode_present = true; 789 break; 790 791 case OPT_USER_ID: 792 ctx->user_id = make_kuid(fsc->user_ns, result.uint_32); 793 if (!uid_valid(ctx->user_id)) 794 return invalfc(fsc, "Invalid user_id"); 795 ctx->user_id_present = true; 796 break; 797 798 case OPT_GROUP_ID: 799 ctx->group_id = make_kgid(fsc->user_ns, result.uint_32); 800 if (!gid_valid(ctx->group_id)) 801 return invalfc(fsc, "Invalid group_id"); 802 ctx->group_id_present = true; 803 break; 804 805 case OPT_DEFAULT_PERMISSIONS: 806 ctx->default_permissions = true; 807 break; 808 809 case OPT_ALLOW_OTHER: 810 ctx->allow_other = true; 811 break; 812 813 case OPT_MAX_READ: 814 ctx->max_read = result.uint_32; 815 break; 816 817 case OPT_BLKSIZE: 818 if (!ctx->is_bdev) 819 return invalfc(fsc, "blksize only supported for fuseblk"); 820 ctx->blksize = result.uint_32; 821 break; 822 823 default: 824 return -EINVAL; 825 } 826 827 return 0; 828 } 829 830 static void fuse_free_fsc(struct fs_context *fsc) 831 { 832 struct fuse_fs_context *ctx = fsc->fs_private; 833 834 if (ctx) { 835 kfree(ctx->subtype); 836 kfree(ctx); 837 } 838 } 839 840 static int fuse_show_options(struct seq_file *m, struct dentry *root) 841 { 842 struct super_block *sb = root->d_sb; 843 struct fuse_conn *fc = get_fuse_conn_super(sb); 844 845 if (fc->legacy_opts_show) { 846 seq_printf(m, ",user_id=%u", 847 from_kuid_munged(fc->user_ns, fc->user_id)); 848 seq_printf(m, ",group_id=%u", 849 from_kgid_munged(fc->user_ns, fc->group_id)); 850 if (fc->default_permissions) 851 seq_puts(m, ",default_permissions"); 852 if (fc->allow_other) 853 seq_puts(m, ",allow_other"); 854 if (fc->max_read != ~0) 855 seq_printf(m, ",max_read=%u", fc->max_read); 856 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 857 seq_printf(m, ",blksize=%lu", sb->s_blocksize); 858 } 859 #ifdef CONFIG_FUSE_DAX 860 if (fc->dax_mode == FUSE_DAX_ALWAYS) 861 seq_puts(m, ",dax=always"); 862 else if (fc->dax_mode == FUSE_DAX_NEVER) 863 seq_puts(m, ",dax=never"); 864 else if (fc->dax_mode == FUSE_DAX_INODE_USER) 865 seq_puts(m, ",dax=inode"); 866 #endif 867 868 return 0; 869 } 870 871 static void fuse_iqueue_init(struct fuse_iqueue *fiq, 872 const struct fuse_iqueue_ops *ops, 873 void *priv) 874 { 875 memset(fiq, 0, sizeof(struct fuse_iqueue)); 876 spin_lock_init(&fiq->lock); 877 init_waitqueue_head(&fiq->waitq); 878 INIT_LIST_HEAD(&fiq->pending); 879 INIT_LIST_HEAD(&fiq->interrupts); 880 fiq->forget_list_tail = &fiq->forget_list_head; 881 fiq->connected = 1; 882 fiq->ops = ops; 883 fiq->priv = priv; 884 } 885 886 static void fuse_pqueue_init(struct fuse_pqueue *fpq) 887 { 888 unsigned int i; 889 890 spin_lock_init(&fpq->lock); 891 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) 892 INIT_LIST_HEAD(&fpq->processing[i]); 893 INIT_LIST_HEAD(&fpq->io); 894 fpq->connected = 1; 895 } 896 897 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm, 898 struct user_namespace *user_ns, 899 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv) 900 { 901 memset(fc, 0, sizeof(*fc)); 902 spin_lock_init(&fc->lock); 903 spin_lock_init(&fc->bg_lock); 904 init_rwsem(&fc->killsb); 905 refcount_set(&fc->count, 1); 906 atomic_set(&fc->dev_count, 1); 907 init_waitqueue_head(&fc->blocked_waitq); 908 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv); 909 INIT_LIST_HEAD(&fc->bg_queue); 910 INIT_LIST_HEAD(&fc->entry); 911 INIT_LIST_HEAD(&fc->devices); 912 atomic_set(&fc->num_waiting, 0); 913 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND; 914 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD; 915 atomic64_set(&fc->khctr, 0); 916 fc->polled_files = RB_ROOT; 917 fc->blocked = 0; 918 fc->initialized = 0; 919 fc->connected = 1; 920 atomic64_set(&fc->attr_version, 1); 921 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 922 fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); 923 fc->user_ns = get_user_ns(user_ns); 924 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ; 925 fc->max_pages_limit = FUSE_MAX_MAX_PAGES; 926 927 INIT_LIST_HEAD(&fc->mounts); 928 list_add(&fm->fc_entry, &fc->mounts); 929 fm->fc = fc; 930 } 931 EXPORT_SYMBOL_GPL(fuse_conn_init); 932 933 static void delayed_release(struct rcu_head *p) 934 { 935 struct fuse_conn *fc = container_of(p, struct fuse_conn, rcu); 936 937 put_user_ns(fc->user_ns); 938 fc->release(fc); 939 } 940 941 void fuse_conn_put(struct fuse_conn *fc) 942 { 943 if (refcount_dec_and_test(&fc->count)) { 944 struct fuse_iqueue *fiq = &fc->iq; 945 struct fuse_sync_bucket *bucket; 946 947 if (IS_ENABLED(CONFIG_FUSE_DAX)) 948 fuse_dax_conn_free(fc); 949 if (fiq->ops->release) 950 fiq->ops->release(fiq); 951 put_pid_ns(fc->pid_ns); 952 bucket = rcu_dereference_protected(fc->curr_bucket, 1); 953 if (bucket) { 954 WARN_ON(atomic_read(&bucket->count) != 1); 955 kfree(bucket); 956 } 957 call_rcu(&fc->rcu, delayed_release); 958 } 959 } 960 EXPORT_SYMBOL_GPL(fuse_conn_put); 961 962 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 963 { 964 refcount_inc(&fc->count); 965 return fc; 966 } 967 EXPORT_SYMBOL_GPL(fuse_conn_get); 968 969 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 970 { 971 struct fuse_attr attr; 972 memset(&attr, 0, sizeof(attr)); 973 974 attr.mode = mode; 975 attr.ino = FUSE_ROOT_ID; 976 attr.nlink = 1; 977 return fuse_iget(sb, 1, 0, &attr, 0, 0); 978 } 979 980 struct fuse_inode_handle { 981 u64 nodeid; 982 u32 generation; 983 }; 984 985 static struct dentry *fuse_get_dentry(struct super_block *sb, 986 struct fuse_inode_handle *handle) 987 { 988 struct fuse_conn *fc = get_fuse_conn_super(sb); 989 struct inode *inode; 990 struct dentry *entry; 991 int err = -ESTALE; 992 993 if (handle->nodeid == 0) 994 goto out_err; 995 996 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 997 if (!inode) { 998 struct fuse_entry_out outarg; 999 const struct qstr name = QSTR_INIT(".", 1); 1000 1001 if (!fc->export_support) 1002 goto out_err; 1003 1004 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 1005 &inode); 1006 if (err && err != -ENOENT) 1007 goto out_err; 1008 if (err || !inode) { 1009 err = -ESTALE; 1010 goto out_err; 1011 } 1012 err = -EIO; 1013 if (get_node_id(inode) != handle->nodeid) 1014 goto out_iput; 1015 } 1016 err = -ESTALE; 1017 if (inode->i_generation != handle->generation) 1018 goto out_iput; 1019 1020 entry = d_obtain_alias(inode); 1021 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) 1022 fuse_invalidate_entry_cache(entry); 1023 1024 return entry; 1025 1026 out_iput: 1027 iput(inode); 1028 out_err: 1029 return ERR_PTR(err); 1030 } 1031 1032 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len, 1033 struct inode *parent) 1034 { 1035 int len = parent ? 6 : 3; 1036 u64 nodeid; 1037 u32 generation; 1038 1039 if (*max_len < len) { 1040 *max_len = len; 1041 return FILEID_INVALID; 1042 } 1043 1044 nodeid = get_fuse_inode(inode)->nodeid; 1045 generation = inode->i_generation; 1046 1047 fh[0] = (u32)(nodeid >> 32); 1048 fh[1] = (u32)(nodeid & 0xffffffff); 1049 fh[2] = generation; 1050 1051 if (parent) { 1052 nodeid = get_fuse_inode(parent)->nodeid; 1053 generation = parent->i_generation; 1054 1055 fh[3] = (u32)(nodeid >> 32); 1056 fh[4] = (u32)(nodeid & 0xffffffff); 1057 fh[5] = generation; 1058 } 1059 1060 *max_len = len; 1061 return parent ? FILEID_INO64_GEN_PARENT : FILEID_INO64_GEN; 1062 } 1063 1064 static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 1065 struct fid *fid, int fh_len, int fh_type) 1066 { 1067 struct fuse_inode_handle handle; 1068 1069 if ((fh_type != FILEID_INO64_GEN && 1070 fh_type != FILEID_INO64_GEN_PARENT) || fh_len < 3) 1071 return NULL; 1072 1073 handle.nodeid = (u64) fid->raw[0] << 32; 1074 handle.nodeid |= (u64) fid->raw[1]; 1075 handle.generation = fid->raw[2]; 1076 return fuse_get_dentry(sb, &handle); 1077 } 1078 1079 static struct dentry *fuse_fh_to_parent(struct super_block *sb, 1080 struct fid *fid, int fh_len, int fh_type) 1081 { 1082 struct fuse_inode_handle parent; 1083 1084 if (fh_type != FILEID_INO64_GEN_PARENT || fh_len < 6) 1085 return NULL; 1086 1087 parent.nodeid = (u64) fid->raw[3] << 32; 1088 parent.nodeid |= (u64) fid->raw[4]; 1089 parent.generation = fid->raw[5]; 1090 return fuse_get_dentry(sb, &parent); 1091 } 1092 1093 static struct dentry *fuse_get_parent(struct dentry *child) 1094 { 1095 struct inode *child_inode = d_inode(child); 1096 struct fuse_conn *fc = get_fuse_conn(child_inode); 1097 struct inode *inode; 1098 struct dentry *parent; 1099 struct fuse_entry_out outarg; 1100 int err; 1101 1102 if (!fc->export_support) 1103 return ERR_PTR(-ESTALE); 1104 1105 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 1106 &dotdot_name, &outarg, &inode); 1107 if (err) { 1108 if (err == -ENOENT) 1109 return ERR_PTR(-ESTALE); 1110 return ERR_PTR(err); 1111 } 1112 1113 parent = d_obtain_alias(inode); 1114 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) 1115 fuse_invalidate_entry_cache(parent); 1116 1117 return parent; 1118 } 1119 1120 static const struct export_operations fuse_export_operations = { 1121 .fh_to_dentry = fuse_fh_to_dentry, 1122 .fh_to_parent = fuse_fh_to_parent, 1123 .encode_fh = fuse_encode_fh, 1124 .get_parent = fuse_get_parent, 1125 }; 1126 1127 static const struct super_operations fuse_super_operations = { 1128 .alloc_inode = fuse_alloc_inode, 1129 .free_inode = fuse_free_inode, 1130 .evict_inode = fuse_evict_inode, 1131 .write_inode = fuse_write_inode, 1132 .drop_inode = generic_delete_inode, 1133 .umount_begin = fuse_umount_begin, 1134 .statfs = fuse_statfs, 1135 .sync_fs = fuse_sync_fs, 1136 .show_options = fuse_show_options, 1137 }; 1138 1139 static void sanitize_global_limit(unsigned *limit) 1140 { 1141 /* 1142 * The default maximum number of async requests is calculated to consume 1143 * 1/2^13 of the total memory, assuming 392 bytes per request. 1144 */ 1145 if (*limit == 0) 1146 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392; 1147 1148 if (*limit >= 1 << 16) 1149 *limit = (1 << 16) - 1; 1150 } 1151 1152 static int set_global_limit(const char *val, const struct kernel_param *kp) 1153 { 1154 int rv; 1155 1156 rv = param_set_uint(val, kp); 1157 if (rv) 1158 return rv; 1159 1160 sanitize_global_limit((unsigned *)kp->arg); 1161 1162 return 0; 1163 } 1164 1165 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg) 1166 { 1167 int cap_sys_admin = capable(CAP_SYS_ADMIN); 1168 1169 if (arg->minor < 13) 1170 return; 1171 1172 sanitize_global_limit(&max_user_bgreq); 1173 sanitize_global_limit(&max_user_congthresh); 1174 1175 spin_lock(&fc->bg_lock); 1176 if (arg->max_background) { 1177 fc->max_background = arg->max_background; 1178 1179 if (!cap_sys_admin && fc->max_background > max_user_bgreq) 1180 fc->max_background = max_user_bgreq; 1181 } 1182 if (arg->congestion_threshold) { 1183 fc->congestion_threshold = arg->congestion_threshold; 1184 1185 if (!cap_sys_admin && 1186 fc->congestion_threshold > max_user_congthresh) 1187 fc->congestion_threshold = max_user_congthresh; 1188 } 1189 spin_unlock(&fc->bg_lock); 1190 } 1191 1192 struct fuse_init_args { 1193 struct fuse_args args; 1194 struct fuse_init_in in; 1195 struct fuse_init_out out; 1196 }; 1197 1198 static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, 1199 int error) 1200 { 1201 struct fuse_conn *fc = fm->fc; 1202 struct fuse_init_args *ia = container_of(args, typeof(*ia), args); 1203 struct fuse_init_out *arg = &ia->out; 1204 bool ok = true; 1205 1206 if (error || arg->major != FUSE_KERNEL_VERSION) 1207 ok = false; 1208 else { 1209 unsigned long ra_pages; 1210 1211 process_init_limits(fc, arg); 1212 1213 if (arg->minor >= 6) { 1214 u64 flags = arg->flags; 1215 1216 if (flags & FUSE_INIT_EXT) 1217 flags |= (u64) arg->flags2 << 32; 1218 1219 ra_pages = arg->max_readahead / PAGE_SIZE; 1220 if (flags & FUSE_ASYNC_READ) 1221 fc->async_read = 1; 1222 if (!(flags & FUSE_POSIX_LOCKS)) 1223 fc->no_lock = 1; 1224 if (arg->minor >= 17) { 1225 if (!(flags & FUSE_FLOCK_LOCKS)) 1226 fc->no_flock = 1; 1227 } else { 1228 if (!(flags & FUSE_POSIX_LOCKS)) 1229 fc->no_flock = 1; 1230 } 1231 if (flags & FUSE_ATOMIC_O_TRUNC) 1232 fc->atomic_o_trunc = 1; 1233 if (arg->minor >= 9) { 1234 /* LOOKUP has dependency on proto version */ 1235 if (flags & FUSE_EXPORT_SUPPORT) 1236 fc->export_support = 1; 1237 } 1238 if (flags & FUSE_BIG_WRITES) 1239 fc->big_writes = 1; 1240 if (flags & FUSE_DONT_MASK) 1241 fc->dont_mask = 1; 1242 if (flags & FUSE_AUTO_INVAL_DATA) 1243 fc->auto_inval_data = 1; 1244 else if (flags & FUSE_EXPLICIT_INVAL_DATA) 1245 fc->explicit_inval_data = 1; 1246 if (flags & FUSE_DO_READDIRPLUS) { 1247 fc->do_readdirplus = 1; 1248 if (flags & FUSE_READDIRPLUS_AUTO) 1249 fc->readdirplus_auto = 1; 1250 } 1251 if (flags & FUSE_ASYNC_DIO) 1252 fc->async_dio = 1; 1253 if (flags & FUSE_WRITEBACK_CACHE) 1254 fc->writeback_cache = 1; 1255 if (flags & FUSE_PARALLEL_DIROPS) 1256 fc->parallel_dirops = 1; 1257 if (flags & FUSE_HANDLE_KILLPRIV) 1258 fc->handle_killpriv = 1; 1259 if (arg->time_gran && arg->time_gran <= 1000000000) 1260 fm->sb->s_time_gran = arg->time_gran; 1261 if ((flags & FUSE_POSIX_ACL)) { 1262 fc->default_permissions = 1; 1263 fc->posix_acl = 1; 1264 } 1265 if (flags & FUSE_CACHE_SYMLINKS) 1266 fc->cache_symlinks = 1; 1267 if (flags & FUSE_ABORT_ERROR) 1268 fc->abort_err = 1; 1269 if (flags & FUSE_MAX_PAGES) { 1270 fc->max_pages = 1271 min_t(unsigned int, fc->max_pages_limit, 1272 max_t(unsigned int, arg->max_pages, 1)); 1273 } 1274 if (IS_ENABLED(CONFIG_FUSE_DAX)) { 1275 if (flags & FUSE_MAP_ALIGNMENT && 1276 !fuse_dax_check_alignment(fc, arg->map_alignment)) { 1277 ok = false; 1278 } 1279 if (flags & FUSE_HAS_INODE_DAX) 1280 fc->inode_dax = 1; 1281 } 1282 if (flags & FUSE_HANDLE_KILLPRIV_V2) { 1283 fc->handle_killpriv_v2 = 1; 1284 fm->sb->s_flags |= SB_NOSEC; 1285 } 1286 if (flags & FUSE_SETXATTR_EXT) 1287 fc->setxattr_ext = 1; 1288 if (flags & FUSE_SECURITY_CTX) 1289 fc->init_security = 1; 1290 if (flags & FUSE_CREATE_SUPP_GROUP) 1291 fc->create_supp_group = 1; 1292 if (flags & FUSE_DIRECT_IO_ALLOW_MMAP) 1293 fc->direct_io_allow_mmap = 1; 1294 } else { 1295 ra_pages = fc->max_read / PAGE_SIZE; 1296 fc->no_lock = 1; 1297 fc->no_flock = 1; 1298 } 1299 1300 fm->sb->s_bdi->ra_pages = 1301 min(fm->sb->s_bdi->ra_pages, ra_pages); 1302 fc->minor = arg->minor; 1303 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 1304 fc->max_write = max_t(unsigned, 4096, fc->max_write); 1305 fc->conn_init = 1; 1306 } 1307 kfree(ia); 1308 1309 if (!ok) { 1310 fc->conn_init = 0; 1311 fc->conn_error = 1; 1312 } 1313 1314 fuse_set_initialized(fc); 1315 wake_up_all(&fc->blocked_waitq); 1316 } 1317 1318 void fuse_send_init(struct fuse_mount *fm) 1319 { 1320 struct fuse_init_args *ia; 1321 u64 flags; 1322 1323 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL); 1324 1325 ia->in.major = FUSE_KERNEL_VERSION; 1326 ia->in.minor = FUSE_KERNEL_MINOR_VERSION; 1327 ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE; 1328 flags = 1329 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 1330 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | 1331 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | 1332 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | 1333 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO | 1334 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT | 1335 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL | 1336 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | 1337 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA | 1338 FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT | 1339 FUSE_SECURITY_CTX | FUSE_CREATE_SUPP_GROUP | 1340 FUSE_HAS_EXPIRE_ONLY | FUSE_DIRECT_IO_ALLOW_MMAP; 1341 #ifdef CONFIG_FUSE_DAX 1342 if (fm->fc->dax) 1343 flags |= FUSE_MAP_ALIGNMENT; 1344 if (fuse_is_inode_dax_mode(fm->fc->dax_mode)) 1345 flags |= FUSE_HAS_INODE_DAX; 1346 #endif 1347 if (fm->fc->auto_submounts) 1348 flags |= FUSE_SUBMOUNTS; 1349 1350 ia->in.flags = flags; 1351 ia->in.flags2 = flags >> 32; 1352 1353 ia->args.opcode = FUSE_INIT; 1354 ia->args.in_numargs = 1; 1355 ia->args.in_args[0].size = sizeof(ia->in); 1356 ia->args.in_args[0].value = &ia->in; 1357 ia->args.out_numargs = 1; 1358 /* Variable length argument used for backward compatibility 1359 with interface version < 7.5. Rest of init_out is zeroed 1360 by do_get_request(), so a short reply is not a problem */ 1361 ia->args.out_argvar = true; 1362 ia->args.out_args[0].size = sizeof(ia->out); 1363 ia->args.out_args[0].value = &ia->out; 1364 ia->args.force = true; 1365 ia->args.nocreds = true; 1366 ia->args.end = process_init_reply; 1367 1368 if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0) 1369 process_init_reply(fm, &ia->args, -ENOTCONN); 1370 } 1371 EXPORT_SYMBOL_GPL(fuse_send_init); 1372 1373 void fuse_free_conn(struct fuse_conn *fc) 1374 { 1375 WARN_ON(!list_empty(&fc->devices)); 1376 kfree(fc); 1377 } 1378 EXPORT_SYMBOL_GPL(fuse_free_conn); 1379 1380 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 1381 { 1382 int err; 1383 char *suffix = ""; 1384 1385 if (sb->s_bdev) { 1386 suffix = "-fuseblk"; 1387 /* 1388 * sb->s_bdi points to blkdev's bdi however we want to redirect 1389 * it to our private bdi... 1390 */ 1391 bdi_put(sb->s_bdi); 1392 sb->s_bdi = &noop_backing_dev_info; 1393 } 1394 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev), 1395 MINOR(fc->dev), suffix); 1396 if (err) 1397 return err; 1398 1399 /* fuse does it's own writeback accounting */ 1400 sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT; 1401 sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT; 1402 1403 /* 1404 * For a single fuse filesystem use max 1% of dirty + 1405 * writeback threshold. 1406 * 1407 * This gives about 1M of write buffer for memory maps on a 1408 * machine with 1G and 10% dirty_ratio, which should be more 1409 * than enough. 1410 * 1411 * Privileged users can raise it by writing to 1412 * 1413 * /sys/class/bdi/<bdi>/max_ratio 1414 */ 1415 bdi_set_max_ratio(sb->s_bdi, 1); 1416 1417 return 0; 1418 } 1419 1420 struct fuse_dev *fuse_dev_alloc(void) 1421 { 1422 struct fuse_dev *fud; 1423 struct list_head *pq; 1424 1425 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL); 1426 if (!fud) 1427 return NULL; 1428 1429 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); 1430 if (!pq) { 1431 kfree(fud); 1432 return NULL; 1433 } 1434 1435 fud->pq.processing = pq; 1436 fuse_pqueue_init(&fud->pq); 1437 1438 return fud; 1439 } 1440 EXPORT_SYMBOL_GPL(fuse_dev_alloc); 1441 1442 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc) 1443 { 1444 fud->fc = fuse_conn_get(fc); 1445 spin_lock(&fc->lock); 1446 list_add_tail(&fud->entry, &fc->devices); 1447 spin_unlock(&fc->lock); 1448 } 1449 EXPORT_SYMBOL_GPL(fuse_dev_install); 1450 1451 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc) 1452 { 1453 struct fuse_dev *fud; 1454 1455 fud = fuse_dev_alloc(); 1456 if (!fud) 1457 return NULL; 1458 1459 fuse_dev_install(fud, fc); 1460 return fud; 1461 } 1462 EXPORT_SYMBOL_GPL(fuse_dev_alloc_install); 1463 1464 void fuse_dev_free(struct fuse_dev *fud) 1465 { 1466 struct fuse_conn *fc = fud->fc; 1467 1468 if (fc) { 1469 spin_lock(&fc->lock); 1470 list_del(&fud->entry); 1471 spin_unlock(&fc->lock); 1472 1473 fuse_conn_put(fc); 1474 } 1475 kfree(fud->pq.processing); 1476 kfree(fud); 1477 } 1478 EXPORT_SYMBOL_GPL(fuse_dev_free); 1479 1480 static void fuse_fill_attr_from_inode(struct fuse_attr *attr, 1481 const struct fuse_inode *fi) 1482 { 1483 struct timespec64 atime = inode_get_atime(&fi->inode); 1484 struct timespec64 mtime = inode_get_mtime(&fi->inode); 1485 struct timespec64 ctime = inode_get_ctime(&fi->inode); 1486 1487 *attr = (struct fuse_attr){ 1488 .ino = fi->inode.i_ino, 1489 .size = fi->inode.i_size, 1490 .blocks = fi->inode.i_blocks, 1491 .atime = atime.tv_sec, 1492 .mtime = mtime.tv_sec, 1493 .ctime = ctime.tv_sec, 1494 .atimensec = atime.tv_nsec, 1495 .mtimensec = mtime.tv_nsec, 1496 .ctimensec = ctime.tv_nsec, 1497 .mode = fi->inode.i_mode, 1498 .nlink = fi->inode.i_nlink, 1499 .uid = fi->inode.i_uid.val, 1500 .gid = fi->inode.i_gid.val, 1501 .rdev = fi->inode.i_rdev, 1502 .blksize = 1u << fi->inode.i_blkbits, 1503 }; 1504 } 1505 1506 static void fuse_sb_defaults(struct super_block *sb) 1507 { 1508 sb->s_magic = FUSE_SUPER_MAGIC; 1509 sb->s_op = &fuse_super_operations; 1510 sb->s_xattr = fuse_xattr_handlers; 1511 sb->s_maxbytes = MAX_LFS_FILESIZE; 1512 sb->s_time_gran = 1; 1513 sb->s_export_op = &fuse_export_operations; 1514 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE; 1515 if (sb->s_user_ns != &init_user_ns) 1516 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; 1517 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); 1518 } 1519 1520 static int fuse_fill_super_submount(struct super_block *sb, 1521 struct fuse_inode *parent_fi) 1522 { 1523 struct fuse_mount *fm = get_fuse_mount_super(sb); 1524 struct super_block *parent_sb = parent_fi->inode.i_sb; 1525 struct fuse_attr root_attr; 1526 struct inode *root; 1527 struct fuse_submount_lookup *sl; 1528 struct fuse_inode *fi; 1529 1530 fuse_sb_defaults(sb); 1531 fm->sb = sb; 1532 1533 WARN_ON(sb->s_bdi != &noop_backing_dev_info); 1534 sb->s_bdi = bdi_get(parent_sb->s_bdi); 1535 1536 sb->s_xattr = parent_sb->s_xattr; 1537 sb->s_time_gran = parent_sb->s_time_gran; 1538 sb->s_blocksize = parent_sb->s_blocksize; 1539 sb->s_blocksize_bits = parent_sb->s_blocksize_bits; 1540 sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL); 1541 if (parent_sb->s_subtype && !sb->s_subtype) 1542 return -ENOMEM; 1543 1544 fuse_fill_attr_from_inode(&root_attr, parent_fi); 1545 root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0); 1546 /* 1547 * This inode is just a duplicate, so it is not looked up and 1548 * its nlookup should not be incremented. fuse_iget() does 1549 * that, though, so undo it here. 1550 */ 1551 fi = get_fuse_inode(root); 1552 fi->nlookup--; 1553 1554 sb->s_d_op = &fuse_dentry_operations; 1555 sb->s_root = d_make_root(root); 1556 if (!sb->s_root) 1557 return -ENOMEM; 1558 1559 /* 1560 * Grab the parent's submount_lookup pointer and take a 1561 * reference on the shared nlookup from the parent. This is to 1562 * prevent the last forget for this nodeid from getting 1563 * triggered until all users have finished with it. 1564 */ 1565 sl = parent_fi->submount_lookup; 1566 WARN_ON(!sl); 1567 if (sl) { 1568 refcount_inc(&sl->count); 1569 fi->submount_lookup = sl; 1570 } 1571 1572 return 0; 1573 } 1574 1575 /* Filesystem context private data holds the FUSE inode of the mount point */ 1576 static int fuse_get_tree_submount(struct fs_context *fsc) 1577 { 1578 struct fuse_mount *fm; 1579 struct fuse_inode *mp_fi = fsc->fs_private; 1580 struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode); 1581 struct super_block *sb; 1582 int err; 1583 1584 fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL); 1585 if (!fm) 1586 return -ENOMEM; 1587 1588 fm->fc = fuse_conn_get(fc); 1589 fsc->s_fs_info = fm; 1590 sb = sget_fc(fsc, NULL, set_anon_super_fc); 1591 if (fsc->s_fs_info) 1592 fuse_mount_destroy(fm); 1593 if (IS_ERR(sb)) 1594 return PTR_ERR(sb); 1595 1596 /* Initialize superblock, making @mp_fi its root */ 1597 err = fuse_fill_super_submount(sb, mp_fi); 1598 if (err) { 1599 deactivate_locked_super(sb); 1600 return err; 1601 } 1602 1603 down_write(&fc->killsb); 1604 list_add_tail(&fm->fc_entry, &fc->mounts); 1605 up_write(&fc->killsb); 1606 1607 sb->s_flags |= SB_ACTIVE; 1608 fsc->root = dget(sb->s_root); 1609 1610 return 0; 1611 } 1612 1613 static const struct fs_context_operations fuse_context_submount_ops = { 1614 .get_tree = fuse_get_tree_submount, 1615 }; 1616 1617 int fuse_init_fs_context_submount(struct fs_context *fsc) 1618 { 1619 fsc->ops = &fuse_context_submount_ops; 1620 return 0; 1621 } 1622 EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount); 1623 1624 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx) 1625 { 1626 struct fuse_dev *fud = NULL; 1627 struct fuse_mount *fm = get_fuse_mount_super(sb); 1628 struct fuse_conn *fc = fm->fc; 1629 struct inode *root; 1630 struct dentry *root_dentry; 1631 int err; 1632 1633 err = -EINVAL; 1634 if (sb->s_flags & SB_MANDLOCK) 1635 goto err; 1636 1637 rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc()); 1638 fuse_sb_defaults(sb); 1639 1640 if (ctx->is_bdev) { 1641 #ifdef CONFIG_BLOCK 1642 err = -EINVAL; 1643 if (!sb_set_blocksize(sb, ctx->blksize)) 1644 goto err; 1645 #endif 1646 } else { 1647 sb->s_blocksize = PAGE_SIZE; 1648 sb->s_blocksize_bits = PAGE_SHIFT; 1649 } 1650 1651 sb->s_subtype = ctx->subtype; 1652 ctx->subtype = NULL; 1653 if (IS_ENABLED(CONFIG_FUSE_DAX)) { 1654 err = fuse_dax_conn_alloc(fc, ctx->dax_mode, ctx->dax_dev); 1655 if (err) 1656 goto err; 1657 } 1658 1659 if (ctx->fudptr) { 1660 err = -ENOMEM; 1661 fud = fuse_dev_alloc_install(fc); 1662 if (!fud) 1663 goto err_free_dax; 1664 } 1665 1666 fc->dev = sb->s_dev; 1667 fm->sb = sb; 1668 err = fuse_bdi_init(fc, sb); 1669 if (err) 1670 goto err_dev_free; 1671 1672 /* Handle umasking inside the fuse code */ 1673 if (sb->s_flags & SB_POSIXACL) 1674 fc->dont_mask = 1; 1675 sb->s_flags |= SB_POSIXACL; 1676 1677 fc->default_permissions = ctx->default_permissions; 1678 fc->allow_other = ctx->allow_other; 1679 fc->user_id = ctx->user_id; 1680 fc->group_id = ctx->group_id; 1681 fc->legacy_opts_show = ctx->legacy_opts_show; 1682 fc->max_read = max_t(unsigned int, 4096, ctx->max_read); 1683 fc->destroy = ctx->destroy; 1684 fc->no_control = ctx->no_control; 1685 fc->no_force_umount = ctx->no_force_umount; 1686 1687 err = -ENOMEM; 1688 root = fuse_get_root_inode(sb, ctx->rootmode); 1689 sb->s_d_op = &fuse_root_dentry_operations; 1690 root_dentry = d_make_root(root); 1691 if (!root_dentry) 1692 goto err_dev_free; 1693 /* Root dentry doesn't have .d_revalidate */ 1694 sb->s_d_op = &fuse_dentry_operations; 1695 1696 mutex_lock(&fuse_mutex); 1697 err = -EINVAL; 1698 if (ctx->fudptr && *ctx->fudptr) 1699 goto err_unlock; 1700 1701 err = fuse_ctl_add_conn(fc); 1702 if (err) 1703 goto err_unlock; 1704 1705 list_add_tail(&fc->entry, &fuse_conn_list); 1706 sb->s_root = root_dentry; 1707 if (ctx->fudptr) 1708 *ctx->fudptr = fud; 1709 mutex_unlock(&fuse_mutex); 1710 return 0; 1711 1712 err_unlock: 1713 mutex_unlock(&fuse_mutex); 1714 dput(root_dentry); 1715 err_dev_free: 1716 if (fud) 1717 fuse_dev_free(fud); 1718 err_free_dax: 1719 if (IS_ENABLED(CONFIG_FUSE_DAX)) 1720 fuse_dax_conn_free(fc); 1721 err: 1722 return err; 1723 } 1724 EXPORT_SYMBOL_GPL(fuse_fill_super_common); 1725 1726 static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc) 1727 { 1728 struct fuse_fs_context *ctx = fsc->fs_private; 1729 int err; 1730 1731 if (!ctx->file || !ctx->rootmode_present || 1732 !ctx->user_id_present || !ctx->group_id_present) 1733 return -EINVAL; 1734 1735 /* 1736 * Require mount to happen from the same user namespace which 1737 * opened /dev/fuse to prevent potential attacks. 1738 */ 1739 if ((ctx->file->f_op != &fuse_dev_operations) || 1740 (ctx->file->f_cred->user_ns != sb->s_user_ns)) 1741 return -EINVAL; 1742 ctx->fudptr = &ctx->file->private_data; 1743 1744 err = fuse_fill_super_common(sb, ctx); 1745 if (err) 1746 return err; 1747 /* file->private_data shall be visible on all CPUs after this */ 1748 smp_mb(); 1749 fuse_send_init(get_fuse_mount_super(sb)); 1750 return 0; 1751 } 1752 1753 /* 1754 * This is the path where user supplied an already initialized fuse dev. In 1755 * this case never create a new super if the old one is gone. 1756 */ 1757 static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc) 1758 { 1759 return -ENOTCONN; 1760 } 1761 1762 static int fuse_test_super(struct super_block *sb, struct fs_context *fsc) 1763 { 1764 1765 return fsc->sget_key == get_fuse_conn_super(sb); 1766 } 1767 1768 static int fuse_get_tree(struct fs_context *fsc) 1769 { 1770 struct fuse_fs_context *ctx = fsc->fs_private; 1771 struct fuse_dev *fud; 1772 struct fuse_conn *fc; 1773 struct fuse_mount *fm; 1774 struct super_block *sb; 1775 int err; 1776 1777 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 1778 if (!fc) 1779 return -ENOMEM; 1780 1781 fm = kzalloc(sizeof(*fm), GFP_KERNEL); 1782 if (!fm) { 1783 kfree(fc); 1784 return -ENOMEM; 1785 } 1786 1787 fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL); 1788 fc->release = fuse_free_conn; 1789 1790 fsc->s_fs_info = fm; 1791 1792 if (ctx->fd_present) 1793 ctx->file = fget(ctx->fd); 1794 1795 if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) { 1796 err = get_tree_bdev(fsc, fuse_fill_super); 1797 goto out; 1798 } 1799 /* 1800 * While block dev mount can be initialized with a dummy device fd 1801 * (found by device name), normal fuse mounts can't 1802 */ 1803 err = -EINVAL; 1804 if (!ctx->file) 1805 goto out; 1806 1807 /* 1808 * Allow creating a fuse mount with an already initialized fuse 1809 * connection 1810 */ 1811 fud = READ_ONCE(ctx->file->private_data); 1812 if (ctx->file->f_op == &fuse_dev_operations && fud) { 1813 fsc->sget_key = fud->fc; 1814 sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super); 1815 err = PTR_ERR_OR_ZERO(sb); 1816 if (!IS_ERR(sb)) 1817 fsc->root = dget(sb->s_root); 1818 } else { 1819 err = get_tree_nodev(fsc, fuse_fill_super); 1820 } 1821 out: 1822 if (fsc->s_fs_info) 1823 fuse_mount_destroy(fm); 1824 if (ctx->file) 1825 fput(ctx->file); 1826 return err; 1827 } 1828 1829 static const struct fs_context_operations fuse_context_ops = { 1830 .free = fuse_free_fsc, 1831 .parse_param = fuse_parse_param, 1832 .reconfigure = fuse_reconfigure, 1833 .get_tree = fuse_get_tree, 1834 }; 1835 1836 /* 1837 * Set up the filesystem mount context. 1838 */ 1839 static int fuse_init_fs_context(struct fs_context *fsc) 1840 { 1841 struct fuse_fs_context *ctx; 1842 1843 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); 1844 if (!ctx) 1845 return -ENOMEM; 1846 1847 ctx->max_read = ~0; 1848 ctx->blksize = FUSE_DEFAULT_BLKSIZE; 1849 ctx->legacy_opts_show = true; 1850 1851 #ifdef CONFIG_BLOCK 1852 if (fsc->fs_type == &fuseblk_fs_type) { 1853 ctx->is_bdev = true; 1854 ctx->destroy = true; 1855 } 1856 #endif 1857 1858 fsc->fs_private = ctx; 1859 fsc->ops = &fuse_context_ops; 1860 return 0; 1861 } 1862 1863 bool fuse_mount_remove(struct fuse_mount *fm) 1864 { 1865 struct fuse_conn *fc = fm->fc; 1866 bool last = false; 1867 1868 down_write(&fc->killsb); 1869 list_del_init(&fm->fc_entry); 1870 if (list_empty(&fc->mounts)) 1871 last = true; 1872 up_write(&fc->killsb); 1873 1874 return last; 1875 } 1876 EXPORT_SYMBOL_GPL(fuse_mount_remove); 1877 1878 void fuse_conn_destroy(struct fuse_mount *fm) 1879 { 1880 struct fuse_conn *fc = fm->fc; 1881 1882 if (fc->destroy) 1883 fuse_send_destroy(fm); 1884 1885 fuse_abort_conn(fc); 1886 fuse_wait_aborted(fc); 1887 1888 if (!list_empty(&fc->entry)) { 1889 mutex_lock(&fuse_mutex); 1890 list_del(&fc->entry); 1891 fuse_ctl_remove_conn(fc); 1892 mutex_unlock(&fuse_mutex); 1893 } 1894 } 1895 EXPORT_SYMBOL_GPL(fuse_conn_destroy); 1896 1897 static void fuse_sb_destroy(struct super_block *sb) 1898 { 1899 struct fuse_mount *fm = get_fuse_mount_super(sb); 1900 bool last; 1901 1902 if (sb->s_root) { 1903 last = fuse_mount_remove(fm); 1904 if (last) 1905 fuse_conn_destroy(fm); 1906 } 1907 } 1908 1909 void fuse_mount_destroy(struct fuse_mount *fm) 1910 { 1911 fuse_conn_put(fm->fc); 1912 kfree_rcu(fm, rcu); 1913 } 1914 EXPORT_SYMBOL(fuse_mount_destroy); 1915 1916 static void fuse_kill_sb_anon(struct super_block *sb) 1917 { 1918 fuse_sb_destroy(sb); 1919 kill_anon_super(sb); 1920 fuse_mount_destroy(get_fuse_mount_super(sb)); 1921 } 1922 1923 static struct file_system_type fuse_fs_type = { 1924 .owner = THIS_MODULE, 1925 .name = "fuse", 1926 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT, 1927 .init_fs_context = fuse_init_fs_context, 1928 .parameters = fuse_fs_parameters, 1929 .kill_sb = fuse_kill_sb_anon, 1930 }; 1931 MODULE_ALIAS_FS("fuse"); 1932 1933 #ifdef CONFIG_BLOCK 1934 static void fuse_kill_sb_blk(struct super_block *sb) 1935 { 1936 fuse_sb_destroy(sb); 1937 kill_block_super(sb); 1938 fuse_mount_destroy(get_fuse_mount_super(sb)); 1939 } 1940 1941 static struct file_system_type fuseblk_fs_type = { 1942 .owner = THIS_MODULE, 1943 .name = "fuseblk", 1944 .init_fs_context = fuse_init_fs_context, 1945 .parameters = fuse_fs_parameters, 1946 .kill_sb = fuse_kill_sb_blk, 1947 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 1948 }; 1949 MODULE_ALIAS_FS("fuseblk"); 1950 1951 static inline int register_fuseblk(void) 1952 { 1953 return register_filesystem(&fuseblk_fs_type); 1954 } 1955 1956 static inline void unregister_fuseblk(void) 1957 { 1958 unregister_filesystem(&fuseblk_fs_type); 1959 } 1960 #else 1961 static inline int register_fuseblk(void) 1962 { 1963 return 0; 1964 } 1965 1966 static inline void unregister_fuseblk(void) 1967 { 1968 } 1969 #endif 1970 1971 static void fuse_inode_init_once(void *foo) 1972 { 1973 struct inode *inode = foo; 1974 1975 inode_init_once(inode); 1976 } 1977 1978 static int __init fuse_fs_init(void) 1979 { 1980 int err; 1981 1982 fuse_inode_cachep = kmem_cache_create("fuse_inode", 1983 sizeof(struct fuse_inode), 0, 1984 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT, 1985 fuse_inode_init_once); 1986 err = -ENOMEM; 1987 if (!fuse_inode_cachep) 1988 goto out; 1989 1990 err = register_fuseblk(); 1991 if (err) 1992 goto out2; 1993 1994 err = register_filesystem(&fuse_fs_type); 1995 if (err) 1996 goto out3; 1997 1998 return 0; 1999 2000 out3: 2001 unregister_fuseblk(); 2002 out2: 2003 kmem_cache_destroy(fuse_inode_cachep); 2004 out: 2005 return err; 2006 } 2007 2008 static void fuse_fs_cleanup(void) 2009 { 2010 unregister_filesystem(&fuse_fs_type); 2011 unregister_fuseblk(); 2012 2013 /* 2014 * Make sure all delayed rcu free inodes are flushed before we 2015 * destroy cache. 2016 */ 2017 rcu_barrier(); 2018 kmem_cache_destroy(fuse_inode_cachep); 2019 } 2020 2021 static struct kobject *fuse_kobj; 2022 2023 static int fuse_sysfs_init(void) 2024 { 2025 int err; 2026 2027 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 2028 if (!fuse_kobj) { 2029 err = -ENOMEM; 2030 goto out_err; 2031 } 2032 2033 err = sysfs_create_mount_point(fuse_kobj, "connections"); 2034 if (err) 2035 goto out_fuse_unregister; 2036 2037 return 0; 2038 2039 out_fuse_unregister: 2040 kobject_put(fuse_kobj); 2041 out_err: 2042 return err; 2043 } 2044 2045 static void fuse_sysfs_cleanup(void) 2046 { 2047 sysfs_remove_mount_point(fuse_kobj, "connections"); 2048 kobject_put(fuse_kobj); 2049 } 2050 2051 static int __init fuse_init(void) 2052 { 2053 int res; 2054 2055 pr_info("init (API version %i.%i)\n", 2056 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 2057 2058 INIT_LIST_HEAD(&fuse_conn_list); 2059 res = fuse_fs_init(); 2060 if (res) 2061 goto err; 2062 2063 res = fuse_dev_init(); 2064 if (res) 2065 goto err_fs_cleanup; 2066 2067 res = fuse_sysfs_init(); 2068 if (res) 2069 goto err_dev_cleanup; 2070 2071 res = fuse_ctl_init(); 2072 if (res) 2073 goto err_sysfs_cleanup; 2074 2075 sanitize_global_limit(&max_user_bgreq); 2076 sanitize_global_limit(&max_user_congthresh); 2077 2078 return 0; 2079 2080 err_sysfs_cleanup: 2081 fuse_sysfs_cleanup(); 2082 err_dev_cleanup: 2083 fuse_dev_cleanup(); 2084 err_fs_cleanup: 2085 fuse_fs_cleanup(); 2086 err: 2087 return res; 2088 } 2089 2090 static void __exit fuse_exit(void) 2091 { 2092 pr_debug("exit\n"); 2093 2094 fuse_ctl_cleanup(); 2095 fuse_sysfs_cleanup(); 2096 fuse_fs_cleanup(); 2097 fuse_dev_cleanup(); 2098 } 2099 2100 module_init(fuse_init); 2101 module_exit(fuse_exit); 2102