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 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) 115 fuse_inode_backing_set(fi, NULL); 116 117 return &fi->inode; 118 119 out_free_forget: 120 kfree(fi->forget); 121 out_free: 122 kmem_cache_free(fuse_inode_cachep, fi); 123 return NULL; 124 } 125 126 static void fuse_free_inode(struct inode *inode) 127 { 128 struct fuse_inode *fi = get_fuse_inode(inode); 129 130 mutex_destroy(&fi->mutex); 131 kfree(fi->forget); 132 #ifdef CONFIG_FUSE_DAX 133 kfree(fi->dax); 134 #endif 135 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) 136 fuse_backing_put(fuse_inode_backing(fi)); 137 138 kmem_cache_free(fuse_inode_cachep, fi); 139 } 140 141 static void fuse_cleanup_submount_lookup(struct fuse_conn *fc, 142 struct fuse_submount_lookup *sl) 143 { 144 if (!refcount_dec_and_test(&sl->count)) 145 return; 146 147 fuse_queue_forget(fc, sl->forget, sl->nodeid, 1); 148 sl->forget = NULL; 149 kfree(sl); 150 } 151 152 static void fuse_evict_inode(struct inode *inode) 153 { 154 struct fuse_inode *fi = get_fuse_inode(inode); 155 156 /* Will write inode on close/munmap and in all other dirtiers */ 157 WARN_ON(inode->i_state & I_DIRTY_INODE); 158 159 truncate_inode_pages_final(&inode->i_data); 160 clear_inode(inode); 161 if (inode->i_sb->s_flags & SB_ACTIVE) { 162 struct fuse_conn *fc = get_fuse_conn(inode); 163 164 if (FUSE_IS_DAX(inode)) 165 fuse_dax_inode_cleanup(inode); 166 if (fi->nlookup) { 167 fuse_queue_forget(fc, fi->forget, fi->nodeid, 168 fi->nlookup); 169 fi->forget = NULL; 170 } 171 172 if (fi->submount_lookup) { 173 fuse_cleanup_submount_lookup(fc, fi->submount_lookup); 174 fi->submount_lookup = NULL; 175 } 176 } 177 if (S_ISREG(inode->i_mode) && !fuse_is_bad(inode)) { 178 WARN_ON(!list_empty(&fi->write_files)); 179 WARN_ON(!list_empty(&fi->queued_writes)); 180 } 181 } 182 183 static int fuse_reconfigure(struct fs_context *fsc) 184 { 185 struct super_block *sb = fsc->root->d_sb; 186 187 sync_filesystem(sb); 188 if (fsc->sb_flags & SB_MANDLOCK) 189 return -EINVAL; 190 191 return 0; 192 } 193 194 /* 195 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down 196 * so that it will fit. 197 */ 198 static ino_t fuse_squash_ino(u64 ino64) 199 { 200 ino_t ino = (ino_t) ino64; 201 if (sizeof(ino_t) < sizeof(u64)) 202 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8; 203 return ino; 204 } 205 206 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, 207 struct fuse_statx *sx, 208 u64 attr_valid, u32 cache_mask) 209 { 210 struct fuse_conn *fc = get_fuse_conn(inode); 211 struct fuse_inode *fi = get_fuse_inode(inode); 212 213 lockdep_assert_held(&fi->lock); 214 215 fi->attr_version = atomic64_inc_return(&fc->attr_version); 216 fi->i_time = attr_valid; 217 /* Clear basic stats from invalid mask */ 218 set_mask_bits(&fi->inval_mask, STATX_BASIC_STATS, 0); 219 220 inode->i_ino = fuse_squash_ino(attr->ino); 221 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 222 set_nlink(inode, attr->nlink); 223 inode->i_uid = make_kuid(fc->user_ns, attr->uid); 224 inode->i_gid = make_kgid(fc->user_ns, attr->gid); 225 inode->i_blocks = attr->blocks; 226 227 /* Sanitize nsecs */ 228 attr->atimensec = min_t(u32, attr->atimensec, NSEC_PER_SEC - 1); 229 attr->mtimensec = min_t(u32, attr->mtimensec, NSEC_PER_SEC - 1); 230 attr->ctimensec = min_t(u32, attr->ctimensec, NSEC_PER_SEC - 1); 231 232 inode_set_atime(inode, attr->atime, attr->atimensec); 233 /* mtime from server may be stale due to local buffered write */ 234 if (!(cache_mask & STATX_MTIME)) { 235 inode_set_mtime(inode, attr->mtime, attr->mtimensec); 236 } 237 if (!(cache_mask & STATX_CTIME)) { 238 inode_set_ctime(inode, attr->ctime, attr->ctimensec); 239 } 240 if (sx) { 241 /* Sanitize nsecs */ 242 sx->btime.tv_nsec = 243 min_t(u32, sx->btime.tv_nsec, NSEC_PER_SEC - 1); 244 245 /* 246 * Btime has been queried, cache is valid (whether or not btime 247 * is available or not) so clear STATX_BTIME from inval_mask. 248 * 249 * Availability of the btime attribute is indicated in 250 * FUSE_I_BTIME 251 */ 252 set_mask_bits(&fi->inval_mask, STATX_BTIME, 0); 253 if (sx->mask & STATX_BTIME) { 254 set_bit(FUSE_I_BTIME, &fi->state); 255 fi->i_btime.tv_sec = sx->btime.tv_sec; 256 fi->i_btime.tv_nsec = sx->btime.tv_nsec; 257 } 258 } 259 260 if (attr->blksize != 0) 261 inode->i_blkbits = ilog2(attr->blksize); 262 else 263 inode->i_blkbits = inode->i_sb->s_blocksize_bits; 264 265 /* 266 * Don't set the sticky bit in i_mode, unless we want the VFS 267 * to check permissions. This prevents failures due to the 268 * check in may_delete(). 269 */ 270 fi->orig_i_mode = inode->i_mode; 271 if (!fc->default_permissions) 272 inode->i_mode &= ~S_ISVTX; 273 274 fi->orig_ino = attr->ino; 275 276 /* 277 * We are refreshing inode data and it is possible that another 278 * client set suid/sgid or security.capability xattr. So clear 279 * S_NOSEC. Ideally, we could have cleared it only if suid/sgid 280 * was set or if security.capability xattr was set. But we don't 281 * know if security.capability has been set or not. So clear it 282 * anyway. Its less efficient but should be safe. 283 */ 284 inode->i_flags &= ~S_NOSEC; 285 } 286 287 u32 fuse_get_cache_mask(struct inode *inode) 288 { 289 struct fuse_conn *fc = get_fuse_conn(inode); 290 291 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) 292 return 0; 293 294 return STATX_MTIME | STATX_CTIME | STATX_SIZE; 295 } 296 297 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, 298 struct fuse_statx *sx, 299 u64 attr_valid, u64 attr_version) 300 { 301 struct fuse_conn *fc = get_fuse_conn(inode); 302 struct fuse_inode *fi = get_fuse_inode(inode); 303 u32 cache_mask; 304 loff_t oldsize; 305 struct timespec64 old_mtime; 306 307 spin_lock(&fi->lock); 308 /* 309 * In case of writeback_cache enabled, writes update mtime, ctime and 310 * may update i_size. In these cases trust the cached value in the 311 * inode. 312 */ 313 cache_mask = fuse_get_cache_mask(inode); 314 if (cache_mask & STATX_SIZE) 315 attr->size = i_size_read(inode); 316 317 if (cache_mask & STATX_MTIME) { 318 attr->mtime = inode_get_mtime_sec(inode); 319 attr->mtimensec = inode_get_mtime_nsec(inode); 320 } 321 if (cache_mask & STATX_CTIME) { 322 attr->ctime = inode_get_ctime_sec(inode); 323 attr->ctimensec = inode_get_ctime_nsec(inode); 324 } 325 326 if ((attr_version != 0 && fi->attr_version > attr_version) || 327 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { 328 spin_unlock(&fi->lock); 329 return; 330 } 331 332 old_mtime = inode_get_mtime(inode); 333 fuse_change_attributes_common(inode, attr, sx, attr_valid, cache_mask); 334 335 oldsize = inode->i_size; 336 /* 337 * In case of writeback_cache enabled, the cached writes beyond EOF 338 * extend local i_size without keeping userspace server in sync. So, 339 * attr->size coming from server can be stale. We cannot trust it. 340 */ 341 if (!(cache_mask & STATX_SIZE)) 342 i_size_write(inode, attr->size); 343 spin_unlock(&fi->lock); 344 345 if (!cache_mask && S_ISREG(inode->i_mode)) { 346 bool inval = false; 347 348 if (oldsize != attr->size) { 349 truncate_pagecache(inode, attr->size); 350 if (!fc->explicit_inval_data) 351 inval = true; 352 } else if (fc->auto_inval_data) { 353 struct timespec64 new_mtime = { 354 .tv_sec = attr->mtime, 355 .tv_nsec = attr->mtimensec, 356 }; 357 358 /* 359 * Auto inval mode also checks and invalidates if mtime 360 * has changed. 361 */ 362 if (!timespec64_equal(&old_mtime, &new_mtime)) 363 inval = true; 364 } 365 366 if (inval) 367 invalidate_inode_pages2(inode->i_mapping); 368 } 369 370 if (IS_ENABLED(CONFIG_FUSE_DAX)) 371 fuse_dax_dontcache(inode, attr->flags); 372 } 373 374 static void fuse_init_submount_lookup(struct fuse_submount_lookup *sl, 375 u64 nodeid) 376 { 377 sl->nodeid = nodeid; 378 refcount_set(&sl->count, 1); 379 } 380 381 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr, 382 struct fuse_conn *fc) 383 { 384 inode->i_mode = attr->mode & S_IFMT; 385 inode->i_size = attr->size; 386 inode_set_mtime(inode, attr->mtime, attr->mtimensec); 387 inode_set_ctime(inode, attr->ctime, attr->ctimensec); 388 if (S_ISREG(inode->i_mode)) { 389 fuse_init_common(inode); 390 fuse_init_file_inode(inode, attr->flags); 391 } else if (S_ISDIR(inode->i_mode)) 392 fuse_init_dir(inode); 393 else if (S_ISLNK(inode->i_mode)) 394 fuse_init_symlink(inode); 395 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || 396 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { 397 fuse_init_common(inode); 398 init_special_inode(inode, inode->i_mode, 399 new_decode_dev(attr->rdev)); 400 } else 401 BUG(); 402 /* 403 * Ensure that we don't cache acls for daemons without FUSE_POSIX_ACL 404 * so they see the exact same behavior as before. 405 */ 406 if (!fc->posix_acl) 407 inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE; 408 } 409 410 static int fuse_inode_eq(struct inode *inode, void *_nodeidp) 411 { 412 u64 nodeid = *(u64 *) _nodeidp; 413 if (get_node_id(inode) == nodeid) 414 return 1; 415 else 416 return 0; 417 } 418 419 static int fuse_inode_set(struct inode *inode, void *_nodeidp) 420 { 421 u64 nodeid = *(u64 *) _nodeidp; 422 get_fuse_inode(inode)->nodeid = nodeid; 423 return 0; 424 } 425 426 struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 427 int generation, struct fuse_attr *attr, 428 u64 attr_valid, u64 attr_version) 429 { 430 struct inode *inode; 431 struct fuse_inode *fi; 432 struct fuse_conn *fc = get_fuse_conn_super(sb); 433 434 /* 435 * Auto mount points get their node id from the submount root, which is 436 * not a unique identifier within this filesystem. 437 * 438 * To avoid conflicts, do not place submount points into the inode hash 439 * table. 440 */ 441 if (fc->auto_submounts && (attr->flags & FUSE_ATTR_SUBMOUNT) && 442 S_ISDIR(attr->mode)) { 443 struct fuse_inode *fi; 444 445 inode = new_inode(sb); 446 if (!inode) 447 return NULL; 448 449 fuse_init_inode(inode, attr, fc); 450 fi = get_fuse_inode(inode); 451 fi->nodeid = nodeid; 452 fi->submount_lookup = fuse_alloc_submount_lookup(); 453 if (!fi->submount_lookup) { 454 iput(inode); 455 return NULL; 456 } 457 /* Sets nlookup = 1 on fi->submount_lookup->nlookup */ 458 fuse_init_submount_lookup(fi->submount_lookup, nodeid); 459 inode->i_flags |= S_AUTOMOUNT; 460 goto done; 461 } 462 463 retry: 464 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); 465 if (!inode) 466 return NULL; 467 468 if ((inode->i_state & I_NEW)) { 469 inode->i_flags |= S_NOATIME; 470 if (!fc->writeback_cache || !S_ISREG(attr->mode)) 471 inode->i_flags |= S_NOCMTIME; 472 inode->i_generation = generation; 473 fuse_init_inode(inode, attr, fc); 474 unlock_new_inode(inode); 475 } else if (fuse_stale_inode(inode, generation, attr)) { 476 /* nodeid was reused, any I/O on the old inode should fail */ 477 fuse_make_bad(inode); 478 if (inode != d_inode(sb->s_root)) { 479 remove_inode_hash(inode); 480 iput(inode); 481 goto retry; 482 } 483 } 484 fi = get_fuse_inode(inode); 485 spin_lock(&fi->lock); 486 fi->nlookup++; 487 spin_unlock(&fi->lock); 488 done: 489 fuse_change_attributes(inode, attr, NULL, attr_valid, attr_version); 490 491 return inode; 492 } 493 494 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid, 495 struct fuse_mount **fm) 496 { 497 struct fuse_mount *fm_iter; 498 struct inode *inode; 499 500 WARN_ON(!rwsem_is_locked(&fc->killsb)); 501 list_for_each_entry(fm_iter, &fc->mounts, fc_entry) { 502 if (!fm_iter->sb) 503 continue; 504 505 inode = ilookup5(fm_iter->sb, nodeid, fuse_inode_eq, &nodeid); 506 if (inode) { 507 if (fm) 508 *fm = fm_iter; 509 return inode; 510 } 511 } 512 513 return NULL; 514 } 515 516 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid, 517 loff_t offset, loff_t len) 518 { 519 struct fuse_inode *fi; 520 struct inode *inode; 521 pgoff_t pg_start; 522 pgoff_t pg_end; 523 524 inode = fuse_ilookup(fc, nodeid, NULL); 525 if (!inode) 526 return -ENOENT; 527 528 fi = get_fuse_inode(inode); 529 spin_lock(&fi->lock); 530 fi->attr_version = atomic64_inc_return(&fc->attr_version); 531 spin_unlock(&fi->lock); 532 533 fuse_invalidate_attr(inode); 534 forget_all_cached_acls(inode); 535 if (offset >= 0) { 536 pg_start = offset >> PAGE_SHIFT; 537 if (len <= 0) 538 pg_end = -1; 539 else 540 pg_end = (offset + len - 1) >> PAGE_SHIFT; 541 invalidate_inode_pages2_range(inode->i_mapping, 542 pg_start, pg_end); 543 } 544 iput(inode); 545 return 0; 546 } 547 548 bool fuse_lock_inode(struct inode *inode) 549 { 550 bool locked = false; 551 552 if (!get_fuse_conn(inode)->parallel_dirops) { 553 mutex_lock(&get_fuse_inode(inode)->mutex); 554 locked = true; 555 } 556 557 return locked; 558 } 559 560 void fuse_unlock_inode(struct inode *inode, bool locked) 561 { 562 if (locked) 563 mutex_unlock(&get_fuse_inode(inode)->mutex); 564 } 565 566 static void fuse_umount_begin(struct super_block *sb) 567 { 568 struct fuse_conn *fc = get_fuse_conn_super(sb); 569 570 if (fc->no_force_umount) 571 return; 572 573 fuse_abort_conn(fc); 574 575 // Only retire block-device-based superblocks. 576 if (sb->s_bdev != NULL) 577 retire_super(sb); 578 } 579 580 static void fuse_send_destroy(struct fuse_mount *fm) 581 { 582 if (fm->fc->conn_init) { 583 FUSE_ARGS(args); 584 585 args.opcode = FUSE_DESTROY; 586 args.force = true; 587 args.nocreds = true; 588 fuse_simple_request(fm, &args); 589 } 590 } 591 592 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 593 { 594 stbuf->f_type = FUSE_SUPER_MAGIC; 595 stbuf->f_bsize = attr->bsize; 596 stbuf->f_frsize = attr->frsize; 597 stbuf->f_blocks = attr->blocks; 598 stbuf->f_bfree = attr->bfree; 599 stbuf->f_bavail = attr->bavail; 600 stbuf->f_files = attr->files; 601 stbuf->f_ffree = attr->ffree; 602 stbuf->f_namelen = attr->namelen; 603 /* fsid is left zero */ 604 } 605 606 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 607 { 608 struct super_block *sb = dentry->d_sb; 609 struct fuse_mount *fm = get_fuse_mount_super(sb); 610 FUSE_ARGS(args); 611 struct fuse_statfs_out outarg; 612 int err; 613 614 if (!fuse_allow_current_process(fm->fc)) { 615 buf->f_type = FUSE_SUPER_MAGIC; 616 return 0; 617 } 618 619 memset(&outarg, 0, sizeof(outarg)); 620 args.in_numargs = 0; 621 args.opcode = FUSE_STATFS; 622 args.nodeid = get_node_id(d_inode(dentry)); 623 args.out_numargs = 1; 624 args.out_args[0].size = sizeof(outarg); 625 args.out_args[0].value = &outarg; 626 err = fuse_simple_request(fm, &args); 627 if (!err) 628 convert_fuse_statfs(buf, &outarg.st); 629 return err; 630 } 631 632 static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void) 633 { 634 struct fuse_sync_bucket *bucket; 635 636 bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL); 637 if (bucket) { 638 init_waitqueue_head(&bucket->waitq); 639 /* Initial active count */ 640 atomic_set(&bucket->count, 1); 641 } 642 return bucket; 643 } 644 645 static void fuse_sync_fs_writes(struct fuse_conn *fc) 646 { 647 struct fuse_sync_bucket *bucket, *new_bucket; 648 int count; 649 650 new_bucket = fuse_sync_bucket_alloc(); 651 spin_lock(&fc->lock); 652 bucket = rcu_dereference_protected(fc->curr_bucket, 1); 653 count = atomic_read(&bucket->count); 654 WARN_ON(count < 1); 655 /* No outstanding writes? */ 656 if (count == 1) { 657 spin_unlock(&fc->lock); 658 kfree(new_bucket); 659 return; 660 } 661 662 /* 663 * Completion of new bucket depends on completion of this bucket, so add 664 * one more count. 665 */ 666 atomic_inc(&new_bucket->count); 667 rcu_assign_pointer(fc->curr_bucket, new_bucket); 668 spin_unlock(&fc->lock); 669 /* 670 * Drop initial active count. At this point if all writes in this and 671 * ancestor buckets complete, the count will go to zero and this task 672 * will be woken up. 673 */ 674 atomic_dec(&bucket->count); 675 676 wait_event(bucket->waitq, atomic_read(&bucket->count) == 0); 677 678 /* Drop temp count on descendant bucket */ 679 fuse_sync_bucket_dec(new_bucket); 680 kfree_rcu(bucket, rcu); 681 } 682 683 static int fuse_sync_fs(struct super_block *sb, int wait) 684 { 685 struct fuse_mount *fm = get_fuse_mount_super(sb); 686 struct fuse_conn *fc = fm->fc; 687 struct fuse_syncfs_in inarg; 688 FUSE_ARGS(args); 689 int err; 690 691 /* 692 * Userspace cannot handle the wait == 0 case. Avoid a 693 * gratuitous roundtrip. 694 */ 695 if (!wait) 696 return 0; 697 698 /* The filesystem is being unmounted. Nothing to do. */ 699 if (!sb->s_root) 700 return 0; 701 702 if (!fc->sync_fs) 703 return 0; 704 705 fuse_sync_fs_writes(fc); 706 707 memset(&inarg, 0, sizeof(inarg)); 708 args.in_numargs = 1; 709 args.in_args[0].size = sizeof(inarg); 710 args.in_args[0].value = &inarg; 711 args.opcode = FUSE_SYNCFS; 712 args.nodeid = get_node_id(sb->s_root->d_inode); 713 args.out_numargs = 0; 714 715 err = fuse_simple_request(fm, &args); 716 if (err == -ENOSYS) { 717 fc->sync_fs = 0; 718 err = 0; 719 } 720 721 return err; 722 } 723 724 enum { 725 OPT_SOURCE, 726 OPT_SUBTYPE, 727 OPT_FD, 728 OPT_ROOTMODE, 729 OPT_USER_ID, 730 OPT_GROUP_ID, 731 OPT_DEFAULT_PERMISSIONS, 732 OPT_ALLOW_OTHER, 733 OPT_MAX_READ, 734 OPT_BLKSIZE, 735 OPT_ERR 736 }; 737 738 static const struct fs_parameter_spec fuse_fs_parameters[] = { 739 fsparam_string ("source", OPT_SOURCE), 740 fsparam_u32 ("fd", OPT_FD), 741 fsparam_u32oct ("rootmode", OPT_ROOTMODE), 742 fsparam_u32 ("user_id", OPT_USER_ID), 743 fsparam_u32 ("group_id", OPT_GROUP_ID), 744 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS), 745 fsparam_flag ("allow_other", OPT_ALLOW_OTHER), 746 fsparam_u32 ("max_read", OPT_MAX_READ), 747 fsparam_u32 ("blksize", OPT_BLKSIZE), 748 fsparam_string ("subtype", OPT_SUBTYPE), 749 {} 750 }; 751 752 static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param) 753 { 754 struct fs_parse_result result; 755 struct fuse_fs_context *ctx = fsc->fs_private; 756 int opt; 757 758 if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { 759 /* 760 * Ignore options coming from mount(MS_REMOUNT) for backward 761 * compatibility. 762 */ 763 if (fsc->oldapi) 764 return 0; 765 766 return invalfc(fsc, "No changes allowed in reconfigure"); 767 } 768 769 opt = fs_parse(fsc, fuse_fs_parameters, param, &result); 770 if (opt < 0) 771 return opt; 772 773 switch (opt) { 774 case OPT_SOURCE: 775 if (fsc->source) 776 return invalfc(fsc, "Multiple sources specified"); 777 fsc->source = param->string; 778 param->string = NULL; 779 break; 780 781 case OPT_SUBTYPE: 782 if (ctx->subtype) 783 return invalfc(fsc, "Multiple subtypes specified"); 784 ctx->subtype = param->string; 785 param->string = NULL; 786 return 0; 787 788 case OPT_FD: 789 ctx->fd = result.uint_32; 790 ctx->fd_present = true; 791 break; 792 793 case OPT_ROOTMODE: 794 if (!fuse_valid_type(result.uint_32)) 795 return invalfc(fsc, "Invalid rootmode"); 796 ctx->rootmode = result.uint_32; 797 ctx->rootmode_present = true; 798 break; 799 800 case OPT_USER_ID: 801 ctx->user_id = make_kuid(fsc->user_ns, result.uint_32); 802 if (!uid_valid(ctx->user_id)) 803 return invalfc(fsc, "Invalid user_id"); 804 ctx->user_id_present = true; 805 break; 806 807 case OPT_GROUP_ID: 808 ctx->group_id = make_kgid(fsc->user_ns, result.uint_32); 809 if (!gid_valid(ctx->group_id)) 810 return invalfc(fsc, "Invalid group_id"); 811 ctx->group_id_present = true; 812 break; 813 814 case OPT_DEFAULT_PERMISSIONS: 815 ctx->default_permissions = true; 816 break; 817 818 case OPT_ALLOW_OTHER: 819 ctx->allow_other = true; 820 break; 821 822 case OPT_MAX_READ: 823 ctx->max_read = result.uint_32; 824 break; 825 826 case OPT_BLKSIZE: 827 if (!ctx->is_bdev) 828 return invalfc(fsc, "blksize only supported for fuseblk"); 829 ctx->blksize = result.uint_32; 830 break; 831 832 default: 833 return -EINVAL; 834 } 835 836 return 0; 837 } 838 839 static void fuse_free_fsc(struct fs_context *fsc) 840 { 841 struct fuse_fs_context *ctx = fsc->fs_private; 842 843 if (ctx) { 844 kfree(ctx->subtype); 845 kfree(ctx); 846 } 847 } 848 849 static int fuse_show_options(struct seq_file *m, struct dentry *root) 850 { 851 struct super_block *sb = root->d_sb; 852 struct fuse_conn *fc = get_fuse_conn_super(sb); 853 854 if (fc->legacy_opts_show) { 855 seq_printf(m, ",user_id=%u", 856 from_kuid_munged(fc->user_ns, fc->user_id)); 857 seq_printf(m, ",group_id=%u", 858 from_kgid_munged(fc->user_ns, fc->group_id)); 859 if (fc->default_permissions) 860 seq_puts(m, ",default_permissions"); 861 if (fc->allow_other) 862 seq_puts(m, ",allow_other"); 863 if (fc->max_read != ~0) 864 seq_printf(m, ",max_read=%u", fc->max_read); 865 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 866 seq_printf(m, ",blksize=%lu", sb->s_blocksize); 867 } 868 #ifdef CONFIG_FUSE_DAX 869 if (fc->dax_mode == FUSE_DAX_ALWAYS) 870 seq_puts(m, ",dax=always"); 871 else if (fc->dax_mode == FUSE_DAX_NEVER) 872 seq_puts(m, ",dax=never"); 873 else if (fc->dax_mode == FUSE_DAX_INODE_USER) 874 seq_puts(m, ",dax=inode"); 875 #endif 876 877 return 0; 878 } 879 880 static void fuse_iqueue_init(struct fuse_iqueue *fiq, 881 const struct fuse_iqueue_ops *ops, 882 void *priv) 883 { 884 memset(fiq, 0, sizeof(struct fuse_iqueue)); 885 spin_lock_init(&fiq->lock); 886 init_waitqueue_head(&fiq->waitq); 887 INIT_LIST_HEAD(&fiq->pending); 888 INIT_LIST_HEAD(&fiq->interrupts); 889 fiq->forget_list_tail = &fiq->forget_list_head; 890 fiq->connected = 1; 891 fiq->ops = ops; 892 fiq->priv = priv; 893 } 894 895 static void fuse_pqueue_init(struct fuse_pqueue *fpq) 896 { 897 unsigned int i; 898 899 spin_lock_init(&fpq->lock); 900 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) 901 INIT_LIST_HEAD(&fpq->processing[i]); 902 INIT_LIST_HEAD(&fpq->io); 903 fpq->connected = 1; 904 } 905 906 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm, 907 struct user_namespace *user_ns, 908 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv) 909 { 910 memset(fc, 0, sizeof(*fc)); 911 spin_lock_init(&fc->lock); 912 spin_lock_init(&fc->bg_lock); 913 init_rwsem(&fc->killsb); 914 refcount_set(&fc->count, 1); 915 atomic_set(&fc->dev_count, 1); 916 init_waitqueue_head(&fc->blocked_waitq); 917 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv); 918 INIT_LIST_HEAD(&fc->bg_queue); 919 INIT_LIST_HEAD(&fc->entry); 920 INIT_LIST_HEAD(&fc->devices); 921 atomic_set(&fc->num_waiting, 0); 922 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND; 923 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD; 924 atomic64_set(&fc->khctr, 0); 925 fc->polled_files = RB_ROOT; 926 fc->blocked = 0; 927 fc->initialized = 0; 928 fc->connected = 1; 929 atomic64_set(&fc->attr_version, 1); 930 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 931 fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); 932 fc->user_ns = get_user_ns(user_ns); 933 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ; 934 fc->max_pages_limit = FUSE_MAX_MAX_PAGES; 935 936 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) 937 fuse_backing_files_init(fc); 938 939 INIT_LIST_HEAD(&fc->mounts); 940 list_add(&fm->fc_entry, &fc->mounts); 941 fm->fc = fc; 942 } 943 EXPORT_SYMBOL_GPL(fuse_conn_init); 944 945 static void delayed_release(struct rcu_head *p) 946 { 947 struct fuse_conn *fc = container_of(p, struct fuse_conn, rcu); 948 949 put_user_ns(fc->user_ns); 950 fc->release(fc); 951 } 952 953 void fuse_conn_put(struct fuse_conn *fc) 954 { 955 if (refcount_dec_and_test(&fc->count)) { 956 struct fuse_iqueue *fiq = &fc->iq; 957 struct fuse_sync_bucket *bucket; 958 959 if (IS_ENABLED(CONFIG_FUSE_DAX)) 960 fuse_dax_conn_free(fc); 961 if (fiq->ops->release) 962 fiq->ops->release(fiq); 963 put_pid_ns(fc->pid_ns); 964 bucket = rcu_dereference_protected(fc->curr_bucket, 1); 965 if (bucket) { 966 WARN_ON(atomic_read(&bucket->count) != 1); 967 kfree(bucket); 968 } 969 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) 970 fuse_backing_files_free(fc); 971 call_rcu(&fc->rcu, delayed_release); 972 } 973 } 974 EXPORT_SYMBOL_GPL(fuse_conn_put); 975 976 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 977 { 978 refcount_inc(&fc->count); 979 return fc; 980 } 981 EXPORT_SYMBOL_GPL(fuse_conn_get); 982 983 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 984 { 985 struct fuse_attr attr; 986 memset(&attr, 0, sizeof(attr)); 987 988 attr.mode = mode; 989 attr.ino = FUSE_ROOT_ID; 990 attr.nlink = 1; 991 return fuse_iget(sb, FUSE_ROOT_ID, 0, &attr, 0, 0); 992 } 993 994 struct fuse_inode_handle { 995 u64 nodeid; 996 u32 generation; 997 }; 998 999 static struct dentry *fuse_get_dentry(struct super_block *sb, 1000 struct fuse_inode_handle *handle) 1001 { 1002 struct fuse_conn *fc = get_fuse_conn_super(sb); 1003 struct inode *inode; 1004 struct dentry *entry; 1005 int err = -ESTALE; 1006 1007 if (handle->nodeid == 0) 1008 goto out_err; 1009 1010 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 1011 if (!inode) { 1012 struct fuse_entry_out outarg; 1013 const struct qstr name = QSTR_INIT(".", 1); 1014 1015 if (!fc->export_support) 1016 goto out_err; 1017 1018 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 1019 &inode); 1020 if (err && err != -ENOENT) 1021 goto out_err; 1022 if (err || !inode) { 1023 err = -ESTALE; 1024 goto out_err; 1025 } 1026 err = -EIO; 1027 if (get_node_id(inode) != handle->nodeid) 1028 goto out_iput; 1029 } 1030 err = -ESTALE; 1031 if (inode->i_generation != handle->generation) 1032 goto out_iput; 1033 1034 entry = d_obtain_alias(inode); 1035 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) 1036 fuse_invalidate_entry_cache(entry); 1037 1038 return entry; 1039 1040 out_iput: 1041 iput(inode); 1042 out_err: 1043 return ERR_PTR(err); 1044 } 1045 1046 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len, 1047 struct inode *parent) 1048 { 1049 int len = parent ? 6 : 3; 1050 u64 nodeid; 1051 u32 generation; 1052 1053 if (*max_len < len) { 1054 *max_len = len; 1055 return FILEID_INVALID; 1056 } 1057 1058 nodeid = get_fuse_inode(inode)->nodeid; 1059 generation = inode->i_generation; 1060 1061 fh[0] = (u32)(nodeid >> 32); 1062 fh[1] = (u32)(nodeid & 0xffffffff); 1063 fh[2] = generation; 1064 1065 if (parent) { 1066 nodeid = get_fuse_inode(parent)->nodeid; 1067 generation = parent->i_generation; 1068 1069 fh[3] = (u32)(nodeid >> 32); 1070 fh[4] = (u32)(nodeid & 0xffffffff); 1071 fh[5] = generation; 1072 } 1073 1074 *max_len = len; 1075 return parent ? FILEID_INO64_GEN_PARENT : FILEID_INO64_GEN; 1076 } 1077 1078 static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 1079 struct fid *fid, int fh_len, int fh_type) 1080 { 1081 struct fuse_inode_handle handle; 1082 1083 if ((fh_type != FILEID_INO64_GEN && 1084 fh_type != FILEID_INO64_GEN_PARENT) || fh_len < 3) 1085 return NULL; 1086 1087 handle.nodeid = (u64) fid->raw[0] << 32; 1088 handle.nodeid |= (u64) fid->raw[1]; 1089 handle.generation = fid->raw[2]; 1090 return fuse_get_dentry(sb, &handle); 1091 } 1092 1093 static struct dentry *fuse_fh_to_parent(struct super_block *sb, 1094 struct fid *fid, int fh_len, int fh_type) 1095 { 1096 struct fuse_inode_handle parent; 1097 1098 if (fh_type != FILEID_INO64_GEN_PARENT || fh_len < 6) 1099 return NULL; 1100 1101 parent.nodeid = (u64) fid->raw[3] << 32; 1102 parent.nodeid |= (u64) fid->raw[4]; 1103 parent.generation = fid->raw[5]; 1104 return fuse_get_dentry(sb, &parent); 1105 } 1106 1107 static struct dentry *fuse_get_parent(struct dentry *child) 1108 { 1109 struct inode *child_inode = d_inode(child); 1110 struct fuse_conn *fc = get_fuse_conn(child_inode); 1111 struct inode *inode; 1112 struct dentry *parent; 1113 struct fuse_entry_out outarg; 1114 int err; 1115 1116 if (!fc->export_support) 1117 return ERR_PTR(-ESTALE); 1118 1119 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 1120 &dotdot_name, &outarg, &inode); 1121 if (err) { 1122 if (err == -ENOENT) 1123 return ERR_PTR(-ESTALE); 1124 return ERR_PTR(err); 1125 } 1126 1127 parent = d_obtain_alias(inode); 1128 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) 1129 fuse_invalidate_entry_cache(parent); 1130 1131 return parent; 1132 } 1133 1134 /* only for fid encoding; no support for file handle */ 1135 static const struct export_operations fuse_export_fid_operations = { 1136 .encode_fh = fuse_encode_fh, 1137 }; 1138 1139 static const struct export_operations fuse_export_operations = { 1140 .fh_to_dentry = fuse_fh_to_dentry, 1141 .fh_to_parent = fuse_fh_to_parent, 1142 .encode_fh = fuse_encode_fh, 1143 .get_parent = fuse_get_parent, 1144 }; 1145 1146 static const struct super_operations fuse_super_operations = { 1147 .alloc_inode = fuse_alloc_inode, 1148 .free_inode = fuse_free_inode, 1149 .evict_inode = fuse_evict_inode, 1150 .write_inode = fuse_write_inode, 1151 .drop_inode = generic_delete_inode, 1152 .umount_begin = fuse_umount_begin, 1153 .statfs = fuse_statfs, 1154 .sync_fs = fuse_sync_fs, 1155 .show_options = fuse_show_options, 1156 }; 1157 1158 static void sanitize_global_limit(unsigned *limit) 1159 { 1160 /* 1161 * The default maximum number of async requests is calculated to consume 1162 * 1/2^13 of the total memory, assuming 392 bytes per request. 1163 */ 1164 if (*limit == 0) 1165 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392; 1166 1167 if (*limit >= 1 << 16) 1168 *limit = (1 << 16) - 1; 1169 } 1170 1171 static int set_global_limit(const char *val, const struct kernel_param *kp) 1172 { 1173 int rv; 1174 1175 rv = param_set_uint(val, kp); 1176 if (rv) 1177 return rv; 1178 1179 sanitize_global_limit((unsigned *)kp->arg); 1180 1181 return 0; 1182 } 1183 1184 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg) 1185 { 1186 int cap_sys_admin = capable(CAP_SYS_ADMIN); 1187 1188 if (arg->minor < 13) 1189 return; 1190 1191 sanitize_global_limit(&max_user_bgreq); 1192 sanitize_global_limit(&max_user_congthresh); 1193 1194 spin_lock(&fc->bg_lock); 1195 if (arg->max_background) { 1196 fc->max_background = arg->max_background; 1197 1198 if (!cap_sys_admin && fc->max_background > max_user_bgreq) 1199 fc->max_background = max_user_bgreq; 1200 } 1201 if (arg->congestion_threshold) { 1202 fc->congestion_threshold = arg->congestion_threshold; 1203 1204 if (!cap_sys_admin && 1205 fc->congestion_threshold > max_user_congthresh) 1206 fc->congestion_threshold = max_user_congthresh; 1207 } 1208 spin_unlock(&fc->bg_lock); 1209 } 1210 1211 struct fuse_init_args { 1212 struct fuse_args args; 1213 struct fuse_init_in in; 1214 struct fuse_init_out out; 1215 }; 1216 1217 static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, 1218 int error) 1219 { 1220 struct fuse_conn *fc = fm->fc; 1221 struct fuse_init_args *ia = container_of(args, typeof(*ia), args); 1222 struct fuse_init_out *arg = &ia->out; 1223 bool ok = true; 1224 1225 if (error || arg->major != FUSE_KERNEL_VERSION) 1226 ok = false; 1227 else { 1228 unsigned long ra_pages; 1229 1230 process_init_limits(fc, arg); 1231 1232 if (arg->minor >= 6) { 1233 u64 flags = arg->flags; 1234 1235 if (flags & FUSE_INIT_EXT) 1236 flags |= (u64) arg->flags2 << 32; 1237 1238 ra_pages = arg->max_readahead / PAGE_SIZE; 1239 if (flags & FUSE_ASYNC_READ) 1240 fc->async_read = 1; 1241 if (!(flags & FUSE_POSIX_LOCKS)) 1242 fc->no_lock = 1; 1243 if (arg->minor >= 17) { 1244 if (!(flags & FUSE_FLOCK_LOCKS)) 1245 fc->no_flock = 1; 1246 } else { 1247 if (!(flags & FUSE_POSIX_LOCKS)) 1248 fc->no_flock = 1; 1249 } 1250 if (flags & FUSE_ATOMIC_O_TRUNC) 1251 fc->atomic_o_trunc = 1; 1252 if (arg->minor >= 9) { 1253 /* LOOKUP has dependency on proto version */ 1254 if (flags & FUSE_EXPORT_SUPPORT) 1255 fc->export_support = 1; 1256 } 1257 if (flags & FUSE_BIG_WRITES) 1258 fc->big_writes = 1; 1259 if (flags & FUSE_DONT_MASK) 1260 fc->dont_mask = 1; 1261 if (flags & FUSE_AUTO_INVAL_DATA) 1262 fc->auto_inval_data = 1; 1263 else if (flags & FUSE_EXPLICIT_INVAL_DATA) 1264 fc->explicit_inval_data = 1; 1265 if (flags & FUSE_DO_READDIRPLUS) { 1266 fc->do_readdirplus = 1; 1267 if (flags & FUSE_READDIRPLUS_AUTO) 1268 fc->readdirplus_auto = 1; 1269 } 1270 if (flags & FUSE_ASYNC_DIO) 1271 fc->async_dio = 1; 1272 if (flags & FUSE_WRITEBACK_CACHE) 1273 fc->writeback_cache = 1; 1274 if (flags & FUSE_PARALLEL_DIROPS) 1275 fc->parallel_dirops = 1; 1276 if (flags & FUSE_HANDLE_KILLPRIV) 1277 fc->handle_killpriv = 1; 1278 if (arg->time_gran && arg->time_gran <= 1000000000) 1279 fm->sb->s_time_gran = arg->time_gran; 1280 if ((flags & FUSE_POSIX_ACL)) { 1281 fc->default_permissions = 1; 1282 fc->posix_acl = 1; 1283 } 1284 if (flags & FUSE_CACHE_SYMLINKS) 1285 fc->cache_symlinks = 1; 1286 if (flags & FUSE_ABORT_ERROR) 1287 fc->abort_err = 1; 1288 if (flags & FUSE_MAX_PAGES) { 1289 fc->max_pages = 1290 min_t(unsigned int, fc->max_pages_limit, 1291 max_t(unsigned int, arg->max_pages, 1)); 1292 } 1293 if (IS_ENABLED(CONFIG_FUSE_DAX)) { 1294 if (flags & FUSE_MAP_ALIGNMENT && 1295 !fuse_dax_check_alignment(fc, arg->map_alignment)) { 1296 ok = false; 1297 } 1298 if (flags & FUSE_HAS_INODE_DAX) 1299 fc->inode_dax = 1; 1300 } 1301 if (flags & FUSE_HANDLE_KILLPRIV_V2) { 1302 fc->handle_killpriv_v2 = 1; 1303 fm->sb->s_flags |= SB_NOSEC; 1304 } 1305 if (flags & FUSE_SETXATTR_EXT) 1306 fc->setxattr_ext = 1; 1307 if (flags & FUSE_SECURITY_CTX) 1308 fc->init_security = 1; 1309 if (flags & FUSE_CREATE_SUPP_GROUP) 1310 fc->create_supp_group = 1; 1311 if (flags & FUSE_DIRECT_IO_ALLOW_MMAP) 1312 fc->direct_io_allow_mmap = 1; 1313 /* 1314 * max_stack_depth is the max stack depth of FUSE fs, 1315 * so it has to be at least 1 to support passthrough 1316 * to backing files. 1317 * 1318 * with max_stack_depth > 1, the backing files can be 1319 * on a stacked fs (e.g. overlayfs) themselves and with 1320 * max_stack_depth == 1, FUSE fs can be stacked as the 1321 * underlying fs of a stacked fs (e.g. overlayfs). 1322 */ 1323 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH) && 1324 (flags & FUSE_PASSTHROUGH) && 1325 arg->max_stack_depth > 0 && 1326 arg->max_stack_depth <= FILESYSTEM_MAX_STACK_DEPTH) { 1327 fc->passthrough = 1; 1328 fc->max_stack_depth = arg->max_stack_depth; 1329 fm->sb->s_stack_depth = arg->max_stack_depth; 1330 } 1331 if (flags & FUSE_NO_EXPORT_SUPPORT) 1332 fm->sb->s_export_op = &fuse_export_fid_operations; 1333 } else { 1334 ra_pages = fc->max_read / PAGE_SIZE; 1335 fc->no_lock = 1; 1336 fc->no_flock = 1; 1337 } 1338 1339 fm->sb->s_bdi->ra_pages = 1340 min(fm->sb->s_bdi->ra_pages, ra_pages); 1341 fc->minor = arg->minor; 1342 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 1343 fc->max_write = max_t(unsigned, 4096, fc->max_write); 1344 fc->conn_init = 1; 1345 } 1346 kfree(ia); 1347 1348 if (!ok) { 1349 fc->conn_init = 0; 1350 fc->conn_error = 1; 1351 } 1352 1353 fuse_set_initialized(fc); 1354 wake_up_all(&fc->blocked_waitq); 1355 } 1356 1357 void fuse_send_init(struct fuse_mount *fm) 1358 { 1359 struct fuse_init_args *ia; 1360 u64 flags; 1361 1362 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL); 1363 1364 ia->in.major = FUSE_KERNEL_VERSION; 1365 ia->in.minor = FUSE_KERNEL_MINOR_VERSION; 1366 ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE; 1367 flags = 1368 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 1369 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | 1370 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | 1371 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | 1372 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO | 1373 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT | 1374 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL | 1375 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | 1376 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA | 1377 FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT | 1378 FUSE_SECURITY_CTX | FUSE_CREATE_SUPP_GROUP | 1379 FUSE_HAS_EXPIRE_ONLY | FUSE_DIRECT_IO_ALLOW_MMAP | 1380 FUSE_NO_EXPORT_SUPPORT | FUSE_HAS_RESEND; 1381 #ifdef CONFIG_FUSE_DAX 1382 if (fm->fc->dax) 1383 flags |= FUSE_MAP_ALIGNMENT; 1384 if (fuse_is_inode_dax_mode(fm->fc->dax_mode)) 1385 flags |= FUSE_HAS_INODE_DAX; 1386 #endif 1387 if (fm->fc->auto_submounts) 1388 flags |= FUSE_SUBMOUNTS; 1389 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) 1390 flags |= FUSE_PASSTHROUGH; 1391 1392 ia->in.flags = flags; 1393 ia->in.flags2 = flags >> 32; 1394 1395 ia->args.opcode = FUSE_INIT; 1396 ia->args.in_numargs = 1; 1397 ia->args.in_args[0].size = sizeof(ia->in); 1398 ia->args.in_args[0].value = &ia->in; 1399 ia->args.out_numargs = 1; 1400 /* Variable length argument used for backward compatibility 1401 with interface version < 7.5. Rest of init_out is zeroed 1402 by do_get_request(), so a short reply is not a problem */ 1403 ia->args.out_argvar = true; 1404 ia->args.out_args[0].size = sizeof(ia->out); 1405 ia->args.out_args[0].value = &ia->out; 1406 ia->args.force = true; 1407 ia->args.nocreds = true; 1408 ia->args.end = process_init_reply; 1409 1410 if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0) 1411 process_init_reply(fm, &ia->args, -ENOTCONN); 1412 } 1413 EXPORT_SYMBOL_GPL(fuse_send_init); 1414 1415 void fuse_free_conn(struct fuse_conn *fc) 1416 { 1417 WARN_ON(!list_empty(&fc->devices)); 1418 kfree(fc); 1419 } 1420 EXPORT_SYMBOL_GPL(fuse_free_conn); 1421 1422 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 1423 { 1424 int err; 1425 char *suffix = ""; 1426 1427 if (sb->s_bdev) { 1428 suffix = "-fuseblk"; 1429 /* 1430 * sb->s_bdi points to blkdev's bdi however we want to redirect 1431 * it to our private bdi... 1432 */ 1433 bdi_put(sb->s_bdi); 1434 sb->s_bdi = &noop_backing_dev_info; 1435 } 1436 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev), 1437 MINOR(fc->dev), suffix); 1438 if (err) 1439 return err; 1440 1441 /* fuse does it's own writeback accounting */ 1442 sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT; 1443 sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT; 1444 1445 /* 1446 * For a single fuse filesystem use max 1% of dirty + 1447 * writeback threshold. 1448 * 1449 * This gives about 1M of write buffer for memory maps on a 1450 * machine with 1G and 10% dirty_ratio, which should be more 1451 * than enough. 1452 * 1453 * Privileged users can raise it by writing to 1454 * 1455 * /sys/class/bdi/<bdi>/max_ratio 1456 */ 1457 bdi_set_max_ratio(sb->s_bdi, 1); 1458 1459 return 0; 1460 } 1461 1462 struct fuse_dev *fuse_dev_alloc(void) 1463 { 1464 struct fuse_dev *fud; 1465 struct list_head *pq; 1466 1467 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL); 1468 if (!fud) 1469 return NULL; 1470 1471 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); 1472 if (!pq) { 1473 kfree(fud); 1474 return NULL; 1475 } 1476 1477 fud->pq.processing = pq; 1478 fuse_pqueue_init(&fud->pq); 1479 1480 return fud; 1481 } 1482 EXPORT_SYMBOL_GPL(fuse_dev_alloc); 1483 1484 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc) 1485 { 1486 fud->fc = fuse_conn_get(fc); 1487 spin_lock(&fc->lock); 1488 list_add_tail(&fud->entry, &fc->devices); 1489 spin_unlock(&fc->lock); 1490 } 1491 EXPORT_SYMBOL_GPL(fuse_dev_install); 1492 1493 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc) 1494 { 1495 struct fuse_dev *fud; 1496 1497 fud = fuse_dev_alloc(); 1498 if (!fud) 1499 return NULL; 1500 1501 fuse_dev_install(fud, fc); 1502 return fud; 1503 } 1504 EXPORT_SYMBOL_GPL(fuse_dev_alloc_install); 1505 1506 void fuse_dev_free(struct fuse_dev *fud) 1507 { 1508 struct fuse_conn *fc = fud->fc; 1509 1510 if (fc) { 1511 spin_lock(&fc->lock); 1512 list_del(&fud->entry); 1513 spin_unlock(&fc->lock); 1514 1515 fuse_conn_put(fc); 1516 } 1517 kfree(fud->pq.processing); 1518 kfree(fud); 1519 } 1520 EXPORT_SYMBOL_GPL(fuse_dev_free); 1521 1522 static void fuse_fill_attr_from_inode(struct fuse_attr *attr, 1523 const struct fuse_inode *fi) 1524 { 1525 struct timespec64 atime = inode_get_atime(&fi->inode); 1526 struct timespec64 mtime = inode_get_mtime(&fi->inode); 1527 struct timespec64 ctime = inode_get_ctime(&fi->inode); 1528 1529 *attr = (struct fuse_attr){ 1530 .ino = fi->inode.i_ino, 1531 .size = fi->inode.i_size, 1532 .blocks = fi->inode.i_blocks, 1533 .atime = atime.tv_sec, 1534 .mtime = mtime.tv_sec, 1535 .ctime = ctime.tv_sec, 1536 .atimensec = atime.tv_nsec, 1537 .mtimensec = mtime.tv_nsec, 1538 .ctimensec = ctime.tv_nsec, 1539 .mode = fi->inode.i_mode, 1540 .nlink = fi->inode.i_nlink, 1541 .uid = __kuid_val(fi->inode.i_uid), 1542 .gid = __kgid_val(fi->inode.i_gid), 1543 .rdev = fi->inode.i_rdev, 1544 .blksize = 1u << fi->inode.i_blkbits, 1545 }; 1546 } 1547 1548 static void fuse_sb_defaults(struct super_block *sb) 1549 { 1550 sb->s_magic = FUSE_SUPER_MAGIC; 1551 sb->s_op = &fuse_super_operations; 1552 sb->s_xattr = fuse_xattr_handlers; 1553 sb->s_maxbytes = MAX_LFS_FILESIZE; 1554 sb->s_time_gran = 1; 1555 sb->s_export_op = &fuse_export_operations; 1556 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE; 1557 if (sb->s_user_ns != &init_user_ns) 1558 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; 1559 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); 1560 } 1561 1562 static int fuse_fill_super_submount(struct super_block *sb, 1563 struct fuse_inode *parent_fi) 1564 { 1565 struct fuse_mount *fm = get_fuse_mount_super(sb); 1566 struct super_block *parent_sb = parent_fi->inode.i_sb; 1567 struct fuse_attr root_attr; 1568 struct inode *root; 1569 struct fuse_submount_lookup *sl; 1570 struct fuse_inode *fi; 1571 1572 fuse_sb_defaults(sb); 1573 fm->sb = sb; 1574 1575 WARN_ON(sb->s_bdi != &noop_backing_dev_info); 1576 sb->s_bdi = bdi_get(parent_sb->s_bdi); 1577 1578 sb->s_xattr = parent_sb->s_xattr; 1579 sb->s_export_op = parent_sb->s_export_op; 1580 sb->s_time_gran = parent_sb->s_time_gran; 1581 sb->s_blocksize = parent_sb->s_blocksize; 1582 sb->s_blocksize_bits = parent_sb->s_blocksize_bits; 1583 sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL); 1584 if (parent_sb->s_subtype && !sb->s_subtype) 1585 return -ENOMEM; 1586 1587 fuse_fill_attr_from_inode(&root_attr, parent_fi); 1588 root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0); 1589 /* 1590 * This inode is just a duplicate, so it is not looked up and 1591 * its nlookup should not be incremented. fuse_iget() does 1592 * that, though, so undo it here. 1593 */ 1594 fi = get_fuse_inode(root); 1595 fi->nlookup--; 1596 1597 sb->s_d_op = &fuse_dentry_operations; 1598 sb->s_root = d_make_root(root); 1599 if (!sb->s_root) 1600 return -ENOMEM; 1601 1602 /* 1603 * Grab the parent's submount_lookup pointer and take a 1604 * reference on the shared nlookup from the parent. This is to 1605 * prevent the last forget for this nodeid from getting 1606 * triggered until all users have finished with it. 1607 */ 1608 sl = parent_fi->submount_lookup; 1609 WARN_ON(!sl); 1610 if (sl) { 1611 refcount_inc(&sl->count); 1612 fi->submount_lookup = sl; 1613 } 1614 1615 return 0; 1616 } 1617 1618 /* Filesystem context private data holds the FUSE inode of the mount point */ 1619 static int fuse_get_tree_submount(struct fs_context *fsc) 1620 { 1621 struct fuse_mount *fm; 1622 struct fuse_inode *mp_fi = fsc->fs_private; 1623 struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode); 1624 struct super_block *sb; 1625 int err; 1626 1627 fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL); 1628 if (!fm) 1629 return -ENOMEM; 1630 1631 fm->fc = fuse_conn_get(fc); 1632 fsc->s_fs_info = fm; 1633 sb = sget_fc(fsc, NULL, set_anon_super_fc); 1634 if (fsc->s_fs_info) 1635 fuse_mount_destroy(fm); 1636 if (IS_ERR(sb)) 1637 return PTR_ERR(sb); 1638 1639 /* Initialize superblock, making @mp_fi its root */ 1640 err = fuse_fill_super_submount(sb, mp_fi); 1641 if (err) { 1642 deactivate_locked_super(sb); 1643 return err; 1644 } 1645 1646 down_write(&fc->killsb); 1647 list_add_tail(&fm->fc_entry, &fc->mounts); 1648 up_write(&fc->killsb); 1649 1650 sb->s_flags |= SB_ACTIVE; 1651 fsc->root = dget(sb->s_root); 1652 1653 return 0; 1654 } 1655 1656 static const struct fs_context_operations fuse_context_submount_ops = { 1657 .get_tree = fuse_get_tree_submount, 1658 }; 1659 1660 int fuse_init_fs_context_submount(struct fs_context *fsc) 1661 { 1662 fsc->ops = &fuse_context_submount_ops; 1663 return 0; 1664 } 1665 EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount); 1666 1667 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx) 1668 { 1669 struct fuse_dev *fud = NULL; 1670 struct fuse_mount *fm = get_fuse_mount_super(sb); 1671 struct fuse_conn *fc = fm->fc; 1672 struct inode *root; 1673 struct dentry *root_dentry; 1674 int err; 1675 1676 err = -EINVAL; 1677 if (sb->s_flags & SB_MANDLOCK) 1678 goto err; 1679 1680 rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc()); 1681 fuse_sb_defaults(sb); 1682 1683 if (ctx->is_bdev) { 1684 #ifdef CONFIG_BLOCK 1685 err = -EINVAL; 1686 if (!sb_set_blocksize(sb, ctx->blksize)) 1687 goto err; 1688 #endif 1689 } else { 1690 sb->s_blocksize = PAGE_SIZE; 1691 sb->s_blocksize_bits = PAGE_SHIFT; 1692 } 1693 1694 sb->s_subtype = ctx->subtype; 1695 ctx->subtype = NULL; 1696 if (IS_ENABLED(CONFIG_FUSE_DAX)) { 1697 err = fuse_dax_conn_alloc(fc, ctx->dax_mode, ctx->dax_dev); 1698 if (err) 1699 goto err; 1700 } 1701 1702 if (ctx->fudptr) { 1703 err = -ENOMEM; 1704 fud = fuse_dev_alloc_install(fc); 1705 if (!fud) 1706 goto err_free_dax; 1707 } 1708 1709 fc->dev = sb->s_dev; 1710 fm->sb = sb; 1711 err = fuse_bdi_init(fc, sb); 1712 if (err) 1713 goto err_dev_free; 1714 1715 /* Handle umasking inside the fuse code */ 1716 if (sb->s_flags & SB_POSIXACL) 1717 fc->dont_mask = 1; 1718 sb->s_flags |= SB_POSIXACL; 1719 1720 fc->default_permissions = ctx->default_permissions; 1721 fc->allow_other = ctx->allow_other; 1722 fc->user_id = ctx->user_id; 1723 fc->group_id = ctx->group_id; 1724 fc->legacy_opts_show = ctx->legacy_opts_show; 1725 fc->max_read = max_t(unsigned int, 4096, ctx->max_read); 1726 fc->destroy = ctx->destroy; 1727 fc->no_control = ctx->no_control; 1728 fc->no_force_umount = ctx->no_force_umount; 1729 1730 err = -ENOMEM; 1731 root = fuse_get_root_inode(sb, ctx->rootmode); 1732 sb->s_d_op = &fuse_root_dentry_operations; 1733 root_dentry = d_make_root(root); 1734 if (!root_dentry) 1735 goto err_dev_free; 1736 /* Root dentry doesn't have .d_revalidate */ 1737 sb->s_d_op = &fuse_dentry_operations; 1738 1739 mutex_lock(&fuse_mutex); 1740 err = -EINVAL; 1741 if (ctx->fudptr && *ctx->fudptr) 1742 goto err_unlock; 1743 1744 err = fuse_ctl_add_conn(fc); 1745 if (err) 1746 goto err_unlock; 1747 1748 list_add_tail(&fc->entry, &fuse_conn_list); 1749 sb->s_root = root_dentry; 1750 if (ctx->fudptr) 1751 *ctx->fudptr = fud; 1752 mutex_unlock(&fuse_mutex); 1753 return 0; 1754 1755 err_unlock: 1756 mutex_unlock(&fuse_mutex); 1757 dput(root_dentry); 1758 err_dev_free: 1759 if (fud) 1760 fuse_dev_free(fud); 1761 err_free_dax: 1762 if (IS_ENABLED(CONFIG_FUSE_DAX)) 1763 fuse_dax_conn_free(fc); 1764 err: 1765 return err; 1766 } 1767 EXPORT_SYMBOL_GPL(fuse_fill_super_common); 1768 1769 static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc) 1770 { 1771 struct fuse_fs_context *ctx = fsc->fs_private; 1772 int err; 1773 1774 if (!ctx->file || !ctx->rootmode_present || 1775 !ctx->user_id_present || !ctx->group_id_present) 1776 return -EINVAL; 1777 1778 /* 1779 * Require mount to happen from the same user namespace which 1780 * opened /dev/fuse to prevent potential attacks. 1781 */ 1782 if ((ctx->file->f_op != &fuse_dev_operations) || 1783 (ctx->file->f_cred->user_ns != sb->s_user_ns)) 1784 return -EINVAL; 1785 ctx->fudptr = &ctx->file->private_data; 1786 1787 err = fuse_fill_super_common(sb, ctx); 1788 if (err) 1789 return err; 1790 /* file->private_data shall be visible on all CPUs after this */ 1791 smp_mb(); 1792 fuse_send_init(get_fuse_mount_super(sb)); 1793 return 0; 1794 } 1795 1796 /* 1797 * This is the path where user supplied an already initialized fuse dev. In 1798 * this case never create a new super if the old one is gone. 1799 */ 1800 static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc) 1801 { 1802 return -ENOTCONN; 1803 } 1804 1805 static int fuse_test_super(struct super_block *sb, struct fs_context *fsc) 1806 { 1807 1808 return fsc->sget_key == get_fuse_conn_super(sb); 1809 } 1810 1811 static int fuse_get_tree(struct fs_context *fsc) 1812 { 1813 struct fuse_fs_context *ctx = fsc->fs_private; 1814 struct fuse_dev *fud; 1815 struct fuse_conn *fc; 1816 struct fuse_mount *fm; 1817 struct super_block *sb; 1818 int err; 1819 1820 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 1821 if (!fc) 1822 return -ENOMEM; 1823 1824 fm = kzalloc(sizeof(*fm), GFP_KERNEL); 1825 if (!fm) { 1826 kfree(fc); 1827 return -ENOMEM; 1828 } 1829 1830 fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL); 1831 fc->release = fuse_free_conn; 1832 1833 fsc->s_fs_info = fm; 1834 1835 if (ctx->fd_present) 1836 ctx->file = fget(ctx->fd); 1837 1838 if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) { 1839 err = get_tree_bdev(fsc, fuse_fill_super); 1840 goto out; 1841 } 1842 /* 1843 * While block dev mount can be initialized with a dummy device fd 1844 * (found by device name), normal fuse mounts can't 1845 */ 1846 err = -EINVAL; 1847 if (!ctx->file) 1848 goto out; 1849 1850 /* 1851 * Allow creating a fuse mount with an already initialized fuse 1852 * connection 1853 */ 1854 fud = READ_ONCE(ctx->file->private_data); 1855 if (ctx->file->f_op == &fuse_dev_operations && fud) { 1856 fsc->sget_key = fud->fc; 1857 sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super); 1858 err = PTR_ERR_OR_ZERO(sb); 1859 if (!IS_ERR(sb)) 1860 fsc->root = dget(sb->s_root); 1861 } else { 1862 err = get_tree_nodev(fsc, fuse_fill_super); 1863 } 1864 out: 1865 if (fsc->s_fs_info) 1866 fuse_mount_destroy(fm); 1867 if (ctx->file) 1868 fput(ctx->file); 1869 return err; 1870 } 1871 1872 static const struct fs_context_operations fuse_context_ops = { 1873 .free = fuse_free_fsc, 1874 .parse_param = fuse_parse_param, 1875 .reconfigure = fuse_reconfigure, 1876 .get_tree = fuse_get_tree, 1877 }; 1878 1879 /* 1880 * Set up the filesystem mount context. 1881 */ 1882 static int fuse_init_fs_context(struct fs_context *fsc) 1883 { 1884 struct fuse_fs_context *ctx; 1885 1886 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); 1887 if (!ctx) 1888 return -ENOMEM; 1889 1890 ctx->max_read = ~0; 1891 ctx->blksize = FUSE_DEFAULT_BLKSIZE; 1892 ctx->legacy_opts_show = true; 1893 1894 #ifdef CONFIG_BLOCK 1895 if (fsc->fs_type == &fuseblk_fs_type) { 1896 ctx->is_bdev = true; 1897 ctx->destroy = true; 1898 } 1899 #endif 1900 1901 fsc->fs_private = ctx; 1902 fsc->ops = &fuse_context_ops; 1903 return 0; 1904 } 1905 1906 bool fuse_mount_remove(struct fuse_mount *fm) 1907 { 1908 struct fuse_conn *fc = fm->fc; 1909 bool last = false; 1910 1911 down_write(&fc->killsb); 1912 list_del_init(&fm->fc_entry); 1913 if (list_empty(&fc->mounts)) 1914 last = true; 1915 up_write(&fc->killsb); 1916 1917 return last; 1918 } 1919 EXPORT_SYMBOL_GPL(fuse_mount_remove); 1920 1921 void fuse_conn_destroy(struct fuse_mount *fm) 1922 { 1923 struct fuse_conn *fc = fm->fc; 1924 1925 if (fc->destroy) 1926 fuse_send_destroy(fm); 1927 1928 fuse_abort_conn(fc); 1929 fuse_wait_aborted(fc); 1930 1931 if (!list_empty(&fc->entry)) { 1932 mutex_lock(&fuse_mutex); 1933 list_del(&fc->entry); 1934 fuse_ctl_remove_conn(fc); 1935 mutex_unlock(&fuse_mutex); 1936 } 1937 } 1938 EXPORT_SYMBOL_GPL(fuse_conn_destroy); 1939 1940 static void fuse_sb_destroy(struct super_block *sb) 1941 { 1942 struct fuse_mount *fm = get_fuse_mount_super(sb); 1943 bool last; 1944 1945 if (sb->s_root) { 1946 last = fuse_mount_remove(fm); 1947 if (last) 1948 fuse_conn_destroy(fm); 1949 } 1950 } 1951 1952 void fuse_mount_destroy(struct fuse_mount *fm) 1953 { 1954 fuse_conn_put(fm->fc); 1955 kfree_rcu(fm, rcu); 1956 } 1957 EXPORT_SYMBOL(fuse_mount_destroy); 1958 1959 static void fuse_kill_sb_anon(struct super_block *sb) 1960 { 1961 fuse_sb_destroy(sb); 1962 kill_anon_super(sb); 1963 fuse_mount_destroy(get_fuse_mount_super(sb)); 1964 } 1965 1966 static struct file_system_type fuse_fs_type = { 1967 .owner = THIS_MODULE, 1968 .name = "fuse", 1969 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT, 1970 .init_fs_context = fuse_init_fs_context, 1971 .parameters = fuse_fs_parameters, 1972 .kill_sb = fuse_kill_sb_anon, 1973 }; 1974 MODULE_ALIAS_FS("fuse"); 1975 1976 #ifdef CONFIG_BLOCK 1977 static void fuse_kill_sb_blk(struct super_block *sb) 1978 { 1979 fuse_sb_destroy(sb); 1980 kill_block_super(sb); 1981 fuse_mount_destroy(get_fuse_mount_super(sb)); 1982 } 1983 1984 static struct file_system_type fuseblk_fs_type = { 1985 .owner = THIS_MODULE, 1986 .name = "fuseblk", 1987 .init_fs_context = fuse_init_fs_context, 1988 .parameters = fuse_fs_parameters, 1989 .kill_sb = fuse_kill_sb_blk, 1990 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 1991 }; 1992 MODULE_ALIAS_FS("fuseblk"); 1993 1994 static inline int register_fuseblk(void) 1995 { 1996 return register_filesystem(&fuseblk_fs_type); 1997 } 1998 1999 static inline void unregister_fuseblk(void) 2000 { 2001 unregister_filesystem(&fuseblk_fs_type); 2002 } 2003 #else 2004 static inline int register_fuseblk(void) 2005 { 2006 return 0; 2007 } 2008 2009 static inline void unregister_fuseblk(void) 2010 { 2011 } 2012 #endif 2013 2014 static void fuse_inode_init_once(void *foo) 2015 { 2016 struct inode *inode = foo; 2017 2018 inode_init_once(inode); 2019 } 2020 2021 static int __init fuse_fs_init(void) 2022 { 2023 int err; 2024 2025 fuse_inode_cachep = kmem_cache_create("fuse_inode", 2026 sizeof(struct fuse_inode), 0, 2027 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT, 2028 fuse_inode_init_once); 2029 err = -ENOMEM; 2030 if (!fuse_inode_cachep) 2031 goto out; 2032 2033 err = register_fuseblk(); 2034 if (err) 2035 goto out2; 2036 2037 err = register_filesystem(&fuse_fs_type); 2038 if (err) 2039 goto out3; 2040 2041 return 0; 2042 2043 out3: 2044 unregister_fuseblk(); 2045 out2: 2046 kmem_cache_destroy(fuse_inode_cachep); 2047 out: 2048 return err; 2049 } 2050 2051 static void fuse_fs_cleanup(void) 2052 { 2053 unregister_filesystem(&fuse_fs_type); 2054 unregister_fuseblk(); 2055 2056 /* 2057 * Make sure all delayed rcu free inodes are flushed before we 2058 * destroy cache. 2059 */ 2060 rcu_barrier(); 2061 kmem_cache_destroy(fuse_inode_cachep); 2062 } 2063 2064 static struct kobject *fuse_kobj; 2065 2066 static int fuse_sysfs_init(void) 2067 { 2068 int err; 2069 2070 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 2071 if (!fuse_kobj) { 2072 err = -ENOMEM; 2073 goto out_err; 2074 } 2075 2076 err = sysfs_create_mount_point(fuse_kobj, "connections"); 2077 if (err) 2078 goto out_fuse_unregister; 2079 2080 return 0; 2081 2082 out_fuse_unregister: 2083 kobject_put(fuse_kobj); 2084 out_err: 2085 return err; 2086 } 2087 2088 static void fuse_sysfs_cleanup(void) 2089 { 2090 sysfs_remove_mount_point(fuse_kobj, "connections"); 2091 kobject_put(fuse_kobj); 2092 } 2093 2094 static int __init fuse_init(void) 2095 { 2096 int res; 2097 2098 pr_info("init (API version %i.%i)\n", 2099 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 2100 2101 INIT_LIST_HEAD(&fuse_conn_list); 2102 res = fuse_fs_init(); 2103 if (res) 2104 goto err; 2105 2106 res = fuse_dev_init(); 2107 if (res) 2108 goto err_fs_cleanup; 2109 2110 res = fuse_sysfs_init(); 2111 if (res) 2112 goto err_dev_cleanup; 2113 2114 res = fuse_ctl_init(); 2115 if (res) 2116 goto err_sysfs_cleanup; 2117 2118 sanitize_global_limit(&max_user_bgreq); 2119 sanitize_global_limit(&max_user_congthresh); 2120 2121 return 0; 2122 2123 err_sysfs_cleanup: 2124 fuse_sysfs_cleanup(); 2125 err_dev_cleanup: 2126 fuse_dev_cleanup(); 2127 err_fs_cleanup: 2128 fuse_fs_cleanup(); 2129 err: 2130 return res; 2131 } 2132 2133 static void __exit fuse_exit(void) 2134 { 2135 pr_debug("exit\n"); 2136 2137 fuse_ctl_cleanup(); 2138 fuse_sysfs_cleanup(); 2139 fuse_fs_cleanup(); 2140 fuse_dev_cleanup(); 2141 } 2142 2143 module_init(fuse_init); 2144 module_exit(fuse_exit); 2145