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 28MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); 29MODULE_DESCRIPTION("Filesystem in Userspace"); 30MODULE_LICENSE("GPL"); 31 32static struct kmem_cache *fuse_inode_cachep; 33struct list_head fuse_conn_list; 34DEFINE_MUTEX(fuse_mutex); 35 36static int set_global_limit(const char *val, const struct kernel_param *kp); 37 38unsigned max_user_bgreq; 39module_param_call(max_user_bgreq, set_global_limit, param_get_uint, 40 &max_user_bgreq, 0644); 41__MODULE_PARM_TYPE(max_user_bgreq, "uint"); 42MODULE_PARM_DESC(max_user_bgreq, 43 "Global limit for the maximum number of backgrounded requests an " 44 "unprivileged user can set"); 45 46unsigned max_user_congthresh; 47module_param_call(max_user_congthresh, set_global_limit, param_get_uint, 48 &max_user_congthresh, 0644); 49__MODULE_PARM_TYPE(max_user_congthresh, "uint"); 50MODULE_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 63static struct file_system_type fuseblk_fs_type; 64#endif 65 66struct fuse_forget_link *fuse_alloc_forget(void) 67{ 68 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL_ACCOUNT); 69} 70 71static 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 84out_free: 85 kfree(sl); 86 return NULL; 87} 88 89static 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 116out_free_forget: 117 kfree(fi->forget); 118out_free: 119 kmem_cache_free(fuse_inode_cachep, fi); 120 return NULL; 121} 122 123static 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 135static 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 146static 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 177static 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 */ 192static 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 200void 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->i_atime.tv_sec = attr->atime; 227 inode->i_atime.tv_nsec = attr->atimensec; 228 /* mtime from server may be stale due to local buffered write */ 229 if (!(cache_mask & STATX_MTIME)) { 230 inode->i_mtime.tv_sec = attr->mtime; 231 inode->i_mtime.tv_nsec = attr->mtimensec; 232 } 233 if (!(cache_mask & STATX_CTIME)) { 234 inode_set_ctime(inode, attr->ctime, attr->ctimensec); 235 } 236 if (sx) { 237 /* Sanitize nsecs */ 238 sx->btime.tv_nsec = 239 min_t(u32, sx->btime.tv_nsec, NSEC_PER_SEC - 1); 240 241 /* 242 * Btime has been queried, cache is valid (whether or not btime 243 * is available or not) so clear STATX_BTIME from inval_mask. 244 * 245 * Availability of the btime attribute is indicated in 246 * FUSE_I_BTIME 247 */ 248 set_mask_bits(&fi->inval_mask, STATX_BTIME, 0); 249 if (sx->mask & STATX_BTIME) { 250 set_bit(FUSE_I_BTIME, &fi->state); 251 fi->i_btime.tv_sec = sx->btime.tv_sec; 252 fi->i_btime.tv_nsec = sx->btime.tv_nsec; 253 } 254 } 255 256 if (attr->blksize != 0) 257 inode->i_blkbits = ilog2(attr->blksize); 258 else 259 inode->i_blkbits = inode->i_sb->s_blocksize_bits; 260 261 /* 262 * Don't set the sticky bit in i_mode, unless we want the VFS 263 * to check permissions. This prevents failures due to the 264 * check in may_delete(). 265 */ 266 fi->orig_i_mode = inode->i_mode; 267 if (!fc->default_permissions) 268 inode->i_mode &= ~S_ISVTX; 269 270 fi->orig_ino = attr->ino; 271 272 /* 273 * We are refreshing inode data and it is possible that another 274 * client set suid/sgid or security.capability xattr. So clear 275 * S_NOSEC. Ideally, we could have cleared it only if suid/sgid 276 * was set or if security.capability xattr was set. But we don't 277 * know if security.capability has been set or not. So clear it 278 * anyway. Its less efficient but should be safe. 279 */ 280 inode->i_flags &= ~S_NOSEC; 281} 282 283u32 fuse_get_cache_mask(struct inode *inode) 284{ 285 struct fuse_conn *fc = get_fuse_conn(inode); 286 287 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) 288 return 0; 289 290 return STATX_MTIME | STATX_CTIME | STATX_SIZE; 291} 292 293void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, 294 struct fuse_statx *sx, 295 u64 attr_valid, u64 attr_version) 296{ 297 struct fuse_conn *fc = get_fuse_conn(inode); 298 struct fuse_inode *fi = get_fuse_inode(inode); 299 u32 cache_mask; 300 loff_t oldsize; 301 struct timespec64 old_mtime; 302 303 spin_lock(&fi->lock); 304 /* 305 * In case of writeback_cache enabled, writes update mtime, ctime and 306 * may update i_size. In these cases trust the cached value in the 307 * inode. 308 */ 309 cache_mask = fuse_get_cache_mask(inode); 310 if (cache_mask & STATX_SIZE) 311 attr->size = i_size_read(inode); 312 313 if (cache_mask & STATX_MTIME) { 314 attr->mtime = inode->i_mtime.tv_sec; 315 attr->mtimensec = inode->i_mtime.tv_nsec; 316 } 317 if (cache_mask & STATX_CTIME) { 318 attr->ctime = inode_get_ctime(inode).tv_sec; 319 attr->ctimensec = inode_get_ctime(inode).tv_nsec; 320 } 321 322 if ((attr_version != 0 && fi->attr_version > attr_version) || 323 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { 324 spin_unlock(&fi->lock); 325 return; 326 } 327 328 old_mtime = inode->i_mtime; 329 fuse_change_attributes_common(inode, attr, sx, attr_valid, cache_mask); 330 331 oldsize = inode->i_size; 332 /* 333 * In case of writeback_cache enabled, the cached writes beyond EOF 334 * extend local i_size without keeping userspace server in sync. So, 335 * attr->size coming from server can be stale. We cannot trust it. 336 */ 337 if (!(cache_mask & STATX_SIZE)) 338 i_size_write(inode, attr->size); 339 spin_unlock(&fi->lock); 340 341 if (!cache_mask && S_ISREG(inode->i_mode)) { 342 bool inval = false; 343 344 if (oldsize != attr->size) { 345 truncate_pagecache(inode, attr->size); 346 if (!fc->explicit_inval_data) 347 inval = true; 348 } else if (fc->auto_inval_data) { 349 struct timespec64 new_mtime = { 350 .tv_sec = attr->mtime, 351 .tv_nsec = attr->mtimensec, 352 }; 353 354 /* 355 * Auto inval mode also checks and invalidates if mtime 356 * has changed. 357 */ 358 if (!timespec64_equal(&old_mtime, &new_mtime)) 359 inval = true; 360 } 361 362 if (inval) 363 invalidate_inode_pages2(inode->i_mapping); 364 } 365 366 if (IS_ENABLED(CONFIG_FUSE_DAX)) 367 fuse_dax_dontcache(inode, attr->flags); 368} 369 370static void fuse_init_submount_lookup(struct fuse_submount_lookup *sl, 371 u64 nodeid) 372{ 373 sl->nodeid = nodeid; 374 refcount_set(&sl->count, 1); 375} 376 377static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr, 378 struct fuse_conn *fc) 379{ 380 inode->i_mode = attr->mode & S_IFMT; 381 inode->i_size = attr->size; 382 inode->i_mtime.tv_sec = attr->mtime; 383 inode->i_mtime.tv_nsec = attr->mtimensec; 384 inode_set_ctime(inode, attr->ctime, attr->ctimensec); 385 if (S_ISREG(inode->i_mode)) { 386 fuse_init_common(inode); 387 fuse_init_file_inode(inode, attr->flags); 388 } else if (S_ISDIR(inode->i_mode)) 389 fuse_init_dir(inode); 390 else if (S_ISLNK(inode->i_mode)) 391 fuse_init_symlink(inode); 392 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || 393 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { 394 fuse_init_common(inode); 395 init_special_inode(inode, inode->i_mode, 396 new_decode_dev(attr->rdev)); 397 } else 398 BUG(); 399 /* 400 * Ensure that we don't cache acls for daemons without FUSE_POSIX_ACL 401 * so they see the exact same behavior as before. 402 */ 403 if (!fc->posix_acl) 404 inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE; 405} 406 407static int fuse_inode_eq(struct inode *inode, void *_nodeidp) 408{ 409 u64 nodeid = *(u64 *) _nodeidp; 410 if (get_node_id(inode) == nodeid) 411 return 1; 412 else 413 return 0; 414} 415 416static int fuse_inode_set(struct inode *inode, void *_nodeidp) 417{ 418 u64 nodeid = *(u64 *) _nodeidp; 419 get_fuse_inode(inode)->nodeid = nodeid; 420 return 0; 421} 422 423struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 424 int generation, struct fuse_attr *attr, 425 u64 attr_valid, u64 attr_version) 426{ 427 struct inode *inode; 428 struct fuse_inode *fi; 429 struct fuse_conn *fc = get_fuse_conn_super(sb); 430 431 /* 432 * Auto mount points get their node id from the submount root, which is 433 * not a unique identifier within this filesystem. 434 * 435 * To avoid conflicts, do not place submount points into the inode hash 436 * table. 437 */ 438 if (fc->auto_submounts && (attr->flags & FUSE_ATTR_SUBMOUNT) && 439 S_ISDIR(attr->mode)) { 440 struct fuse_inode *fi; 441 442 inode = new_inode(sb); 443 if (!inode) 444 return NULL; 445 446 fuse_init_inode(inode, attr, fc); 447 fi = get_fuse_inode(inode); 448 fi->nodeid = nodeid; 449 fi->submount_lookup = fuse_alloc_submount_lookup(); 450 if (!fi->submount_lookup) { 451 iput(inode); 452 return NULL; 453 } 454 /* Sets nlookup = 1 on fi->submount_lookup->nlookup */ 455 fuse_init_submount_lookup(fi->submount_lookup, nodeid); 456 inode->i_flags |= S_AUTOMOUNT; 457 goto done; 458 } 459 460retry: 461 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); 462 if (!inode) 463 return NULL; 464 465 if ((inode->i_state & I_NEW)) { 466 inode->i_flags |= S_NOATIME; 467 if (!fc->writeback_cache || !S_ISREG(attr->mode)) 468 inode->i_flags |= S_NOCMTIME; 469 inode->i_generation = generation; 470 fuse_init_inode(inode, attr, fc); 471 unlock_new_inode(inode); 472 } else if (fuse_stale_inode(inode, generation, attr)) { 473 /* nodeid was reused, any I/O on the old inode should fail */ 474 fuse_make_bad(inode); 475 if (inode != d_inode(sb->s_root)) { 476 remove_inode_hash(inode); 477 iput(inode); 478 goto retry; 479 } 480 } 481 fi = get_fuse_inode(inode); 482 spin_lock(&fi->lock); 483 fi->nlookup++; 484 spin_unlock(&fi->lock); 485done: 486 fuse_change_attributes(inode, attr, NULL, attr_valid, attr_version); 487 488 return inode; 489} 490 491struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid, 492 struct fuse_mount **fm) 493{ 494 struct fuse_mount *fm_iter; 495 struct inode *inode; 496 497 WARN_ON(!rwsem_is_locked(&fc->killsb)); 498 list_for_each_entry(fm_iter, &fc->mounts, fc_entry) { 499 if (!fm_iter->sb) 500 continue; 501 502 inode = ilookup5(fm_iter->sb, nodeid, fuse_inode_eq, &nodeid); 503 if (inode) { 504 if (fm) 505 *fm = fm_iter; 506 return inode; 507 } 508 } 509 510 return NULL; 511} 512 513int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid, 514 loff_t offset, loff_t len) 515{ 516 struct fuse_inode *fi; 517 struct inode *inode; 518 pgoff_t pg_start; 519 pgoff_t pg_end; 520 521 inode = fuse_ilookup(fc, nodeid, NULL); 522 if (!inode) 523 return -ENOENT; 524 525 fi = get_fuse_inode(inode); 526 spin_lock(&fi->lock); 527 fi->attr_version = atomic64_inc_return(&fc->attr_version); 528 spin_unlock(&fi->lock); 529 530 fuse_invalidate_attr(inode); 531 forget_all_cached_acls(inode); 532 if (offset >= 0) { 533 pg_start = offset >> PAGE_SHIFT; 534 if (len <= 0) 535 pg_end = -1; 536 else 537 pg_end = (offset + len - 1) >> PAGE_SHIFT; 538 invalidate_inode_pages2_range(inode->i_mapping, 539 pg_start, pg_end); 540 } 541 iput(inode); 542 return 0; 543} 544 545bool fuse_lock_inode(struct inode *inode) 546{ 547 bool locked = false; 548 549 if (!get_fuse_conn(inode)->parallel_dirops) { 550 mutex_lock(&get_fuse_inode(inode)->mutex); 551 locked = true; 552 } 553 554 return locked; 555} 556 557void fuse_unlock_inode(struct inode *inode, bool locked) 558{ 559 if (locked) 560 mutex_unlock(&get_fuse_inode(inode)->mutex); 561} 562 563static void fuse_umount_begin(struct super_block *sb) 564{ 565 struct fuse_conn *fc = get_fuse_conn_super(sb); 566 567 if (fc->no_force_umount) 568 return; 569 570 fuse_abort_conn(fc); 571 572 // Only retire block-device-based superblocks. 573 if (sb->s_bdev != NULL) 574 retire_super(sb); 575} 576 577static void fuse_send_destroy(struct fuse_mount *fm) 578{ 579 if (fm->fc->conn_init) { 580 FUSE_ARGS(args); 581 582 args.opcode = FUSE_DESTROY; 583 args.force = true; 584 args.nocreds = true; 585 fuse_simple_request(fm, &args); 586 } 587} 588 589static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 590{ 591 stbuf->f_type = FUSE_SUPER_MAGIC; 592 stbuf->f_bsize = attr->bsize; 593 stbuf->f_frsize = attr->frsize; 594 stbuf->f_blocks = attr->blocks; 595 stbuf->f_bfree = attr->bfree; 596 stbuf->f_bavail = attr->bavail; 597 stbuf->f_files = attr->files; 598 stbuf->f_ffree = attr->ffree; 599 stbuf->f_namelen = attr->namelen; 600 /* fsid is left zero */ 601} 602 603static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 604{ 605 struct super_block *sb = dentry->d_sb; 606 struct fuse_mount *fm = get_fuse_mount_super(sb); 607 FUSE_ARGS(args); 608 struct fuse_statfs_out outarg; 609 int err; 610 611 if (!fuse_allow_current_process(fm->fc)) { 612 buf->f_type = FUSE_SUPER_MAGIC; 613 return 0; 614 } 615 616 memset(&outarg, 0, sizeof(outarg)); 617 args.in_numargs = 0; 618 args.opcode = FUSE_STATFS; 619 args.nodeid = get_node_id(d_inode(dentry)); 620 args.out_numargs = 1; 621 args.out_args[0].size = sizeof(outarg); 622 args.out_args[0].value = &outarg; 623 err = fuse_simple_request(fm, &args); 624 if (!err) 625 convert_fuse_statfs(buf, &outarg.st); 626 return err; 627} 628 629static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void) 630{ 631 struct fuse_sync_bucket *bucket; 632 633 bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL); 634 if (bucket) { 635 init_waitqueue_head(&bucket->waitq); 636 /* Initial active count */ 637 atomic_set(&bucket->count, 1); 638 } 639 return bucket; 640} 641 642static void fuse_sync_fs_writes(struct fuse_conn *fc) 643{ 644 struct fuse_sync_bucket *bucket, *new_bucket; 645 int count; 646 647 new_bucket = fuse_sync_bucket_alloc(); 648 spin_lock(&fc->lock); 649 bucket = rcu_dereference_protected(fc->curr_bucket, 1); 650 count = atomic_read(&bucket->count); 651 WARN_ON(count < 1); 652 /* No outstanding writes? */ 653 if (count == 1) { 654 spin_unlock(&fc->lock); 655 kfree(new_bucket); 656 return; 657 } 658 659 /* 660 * Completion of new bucket depends on completion of this bucket, so add 661 * one more count. 662 */ 663 atomic_inc(&new_bucket->count); 664 rcu_assign_pointer(fc->curr_bucket, new_bucket); 665 spin_unlock(&fc->lock); 666 /* 667 * Drop initial active count. At this point if all writes in this and 668 * ancestor buckets complete, the count will go to zero and this task 669 * will be woken up. 670 */ 671 atomic_dec(&bucket->count); 672 673 wait_event(bucket->waitq, atomic_read(&bucket->count) == 0); 674 675 /* Drop temp count on descendant bucket */ 676 fuse_sync_bucket_dec(new_bucket); 677 kfree_rcu(bucket, rcu); 678} 679 680static int fuse_sync_fs(struct super_block *sb, int wait) 681{ 682 struct fuse_mount *fm = get_fuse_mount_super(sb); 683 struct fuse_conn *fc = fm->fc; 684 struct fuse_syncfs_in inarg; 685 FUSE_ARGS(args); 686 int err; 687 688 /* 689 * Userspace cannot handle the wait == 0 case. Avoid a 690 * gratuitous roundtrip. 691 */ 692 if (!wait) 693 return 0; 694 695 /* The filesystem is being unmounted. Nothing to do. */ 696 if (!sb->s_root) 697 return 0; 698 699 if (!fc->sync_fs) 700 return 0; 701 702 fuse_sync_fs_writes(fc); 703 704 memset(&inarg, 0, sizeof(inarg)); 705 args.in_numargs = 1; 706 args.in_args[0].size = sizeof(inarg); 707 args.in_args[0].value = &inarg; 708 args.opcode = FUSE_SYNCFS; 709 args.nodeid = get_node_id(sb->s_root->d_inode); 710 args.out_numargs = 0; 711 712 err = fuse_simple_request(fm, &args); 713 if (err == -ENOSYS) { 714 fc->sync_fs = 0; 715 err = 0; 716 } 717 718 return err; 719} 720 721enum { 722 OPT_SOURCE, 723 OPT_SUBTYPE, 724 OPT_FD, 725 OPT_ROOTMODE, 726 OPT_USER_ID, 727 OPT_GROUP_ID, 728 OPT_DEFAULT_PERMISSIONS, 729 OPT_ALLOW_OTHER, 730 OPT_MAX_READ, 731 OPT_BLKSIZE, 732 OPT_ERR 733}; 734 735static const struct fs_parameter_spec fuse_fs_parameters[] = { 736 fsparam_string ("source", OPT_SOURCE), 737 fsparam_u32 ("fd", OPT_FD), 738 fsparam_u32oct ("rootmode", OPT_ROOTMODE), 739 fsparam_u32 ("user_id", OPT_USER_ID), 740 fsparam_u32 ("group_id", OPT_GROUP_ID), 741 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS), 742 fsparam_flag ("allow_other", OPT_ALLOW_OTHER), 743 fsparam_u32 ("max_read", OPT_MAX_READ), 744 fsparam_u32 ("blksize", OPT_BLKSIZE), 745 fsparam_string ("subtype", OPT_SUBTYPE), 746 {} 747}; 748 749static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param) 750{ 751 struct fs_parse_result result; 752 struct fuse_fs_context *ctx = fsc->fs_private; 753 int opt; 754 755 if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { 756 /* 757 * Ignore options coming from mount(MS_REMOUNT) for backward 758 * compatibility. 759 */ 760 if (fsc->oldapi) 761 return 0; 762 763 return invalfc(fsc, "No changes allowed in reconfigure"); 764 } 765 766 opt = fs_parse(fsc, fuse_fs_parameters, param, &result); 767 if (opt < 0) 768 return opt; 769 770 switch (opt) { 771 case OPT_SOURCE: 772 if (fsc->source) 773 return invalfc(fsc, "Multiple sources specified"); 774 fsc->source = param->string; 775 param->string = NULL; 776 break; 777 778 case OPT_SUBTYPE: 779 if (ctx->subtype) 780 return invalfc(fsc, "Multiple subtypes specified"); 781 ctx->subtype = param->string; 782 param->string = NULL; 783 return 0; 784 785 case OPT_FD: 786 ctx->fd = result.uint_32; 787 ctx->fd_present = true; 788 break; 789 790 case OPT_ROOTMODE: 791 if (!fuse_valid_type(result.uint_32)) 792 return invalfc(fsc, "Invalid rootmode"); 793 ctx->rootmode = result.uint_32; 794 ctx->rootmode_present = true; 795 break; 796 797 case OPT_USER_ID: 798 ctx->user_id = make_kuid(fsc->user_ns, result.uint_32); 799 if (!uid_valid(ctx->user_id)) 800 return invalfc(fsc, "Invalid user_id"); 801 ctx->user_id_present = true; 802 break; 803 804 case OPT_GROUP_ID: 805 ctx->group_id = make_kgid(fsc->user_ns, result.uint_32); 806 if (!gid_valid(ctx->group_id)) 807 return invalfc(fsc, "Invalid group_id"); 808 ctx->group_id_present = true; 809 break; 810 811 case OPT_DEFAULT_PERMISSIONS: 812 ctx->default_permissions = true; 813 break; 814 815 case OPT_ALLOW_OTHER: 816 ctx->allow_other = true; 817 break; 818 819 case OPT_MAX_READ: 820 ctx->max_read = result.uint_32; 821 break; 822 823 case OPT_BLKSIZE: 824 if (!ctx->is_bdev) 825 return invalfc(fsc, "blksize only supported for fuseblk"); 826 ctx->blksize = result.uint_32; 827 break; 828 829 default: 830 return -EINVAL; 831 } 832 833 return 0; 834} 835 836static void fuse_free_fsc(struct fs_context *fsc) 837{ 838 struct fuse_fs_context *ctx = fsc->fs_private; 839 840 if (ctx) { 841 kfree(ctx->subtype); 842 kfree(ctx); 843 } 844} 845 846static int fuse_show_options(struct seq_file *m, struct dentry *root) 847{ 848 struct super_block *sb = root->d_sb; 849 struct fuse_conn *fc = get_fuse_conn_super(sb); 850 851 if (fc->legacy_opts_show) { 852 seq_printf(m, ",user_id=%u", 853 from_kuid_munged(fc->user_ns, fc->user_id)); 854 seq_printf(m, ",group_id=%u", 855 from_kgid_munged(fc->user_ns, fc->group_id)); 856 if (fc->default_permissions) 857 seq_puts(m, ",default_permissions"); 858 if (fc->allow_other) 859 seq_puts(m, ",allow_other"); 860 if (fc->max_read != ~0) 861 seq_printf(m, ",max_read=%u", fc->max_read); 862 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 863 seq_printf(m, ",blksize=%lu", sb->s_blocksize); 864 } 865#ifdef CONFIG_FUSE_DAX 866 if (fc->dax_mode == FUSE_DAX_ALWAYS) 867 seq_puts(m, ",dax=always"); 868 else if (fc->dax_mode == FUSE_DAX_NEVER) 869 seq_puts(m, ",dax=never"); 870 else if (fc->dax_mode == FUSE_DAX_INODE_USER) 871 seq_puts(m, ",dax=inode"); 872#endif 873 874 return 0; 875} 876 877static void fuse_iqueue_init(struct fuse_iqueue *fiq, 878 const struct fuse_iqueue_ops *ops, 879 void *priv) 880{ 881 memset(fiq, 0, sizeof(struct fuse_iqueue)); 882 spin_lock_init(&fiq->lock); 883 init_waitqueue_head(&fiq->waitq); 884 INIT_LIST_HEAD(&fiq->pending); 885 INIT_LIST_HEAD(&fiq->interrupts); 886 fiq->forget_list_tail = &fiq->forget_list_head; 887 fiq->connected = 1; 888 fiq->ops = ops; 889 fiq->priv = priv; 890} 891 892static void fuse_pqueue_init(struct fuse_pqueue *fpq) 893{ 894 unsigned int i; 895 896 spin_lock_init(&fpq->lock); 897 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) 898 INIT_LIST_HEAD(&fpq->processing[i]); 899 INIT_LIST_HEAD(&fpq->io); 900 fpq->connected = 1; 901} 902 903void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm, 904 struct user_namespace *user_ns, 905 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv) 906{ 907 memset(fc, 0, sizeof(*fc)); 908 spin_lock_init(&fc->lock); 909 spin_lock_init(&fc->bg_lock); 910 init_rwsem(&fc->killsb); 911 refcount_set(&fc->count, 1); 912 atomic_set(&fc->dev_count, 1); 913 init_waitqueue_head(&fc->blocked_waitq); 914 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv); 915 INIT_LIST_HEAD(&fc->bg_queue); 916 INIT_LIST_HEAD(&fc->entry); 917 INIT_LIST_HEAD(&fc->devices); 918 atomic_set(&fc->num_waiting, 0); 919 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND; 920 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD; 921 atomic64_set(&fc->khctr, 0); 922 fc->polled_files = RB_ROOT; 923 fc->blocked = 0; 924 fc->initialized = 0; 925 fc->connected = 1; 926 atomic64_set(&fc->attr_version, 1); 927 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 928 fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); 929 fc->user_ns = get_user_ns(user_ns); 930 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ; 931 fc->max_pages_limit = FUSE_MAX_MAX_PAGES; 932 933 INIT_LIST_HEAD(&fc->mounts); 934 list_add(&fm->fc_entry, &fc->mounts); 935 fm->fc = fc; 936} 937EXPORT_SYMBOL_GPL(fuse_conn_init); 938 939void fuse_conn_put(struct fuse_conn *fc) 940{ 941 if (refcount_dec_and_test(&fc->count)) { 942 struct fuse_iqueue *fiq = &fc->iq; 943 struct fuse_sync_bucket *bucket; 944 945 if (IS_ENABLED(CONFIG_FUSE_DAX)) 946 fuse_dax_conn_free(fc); 947 if (fiq->ops->release) 948 fiq->ops->release(fiq); 949 put_pid_ns(fc->pid_ns); 950 put_user_ns(fc->user_ns); 951 bucket = rcu_dereference_protected(fc->curr_bucket, 1); 952 if (bucket) { 953 WARN_ON(atomic_read(&bucket->count) != 1); 954 kfree(bucket); 955 } 956 fc->release(fc); 957 } 958} 959EXPORT_SYMBOL_GPL(fuse_conn_put); 960 961struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 962{ 963 refcount_inc(&fc->count); 964 return fc; 965} 966EXPORT_SYMBOL_GPL(fuse_conn_get); 967 968static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 969{ 970 struct fuse_attr attr; 971 memset(&attr, 0, sizeof(attr)); 972 973 attr.mode = mode; 974 attr.ino = FUSE_ROOT_ID; 975 attr.nlink = 1; 976 return fuse_iget(sb, 1, 0, &attr, 0, 0); 977} 978 979struct fuse_inode_handle { 980 u64 nodeid; 981 u32 generation; 982}; 983 984static struct dentry *fuse_get_dentry(struct super_block *sb, 985 struct fuse_inode_handle *handle) 986{ 987 struct fuse_conn *fc = get_fuse_conn_super(sb); 988 struct inode *inode; 989 struct dentry *entry; 990 int err = -ESTALE; 991 992 if (handle->nodeid == 0) 993 goto out_err; 994 995 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 996 if (!inode) { 997 struct fuse_entry_out outarg; 998 const struct qstr name = QSTR_INIT(".", 1); 999 1000 if (!fc->export_support) 1001 goto out_err; 1002 1003 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 1004 &inode); 1005 if (err && err != -ENOENT) 1006 goto out_err; 1007 if (err || !inode) { 1008 err = -ESTALE; 1009 goto out_err; 1010 } 1011 err = -EIO; 1012 if (get_node_id(inode) != handle->nodeid) 1013 goto out_iput; 1014 } 1015 err = -ESTALE; 1016 if (inode->i_generation != handle->generation) 1017 goto out_iput; 1018 1019 entry = d_obtain_alias(inode); 1020 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) 1021 fuse_invalidate_entry_cache(entry); 1022 1023 return entry; 1024 1025 out_iput: 1026 iput(inode); 1027 out_err: 1028 return ERR_PTR(err); 1029} 1030 1031static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len, 1032 struct inode *parent) 1033{ 1034 int len = parent ? 6 : 3; 1035 u64 nodeid; 1036 u32 generation; 1037 1038 if (*max_len < len) { 1039 *max_len = len; 1040 return FILEID_INVALID; 1041 } 1042 1043 nodeid = get_fuse_inode(inode)->nodeid; 1044 generation = inode->i_generation; 1045 1046 fh[0] = (u32)(nodeid >> 32); 1047 fh[1] = (u32)(nodeid & 0xffffffff); 1048 fh[2] = generation; 1049 1050 if (parent) { 1051 nodeid = get_fuse_inode(parent)->nodeid; 1052 generation = parent->i_generation; 1053 1054 fh[3] = (u32)(nodeid >> 32); 1055 fh[4] = (u32)(nodeid & 0xffffffff); 1056 fh[5] = generation; 1057 } 1058 1059 *max_len = len; 1060 return parent ? 0x82 : 0x81; 1061} 1062 1063static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 1064 struct fid *fid, int fh_len, int fh_type) 1065{ 1066 struct fuse_inode_handle handle; 1067 1068 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) 1069 return NULL; 1070 1071 handle.nodeid = (u64) fid->raw[0] << 32; 1072 handle.nodeid |= (u64) fid->raw[1]; 1073 handle.generation = fid->raw[2]; 1074 return fuse_get_dentry(sb, &handle); 1075} 1076 1077static struct dentry *fuse_fh_to_parent(struct super_block *sb, 1078 struct fid *fid, int fh_len, int fh_type) 1079{ 1080 struct fuse_inode_handle parent; 1081 1082 if (fh_type != 0x82 || fh_len < 6) 1083 return NULL; 1084 1085 parent.nodeid = (u64) fid->raw[3] << 32; 1086 parent.nodeid |= (u64) fid->raw[4]; 1087 parent.generation = fid->raw[5]; 1088 return fuse_get_dentry(sb, &parent); 1089} 1090 1091static struct dentry *fuse_get_parent(struct dentry *child) 1092{ 1093 struct inode *child_inode = d_inode(child); 1094 struct fuse_conn *fc = get_fuse_conn(child_inode); 1095 struct inode *inode; 1096 struct dentry *parent; 1097 struct fuse_entry_out outarg; 1098 int err; 1099 1100 if (!fc->export_support) 1101 return ERR_PTR(-ESTALE); 1102 1103 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 1104 &dotdot_name, &outarg, &inode); 1105 if (err) { 1106 if (err == -ENOENT) 1107 return ERR_PTR(-ESTALE); 1108 return ERR_PTR(err); 1109 } 1110 1111 parent = d_obtain_alias(inode); 1112 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) 1113 fuse_invalidate_entry_cache(parent); 1114 1115 return parent; 1116} 1117 1118static const struct export_operations fuse_export_operations = { 1119 .fh_to_dentry = fuse_fh_to_dentry, 1120 .fh_to_parent = fuse_fh_to_parent, 1121 .encode_fh = fuse_encode_fh, 1122 .get_parent = fuse_get_parent, 1123}; 1124 1125static const struct super_operations fuse_super_operations = { 1126 .alloc_inode = fuse_alloc_inode, 1127 .free_inode = fuse_free_inode, 1128 .evict_inode = fuse_evict_inode, 1129 .write_inode = fuse_write_inode, 1130 .drop_inode = generic_delete_inode, 1131 .umount_begin = fuse_umount_begin, 1132 .statfs = fuse_statfs, 1133 .sync_fs = fuse_sync_fs, 1134 .show_options = fuse_show_options, 1135}; 1136 1137static void sanitize_global_limit(unsigned *limit) 1138{ 1139 /* 1140 * The default maximum number of async requests is calculated to consume 1141 * 1/2^13 of the total memory, assuming 392 bytes per request. 1142 */ 1143 if (*limit == 0) 1144 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392; 1145 1146 if (*limit >= 1 << 16) 1147 *limit = (1 << 16) - 1; 1148} 1149 1150static int set_global_limit(const char *val, const struct kernel_param *kp) 1151{ 1152 int rv; 1153 1154 rv = param_set_uint(val, kp); 1155 if (rv) 1156 return rv; 1157 1158 sanitize_global_limit((unsigned *)kp->arg); 1159 1160 return 0; 1161} 1162 1163static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg) 1164{ 1165 int cap_sys_admin = capable(CAP_SYS_ADMIN); 1166 1167 if (arg->minor < 13) 1168 return; 1169 1170 sanitize_global_limit(&max_user_bgreq); 1171 sanitize_global_limit(&max_user_congthresh); 1172 1173 spin_lock(&fc->bg_lock); 1174 if (arg->max_background) { 1175 fc->max_background = arg->max_background; 1176 1177 if (!cap_sys_admin && fc->max_background > max_user_bgreq) 1178 fc->max_background = max_user_bgreq; 1179 } 1180 if (arg->congestion_threshold) { 1181 fc->congestion_threshold = arg->congestion_threshold; 1182 1183 if (!cap_sys_admin && 1184 fc->congestion_threshold > max_user_congthresh) 1185 fc->congestion_threshold = max_user_congthresh; 1186 } 1187 spin_unlock(&fc->bg_lock); 1188} 1189 1190struct fuse_init_args { 1191 struct fuse_args args; 1192 struct fuse_init_in in; 1193 struct fuse_init_out out; 1194}; 1195 1196static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, 1197 int error) 1198{ 1199 struct fuse_conn *fc = fm->fc; 1200 struct fuse_init_args *ia = container_of(args, typeof(*ia), args); 1201 struct fuse_init_out *arg = &ia->out; 1202 bool ok = true; 1203 1204 if (error || arg->major != FUSE_KERNEL_VERSION) 1205 ok = false; 1206 else { 1207 unsigned long ra_pages; 1208 1209 process_init_limits(fc, arg); 1210 1211 if (arg->minor >= 6) { 1212 u64 flags = arg->flags; 1213 1214 if (flags & FUSE_INIT_EXT) 1215 flags |= (u64) arg->flags2 << 32; 1216 1217 ra_pages = arg->max_readahead / PAGE_SIZE; 1218 if (flags & FUSE_ASYNC_READ) 1219 fc->async_read = 1; 1220 if (!(flags & FUSE_POSIX_LOCKS)) 1221 fc->no_lock = 1; 1222 if (arg->minor >= 17) { 1223 if (!(flags & FUSE_FLOCK_LOCKS)) 1224 fc->no_flock = 1; 1225 } else { 1226 if (!(flags & FUSE_POSIX_LOCKS)) 1227 fc->no_flock = 1; 1228 } 1229 if (flags & FUSE_ATOMIC_O_TRUNC) 1230 fc->atomic_o_trunc = 1; 1231 if (arg->minor >= 9) { 1232 /* LOOKUP has dependency on proto version */ 1233 if (flags & FUSE_EXPORT_SUPPORT) 1234 fc->export_support = 1; 1235 } 1236 if (flags & FUSE_BIG_WRITES) 1237 fc->big_writes = 1; 1238 if (flags & FUSE_DONT_MASK) 1239 fc->dont_mask = 1; 1240 if (flags & FUSE_AUTO_INVAL_DATA) 1241 fc->auto_inval_data = 1; 1242 else if (flags & FUSE_EXPLICIT_INVAL_DATA) 1243 fc->explicit_inval_data = 1; 1244 if (flags & FUSE_DO_READDIRPLUS) { 1245 fc->do_readdirplus = 1; 1246 if (flags & FUSE_READDIRPLUS_AUTO) 1247 fc->readdirplus_auto = 1; 1248 } 1249 if (flags & FUSE_ASYNC_DIO) 1250 fc->async_dio = 1; 1251 if (flags & FUSE_WRITEBACK_CACHE) 1252 fc->writeback_cache = 1; 1253 if (flags & FUSE_PARALLEL_DIROPS) 1254 fc->parallel_dirops = 1; 1255 if (flags & FUSE_HANDLE_KILLPRIV) 1256 fc->handle_killpriv = 1; 1257 if (arg->time_gran && arg->time_gran <= 1000000000) 1258 fm->sb->s_time_gran = arg->time_gran; 1259 if ((flags & FUSE_POSIX_ACL)) { 1260 fc->default_permissions = 1; 1261 fc->posix_acl = 1; 1262 } 1263 if (flags & FUSE_CACHE_SYMLINKS) 1264 fc->cache_symlinks = 1; 1265 if (flags & FUSE_ABORT_ERROR) 1266 fc->abort_err = 1; 1267 if (flags & FUSE_MAX_PAGES) { 1268 fc->max_pages = 1269 min_t(unsigned int, fc->max_pages_limit, 1270 max_t(unsigned int, arg->max_pages, 1)); 1271 } 1272 if (IS_ENABLED(CONFIG_FUSE_DAX)) { 1273 if (flags & FUSE_MAP_ALIGNMENT && 1274 !fuse_dax_check_alignment(fc, arg->map_alignment)) { 1275 ok = false; 1276 } 1277 if (flags & FUSE_HAS_INODE_DAX) 1278 fc->inode_dax = 1; 1279 } 1280 if (flags & FUSE_HANDLE_KILLPRIV_V2) { 1281 fc->handle_killpriv_v2 = 1; 1282 fm->sb->s_flags |= SB_NOSEC; 1283 } 1284 if (flags & FUSE_SETXATTR_EXT) 1285 fc->setxattr_ext = 1; 1286 if (flags & FUSE_SECURITY_CTX) 1287 fc->init_security = 1; 1288 if (flags & FUSE_CREATE_SUPP_GROUP) 1289 fc->create_supp_group = 1; 1290 if (flags & FUSE_DIRECT_IO_ALLOW_MMAP) 1291 fc->direct_io_allow_mmap = 1; 1292 } else { 1293 ra_pages = fc->max_read / PAGE_SIZE; 1294 fc->no_lock = 1; 1295 fc->no_flock = 1; 1296 } 1297 1298 fm->sb->s_bdi->ra_pages = 1299 min(fm->sb->s_bdi->ra_pages, ra_pages); 1300 fc->minor = arg->minor; 1301 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 1302 fc->max_write = max_t(unsigned, 4096, fc->max_write); 1303 fc->conn_init = 1; 1304 } 1305 kfree(ia); 1306 1307 if (!ok) { 1308 fc->conn_init = 0; 1309 fc->conn_error = 1; 1310 } 1311 1312 fuse_set_initialized(fc); 1313 wake_up_all(&fc->blocked_waitq); 1314} 1315 1316void fuse_send_init(struct fuse_mount *fm) 1317{ 1318 struct fuse_init_args *ia; 1319 u64 flags; 1320 1321 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL); 1322 1323 ia->in.major = FUSE_KERNEL_VERSION; 1324 ia->in.minor = FUSE_KERNEL_MINOR_VERSION; 1325 ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE; 1326 flags = 1327 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 1328 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | 1329 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | 1330 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | 1331 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO | 1332 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT | 1333 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL | 1334 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | 1335 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA | 1336 FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT | 1337 FUSE_SECURITY_CTX | FUSE_CREATE_SUPP_GROUP | 1338 FUSE_HAS_EXPIRE_ONLY | FUSE_DIRECT_IO_ALLOW_MMAP; 1339#ifdef CONFIG_FUSE_DAX 1340 if (fm->fc->dax) 1341 flags |= FUSE_MAP_ALIGNMENT; 1342 if (fuse_is_inode_dax_mode(fm->fc->dax_mode)) 1343 flags |= FUSE_HAS_INODE_DAX; 1344#endif 1345 if (fm->fc->auto_submounts) 1346 flags |= FUSE_SUBMOUNTS; 1347 1348 ia->in.flags = flags; 1349 ia->in.flags2 = flags >> 32; 1350 1351 ia->args.opcode = FUSE_INIT; 1352 ia->args.in_numargs = 1; 1353 ia->args.in_args[0].size = sizeof(ia->in); 1354 ia->args.in_args[0].value = &ia->in; 1355 ia->args.out_numargs = 1; 1356 /* Variable length argument used for backward compatibility 1357 with interface version < 7.5. Rest of init_out is zeroed 1358 by do_get_request(), so a short reply is not a problem */ 1359 ia->args.out_argvar = true; 1360 ia->args.out_args[0].size = sizeof(ia->out); 1361 ia->args.out_args[0].value = &ia->out; 1362 ia->args.force = true; 1363 ia->args.nocreds = true; 1364 ia->args.end = process_init_reply; 1365 1366 if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0) 1367 process_init_reply(fm, &ia->args, -ENOTCONN); 1368} 1369EXPORT_SYMBOL_GPL(fuse_send_init); 1370 1371void fuse_free_conn(struct fuse_conn *fc) 1372{ 1373 WARN_ON(!list_empty(&fc->devices)); 1374 kfree_rcu(fc, rcu); 1375} 1376EXPORT_SYMBOL_GPL(fuse_free_conn); 1377 1378static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 1379{ 1380 int err; 1381 char *suffix = ""; 1382 1383 if (sb->s_bdev) { 1384 suffix = "-fuseblk"; 1385 /* 1386 * sb->s_bdi points to blkdev's bdi however we want to redirect 1387 * it to our private bdi... 1388 */ 1389 bdi_put(sb->s_bdi); 1390 sb->s_bdi = &noop_backing_dev_info; 1391 } 1392 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev), 1393 MINOR(fc->dev), suffix); 1394 if (err) 1395 return err; 1396 1397 /* fuse does it's own writeback accounting */ 1398 sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT; 1399 sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT; 1400 1401 /* 1402 * For a single fuse filesystem use max 1% of dirty + 1403 * writeback threshold. 1404 * 1405 * This gives about 1M of write buffer for memory maps on a 1406 * machine with 1G and 10% dirty_ratio, which should be more 1407 * than enough. 1408 * 1409 * Privileged users can raise it by writing to 1410 * 1411 * /sys/class/bdi/<bdi>/max_ratio 1412 */ 1413 bdi_set_max_ratio(sb->s_bdi, 1); 1414 1415 return 0; 1416} 1417 1418struct fuse_dev *fuse_dev_alloc(void) 1419{ 1420 struct fuse_dev *fud; 1421 struct list_head *pq; 1422 1423 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL); 1424 if (!fud) 1425 return NULL; 1426 1427 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); 1428 if (!pq) { 1429 kfree(fud); 1430 return NULL; 1431 } 1432 1433 fud->pq.processing = pq; 1434 fuse_pqueue_init(&fud->pq); 1435 1436 return fud; 1437} 1438EXPORT_SYMBOL_GPL(fuse_dev_alloc); 1439 1440void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc) 1441{ 1442 fud->fc = fuse_conn_get(fc); 1443 spin_lock(&fc->lock); 1444 list_add_tail(&fud->entry, &fc->devices); 1445 spin_unlock(&fc->lock); 1446} 1447EXPORT_SYMBOL_GPL(fuse_dev_install); 1448 1449struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc) 1450{ 1451 struct fuse_dev *fud; 1452 1453 fud = fuse_dev_alloc(); 1454 if (!fud) 1455 return NULL; 1456 1457 fuse_dev_install(fud, fc); 1458 return fud; 1459} 1460EXPORT_SYMBOL_GPL(fuse_dev_alloc_install); 1461 1462void fuse_dev_free(struct fuse_dev *fud) 1463{ 1464 struct fuse_conn *fc = fud->fc; 1465 1466 if (fc) { 1467 spin_lock(&fc->lock); 1468 list_del(&fud->entry); 1469 spin_unlock(&fc->lock); 1470 1471 fuse_conn_put(fc); 1472 } 1473 kfree(fud->pq.processing); 1474 kfree(fud); 1475} 1476EXPORT_SYMBOL_GPL(fuse_dev_free); 1477 1478static void fuse_fill_attr_from_inode(struct fuse_attr *attr, 1479 const struct fuse_inode *fi) 1480{ 1481 struct timespec64 ctime = inode_get_ctime(&fi->inode); 1482 1483 *attr = (struct fuse_attr){ 1484 .ino = fi->inode.i_ino, 1485 .size = fi->inode.i_size, 1486 .blocks = fi->inode.i_blocks, 1487 .atime = fi->inode.i_atime.tv_sec, 1488 .mtime = fi->inode.i_mtime.tv_sec, 1489 .ctime = ctime.tv_sec, 1490 .atimensec = fi->inode.i_atime.tv_nsec, 1491 .mtimensec = fi->inode.i_mtime.tv_nsec, 1492 .ctimensec = ctime.tv_nsec, 1493 .mode = fi->inode.i_mode, 1494 .nlink = fi->inode.i_nlink, 1495 .uid = fi->inode.i_uid.val, 1496 .gid = fi->inode.i_gid.val, 1497 .rdev = fi->inode.i_rdev, 1498 .blksize = 1u << fi->inode.i_blkbits, 1499 }; 1500} 1501 1502static void fuse_sb_defaults(struct super_block *sb) 1503{ 1504 sb->s_magic = FUSE_SUPER_MAGIC; 1505 sb->s_op = &fuse_super_operations; 1506 sb->s_xattr = fuse_xattr_handlers; 1507 sb->s_maxbytes = MAX_LFS_FILESIZE; 1508 sb->s_time_gran = 1; 1509 sb->s_export_op = &fuse_export_operations; 1510 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE; 1511 if (sb->s_user_ns != &init_user_ns) 1512 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; 1513 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); 1514} 1515 1516static int fuse_fill_super_submount(struct super_block *sb, 1517 struct fuse_inode *parent_fi) 1518{ 1519 struct fuse_mount *fm = get_fuse_mount_super(sb); 1520 struct super_block *parent_sb = parent_fi->inode.i_sb; 1521 struct fuse_attr root_attr; 1522 struct inode *root; 1523 struct fuse_submount_lookup *sl; 1524 struct fuse_inode *fi; 1525 1526 fuse_sb_defaults(sb); 1527 fm->sb = sb; 1528 1529 WARN_ON(sb->s_bdi != &noop_backing_dev_info); 1530 sb->s_bdi = bdi_get(parent_sb->s_bdi); 1531 1532 sb->s_xattr = parent_sb->s_xattr; 1533 sb->s_time_gran = parent_sb->s_time_gran; 1534 sb->s_blocksize = parent_sb->s_blocksize; 1535 sb->s_blocksize_bits = parent_sb->s_blocksize_bits; 1536 sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL); 1537 if (parent_sb->s_subtype && !sb->s_subtype) 1538 return -ENOMEM; 1539 1540 fuse_fill_attr_from_inode(&root_attr, parent_fi); 1541 root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0); 1542 /* 1543 * This inode is just a duplicate, so it is not looked up and 1544 * its nlookup should not be incremented. fuse_iget() does 1545 * that, though, so undo it here. 1546 */ 1547 fi = get_fuse_inode(root); 1548 fi->nlookup--; 1549 1550 sb->s_d_op = &fuse_dentry_operations; 1551 sb->s_root = d_make_root(root); 1552 if (!sb->s_root) 1553 return -ENOMEM; 1554 1555 /* 1556 * Grab the parent's submount_lookup pointer and take a 1557 * reference on the shared nlookup from the parent. This is to 1558 * prevent the last forget for this nodeid from getting 1559 * triggered until all users have finished with it. 1560 */ 1561 sl = parent_fi->submount_lookup; 1562 WARN_ON(!sl); 1563 if (sl) { 1564 refcount_inc(&sl->count); 1565 fi->submount_lookup = sl; 1566 } 1567 1568 return 0; 1569} 1570 1571/* Filesystem context private data holds the FUSE inode of the mount point */ 1572static int fuse_get_tree_submount(struct fs_context *fsc) 1573{ 1574 struct fuse_mount *fm; 1575 struct fuse_inode *mp_fi = fsc->fs_private; 1576 struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode); 1577 struct super_block *sb; 1578 int err; 1579 1580 fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL); 1581 if (!fm) 1582 return -ENOMEM; 1583 1584 fm->fc = fuse_conn_get(fc); 1585 fsc->s_fs_info = fm; 1586 sb = sget_fc(fsc, NULL, set_anon_super_fc); 1587 if (fsc->s_fs_info) 1588 fuse_mount_destroy(fm); 1589 if (IS_ERR(sb)) 1590 return PTR_ERR(sb); 1591 1592 /* Initialize superblock, making @mp_fi its root */ 1593 err = fuse_fill_super_submount(sb, mp_fi); 1594 if (err) { 1595 deactivate_locked_super(sb); 1596 return err; 1597 } 1598 1599 down_write(&fc->killsb); 1600 list_add_tail(&fm->fc_entry, &fc->mounts); 1601 up_write(&fc->killsb); 1602 1603 sb->s_flags |= SB_ACTIVE; 1604 fsc->root = dget(sb->s_root); 1605 1606 return 0; 1607} 1608 1609static const struct fs_context_operations fuse_context_submount_ops = { 1610 .get_tree = fuse_get_tree_submount, 1611}; 1612 1613int fuse_init_fs_context_submount(struct fs_context *fsc) 1614{ 1615 fsc->ops = &fuse_context_submount_ops; 1616 return 0; 1617} 1618EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount); 1619 1620int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx) 1621{ 1622 struct fuse_dev *fud = NULL; 1623 struct fuse_mount *fm = get_fuse_mount_super(sb); 1624 struct fuse_conn *fc = fm->fc; 1625 struct inode *root; 1626 struct dentry *root_dentry; 1627 int err; 1628 1629 err = -EINVAL; 1630 if (sb->s_flags & SB_MANDLOCK) 1631 goto err; 1632 1633 rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc()); 1634 fuse_sb_defaults(sb); 1635 1636 if (ctx->is_bdev) { 1637#ifdef CONFIG_BLOCK 1638 err = -EINVAL; 1639 if (!sb_set_blocksize(sb, ctx->blksize)) 1640 goto err; 1641#endif 1642 } else { 1643 sb->s_blocksize = PAGE_SIZE; 1644 sb->s_blocksize_bits = PAGE_SHIFT; 1645 } 1646 1647 sb->s_subtype = ctx->subtype; 1648 ctx->subtype = NULL; 1649 if (IS_ENABLED(CONFIG_FUSE_DAX)) { 1650 err = fuse_dax_conn_alloc(fc, ctx->dax_mode, ctx->dax_dev); 1651 if (err) 1652 goto err; 1653 } 1654 1655 if (ctx->fudptr) { 1656 err = -ENOMEM; 1657 fud = fuse_dev_alloc_install(fc); 1658 if (!fud) 1659 goto err_free_dax; 1660 } 1661 1662 fc->dev = sb->s_dev; 1663 fm->sb = sb; 1664 err = fuse_bdi_init(fc, sb); 1665 if (err) 1666 goto err_dev_free; 1667 1668 /* Handle umasking inside the fuse code */ 1669 if (sb->s_flags & SB_POSIXACL) 1670 fc->dont_mask = 1; 1671 sb->s_flags |= SB_POSIXACL; 1672 1673 fc->default_permissions = ctx->default_permissions; 1674 fc->allow_other = ctx->allow_other; 1675 fc->user_id = ctx->user_id; 1676 fc->group_id = ctx->group_id; 1677 fc->legacy_opts_show = ctx->legacy_opts_show; 1678 fc->max_read = max_t(unsigned int, 4096, ctx->max_read); 1679 fc->destroy = ctx->destroy; 1680 fc->no_control = ctx->no_control; 1681 fc->no_force_umount = ctx->no_force_umount; 1682 1683 err = -ENOMEM; 1684 root = fuse_get_root_inode(sb, ctx->rootmode); 1685 sb->s_d_op = &fuse_root_dentry_operations; 1686 root_dentry = d_make_root(root); 1687 if (!root_dentry) 1688 goto err_dev_free; 1689 /* Root dentry doesn't have .d_revalidate */ 1690 sb->s_d_op = &fuse_dentry_operations; 1691 1692 mutex_lock(&fuse_mutex); 1693 err = -EINVAL; 1694 if (ctx->fudptr && *ctx->fudptr) 1695 goto err_unlock; 1696 1697 err = fuse_ctl_add_conn(fc); 1698 if (err) 1699 goto err_unlock; 1700 1701 list_add_tail(&fc->entry, &fuse_conn_list); 1702 sb->s_root = root_dentry; 1703 if (ctx->fudptr) 1704 *ctx->fudptr = fud; 1705 mutex_unlock(&fuse_mutex); 1706 return 0; 1707 1708 err_unlock: 1709 mutex_unlock(&fuse_mutex); 1710 dput(root_dentry); 1711 err_dev_free: 1712 if (fud) 1713 fuse_dev_free(fud); 1714 err_free_dax: 1715 if (IS_ENABLED(CONFIG_FUSE_DAX)) 1716 fuse_dax_conn_free(fc); 1717 err: 1718 return err; 1719} 1720EXPORT_SYMBOL_GPL(fuse_fill_super_common); 1721 1722static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc) 1723{ 1724 struct fuse_fs_context *ctx = fsc->fs_private; 1725 int err; 1726 1727 if (!ctx->file || !ctx->rootmode_present || 1728 !ctx->user_id_present || !ctx->group_id_present) 1729 return -EINVAL; 1730 1731 /* 1732 * Require mount to happen from the same user namespace which 1733 * opened /dev/fuse to prevent potential attacks. 1734 */ 1735 if ((ctx->file->f_op != &fuse_dev_operations) || 1736 (ctx->file->f_cred->user_ns != sb->s_user_ns)) 1737 return -EINVAL; 1738 ctx->fudptr = &ctx->file->private_data; 1739 1740 err = fuse_fill_super_common(sb, ctx); 1741 if (err) 1742 return err; 1743 /* file->private_data shall be visible on all CPUs after this */ 1744 smp_mb(); 1745 fuse_send_init(get_fuse_mount_super(sb)); 1746 return 0; 1747} 1748 1749/* 1750 * This is the path where user supplied an already initialized fuse dev. In 1751 * this case never create a new super if the old one is gone. 1752 */ 1753static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc) 1754{ 1755 return -ENOTCONN; 1756} 1757 1758static int fuse_test_super(struct super_block *sb, struct fs_context *fsc) 1759{ 1760 1761 return fsc->sget_key == get_fuse_conn_super(sb); 1762} 1763 1764static int fuse_get_tree(struct fs_context *fsc) 1765{ 1766 struct fuse_fs_context *ctx = fsc->fs_private; 1767 struct fuse_dev *fud; 1768 struct fuse_conn *fc; 1769 struct fuse_mount *fm; 1770 struct super_block *sb; 1771 int err; 1772 1773 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 1774 if (!fc) 1775 return -ENOMEM; 1776 1777 fm = kzalloc(sizeof(*fm), GFP_KERNEL); 1778 if (!fm) { 1779 kfree(fc); 1780 return -ENOMEM; 1781 } 1782 1783 fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL); 1784 fc->release = fuse_free_conn; 1785 1786 fsc->s_fs_info = fm; 1787 1788 if (ctx->fd_present) 1789 ctx->file = fget(ctx->fd); 1790 1791 if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) { 1792 err = get_tree_bdev(fsc, fuse_fill_super); 1793 goto out; 1794 } 1795 /* 1796 * While block dev mount can be initialized with a dummy device fd 1797 * (found by device name), normal fuse mounts can't 1798 */ 1799 err = -EINVAL; 1800 if (!ctx->file) 1801 goto out; 1802 1803 /* 1804 * Allow creating a fuse mount with an already initialized fuse 1805 * connection 1806 */ 1807 fud = READ_ONCE(ctx->file->private_data); 1808 if (ctx->file->f_op == &fuse_dev_operations && fud) { 1809 fsc->sget_key = fud->fc; 1810 sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super); 1811 err = PTR_ERR_OR_ZERO(sb); 1812 if (!IS_ERR(sb)) 1813 fsc->root = dget(sb->s_root); 1814 } else { 1815 err = get_tree_nodev(fsc, fuse_fill_super); 1816 } 1817out: 1818 if (fsc->s_fs_info) 1819 fuse_mount_destroy(fm); 1820 if (ctx->file) 1821 fput(ctx->file); 1822 return err; 1823} 1824 1825static const struct fs_context_operations fuse_context_ops = { 1826 .free = fuse_free_fsc, 1827 .parse_param = fuse_parse_param, 1828 .reconfigure = fuse_reconfigure, 1829 .get_tree = fuse_get_tree, 1830}; 1831 1832/* 1833 * Set up the filesystem mount context. 1834 */ 1835static int fuse_init_fs_context(struct fs_context *fsc) 1836{ 1837 struct fuse_fs_context *ctx; 1838 1839 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); 1840 if (!ctx) 1841 return -ENOMEM; 1842 1843 ctx->max_read = ~0; 1844 ctx->blksize = FUSE_DEFAULT_BLKSIZE; 1845 ctx->legacy_opts_show = true; 1846 1847#ifdef CONFIG_BLOCK 1848 if (fsc->fs_type == &fuseblk_fs_type) { 1849 ctx->is_bdev = true; 1850 ctx->destroy = true; 1851 } 1852#endif 1853 1854 fsc->fs_private = ctx; 1855 fsc->ops = &fuse_context_ops; 1856 return 0; 1857} 1858 1859bool fuse_mount_remove(struct fuse_mount *fm) 1860{ 1861 struct fuse_conn *fc = fm->fc; 1862 bool last = false; 1863 1864 down_write(&fc->killsb); 1865 list_del_init(&fm->fc_entry); 1866 if (list_empty(&fc->mounts)) 1867 last = true; 1868 up_write(&fc->killsb); 1869 1870 return last; 1871} 1872EXPORT_SYMBOL_GPL(fuse_mount_remove); 1873 1874void fuse_conn_destroy(struct fuse_mount *fm) 1875{ 1876 struct fuse_conn *fc = fm->fc; 1877 1878 if (fc->destroy) 1879 fuse_send_destroy(fm); 1880 1881 fuse_abort_conn(fc); 1882 fuse_wait_aborted(fc); 1883 1884 if (!list_empty(&fc->entry)) { 1885 mutex_lock(&fuse_mutex); 1886 list_del(&fc->entry); 1887 fuse_ctl_remove_conn(fc); 1888 mutex_unlock(&fuse_mutex); 1889 } 1890} 1891EXPORT_SYMBOL_GPL(fuse_conn_destroy); 1892 1893static void fuse_sb_destroy(struct super_block *sb) 1894{ 1895 struct fuse_mount *fm = get_fuse_mount_super(sb); 1896 bool last; 1897 1898 if (sb->s_root) { 1899 last = fuse_mount_remove(fm); 1900 if (last) 1901 fuse_conn_destroy(fm); 1902 } 1903} 1904 1905void fuse_mount_destroy(struct fuse_mount *fm) 1906{ 1907 fuse_conn_put(fm->fc); 1908 kfree(fm); 1909} 1910EXPORT_SYMBOL(fuse_mount_destroy); 1911 1912static void fuse_kill_sb_anon(struct super_block *sb) 1913{ 1914 fuse_sb_destroy(sb); 1915 kill_anon_super(sb); 1916 fuse_mount_destroy(get_fuse_mount_super(sb)); 1917} 1918 1919static struct file_system_type fuse_fs_type = { 1920 .owner = THIS_MODULE, 1921 .name = "fuse", 1922 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT, 1923 .init_fs_context = fuse_init_fs_context, 1924 .parameters = fuse_fs_parameters, 1925 .kill_sb = fuse_kill_sb_anon, 1926}; 1927MODULE_ALIAS_FS("fuse"); 1928 1929#ifdef CONFIG_BLOCK 1930static void fuse_kill_sb_blk(struct super_block *sb) 1931{ 1932 fuse_sb_destroy(sb); 1933 kill_block_super(sb); 1934 fuse_mount_destroy(get_fuse_mount_super(sb)); 1935} 1936 1937static struct file_system_type fuseblk_fs_type = { 1938 .owner = THIS_MODULE, 1939 .name = "fuseblk", 1940 .init_fs_context = fuse_init_fs_context, 1941 .parameters = fuse_fs_parameters, 1942 .kill_sb = fuse_kill_sb_blk, 1943 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 1944}; 1945MODULE_ALIAS_FS("fuseblk"); 1946 1947static inline int register_fuseblk(void) 1948{ 1949 return register_filesystem(&fuseblk_fs_type); 1950} 1951 1952static inline void unregister_fuseblk(void) 1953{ 1954 unregister_filesystem(&fuseblk_fs_type); 1955} 1956#else 1957static inline int register_fuseblk(void) 1958{ 1959 return 0; 1960} 1961 1962static inline void unregister_fuseblk(void) 1963{ 1964} 1965#endif 1966 1967static void fuse_inode_init_once(void *foo) 1968{ 1969 struct inode *inode = foo; 1970 1971 inode_init_once(inode); 1972} 1973 1974static int __init fuse_fs_init(void) 1975{ 1976 int err; 1977 1978 fuse_inode_cachep = kmem_cache_create("fuse_inode", 1979 sizeof(struct fuse_inode), 0, 1980 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT, 1981 fuse_inode_init_once); 1982 err = -ENOMEM; 1983 if (!fuse_inode_cachep) 1984 goto out; 1985 1986 err = register_fuseblk(); 1987 if (err) 1988 goto out2; 1989 1990 err = register_filesystem(&fuse_fs_type); 1991 if (err) 1992 goto out3; 1993 1994 return 0; 1995 1996 out3: 1997 unregister_fuseblk(); 1998 out2: 1999 kmem_cache_destroy(fuse_inode_cachep); 2000 out: 2001 return err; 2002} 2003 2004static void fuse_fs_cleanup(void) 2005{ 2006 unregister_filesystem(&fuse_fs_type); 2007 unregister_fuseblk(); 2008 2009 /* 2010 * Make sure all delayed rcu free inodes are flushed before we 2011 * destroy cache. 2012 */ 2013 rcu_barrier(); 2014 kmem_cache_destroy(fuse_inode_cachep); 2015} 2016 2017static struct kobject *fuse_kobj; 2018 2019static int fuse_sysfs_init(void) 2020{ 2021 int err; 2022 2023 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 2024 if (!fuse_kobj) { 2025 err = -ENOMEM; 2026 goto out_err; 2027 } 2028 2029 err = sysfs_create_mount_point(fuse_kobj, "connections"); 2030 if (err) 2031 goto out_fuse_unregister; 2032 2033 return 0; 2034 2035 out_fuse_unregister: 2036 kobject_put(fuse_kobj); 2037 out_err: 2038 return err; 2039} 2040 2041static void fuse_sysfs_cleanup(void) 2042{ 2043 sysfs_remove_mount_point(fuse_kobj, "connections"); 2044 kobject_put(fuse_kobj); 2045} 2046 2047static int __init fuse_init(void) 2048{ 2049 int res; 2050 2051 pr_info("init (API version %i.%i)\n", 2052 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 2053 2054 INIT_LIST_HEAD(&fuse_conn_list); 2055 res = fuse_fs_init(); 2056 if (res) 2057 goto err; 2058 2059 res = fuse_dev_init(); 2060 if (res) 2061 goto err_fs_cleanup; 2062 2063 res = fuse_sysfs_init(); 2064 if (res) 2065 goto err_dev_cleanup; 2066 2067 res = fuse_ctl_init(); 2068 if (res) 2069 goto err_sysfs_cleanup; 2070 2071 sanitize_global_limit(&max_user_bgreq); 2072 sanitize_global_limit(&max_user_congthresh); 2073 2074 return 0; 2075 2076 err_sysfs_cleanup: 2077 fuse_sysfs_cleanup(); 2078 err_dev_cleanup: 2079 fuse_dev_cleanup(); 2080 err_fs_cleanup: 2081 fuse_fs_cleanup(); 2082 err: 2083 return res; 2084} 2085 2086static void __exit fuse_exit(void) 2087{ 2088 pr_debug("exit\n"); 2089 2090 fuse_ctl_cleanup(); 2091 fuse_sysfs_cleanup(); 2092 fuse_fs_cleanup(); 2093 fuse_dev_cleanup(); 2094} 2095 2096module_init(fuse_init); 2097module_exit(fuse_exit); 2098