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 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) 115 fuse_inode_backing_set(fi, NULL); 116 117 return &fi->inode; 118 119out_free_forget: 120 kfree(fi->forget); 121out_free: 122 kmem_cache_free(fuse_inode_cachep, fi); 123 return NULL; 124} 125 126static 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 141static 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 152static 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(fi->iocachectr != 0); 179 WARN_ON(!list_empty(&fi->write_files)); 180 WARN_ON(!list_empty(&fi->queued_writes)); 181 } 182} 183 184static int fuse_reconfigure(struct fs_context *fsc) 185{ 186 struct super_block *sb = fsc->root->d_sb; 187 188 sync_filesystem(sb); 189 if (fsc->sb_flags & SB_MANDLOCK) 190 return -EINVAL; 191 192 return 0; 193} 194 195/* 196 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down 197 * so that it will fit. 198 */ 199static ino_t fuse_squash_ino(u64 ino64) 200{ 201 ino_t ino = (ino_t) ino64; 202 if (sizeof(ino_t) < sizeof(u64)) 203 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8; 204 return ino; 205} 206 207void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, 208 struct fuse_statx *sx, 209 u64 attr_valid, u32 cache_mask) 210{ 211 struct fuse_conn *fc = get_fuse_conn(inode); 212 struct fuse_inode *fi = get_fuse_inode(inode); 213 214 lockdep_assert_held(&fi->lock); 215 216 fi->attr_version = atomic64_inc_return(&fc->attr_version); 217 fi->i_time = attr_valid; 218 /* Clear basic stats from invalid mask */ 219 set_mask_bits(&fi->inval_mask, STATX_BASIC_STATS, 0); 220 221 inode->i_ino = fuse_squash_ino(attr->ino); 222 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 223 set_nlink(inode, attr->nlink); 224 inode->i_uid = make_kuid(fc->user_ns, attr->uid); 225 inode->i_gid = make_kgid(fc->user_ns, attr->gid); 226 inode->i_blocks = attr->blocks; 227 228 /* Sanitize nsecs */ 229 attr->atimensec = min_t(u32, attr->atimensec, NSEC_PER_SEC - 1); 230 attr->mtimensec = min_t(u32, attr->mtimensec, NSEC_PER_SEC - 1); 231 attr->ctimensec = min_t(u32, attr->ctimensec, NSEC_PER_SEC - 1); 232 233 inode_set_atime(inode, attr->atime, attr->atimensec); 234 /* mtime from server may be stale due to local buffered write */ 235 if (!(cache_mask & STATX_MTIME)) { 236 inode_set_mtime(inode, attr->mtime, attr->mtimensec); 237 } 238 if (!(cache_mask & STATX_CTIME)) { 239 inode_set_ctime(inode, attr->ctime, attr->ctimensec); 240 } 241 if (sx) { 242 /* Sanitize nsecs */ 243 sx->btime.tv_nsec = 244 min_t(u32, sx->btime.tv_nsec, NSEC_PER_SEC - 1); 245 246 /* 247 * Btime has been queried, cache is valid (whether or not btime 248 * is available or not) so clear STATX_BTIME from inval_mask. 249 * 250 * Availability of the btime attribute is indicated in 251 * FUSE_I_BTIME 252 */ 253 set_mask_bits(&fi->inval_mask, STATX_BTIME, 0); 254 if (sx->mask & STATX_BTIME) { 255 set_bit(FUSE_I_BTIME, &fi->state); 256 fi->i_btime.tv_sec = sx->btime.tv_sec; 257 fi->i_btime.tv_nsec = sx->btime.tv_nsec; 258 } 259 } 260 261 if (attr->blksize != 0) 262 inode->i_blkbits = ilog2(attr->blksize); 263 else 264 inode->i_blkbits = inode->i_sb->s_blocksize_bits; 265 266 /* 267 * Don't set the sticky bit in i_mode, unless we want the VFS 268 * to check permissions. This prevents failures due to the 269 * check in may_delete(). 270 */ 271 fi->orig_i_mode = inode->i_mode; 272 if (!fc->default_permissions) 273 inode->i_mode &= ~S_ISVTX; 274 275 fi->orig_ino = attr->ino; 276 277 /* 278 * We are refreshing inode data and it is possible that another 279 * client set suid/sgid or security.capability xattr. So clear 280 * S_NOSEC. Ideally, we could have cleared it only if suid/sgid 281 * was set or if security.capability xattr was set. But we don't 282 * know if security.capability has been set or not. So clear it 283 * anyway. Its less efficient but should be safe. 284 */ 285 inode->i_flags &= ~S_NOSEC; 286} 287 288u32 fuse_get_cache_mask(struct inode *inode) 289{ 290 struct fuse_conn *fc = get_fuse_conn(inode); 291 292 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) 293 return 0; 294 295 return STATX_MTIME | STATX_CTIME | STATX_SIZE; 296} 297 298void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, 299 struct fuse_statx *sx, 300 u64 attr_valid, u64 attr_version) 301{ 302 struct fuse_conn *fc = get_fuse_conn(inode); 303 struct fuse_inode *fi = get_fuse_inode(inode); 304 u32 cache_mask; 305 loff_t oldsize; 306 struct timespec64 old_mtime; 307 308 spin_lock(&fi->lock); 309 /* 310 * In case of writeback_cache enabled, writes update mtime, ctime and 311 * may update i_size. In these cases trust the cached value in the 312 * inode. 313 */ 314 cache_mask = fuse_get_cache_mask(inode); 315 if (cache_mask & STATX_SIZE) 316 attr->size = i_size_read(inode); 317 318 if (cache_mask & STATX_MTIME) { 319 attr->mtime = inode_get_mtime_sec(inode); 320 attr->mtimensec = inode_get_mtime_nsec(inode); 321 } 322 if (cache_mask & STATX_CTIME) { 323 attr->ctime = inode_get_ctime_sec(inode); 324 attr->ctimensec = inode_get_ctime_nsec(inode); 325 } 326 327 if ((attr_version != 0 && fi->attr_version > attr_version) || 328 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { 329 spin_unlock(&fi->lock); 330 return; 331 } 332 333 old_mtime = inode_get_mtime(inode); 334 fuse_change_attributes_common(inode, attr, sx, attr_valid, cache_mask); 335 336 oldsize = inode->i_size; 337 /* 338 * In case of writeback_cache enabled, the cached writes beyond EOF 339 * extend local i_size without keeping userspace server in sync. So, 340 * attr->size coming from server can be stale. We cannot trust it. 341 */ 342 if (!(cache_mask & STATX_SIZE)) 343 i_size_write(inode, attr->size); 344 spin_unlock(&fi->lock); 345 346 if (!cache_mask && S_ISREG(inode->i_mode)) { 347 bool inval = false; 348 349 if (oldsize != attr->size) { 350 truncate_pagecache(inode, attr->size); 351 if (!fc->explicit_inval_data) 352 inval = true; 353 } else if (fc->auto_inval_data) { 354 struct timespec64 new_mtime = { 355 .tv_sec = attr->mtime, 356 .tv_nsec = attr->mtimensec, 357 }; 358 359 /* 360 * Auto inval mode also checks and invalidates if mtime 361 * has changed. 362 */ 363 if (!timespec64_equal(&old_mtime, &new_mtime)) 364 inval = true; 365 } 366 367 if (inval) 368 invalidate_inode_pages2(inode->i_mapping); 369 } 370 371 if (IS_ENABLED(CONFIG_FUSE_DAX)) 372 fuse_dax_dontcache(inode, attr->flags); 373} 374 375static void fuse_init_submount_lookup(struct fuse_submount_lookup *sl, 376 u64 nodeid) 377{ 378 sl->nodeid = nodeid; 379 refcount_set(&sl->count, 1); 380} 381 382static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr, 383 struct fuse_conn *fc) 384{ 385 inode->i_mode = attr->mode & S_IFMT; 386 inode->i_size = attr->size; 387 inode_set_mtime(inode, attr->mtime, attr->mtimensec); 388 inode_set_ctime(inode, attr->ctime, attr->ctimensec); 389 if (S_ISREG(inode->i_mode)) { 390 fuse_init_common(inode); 391 fuse_init_file_inode(inode, attr->flags); 392 } else if (S_ISDIR(inode->i_mode)) 393 fuse_init_dir(inode); 394 else if (S_ISLNK(inode->i_mode)) 395 fuse_init_symlink(inode); 396 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || 397 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { 398 fuse_init_common(inode); 399 init_special_inode(inode, inode->i_mode, 400 new_decode_dev(attr->rdev)); 401 } else 402 BUG(); 403 /* 404 * Ensure that we don't cache acls for daemons without FUSE_POSIX_ACL 405 * so they see the exact same behavior as before. 406 */ 407 if (!fc->posix_acl) 408 inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE; 409} 410 411static int fuse_inode_eq(struct inode *inode, void *_nodeidp) 412{ 413 u64 nodeid = *(u64 *) _nodeidp; 414 if (get_node_id(inode) == nodeid) 415 return 1; 416 else 417 return 0; 418} 419 420static int fuse_inode_set(struct inode *inode, void *_nodeidp) 421{ 422 u64 nodeid = *(u64 *) _nodeidp; 423 get_fuse_inode(inode)->nodeid = nodeid; 424 return 0; 425} 426 427struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 428 int generation, struct fuse_attr *attr, 429 u64 attr_valid, u64 attr_version) 430{ 431 struct inode *inode; 432 struct fuse_inode *fi; 433 struct fuse_conn *fc = get_fuse_conn_super(sb); 434 435 /* 436 * Auto mount points get their node id from the submount root, which is 437 * not a unique identifier within this filesystem. 438 * 439 * To avoid conflicts, do not place submount points into the inode hash 440 * table. 441 */ 442 if (fc->auto_submounts && (attr->flags & FUSE_ATTR_SUBMOUNT) && 443 S_ISDIR(attr->mode)) { 444 struct fuse_inode *fi; 445 446 inode = new_inode(sb); 447 if (!inode) 448 return NULL; 449 450 fuse_init_inode(inode, attr, fc); 451 fi = get_fuse_inode(inode); 452 fi->nodeid = nodeid; 453 fi->submount_lookup = fuse_alloc_submount_lookup(); 454 if (!fi->submount_lookup) { 455 iput(inode); 456 return NULL; 457 } 458 /* Sets nlookup = 1 on fi->submount_lookup->nlookup */ 459 fuse_init_submount_lookup(fi->submount_lookup, nodeid); 460 inode->i_flags |= S_AUTOMOUNT; 461 goto done; 462 } 463 464retry: 465 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); 466 if (!inode) 467 return NULL; 468 469 if ((inode->i_state & I_NEW)) { 470 inode->i_flags |= S_NOATIME; 471 if (!fc->writeback_cache || !S_ISREG(attr->mode)) 472 inode->i_flags |= S_NOCMTIME; 473 inode->i_generation = generation; 474 fuse_init_inode(inode, attr, fc); 475 unlock_new_inode(inode); 476 } else if (fuse_stale_inode(inode, generation, attr)) { 477 /* nodeid was reused, any I/O on the old inode should fail */ 478 fuse_make_bad(inode); 479 if (inode != d_inode(sb->s_root)) { 480 remove_inode_hash(inode); 481 iput(inode); 482 goto retry; 483 } 484 } 485 fi = get_fuse_inode(inode); 486 spin_lock(&fi->lock); 487 fi->nlookup++; 488 spin_unlock(&fi->lock); 489done: 490 fuse_change_attributes(inode, attr, NULL, attr_valid, attr_version); 491 492 return inode; 493} 494 495struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid, 496 struct fuse_mount **fm) 497{ 498 struct fuse_mount *fm_iter; 499 struct inode *inode; 500 501 WARN_ON(!rwsem_is_locked(&fc->killsb)); 502 list_for_each_entry(fm_iter, &fc->mounts, fc_entry) { 503 if (!fm_iter->sb) 504 continue; 505 506 inode = ilookup5(fm_iter->sb, nodeid, fuse_inode_eq, &nodeid); 507 if (inode) { 508 if (fm) 509 *fm = fm_iter; 510 return inode; 511 } 512 } 513 514 return NULL; 515} 516 517int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid, 518 loff_t offset, loff_t len) 519{ 520 struct fuse_inode *fi; 521 struct inode *inode; 522 pgoff_t pg_start; 523 pgoff_t pg_end; 524 525 inode = fuse_ilookup(fc, nodeid, NULL); 526 if (!inode) 527 return -ENOENT; 528 529 fi = get_fuse_inode(inode); 530 spin_lock(&fi->lock); 531 fi->attr_version = atomic64_inc_return(&fc->attr_version); 532 spin_unlock(&fi->lock); 533 534 fuse_invalidate_attr(inode); 535 forget_all_cached_acls(inode); 536 if (offset >= 0) { 537 pg_start = offset >> PAGE_SHIFT; 538 if (len <= 0) 539 pg_end = -1; 540 else 541 pg_end = (offset + len - 1) >> PAGE_SHIFT; 542 invalidate_inode_pages2_range(inode->i_mapping, 543 pg_start, pg_end); 544 } 545 iput(inode); 546 return 0; 547} 548 549bool fuse_lock_inode(struct inode *inode) 550{ 551 bool locked = false; 552 553 if (!get_fuse_conn(inode)->parallel_dirops) { 554 mutex_lock(&get_fuse_inode(inode)->mutex); 555 locked = true; 556 } 557 558 return locked; 559} 560 561void fuse_unlock_inode(struct inode *inode, bool locked) 562{ 563 if (locked) 564 mutex_unlock(&get_fuse_inode(inode)->mutex); 565} 566 567static void fuse_umount_begin(struct super_block *sb) 568{ 569 struct fuse_conn *fc = get_fuse_conn_super(sb); 570 571 if (fc->no_force_umount) 572 return; 573 574 fuse_abort_conn(fc); 575 576 // Only retire block-device-based superblocks. 577 if (sb->s_bdev != NULL) 578 retire_super(sb); 579} 580 581static void fuse_send_destroy(struct fuse_mount *fm) 582{ 583 if (fm->fc->conn_init) { 584 FUSE_ARGS(args); 585 586 args.opcode = FUSE_DESTROY; 587 args.force = true; 588 args.nocreds = true; 589 fuse_simple_request(fm, &args); 590 } 591} 592 593static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 594{ 595 stbuf->f_type = FUSE_SUPER_MAGIC; 596 stbuf->f_bsize = attr->bsize; 597 stbuf->f_frsize = attr->frsize; 598 stbuf->f_blocks = attr->blocks; 599 stbuf->f_bfree = attr->bfree; 600 stbuf->f_bavail = attr->bavail; 601 stbuf->f_files = attr->files; 602 stbuf->f_ffree = attr->ffree; 603 stbuf->f_namelen = attr->namelen; 604 /* fsid is left zero */ 605} 606 607static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 608{ 609 struct super_block *sb = dentry->d_sb; 610 struct fuse_mount *fm = get_fuse_mount_super(sb); 611 FUSE_ARGS(args); 612 struct fuse_statfs_out outarg; 613 int err; 614 615 if (!fuse_allow_current_process(fm->fc)) { 616 buf->f_type = FUSE_SUPER_MAGIC; 617 return 0; 618 } 619 620 memset(&outarg, 0, sizeof(outarg)); 621 args.in_numargs = 0; 622 args.opcode = FUSE_STATFS; 623 args.nodeid = get_node_id(d_inode(dentry)); 624 args.out_numargs = 1; 625 args.out_args[0].size = sizeof(outarg); 626 args.out_args[0].value = &outarg; 627 err = fuse_simple_request(fm, &args); 628 if (!err) 629 convert_fuse_statfs(buf, &outarg.st); 630 return err; 631} 632 633static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void) 634{ 635 struct fuse_sync_bucket *bucket; 636 637 bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL); 638 if (bucket) { 639 init_waitqueue_head(&bucket->waitq); 640 /* Initial active count */ 641 atomic_set(&bucket->count, 1); 642 } 643 return bucket; 644} 645 646static void fuse_sync_fs_writes(struct fuse_conn *fc) 647{ 648 struct fuse_sync_bucket *bucket, *new_bucket; 649 int count; 650 651 new_bucket = fuse_sync_bucket_alloc(); 652 spin_lock(&fc->lock); 653 bucket = rcu_dereference_protected(fc->curr_bucket, 1); 654 count = atomic_read(&bucket->count); 655 WARN_ON(count < 1); 656 /* No outstanding writes? */ 657 if (count == 1) { 658 spin_unlock(&fc->lock); 659 kfree(new_bucket); 660 return; 661 } 662 663 /* 664 * Completion of new bucket depends on completion of this bucket, so add 665 * one more count. 666 */ 667 atomic_inc(&new_bucket->count); 668 rcu_assign_pointer(fc->curr_bucket, new_bucket); 669 spin_unlock(&fc->lock); 670 /* 671 * Drop initial active count. At this point if all writes in this and 672 * ancestor buckets complete, the count will go to zero and this task 673 * will be woken up. 674 */ 675 atomic_dec(&bucket->count); 676 677 wait_event(bucket->waitq, atomic_read(&bucket->count) == 0); 678 679 /* Drop temp count on descendant bucket */ 680 fuse_sync_bucket_dec(new_bucket); 681 kfree_rcu(bucket, rcu); 682} 683 684static int fuse_sync_fs(struct super_block *sb, int wait) 685{ 686 struct fuse_mount *fm = get_fuse_mount_super(sb); 687 struct fuse_conn *fc = fm->fc; 688 struct fuse_syncfs_in inarg; 689 FUSE_ARGS(args); 690 int err; 691 692 /* 693 * Userspace cannot handle the wait == 0 case. Avoid a 694 * gratuitous roundtrip. 695 */ 696 if (!wait) 697 return 0; 698 699 /* The filesystem is being unmounted. Nothing to do. */ 700 if (!sb->s_root) 701 return 0; 702 703 if (!fc->sync_fs) 704 return 0; 705 706 fuse_sync_fs_writes(fc); 707 708 memset(&inarg, 0, sizeof(inarg)); 709 args.in_numargs = 1; 710 args.in_args[0].size = sizeof(inarg); 711 args.in_args[0].value = &inarg; 712 args.opcode = FUSE_SYNCFS; 713 args.nodeid = get_node_id(sb->s_root->d_inode); 714 args.out_numargs = 0; 715 716 err = fuse_simple_request(fm, &args); 717 if (err == -ENOSYS) { 718 fc->sync_fs = 0; 719 err = 0; 720 } 721 722 return err; 723} 724 725enum { 726 OPT_SOURCE, 727 OPT_SUBTYPE, 728 OPT_FD, 729 OPT_ROOTMODE, 730 OPT_USER_ID, 731 OPT_GROUP_ID, 732 OPT_DEFAULT_PERMISSIONS, 733 OPT_ALLOW_OTHER, 734 OPT_MAX_READ, 735 OPT_BLKSIZE, 736 OPT_ERR 737}; 738 739static const struct fs_parameter_spec fuse_fs_parameters[] = { 740 fsparam_string ("source", OPT_SOURCE), 741 fsparam_u32 ("fd", OPT_FD), 742 fsparam_u32oct ("rootmode", OPT_ROOTMODE), 743 fsparam_u32 ("user_id", OPT_USER_ID), 744 fsparam_u32 ("group_id", OPT_GROUP_ID), 745 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS), 746 fsparam_flag ("allow_other", OPT_ALLOW_OTHER), 747 fsparam_u32 ("max_read", OPT_MAX_READ), 748 fsparam_u32 ("blksize", OPT_BLKSIZE), 749 fsparam_string ("subtype", OPT_SUBTYPE), 750 {} 751}; 752 753static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param) 754{ 755 struct fs_parse_result result; 756 struct fuse_fs_context *ctx = fsc->fs_private; 757 int opt; 758 759 if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { 760 /* 761 * Ignore options coming from mount(MS_REMOUNT) for backward 762 * compatibility. 763 */ 764 if (fsc->oldapi) 765 return 0; 766 767 return invalfc(fsc, "No changes allowed in reconfigure"); 768 } 769 770 opt = fs_parse(fsc, fuse_fs_parameters, param, &result); 771 if (opt < 0) 772 return opt; 773 774 switch (opt) { 775 case OPT_SOURCE: 776 if (fsc->source) 777 return invalfc(fsc, "Multiple sources specified"); 778 fsc->source = param->string; 779 param->string = NULL; 780 break; 781 782 case OPT_SUBTYPE: 783 if (ctx->subtype) 784 return invalfc(fsc, "Multiple subtypes specified"); 785 ctx->subtype = param->string; 786 param->string = NULL; 787 return 0; 788 789 case OPT_FD: 790 ctx->fd = result.uint_32; 791 ctx->fd_present = true; 792 break; 793 794 case OPT_ROOTMODE: 795 if (!fuse_valid_type(result.uint_32)) 796 return invalfc(fsc, "Invalid rootmode"); 797 ctx->rootmode = result.uint_32; 798 ctx->rootmode_present = true; 799 break; 800 801 case OPT_USER_ID: 802 ctx->user_id = make_kuid(fsc->user_ns, result.uint_32); 803 if (!uid_valid(ctx->user_id)) 804 return invalfc(fsc, "Invalid user_id"); 805 ctx->user_id_present = true; 806 break; 807 808 case OPT_GROUP_ID: 809 ctx->group_id = make_kgid(fsc->user_ns, result.uint_32); 810 if (!gid_valid(ctx->group_id)) 811 return invalfc(fsc, "Invalid group_id"); 812 ctx->group_id_present = true; 813 break; 814 815 case OPT_DEFAULT_PERMISSIONS: 816 ctx->default_permissions = true; 817 break; 818 819 case OPT_ALLOW_OTHER: 820 ctx->allow_other = true; 821 break; 822 823 case OPT_MAX_READ: 824 ctx->max_read = result.uint_32; 825 break; 826 827 case OPT_BLKSIZE: 828 if (!ctx->is_bdev) 829 return invalfc(fsc, "blksize only supported for fuseblk"); 830 ctx->blksize = result.uint_32; 831 break; 832 833 default: 834 return -EINVAL; 835 } 836 837 return 0; 838} 839 840static void fuse_free_fsc(struct fs_context *fsc) 841{ 842 struct fuse_fs_context *ctx = fsc->fs_private; 843 844 if (ctx) { 845 kfree(ctx->subtype); 846 kfree(ctx); 847 } 848} 849 850static int fuse_show_options(struct seq_file *m, struct dentry *root) 851{ 852 struct super_block *sb = root->d_sb; 853 struct fuse_conn *fc = get_fuse_conn_super(sb); 854 855 if (fc->legacy_opts_show) { 856 seq_printf(m, ",user_id=%u", 857 from_kuid_munged(fc->user_ns, fc->user_id)); 858 seq_printf(m, ",group_id=%u", 859 from_kgid_munged(fc->user_ns, fc->group_id)); 860 if (fc->default_permissions) 861 seq_puts(m, ",default_permissions"); 862 if (fc->allow_other) 863 seq_puts(m, ",allow_other"); 864 if (fc->max_read != ~0) 865 seq_printf(m, ",max_read=%u", fc->max_read); 866 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 867 seq_printf(m, ",blksize=%lu", sb->s_blocksize); 868 } 869#ifdef CONFIG_FUSE_DAX 870 if (fc->dax_mode == FUSE_DAX_ALWAYS) 871 seq_puts(m, ",dax=always"); 872 else if (fc->dax_mode == FUSE_DAX_NEVER) 873 seq_puts(m, ",dax=never"); 874 else if (fc->dax_mode == FUSE_DAX_INODE_USER) 875 seq_puts(m, ",dax=inode"); 876#endif 877 878 return 0; 879} 880 881static void fuse_iqueue_init(struct fuse_iqueue *fiq, 882 const struct fuse_iqueue_ops *ops, 883 void *priv) 884{ 885 memset(fiq, 0, sizeof(struct fuse_iqueue)); 886 spin_lock_init(&fiq->lock); 887 init_waitqueue_head(&fiq->waitq); 888 INIT_LIST_HEAD(&fiq->pending); 889 INIT_LIST_HEAD(&fiq->interrupts); 890 fiq->forget_list_tail = &fiq->forget_list_head; 891 fiq->connected = 1; 892 fiq->ops = ops; 893 fiq->priv = priv; 894} 895 896static void fuse_pqueue_init(struct fuse_pqueue *fpq) 897{ 898 unsigned int i; 899 900 spin_lock_init(&fpq->lock); 901 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) 902 INIT_LIST_HEAD(&fpq->processing[i]); 903 INIT_LIST_HEAD(&fpq->io); 904 fpq->connected = 1; 905} 906 907void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm, 908 struct user_namespace *user_ns, 909 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv) 910{ 911 memset(fc, 0, sizeof(*fc)); 912 spin_lock_init(&fc->lock); 913 spin_lock_init(&fc->bg_lock); 914 init_rwsem(&fc->killsb); 915 refcount_set(&fc->count, 1); 916 atomic_set(&fc->dev_count, 1); 917 init_waitqueue_head(&fc->blocked_waitq); 918 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv); 919 INIT_LIST_HEAD(&fc->bg_queue); 920 INIT_LIST_HEAD(&fc->entry); 921 INIT_LIST_HEAD(&fc->devices); 922 atomic_set(&fc->num_waiting, 0); 923 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND; 924 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD; 925 atomic64_set(&fc->khctr, 0); 926 fc->polled_files = RB_ROOT; 927 fc->blocked = 0; 928 fc->initialized = 0; 929 fc->connected = 1; 930 atomic64_set(&fc->attr_version, 1); 931 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 932 fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); 933 fc->user_ns = get_user_ns(user_ns); 934 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ; 935 fc->max_pages_limit = FUSE_MAX_MAX_PAGES; 936 937 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) 938 fuse_backing_files_init(fc); 939 940 INIT_LIST_HEAD(&fc->mounts); 941 list_add(&fm->fc_entry, &fc->mounts); 942 fm->fc = fc; 943} 944EXPORT_SYMBOL_GPL(fuse_conn_init); 945 946static void delayed_release(struct rcu_head *p) 947{ 948 struct fuse_conn *fc = container_of(p, struct fuse_conn, rcu); 949 950 put_user_ns(fc->user_ns); 951 fc->release(fc); 952} 953 954void fuse_conn_put(struct fuse_conn *fc) 955{ 956 if (refcount_dec_and_test(&fc->count)) { 957 struct fuse_iqueue *fiq = &fc->iq; 958 struct fuse_sync_bucket *bucket; 959 960 if (IS_ENABLED(CONFIG_FUSE_DAX)) 961 fuse_dax_conn_free(fc); 962 if (fiq->ops->release) 963 fiq->ops->release(fiq); 964 put_pid_ns(fc->pid_ns); 965 bucket = rcu_dereference_protected(fc->curr_bucket, 1); 966 if (bucket) { 967 WARN_ON(atomic_read(&bucket->count) != 1); 968 kfree(bucket); 969 } 970 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) 971 fuse_backing_files_free(fc); 972 call_rcu(&fc->rcu, delayed_release); 973 } 974} 975EXPORT_SYMBOL_GPL(fuse_conn_put); 976 977struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 978{ 979 refcount_inc(&fc->count); 980 return fc; 981} 982EXPORT_SYMBOL_GPL(fuse_conn_get); 983 984static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 985{ 986 struct fuse_attr attr; 987 memset(&attr, 0, sizeof(attr)); 988 989 attr.mode = mode; 990 attr.ino = FUSE_ROOT_ID; 991 attr.nlink = 1; 992 return fuse_iget(sb, FUSE_ROOT_ID, 0, &attr, 0, 0); 993} 994 995struct fuse_inode_handle { 996 u64 nodeid; 997 u32 generation; 998}; 999 1000static struct dentry *fuse_get_dentry(struct super_block *sb, 1001 struct fuse_inode_handle *handle) 1002{ 1003 struct fuse_conn *fc = get_fuse_conn_super(sb); 1004 struct inode *inode; 1005 struct dentry *entry; 1006 int err = -ESTALE; 1007 1008 if (handle->nodeid == 0) 1009 goto out_err; 1010 1011 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 1012 if (!inode) { 1013 struct fuse_entry_out outarg; 1014 const struct qstr name = QSTR_INIT(".", 1); 1015 1016 if (!fc->export_support) 1017 goto out_err; 1018 1019 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 1020 &inode); 1021 if (err && err != -ENOENT) 1022 goto out_err; 1023 if (err || !inode) { 1024 err = -ESTALE; 1025 goto out_err; 1026 } 1027 err = -EIO; 1028 if (get_node_id(inode) != handle->nodeid) 1029 goto out_iput; 1030 } 1031 err = -ESTALE; 1032 if (inode->i_generation != handle->generation) 1033 goto out_iput; 1034 1035 entry = d_obtain_alias(inode); 1036 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) 1037 fuse_invalidate_entry_cache(entry); 1038 1039 return entry; 1040 1041 out_iput: 1042 iput(inode); 1043 out_err: 1044 return ERR_PTR(err); 1045} 1046 1047static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len, 1048 struct inode *parent) 1049{ 1050 int len = parent ? 6 : 3; 1051 u64 nodeid; 1052 u32 generation; 1053 1054 if (*max_len < len) { 1055 *max_len = len; 1056 return FILEID_INVALID; 1057 } 1058 1059 nodeid = get_fuse_inode(inode)->nodeid; 1060 generation = inode->i_generation; 1061 1062 fh[0] = (u32)(nodeid >> 32); 1063 fh[1] = (u32)(nodeid & 0xffffffff); 1064 fh[2] = generation; 1065 1066 if (parent) { 1067 nodeid = get_fuse_inode(parent)->nodeid; 1068 generation = parent->i_generation; 1069 1070 fh[3] = (u32)(nodeid >> 32); 1071 fh[4] = (u32)(nodeid & 0xffffffff); 1072 fh[5] = generation; 1073 } 1074 1075 *max_len = len; 1076 return parent ? FILEID_INO64_GEN_PARENT : FILEID_INO64_GEN; 1077} 1078 1079static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 1080 struct fid *fid, int fh_len, int fh_type) 1081{ 1082 struct fuse_inode_handle handle; 1083 1084 if ((fh_type != FILEID_INO64_GEN && 1085 fh_type != FILEID_INO64_GEN_PARENT) || fh_len < 3) 1086 return NULL; 1087 1088 handle.nodeid = (u64) fid->raw[0] << 32; 1089 handle.nodeid |= (u64) fid->raw[1]; 1090 handle.generation = fid->raw[2]; 1091 return fuse_get_dentry(sb, &handle); 1092} 1093 1094static struct dentry *fuse_fh_to_parent(struct super_block *sb, 1095 struct fid *fid, int fh_len, int fh_type) 1096{ 1097 struct fuse_inode_handle parent; 1098 1099 if (fh_type != FILEID_INO64_GEN_PARENT || fh_len < 6) 1100 return NULL; 1101 1102 parent.nodeid = (u64) fid->raw[3] << 32; 1103 parent.nodeid |= (u64) fid->raw[4]; 1104 parent.generation = fid->raw[5]; 1105 return fuse_get_dentry(sb, &parent); 1106} 1107 1108static struct dentry *fuse_get_parent(struct dentry *child) 1109{ 1110 struct inode *child_inode = d_inode(child); 1111 struct fuse_conn *fc = get_fuse_conn(child_inode); 1112 struct inode *inode; 1113 struct dentry *parent; 1114 struct fuse_entry_out outarg; 1115 int err; 1116 1117 if (!fc->export_support) 1118 return ERR_PTR(-ESTALE); 1119 1120 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 1121 &dotdot_name, &outarg, &inode); 1122 if (err) { 1123 if (err == -ENOENT) 1124 return ERR_PTR(-ESTALE); 1125 return ERR_PTR(err); 1126 } 1127 1128 parent = d_obtain_alias(inode); 1129 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) 1130 fuse_invalidate_entry_cache(parent); 1131 1132 return parent; 1133} 1134 1135/* only for fid encoding; no support for file handle */ 1136static const struct export_operations fuse_export_fid_operations = { 1137 .encode_fh = fuse_encode_fh, 1138}; 1139 1140static const struct export_operations fuse_export_operations = { 1141 .fh_to_dentry = fuse_fh_to_dentry, 1142 .fh_to_parent = fuse_fh_to_parent, 1143 .encode_fh = fuse_encode_fh, 1144 .get_parent = fuse_get_parent, 1145}; 1146 1147static const struct super_operations fuse_super_operations = { 1148 .alloc_inode = fuse_alloc_inode, 1149 .free_inode = fuse_free_inode, 1150 .evict_inode = fuse_evict_inode, 1151 .write_inode = fuse_write_inode, 1152 .drop_inode = generic_delete_inode, 1153 .umount_begin = fuse_umount_begin, 1154 .statfs = fuse_statfs, 1155 .sync_fs = fuse_sync_fs, 1156 .show_options = fuse_show_options, 1157}; 1158 1159static void sanitize_global_limit(unsigned *limit) 1160{ 1161 /* 1162 * The default maximum number of async requests is calculated to consume 1163 * 1/2^13 of the total memory, assuming 392 bytes per request. 1164 */ 1165 if (*limit == 0) 1166 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392; 1167 1168 if (*limit >= 1 << 16) 1169 *limit = (1 << 16) - 1; 1170} 1171 1172static int set_global_limit(const char *val, const struct kernel_param *kp) 1173{ 1174 int rv; 1175 1176 rv = param_set_uint(val, kp); 1177 if (rv) 1178 return rv; 1179 1180 sanitize_global_limit((unsigned *)kp->arg); 1181 1182 return 0; 1183} 1184 1185static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg) 1186{ 1187 int cap_sys_admin = capable(CAP_SYS_ADMIN); 1188 1189 if (arg->minor < 13) 1190 return; 1191 1192 sanitize_global_limit(&max_user_bgreq); 1193 sanitize_global_limit(&max_user_congthresh); 1194 1195 spin_lock(&fc->bg_lock); 1196 if (arg->max_background) { 1197 fc->max_background = arg->max_background; 1198 1199 if (!cap_sys_admin && fc->max_background > max_user_bgreq) 1200 fc->max_background = max_user_bgreq; 1201 } 1202 if (arg->congestion_threshold) { 1203 fc->congestion_threshold = arg->congestion_threshold; 1204 1205 if (!cap_sys_admin && 1206 fc->congestion_threshold > max_user_congthresh) 1207 fc->congestion_threshold = max_user_congthresh; 1208 } 1209 spin_unlock(&fc->bg_lock); 1210} 1211 1212struct fuse_init_args { 1213 struct fuse_args args; 1214 struct fuse_init_in in; 1215 struct fuse_init_out out; 1216}; 1217 1218static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, 1219 int error) 1220{ 1221 struct fuse_conn *fc = fm->fc; 1222 struct fuse_init_args *ia = container_of(args, typeof(*ia), args); 1223 struct fuse_init_out *arg = &ia->out; 1224 bool ok = true; 1225 1226 if (error || arg->major != FUSE_KERNEL_VERSION) 1227 ok = false; 1228 else { 1229 unsigned long ra_pages; 1230 1231 process_init_limits(fc, arg); 1232 1233 if (arg->minor >= 6) { 1234 u64 flags = arg->flags; 1235 1236 if (flags & FUSE_INIT_EXT) 1237 flags |= (u64) arg->flags2 << 32; 1238 1239 ra_pages = arg->max_readahead / PAGE_SIZE; 1240 if (flags & FUSE_ASYNC_READ) 1241 fc->async_read = 1; 1242 if (!(flags & FUSE_POSIX_LOCKS)) 1243 fc->no_lock = 1; 1244 if (arg->minor >= 17) { 1245 if (!(flags & FUSE_FLOCK_LOCKS)) 1246 fc->no_flock = 1; 1247 } else { 1248 if (!(flags & FUSE_POSIX_LOCKS)) 1249 fc->no_flock = 1; 1250 } 1251 if (flags & FUSE_ATOMIC_O_TRUNC) 1252 fc->atomic_o_trunc = 1; 1253 if (arg->minor >= 9) { 1254 /* LOOKUP has dependency on proto version */ 1255 if (flags & FUSE_EXPORT_SUPPORT) 1256 fc->export_support = 1; 1257 } 1258 if (flags & FUSE_BIG_WRITES) 1259 fc->big_writes = 1; 1260 if (flags & FUSE_DONT_MASK) 1261 fc->dont_mask = 1; 1262 if (flags & FUSE_AUTO_INVAL_DATA) 1263 fc->auto_inval_data = 1; 1264 else if (flags & FUSE_EXPLICIT_INVAL_DATA) 1265 fc->explicit_inval_data = 1; 1266 if (flags & FUSE_DO_READDIRPLUS) { 1267 fc->do_readdirplus = 1; 1268 if (flags & FUSE_READDIRPLUS_AUTO) 1269 fc->readdirplus_auto = 1; 1270 } 1271 if (flags & FUSE_ASYNC_DIO) 1272 fc->async_dio = 1; 1273 if (flags & FUSE_WRITEBACK_CACHE) 1274 fc->writeback_cache = 1; 1275 if (flags & FUSE_PARALLEL_DIROPS) 1276 fc->parallel_dirops = 1; 1277 if (flags & FUSE_HANDLE_KILLPRIV) 1278 fc->handle_killpriv = 1; 1279 if (arg->time_gran && arg->time_gran <= 1000000000) 1280 fm->sb->s_time_gran = arg->time_gran; 1281 if ((flags & FUSE_POSIX_ACL)) { 1282 fc->default_permissions = 1; 1283 fc->posix_acl = 1; 1284 } 1285 if (flags & FUSE_CACHE_SYMLINKS) 1286 fc->cache_symlinks = 1; 1287 if (flags & FUSE_ABORT_ERROR) 1288 fc->abort_err = 1; 1289 if (flags & FUSE_MAX_PAGES) { 1290 fc->max_pages = 1291 min_t(unsigned int, fc->max_pages_limit, 1292 max_t(unsigned int, arg->max_pages, 1)); 1293 } 1294 if (IS_ENABLED(CONFIG_FUSE_DAX)) { 1295 if (flags & FUSE_MAP_ALIGNMENT && 1296 !fuse_dax_check_alignment(fc, arg->map_alignment)) { 1297 ok = false; 1298 } 1299 if (flags & FUSE_HAS_INODE_DAX) 1300 fc->inode_dax = 1; 1301 } 1302 if (flags & FUSE_HANDLE_KILLPRIV_V2) { 1303 fc->handle_killpriv_v2 = 1; 1304 fm->sb->s_flags |= SB_NOSEC; 1305 } 1306 if (flags & FUSE_SETXATTR_EXT) 1307 fc->setxattr_ext = 1; 1308 if (flags & FUSE_SECURITY_CTX) 1309 fc->init_security = 1; 1310 if (flags & FUSE_CREATE_SUPP_GROUP) 1311 fc->create_supp_group = 1; 1312 if (flags & FUSE_DIRECT_IO_ALLOW_MMAP) 1313 fc->direct_io_allow_mmap = 1; 1314 /* 1315 * max_stack_depth is the max stack depth of FUSE fs, 1316 * so it has to be at least 1 to support passthrough 1317 * to backing files. 1318 * 1319 * with max_stack_depth > 1, the backing files can be 1320 * on a stacked fs (e.g. overlayfs) themselves and with 1321 * max_stack_depth == 1, FUSE fs can be stacked as the 1322 * underlying fs of a stacked fs (e.g. overlayfs). 1323 */ 1324 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH) && 1325 (flags & FUSE_PASSTHROUGH) && 1326 arg->max_stack_depth > 0 && 1327 arg->max_stack_depth <= FILESYSTEM_MAX_STACK_DEPTH) { 1328 fc->passthrough = 1; 1329 fc->max_stack_depth = arg->max_stack_depth; 1330 fm->sb->s_stack_depth = arg->max_stack_depth; 1331 } 1332 if (flags & FUSE_NO_EXPORT_SUPPORT) 1333 fm->sb->s_export_op = &fuse_export_fid_operations; 1334 } else { 1335 ra_pages = fc->max_read / PAGE_SIZE; 1336 fc->no_lock = 1; 1337 fc->no_flock = 1; 1338 } 1339 1340 fm->sb->s_bdi->ra_pages = 1341 min(fm->sb->s_bdi->ra_pages, ra_pages); 1342 fc->minor = arg->minor; 1343 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 1344 fc->max_write = max_t(unsigned, 4096, fc->max_write); 1345 fc->conn_init = 1; 1346 } 1347 kfree(ia); 1348 1349 if (!ok) { 1350 fc->conn_init = 0; 1351 fc->conn_error = 1; 1352 } 1353 1354 fuse_set_initialized(fc); 1355 wake_up_all(&fc->blocked_waitq); 1356} 1357 1358void fuse_send_init(struct fuse_mount *fm) 1359{ 1360 struct fuse_init_args *ia; 1361 u64 flags; 1362 1363 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL); 1364 1365 ia->in.major = FUSE_KERNEL_VERSION; 1366 ia->in.minor = FUSE_KERNEL_MINOR_VERSION; 1367 ia->in.max_readahead = fm->sb->s_bdi->ra_pages * PAGE_SIZE; 1368 flags = 1369 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 1370 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | 1371 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | 1372 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | 1373 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO | 1374 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT | 1375 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL | 1376 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | 1377 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA | 1378 FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT | 1379 FUSE_SECURITY_CTX | FUSE_CREATE_SUPP_GROUP | 1380 FUSE_HAS_EXPIRE_ONLY | FUSE_DIRECT_IO_ALLOW_MMAP | 1381 FUSE_NO_EXPORT_SUPPORT | FUSE_HAS_RESEND; 1382#ifdef CONFIG_FUSE_DAX 1383 if (fm->fc->dax) 1384 flags |= FUSE_MAP_ALIGNMENT; 1385 if (fuse_is_inode_dax_mode(fm->fc->dax_mode)) 1386 flags |= FUSE_HAS_INODE_DAX; 1387#endif 1388 if (fm->fc->auto_submounts) 1389 flags |= FUSE_SUBMOUNTS; 1390 if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) 1391 flags |= FUSE_PASSTHROUGH; 1392 1393 ia->in.flags = flags; 1394 ia->in.flags2 = flags >> 32; 1395 1396 ia->args.opcode = FUSE_INIT; 1397 ia->args.in_numargs = 1; 1398 ia->args.in_args[0].size = sizeof(ia->in); 1399 ia->args.in_args[0].value = &ia->in; 1400 ia->args.out_numargs = 1; 1401 /* Variable length argument used for backward compatibility 1402 with interface version < 7.5. Rest of init_out is zeroed 1403 by do_get_request(), so a short reply is not a problem */ 1404 ia->args.out_argvar = true; 1405 ia->args.out_args[0].size = sizeof(ia->out); 1406 ia->args.out_args[0].value = &ia->out; 1407 ia->args.force = true; 1408 ia->args.nocreds = true; 1409 ia->args.end = process_init_reply; 1410 1411 if (fuse_simple_background(fm, &ia->args, GFP_KERNEL) != 0) 1412 process_init_reply(fm, &ia->args, -ENOTCONN); 1413} 1414EXPORT_SYMBOL_GPL(fuse_send_init); 1415 1416void fuse_free_conn(struct fuse_conn *fc) 1417{ 1418 WARN_ON(!list_empty(&fc->devices)); 1419 kfree(fc); 1420} 1421EXPORT_SYMBOL_GPL(fuse_free_conn); 1422 1423static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 1424{ 1425 int err; 1426 char *suffix = ""; 1427 1428 if (sb->s_bdev) { 1429 suffix = "-fuseblk"; 1430 /* 1431 * sb->s_bdi points to blkdev's bdi however we want to redirect 1432 * it to our private bdi... 1433 */ 1434 bdi_put(sb->s_bdi); 1435 sb->s_bdi = &noop_backing_dev_info; 1436 } 1437 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev), 1438 MINOR(fc->dev), suffix); 1439 if (err) 1440 return err; 1441 1442 /* fuse does it's own writeback accounting */ 1443 sb->s_bdi->capabilities &= ~BDI_CAP_WRITEBACK_ACCT; 1444 sb->s_bdi->capabilities |= BDI_CAP_STRICTLIMIT; 1445 1446 /* 1447 * For a single fuse filesystem use max 1% of dirty + 1448 * writeback threshold. 1449 * 1450 * This gives about 1M of write buffer for memory maps on a 1451 * machine with 1G and 10% dirty_ratio, which should be more 1452 * than enough. 1453 * 1454 * Privileged users can raise it by writing to 1455 * 1456 * /sys/class/bdi/<bdi>/max_ratio 1457 */ 1458 bdi_set_max_ratio(sb->s_bdi, 1); 1459 1460 return 0; 1461} 1462 1463struct fuse_dev *fuse_dev_alloc(void) 1464{ 1465 struct fuse_dev *fud; 1466 struct list_head *pq; 1467 1468 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL); 1469 if (!fud) 1470 return NULL; 1471 1472 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); 1473 if (!pq) { 1474 kfree(fud); 1475 return NULL; 1476 } 1477 1478 fud->pq.processing = pq; 1479 fuse_pqueue_init(&fud->pq); 1480 1481 return fud; 1482} 1483EXPORT_SYMBOL_GPL(fuse_dev_alloc); 1484 1485void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc) 1486{ 1487 fud->fc = fuse_conn_get(fc); 1488 spin_lock(&fc->lock); 1489 list_add_tail(&fud->entry, &fc->devices); 1490 spin_unlock(&fc->lock); 1491} 1492EXPORT_SYMBOL_GPL(fuse_dev_install); 1493 1494struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc) 1495{ 1496 struct fuse_dev *fud; 1497 1498 fud = fuse_dev_alloc(); 1499 if (!fud) 1500 return NULL; 1501 1502 fuse_dev_install(fud, fc); 1503 return fud; 1504} 1505EXPORT_SYMBOL_GPL(fuse_dev_alloc_install); 1506 1507void fuse_dev_free(struct fuse_dev *fud) 1508{ 1509 struct fuse_conn *fc = fud->fc; 1510 1511 if (fc) { 1512 spin_lock(&fc->lock); 1513 list_del(&fud->entry); 1514 spin_unlock(&fc->lock); 1515 1516 fuse_conn_put(fc); 1517 } 1518 kfree(fud->pq.processing); 1519 kfree(fud); 1520} 1521EXPORT_SYMBOL_GPL(fuse_dev_free); 1522 1523static void fuse_fill_attr_from_inode(struct fuse_attr *attr, 1524 const struct fuse_inode *fi) 1525{ 1526 struct timespec64 atime = inode_get_atime(&fi->inode); 1527 struct timespec64 mtime = inode_get_mtime(&fi->inode); 1528 struct timespec64 ctime = inode_get_ctime(&fi->inode); 1529 1530 *attr = (struct fuse_attr){ 1531 .ino = fi->inode.i_ino, 1532 .size = fi->inode.i_size, 1533 .blocks = fi->inode.i_blocks, 1534 .atime = atime.tv_sec, 1535 .mtime = mtime.tv_sec, 1536 .ctime = ctime.tv_sec, 1537 .atimensec = atime.tv_nsec, 1538 .mtimensec = mtime.tv_nsec, 1539 .ctimensec = ctime.tv_nsec, 1540 .mode = fi->inode.i_mode, 1541 .nlink = fi->inode.i_nlink, 1542 .uid = __kuid_val(fi->inode.i_uid), 1543 .gid = __kgid_val(fi->inode.i_gid), 1544 .rdev = fi->inode.i_rdev, 1545 .blksize = 1u << fi->inode.i_blkbits, 1546 }; 1547} 1548 1549static void fuse_sb_defaults(struct super_block *sb) 1550{ 1551 sb->s_magic = FUSE_SUPER_MAGIC; 1552 sb->s_op = &fuse_super_operations; 1553 sb->s_xattr = fuse_xattr_handlers; 1554 sb->s_maxbytes = MAX_LFS_FILESIZE; 1555 sb->s_time_gran = 1; 1556 sb->s_export_op = &fuse_export_operations; 1557 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE; 1558 if (sb->s_user_ns != &init_user_ns) 1559 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; 1560 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); 1561} 1562 1563static int fuse_fill_super_submount(struct super_block *sb, 1564 struct fuse_inode *parent_fi) 1565{ 1566 struct fuse_mount *fm = get_fuse_mount_super(sb); 1567 struct super_block *parent_sb = parent_fi->inode.i_sb; 1568 struct fuse_attr root_attr; 1569 struct inode *root; 1570 struct fuse_submount_lookup *sl; 1571 struct fuse_inode *fi; 1572 1573 fuse_sb_defaults(sb); 1574 fm->sb = sb; 1575 1576 WARN_ON(sb->s_bdi != &noop_backing_dev_info); 1577 sb->s_bdi = bdi_get(parent_sb->s_bdi); 1578 1579 sb->s_xattr = parent_sb->s_xattr; 1580 sb->s_export_op = parent_sb->s_export_op; 1581 sb->s_time_gran = parent_sb->s_time_gran; 1582 sb->s_blocksize = parent_sb->s_blocksize; 1583 sb->s_blocksize_bits = parent_sb->s_blocksize_bits; 1584 sb->s_subtype = kstrdup(parent_sb->s_subtype, GFP_KERNEL); 1585 if (parent_sb->s_subtype && !sb->s_subtype) 1586 return -ENOMEM; 1587 1588 fuse_fill_attr_from_inode(&root_attr, parent_fi); 1589 root = fuse_iget(sb, parent_fi->nodeid, 0, &root_attr, 0, 0); 1590 /* 1591 * This inode is just a duplicate, so it is not looked up and 1592 * its nlookup should not be incremented. fuse_iget() does 1593 * that, though, so undo it here. 1594 */ 1595 fi = get_fuse_inode(root); 1596 fi->nlookup--; 1597 1598 sb->s_d_op = &fuse_dentry_operations; 1599 sb->s_root = d_make_root(root); 1600 if (!sb->s_root) 1601 return -ENOMEM; 1602 1603 /* 1604 * Grab the parent's submount_lookup pointer and take a 1605 * reference on the shared nlookup from the parent. This is to 1606 * prevent the last forget for this nodeid from getting 1607 * triggered until all users have finished with it. 1608 */ 1609 sl = parent_fi->submount_lookup; 1610 WARN_ON(!sl); 1611 if (sl) { 1612 refcount_inc(&sl->count); 1613 fi->submount_lookup = sl; 1614 } 1615 1616 return 0; 1617} 1618 1619/* Filesystem context private data holds the FUSE inode of the mount point */ 1620static int fuse_get_tree_submount(struct fs_context *fsc) 1621{ 1622 struct fuse_mount *fm; 1623 struct fuse_inode *mp_fi = fsc->fs_private; 1624 struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode); 1625 struct super_block *sb; 1626 int err; 1627 1628 fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL); 1629 if (!fm) 1630 return -ENOMEM; 1631 1632 fm->fc = fuse_conn_get(fc); 1633 fsc->s_fs_info = fm; 1634 sb = sget_fc(fsc, NULL, set_anon_super_fc); 1635 if (fsc->s_fs_info) 1636 fuse_mount_destroy(fm); 1637 if (IS_ERR(sb)) 1638 return PTR_ERR(sb); 1639 1640 /* Initialize superblock, making @mp_fi its root */ 1641 err = fuse_fill_super_submount(sb, mp_fi); 1642 if (err) { 1643 deactivate_locked_super(sb); 1644 return err; 1645 } 1646 1647 down_write(&fc->killsb); 1648 list_add_tail(&fm->fc_entry, &fc->mounts); 1649 up_write(&fc->killsb); 1650 1651 sb->s_flags |= SB_ACTIVE; 1652 fsc->root = dget(sb->s_root); 1653 1654 return 0; 1655} 1656 1657static const struct fs_context_operations fuse_context_submount_ops = { 1658 .get_tree = fuse_get_tree_submount, 1659}; 1660 1661int fuse_init_fs_context_submount(struct fs_context *fsc) 1662{ 1663 fsc->ops = &fuse_context_submount_ops; 1664 return 0; 1665} 1666EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount); 1667 1668int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx) 1669{ 1670 struct fuse_dev *fud = NULL; 1671 struct fuse_mount *fm = get_fuse_mount_super(sb); 1672 struct fuse_conn *fc = fm->fc; 1673 struct inode *root; 1674 struct dentry *root_dentry; 1675 int err; 1676 1677 err = -EINVAL; 1678 if (sb->s_flags & SB_MANDLOCK) 1679 goto err; 1680 1681 rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc()); 1682 fuse_sb_defaults(sb); 1683 1684 if (ctx->is_bdev) { 1685#ifdef CONFIG_BLOCK 1686 err = -EINVAL; 1687 if (!sb_set_blocksize(sb, ctx->blksize)) 1688 goto err; 1689#endif 1690 } else { 1691 sb->s_blocksize = PAGE_SIZE; 1692 sb->s_blocksize_bits = PAGE_SHIFT; 1693 } 1694 1695 sb->s_subtype = ctx->subtype; 1696 ctx->subtype = NULL; 1697 if (IS_ENABLED(CONFIG_FUSE_DAX)) { 1698 err = fuse_dax_conn_alloc(fc, ctx->dax_mode, ctx->dax_dev); 1699 if (err) 1700 goto err; 1701 } 1702 1703 if (ctx->fudptr) { 1704 err = -ENOMEM; 1705 fud = fuse_dev_alloc_install(fc); 1706 if (!fud) 1707 goto err_free_dax; 1708 } 1709 1710 fc->dev = sb->s_dev; 1711 fm->sb = sb; 1712 err = fuse_bdi_init(fc, sb); 1713 if (err) 1714 goto err_dev_free; 1715 1716 /* Handle umasking inside the fuse code */ 1717 if (sb->s_flags & SB_POSIXACL) 1718 fc->dont_mask = 1; 1719 sb->s_flags |= SB_POSIXACL; 1720 1721 fc->default_permissions = ctx->default_permissions; 1722 fc->allow_other = ctx->allow_other; 1723 fc->user_id = ctx->user_id; 1724 fc->group_id = ctx->group_id; 1725 fc->legacy_opts_show = ctx->legacy_opts_show; 1726 fc->max_read = max_t(unsigned int, 4096, ctx->max_read); 1727 fc->destroy = ctx->destroy; 1728 fc->no_control = ctx->no_control; 1729 fc->no_force_umount = ctx->no_force_umount; 1730 1731 err = -ENOMEM; 1732 root = fuse_get_root_inode(sb, ctx->rootmode); 1733 sb->s_d_op = &fuse_root_dentry_operations; 1734 root_dentry = d_make_root(root); 1735 if (!root_dentry) 1736 goto err_dev_free; 1737 /* Root dentry doesn't have .d_revalidate */ 1738 sb->s_d_op = &fuse_dentry_operations; 1739 1740 mutex_lock(&fuse_mutex); 1741 err = -EINVAL; 1742 if (ctx->fudptr && *ctx->fudptr) 1743 goto err_unlock; 1744 1745 err = fuse_ctl_add_conn(fc); 1746 if (err) 1747 goto err_unlock; 1748 1749 list_add_tail(&fc->entry, &fuse_conn_list); 1750 sb->s_root = root_dentry; 1751 if (ctx->fudptr) 1752 *ctx->fudptr = fud; 1753 mutex_unlock(&fuse_mutex); 1754 return 0; 1755 1756 err_unlock: 1757 mutex_unlock(&fuse_mutex); 1758 dput(root_dentry); 1759 err_dev_free: 1760 if (fud) 1761 fuse_dev_free(fud); 1762 err_free_dax: 1763 if (IS_ENABLED(CONFIG_FUSE_DAX)) 1764 fuse_dax_conn_free(fc); 1765 err: 1766 return err; 1767} 1768EXPORT_SYMBOL_GPL(fuse_fill_super_common); 1769 1770static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc) 1771{ 1772 struct fuse_fs_context *ctx = fsc->fs_private; 1773 int err; 1774 1775 if (!ctx->file || !ctx->rootmode_present || 1776 !ctx->user_id_present || !ctx->group_id_present) 1777 return -EINVAL; 1778 1779 /* 1780 * Require mount to happen from the same user namespace which 1781 * opened /dev/fuse to prevent potential attacks. 1782 */ 1783 if ((ctx->file->f_op != &fuse_dev_operations) || 1784 (ctx->file->f_cred->user_ns != sb->s_user_ns)) 1785 return -EINVAL; 1786 ctx->fudptr = &ctx->file->private_data; 1787 1788 err = fuse_fill_super_common(sb, ctx); 1789 if (err) 1790 return err; 1791 /* file->private_data shall be visible on all CPUs after this */ 1792 smp_mb(); 1793 fuse_send_init(get_fuse_mount_super(sb)); 1794 return 0; 1795} 1796 1797/* 1798 * This is the path where user supplied an already initialized fuse dev. In 1799 * this case never create a new super if the old one is gone. 1800 */ 1801static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc) 1802{ 1803 return -ENOTCONN; 1804} 1805 1806static int fuse_test_super(struct super_block *sb, struct fs_context *fsc) 1807{ 1808 1809 return fsc->sget_key == get_fuse_conn_super(sb); 1810} 1811 1812static int fuse_get_tree(struct fs_context *fsc) 1813{ 1814 struct fuse_fs_context *ctx = fsc->fs_private; 1815 struct fuse_dev *fud; 1816 struct fuse_conn *fc; 1817 struct fuse_mount *fm; 1818 struct super_block *sb; 1819 int err; 1820 1821 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 1822 if (!fc) 1823 return -ENOMEM; 1824 1825 fm = kzalloc(sizeof(*fm), GFP_KERNEL); 1826 if (!fm) { 1827 kfree(fc); 1828 return -ENOMEM; 1829 } 1830 1831 fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL); 1832 fc->release = fuse_free_conn; 1833 1834 fsc->s_fs_info = fm; 1835 1836 if (ctx->fd_present) 1837 ctx->file = fget(ctx->fd); 1838 1839 if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) { 1840 err = get_tree_bdev(fsc, fuse_fill_super); 1841 goto out; 1842 } 1843 /* 1844 * While block dev mount can be initialized with a dummy device fd 1845 * (found by device name), normal fuse mounts can't 1846 */ 1847 err = -EINVAL; 1848 if (!ctx->file) 1849 goto out; 1850 1851 /* 1852 * Allow creating a fuse mount with an already initialized fuse 1853 * connection 1854 */ 1855 fud = READ_ONCE(ctx->file->private_data); 1856 if (ctx->file->f_op == &fuse_dev_operations && fud) { 1857 fsc->sget_key = fud->fc; 1858 sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super); 1859 err = PTR_ERR_OR_ZERO(sb); 1860 if (!IS_ERR(sb)) 1861 fsc->root = dget(sb->s_root); 1862 } else { 1863 err = get_tree_nodev(fsc, fuse_fill_super); 1864 } 1865out: 1866 if (fsc->s_fs_info) 1867 fuse_mount_destroy(fm); 1868 if (ctx->file) 1869 fput(ctx->file); 1870 return err; 1871} 1872 1873static const struct fs_context_operations fuse_context_ops = { 1874 .free = fuse_free_fsc, 1875 .parse_param = fuse_parse_param, 1876 .reconfigure = fuse_reconfigure, 1877 .get_tree = fuse_get_tree, 1878}; 1879 1880/* 1881 * Set up the filesystem mount context. 1882 */ 1883static int fuse_init_fs_context(struct fs_context *fsc) 1884{ 1885 struct fuse_fs_context *ctx; 1886 1887 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); 1888 if (!ctx) 1889 return -ENOMEM; 1890 1891 ctx->max_read = ~0; 1892 ctx->blksize = FUSE_DEFAULT_BLKSIZE; 1893 ctx->legacy_opts_show = true; 1894 1895#ifdef CONFIG_BLOCK 1896 if (fsc->fs_type == &fuseblk_fs_type) { 1897 ctx->is_bdev = true; 1898 ctx->destroy = true; 1899 } 1900#endif 1901 1902 fsc->fs_private = ctx; 1903 fsc->ops = &fuse_context_ops; 1904 return 0; 1905} 1906 1907bool fuse_mount_remove(struct fuse_mount *fm) 1908{ 1909 struct fuse_conn *fc = fm->fc; 1910 bool last = false; 1911 1912 down_write(&fc->killsb); 1913 list_del_init(&fm->fc_entry); 1914 if (list_empty(&fc->mounts)) 1915 last = true; 1916 up_write(&fc->killsb); 1917 1918 return last; 1919} 1920EXPORT_SYMBOL_GPL(fuse_mount_remove); 1921 1922void fuse_conn_destroy(struct fuse_mount *fm) 1923{ 1924 struct fuse_conn *fc = fm->fc; 1925 1926 if (fc->destroy) 1927 fuse_send_destroy(fm); 1928 1929 fuse_abort_conn(fc); 1930 fuse_wait_aborted(fc); 1931 1932 if (!list_empty(&fc->entry)) { 1933 mutex_lock(&fuse_mutex); 1934 list_del(&fc->entry); 1935 fuse_ctl_remove_conn(fc); 1936 mutex_unlock(&fuse_mutex); 1937 } 1938} 1939EXPORT_SYMBOL_GPL(fuse_conn_destroy); 1940 1941static void fuse_sb_destroy(struct super_block *sb) 1942{ 1943 struct fuse_mount *fm = get_fuse_mount_super(sb); 1944 bool last; 1945 1946 if (sb->s_root) { 1947 last = fuse_mount_remove(fm); 1948 if (last) 1949 fuse_conn_destroy(fm); 1950 } 1951} 1952 1953void fuse_mount_destroy(struct fuse_mount *fm) 1954{ 1955 fuse_conn_put(fm->fc); 1956 kfree_rcu(fm, rcu); 1957} 1958EXPORT_SYMBOL(fuse_mount_destroy); 1959 1960static void fuse_kill_sb_anon(struct super_block *sb) 1961{ 1962 fuse_sb_destroy(sb); 1963 kill_anon_super(sb); 1964 fuse_mount_destroy(get_fuse_mount_super(sb)); 1965} 1966 1967static struct file_system_type fuse_fs_type = { 1968 .owner = THIS_MODULE, 1969 .name = "fuse", 1970 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT, 1971 .init_fs_context = fuse_init_fs_context, 1972 .parameters = fuse_fs_parameters, 1973 .kill_sb = fuse_kill_sb_anon, 1974}; 1975MODULE_ALIAS_FS("fuse"); 1976 1977#ifdef CONFIG_BLOCK 1978static void fuse_kill_sb_blk(struct super_block *sb) 1979{ 1980 fuse_sb_destroy(sb); 1981 kill_block_super(sb); 1982 fuse_mount_destroy(get_fuse_mount_super(sb)); 1983} 1984 1985static struct file_system_type fuseblk_fs_type = { 1986 .owner = THIS_MODULE, 1987 .name = "fuseblk", 1988 .init_fs_context = fuse_init_fs_context, 1989 .parameters = fuse_fs_parameters, 1990 .kill_sb = fuse_kill_sb_blk, 1991 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 1992}; 1993MODULE_ALIAS_FS("fuseblk"); 1994 1995static inline int register_fuseblk(void) 1996{ 1997 return register_filesystem(&fuseblk_fs_type); 1998} 1999 2000static inline void unregister_fuseblk(void) 2001{ 2002 unregister_filesystem(&fuseblk_fs_type); 2003} 2004#else 2005static inline int register_fuseblk(void) 2006{ 2007 return 0; 2008} 2009 2010static inline void unregister_fuseblk(void) 2011{ 2012} 2013#endif 2014 2015static void fuse_inode_init_once(void *foo) 2016{ 2017 struct inode *inode = foo; 2018 2019 inode_init_once(inode); 2020} 2021 2022static int __init fuse_fs_init(void) 2023{ 2024 int err; 2025 2026 fuse_inode_cachep = kmem_cache_create("fuse_inode", 2027 sizeof(struct fuse_inode), 0, 2028 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT, 2029 fuse_inode_init_once); 2030 err = -ENOMEM; 2031 if (!fuse_inode_cachep) 2032 goto out; 2033 2034 err = register_fuseblk(); 2035 if (err) 2036 goto out2; 2037 2038 err = register_filesystem(&fuse_fs_type); 2039 if (err) 2040 goto out3; 2041 2042 return 0; 2043 2044 out3: 2045 unregister_fuseblk(); 2046 out2: 2047 kmem_cache_destroy(fuse_inode_cachep); 2048 out: 2049 return err; 2050} 2051 2052static void fuse_fs_cleanup(void) 2053{ 2054 unregister_filesystem(&fuse_fs_type); 2055 unregister_fuseblk(); 2056 2057 /* 2058 * Make sure all delayed rcu free inodes are flushed before we 2059 * destroy cache. 2060 */ 2061 rcu_barrier(); 2062 kmem_cache_destroy(fuse_inode_cachep); 2063} 2064 2065static struct kobject *fuse_kobj; 2066 2067static int fuse_sysfs_init(void) 2068{ 2069 int err; 2070 2071 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 2072 if (!fuse_kobj) { 2073 err = -ENOMEM; 2074 goto out_err; 2075 } 2076 2077 err = sysfs_create_mount_point(fuse_kobj, "connections"); 2078 if (err) 2079 goto out_fuse_unregister; 2080 2081 return 0; 2082 2083 out_fuse_unregister: 2084 kobject_put(fuse_kobj); 2085 out_err: 2086 return err; 2087} 2088 2089static void fuse_sysfs_cleanup(void) 2090{ 2091 sysfs_remove_mount_point(fuse_kobj, "connections"); 2092 kobject_put(fuse_kobj); 2093} 2094 2095static int __init fuse_init(void) 2096{ 2097 int res; 2098 2099 pr_info("init (API version %i.%i)\n", 2100 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 2101 2102 INIT_LIST_HEAD(&fuse_conn_list); 2103 res = fuse_fs_init(); 2104 if (res) 2105 goto err; 2106 2107 res = fuse_dev_init(); 2108 if (res) 2109 goto err_fs_cleanup; 2110 2111 res = fuse_sysfs_init(); 2112 if (res) 2113 goto err_dev_cleanup; 2114 2115 res = fuse_ctl_init(); 2116 if (res) 2117 goto err_sysfs_cleanup; 2118 2119 sanitize_global_limit(&max_user_bgreq); 2120 sanitize_global_limit(&max_user_congthresh); 2121 2122 return 0; 2123 2124 err_sysfs_cleanup: 2125 fuse_sysfs_cleanup(); 2126 err_dev_cleanup: 2127 fuse_dev_cleanup(); 2128 err_fs_cleanup: 2129 fuse_fs_cleanup(); 2130 err: 2131 return res; 2132} 2133 2134static void __exit fuse_exit(void) 2135{ 2136 pr_debug("exit\n"); 2137 2138 fuse_ctl_cleanup(); 2139 fuse_sysfs_cleanup(); 2140 fuse_fs_cleanup(); 2141 fuse_dev_cleanup(); 2142} 2143 2144module_init(fuse_init); 2145module_exit(fuse_exit); 2146