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/parser.h> 19 #include <linux/statfs.h> 20 #include <linux/random.h> 21 #include <linux/sched.h> 22 #include <linux/exportfs.h> 23 #include <linux/posix_acl.h> 24 #include <linux/pid_namespace.h> 25 26 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); 27 MODULE_DESCRIPTION("Filesystem in Userspace"); 28 MODULE_LICENSE("GPL"); 29 30 static struct kmem_cache *fuse_inode_cachep; 31 struct list_head fuse_conn_list; 32 DEFINE_MUTEX(fuse_mutex); 33 34 static int set_global_limit(const char *val, const struct kernel_param *kp); 35 36 unsigned max_user_bgreq; 37 module_param_call(max_user_bgreq, set_global_limit, param_get_uint, 38 &max_user_bgreq, 0644); 39 __MODULE_PARM_TYPE(max_user_bgreq, "uint"); 40 MODULE_PARM_DESC(max_user_bgreq, 41 "Global limit for the maximum number of backgrounded requests an " 42 "unprivileged user can set"); 43 44 unsigned max_user_congthresh; 45 module_param_call(max_user_congthresh, set_global_limit, param_get_uint, 46 &max_user_congthresh, 0644); 47 __MODULE_PARM_TYPE(max_user_congthresh, "uint"); 48 MODULE_PARM_DESC(max_user_congthresh, 49 "Global limit for the maximum congestion threshold an " 50 "unprivileged user can set"); 51 52 #define FUSE_SUPER_MAGIC 0x65735546 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 struct fuse_mount_data { 63 int fd; 64 unsigned rootmode; 65 kuid_t user_id; 66 kgid_t group_id; 67 unsigned fd_present:1; 68 unsigned rootmode_present:1; 69 unsigned user_id_present:1; 70 unsigned group_id_present:1; 71 unsigned default_permissions:1; 72 unsigned allow_other:1; 73 unsigned max_read; 74 unsigned blksize; 75 }; 76 77 struct fuse_forget_link *fuse_alloc_forget(void) 78 { 79 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL); 80 } 81 82 static struct inode *fuse_alloc_inode(struct super_block *sb) 83 { 84 struct inode *inode; 85 struct fuse_inode *fi; 86 87 inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL); 88 if (!inode) 89 return NULL; 90 91 fi = get_fuse_inode(inode); 92 fi->i_time = 0; 93 fi->inval_mask = 0; 94 fi->nodeid = 0; 95 fi->nlookup = 0; 96 fi->attr_version = 0; 97 fi->orig_ino = 0; 98 fi->state = 0; 99 mutex_init(&fi->mutex); 100 spin_lock_init(&fi->lock); 101 fi->forget = fuse_alloc_forget(); 102 if (!fi->forget) { 103 kmem_cache_free(fuse_inode_cachep, inode); 104 return NULL; 105 } 106 107 return inode; 108 } 109 110 static void fuse_i_callback(struct rcu_head *head) 111 { 112 struct inode *inode = container_of(head, struct inode, i_rcu); 113 kmem_cache_free(fuse_inode_cachep, inode); 114 } 115 116 static void fuse_destroy_inode(struct inode *inode) 117 { 118 struct fuse_inode *fi = get_fuse_inode(inode); 119 if (S_ISREG(inode->i_mode) && !is_bad_inode(inode)) { 120 WARN_ON(!list_empty(&fi->write_files)); 121 WARN_ON(!list_empty(&fi->queued_writes)); 122 } 123 mutex_destroy(&fi->mutex); 124 kfree(fi->forget); 125 call_rcu(&inode->i_rcu, fuse_i_callback); 126 } 127 128 static void fuse_evict_inode(struct inode *inode) 129 { 130 truncate_inode_pages_final(&inode->i_data); 131 clear_inode(inode); 132 if (inode->i_sb->s_flags & SB_ACTIVE) { 133 struct fuse_conn *fc = get_fuse_conn(inode); 134 struct fuse_inode *fi = get_fuse_inode(inode); 135 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup); 136 fi->forget = NULL; 137 } 138 } 139 140 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data) 141 { 142 sync_filesystem(sb); 143 if (*flags & SB_MANDLOCK) 144 return -EINVAL; 145 146 return 0; 147 } 148 149 /* 150 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down 151 * so that it will fit. 152 */ 153 static ino_t fuse_squash_ino(u64 ino64) 154 { 155 ino_t ino = (ino_t) ino64; 156 if (sizeof(ino_t) < sizeof(u64)) 157 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8; 158 return ino; 159 } 160 161 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, 162 u64 attr_valid) 163 { 164 struct fuse_conn *fc = get_fuse_conn(inode); 165 struct fuse_inode *fi = get_fuse_inode(inode); 166 167 lockdep_assert_held(&fi->lock); 168 169 fi->attr_version = atomic64_inc_return(&fc->attr_version); 170 fi->i_time = attr_valid; 171 WRITE_ONCE(fi->inval_mask, 0); 172 173 inode->i_ino = fuse_squash_ino(attr->ino); 174 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 175 set_nlink(inode, attr->nlink); 176 inode->i_uid = make_kuid(fc->user_ns, attr->uid); 177 inode->i_gid = make_kgid(fc->user_ns, attr->gid); 178 inode->i_blocks = attr->blocks; 179 inode->i_atime.tv_sec = attr->atime; 180 inode->i_atime.tv_nsec = attr->atimensec; 181 /* mtime from server may be stale due to local buffered write */ 182 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) { 183 inode->i_mtime.tv_sec = attr->mtime; 184 inode->i_mtime.tv_nsec = attr->mtimensec; 185 inode->i_ctime.tv_sec = attr->ctime; 186 inode->i_ctime.tv_nsec = attr->ctimensec; 187 } 188 189 if (attr->blksize != 0) 190 inode->i_blkbits = ilog2(attr->blksize); 191 else 192 inode->i_blkbits = inode->i_sb->s_blocksize_bits; 193 194 /* 195 * Don't set the sticky bit in i_mode, unless we want the VFS 196 * to check permissions. This prevents failures due to the 197 * check in may_delete(). 198 */ 199 fi->orig_i_mode = inode->i_mode; 200 if (!fc->default_permissions) 201 inode->i_mode &= ~S_ISVTX; 202 203 fi->orig_ino = attr->ino; 204 } 205 206 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, 207 u64 attr_valid, u64 attr_version) 208 { 209 struct fuse_conn *fc = get_fuse_conn(inode); 210 struct fuse_inode *fi = get_fuse_inode(inode); 211 bool is_wb = fc->writeback_cache; 212 loff_t oldsize; 213 struct timespec64 old_mtime; 214 215 spin_lock(&fi->lock); 216 if ((attr_version != 0 && fi->attr_version > attr_version) || 217 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { 218 spin_unlock(&fi->lock); 219 return; 220 } 221 222 old_mtime = inode->i_mtime; 223 fuse_change_attributes_common(inode, attr, attr_valid); 224 225 oldsize = inode->i_size; 226 /* 227 * In case of writeback_cache enabled, the cached writes beyond EOF 228 * extend local i_size without keeping userspace server in sync. So, 229 * attr->size coming from server can be stale. We cannot trust it. 230 */ 231 if (!is_wb || !S_ISREG(inode->i_mode)) 232 i_size_write(inode, attr->size); 233 spin_unlock(&fi->lock); 234 235 if (!is_wb && S_ISREG(inode->i_mode)) { 236 bool inval = false; 237 238 if (oldsize != attr->size) { 239 truncate_pagecache(inode, attr->size); 240 inval = true; 241 } else if (fc->auto_inval_data) { 242 struct timespec64 new_mtime = { 243 .tv_sec = attr->mtime, 244 .tv_nsec = attr->mtimensec, 245 }; 246 247 /* 248 * Auto inval mode also checks and invalidates if mtime 249 * has changed. 250 */ 251 if (!timespec64_equal(&old_mtime, &new_mtime)) 252 inval = true; 253 } 254 255 if (inval) 256 invalidate_inode_pages2(inode->i_mapping); 257 } 258 } 259 260 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) 261 { 262 inode->i_mode = attr->mode & S_IFMT; 263 inode->i_size = attr->size; 264 inode->i_mtime.tv_sec = attr->mtime; 265 inode->i_mtime.tv_nsec = attr->mtimensec; 266 inode->i_ctime.tv_sec = attr->ctime; 267 inode->i_ctime.tv_nsec = attr->ctimensec; 268 if (S_ISREG(inode->i_mode)) { 269 fuse_init_common(inode); 270 fuse_init_file_inode(inode); 271 } else if (S_ISDIR(inode->i_mode)) 272 fuse_init_dir(inode); 273 else if (S_ISLNK(inode->i_mode)) 274 fuse_init_symlink(inode); 275 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || 276 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { 277 fuse_init_common(inode); 278 init_special_inode(inode, inode->i_mode, 279 new_decode_dev(attr->rdev)); 280 } else 281 BUG(); 282 } 283 284 int fuse_inode_eq(struct inode *inode, void *_nodeidp) 285 { 286 u64 nodeid = *(u64 *) _nodeidp; 287 if (get_node_id(inode) == nodeid) 288 return 1; 289 else 290 return 0; 291 } 292 293 static int fuse_inode_set(struct inode *inode, void *_nodeidp) 294 { 295 u64 nodeid = *(u64 *) _nodeidp; 296 get_fuse_inode(inode)->nodeid = nodeid; 297 return 0; 298 } 299 300 struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 301 int generation, struct fuse_attr *attr, 302 u64 attr_valid, u64 attr_version) 303 { 304 struct inode *inode; 305 struct fuse_inode *fi; 306 struct fuse_conn *fc = get_fuse_conn_super(sb); 307 308 retry: 309 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); 310 if (!inode) 311 return NULL; 312 313 if ((inode->i_state & I_NEW)) { 314 inode->i_flags |= S_NOATIME; 315 if (!fc->writeback_cache || !S_ISREG(attr->mode)) 316 inode->i_flags |= S_NOCMTIME; 317 inode->i_generation = generation; 318 fuse_init_inode(inode, attr); 319 unlock_new_inode(inode); 320 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) { 321 /* Inode has changed type, any I/O on the old should fail */ 322 make_bad_inode(inode); 323 iput(inode); 324 goto retry; 325 } 326 327 fi = get_fuse_inode(inode); 328 spin_lock(&fi->lock); 329 fi->nlookup++; 330 spin_unlock(&fi->lock); 331 fuse_change_attributes(inode, attr, attr_valid, attr_version); 332 333 return inode; 334 } 335 336 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid, 337 loff_t offset, loff_t len) 338 { 339 struct inode *inode; 340 pgoff_t pg_start; 341 pgoff_t pg_end; 342 343 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid); 344 if (!inode) 345 return -ENOENT; 346 347 fuse_invalidate_attr(inode); 348 forget_all_cached_acls(inode); 349 if (offset >= 0) { 350 pg_start = offset >> PAGE_SHIFT; 351 if (len <= 0) 352 pg_end = -1; 353 else 354 pg_end = (offset + len - 1) >> PAGE_SHIFT; 355 invalidate_inode_pages2_range(inode->i_mapping, 356 pg_start, pg_end); 357 } 358 iput(inode); 359 return 0; 360 } 361 362 bool fuse_lock_inode(struct inode *inode) 363 { 364 bool locked = false; 365 366 if (!get_fuse_conn(inode)->parallel_dirops) { 367 mutex_lock(&get_fuse_inode(inode)->mutex); 368 locked = true; 369 } 370 371 return locked; 372 } 373 374 void fuse_unlock_inode(struct inode *inode, bool locked) 375 { 376 if (locked) 377 mutex_unlock(&get_fuse_inode(inode)->mutex); 378 } 379 380 static void fuse_umount_begin(struct super_block *sb) 381 { 382 fuse_abort_conn(get_fuse_conn_super(sb)); 383 } 384 385 static void fuse_send_destroy(struct fuse_conn *fc) 386 { 387 struct fuse_req *req = fc->destroy_req; 388 if (req && fc->conn_init) { 389 fc->destroy_req = NULL; 390 req->in.h.opcode = FUSE_DESTROY; 391 __set_bit(FR_FORCE, &req->flags); 392 __clear_bit(FR_BACKGROUND, &req->flags); 393 fuse_request_send(fc, req); 394 fuse_put_request(fc, req); 395 } 396 } 397 398 static void fuse_put_super(struct super_block *sb) 399 { 400 struct fuse_conn *fc = get_fuse_conn_super(sb); 401 402 mutex_lock(&fuse_mutex); 403 list_del(&fc->entry); 404 fuse_ctl_remove_conn(fc); 405 mutex_unlock(&fuse_mutex); 406 407 fuse_conn_put(fc); 408 } 409 410 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 411 { 412 stbuf->f_type = FUSE_SUPER_MAGIC; 413 stbuf->f_bsize = attr->bsize; 414 stbuf->f_frsize = attr->frsize; 415 stbuf->f_blocks = attr->blocks; 416 stbuf->f_bfree = attr->bfree; 417 stbuf->f_bavail = attr->bavail; 418 stbuf->f_files = attr->files; 419 stbuf->f_ffree = attr->ffree; 420 stbuf->f_namelen = attr->namelen; 421 /* fsid is left zero */ 422 } 423 424 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 425 { 426 struct super_block *sb = dentry->d_sb; 427 struct fuse_conn *fc = get_fuse_conn_super(sb); 428 FUSE_ARGS(args); 429 struct fuse_statfs_out outarg; 430 int err; 431 432 if (!fuse_allow_current_process(fc)) { 433 buf->f_type = FUSE_SUPER_MAGIC; 434 return 0; 435 } 436 437 memset(&outarg, 0, sizeof(outarg)); 438 args.in.numargs = 0; 439 args.in.h.opcode = FUSE_STATFS; 440 args.in.h.nodeid = get_node_id(d_inode(dentry)); 441 args.out.numargs = 1; 442 args.out.args[0].size = sizeof(outarg); 443 args.out.args[0].value = &outarg; 444 err = fuse_simple_request(fc, &args); 445 if (!err) 446 convert_fuse_statfs(buf, &outarg.st); 447 return err; 448 } 449 450 enum { 451 OPT_FD, 452 OPT_ROOTMODE, 453 OPT_USER_ID, 454 OPT_GROUP_ID, 455 OPT_DEFAULT_PERMISSIONS, 456 OPT_ALLOW_OTHER, 457 OPT_MAX_READ, 458 OPT_BLKSIZE, 459 OPT_ERR 460 }; 461 462 static const match_table_t tokens = { 463 {OPT_FD, "fd=%u"}, 464 {OPT_ROOTMODE, "rootmode=%o"}, 465 {OPT_USER_ID, "user_id=%u"}, 466 {OPT_GROUP_ID, "group_id=%u"}, 467 {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, 468 {OPT_ALLOW_OTHER, "allow_other"}, 469 {OPT_MAX_READ, "max_read=%u"}, 470 {OPT_BLKSIZE, "blksize=%u"}, 471 {OPT_ERR, NULL} 472 }; 473 474 static int fuse_match_uint(substring_t *s, unsigned int *res) 475 { 476 int err = -ENOMEM; 477 char *buf = match_strdup(s); 478 if (buf) { 479 err = kstrtouint(buf, 10, res); 480 kfree(buf); 481 } 482 return err; 483 } 484 485 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev, 486 struct user_namespace *user_ns) 487 { 488 char *p; 489 memset(d, 0, sizeof(struct fuse_mount_data)); 490 d->max_read = ~0; 491 d->blksize = FUSE_DEFAULT_BLKSIZE; 492 493 while ((p = strsep(&opt, ",")) != NULL) { 494 int token; 495 int value; 496 unsigned uv; 497 substring_t args[MAX_OPT_ARGS]; 498 if (!*p) 499 continue; 500 501 token = match_token(p, tokens, args); 502 switch (token) { 503 case OPT_FD: 504 if (match_int(&args[0], &value)) 505 return 0; 506 d->fd = value; 507 d->fd_present = 1; 508 break; 509 510 case OPT_ROOTMODE: 511 if (match_octal(&args[0], &value)) 512 return 0; 513 if (!fuse_valid_type(value)) 514 return 0; 515 d->rootmode = value; 516 d->rootmode_present = 1; 517 break; 518 519 case OPT_USER_ID: 520 if (fuse_match_uint(&args[0], &uv)) 521 return 0; 522 d->user_id = make_kuid(user_ns, uv); 523 if (!uid_valid(d->user_id)) 524 return 0; 525 d->user_id_present = 1; 526 break; 527 528 case OPT_GROUP_ID: 529 if (fuse_match_uint(&args[0], &uv)) 530 return 0; 531 d->group_id = make_kgid(user_ns, uv); 532 if (!gid_valid(d->group_id)) 533 return 0; 534 d->group_id_present = 1; 535 break; 536 537 case OPT_DEFAULT_PERMISSIONS: 538 d->default_permissions = 1; 539 break; 540 541 case OPT_ALLOW_OTHER: 542 d->allow_other = 1; 543 break; 544 545 case OPT_MAX_READ: 546 if (match_int(&args[0], &value)) 547 return 0; 548 d->max_read = value; 549 break; 550 551 case OPT_BLKSIZE: 552 if (!is_bdev || match_int(&args[0], &value)) 553 return 0; 554 d->blksize = value; 555 break; 556 557 default: 558 return 0; 559 } 560 } 561 562 if (!d->fd_present || !d->rootmode_present || 563 !d->user_id_present || !d->group_id_present) 564 return 0; 565 566 return 1; 567 } 568 569 static int fuse_show_options(struct seq_file *m, struct dentry *root) 570 { 571 struct super_block *sb = root->d_sb; 572 struct fuse_conn *fc = get_fuse_conn_super(sb); 573 574 seq_printf(m, ",user_id=%u", from_kuid_munged(fc->user_ns, fc->user_id)); 575 seq_printf(m, ",group_id=%u", from_kgid_munged(fc->user_ns, fc->group_id)); 576 if (fc->default_permissions) 577 seq_puts(m, ",default_permissions"); 578 if (fc->allow_other) 579 seq_puts(m, ",allow_other"); 580 if (fc->max_read != ~0) 581 seq_printf(m, ",max_read=%u", fc->max_read); 582 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 583 seq_printf(m, ",blksize=%lu", sb->s_blocksize); 584 return 0; 585 } 586 587 static void fuse_iqueue_init(struct fuse_iqueue *fiq) 588 { 589 memset(fiq, 0, sizeof(struct fuse_iqueue)); 590 init_waitqueue_head(&fiq->waitq); 591 INIT_LIST_HEAD(&fiq->pending); 592 INIT_LIST_HEAD(&fiq->interrupts); 593 fiq->forget_list_tail = &fiq->forget_list_head; 594 fiq->connected = 1; 595 } 596 597 static void fuse_pqueue_init(struct fuse_pqueue *fpq) 598 { 599 unsigned int i; 600 601 spin_lock_init(&fpq->lock); 602 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) 603 INIT_LIST_HEAD(&fpq->processing[i]); 604 INIT_LIST_HEAD(&fpq->io); 605 fpq->connected = 1; 606 } 607 608 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns) 609 { 610 memset(fc, 0, sizeof(*fc)); 611 spin_lock_init(&fc->lock); 612 spin_lock_init(&fc->bg_lock); 613 init_rwsem(&fc->killsb); 614 refcount_set(&fc->count, 1); 615 atomic_set(&fc->dev_count, 1); 616 init_waitqueue_head(&fc->blocked_waitq); 617 init_waitqueue_head(&fc->reserved_req_waitq); 618 fuse_iqueue_init(&fc->iq); 619 INIT_LIST_HEAD(&fc->bg_queue); 620 INIT_LIST_HEAD(&fc->entry); 621 INIT_LIST_HEAD(&fc->devices); 622 atomic_set(&fc->num_waiting, 0); 623 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND; 624 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD; 625 atomic64_set(&fc->khctr, 0); 626 fc->polled_files = RB_ROOT; 627 fc->blocked = 0; 628 fc->initialized = 0; 629 fc->connected = 1; 630 atomic64_set(&fc->attr_version, 1); 631 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 632 fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); 633 fc->user_ns = get_user_ns(user_ns); 634 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ; 635 } 636 EXPORT_SYMBOL_GPL(fuse_conn_init); 637 638 void fuse_conn_put(struct fuse_conn *fc) 639 { 640 if (refcount_dec_and_test(&fc->count)) { 641 if (fc->destroy_req) 642 fuse_request_free(fc->destroy_req); 643 put_pid_ns(fc->pid_ns); 644 put_user_ns(fc->user_ns); 645 fc->release(fc); 646 } 647 } 648 EXPORT_SYMBOL_GPL(fuse_conn_put); 649 650 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 651 { 652 refcount_inc(&fc->count); 653 return fc; 654 } 655 EXPORT_SYMBOL_GPL(fuse_conn_get); 656 657 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 658 { 659 struct fuse_attr attr; 660 memset(&attr, 0, sizeof(attr)); 661 662 attr.mode = mode; 663 attr.ino = FUSE_ROOT_ID; 664 attr.nlink = 1; 665 return fuse_iget(sb, 1, 0, &attr, 0, 0); 666 } 667 668 struct fuse_inode_handle { 669 u64 nodeid; 670 u32 generation; 671 }; 672 673 static struct dentry *fuse_get_dentry(struct super_block *sb, 674 struct fuse_inode_handle *handle) 675 { 676 struct fuse_conn *fc = get_fuse_conn_super(sb); 677 struct inode *inode; 678 struct dentry *entry; 679 int err = -ESTALE; 680 681 if (handle->nodeid == 0) 682 goto out_err; 683 684 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 685 if (!inode) { 686 struct fuse_entry_out outarg; 687 const struct qstr name = QSTR_INIT(".", 1); 688 689 if (!fc->export_support) 690 goto out_err; 691 692 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 693 &inode); 694 if (err && err != -ENOENT) 695 goto out_err; 696 if (err || !inode) { 697 err = -ESTALE; 698 goto out_err; 699 } 700 err = -EIO; 701 if (get_node_id(inode) != handle->nodeid) 702 goto out_iput; 703 } 704 err = -ESTALE; 705 if (inode->i_generation != handle->generation) 706 goto out_iput; 707 708 entry = d_obtain_alias(inode); 709 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) 710 fuse_invalidate_entry_cache(entry); 711 712 return entry; 713 714 out_iput: 715 iput(inode); 716 out_err: 717 return ERR_PTR(err); 718 } 719 720 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len, 721 struct inode *parent) 722 { 723 int len = parent ? 6 : 3; 724 u64 nodeid; 725 u32 generation; 726 727 if (*max_len < len) { 728 *max_len = len; 729 return FILEID_INVALID; 730 } 731 732 nodeid = get_fuse_inode(inode)->nodeid; 733 generation = inode->i_generation; 734 735 fh[0] = (u32)(nodeid >> 32); 736 fh[1] = (u32)(nodeid & 0xffffffff); 737 fh[2] = generation; 738 739 if (parent) { 740 nodeid = get_fuse_inode(parent)->nodeid; 741 generation = parent->i_generation; 742 743 fh[3] = (u32)(nodeid >> 32); 744 fh[4] = (u32)(nodeid & 0xffffffff); 745 fh[5] = generation; 746 } 747 748 *max_len = len; 749 return parent ? 0x82 : 0x81; 750 } 751 752 static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 753 struct fid *fid, int fh_len, int fh_type) 754 { 755 struct fuse_inode_handle handle; 756 757 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) 758 return NULL; 759 760 handle.nodeid = (u64) fid->raw[0] << 32; 761 handle.nodeid |= (u64) fid->raw[1]; 762 handle.generation = fid->raw[2]; 763 return fuse_get_dentry(sb, &handle); 764 } 765 766 static struct dentry *fuse_fh_to_parent(struct super_block *sb, 767 struct fid *fid, int fh_len, int fh_type) 768 { 769 struct fuse_inode_handle parent; 770 771 if (fh_type != 0x82 || fh_len < 6) 772 return NULL; 773 774 parent.nodeid = (u64) fid->raw[3] << 32; 775 parent.nodeid |= (u64) fid->raw[4]; 776 parent.generation = fid->raw[5]; 777 return fuse_get_dentry(sb, &parent); 778 } 779 780 static struct dentry *fuse_get_parent(struct dentry *child) 781 { 782 struct inode *child_inode = d_inode(child); 783 struct fuse_conn *fc = get_fuse_conn(child_inode); 784 struct inode *inode; 785 struct dentry *parent; 786 struct fuse_entry_out outarg; 787 const struct qstr name = QSTR_INIT("..", 2); 788 int err; 789 790 if (!fc->export_support) 791 return ERR_PTR(-ESTALE); 792 793 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 794 &name, &outarg, &inode); 795 if (err) { 796 if (err == -ENOENT) 797 return ERR_PTR(-ESTALE); 798 return ERR_PTR(err); 799 } 800 801 parent = d_obtain_alias(inode); 802 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) 803 fuse_invalidate_entry_cache(parent); 804 805 return parent; 806 } 807 808 static const struct export_operations fuse_export_operations = { 809 .fh_to_dentry = fuse_fh_to_dentry, 810 .fh_to_parent = fuse_fh_to_parent, 811 .encode_fh = fuse_encode_fh, 812 .get_parent = fuse_get_parent, 813 }; 814 815 static const struct super_operations fuse_super_operations = { 816 .alloc_inode = fuse_alloc_inode, 817 .destroy_inode = fuse_destroy_inode, 818 .evict_inode = fuse_evict_inode, 819 .write_inode = fuse_write_inode, 820 .drop_inode = generic_delete_inode, 821 .remount_fs = fuse_remount_fs, 822 .put_super = fuse_put_super, 823 .umount_begin = fuse_umount_begin, 824 .statfs = fuse_statfs, 825 .show_options = fuse_show_options, 826 }; 827 828 static void sanitize_global_limit(unsigned *limit) 829 { 830 if (*limit == 0) 831 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 832 sizeof(struct fuse_req); 833 834 if (*limit >= 1 << 16) 835 *limit = (1 << 16) - 1; 836 } 837 838 static int set_global_limit(const char *val, const struct kernel_param *kp) 839 { 840 int rv; 841 842 rv = param_set_uint(val, kp); 843 if (rv) 844 return rv; 845 846 sanitize_global_limit((unsigned *)kp->arg); 847 848 return 0; 849 } 850 851 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg) 852 { 853 int cap_sys_admin = capable(CAP_SYS_ADMIN); 854 855 if (arg->minor < 13) 856 return; 857 858 sanitize_global_limit(&max_user_bgreq); 859 sanitize_global_limit(&max_user_congthresh); 860 861 spin_lock(&fc->bg_lock); 862 if (arg->max_background) { 863 fc->max_background = arg->max_background; 864 865 if (!cap_sys_admin && fc->max_background > max_user_bgreq) 866 fc->max_background = max_user_bgreq; 867 } 868 if (arg->congestion_threshold) { 869 fc->congestion_threshold = arg->congestion_threshold; 870 871 if (!cap_sys_admin && 872 fc->congestion_threshold > max_user_congthresh) 873 fc->congestion_threshold = max_user_congthresh; 874 } 875 spin_unlock(&fc->bg_lock); 876 } 877 878 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) 879 { 880 struct fuse_init_out *arg = &req->misc.init_out; 881 882 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION) 883 fc->conn_error = 1; 884 else { 885 unsigned long ra_pages; 886 887 process_init_limits(fc, arg); 888 889 if (arg->minor >= 6) { 890 ra_pages = arg->max_readahead / PAGE_SIZE; 891 if (arg->flags & FUSE_ASYNC_READ) 892 fc->async_read = 1; 893 if (!(arg->flags & FUSE_POSIX_LOCKS)) 894 fc->no_lock = 1; 895 if (arg->minor >= 17) { 896 if (!(arg->flags & FUSE_FLOCK_LOCKS)) 897 fc->no_flock = 1; 898 } else { 899 if (!(arg->flags & FUSE_POSIX_LOCKS)) 900 fc->no_flock = 1; 901 } 902 if (arg->flags & FUSE_ATOMIC_O_TRUNC) 903 fc->atomic_o_trunc = 1; 904 if (arg->minor >= 9) { 905 /* LOOKUP has dependency on proto version */ 906 if (arg->flags & FUSE_EXPORT_SUPPORT) 907 fc->export_support = 1; 908 } 909 if (arg->flags & FUSE_BIG_WRITES) 910 fc->big_writes = 1; 911 if (arg->flags & FUSE_DONT_MASK) 912 fc->dont_mask = 1; 913 if (arg->flags & FUSE_AUTO_INVAL_DATA) 914 fc->auto_inval_data = 1; 915 if (arg->flags & FUSE_DO_READDIRPLUS) { 916 fc->do_readdirplus = 1; 917 if (arg->flags & FUSE_READDIRPLUS_AUTO) 918 fc->readdirplus_auto = 1; 919 } 920 if (arg->flags & FUSE_ASYNC_DIO) 921 fc->async_dio = 1; 922 if (arg->flags & FUSE_WRITEBACK_CACHE) 923 fc->writeback_cache = 1; 924 if (arg->flags & FUSE_PARALLEL_DIROPS) 925 fc->parallel_dirops = 1; 926 if (arg->flags & FUSE_HANDLE_KILLPRIV) 927 fc->handle_killpriv = 1; 928 if (arg->time_gran && arg->time_gran <= 1000000000) 929 fc->sb->s_time_gran = arg->time_gran; 930 if ((arg->flags & FUSE_POSIX_ACL)) { 931 fc->default_permissions = 1; 932 fc->posix_acl = 1; 933 fc->sb->s_xattr = fuse_acl_xattr_handlers; 934 } 935 if (arg->flags & FUSE_CACHE_SYMLINKS) 936 fc->cache_symlinks = 1; 937 if (arg->flags & FUSE_ABORT_ERROR) 938 fc->abort_err = 1; 939 if (arg->flags & FUSE_MAX_PAGES) { 940 fc->max_pages = 941 min_t(unsigned int, FUSE_MAX_MAX_PAGES, 942 max_t(unsigned int, arg->max_pages, 1)); 943 } 944 } else { 945 ra_pages = fc->max_read / PAGE_SIZE; 946 fc->no_lock = 1; 947 fc->no_flock = 1; 948 } 949 950 fc->sb->s_bdi->ra_pages = 951 min(fc->sb->s_bdi->ra_pages, ra_pages); 952 fc->minor = arg->minor; 953 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 954 fc->max_write = max_t(unsigned, 4096, fc->max_write); 955 fc->conn_init = 1; 956 } 957 fuse_set_initialized(fc); 958 wake_up_all(&fc->blocked_waitq); 959 } 960 961 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) 962 { 963 struct fuse_init_in *arg = &req->misc.init_in; 964 965 arg->major = FUSE_KERNEL_VERSION; 966 arg->minor = FUSE_KERNEL_MINOR_VERSION; 967 arg->max_readahead = fc->sb->s_bdi->ra_pages * PAGE_SIZE; 968 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 969 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | 970 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | 971 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | 972 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO | 973 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT | 974 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL | 975 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | 976 FUSE_NO_OPENDIR_SUPPORT; 977 req->in.h.opcode = FUSE_INIT; 978 req->in.numargs = 1; 979 req->in.args[0].size = sizeof(*arg); 980 req->in.args[0].value = arg; 981 req->out.numargs = 1; 982 /* Variable length argument used for backward compatibility 983 with interface version < 7.5. Rest of init_out is zeroed 984 by do_get_request(), so a short reply is not a problem */ 985 req->out.argvar = 1; 986 req->out.args[0].size = sizeof(struct fuse_init_out); 987 req->out.args[0].value = &req->misc.init_out; 988 req->end = process_init_reply; 989 fuse_request_send_background(fc, req); 990 } 991 992 static void fuse_free_conn(struct fuse_conn *fc) 993 { 994 WARN_ON(!list_empty(&fc->devices)); 995 kfree_rcu(fc, rcu); 996 } 997 998 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 999 { 1000 int err; 1001 char *suffix = ""; 1002 1003 if (sb->s_bdev) { 1004 suffix = "-fuseblk"; 1005 /* 1006 * sb->s_bdi points to blkdev's bdi however we want to redirect 1007 * it to our private bdi... 1008 */ 1009 bdi_put(sb->s_bdi); 1010 sb->s_bdi = &noop_backing_dev_info; 1011 } 1012 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev), 1013 MINOR(fc->dev), suffix); 1014 if (err) 1015 return err; 1016 1017 sb->s_bdi->ra_pages = VM_READAHEAD_PAGES; 1018 /* fuse does it's own writeback accounting */ 1019 sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT; 1020 1021 /* 1022 * For a single fuse filesystem use max 1% of dirty + 1023 * writeback threshold. 1024 * 1025 * This gives about 1M of write buffer for memory maps on a 1026 * machine with 1G and 10% dirty_ratio, which should be more 1027 * than enough. 1028 * 1029 * Privileged users can raise it by writing to 1030 * 1031 * /sys/class/bdi/<bdi>/max_ratio 1032 */ 1033 bdi_set_max_ratio(sb->s_bdi, 1); 1034 1035 return 0; 1036 } 1037 1038 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc) 1039 { 1040 struct fuse_dev *fud; 1041 struct list_head *pq; 1042 1043 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL); 1044 if (!fud) 1045 return NULL; 1046 1047 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); 1048 if (!pq) { 1049 kfree(fud); 1050 return NULL; 1051 } 1052 1053 fud->pq.processing = pq; 1054 fud->fc = fuse_conn_get(fc); 1055 fuse_pqueue_init(&fud->pq); 1056 1057 spin_lock(&fc->lock); 1058 list_add_tail(&fud->entry, &fc->devices); 1059 spin_unlock(&fc->lock); 1060 1061 return fud; 1062 } 1063 EXPORT_SYMBOL_GPL(fuse_dev_alloc); 1064 1065 void fuse_dev_free(struct fuse_dev *fud) 1066 { 1067 struct fuse_conn *fc = fud->fc; 1068 1069 if (fc) { 1070 spin_lock(&fc->lock); 1071 list_del(&fud->entry); 1072 spin_unlock(&fc->lock); 1073 1074 fuse_conn_put(fc); 1075 } 1076 kfree(fud->pq.processing); 1077 kfree(fud); 1078 } 1079 EXPORT_SYMBOL_GPL(fuse_dev_free); 1080 1081 static int fuse_fill_super(struct super_block *sb, void *data, int silent) 1082 { 1083 struct fuse_dev *fud; 1084 struct fuse_conn *fc; 1085 struct inode *root; 1086 struct fuse_mount_data d; 1087 struct file *file; 1088 struct dentry *root_dentry; 1089 struct fuse_req *init_req; 1090 int err; 1091 int is_bdev = sb->s_bdev != NULL; 1092 1093 err = -EINVAL; 1094 if (sb->s_flags & SB_MANDLOCK) 1095 goto err; 1096 1097 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); 1098 1099 if (!parse_fuse_opt(data, &d, is_bdev, sb->s_user_ns)) 1100 goto err; 1101 1102 if (is_bdev) { 1103 #ifdef CONFIG_BLOCK 1104 err = -EINVAL; 1105 if (!sb_set_blocksize(sb, d.blksize)) 1106 goto err; 1107 #endif 1108 } else { 1109 sb->s_blocksize = PAGE_SIZE; 1110 sb->s_blocksize_bits = PAGE_SHIFT; 1111 } 1112 sb->s_magic = FUSE_SUPER_MAGIC; 1113 sb->s_op = &fuse_super_operations; 1114 sb->s_xattr = fuse_xattr_handlers; 1115 sb->s_maxbytes = MAX_LFS_FILESIZE; 1116 sb->s_time_gran = 1; 1117 sb->s_export_op = &fuse_export_operations; 1118 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE; 1119 if (sb->s_user_ns != &init_user_ns) 1120 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; 1121 1122 file = fget(d.fd); 1123 err = -EINVAL; 1124 if (!file) 1125 goto err; 1126 1127 /* 1128 * Require mount to happen from the same user namespace which 1129 * opened /dev/fuse to prevent potential attacks. 1130 */ 1131 if (file->f_op != &fuse_dev_operations || 1132 file->f_cred->user_ns != sb->s_user_ns) 1133 goto err_fput; 1134 1135 /* 1136 * If we are not in the initial user namespace posix 1137 * acls must be translated. 1138 */ 1139 if (sb->s_user_ns != &init_user_ns) 1140 sb->s_xattr = fuse_no_acl_xattr_handlers; 1141 1142 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 1143 err = -ENOMEM; 1144 if (!fc) 1145 goto err_fput; 1146 1147 fuse_conn_init(fc, sb->s_user_ns); 1148 fc->release = fuse_free_conn; 1149 1150 fud = fuse_dev_alloc(fc); 1151 if (!fud) 1152 goto err_put_conn; 1153 1154 fc->dev = sb->s_dev; 1155 fc->sb = sb; 1156 err = fuse_bdi_init(fc, sb); 1157 if (err) 1158 goto err_dev_free; 1159 1160 /* Handle umasking inside the fuse code */ 1161 if (sb->s_flags & SB_POSIXACL) 1162 fc->dont_mask = 1; 1163 sb->s_flags |= SB_POSIXACL; 1164 1165 fc->default_permissions = d.default_permissions; 1166 fc->allow_other = d.allow_other; 1167 fc->user_id = d.user_id; 1168 fc->group_id = d.group_id; 1169 fc->max_read = max_t(unsigned, 4096, d.max_read); 1170 1171 /* Used by get_root_inode() */ 1172 sb->s_fs_info = fc; 1173 1174 err = -ENOMEM; 1175 root = fuse_get_root_inode(sb, d.rootmode); 1176 sb->s_d_op = &fuse_root_dentry_operations; 1177 root_dentry = d_make_root(root); 1178 if (!root_dentry) 1179 goto err_dev_free; 1180 /* Root dentry doesn't have .d_revalidate */ 1181 sb->s_d_op = &fuse_dentry_operations; 1182 1183 init_req = fuse_request_alloc(0); 1184 if (!init_req) 1185 goto err_put_root; 1186 __set_bit(FR_BACKGROUND, &init_req->flags); 1187 1188 if (is_bdev) { 1189 fc->destroy_req = fuse_request_alloc(0); 1190 if (!fc->destroy_req) 1191 goto err_free_init_req; 1192 } 1193 1194 mutex_lock(&fuse_mutex); 1195 err = -EINVAL; 1196 if (file->private_data) 1197 goto err_unlock; 1198 1199 err = fuse_ctl_add_conn(fc); 1200 if (err) 1201 goto err_unlock; 1202 1203 list_add_tail(&fc->entry, &fuse_conn_list); 1204 sb->s_root = root_dentry; 1205 file->private_data = fud; 1206 mutex_unlock(&fuse_mutex); 1207 /* 1208 * atomic_dec_and_test() in fput() provides the necessary 1209 * memory barrier for file->private_data to be visible on all 1210 * CPUs after this 1211 */ 1212 fput(file); 1213 1214 fuse_send_init(fc, init_req); 1215 1216 return 0; 1217 1218 err_unlock: 1219 mutex_unlock(&fuse_mutex); 1220 err_free_init_req: 1221 fuse_request_free(init_req); 1222 err_put_root: 1223 dput(root_dentry); 1224 err_dev_free: 1225 fuse_dev_free(fud); 1226 err_put_conn: 1227 fuse_conn_put(fc); 1228 sb->s_fs_info = NULL; 1229 err_fput: 1230 fput(file); 1231 err: 1232 return err; 1233 } 1234 1235 static struct dentry *fuse_mount(struct file_system_type *fs_type, 1236 int flags, const char *dev_name, 1237 void *raw_data) 1238 { 1239 return mount_nodev(fs_type, flags, raw_data, fuse_fill_super); 1240 } 1241 1242 static void fuse_sb_destroy(struct super_block *sb) 1243 { 1244 struct fuse_conn *fc = get_fuse_conn_super(sb); 1245 1246 if (fc) { 1247 fuse_send_destroy(fc); 1248 1249 fuse_abort_conn(fc); 1250 fuse_wait_aborted(fc); 1251 1252 down_write(&fc->killsb); 1253 fc->sb = NULL; 1254 up_write(&fc->killsb); 1255 } 1256 } 1257 1258 static void fuse_kill_sb_anon(struct super_block *sb) 1259 { 1260 fuse_sb_destroy(sb); 1261 kill_anon_super(sb); 1262 } 1263 1264 static struct file_system_type fuse_fs_type = { 1265 .owner = THIS_MODULE, 1266 .name = "fuse", 1267 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT, 1268 .mount = fuse_mount, 1269 .kill_sb = fuse_kill_sb_anon, 1270 }; 1271 MODULE_ALIAS_FS("fuse"); 1272 1273 #ifdef CONFIG_BLOCK 1274 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type, 1275 int flags, const char *dev_name, 1276 void *raw_data) 1277 { 1278 return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super); 1279 } 1280 1281 static void fuse_kill_sb_blk(struct super_block *sb) 1282 { 1283 fuse_sb_destroy(sb); 1284 kill_block_super(sb); 1285 } 1286 1287 static struct file_system_type fuseblk_fs_type = { 1288 .owner = THIS_MODULE, 1289 .name = "fuseblk", 1290 .mount = fuse_mount_blk, 1291 .kill_sb = fuse_kill_sb_blk, 1292 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 1293 }; 1294 MODULE_ALIAS_FS("fuseblk"); 1295 1296 static inline int register_fuseblk(void) 1297 { 1298 return register_filesystem(&fuseblk_fs_type); 1299 } 1300 1301 static inline void unregister_fuseblk(void) 1302 { 1303 unregister_filesystem(&fuseblk_fs_type); 1304 } 1305 #else 1306 static inline int register_fuseblk(void) 1307 { 1308 return 0; 1309 } 1310 1311 static inline void unregister_fuseblk(void) 1312 { 1313 } 1314 #endif 1315 1316 static void fuse_inode_init_once(void *foo) 1317 { 1318 struct inode *inode = foo; 1319 1320 inode_init_once(inode); 1321 } 1322 1323 static int __init fuse_fs_init(void) 1324 { 1325 int err; 1326 1327 fuse_inode_cachep = kmem_cache_create("fuse_inode", 1328 sizeof(struct fuse_inode), 0, 1329 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT, 1330 fuse_inode_init_once); 1331 err = -ENOMEM; 1332 if (!fuse_inode_cachep) 1333 goto out; 1334 1335 err = register_fuseblk(); 1336 if (err) 1337 goto out2; 1338 1339 err = register_filesystem(&fuse_fs_type); 1340 if (err) 1341 goto out3; 1342 1343 return 0; 1344 1345 out3: 1346 unregister_fuseblk(); 1347 out2: 1348 kmem_cache_destroy(fuse_inode_cachep); 1349 out: 1350 return err; 1351 } 1352 1353 static void fuse_fs_cleanup(void) 1354 { 1355 unregister_filesystem(&fuse_fs_type); 1356 unregister_fuseblk(); 1357 1358 /* 1359 * Make sure all delayed rcu free inodes are flushed before we 1360 * destroy cache. 1361 */ 1362 rcu_barrier(); 1363 kmem_cache_destroy(fuse_inode_cachep); 1364 } 1365 1366 static struct kobject *fuse_kobj; 1367 1368 static int fuse_sysfs_init(void) 1369 { 1370 int err; 1371 1372 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 1373 if (!fuse_kobj) { 1374 err = -ENOMEM; 1375 goto out_err; 1376 } 1377 1378 err = sysfs_create_mount_point(fuse_kobj, "connections"); 1379 if (err) 1380 goto out_fuse_unregister; 1381 1382 return 0; 1383 1384 out_fuse_unregister: 1385 kobject_put(fuse_kobj); 1386 out_err: 1387 return err; 1388 } 1389 1390 static void fuse_sysfs_cleanup(void) 1391 { 1392 sysfs_remove_mount_point(fuse_kobj, "connections"); 1393 kobject_put(fuse_kobj); 1394 } 1395 1396 static int __init fuse_init(void) 1397 { 1398 int res; 1399 1400 printk(KERN_INFO "fuse init (API version %i.%i)\n", 1401 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 1402 1403 INIT_LIST_HEAD(&fuse_conn_list); 1404 res = fuse_fs_init(); 1405 if (res) 1406 goto err; 1407 1408 res = fuse_dev_init(); 1409 if (res) 1410 goto err_fs_cleanup; 1411 1412 res = fuse_sysfs_init(); 1413 if (res) 1414 goto err_dev_cleanup; 1415 1416 res = fuse_ctl_init(); 1417 if (res) 1418 goto err_sysfs_cleanup; 1419 1420 sanitize_global_limit(&max_user_bgreq); 1421 sanitize_global_limit(&max_user_congthresh); 1422 1423 return 0; 1424 1425 err_sysfs_cleanup: 1426 fuse_sysfs_cleanup(); 1427 err_dev_cleanup: 1428 fuse_dev_cleanup(); 1429 err_fs_cleanup: 1430 fuse_fs_cleanup(); 1431 err: 1432 return res; 1433 } 1434 1435 static void __exit fuse_exit(void) 1436 { 1437 printk(KERN_DEBUG "fuse exit\n"); 1438 1439 fuse_ctl_cleanup(); 1440 fuse_sysfs_cleanup(); 1441 fuse_fs_cleanup(); 1442 fuse_dev_cleanup(); 1443 } 1444 1445 module_init(fuse_init); 1446 module_exit(fuse_exit); 1447