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