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 27 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); 28 MODULE_DESCRIPTION("Filesystem in Userspace"); 29 MODULE_LICENSE("GPL"); 30 31 static struct kmem_cache *fuse_inode_cachep; 32 struct list_head fuse_conn_list; 33 DEFINE_MUTEX(fuse_mutex); 34 35 static int set_global_limit(const char *val, const struct kernel_param *kp); 36 37 unsigned max_user_bgreq; 38 module_param_call(max_user_bgreq, set_global_limit, param_get_uint, 39 &max_user_bgreq, 0644); 40 __MODULE_PARM_TYPE(max_user_bgreq, "uint"); 41 MODULE_PARM_DESC(max_user_bgreq, 42 "Global limit for the maximum number of backgrounded requests an " 43 "unprivileged user can set"); 44 45 unsigned max_user_congthresh; 46 module_param_call(max_user_congthresh, set_global_limit, param_get_uint, 47 &max_user_congthresh, 0644); 48 __MODULE_PARM_TYPE(max_user_congthresh, "uint"); 49 MODULE_PARM_DESC(max_user_congthresh, 50 "Global limit for the maximum congestion threshold an " 51 "unprivileged user can set"); 52 53 #define FUSE_SUPER_MAGIC 0x65735546 54 55 #define FUSE_DEFAULT_BLKSIZE 512 56 57 /** Maximum number of outstanding background requests */ 58 #define FUSE_DEFAULT_MAX_BACKGROUND 12 59 60 /** Congestion starts at 75% of maximum */ 61 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4) 62 63 #ifdef CONFIG_BLOCK 64 static struct file_system_type fuseblk_fs_type; 65 #endif 66 67 struct fuse_forget_link *fuse_alloc_forget(void) 68 { 69 return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL_ACCOUNT); 70 } 71 72 static struct inode *fuse_alloc_inode(struct super_block *sb) 73 { 74 struct fuse_inode *fi; 75 76 fi = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL); 77 if (!fi) 78 return NULL; 79 80 fi->i_time = 0; 81 fi->inval_mask = 0; 82 fi->nodeid = 0; 83 fi->nlookup = 0; 84 fi->attr_version = 0; 85 fi->orig_ino = 0; 86 fi->state = 0; 87 mutex_init(&fi->mutex); 88 spin_lock_init(&fi->lock); 89 fi->forget = fuse_alloc_forget(); 90 if (!fi->forget) { 91 kmem_cache_free(fuse_inode_cachep, fi); 92 return NULL; 93 } 94 95 return &fi->inode; 96 } 97 98 static void fuse_free_inode(struct inode *inode) 99 { 100 struct fuse_inode *fi = get_fuse_inode(inode); 101 102 mutex_destroy(&fi->mutex); 103 kfree(fi->forget); 104 kmem_cache_free(fuse_inode_cachep, fi); 105 } 106 107 static void fuse_evict_inode(struct inode *inode) 108 { 109 struct fuse_inode *fi = get_fuse_inode(inode); 110 111 truncate_inode_pages_final(&inode->i_data); 112 clear_inode(inode); 113 if (inode->i_sb->s_flags & SB_ACTIVE) { 114 struct fuse_conn *fc = get_fuse_conn(inode); 115 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup); 116 fi->forget = NULL; 117 } 118 if (S_ISREG(inode->i_mode) && !is_bad_inode(inode)) { 119 WARN_ON(!list_empty(&fi->write_files)); 120 WARN_ON(!list_empty(&fi->queued_writes)); 121 } 122 } 123 124 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data) 125 { 126 sync_filesystem(sb); 127 if (*flags & SB_MANDLOCK) 128 return -EINVAL; 129 130 return 0; 131 } 132 133 /* 134 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down 135 * so that it will fit. 136 */ 137 static ino_t fuse_squash_ino(u64 ino64) 138 { 139 ino_t ino = (ino_t) ino64; 140 if (sizeof(ino_t) < sizeof(u64)) 141 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8; 142 return ino; 143 } 144 145 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, 146 u64 attr_valid) 147 { 148 struct fuse_conn *fc = get_fuse_conn(inode); 149 struct fuse_inode *fi = get_fuse_inode(inode); 150 151 lockdep_assert_held(&fi->lock); 152 153 fi->attr_version = atomic64_inc_return(&fc->attr_version); 154 fi->i_time = attr_valid; 155 WRITE_ONCE(fi->inval_mask, 0); 156 157 inode->i_ino = fuse_squash_ino(attr->ino); 158 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 159 set_nlink(inode, attr->nlink); 160 inode->i_uid = make_kuid(fc->user_ns, attr->uid); 161 inode->i_gid = make_kgid(fc->user_ns, attr->gid); 162 inode->i_blocks = attr->blocks; 163 inode->i_atime.tv_sec = attr->atime; 164 inode->i_atime.tv_nsec = attr->atimensec; 165 /* mtime from server may be stale due to local buffered write */ 166 if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) { 167 inode->i_mtime.tv_sec = attr->mtime; 168 inode->i_mtime.tv_nsec = attr->mtimensec; 169 inode->i_ctime.tv_sec = attr->ctime; 170 inode->i_ctime.tv_nsec = attr->ctimensec; 171 } 172 173 if (attr->blksize != 0) 174 inode->i_blkbits = ilog2(attr->blksize); 175 else 176 inode->i_blkbits = inode->i_sb->s_blocksize_bits; 177 178 /* 179 * Don't set the sticky bit in i_mode, unless we want the VFS 180 * to check permissions. This prevents failures due to the 181 * check in may_delete(). 182 */ 183 fi->orig_i_mode = inode->i_mode; 184 if (!fc->default_permissions) 185 inode->i_mode &= ~S_ISVTX; 186 187 fi->orig_ino = attr->ino; 188 } 189 190 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, 191 u64 attr_valid, u64 attr_version) 192 { 193 struct fuse_conn *fc = get_fuse_conn(inode); 194 struct fuse_inode *fi = get_fuse_inode(inode); 195 bool is_wb = fc->writeback_cache; 196 loff_t oldsize; 197 struct timespec64 old_mtime; 198 199 spin_lock(&fi->lock); 200 if ((attr_version != 0 && fi->attr_version > attr_version) || 201 test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) { 202 spin_unlock(&fi->lock); 203 return; 204 } 205 206 old_mtime = inode->i_mtime; 207 fuse_change_attributes_common(inode, attr, attr_valid); 208 209 oldsize = inode->i_size; 210 /* 211 * In case of writeback_cache enabled, the cached writes beyond EOF 212 * extend local i_size without keeping userspace server in sync. So, 213 * attr->size coming from server can be stale. We cannot trust it. 214 */ 215 if (!is_wb || !S_ISREG(inode->i_mode)) 216 i_size_write(inode, attr->size); 217 spin_unlock(&fi->lock); 218 219 if (!is_wb && S_ISREG(inode->i_mode)) { 220 bool inval = false; 221 222 if (oldsize != attr->size) { 223 truncate_pagecache(inode, attr->size); 224 if (!fc->explicit_inval_data) 225 inval = true; 226 } else if (fc->auto_inval_data) { 227 struct timespec64 new_mtime = { 228 .tv_sec = attr->mtime, 229 .tv_nsec = attr->mtimensec, 230 }; 231 232 /* 233 * Auto inval mode also checks and invalidates if mtime 234 * has changed. 235 */ 236 if (!timespec64_equal(&old_mtime, &new_mtime)) 237 inval = true; 238 } 239 240 if (inval) 241 invalidate_inode_pages2(inode->i_mapping); 242 } 243 } 244 245 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) 246 { 247 inode->i_mode = attr->mode & S_IFMT; 248 inode->i_size = attr->size; 249 inode->i_mtime.tv_sec = attr->mtime; 250 inode->i_mtime.tv_nsec = attr->mtimensec; 251 inode->i_ctime.tv_sec = attr->ctime; 252 inode->i_ctime.tv_nsec = attr->ctimensec; 253 if (S_ISREG(inode->i_mode)) { 254 fuse_init_common(inode); 255 fuse_init_file_inode(inode); 256 } else if (S_ISDIR(inode->i_mode)) 257 fuse_init_dir(inode); 258 else if (S_ISLNK(inode->i_mode)) 259 fuse_init_symlink(inode); 260 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || 261 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { 262 fuse_init_common(inode); 263 init_special_inode(inode, inode->i_mode, 264 new_decode_dev(attr->rdev)); 265 } else 266 BUG(); 267 } 268 269 int fuse_inode_eq(struct inode *inode, void *_nodeidp) 270 { 271 u64 nodeid = *(u64 *) _nodeidp; 272 if (get_node_id(inode) == nodeid) 273 return 1; 274 else 275 return 0; 276 } 277 278 static int fuse_inode_set(struct inode *inode, void *_nodeidp) 279 { 280 u64 nodeid = *(u64 *) _nodeidp; 281 get_fuse_inode(inode)->nodeid = nodeid; 282 return 0; 283 } 284 285 struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 286 int generation, struct fuse_attr *attr, 287 u64 attr_valid, u64 attr_version) 288 { 289 struct inode *inode; 290 struct fuse_inode *fi; 291 struct fuse_conn *fc = get_fuse_conn_super(sb); 292 293 retry: 294 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); 295 if (!inode) 296 return NULL; 297 298 if ((inode->i_state & I_NEW)) { 299 inode->i_flags |= S_NOATIME; 300 if (!fc->writeback_cache || !S_ISREG(attr->mode)) 301 inode->i_flags |= S_NOCMTIME; 302 inode->i_generation = generation; 303 fuse_init_inode(inode, attr); 304 unlock_new_inode(inode); 305 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) { 306 /* Inode has changed type, any I/O on the old should fail */ 307 make_bad_inode(inode); 308 iput(inode); 309 goto retry; 310 } 311 312 fi = get_fuse_inode(inode); 313 spin_lock(&fi->lock); 314 fi->nlookup++; 315 spin_unlock(&fi->lock); 316 fuse_change_attributes(inode, attr, attr_valid, attr_version); 317 318 return inode; 319 } 320 321 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid, 322 loff_t offset, loff_t len) 323 { 324 struct inode *inode; 325 pgoff_t pg_start; 326 pgoff_t pg_end; 327 328 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid); 329 if (!inode) 330 return -ENOENT; 331 332 fuse_invalidate_attr(inode); 333 forget_all_cached_acls(inode); 334 if (offset >= 0) { 335 pg_start = offset >> PAGE_SHIFT; 336 if (len <= 0) 337 pg_end = -1; 338 else 339 pg_end = (offset + len - 1) >> PAGE_SHIFT; 340 invalidate_inode_pages2_range(inode->i_mapping, 341 pg_start, pg_end); 342 } 343 iput(inode); 344 return 0; 345 } 346 347 bool fuse_lock_inode(struct inode *inode) 348 { 349 bool locked = false; 350 351 if (!get_fuse_conn(inode)->parallel_dirops) { 352 mutex_lock(&get_fuse_inode(inode)->mutex); 353 locked = true; 354 } 355 356 return locked; 357 } 358 359 void fuse_unlock_inode(struct inode *inode, bool locked) 360 { 361 if (locked) 362 mutex_unlock(&get_fuse_inode(inode)->mutex); 363 } 364 365 static void fuse_umount_begin(struct super_block *sb) 366 { 367 struct fuse_conn *fc = get_fuse_conn_super(sb); 368 369 if (!fc->no_force_umount) 370 fuse_abort_conn(fc); 371 } 372 373 static void fuse_send_destroy(struct fuse_conn *fc) 374 { 375 if (fc->conn_init) { 376 FUSE_ARGS(args); 377 378 args.opcode = FUSE_DESTROY; 379 args.force = true; 380 args.nocreds = true; 381 fuse_simple_request(fc, &args); 382 } 383 } 384 385 static void fuse_put_super(struct super_block *sb) 386 { 387 struct fuse_conn *fc = get_fuse_conn_super(sb); 388 389 mutex_lock(&fuse_mutex); 390 list_del(&fc->entry); 391 fuse_ctl_remove_conn(fc); 392 mutex_unlock(&fuse_mutex); 393 394 fuse_conn_put(fc); 395 } 396 397 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 398 { 399 stbuf->f_type = FUSE_SUPER_MAGIC; 400 stbuf->f_bsize = attr->bsize; 401 stbuf->f_frsize = attr->frsize; 402 stbuf->f_blocks = attr->blocks; 403 stbuf->f_bfree = attr->bfree; 404 stbuf->f_bavail = attr->bavail; 405 stbuf->f_files = attr->files; 406 stbuf->f_ffree = attr->ffree; 407 stbuf->f_namelen = attr->namelen; 408 /* fsid is left zero */ 409 } 410 411 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 412 { 413 struct super_block *sb = dentry->d_sb; 414 struct fuse_conn *fc = get_fuse_conn_super(sb); 415 FUSE_ARGS(args); 416 struct fuse_statfs_out outarg; 417 int err; 418 419 if (!fuse_allow_current_process(fc)) { 420 buf->f_type = FUSE_SUPER_MAGIC; 421 return 0; 422 } 423 424 memset(&outarg, 0, sizeof(outarg)); 425 args.in_numargs = 0; 426 args.opcode = FUSE_STATFS; 427 args.nodeid = get_node_id(d_inode(dentry)); 428 args.out_numargs = 1; 429 args.out_args[0].size = sizeof(outarg); 430 args.out_args[0].value = &outarg; 431 err = fuse_simple_request(fc, &args); 432 if (!err) 433 convert_fuse_statfs(buf, &outarg.st); 434 return err; 435 } 436 437 enum { 438 OPT_SOURCE, 439 OPT_SUBTYPE, 440 OPT_FD, 441 OPT_ROOTMODE, 442 OPT_USER_ID, 443 OPT_GROUP_ID, 444 OPT_DEFAULT_PERMISSIONS, 445 OPT_ALLOW_OTHER, 446 OPT_MAX_READ, 447 OPT_BLKSIZE, 448 OPT_ERR 449 }; 450 451 static const struct fs_parameter_spec fuse_param_specs[] = { 452 fsparam_string ("source", OPT_SOURCE), 453 fsparam_u32 ("fd", OPT_FD), 454 fsparam_u32oct ("rootmode", OPT_ROOTMODE), 455 fsparam_u32 ("user_id", OPT_USER_ID), 456 fsparam_u32 ("group_id", OPT_GROUP_ID), 457 fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS), 458 fsparam_flag ("allow_other", OPT_ALLOW_OTHER), 459 fsparam_u32 ("max_read", OPT_MAX_READ), 460 fsparam_u32 ("blksize", OPT_BLKSIZE), 461 fsparam_string ("subtype", OPT_SUBTYPE), 462 {} 463 }; 464 465 static const struct fs_parameter_description fuse_fs_parameters = { 466 .name = "fuse", 467 .specs = fuse_param_specs, 468 }; 469 470 static int fuse_parse_param(struct fs_context *fc, struct fs_parameter *param) 471 { 472 struct fs_parse_result result; 473 struct fuse_fs_context *ctx = fc->fs_private; 474 int opt; 475 476 opt = fs_parse(fc, &fuse_fs_parameters, param, &result); 477 if (opt < 0) 478 return opt; 479 480 switch (opt) { 481 case OPT_SOURCE: 482 if (fc->source) 483 return invalf(fc, "fuse: Multiple sources specified"); 484 fc->source = param->string; 485 param->string = NULL; 486 break; 487 488 case OPT_SUBTYPE: 489 if (ctx->subtype) 490 return invalf(fc, "fuse: Multiple subtypes specified"); 491 ctx->subtype = param->string; 492 param->string = NULL; 493 return 0; 494 495 case OPT_FD: 496 ctx->fd = result.uint_32; 497 ctx->fd_present = 1; 498 break; 499 500 case OPT_ROOTMODE: 501 if (!fuse_valid_type(result.uint_32)) 502 return invalf(fc, "fuse: Invalid rootmode"); 503 ctx->rootmode = result.uint_32; 504 ctx->rootmode_present = 1; 505 break; 506 507 case OPT_USER_ID: 508 ctx->user_id = make_kuid(fc->user_ns, result.uint_32); 509 if (!uid_valid(ctx->user_id)) 510 return invalf(fc, "fuse: Invalid user_id"); 511 ctx->user_id_present = 1; 512 break; 513 514 case OPT_GROUP_ID: 515 ctx->group_id = make_kgid(fc->user_ns, result.uint_32); 516 if (!gid_valid(ctx->group_id)) 517 return invalf(fc, "fuse: Invalid group_id"); 518 ctx->group_id_present = 1; 519 break; 520 521 case OPT_DEFAULT_PERMISSIONS: 522 ctx->default_permissions = 1; 523 break; 524 525 case OPT_ALLOW_OTHER: 526 ctx->allow_other = 1; 527 break; 528 529 case OPT_MAX_READ: 530 ctx->max_read = result.uint_32; 531 break; 532 533 case OPT_BLKSIZE: 534 if (!ctx->is_bdev) 535 return invalf(fc, "fuse: blksize only supported for fuseblk"); 536 ctx->blksize = result.uint_32; 537 break; 538 539 default: 540 return -EINVAL; 541 } 542 543 return 0; 544 } 545 546 static void fuse_free_fc(struct fs_context *fc) 547 { 548 struct fuse_fs_context *ctx = fc->fs_private; 549 550 if (ctx) { 551 kfree(ctx->subtype); 552 kfree(ctx); 553 } 554 } 555 556 static int fuse_show_options(struct seq_file *m, struct dentry *root) 557 { 558 struct super_block *sb = root->d_sb; 559 struct fuse_conn *fc = get_fuse_conn_super(sb); 560 561 seq_printf(m, ",user_id=%u", from_kuid_munged(fc->user_ns, fc->user_id)); 562 seq_printf(m, ",group_id=%u", from_kgid_munged(fc->user_ns, fc->group_id)); 563 if (fc->default_permissions) 564 seq_puts(m, ",default_permissions"); 565 if (fc->allow_other) 566 seq_puts(m, ",allow_other"); 567 if (fc->max_read != ~0) 568 seq_printf(m, ",max_read=%u", fc->max_read); 569 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 570 seq_printf(m, ",blksize=%lu", sb->s_blocksize); 571 return 0; 572 } 573 574 static void fuse_iqueue_init(struct fuse_iqueue *fiq, 575 const struct fuse_iqueue_ops *ops, 576 void *priv) 577 { 578 memset(fiq, 0, sizeof(struct fuse_iqueue)); 579 spin_lock_init(&fiq->lock); 580 init_waitqueue_head(&fiq->waitq); 581 INIT_LIST_HEAD(&fiq->pending); 582 INIT_LIST_HEAD(&fiq->interrupts); 583 fiq->forget_list_tail = &fiq->forget_list_head; 584 fiq->connected = 1; 585 fiq->ops = ops; 586 fiq->priv = priv; 587 } 588 589 static void fuse_pqueue_init(struct fuse_pqueue *fpq) 590 { 591 unsigned int i; 592 593 spin_lock_init(&fpq->lock); 594 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) 595 INIT_LIST_HEAD(&fpq->processing[i]); 596 INIT_LIST_HEAD(&fpq->io); 597 fpq->connected = 1; 598 } 599 600 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns, 601 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv) 602 { 603 memset(fc, 0, sizeof(*fc)); 604 spin_lock_init(&fc->lock); 605 spin_lock_init(&fc->bg_lock); 606 init_rwsem(&fc->killsb); 607 refcount_set(&fc->count, 1); 608 atomic_set(&fc->dev_count, 1); 609 init_waitqueue_head(&fc->blocked_waitq); 610 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv); 611 INIT_LIST_HEAD(&fc->bg_queue); 612 INIT_LIST_HEAD(&fc->entry); 613 INIT_LIST_HEAD(&fc->devices); 614 atomic_set(&fc->num_waiting, 0); 615 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND; 616 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD; 617 atomic64_set(&fc->khctr, 0); 618 fc->polled_files = RB_ROOT; 619 fc->blocked = 0; 620 fc->initialized = 0; 621 fc->connected = 1; 622 atomic64_set(&fc->attr_version, 1); 623 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 624 fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); 625 fc->user_ns = get_user_ns(user_ns); 626 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ; 627 } 628 EXPORT_SYMBOL_GPL(fuse_conn_init); 629 630 void fuse_conn_put(struct fuse_conn *fc) 631 { 632 if (refcount_dec_and_test(&fc->count)) { 633 struct fuse_iqueue *fiq = &fc->iq; 634 635 if (fiq->ops->release) 636 fiq->ops->release(fiq); 637 put_pid_ns(fc->pid_ns); 638 put_user_ns(fc->user_ns); 639 fc->release(fc); 640 } 641 } 642 EXPORT_SYMBOL_GPL(fuse_conn_put); 643 644 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 645 { 646 refcount_inc(&fc->count); 647 return fc; 648 } 649 EXPORT_SYMBOL_GPL(fuse_conn_get); 650 651 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 652 { 653 struct fuse_attr attr; 654 memset(&attr, 0, sizeof(attr)); 655 656 attr.mode = mode; 657 attr.ino = FUSE_ROOT_ID; 658 attr.nlink = 1; 659 return fuse_iget(sb, 1, 0, &attr, 0, 0); 660 } 661 662 struct fuse_inode_handle { 663 u64 nodeid; 664 u32 generation; 665 }; 666 667 static struct dentry *fuse_get_dentry(struct super_block *sb, 668 struct fuse_inode_handle *handle) 669 { 670 struct fuse_conn *fc = get_fuse_conn_super(sb); 671 struct inode *inode; 672 struct dentry *entry; 673 int err = -ESTALE; 674 675 if (handle->nodeid == 0) 676 goto out_err; 677 678 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 679 if (!inode) { 680 struct fuse_entry_out outarg; 681 const struct qstr name = QSTR_INIT(".", 1); 682 683 if (!fc->export_support) 684 goto out_err; 685 686 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 687 &inode); 688 if (err && err != -ENOENT) 689 goto out_err; 690 if (err || !inode) { 691 err = -ESTALE; 692 goto out_err; 693 } 694 err = -EIO; 695 if (get_node_id(inode) != handle->nodeid) 696 goto out_iput; 697 } 698 err = -ESTALE; 699 if (inode->i_generation != handle->generation) 700 goto out_iput; 701 702 entry = d_obtain_alias(inode); 703 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) 704 fuse_invalidate_entry_cache(entry); 705 706 return entry; 707 708 out_iput: 709 iput(inode); 710 out_err: 711 return ERR_PTR(err); 712 } 713 714 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len, 715 struct inode *parent) 716 { 717 int len = parent ? 6 : 3; 718 u64 nodeid; 719 u32 generation; 720 721 if (*max_len < len) { 722 *max_len = len; 723 return FILEID_INVALID; 724 } 725 726 nodeid = get_fuse_inode(inode)->nodeid; 727 generation = inode->i_generation; 728 729 fh[0] = (u32)(nodeid >> 32); 730 fh[1] = (u32)(nodeid & 0xffffffff); 731 fh[2] = generation; 732 733 if (parent) { 734 nodeid = get_fuse_inode(parent)->nodeid; 735 generation = parent->i_generation; 736 737 fh[3] = (u32)(nodeid >> 32); 738 fh[4] = (u32)(nodeid & 0xffffffff); 739 fh[5] = generation; 740 } 741 742 *max_len = len; 743 return parent ? 0x82 : 0x81; 744 } 745 746 static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 747 struct fid *fid, int fh_len, int fh_type) 748 { 749 struct fuse_inode_handle handle; 750 751 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) 752 return NULL; 753 754 handle.nodeid = (u64) fid->raw[0] << 32; 755 handle.nodeid |= (u64) fid->raw[1]; 756 handle.generation = fid->raw[2]; 757 return fuse_get_dentry(sb, &handle); 758 } 759 760 static struct dentry *fuse_fh_to_parent(struct super_block *sb, 761 struct fid *fid, int fh_len, int fh_type) 762 { 763 struct fuse_inode_handle parent; 764 765 if (fh_type != 0x82 || fh_len < 6) 766 return NULL; 767 768 parent.nodeid = (u64) fid->raw[3] << 32; 769 parent.nodeid |= (u64) fid->raw[4]; 770 parent.generation = fid->raw[5]; 771 return fuse_get_dentry(sb, &parent); 772 } 773 774 static struct dentry *fuse_get_parent(struct dentry *child) 775 { 776 struct inode *child_inode = d_inode(child); 777 struct fuse_conn *fc = get_fuse_conn(child_inode); 778 struct inode *inode; 779 struct dentry *parent; 780 struct fuse_entry_out outarg; 781 const struct qstr name = QSTR_INIT("..", 2); 782 int err; 783 784 if (!fc->export_support) 785 return ERR_PTR(-ESTALE); 786 787 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 788 &name, &outarg, &inode); 789 if (err) { 790 if (err == -ENOENT) 791 return ERR_PTR(-ESTALE); 792 return ERR_PTR(err); 793 } 794 795 parent = d_obtain_alias(inode); 796 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) 797 fuse_invalidate_entry_cache(parent); 798 799 return parent; 800 } 801 802 static const struct export_operations fuse_export_operations = { 803 .fh_to_dentry = fuse_fh_to_dentry, 804 .fh_to_parent = fuse_fh_to_parent, 805 .encode_fh = fuse_encode_fh, 806 .get_parent = fuse_get_parent, 807 }; 808 809 static const struct super_operations fuse_super_operations = { 810 .alloc_inode = fuse_alloc_inode, 811 .free_inode = fuse_free_inode, 812 .evict_inode = fuse_evict_inode, 813 .write_inode = fuse_write_inode, 814 .drop_inode = generic_delete_inode, 815 .remount_fs = fuse_remount_fs, 816 .put_super = fuse_put_super, 817 .umount_begin = fuse_umount_begin, 818 .statfs = fuse_statfs, 819 .show_options = fuse_show_options, 820 }; 821 822 static void sanitize_global_limit(unsigned *limit) 823 { 824 /* 825 * The default maximum number of async requests is calculated to consume 826 * 1/2^13 of the total memory, assuming 392 bytes per request. 827 */ 828 if (*limit == 0) 829 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392; 830 831 if (*limit >= 1 << 16) 832 *limit = (1 << 16) - 1; 833 } 834 835 static int set_global_limit(const char *val, const struct kernel_param *kp) 836 { 837 int rv; 838 839 rv = param_set_uint(val, kp); 840 if (rv) 841 return rv; 842 843 sanitize_global_limit((unsigned *)kp->arg); 844 845 return 0; 846 } 847 848 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg) 849 { 850 int cap_sys_admin = capable(CAP_SYS_ADMIN); 851 852 if (arg->minor < 13) 853 return; 854 855 sanitize_global_limit(&max_user_bgreq); 856 sanitize_global_limit(&max_user_congthresh); 857 858 spin_lock(&fc->bg_lock); 859 if (arg->max_background) { 860 fc->max_background = arg->max_background; 861 862 if (!cap_sys_admin && fc->max_background > max_user_bgreq) 863 fc->max_background = max_user_bgreq; 864 } 865 if (arg->congestion_threshold) { 866 fc->congestion_threshold = arg->congestion_threshold; 867 868 if (!cap_sys_admin && 869 fc->congestion_threshold > max_user_congthresh) 870 fc->congestion_threshold = max_user_congthresh; 871 } 872 spin_unlock(&fc->bg_lock); 873 } 874 875 struct fuse_init_args { 876 struct fuse_args args; 877 struct fuse_init_in in; 878 struct fuse_init_out out; 879 }; 880 881 static void process_init_reply(struct fuse_conn *fc, struct fuse_args *args, 882 int error) 883 { 884 struct fuse_init_args *ia = container_of(args, typeof(*ia), args); 885 struct fuse_init_out *arg = &ia->out; 886 887 if (error || arg->major != FUSE_KERNEL_VERSION) 888 fc->conn_error = 1; 889 else { 890 unsigned long ra_pages; 891 892 process_init_limits(fc, arg); 893 894 if (arg->minor >= 6) { 895 ra_pages = arg->max_readahead / PAGE_SIZE; 896 if (arg->flags & FUSE_ASYNC_READ) 897 fc->async_read = 1; 898 if (!(arg->flags & FUSE_POSIX_LOCKS)) 899 fc->no_lock = 1; 900 if (arg->minor >= 17) { 901 if (!(arg->flags & FUSE_FLOCK_LOCKS)) 902 fc->no_flock = 1; 903 } else { 904 if (!(arg->flags & FUSE_POSIX_LOCKS)) 905 fc->no_flock = 1; 906 } 907 if (arg->flags & FUSE_ATOMIC_O_TRUNC) 908 fc->atomic_o_trunc = 1; 909 if (arg->minor >= 9) { 910 /* LOOKUP has dependency on proto version */ 911 if (arg->flags & FUSE_EXPORT_SUPPORT) 912 fc->export_support = 1; 913 } 914 if (arg->flags & FUSE_BIG_WRITES) 915 fc->big_writes = 1; 916 if (arg->flags & FUSE_DONT_MASK) 917 fc->dont_mask = 1; 918 if (arg->flags & FUSE_AUTO_INVAL_DATA) 919 fc->auto_inval_data = 1; 920 else if (arg->flags & FUSE_EXPLICIT_INVAL_DATA) 921 fc->explicit_inval_data = 1; 922 if (arg->flags & FUSE_DO_READDIRPLUS) { 923 fc->do_readdirplus = 1; 924 if (arg->flags & FUSE_READDIRPLUS_AUTO) 925 fc->readdirplus_auto = 1; 926 } 927 if (arg->flags & FUSE_ASYNC_DIO) 928 fc->async_dio = 1; 929 if (arg->flags & FUSE_WRITEBACK_CACHE) 930 fc->writeback_cache = 1; 931 if (arg->flags & FUSE_PARALLEL_DIROPS) 932 fc->parallel_dirops = 1; 933 if (arg->flags & FUSE_HANDLE_KILLPRIV) 934 fc->handle_killpriv = 1; 935 if (arg->time_gran && arg->time_gran <= 1000000000) 936 fc->sb->s_time_gran = arg->time_gran; 937 if ((arg->flags & FUSE_POSIX_ACL)) { 938 fc->default_permissions = 1; 939 fc->posix_acl = 1; 940 fc->sb->s_xattr = fuse_acl_xattr_handlers; 941 } 942 if (arg->flags & FUSE_CACHE_SYMLINKS) 943 fc->cache_symlinks = 1; 944 if (arg->flags & FUSE_ABORT_ERROR) 945 fc->abort_err = 1; 946 if (arg->flags & FUSE_MAX_PAGES) { 947 fc->max_pages = 948 min_t(unsigned int, FUSE_MAX_MAX_PAGES, 949 max_t(unsigned int, arg->max_pages, 1)); 950 } 951 } else { 952 ra_pages = fc->max_read / PAGE_SIZE; 953 fc->no_lock = 1; 954 fc->no_flock = 1; 955 } 956 957 fc->sb->s_bdi->ra_pages = 958 min(fc->sb->s_bdi->ra_pages, ra_pages); 959 fc->minor = arg->minor; 960 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 961 fc->max_write = max_t(unsigned, 4096, fc->max_write); 962 fc->conn_init = 1; 963 } 964 kfree(ia); 965 966 fuse_set_initialized(fc); 967 wake_up_all(&fc->blocked_waitq); 968 } 969 970 void fuse_send_init(struct fuse_conn *fc) 971 { 972 struct fuse_init_args *ia; 973 974 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL); 975 976 ia->in.major = FUSE_KERNEL_VERSION; 977 ia->in.minor = FUSE_KERNEL_MINOR_VERSION; 978 ia->in.max_readahead = fc->sb->s_bdi->ra_pages * PAGE_SIZE; 979 ia->in.flags |= 980 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 981 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | 982 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | 983 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | 984 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO | 985 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT | 986 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL | 987 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | 988 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA; 989 ia->args.opcode = FUSE_INIT; 990 ia->args.in_numargs = 1; 991 ia->args.in_args[0].size = sizeof(ia->in); 992 ia->args.in_args[0].value = &ia->in; 993 ia->args.out_numargs = 1; 994 /* Variable length argument used for backward compatibility 995 with interface version < 7.5. Rest of init_out is zeroed 996 by do_get_request(), so a short reply is not a problem */ 997 ia->args.out_argvar = 1; 998 ia->args.out_args[0].size = sizeof(ia->out); 999 ia->args.out_args[0].value = &ia->out; 1000 ia->args.force = true; 1001 ia->args.nocreds = true; 1002 ia->args.end = process_init_reply; 1003 1004 if (fuse_simple_background(fc, &ia->args, GFP_KERNEL) != 0) 1005 process_init_reply(fc, &ia->args, -ENOTCONN); 1006 } 1007 EXPORT_SYMBOL_GPL(fuse_send_init); 1008 1009 void fuse_free_conn(struct fuse_conn *fc) 1010 { 1011 WARN_ON(!list_empty(&fc->devices)); 1012 kfree_rcu(fc, rcu); 1013 } 1014 EXPORT_SYMBOL_GPL(fuse_free_conn); 1015 1016 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 1017 { 1018 int err; 1019 char *suffix = ""; 1020 1021 if (sb->s_bdev) { 1022 suffix = "-fuseblk"; 1023 /* 1024 * sb->s_bdi points to blkdev's bdi however we want to redirect 1025 * it to our private bdi... 1026 */ 1027 bdi_put(sb->s_bdi); 1028 sb->s_bdi = &noop_backing_dev_info; 1029 } 1030 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev), 1031 MINOR(fc->dev), suffix); 1032 if (err) 1033 return err; 1034 1035 sb->s_bdi->ra_pages = VM_READAHEAD_PAGES; 1036 /* fuse does it's own writeback accounting */ 1037 sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT; 1038 1039 /* 1040 * For a single fuse filesystem use max 1% of dirty + 1041 * writeback threshold. 1042 * 1043 * This gives about 1M of write buffer for memory maps on a 1044 * machine with 1G and 10% dirty_ratio, which should be more 1045 * than enough. 1046 * 1047 * Privileged users can raise it by writing to 1048 * 1049 * /sys/class/bdi/<bdi>/max_ratio 1050 */ 1051 bdi_set_max_ratio(sb->s_bdi, 1); 1052 1053 return 0; 1054 } 1055 1056 struct fuse_dev *fuse_dev_alloc(void) 1057 { 1058 struct fuse_dev *fud; 1059 struct list_head *pq; 1060 1061 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL); 1062 if (!fud) 1063 return NULL; 1064 1065 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); 1066 if (!pq) { 1067 kfree(fud); 1068 return NULL; 1069 } 1070 1071 fud->pq.processing = pq; 1072 fuse_pqueue_init(&fud->pq); 1073 1074 return fud; 1075 } 1076 EXPORT_SYMBOL_GPL(fuse_dev_alloc); 1077 1078 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc) 1079 { 1080 fud->fc = fuse_conn_get(fc); 1081 spin_lock(&fc->lock); 1082 list_add_tail(&fud->entry, &fc->devices); 1083 spin_unlock(&fc->lock); 1084 } 1085 EXPORT_SYMBOL_GPL(fuse_dev_install); 1086 1087 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc) 1088 { 1089 struct fuse_dev *fud; 1090 1091 fud = fuse_dev_alloc(); 1092 if (!fud) 1093 return NULL; 1094 1095 fuse_dev_install(fud, fc); 1096 return fud; 1097 } 1098 EXPORT_SYMBOL_GPL(fuse_dev_alloc_install); 1099 1100 void fuse_dev_free(struct fuse_dev *fud) 1101 { 1102 struct fuse_conn *fc = fud->fc; 1103 1104 if (fc) { 1105 spin_lock(&fc->lock); 1106 list_del(&fud->entry); 1107 spin_unlock(&fc->lock); 1108 1109 fuse_conn_put(fc); 1110 } 1111 kfree(fud->pq.processing); 1112 kfree(fud); 1113 } 1114 EXPORT_SYMBOL_GPL(fuse_dev_free); 1115 1116 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx) 1117 { 1118 struct fuse_dev *fud; 1119 struct fuse_conn *fc = get_fuse_conn_super(sb); 1120 struct inode *root; 1121 struct dentry *root_dentry; 1122 int err; 1123 1124 err = -EINVAL; 1125 if (sb->s_flags & SB_MANDLOCK) 1126 goto err; 1127 1128 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); 1129 1130 if (ctx->is_bdev) { 1131 #ifdef CONFIG_BLOCK 1132 err = -EINVAL; 1133 if (!sb_set_blocksize(sb, ctx->blksize)) 1134 goto err; 1135 #endif 1136 } else { 1137 sb->s_blocksize = PAGE_SIZE; 1138 sb->s_blocksize_bits = PAGE_SHIFT; 1139 } 1140 1141 sb->s_subtype = ctx->subtype; 1142 ctx->subtype = NULL; 1143 sb->s_magic = FUSE_SUPER_MAGIC; 1144 sb->s_op = &fuse_super_operations; 1145 sb->s_xattr = fuse_xattr_handlers; 1146 sb->s_maxbytes = MAX_LFS_FILESIZE; 1147 sb->s_time_gran = 1; 1148 sb->s_export_op = &fuse_export_operations; 1149 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE; 1150 if (sb->s_user_ns != &init_user_ns) 1151 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; 1152 1153 /* 1154 * If we are not in the initial user namespace posix 1155 * acls must be translated. 1156 */ 1157 if (sb->s_user_ns != &init_user_ns) 1158 sb->s_xattr = fuse_no_acl_xattr_handlers; 1159 1160 fud = fuse_dev_alloc_install(fc); 1161 if (!fud) 1162 goto err; 1163 1164 fc->dev = sb->s_dev; 1165 fc->sb = sb; 1166 err = fuse_bdi_init(fc, sb); 1167 if (err) 1168 goto err_dev_free; 1169 1170 /* Handle umasking inside the fuse code */ 1171 if (sb->s_flags & SB_POSIXACL) 1172 fc->dont_mask = 1; 1173 sb->s_flags |= SB_POSIXACL; 1174 1175 fc->default_permissions = ctx->default_permissions; 1176 fc->allow_other = ctx->allow_other; 1177 fc->user_id = ctx->user_id; 1178 fc->group_id = ctx->group_id; 1179 fc->max_read = max_t(unsigned, 4096, ctx->max_read); 1180 fc->destroy = ctx->destroy; 1181 fc->no_control = ctx->no_control; 1182 fc->no_force_umount = ctx->no_force_umount; 1183 1184 err = -ENOMEM; 1185 root = fuse_get_root_inode(sb, ctx->rootmode); 1186 sb->s_d_op = &fuse_root_dentry_operations; 1187 root_dentry = d_make_root(root); 1188 if (!root_dentry) 1189 goto err_dev_free; 1190 /* Root dentry doesn't have .d_revalidate */ 1191 sb->s_d_op = &fuse_dentry_operations; 1192 1193 mutex_lock(&fuse_mutex); 1194 err = -EINVAL; 1195 if (*ctx->fudptr) 1196 goto err_unlock; 1197 1198 err = fuse_ctl_add_conn(fc); 1199 if (err) 1200 goto err_unlock; 1201 1202 list_add_tail(&fc->entry, &fuse_conn_list); 1203 sb->s_root = root_dentry; 1204 *ctx->fudptr = fud; 1205 mutex_unlock(&fuse_mutex); 1206 return 0; 1207 1208 err_unlock: 1209 mutex_unlock(&fuse_mutex); 1210 dput(root_dentry); 1211 err_dev_free: 1212 fuse_dev_free(fud); 1213 err: 1214 return err; 1215 } 1216 EXPORT_SYMBOL_GPL(fuse_fill_super_common); 1217 1218 static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc) 1219 { 1220 struct fuse_fs_context *ctx = fsc->fs_private; 1221 struct file *file; 1222 int err; 1223 struct fuse_conn *fc; 1224 1225 err = -EINVAL; 1226 file = fget(ctx->fd); 1227 if (!file) 1228 goto err; 1229 1230 /* 1231 * Require mount to happen from the same user namespace which 1232 * opened /dev/fuse to prevent potential attacks. 1233 */ 1234 if ((file->f_op != &fuse_dev_operations) || 1235 (file->f_cred->user_ns != sb->s_user_ns)) 1236 goto err_fput; 1237 ctx->fudptr = &file->private_data; 1238 1239 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 1240 err = -ENOMEM; 1241 if (!fc) 1242 goto err_fput; 1243 1244 fuse_conn_init(fc, sb->s_user_ns, &fuse_dev_fiq_ops, NULL); 1245 fc->release = fuse_free_conn; 1246 sb->s_fs_info = fc; 1247 1248 err = fuse_fill_super_common(sb, ctx); 1249 if (err) 1250 goto err_put_conn; 1251 /* 1252 * atomic_dec_and_test() in fput() provides the necessary 1253 * memory barrier for file->private_data to be visible on all 1254 * CPUs after this 1255 */ 1256 fput(file); 1257 fuse_send_init(get_fuse_conn_super(sb)); 1258 return 0; 1259 1260 err_put_conn: 1261 fuse_conn_put(fc); 1262 sb->s_fs_info = NULL; 1263 err_fput: 1264 fput(file); 1265 err: 1266 return err; 1267 } 1268 1269 static int fuse_get_tree(struct fs_context *fc) 1270 { 1271 struct fuse_fs_context *ctx = fc->fs_private; 1272 1273 if (!ctx->fd_present || !ctx->rootmode_present || 1274 !ctx->user_id_present || !ctx->group_id_present) 1275 return -EINVAL; 1276 1277 #ifdef CONFIG_BLOCK 1278 if (ctx->is_bdev) 1279 return get_tree_bdev(fc, fuse_fill_super); 1280 #endif 1281 1282 return get_tree_nodev(fc, fuse_fill_super); 1283 } 1284 1285 static const struct fs_context_operations fuse_context_ops = { 1286 .free = fuse_free_fc, 1287 .parse_param = fuse_parse_param, 1288 .get_tree = fuse_get_tree, 1289 }; 1290 1291 /* 1292 * Set up the filesystem mount context. 1293 */ 1294 static int fuse_init_fs_context(struct fs_context *fc) 1295 { 1296 struct fuse_fs_context *ctx; 1297 1298 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); 1299 if (!ctx) 1300 return -ENOMEM; 1301 1302 ctx->max_read = ~0; 1303 ctx->blksize = FUSE_DEFAULT_BLKSIZE; 1304 1305 #ifdef CONFIG_BLOCK 1306 if (fc->fs_type == &fuseblk_fs_type) { 1307 ctx->is_bdev = true; 1308 ctx->destroy = true; 1309 } 1310 #endif 1311 1312 fc->fs_private = ctx; 1313 fc->ops = &fuse_context_ops; 1314 return 0; 1315 } 1316 1317 static void fuse_sb_destroy(struct super_block *sb) 1318 { 1319 struct fuse_conn *fc = get_fuse_conn_super(sb); 1320 1321 if (fc) { 1322 if (fc->destroy) 1323 fuse_send_destroy(fc); 1324 1325 fuse_abort_conn(fc); 1326 fuse_wait_aborted(fc); 1327 1328 down_write(&fc->killsb); 1329 fc->sb = NULL; 1330 up_write(&fc->killsb); 1331 } 1332 } 1333 1334 void fuse_kill_sb_anon(struct super_block *sb) 1335 { 1336 fuse_sb_destroy(sb); 1337 kill_anon_super(sb); 1338 } 1339 EXPORT_SYMBOL_GPL(fuse_kill_sb_anon); 1340 1341 static struct file_system_type fuse_fs_type = { 1342 .owner = THIS_MODULE, 1343 .name = "fuse", 1344 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT, 1345 .init_fs_context = fuse_init_fs_context, 1346 .parameters = &fuse_fs_parameters, 1347 .kill_sb = fuse_kill_sb_anon, 1348 }; 1349 MODULE_ALIAS_FS("fuse"); 1350 1351 #ifdef CONFIG_BLOCK 1352 static void fuse_kill_sb_blk(struct super_block *sb) 1353 { 1354 fuse_sb_destroy(sb); 1355 kill_block_super(sb); 1356 } 1357 1358 static struct file_system_type fuseblk_fs_type = { 1359 .owner = THIS_MODULE, 1360 .name = "fuseblk", 1361 .init_fs_context = fuse_init_fs_context, 1362 .parameters = &fuse_fs_parameters, 1363 .kill_sb = fuse_kill_sb_blk, 1364 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 1365 }; 1366 MODULE_ALIAS_FS("fuseblk"); 1367 1368 static inline int register_fuseblk(void) 1369 { 1370 return register_filesystem(&fuseblk_fs_type); 1371 } 1372 1373 static inline void unregister_fuseblk(void) 1374 { 1375 unregister_filesystem(&fuseblk_fs_type); 1376 } 1377 #else 1378 static inline int register_fuseblk(void) 1379 { 1380 return 0; 1381 } 1382 1383 static inline void unregister_fuseblk(void) 1384 { 1385 } 1386 #endif 1387 1388 static void fuse_inode_init_once(void *foo) 1389 { 1390 struct inode *inode = foo; 1391 1392 inode_init_once(inode); 1393 } 1394 1395 static int __init fuse_fs_init(void) 1396 { 1397 int err; 1398 1399 fuse_inode_cachep = kmem_cache_create("fuse_inode", 1400 sizeof(struct fuse_inode), 0, 1401 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT, 1402 fuse_inode_init_once); 1403 err = -ENOMEM; 1404 if (!fuse_inode_cachep) 1405 goto out; 1406 1407 err = register_fuseblk(); 1408 if (err) 1409 goto out2; 1410 1411 err = register_filesystem(&fuse_fs_type); 1412 if (err) 1413 goto out3; 1414 1415 return 0; 1416 1417 out3: 1418 unregister_fuseblk(); 1419 out2: 1420 kmem_cache_destroy(fuse_inode_cachep); 1421 out: 1422 return err; 1423 } 1424 1425 static void fuse_fs_cleanup(void) 1426 { 1427 unregister_filesystem(&fuse_fs_type); 1428 unregister_fuseblk(); 1429 1430 /* 1431 * Make sure all delayed rcu free inodes are flushed before we 1432 * destroy cache. 1433 */ 1434 rcu_barrier(); 1435 kmem_cache_destroy(fuse_inode_cachep); 1436 } 1437 1438 static struct kobject *fuse_kobj; 1439 1440 static int fuse_sysfs_init(void) 1441 { 1442 int err; 1443 1444 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 1445 if (!fuse_kobj) { 1446 err = -ENOMEM; 1447 goto out_err; 1448 } 1449 1450 err = sysfs_create_mount_point(fuse_kobj, "connections"); 1451 if (err) 1452 goto out_fuse_unregister; 1453 1454 return 0; 1455 1456 out_fuse_unregister: 1457 kobject_put(fuse_kobj); 1458 out_err: 1459 return err; 1460 } 1461 1462 static void fuse_sysfs_cleanup(void) 1463 { 1464 sysfs_remove_mount_point(fuse_kobj, "connections"); 1465 kobject_put(fuse_kobj); 1466 } 1467 1468 static int __init fuse_init(void) 1469 { 1470 int res; 1471 1472 pr_info("init (API version %i.%i)\n", 1473 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 1474 1475 INIT_LIST_HEAD(&fuse_conn_list); 1476 res = fuse_fs_init(); 1477 if (res) 1478 goto err; 1479 1480 res = fuse_dev_init(); 1481 if (res) 1482 goto err_fs_cleanup; 1483 1484 res = fuse_sysfs_init(); 1485 if (res) 1486 goto err_dev_cleanup; 1487 1488 res = fuse_ctl_init(); 1489 if (res) 1490 goto err_sysfs_cleanup; 1491 1492 sanitize_global_limit(&max_user_bgreq); 1493 sanitize_global_limit(&max_user_congthresh); 1494 1495 return 0; 1496 1497 err_sysfs_cleanup: 1498 fuse_sysfs_cleanup(); 1499 err_dev_cleanup: 1500 fuse_dev_cleanup(); 1501 err_fs_cleanup: 1502 fuse_fs_cleanup(); 1503 err: 1504 return res; 1505 } 1506 1507 static void __exit fuse_exit(void) 1508 { 1509 pr_debug("exit\n"); 1510 1511 fuse_ctl_cleanup(); 1512 fuse_sysfs_cleanup(); 1513 fuse_fs_cleanup(); 1514 fuse_dev_cleanup(); 1515 } 1516 1517 module_init(fuse_init); 1518 module_exit(fuse_exit); 1519