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_fs_parameters[] = { 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 int fuse_parse_param(struct fs_context *fc, struct fs_parameter *param) 466 { 467 struct fs_parse_result result; 468 struct fuse_fs_context *ctx = fc->fs_private; 469 int opt; 470 471 opt = fs_parse(fc, fuse_fs_parameters, param, &result); 472 if (opt < 0) 473 return opt; 474 475 switch (opt) { 476 case OPT_SOURCE: 477 if (fc->source) 478 return invalfc(fc, "Multiple sources specified"); 479 fc->source = param->string; 480 param->string = NULL; 481 break; 482 483 case OPT_SUBTYPE: 484 if (ctx->subtype) 485 return invalfc(fc, "Multiple subtypes specified"); 486 ctx->subtype = param->string; 487 param->string = NULL; 488 return 0; 489 490 case OPT_FD: 491 ctx->fd = result.uint_32; 492 ctx->fd_present = true; 493 break; 494 495 case OPT_ROOTMODE: 496 if (!fuse_valid_type(result.uint_32)) 497 return invalfc(fc, "Invalid rootmode"); 498 ctx->rootmode = result.uint_32; 499 ctx->rootmode_present = true; 500 break; 501 502 case OPT_USER_ID: 503 ctx->user_id = make_kuid(fc->user_ns, result.uint_32); 504 if (!uid_valid(ctx->user_id)) 505 return invalfc(fc, "Invalid user_id"); 506 ctx->user_id_present = true; 507 break; 508 509 case OPT_GROUP_ID: 510 ctx->group_id = make_kgid(fc->user_ns, result.uint_32); 511 if (!gid_valid(ctx->group_id)) 512 return invalfc(fc, "Invalid group_id"); 513 ctx->group_id_present = true; 514 break; 515 516 case OPT_DEFAULT_PERMISSIONS: 517 ctx->default_permissions = true; 518 break; 519 520 case OPT_ALLOW_OTHER: 521 ctx->allow_other = true; 522 break; 523 524 case OPT_MAX_READ: 525 ctx->max_read = result.uint_32; 526 break; 527 528 case OPT_BLKSIZE: 529 if (!ctx->is_bdev) 530 return invalfc(fc, "blksize only supported for fuseblk"); 531 ctx->blksize = result.uint_32; 532 break; 533 534 default: 535 return -EINVAL; 536 } 537 538 return 0; 539 } 540 541 static void fuse_free_fc(struct fs_context *fc) 542 { 543 struct fuse_fs_context *ctx = fc->fs_private; 544 545 if (ctx) { 546 kfree(ctx->subtype); 547 kfree(ctx); 548 } 549 } 550 551 static int fuse_show_options(struct seq_file *m, struct dentry *root) 552 { 553 struct super_block *sb = root->d_sb; 554 struct fuse_conn *fc = get_fuse_conn_super(sb); 555 556 if (fc->no_mount_options) 557 return 0; 558 559 seq_printf(m, ",user_id=%u", from_kuid_munged(fc->user_ns, fc->user_id)); 560 seq_printf(m, ",group_id=%u", from_kgid_munged(fc->user_ns, fc->group_id)); 561 if (fc->default_permissions) 562 seq_puts(m, ",default_permissions"); 563 if (fc->allow_other) 564 seq_puts(m, ",allow_other"); 565 if (fc->max_read != ~0) 566 seq_printf(m, ",max_read=%u", fc->max_read); 567 if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 568 seq_printf(m, ",blksize=%lu", sb->s_blocksize); 569 return 0; 570 } 571 572 static void fuse_iqueue_init(struct fuse_iqueue *fiq, 573 const struct fuse_iqueue_ops *ops, 574 void *priv) 575 { 576 memset(fiq, 0, sizeof(struct fuse_iqueue)); 577 spin_lock_init(&fiq->lock); 578 init_waitqueue_head(&fiq->waitq); 579 INIT_LIST_HEAD(&fiq->pending); 580 INIT_LIST_HEAD(&fiq->interrupts); 581 fiq->forget_list_tail = &fiq->forget_list_head; 582 fiq->connected = 1; 583 fiq->ops = ops; 584 fiq->priv = priv; 585 } 586 587 static void fuse_pqueue_init(struct fuse_pqueue *fpq) 588 { 589 unsigned int i; 590 591 spin_lock_init(&fpq->lock); 592 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++) 593 INIT_LIST_HEAD(&fpq->processing[i]); 594 INIT_LIST_HEAD(&fpq->io); 595 fpq->connected = 1; 596 } 597 598 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns, 599 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv) 600 { 601 memset(fc, 0, sizeof(*fc)); 602 spin_lock_init(&fc->lock); 603 spin_lock_init(&fc->bg_lock); 604 init_rwsem(&fc->killsb); 605 refcount_set(&fc->count, 1); 606 atomic_set(&fc->dev_count, 1); 607 init_waitqueue_head(&fc->blocked_waitq); 608 fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv); 609 INIT_LIST_HEAD(&fc->bg_queue); 610 INIT_LIST_HEAD(&fc->entry); 611 INIT_LIST_HEAD(&fc->devices); 612 atomic_set(&fc->num_waiting, 0); 613 fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND; 614 fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD; 615 atomic64_set(&fc->khctr, 0); 616 fc->polled_files = RB_ROOT; 617 fc->blocked = 0; 618 fc->initialized = 0; 619 fc->connected = 1; 620 atomic64_set(&fc->attr_version, 1); 621 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 622 fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); 623 fc->user_ns = get_user_ns(user_ns); 624 fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ; 625 } 626 EXPORT_SYMBOL_GPL(fuse_conn_init); 627 628 void fuse_conn_put(struct fuse_conn *fc) 629 { 630 if (refcount_dec_and_test(&fc->count)) { 631 struct fuse_iqueue *fiq = &fc->iq; 632 633 if (fiq->ops->release) 634 fiq->ops->release(fiq); 635 put_pid_ns(fc->pid_ns); 636 put_user_ns(fc->user_ns); 637 fc->release(fc); 638 } 639 } 640 EXPORT_SYMBOL_GPL(fuse_conn_put); 641 642 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 643 { 644 refcount_inc(&fc->count); 645 return fc; 646 } 647 EXPORT_SYMBOL_GPL(fuse_conn_get); 648 649 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 650 { 651 struct fuse_attr attr; 652 memset(&attr, 0, sizeof(attr)); 653 654 attr.mode = mode; 655 attr.ino = FUSE_ROOT_ID; 656 attr.nlink = 1; 657 return fuse_iget(sb, 1, 0, &attr, 0, 0); 658 } 659 660 struct fuse_inode_handle { 661 u64 nodeid; 662 u32 generation; 663 }; 664 665 static struct dentry *fuse_get_dentry(struct super_block *sb, 666 struct fuse_inode_handle *handle) 667 { 668 struct fuse_conn *fc = get_fuse_conn_super(sb); 669 struct inode *inode; 670 struct dentry *entry; 671 int err = -ESTALE; 672 673 if (handle->nodeid == 0) 674 goto out_err; 675 676 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 677 if (!inode) { 678 struct fuse_entry_out outarg; 679 const struct qstr name = QSTR_INIT(".", 1); 680 681 if (!fc->export_support) 682 goto out_err; 683 684 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 685 &inode); 686 if (err && err != -ENOENT) 687 goto out_err; 688 if (err || !inode) { 689 err = -ESTALE; 690 goto out_err; 691 } 692 err = -EIO; 693 if (get_node_id(inode) != handle->nodeid) 694 goto out_iput; 695 } 696 err = -ESTALE; 697 if (inode->i_generation != handle->generation) 698 goto out_iput; 699 700 entry = d_obtain_alias(inode); 701 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) 702 fuse_invalidate_entry_cache(entry); 703 704 return entry; 705 706 out_iput: 707 iput(inode); 708 out_err: 709 return ERR_PTR(err); 710 } 711 712 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len, 713 struct inode *parent) 714 { 715 int len = parent ? 6 : 3; 716 u64 nodeid; 717 u32 generation; 718 719 if (*max_len < len) { 720 *max_len = len; 721 return FILEID_INVALID; 722 } 723 724 nodeid = get_fuse_inode(inode)->nodeid; 725 generation = inode->i_generation; 726 727 fh[0] = (u32)(nodeid >> 32); 728 fh[1] = (u32)(nodeid & 0xffffffff); 729 fh[2] = generation; 730 731 if (parent) { 732 nodeid = get_fuse_inode(parent)->nodeid; 733 generation = parent->i_generation; 734 735 fh[3] = (u32)(nodeid >> 32); 736 fh[4] = (u32)(nodeid & 0xffffffff); 737 fh[5] = generation; 738 } 739 740 *max_len = len; 741 return parent ? 0x82 : 0x81; 742 } 743 744 static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 745 struct fid *fid, int fh_len, int fh_type) 746 { 747 struct fuse_inode_handle handle; 748 749 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) 750 return NULL; 751 752 handle.nodeid = (u64) fid->raw[0] << 32; 753 handle.nodeid |= (u64) fid->raw[1]; 754 handle.generation = fid->raw[2]; 755 return fuse_get_dentry(sb, &handle); 756 } 757 758 static struct dentry *fuse_fh_to_parent(struct super_block *sb, 759 struct fid *fid, int fh_len, int fh_type) 760 { 761 struct fuse_inode_handle parent; 762 763 if (fh_type != 0x82 || fh_len < 6) 764 return NULL; 765 766 parent.nodeid = (u64) fid->raw[3] << 32; 767 parent.nodeid |= (u64) fid->raw[4]; 768 parent.generation = fid->raw[5]; 769 return fuse_get_dentry(sb, &parent); 770 } 771 772 static struct dentry *fuse_get_parent(struct dentry *child) 773 { 774 struct inode *child_inode = d_inode(child); 775 struct fuse_conn *fc = get_fuse_conn(child_inode); 776 struct inode *inode; 777 struct dentry *parent; 778 struct fuse_entry_out outarg; 779 const struct qstr name = QSTR_INIT("..", 2); 780 int err; 781 782 if (!fc->export_support) 783 return ERR_PTR(-ESTALE); 784 785 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 786 &name, &outarg, &inode); 787 if (err) { 788 if (err == -ENOENT) 789 return ERR_PTR(-ESTALE); 790 return ERR_PTR(err); 791 } 792 793 parent = d_obtain_alias(inode); 794 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) 795 fuse_invalidate_entry_cache(parent); 796 797 return parent; 798 } 799 800 static const struct export_operations fuse_export_operations = { 801 .fh_to_dentry = fuse_fh_to_dentry, 802 .fh_to_parent = fuse_fh_to_parent, 803 .encode_fh = fuse_encode_fh, 804 .get_parent = fuse_get_parent, 805 }; 806 807 static const struct super_operations fuse_super_operations = { 808 .alloc_inode = fuse_alloc_inode, 809 .free_inode = fuse_free_inode, 810 .evict_inode = fuse_evict_inode, 811 .write_inode = fuse_write_inode, 812 .drop_inode = generic_delete_inode, 813 .remount_fs = fuse_remount_fs, 814 .put_super = fuse_put_super, 815 .umount_begin = fuse_umount_begin, 816 .statfs = fuse_statfs, 817 .show_options = fuse_show_options, 818 }; 819 820 static void sanitize_global_limit(unsigned *limit) 821 { 822 /* 823 * The default maximum number of async requests is calculated to consume 824 * 1/2^13 of the total memory, assuming 392 bytes per request. 825 */ 826 if (*limit == 0) 827 *limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392; 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 struct fuse_init_args { 874 struct fuse_args args; 875 struct fuse_init_in in; 876 struct fuse_init_out out; 877 }; 878 879 static void process_init_reply(struct fuse_conn *fc, struct fuse_args *args, 880 int error) 881 { 882 struct fuse_init_args *ia = container_of(args, typeof(*ia), args); 883 struct fuse_init_out *arg = &ia->out; 884 885 if (error || arg->major != FUSE_KERNEL_VERSION) 886 fc->conn_error = 1; 887 else { 888 unsigned long ra_pages; 889 890 process_init_limits(fc, arg); 891 892 if (arg->minor >= 6) { 893 ra_pages = arg->max_readahead / PAGE_SIZE; 894 if (arg->flags & FUSE_ASYNC_READ) 895 fc->async_read = 1; 896 if (!(arg->flags & FUSE_POSIX_LOCKS)) 897 fc->no_lock = 1; 898 if (arg->minor >= 17) { 899 if (!(arg->flags & FUSE_FLOCK_LOCKS)) 900 fc->no_flock = 1; 901 } else { 902 if (!(arg->flags & FUSE_POSIX_LOCKS)) 903 fc->no_flock = 1; 904 } 905 if (arg->flags & FUSE_ATOMIC_O_TRUNC) 906 fc->atomic_o_trunc = 1; 907 if (arg->minor >= 9) { 908 /* LOOKUP has dependency on proto version */ 909 if (arg->flags & FUSE_EXPORT_SUPPORT) 910 fc->export_support = 1; 911 } 912 if (arg->flags & FUSE_BIG_WRITES) 913 fc->big_writes = 1; 914 if (arg->flags & FUSE_DONT_MASK) 915 fc->dont_mask = 1; 916 if (arg->flags & FUSE_AUTO_INVAL_DATA) 917 fc->auto_inval_data = 1; 918 else if (arg->flags & FUSE_EXPLICIT_INVAL_DATA) 919 fc->explicit_inval_data = 1; 920 if (arg->flags & FUSE_DO_READDIRPLUS) { 921 fc->do_readdirplus = 1; 922 if (arg->flags & FUSE_READDIRPLUS_AUTO) 923 fc->readdirplus_auto = 1; 924 } 925 if (arg->flags & FUSE_ASYNC_DIO) 926 fc->async_dio = 1; 927 if (arg->flags & FUSE_WRITEBACK_CACHE) 928 fc->writeback_cache = 1; 929 if (arg->flags & FUSE_PARALLEL_DIROPS) 930 fc->parallel_dirops = 1; 931 if (arg->flags & FUSE_HANDLE_KILLPRIV) 932 fc->handle_killpriv = 1; 933 if (arg->time_gran && arg->time_gran <= 1000000000) 934 fc->sb->s_time_gran = arg->time_gran; 935 if ((arg->flags & FUSE_POSIX_ACL)) { 936 fc->default_permissions = 1; 937 fc->posix_acl = 1; 938 fc->sb->s_xattr = fuse_acl_xattr_handlers; 939 } 940 if (arg->flags & FUSE_CACHE_SYMLINKS) 941 fc->cache_symlinks = 1; 942 if (arg->flags & FUSE_ABORT_ERROR) 943 fc->abort_err = 1; 944 if (arg->flags & FUSE_MAX_PAGES) { 945 fc->max_pages = 946 min_t(unsigned int, FUSE_MAX_MAX_PAGES, 947 max_t(unsigned int, arg->max_pages, 1)); 948 } 949 } else { 950 ra_pages = fc->max_read / PAGE_SIZE; 951 fc->no_lock = 1; 952 fc->no_flock = 1; 953 } 954 955 fc->sb->s_bdi->ra_pages = 956 min(fc->sb->s_bdi->ra_pages, ra_pages); 957 fc->minor = arg->minor; 958 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 959 fc->max_write = max_t(unsigned, 4096, fc->max_write); 960 fc->conn_init = 1; 961 } 962 kfree(ia); 963 964 fuse_set_initialized(fc); 965 wake_up_all(&fc->blocked_waitq); 966 } 967 968 void fuse_send_init(struct fuse_conn *fc) 969 { 970 struct fuse_init_args *ia; 971 972 ia = kzalloc(sizeof(*ia), GFP_KERNEL | __GFP_NOFAIL); 973 974 ia->in.major = FUSE_KERNEL_VERSION; 975 ia->in.minor = FUSE_KERNEL_MINOR_VERSION; 976 ia->in.max_readahead = fc->sb->s_bdi->ra_pages * PAGE_SIZE; 977 ia->in.flags |= 978 FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 979 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | 980 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | 981 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | 982 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO | 983 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT | 984 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL | 985 FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | 986 FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA; 987 ia->args.opcode = FUSE_INIT; 988 ia->args.in_numargs = 1; 989 ia->args.in_args[0].size = sizeof(ia->in); 990 ia->args.in_args[0].value = &ia->in; 991 ia->args.out_numargs = 1; 992 /* Variable length argument used for backward compatibility 993 with interface version < 7.5. Rest of init_out is zeroed 994 by do_get_request(), so a short reply is not a problem */ 995 ia->args.out_argvar = true; 996 ia->args.out_args[0].size = sizeof(ia->out); 997 ia->args.out_args[0].value = &ia->out; 998 ia->args.force = true; 999 ia->args.nocreds = true; 1000 ia->args.end = process_init_reply; 1001 1002 if (fuse_simple_background(fc, &ia->args, GFP_KERNEL) != 0) 1003 process_init_reply(fc, &ia->args, -ENOTCONN); 1004 } 1005 EXPORT_SYMBOL_GPL(fuse_send_init); 1006 1007 void fuse_free_conn(struct fuse_conn *fc) 1008 { 1009 WARN_ON(!list_empty(&fc->devices)); 1010 kfree_rcu(fc, rcu); 1011 } 1012 EXPORT_SYMBOL_GPL(fuse_free_conn); 1013 1014 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 1015 { 1016 int err; 1017 char *suffix = ""; 1018 1019 if (sb->s_bdev) { 1020 suffix = "-fuseblk"; 1021 /* 1022 * sb->s_bdi points to blkdev's bdi however we want to redirect 1023 * it to our private bdi... 1024 */ 1025 bdi_put(sb->s_bdi); 1026 sb->s_bdi = &noop_backing_dev_info; 1027 } 1028 err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev), 1029 MINOR(fc->dev), suffix); 1030 if (err) 1031 return err; 1032 1033 sb->s_bdi->ra_pages = VM_READAHEAD_PAGES; 1034 /* fuse does it's own writeback accounting */ 1035 sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT; 1036 1037 /* 1038 * For a single fuse filesystem use max 1% of dirty + 1039 * writeback threshold. 1040 * 1041 * This gives about 1M of write buffer for memory maps on a 1042 * machine with 1G and 10% dirty_ratio, which should be more 1043 * than enough. 1044 * 1045 * Privileged users can raise it by writing to 1046 * 1047 * /sys/class/bdi/<bdi>/max_ratio 1048 */ 1049 bdi_set_max_ratio(sb->s_bdi, 1); 1050 1051 return 0; 1052 } 1053 1054 struct fuse_dev *fuse_dev_alloc(void) 1055 { 1056 struct fuse_dev *fud; 1057 struct list_head *pq; 1058 1059 fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL); 1060 if (!fud) 1061 return NULL; 1062 1063 pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); 1064 if (!pq) { 1065 kfree(fud); 1066 return NULL; 1067 } 1068 1069 fud->pq.processing = pq; 1070 fuse_pqueue_init(&fud->pq); 1071 1072 return fud; 1073 } 1074 EXPORT_SYMBOL_GPL(fuse_dev_alloc); 1075 1076 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc) 1077 { 1078 fud->fc = fuse_conn_get(fc); 1079 spin_lock(&fc->lock); 1080 list_add_tail(&fud->entry, &fc->devices); 1081 spin_unlock(&fc->lock); 1082 } 1083 EXPORT_SYMBOL_GPL(fuse_dev_install); 1084 1085 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc) 1086 { 1087 struct fuse_dev *fud; 1088 1089 fud = fuse_dev_alloc(); 1090 if (!fud) 1091 return NULL; 1092 1093 fuse_dev_install(fud, fc); 1094 return fud; 1095 } 1096 EXPORT_SYMBOL_GPL(fuse_dev_alloc_install); 1097 1098 void fuse_dev_free(struct fuse_dev *fud) 1099 { 1100 struct fuse_conn *fc = fud->fc; 1101 1102 if (fc) { 1103 spin_lock(&fc->lock); 1104 list_del(&fud->entry); 1105 spin_unlock(&fc->lock); 1106 1107 fuse_conn_put(fc); 1108 } 1109 kfree(fud->pq.processing); 1110 kfree(fud); 1111 } 1112 EXPORT_SYMBOL_GPL(fuse_dev_free); 1113 1114 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx) 1115 { 1116 struct fuse_dev *fud; 1117 struct fuse_conn *fc = get_fuse_conn_super(sb); 1118 struct inode *root; 1119 struct dentry *root_dentry; 1120 int err; 1121 1122 err = -EINVAL; 1123 if (sb->s_flags & SB_MANDLOCK) 1124 goto err; 1125 1126 sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); 1127 1128 if (ctx->is_bdev) { 1129 #ifdef CONFIG_BLOCK 1130 err = -EINVAL; 1131 if (!sb_set_blocksize(sb, ctx->blksize)) 1132 goto err; 1133 #endif 1134 } else { 1135 sb->s_blocksize = PAGE_SIZE; 1136 sb->s_blocksize_bits = PAGE_SHIFT; 1137 } 1138 1139 sb->s_subtype = ctx->subtype; 1140 ctx->subtype = NULL; 1141 sb->s_magic = FUSE_SUPER_MAGIC; 1142 sb->s_op = &fuse_super_operations; 1143 sb->s_xattr = fuse_xattr_handlers; 1144 sb->s_maxbytes = MAX_LFS_FILESIZE; 1145 sb->s_time_gran = 1; 1146 sb->s_export_op = &fuse_export_operations; 1147 sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE; 1148 if (sb->s_user_ns != &init_user_ns) 1149 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; 1150 1151 /* 1152 * If we are not in the initial user namespace posix 1153 * acls must be translated. 1154 */ 1155 if (sb->s_user_ns != &init_user_ns) 1156 sb->s_xattr = fuse_no_acl_xattr_handlers; 1157 1158 fud = fuse_dev_alloc_install(fc); 1159 if (!fud) 1160 goto err; 1161 1162 fc->dev = sb->s_dev; 1163 fc->sb = sb; 1164 err = fuse_bdi_init(fc, sb); 1165 if (err) 1166 goto err_dev_free; 1167 1168 /* Handle umasking inside the fuse code */ 1169 if (sb->s_flags & SB_POSIXACL) 1170 fc->dont_mask = 1; 1171 sb->s_flags |= SB_POSIXACL; 1172 1173 fc->default_permissions = ctx->default_permissions; 1174 fc->allow_other = ctx->allow_other; 1175 fc->user_id = ctx->user_id; 1176 fc->group_id = ctx->group_id; 1177 fc->max_read = max_t(unsigned, 4096, ctx->max_read); 1178 fc->destroy = ctx->destroy; 1179 fc->no_control = ctx->no_control; 1180 fc->no_force_umount = ctx->no_force_umount; 1181 fc->no_mount_options = ctx->no_mount_options; 1182 1183 err = -ENOMEM; 1184 root = fuse_get_root_inode(sb, ctx->rootmode); 1185 sb->s_d_op = &fuse_root_dentry_operations; 1186 root_dentry = d_make_root(root); 1187 if (!root_dentry) 1188 goto err_dev_free; 1189 /* Root dentry doesn't have .d_revalidate */ 1190 sb->s_d_op = &fuse_dentry_operations; 1191 1192 mutex_lock(&fuse_mutex); 1193 err = -EINVAL; 1194 if (*ctx->fudptr) 1195 goto err_unlock; 1196 1197 err = fuse_ctl_add_conn(fc); 1198 if (err) 1199 goto err_unlock; 1200 1201 list_add_tail(&fc->entry, &fuse_conn_list); 1202 sb->s_root = root_dentry; 1203 *ctx->fudptr = fud; 1204 mutex_unlock(&fuse_mutex); 1205 return 0; 1206 1207 err_unlock: 1208 mutex_unlock(&fuse_mutex); 1209 dput(root_dentry); 1210 err_dev_free: 1211 fuse_dev_free(fud); 1212 err: 1213 return err; 1214 } 1215 EXPORT_SYMBOL_GPL(fuse_fill_super_common); 1216 1217 static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc) 1218 { 1219 struct fuse_fs_context *ctx = fsc->fs_private; 1220 struct file *file; 1221 int err; 1222 struct fuse_conn *fc; 1223 1224 err = -EINVAL; 1225 file = fget(ctx->fd); 1226 if (!file) 1227 goto err; 1228 1229 /* 1230 * Require mount to happen from the same user namespace which 1231 * opened /dev/fuse to prevent potential attacks. 1232 */ 1233 if ((file->f_op != &fuse_dev_operations) || 1234 (file->f_cred->user_ns != sb->s_user_ns)) 1235 goto err_fput; 1236 ctx->fudptr = &file->private_data; 1237 1238 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 1239 err = -ENOMEM; 1240 if (!fc) 1241 goto err_fput; 1242 1243 fuse_conn_init(fc, sb->s_user_ns, &fuse_dev_fiq_ops, NULL); 1244 fc->release = fuse_free_conn; 1245 sb->s_fs_info = fc; 1246 1247 err = fuse_fill_super_common(sb, ctx); 1248 if (err) 1249 goto err_put_conn; 1250 /* 1251 * atomic_dec_and_test() in fput() provides the necessary 1252 * memory barrier for file->private_data to be visible on all 1253 * CPUs after this 1254 */ 1255 fput(file); 1256 fuse_send_init(get_fuse_conn_super(sb)); 1257 return 0; 1258 1259 err_put_conn: 1260 fuse_conn_put(fc); 1261 sb->s_fs_info = NULL; 1262 err_fput: 1263 fput(file); 1264 err: 1265 return err; 1266 } 1267 1268 static int fuse_get_tree(struct fs_context *fc) 1269 { 1270 struct fuse_fs_context *ctx = fc->fs_private; 1271 1272 if (!ctx->fd_present || !ctx->rootmode_present || 1273 !ctx->user_id_present || !ctx->group_id_present) 1274 return -EINVAL; 1275 1276 #ifdef CONFIG_BLOCK 1277 if (ctx->is_bdev) 1278 return get_tree_bdev(fc, fuse_fill_super); 1279 #endif 1280 1281 return get_tree_nodev(fc, fuse_fill_super); 1282 } 1283 1284 static const struct fs_context_operations fuse_context_ops = { 1285 .free = fuse_free_fc, 1286 .parse_param = fuse_parse_param, 1287 .get_tree = fuse_get_tree, 1288 }; 1289 1290 /* 1291 * Set up the filesystem mount context. 1292 */ 1293 static int fuse_init_fs_context(struct fs_context *fc) 1294 { 1295 struct fuse_fs_context *ctx; 1296 1297 ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); 1298 if (!ctx) 1299 return -ENOMEM; 1300 1301 ctx->max_read = ~0; 1302 ctx->blksize = FUSE_DEFAULT_BLKSIZE; 1303 1304 #ifdef CONFIG_BLOCK 1305 if (fc->fs_type == &fuseblk_fs_type) { 1306 ctx->is_bdev = true; 1307 ctx->destroy = true; 1308 } 1309 #endif 1310 1311 fc->fs_private = ctx; 1312 fc->ops = &fuse_context_ops; 1313 return 0; 1314 } 1315 1316 static void fuse_sb_destroy(struct super_block *sb) 1317 { 1318 struct fuse_conn *fc = get_fuse_conn_super(sb); 1319 1320 if (fc) { 1321 if (fc->destroy) 1322 fuse_send_destroy(fc); 1323 1324 fuse_abort_conn(fc); 1325 fuse_wait_aborted(fc); 1326 1327 down_write(&fc->killsb); 1328 fc->sb = NULL; 1329 up_write(&fc->killsb); 1330 } 1331 } 1332 1333 void fuse_kill_sb_anon(struct super_block *sb) 1334 { 1335 fuse_sb_destroy(sb); 1336 kill_anon_super(sb); 1337 } 1338 EXPORT_SYMBOL_GPL(fuse_kill_sb_anon); 1339 1340 static struct file_system_type fuse_fs_type = { 1341 .owner = THIS_MODULE, 1342 .name = "fuse", 1343 .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT, 1344 .init_fs_context = fuse_init_fs_context, 1345 .parameters = fuse_fs_parameters, 1346 .kill_sb = fuse_kill_sb_anon, 1347 }; 1348 MODULE_ALIAS_FS("fuse"); 1349 1350 #ifdef CONFIG_BLOCK 1351 static void fuse_kill_sb_blk(struct super_block *sb) 1352 { 1353 fuse_sb_destroy(sb); 1354 kill_block_super(sb); 1355 } 1356 1357 static struct file_system_type fuseblk_fs_type = { 1358 .owner = THIS_MODULE, 1359 .name = "fuseblk", 1360 .init_fs_context = fuse_init_fs_context, 1361 .parameters = fuse_fs_parameters, 1362 .kill_sb = fuse_kill_sb_blk, 1363 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 1364 }; 1365 MODULE_ALIAS_FS("fuseblk"); 1366 1367 static inline int register_fuseblk(void) 1368 { 1369 return register_filesystem(&fuseblk_fs_type); 1370 } 1371 1372 static inline void unregister_fuseblk(void) 1373 { 1374 unregister_filesystem(&fuseblk_fs_type); 1375 } 1376 #else 1377 static inline int register_fuseblk(void) 1378 { 1379 return 0; 1380 } 1381 1382 static inline void unregister_fuseblk(void) 1383 { 1384 } 1385 #endif 1386 1387 static void fuse_inode_init_once(void *foo) 1388 { 1389 struct inode *inode = foo; 1390 1391 inode_init_once(inode); 1392 } 1393 1394 static int __init fuse_fs_init(void) 1395 { 1396 int err; 1397 1398 fuse_inode_cachep = kmem_cache_create("fuse_inode", 1399 sizeof(struct fuse_inode), 0, 1400 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT, 1401 fuse_inode_init_once); 1402 err = -ENOMEM; 1403 if (!fuse_inode_cachep) 1404 goto out; 1405 1406 err = register_fuseblk(); 1407 if (err) 1408 goto out2; 1409 1410 err = register_filesystem(&fuse_fs_type); 1411 if (err) 1412 goto out3; 1413 1414 return 0; 1415 1416 out3: 1417 unregister_fuseblk(); 1418 out2: 1419 kmem_cache_destroy(fuse_inode_cachep); 1420 out: 1421 return err; 1422 } 1423 1424 static void fuse_fs_cleanup(void) 1425 { 1426 unregister_filesystem(&fuse_fs_type); 1427 unregister_fuseblk(); 1428 1429 /* 1430 * Make sure all delayed rcu free inodes are flushed before we 1431 * destroy cache. 1432 */ 1433 rcu_barrier(); 1434 kmem_cache_destroy(fuse_inode_cachep); 1435 } 1436 1437 static struct kobject *fuse_kobj; 1438 1439 static int fuse_sysfs_init(void) 1440 { 1441 int err; 1442 1443 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 1444 if (!fuse_kobj) { 1445 err = -ENOMEM; 1446 goto out_err; 1447 } 1448 1449 err = sysfs_create_mount_point(fuse_kobj, "connections"); 1450 if (err) 1451 goto out_fuse_unregister; 1452 1453 return 0; 1454 1455 out_fuse_unregister: 1456 kobject_put(fuse_kobj); 1457 out_err: 1458 return err; 1459 } 1460 1461 static void fuse_sysfs_cleanup(void) 1462 { 1463 sysfs_remove_mount_point(fuse_kobj, "connections"); 1464 kobject_put(fuse_kobj); 1465 } 1466 1467 static int __init fuse_init(void) 1468 { 1469 int res; 1470 1471 pr_info("init (API version %i.%i)\n", 1472 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 1473 1474 INIT_LIST_HEAD(&fuse_conn_list); 1475 res = fuse_fs_init(); 1476 if (res) 1477 goto err; 1478 1479 res = fuse_dev_init(); 1480 if (res) 1481 goto err_fs_cleanup; 1482 1483 res = fuse_sysfs_init(); 1484 if (res) 1485 goto err_dev_cleanup; 1486 1487 res = fuse_ctl_init(); 1488 if (res) 1489 goto err_sysfs_cleanup; 1490 1491 sanitize_global_limit(&max_user_bgreq); 1492 sanitize_global_limit(&max_user_congthresh); 1493 1494 return 0; 1495 1496 err_sysfs_cleanup: 1497 fuse_sysfs_cleanup(); 1498 err_dev_cleanup: 1499 fuse_dev_cleanup(); 1500 err_fs_cleanup: 1501 fuse_fs_cleanup(); 1502 err: 1503 return res; 1504 } 1505 1506 static void __exit fuse_exit(void) 1507 { 1508 pr_debug("exit\n"); 1509 1510 fuse_ctl_cleanup(); 1511 fuse_sysfs_cleanup(); 1512 fuse_fs_cleanup(); 1513 fuse_dev_cleanup(); 1514 } 1515 1516 module_init(fuse_init); 1517 module_exit(fuse_exit); 1518