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/parser.h> 18 #include <linux/statfs.h> 19 #include <linux/random.h> 20 #include <linux/sched.h> 21 #include <linux/exportfs.h> 22 23 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); 24 MODULE_DESCRIPTION("Filesystem in Userspace"); 25 MODULE_LICENSE("GPL"); 26 27 static struct kmem_cache *fuse_inode_cachep; 28 struct list_head fuse_conn_list; 29 DEFINE_MUTEX(fuse_mutex); 30 31 #define FUSE_SUPER_MAGIC 0x65735546 32 33 #define FUSE_DEFAULT_BLKSIZE 512 34 35 struct fuse_mount_data { 36 int fd; 37 unsigned rootmode; 38 unsigned user_id; 39 unsigned group_id; 40 unsigned fd_present:1; 41 unsigned rootmode_present:1; 42 unsigned user_id_present:1; 43 unsigned group_id_present:1; 44 unsigned flags; 45 unsigned max_read; 46 unsigned blksize; 47 }; 48 49 static struct inode *fuse_alloc_inode(struct super_block *sb) 50 { 51 struct inode *inode; 52 struct fuse_inode *fi; 53 54 inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL); 55 if (!inode) 56 return NULL; 57 58 fi = get_fuse_inode(inode); 59 fi->i_time = 0; 60 fi->nodeid = 0; 61 fi->nlookup = 0; 62 fi->attr_version = 0; 63 fi->writectr = 0; 64 INIT_LIST_HEAD(&fi->write_files); 65 INIT_LIST_HEAD(&fi->queued_writes); 66 INIT_LIST_HEAD(&fi->writepages); 67 init_waitqueue_head(&fi->page_waitq); 68 fi->forget_req = fuse_request_alloc(); 69 if (!fi->forget_req) { 70 kmem_cache_free(fuse_inode_cachep, inode); 71 return NULL; 72 } 73 74 return inode; 75 } 76 77 static void fuse_destroy_inode(struct inode *inode) 78 { 79 struct fuse_inode *fi = get_fuse_inode(inode); 80 BUG_ON(!list_empty(&fi->write_files)); 81 BUG_ON(!list_empty(&fi->queued_writes)); 82 if (fi->forget_req) 83 fuse_request_free(fi->forget_req); 84 kmem_cache_free(fuse_inode_cachep, inode); 85 } 86 87 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, 88 u64 nodeid, u64 nlookup) 89 { 90 struct fuse_forget_in *inarg = &req->misc.forget_in; 91 inarg->nlookup = nlookup; 92 req->in.h.opcode = FUSE_FORGET; 93 req->in.h.nodeid = nodeid; 94 req->in.numargs = 1; 95 req->in.args[0].size = sizeof(struct fuse_forget_in); 96 req->in.args[0].value = inarg; 97 fuse_request_send_noreply(fc, req); 98 } 99 100 static void fuse_clear_inode(struct inode *inode) 101 { 102 if (inode->i_sb->s_flags & MS_ACTIVE) { 103 struct fuse_conn *fc = get_fuse_conn(inode); 104 struct fuse_inode *fi = get_fuse_inode(inode); 105 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup); 106 fi->forget_req = NULL; 107 } 108 } 109 110 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data) 111 { 112 if (*flags & MS_MANDLOCK) 113 return -EINVAL; 114 115 return 0; 116 } 117 118 void fuse_truncate(struct address_space *mapping, loff_t offset) 119 { 120 /* See vmtruncate() */ 121 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); 122 truncate_inode_pages(mapping, offset); 123 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); 124 } 125 126 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, 127 u64 attr_valid) 128 { 129 struct fuse_conn *fc = get_fuse_conn(inode); 130 struct fuse_inode *fi = get_fuse_inode(inode); 131 132 fi->attr_version = ++fc->attr_version; 133 fi->i_time = attr_valid; 134 135 inode->i_ino = attr->ino; 136 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 137 inode->i_nlink = attr->nlink; 138 inode->i_uid = attr->uid; 139 inode->i_gid = attr->gid; 140 inode->i_blocks = attr->blocks; 141 inode->i_atime.tv_sec = attr->atime; 142 inode->i_atime.tv_nsec = attr->atimensec; 143 inode->i_mtime.tv_sec = attr->mtime; 144 inode->i_mtime.tv_nsec = attr->mtimensec; 145 inode->i_ctime.tv_sec = attr->ctime; 146 inode->i_ctime.tv_nsec = attr->ctimensec; 147 148 if (attr->blksize != 0) 149 inode->i_blkbits = ilog2(attr->blksize); 150 else 151 inode->i_blkbits = inode->i_sb->s_blocksize_bits; 152 153 /* 154 * Don't set the sticky bit in i_mode, unless we want the VFS 155 * to check permissions. This prevents failures due to the 156 * check in may_delete(). 157 */ 158 fi->orig_i_mode = inode->i_mode; 159 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS)) 160 inode->i_mode &= ~S_ISVTX; 161 } 162 163 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, 164 u64 attr_valid, u64 attr_version) 165 { 166 struct fuse_conn *fc = get_fuse_conn(inode); 167 struct fuse_inode *fi = get_fuse_inode(inode); 168 loff_t oldsize; 169 170 spin_lock(&fc->lock); 171 if (attr_version != 0 && fi->attr_version > attr_version) { 172 spin_unlock(&fc->lock); 173 return; 174 } 175 176 fuse_change_attributes_common(inode, attr, attr_valid); 177 178 oldsize = inode->i_size; 179 i_size_write(inode, attr->size); 180 spin_unlock(&fc->lock); 181 182 if (S_ISREG(inode->i_mode) && oldsize != attr->size) { 183 if (attr->size < oldsize) 184 fuse_truncate(inode->i_mapping, attr->size); 185 invalidate_inode_pages2(inode->i_mapping); 186 } 187 } 188 189 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) 190 { 191 inode->i_mode = attr->mode & S_IFMT; 192 inode->i_size = attr->size; 193 if (S_ISREG(inode->i_mode)) { 194 fuse_init_common(inode); 195 fuse_init_file_inode(inode); 196 } else if (S_ISDIR(inode->i_mode)) 197 fuse_init_dir(inode); 198 else if (S_ISLNK(inode->i_mode)) 199 fuse_init_symlink(inode); 200 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || 201 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { 202 fuse_init_common(inode); 203 init_special_inode(inode, inode->i_mode, 204 new_decode_dev(attr->rdev)); 205 } else 206 BUG(); 207 } 208 209 int fuse_inode_eq(struct inode *inode, void *_nodeidp) 210 { 211 u64 nodeid = *(u64 *) _nodeidp; 212 if (get_node_id(inode) == nodeid) 213 return 1; 214 else 215 return 0; 216 } 217 218 static int fuse_inode_set(struct inode *inode, void *_nodeidp) 219 { 220 u64 nodeid = *(u64 *) _nodeidp; 221 get_fuse_inode(inode)->nodeid = nodeid; 222 return 0; 223 } 224 225 struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 226 int generation, struct fuse_attr *attr, 227 u64 attr_valid, u64 attr_version) 228 { 229 struct inode *inode; 230 struct fuse_inode *fi; 231 struct fuse_conn *fc = get_fuse_conn_super(sb); 232 233 retry: 234 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); 235 if (!inode) 236 return NULL; 237 238 if ((inode->i_state & I_NEW)) { 239 inode->i_flags |= S_NOATIME|S_NOCMTIME; 240 inode->i_generation = generation; 241 inode->i_data.backing_dev_info = &fc->bdi; 242 fuse_init_inode(inode, attr); 243 unlock_new_inode(inode); 244 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) { 245 /* Inode has changed type, any I/O on the old should fail */ 246 make_bad_inode(inode); 247 iput(inode); 248 goto retry; 249 } 250 251 fi = get_fuse_inode(inode); 252 spin_lock(&fc->lock); 253 fi->nlookup++; 254 spin_unlock(&fc->lock); 255 fuse_change_attributes(inode, attr, attr_valid, attr_version); 256 257 return inode; 258 } 259 260 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid, 261 loff_t offset, loff_t len) 262 { 263 struct inode *inode; 264 pgoff_t pg_start; 265 pgoff_t pg_end; 266 267 inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid); 268 if (!inode) 269 return -ENOENT; 270 271 fuse_invalidate_attr(inode); 272 if (offset >= 0) { 273 pg_start = offset >> PAGE_CACHE_SHIFT; 274 if (len <= 0) 275 pg_end = -1; 276 else 277 pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT; 278 invalidate_inode_pages2_range(inode->i_mapping, 279 pg_start, pg_end); 280 } 281 iput(inode); 282 return 0; 283 } 284 285 static void fuse_umount_begin(struct super_block *sb) 286 { 287 fuse_abort_conn(get_fuse_conn_super(sb)); 288 } 289 290 static void fuse_send_destroy(struct fuse_conn *fc) 291 { 292 struct fuse_req *req = fc->destroy_req; 293 if (req && fc->conn_init) { 294 fc->destroy_req = NULL; 295 req->in.h.opcode = FUSE_DESTROY; 296 req->force = 1; 297 fuse_request_send(fc, req); 298 fuse_put_request(fc, req); 299 } 300 } 301 302 static void fuse_bdi_destroy(struct fuse_conn *fc) 303 { 304 if (fc->bdi_initialized) 305 bdi_destroy(&fc->bdi); 306 } 307 308 void fuse_conn_kill(struct fuse_conn *fc) 309 { 310 spin_lock(&fc->lock); 311 fc->connected = 0; 312 fc->blocked = 0; 313 spin_unlock(&fc->lock); 314 /* Flush all readers on this fs */ 315 kill_fasync(&fc->fasync, SIGIO, POLL_IN); 316 wake_up_all(&fc->waitq); 317 wake_up_all(&fc->blocked_waitq); 318 wake_up_all(&fc->reserved_req_waitq); 319 mutex_lock(&fuse_mutex); 320 list_del(&fc->entry); 321 fuse_ctl_remove_conn(fc); 322 mutex_unlock(&fuse_mutex); 323 fuse_bdi_destroy(fc); 324 } 325 EXPORT_SYMBOL_GPL(fuse_conn_kill); 326 327 static void fuse_put_super(struct super_block *sb) 328 { 329 struct fuse_conn *fc = get_fuse_conn_super(sb); 330 331 fuse_send_destroy(fc); 332 fuse_conn_kill(fc); 333 fuse_conn_put(fc); 334 } 335 336 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 337 { 338 stbuf->f_type = FUSE_SUPER_MAGIC; 339 stbuf->f_bsize = attr->bsize; 340 stbuf->f_frsize = attr->frsize; 341 stbuf->f_blocks = attr->blocks; 342 stbuf->f_bfree = attr->bfree; 343 stbuf->f_bavail = attr->bavail; 344 stbuf->f_files = attr->files; 345 stbuf->f_ffree = attr->ffree; 346 stbuf->f_namelen = attr->namelen; 347 /* fsid is left zero */ 348 } 349 350 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 351 { 352 struct super_block *sb = dentry->d_sb; 353 struct fuse_conn *fc = get_fuse_conn_super(sb); 354 struct fuse_req *req; 355 struct fuse_statfs_out outarg; 356 int err; 357 358 if (!fuse_allow_task(fc, current)) { 359 buf->f_type = FUSE_SUPER_MAGIC; 360 return 0; 361 } 362 363 req = fuse_get_req(fc); 364 if (IS_ERR(req)) 365 return PTR_ERR(req); 366 367 memset(&outarg, 0, sizeof(outarg)); 368 req->in.numargs = 0; 369 req->in.h.opcode = FUSE_STATFS; 370 req->in.h.nodeid = get_node_id(dentry->d_inode); 371 req->out.numargs = 1; 372 req->out.args[0].size = 373 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg); 374 req->out.args[0].value = &outarg; 375 fuse_request_send(fc, req); 376 err = req->out.h.error; 377 if (!err) 378 convert_fuse_statfs(buf, &outarg.st); 379 fuse_put_request(fc, req); 380 return err; 381 } 382 383 enum { 384 OPT_FD, 385 OPT_ROOTMODE, 386 OPT_USER_ID, 387 OPT_GROUP_ID, 388 OPT_DEFAULT_PERMISSIONS, 389 OPT_ALLOW_OTHER, 390 OPT_MAX_READ, 391 OPT_BLKSIZE, 392 OPT_ERR 393 }; 394 395 static const match_table_t tokens = { 396 {OPT_FD, "fd=%u"}, 397 {OPT_ROOTMODE, "rootmode=%o"}, 398 {OPT_USER_ID, "user_id=%u"}, 399 {OPT_GROUP_ID, "group_id=%u"}, 400 {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, 401 {OPT_ALLOW_OTHER, "allow_other"}, 402 {OPT_MAX_READ, "max_read=%u"}, 403 {OPT_BLKSIZE, "blksize=%u"}, 404 {OPT_ERR, NULL} 405 }; 406 407 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev) 408 { 409 char *p; 410 memset(d, 0, sizeof(struct fuse_mount_data)); 411 d->max_read = ~0; 412 d->blksize = FUSE_DEFAULT_BLKSIZE; 413 414 while ((p = strsep(&opt, ",")) != NULL) { 415 int token; 416 int value; 417 substring_t args[MAX_OPT_ARGS]; 418 if (!*p) 419 continue; 420 421 token = match_token(p, tokens, args); 422 switch (token) { 423 case OPT_FD: 424 if (match_int(&args[0], &value)) 425 return 0; 426 d->fd = value; 427 d->fd_present = 1; 428 break; 429 430 case OPT_ROOTMODE: 431 if (match_octal(&args[0], &value)) 432 return 0; 433 if (!fuse_valid_type(value)) 434 return 0; 435 d->rootmode = value; 436 d->rootmode_present = 1; 437 break; 438 439 case OPT_USER_ID: 440 if (match_int(&args[0], &value)) 441 return 0; 442 d->user_id = value; 443 d->user_id_present = 1; 444 break; 445 446 case OPT_GROUP_ID: 447 if (match_int(&args[0], &value)) 448 return 0; 449 d->group_id = value; 450 d->group_id_present = 1; 451 break; 452 453 case OPT_DEFAULT_PERMISSIONS: 454 d->flags |= FUSE_DEFAULT_PERMISSIONS; 455 break; 456 457 case OPT_ALLOW_OTHER: 458 d->flags |= FUSE_ALLOW_OTHER; 459 break; 460 461 case OPT_MAX_READ: 462 if (match_int(&args[0], &value)) 463 return 0; 464 d->max_read = value; 465 break; 466 467 case OPT_BLKSIZE: 468 if (!is_bdev || match_int(&args[0], &value)) 469 return 0; 470 d->blksize = value; 471 break; 472 473 default: 474 return 0; 475 } 476 } 477 478 if (!d->fd_present || !d->rootmode_present || 479 !d->user_id_present || !d->group_id_present) 480 return 0; 481 482 return 1; 483 } 484 485 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) 486 { 487 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb); 488 489 seq_printf(m, ",user_id=%u", fc->user_id); 490 seq_printf(m, ",group_id=%u", fc->group_id); 491 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) 492 seq_puts(m, ",default_permissions"); 493 if (fc->flags & FUSE_ALLOW_OTHER) 494 seq_puts(m, ",allow_other"); 495 if (fc->max_read != ~0) 496 seq_printf(m, ",max_read=%u", fc->max_read); 497 if (mnt->mnt_sb->s_bdev && 498 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 499 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize); 500 return 0; 501 } 502 503 void fuse_conn_init(struct fuse_conn *fc) 504 { 505 memset(fc, 0, sizeof(*fc)); 506 spin_lock_init(&fc->lock); 507 mutex_init(&fc->inst_mutex); 508 init_rwsem(&fc->killsb); 509 atomic_set(&fc->count, 1); 510 init_waitqueue_head(&fc->waitq); 511 init_waitqueue_head(&fc->blocked_waitq); 512 init_waitqueue_head(&fc->reserved_req_waitq); 513 INIT_LIST_HEAD(&fc->pending); 514 INIT_LIST_HEAD(&fc->processing); 515 INIT_LIST_HEAD(&fc->io); 516 INIT_LIST_HEAD(&fc->interrupts); 517 INIT_LIST_HEAD(&fc->bg_queue); 518 INIT_LIST_HEAD(&fc->entry); 519 atomic_set(&fc->num_waiting, 0); 520 fc->khctr = 0; 521 fc->polled_files = RB_ROOT; 522 fc->reqctr = 0; 523 fc->blocked = 1; 524 fc->attr_version = 1; 525 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 526 } 527 EXPORT_SYMBOL_GPL(fuse_conn_init); 528 529 void fuse_conn_put(struct fuse_conn *fc) 530 { 531 if (atomic_dec_and_test(&fc->count)) { 532 if (fc->destroy_req) 533 fuse_request_free(fc->destroy_req); 534 mutex_destroy(&fc->inst_mutex); 535 fc->release(fc); 536 } 537 } 538 EXPORT_SYMBOL_GPL(fuse_conn_put); 539 540 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 541 { 542 atomic_inc(&fc->count); 543 return fc; 544 } 545 EXPORT_SYMBOL_GPL(fuse_conn_get); 546 547 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 548 { 549 struct fuse_attr attr; 550 memset(&attr, 0, sizeof(attr)); 551 552 attr.mode = mode; 553 attr.ino = FUSE_ROOT_ID; 554 attr.nlink = 1; 555 return fuse_iget(sb, 1, 0, &attr, 0, 0); 556 } 557 558 struct fuse_inode_handle { 559 u64 nodeid; 560 u32 generation; 561 }; 562 563 static struct dentry *fuse_get_dentry(struct super_block *sb, 564 struct fuse_inode_handle *handle) 565 { 566 struct fuse_conn *fc = get_fuse_conn_super(sb); 567 struct inode *inode; 568 struct dentry *entry; 569 int err = -ESTALE; 570 571 if (handle->nodeid == 0) 572 goto out_err; 573 574 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 575 if (!inode) { 576 struct fuse_entry_out outarg; 577 struct qstr name; 578 579 if (!fc->export_support) 580 goto out_err; 581 582 name.len = 1; 583 name.name = "."; 584 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 585 &inode); 586 if (err && err != -ENOENT) 587 goto out_err; 588 if (err || !inode) { 589 err = -ESTALE; 590 goto out_err; 591 } 592 err = -EIO; 593 if (get_node_id(inode) != handle->nodeid) 594 goto out_iput; 595 } 596 err = -ESTALE; 597 if (inode->i_generation != handle->generation) 598 goto out_iput; 599 600 entry = d_obtain_alias(inode); 601 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) { 602 entry->d_op = &fuse_dentry_operations; 603 fuse_invalidate_entry_cache(entry); 604 } 605 606 return entry; 607 608 out_iput: 609 iput(inode); 610 out_err: 611 return ERR_PTR(err); 612 } 613 614 static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, 615 int connectable) 616 { 617 struct inode *inode = dentry->d_inode; 618 bool encode_parent = connectable && !S_ISDIR(inode->i_mode); 619 int len = encode_parent ? 6 : 3; 620 u64 nodeid; 621 u32 generation; 622 623 if (*max_len < len) 624 return 255; 625 626 nodeid = get_fuse_inode(inode)->nodeid; 627 generation = inode->i_generation; 628 629 fh[0] = (u32)(nodeid >> 32); 630 fh[1] = (u32)(nodeid & 0xffffffff); 631 fh[2] = generation; 632 633 if (encode_parent) { 634 struct inode *parent; 635 636 spin_lock(&dentry->d_lock); 637 parent = dentry->d_parent->d_inode; 638 nodeid = get_fuse_inode(parent)->nodeid; 639 generation = parent->i_generation; 640 spin_unlock(&dentry->d_lock); 641 642 fh[3] = (u32)(nodeid >> 32); 643 fh[4] = (u32)(nodeid & 0xffffffff); 644 fh[5] = generation; 645 } 646 647 *max_len = len; 648 return encode_parent ? 0x82 : 0x81; 649 } 650 651 static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 652 struct fid *fid, int fh_len, int fh_type) 653 { 654 struct fuse_inode_handle handle; 655 656 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) 657 return NULL; 658 659 handle.nodeid = (u64) fid->raw[0] << 32; 660 handle.nodeid |= (u64) fid->raw[1]; 661 handle.generation = fid->raw[2]; 662 return fuse_get_dentry(sb, &handle); 663 } 664 665 static struct dentry *fuse_fh_to_parent(struct super_block *sb, 666 struct fid *fid, int fh_len, int fh_type) 667 { 668 struct fuse_inode_handle parent; 669 670 if (fh_type != 0x82 || fh_len < 6) 671 return NULL; 672 673 parent.nodeid = (u64) fid->raw[3] << 32; 674 parent.nodeid |= (u64) fid->raw[4]; 675 parent.generation = fid->raw[5]; 676 return fuse_get_dentry(sb, &parent); 677 } 678 679 static struct dentry *fuse_get_parent(struct dentry *child) 680 { 681 struct inode *child_inode = child->d_inode; 682 struct fuse_conn *fc = get_fuse_conn(child_inode); 683 struct inode *inode; 684 struct dentry *parent; 685 struct fuse_entry_out outarg; 686 struct qstr name; 687 int err; 688 689 if (!fc->export_support) 690 return ERR_PTR(-ESTALE); 691 692 name.len = 2; 693 name.name = ".."; 694 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 695 &name, &outarg, &inode); 696 if (err) { 697 if (err == -ENOENT) 698 return ERR_PTR(-ESTALE); 699 return ERR_PTR(err); 700 } 701 702 parent = d_obtain_alias(inode); 703 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) { 704 parent->d_op = &fuse_dentry_operations; 705 fuse_invalidate_entry_cache(parent); 706 } 707 708 return parent; 709 } 710 711 static const struct export_operations fuse_export_operations = { 712 .fh_to_dentry = fuse_fh_to_dentry, 713 .fh_to_parent = fuse_fh_to_parent, 714 .encode_fh = fuse_encode_fh, 715 .get_parent = fuse_get_parent, 716 }; 717 718 static const struct super_operations fuse_super_operations = { 719 .alloc_inode = fuse_alloc_inode, 720 .destroy_inode = fuse_destroy_inode, 721 .clear_inode = fuse_clear_inode, 722 .drop_inode = generic_delete_inode, 723 .remount_fs = fuse_remount_fs, 724 .put_super = fuse_put_super, 725 .umount_begin = fuse_umount_begin, 726 .statfs = fuse_statfs, 727 .show_options = fuse_show_options, 728 }; 729 730 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) 731 { 732 struct fuse_init_out *arg = &req->misc.init_out; 733 734 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION) 735 fc->conn_error = 1; 736 else { 737 unsigned long ra_pages; 738 739 if (arg->minor >= 6) { 740 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE; 741 if (arg->flags & FUSE_ASYNC_READ) 742 fc->async_read = 1; 743 if (!(arg->flags & FUSE_POSIX_LOCKS)) 744 fc->no_lock = 1; 745 if (arg->flags & FUSE_ATOMIC_O_TRUNC) 746 fc->atomic_o_trunc = 1; 747 if (arg->minor >= 9) { 748 /* LOOKUP has dependency on proto version */ 749 if (arg->flags & FUSE_EXPORT_SUPPORT) 750 fc->export_support = 1; 751 } 752 if (arg->flags & FUSE_BIG_WRITES) 753 fc->big_writes = 1; 754 if (arg->flags & FUSE_DONT_MASK) 755 fc->dont_mask = 1; 756 } else { 757 ra_pages = fc->max_read / PAGE_CACHE_SIZE; 758 fc->no_lock = 1; 759 } 760 761 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages); 762 fc->minor = arg->minor; 763 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 764 fc->max_write = max_t(unsigned, 4096, fc->max_write); 765 fc->conn_init = 1; 766 } 767 fc->blocked = 0; 768 wake_up_all(&fc->blocked_waitq); 769 } 770 771 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) 772 { 773 struct fuse_init_in *arg = &req->misc.init_in; 774 775 arg->major = FUSE_KERNEL_VERSION; 776 arg->minor = FUSE_KERNEL_MINOR_VERSION; 777 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE; 778 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 779 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK; 780 req->in.h.opcode = FUSE_INIT; 781 req->in.numargs = 1; 782 req->in.args[0].size = sizeof(*arg); 783 req->in.args[0].value = arg; 784 req->out.numargs = 1; 785 /* Variable length arguement used for backward compatibility 786 with interface version < 7.5. Rest of init_out is zeroed 787 by do_get_request(), so a short reply is not a problem */ 788 req->out.argvar = 1; 789 req->out.args[0].size = sizeof(struct fuse_init_out); 790 req->out.args[0].value = &req->misc.init_out; 791 req->end = process_init_reply; 792 fuse_request_send_background(fc, req); 793 } 794 795 static void fuse_free_conn(struct fuse_conn *fc) 796 { 797 kfree(fc); 798 } 799 800 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 801 { 802 int err; 803 804 fc->bdi.name = "fuse"; 805 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; 806 fc->bdi.unplug_io_fn = default_unplug_io_fn; 807 /* fuse does it's own writeback accounting */ 808 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB; 809 810 err = bdi_init(&fc->bdi); 811 if (err) 812 return err; 813 814 fc->bdi_initialized = 1; 815 816 if (sb->s_bdev) { 817 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk", 818 MAJOR(fc->dev), MINOR(fc->dev)); 819 } else { 820 err = bdi_register_dev(&fc->bdi, fc->dev); 821 } 822 823 if (err) 824 return err; 825 826 /* 827 * For a single fuse filesystem use max 1% of dirty + 828 * writeback threshold. 829 * 830 * This gives about 1M of write buffer for memory maps on a 831 * machine with 1G and 10% dirty_ratio, which should be more 832 * than enough. 833 * 834 * Privileged users can raise it by writing to 835 * 836 * /sys/class/bdi/<bdi>/max_ratio 837 */ 838 bdi_set_max_ratio(&fc->bdi, 1); 839 840 return 0; 841 } 842 843 static int fuse_fill_super(struct super_block *sb, void *data, int silent) 844 { 845 struct fuse_conn *fc; 846 struct inode *root; 847 struct fuse_mount_data d; 848 struct file *file; 849 struct dentry *root_dentry; 850 struct fuse_req *init_req; 851 int err; 852 int is_bdev = sb->s_bdev != NULL; 853 854 err = -EINVAL; 855 if (sb->s_flags & MS_MANDLOCK) 856 goto err; 857 858 if (!parse_fuse_opt((char *) data, &d, is_bdev)) 859 goto err; 860 861 if (is_bdev) { 862 #ifdef CONFIG_BLOCK 863 err = -EINVAL; 864 if (!sb_set_blocksize(sb, d.blksize)) 865 goto err; 866 #endif 867 } else { 868 sb->s_blocksize = PAGE_CACHE_SIZE; 869 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 870 } 871 sb->s_magic = FUSE_SUPER_MAGIC; 872 sb->s_op = &fuse_super_operations; 873 sb->s_maxbytes = MAX_LFS_FILESIZE; 874 sb->s_export_op = &fuse_export_operations; 875 876 file = fget(d.fd); 877 err = -EINVAL; 878 if (!file) 879 goto err; 880 881 if (file->f_op != &fuse_dev_operations) 882 goto err_fput; 883 884 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 885 err = -ENOMEM; 886 if (!fc) 887 goto err_fput; 888 889 fuse_conn_init(fc); 890 891 fc->dev = sb->s_dev; 892 fc->sb = sb; 893 err = fuse_bdi_init(fc, sb); 894 if (err) 895 goto err_put_conn; 896 897 sb->s_bdi = &fc->bdi; 898 899 /* Handle umasking inside the fuse code */ 900 if (sb->s_flags & MS_POSIXACL) 901 fc->dont_mask = 1; 902 sb->s_flags |= MS_POSIXACL; 903 904 fc->release = fuse_free_conn; 905 fc->flags = d.flags; 906 fc->user_id = d.user_id; 907 fc->group_id = d.group_id; 908 fc->max_read = max_t(unsigned, 4096, d.max_read); 909 910 /* Used by get_root_inode() */ 911 sb->s_fs_info = fc; 912 913 err = -ENOMEM; 914 root = fuse_get_root_inode(sb, d.rootmode); 915 if (!root) 916 goto err_put_conn; 917 918 root_dentry = d_alloc_root(root); 919 if (!root_dentry) { 920 iput(root); 921 goto err_put_conn; 922 } 923 924 init_req = fuse_request_alloc(); 925 if (!init_req) 926 goto err_put_root; 927 928 if (is_bdev) { 929 fc->destroy_req = fuse_request_alloc(); 930 if (!fc->destroy_req) 931 goto err_free_init_req; 932 } 933 934 mutex_lock(&fuse_mutex); 935 err = -EINVAL; 936 if (file->private_data) 937 goto err_unlock; 938 939 err = fuse_ctl_add_conn(fc); 940 if (err) 941 goto err_unlock; 942 943 list_add_tail(&fc->entry, &fuse_conn_list); 944 sb->s_root = root_dentry; 945 fc->connected = 1; 946 file->private_data = fuse_conn_get(fc); 947 mutex_unlock(&fuse_mutex); 948 /* 949 * atomic_dec_and_test() in fput() provides the necessary 950 * memory barrier for file->private_data to be visible on all 951 * CPUs after this 952 */ 953 fput(file); 954 955 fuse_send_init(fc, init_req); 956 957 return 0; 958 959 err_unlock: 960 mutex_unlock(&fuse_mutex); 961 err_free_init_req: 962 fuse_request_free(init_req); 963 err_put_root: 964 dput(root_dentry); 965 err_put_conn: 966 fuse_bdi_destroy(fc); 967 fuse_conn_put(fc); 968 err_fput: 969 fput(file); 970 err: 971 return err; 972 } 973 974 static int fuse_get_sb(struct file_system_type *fs_type, 975 int flags, const char *dev_name, 976 void *raw_data, struct vfsmount *mnt) 977 { 978 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt); 979 } 980 981 static void fuse_kill_sb_anon(struct super_block *sb) 982 { 983 struct fuse_conn *fc = get_fuse_conn_super(sb); 984 985 if (fc) { 986 down_write(&fc->killsb); 987 fc->sb = NULL; 988 up_write(&fc->killsb); 989 } 990 991 kill_anon_super(sb); 992 } 993 994 static struct file_system_type fuse_fs_type = { 995 .owner = THIS_MODULE, 996 .name = "fuse", 997 .fs_flags = FS_HAS_SUBTYPE, 998 .get_sb = fuse_get_sb, 999 .kill_sb = fuse_kill_sb_anon, 1000 }; 1001 1002 #ifdef CONFIG_BLOCK 1003 static int fuse_get_sb_blk(struct file_system_type *fs_type, 1004 int flags, const char *dev_name, 1005 void *raw_data, struct vfsmount *mnt) 1006 { 1007 return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super, 1008 mnt); 1009 } 1010 1011 static void fuse_kill_sb_blk(struct super_block *sb) 1012 { 1013 struct fuse_conn *fc = get_fuse_conn_super(sb); 1014 1015 if (fc) { 1016 down_write(&fc->killsb); 1017 fc->sb = NULL; 1018 up_write(&fc->killsb); 1019 } 1020 1021 kill_block_super(sb); 1022 } 1023 1024 static struct file_system_type fuseblk_fs_type = { 1025 .owner = THIS_MODULE, 1026 .name = "fuseblk", 1027 .get_sb = fuse_get_sb_blk, 1028 .kill_sb = fuse_kill_sb_blk, 1029 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 1030 }; 1031 1032 static inline int register_fuseblk(void) 1033 { 1034 return register_filesystem(&fuseblk_fs_type); 1035 } 1036 1037 static inline void unregister_fuseblk(void) 1038 { 1039 unregister_filesystem(&fuseblk_fs_type); 1040 } 1041 #else 1042 static inline int register_fuseblk(void) 1043 { 1044 return 0; 1045 } 1046 1047 static inline void unregister_fuseblk(void) 1048 { 1049 } 1050 #endif 1051 1052 static void fuse_inode_init_once(void *foo) 1053 { 1054 struct inode *inode = foo; 1055 1056 inode_init_once(inode); 1057 } 1058 1059 static int __init fuse_fs_init(void) 1060 { 1061 int err; 1062 1063 err = register_filesystem(&fuse_fs_type); 1064 if (err) 1065 goto out; 1066 1067 err = register_fuseblk(); 1068 if (err) 1069 goto out_unreg; 1070 1071 fuse_inode_cachep = kmem_cache_create("fuse_inode", 1072 sizeof(struct fuse_inode), 1073 0, SLAB_HWCACHE_ALIGN, 1074 fuse_inode_init_once); 1075 err = -ENOMEM; 1076 if (!fuse_inode_cachep) 1077 goto out_unreg2; 1078 1079 return 0; 1080 1081 out_unreg2: 1082 unregister_fuseblk(); 1083 out_unreg: 1084 unregister_filesystem(&fuse_fs_type); 1085 out: 1086 return err; 1087 } 1088 1089 static void fuse_fs_cleanup(void) 1090 { 1091 unregister_filesystem(&fuse_fs_type); 1092 unregister_fuseblk(); 1093 kmem_cache_destroy(fuse_inode_cachep); 1094 } 1095 1096 static struct kobject *fuse_kobj; 1097 static struct kobject *connections_kobj; 1098 1099 static int fuse_sysfs_init(void) 1100 { 1101 int err; 1102 1103 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 1104 if (!fuse_kobj) { 1105 err = -ENOMEM; 1106 goto out_err; 1107 } 1108 1109 connections_kobj = kobject_create_and_add("connections", fuse_kobj); 1110 if (!connections_kobj) { 1111 err = -ENOMEM; 1112 goto out_fuse_unregister; 1113 } 1114 1115 return 0; 1116 1117 out_fuse_unregister: 1118 kobject_put(fuse_kobj); 1119 out_err: 1120 return err; 1121 } 1122 1123 static void fuse_sysfs_cleanup(void) 1124 { 1125 kobject_put(connections_kobj); 1126 kobject_put(fuse_kobj); 1127 } 1128 1129 static int __init fuse_init(void) 1130 { 1131 int res; 1132 1133 printk(KERN_INFO "fuse init (API version %i.%i)\n", 1134 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 1135 1136 INIT_LIST_HEAD(&fuse_conn_list); 1137 res = fuse_fs_init(); 1138 if (res) 1139 goto err; 1140 1141 res = fuse_dev_init(); 1142 if (res) 1143 goto err_fs_cleanup; 1144 1145 res = fuse_sysfs_init(); 1146 if (res) 1147 goto err_dev_cleanup; 1148 1149 res = fuse_ctl_init(); 1150 if (res) 1151 goto err_sysfs_cleanup; 1152 1153 return 0; 1154 1155 err_sysfs_cleanup: 1156 fuse_sysfs_cleanup(); 1157 err_dev_cleanup: 1158 fuse_dev_cleanup(); 1159 err_fs_cleanup: 1160 fuse_fs_cleanup(); 1161 err: 1162 return res; 1163 } 1164 1165 static void __exit fuse_exit(void) 1166 { 1167 printk(KERN_DEBUG "fuse exit\n"); 1168 1169 fuse_ctl_cleanup(); 1170 fuse_sysfs_cleanup(); 1171 fuse_fs_cleanup(); 1172 fuse_dev_cleanup(); 1173 } 1174 1175 module_init(fuse_init); 1176 module_exit(fuse_exit); 1177