1 /* 2 FUSE: Filesystem in Userspace 3 Copyright (C) 2001-2006 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 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 static 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 static void fuse_umount_begin(struct super_block *sb) 261 { 262 fuse_abort_conn(get_fuse_conn_super(sb)); 263 } 264 265 static void fuse_send_destroy(struct fuse_conn *fc) 266 { 267 struct fuse_req *req = fc->destroy_req; 268 if (req && fc->conn_init) { 269 fc->destroy_req = NULL; 270 req->in.h.opcode = FUSE_DESTROY; 271 req->force = 1; 272 request_send(fc, req); 273 fuse_put_request(fc, req); 274 } 275 } 276 277 static void fuse_put_super(struct super_block *sb) 278 { 279 struct fuse_conn *fc = get_fuse_conn_super(sb); 280 281 fuse_send_destroy(fc); 282 spin_lock(&fc->lock); 283 fc->connected = 0; 284 fc->blocked = 0; 285 spin_unlock(&fc->lock); 286 /* Flush all readers on this fs */ 287 kill_fasync(&fc->fasync, SIGIO, POLL_IN); 288 wake_up_all(&fc->waitq); 289 wake_up_all(&fc->blocked_waitq); 290 wake_up_all(&fc->reserved_req_waitq); 291 mutex_lock(&fuse_mutex); 292 list_del(&fc->entry); 293 fuse_ctl_remove_conn(fc); 294 mutex_unlock(&fuse_mutex); 295 fuse_conn_put(fc); 296 } 297 298 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 299 { 300 stbuf->f_type = FUSE_SUPER_MAGIC; 301 stbuf->f_bsize = attr->bsize; 302 stbuf->f_frsize = attr->frsize; 303 stbuf->f_blocks = attr->blocks; 304 stbuf->f_bfree = attr->bfree; 305 stbuf->f_bavail = attr->bavail; 306 stbuf->f_files = attr->files; 307 stbuf->f_ffree = attr->ffree; 308 stbuf->f_namelen = attr->namelen; 309 /* fsid is left zero */ 310 } 311 312 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 313 { 314 struct super_block *sb = dentry->d_sb; 315 struct fuse_conn *fc = get_fuse_conn_super(sb); 316 struct fuse_req *req; 317 struct fuse_statfs_out outarg; 318 int err; 319 320 if (!fuse_allow_task(fc, current)) { 321 buf->f_type = FUSE_SUPER_MAGIC; 322 return 0; 323 } 324 325 req = fuse_get_req(fc); 326 if (IS_ERR(req)) 327 return PTR_ERR(req); 328 329 memset(&outarg, 0, sizeof(outarg)); 330 req->in.numargs = 0; 331 req->in.h.opcode = FUSE_STATFS; 332 req->in.h.nodeid = get_node_id(dentry->d_inode); 333 req->out.numargs = 1; 334 req->out.args[0].size = 335 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg); 336 req->out.args[0].value = &outarg; 337 request_send(fc, req); 338 err = req->out.h.error; 339 if (!err) 340 convert_fuse_statfs(buf, &outarg.st); 341 fuse_put_request(fc, req); 342 return err; 343 } 344 345 enum { 346 OPT_FD, 347 OPT_ROOTMODE, 348 OPT_USER_ID, 349 OPT_GROUP_ID, 350 OPT_DEFAULT_PERMISSIONS, 351 OPT_ALLOW_OTHER, 352 OPT_MAX_READ, 353 OPT_BLKSIZE, 354 OPT_ERR 355 }; 356 357 static match_table_t tokens = { 358 {OPT_FD, "fd=%u"}, 359 {OPT_ROOTMODE, "rootmode=%o"}, 360 {OPT_USER_ID, "user_id=%u"}, 361 {OPT_GROUP_ID, "group_id=%u"}, 362 {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, 363 {OPT_ALLOW_OTHER, "allow_other"}, 364 {OPT_MAX_READ, "max_read=%u"}, 365 {OPT_BLKSIZE, "blksize=%u"}, 366 {OPT_ERR, NULL} 367 }; 368 369 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev) 370 { 371 char *p; 372 memset(d, 0, sizeof(struct fuse_mount_data)); 373 d->max_read = ~0; 374 d->blksize = FUSE_DEFAULT_BLKSIZE; 375 376 while ((p = strsep(&opt, ",")) != NULL) { 377 int token; 378 int value; 379 substring_t args[MAX_OPT_ARGS]; 380 if (!*p) 381 continue; 382 383 token = match_token(p, tokens, args); 384 switch (token) { 385 case OPT_FD: 386 if (match_int(&args[0], &value)) 387 return 0; 388 d->fd = value; 389 d->fd_present = 1; 390 break; 391 392 case OPT_ROOTMODE: 393 if (match_octal(&args[0], &value)) 394 return 0; 395 if (!fuse_valid_type(value)) 396 return 0; 397 d->rootmode = value; 398 d->rootmode_present = 1; 399 break; 400 401 case OPT_USER_ID: 402 if (match_int(&args[0], &value)) 403 return 0; 404 d->user_id = value; 405 d->user_id_present = 1; 406 break; 407 408 case OPT_GROUP_ID: 409 if (match_int(&args[0], &value)) 410 return 0; 411 d->group_id = value; 412 d->group_id_present = 1; 413 break; 414 415 case OPT_DEFAULT_PERMISSIONS: 416 d->flags |= FUSE_DEFAULT_PERMISSIONS; 417 break; 418 419 case OPT_ALLOW_OTHER: 420 d->flags |= FUSE_ALLOW_OTHER; 421 break; 422 423 case OPT_MAX_READ: 424 if (match_int(&args[0], &value)) 425 return 0; 426 d->max_read = value; 427 break; 428 429 case OPT_BLKSIZE: 430 if (!is_bdev || match_int(&args[0], &value)) 431 return 0; 432 d->blksize = value; 433 break; 434 435 default: 436 return 0; 437 } 438 } 439 440 if (!d->fd_present || !d->rootmode_present || 441 !d->user_id_present || !d->group_id_present) 442 return 0; 443 444 return 1; 445 } 446 447 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) 448 { 449 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb); 450 451 seq_printf(m, ",user_id=%u", fc->user_id); 452 seq_printf(m, ",group_id=%u", fc->group_id); 453 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) 454 seq_puts(m, ",default_permissions"); 455 if (fc->flags & FUSE_ALLOW_OTHER) 456 seq_puts(m, ",allow_other"); 457 if (fc->max_read != ~0) 458 seq_printf(m, ",max_read=%u", fc->max_read); 459 if (mnt->mnt_sb->s_bdev && 460 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 461 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize); 462 return 0; 463 } 464 465 static struct fuse_conn *new_conn(struct super_block *sb) 466 { 467 struct fuse_conn *fc; 468 int err; 469 470 fc = kzalloc(sizeof(*fc), GFP_KERNEL); 471 if (fc) { 472 spin_lock_init(&fc->lock); 473 mutex_init(&fc->inst_mutex); 474 atomic_set(&fc->count, 1); 475 init_waitqueue_head(&fc->waitq); 476 init_waitqueue_head(&fc->blocked_waitq); 477 init_waitqueue_head(&fc->reserved_req_waitq); 478 INIT_LIST_HEAD(&fc->pending); 479 INIT_LIST_HEAD(&fc->processing); 480 INIT_LIST_HEAD(&fc->io); 481 INIT_LIST_HEAD(&fc->interrupts); 482 INIT_LIST_HEAD(&fc->bg_queue); 483 atomic_set(&fc->num_waiting, 0); 484 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; 485 fc->bdi.unplug_io_fn = default_unplug_io_fn; 486 /* fuse does it's own writeback accounting */ 487 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB; 488 fc->dev = sb->s_dev; 489 err = bdi_init(&fc->bdi); 490 if (err) 491 goto error_kfree; 492 if (sb->s_bdev) { 493 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk", 494 MAJOR(fc->dev), MINOR(fc->dev)); 495 } else { 496 err = bdi_register_dev(&fc->bdi, fc->dev); 497 } 498 if (err) 499 goto error_bdi_destroy; 500 /* 501 * For a single fuse filesystem use max 1% of dirty + 502 * writeback threshold. 503 * 504 * This gives about 1M of write buffer for memory maps on a 505 * machine with 1G and 10% dirty_ratio, which should be more 506 * than enough. 507 * 508 * Privileged users can raise it by writing to 509 * 510 * /sys/class/bdi/<bdi>/max_ratio 511 */ 512 bdi_set_max_ratio(&fc->bdi, 1); 513 fc->reqctr = 0; 514 fc->blocked = 1; 515 fc->attr_version = 1; 516 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 517 } 518 return fc; 519 520 error_bdi_destroy: 521 bdi_destroy(&fc->bdi); 522 error_kfree: 523 mutex_destroy(&fc->inst_mutex); 524 kfree(fc); 525 return NULL; 526 } 527 528 void fuse_conn_put(struct fuse_conn *fc) 529 { 530 if (atomic_dec_and_test(&fc->count)) { 531 if (fc->destroy_req) 532 fuse_request_free(fc->destroy_req); 533 mutex_destroy(&fc->inst_mutex); 534 bdi_destroy(&fc->bdi); 535 kfree(fc); 536 } 537 } 538 539 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 540 { 541 atomic_inc(&fc->count); 542 return fc; 543 } 544 545 static struct inode *get_root_inode(struct super_block *sb, unsigned mode) 546 { 547 struct fuse_attr attr; 548 memset(&attr, 0, sizeof(attr)); 549 550 attr.mode = mode; 551 attr.ino = FUSE_ROOT_ID; 552 attr.nlink = 1; 553 return fuse_iget(sb, 1, 0, &attr, 0, 0); 554 } 555 556 struct fuse_inode_handle 557 { 558 u64 nodeid; 559 u32 generation; 560 }; 561 562 static struct dentry *fuse_get_dentry(struct super_block *sb, 563 struct fuse_inode_handle *handle) 564 { 565 struct fuse_conn *fc = get_fuse_conn_super(sb); 566 struct inode *inode; 567 struct dentry *entry; 568 int err = -ESTALE; 569 570 if (handle->nodeid == 0) 571 goto out_err; 572 573 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 574 if (!inode) { 575 struct fuse_entry_out outarg; 576 struct qstr name; 577 578 if (!fc->export_support) 579 goto out_err; 580 581 name.len = 1; 582 name.name = "."; 583 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 584 &inode); 585 if (err && err != -ENOENT) 586 goto out_err; 587 if (err || !inode) { 588 err = -ESTALE; 589 goto out_err; 590 } 591 err = -EIO; 592 if (get_node_id(inode) != handle->nodeid) 593 goto out_iput; 594 } 595 err = -ESTALE; 596 if (inode->i_generation != handle->generation) 597 goto out_iput; 598 599 entry = d_alloc_anon(inode); 600 err = -ENOMEM; 601 if (!entry) 602 goto out_iput; 603 604 if (get_node_id(inode) != FUSE_ROOT_ID) { 605 entry->d_op = &fuse_dentry_operations; 606 fuse_invalidate_entry_cache(entry); 607 } 608 609 return entry; 610 611 out_iput: 612 iput(inode); 613 out_err: 614 return ERR_PTR(err); 615 } 616 617 static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, 618 int connectable) 619 { 620 struct inode *inode = dentry->d_inode; 621 bool encode_parent = connectable && !S_ISDIR(inode->i_mode); 622 int len = encode_parent ? 6 : 3; 623 u64 nodeid; 624 u32 generation; 625 626 if (*max_len < len) 627 return 255; 628 629 nodeid = get_fuse_inode(inode)->nodeid; 630 generation = inode->i_generation; 631 632 fh[0] = (u32)(nodeid >> 32); 633 fh[1] = (u32)(nodeid & 0xffffffff); 634 fh[2] = generation; 635 636 if (encode_parent) { 637 struct inode *parent; 638 639 spin_lock(&dentry->d_lock); 640 parent = dentry->d_parent->d_inode; 641 nodeid = get_fuse_inode(parent)->nodeid; 642 generation = parent->i_generation; 643 spin_unlock(&dentry->d_lock); 644 645 fh[3] = (u32)(nodeid >> 32); 646 fh[4] = (u32)(nodeid & 0xffffffff); 647 fh[5] = generation; 648 } 649 650 *max_len = len; 651 return encode_parent ? 0x82 : 0x81; 652 } 653 654 static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 655 struct fid *fid, int fh_len, int fh_type) 656 { 657 struct fuse_inode_handle handle; 658 659 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) 660 return NULL; 661 662 handle.nodeid = (u64) fid->raw[0] << 32; 663 handle.nodeid |= (u64) fid->raw[1]; 664 handle.generation = fid->raw[2]; 665 return fuse_get_dentry(sb, &handle); 666 } 667 668 static struct dentry *fuse_fh_to_parent(struct super_block *sb, 669 struct fid *fid, int fh_len, int fh_type) 670 { 671 struct fuse_inode_handle parent; 672 673 if (fh_type != 0x82 || fh_len < 6) 674 return NULL; 675 676 parent.nodeid = (u64) fid->raw[3] << 32; 677 parent.nodeid |= (u64) fid->raw[4]; 678 parent.generation = fid->raw[5]; 679 return fuse_get_dentry(sb, &parent); 680 } 681 682 static struct dentry *fuse_get_parent(struct dentry *child) 683 { 684 struct inode *child_inode = child->d_inode; 685 struct fuse_conn *fc = get_fuse_conn(child_inode); 686 struct inode *inode; 687 struct dentry *parent; 688 struct fuse_entry_out outarg; 689 struct qstr name; 690 int err; 691 692 if (!fc->export_support) 693 return ERR_PTR(-ESTALE); 694 695 name.len = 2; 696 name.name = ".."; 697 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 698 &name, &outarg, &inode); 699 if (err && err != -ENOENT) 700 return ERR_PTR(err); 701 if (err || !inode) 702 return ERR_PTR(-ESTALE); 703 704 parent = d_alloc_anon(inode); 705 if (!parent) { 706 iput(inode); 707 return ERR_PTR(-ENOMEM); 708 } 709 if (get_node_id(inode) != FUSE_ROOT_ID) { 710 parent->d_op = &fuse_dentry_operations; 711 fuse_invalidate_entry_cache(parent); 712 } 713 714 return parent; 715 } 716 717 static const struct export_operations fuse_export_operations = { 718 .fh_to_dentry = fuse_fh_to_dentry, 719 .fh_to_parent = fuse_fh_to_parent, 720 .encode_fh = fuse_encode_fh, 721 .get_parent = fuse_get_parent, 722 }; 723 724 static const struct super_operations fuse_super_operations = { 725 .alloc_inode = fuse_alloc_inode, 726 .destroy_inode = fuse_destroy_inode, 727 .clear_inode = fuse_clear_inode, 728 .drop_inode = generic_delete_inode, 729 .remount_fs = fuse_remount_fs, 730 .put_super = fuse_put_super, 731 .umount_begin = fuse_umount_begin, 732 .statfs = fuse_statfs, 733 .show_options = fuse_show_options, 734 }; 735 736 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) 737 { 738 struct fuse_init_out *arg = &req->misc.init_out; 739 740 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION) 741 fc->conn_error = 1; 742 else { 743 unsigned long ra_pages; 744 745 if (arg->minor >= 6) { 746 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE; 747 if (arg->flags & FUSE_ASYNC_READ) 748 fc->async_read = 1; 749 if (!(arg->flags & FUSE_POSIX_LOCKS)) 750 fc->no_lock = 1; 751 if (arg->flags & FUSE_ATOMIC_O_TRUNC) 752 fc->atomic_o_trunc = 1; 753 if (arg->minor >= 9) { 754 /* LOOKUP has dependency on proto version */ 755 if (arg->flags & FUSE_EXPORT_SUPPORT) 756 fc->export_support = 1; 757 } 758 if (arg->flags & FUSE_BIG_WRITES) 759 fc->big_writes = 1; 760 } else { 761 ra_pages = fc->max_read / PAGE_CACHE_SIZE; 762 fc->no_lock = 1; 763 } 764 765 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages); 766 fc->minor = arg->minor; 767 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 768 fc->max_write = max_t(unsigned, 4096, fc->max_write); 769 fc->conn_init = 1; 770 } 771 fuse_put_request(fc, req); 772 fc->blocked = 0; 773 wake_up_all(&fc->blocked_waitq); 774 } 775 776 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) 777 { 778 struct fuse_init_in *arg = &req->misc.init_in; 779 780 arg->major = FUSE_KERNEL_VERSION; 781 arg->minor = FUSE_KERNEL_MINOR_VERSION; 782 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE; 783 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 784 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES; 785 req->in.h.opcode = FUSE_INIT; 786 req->in.numargs = 1; 787 req->in.args[0].size = sizeof(*arg); 788 req->in.args[0].value = arg; 789 req->out.numargs = 1; 790 /* Variable length arguement used for backward compatibility 791 with interface version < 7.5. Rest of init_out is zeroed 792 by do_get_request(), so a short reply is not a problem */ 793 req->out.argvar = 1; 794 req->out.args[0].size = sizeof(struct fuse_init_out); 795 req->out.args[0].value = &req->misc.init_out; 796 req->end = process_init_reply; 797 request_send_background(fc, req); 798 } 799 800 static int fuse_fill_super(struct super_block *sb, void *data, int silent) 801 { 802 struct fuse_conn *fc; 803 struct inode *root; 804 struct fuse_mount_data d; 805 struct file *file; 806 struct dentry *root_dentry; 807 struct fuse_req *init_req; 808 int err; 809 int is_bdev = sb->s_bdev != NULL; 810 811 if (sb->s_flags & MS_MANDLOCK) 812 return -EINVAL; 813 814 if (!parse_fuse_opt((char *) data, &d, is_bdev)) 815 return -EINVAL; 816 817 if (is_bdev) { 818 #ifdef CONFIG_BLOCK 819 if (!sb_set_blocksize(sb, d.blksize)) 820 return -EINVAL; 821 #endif 822 } else { 823 sb->s_blocksize = PAGE_CACHE_SIZE; 824 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 825 } 826 sb->s_magic = FUSE_SUPER_MAGIC; 827 sb->s_op = &fuse_super_operations; 828 sb->s_maxbytes = MAX_LFS_FILESIZE; 829 sb->s_export_op = &fuse_export_operations; 830 831 file = fget(d.fd); 832 if (!file) 833 return -EINVAL; 834 835 if (file->f_op != &fuse_dev_operations) 836 return -EINVAL; 837 838 fc = new_conn(sb); 839 if (!fc) 840 return -ENOMEM; 841 842 fc->flags = d.flags; 843 fc->user_id = d.user_id; 844 fc->group_id = d.group_id; 845 fc->max_read = max_t(unsigned, 4096, d.max_read); 846 847 /* Used by get_root_inode() */ 848 sb->s_fs_info = fc; 849 850 err = -ENOMEM; 851 root = get_root_inode(sb, d.rootmode); 852 if (!root) 853 goto err; 854 855 root_dentry = d_alloc_root(root); 856 if (!root_dentry) { 857 iput(root); 858 goto err; 859 } 860 861 init_req = fuse_request_alloc(); 862 if (!init_req) 863 goto err_put_root; 864 865 if (is_bdev) { 866 fc->destroy_req = fuse_request_alloc(); 867 if (!fc->destroy_req) 868 goto err_put_root; 869 } 870 871 mutex_lock(&fuse_mutex); 872 err = -EINVAL; 873 if (file->private_data) 874 goto err_unlock; 875 876 err = fuse_ctl_add_conn(fc); 877 if (err) 878 goto err_unlock; 879 880 list_add_tail(&fc->entry, &fuse_conn_list); 881 sb->s_root = root_dentry; 882 fc->connected = 1; 883 file->private_data = fuse_conn_get(fc); 884 mutex_unlock(&fuse_mutex); 885 /* 886 * atomic_dec_and_test() in fput() provides the necessary 887 * memory barrier for file->private_data to be visible on all 888 * CPUs after this 889 */ 890 fput(file); 891 892 fuse_send_init(fc, init_req); 893 894 return 0; 895 896 err_unlock: 897 mutex_unlock(&fuse_mutex); 898 fuse_request_free(init_req); 899 err_put_root: 900 dput(root_dentry); 901 err: 902 fput(file); 903 fuse_conn_put(fc); 904 return err; 905 } 906 907 static int fuse_get_sb(struct file_system_type *fs_type, 908 int flags, const char *dev_name, 909 void *raw_data, struct vfsmount *mnt) 910 { 911 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt); 912 } 913 914 static struct file_system_type fuse_fs_type = { 915 .owner = THIS_MODULE, 916 .name = "fuse", 917 .fs_flags = FS_HAS_SUBTYPE, 918 .get_sb = fuse_get_sb, 919 .kill_sb = kill_anon_super, 920 }; 921 922 #ifdef CONFIG_BLOCK 923 static int fuse_get_sb_blk(struct file_system_type *fs_type, 924 int flags, const char *dev_name, 925 void *raw_data, struct vfsmount *mnt) 926 { 927 return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super, 928 mnt); 929 } 930 931 static struct file_system_type fuseblk_fs_type = { 932 .owner = THIS_MODULE, 933 .name = "fuseblk", 934 .get_sb = fuse_get_sb_blk, 935 .kill_sb = kill_block_super, 936 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 937 }; 938 939 static inline int register_fuseblk(void) 940 { 941 return register_filesystem(&fuseblk_fs_type); 942 } 943 944 static inline void unregister_fuseblk(void) 945 { 946 unregister_filesystem(&fuseblk_fs_type); 947 } 948 #else 949 static inline int register_fuseblk(void) 950 { 951 return 0; 952 } 953 954 static inline void unregister_fuseblk(void) 955 { 956 } 957 #endif 958 959 static void fuse_inode_init_once(void *foo) 960 { 961 struct inode * inode = foo; 962 963 inode_init_once(inode); 964 } 965 966 static int __init fuse_fs_init(void) 967 { 968 int err; 969 970 err = register_filesystem(&fuse_fs_type); 971 if (err) 972 goto out; 973 974 err = register_fuseblk(); 975 if (err) 976 goto out_unreg; 977 978 fuse_inode_cachep = kmem_cache_create("fuse_inode", 979 sizeof(struct fuse_inode), 980 0, SLAB_HWCACHE_ALIGN, 981 fuse_inode_init_once); 982 err = -ENOMEM; 983 if (!fuse_inode_cachep) 984 goto out_unreg2; 985 986 return 0; 987 988 out_unreg2: 989 unregister_fuseblk(); 990 out_unreg: 991 unregister_filesystem(&fuse_fs_type); 992 out: 993 return err; 994 } 995 996 static void fuse_fs_cleanup(void) 997 { 998 unregister_filesystem(&fuse_fs_type); 999 unregister_fuseblk(); 1000 kmem_cache_destroy(fuse_inode_cachep); 1001 } 1002 1003 static struct kobject *fuse_kobj; 1004 static struct kobject *connections_kobj; 1005 1006 static int fuse_sysfs_init(void) 1007 { 1008 int err; 1009 1010 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 1011 if (!fuse_kobj) { 1012 err = -ENOMEM; 1013 goto out_err; 1014 } 1015 1016 connections_kobj = kobject_create_and_add("connections", fuse_kobj); 1017 if (!connections_kobj) { 1018 err = -ENOMEM; 1019 goto out_fuse_unregister; 1020 } 1021 1022 return 0; 1023 1024 out_fuse_unregister: 1025 kobject_put(fuse_kobj); 1026 out_err: 1027 return err; 1028 } 1029 1030 static void fuse_sysfs_cleanup(void) 1031 { 1032 kobject_put(connections_kobj); 1033 kobject_put(fuse_kobj); 1034 } 1035 1036 static int __init fuse_init(void) 1037 { 1038 int res; 1039 1040 printk("fuse init (API version %i.%i)\n", 1041 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 1042 1043 INIT_LIST_HEAD(&fuse_conn_list); 1044 res = fuse_fs_init(); 1045 if (res) 1046 goto err; 1047 1048 res = fuse_dev_init(); 1049 if (res) 1050 goto err_fs_cleanup; 1051 1052 res = fuse_sysfs_init(); 1053 if (res) 1054 goto err_dev_cleanup; 1055 1056 res = fuse_ctl_init(); 1057 if (res) 1058 goto err_sysfs_cleanup; 1059 1060 return 0; 1061 1062 err_sysfs_cleanup: 1063 fuse_sysfs_cleanup(); 1064 err_dev_cleanup: 1065 fuse_dev_cleanup(); 1066 err_fs_cleanup: 1067 fuse_fs_cleanup(); 1068 err: 1069 return res; 1070 } 1071 1072 static void __exit fuse_exit(void) 1073 { 1074 printk(KERN_DEBUG "fuse exit\n"); 1075 1076 fuse_ctl_cleanup(); 1077 fuse_sysfs_cleanup(); 1078 fuse_fs_cleanup(); 1079 fuse_dev_cleanup(); 1080 } 1081 1082 module_init(fuse_init); 1083 module_exit(fuse_exit); 1084