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 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 fuse_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 bdi_destroy(&fc->bdi); 296 fuse_conn_put(fc); 297 } 298 299 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 300 { 301 stbuf->f_type = FUSE_SUPER_MAGIC; 302 stbuf->f_bsize = attr->bsize; 303 stbuf->f_frsize = attr->frsize; 304 stbuf->f_blocks = attr->blocks; 305 stbuf->f_bfree = attr->bfree; 306 stbuf->f_bavail = attr->bavail; 307 stbuf->f_files = attr->files; 308 stbuf->f_ffree = attr->ffree; 309 stbuf->f_namelen = attr->namelen; 310 /* fsid is left zero */ 311 } 312 313 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 314 { 315 struct super_block *sb = dentry->d_sb; 316 struct fuse_conn *fc = get_fuse_conn_super(sb); 317 struct fuse_req *req; 318 struct fuse_statfs_out outarg; 319 int err; 320 321 if (!fuse_allow_task(fc, current)) { 322 buf->f_type = FUSE_SUPER_MAGIC; 323 return 0; 324 } 325 326 req = fuse_get_req(fc); 327 if (IS_ERR(req)) 328 return PTR_ERR(req); 329 330 memset(&outarg, 0, sizeof(outarg)); 331 req->in.numargs = 0; 332 req->in.h.opcode = FUSE_STATFS; 333 req->in.h.nodeid = get_node_id(dentry->d_inode); 334 req->out.numargs = 1; 335 req->out.args[0].size = 336 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg); 337 req->out.args[0].value = &outarg; 338 fuse_request_send(fc, req); 339 err = req->out.h.error; 340 if (!err) 341 convert_fuse_statfs(buf, &outarg.st); 342 fuse_put_request(fc, req); 343 return err; 344 } 345 346 enum { 347 OPT_FD, 348 OPT_ROOTMODE, 349 OPT_USER_ID, 350 OPT_GROUP_ID, 351 OPT_DEFAULT_PERMISSIONS, 352 OPT_ALLOW_OTHER, 353 OPT_MAX_READ, 354 OPT_BLKSIZE, 355 OPT_ERR 356 }; 357 358 static const match_table_t tokens = { 359 {OPT_FD, "fd=%u"}, 360 {OPT_ROOTMODE, "rootmode=%o"}, 361 {OPT_USER_ID, "user_id=%u"}, 362 {OPT_GROUP_ID, "group_id=%u"}, 363 {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, 364 {OPT_ALLOW_OTHER, "allow_other"}, 365 {OPT_MAX_READ, "max_read=%u"}, 366 {OPT_BLKSIZE, "blksize=%u"}, 367 {OPT_ERR, NULL} 368 }; 369 370 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev) 371 { 372 char *p; 373 memset(d, 0, sizeof(struct fuse_mount_data)); 374 d->max_read = ~0; 375 d->blksize = FUSE_DEFAULT_BLKSIZE; 376 377 while ((p = strsep(&opt, ",")) != NULL) { 378 int token; 379 int value; 380 substring_t args[MAX_OPT_ARGS]; 381 if (!*p) 382 continue; 383 384 token = match_token(p, tokens, args); 385 switch (token) { 386 case OPT_FD: 387 if (match_int(&args[0], &value)) 388 return 0; 389 d->fd = value; 390 d->fd_present = 1; 391 break; 392 393 case OPT_ROOTMODE: 394 if (match_octal(&args[0], &value)) 395 return 0; 396 if (!fuse_valid_type(value)) 397 return 0; 398 d->rootmode = value; 399 d->rootmode_present = 1; 400 break; 401 402 case OPT_USER_ID: 403 if (match_int(&args[0], &value)) 404 return 0; 405 d->user_id = value; 406 d->user_id_present = 1; 407 break; 408 409 case OPT_GROUP_ID: 410 if (match_int(&args[0], &value)) 411 return 0; 412 d->group_id = value; 413 d->group_id_present = 1; 414 break; 415 416 case OPT_DEFAULT_PERMISSIONS: 417 d->flags |= FUSE_DEFAULT_PERMISSIONS; 418 break; 419 420 case OPT_ALLOW_OTHER: 421 d->flags |= FUSE_ALLOW_OTHER; 422 break; 423 424 case OPT_MAX_READ: 425 if (match_int(&args[0], &value)) 426 return 0; 427 d->max_read = value; 428 break; 429 430 case OPT_BLKSIZE: 431 if (!is_bdev || match_int(&args[0], &value)) 432 return 0; 433 d->blksize = value; 434 break; 435 436 default: 437 return 0; 438 } 439 } 440 441 if (!d->fd_present || !d->rootmode_present || 442 !d->user_id_present || !d->group_id_present) 443 return 0; 444 445 return 1; 446 } 447 448 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) 449 { 450 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb); 451 452 seq_printf(m, ",user_id=%u", fc->user_id); 453 seq_printf(m, ",group_id=%u", fc->group_id); 454 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) 455 seq_puts(m, ",default_permissions"); 456 if (fc->flags & FUSE_ALLOW_OTHER) 457 seq_puts(m, ",allow_other"); 458 if (fc->max_read != ~0) 459 seq_printf(m, ",max_read=%u", fc->max_read); 460 if (mnt->mnt_sb->s_bdev && 461 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 462 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize); 463 return 0; 464 } 465 466 int fuse_conn_init(struct fuse_conn *fc, struct super_block *sb) 467 { 468 int err; 469 470 memset(fc, 0, sizeof(*fc)); 471 spin_lock_init(&fc->lock); 472 mutex_init(&fc->inst_mutex); 473 atomic_set(&fc->count, 1); 474 init_waitqueue_head(&fc->waitq); 475 init_waitqueue_head(&fc->blocked_waitq); 476 init_waitqueue_head(&fc->reserved_req_waitq); 477 INIT_LIST_HEAD(&fc->pending); 478 INIT_LIST_HEAD(&fc->processing); 479 INIT_LIST_HEAD(&fc->io); 480 INIT_LIST_HEAD(&fc->interrupts); 481 INIT_LIST_HEAD(&fc->bg_queue); 482 INIT_LIST_HEAD(&fc->entry); 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->khctr = 0; 489 fc->polled_files = RB_ROOT; 490 fc->dev = sb->s_dev; 491 err = bdi_init(&fc->bdi); 492 if (err) 493 goto error_mutex_destroy; 494 if (sb->s_bdev) { 495 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk", 496 MAJOR(fc->dev), MINOR(fc->dev)); 497 } else { 498 err = bdi_register_dev(&fc->bdi, fc->dev); 499 } 500 if (err) 501 goto error_bdi_destroy; 502 /* 503 * For a single fuse filesystem use max 1% of dirty + 504 * writeback threshold. 505 * 506 * This gives about 1M of write buffer for memory maps on a 507 * machine with 1G and 10% dirty_ratio, which should be more 508 * than enough. 509 * 510 * Privileged users can raise it by writing to 511 * 512 * /sys/class/bdi/<bdi>/max_ratio 513 */ 514 bdi_set_max_ratio(&fc->bdi, 1); 515 fc->reqctr = 0; 516 fc->blocked = 1; 517 fc->attr_version = 1; 518 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 519 520 return 0; 521 522 error_bdi_destroy: 523 bdi_destroy(&fc->bdi); 524 error_mutex_destroy: 525 mutex_destroy(&fc->inst_mutex); 526 return err; 527 } 528 EXPORT_SYMBOL_GPL(fuse_conn_init); 529 530 void fuse_conn_put(struct fuse_conn *fc) 531 { 532 if (atomic_dec_and_test(&fc->count)) { 533 if (fc->destroy_req) 534 fuse_request_free(fc->destroy_req); 535 mutex_destroy(&fc->inst_mutex); 536 fc->release(fc); 537 } 538 } 539 540 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 541 { 542 atomic_inc(&fc->count); 543 return fc; 544 } 545 546 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 547 { 548 struct fuse_attr attr; 549 memset(&attr, 0, sizeof(attr)); 550 551 attr.mode = mode; 552 attr.ino = FUSE_ROOT_ID; 553 attr.nlink = 1; 554 return fuse_iget(sb, 1, 0, &attr, 0, 0); 555 } 556 557 struct fuse_inode_handle { 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_obtain_alias(inode); 600 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) { 601 entry->d_op = &fuse_dentry_operations; 602 fuse_invalidate_entry_cache(entry); 603 } 604 605 return entry; 606 607 out_iput: 608 iput(inode); 609 out_err: 610 return ERR_PTR(err); 611 } 612 613 static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, 614 int connectable) 615 { 616 struct inode *inode = dentry->d_inode; 617 bool encode_parent = connectable && !S_ISDIR(inode->i_mode); 618 int len = encode_parent ? 6 : 3; 619 u64 nodeid; 620 u32 generation; 621 622 if (*max_len < len) 623 return 255; 624 625 nodeid = get_fuse_inode(inode)->nodeid; 626 generation = inode->i_generation; 627 628 fh[0] = (u32)(nodeid >> 32); 629 fh[1] = (u32)(nodeid & 0xffffffff); 630 fh[2] = generation; 631 632 if (encode_parent) { 633 struct inode *parent; 634 635 spin_lock(&dentry->d_lock); 636 parent = dentry->d_parent->d_inode; 637 nodeid = get_fuse_inode(parent)->nodeid; 638 generation = parent->i_generation; 639 spin_unlock(&dentry->d_lock); 640 641 fh[3] = (u32)(nodeid >> 32); 642 fh[4] = (u32)(nodeid & 0xffffffff); 643 fh[5] = generation; 644 } 645 646 *max_len = len; 647 return encode_parent ? 0x82 : 0x81; 648 } 649 650 static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 651 struct fid *fid, int fh_len, int fh_type) 652 { 653 struct fuse_inode_handle handle; 654 655 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) 656 return NULL; 657 658 handle.nodeid = (u64) fid->raw[0] << 32; 659 handle.nodeid |= (u64) fid->raw[1]; 660 handle.generation = fid->raw[2]; 661 return fuse_get_dentry(sb, &handle); 662 } 663 664 static struct dentry *fuse_fh_to_parent(struct super_block *sb, 665 struct fid *fid, int fh_len, int fh_type) 666 { 667 struct fuse_inode_handle parent; 668 669 if (fh_type != 0x82 || fh_len < 6) 670 return NULL; 671 672 parent.nodeid = (u64) fid->raw[3] << 32; 673 parent.nodeid |= (u64) fid->raw[4]; 674 parent.generation = fid->raw[5]; 675 return fuse_get_dentry(sb, &parent); 676 } 677 678 static struct dentry *fuse_get_parent(struct dentry *child) 679 { 680 struct inode *child_inode = child->d_inode; 681 struct fuse_conn *fc = get_fuse_conn(child_inode); 682 struct inode *inode; 683 struct dentry *parent; 684 struct fuse_entry_out outarg; 685 struct qstr name; 686 int err; 687 688 if (!fc->export_support) 689 return ERR_PTR(-ESTALE); 690 691 name.len = 2; 692 name.name = ".."; 693 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 694 &name, &outarg, &inode); 695 if (err) { 696 if (err == -ENOENT) 697 return ERR_PTR(-ESTALE); 698 return ERR_PTR(err); 699 } 700 701 parent = d_obtain_alias(inode); 702 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) { 703 parent->d_op = &fuse_dentry_operations; 704 fuse_invalidate_entry_cache(parent); 705 } 706 707 return parent; 708 } 709 710 static const struct export_operations fuse_export_operations = { 711 .fh_to_dentry = fuse_fh_to_dentry, 712 .fh_to_parent = fuse_fh_to_parent, 713 .encode_fh = fuse_encode_fh, 714 .get_parent = fuse_get_parent, 715 }; 716 717 static const struct super_operations fuse_super_operations = { 718 .alloc_inode = fuse_alloc_inode, 719 .destroy_inode = fuse_destroy_inode, 720 .clear_inode = fuse_clear_inode, 721 .drop_inode = generic_delete_inode, 722 .remount_fs = fuse_remount_fs, 723 .put_super = fuse_put_super, 724 .umount_begin = fuse_umount_begin, 725 .statfs = fuse_statfs, 726 .show_options = fuse_show_options, 727 }; 728 729 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) 730 { 731 struct fuse_init_out *arg = &req->misc.init_out; 732 733 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION) 734 fc->conn_error = 1; 735 else { 736 unsigned long ra_pages; 737 738 if (arg->minor >= 6) { 739 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE; 740 if (arg->flags & FUSE_ASYNC_READ) 741 fc->async_read = 1; 742 if (!(arg->flags & FUSE_POSIX_LOCKS)) 743 fc->no_lock = 1; 744 if (arg->flags & FUSE_ATOMIC_O_TRUNC) 745 fc->atomic_o_trunc = 1; 746 if (arg->minor >= 9) { 747 /* LOOKUP has dependency on proto version */ 748 if (arg->flags & FUSE_EXPORT_SUPPORT) 749 fc->export_support = 1; 750 } 751 if (arg->flags & FUSE_BIG_WRITES) 752 fc->big_writes = 1; 753 } else { 754 ra_pages = fc->max_read / PAGE_CACHE_SIZE; 755 fc->no_lock = 1; 756 } 757 758 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages); 759 fc->minor = arg->minor; 760 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 761 fc->max_write = max_t(unsigned, 4096, fc->max_write); 762 fc->conn_init = 1; 763 } 764 fc->blocked = 0; 765 wake_up_all(&fc->blocked_waitq); 766 } 767 768 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) 769 { 770 struct fuse_init_in *arg = &req->misc.init_in; 771 772 arg->major = FUSE_KERNEL_VERSION; 773 arg->minor = FUSE_KERNEL_MINOR_VERSION; 774 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE; 775 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 776 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES; 777 req->in.h.opcode = FUSE_INIT; 778 req->in.numargs = 1; 779 req->in.args[0].size = sizeof(*arg); 780 req->in.args[0].value = arg; 781 req->out.numargs = 1; 782 /* Variable length arguement used for backward compatibility 783 with interface version < 7.5. Rest of init_out is zeroed 784 by do_get_request(), so a short reply is not a problem */ 785 req->out.argvar = 1; 786 req->out.args[0].size = sizeof(struct fuse_init_out); 787 req->out.args[0].value = &req->misc.init_out; 788 req->end = process_init_reply; 789 fuse_request_send_background(fc, req); 790 } 791 792 static void fuse_free_conn(struct fuse_conn *fc) 793 { 794 kfree(fc); 795 } 796 797 static int fuse_fill_super(struct super_block *sb, void *data, int silent) 798 { 799 struct fuse_conn *fc; 800 struct inode *root; 801 struct fuse_mount_data d; 802 struct file *file; 803 struct dentry *root_dentry; 804 struct fuse_req *init_req; 805 int err; 806 int is_bdev = sb->s_bdev != NULL; 807 808 err = -EINVAL; 809 if (sb->s_flags & MS_MANDLOCK) 810 goto err; 811 812 if (!parse_fuse_opt((char *) data, &d, is_bdev)) 813 goto err; 814 815 if (is_bdev) { 816 #ifdef CONFIG_BLOCK 817 err = -EINVAL; 818 if (!sb_set_blocksize(sb, d.blksize)) 819 goto err; 820 #endif 821 } else { 822 sb->s_blocksize = PAGE_CACHE_SIZE; 823 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 824 } 825 sb->s_magic = FUSE_SUPER_MAGIC; 826 sb->s_op = &fuse_super_operations; 827 sb->s_maxbytes = MAX_LFS_FILESIZE; 828 sb->s_export_op = &fuse_export_operations; 829 830 file = fget(d.fd); 831 err = -EINVAL; 832 if (!file) 833 goto err; 834 835 if (file->f_op != &fuse_dev_operations) 836 goto err_fput; 837 838 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 839 err = -ENOMEM; 840 if (!fc) 841 goto err_fput; 842 843 err = fuse_conn_init(fc, sb); 844 if (err) { 845 kfree(fc); 846 goto err_fput; 847 } 848 849 fc->release = fuse_free_conn; 850 fc->flags = d.flags; 851 fc->user_id = d.user_id; 852 fc->group_id = d.group_id; 853 fc->max_read = max_t(unsigned, 4096, d.max_read); 854 855 /* Used by get_root_inode() */ 856 sb->s_fs_info = fc; 857 858 err = -ENOMEM; 859 root = fuse_get_root_inode(sb, d.rootmode); 860 if (!root) 861 goto err_put_conn; 862 863 root_dentry = d_alloc_root(root); 864 if (!root_dentry) { 865 iput(root); 866 goto err_put_conn; 867 } 868 869 init_req = fuse_request_alloc(); 870 if (!init_req) 871 goto err_put_root; 872 873 if (is_bdev) { 874 fc->destroy_req = fuse_request_alloc(); 875 if (!fc->destroy_req) 876 goto err_free_init_req; 877 } 878 879 mutex_lock(&fuse_mutex); 880 err = -EINVAL; 881 if (file->private_data) 882 goto err_unlock; 883 884 err = fuse_ctl_add_conn(fc); 885 if (err) 886 goto err_unlock; 887 888 list_add_tail(&fc->entry, &fuse_conn_list); 889 sb->s_root = root_dentry; 890 fc->connected = 1; 891 file->private_data = fuse_conn_get(fc); 892 mutex_unlock(&fuse_mutex); 893 /* 894 * atomic_dec_and_test() in fput() provides the necessary 895 * memory barrier for file->private_data to be visible on all 896 * CPUs after this 897 */ 898 fput(file); 899 900 fuse_send_init(fc, init_req); 901 902 return 0; 903 904 err_unlock: 905 mutex_unlock(&fuse_mutex); 906 err_free_init_req: 907 fuse_request_free(init_req); 908 err_put_root: 909 dput(root_dentry); 910 err_put_conn: 911 fuse_conn_put(fc); 912 err_fput: 913 fput(file); 914 err: 915 return err; 916 } 917 918 static int fuse_get_sb(struct file_system_type *fs_type, 919 int flags, const char *dev_name, 920 void *raw_data, struct vfsmount *mnt) 921 { 922 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt); 923 } 924 925 static struct file_system_type fuse_fs_type = { 926 .owner = THIS_MODULE, 927 .name = "fuse", 928 .fs_flags = FS_HAS_SUBTYPE, 929 .get_sb = fuse_get_sb, 930 .kill_sb = kill_anon_super, 931 }; 932 933 #ifdef CONFIG_BLOCK 934 static int fuse_get_sb_blk(struct file_system_type *fs_type, 935 int flags, const char *dev_name, 936 void *raw_data, struct vfsmount *mnt) 937 { 938 return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super, 939 mnt); 940 } 941 942 static struct file_system_type fuseblk_fs_type = { 943 .owner = THIS_MODULE, 944 .name = "fuseblk", 945 .get_sb = fuse_get_sb_blk, 946 .kill_sb = kill_block_super, 947 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 948 }; 949 950 static inline int register_fuseblk(void) 951 { 952 return register_filesystem(&fuseblk_fs_type); 953 } 954 955 static inline void unregister_fuseblk(void) 956 { 957 unregister_filesystem(&fuseblk_fs_type); 958 } 959 #else 960 static inline int register_fuseblk(void) 961 { 962 return 0; 963 } 964 965 static inline void unregister_fuseblk(void) 966 { 967 } 968 #endif 969 970 static void fuse_inode_init_once(void *foo) 971 { 972 struct inode *inode = foo; 973 974 inode_init_once(inode); 975 } 976 977 static int __init fuse_fs_init(void) 978 { 979 int err; 980 981 err = register_filesystem(&fuse_fs_type); 982 if (err) 983 goto out; 984 985 err = register_fuseblk(); 986 if (err) 987 goto out_unreg; 988 989 fuse_inode_cachep = kmem_cache_create("fuse_inode", 990 sizeof(struct fuse_inode), 991 0, SLAB_HWCACHE_ALIGN, 992 fuse_inode_init_once); 993 err = -ENOMEM; 994 if (!fuse_inode_cachep) 995 goto out_unreg2; 996 997 return 0; 998 999 out_unreg2: 1000 unregister_fuseblk(); 1001 out_unreg: 1002 unregister_filesystem(&fuse_fs_type); 1003 out: 1004 return err; 1005 } 1006 1007 static void fuse_fs_cleanup(void) 1008 { 1009 unregister_filesystem(&fuse_fs_type); 1010 unregister_fuseblk(); 1011 kmem_cache_destroy(fuse_inode_cachep); 1012 } 1013 1014 static struct kobject *fuse_kobj; 1015 static struct kobject *connections_kobj; 1016 1017 static int fuse_sysfs_init(void) 1018 { 1019 int err; 1020 1021 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 1022 if (!fuse_kobj) { 1023 err = -ENOMEM; 1024 goto out_err; 1025 } 1026 1027 connections_kobj = kobject_create_and_add("connections", fuse_kobj); 1028 if (!connections_kobj) { 1029 err = -ENOMEM; 1030 goto out_fuse_unregister; 1031 } 1032 1033 return 0; 1034 1035 out_fuse_unregister: 1036 kobject_put(fuse_kobj); 1037 out_err: 1038 return err; 1039 } 1040 1041 static void fuse_sysfs_cleanup(void) 1042 { 1043 kobject_put(connections_kobj); 1044 kobject_put(fuse_kobj); 1045 } 1046 1047 static int __init fuse_init(void) 1048 { 1049 int res; 1050 1051 printk(KERN_INFO "fuse init (API version %i.%i)\n", 1052 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 1053 1054 INIT_LIST_HEAD(&fuse_conn_list); 1055 res = fuse_fs_init(); 1056 if (res) 1057 goto err; 1058 1059 res = fuse_dev_init(); 1060 if (res) 1061 goto err_fs_cleanup; 1062 1063 res = fuse_sysfs_init(); 1064 if (res) 1065 goto err_dev_cleanup; 1066 1067 res = fuse_ctl_init(); 1068 if (res) 1069 goto err_sysfs_cleanup; 1070 1071 return 0; 1072 1073 err_sysfs_cleanup: 1074 fuse_sysfs_cleanup(); 1075 err_dev_cleanup: 1076 fuse_dev_cleanup(); 1077 err_fs_cleanup: 1078 fuse_fs_cleanup(); 1079 err: 1080 return res; 1081 } 1082 1083 static void __exit fuse_exit(void) 1084 { 1085 printk(KERN_DEBUG "fuse exit\n"); 1086 1087 fuse_ctl_cleanup(); 1088 fuse_sysfs_cleanup(); 1089 fuse_fs_cleanup(); 1090 fuse_dev_cleanup(); 1091 } 1092 1093 module_init(fuse_init); 1094 module_exit(fuse_exit); 1095