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_bdi_destroy(struct fuse_conn *fc) 278 { 279 if (fc->bdi_initialized) 280 bdi_destroy(&fc->bdi); 281 } 282 283 void fuse_conn_kill(struct fuse_conn *fc) 284 { 285 spin_lock(&fc->lock); 286 fc->connected = 0; 287 fc->blocked = 0; 288 spin_unlock(&fc->lock); 289 /* Flush all readers on this fs */ 290 kill_fasync(&fc->fasync, SIGIO, POLL_IN); 291 wake_up_all(&fc->waitq); 292 wake_up_all(&fc->blocked_waitq); 293 wake_up_all(&fc->reserved_req_waitq); 294 mutex_lock(&fuse_mutex); 295 list_del(&fc->entry); 296 fuse_ctl_remove_conn(fc); 297 mutex_unlock(&fuse_mutex); 298 fuse_bdi_destroy(fc); 299 } 300 EXPORT_SYMBOL_GPL(fuse_conn_kill); 301 302 static void fuse_put_super(struct super_block *sb) 303 { 304 struct fuse_conn *fc = get_fuse_conn_super(sb); 305 306 fuse_send_destroy(fc); 307 fuse_conn_kill(fc); 308 fuse_conn_put(fc); 309 } 310 311 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 312 { 313 stbuf->f_type = FUSE_SUPER_MAGIC; 314 stbuf->f_bsize = attr->bsize; 315 stbuf->f_frsize = attr->frsize; 316 stbuf->f_blocks = attr->blocks; 317 stbuf->f_bfree = attr->bfree; 318 stbuf->f_bavail = attr->bavail; 319 stbuf->f_files = attr->files; 320 stbuf->f_ffree = attr->ffree; 321 stbuf->f_namelen = attr->namelen; 322 /* fsid is left zero */ 323 } 324 325 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 326 { 327 struct super_block *sb = dentry->d_sb; 328 struct fuse_conn *fc = get_fuse_conn_super(sb); 329 struct fuse_req *req; 330 struct fuse_statfs_out outarg; 331 int err; 332 333 if (!fuse_allow_task(fc, current)) { 334 buf->f_type = FUSE_SUPER_MAGIC; 335 return 0; 336 } 337 338 req = fuse_get_req(fc); 339 if (IS_ERR(req)) 340 return PTR_ERR(req); 341 342 memset(&outarg, 0, sizeof(outarg)); 343 req->in.numargs = 0; 344 req->in.h.opcode = FUSE_STATFS; 345 req->in.h.nodeid = get_node_id(dentry->d_inode); 346 req->out.numargs = 1; 347 req->out.args[0].size = 348 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg); 349 req->out.args[0].value = &outarg; 350 fuse_request_send(fc, req); 351 err = req->out.h.error; 352 if (!err) 353 convert_fuse_statfs(buf, &outarg.st); 354 fuse_put_request(fc, req); 355 return err; 356 } 357 358 enum { 359 OPT_FD, 360 OPT_ROOTMODE, 361 OPT_USER_ID, 362 OPT_GROUP_ID, 363 OPT_DEFAULT_PERMISSIONS, 364 OPT_ALLOW_OTHER, 365 OPT_MAX_READ, 366 OPT_BLKSIZE, 367 OPT_ERR 368 }; 369 370 static const match_table_t tokens = { 371 {OPT_FD, "fd=%u"}, 372 {OPT_ROOTMODE, "rootmode=%o"}, 373 {OPT_USER_ID, "user_id=%u"}, 374 {OPT_GROUP_ID, "group_id=%u"}, 375 {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, 376 {OPT_ALLOW_OTHER, "allow_other"}, 377 {OPT_MAX_READ, "max_read=%u"}, 378 {OPT_BLKSIZE, "blksize=%u"}, 379 {OPT_ERR, NULL} 380 }; 381 382 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev) 383 { 384 char *p; 385 memset(d, 0, sizeof(struct fuse_mount_data)); 386 d->max_read = ~0; 387 d->blksize = FUSE_DEFAULT_BLKSIZE; 388 389 while ((p = strsep(&opt, ",")) != NULL) { 390 int token; 391 int value; 392 substring_t args[MAX_OPT_ARGS]; 393 if (!*p) 394 continue; 395 396 token = match_token(p, tokens, args); 397 switch (token) { 398 case OPT_FD: 399 if (match_int(&args[0], &value)) 400 return 0; 401 d->fd = value; 402 d->fd_present = 1; 403 break; 404 405 case OPT_ROOTMODE: 406 if (match_octal(&args[0], &value)) 407 return 0; 408 if (!fuse_valid_type(value)) 409 return 0; 410 d->rootmode = value; 411 d->rootmode_present = 1; 412 break; 413 414 case OPT_USER_ID: 415 if (match_int(&args[0], &value)) 416 return 0; 417 d->user_id = value; 418 d->user_id_present = 1; 419 break; 420 421 case OPT_GROUP_ID: 422 if (match_int(&args[0], &value)) 423 return 0; 424 d->group_id = value; 425 d->group_id_present = 1; 426 break; 427 428 case OPT_DEFAULT_PERMISSIONS: 429 d->flags |= FUSE_DEFAULT_PERMISSIONS; 430 break; 431 432 case OPT_ALLOW_OTHER: 433 d->flags |= FUSE_ALLOW_OTHER; 434 break; 435 436 case OPT_MAX_READ: 437 if (match_int(&args[0], &value)) 438 return 0; 439 d->max_read = value; 440 break; 441 442 case OPT_BLKSIZE: 443 if (!is_bdev || match_int(&args[0], &value)) 444 return 0; 445 d->blksize = value; 446 break; 447 448 default: 449 return 0; 450 } 451 } 452 453 if (!d->fd_present || !d->rootmode_present || 454 !d->user_id_present || !d->group_id_present) 455 return 0; 456 457 return 1; 458 } 459 460 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) 461 { 462 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb); 463 464 seq_printf(m, ",user_id=%u", fc->user_id); 465 seq_printf(m, ",group_id=%u", fc->group_id); 466 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) 467 seq_puts(m, ",default_permissions"); 468 if (fc->flags & FUSE_ALLOW_OTHER) 469 seq_puts(m, ",allow_other"); 470 if (fc->max_read != ~0) 471 seq_printf(m, ",max_read=%u", fc->max_read); 472 if (mnt->mnt_sb->s_bdev && 473 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 474 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize); 475 return 0; 476 } 477 478 void fuse_conn_init(struct fuse_conn *fc) 479 { 480 memset(fc, 0, sizeof(*fc)); 481 spin_lock_init(&fc->lock); 482 mutex_init(&fc->inst_mutex); 483 atomic_set(&fc->count, 1); 484 init_waitqueue_head(&fc->waitq); 485 init_waitqueue_head(&fc->blocked_waitq); 486 init_waitqueue_head(&fc->reserved_req_waitq); 487 INIT_LIST_HEAD(&fc->pending); 488 INIT_LIST_HEAD(&fc->processing); 489 INIT_LIST_HEAD(&fc->io); 490 INIT_LIST_HEAD(&fc->interrupts); 491 INIT_LIST_HEAD(&fc->bg_queue); 492 INIT_LIST_HEAD(&fc->entry); 493 atomic_set(&fc->num_waiting, 0); 494 fc->khctr = 0; 495 fc->polled_files = RB_ROOT; 496 fc->reqctr = 0; 497 fc->blocked = 1; 498 fc->attr_version = 1; 499 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 500 } 501 EXPORT_SYMBOL_GPL(fuse_conn_init); 502 503 void fuse_conn_put(struct fuse_conn *fc) 504 { 505 if (atomic_dec_and_test(&fc->count)) { 506 if (fc->destroy_req) 507 fuse_request_free(fc->destroy_req); 508 mutex_destroy(&fc->inst_mutex); 509 fc->release(fc); 510 } 511 } 512 EXPORT_SYMBOL_GPL(fuse_conn_put); 513 514 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 515 { 516 atomic_inc(&fc->count); 517 return fc; 518 } 519 EXPORT_SYMBOL_GPL(fuse_conn_get); 520 521 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode) 522 { 523 struct fuse_attr attr; 524 memset(&attr, 0, sizeof(attr)); 525 526 attr.mode = mode; 527 attr.ino = FUSE_ROOT_ID; 528 attr.nlink = 1; 529 return fuse_iget(sb, 1, 0, &attr, 0, 0); 530 } 531 532 struct fuse_inode_handle { 533 u64 nodeid; 534 u32 generation; 535 }; 536 537 static struct dentry *fuse_get_dentry(struct super_block *sb, 538 struct fuse_inode_handle *handle) 539 { 540 struct fuse_conn *fc = get_fuse_conn_super(sb); 541 struct inode *inode; 542 struct dentry *entry; 543 int err = -ESTALE; 544 545 if (handle->nodeid == 0) 546 goto out_err; 547 548 inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); 549 if (!inode) { 550 struct fuse_entry_out outarg; 551 struct qstr name; 552 553 if (!fc->export_support) 554 goto out_err; 555 556 name.len = 1; 557 name.name = "."; 558 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, 559 &inode); 560 if (err && err != -ENOENT) 561 goto out_err; 562 if (err || !inode) { 563 err = -ESTALE; 564 goto out_err; 565 } 566 err = -EIO; 567 if (get_node_id(inode) != handle->nodeid) 568 goto out_iput; 569 } 570 err = -ESTALE; 571 if (inode->i_generation != handle->generation) 572 goto out_iput; 573 574 entry = d_obtain_alias(inode); 575 if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) { 576 entry->d_op = &fuse_dentry_operations; 577 fuse_invalidate_entry_cache(entry); 578 } 579 580 return entry; 581 582 out_iput: 583 iput(inode); 584 out_err: 585 return ERR_PTR(err); 586 } 587 588 static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, 589 int connectable) 590 { 591 struct inode *inode = dentry->d_inode; 592 bool encode_parent = connectable && !S_ISDIR(inode->i_mode); 593 int len = encode_parent ? 6 : 3; 594 u64 nodeid; 595 u32 generation; 596 597 if (*max_len < len) 598 return 255; 599 600 nodeid = get_fuse_inode(inode)->nodeid; 601 generation = inode->i_generation; 602 603 fh[0] = (u32)(nodeid >> 32); 604 fh[1] = (u32)(nodeid & 0xffffffff); 605 fh[2] = generation; 606 607 if (encode_parent) { 608 struct inode *parent; 609 610 spin_lock(&dentry->d_lock); 611 parent = dentry->d_parent->d_inode; 612 nodeid = get_fuse_inode(parent)->nodeid; 613 generation = parent->i_generation; 614 spin_unlock(&dentry->d_lock); 615 616 fh[3] = (u32)(nodeid >> 32); 617 fh[4] = (u32)(nodeid & 0xffffffff); 618 fh[5] = generation; 619 } 620 621 *max_len = len; 622 return encode_parent ? 0x82 : 0x81; 623 } 624 625 static struct dentry *fuse_fh_to_dentry(struct super_block *sb, 626 struct fid *fid, int fh_len, int fh_type) 627 { 628 struct fuse_inode_handle handle; 629 630 if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) 631 return NULL; 632 633 handle.nodeid = (u64) fid->raw[0] << 32; 634 handle.nodeid |= (u64) fid->raw[1]; 635 handle.generation = fid->raw[2]; 636 return fuse_get_dentry(sb, &handle); 637 } 638 639 static struct dentry *fuse_fh_to_parent(struct super_block *sb, 640 struct fid *fid, int fh_len, int fh_type) 641 { 642 struct fuse_inode_handle parent; 643 644 if (fh_type != 0x82 || fh_len < 6) 645 return NULL; 646 647 parent.nodeid = (u64) fid->raw[3] << 32; 648 parent.nodeid |= (u64) fid->raw[4]; 649 parent.generation = fid->raw[5]; 650 return fuse_get_dentry(sb, &parent); 651 } 652 653 static struct dentry *fuse_get_parent(struct dentry *child) 654 { 655 struct inode *child_inode = child->d_inode; 656 struct fuse_conn *fc = get_fuse_conn(child_inode); 657 struct inode *inode; 658 struct dentry *parent; 659 struct fuse_entry_out outarg; 660 struct qstr name; 661 int err; 662 663 if (!fc->export_support) 664 return ERR_PTR(-ESTALE); 665 666 name.len = 2; 667 name.name = ".."; 668 err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), 669 &name, &outarg, &inode); 670 if (err) { 671 if (err == -ENOENT) 672 return ERR_PTR(-ESTALE); 673 return ERR_PTR(err); 674 } 675 676 parent = d_obtain_alias(inode); 677 if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) { 678 parent->d_op = &fuse_dentry_operations; 679 fuse_invalidate_entry_cache(parent); 680 } 681 682 return parent; 683 } 684 685 static const struct export_operations fuse_export_operations = { 686 .fh_to_dentry = fuse_fh_to_dentry, 687 .fh_to_parent = fuse_fh_to_parent, 688 .encode_fh = fuse_encode_fh, 689 .get_parent = fuse_get_parent, 690 }; 691 692 static const struct super_operations fuse_super_operations = { 693 .alloc_inode = fuse_alloc_inode, 694 .destroy_inode = fuse_destroy_inode, 695 .clear_inode = fuse_clear_inode, 696 .drop_inode = generic_delete_inode, 697 .remount_fs = fuse_remount_fs, 698 .put_super = fuse_put_super, 699 .umount_begin = fuse_umount_begin, 700 .statfs = fuse_statfs, 701 .show_options = fuse_show_options, 702 }; 703 704 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) 705 { 706 struct fuse_init_out *arg = &req->misc.init_out; 707 708 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION) 709 fc->conn_error = 1; 710 else { 711 unsigned long ra_pages; 712 713 if (arg->minor >= 6) { 714 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE; 715 if (arg->flags & FUSE_ASYNC_READ) 716 fc->async_read = 1; 717 if (!(arg->flags & FUSE_POSIX_LOCKS)) 718 fc->no_lock = 1; 719 if (arg->flags & FUSE_ATOMIC_O_TRUNC) 720 fc->atomic_o_trunc = 1; 721 if (arg->minor >= 9) { 722 /* LOOKUP has dependency on proto version */ 723 if (arg->flags & FUSE_EXPORT_SUPPORT) 724 fc->export_support = 1; 725 } 726 if (arg->flags & FUSE_BIG_WRITES) 727 fc->big_writes = 1; 728 } else { 729 ra_pages = fc->max_read / PAGE_CACHE_SIZE; 730 fc->no_lock = 1; 731 } 732 733 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages); 734 fc->minor = arg->minor; 735 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 736 fc->max_write = max_t(unsigned, 4096, fc->max_write); 737 fc->conn_init = 1; 738 } 739 fc->blocked = 0; 740 wake_up_all(&fc->blocked_waitq); 741 } 742 743 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) 744 { 745 struct fuse_init_in *arg = &req->misc.init_in; 746 747 arg->major = FUSE_KERNEL_VERSION; 748 arg->minor = FUSE_KERNEL_MINOR_VERSION; 749 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE; 750 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 751 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES; 752 req->in.h.opcode = FUSE_INIT; 753 req->in.numargs = 1; 754 req->in.args[0].size = sizeof(*arg); 755 req->in.args[0].value = arg; 756 req->out.numargs = 1; 757 /* Variable length arguement used for backward compatibility 758 with interface version < 7.5. Rest of init_out is zeroed 759 by do_get_request(), so a short reply is not a problem */ 760 req->out.argvar = 1; 761 req->out.args[0].size = sizeof(struct fuse_init_out); 762 req->out.args[0].value = &req->misc.init_out; 763 req->end = process_init_reply; 764 fuse_request_send_background(fc, req); 765 } 766 767 static void fuse_free_conn(struct fuse_conn *fc) 768 { 769 kfree(fc); 770 } 771 772 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 773 { 774 int err; 775 776 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; 777 fc->bdi.unplug_io_fn = default_unplug_io_fn; 778 /* fuse does it's own writeback accounting */ 779 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB; 780 781 err = bdi_init(&fc->bdi); 782 if (err) 783 return err; 784 785 fc->bdi_initialized = 1; 786 787 if (sb->s_bdev) { 788 err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk", 789 MAJOR(fc->dev), MINOR(fc->dev)); 790 } else { 791 err = bdi_register_dev(&fc->bdi, fc->dev); 792 } 793 794 if (err) 795 return err; 796 797 /* 798 * For a single fuse filesystem use max 1% of dirty + 799 * writeback threshold. 800 * 801 * This gives about 1M of write buffer for memory maps on a 802 * machine with 1G and 10% dirty_ratio, which should be more 803 * than enough. 804 * 805 * Privileged users can raise it by writing to 806 * 807 * /sys/class/bdi/<bdi>/max_ratio 808 */ 809 bdi_set_max_ratio(&fc->bdi, 1); 810 811 return 0; 812 } 813 814 static int fuse_fill_super(struct super_block *sb, void *data, int silent) 815 { 816 struct fuse_conn *fc; 817 struct inode *root; 818 struct fuse_mount_data d; 819 struct file *file; 820 struct dentry *root_dentry; 821 struct fuse_req *init_req; 822 int err; 823 int is_bdev = sb->s_bdev != NULL; 824 825 err = -EINVAL; 826 if (sb->s_flags & MS_MANDLOCK) 827 goto err; 828 829 if (!parse_fuse_opt((char *) data, &d, is_bdev)) 830 goto err; 831 832 if (is_bdev) { 833 #ifdef CONFIG_BLOCK 834 err = -EINVAL; 835 if (!sb_set_blocksize(sb, d.blksize)) 836 goto err; 837 #endif 838 } else { 839 sb->s_blocksize = PAGE_CACHE_SIZE; 840 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 841 } 842 sb->s_magic = FUSE_SUPER_MAGIC; 843 sb->s_op = &fuse_super_operations; 844 sb->s_maxbytes = MAX_LFS_FILESIZE; 845 sb->s_export_op = &fuse_export_operations; 846 847 file = fget(d.fd); 848 err = -EINVAL; 849 if (!file) 850 goto err; 851 852 if (file->f_op != &fuse_dev_operations) 853 goto err_fput; 854 855 fc = kmalloc(sizeof(*fc), GFP_KERNEL); 856 err = -ENOMEM; 857 if (!fc) 858 goto err_fput; 859 860 fuse_conn_init(fc); 861 862 fc->dev = sb->s_dev; 863 err = fuse_bdi_init(fc, sb); 864 if (err) 865 goto err_put_conn; 866 867 fc->release = fuse_free_conn; 868 fc->flags = d.flags; 869 fc->user_id = d.user_id; 870 fc->group_id = d.group_id; 871 fc->max_read = max_t(unsigned, 4096, d.max_read); 872 873 /* Used by get_root_inode() */ 874 sb->s_fs_info = fc; 875 876 err = -ENOMEM; 877 root = fuse_get_root_inode(sb, d.rootmode); 878 if (!root) 879 goto err_put_conn; 880 881 root_dentry = d_alloc_root(root); 882 if (!root_dentry) { 883 iput(root); 884 goto err_put_conn; 885 } 886 887 init_req = fuse_request_alloc(); 888 if (!init_req) 889 goto err_put_root; 890 891 if (is_bdev) { 892 fc->destroy_req = fuse_request_alloc(); 893 if (!fc->destroy_req) 894 goto err_free_init_req; 895 } 896 897 mutex_lock(&fuse_mutex); 898 err = -EINVAL; 899 if (file->private_data) 900 goto err_unlock; 901 902 err = fuse_ctl_add_conn(fc); 903 if (err) 904 goto err_unlock; 905 906 list_add_tail(&fc->entry, &fuse_conn_list); 907 sb->s_root = root_dentry; 908 fc->connected = 1; 909 file->private_data = fuse_conn_get(fc); 910 mutex_unlock(&fuse_mutex); 911 /* 912 * atomic_dec_and_test() in fput() provides the necessary 913 * memory barrier for file->private_data to be visible on all 914 * CPUs after this 915 */ 916 fput(file); 917 918 fuse_send_init(fc, init_req); 919 920 return 0; 921 922 err_unlock: 923 mutex_unlock(&fuse_mutex); 924 err_free_init_req: 925 fuse_request_free(init_req); 926 err_put_root: 927 dput(root_dentry); 928 err_put_conn: 929 fuse_bdi_destroy(fc); 930 fuse_conn_put(fc); 931 err_fput: 932 fput(file); 933 err: 934 return err; 935 } 936 937 static int fuse_get_sb(struct file_system_type *fs_type, 938 int flags, const char *dev_name, 939 void *raw_data, struct vfsmount *mnt) 940 { 941 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt); 942 } 943 944 static struct file_system_type fuse_fs_type = { 945 .owner = THIS_MODULE, 946 .name = "fuse", 947 .fs_flags = FS_HAS_SUBTYPE, 948 .get_sb = fuse_get_sb, 949 .kill_sb = kill_anon_super, 950 }; 951 952 #ifdef CONFIG_BLOCK 953 static int fuse_get_sb_blk(struct file_system_type *fs_type, 954 int flags, const char *dev_name, 955 void *raw_data, struct vfsmount *mnt) 956 { 957 return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super, 958 mnt); 959 } 960 961 static struct file_system_type fuseblk_fs_type = { 962 .owner = THIS_MODULE, 963 .name = "fuseblk", 964 .get_sb = fuse_get_sb_blk, 965 .kill_sb = kill_block_super, 966 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 967 }; 968 969 static inline int register_fuseblk(void) 970 { 971 return register_filesystem(&fuseblk_fs_type); 972 } 973 974 static inline void unregister_fuseblk(void) 975 { 976 unregister_filesystem(&fuseblk_fs_type); 977 } 978 #else 979 static inline int register_fuseblk(void) 980 { 981 return 0; 982 } 983 984 static inline void unregister_fuseblk(void) 985 { 986 } 987 #endif 988 989 static void fuse_inode_init_once(void *foo) 990 { 991 struct inode *inode = foo; 992 993 inode_init_once(inode); 994 } 995 996 static int __init fuse_fs_init(void) 997 { 998 int err; 999 1000 err = register_filesystem(&fuse_fs_type); 1001 if (err) 1002 goto out; 1003 1004 err = register_fuseblk(); 1005 if (err) 1006 goto out_unreg; 1007 1008 fuse_inode_cachep = kmem_cache_create("fuse_inode", 1009 sizeof(struct fuse_inode), 1010 0, SLAB_HWCACHE_ALIGN, 1011 fuse_inode_init_once); 1012 err = -ENOMEM; 1013 if (!fuse_inode_cachep) 1014 goto out_unreg2; 1015 1016 return 0; 1017 1018 out_unreg2: 1019 unregister_fuseblk(); 1020 out_unreg: 1021 unregister_filesystem(&fuse_fs_type); 1022 out: 1023 return err; 1024 } 1025 1026 static void fuse_fs_cleanup(void) 1027 { 1028 unregister_filesystem(&fuse_fs_type); 1029 unregister_fuseblk(); 1030 kmem_cache_destroy(fuse_inode_cachep); 1031 } 1032 1033 static struct kobject *fuse_kobj; 1034 static struct kobject *connections_kobj; 1035 1036 static int fuse_sysfs_init(void) 1037 { 1038 int err; 1039 1040 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 1041 if (!fuse_kobj) { 1042 err = -ENOMEM; 1043 goto out_err; 1044 } 1045 1046 connections_kobj = kobject_create_and_add("connections", fuse_kobj); 1047 if (!connections_kobj) { 1048 err = -ENOMEM; 1049 goto out_fuse_unregister; 1050 } 1051 1052 return 0; 1053 1054 out_fuse_unregister: 1055 kobject_put(fuse_kobj); 1056 out_err: 1057 return err; 1058 } 1059 1060 static void fuse_sysfs_cleanup(void) 1061 { 1062 kobject_put(connections_kobj); 1063 kobject_put(fuse_kobj); 1064 } 1065 1066 static int __init fuse_init(void) 1067 { 1068 int res; 1069 1070 printk(KERN_INFO "fuse init (API version %i.%i)\n", 1071 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 1072 1073 INIT_LIST_HEAD(&fuse_conn_list); 1074 res = fuse_fs_init(); 1075 if (res) 1076 goto err; 1077 1078 res = fuse_dev_init(); 1079 if (res) 1080 goto err_fs_cleanup; 1081 1082 res = fuse_sysfs_init(); 1083 if (res) 1084 goto err_dev_cleanup; 1085 1086 res = fuse_ctl_init(); 1087 if (res) 1088 goto err_sysfs_cleanup; 1089 1090 return 0; 1091 1092 err_sysfs_cleanup: 1093 fuse_sysfs_cleanup(); 1094 err_dev_cleanup: 1095 fuse_dev_cleanup(); 1096 err_fs_cleanup: 1097 fuse_fs_cleanup(); 1098 err: 1099 return res; 1100 } 1101 1102 static void __exit fuse_exit(void) 1103 { 1104 printk(KERN_DEBUG "fuse exit\n"); 1105 1106 fuse_ctl_cleanup(); 1107 fuse_sysfs_cleanup(); 1108 fuse_fs_cleanup(); 1109 fuse_dev_cleanup(); 1110 } 1111 1112 module_init(fuse_init); 1113 module_exit(fuse_exit); 1114