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