1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/befs/linuxvfs.c 4 * 5 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com 6 * 7 */ 8 9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 10 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/fs.h> 14 #include <linux/errno.h> 15 #include <linux/stat.h> 16 #include <linux/nls.h> 17 #include <linux/buffer_head.h> 18 #include <linux/vfs.h> 19 #include <linux/parser.h> 20 #include <linux/namei.h> 21 #include <linux/sched.h> 22 #include <linux/cred.h> 23 #include <linux/exportfs.h> 24 #include <linux/seq_file.h> 25 #include <linux/blkdev.h> 26 27 #include "befs.h" 28 #include "btree.h" 29 #include "inode.h" 30 #include "datastream.h" 31 #include "super.h" 32 #include "io.h" 33 34 MODULE_DESCRIPTION("BeOS File System (BeFS) driver"); 35 MODULE_AUTHOR("Will Dyson"); 36 MODULE_LICENSE("GPL"); 37 38 /* The units the vfs expects inode->i_blocks to be in */ 39 #define VFS_BLOCK_SIZE 512 40 41 static int befs_readdir(struct file *, struct dir_context *); 42 static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int); 43 static int befs_read_folio(struct file *file, struct folio *folio); 44 static sector_t befs_bmap(struct address_space *mapping, sector_t block); 45 static struct dentry *befs_lookup(struct inode *, struct dentry *, 46 unsigned int); 47 static struct inode *befs_iget(struct super_block *, unsigned long); 48 static struct inode *befs_alloc_inode(struct super_block *sb); 49 static void befs_free_inode(struct inode *inode); 50 static void befs_destroy_inodecache(void); 51 static int befs_symlink_read_folio(struct file *, struct folio *); 52 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len, 53 char **out, int *out_len); 54 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len, 55 char **out, int *out_len); 56 static void befs_put_super(struct super_block *); 57 static int befs_remount(struct super_block *, int *, char *); 58 static int befs_statfs(struct dentry *, struct kstatfs *); 59 static int befs_show_options(struct seq_file *, struct dentry *); 60 static int parse_options(char *, struct befs_mount_options *); 61 static struct dentry *befs_fh_to_dentry(struct super_block *sb, 62 struct fid *fid, int fh_len, int fh_type); 63 static struct dentry *befs_fh_to_parent(struct super_block *sb, 64 struct fid *fid, int fh_len, int fh_type); 65 static struct dentry *befs_get_parent(struct dentry *child); 66 67 static const struct super_operations befs_sops = { 68 .alloc_inode = befs_alloc_inode, /* allocate a new inode */ 69 .free_inode = befs_free_inode, /* deallocate an inode */ 70 .put_super = befs_put_super, /* uninit super */ 71 .statfs = befs_statfs, /* statfs */ 72 .remount_fs = befs_remount, 73 .show_options = befs_show_options, 74 }; 75 76 /* slab cache for befs_inode_info objects */ 77 static struct kmem_cache *befs_inode_cachep; 78 79 static const struct file_operations befs_dir_operations = { 80 .read = generic_read_dir, 81 .iterate_shared = befs_readdir, 82 .llseek = generic_file_llseek, 83 }; 84 85 static const struct inode_operations befs_dir_inode_operations = { 86 .lookup = befs_lookup, 87 }; 88 89 static const struct address_space_operations befs_aops = { 90 .read_folio = befs_read_folio, 91 .bmap = befs_bmap, 92 }; 93 94 static const struct address_space_operations befs_symlink_aops = { 95 .read_folio = befs_symlink_read_folio, 96 }; 97 98 static const struct export_operations befs_export_operations = { 99 .fh_to_dentry = befs_fh_to_dentry, 100 .fh_to_parent = befs_fh_to_parent, 101 .get_parent = befs_get_parent, 102 }; 103 104 /* 105 * Called by generic_file_read() to read a folio of data 106 * 107 * In turn, simply calls a generic block read function and 108 * passes it the address of befs_get_block, for mapping file 109 * positions to disk blocks. 110 */ 111 static int 112 befs_read_folio(struct file *file, struct folio *folio) 113 { 114 return block_read_full_folio(folio, befs_get_block); 115 } 116 117 static sector_t 118 befs_bmap(struct address_space *mapping, sector_t block) 119 { 120 return generic_block_bmap(mapping, block, befs_get_block); 121 } 122 123 /* 124 * Generic function to map a file position (block) to a 125 * disk offset (passed back in bh_result). 126 * 127 * Used by many higher level functions. 128 * 129 * Calls befs_fblock2brun() in datastream.c to do the real work. 130 */ 131 132 static int 133 befs_get_block(struct inode *inode, sector_t block, 134 struct buffer_head *bh_result, int create) 135 { 136 struct super_block *sb = inode->i_sb; 137 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds; 138 befs_block_run run = BAD_IADDR; 139 int res; 140 ulong disk_off; 141 142 befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld", 143 (unsigned long)inode->i_ino, (long)block); 144 if (create) { 145 befs_error(sb, "befs_get_block() was asked to write to " 146 "block %ld in inode %lu", (long)block, 147 (unsigned long)inode->i_ino); 148 return -EPERM; 149 } 150 151 res = befs_fblock2brun(sb, ds, block, &run); 152 if (res != BEFS_OK) { 153 befs_error(sb, 154 "<--- %s for inode %lu, block %ld ERROR", 155 __func__, (unsigned long)inode->i_ino, 156 (long)block); 157 return -EFBIG; 158 } 159 160 disk_off = (ulong) iaddr2blockno(sb, &run); 161 162 map_bh(bh_result, inode->i_sb, disk_off); 163 164 befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu", 165 __func__, (unsigned long)inode->i_ino, (long)block, 166 (unsigned long)disk_off); 167 168 return 0; 169 } 170 171 static struct dentry * 172 befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 173 { 174 struct inode *inode; 175 struct super_block *sb = dir->i_sb; 176 const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds; 177 befs_off_t offset; 178 int ret; 179 int utfnamelen; 180 char *utfname; 181 const char *name = dentry->d_name.name; 182 183 befs_debug(sb, "---> %s name %pd inode %ld", __func__, 184 dentry, dir->i_ino); 185 186 /* Convert to UTF-8 */ 187 if (BEFS_SB(sb)->nls) { 188 ret = 189 befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen); 190 if (ret < 0) { 191 befs_debug(sb, "<--- %s ERROR", __func__); 192 return ERR_PTR(ret); 193 } 194 ret = befs_btree_find(sb, ds, utfname, &offset); 195 kfree(utfname); 196 197 } else { 198 ret = befs_btree_find(sb, ds, name, &offset); 199 } 200 201 if (ret == BEFS_BT_NOT_FOUND) { 202 befs_debug(sb, "<--- %s %pd not found", __func__, dentry); 203 inode = NULL; 204 } else if (ret != BEFS_OK || offset == 0) { 205 befs_error(sb, "<--- %s Error", __func__); 206 inode = ERR_PTR(-ENODATA); 207 } else { 208 inode = befs_iget(dir->i_sb, (ino_t) offset); 209 } 210 befs_debug(sb, "<--- %s", __func__); 211 212 return d_splice_alias(inode, dentry); 213 } 214 215 static int 216 befs_readdir(struct file *file, struct dir_context *ctx) 217 { 218 struct inode *inode = file_inode(file); 219 struct super_block *sb = inode->i_sb; 220 const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds; 221 befs_off_t value; 222 int result; 223 size_t keysize; 224 char keybuf[BEFS_NAME_LEN + 1]; 225 226 befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld", 227 __func__, file, inode->i_ino, ctx->pos); 228 229 while (1) { 230 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1, 231 keybuf, &keysize, &value); 232 233 if (result == BEFS_ERR) { 234 befs_debug(sb, "<--- %s ERROR", __func__); 235 befs_error(sb, "IO error reading %pD (inode %lu)", 236 file, inode->i_ino); 237 return -EIO; 238 239 } else if (result == BEFS_BT_END) { 240 befs_debug(sb, "<--- %s END", __func__); 241 return 0; 242 243 } else if (result == BEFS_BT_EMPTY) { 244 befs_debug(sb, "<--- %s Empty directory", __func__); 245 return 0; 246 } 247 248 /* Convert to NLS */ 249 if (BEFS_SB(sb)->nls) { 250 char *nlsname; 251 int nlsnamelen; 252 253 result = 254 befs_utf2nls(sb, keybuf, keysize, &nlsname, 255 &nlsnamelen); 256 if (result < 0) { 257 befs_debug(sb, "<--- %s ERROR", __func__); 258 return result; 259 } 260 if (!dir_emit(ctx, nlsname, nlsnamelen, 261 (ino_t) value, DT_UNKNOWN)) { 262 kfree(nlsname); 263 return 0; 264 } 265 kfree(nlsname); 266 } else { 267 if (!dir_emit(ctx, keybuf, keysize, 268 (ino_t) value, DT_UNKNOWN)) 269 return 0; 270 } 271 ctx->pos++; 272 } 273 } 274 275 static struct inode * 276 befs_alloc_inode(struct super_block *sb) 277 { 278 struct befs_inode_info *bi; 279 280 bi = alloc_inode_sb(sb, befs_inode_cachep, GFP_KERNEL); 281 if (!bi) 282 return NULL; 283 return &bi->vfs_inode; 284 } 285 286 static void befs_free_inode(struct inode *inode) 287 { 288 kmem_cache_free(befs_inode_cachep, BEFS_I(inode)); 289 } 290 291 static void init_once(void *foo) 292 { 293 struct befs_inode_info *bi = (struct befs_inode_info *) foo; 294 295 inode_init_once(&bi->vfs_inode); 296 } 297 298 static struct inode *befs_iget(struct super_block *sb, unsigned long ino) 299 { 300 struct buffer_head *bh; 301 befs_inode *raw_inode; 302 struct befs_sb_info *befs_sb = BEFS_SB(sb); 303 struct befs_inode_info *befs_ino; 304 struct inode *inode; 305 306 befs_debug(sb, "---> %s inode = %lu", __func__, ino); 307 308 inode = iget_locked(sb, ino); 309 if (!inode) 310 return ERR_PTR(-ENOMEM); 311 if (!(inode->i_state & I_NEW)) 312 return inode; 313 314 befs_ino = BEFS_I(inode); 315 316 /* convert from vfs's inode number to befs's inode number */ 317 befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino); 318 319 befs_debug(sb, " real inode number [%u, %hu, %hu]", 320 befs_ino->i_inode_num.allocation_group, 321 befs_ino->i_inode_num.start, befs_ino->i_inode_num.len); 322 323 bh = sb_bread(sb, inode->i_ino); 324 if (!bh) { 325 befs_error(sb, "unable to read inode block - " 326 "inode = %lu", inode->i_ino); 327 goto unacquire_none; 328 } 329 330 raw_inode = (befs_inode *) bh->b_data; 331 332 befs_dump_inode(sb, raw_inode); 333 334 if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) { 335 befs_error(sb, "Bad inode: %lu", inode->i_ino); 336 goto unacquire_bh; 337 } 338 339 inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode); 340 341 /* 342 * set uid and gid. But since current BeOS is single user OS, so 343 * you can change by "uid" or "gid" options. 344 */ 345 346 inode->i_uid = befs_sb->mount_opts.use_uid ? 347 befs_sb->mount_opts.uid : 348 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid)); 349 inode->i_gid = befs_sb->mount_opts.use_gid ? 350 befs_sb->mount_opts.gid : 351 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid)); 352 353 set_nlink(inode, 1); 354 355 /* 356 * BEFS's time is 64 bits, but current VFS is 32 bits... 357 * BEFS don't have access time. Nor inode change time. VFS 358 * doesn't have creation time. 359 * Also, the lower 16 bits of the last_modified_time and 360 * create_time are just a counter to help ensure uniqueness 361 * for indexing purposes. (PFD, page 54) 362 */ 363 364 inode->i_mtime.tv_sec = 365 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16; 366 inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */ 367 inode->i_ctime = inode->i_mtime; 368 inode->i_atime = inode->i_mtime; 369 370 befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num); 371 befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent); 372 befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes); 373 befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags); 374 375 if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){ 376 inode->i_size = 0; 377 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE; 378 strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink, 379 BEFS_SYMLINK_LEN); 380 } else { 381 int num_blks; 382 383 befs_ino->i_data.ds = 384 fsds_to_cpu(sb, &raw_inode->data.datastream); 385 386 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds); 387 inode->i_blocks = 388 num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE); 389 inode->i_size = befs_ino->i_data.ds.size; 390 } 391 392 inode->i_mapping->a_ops = &befs_aops; 393 394 if (S_ISREG(inode->i_mode)) { 395 inode->i_fop = &generic_ro_fops; 396 } else if (S_ISDIR(inode->i_mode)) { 397 inode->i_op = &befs_dir_inode_operations; 398 inode->i_fop = &befs_dir_operations; 399 } else if (S_ISLNK(inode->i_mode)) { 400 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) { 401 inode->i_op = &page_symlink_inode_operations; 402 inode_nohighmem(inode); 403 inode->i_mapping->a_ops = &befs_symlink_aops; 404 } else { 405 inode->i_link = befs_ino->i_data.symlink; 406 inode->i_op = &simple_symlink_inode_operations; 407 } 408 } else { 409 befs_error(sb, "Inode %lu is not a regular file, " 410 "directory or symlink. THAT IS WRONG! BeFS has no " 411 "on disk special files", inode->i_ino); 412 goto unacquire_bh; 413 } 414 415 brelse(bh); 416 befs_debug(sb, "<--- %s", __func__); 417 unlock_new_inode(inode); 418 return inode; 419 420 unacquire_bh: 421 brelse(bh); 422 423 unacquire_none: 424 iget_failed(inode); 425 befs_debug(sb, "<--- %s - Bad inode", __func__); 426 return ERR_PTR(-EIO); 427 } 428 429 /* Initialize the inode cache. Called at fs setup. 430 * 431 * Taken from NFS implementation by Al Viro. 432 */ 433 static int __init 434 befs_init_inodecache(void) 435 { 436 befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache", 437 sizeof(struct befs_inode_info), 0, 438 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| 439 SLAB_ACCOUNT), 440 offsetof(struct befs_inode_info, 441 i_data.symlink), 442 sizeof_field(struct befs_inode_info, 443 i_data.symlink), 444 init_once); 445 if (befs_inode_cachep == NULL) 446 return -ENOMEM; 447 448 return 0; 449 } 450 451 /* Called at fs teardown. 452 * 453 * Taken from NFS implementation by Al Viro. 454 */ 455 static void 456 befs_destroy_inodecache(void) 457 { 458 /* 459 * Make sure all delayed rcu free inodes are flushed before we 460 * destroy cache. 461 */ 462 rcu_barrier(); 463 kmem_cache_destroy(befs_inode_cachep); 464 } 465 466 /* 467 * The inode of symbolic link is different to data stream. 468 * The data stream become link name. Unless the LONG_SYMLINK 469 * flag is set. 470 */ 471 static int befs_symlink_read_folio(struct file *unused, struct folio *folio) 472 { 473 struct page *page = &folio->page; 474 struct inode *inode = page->mapping->host; 475 struct super_block *sb = inode->i_sb; 476 struct befs_inode_info *befs_ino = BEFS_I(inode); 477 befs_data_stream *data = &befs_ino->i_data.ds; 478 befs_off_t len = data->size; 479 char *link = page_address(page); 480 481 if (len == 0 || len > PAGE_SIZE) { 482 befs_error(sb, "Long symlink with illegal length"); 483 goto fail; 484 } 485 befs_debug(sb, "Follow long symlink"); 486 487 if (befs_read_lsymlink(sb, data, link, len) != len) { 488 befs_error(sb, "Failed to read entire long symlink"); 489 goto fail; 490 } 491 link[len - 1] = '\0'; 492 SetPageUptodate(page); 493 unlock_page(page); 494 return 0; 495 fail: 496 SetPageError(page); 497 unlock_page(page); 498 return -EIO; 499 } 500 501 /* 502 * UTF-8 to NLS charset convert routine 503 * 504 * Uses uni2char() / char2uni() rather than the nls tables directly 505 */ 506 static int 507 befs_utf2nls(struct super_block *sb, const char *in, 508 int in_len, char **out, int *out_len) 509 { 510 struct nls_table *nls = BEFS_SB(sb)->nls; 511 int i, o; 512 unicode_t uni; 513 int unilen, utflen; 514 char *result; 515 /* The utf8->nls conversion won't make the final nls string bigger 516 * than the utf one, but if the string is pure ascii they'll have the 517 * same width and an extra char is needed to save the additional \0 518 */ 519 int maxlen = in_len + 1; 520 521 befs_debug(sb, "---> %s", __func__); 522 523 if (!nls) { 524 befs_error(sb, "%s called with no NLS table loaded", __func__); 525 return -EINVAL; 526 } 527 528 *out = result = kmalloc(maxlen, GFP_NOFS); 529 if (!*out) 530 return -ENOMEM; 531 532 for (i = o = 0; i < in_len; i += utflen, o += unilen) { 533 534 /* convert from UTF-8 to Unicode */ 535 utflen = utf8_to_utf32(&in[i], in_len - i, &uni); 536 if (utflen < 0) 537 goto conv_err; 538 539 /* convert from Unicode to nls */ 540 if (uni > MAX_WCHAR_T) 541 goto conv_err; 542 unilen = nls->uni2char(uni, &result[o], in_len - o); 543 if (unilen < 0) 544 goto conv_err; 545 } 546 result[o] = '\0'; 547 *out_len = o; 548 549 befs_debug(sb, "<--- %s", __func__); 550 551 return o; 552 553 conv_err: 554 befs_error(sb, "Name using character set %s contains a character that " 555 "cannot be converted to unicode.", nls->charset); 556 befs_debug(sb, "<--- %s", __func__); 557 kfree(result); 558 return -EILSEQ; 559 } 560 561 /** 562 * befs_nls2utf - Convert NLS string to utf8 encodeing 563 * @sb: Superblock 564 * @in: Input string buffer in NLS format 565 * @in_len: Length of input string in bytes 566 * @out: The output string in UTF-8 format 567 * @out_len: Length of the output buffer 568 * 569 * Converts input string @in, which is in the format of the loaded NLS map, 570 * into a utf8 string. 571 * 572 * The destination string @out is allocated by this function and the caller is 573 * responsible for freeing it with kfree() 574 * 575 * On return, *@out_len is the length of @out in bytes. 576 * 577 * On success, the return value is the number of utf8 characters written to 578 * the output buffer @out. 579 * 580 * On Failure, a negative number coresponding to the error code is returned. 581 */ 582 583 static int 584 befs_nls2utf(struct super_block *sb, const char *in, 585 int in_len, char **out, int *out_len) 586 { 587 struct nls_table *nls = BEFS_SB(sb)->nls; 588 int i, o; 589 wchar_t uni; 590 int unilen, utflen; 591 char *result; 592 /* 593 * There are nls characters that will translate to 3-chars-wide UTF-8 594 * characters, an additional byte is needed to save the final \0 595 * in special cases 596 */ 597 int maxlen = (3 * in_len) + 1; 598 599 befs_debug(sb, "---> %s\n", __func__); 600 601 if (!nls) { 602 befs_error(sb, "%s called with no NLS table loaded.", 603 __func__); 604 return -EINVAL; 605 } 606 607 *out = result = kmalloc(maxlen, GFP_NOFS); 608 if (!*out) { 609 *out_len = 0; 610 return -ENOMEM; 611 } 612 613 for (i = o = 0; i < in_len; i += unilen, o += utflen) { 614 615 /* convert from nls to unicode */ 616 unilen = nls->char2uni(&in[i], in_len - i, &uni); 617 if (unilen < 0) 618 goto conv_err; 619 620 /* convert from unicode to UTF-8 */ 621 utflen = utf32_to_utf8(uni, &result[o], 3); 622 if (utflen <= 0) 623 goto conv_err; 624 } 625 626 result[o] = '\0'; 627 *out_len = o; 628 629 befs_debug(sb, "<--- %s", __func__); 630 631 return i; 632 633 conv_err: 634 befs_error(sb, "Name using character set %s contains a character that " 635 "cannot be converted to unicode.", nls->charset); 636 befs_debug(sb, "<--- %s", __func__); 637 kfree(result); 638 return -EILSEQ; 639 } 640 641 static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino, 642 uint32_t generation) 643 { 644 /* No need to handle i_generation */ 645 return befs_iget(sb, ino); 646 } 647 648 /* 649 * Map a NFS file handle to a corresponding dentry 650 */ 651 static struct dentry *befs_fh_to_dentry(struct super_block *sb, 652 struct fid *fid, int fh_len, int fh_type) 653 { 654 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 655 befs_nfs_get_inode); 656 } 657 658 /* 659 * Find the parent for a file specified by NFS handle 660 */ 661 static struct dentry *befs_fh_to_parent(struct super_block *sb, 662 struct fid *fid, int fh_len, int fh_type) 663 { 664 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 665 befs_nfs_get_inode); 666 } 667 668 static struct dentry *befs_get_parent(struct dentry *child) 669 { 670 struct inode *parent; 671 struct befs_inode_info *befs_ino = BEFS_I(d_inode(child)); 672 673 parent = befs_iget(child->d_sb, 674 (unsigned long)befs_ino->i_parent.start); 675 if (IS_ERR(parent)) 676 return ERR_CAST(parent); 677 678 return d_obtain_alias(parent); 679 } 680 681 enum { 682 Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err, 683 }; 684 685 static const match_table_t befs_tokens = { 686 {Opt_uid, "uid=%d"}, 687 {Opt_gid, "gid=%d"}, 688 {Opt_charset, "iocharset=%s"}, 689 {Opt_debug, "debug"}, 690 {Opt_err, NULL} 691 }; 692 693 static int 694 parse_options(char *options, struct befs_mount_options *opts) 695 { 696 char *p; 697 substring_t args[MAX_OPT_ARGS]; 698 int option; 699 kuid_t uid; 700 kgid_t gid; 701 702 /* Initialize options */ 703 opts->uid = GLOBAL_ROOT_UID; 704 opts->gid = GLOBAL_ROOT_GID; 705 opts->use_uid = 0; 706 opts->use_gid = 0; 707 opts->iocharset = NULL; 708 opts->debug = 0; 709 710 if (!options) 711 return 1; 712 713 while ((p = strsep(&options, ",")) != NULL) { 714 int token; 715 716 if (!*p) 717 continue; 718 719 token = match_token(p, befs_tokens, args); 720 switch (token) { 721 case Opt_uid: 722 if (match_int(&args[0], &option)) 723 return 0; 724 uid = INVALID_UID; 725 if (option >= 0) 726 uid = make_kuid(current_user_ns(), option); 727 if (!uid_valid(uid)) { 728 pr_err("Invalid uid %d, " 729 "using default\n", option); 730 break; 731 } 732 opts->uid = uid; 733 opts->use_uid = 1; 734 break; 735 case Opt_gid: 736 if (match_int(&args[0], &option)) 737 return 0; 738 gid = INVALID_GID; 739 if (option >= 0) 740 gid = make_kgid(current_user_ns(), option); 741 if (!gid_valid(gid)) { 742 pr_err("Invalid gid %d, " 743 "using default\n", option); 744 break; 745 } 746 opts->gid = gid; 747 opts->use_gid = 1; 748 break; 749 case Opt_charset: 750 kfree(opts->iocharset); 751 opts->iocharset = match_strdup(&args[0]); 752 if (!opts->iocharset) { 753 pr_err("allocation failure for " 754 "iocharset string\n"); 755 return 0; 756 } 757 break; 758 case Opt_debug: 759 opts->debug = 1; 760 break; 761 default: 762 pr_err("Unrecognized mount option \"%s\" " 763 "or missing value\n", p); 764 return 0; 765 } 766 } 767 return 1; 768 } 769 770 static int befs_show_options(struct seq_file *m, struct dentry *root) 771 { 772 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb); 773 struct befs_mount_options *opts = &befs_sb->mount_opts; 774 775 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) 776 seq_printf(m, ",uid=%u", 777 from_kuid_munged(&init_user_ns, opts->uid)); 778 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) 779 seq_printf(m, ",gid=%u", 780 from_kgid_munged(&init_user_ns, opts->gid)); 781 if (opts->iocharset) 782 seq_printf(m, ",charset=%s", opts->iocharset); 783 if (opts->debug) 784 seq_puts(m, ",debug"); 785 return 0; 786 } 787 788 /* This function has the responsibiltiy of getting the 789 * filesystem ready for unmounting. 790 * Basically, we free everything that we allocated in 791 * befs_read_inode 792 */ 793 static void 794 befs_put_super(struct super_block *sb) 795 { 796 kfree(BEFS_SB(sb)->mount_opts.iocharset); 797 BEFS_SB(sb)->mount_opts.iocharset = NULL; 798 unload_nls(BEFS_SB(sb)->nls); 799 kfree(sb->s_fs_info); 800 sb->s_fs_info = NULL; 801 } 802 803 /* Allocate private field of the superblock, fill it. 804 * 805 * Finish filling the public superblock fields 806 * Make the root directory 807 * Load a set of NLS translations if needed. 808 */ 809 static int 810 befs_fill_super(struct super_block *sb, void *data, int silent) 811 { 812 struct buffer_head *bh; 813 struct befs_sb_info *befs_sb; 814 befs_super_block *disk_sb; 815 struct inode *root; 816 long ret = -EINVAL; 817 const unsigned long sb_block = 0; 818 const off_t x86_sb_off = 512; 819 int blocksize; 820 821 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL); 822 if (sb->s_fs_info == NULL) 823 goto unacquire_none; 824 825 befs_sb = BEFS_SB(sb); 826 827 if (!parse_options((char *) data, &befs_sb->mount_opts)) { 828 if (!silent) 829 befs_error(sb, "cannot parse mount options"); 830 goto unacquire_priv_sbp; 831 } 832 833 befs_debug(sb, "---> %s", __func__); 834 835 if (!sb_rdonly(sb)) { 836 befs_warning(sb, 837 "No write support. Marking filesystem read-only"); 838 sb->s_flags |= SB_RDONLY; 839 } 840 841 /* 842 * Set dummy blocksize to read super block. 843 * Will be set to real fs blocksize later. 844 * 845 * Linux 2.4.10 and later refuse to read blocks smaller than 846 * the logical block size for the device. But we also need to read at 847 * least 1k to get the second 512 bytes of the volume. 848 */ 849 blocksize = sb_min_blocksize(sb, 1024); 850 if (!blocksize) { 851 if (!silent) 852 befs_error(sb, "unable to set blocksize"); 853 goto unacquire_priv_sbp; 854 } 855 856 bh = sb_bread(sb, sb_block); 857 if (!bh) { 858 if (!silent) 859 befs_error(sb, "unable to read superblock"); 860 goto unacquire_priv_sbp; 861 } 862 863 /* account for offset of super block on x86 */ 864 disk_sb = (befs_super_block *) bh->b_data; 865 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) || 866 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) { 867 befs_debug(sb, "Using PPC superblock location"); 868 } else { 869 befs_debug(sb, "Using x86 superblock location"); 870 disk_sb = 871 (befs_super_block *) ((void *) bh->b_data + x86_sb_off); 872 } 873 874 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) || 875 (befs_check_sb(sb) != BEFS_OK)) 876 goto unacquire_bh; 877 878 befs_dump_super_block(sb, disk_sb); 879 880 brelse(bh); 881 882 if (befs_sb->num_blocks > ~((sector_t)0)) { 883 if (!silent) 884 befs_error(sb, "blocks count: %llu is larger than the host can use", 885 befs_sb->num_blocks); 886 goto unacquire_priv_sbp; 887 } 888 889 /* 890 * set up enough so that it can read an inode 891 * Fill in kernel superblock fields from private sb 892 */ 893 sb->s_magic = BEFS_SUPER_MAGIC; 894 /* Set real blocksize of fs */ 895 sb_set_blocksize(sb, (ulong) befs_sb->block_size); 896 sb->s_op = &befs_sops; 897 sb->s_export_op = &befs_export_operations; 898 sb->s_time_min = 0; 899 sb->s_time_max = 0xffffffffffffll; 900 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir))); 901 if (IS_ERR(root)) { 902 ret = PTR_ERR(root); 903 goto unacquire_priv_sbp; 904 } 905 sb->s_root = d_make_root(root); 906 if (!sb->s_root) { 907 if (!silent) 908 befs_error(sb, "get root inode failed"); 909 goto unacquire_priv_sbp; 910 } 911 912 /* load nls library */ 913 if (befs_sb->mount_opts.iocharset) { 914 befs_debug(sb, "Loading nls: %s", 915 befs_sb->mount_opts.iocharset); 916 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset); 917 if (!befs_sb->nls) { 918 befs_warning(sb, "Cannot load nls %s" 919 " loading default nls", 920 befs_sb->mount_opts.iocharset); 921 befs_sb->nls = load_nls_default(); 922 } 923 /* load default nls if none is specified in mount options */ 924 } else { 925 befs_debug(sb, "Loading default nls"); 926 befs_sb->nls = load_nls_default(); 927 } 928 929 return 0; 930 931 unacquire_bh: 932 brelse(bh); 933 934 unacquire_priv_sbp: 935 kfree(befs_sb->mount_opts.iocharset); 936 kfree(sb->s_fs_info); 937 sb->s_fs_info = NULL; 938 939 unacquire_none: 940 return ret; 941 } 942 943 static int 944 befs_remount(struct super_block *sb, int *flags, char *data) 945 { 946 sync_filesystem(sb); 947 if (!(*flags & SB_RDONLY)) 948 return -EINVAL; 949 return 0; 950 } 951 952 static int 953 befs_statfs(struct dentry *dentry, struct kstatfs *buf) 954 { 955 struct super_block *sb = dentry->d_sb; 956 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 957 958 befs_debug(sb, "---> %s", __func__); 959 960 buf->f_type = BEFS_SUPER_MAGIC; 961 buf->f_bsize = sb->s_blocksize; 962 buf->f_blocks = BEFS_SB(sb)->num_blocks; 963 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks; 964 buf->f_bavail = buf->f_bfree; 965 buf->f_files = 0; /* UNKNOWN */ 966 buf->f_ffree = 0; /* UNKNOWN */ 967 buf->f_fsid = u64_to_fsid(id); 968 buf->f_namelen = BEFS_NAME_LEN; 969 970 befs_debug(sb, "<--- %s", __func__); 971 972 return 0; 973 } 974 975 static struct dentry * 976 befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, 977 void *data) 978 { 979 return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super); 980 } 981 982 static struct file_system_type befs_fs_type = { 983 .owner = THIS_MODULE, 984 .name = "befs", 985 .mount = befs_mount, 986 .kill_sb = kill_block_super, 987 .fs_flags = FS_REQUIRES_DEV, 988 }; 989 MODULE_ALIAS_FS("befs"); 990 991 static int __init 992 init_befs_fs(void) 993 { 994 int err; 995 996 pr_info("version: %s\n", BEFS_VERSION); 997 998 err = befs_init_inodecache(); 999 if (err) 1000 goto unacquire_none; 1001 1002 err = register_filesystem(&befs_fs_type); 1003 if (err) 1004 goto unacquire_inodecache; 1005 1006 return 0; 1007 1008 unacquire_inodecache: 1009 befs_destroy_inodecache(); 1010 1011 unacquire_none: 1012 return err; 1013 } 1014 1015 static void __exit 1016 exit_befs_fs(void) 1017 { 1018 befs_destroy_inodecache(); 1019 1020 unregister_filesystem(&befs_fs_type); 1021 } 1022 1023 /* 1024 * Macros that typecheck the init and exit functions, 1025 * ensures that they are called at init and cleanup, 1026 * and eliminates warnings about unused functions. 1027 */ 1028 module_init(init_befs_fs) 1029 module_exit(exit_befs_fs) 1030