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