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/fs_context.h> 15 #include <linux/fs_parser.h> 16 #include <linux/errno.h> 17 #include <linux/filelock.h> 18 #include <linux/stat.h> 19 #include <linux/nls.h> 20 #include <linux/buffer_head.h> 21 #include <linux/vfs.h> 22 #include <linux/namei.h> 23 #include <linux/sched.h> 24 #include <linux/cred.h> 25 #include <linux/exportfs.h> 26 #include <linux/seq_file.h> 27 #include <linux/blkdev.h> 28 29 #include "befs.h" 30 #include "btree.h" 31 #include "inode.h" 32 #include "datastream.h" 33 #include "super.h" 34 #include "io.h" 35 36 MODULE_DESCRIPTION("BeOS File System (BeFS) driver"); 37 MODULE_AUTHOR("Will Dyson"); 38 MODULE_LICENSE("GPL"); 39 40 /* The units the vfs expects inode->i_blocks to be in */ 41 #define VFS_BLOCK_SIZE 512 42 43 static int befs_readdir(struct file *, struct dir_context *); 44 static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int); 45 static int befs_read_folio(struct file *file, struct folio *folio); 46 static sector_t befs_bmap(struct address_space *mapping, sector_t block); 47 static struct dentry *befs_lookup(struct inode *, struct dentry *, 48 unsigned int); 49 static struct inode *befs_iget(struct super_block *, unsigned long); 50 static struct inode *befs_alloc_inode(struct super_block *sb); 51 static void befs_free_inode(struct inode *inode); 52 static void befs_destroy_inodecache(void); 53 static int befs_symlink_read_folio(struct file *, struct folio *); 54 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len, 55 char **out, int *out_len); 56 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len, 57 char **out, int *out_len); 58 static void befs_put_super(struct super_block *); 59 static int befs_statfs(struct dentry *, struct kstatfs *); 60 static int befs_show_options(struct seq_file *, struct dentry *); 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 static void befs_free_fc(struct fs_context *fc); 67 68 static const struct super_operations befs_sops = { 69 .alloc_inode = befs_alloc_inode, /* allocate a new inode */ 70 .free_inode = befs_free_inode, /* deallocate an inode */ 71 .put_super = befs_put_super, /* uninit super */ 72 .statfs = befs_statfs, /* statfs */ 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 .setlease = generic_setlease, 84 }; 85 86 static const struct inode_operations befs_dir_inode_operations = { 87 .lookup = befs_lookup, 88 }; 89 90 static const struct address_space_operations befs_aops = { 91 .read_folio = befs_read_folio, 92 .bmap = befs_bmap, 93 }; 94 95 static const struct address_space_operations befs_symlink_aops = { 96 .read_folio = befs_symlink_read_folio, 97 }; 98 99 static const struct export_operations befs_export_operations = { 100 .encode_fh = generic_encode_ino32_fh, 101 .fh_to_dentry = befs_fh_to_dentry, 102 .fh_to_parent = befs_fh_to_parent, 103 .get_parent = befs_get_parent, 104 }; 105 106 /* 107 * Called by generic_file_read() to read a folio of data 108 * 109 * In turn, simply calls a generic block read function and 110 * passes it the address of befs_get_block, for mapping file 111 * positions to disk blocks. 112 */ 113 static int befs_read_folio(struct file *file, struct folio *folio) 114 { 115 return block_read_full_folio(folio, befs_get_block); 116 } 117 118 static sector_t 119 befs_bmap(struct address_space *mapping, sector_t block) 120 { 121 return generic_block_bmap(mapping, block, befs_get_block); 122 } 123 124 /* 125 * Generic function to map a file position (block) to a 126 * disk offset (passed back in bh_result). 127 * 128 * Used by many higher level functions. 129 * 130 * Calls befs_fblock2brun() in datastream.c to do the real work. 131 */ 132 133 static int 134 befs_get_block(struct inode *inode, sector_t block, 135 struct buffer_head *bh_result, int create) 136 { 137 struct super_block *sb = inode->i_sb; 138 befs_data_stream *ds = &BEFS_I(inode)->i_data.ds; 139 befs_block_run run = BAD_IADDR; 140 int res; 141 ulong disk_off; 142 143 befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld", 144 (unsigned long)inode->i_ino, (long)block); 145 if (create) { 146 befs_error(sb, "befs_get_block() was asked to write to " 147 "block %ld in inode %lu", (long)block, 148 (unsigned long)inode->i_ino); 149 return -EPERM; 150 } 151 152 res = befs_fblock2brun(sb, ds, block, &run); 153 if (res != BEFS_OK) { 154 befs_error(sb, 155 "<--- %s for inode %lu, block %ld ERROR", 156 __func__, (unsigned long)inode->i_ino, 157 (long)block); 158 return -EFBIG; 159 } 160 161 disk_off = (ulong) iaddr2blockno(sb, &run); 162 163 map_bh(bh_result, inode->i_sb, disk_off); 164 165 befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu", 166 __func__, (unsigned long)inode->i_ino, (long)block, 167 (unsigned long)disk_off); 168 169 return 0; 170 } 171 172 static struct dentry * 173 befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 174 { 175 struct inode *inode; 176 struct super_block *sb = dir->i_sb; 177 const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds; 178 befs_off_t offset; 179 int ret; 180 int utfnamelen; 181 char *utfname; 182 const char *name = dentry->d_name.name; 183 184 befs_debug(sb, "---> %s name %pd inode %ld", __func__, 185 dentry, dir->i_ino); 186 187 /* Convert to UTF-8 */ 188 if (BEFS_SB(sb)->nls) { 189 ret = 190 befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen); 191 if (ret < 0) { 192 befs_debug(sb, "<--- %s ERROR", __func__); 193 return ERR_PTR(ret); 194 } 195 ret = befs_btree_find(sb, ds, utfname, &offset); 196 kfree(utfname); 197 198 } else { 199 ret = befs_btree_find(sb, ds, name, &offset); 200 } 201 202 if (ret == BEFS_BT_NOT_FOUND) { 203 befs_debug(sb, "<--- %s %pd not found", __func__, dentry); 204 inode = NULL; 205 } else if (ret != BEFS_OK || offset == 0) { 206 befs_error(sb, "<--- %s Error", __func__); 207 inode = ERR_PTR(-ENODATA); 208 } else { 209 inode = befs_iget(dir->i_sb, (ino_t) offset); 210 } 211 befs_debug(sb, "<--- %s", __func__); 212 213 return d_splice_alias(inode, dentry); 214 } 215 216 static int 217 befs_readdir(struct file *file, struct dir_context *ctx) 218 { 219 struct inode *inode = file_inode(file); 220 struct super_block *sb = inode->i_sb; 221 const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds; 222 befs_off_t value; 223 int result; 224 size_t keysize; 225 char keybuf[BEFS_NAME_LEN + 1]; 226 227 befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld", 228 __func__, file, inode->i_ino, ctx->pos); 229 230 while (1) { 231 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1, 232 keybuf, &keysize, &value); 233 234 if (result == BEFS_ERR) { 235 befs_debug(sb, "<--- %s ERROR", __func__); 236 befs_error(sb, "IO error reading %pD (inode %lu)", 237 file, inode->i_ino); 238 return -EIO; 239 240 } else if (result == BEFS_BT_END) { 241 befs_debug(sb, "<--- %s END", __func__); 242 return 0; 243 244 } else if (result == BEFS_BT_EMPTY) { 245 befs_debug(sb, "<--- %s Empty directory", __func__); 246 return 0; 247 } 248 249 /* Convert to NLS */ 250 if (BEFS_SB(sb)->nls) { 251 char *nlsname; 252 int nlsnamelen; 253 254 result = 255 befs_utf2nls(sb, keybuf, keysize, &nlsname, 256 &nlsnamelen); 257 if (result < 0) { 258 befs_debug(sb, "<--- %s ERROR", __func__); 259 return result; 260 } 261 if (!dir_emit(ctx, nlsname, nlsnamelen, 262 (ino_t) value, DT_UNKNOWN)) { 263 kfree(nlsname); 264 return 0; 265 } 266 kfree(nlsname); 267 } else { 268 if (!dir_emit(ctx, keybuf, keysize, 269 (ino_t) value, DT_UNKNOWN)) 270 return 0; 271 } 272 ctx->pos++; 273 } 274 } 275 276 static struct inode * 277 befs_alloc_inode(struct super_block *sb) 278 { 279 struct befs_inode_info *bi; 280 281 bi = alloc_inode_sb(sb, befs_inode_cachep, GFP_KERNEL); 282 if (!bi) 283 return NULL; 284 return &bi->vfs_inode; 285 } 286 287 static void befs_free_inode(struct inode *inode) 288 { 289 kmem_cache_free(befs_inode_cachep, BEFS_I(inode)); 290 } 291 292 static void init_once(void *foo) 293 { 294 struct befs_inode_info *bi = (struct befs_inode_info *) foo; 295 296 inode_init_once(&bi->vfs_inode); 297 } 298 299 static struct inode *befs_iget(struct super_block *sb, unsigned long ino) 300 { 301 struct buffer_head *bh; 302 befs_inode *raw_inode; 303 struct befs_sb_info *befs_sb = BEFS_SB(sb); 304 struct befs_inode_info *befs_ino; 305 struct inode *inode; 306 307 befs_debug(sb, "---> %s inode = %lu", __func__, ino); 308 309 inode = iget_locked(sb, ino); 310 if (!inode) 311 return ERR_PTR(-ENOMEM); 312 if (!(inode_state_read_once(inode) & I_NEW)) 313 return inode; 314 315 befs_ino = BEFS_I(inode); 316 317 /* convert from vfs's inode number to befs's inode number */ 318 befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino); 319 320 befs_debug(sb, " real inode number [%u, %hu, %hu]", 321 befs_ino->i_inode_num.allocation_group, 322 befs_ino->i_inode_num.start, befs_ino->i_inode_num.len); 323 324 bh = sb_bread(sb, inode->i_ino); 325 if (!bh) { 326 befs_error(sb, "unable to read inode block - " 327 "inode = %lu", inode->i_ino); 328 goto unacquire_none; 329 } 330 331 raw_inode = (befs_inode *) bh->b_data; 332 333 befs_dump_inode(sb, raw_inode); 334 335 if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) { 336 befs_error(sb, "Bad inode: %lu", inode->i_ino); 337 goto unacquire_bh; 338 } 339 340 inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode); 341 342 /* 343 * set uid and gid. But since current BeOS is single user OS, so 344 * you can change by "uid" or "gid" options. 345 */ 346 347 inode->i_uid = befs_sb->mount_opts.use_uid ? 348 befs_sb->mount_opts.uid : 349 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid)); 350 inode->i_gid = befs_sb->mount_opts.use_gid ? 351 befs_sb->mount_opts.gid : 352 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid)); 353 354 set_nlink(inode, 1); 355 356 /* 357 * BEFS's time is 64 bits, but current VFS is 32 bits... 358 * BEFS don't have access time. Nor inode change time. VFS 359 * doesn't have creation time. 360 * Also, the lower 16 bits of the last_modified_time and 361 * create_time are just a counter to help ensure uniqueness 362 * for indexing purposes. (PFD, page 54) 363 */ 364 365 inode_set_mtime(inode, 366 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16, 367 0);/* lower 16 bits are not a time */ 368 inode_set_ctime_to_ts(inode, inode_get_mtime(inode)); 369 inode_set_atime_to_ts(inode, inode_get_mtime(inode)); 370 371 befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num); 372 befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent); 373 befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes); 374 befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags); 375 376 if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){ 377 inode->i_size = 0; 378 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE; 379 strscpy(befs_ino->i_data.symlink, raw_inode->data.symlink, 380 BEFS_SYMLINK_LEN); 381 } else { 382 int num_blks; 383 384 befs_ino->i_data.ds = 385 fsds_to_cpu(sb, &raw_inode->data.datastream); 386 387 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds); 388 inode->i_blocks = 389 num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE); 390 inode->i_size = befs_ino->i_data.ds.size; 391 } 392 393 inode->i_mapping->a_ops = &befs_aops; 394 395 if (S_ISREG(inode->i_mode)) { 396 inode->i_fop = &generic_ro_fops; 397 } else if (S_ISDIR(inode->i_mode)) { 398 inode->i_op = &befs_dir_inode_operations; 399 inode->i_fop = &befs_dir_operations; 400 } else if (S_ISLNK(inode->i_mode)) { 401 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) { 402 inode->i_op = &page_symlink_inode_operations; 403 inode_nohighmem(inode); 404 inode->i_mapping->a_ops = &befs_symlink_aops; 405 } else { 406 inode->i_link = befs_ino->i_data.symlink; 407 inode->i_op = &simple_symlink_inode_operations; 408 } 409 } else { 410 befs_error(sb, "Inode %lu is not a regular file, " 411 "directory or symlink. THAT IS WRONG! BeFS has no " 412 "on disk special files", inode->i_ino); 413 goto unacquire_bh; 414 } 415 416 brelse(bh); 417 befs_debug(sb, "<--- %s", __func__); 418 unlock_new_inode(inode); 419 return inode; 420 421 unacquire_bh: 422 brelse(bh); 423 424 unacquire_none: 425 iget_failed(inode); 426 befs_debug(sb, "<--- %s - Bad inode", __func__); 427 return ERR_PTR(-EIO); 428 } 429 430 /* Initialize the inode cache. Called at fs setup. 431 * 432 * Taken from NFS implementation by Al Viro. 433 */ 434 static int __init 435 befs_init_inodecache(void) 436 { 437 befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache", 438 sizeof(struct befs_inode_info), 0, 439 SLAB_RECLAIM_ACCOUNT | 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 inode *inode = folio->mapping->host; 474 struct super_block *sb = inode->i_sb; 475 struct befs_inode_info *befs_ino = BEFS_I(inode); 476 befs_data_stream *data = &befs_ino->i_data.ds; 477 befs_off_t len = data->size; 478 char *link = folio_address(folio); 479 int err = -EIO; 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 err = 0; 493 fail: 494 folio_end_read(folio, err == 0); 495 return err; 496 } 497 498 /* 499 * UTF-8 to NLS charset convert routine 500 * 501 * Uses uni2char() / char2uni() rather than the nls tables directly 502 */ 503 static int 504 befs_utf2nls(struct super_block *sb, const char *in, 505 int in_len, char **out, int *out_len) 506 { 507 struct nls_table *nls = BEFS_SB(sb)->nls; 508 int i, o; 509 unicode_t uni; 510 int unilen, utflen; 511 char *result; 512 /* The utf8->nls conversion won't make the final nls string bigger 513 * than the utf one, but if the string is pure ascii they'll have the 514 * same width and an extra char is needed to save the additional \0 515 */ 516 int maxlen = in_len + 1; 517 518 befs_debug(sb, "---> %s", __func__); 519 520 if (!nls) { 521 befs_error(sb, "%s called with no NLS table loaded", __func__); 522 return -EINVAL; 523 } 524 525 *out = result = kmalloc(maxlen, GFP_NOFS); 526 if (!*out) 527 return -ENOMEM; 528 529 for (i = o = 0; i < in_len; i += utflen, o += unilen) { 530 531 /* convert from UTF-8 to Unicode */ 532 utflen = utf8_to_utf32(&in[i], in_len - i, &uni); 533 if (utflen < 0) 534 goto conv_err; 535 536 /* convert from Unicode to nls */ 537 if (uni > MAX_WCHAR_T) 538 goto conv_err; 539 unilen = nls->uni2char(uni, &result[o], in_len - o); 540 if (unilen < 0) 541 goto conv_err; 542 } 543 result[o] = '\0'; 544 *out_len = o; 545 546 befs_debug(sb, "<--- %s", __func__); 547 548 return o; 549 550 conv_err: 551 befs_error(sb, "Name using character set %s contains a character that " 552 "cannot be converted to unicode.", nls->charset); 553 befs_debug(sb, "<--- %s", __func__); 554 kfree(result); 555 return -EILSEQ; 556 } 557 558 /** 559 * befs_nls2utf - Convert NLS string to utf8 encodeing 560 * @sb: Superblock 561 * @in: Input string buffer in NLS format 562 * @in_len: Length of input string in bytes 563 * @out: The output string in UTF-8 format 564 * @out_len: Length of the output buffer 565 * 566 * Converts input string @in, which is in the format of the loaded NLS map, 567 * into a utf8 string. 568 * 569 * The destination string @out is allocated by this function and the caller is 570 * responsible for freeing it with kfree() 571 * 572 * On return, *@out_len is the length of @out in bytes. 573 * 574 * On success, the return value is the number of utf8 characters written to 575 * the output buffer @out. 576 * 577 * On Failure, a negative number coresponding to the error code is returned. 578 */ 579 580 static int 581 befs_nls2utf(struct super_block *sb, const char *in, 582 int in_len, char **out, int *out_len) 583 { 584 struct nls_table *nls = BEFS_SB(sb)->nls; 585 int i, o; 586 wchar_t uni; 587 int unilen, utflen; 588 char *result; 589 /* 590 * There are nls characters that will translate to 3-chars-wide UTF-8 591 * characters, an additional byte is needed to save the final \0 592 * in special cases 593 */ 594 int maxlen = (3 * in_len) + 1; 595 596 befs_debug(sb, "---> %s\n", __func__); 597 598 if (!nls) { 599 befs_error(sb, "%s called with no NLS table loaded.", 600 __func__); 601 return -EINVAL; 602 } 603 604 *out = result = kmalloc(maxlen, GFP_NOFS); 605 if (!*out) { 606 *out_len = 0; 607 return -ENOMEM; 608 } 609 610 for (i = o = 0; i < in_len; i += unilen, o += utflen) { 611 612 /* convert from nls to unicode */ 613 unilen = nls->char2uni(&in[i], in_len - i, &uni); 614 if (unilen < 0) 615 goto conv_err; 616 617 /* convert from unicode to UTF-8 */ 618 utflen = utf32_to_utf8(uni, &result[o], 3); 619 if (utflen <= 0) 620 goto conv_err; 621 } 622 623 result[o] = '\0'; 624 *out_len = o; 625 626 befs_debug(sb, "<--- %s", __func__); 627 628 return i; 629 630 conv_err: 631 befs_error(sb, "Name using character set %s contains a character that " 632 "cannot be converted to unicode.", nls->charset); 633 befs_debug(sb, "<--- %s", __func__); 634 kfree(result); 635 return -EILSEQ; 636 } 637 638 static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino, 639 uint32_t generation) 640 { 641 /* No need to handle i_generation */ 642 return befs_iget(sb, ino); 643 } 644 645 /* 646 * Map a NFS file handle to a corresponding dentry 647 */ 648 static struct dentry *befs_fh_to_dentry(struct super_block *sb, 649 struct fid *fid, int fh_len, int fh_type) 650 { 651 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 652 befs_nfs_get_inode); 653 } 654 655 /* 656 * Find the parent for a file specified by NFS handle 657 */ 658 static struct dentry *befs_fh_to_parent(struct super_block *sb, 659 struct fid *fid, int fh_len, int fh_type) 660 { 661 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 662 befs_nfs_get_inode); 663 } 664 665 static struct dentry *befs_get_parent(struct dentry *child) 666 { 667 struct inode *parent; 668 struct befs_inode_info *befs_ino = BEFS_I(d_inode(child)); 669 670 parent = befs_iget(child->d_sb, 671 (unsigned long)befs_ino->i_parent.start); 672 return d_obtain_alias(parent); 673 } 674 675 enum { 676 Opt_uid, Opt_gid, Opt_charset, Opt_debug, 677 }; 678 679 static const struct fs_parameter_spec befs_param_spec[] = { 680 fsparam_uid ("uid", Opt_uid), 681 fsparam_gid ("gid", Opt_gid), 682 fsparam_string ("iocharset", Opt_charset), 683 fsparam_flag ("debug", Opt_debug), 684 {} 685 }; 686 687 static int 688 befs_parse_param(struct fs_context *fc, struct fs_parameter *param) 689 { 690 struct befs_mount_options *opts = fc->fs_private; 691 int token; 692 struct fs_parse_result result; 693 694 /* befs ignores all options on remount */ 695 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) 696 return 0; 697 698 token = fs_parse(fc, befs_param_spec, param, &result); 699 if (token < 0) 700 return token; 701 702 switch (token) { 703 case Opt_uid: 704 opts->uid = result.uid; 705 opts->use_uid = 1; 706 break; 707 case Opt_gid: 708 opts->gid = result.gid; 709 opts->use_gid = 1; 710 break; 711 case Opt_charset: 712 kfree(opts->iocharset); 713 opts->iocharset = param->string; 714 param->string = NULL; 715 break; 716 case Opt_debug: 717 opts->debug = 1; 718 break; 719 default: 720 return -EINVAL; 721 } 722 return 0; 723 } 724 725 static int befs_show_options(struct seq_file *m, struct dentry *root) 726 { 727 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb); 728 struct befs_mount_options *opts = &befs_sb->mount_opts; 729 730 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) 731 seq_printf(m, ",uid=%u", 732 from_kuid_munged(&init_user_ns, opts->uid)); 733 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) 734 seq_printf(m, ",gid=%u", 735 from_kgid_munged(&init_user_ns, opts->gid)); 736 if (opts->iocharset) 737 seq_printf(m, ",charset=%s", opts->iocharset); 738 if (opts->debug) 739 seq_puts(m, ",debug"); 740 return 0; 741 } 742 743 /* This function has the responsibiltiy of getting the 744 * filesystem ready for unmounting. 745 * Basically, we free everything that we allocated in 746 * befs_read_inode 747 */ 748 static void 749 befs_put_super(struct super_block *sb) 750 { 751 kfree(BEFS_SB(sb)->mount_opts.iocharset); 752 BEFS_SB(sb)->mount_opts.iocharset = NULL; 753 unload_nls(BEFS_SB(sb)->nls); 754 kfree(sb->s_fs_info); 755 sb->s_fs_info = NULL; 756 } 757 758 /* 759 * Copy the parsed options into the sbi mount_options member 760 */ 761 static void 762 befs_set_options(struct befs_sb_info *sbi, struct befs_mount_options *opts) 763 { 764 sbi->mount_opts.uid = opts->uid; 765 sbi->mount_opts.gid = opts->gid; 766 sbi->mount_opts.use_uid = opts->use_uid; 767 sbi->mount_opts.use_gid = opts->use_gid; 768 sbi->mount_opts.debug = opts->debug; 769 sbi->mount_opts.iocharset = opts->iocharset; 770 opts->iocharset = NULL; 771 } 772 773 /* Allocate private field of the superblock, fill it. 774 * 775 * Finish filling the public superblock fields 776 * Make the root directory 777 * Load a set of NLS translations if needed. 778 */ 779 static int 780 befs_fill_super(struct super_block *sb, struct fs_context *fc) 781 { 782 struct buffer_head *bh; 783 struct befs_sb_info *befs_sb; 784 befs_super_block *disk_sb; 785 struct inode *root; 786 long ret = -EINVAL; 787 const unsigned long sb_block = 0; 788 const off_t x86_sb_off = 512; 789 int blocksize; 790 struct befs_mount_options *parsed_opts = fc->fs_private; 791 int silent = fc->sb_flags & SB_SILENT; 792 793 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL); 794 if (sb->s_fs_info == NULL) 795 goto unacquire_none; 796 797 befs_sb = BEFS_SB(sb); 798 799 befs_set_options(befs_sb, parsed_opts); 800 801 befs_debug(sb, "---> %s", __func__); 802 803 if (!sb_rdonly(sb)) { 804 befs_warning(sb, 805 "No write support. Marking filesystem read-only"); 806 sb->s_flags |= SB_RDONLY; 807 } 808 809 /* 810 * Set dummy blocksize to read super block. 811 * Will be set to real fs blocksize later. 812 * 813 * Linux 2.4.10 and later refuse to read blocks smaller than 814 * the logical block size for the device. But we also need to read at 815 * least 1k to get the second 512 bytes of the volume. 816 */ 817 blocksize = sb_min_blocksize(sb, 1024); 818 if (!blocksize) { 819 if (!silent) 820 befs_error(sb, "unable to set blocksize"); 821 goto unacquire_priv_sbp; 822 } 823 824 bh = sb_bread(sb, sb_block); 825 if (!bh) { 826 if (!silent) 827 befs_error(sb, "unable to read superblock"); 828 goto unacquire_priv_sbp; 829 } 830 831 /* account for offset of super block on x86 */ 832 disk_sb = (befs_super_block *) bh->b_data; 833 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) || 834 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) { 835 befs_debug(sb, "Using PPC superblock location"); 836 } else { 837 befs_debug(sb, "Using x86 superblock location"); 838 disk_sb = 839 (befs_super_block *) ((void *) bh->b_data + x86_sb_off); 840 } 841 842 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) || 843 (befs_check_sb(sb) != BEFS_OK)) 844 goto unacquire_bh; 845 846 befs_dump_super_block(sb, disk_sb); 847 848 brelse(bh); 849 850 if (befs_sb->num_blocks > ~((sector_t)0)) { 851 if (!silent) 852 befs_error(sb, "blocks count: %llu is larger than the host can use", 853 befs_sb->num_blocks); 854 goto unacquire_priv_sbp; 855 } 856 857 /* 858 * set up enough so that it can read an inode 859 * Fill in kernel superblock fields from private sb 860 */ 861 sb->s_magic = BEFS_SUPER_MAGIC; 862 /* Set real blocksize of fs */ 863 sb_set_blocksize(sb, (ulong) befs_sb->block_size); 864 sb->s_op = &befs_sops; 865 sb->s_export_op = &befs_export_operations; 866 sb->s_time_min = 0; 867 sb->s_time_max = 0xffffffffffffll; 868 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir))); 869 if (IS_ERR(root)) { 870 ret = PTR_ERR(root); 871 goto unacquire_priv_sbp; 872 } 873 sb->s_root = d_make_root(root); 874 if (!sb->s_root) { 875 if (!silent) 876 befs_error(sb, "get root inode failed"); 877 goto unacquire_priv_sbp; 878 } 879 880 /* load nls library */ 881 if (befs_sb->mount_opts.iocharset) { 882 befs_debug(sb, "Loading nls: %s", 883 befs_sb->mount_opts.iocharset); 884 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset); 885 if (!befs_sb->nls) { 886 befs_warning(sb, "Cannot load nls %s" 887 " loading default nls", 888 befs_sb->mount_opts.iocharset); 889 befs_sb->nls = load_nls_default(); 890 } 891 /* load default nls if none is specified in mount options */ 892 } else { 893 befs_debug(sb, "Loading default nls"); 894 befs_sb->nls = load_nls_default(); 895 } 896 897 return 0; 898 899 unacquire_bh: 900 brelse(bh); 901 902 unacquire_priv_sbp: 903 kfree(befs_sb->mount_opts.iocharset); 904 kfree(sb->s_fs_info); 905 sb->s_fs_info = NULL; 906 907 unacquire_none: 908 return ret; 909 } 910 911 static int 912 befs_reconfigure(struct fs_context *fc) 913 { 914 sync_filesystem(fc->root->d_sb); 915 if (!(fc->sb_flags & SB_RDONLY)) 916 return -EINVAL; 917 return 0; 918 } 919 920 static int 921 befs_statfs(struct dentry *dentry, struct kstatfs *buf) 922 { 923 struct super_block *sb = dentry->d_sb; 924 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 925 926 befs_debug(sb, "---> %s", __func__); 927 928 buf->f_type = BEFS_SUPER_MAGIC; 929 buf->f_bsize = sb->s_blocksize; 930 buf->f_blocks = BEFS_SB(sb)->num_blocks; 931 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks; 932 buf->f_bavail = buf->f_bfree; 933 buf->f_files = 0; /* UNKNOWN */ 934 buf->f_ffree = 0; /* UNKNOWN */ 935 buf->f_fsid = u64_to_fsid(id); 936 buf->f_namelen = BEFS_NAME_LEN; 937 938 befs_debug(sb, "<--- %s", __func__); 939 940 return 0; 941 } 942 943 static int befs_get_tree(struct fs_context *fc) 944 { 945 return get_tree_bdev(fc, befs_fill_super); 946 } 947 948 static const struct fs_context_operations befs_context_ops = { 949 .parse_param = befs_parse_param, 950 .get_tree = befs_get_tree, 951 .reconfigure = befs_reconfigure, 952 .free = befs_free_fc, 953 }; 954 955 static int befs_init_fs_context(struct fs_context *fc) 956 { 957 struct befs_mount_options *opts; 958 959 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 960 if (!opts) 961 return -ENOMEM; 962 963 /* Initialize options */ 964 opts->uid = GLOBAL_ROOT_UID; 965 opts->gid = GLOBAL_ROOT_GID; 966 967 fc->fs_private = opts; 968 fc->ops = &befs_context_ops; 969 970 return 0; 971 } 972 973 static void befs_free_fc(struct fs_context *fc) 974 { 975 struct befs_mount_options *opts = fc->fs_private; 976 977 kfree(opts->iocharset); 978 kfree(fc->fs_private); 979 } 980 981 static struct file_system_type befs_fs_type = { 982 .owner = THIS_MODULE, 983 .name = "befs", 984 .kill_sb = kill_block_super, 985 .fs_flags = FS_REQUIRES_DEV, 986 .init_fs_context = befs_init_fs_context, 987 .parameters = befs_param_spec, 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