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/stat.h> 18 #include <linux/nls.h> 19 #include <linux/buffer_head.h> 20 #include <linux/vfs.h> 21 #include <linux/namei.h> 22 #include <linux/sched.h> 23 #include <linux/cred.h> 24 #include <linux/exportfs.h> 25 #include <linux/seq_file.h> 26 #include <linux/blkdev.h> 27 28 #include "befs.h" 29 #include "btree.h" 30 #include "inode.h" 31 #include "datastream.h" 32 #include "super.h" 33 #include "io.h" 34 35 MODULE_DESCRIPTION("BeOS File System (BeFS) driver"); 36 MODULE_AUTHOR("Will Dyson"); 37 MODULE_LICENSE("GPL"); 38 39 /* The units the vfs expects inode->i_blocks to be in */ 40 #define VFS_BLOCK_SIZE 512 41 42 static int befs_readdir(struct file *, struct dir_context *); 43 static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int); 44 static int befs_read_folio(struct file *file, struct folio *folio); 45 static sector_t befs_bmap(struct address_space *mapping, sector_t block); 46 static struct dentry *befs_lookup(struct inode *, struct dentry *, 47 unsigned int); 48 static struct inode *befs_iget(struct super_block *, unsigned long); 49 static struct inode *befs_alloc_inode(struct super_block *sb); 50 static void befs_free_inode(struct inode *inode); 51 static void befs_destroy_inodecache(void); 52 static int befs_symlink_read_folio(struct file *, struct folio *); 53 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len, 54 char **out, int *out_len); 55 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len, 56 char **out, int *out_len); 57 static void befs_put_super(struct super_block *); 58 static int befs_statfs(struct dentry *, struct kstatfs *); 59 static int befs_show_options(struct seq_file *, struct dentry *); 60 static struct dentry *befs_fh_to_dentry(struct super_block *sb, 61 struct fid *fid, int fh_len, int fh_type); 62 static struct dentry *befs_fh_to_parent(struct super_block *sb, 63 struct fid *fid, int fh_len, int fh_type); 64 static struct dentry *befs_get_parent(struct dentry *child); 65 static void befs_free_fc(struct fs_context *fc); 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 .show_options = befs_show_options, 73 }; 74 75 /* slab cache for befs_inode_info objects */ 76 static struct kmem_cache *befs_inode_cachep; 77 78 static const struct file_operations befs_dir_operations = { 79 .read = generic_read_dir, 80 .iterate_shared = befs_readdir, 81 .llseek = generic_file_llseek, 82 }; 83 84 static const struct inode_operations befs_dir_inode_operations = { 85 .lookup = befs_lookup, 86 }; 87 88 static const struct address_space_operations befs_aops = { 89 .read_folio = befs_read_folio, 90 .bmap = befs_bmap, 91 }; 92 93 static const struct address_space_operations befs_symlink_aops = { 94 .read_folio = befs_symlink_read_folio, 95 }; 96 97 static const struct export_operations befs_export_operations = { 98 .encode_fh = generic_encode_ino32_fh, 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_set_mtime(inode, 364 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16, 365 0);/* lower 16 bits are not a time */ 366 inode_set_ctime_to_ts(inode, inode_get_mtime(inode)); 367 inode_set_atime_to_ts(inode, inode_get_mtime(inode)); 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_ACCOUNT, 438 offsetof(struct befs_inode_info, 439 i_data.symlink), 440 sizeof_field(struct befs_inode_info, 441 i_data.symlink), 442 init_once); 443 if (befs_inode_cachep == NULL) 444 return -ENOMEM; 445 446 return 0; 447 } 448 449 /* Called at fs teardown. 450 * 451 * Taken from NFS implementation by Al Viro. 452 */ 453 static void 454 befs_destroy_inodecache(void) 455 { 456 /* 457 * Make sure all delayed rcu free inodes are flushed before we 458 * destroy cache. 459 */ 460 rcu_barrier(); 461 kmem_cache_destroy(befs_inode_cachep); 462 } 463 464 /* 465 * The inode of symbolic link is different to data stream. 466 * The data stream become link name. Unless the LONG_SYMLINK 467 * flag is set. 468 */ 469 static int befs_symlink_read_folio(struct file *unused, struct folio *folio) 470 { 471 struct inode *inode = folio->mapping->host; 472 struct super_block *sb = inode->i_sb; 473 struct befs_inode_info *befs_ino = BEFS_I(inode); 474 befs_data_stream *data = &befs_ino->i_data.ds; 475 befs_off_t len = data->size; 476 char *link = folio_address(folio); 477 int err = -EIO; 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 err = 0; 491 fail: 492 folio_end_read(folio, err == 0); 493 return err; 494 } 495 496 /* 497 * UTF-8 to NLS charset convert routine 498 * 499 * Uses uni2char() / char2uni() rather than the nls tables directly 500 */ 501 static int 502 befs_utf2nls(struct super_block *sb, const char *in, 503 int in_len, char **out, int *out_len) 504 { 505 struct nls_table *nls = BEFS_SB(sb)->nls; 506 int i, o; 507 unicode_t uni; 508 int unilen, utflen; 509 char *result; 510 /* The utf8->nls conversion won't make the final nls string bigger 511 * than the utf one, but if the string is pure ascii they'll have the 512 * same width and an extra char is needed to save the additional \0 513 */ 514 int maxlen = in_len + 1; 515 516 befs_debug(sb, "---> %s", __func__); 517 518 if (!nls) { 519 befs_error(sb, "%s called with no NLS table loaded", __func__); 520 return -EINVAL; 521 } 522 523 *out = result = kmalloc(maxlen, GFP_NOFS); 524 if (!*out) 525 return -ENOMEM; 526 527 for (i = o = 0; i < in_len; i += utflen, o += unilen) { 528 529 /* convert from UTF-8 to Unicode */ 530 utflen = utf8_to_utf32(&in[i], in_len - i, &uni); 531 if (utflen < 0) 532 goto conv_err; 533 534 /* convert from Unicode to nls */ 535 if (uni > MAX_WCHAR_T) 536 goto conv_err; 537 unilen = nls->uni2char(uni, &result[o], in_len - o); 538 if (unilen < 0) 539 goto conv_err; 540 } 541 result[o] = '\0'; 542 *out_len = o; 543 544 befs_debug(sb, "<--- %s", __func__); 545 546 return o; 547 548 conv_err: 549 befs_error(sb, "Name using character set %s contains a character that " 550 "cannot be converted to unicode.", nls->charset); 551 befs_debug(sb, "<--- %s", __func__); 552 kfree(result); 553 return -EILSEQ; 554 } 555 556 /** 557 * befs_nls2utf - Convert NLS string to utf8 encodeing 558 * @sb: Superblock 559 * @in: Input string buffer in NLS format 560 * @in_len: Length of input string in bytes 561 * @out: The output string in UTF-8 format 562 * @out_len: Length of the output buffer 563 * 564 * Converts input string @in, which is in the format of the loaded NLS map, 565 * into a utf8 string. 566 * 567 * The destination string @out is allocated by this function and the caller is 568 * responsible for freeing it with kfree() 569 * 570 * On return, *@out_len is the length of @out in bytes. 571 * 572 * On success, the return value is the number of utf8 characters written to 573 * the output buffer @out. 574 * 575 * On Failure, a negative number coresponding to the error code is returned. 576 */ 577 578 static int 579 befs_nls2utf(struct super_block *sb, const char *in, 580 int in_len, char **out, int *out_len) 581 { 582 struct nls_table *nls = BEFS_SB(sb)->nls; 583 int i, o; 584 wchar_t uni; 585 int unilen, utflen; 586 char *result; 587 /* 588 * There are nls characters that will translate to 3-chars-wide UTF-8 589 * characters, an additional byte is needed to save the final \0 590 * in special cases 591 */ 592 int maxlen = (3 * in_len) + 1; 593 594 befs_debug(sb, "---> %s\n", __func__); 595 596 if (!nls) { 597 befs_error(sb, "%s called with no NLS table loaded.", 598 __func__); 599 return -EINVAL; 600 } 601 602 *out = result = kmalloc(maxlen, GFP_NOFS); 603 if (!*out) { 604 *out_len = 0; 605 return -ENOMEM; 606 } 607 608 for (i = o = 0; i < in_len; i += unilen, o += utflen) { 609 610 /* convert from nls to unicode */ 611 unilen = nls->char2uni(&in[i], in_len - i, &uni); 612 if (unilen < 0) 613 goto conv_err; 614 615 /* convert from unicode to UTF-8 */ 616 utflen = utf32_to_utf8(uni, &result[o], 3); 617 if (utflen <= 0) 618 goto conv_err; 619 } 620 621 result[o] = '\0'; 622 *out_len = o; 623 624 befs_debug(sb, "<--- %s", __func__); 625 626 return i; 627 628 conv_err: 629 befs_error(sb, "Name using character set %s contains a character that " 630 "cannot be converted to unicode.", nls->charset); 631 befs_debug(sb, "<--- %s", __func__); 632 kfree(result); 633 return -EILSEQ; 634 } 635 636 static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino, 637 uint32_t generation) 638 { 639 /* No need to handle i_generation */ 640 return befs_iget(sb, ino); 641 } 642 643 /* 644 * Map a NFS file handle to a corresponding dentry 645 */ 646 static struct dentry *befs_fh_to_dentry(struct super_block *sb, 647 struct fid *fid, int fh_len, int fh_type) 648 { 649 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 650 befs_nfs_get_inode); 651 } 652 653 /* 654 * Find the parent for a file specified by NFS handle 655 */ 656 static struct dentry *befs_fh_to_parent(struct super_block *sb, 657 struct fid *fid, int fh_len, int fh_type) 658 { 659 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 660 befs_nfs_get_inode); 661 } 662 663 static struct dentry *befs_get_parent(struct dentry *child) 664 { 665 struct inode *parent; 666 struct befs_inode_info *befs_ino = BEFS_I(d_inode(child)); 667 668 parent = befs_iget(child->d_sb, 669 (unsigned long)befs_ino->i_parent.start); 670 return d_obtain_alias(parent); 671 } 672 673 enum { 674 Opt_uid, Opt_gid, Opt_charset, Opt_debug, 675 }; 676 677 static const struct fs_parameter_spec befs_param_spec[] = { 678 fsparam_uid ("uid", Opt_uid), 679 fsparam_gid ("gid", Opt_gid), 680 fsparam_string ("iocharset", Opt_charset), 681 fsparam_flag ("debug", Opt_debug), 682 {} 683 }; 684 685 static int 686 befs_parse_param(struct fs_context *fc, struct fs_parameter *param) 687 { 688 struct befs_mount_options *opts = fc->fs_private; 689 int token; 690 struct fs_parse_result result; 691 692 /* befs ignores all options on remount */ 693 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) 694 return 0; 695 696 token = fs_parse(fc, befs_param_spec, param, &result); 697 if (token < 0) 698 return token; 699 700 switch (token) { 701 case Opt_uid: 702 opts->uid = result.uid; 703 opts->use_uid = 1; 704 break; 705 case Opt_gid: 706 opts->gid = result.gid; 707 opts->use_gid = 1; 708 break; 709 case Opt_charset: 710 kfree(opts->iocharset); 711 opts->iocharset = param->string; 712 param->string = NULL; 713 break; 714 case Opt_debug: 715 opts->debug = 1; 716 break; 717 default: 718 return -EINVAL; 719 } 720 return 0; 721 } 722 723 static int befs_show_options(struct seq_file *m, struct dentry *root) 724 { 725 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb); 726 struct befs_mount_options *opts = &befs_sb->mount_opts; 727 728 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) 729 seq_printf(m, ",uid=%u", 730 from_kuid_munged(&init_user_ns, opts->uid)); 731 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) 732 seq_printf(m, ",gid=%u", 733 from_kgid_munged(&init_user_ns, opts->gid)); 734 if (opts->iocharset) 735 seq_printf(m, ",charset=%s", opts->iocharset); 736 if (opts->debug) 737 seq_puts(m, ",debug"); 738 return 0; 739 } 740 741 /* This function has the responsibiltiy of getting the 742 * filesystem ready for unmounting. 743 * Basically, we free everything that we allocated in 744 * befs_read_inode 745 */ 746 static void 747 befs_put_super(struct super_block *sb) 748 { 749 kfree(BEFS_SB(sb)->mount_opts.iocharset); 750 BEFS_SB(sb)->mount_opts.iocharset = NULL; 751 unload_nls(BEFS_SB(sb)->nls); 752 kfree(sb->s_fs_info); 753 sb->s_fs_info = NULL; 754 } 755 756 /* 757 * Copy the parsed options into the sbi mount_options member 758 */ 759 static void 760 befs_set_options(struct befs_sb_info *sbi, struct befs_mount_options *opts) 761 { 762 sbi->mount_opts.uid = opts->uid; 763 sbi->mount_opts.gid = opts->gid; 764 sbi->mount_opts.use_uid = opts->use_uid; 765 sbi->mount_opts.use_gid = opts->use_gid; 766 sbi->mount_opts.debug = opts->debug; 767 sbi->mount_opts.iocharset = opts->iocharset; 768 opts->iocharset = NULL; 769 } 770 771 /* Allocate private field of the superblock, fill it. 772 * 773 * Finish filling the public superblock fields 774 * Make the root directory 775 * Load a set of NLS translations if needed. 776 */ 777 static int 778 befs_fill_super(struct super_block *sb, struct fs_context *fc) 779 { 780 struct buffer_head *bh; 781 struct befs_sb_info *befs_sb; 782 befs_super_block *disk_sb; 783 struct inode *root; 784 long ret = -EINVAL; 785 const unsigned long sb_block = 0; 786 const off_t x86_sb_off = 512; 787 int blocksize; 788 struct befs_mount_options *parsed_opts = fc->fs_private; 789 int silent = fc->sb_flags & SB_SILENT; 790 791 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL); 792 if (sb->s_fs_info == NULL) 793 goto unacquire_none; 794 795 befs_sb = BEFS_SB(sb); 796 797 befs_set_options(befs_sb, parsed_opts); 798 799 befs_debug(sb, "---> %s", __func__); 800 801 if (!sb_rdonly(sb)) { 802 befs_warning(sb, 803 "No write support. Marking filesystem read-only"); 804 sb->s_flags |= SB_RDONLY; 805 } 806 807 /* 808 * Set dummy blocksize to read super block. 809 * Will be set to real fs blocksize later. 810 * 811 * Linux 2.4.10 and later refuse to read blocks smaller than 812 * the logical block size for the device. But we also need to read at 813 * least 1k to get the second 512 bytes of the volume. 814 */ 815 blocksize = sb_min_blocksize(sb, 1024); 816 if (!blocksize) { 817 if (!silent) 818 befs_error(sb, "unable to set blocksize"); 819 goto unacquire_priv_sbp; 820 } 821 822 bh = sb_bread(sb, sb_block); 823 if (!bh) { 824 if (!silent) 825 befs_error(sb, "unable to read superblock"); 826 goto unacquire_priv_sbp; 827 } 828 829 /* account for offset of super block on x86 */ 830 disk_sb = (befs_super_block *) bh->b_data; 831 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) || 832 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) { 833 befs_debug(sb, "Using PPC superblock location"); 834 } else { 835 befs_debug(sb, "Using x86 superblock location"); 836 disk_sb = 837 (befs_super_block *) ((void *) bh->b_data + x86_sb_off); 838 } 839 840 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) || 841 (befs_check_sb(sb) != BEFS_OK)) 842 goto unacquire_bh; 843 844 befs_dump_super_block(sb, disk_sb); 845 846 brelse(bh); 847 848 if (befs_sb->num_blocks > ~((sector_t)0)) { 849 if (!silent) 850 befs_error(sb, "blocks count: %llu is larger than the host can use", 851 befs_sb->num_blocks); 852 goto unacquire_priv_sbp; 853 } 854 855 /* 856 * set up enough so that it can read an inode 857 * Fill in kernel superblock fields from private sb 858 */ 859 sb->s_magic = BEFS_SUPER_MAGIC; 860 /* Set real blocksize of fs */ 861 sb_set_blocksize(sb, (ulong) befs_sb->block_size); 862 sb->s_op = &befs_sops; 863 sb->s_export_op = &befs_export_operations; 864 sb->s_time_min = 0; 865 sb->s_time_max = 0xffffffffffffll; 866 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir))); 867 if (IS_ERR(root)) { 868 ret = PTR_ERR(root); 869 goto unacquire_priv_sbp; 870 } 871 sb->s_root = d_make_root(root); 872 if (!sb->s_root) { 873 if (!silent) 874 befs_error(sb, "get root inode failed"); 875 goto unacquire_priv_sbp; 876 } 877 878 /* load nls library */ 879 if (befs_sb->mount_opts.iocharset) { 880 befs_debug(sb, "Loading nls: %s", 881 befs_sb->mount_opts.iocharset); 882 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset); 883 if (!befs_sb->nls) { 884 befs_warning(sb, "Cannot load nls %s" 885 " loading default nls", 886 befs_sb->mount_opts.iocharset); 887 befs_sb->nls = load_nls_default(); 888 } 889 /* load default nls if none is specified in mount options */ 890 } else { 891 befs_debug(sb, "Loading default nls"); 892 befs_sb->nls = load_nls_default(); 893 } 894 895 return 0; 896 897 unacquire_bh: 898 brelse(bh); 899 900 unacquire_priv_sbp: 901 kfree(befs_sb->mount_opts.iocharset); 902 kfree(sb->s_fs_info); 903 sb->s_fs_info = NULL; 904 905 unacquire_none: 906 return ret; 907 } 908 909 static int 910 befs_reconfigure(struct fs_context *fc) 911 { 912 sync_filesystem(fc->root->d_sb); 913 if (!(fc->sb_flags & SB_RDONLY)) 914 return -EINVAL; 915 return 0; 916 } 917 918 static int 919 befs_statfs(struct dentry *dentry, struct kstatfs *buf) 920 { 921 struct super_block *sb = dentry->d_sb; 922 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 923 924 befs_debug(sb, "---> %s", __func__); 925 926 buf->f_type = BEFS_SUPER_MAGIC; 927 buf->f_bsize = sb->s_blocksize; 928 buf->f_blocks = BEFS_SB(sb)->num_blocks; 929 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks; 930 buf->f_bavail = buf->f_bfree; 931 buf->f_files = 0; /* UNKNOWN */ 932 buf->f_ffree = 0; /* UNKNOWN */ 933 buf->f_fsid = u64_to_fsid(id); 934 buf->f_namelen = BEFS_NAME_LEN; 935 936 befs_debug(sb, "<--- %s", __func__); 937 938 return 0; 939 } 940 941 static int befs_get_tree(struct fs_context *fc) 942 { 943 return get_tree_bdev(fc, befs_fill_super); 944 } 945 946 static const struct fs_context_operations befs_context_ops = { 947 .parse_param = befs_parse_param, 948 .get_tree = befs_get_tree, 949 .reconfigure = befs_reconfigure, 950 .free = befs_free_fc, 951 }; 952 953 static int befs_init_fs_context(struct fs_context *fc) 954 { 955 struct befs_mount_options *opts; 956 957 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 958 if (!opts) 959 return -ENOMEM; 960 961 /* Initialize options */ 962 opts->uid = GLOBAL_ROOT_UID; 963 opts->gid = GLOBAL_ROOT_GID; 964 965 fc->fs_private = opts; 966 fc->ops = &befs_context_ops; 967 968 return 0; 969 } 970 971 static void befs_free_fc(struct fs_context *fc) 972 { 973 struct befs_mount_options *opts = fc->fs_private; 974 975 kfree(opts->iocharset); 976 kfree(fc->fs_private); 977 } 978 979 static struct file_system_type befs_fs_type = { 980 .owner = THIS_MODULE, 981 .name = "befs", 982 .kill_sb = kill_block_super, 983 .fs_flags = FS_REQUIRES_DEV, 984 .init_fs_context = befs_init_fs_context, 985 .parameters = befs_param_spec, 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