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 34MODULE_DESCRIPTION("BeOS File System (BeFS) driver"); 35MODULE_AUTHOR("Will Dyson"); 36MODULE_LICENSE("GPL"); 37 38/* The units the vfs expects inode->i_blocks to be in */ 39#define VFS_BLOCK_SIZE 512 40 41static int befs_readdir(struct file *, struct dir_context *); 42static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int); 43static int befs_read_folio(struct file *file, struct folio *folio); 44static sector_t befs_bmap(struct address_space *mapping, sector_t block); 45static struct dentry *befs_lookup(struct inode *, struct dentry *, 46 unsigned int); 47static struct inode *befs_iget(struct super_block *, unsigned long); 48static struct inode *befs_alloc_inode(struct super_block *sb); 49static void befs_free_inode(struct inode *inode); 50static void befs_destroy_inodecache(void); 51static int befs_symlink_read_folio(struct file *, struct folio *); 52static int befs_utf2nls(struct super_block *sb, const char *in, int in_len, 53 char **out, int *out_len); 54static int befs_nls2utf(struct super_block *sb, const char *in, int in_len, 55 char **out, int *out_len); 56static void befs_put_super(struct super_block *); 57static int befs_remount(struct super_block *, int *, char *); 58static int befs_statfs(struct dentry *, struct kstatfs *); 59static int befs_show_options(struct seq_file *, struct dentry *); 60static int parse_options(char *, struct befs_mount_options *); 61static struct dentry *befs_fh_to_dentry(struct super_block *sb, 62 struct fid *fid, int fh_len, int fh_type); 63static struct dentry *befs_fh_to_parent(struct super_block *sb, 64 struct fid *fid, int fh_len, int fh_type); 65static struct dentry *befs_get_parent(struct dentry *child); 66 67static 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 */ 77static struct kmem_cache *befs_inode_cachep; 78 79static const struct file_operations befs_dir_operations = { 80 .read = generic_read_dir, 81 .iterate_shared = befs_readdir, 82 .llseek = generic_file_llseek, 83}; 84 85static const struct inode_operations befs_dir_inode_operations = { 86 .lookup = befs_lookup, 87}; 88 89static const struct address_space_operations befs_aops = { 90 .read_folio = befs_read_folio, 91 .bmap = befs_bmap, 92}; 93 94static const struct address_space_operations befs_symlink_aops = { 95 .read_folio = befs_symlink_read_folio, 96}; 97 98static const struct export_operations befs_export_operations = { 99 .encode_fh = generic_encode_ino32_fh, 100 .fh_to_dentry = befs_fh_to_dentry, 101 .fh_to_parent = befs_fh_to_parent, 102 .get_parent = befs_get_parent, 103}; 104 105/* 106 * Called by generic_file_read() to read a folio of data 107 * 108 * In turn, simply calls a generic block read function and 109 * passes it the address of befs_get_block, for mapping file 110 * positions to disk blocks. 111 */ 112static int befs_read_folio(struct file *file, struct folio *folio) 113{ 114 return block_read_full_folio(folio, befs_get_block); 115} 116 117static sector_t 118befs_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 132static int 133befs_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 171static struct dentry * 172befs_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 215static int 216befs_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 275static struct inode * 276befs_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 286static void befs_free_inode(struct inode *inode) 287{ 288 kmem_cache_free(befs_inode_cachep, BEFS_I(inode)); 289} 290 291static 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 298static 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_set_mtime(inode, 365 fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16, 366 0);/* lower 16 bits are not a time */ 367 inode_set_ctime_to_ts(inode, inode_get_mtime(inode)); 368 inode_set_atime_to_ts(inode, inode_get_mtime(inode)); 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 strscpy(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 420unacquire_bh: 421 brelse(bh); 422 423unacquire_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 */ 433static int __init 434befs_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_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 */ 454static void 455befs_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 */ 470static 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; 493fail: 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 */ 504static int 505befs_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 551conv_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 581static int 582befs_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 631conv_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 639static 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 */ 649static 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 */ 659static 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 666static 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 return d_obtain_alias(parent); 674} 675 676enum { 677 Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err, 678}; 679 680static const match_table_t befs_tokens = { 681 {Opt_uid, "uid=%d"}, 682 {Opt_gid, "gid=%d"}, 683 {Opt_charset, "iocharset=%s"}, 684 {Opt_debug, "debug"}, 685 {Opt_err, NULL} 686}; 687 688static int 689parse_options(char *options, struct befs_mount_options *opts) 690{ 691 char *p; 692 substring_t args[MAX_OPT_ARGS]; 693 int option; 694 kuid_t uid; 695 kgid_t gid; 696 697 /* Initialize options */ 698 opts->uid = GLOBAL_ROOT_UID; 699 opts->gid = GLOBAL_ROOT_GID; 700 opts->use_uid = 0; 701 opts->use_gid = 0; 702 opts->iocharset = NULL; 703 opts->debug = 0; 704 705 if (!options) 706 return 1; 707 708 while ((p = strsep(&options, ",")) != NULL) { 709 int token; 710 711 if (!*p) 712 continue; 713 714 token = match_token(p, befs_tokens, args); 715 switch (token) { 716 case Opt_uid: 717 if (match_int(&args[0], &option)) 718 return 0; 719 uid = INVALID_UID; 720 if (option >= 0) 721 uid = make_kuid(current_user_ns(), option); 722 if (!uid_valid(uid)) { 723 pr_err("Invalid uid %d, " 724 "using default\n", option); 725 break; 726 } 727 opts->uid = uid; 728 opts->use_uid = 1; 729 break; 730 case Opt_gid: 731 if (match_int(&args[0], &option)) 732 return 0; 733 gid = INVALID_GID; 734 if (option >= 0) 735 gid = make_kgid(current_user_ns(), option); 736 if (!gid_valid(gid)) { 737 pr_err("Invalid gid %d, " 738 "using default\n", option); 739 break; 740 } 741 opts->gid = gid; 742 opts->use_gid = 1; 743 break; 744 case Opt_charset: 745 kfree(opts->iocharset); 746 opts->iocharset = match_strdup(&args[0]); 747 if (!opts->iocharset) { 748 pr_err("allocation failure for " 749 "iocharset string\n"); 750 return 0; 751 } 752 break; 753 case Opt_debug: 754 opts->debug = 1; 755 break; 756 default: 757 pr_err("Unrecognized mount option \"%s\" " 758 "or missing value\n", p); 759 return 0; 760 } 761 } 762 return 1; 763} 764 765static int befs_show_options(struct seq_file *m, struct dentry *root) 766{ 767 struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb); 768 struct befs_mount_options *opts = &befs_sb->mount_opts; 769 770 if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) 771 seq_printf(m, ",uid=%u", 772 from_kuid_munged(&init_user_ns, opts->uid)); 773 if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) 774 seq_printf(m, ",gid=%u", 775 from_kgid_munged(&init_user_ns, opts->gid)); 776 if (opts->iocharset) 777 seq_printf(m, ",charset=%s", opts->iocharset); 778 if (opts->debug) 779 seq_puts(m, ",debug"); 780 return 0; 781} 782 783/* This function has the responsibiltiy of getting the 784 * filesystem ready for unmounting. 785 * Basically, we free everything that we allocated in 786 * befs_read_inode 787 */ 788static void 789befs_put_super(struct super_block *sb) 790{ 791 kfree(BEFS_SB(sb)->mount_opts.iocharset); 792 BEFS_SB(sb)->mount_opts.iocharset = NULL; 793 unload_nls(BEFS_SB(sb)->nls); 794 kfree(sb->s_fs_info); 795 sb->s_fs_info = NULL; 796} 797 798/* Allocate private field of the superblock, fill it. 799 * 800 * Finish filling the public superblock fields 801 * Make the root directory 802 * Load a set of NLS translations if needed. 803 */ 804static int 805befs_fill_super(struct super_block *sb, void *data, int silent) 806{ 807 struct buffer_head *bh; 808 struct befs_sb_info *befs_sb; 809 befs_super_block *disk_sb; 810 struct inode *root; 811 long ret = -EINVAL; 812 const unsigned long sb_block = 0; 813 const off_t x86_sb_off = 512; 814 int blocksize; 815 816 sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL); 817 if (sb->s_fs_info == NULL) 818 goto unacquire_none; 819 820 befs_sb = BEFS_SB(sb); 821 822 if (!parse_options((char *) data, &befs_sb->mount_opts)) { 823 if (!silent) 824 befs_error(sb, "cannot parse mount options"); 825 goto unacquire_priv_sbp; 826 } 827 828 befs_debug(sb, "---> %s", __func__); 829 830 if (!sb_rdonly(sb)) { 831 befs_warning(sb, 832 "No write support. Marking filesystem read-only"); 833 sb->s_flags |= SB_RDONLY; 834 } 835 836 /* 837 * Set dummy blocksize to read super block. 838 * Will be set to real fs blocksize later. 839 * 840 * Linux 2.4.10 and later refuse to read blocks smaller than 841 * the logical block size for the device. But we also need to read at 842 * least 1k to get the second 512 bytes of the volume. 843 */ 844 blocksize = sb_min_blocksize(sb, 1024); 845 if (!blocksize) { 846 if (!silent) 847 befs_error(sb, "unable to set blocksize"); 848 goto unacquire_priv_sbp; 849 } 850 851 bh = sb_bread(sb, sb_block); 852 if (!bh) { 853 if (!silent) 854 befs_error(sb, "unable to read superblock"); 855 goto unacquire_priv_sbp; 856 } 857 858 /* account for offset of super block on x86 */ 859 disk_sb = (befs_super_block *) bh->b_data; 860 if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) || 861 (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) { 862 befs_debug(sb, "Using PPC superblock location"); 863 } else { 864 befs_debug(sb, "Using x86 superblock location"); 865 disk_sb = 866 (befs_super_block *) ((void *) bh->b_data + x86_sb_off); 867 } 868 869 if ((befs_load_sb(sb, disk_sb) != BEFS_OK) || 870 (befs_check_sb(sb) != BEFS_OK)) 871 goto unacquire_bh; 872 873 befs_dump_super_block(sb, disk_sb); 874 875 brelse(bh); 876 877 if (befs_sb->num_blocks > ~((sector_t)0)) { 878 if (!silent) 879 befs_error(sb, "blocks count: %llu is larger than the host can use", 880 befs_sb->num_blocks); 881 goto unacquire_priv_sbp; 882 } 883 884 /* 885 * set up enough so that it can read an inode 886 * Fill in kernel superblock fields from private sb 887 */ 888 sb->s_magic = BEFS_SUPER_MAGIC; 889 /* Set real blocksize of fs */ 890 sb_set_blocksize(sb, (ulong) befs_sb->block_size); 891 sb->s_op = &befs_sops; 892 sb->s_export_op = &befs_export_operations; 893 sb->s_time_min = 0; 894 sb->s_time_max = 0xffffffffffffll; 895 root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir))); 896 if (IS_ERR(root)) { 897 ret = PTR_ERR(root); 898 goto unacquire_priv_sbp; 899 } 900 sb->s_root = d_make_root(root); 901 if (!sb->s_root) { 902 if (!silent) 903 befs_error(sb, "get root inode failed"); 904 goto unacquire_priv_sbp; 905 } 906 907 /* load nls library */ 908 if (befs_sb->mount_opts.iocharset) { 909 befs_debug(sb, "Loading nls: %s", 910 befs_sb->mount_opts.iocharset); 911 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset); 912 if (!befs_sb->nls) { 913 befs_warning(sb, "Cannot load nls %s" 914 " loading default nls", 915 befs_sb->mount_opts.iocharset); 916 befs_sb->nls = load_nls_default(); 917 } 918 /* load default nls if none is specified in mount options */ 919 } else { 920 befs_debug(sb, "Loading default nls"); 921 befs_sb->nls = load_nls_default(); 922 } 923 924 return 0; 925 926unacquire_bh: 927 brelse(bh); 928 929unacquire_priv_sbp: 930 kfree(befs_sb->mount_opts.iocharset); 931 kfree(sb->s_fs_info); 932 sb->s_fs_info = NULL; 933 934unacquire_none: 935 return ret; 936} 937 938static int 939befs_remount(struct super_block *sb, int *flags, char *data) 940{ 941 sync_filesystem(sb); 942 if (!(*flags & SB_RDONLY)) 943 return -EINVAL; 944 return 0; 945} 946 947static int 948befs_statfs(struct dentry *dentry, struct kstatfs *buf) 949{ 950 struct super_block *sb = dentry->d_sb; 951 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 952 953 befs_debug(sb, "---> %s", __func__); 954 955 buf->f_type = BEFS_SUPER_MAGIC; 956 buf->f_bsize = sb->s_blocksize; 957 buf->f_blocks = BEFS_SB(sb)->num_blocks; 958 buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks; 959 buf->f_bavail = buf->f_bfree; 960 buf->f_files = 0; /* UNKNOWN */ 961 buf->f_ffree = 0; /* UNKNOWN */ 962 buf->f_fsid = u64_to_fsid(id); 963 buf->f_namelen = BEFS_NAME_LEN; 964 965 befs_debug(sb, "<--- %s", __func__); 966 967 return 0; 968} 969 970static struct dentry * 971befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, 972 void *data) 973{ 974 return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super); 975} 976 977static struct file_system_type befs_fs_type = { 978 .owner = THIS_MODULE, 979 .name = "befs", 980 .mount = befs_mount, 981 .kill_sb = kill_block_super, 982 .fs_flags = FS_REQUIRES_DEV, 983}; 984MODULE_ALIAS_FS("befs"); 985 986static int __init 987init_befs_fs(void) 988{ 989 int err; 990 991 pr_info("version: %s\n", BEFS_VERSION); 992 993 err = befs_init_inodecache(); 994 if (err) 995 goto unacquire_none; 996 997 err = register_filesystem(&befs_fs_type); 998 if (err) 999 goto unacquire_inodecache; 1000 1001 return 0; 1002 1003unacquire_inodecache: 1004 befs_destroy_inodecache(); 1005 1006unacquire_none: 1007 return err; 1008} 1009 1010static void __exit 1011exit_befs_fs(void) 1012{ 1013 befs_destroy_inodecache(); 1014 1015 unregister_filesystem(&befs_fs_type); 1016} 1017 1018/* 1019 * Macros that typecheck the init and exit functions, 1020 * ensures that they are called at init and cleanup, 1021 * and eliminates warnings about unused functions. 1022 */ 1023module_init(init_befs_fs) 1024module_exit(exit_befs_fs) 1025