1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. 4 */ 5 6 #include <linux/fs_context.h> 7 #include <linux/fs_parser.h> 8 #include <linux/module.h> 9 #include <linux/init.h> 10 #include <linux/time.h> 11 #include <linux/mount.h> 12 #include <linux/cred.h> 13 #include <linux/statfs.h> 14 #include <linux/seq_file.h> 15 #include <linux/blkdev.h> 16 #include <linux/fs_struct.h> 17 #include <linux/iversion.h> 18 #include <linux/nls.h> 19 #include <linux/buffer_head.h> 20 #include <linux/magic.h> 21 22 #include "exfat_raw.h" 23 #include "exfat_fs.h" 24 25 static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET; 26 static struct kmem_cache *exfat_inode_cachep; 27 28 static void exfat_free_iocharset(struct exfat_sb_info *sbi) 29 { 30 if (sbi->options.iocharset != exfat_default_iocharset) 31 kfree(sbi->options.iocharset); 32 } 33 34 static void exfat_put_super(struct super_block *sb) 35 { 36 struct exfat_sb_info *sbi = EXFAT_SB(sb); 37 38 mutex_lock(&sbi->s_lock); 39 exfat_clear_volume_dirty(sb); 40 exfat_free_bitmap(sbi); 41 brelse(sbi->boot_bh); 42 mutex_unlock(&sbi->s_lock); 43 } 44 45 static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf) 46 { 47 struct super_block *sb = dentry->d_sb; 48 struct exfat_sb_info *sbi = EXFAT_SB(sb); 49 unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev); 50 51 buf->f_type = sb->s_magic; 52 buf->f_bsize = sbi->cluster_size; 53 buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */ 54 buf->f_bfree = buf->f_blocks - sbi->used_clusters; 55 buf->f_bavail = buf->f_bfree; 56 buf->f_fsid = u64_to_fsid(id); 57 /* Unicode utf16 255 characters */ 58 buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE; 59 return 0; 60 } 61 62 static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags) 63 { 64 struct exfat_sb_info *sbi = EXFAT_SB(sb); 65 struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data; 66 67 /* retain persistent-flags */ 68 new_flags |= sbi->vol_flags_persistent; 69 70 /* flags are not changed */ 71 if (sbi->vol_flags == new_flags) 72 return 0; 73 74 sbi->vol_flags = new_flags; 75 76 /* skip updating volume dirty flag, 77 * if this volume has been mounted with read-only 78 */ 79 if (sb_rdonly(sb)) 80 return 0; 81 82 p_boot->vol_flags = cpu_to_le16(new_flags); 83 84 set_buffer_uptodate(sbi->boot_bh); 85 mark_buffer_dirty(sbi->boot_bh); 86 87 __sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH); 88 89 return 0; 90 } 91 92 int exfat_set_volume_dirty(struct super_block *sb) 93 { 94 struct exfat_sb_info *sbi = EXFAT_SB(sb); 95 96 return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY); 97 } 98 99 int exfat_clear_volume_dirty(struct super_block *sb) 100 { 101 struct exfat_sb_info *sbi = EXFAT_SB(sb); 102 103 return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY); 104 } 105 106 static int exfat_show_options(struct seq_file *m, struct dentry *root) 107 { 108 struct super_block *sb = root->d_sb; 109 struct exfat_sb_info *sbi = EXFAT_SB(sb); 110 struct exfat_mount_options *opts = &sbi->options; 111 112 /* Show partition info */ 113 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 114 seq_printf(m, ",uid=%u", 115 from_kuid_munged(&init_user_ns, opts->fs_uid)); 116 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 117 seq_printf(m, ",gid=%u", 118 from_kgid_munged(&init_user_ns, opts->fs_gid)); 119 seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask); 120 if (opts->allow_utime) 121 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 122 if (opts->utf8) 123 seq_puts(m, ",iocharset=utf8"); 124 else if (sbi->nls_io) 125 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 126 if (opts->errors == EXFAT_ERRORS_CONT) 127 seq_puts(m, ",errors=continue"); 128 else if (opts->errors == EXFAT_ERRORS_PANIC) 129 seq_puts(m, ",errors=panic"); 130 else 131 seq_puts(m, ",errors=remount-ro"); 132 if (opts->discard) 133 seq_puts(m, ",discard"); 134 if (opts->keep_last_dots) 135 seq_puts(m, ",keep_last_dots"); 136 if (opts->sys_tz) 137 seq_puts(m, ",sys_tz"); 138 else if (opts->time_offset) 139 seq_printf(m, ",time_offset=%d", opts->time_offset); 140 if (opts->zero_size_dir) 141 seq_puts(m, ",zero_size_dir"); 142 return 0; 143 } 144 145 int exfat_force_shutdown(struct super_block *sb, u32 flags) 146 { 147 int ret; 148 struct exfat_sb_info *sbi = sb->s_fs_info; 149 struct exfat_mount_options *opts = &sbi->options; 150 151 if (exfat_forced_shutdown(sb)) 152 return 0; 153 154 switch (flags) { 155 case EXFAT_GOING_DOWN_DEFAULT: 156 case EXFAT_GOING_DOWN_FULLSYNC: 157 ret = bdev_freeze(sb->s_bdev); 158 if (ret) 159 return ret; 160 bdev_thaw(sb->s_bdev); 161 set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags); 162 break; 163 case EXFAT_GOING_DOWN_NOSYNC: 164 set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags); 165 break; 166 default: 167 return -EINVAL; 168 } 169 170 if (opts->discard) 171 opts->discard = 0; 172 return 0; 173 } 174 175 static void exfat_shutdown(struct super_block *sb) 176 { 177 exfat_force_shutdown(sb, EXFAT_GOING_DOWN_NOSYNC); 178 } 179 180 static struct inode *exfat_alloc_inode(struct super_block *sb) 181 { 182 struct exfat_inode_info *ei; 183 184 ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS); 185 if (!ei) 186 return NULL; 187 188 init_rwsem(&ei->truncate_lock); 189 return &ei->vfs_inode; 190 } 191 192 static void exfat_free_inode(struct inode *inode) 193 { 194 kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode)); 195 } 196 197 static const struct super_operations exfat_sops = { 198 .alloc_inode = exfat_alloc_inode, 199 .free_inode = exfat_free_inode, 200 .write_inode = exfat_write_inode, 201 .evict_inode = exfat_evict_inode, 202 .put_super = exfat_put_super, 203 .statfs = exfat_statfs, 204 .show_options = exfat_show_options, 205 .shutdown = exfat_shutdown, 206 }; 207 208 enum { 209 Opt_uid, 210 Opt_gid, 211 Opt_umask, 212 Opt_dmask, 213 Opt_fmask, 214 Opt_allow_utime, 215 Opt_charset, 216 Opt_errors, 217 Opt_discard, 218 Opt_keep_last_dots, 219 Opt_sys_tz, 220 Opt_time_offset, 221 Opt_zero_size_dir, 222 223 /* Deprecated options */ 224 Opt_utf8, 225 Opt_debug, 226 Opt_namecase, 227 Opt_codepage, 228 }; 229 230 static const struct constant_table exfat_param_enums[] = { 231 { "continue", EXFAT_ERRORS_CONT }, 232 { "panic", EXFAT_ERRORS_PANIC }, 233 { "remount-ro", EXFAT_ERRORS_RO }, 234 {} 235 }; 236 237 static const struct fs_parameter_spec exfat_parameters[] = { 238 fsparam_uid("uid", Opt_uid), 239 fsparam_gid("gid", Opt_gid), 240 fsparam_u32oct("umask", Opt_umask), 241 fsparam_u32oct("dmask", Opt_dmask), 242 fsparam_u32oct("fmask", Opt_fmask), 243 fsparam_u32oct("allow_utime", Opt_allow_utime), 244 fsparam_string("iocharset", Opt_charset), 245 fsparam_enum("errors", Opt_errors, exfat_param_enums), 246 fsparam_flag("discard", Opt_discard), 247 fsparam_flag("keep_last_dots", Opt_keep_last_dots), 248 fsparam_flag("sys_tz", Opt_sys_tz), 249 fsparam_s32("time_offset", Opt_time_offset), 250 fsparam_flag("zero_size_dir", Opt_zero_size_dir), 251 __fsparam(NULL, "utf8", Opt_utf8, fs_param_deprecated, 252 NULL), 253 __fsparam(NULL, "debug", Opt_debug, fs_param_deprecated, 254 NULL), 255 __fsparam(fs_param_is_u32, "namecase", Opt_namecase, 256 fs_param_deprecated, NULL), 257 __fsparam(fs_param_is_u32, "codepage", Opt_codepage, 258 fs_param_deprecated, NULL), 259 {} 260 }; 261 262 static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param) 263 { 264 struct exfat_sb_info *sbi = fc->s_fs_info; 265 struct exfat_mount_options *opts = &sbi->options; 266 struct fs_parse_result result; 267 int opt; 268 269 opt = fs_parse(fc, exfat_parameters, param, &result); 270 if (opt < 0) 271 return opt; 272 273 switch (opt) { 274 case Opt_uid: 275 opts->fs_uid = result.uid; 276 break; 277 case Opt_gid: 278 opts->fs_gid = result.gid; 279 break; 280 case Opt_umask: 281 opts->fs_fmask = result.uint_32; 282 opts->fs_dmask = result.uint_32; 283 break; 284 case Opt_dmask: 285 opts->fs_dmask = result.uint_32; 286 break; 287 case Opt_fmask: 288 opts->fs_fmask = result.uint_32; 289 break; 290 case Opt_allow_utime: 291 opts->allow_utime = result.uint_32 & 0022; 292 break; 293 case Opt_charset: 294 exfat_free_iocharset(sbi); 295 opts->iocharset = param->string; 296 param->string = NULL; 297 break; 298 case Opt_errors: 299 opts->errors = result.uint_32; 300 break; 301 case Opt_discard: 302 opts->discard = 1; 303 break; 304 case Opt_keep_last_dots: 305 opts->keep_last_dots = 1; 306 break; 307 case Opt_sys_tz: 308 opts->sys_tz = 1; 309 break; 310 case Opt_time_offset: 311 /* 312 * Make the limit 24 just in case someone invents something 313 * unusual. 314 */ 315 if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60) 316 return -EINVAL; 317 opts->time_offset = result.int_32; 318 break; 319 case Opt_zero_size_dir: 320 opts->zero_size_dir = true; 321 break; 322 case Opt_utf8: 323 case Opt_debug: 324 case Opt_namecase: 325 case Opt_codepage: 326 break; 327 default: 328 return -EINVAL; 329 } 330 331 return 0; 332 } 333 334 static void exfat_hash_init(struct super_block *sb) 335 { 336 struct exfat_sb_info *sbi = EXFAT_SB(sb); 337 int i; 338 339 spin_lock_init(&sbi->inode_hash_lock); 340 for (i = 0; i < EXFAT_HASH_SIZE; i++) 341 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 342 } 343 344 static int exfat_read_root(struct inode *inode, struct exfat_chain *root_clu) 345 { 346 struct super_block *sb = inode->i_sb; 347 struct exfat_sb_info *sbi = EXFAT_SB(sb); 348 struct exfat_inode_info *ei = EXFAT_I(inode); 349 int num_subdirs; 350 351 exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 352 ei->entry = -1; 353 ei->start_clu = sbi->root_dir; 354 ei->flags = ALLOC_FAT_CHAIN; 355 ei->type = TYPE_DIR; 356 ei->version = 0; 357 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 358 ei->hint_stat.eidx = 0; 359 ei->hint_stat.clu = sbi->root_dir; 360 ei->hint_femp.eidx = EXFAT_HINT_NONE; 361 362 i_size_write(inode, EXFAT_CLU_TO_B(root_clu->size, sbi)); 363 364 num_subdirs = exfat_count_dir_entries(sb, root_clu); 365 if (num_subdirs < 0) 366 return -EIO; 367 set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR); 368 369 inode->i_uid = sbi->options.fs_uid; 370 inode->i_gid = sbi->options.fs_gid; 371 inode_inc_iversion(inode); 372 inode->i_generation = 0; 373 inode->i_mode = exfat_make_mode(sbi, EXFAT_ATTR_SUBDIR, 0777); 374 inode->i_op = &exfat_dir_inode_operations; 375 inode->i_fop = &exfat_dir_operations; 376 377 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9; 378 ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff; 379 380 exfat_save_attr(inode, EXFAT_ATTR_SUBDIR); 381 ei->i_crtime = simple_inode_init_ts(inode); 382 exfat_truncate_inode_atime(inode); 383 return 0; 384 } 385 386 static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect) 387 { 388 struct exfat_sb_info *sbi = EXFAT_SB(sb); 389 390 if (!is_power_of_2(logical_sect)) { 391 exfat_err(sb, "bogus logical sector size %u", logical_sect); 392 return -EIO; 393 } 394 395 if (logical_sect < sb->s_blocksize) { 396 exfat_err(sb, "logical sector size too small for device (logical sector size = %u)", 397 logical_sect); 398 return -EIO; 399 } 400 401 if (logical_sect > sb->s_blocksize) { 402 brelse(sbi->boot_bh); 403 sbi->boot_bh = NULL; 404 405 if (!sb_set_blocksize(sb, logical_sect)) { 406 exfat_err(sb, "unable to set blocksize %u", 407 logical_sect); 408 return -EIO; 409 } 410 sbi->boot_bh = sb_bread(sb, 0); 411 if (!sbi->boot_bh) { 412 exfat_err(sb, "unable to read boot sector (logical sector size = %lu)", 413 sb->s_blocksize); 414 return -EIO; 415 } 416 } 417 return 0; 418 } 419 420 static int exfat_read_boot_sector(struct super_block *sb) 421 { 422 struct boot_sector *p_boot; 423 struct exfat_sb_info *sbi = EXFAT_SB(sb); 424 425 /* set block size to read super block */ 426 sb_min_blocksize(sb, 512); 427 428 /* read boot sector */ 429 sbi->boot_bh = sb_bread(sb, 0); 430 if (!sbi->boot_bh) { 431 exfat_err(sb, "unable to read boot sector"); 432 return -EIO; 433 } 434 p_boot = (struct boot_sector *)sbi->boot_bh->b_data; 435 436 /* check the validity of BOOT */ 437 if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) { 438 exfat_err(sb, "invalid boot record signature"); 439 return -EINVAL; 440 } 441 442 if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) { 443 exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */ 444 return -EINVAL; 445 } 446 447 /* 448 * must_be_zero field must be filled with zero to prevent mounting 449 * from FAT volume. 450 */ 451 if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero))) 452 return -EINVAL; 453 454 if (p_boot->num_fats != 1 && p_boot->num_fats != 2) { 455 exfat_err(sb, "bogus number of FAT structure"); 456 return -EINVAL; 457 } 458 459 /* 460 * sect_size_bits could be at least 9 and at most 12. 461 */ 462 if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS || 463 p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) { 464 exfat_err(sb, "bogus sector size bits : %u", 465 p_boot->sect_size_bits); 466 return -EINVAL; 467 } 468 469 /* 470 * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits. 471 */ 472 if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) { 473 exfat_err(sb, "bogus sectors bits per cluster : %u", 474 p_boot->sect_per_clus_bits); 475 return -EINVAL; 476 } 477 478 sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits; 479 sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits; 480 sbi->cluster_size_bits = p_boot->sect_per_clus_bits + 481 p_boot->sect_size_bits; 482 sbi->cluster_size = 1 << sbi->cluster_size_bits; 483 sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length); 484 sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset); 485 sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset); 486 if (p_boot->num_fats == 2) 487 sbi->FAT2_start_sector += sbi->num_FAT_sectors; 488 sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset); 489 sbi->num_sectors = le64_to_cpu(p_boot->vol_length); 490 /* because the cluster index starts with 2 */ 491 sbi->num_clusters = le32_to_cpu(p_boot->clu_count) + 492 EXFAT_RESERVED_CLUSTERS; 493 494 sbi->root_dir = le32_to_cpu(p_boot->root_cluster); 495 sbi->dentries_per_clu = 1 << 496 (sbi->cluster_size_bits - DENTRY_SIZE_BITS); 497 498 sbi->vol_flags = le16_to_cpu(p_boot->vol_flags); 499 sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE); 500 sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER; 501 502 /* check consistencies */ 503 if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits < 504 (u64)sbi->num_clusters * 4) { 505 exfat_err(sb, "bogus fat length"); 506 return -EINVAL; 507 } 508 509 if (sbi->data_start_sector < 510 (u64)sbi->FAT1_start_sector + 511 (u64)sbi->num_FAT_sectors * p_boot->num_fats) { 512 exfat_err(sb, "bogus data start sector"); 513 return -EINVAL; 514 } 515 516 if (sbi->vol_flags & VOLUME_DIRTY) 517 exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck."); 518 if (sbi->vol_flags & MEDIA_FAILURE) 519 exfat_warn(sb, "Medium has reported failures. Some data may be lost."); 520 521 /* exFAT file size is limited by a disk volume size */ 522 sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) << 523 sbi->cluster_size_bits; 524 525 /* check logical sector size */ 526 if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits)) 527 return -EIO; 528 529 return 0; 530 } 531 532 static int exfat_verify_boot_region(struct super_block *sb) 533 { 534 struct buffer_head *bh = NULL; 535 u32 chksum = 0; 536 __le32 *p_sig, *p_chksum; 537 int sn, i; 538 539 /* read boot sector sub-regions */ 540 for (sn = 0; sn < 11; sn++) { 541 bh = sb_bread(sb, sn); 542 if (!bh) 543 return -EIO; 544 545 if (sn != 0 && sn <= 8) { 546 /* extended boot sector sub-regions */ 547 p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4]; 548 if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE) 549 exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x", 550 sn, le32_to_cpu(*p_sig)); 551 } 552 553 chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize, 554 chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR); 555 brelse(bh); 556 } 557 558 /* boot checksum sub-regions */ 559 bh = sb_bread(sb, sn); 560 if (!bh) 561 return -EIO; 562 563 for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) { 564 p_chksum = (__le32 *)&bh->b_data[i]; 565 if (le32_to_cpu(*p_chksum) != chksum) { 566 exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)", 567 le32_to_cpu(*p_chksum), chksum); 568 brelse(bh); 569 return -EINVAL; 570 } 571 } 572 brelse(bh); 573 return 0; 574 } 575 576 /* mount the file system volume */ 577 static int __exfat_fill_super(struct super_block *sb, 578 struct exfat_chain *root_clu) 579 { 580 int ret; 581 struct exfat_sb_info *sbi = EXFAT_SB(sb); 582 583 ret = exfat_read_boot_sector(sb); 584 if (ret) { 585 exfat_err(sb, "failed to read boot sector"); 586 goto free_bh; 587 } 588 589 ret = exfat_verify_boot_region(sb); 590 if (ret) { 591 exfat_err(sb, "invalid boot region"); 592 goto free_bh; 593 } 594 595 /* 596 * Call exfat_count_num_cluster() before searching for up-case and 597 * bitmap directory entries to avoid infinite loop if they are missing 598 * and the cluster chain includes a loop. 599 */ 600 exfat_chain_set(root_clu, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 601 ret = exfat_count_num_clusters(sb, root_clu, &root_clu->size); 602 if (ret) { 603 exfat_err(sb, "failed to count the number of clusters in root"); 604 goto free_bh; 605 } 606 607 ret = exfat_create_upcase_table(sb); 608 if (ret) { 609 exfat_err(sb, "failed to load upcase table"); 610 goto free_bh; 611 } 612 613 ret = exfat_load_bitmap(sb); 614 if (ret) { 615 exfat_err(sb, "failed to load alloc-bitmap"); 616 goto free_bh; 617 } 618 619 ret = exfat_count_used_clusters(sb, &sbi->used_clusters); 620 if (ret) { 621 exfat_err(sb, "failed to scan clusters"); 622 goto free_alloc_bitmap; 623 } 624 625 return 0; 626 627 free_alloc_bitmap: 628 exfat_free_bitmap(sbi); 629 free_bh: 630 brelse(sbi->boot_bh); 631 return ret; 632 } 633 634 static int exfat_fill_super(struct super_block *sb, struct fs_context *fc) 635 { 636 struct exfat_sb_info *sbi = sb->s_fs_info; 637 struct exfat_mount_options *opts = &sbi->options; 638 struct inode *root_inode; 639 struct exfat_chain root_clu; 640 int err; 641 642 if (opts->allow_utime == (unsigned short)-1) 643 opts->allow_utime = ~opts->fs_dmask & 0022; 644 645 if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) { 646 exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard"); 647 opts->discard = 0; 648 } 649 650 sb->s_flags |= SB_NODIRATIME; 651 sb->s_magic = EXFAT_SUPER_MAGIC; 652 sb->s_op = &exfat_sops; 653 654 sb->s_time_gran = 10 * NSEC_PER_MSEC; 655 sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS; 656 sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS; 657 658 err = __exfat_fill_super(sb, &root_clu); 659 if (err) { 660 exfat_err(sb, "failed to recognize exfat type"); 661 goto check_nls_io; 662 } 663 664 /* set up enough so that it can read an inode */ 665 exfat_hash_init(sb); 666 667 if (!strcmp(sbi->options.iocharset, "utf8")) 668 opts->utf8 = 1; 669 else { 670 sbi->nls_io = load_nls(sbi->options.iocharset); 671 if (!sbi->nls_io) { 672 exfat_err(sb, "IO charset %s not found", 673 sbi->options.iocharset); 674 err = -EINVAL; 675 goto free_table; 676 } 677 } 678 679 if (sbi->options.utf8) 680 set_default_d_op(sb, &exfat_utf8_dentry_ops); 681 else 682 set_default_d_op(sb, &exfat_dentry_ops); 683 684 root_inode = new_inode(sb); 685 if (!root_inode) { 686 exfat_err(sb, "failed to allocate root inode"); 687 err = -ENOMEM; 688 goto free_table; 689 } 690 691 root_inode->i_ino = EXFAT_ROOT_INO; 692 inode_set_iversion(root_inode, 1); 693 err = exfat_read_root(root_inode, &root_clu); 694 if (err) { 695 exfat_err(sb, "failed to initialize root inode"); 696 goto put_inode; 697 } 698 699 exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos); 700 insert_inode_hash(root_inode); 701 702 sb->s_root = d_make_root(root_inode); 703 if (!sb->s_root) { 704 exfat_err(sb, "failed to get the root dentry"); 705 err = -ENOMEM; 706 goto free_table; 707 } 708 709 return 0; 710 711 put_inode: 712 iput(root_inode); 713 sb->s_root = NULL; 714 715 free_table: 716 exfat_free_bitmap(sbi); 717 brelse(sbi->boot_bh); 718 719 check_nls_io: 720 return err; 721 } 722 723 static int exfat_get_tree(struct fs_context *fc) 724 { 725 return get_tree_bdev(fc, exfat_fill_super); 726 } 727 728 static void exfat_free_sbi(struct exfat_sb_info *sbi) 729 { 730 exfat_free_iocharset(sbi); 731 kfree(sbi); 732 } 733 734 static void exfat_free(struct fs_context *fc) 735 { 736 struct exfat_sb_info *sbi = fc->s_fs_info; 737 738 if (sbi) 739 exfat_free_sbi(sbi); 740 } 741 742 static int exfat_reconfigure(struct fs_context *fc) 743 { 744 struct super_block *sb = fc->root->d_sb; 745 fc->sb_flags |= SB_NODIRATIME; 746 747 sync_filesystem(sb); 748 mutex_lock(&EXFAT_SB(sb)->s_lock); 749 exfat_clear_volume_dirty(sb); 750 mutex_unlock(&EXFAT_SB(sb)->s_lock); 751 752 return 0; 753 } 754 755 static const struct fs_context_operations exfat_context_ops = { 756 .parse_param = exfat_parse_param, 757 .get_tree = exfat_get_tree, 758 .free = exfat_free, 759 .reconfigure = exfat_reconfigure, 760 }; 761 762 static int exfat_init_fs_context(struct fs_context *fc) 763 { 764 struct exfat_sb_info *sbi; 765 766 sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL); 767 if (!sbi) 768 return -ENOMEM; 769 770 mutex_init(&sbi->s_lock); 771 mutex_init(&sbi->bitmap_lock); 772 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 773 DEFAULT_RATELIMIT_BURST); 774 775 sbi->options.fs_uid = current_uid(); 776 sbi->options.fs_gid = current_gid(); 777 sbi->options.fs_fmask = current->fs->umask; 778 sbi->options.fs_dmask = current->fs->umask; 779 sbi->options.allow_utime = -1; 780 sbi->options.iocharset = exfat_default_iocharset; 781 sbi->options.errors = EXFAT_ERRORS_RO; 782 783 fc->s_fs_info = sbi; 784 fc->ops = &exfat_context_ops; 785 return 0; 786 } 787 788 static void delayed_free(struct rcu_head *p) 789 { 790 struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu); 791 792 unload_nls(sbi->nls_io); 793 exfat_free_upcase_table(sbi); 794 exfat_free_sbi(sbi); 795 } 796 797 static void exfat_kill_sb(struct super_block *sb) 798 { 799 struct exfat_sb_info *sbi = sb->s_fs_info; 800 801 kill_block_super(sb); 802 if (sbi) 803 call_rcu(&sbi->rcu, delayed_free); 804 } 805 806 static struct file_system_type exfat_fs_type = { 807 .owner = THIS_MODULE, 808 .name = "exfat", 809 .init_fs_context = exfat_init_fs_context, 810 .parameters = exfat_parameters, 811 .kill_sb = exfat_kill_sb, 812 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, 813 }; 814 815 static void exfat_inode_init_once(void *foo) 816 { 817 struct exfat_inode_info *ei = (struct exfat_inode_info *)foo; 818 819 spin_lock_init(&ei->cache_lru_lock); 820 ei->nr_caches = 0; 821 ei->cache_valid_id = EXFAT_CACHE_VALID + 1; 822 INIT_LIST_HEAD(&ei->cache_lru); 823 INIT_HLIST_NODE(&ei->i_hash_fat); 824 inode_init_once(&ei->vfs_inode); 825 } 826 827 static int __init init_exfat_fs(void) 828 { 829 int err; 830 831 err = exfat_cache_init(); 832 if (err) 833 return err; 834 835 exfat_inode_cachep = kmem_cache_create("exfat_inode_cache", 836 sizeof(struct exfat_inode_info), 837 0, SLAB_RECLAIM_ACCOUNT, 838 exfat_inode_init_once); 839 if (!exfat_inode_cachep) { 840 err = -ENOMEM; 841 goto shutdown_cache; 842 } 843 844 err = register_filesystem(&exfat_fs_type); 845 if (err) 846 goto destroy_cache; 847 848 return 0; 849 850 destroy_cache: 851 kmem_cache_destroy(exfat_inode_cachep); 852 shutdown_cache: 853 exfat_cache_shutdown(); 854 return err; 855 } 856 857 static void __exit exit_exfat_fs(void) 858 { 859 /* 860 * Make sure all delayed rcu free inodes are flushed before we 861 * destroy cache. 862 */ 863 rcu_barrier(); 864 kmem_cache_destroy(exfat_inode_cachep); 865 unregister_filesystem(&exfat_fs_type); 866 exfat_cache_shutdown(); 867 } 868 869 module_init(init_exfat_fs); 870 module_exit(exit_exfat_fs); 871 872 MODULE_ALIAS_FS("exfat"); 873 MODULE_LICENSE("GPL"); 874 MODULE_DESCRIPTION("exFAT filesystem support"); 875 MODULE_AUTHOR("Samsung Electronics Co., Ltd."); 876