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_free_bitmap(sbi); 40 brelse(sbi->boot_bh); 41 mutex_unlock(&sbi->s_lock); 42 } 43 44 static int exfat_sync_fs(struct super_block *sb, int wait) 45 { 46 struct exfat_sb_info *sbi = EXFAT_SB(sb); 47 int err = 0; 48 49 if (unlikely(exfat_forced_shutdown(sb))) 50 return 0; 51 52 if (!wait) 53 return 0; 54 55 /* If there are some dirty buffers in the bdev inode */ 56 mutex_lock(&sbi->s_lock); 57 sync_blockdev(sb->s_bdev); 58 if (exfat_clear_volume_dirty(sb)) 59 err = -EIO; 60 mutex_unlock(&sbi->s_lock); 61 return err; 62 } 63 64 static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf) 65 { 66 struct super_block *sb = dentry->d_sb; 67 struct exfat_sb_info *sbi = EXFAT_SB(sb); 68 unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev); 69 70 if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) { 71 mutex_lock(&sbi->s_lock); 72 if (exfat_count_used_clusters(sb, &sbi->used_clusters)) { 73 mutex_unlock(&sbi->s_lock); 74 return -EIO; 75 } 76 mutex_unlock(&sbi->s_lock); 77 } 78 79 buf->f_type = sb->s_magic; 80 buf->f_bsize = sbi->cluster_size; 81 buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */ 82 buf->f_bfree = buf->f_blocks - sbi->used_clusters; 83 buf->f_bavail = buf->f_bfree; 84 buf->f_fsid = u64_to_fsid(id); 85 /* Unicode utf16 255 characters */ 86 buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE; 87 return 0; 88 } 89 90 static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags) 91 { 92 struct exfat_sb_info *sbi = EXFAT_SB(sb); 93 struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data; 94 95 /* retain persistent-flags */ 96 new_flags |= sbi->vol_flags_persistent; 97 98 /* flags are not changed */ 99 if (sbi->vol_flags == new_flags) 100 return 0; 101 102 sbi->vol_flags = new_flags; 103 104 /* skip updating volume dirty flag, 105 * if this volume has been mounted with read-only 106 */ 107 if (sb_rdonly(sb)) 108 return 0; 109 110 p_boot->vol_flags = cpu_to_le16(new_flags); 111 112 set_buffer_uptodate(sbi->boot_bh); 113 mark_buffer_dirty(sbi->boot_bh); 114 115 __sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH); 116 117 return 0; 118 } 119 120 int exfat_set_volume_dirty(struct super_block *sb) 121 { 122 struct exfat_sb_info *sbi = EXFAT_SB(sb); 123 124 return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY); 125 } 126 127 int exfat_clear_volume_dirty(struct super_block *sb) 128 { 129 struct exfat_sb_info *sbi = EXFAT_SB(sb); 130 131 return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY); 132 } 133 134 static int exfat_show_options(struct seq_file *m, struct dentry *root) 135 { 136 struct super_block *sb = root->d_sb; 137 struct exfat_sb_info *sbi = EXFAT_SB(sb); 138 struct exfat_mount_options *opts = &sbi->options; 139 140 /* Show partition info */ 141 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 142 seq_printf(m, ",uid=%u", 143 from_kuid_munged(&init_user_ns, opts->fs_uid)); 144 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 145 seq_printf(m, ",gid=%u", 146 from_kgid_munged(&init_user_ns, opts->fs_gid)); 147 seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask); 148 if (opts->allow_utime) 149 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 150 if (opts->utf8) 151 seq_puts(m, ",iocharset=utf8"); 152 else if (sbi->nls_io) 153 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 154 if (opts->errors == EXFAT_ERRORS_CONT) 155 seq_puts(m, ",errors=continue"); 156 else if (opts->errors == EXFAT_ERRORS_PANIC) 157 seq_puts(m, ",errors=panic"); 158 else 159 seq_puts(m, ",errors=remount-ro"); 160 if (opts->discard) 161 seq_puts(m, ",discard"); 162 if (opts->keep_last_dots) 163 seq_puts(m, ",keep_last_dots"); 164 if (opts->sys_tz) 165 seq_puts(m, ",sys_tz"); 166 else if (opts->time_offset) 167 seq_printf(m, ",time_offset=%d", opts->time_offset); 168 if (opts->zero_size_dir) 169 seq_puts(m, ",zero_size_dir"); 170 return 0; 171 } 172 173 int exfat_force_shutdown(struct super_block *sb, u32 flags) 174 { 175 int ret; 176 struct exfat_sb_info *sbi = sb->s_fs_info; 177 struct exfat_mount_options *opts = &sbi->options; 178 179 if (exfat_forced_shutdown(sb)) 180 return 0; 181 182 switch (flags) { 183 case EXFAT_GOING_DOWN_DEFAULT: 184 case EXFAT_GOING_DOWN_FULLSYNC: 185 ret = bdev_freeze(sb->s_bdev); 186 if (ret) 187 return ret; 188 bdev_thaw(sb->s_bdev); 189 set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags); 190 break; 191 case EXFAT_GOING_DOWN_NOSYNC: 192 set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags); 193 break; 194 default: 195 return -EINVAL; 196 } 197 198 if (opts->discard) 199 opts->discard = 0; 200 return 0; 201 } 202 203 static void exfat_shutdown(struct super_block *sb) 204 { 205 exfat_force_shutdown(sb, EXFAT_GOING_DOWN_NOSYNC); 206 } 207 208 static struct inode *exfat_alloc_inode(struct super_block *sb) 209 { 210 struct exfat_inode_info *ei; 211 212 ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS); 213 if (!ei) 214 return NULL; 215 216 init_rwsem(&ei->truncate_lock); 217 return &ei->vfs_inode; 218 } 219 220 static void exfat_free_inode(struct inode *inode) 221 { 222 kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode)); 223 } 224 225 static const struct super_operations exfat_sops = { 226 .alloc_inode = exfat_alloc_inode, 227 .free_inode = exfat_free_inode, 228 .write_inode = exfat_write_inode, 229 .evict_inode = exfat_evict_inode, 230 .put_super = exfat_put_super, 231 .sync_fs = exfat_sync_fs, 232 .statfs = exfat_statfs, 233 .show_options = exfat_show_options, 234 .shutdown = exfat_shutdown, 235 }; 236 237 enum { 238 Opt_uid, 239 Opt_gid, 240 Opt_umask, 241 Opt_dmask, 242 Opt_fmask, 243 Opt_allow_utime, 244 Opt_charset, 245 Opt_errors, 246 Opt_discard, 247 Opt_keep_last_dots, 248 Opt_sys_tz, 249 Opt_time_offset, 250 Opt_zero_size_dir, 251 252 /* Deprecated options */ 253 Opt_utf8, 254 Opt_debug, 255 Opt_namecase, 256 Opt_codepage, 257 }; 258 259 static const struct constant_table exfat_param_enums[] = { 260 { "continue", EXFAT_ERRORS_CONT }, 261 { "panic", EXFAT_ERRORS_PANIC }, 262 { "remount-ro", EXFAT_ERRORS_RO }, 263 {} 264 }; 265 266 static const struct fs_parameter_spec exfat_parameters[] = { 267 fsparam_uid("uid", Opt_uid), 268 fsparam_gid("gid", Opt_gid), 269 fsparam_u32oct("umask", Opt_umask), 270 fsparam_u32oct("dmask", Opt_dmask), 271 fsparam_u32oct("fmask", Opt_fmask), 272 fsparam_u32oct("allow_utime", Opt_allow_utime), 273 fsparam_string("iocharset", Opt_charset), 274 fsparam_enum("errors", Opt_errors, exfat_param_enums), 275 fsparam_flag("discard", Opt_discard), 276 fsparam_flag("keep_last_dots", Opt_keep_last_dots), 277 fsparam_flag("sys_tz", Opt_sys_tz), 278 fsparam_s32("time_offset", Opt_time_offset), 279 fsparam_flag("zero_size_dir", Opt_zero_size_dir), 280 __fsparam(NULL, "utf8", Opt_utf8, fs_param_deprecated, 281 NULL), 282 __fsparam(NULL, "debug", Opt_debug, fs_param_deprecated, 283 NULL), 284 __fsparam(fs_param_is_u32, "namecase", Opt_namecase, 285 fs_param_deprecated, NULL), 286 __fsparam(fs_param_is_u32, "codepage", Opt_codepage, 287 fs_param_deprecated, NULL), 288 {} 289 }; 290 291 static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param) 292 { 293 struct exfat_sb_info *sbi = fc->s_fs_info; 294 struct exfat_mount_options *opts = &sbi->options; 295 struct fs_parse_result result; 296 int opt; 297 298 opt = fs_parse(fc, exfat_parameters, param, &result); 299 if (opt < 0) 300 return opt; 301 302 switch (opt) { 303 case Opt_uid: 304 opts->fs_uid = result.uid; 305 break; 306 case Opt_gid: 307 opts->fs_gid = result.gid; 308 break; 309 case Opt_umask: 310 opts->fs_fmask = result.uint_32; 311 opts->fs_dmask = result.uint_32; 312 break; 313 case Opt_dmask: 314 opts->fs_dmask = result.uint_32; 315 break; 316 case Opt_fmask: 317 opts->fs_fmask = result.uint_32; 318 break; 319 case Opt_allow_utime: 320 opts->allow_utime = result.uint_32 & 0022; 321 break; 322 case Opt_charset: 323 exfat_free_iocharset(sbi); 324 opts->iocharset = param->string; 325 param->string = NULL; 326 break; 327 case Opt_errors: 328 opts->errors = result.uint_32; 329 break; 330 case Opt_discard: 331 opts->discard = 1; 332 break; 333 case Opt_keep_last_dots: 334 opts->keep_last_dots = 1; 335 break; 336 case Opt_sys_tz: 337 opts->sys_tz = 1; 338 break; 339 case Opt_time_offset: 340 /* 341 * Make the limit 24 just in case someone invents something 342 * unusual. 343 */ 344 if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60) 345 return -EINVAL; 346 opts->time_offset = result.int_32; 347 break; 348 case Opt_zero_size_dir: 349 opts->zero_size_dir = true; 350 break; 351 case Opt_utf8: 352 case Opt_debug: 353 case Opt_namecase: 354 case Opt_codepage: 355 break; 356 default: 357 return -EINVAL; 358 } 359 360 return 0; 361 } 362 363 static void exfat_hash_init(struct super_block *sb) 364 { 365 struct exfat_sb_info *sbi = EXFAT_SB(sb); 366 int i; 367 368 spin_lock_init(&sbi->inode_hash_lock); 369 for (i = 0; i < EXFAT_HASH_SIZE; i++) 370 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 371 } 372 373 static int exfat_read_root(struct inode *inode) 374 { 375 struct super_block *sb = inode->i_sb; 376 struct exfat_sb_info *sbi = EXFAT_SB(sb); 377 struct exfat_inode_info *ei = EXFAT_I(inode); 378 struct exfat_chain cdir; 379 int num_subdirs, num_clu = 0; 380 381 exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 382 ei->entry = -1; 383 ei->start_clu = sbi->root_dir; 384 ei->flags = ALLOC_FAT_CHAIN; 385 ei->type = TYPE_DIR; 386 ei->version = 0; 387 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 388 ei->hint_stat.eidx = 0; 389 ei->hint_stat.clu = sbi->root_dir; 390 ei->hint_femp.eidx = EXFAT_HINT_NONE; 391 392 exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 393 if (exfat_count_num_clusters(sb, &cdir, &num_clu)) 394 return -EIO; 395 i_size_write(inode, num_clu << sbi->cluster_size_bits); 396 397 num_subdirs = exfat_count_dir_entries(sb, &cdir); 398 if (num_subdirs < 0) 399 return -EIO; 400 set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR); 401 402 inode->i_uid = sbi->options.fs_uid; 403 inode->i_gid = sbi->options.fs_gid; 404 inode_inc_iversion(inode); 405 inode->i_generation = 0; 406 inode->i_mode = exfat_make_mode(sbi, EXFAT_ATTR_SUBDIR, 0777); 407 inode->i_op = &exfat_dir_inode_operations; 408 inode->i_fop = &exfat_dir_operations; 409 410 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9; 411 ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff; 412 413 exfat_save_attr(inode, EXFAT_ATTR_SUBDIR); 414 ei->i_crtime = simple_inode_init_ts(inode); 415 exfat_truncate_inode_atime(inode); 416 return 0; 417 } 418 419 static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect) 420 { 421 struct exfat_sb_info *sbi = EXFAT_SB(sb); 422 423 if (!is_power_of_2(logical_sect)) { 424 exfat_err(sb, "bogus logical sector size %u", logical_sect); 425 return -EIO; 426 } 427 428 if (logical_sect < sb->s_blocksize) { 429 exfat_err(sb, "logical sector size too small for device (logical sector size = %u)", 430 logical_sect); 431 return -EIO; 432 } 433 434 if (logical_sect > sb->s_blocksize) { 435 brelse(sbi->boot_bh); 436 sbi->boot_bh = NULL; 437 438 if (!sb_set_blocksize(sb, logical_sect)) { 439 exfat_err(sb, "unable to set blocksize %u", 440 logical_sect); 441 return -EIO; 442 } 443 sbi->boot_bh = sb_bread(sb, 0); 444 if (!sbi->boot_bh) { 445 exfat_err(sb, "unable to read boot sector (logical sector size = %lu)", 446 sb->s_blocksize); 447 return -EIO; 448 } 449 } 450 return 0; 451 } 452 453 static int exfat_read_boot_sector(struct super_block *sb) 454 { 455 struct boot_sector *p_boot; 456 struct exfat_sb_info *sbi = EXFAT_SB(sb); 457 458 /* set block size to read super block */ 459 sb_min_blocksize(sb, 512); 460 461 /* read boot sector */ 462 sbi->boot_bh = sb_bread(sb, 0); 463 if (!sbi->boot_bh) { 464 exfat_err(sb, "unable to read boot sector"); 465 return -EIO; 466 } 467 p_boot = (struct boot_sector *)sbi->boot_bh->b_data; 468 469 /* check the validity of BOOT */ 470 if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) { 471 exfat_err(sb, "invalid boot record signature"); 472 return -EINVAL; 473 } 474 475 if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) { 476 exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */ 477 return -EINVAL; 478 } 479 480 /* 481 * must_be_zero field must be filled with zero to prevent mounting 482 * from FAT volume. 483 */ 484 if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero))) 485 return -EINVAL; 486 487 if (p_boot->num_fats != 1 && p_boot->num_fats != 2) { 488 exfat_err(sb, "bogus number of FAT structure"); 489 return -EINVAL; 490 } 491 492 /* 493 * sect_size_bits could be at least 9 and at most 12. 494 */ 495 if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS || 496 p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) { 497 exfat_err(sb, "bogus sector size bits : %u", 498 p_boot->sect_size_bits); 499 return -EINVAL; 500 } 501 502 /* 503 * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits. 504 */ 505 if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) { 506 exfat_err(sb, "bogus sectors bits per cluster : %u", 507 p_boot->sect_per_clus_bits); 508 return -EINVAL; 509 } 510 511 sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits; 512 sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits; 513 sbi->cluster_size_bits = p_boot->sect_per_clus_bits + 514 p_boot->sect_size_bits; 515 sbi->cluster_size = 1 << sbi->cluster_size_bits; 516 sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length); 517 sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset); 518 sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset); 519 if (p_boot->num_fats == 2) 520 sbi->FAT2_start_sector += sbi->num_FAT_sectors; 521 sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset); 522 sbi->num_sectors = le64_to_cpu(p_boot->vol_length); 523 /* because the cluster index starts with 2 */ 524 sbi->num_clusters = le32_to_cpu(p_boot->clu_count) + 525 EXFAT_RESERVED_CLUSTERS; 526 527 sbi->root_dir = le32_to_cpu(p_boot->root_cluster); 528 sbi->dentries_per_clu = 1 << 529 (sbi->cluster_size_bits - DENTRY_SIZE_BITS); 530 531 sbi->vol_flags = le16_to_cpu(p_boot->vol_flags); 532 sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE); 533 sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER; 534 sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED; 535 536 /* check consistencies */ 537 if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits < 538 (u64)sbi->num_clusters * 4) { 539 exfat_err(sb, "bogus fat length"); 540 return -EINVAL; 541 } 542 543 if (sbi->data_start_sector < 544 (u64)sbi->FAT1_start_sector + 545 (u64)sbi->num_FAT_sectors * p_boot->num_fats) { 546 exfat_err(sb, "bogus data start sector"); 547 return -EINVAL; 548 } 549 550 if (sbi->vol_flags & VOLUME_DIRTY) 551 exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck."); 552 if (sbi->vol_flags & MEDIA_FAILURE) 553 exfat_warn(sb, "Medium has reported failures. Some data may be lost."); 554 555 /* exFAT file size is limited by a disk volume size */ 556 sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) << 557 sbi->cluster_size_bits; 558 559 /* check logical sector size */ 560 if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits)) 561 return -EIO; 562 563 return 0; 564 } 565 566 static int exfat_verify_boot_region(struct super_block *sb) 567 { 568 struct buffer_head *bh = NULL; 569 u32 chksum = 0; 570 __le32 *p_sig, *p_chksum; 571 int sn, i; 572 573 /* read boot sector sub-regions */ 574 for (sn = 0; sn < 11; sn++) { 575 bh = sb_bread(sb, sn); 576 if (!bh) 577 return -EIO; 578 579 if (sn != 0 && sn <= 8) { 580 /* extended boot sector sub-regions */ 581 p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4]; 582 if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE) 583 exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x", 584 sn, le32_to_cpu(*p_sig)); 585 } 586 587 chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize, 588 chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR); 589 brelse(bh); 590 } 591 592 /* boot checksum sub-regions */ 593 bh = sb_bread(sb, sn); 594 if (!bh) 595 return -EIO; 596 597 for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) { 598 p_chksum = (__le32 *)&bh->b_data[i]; 599 if (le32_to_cpu(*p_chksum) != chksum) { 600 exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)", 601 le32_to_cpu(*p_chksum), chksum); 602 brelse(bh); 603 return -EINVAL; 604 } 605 } 606 brelse(bh); 607 return 0; 608 } 609 610 /* mount the file system volume */ 611 static int __exfat_fill_super(struct super_block *sb) 612 { 613 int ret; 614 struct exfat_sb_info *sbi = EXFAT_SB(sb); 615 616 ret = exfat_read_boot_sector(sb); 617 if (ret) { 618 exfat_err(sb, "failed to read boot sector"); 619 goto free_bh; 620 } 621 622 ret = exfat_verify_boot_region(sb); 623 if (ret) { 624 exfat_err(sb, "invalid boot region"); 625 goto free_bh; 626 } 627 628 ret = exfat_create_upcase_table(sb); 629 if (ret) { 630 exfat_err(sb, "failed to load upcase table"); 631 goto free_bh; 632 } 633 634 ret = exfat_load_bitmap(sb); 635 if (ret) { 636 exfat_err(sb, "failed to load alloc-bitmap"); 637 goto free_bh; 638 } 639 640 ret = exfat_count_used_clusters(sb, &sbi->used_clusters); 641 if (ret) { 642 exfat_err(sb, "failed to scan clusters"); 643 goto free_alloc_bitmap; 644 } 645 646 return 0; 647 648 free_alloc_bitmap: 649 exfat_free_bitmap(sbi); 650 free_bh: 651 brelse(sbi->boot_bh); 652 return ret; 653 } 654 655 static int exfat_fill_super(struct super_block *sb, struct fs_context *fc) 656 { 657 struct exfat_sb_info *sbi = sb->s_fs_info; 658 struct exfat_mount_options *opts = &sbi->options; 659 struct inode *root_inode; 660 int err; 661 662 if (opts->allow_utime == (unsigned short)-1) 663 opts->allow_utime = ~opts->fs_dmask & 0022; 664 665 if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) { 666 exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard"); 667 opts->discard = 0; 668 } 669 670 sb->s_flags |= SB_NODIRATIME; 671 sb->s_magic = EXFAT_SUPER_MAGIC; 672 sb->s_op = &exfat_sops; 673 674 sb->s_time_gran = 10 * NSEC_PER_MSEC; 675 sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS; 676 sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS; 677 678 err = __exfat_fill_super(sb); 679 if (err) { 680 exfat_err(sb, "failed to recognize exfat type"); 681 goto check_nls_io; 682 } 683 684 /* set up enough so that it can read an inode */ 685 exfat_hash_init(sb); 686 687 if (!strcmp(sbi->options.iocharset, "utf8")) 688 opts->utf8 = 1; 689 else { 690 sbi->nls_io = load_nls(sbi->options.iocharset); 691 if (!sbi->nls_io) { 692 exfat_err(sb, "IO charset %s not found", 693 sbi->options.iocharset); 694 err = -EINVAL; 695 goto free_table; 696 } 697 } 698 699 if (sbi->options.utf8) 700 sb->s_d_op = &exfat_utf8_dentry_ops; 701 else 702 sb->s_d_op = &exfat_dentry_ops; 703 704 root_inode = new_inode(sb); 705 if (!root_inode) { 706 exfat_err(sb, "failed to allocate root inode"); 707 err = -ENOMEM; 708 goto free_table; 709 } 710 711 root_inode->i_ino = EXFAT_ROOT_INO; 712 inode_set_iversion(root_inode, 1); 713 err = exfat_read_root(root_inode); 714 if (err) { 715 exfat_err(sb, "failed to initialize root inode"); 716 goto put_inode; 717 } 718 719 exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos); 720 insert_inode_hash(root_inode); 721 722 sb->s_root = d_make_root(root_inode); 723 if (!sb->s_root) { 724 exfat_err(sb, "failed to get the root dentry"); 725 err = -ENOMEM; 726 goto free_table; 727 } 728 729 return 0; 730 731 put_inode: 732 iput(root_inode); 733 sb->s_root = NULL; 734 735 free_table: 736 exfat_free_bitmap(sbi); 737 brelse(sbi->boot_bh); 738 739 check_nls_io: 740 return err; 741 } 742 743 static int exfat_get_tree(struct fs_context *fc) 744 { 745 return get_tree_bdev(fc, exfat_fill_super); 746 } 747 748 static void exfat_free_sbi(struct exfat_sb_info *sbi) 749 { 750 exfat_free_iocharset(sbi); 751 kfree(sbi); 752 } 753 754 static void exfat_free(struct fs_context *fc) 755 { 756 struct exfat_sb_info *sbi = fc->s_fs_info; 757 758 if (sbi) 759 exfat_free_sbi(sbi); 760 } 761 762 static int exfat_reconfigure(struct fs_context *fc) 763 { 764 fc->sb_flags |= SB_NODIRATIME; 765 766 /* volume flag will be updated in exfat_sync_fs */ 767 sync_filesystem(fc->root->d_sb); 768 return 0; 769 } 770 771 static const struct fs_context_operations exfat_context_ops = { 772 .parse_param = exfat_parse_param, 773 .get_tree = exfat_get_tree, 774 .free = exfat_free, 775 .reconfigure = exfat_reconfigure, 776 }; 777 778 static int exfat_init_fs_context(struct fs_context *fc) 779 { 780 struct exfat_sb_info *sbi; 781 782 sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL); 783 if (!sbi) 784 return -ENOMEM; 785 786 mutex_init(&sbi->s_lock); 787 mutex_init(&sbi->bitmap_lock); 788 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 789 DEFAULT_RATELIMIT_BURST); 790 791 sbi->options.fs_uid = current_uid(); 792 sbi->options.fs_gid = current_gid(); 793 sbi->options.fs_fmask = current->fs->umask; 794 sbi->options.fs_dmask = current->fs->umask; 795 sbi->options.allow_utime = -1; 796 sbi->options.iocharset = exfat_default_iocharset; 797 sbi->options.errors = EXFAT_ERRORS_RO; 798 799 fc->s_fs_info = sbi; 800 fc->ops = &exfat_context_ops; 801 return 0; 802 } 803 804 static void delayed_free(struct rcu_head *p) 805 { 806 struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu); 807 808 unload_nls(sbi->nls_io); 809 exfat_free_upcase_table(sbi); 810 exfat_free_sbi(sbi); 811 } 812 813 static void exfat_kill_sb(struct super_block *sb) 814 { 815 struct exfat_sb_info *sbi = sb->s_fs_info; 816 817 kill_block_super(sb); 818 if (sbi) 819 call_rcu(&sbi->rcu, delayed_free); 820 } 821 822 static struct file_system_type exfat_fs_type = { 823 .owner = THIS_MODULE, 824 .name = "exfat", 825 .init_fs_context = exfat_init_fs_context, 826 .parameters = exfat_parameters, 827 .kill_sb = exfat_kill_sb, 828 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, 829 }; 830 831 static void exfat_inode_init_once(void *foo) 832 { 833 struct exfat_inode_info *ei = (struct exfat_inode_info *)foo; 834 835 spin_lock_init(&ei->cache_lru_lock); 836 ei->nr_caches = 0; 837 ei->cache_valid_id = EXFAT_CACHE_VALID + 1; 838 INIT_LIST_HEAD(&ei->cache_lru); 839 INIT_HLIST_NODE(&ei->i_hash_fat); 840 inode_init_once(&ei->vfs_inode); 841 } 842 843 static int __init init_exfat_fs(void) 844 { 845 int err; 846 847 err = exfat_cache_init(); 848 if (err) 849 return err; 850 851 exfat_inode_cachep = kmem_cache_create("exfat_inode_cache", 852 sizeof(struct exfat_inode_info), 853 0, SLAB_RECLAIM_ACCOUNT, 854 exfat_inode_init_once); 855 if (!exfat_inode_cachep) { 856 err = -ENOMEM; 857 goto shutdown_cache; 858 } 859 860 err = register_filesystem(&exfat_fs_type); 861 if (err) 862 goto destroy_cache; 863 864 return 0; 865 866 destroy_cache: 867 kmem_cache_destroy(exfat_inode_cachep); 868 shutdown_cache: 869 exfat_cache_shutdown(); 870 return err; 871 } 872 873 static void __exit exit_exfat_fs(void) 874 { 875 /* 876 * Make sure all delayed rcu free inodes are flushed before we 877 * destroy cache. 878 */ 879 rcu_barrier(); 880 kmem_cache_destroy(exfat_inode_cachep); 881 unregister_filesystem(&exfat_fs_type); 882 exfat_cache_shutdown(); 883 } 884 885 module_init(init_exfat_fs); 886 module_exit(exit_exfat_fs); 887 888 MODULE_ALIAS_FS("exfat"); 889 MODULE_LICENSE("GPL"); 890 MODULE_DESCRIPTION("exFAT filesystem support"); 891 MODULE_AUTHOR("Samsung Electronics Co., Ltd."); 892