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) 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 struct exfat_chain cdir; 350 int num_subdirs, num_clu = 0; 351 352 exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 353 ei->entry = -1; 354 ei->start_clu = sbi->root_dir; 355 ei->flags = ALLOC_FAT_CHAIN; 356 ei->type = TYPE_DIR; 357 ei->version = 0; 358 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 359 ei->hint_stat.eidx = 0; 360 ei->hint_stat.clu = sbi->root_dir; 361 ei->hint_femp.eidx = EXFAT_HINT_NONE; 362 363 exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 364 if (exfat_count_num_clusters(sb, &cdir, &num_clu)) 365 return -EIO; 366 i_size_write(inode, num_clu << sbi->cluster_size_bits); 367 368 num_subdirs = exfat_count_dir_entries(sb, &cdir); 369 if (num_subdirs < 0) 370 return -EIO; 371 set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR); 372 373 inode->i_uid = sbi->options.fs_uid; 374 inode->i_gid = sbi->options.fs_gid; 375 inode_inc_iversion(inode); 376 inode->i_generation = 0; 377 inode->i_mode = exfat_make_mode(sbi, EXFAT_ATTR_SUBDIR, 0777); 378 inode->i_op = &exfat_dir_inode_operations; 379 inode->i_fop = &exfat_dir_operations; 380 381 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9; 382 ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff; 383 384 exfat_save_attr(inode, EXFAT_ATTR_SUBDIR); 385 ei->i_crtime = simple_inode_init_ts(inode); 386 exfat_truncate_inode_atime(inode); 387 return 0; 388 } 389 390 static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect) 391 { 392 struct exfat_sb_info *sbi = EXFAT_SB(sb); 393 394 if (!is_power_of_2(logical_sect)) { 395 exfat_err(sb, "bogus logical sector size %u", logical_sect); 396 return -EIO; 397 } 398 399 if (logical_sect < sb->s_blocksize) { 400 exfat_err(sb, "logical sector size too small for device (logical sector size = %u)", 401 logical_sect); 402 return -EIO; 403 } 404 405 if (logical_sect > sb->s_blocksize) { 406 brelse(sbi->boot_bh); 407 sbi->boot_bh = NULL; 408 409 if (!sb_set_blocksize(sb, logical_sect)) { 410 exfat_err(sb, "unable to set blocksize %u", 411 logical_sect); 412 return -EIO; 413 } 414 sbi->boot_bh = sb_bread(sb, 0); 415 if (!sbi->boot_bh) { 416 exfat_err(sb, "unable to read boot sector (logical sector size = %lu)", 417 sb->s_blocksize); 418 return -EIO; 419 } 420 } 421 return 0; 422 } 423 424 static int exfat_read_boot_sector(struct super_block *sb) 425 { 426 struct boot_sector *p_boot; 427 struct exfat_sb_info *sbi = EXFAT_SB(sb); 428 429 /* set block size to read super block */ 430 sb_min_blocksize(sb, 512); 431 432 /* read boot sector */ 433 sbi->boot_bh = sb_bread(sb, 0); 434 if (!sbi->boot_bh) { 435 exfat_err(sb, "unable to read boot sector"); 436 return -EIO; 437 } 438 p_boot = (struct boot_sector *)sbi->boot_bh->b_data; 439 440 /* check the validity of BOOT */ 441 if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) { 442 exfat_err(sb, "invalid boot record signature"); 443 return -EINVAL; 444 } 445 446 if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) { 447 exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */ 448 return -EINVAL; 449 } 450 451 /* 452 * must_be_zero field must be filled with zero to prevent mounting 453 * from FAT volume. 454 */ 455 if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero))) 456 return -EINVAL; 457 458 if (p_boot->num_fats != 1 && p_boot->num_fats != 2) { 459 exfat_err(sb, "bogus number of FAT structure"); 460 return -EINVAL; 461 } 462 463 /* 464 * sect_size_bits could be at least 9 and at most 12. 465 */ 466 if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS || 467 p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) { 468 exfat_err(sb, "bogus sector size bits : %u", 469 p_boot->sect_size_bits); 470 return -EINVAL; 471 } 472 473 /* 474 * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits. 475 */ 476 if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) { 477 exfat_err(sb, "bogus sectors bits per cluster : %u", 478 p_boot->sect_per_clus_bits); 479 return -EINVAL; 480 } 481 482 sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits; 483 sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits; 484 sbi->cluster_size_bits = p_boot->sect_per_clus_bits + 485 p_boot->sect_size_bits; 486 sbi->cluster_size = 1 << sbi->cluster_size_bits; 487 sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length); 488 sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset); 489 sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset); 490 if (p_boot->num_fats == 2) 491 sbi->FAT2_start_sector += sbi->num_FAT_sectors; 492 sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset); 493 sbi->num_sectors = le64_to_cpu(p_boot->vol_length); 494 /* because the cluster index starts with 2 */ 495 sbi->num_clusters = le32_to_cpu(p_boot->clu_count) + 496 EXFAT_RESERVED_CLUSTERS; 497 498 sbi->root_dir = le32_to_cpu(p_boot->root_cluster); 499 sbi->dentries_per_clu = 1 << 500 (sbi->cluster_size_bits - DENTRY_SIZE_BITS); 501 502 sbi->vol_flags = le16_to_cpu(p_boot->vol_flags); 503 sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE); 504 sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER; 505 506 /* check consistencies */ 507 if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits < 508 (u64)sbi->num_clusters * 4) { 509 exfat_err(sb, "bogus fat length"); 510 return -EINVAL; 511 } 512 513 if (sbi->data_start_sector < 514 (u64)sbi->FAT1_start_sector + 515 (u64)sbi->num_FAT_sectors * p_boot->num_fats) { 516 exfat_err(sb, "bogus data start sector"); 517 return -EINVAL; 518 } 519 520 if (sbi->vol_flags & VOLUME_DIRTY) 521 exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck."); 522 if (sbi->vol_flags & MEDIA_FAILURE) 523 exfat_warn(sb, "Medium has reported failures. Some data may be lost."); 524 525 /* exFAT file size is limited by a disk volume size */ 526 sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) << 527 sbi->cluster_size_bits; 528 529 /* check logical sector size */ 530 if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits)) 531 return -EIO; 532 533 return 0; 534 } 535 536 static int exfat_verify_boot_region(struct super_block *sb) 537 { 538 struct buffer_head *bh = NULL; 539 u32 chksum = 0; 540 __le32 *p_sig, *p_chksum; 541 int sn, i; 542 543 /* read boot sector sub-regions */ 544 for (sn = 0; sn < 11; sn++) { 545 bh = sb_bread(sb, sn); 546 if (!bh) 547 return -EIO; 548 549 if (sn != 0 && sn <= 8) { 550 /* extended boot sector sub-regions */ 551 p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4]; 552 if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE) 553 exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x", 554 sn, le32_to_cpu(*p_sig)); 555 } 556 557 chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize, 558 chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR); 559 brelse(bh); 560 } 561 562 /* boot checksum sub-regions */ 563 bh = sb_bread(sb, sn); 564 if (!bh) 565 return -EIO; 566 567 for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) { 568 p_chksum = (__le32 *)&bh->b_data[i]; 569 if (le32_to_cpu(*p_chksum) != chksum) { 570 exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)", 571 le32_to_cpu(*p_chksum), chksum); 572 brelse(bh); 573 return -EINVAL; 574 } 575 } 576 brelse(bh); 577 return 0; 578 } 579 580 /* mount the file system volume */ 581 static int __exfat_fill_super(struct super_block *sb) 582 { 583 int ret; 584 struct exfat_sb_info *sbi = EXFAT_SB(sb); 585 586 ret = exfat_read_boot_sector(sb); 587 if (ret) { 588 exfat_err(sb, "failed to read boot sector"); 589 goto free_bh; 590 } 591 592 ret = exfat_verify_boot_region(sb); 593 if (ret) { 594 exfat_err(sb, "invalid boot region"); 595 goto free_bh; 596 } 597 598 ret = exfat_create_upcase_table(sb); 599 if (ret) { 600 exfat_err(sb, "failed to load upcase table"); 601 goto free_bh; 602 } 603 604 ret = exfat_load_bitmap(sb); 605 if (ret) { 606 exfat_err(sb, "failed to load alloc-bitmap"); 607 goto free_bh; 608 } 609 610 ret = exfat_count_used_clusters(sb, &sbi->used_clusters); 611 if (ret) { 612 exfat_err(sb, "failed to scan clusters"); 613 goto free_alloc_bitmap; 614 } 615 616 return 0; 617 618 free_alloc_bitmap: 619 exfat_free_bitmap(sbi); 620 free_bh: 621 brelse(sbi->boot_bh); 622 return ret; 623 } 624 625 static int exfat_fill_super(struct super_block *sb, struct fs_context *fc) 626 { 627 struct exfat_sb_info *sbi = sb->s_fs_info; 628 struct exfat_mount_options *opts = &sbi->options; 629 struct inode *root_inode; 630 int err; 631 632 if (opts->allow_utime == (unsigned short)-1) 633 opts->allow_utime = ~opts->fs_dmask & 0022; 634 635 if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) { 636 exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard"); 637 opts->discard = 0; 638 } 639 640 sb->s_flags |= SB_NODIRATIME; 641 sb->s_magic = EXFAT_SUPER_MAGIC; 642 sb->s_op = &exfat_sops; 643 644 sb->s_time_gran = 10 * NSEC_PER_MSEC; 645 sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS; 646 sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS; 647 648 err = __exfat_fill_super(sb); 649 if (err) { 650 exfat_err(sb, "failed to recognize exfat type"); 651 goto check_nls_io; 652 } 653 654 /* set up enough so that it can read an inode */ 655 exfat_hash_init(sb); 656 657 if (!strcmp(sbi->options.iocharset, "utf8")) 658 opts->utf8 = 1; 659 else { 660 sbi->nls_io = load_nls(sbi->options.iocharset); 661 if (!sbi->nls_io) { 662 exfat_err(sb, "IO charset %s not found", 663 sbi->options.iocharset); 664 err = -EINVAL; 665 goto free_table; 666 } 667 } 668 669 if (sbi->options.utf8) 670 sb->s_d_op = &exfat_utf8_dentry_ops; 671 else 672 sb->s_d_op = &exfat_dentry_ops; 673 674 root_inode = new_inode(sb); 675 if (!root_inode) { 676 exfat_err(sb, "failed to allocate root inode"); 677 err = -ENOMEM; 678 goto free_table; 679 } 680 681 root_inode->i_ino = EXFAT_ROOT_INO; 682 inode_set_iversion(root_inode, 1); 683 err = exfat_read_root(root_inode); 684 if (err) { 685 exfat_err(sb, "failed to initialize root inode"); 686 goto put_inode; 687 } 688 689 exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos); 690 insert_inode_hash(root_inode); 691 692 sb->s_root = d_make_root(root_inode); 693 if (!sb->s_root) { 694 exfat_err(sb, "failed to get the root dentry"); 695 err = -ENOMEM; 696 goto free_table; 697 } 698 699 return 0; 700 701 put_inode: 702 iput(root_inode); 703 sb->s_root = NULL; 704 705 free_table: 706 exfat_free_bitmap(sbi); 707 brelse(sbi->boot_bh); 708 709 check_nls_io: 710 return err; 711 } 712 713 static int exfat_get_tree(struct fs_context *fc) 714 { 715 return get_tree_bdev(fc, exfat_fill_super); 716 } 717 718 static void exfat_free_sbi(struct exfat_sb_info *sbi) 719 { 720 exfat_free_iocharset(sbi); 721 kfree(sbi); 722 } 723 724 static void exfat_free(struct fs_context *fc) 725 { 726 struct exfat_sb_info *sbi = fc->s_fs_info; 727 728 if (sbi) 729 exfat_free_sbi(sbi); 730 } 731 732 static int exfat_reconfigure(struct fs_context *fc) 733 { 734 struct super_block *sb = fc->root->d_sb; 735 fc->sb_flags |= SB_NODIRATIME; 736 737 sync_filesystem(sb); 738 mutex_lock(&EXFAT_SB(sb)->s_lock); 739 exfat_clear_volume_dirty(sb); 740 mutex_unlock(&EXFAT_SB(sb)->s_lock); 741 742 return 0; 743 } 744 745 static const struct fs_context_operations exfat_context_ops = { 746 .parse_param = exfat_parse_param, 747 .get_tree = exfat_get_tree, 748 .free = exfat_free, 749 .reconfigure = exfat_reconfigure, 750 }; 751 752 static int exfat_init_fs_context(struct fs_context *fc) 753 { 754 struct exfat_sb_info *sbi; 755 756 sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL); 757 if (!sbi) 758 return -ENOMEM; 759 760 mutex_init(&sbi->s_lock); 761 mutex_init(&sbi->bitmap_lock); 762 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 763 DEFAULT_RATELIMIT_BURST); 764 765 sbi->options.fs_uid = current_uid(); 766 sbi->options.fs_gid = current_gid(); 767 sbi->options.fs_fmask = current->fs->umask; 768 sbi->options.fs_dmask = current->fs->umask; 769 sbi->options.allow_utime = -1; 770 sbi->options.iocharset = exfat_default_iocharset; 771 sbi->options.errors = EXFAT_ERRORS_RO; 772 773 fc->s_fs_info = sbi; 774 fc->ops = &exfat_context_ops; 775 return 0; 776 } 777 778 static void delayed_free(struct rcu_head *p) 779 { 780 struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu); 781 782 unload_nls(sbi->nls_io); 783 exfat_free_upcase_table(sbi); 784 exfat_free_sbi(sbi); 785 } 786 787 static void exfat_kill_sb(struct super_block *sb) 788 { 789 struct exfat_sb_info *sbi = sb->s_fs_info; 790 791 kill_block_super(sb); 792 if (sbi) 793 call_rcu(&sbi->rcu, delayed_free); 794 } 795 796 static struct file_system_type exfat_fs_type = { 797 .owner = THIS_MODULE, 798 .name = "exfat", 799 .init_fs_context = exfat_init_fs_context, 800 .parameters = exfat_parameters, 801 .kill_sb = exfat_kill_sb, 802 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, 803 }; 804 805 static void exfat_inode_init_once(void *foo) 806 { 807 struct exfat_inode_info *ei = (struct exfat_inode_info *)foo; 808 809 spin_lock_init(&ei->cache_lru_lock); 810 ei->nr_caches = 0; 811 ei->cache_valid_id = EXFAT_CACHE_VALID + 1; 812 INIT_LIST_HEAD(&ei->cache_lru); 813 INIT_HLIST_NODE(&ei->i_hash_fat); 814 inode_init_once(&ei->vfs_inode); 815 } 816 817 static int __init init_exfat_fs(void) 818 { 819 int err; 820 821 err = exfat_cache_init(); 822 if (err) 823 return err; 824 825 exfat_inode_cachep = kmem_cache_create("exfat_inode_cache", 826 sizeof(struct exfat_inode_info), 827 0, SLAB_RECLAIM_ACCOUNT, 828 exfat_inode_init_once); 829 if (!exfat_inode_cachep) { 830 err = -ENOMEM; 831 goto shutdown_cache; 832 } 833 834 err = register_filesystem(&exfat_fs_type); 835 if (err) 836 goto destroy_cache; 837 838 return 0; 839 840 destroy_cache: 841 kmem_cache_destroy(exfat_inode_cachep); 842 shutdown_cache: 843 exfat_cache_shutdown(); 844 return err; 845 } 846 847 static void __exit exit_exfat_fs(void) 848 { 849 /* 850 * Make sure all delayed rcu free inodes are flushed before we 851 * destroy cache. 852 */ 853 rcu_barrier(); 854 kmem_cache_destroy(exfat_inode_cachep); 855 unregister_filesystem(&exfat_fs_type); 856 exfat_cache_shutdown(); 857 } 858 859 module_init(init_exfat_fs); 860 module_exit(exit_exfat_fs); 861 862 MODULE_ALIAS_FS("exfat"); 863 MODULE_LICENSE("GPL"); 864 MODULE_DESCRIPTION("exFAT filesystem support"); 865 MODULE_AUTHOR("Samsung Electronics Co., Ltd."); 866