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_delayed_free(struct rcu_head *p) 35 { 36 struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu); 37 38 unload_nls(sbi->nls_io); 39 exfat_free_iocharset(sbi); 40 exfat_free_upcase_table(sbi); 41 kfree(sbi); 42 } 43 44 static void exfat_put_super(struct super_block *sb) 45 { 46 struct exfat_sb_info *sbi = EXFAT_SB(sb); 47 48 mutex_lock(&sbi->s_lock); 49 exfat_free_bitmap(sbi); 50 brelse(sbi->boot_bh); 51 mutex_unlock(&sbi->s_lock); 52 53 call_rcu(&sbi->rcu, exfat_delayed_free); 54 } 55 56 static int exfat_sync_fs(struct super_block *sb, int wait) 57 { 58 struct exfat_sb_info *sbi = EXFAT_SB(sb); 59 int err = 0; 60 61 if (!wait) 62 return 0; 63 64 /* If there are some dirty buffers in the bdev inode */ 65 mutex_lock(&sbi->s_lock); 66 sync_blockdev(sb->s_bdev); 67 if (exfat_clear_volume_dirty(sb)) 68 err = -EIO; 69 mutex_unlock(&sbi->s_lock); 70 return err; 71 } 72 73 static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf) 74 { 75 struct super_block *sb = dentry->d_sb; 76 struct exfat_sb_info *sbi = EXFAT_SB(sb); 77 unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev); 78 79 if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) { 80 mutex_lock(&sbi->s_lock); 81 if (exfat_count_used_clusters(sb, &sbi->used_clusters)) { 82 mutex_unlock(&sbi->s_lock); 83 return -EIO; 84 } 85 mutex_unlock(&sbi->s_lock); 86 } 87 88 buf->f_type = sb->s_magic; 89 buf->f_bsize = sbi->cluster_size; 90 buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */ 91 buf->f_bfree = buf->f_blocks - sbi->used_clusters; 92 buf->f_bavail = buf->f_bfree; 93 buf->f_fsid = u64_to_fsid(id); 94 /* Unicode utf16 255 characters */ 95 buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE; 96 return 0; 97 } 98 99 static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags) 100 { 101 struct exfat_sb_info *sbi = EXFAT_SB(sb); 102 struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data; 103 104 /* retain persistent-flags */ 105 new_flags |= sbi->vol_flags_persistent; 106 107 /* flags are not changed */ 108 if (sbi->vol_flags == new_flags) 109 return 0; 110 111 sbi->vol_flags = new_flags; 112 113 /* skip updating volume dirty flag, 114 * if this volume has been mounted with read-only 115 */ 116 if (sb_rdonly(sb)) 117 return 0; 118 119 p_boot->vol_flags = cpu_to_le16(new_flags); 120 121 set_buffer_uptodate(sbi->boot_bh); 122 mark_buffer_dirty(sbi->boot_bh); 123 124 __sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH); 125 126 return 0; 127 } 128 129 int exfat_set_volume_dirty(struct super_block *sb) 130 { 131 struct exfat_sb_info *sbi = EXFAT_SB(sb); 132 133 return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY); 134 } 135 136 int exfat_clear_volume_dirty(struct super_block *sb) 137 { 138 struct exfat_sb_info *sbi = EXFAT_SB(sb); 139 140 return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY); 141 } 142 143 static int exfat_show_options(struct seq_file *m, struct dentry *root) 144 { 145 struct super_block *sb = root->d_sb; 146 struct exfat_sb_info *sbi = EXFAT_SB(sb); 147 struct exfat_mount_options *opts = &sbi->options; 148 149 /* Show partition info */ 150 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 151 seq_printf(m, ",uid=%u", 152 from_kuid_munged(&init_user_ns, opts->fs_uid)); 153 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 154 seq_printf(m, ",gid=%u", 155 from_kgid_munged(&init_user_ns, opts->fs_gid)); 156 seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask); 157 if (opts->allow_utime) 158 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 159 if (opts->utf8) 160 seq_puts(m, ",iocharset=utf8"); 161 else if (sbi->nls_io) 162 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 163 if (opts->errors == EXFAT_ERRORS_CONT) 164 seq_puts(m, ",errors=continue"); 165 else if (opts->errors == EXFAT_ERRORS_PANIC) 166 seq_puts(m, ",errors=panic"); 167 else 168 seq_puts(m, ",errors=remount-ro"); 169 if (opts->discard) 170 seq_puts(m, ",discard"); 171 if (opts->keep_last_dots) 172 seq_puts(m, ",keep_last_dots"); 173 if (opts->sys_tz) 174 seq_puts(m, ",sys_tz"); 175 else if (opts->time_offset) 176 seq_printf(m, ",time_offset=%d", opts->time_offset); 177 return 0; 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 .sync_fs = exfat_sync_fs, 204 .statfs = exfat_statfs, 205 .show_options = exfat_show_options, 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, 221 222 /* Deprecated options */ 223 Opt_utf8, 224 Opt_debug, 225 Opt_namecase, 226 Opt_codepage, 227 }; 228 229 static const struct constant_table exfat_param_enums[] = { 230 { "continue", EXFAT_ERRORS_CONT }, 231 { "panic", EXFAT_ERRORS_PANIC }, 232 { "remount-ro", EXFAT_ERRORS_RO }, 233 {} 234 }; 235 236 static const struct fs_parameter_spec exfat_parameters[] = { 237 fsparam_u32("uid", Opt_uid), 238 fsparam_u32("gid", Opt_gid), 239 fsparam_u32oct("umask", Opt_umask), 240 fsparam_u32oct("dmask", Opt_dmask), 241 fsparam_u32oct("fmask", Opt_fmask), 242 fsparam_u32oct("allow_utime", Opt_allow_utime), 243 fsparam_string("iocharset", Opt_charset), 244 fsparam_enum("errors", Opt_errors, exfat_param_enums), 245 fsparam_flag("discard", Opt_discard), 246 fsparam_flag("keep_last_dots", Opt_keep_last_dots), 247 fsparam_flag("sys_tz", Opt_sys_tz), 248 fsparam_s32("time_offset", Opt_time_offset), 249 __fsparam(NULL, "utf8", Opt_utf8, fs_param_deprecated, 250 NULL), 251 __fsparam(NULL, "debug", Opt_debug, fs_param_deprecated, 252 NULL), 253 __fsparam(fs_param_is_u32, "namecase", Opt_namecase, 254 fs_param_deprecated, NULL), 255 __fsparam(fs_param_is_u32, "codepage", Opt_codepage, 256 fs_param_deprecated, NULL), 257 {} 258 }; 259 260 static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param) 261 { 262 struct exfat_sb_info *sbi = fc->s_fs_info; 263 struct exfat_mount_options *opts = &sbi->options; 264 struct fs_parse_result result; 265 int opt; 266 267 opt = fs_parse(fc, exfat_parameters, param, &result); 268 if (opt < 0) 269 return opt; 270 271 switch (opt) { 272 case Opt_uid: 273 opts->fs_uid = make_kuid(current_user_ns(), result.uint_32); 274 break; 275 case Opt_gid: 276 opts->fs_gid = make_kgid(current_user_ns(), result.uint_32); 277 break; 278 case Opt_umask: 279 opts->fs_fmask = result.uint_32; 280 opts->fs_dmask = result.uint_32; 281 break; 282 case Opt_dmask: 283 opts->fs_dmask = result.uint_32; 284 break; 285 case Opt_fmask: 286 opts->fs_fmask = result.uint_32; 287 break; 288 case Opt_allow_utime: 289 opts->allow_utime = result.uint_32 & 0022; 290 break; 291 case Opt_charset: 292 exfat_free_iocharset(sbi); 293 opts->iocharset = param->string; 294 param->string = NULL; 295 break; 296 case Opt_errors: 297 opts->errors = result.uint_32; 298 break; 299 case Opt_discard: 300 opts->discard = 1; 301 break; 302 case Opt_keep_last_dots: 303 opts->keep_last_dots = 1; 304 break; 305 case Opt_sys_tz: 306 opts->sys_tz = 1; 307 break; 308 case Opt_time_offset: 309 /* 310 * Make the limit 24 just in case someone invents something 311 * unusual. 312 */ 313 if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60) 314 return -EINVAL; 315 opts->time_offset = result.int_32; 316 break; 317 case Opt_utf8: 318 case Opt_debug: 319 case Opt_namecase: 320 case Opt_codepage: 321 break; 322 default: 323 return -EINVAL; 324 } 325 326 return 0; 327 } 328 329 static void exfat_hash_init(struct super_block *sb) 330 { 331 struct exfat_sb_info *sbi = EXFAT_SB(sb); 332 int i; 333 334 spin_lock_init(&sbi->inode_hash_lock); 335 for (i = 0; i < EXFAT_HASH_SIZE; i++) 336 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 337 } 338 339 static int exfat_read_root(struct inode *inode) 340 { 341 struct super_block *sb = inode->i_sb; 342 struct exfat_sb_info *sbi = EXFAT_SB(sb); 343 struct exfat_inode_info *ei = EXFAT_I(inode); 344 struct exfat_chain cdir; 345 int num_subdirs, num_clu = 0; 346 347 exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 348 ei->entry = -1; 349 ei->start_clu = sbi->root_dir; 350 ei->flags = ALLOC_FAT_CHAIN; 351 ei->type = TYPE_DIR; 352 ei->version = 0; 353 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 354 ei->hint_stat.eidx = 0; 355 ei->hint_stat.clu = sbi->root_dir; 356 ei->hint_femp.eidx = EXFAT_HINT_NONE; 357 358 exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 359 if (exfat_count_num_clusters(sb, &cdir, &num_clu)) 360 return -EIO; 361 i_size_write(inode, num_clu << sbi->cluster_size_bits); 362 363 num_subdirs = exfat_count_dir_entries(sb, &cdir); 364 if (num_subdirs < 0) 365 return -EIO; 366 set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR); 367 368 inode->i_uid = sbi->options.fs_uid; 369 inode->i_gid = sbi->options.fs_gid; 370 inode_inc_iversion(inode); 371 inode->i_generation = 0; 372 inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777); 373 inode->i_op = &exfat_dir_inode_operations; 374 inode->i_fop = &exfat_dir_operations; 375 376 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 377 inode->i_blkbits; 378 ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff; 379 ei->i_size_aligned = i_size_read(inode); 380 ei->i_size_ondisk = i_size_read(inode); 381 382 exfat_save_attr(inode, ATTR_SUBDIR); 383 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime = 384 current_time(inode); 385 exfat_truncate_atime(&inode->i_atime); 386 return 0; 387 } 388 389 static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect) 390 { 391 struct exfat_sb_info *sbi = EXFAT_SB(sb); 392 393 if (!is_power_of_2(logical_sect)) { 394 exfat_err(sb, "bogus logical sector size %u", logical_sect); 395 return -EIO; 396 } 397 398 if (logical_sect < sb->s_blocksize) { 399 exfat_err(sb, "logical sector size too small for device (logical sector size = %u)", 400 logical_sect); 401 return -EIO; 402 } 403 404 if (logical_sect > sb->s_blocksize) { 405 brelse(sbi->boot_bh); 406 sbi->boot_bh = NULL; 407 408 if (!sb_set_blocksize(sb, logical_sect)) { 409 exfat_err(sb, "unable to set blocksize %u", 410 logical_sect); 411 return -EIO; 412 } 413 sbi->boot_bh = sb_bread(sb, 0); 414 if (!sbi->boot_bh) { 415 exfat_err(sb, "unable to read boot sector (logical sector size = %lu)", 416 sb->s_blocksize); 417 return -EIO; 418 } 419 } 420 return 0; 421 } 422 423 static int exfat_read_boot_sector(struct super_block *sb) 424 { 425 struct boot_sector *p_boot; 426 struct exfat_sb_info *sbi = EXFAT_SB(sb); 427 428 /* set block size to read super block */ 429 sb_min_blocksize(sb, 512); 430 431 /* read boot sector */ 432 sbi->boot_bh = sb_bread(sb, 0); 433 if (!sbi->boot_bh) { 434 exfat_err(sb, "unable to read boot sector"); 435 return -EIO; 436 } 437 p_boot = (struct boot_sector *)sbi->boot_bh->b_data; 438 439 /* check the validity of BOOT */ 440 if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) { 441 exfat_err(sb, "invalid boot record signature"); 442 return -EINVAL; 443 } 444 445 if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) { 446 exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */ 447 return -EINVAL; 448 } 449 450 /* 451 * must_be_zero field must be filled with zero to prevent mounting 452 * from FAT volume. 453 */ 454 if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero))) 455 return -EINVAL; 456 457 if (p_boot->num_fats != 1 && p_boot->num_fats != 2) { 458 exfat_err(sb, "bogus number of FAT structure"); 459 return -EINVAL; 460 } 461 462 /* 463 * sect_size_bits could be at least 9 and at most 12. 464 */ 465 if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS || 466 p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) { 467 exfat_err(sb, "bogus sector size bits : %u", 468 p_boot->sect_size_bits); 469 return -EINVAL; 470 } 471 472 /* 473 * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits. 474 */ 475 if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) { 476 exfat_err(sb, "bogus sectors bits per cluster : %u", 477 p_boot->sect_per_clus_bits); 478 return -EINVAL; 479 } 480 481 sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits; 482 sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits; 483 sbi->cluster_size_bits = p_boot->sect_per_clus_bits + 484 p_boot->sect_size_bits; 485 sbi->cluster_size = 1 << sbi->cluster_size_bits; 486 sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length); 487 sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset); 488 sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset); 489 if (p_boot->num_fats == 2) 490 sbi->FAT2_start_sector += sbi->num_FAT_sectors; 491 sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset); 492 sbi->num_sectors = le64_to_cpu(p_boot->vol_length); 493 /* because the cluster index starts with 2 */ 494 sbi->num_clusters = le32_to_cpu(p_boot->clu_count) + 495 EXFAT_RESERVED_CLUSTERS; 496 497 sbi->root_dir = le32_to_cpu(p_boot->root_cluster); 498 sbi->dentries_per_clu = 1 << 499 (sbi->cluster_size_bits - DENTRY_SIZE_BITS); 500 501 sbi->vol_flags = le16_to_cpu(p_boot->vol_flags); 502 sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE); 503 sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER; 504 sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED; 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_upcase_table; 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_upcase_table: 621 exfat_free_upcase_table(sbi); 622 free_bh: 623 brelse(sbi->boot_bh); 624 return ret; 625 } 626 627 static int exfat_fill_super(struct super_block *sb, struct fs_context *fc) 628 { 629 struct exfat_sb_info *sbi = sb->s_fs_info; 630 struct exfat_mount_options *opts = &sbi->options; 631 struct inode *root_inode; 632 int err; 633 634 if (opts->allow_utime == (unsigned short)-1) 635 opts->allow_utime = ~opts->fs_dmask & 0022; 636 637 if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) { 638 exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard"); 639 opts->discard = 0; 640 } 641 642 sb->s_flags |= SB_NODIRATIME; 643 sb->s_magic = EXFAT_SUPER_MAGIC; 644 sb->s_op = &exfat_sops; 645 646 sb->s_time_gran = 10 * NSEC_PER_MSEC; 647 sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS; 648 sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS; 649 650 err = __exfat_fill_super(sb); 651 if (err) { 652 exfat_err(sb, "failed to recognize exfat type"); 653 goto check_nls_io; 654 } 655 656 /* set up enough so that it can read an inode */ 657 exfat_hash_init(sb); 658 659 if (!strcmp(sbi->options.iocharset, "utf8")) 660 opts->utf8 = 1; 661 else { 662 sbi->nls_io = load_nls(sbi->options.iocharset); 663 if (!sbi->nls_io) { 664 exfat_err(sb, "IO charset %s not found", 665 sbi->options.iocharset); 666 err = -EINVAL; 667 goto free_table; 668 } 669 } 670 671 if (sbi->options.utf8) 672 sb->s_d_op = &exfat_utf8_dentry_ops; 673 else 674 sb->s_d_op = &exfat_dentry_ops; 675 676 root_inode = new_inode(sb); 677 if (!root_inode) { 678 exfat_err(sb, "failed to allocate root inode"); 679 err = -ENOMEM; 680 goto free_table; 681 } 682 683 root_inode->i_ino = EXFAT_ROOT_INO; 684 inode_set_iversion(root_inode, 1); 685 err = exfat_read_root(root_inode); 686 if (err) { 687 exfat_err(sb, "failed to initialize root inode"); 688 goto put_inode; 689 } 690 691 exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos); 692 insert_inode_hash(root_inode); 693 694 sb->s_root = d_make_root(root_inode); 695 if (!sb->s_root) { 696 exfat_err(sb, "failed to get the root dentry"); 697 err = -ENOMEM; 698 goto free_table; 699 } 700 701 return 0; 702 703 put_inode: 704 iput(root_inode); 705 sb->s_root = NULL; 706 707 free_table: 708 exfat_free_upcase_table(sbi); 709 exfat_free_bitmap(sbi); 710 brelse(sbi->boot_bh); 711 712 check_nls_io: 713 unload_nls(sbi->nls_io); 714 exfat_free_iocharset(sbi); 715 sb->s_fs_info = NULL; 716 kfree(sbi); 717 return err; 718 } 719 720 static int exfat_get_tree(struct fs_context *fc) 721 { 722 return get_tree_bdev(fc, exfat_fill_super); 723 } 724 725 static void exfat_free(struct fs_context *fc) 726 { 727 struct exfat_sb_info *sbi = fc->s_fs_info; 728 729 if (sbi) { 730 exfat_free_iocharset(sbi); 731 kfree(sbi); 732 } 733 } 734 735 static int exfat_reconfigure(struct fs_context *fc) 736 { 737 fc->sb_flags |= SB_NODIRATIME; 738 739 /* volume flag will be updated in exfat_sync_fs */ 740 sync_filesystem(fc->root->d_sb); 741 return 0; 742 } 743 744 static const struct fs_context_operations exfat_context_ops = { 745 .parse_param = exfat_parse_param, 746 .get_tree = exfat_get_tree, 747 .free = exfat_free, 748 .reconfigure = exfat_reconfigure, 749 }; 750 751 static int exfat_init_fs_context(struct fs_context *fc) 752 { 753 struct exfat_sb_info *sbi; 754 755 sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL); 756 if (!sbi) 757 return -ENOMEM; 758 759 mutex_init(&sbi->s_lock); 760 mutex_init(&sbi->bitmap_lock); 761 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 762 DEFAULT_RATELIMIT_BURST); 763 764 sbi->options.fs_uid = current_uid(); 765 sbi->options.fs_gid = current_gid(); 766 sbi->options.fs_fmask = current->fs->umask; 767 sbi->options.fs_dmask = current->fs->umask; 768 sbi->options.allow_utime = -1; 769 sbi->options.iocharset = exfat_default_iocharset; 770 sbi->options.errors = EXFAT_ERRORS_RO; 771 772 fc->s_fs_info = sbi; 773 fc->ops = &exfat_context_ops; 774 return 0; 775 } 776 777 static struct file_system_type exfat_fs_type = { 778 .owner = THIS_MODULE, 779 .name = "exfat", 780 .init_fs_context = exfat_init_fs_context, 781 .parameters = exfat_parameters, 782 .kill_sb = kill_block_super, 783 .fs_flags = FS_REQUIRES_DEV, 784 }; 785 786 static void exfat_inode_init_once(void *foo) 787 { 788 struct exfat_inode_info *ei = (struct exfat_inode_info *)foo; 789 790 spin_lock_init(&ei->cache_lru_lock); 791 ei->nr_caches = 0; 792 ei->cache_valid_id = EXFAT_CACHE_VALID + 1; 793 INIT_LIST_HEAD(&ei->cache_lru); 794 INIT_HLIST_NODE(&ei->i_hash_fat); 795 inode_init_once(&ei->vfs_inode); 796 } 797 798 static int __init init_exfat_fs(void) 799 { 800 int err; 801 802 err = exfat_cache_init(); 803 if (err) 804 return err; 805 806 exfat_inode_cachep = kmem_cache_create("exfat_inode_cache", 807 sizeof(struct exfat_inode_info), 808 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, 809 exfat_inode_init_once); 810 if (!exfat_inode_cachep) { 811 err = -ENOMEM; 812 goto shutdown_cache; 813 } 814 815 err = register_filesystem(&exfat_fs_type); 816 if (err) 817 goto destroy_cache; 818 819 return 0; 820 821 destroy_cache: 822 kmem_cache_destroy(exfat_inode_cachep); 823 shutdown_cache: 824 exfat_cache_shutdown(); 825 return err; 826 } 827 828 static void __exit exit_exfat_fs(void) 829 { 830 /* 831 * Make sure all delayed rcu free inodes are flushed before we 832 * destroy cache. 833 */ 834 rcu_barrier(); 835 kmem_cache_destroy(exfat_inode_cachep); 836 unregister_filesystem(&exfat_fs_type); 837 exfat_cache_shutdown(); 838 } 839 840 module_init(init_exfat_fs); 841 module_exit(exit_exfat_fs); 842 843 MODULE_ALIAS_FS("exfat"); 844 MODULE_LICENSE("GPL"); 845 MODULE_DESCRIPTION("exFAT filesystem support"); 846 MODULE_AUTHOR("Samsung Electronics Co., Ltd."); 847