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