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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.4 */5 6#include <linux/slab.h>7#include <linux/compat.h>8#include <linux/bio.h>9#include <linux/buffer_head.h>10 11#include "exfat_raw.h"12#include "exfat_fs.h"13 14static int exfat_extract_uni_name(struct exfat_dentry *ep,15 unsigned short *uniname)16{17 int i, len = 0;18 19 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {20 *uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]);21 if (*uniname == 0x0)22 return len;23 uniname++;24 len++;25 }26 27 *uniname = 0x0;28 return len;29 30}31 32static int exfat_get_uniname_from_ext_entry(struct super_block *sb,33 struct exfat_chain *p_dir, int entry, unsigned short *uniname)34{35 int i, err;36 struct exfat_entry_set_cache es;37 unsigned int uni_len = 0, len;38 39 err = exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES);40 if (err)41 return err;42 43 /*44 * First entry : file entry45 * Second entry : stream-extension entry46 * Third entry : first file-name entry47 * So, the index of first file-name dentry should start from 2.48 */49 for (i = ES_IDX_FIRST_FILENAME; i < es.num_entries; i++) {50 struct exfat_dentry *ep = exfat_get_dentry_cached(&es, i);51 52 /* end of name entry */53 if (exfat_get_entry_type(ep) != TYPE_EXTEND)54 break;55 56 len = exfat_extract_uni_name(ep, uniname);57 uni_len += len;58 if (len != EXFAT_FILE_NAME_LEN || uni_len >= MAX_NAME_LENGTH)59 break;60 uniname += EXFAT_FILE_NAME_LEN;61 }62 63 exfat_put_dentry_set(&es, false);64 return 0;65}66 67/* read a directory entry from the opened directory */68static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry)69{70 int i, dentries_per_clu, num_ext, err;71 unsigned int type, clu_offset, max_dentries;72 struct exfat_chain dir, clu;73 struct exfat_uni_name uni_name;74 struct exfat_dentry *ep;75 struct super_block *sb = inode->i_sb;76 struct exfat_sb_info *sbi = EXFAT_SB(sb);77 struct exfat_inode_info *ei = EXFAT_I(inode);78 unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF;79 struct buffer_head *bh;80 81 /* check if the given file ID is opened */82 if (ei->type != TYPE_DIR)83 return -EPERM;84 85 if (ei->entry == -1)86 exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);87 else88 exfat_chain_set(&dir, ei->start_clu,89 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);90 91 dentries_per_clu = sbi->dentries_per_clu;92 max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES,93 (u64)EXFAT_CLU_TO_DEN(sbi->num_clusters, sbi));94 95 clu_offset = EXFAT_DEN_TO_CLU(dentry, sbi);96 exfat_chain_dup(&clu, &dir);97 98 if (clu.flags == ALLOC_NO_FAT_CHAIN) {99 clu.dir += clu_offset;100 clu.size -= clu_offset;101 } else {102 /* hint_information */103 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&104 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {105 clu_offset -= ei->hint_bmap.off;106 clu.dir = ei->hint_bmap.clu;107 }108 109 while (clu_offset > 0 && clu.dir != EXFAT_EOF_CLUSTER) {110 if (exfat_get_next_cluster(sb, &(clu.dir)))111 return -EIO;112 113 clu_offset--;114 }115 }116 117 while (clu.dir != EXFAT_EOF_CLUSTER && dentry < max_dentries) {118 i = dentry & (dentries_per_clu - 1);119 120 for ( ; i < dentries_per_clu; i++, dentry++) {121 ep = exfat_get_dentry(sb, &clu, i, &bh);122 if (!ep)123 return -EIO;124 125 type = exfat_get_entry_type(ep);126 if (type == TYPE_UNUSED) {127 brelse(bh);128 break;129 }130 131 if (type != TYPE_FILE && type != TYPE_DIR) {132 brelse(bh);133 continue;134 }135 136 num_ext = ep->dentry.file.num_ext;137 dir_entry->attr = le16_to_cpu(ep->dentry.file.attr);138 exfat_get_entry_time(sbi, &dir_entry->crtime,139 ep->dentry.file.create_tz,140 ep->dentry.file.create_time,141 ep->dentry.file.create_date,142 ep->dentry.file.create_time_cs);143 exfat_get_entry_time(sbi, &dir_entry->mtime,144 ep->dentry.file.modify_tz,145 ep->dentry.file.modify_time,146 ep->dentry.file.modify_date,147 ep->dentry.file.modify_time_cs);148 exfat_get_entry_time(sbi, &dir_entry->atime,149 ep->dentry.file.access_tz,150 ep->dentry.file.access_time,151 ep->dentry.file.access_date,152 0);153 154 *uni_name.name = 0x0;155 err = exfat_get_uniname_from_ext_entry(sb, &clu, i,156 uni_name.name);157 if (err) {158 brelse(bh);159 continue;160 }161 exfat_utf16_to_nls(sb, &uni_name,162 dir_entry->namebuf.lfn,163 dir_entry->namebuf.lfnbuf_len);164 brelse(bh);165 166 ep = exfat_get_dentry(sb, &clu, i + 1, &bh);167 if (!ep)168 return -EIO;169 dir_entry->size =170 le64_to_cpu(ep->dentry.stream.valid_size);171 dir_entry->entry = dentry;172 brelse(bh);173 174 ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi);175 ei->hint_bmap.clu = clu.dir;176 177 *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext);178 return 0;179 }180 181 if (clu.flags == ALLOC_NO_FAT_CHAIN) {182 if (--clu.size > 0)183 clu.dir++;184 else185 clu.dir = EXFAT_EOF_CLUSTER;186 } else {187 if (exfat_get_next_cluster(sb, &(clu.dir)))188 return -EIO;189 }190 }191 192 dir_entry->namebuf.lfn[0] = '\0';193 *cpos = EXFAT_DEN_TO_B(dentry);194 return 0;195}196 197static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb)198{199 nb->lfn = NULL;200 nb->lfnbuf_len = 0;201}202 203static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb)204{205 nb->lfn = __getname();206 if (!nb->lfn)207 return -ENOMEM;208 nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE;209 return 0;210}211 212static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb)213{214 if (!nb->lfn)215 return;216 217 __putname(nb->lfn);218 exfat_init_namebuf(nb);219}220 221/*222 * Before calling dir_emit*(), sbi->s_lock should be released223 * because page fault can occur in dir_emit*().224 */225#define ITER_POS_FILLED_DOTS (2)226static int exfat_iterate(struct file *file, struct dir_context *ctx)227{228 struct inode *inode = file_inode(file);229 struct super_block *sb = inode->i_sb;230 struct inode *tmp;231 struct exfat_dir_entry de;232 struct exfat_dentry_namebuf *nb = &(de.namebuf);233 struct exfat_inode_info *ei = EXFAT_I(inode);234 unsigned long inum;235 loff_t cpos, i_pos;236 int err = 0, fake_offset = 0;237 238 exfat_init_namebuf(nb);239 240 cpos = ctx->pos;241 if (!dir_emit_dots(file, ctx))242 goto out;243 244 if (ctx->pos == ITER_POS_FILLED_DOTS) {245 cpos = 0;246 fake_offset = 1;247 }248 249 cpos = round_up(cpos, DENTRY_SIZE);250 251 /* name buffer should be allocated before use */252 err = exfat_alloc_namebuf(nb);253 if (err)254 goto out;255get_new:256 mutex_lock(&EXFAT_SB(sb)->s_lock);257 258 if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode))259 goto end_of_dir;260 261 err = exfat_readdir(inode, &cpos, &de);262 if (err) {263 /*264 * At least we tried to read a sector.265 * Move cpos to next sector position (should be aligned).266 */267 if (err == -EIO) {268 cpos += 1 << (sb->s_blocksize_bits);269 cpos &= ~(sb->s_blocksize - 1);270 }271 272 err = -EIO;273 goto end_of_dir;274 }275 276 if (!nb->lfn[0])277 goto end_of_dir;278 279 i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff);280 tmp = exfat_iget(sb, i_pos);281 if (tmp) {282 inum = tmp->i_ino;283 iput(tmp);284 } else {285 inum = iunique(sb, EXFAT_ROOT_INO);286 }287 288 mutex_unlock(&EXFAT_SB(sb)->s_lock);289 if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum,290 (de.attr & EXFAT_ATTR_SUBDIR) ? DT_DIR : DT_REG))291 goto out;292 ctx->pos = cpos;293 goto get_new;294 295end_of_dir:296 if (!cpos && fake_offset)297 cpos = ITER_POS_FILLED_DOTS;298 ctx->pos = cpos;299 mutex_unlock(&EXFAT_SB(sb)->s_lock);300out:301 /*302 * To improve performance, free namebuf after unlock sb_lock.303 * If namebuf is not allocated, this function do nothing304 */305 exfat_free_namebuf(nb);306 return err;307}308 309WRAP_DIR_ITER(exfat_iterate) // FIXME!310const struct file_operations exfat_dir_operations = {311 .llseek = generic_file_llseek,312 .read = generic_read_dir,313 .iterate_shared = shared_exfat_iterate,314 .unlocked_ioctl = exfat_ioctl,315#ifdef CONFIG_COMPAT316 .compat_ioctl = exfat_compat_ioctl,317#endif318 .fsync = exfat_file_fsync,319};320 321int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu)322{323 int ret;324 325 exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN);326 327 ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode));328 if (ret)329 return ret;330 331 return exfat_zeroed_cluster(inode, clu->dir);332}333 334int exfat_calc_num_entries(struct exfat_uni_name *p_uniname)335{336 int len;337 338 len = p_uniname->name_len;339 if (len == 0)340 return -EINVAL;341 342 /* 1 file entry + 1 stream entry + name entries */343 return ES_ENTRY_NUM(len);344}345 346unsigned int exfat_get_entry_type(struct exfat_dentry *ep)347{348 if (ep->type == EXFAT_UNUSED)349 return TYPE_UNUSED;350 if (IS_EXFAT_DELETED(ep->type))351 return TYPE_DELETED;352 if (ep->type == EXFAT_INVAL)353 return TYPE_INVALID;354 if (IS_EXFAT_CRITICAL_PRI(ep->type)) {355 if (ep->type == EXFAT_BITMAP)356 return TYPE_BITMAP;357 if (ep->type == EXFAT_UPCASE)358 return TYPE_UPCASE;359 if (ep->type == EXFAT_VOLUME)360 return TYPE_VOLUME;361 if (ep->type == EXFAT_FILE) {362 if (le16_to_cpu(ep->dentry.file.attr) & EXFAT_ATTR_SUBDIR)363 return TYPE_DIR;364 return TYPE_FILE;365 }366 return TYPE_CRITICAL_PRI;367 }368 if (IS_EXFAT_BENIGN_PRI(ep->type)) {369 if (ep->type == EXFAT_GUID)370 return TYPE_GUID;371 if (ep->type == EXFAT_PADDING)372 return TYPE_PADDING;373 if (ep->type == EXFAT_ACLTAB)374 return TYPE_ACLTAB;375 return TYPE_BENIGN_PRI;376 }377 if (IS_EXFAT_CRITICAL_SEC(ep->type)) {378 if (ep->type == EXFAT_STREAM)379 return TYPE_STREAM;380 if (ep->type == EXFAT_NAME)381 return TYPE_EXTEND;382 if (ep->type == EXFAT_ACL)383 return TYPE_ACL;384 return TYPE_CRITICAL_SEC;385 }386 387 if (ep->type == EXFAT_VENDOR_EXT)388 return TYPE_VENDOR_EXT;389 if (ep->type == EXFAT_VENDOR_ALLOC)390 return TYPE_VENDOR_ALLOC;391 392 return TYPE_BENIGN_SEC;393}394 395static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type)396{397 if (type == TYPE_UNUSED) {398 ep->type = EXFAT_UNUSED;399 } else if (type == TYPE_DELETED) {400 ep->type &= EXFAT_DELETE;401 } else if (type == TYPE_STREAM) {402 ep->type = EXFAT_STREAM;403 } else if (type == TYPE_EXTEND) {404 ep->type = EXFAT_NAME;405 } else if (type == TYPE_BITMAP) {406 ep->type = EXFAT_BITMAP;407 } else if (type == TYPE_UPCASE) {408 ep->type = EXFAT_UPCASE;409 } else if (type == TYPE_VOLUME) {410 ep->type = EXFAT_VOLUME;411 } else if (type == TYPE_DIR) {412 ep->type = EXFAT_FILE;413 ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_SUBDIR);414 } else if (type == TYPE_FILE) {415 ep->type = EXFAT_FILE;416 ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_ARCHIVE);417 }418}419 420static void exfat_init_stream_entry(struct exfat_dentry *ep,421 unsigned int start_clu, unsigned long long size)422{423 memset(ep, 0, sizeof(*ep));424 exfat_set_entry_type(ep, TYPE_STREAM);425 if (size == 0)426 ep->dentry.stream.flags = ALLOC_FAT_CHAIN;427 else428 ep->dentry.stream.flags = ALLOC_NO_FAT_CHAIN;429 ep->dentry.stream.start_clu = cpu_to_le32(start_clu);430 ep->dentry.stream.valid_size = cpu_to_le64(size);431 ep->dentry.stream.size = cpu_to_le64(size);432}433 434static void exfat_init_name_entry(struct exfat_dentry *ep,435 unsigned short *uniname)436{437 int i;438 439 exfat_set_entry_type(ep, TYPE_EXTEND);440 ep->dentry.name.flags = 0x0;441 442 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {443 if (*uniname != 0x0) {444 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname);445 uniname++;446 } else {447 ep->dentry.name.unicode_0_14[i] = 0x0;448 }449 }450}451 452void exfat_init_dir_entry(struct exfat_entry_set_cache *es,453 unsigned int type, unsigned int start_clu,454 unsigned long long size, struct timespec64 *ts)455{456 struct super_block *sb = es->sb;457 struct exfat_sb_info *sbi = EXFAT_SB(sb);458 struct exfat_dentry *ep;459 460 ep = exfat_get_dentry_cached(es, ES_IDX_FILE);461 memset(ep, 0, sizeof(*ep));462 exfat_set_entry_type(ep, type);463 exfat_set_entry_time(sbi, ts,464 &ep->dentry.file.create_tz,465 &ep->dentry.file.create_time,466 &ep->dentry.file.create_date,467 &ep->dentry.file.create_time_cs);468 exfat_set_entry_time(sbi, ts,469 &ep->dentry.file.modify_tz,470 &ep->dentry.file.modify_time,471 &ep->dentry.file.modify_date,472 &ep->dentry.file.modify_time_cs);473 exfat_set_entry_time(sbi, ts,474 &ep->dentry.file.access_tz,475 &ep->dentry.file.access_time,476 &ep->dentry.file.access_date,477 NULL);478 479 ep = exfat_get_dentry_cached(es, ES_IDX_STREAM);480 exfat_init_stream_entry(ep, start_clu, size);481}482 483static void exfat_free_benign_secondary_clusters(struct inode *inode,484 struct exfat_dentry *ep)485{486 struct super_block *sb = inode->i_sb;487 struct exfat_chain dir;488 unsigned int start_clu =489 le32_to_cpu(ep->dentry.generic_secondary.start_clu);490 u64 size = le64_to_cpu(ep->dentry.generic_secondary.size);491 unsigned char flags = ep->dentry.generic_secondary.flags;492 493 if (!(flags & ALLOC_POSSIBLE) || !start_clu || !size)494 return;495 496 exfat_chain_set(&dir, start_clu,497 EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)),498 flags);499 exfat_free_cluster(inode, &dir);500}501 502void exfat_init_ext_entry(struct exfat_entry_set_cache *es, int num_entries,503 struct exfat_uni_name *p_uniname)504{505 int i;506 unsigned short *uniname = p_uniname->name;507 struct exfat_dentry *ep;508 509 ep = exfat_get_dentry_cached(es, ES_IDX_FILE);510 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1);511 512 ep = exfat_get_dentry_cached(es, ES_IDX_STREAM);513 ep->dentry.stream.name_len = p_uniname->name_len;514 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash);515 516 for (i = ES_IDX_FIRST_FILENAME; i < num_entries; i++) {517 ep = exfat_get_dentry_cached(es, i);518 exfat_init_name_entry(ep, uniname);519 uniname += EXFAT_FILE_NAME_LEN;520 }521 522 exfat_update_dir_chksum(es);523}524 525void exfat_remove_entries(struct inode *inode, struct exfat_entry_set_cache *es,526 int order)527{528 int i;529 struct exfat_dentry *ep;530 531 for (i = order; i < es->num_entries; i++) {532 ep = exfat_get_dentry_cached(es, i);533 534 if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC)535 exfat_free_benign_secondary_clusters(inode, ep);536 537 exfat_set_entry_type(ep, TYPE_DELETED);538 }539 540 if (order < es->num_entries)541 es->modified = true;542}543 544void exfat_update_dir_chksum(struct exfat_entry_set_cache *es)545{546 int chksum_type = CS_DIR_ENTRY, i;547 unsigned short chksum = 0;548 struct exfat_dentry *ep;549 550 for (i = ES_IDX_FILE; i < es->num_entries; i++) {551 ep = exfat_get_dentry_cached(es, i);552 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,553 chksum_type);554 chksum_type = CS_DEFAULT;555 }556 ep = exfat_get_dentry_cached(es, ES_IDX_FILE);557 ep->dentry.file.checksum = cpu_to_le16(chksum);558 es->modified = true;559}560 561int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync)562{563 int i, err = 0;564 565 if (es->modified)566 err = exfat_update_bhs(es->bh, es->num_bh, sync);567 568 for (i = 0; i < es->num_bh; i++)569 if (err)570 bforget(es->bh[i]);571 else572 brelse(es->bh[i]);573 574 if (IS_DYNAMIC_ES(es))575 kfree(es->bh);576 577 return err;578}579 580static int exfat_walk_fat_chain(struct super_block *sb,581 struct exfat_chain *p_dir, unsigned int byte_offset,582 unsigned int *clu)583{584 struct exfat_sb_info *sbi = EXFAT_SB(sb);585 unsigned int clu_offset;586 unsigned int cur_clu;587 588 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi);589 cur_clu = p_dir->dir;590 591 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) {592 cur_clu += clu_offset;593 } else {594 while (clu_offset > 0) {595 if (exfat_get_next_cluster(sb, &cur_clu))596 return -EIO;597 if (cur_clu == EXFAT_EOF_CLUSTER) {598 exfat_fs_error(sb,599 "invalid dentry access beyond EOF (clu : %u, eidx : %d)",600 p_dir->dir,601 EXFAT_B_TO_DEN(byte_offset));602 return -EIO;603 }604 clu_offset--;605 }606 }607 608 *clu = cur_clu;609 return 0;610}611 612static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,613 int entry, sector_t *sector, int *offset)614{615 int ret;616 unsigned int off, clu = 0;617 struct exfat_sb_info *sbi = EXFAT_SB(sb);618 619 off = EXFAT_DEN_TO_B(entry);620 621 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu);622 if (ret)623 return ret;624 625 /* byte offset in cluster */626 off = EXFAT_CLU_OFFSET(off, sbi);627 628 /* byte offset in sector */629 *offset = EXFAT_BLK_OFFSET(off, sb);630 631 /* sector offset in cluster */632 *sector = EXFAT_B_TO_BLK(off, sb);633 *sector += exfat_cluster_to_sector(sbi, clu);634 return 0;635}636 637#define EXFAT_MAX_RA_SIZE (128*1024)638static int exfat_dir_readahead(struct super_block *sb, sector_t sec)639{640 struct exfat_sb_info *sbi = EXFAT_SB(sb);641 struct buffer_head *bh;642 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits;643 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits;644 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count);645 unsigned int ra_count = min(adj_ra_count, max_ra_count);646 647 /* Read-ahead is not required */648 if (sbi->sect_per_clus == 1)649 return 0;650 651 if (sec < sbi->data_start_sector) {652 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)",653 (unsigned long long)sec, sbi->data_start_sector);654 return -EIO;655 }656 657 /* Not sector aligned with ra_count, resize ra_count to page size */658 if ((sec - sbi->data_start_sector) & (ra_count - 1))659 ra_count = page_ra_count;660 661 bh = sb_find_get_block(sb, sec);662 if (!bh || !buffer_uptodate(bh)) {663 unsigned int i;664 665 for (i = 0; i < ra_count; i++)666 sb_breadahead(sb, (sector_t)(sec + i));667 }668 brelse(bh);669 return 0;670}671 672struct exfat_dentry *exfat_get_dentry(struct super_block *sb,673 struct exfat_chain *p_dir, int entry, struct buffer_head **bh)674{675 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE);676 int off;677 sector_t sec;678 679 if (p_dir->dir == DIR_DELETED) {680 exfat_err(sb, "abnormal access to deleted dentry");681 return NULL;682 }683 684 if (exfat_find_location(sb, p_dir, entry, &sec, &off))685 return NULL;686 687 if (p_dir->dir != EXFAT_FREE_CLUSTER &&688 !(entry & (dentries_per_page - 1)))689 exfat_dir_readahead(sb, sec);690 691 *bh = sb_bread(sb, sec);692 if (!*bh)693 return NULL;694 695 return (struct exfat_dentry *)((*bh)->b_data + off);696}697 698enum exfat_validate_dentry_mode {699 ES_MODE_GET_FILE_ENTRY,700 ES_MODE_GET_STRM_ENTRY,701 ES_MODE_GET_NAME_ENTRY,702 ES_MODE_GET_CRITICAL_SEC_ENTRY,703 ES_MODE_GET_BENIGN_SEC_ENTRY,704};705 706static bool exfat_validate_entry(unsigned int type,707 enum exfat_validate_dentry_mode *mode)708{709 if (type == TYPE_UNUSED || type == TYPE_DELETED)710 return false;711 712 switch (*mode) {713 case ES_MODE_GET_FILE_ENTRY:714 if (type != TYPE_STREAM)715 return false;716 *mode = ES_MODE_GET_STRM_ENTRY;717 break;718 case ES_MODE_GET_STRM_ENTRY:719 if (type != TYPE_EXTEND)720 return false;721 *mode = ES_MODE_GET_NAME_ENTRY;722 break;723 case ES_MODE_GET_NAME_ENTRY:724 if (type & TYPE_BENIGN_SEC)725 *mode = ES_MODE_GET_BENIGN_SEC_ENTRY;726 else if (type != TYPE_EXTEND)727 return false;728 break;729 case ES_MODE_GET_BENIGN_SEC_ENTRY:730 /* Assume unreconized benign secondary entry */731 if (!(type & TYPE_BENIGN_SEC))732 return false;733 break;734 default:735 return false;736 }737 738 return true;739}740 741struct exfat_dentry *exfat_get_dentry_cached(742 struct exfat_entry_set_cache *es, int num)743{744 int off = es->start_off + num * DENTRY_SIZE;745 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];746 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb);747 748 return (struct exfat_dentry *)p;749}750 751/*752 * Returns a set of dentries.753 *754 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached().755 * User should call exfat_get_dentry_set() after setting 'modified' to apply756 * changes made in this entry set to the real device.757 *758 * in:759 * sb+p_dir+entry: indicates a file/dir760 * num_entries: specifies how many dentries should be included.761 * It will be set to es->num_entries if it is not 0.762 * If num_entries is 0, es->num_entries will be obtained763 * from the first dentry.764 * out:765 * es: pointer of entry set on success.766 * return:767 * 0 on success768 * -error code on failure769 */770static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es,771 struct super_block *sb, struct exfat_chain *p_dir, int entry,772 unsigned int num_entries)773{774 int ret, i, num_bh;775 unsigned int off;776 sector_t sec;777 struct exfat_sb_info *sbi = EXFAT_SB(sb);778 struct buffer_head *bh;779 780 if (p_dir->dir == DIR_DELETED) {781 exfat_err(sb, "access to deleted dentry");782 return -EIO;783 }784 785 ret = exfat_find_location(sb, p_dir, entry, &sec, &off);786 if (ret)787 return ret;788 789 memset(es, 0, sizeof(*es));790 es->sb = sb;791 es->modified = false;792 es->start_off = off;793 es->bh = es->__bh;794 795 bh = sb_bread(sb, sec);796 if (!bh)797 return -EIO;798 es->bh[es->num_bh++] = bh;799 800 if (num_entries == ES_ALL_ENTRIES) {801 struct exfat_dentry *ep;802 803 ep = exfat_get_dentry_cached(es, ES_IDX_FILE);804 if (ep->type != EXFAT_FILE) {805 brelse(bh);806 return -EIO;807 }808 809 num_entries = ep->dentry.file.num_ext + 1;810 }811 812 es->num_entries = num_entries;813 814 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb);815 if (num_bh > ARRAY_SIZE(es->__bh)) {816 es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_NOFS);817 if (!es->bh) {818 brelse(bh);819 return -ENOMEM;820 }821 es->bh[0] = bh;822 }823 824 for (i = 1; i < num_bh; i++) {825 /* get the next sector */826 if (exfat_is_last_sector_in_cluster(sbi, sec)) {827 unsigned int clu = exfat_sector_to_cluster(sbi, sec);828 829 if (p_dir->flags == ALLOC_NO_FAT_CHAIN)830 clu++;831 else if (exfat_get_next_cluster(sb, &clu))832 goto put_es;833 sec = exfat_cluster_to_sector(sbi, clu);834 } else {835 sec++;836 }837 838 bh = sb_bread(sb, sec);839 if (!bh)840 goto put_es;841 es->bh[es->num_bh++] = bh;842 }843 844 return 0;845 846put_es:847 exfat_put_dentry_set(es, false);848 return -EIO;849}850 851int exfat_get_dentry_set(struct exfat_entry_set_cache *es,852 struct super_block *sb, struct exfat_chain *p_dir,853 int entry, unsigned int num_entries)854{855 int ret, i;856 struct exfat_dentry *ep;857 enum exfat_validate_dentry_mode mode = ES_MODE_GET_FILE_ENTRY;858 859 ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries);860 if (ret < 0)861 return ret;862 863 /* validate cached dentries */864 for (i = ES_IDX_STREAM; i < es->num_entries; i++) {865 ep = exfat_get_dentry_cached(es, i);866 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))867 goto put_es;868 }869 return 0;870 871put_es:872 exfat_put_dentry_set(es, false);873 return -EIO;874}875 876static int exfat_validate_empty_dentry_set(struct exfat_entry_set_cache *es)877{878 struct exfat_dentry *ep;879 struct buffer_head *bh;880 int i, off;881 bool unused_hit = false;882 883 /*884 * ONLY UNUSED OR DELETED DENTRIES ARE ALLOWED:885 * Although it violates the specification for a deleted entry to886 * follow an unused entry, some exFAT implementations could work887 * like this. Therefore, to improve compatibility, let's allow it.888 */889 for (i = 0; i < es->num_entries; i++) {890 ep = exfat_get_dentry_cached(es, i);891 if (ep->type == EXFAT_UNUSED) {892 unused_hit = true;893 } else if (!IS_EXFAT_DELETED(ep->type)) {894 if (unused_hit)895 goto err_used_follow_unused;896 i++;897 goto count_skip_entries;898 }899 }900 901 return 0;902 903err_used_follow_unused:904 off = es->start_off + (i << DENTRY_SIZE_BITS);905 bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];906 907 exfat_fs_error(es->sb,908 "in sector %lld, dentry %d should be unused, but 0x%x",909 bh->b_blocknr, off >> DENTRY_SIZE_BITS, ep->type);910 911 return -EIO;912 913count_skip_entries:914 es->num_entries = EXFAT_B_TO_DEN(EXFAT_BLK_TO_B(es->num_bh, es->sb) - es->start_off);915 for (; i < es->num_entries; i++) {916 ep = exfat_get_dentry_cached(es, i);917 if (IS_EXFAT_DELETED(ep->type))918 break;919 }920 921 return i;922}923 924/*925 * Get an empty dentry set.926 *927 * in:928 * sb+p_dir+entry: indicates the empty dentry location929 * num_entries: specifies how many empty dentries should be included.930 * out:931 * es: pointer of empty dentry set on success.932 * return:933 * 0 : on success934 * >0 : the dentries are not empty, the return value is the number of935 * dentries to be skipped for the next lookup.936 * <0 : on failure937 */938int exfat_get_empty_dentry_set(struct exfat_entry_set_cache *es,939 struct super_block *sb, struct exfat_chain *p_dir,940 int entry, unsigned int num_entries)941{942 int ret;943 944 ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries);945 if (ret < 0)946 return ret;947 948 ret = exfat_validate_empty_dentry_set(es);949 if (ret)950 exfat_put_dentry_set(es, false);951 952 return ret;953}954 955static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp)956{957 hint_femp->eidx = EXFAT_HINT_NONE;958 hint_femp->count = 0;959}960 961static inline void exfat_set_empty_hint(struct exfat_inode_info *ei,962 struct exfat_hint_femp *candi_empty, struct exfat_chain *clu,963 int dentry, int num_entries, int entry_type)964{965 if (ei->hint_femp.eidx == EXFAT_HINT_NONE ||966 ei->hint_femp.eidx > dentry) {967 int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode));968 969 if (candi_empty->count == 0) {970 candi_empty->cur = *clu;971 candi_empty->eidx = dentry;972 }973 974 if (entry_type == TYPE_UNUSED)975 candi_empty->count += total_entries - dentry;976 else977 candi_empty->count++;978 979 if (candi_empty->count == num_entries ||980 candi_empty->count + candi_empty->eidx == total_entries)981 ei->hint_femp = *candi_empty;982 }983}984 985enum {986 DIRENT_STEP_FILE,987 DIRENT_STEP_STRM,988 DIRENT_STEP_NAME,989 DIRENT_STEP_SECD,990};991 992/*993 * @ei: inode info of parent directory994 * @p_dir: directory structure of parent directory995 * @num_entries:entry size of p_uniname996 * @hint_opt: If p_uniname is found, filled with optimized dir/entry997 * for traversing cluster chain.998 * @return:999 * >= 0: file directory entry position where the name exists1000 * -ENOENT: entry with the name does not exist1001 * -EIO: I/O error1002 */1003int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,1004 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,1005 struct exfat_hint *hint_opt)1006{1007 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len;1008 int order, step, name_len = 0;1009 int dentries_per_clu;1010 unsigned int entry_type;1011 unsigned short *uniname = NULL;1012 struct exfat_chain clu;1013 struct exfat_hint *hint_stat = &ei->hint_stat;1014 struct exfat_hint_femp candi_empty;1015 struct exfat_sb_info *sbi = EXFAT_SB(sb);1016 int num_entries = exfat_calc_num_entries(p_uniname);1017 1018 if (num_entries < 0)1019 return num_entries;1020 1021 dentries_per_clu = sbi->dentries_per_clu;1022 1023 exfat_chain_dup(&clu, p_dir);1024 1025 if (hint_stat->eidx) {1026 clu.dir = hint_stat->clu;1027 dentry = hint_stat->eidx;1028 end_eidx = dentry;1029 }1030 1031 exfat_reset_empty_hint(&ei->hint_femp);1032 1033rewind:1034 order = 0;1035 step = DIRENT_STEP_FILE;1036 exfat_reset_empty_hint(&candi_empty);1037 1038 while (clu.dir != EXFAT_EOF_CLUSTER) {1039 i = dentry & (dentries_per_clu - 1);1040 for (; i < dentries_per_clu; i++, dentry++) {1041 struct exfat_dentry *ep;1042 struct buffer_head *bh;1043 1044 if (rewind && dentry == end_eidx)1045 goto not_found;1046 1047 ep = exfat_get_dentry(sb, &clu, i, &bh);1048 if (!ep)1049 return -EIO;1050 1051 entry_type = exfat_get_entry_type(ep);1052 1053 if (entry_type == TYPE_UNUSED ||1054 entry_type == TYPE_DELETED) {1055 step = DIRENT_STEP_FILE;1056 1057 exfat_set_empty_hint(ei, &candi_empty, &clu,1058 dentry, num_entries,1059 entry_type);1060 1061 brelse(bh);1062 if (entry_type == TYPE_UNUSED)1063 goto not_found;1064 continue;1065 }1066 1067 exfat_reset_empty_hint(&candi_empty);1068 1069 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) {1070 step = DIRENT_STEP_FILE;1071 hint_opt->clu = clu.dir;1072 hint_opt->eidx = i;1073 num_ext = ep->dentry.file.num_ext;1074 step = DIRENT_STEP_STRM;1075 brelse(bh);1076 continue;1077 }1078 1079 if (entry_type == TYPE_STREAM) {1080 u16 name_hash;1081 1082 if (step != DIRENT_STEP_STRM) {1083 step = DIRENT_STEP_FILE;1084 brelse(bh);1085 continue;1086 }1087 step = DIRENT_STEP_FILE;1088 name_hash = le16_to_cpu(1089 ep->dentry.stream.name_hash);1090 if (p_uniname->name_hash == name_hash &&1091 p_uniname->name_len ==1092 ep->dentry.stream.name_len) {1093 step = DIRENT_STEP_NAME;1094 order = 1;1095 name_len = 0;1096 }1097 brelse(bh);1098 continue;1099 }1100 1101 brelse(bh);1102 if (entry_type == TYPE_EXTEND) {1103 unsigned short entry_uniname[16], unichar;1104 1105 if (step != DIRENT_STEP_NAME ||1106 name_len >= MAX_NAME_LENGTH) {1107 step = DIRENT_STEP_FILE;1108 continue;1109 }1110 1111 if (++order == 2)1112 uniname = p_uniname->name;1113 else1114 uniname += EXFAT_FILE_NAME_LEN;1115 1116 len = exfat_extract_uni_name(ep, entry_uniname);1117 name_len += len;1118 1119 unichar = *(uniname+len);1120 *(uniname+len) = 0x0;1121 1122 if (exfat_uniname_ncmp(sb, uniname,1123 entry_uniname, len)) {1124 step = DIRENT_STEP_FILE;1125 } else if (p_uniname->name_len == name_len) {1126 if (order == num_ext)1127 goto found;1128 step = DIRENT_STEP_SECD;1129 }1130 1131 *(uniname+len) = unichar;1132 continue;1133 }1134 1135 if (entry_type &1136 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) {1137 if (step == DIRENT_STEP_SECD) {1138 if (++order == num_ext)1139 goto found;1140 continue;1141 }1142 }1143 step = DIRENT_STEP_FILE;1144 }1145 1146 if (clu.flags == ALLOC_NO_FAT_CHAIN) {1147 if (--clu.size > 0)1148 clu.dir++;1149 else1150 clu.dir = EXFAT_EOF_CLUSTER;1151 } else {1152 if (exfat_get_next_cluster(sb, &clu.dir))1153 return -EIO;1154 }1155 }1156 1157not_found:1158 /*1159 * We started at not 0 index,so we should try to find target1160 * from 0 index to the index we started at.1161 */1162 if (!rewind && end_eidx) {1163 rewind = 1;1164 dentry = 0;1165 clu.dir = p_dir->dir;1166 goto rewind;1167 }1168 1169 /*1170 * set the EXFAT_EOF_CLUSTER flag to avoid search1171 * from the beginning again when allocated a new cluster1172 */1173 if (ei->hint_femp.eidx == EXFAT_HINT_NONE) {1174 ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER;1175 ei->hint_femp.eidx = p_dir->size * dentries_per_clu;1176 ei->hint_femp.count = 0;1177 }1178 1179 /* initialized hint_stat */1180 hint_stat->clu = p_dir->dir;1181 hint_stat->eidx = 0;1182 return -ENOENT;1183 1184found:1185 /* next dentry we'll find is out of this cluster */1186 if (!((dentry + 1) & (dentries_per_clu - 1))) {1187 int ret = 0;1188 1189 if (clu.flags == ALLOC_NO_FAT_CHAIN) {1190 if (--clu.size > 0)1191 clu.dir++;1192 else1193 clu.dir = EXFAT_EOF_CLUSTER;1194 } else {1195 ret = exfat_get_next_cluster(sb, &clu.dir);1196 }1197 1198 if (ret || clu.dir == EXFAT_EOF_CLUSTER) {1199 /* just initialized hint_stat */1200 hint_stat->clu = p_dir->dir;1201 hint_stat->eidx = 0;1202 return (dentry - num_ext);1203 }1204 }1205 1206 hint_stat->clu = clu.dir;1207 hint_stat->eidx = dentry + 1;1208 return dentry - num_ext;1209}1210 1211int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir)1212{1213 int i, count = 0;1214 int dentries_per_clu;1215 unsigned int entry_type;1216 struct exfat_chain clu;1217 struct exfat_dentry *ep;1218 struct exfat_sb_info *sbi = EXFAT_SB(sb);1219 struct buffer_head *bh;1220 1221 dentries_per_clu = sbi->dentries_per_clu;1222 1223 exfat_chain_dup(&clu, p_dir);1224 1225 while (clu.dir != EXFAT_EOF_CLUSTER) {1226 for (i = 0; i < dentries_per_clu; i++) {1227 ep = exfat_get_dentry(sb, &clu, i, &bh);1228 if (!ep)1229 return -EIO;1230 entry_type = exfat_get_entry_type(ep);1231 brelse(bh);1232 1233 if (entry_type == TYPE_UNUSED)1234 return count;1235 if (entry_type != TYPE_DIR)1236 continue;1237 count++;1238 }1239 1240 if (clu.flags == ALLOC_NO_FAT_CHAIN) {1241 if (--clu.size > 0)1242 clu.dir++;1243 else1244 clu.dir = EXFAT_EOF_CLUSTER;1245 } else {1246 if (exfat_get_next_cluster(sb, &(clu.dir)))1247 return -EIO;1248 }1249 }1250 1251 return count;1252}1253