| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. |
| */ |
| |
| #include <linux/slab.h> |
| #include <linux/compat.h> |
| #include <linux/bio.h> |
| #include <linux/buffer_head.h> |
| |
| #include "exfat_raw.h" |
| #include "exfat_fs.h" |
| |
| static int exfat_extract_uni_name(struct exfat_dentry *ep, |
| unsigned short *uniname) |
| { |
| int i, len = 0; |
| |
| for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { |
| *uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]); |
| if (*uniname == 0x0) |
| return len; |
| uniname++; |
| len++; |
| } |
| |
| *uniname = 0x0; |
| return len; |
| |
| } |
| |
| static void exfat_get_uniname_from_ext_entry(struct super_block *sb, |
| struct exfat_chain *p_dir, int entry, unsigned short *uniname) |
| { |
| int i; |
| struct exfat_entry_set_cache *es; |
| |
| es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES); |
| if (!es) |
| return; |
| |
| /* |
| * First entry : file entry |
| * Second entry : stream-extension entry |
| * Third entry : first file-name entry |
| * So, the index of first file-name dentry should start from 2. |
| */ |
| for (i = 2; i < es->num_entries; i++) { |
| struct exfat_dentry *ep = exfat_get_dentry_cached(es, i); |
| |
| /* end of name entry */ |
| if (exfat_get_entry_type(ep) != TYPE_EXTEND) |
| break; |
| |
| exfat_extract_uni_name(ep, uniname); |
| uniname += EXFAT_FILE_NAME_LEN; |
| } |
| |
| exfat_free_dentry_set(es, false); |
| } |
| |
| /* read a directory entry from the opened directory */ |
| static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry) |
| { |
| int i, dentries_per_clu, dentries_per_clu_bits = 0, num_ext; |
| unsigned int type, clu_offset, max_dentries; |
| struct exfat_chain dir, clu; |
| struct exfat_uni_name uni_name; |
| struct exfat_dentry *ep; |
| struct super_block *sb = inode->i_sb; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| struct exfat_inode_info *ei = EXFAT_I(inode); |
| unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF; |
| struct buffer_head *bh; |
| |
| /* check if the given file ID is opened */ |
| if (ei->type != TYPE_DIR) |
| return -EPERM; |
| |
| if (ei->entry == -1) |
| exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); |
| else |
| exfat_chain_set(&dir, ei->start_clu, |
| EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags); |
| |
| dentries_per_clu = sbi->dentries_per_clu; |
| dentries_per_clu_bits = ilog2(dentries_per_clu); |
| max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES, |
| (u64)sbi->num_clusters << dentries_per_clu_bits); |
| |
| clu_offset = dentry >> dentries_per_clu_bits; |
| exfat_chain_dup(&clu, &dir); |
| |
| if (clu.flags == ALLOC_NO_FAT_CHAIN) { |
| clu.dir += clu_offset; |
| clu.size -= clu_offset; |
| } else { |
| /* hint_information */ |
| if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && |
| ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { |
| clu_offset -= ei->hint_bmap.off; |
| clu.dir = ei->hint_bmap.clu; |
| } |
| |
| while (clu_offset > 0) { |
| if (exfat_get_next_cluster(sb, &(clu.dir))) |
| return -EIO; |
| |
| clu_offset--; |
| } |
| } |
| |
| while (clu.dir != EXFAT_EOF_CLUSTER && dentry < max_dentries) { |
| i = dentry & (dentries_per_clu - 1); |
| |
| for ( ; i < dentries_per_clu; i++, dentry++) { |
| ep = exfat_get_dentry(sb, &clu, i, &bh); |
| if (!ep) |
| return -EIO; |
| |
| type = exfat_get_entry_type(ep); |
| if (type == TYPE_UNUSED) { |
| brelse(bh); |
| break; |
| } |
| |
| if (type != TYPE_FILE && type != TYPE_DIR) { |
| brelse(bh); |
| continue; |
| } |
| |
| num_ext = ep->dentry.file.num_ext; |
| dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); |
| exfat_get_entry_time(sbi, &dir_entry->crtime, |
| ep->dentry.file.create_tz, |
| ep->dentry.file.create_time, |
| ep->dentry.file.create_date, |
| ep->dentry.file.create_time_cs); |
| exfat_get_entry_time(sbi, &dir_entry->mtime, |
| ep->dentry.file.modify_tz, |
| ep->dentry.file.modify_time, |
| ep->dentry.file.modify_date, |
| ep->dentry.file.modify_time_cs); |
| exfat_get_entry_time(sbi, &dir_entry->atime, |
| ep->dentry.file.access_tz, |
| ep->dentry.file.access_time, |
| ep->dentry.file.access_date, |
| 0); |
| |
| *uni_name.name = 0x0; |
| exfat_get_uniname_from_ext_entry(sb, &clu, i, |
| uni_name.name); |
| exfat_utf16_to_nls(sb, &uni_name, |
| dir_entry->namebuf.lfn, |
| dir_entry->namebuf.lfnbuf_len); |
| brelse(bh); |
| |
| ep = exfat_get_dentry(sb, &clu, i + 1, &bh); |
| if (!ep) |
| return -EIO; |
| dir_entry->size = |
| le64_to_cpu(ep->dentry.stream.valid_size); |
| dir_entry->entry = dentry; |
| brelse(bh); |
| |
| ei->hint_bmap.off = dentry >> dentries_per_clu_bits; |
| ei->hint_bmap.clu = clu.dir; |
| |
| *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext); |
| return 0; |
| } |
| |
| if (clu.flags == ALLOC_NO_FAT_CHAIN) { |
| if (--clu.size > 0) |
| clu.dir++; |
| else |
| clu.dir = EXFAT_EOF_CLUSTER; |
| } else { |
| if (exfat_get_next_cluster(sb, &(clu.dir))) |
| return -EIO; |
| } |
| } |
| |
| dir_entry->namebuf.lfn[0] = '\0'; |
| *cpos = EXFAT_DEN_TO_B(dentry); |
| return 0; |
| } |
| |
| static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb) |
| { |
| nb->lfn = NULL; |
| nb->lfnbuf_len = 0; |
| } |
| |
| static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb) |
| { |
| nb->lfn = __getname(); |
| if (!nb->lfn) |
| return -ENOMEM; |
| nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE; |
| return 0; |
| } |
| |
| static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) |
| { |
| if (!nb->lfn) |
| return; |
| |
| __putname(nb->lfn); |
| exfat_init_namebuf(nb); |
| } |
| |
| /* skip iterating emit_dots when dir is empty */ |
| #define ITER_POS_FILLED_DOTS (2) |
| static int exfat_iterate(struct file *filp, struct dir_context *ctx) |
| { |
| struct inode *inode = filp->f_path.dentry->d_inode; |
| struct super_block *sb = inode->i_sb; |
| struct inode *tmp; |
| struct exfat_dir_entry de; |
| struct exfat_dentry_namebuf *nb = &(de.namebuf); |
| struct exfat_inode_info *ei = EXFAT_I(inode); |
| unsigned long inum; |
| loff_t cpos, i_pos; |
| int err = 0, fake_offset = 0; |
| |
| exfat_init_namebuf(nb); |
| mutex_lock(&EXFAT_SB(sb)->s_lock); |
| |
| cpos = ctx->pos; |
| if (!dir_emit_dots(filp, ctx)) |
| goto unlock; |
| |
| if (ctx->pos == ITER_POS_FILLED_DOTS) { |
| cpos = 0; |
| fake_offset = 1; |
| } |
| |
| if (cpos & (DENTRY_SIZE - 1)) { |
| err = -ENOENT; |
| goto unlock; |
| } |
| |
| /* name buffer should be allocated before use */ |
| err = exfat_alloc_namebuf(nb); |
| if (err) |
| goto unlock; |
| get_new: |
| if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode)) |
| goto end_of_dir; |
| |
| err = exfat_readdir(inode, &cpos, &de); |
| if (err) { |
| /* |
| * At least we tried to read a sector. Move cpos to next sector |
| * position (should be aligned). |
| */ |
| if (err == -EIO) { |
| cpos += 1 << (sb->s_blocksize_bits); |
| cpos &= ~(sb->s_blocksize - 1); |
| } |
| |
| err = -EIO; |
| goto end_of_dir; |
| } |
| |
| if (!nb->lfn[0]) |
| goto end_of_dir; |
| |
| i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff); |
| tmp = exfat_iget(sb, i_pos); |
| if (tmp) { |
| inum = tmp->i_ino; |
| iput(tmp); |
| } else { |
| inum = iunique(sb, EXFAT_ROOT_INO); |
| } |
| |
| /* |
| * Before calling dir_emit(), sb_lock should be released. |
| * Because page fault can occur in dir_emit() when the size |
| * of buffer given from user is larger than one page size. |
| */ |
| mutex_unlock(&EXFAT_SB(sb)->s_lock); |
| if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, |
| (de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG)) |
| goto out_unlocked; |
| mutex_lock(&EXFAT_SB(sb)->s_lock); |
| ctx->pos = cpos; |
| goto get_new; |
| |
| end_of_dir: |
| if (!cpos && fake_offset) |
| cpos = ITER_POS_FILLED_DOTS; |
| ctx->pos = cpos; |
| unlock: |
| mutex_unlock(&EXFAT_SB(sb)->s_lock); |
| out_unlocked: |
| /* |
| * To improve performance, free namebuf after unlock sb_lock. |
| * If namebuf is not allocated, this function do nothing |
| */ |
| exfat_free_namebuf(nb); |
| return err; |
| } |
| |
| const struct file_operations exfat_dir_operations = { |
| .llseek = generic_file_llseek, |
| .read = generic_read_dir, |
| .iterate = exfat_iterate, |
| .unlocked_ioctl = exfat_ioctl, |
| #ifdef CONFIG_COMPAT |
| .compat_ioctl = exfat_compat_ioctl, |
| #endif |
| .fsync = exfat_file_fsync, |
| }; |
| |
| int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu) |
| { |
| int ret; |
| |
| exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN); |
| |
| ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode)); |
| if (ret) |
| return ret; |
| |
| return exfat_zeroed_cluster(inode, clu->dir); |
| } |
| |
| int exfat_calc_num_entries(struct exfat_uni_name *p_uniname) |
| { |
| int len; |
| |
| len = p_uniname->name_len; |
| if (len == 0) |
| return -EINVAL; |
| |
| /* 1 file entry + 1 stream entry + name entries */ |
| return ((len - 1) / EXFAT_FILE_NAME_LEN + 3); |
| } |
| |
| unsigned int exfat_get_entry_type(struct exfat_dentry *ep) |
| { |
| if (ep->type == EXFAT_UNUSED) |
| return TYPE_UNUSED; |
| if (IS_EXFAT_DELETED(ep->type)) |
| return TYPE_DELETED; |
| if (ep->type == EXFAT_INVAL) |
| return TYPE_INVALID; |
| if (IS_EXFAT_CRITICAL_PRI(ep->type)) { |
| if (ep->type == EXFAT_BITMAP) |
| return TYPE_BITMAP; |
| if (ep->type == EXFAT_UPCASE) |
| return TYPE_UPCASE; |
| if (ep->type == EXFAT_VOLUME) |
| return TYPE_VOLUME; |
| if (ep->type == EXFAT_FILE) { |
| if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR) |
| return TYPE_DIR; |
| return TYPE_FILE; |
| } |
| return TYPE_CRITICAL_PRI; |
| } |
| if (IS_EXFAT_BENIGN_PRI(ep->type)) { |
| if (ep->type == EXFAT_GUID) |
| return TYPE_GUID; |
| if (ep->type == EXFAT_PADDING) |
| return TYPE_PADDING; |
| if (ep->type == EXFAT_ACLTAB) |
| return TYPE_ACLTAB; |
| return TYPE_BENIGN_PRI; |
| } |
| if (IS_EXFAT_CRITICAL_SEC(ep->type)) { |
| if (ep->type == EXFAT_STREAM) |
| return TYPE_STREAM; |
| if (ep->type == EXFAT_NAME) |
| return TYPE_EXTEND; |
| if (ep->type == EXFAT_ACL) |
| return TYPE_ACL; |
| return TYPE_CRITICAL_SEC; |
| } |
| return TYPE_BENIGN_SEC; |
| } |
| |
| static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) |
| { |
| if (type == TYPE_UNUSED) { |
| ep->type = EXFAT_UNUSED; |
| } else if (type == TYPE_DELETED) { |
| ep->type &= EXFAT_DELETE; |
| } else if (type == TYPE_STREAM) { |
| ep->type = EXFAT_STREAM; |
| } else if (type == TYPE_EXTEND) { |
| ep->type = EXFAT_NAME; |
| } else if (type == TYPE_BITMAP) { |
| ep->type = EXFAT_BITMAP; |
| } else if (type == TYPE_UPCASE) { |
| ep->type = EXFAT_UPCASE; |
| } else if (type == TYPE_VOLUME) { |
| ep->type = EXFAT_VOLUME; |
| } else if (type == TYPE_DIR) { |
| ep->type = EXFAT_FILE; |
| ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR); |
| } else if (type == TYPE_FILE) { |
| ep->type = EXFAT_FILE; |
| ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE); |
| } |
| } |
| |
| static void exfat_init_stream_entry(struct exfat_dentry *ep, |
| unsigned char flags, unsigned int start_clu, |
| unsigned long long size) |
| { |
| exfat_set_entry_type(ep, TYPE_STREAM); |
| ep->dentry.stream.flags = flags; |
| ep->dentry.stream.start_clu = cpu_to_le32(start_clu); |
| ep->dentry.stream.valid_size = cpu_to_le64(size); |
| ep->dentry.stream.size = cpu_to_le64(size); |
| } |
| |
| static void exfat_init_name_entry(struct exfat_dentry *ep, |
| unsigned short *uniname) |
| { |
| int i; |
| |
| exfat_set_entry_type(ep, TYPE_EXTEND); |
| ep->dentry.name.flags = 0x0; |
| |
| for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { |
| if (*uniname != 0x0) { |
| ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); |
| uniname++; |
| } else { |
| ep->dentry.name.unicode_0_14[i] = 0x0; |
| } |
| } |
| } |
| |
| int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir, |
| int entry, unsigned int type, unsigned int start_clu, |
| unsigned long long size) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| struct timespec64 ts = current_time(inode); |
| struct exfat_dentry *ep; |
| struct buffer_head *bh; |
| |
| /* |
| * We cannot use exfat_get_dentry_set here because file ep is not |
| * initialized yet. |
| */ |
| ep = exfat_get_dentry(sb, p_dir, entry, &bh); |
| if (!ep) |
| return -EIO; |
| |
| exfat_set_entry_type(ep, type); |
| exfat_set_entry_time(sbi, &ts, |
| &ep->dentry.file.create_tz, |
| &ep->dentry.file.create_time, |
| &ep->dentry.file.create_date, |
| &ep->dentry.file.create_time_cs); |
| exfat_set_entry_time(sbi, &ts, |
| &ep->dentry.file.modify_tz, |
| &ep->dentry.file.modify_time, |
| &ep->dentry.file.modify_date, |
| &ep->dentry.file.modify_time_cs); |
| exfat_set_entry_time(sbi, &ts, |
| &ep->dentry.file.access_tz, |
| &ep->dentry.file.access_time, |
| &ep->dentry.file.access_date, |
| NULL); |
| |
| exfat_update_bh(bh, IS_DIRSYNC(inode)); |
| brelse(bh); |
| |
| ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); |
| if (!ep) |
| return -EIO; |
| |
| exfat_init_stream_entry(ep, |
| (type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN, |
| start_clu, size); |
| exfat_update_bh(bh, IS_DIRSYNC(inode)); |
| brelse(bh); |
| |
| return 0; |
| } |
| |
| int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir, |
| int entry) |
| { |
| struct super_block *sb = inode->i_sb; |
| int ret = 0; |
| int i, num_entries; |
| u16 chksum; |
| struct exfat_dentry *ep, *fep; |
| struct buffer_head *fbh, *bh; |
| |
| fep = exfat_get_dentry(sb, p_dir, entry, &fbh); |
| if (!fep) |
| return -EIO; |
| |
| num_entries = fep->dentry.file.num_ext + 1; |
| chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY); |
| |
| for (i = 1; i < num_entries; i++) { |
| ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); |
| if (!ep) { |
| ret = -EIO; |
| goto release_fbh; |
| } |
| chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, |
| CS_DEFAULT); |
| brelse(bh); |
| } |
| |
| fep->dentry.file.checksum = cpu_to_le16(chksum); |
| exfat_update_bh(fbh, IS_DIRSYNC(inode)); |
| release_fbh: |
| brelse(fbh); |
| return ret; |
| } |
| |
| int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir, |
| int entry, int num_entries, struct exfat_uni_name *p_uniname) |
| { |
| struct super_block *sb = inode->i_sb; |
| int i; |
| unsigned short *uniname = p_uniname->name; |
| struct exfat_dentry *ep; |
| struct buffer_head *bh; |
| int sync = IS_DIRSYNC(inode); |
| |
| ep = exfat_get_dentry(sb, p_dir, entry, &bh); |
| if (!ep) |
| return -EIO; |
| |
| ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); |
| exfat_update_bh(bh, sync); |
| brelse(bh); |
| |
| ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); |
| if (!ep) |
| return -EIO; |
| |
| ep->dentry.stream.name_len = p_uniname->name_len; |
| ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); |
| exfat_update_bh(bh, sync); |
| brelse(bh); |
| |
| for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { |
| ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); |
| if (!ep) |
| return -EIO; |
| |
| exfat_init_name_entry(ep, uniname); |
| exfat_update_bh(bh, sync); |
| brelse(bh); |
| uniname += EXFAT_FILE_NAME_LEN; |
| } |
| |
| exfat_update_dir_chksum(inode, p_dir, entry); |
| return 0; |
| } |
| |
| int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, |
| int entry, int order, int num_entries) |
| { |
| struct super_block *sb = inode->i_sb; |
| int i; |
| struct exfat_dentry *ep; |
| struct buffer_head *bh; |
| |
| for (i = order; i < num_entries; i++) { |
| ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); |
| if (!ep) |
| return -EIO; |
| |
| exfat_set_entry_type(ep, TYPE_DELETED); |
| exfat_update_bh(bh, IS_DIRSYNC(inode)); |
| brelse(bh); |
| } |
| |
| return 0; |
| } |
| |
| void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es) |
| { |
| int chksum_type = CS_DIR_ENTRY, i; |
| unsigned short chksum = 0; |
| struct exfat_dentry *ep; |
| |
| for (i = 0; i < es->num_entries; i++) { |
| ep = exfat_get_dentry_cached(es, i); |
| chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, |
| chksum_type); |
| chksum_type = CS_DEFAULT; |
| } |
| ep = exfat_get_dentry_cached(es, 0); |
| ep->dentry.file.checksum = cpu_to_le16(chksum); |
| es->modified = true; |
| } |
| |
| int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync) |
| { |
| int i, err = 0; |
| |
| if (es->modified) |
| err = exfat_update_bhs(es->bh, es->num_bh, sync); |
| |
| for (i = 0; i < es->num_bh; i++) |
| if (err) |
| bforget(es->bh[i]); |
| else |
| brelse(es->bh[i]); |
| kfree(es); |
| return err; |
| } |
| |
| static int exfat_walk_fat_chain(struct super_block *sb, |
| struct exfat_chain *p_dir, unsigned int byte_offset, |
| unsigned int *clu) |
| { |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| unsigned int clu_offset; |
| unsigned int cur_clu; |
| |
| clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); |
| cur_clu = p_dir->dir; |
| |
| if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { |
| cur_clu += clu_offset; |
| } else { |
| while (clu_offset > 0) { |
| if (exfat_get_next_cluster(sb, &cur_clu)) |
| return -EIO; |
| if (cur_clu == EXFAT_EOF_CLUSTER) { |
| exfat_fs_error(sb, |
| "invalid dentry access beyond EOF (clu : %u, eidx : %d)", |
| p_dir->dir, |
| EXFAT_B_TO_DEN(byte_offset)); |
| return -EIO; |
| } |
| clu_offset--; |
| } |
| } |
| |
| *clu = cur_clu; |
| return 0; |
| } |
| |
| static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, |
| int entry, sector_t *sector, int *offset) |
| { |
| int ret; |
| unsigned int off, clu = 0; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| |
| off = EXFAT_DEN_TO_B(entry); |
| |
| ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); |
| if (ret) |
| return ret; |
| |
| /* byte offset in cluster */ |
| off = EXFAT_CLU_OFFSET(off, sbi); |
| |
| /* byte offset in sector */ |
| *offset = EXFAT_BLK_OFFSET(off, sb); |
| |
| /* sector offset in cluster */ |
| *sector = EXFAT_B_TO_BLK(off, sb); |
| *sector += exfat_cluster_to_sector(sbi, clu); |
| return 0; |
| } |
| |
| #define EXFAT_MAX_RA_SIZE (128*1024) |
| static int exfat_dir_readahead(struct super_block *sb, sector_t sec) |
| { |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| struct buffer_head *bh; |
| unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; |
| unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; |
| unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); |
| unsigned int ra_count = min(adj_ra_count, max_ra_count); |
| |
| /* Read-ahead is not required */ |
| if (sbi->sect_per_clus == 1) |
| return 0; |
| |
| if (sec < sbi->data_start_sector) { |
| exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", |
| (unsigned long long)sec, sbi->data_start_sector); |
| return -EIO; |
| } |
| |
| /* Not sector aligned with ra_count, resize ra_count to page size */ |
| if ((sec - sbi->data_start_sector) & (ra_count - 1)) |
| ra_count = page_ra_count; |
| |
| bh = sb_find_get_block(sb, sec); |
| if (!bh || !buffer_uptodate(bh)) { |
| unsigned int i; |
| |
| for (i = 0; i < ra_count; i++) |
| sb_breadahead(sb, (sector_t)(sec + i)); |
| } |
| brelse(bh); |
| return 0; |
| } |
| |
| struct exfat_dentry *exfat_get_dentry(struct super_block *sb, |
| struct exfat_chain *p_dir, int entry, struct buffer_head **bh) |
| { |
| unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); |
| int off; |
| sector_t sec; |
| |
| if (p_dir->dir == DIR_DELETED) { |
| exfat_err(sb, "abnormal access to deleted dentry"); |
| return NULL; |
| } |
| |
| if (exfat_find_location(sb, p_dir, entry, &sec, &off)) |
| return NULL; |
| |
| if (p_dir->dir != EXFAT_FREE_CLUSTER && |
| !(entry & (dentries_per_page - 1))) |
| exfat_dir_readahead(sb, sec); |
| |
| *bh = sb_bread(sb, sec); |
| if (!*bh) |
| return NULL; |
| |
| return (struct exfat_dentry *)((*bh)->b_data + off); |
| } |
| |
| enum exfat_validate_dentry_mode { |
| ES_MODE_STARTED, |
| ES_MODE_GET_FILE_ENTRY, |
| ES_MODE_GET_STRM_ENTRY, |
| ES_MODE_GET_NAME_ENTRY, |
| ES_MODE_GET_CRITICAL_SEC_ENTRY, |
| }; |
| |
| static bool exfat_validate_entry(unsigned int type, |
| enum exfat_validate_dentry_mode *mode) |
| { |
| if (type == TYPE_UNUSED || type == TYPE_DELETED) |
| return false; |
| |
| switch (*mode) { |
| case ES_MODE_STARTED: |
| if (type != TYPE_FILE && type != TYPE_DIR) |
| return false; |
| *mode = ES_MODE_GET_FILE_ENTRY; |
| return true; |
| case ES_MODE_GET_FILE_ENTRY: |
| if (type != TYPE_STREAM) |
| return false; |
| *mode = ES_MODE_GET_STRM_ENTRY; |
| return true; |
| case ES_MODE_GET_STRM_ENTRY: |
| if (type != TYPE_EXTEND) |
| return false; |
| *mode = ES_MODE_GET_NAME_ENTRY; |
| return true; |
| case ES_MODE_GET_NAME_ENTRY: |
| if (type == TYPE_STREAM) |
| return false; |
| if (type != TYPE_EXTEND) { |
| if (!(type & TYPE_CRITICAL_SEC)) |
| return false; |
| *mode = ES_MODE_GET_CRITICAL_SEC_ENTRY; |
| } |
| return true; |
| case ES_MODE_GET_CRITICAL_SEC_ENTRY: |
| if (type == TYPE_EXTEND || type == TYPE_STREAM) |
| return false; |
| if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC) |
| return false; |
| return true; |
| default: |
| WARN_ON_ONCE(1); |
| return false; |
| } |
| } |
| |
| struct exfat_dentry *exfat_get_dentry_cached( |
| struct exfat_entry_set_cache *es, int num) |
| { |
| int off = es->start_off + num * DENTRY_SIZE; |
| struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; |
| char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); |
| |
| return (struct exfat_dentry *)p; |
| } |
| |
| /* |
| * Returns a set of dentries for a file or dir. |
| * |
| * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). |
| * User should call exfat_get_dentry_set() after setting 'modified' to apply |
| * changes made in this entry set to the real device. |
| * |
| * in: |
| * sb+p_dir+entry: indicates a file/dir |
| * type: specifies how many dentries should be included. |
| * return: |
| * pointer of entry set on success, |
| * NULL on failure. |
| */ |
| struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, |
| struct exfat_chain *p_dir, int entry, unsigned int type) |
| { |
| int ret, i, num_bh; |
| unsigned int off, byte_offset, clu = 0; |
| sector_t sec; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| struct exfat_entry_set_cache *es; |
| struct exfat_dentry *ep; |
| int num_entries; |
| enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; |
| struct buffer_head *bh; |
| |
| if (p_dir->dir == DIR_DELETED) { |
| exfat_err(sb, "access to deleted dentry"); |
| return NULL; |
| } |
| |
| byte_offset = EXFAT_DEN_TO_B(entry); |
| ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu); |
| if (ret) |
| return NULL; |
| |
| es = kzalloc(sizeof(*es), GFP_KERNEL); |
| if (!es) |
| return NULL; |
| es->sb = sb; |
| es->modified = false; |
| |
| /* byte offset in cluster */ |
| byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi); |
| |
| /* byte offset in sector */ |
| off = EXFAT_BLK_OFFSET(byte_offset, sb); |
| es->start_off = off; |
| |
| /* sector offset in cluster */ |
| sec = EXFAT_B_TO_BLK(byte_offset, sb); |
| sec += exfat_cluster_to_sector(sbi, clu); |
| |
| bh = sb_bread(sb, sec); |
| if (!bh) |
| goto free_es; |
| es->bh[es->num_bh++] = bh; |
| |
| ep = exfat_get_dentry_cached(es, 0); |
| if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) |
| goto free_es; |
| |
| num_entries = type == ES_ALL_ENTRIES ? |
| ep->dentry.file.num_ext + 1 : type; |
| es->num_entries = num_entries; |
| |
| num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); |
| for (i = 1; i < num_bh; i++) { |
| /* get the next sector */ |
| if (exfat_is_last_sector_in_cluster(sbi, sec)) { |
| if (p_dir->flags == ALLOC_NO_FAT_CHAIN) |
| clu++; |
| else if (exfat_get_next_cluster(sb, &clu)) |
| goto free_es; |
| sec = exfat_cluster_to_sector(sbi, clu); |
| } else { |
| sec++; |
| } |
| |
| bh = sb_bread(sb, sec); |
| if (!bh) |
| goto free_es; |
| es->bh[es->num_bh++] = bh; |
| } |
| |
| /* validate cached dentries */ |
| for (i = 1; i < num_entries; i++) { |
| ep = exfat_get_dentry_cached(es, i); |
| if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) |
| goto free_es; |
| } |
| return es; |
| |
| free_es: |
| exfat_free_dentry_set(es, false); |
| return NULL; |
| } |
| |
| enum { |
| DIRENT_STEP_FILE, |
| DIRENT_STEP_STRM, |
| DIRENT_STEP_NAME, |
| DIRENT_STEP_SECD, |
| }; |
| |
| /* |
| * @ei: inode info of parent directory |
| * @p_dir: directory structure of parent directory |
| * @num_entries:entry size of p_uniname |
| * @hint_opt: If p_uniname is found, filled with optimized dir/entry |
| * for traversing cluster chain. |
| * @return: |
| * >= 0: file directory entry position where the name exists |
| * -ENOENT: entry with the name does not exist |
| * -EIO: I/O error |
| */ |
| int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, |
| struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, |
| int num_entries, unsigned int type, struct exfat_hint *hint_opt) |
| { |
| int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; |
| int order, step, name_len = 0; |
| int dentries_per_clu, num_empty = 0; |
| unsigned int entry_type; |
| unsigned short *uniname = NULL; |
| struct exfat_chain clu; |
| struct exfat_hint *hint_stat = &ei->hint_stat; |
| struct exfat_hint_femp candi_empty; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| |
| dentries_per_clu = sbi->dentries_per_clu; |
| |
| exfat_chain_dup(&clu, p_dir); |
| |
| if (hint_stat->eidx) { |
| clu.dir = hint_stat->clu; |
| dentry = hint_stat->eidx; |
| end_eidx = dentry; |
| } |
| |
| candi_empty.eidx = EXFAT_HINT_NONE; |
| rewind: |
| order = 0; |
| step = DIRENT_STEP_FILE; |
| while (clu.dir != EXFAT_EOF_CLUSTER) { |
| i = dentry & (dentries_per_clu - 1); |
| for (; i < dentries_per_clu; i++, dentry++) { |
| struct exfat_dentry *ep; |
| struct buffer_head *bh; |
| |
| if (rewind && dentry == end_eidx) |
| goto not_found; |
| |
| ep = exfat_get_dentry(sb, &clu, i, &bh); |
| if (!ep) |
| return -EIO; |
| |
| entry_type = exfat_get_entry_type(ep); |
| |
| if (entry_type == TYPE_UNUSED || |
| entry_type == TYPE_DELETED) { |
| step = DIRENT_STEP_FILE; |
| |
| num_empty++; |
| if (candi_empty.eidx == EXFAT_HINT_NONE && |
| num_empty == 1) { |
| exfat_chain_set(&candi_empty.cur, |
| clu.dir, clu.size, clu.flags); |
| } |
| |
| if (candi_empty.eidx == EXFAT_HINT_NONE && |
| num_empty >= num_entries) { |
| candi_empty.eidx = |
| dentry - (num_empty - 1); |
| WARN_ON(candi_empty.eidx < 0); |
| candi_empty.count = num_empty; |
| |
| if (ei->hint_femp.eidx == |
| EXFAT_HINT_NONE || |
| candi_empty.eidx <= |
| ei->hint_femp.eidx) |
| ei->hint_femp = candi_empty; |
| } |
| |
| brelse(bh); |
| if (entry_type == TYPE_UNUSED) |
| goto not_found; |
| continue; |
| } |
| |
| num_empty = 0; |
| candi_empty.eidx = EXFAT_HINT_NONE; |
| |
| if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { |
| step = DIRENT_STEP_FILE; |
| hint_opt->clu = clu.dir; |
| hint_opt->eidx = i; |
| if (type == TYPE_ALL || type == entry_type) { |
| num_ext = ep->dentry.file.num_ext; |
| step = DIRENT_STEP_STRM; |
| } |
| brelse(bh); |
| continue; |
| } |
| |
| if (entry_type == TYPE_STREAM) { |
| u16 name_hash; |
| |
| if (step != DIRENT_STEP_STRM) { |
| step = DIRENT_STEP_FILE; |
| brelse(bh); |
| continue; |
| } |
| step = DIRENT_STEP_FILE; |
| name_hash = le16_to_cpu( |
| ep->dentry.stream.name_hash); |
| if (p_uniname->name_hash == name_hash && |
| p_uniname->name_len == |
| ep->dentry.stream.name_len) { |
| step = DIRENT_STEP_NAME; |
| order = 1; |
| name_len = 0; |
| } |
| brelse(bh); |
| continue; |
| } |
| |
| brelse(bh); |
| if (entry_type == TYPE_EXTEND) { |
| unsigned short entry_uniname[16], unichar; |
| |
| if (step != DIRENT_STEP_NAME) { |
| step = DIRENT_STEP_FILE; |
| continue; |
| } |
| |
| if (++order == 2) |
| uniname = p_uniname->name; |
| else |
| uniname += EXFAT_FILE_NAME_LEN; |
| |
| len = exfat_extract_uni_name(ep, entry_uniname); |
| name_len += len; |
| |
| unichar = *(uniname+len); |
| *(uniname+len) = 0x0; |
| |
| if (exfat_uniname_ncmp(sb, uniname, |
| entry_uniname, len)) { |
| step = DIRENT_STEP_FILE; |
| } else if (p_uniname->name_len == name_len) { |
| if (order == num_ext) |
| goto found; |
| step = DIRENT_STEP_SECD; |
| } |
| |
| *(uniname+len) = unichar; |
| continue; |
| } |
| |
| if (entry_type & |
| (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { |
| if (step == DIRENT_STEP_SECD) { |
| if (++order == num_ext) |
| goto found; |
| continue; |
| } |
| } |
| step = DIRENT_STEP_FILE; |
| } |
| |
| if (clu.flags == ALLOC_NO_FAT_CHAIN) { |
| if (--clu.size > 0) |
| clu.dir++; |
| else |
| clu.dir = EXFAT_EOF_CLUSTER; |
| } else { |
| if (exfat_get_next_cluster(sb, &clu.dir)) |
| return -EIO; |
| } |
| } |
| |
| not_found: |
| /* |
| * We started at not 0 index,so we should try to find target |
| * from 0 index to the index we started at. |
| */ |
| if (!rewind && end_eidx) { |
| rewind = 1; |
| dentry = 0; |
| clu.dir = p_dir->dir; |
| /* reset empty hint */ |
| num_empty = 0; |
| candi_empty.eidx = EXFAT_HINT_NONE; |
| goto rewind; |
| } |
| |
| /* initialized hint_stat */ |
| hint_stat->clu = p_dir->dir; |
| hint_stat->eidx = 0; |
| return -ENOENT; |
| |
| found: |
| /* next dentry we'll find is out of this cluster */ |
| if (!((dentry + 1) & (dentries_per_clu - 1))) { |
| int ret = 0; |
| |
| if (clu.flags == ALLOC_NO_FAT_CHAIN) { |
| if (--clu.size > 0) |
| clu.dir++; |
| else |
| clu.dir = EXFAT_EOF_CLUSTER; |
| } else { |
| ret = exfat_get_next_cluster(sb, &clu.dir); |
| } |
| |
| if (ret || clu.dir == EXFAT_EOF_CLUSTER) { |
| /* just initialized hint_stat */ |
| hint_stat->clu = p_dir->dir; |
| hint_stat->eidx = 0; |
| return (dentry - num_ext); |
| } |
| } |
| |
| hint_stat->clu = clu.dir; |
| hint_stat->eidx = dentry + 1; |
| return dentry - num_ext; |
| } |
| |
| int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir, |
| int entry, struct exfat_dentry *ep) |
| { |
| int i, count = 0; |
| unsigned int type; |
| struct exfat_dentry *ext_ep; |
| struct buffer_head *bh; |
| |
| for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) { |
| ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh); |
| if (!ext_ep) |
| return -EIO; |
| |
| type = exfat_get_entry_type(ext_ep); |
| brelse(bh); |
| if (type == TYPE_EXTEND || type == TYPE_STREAM) |
| count++; |
| else |
| break; |
| } |
| return count; |
| } |
| |
| int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) |
| { |
| int i, count = 0; |
| int dentries_per_clu; |
| unsigned int entry_type; |
| struct exfat_chain clu; |
| struct exfat_dentry *ep; |
| struct exfat_sb_info *sbi = EXFAT_SB(sb); |
| struct buffer_head *bh; |
| |
| dentries_per_clu = sbi->dentries_per_clu; |
| |
| exfat_chain_dup(&clu, p_dir); |
| |
| while (clu.dir != EXFAT_EOF_CLUSTER) { |
| for (i = 0; i < dentries_per_clu; i++) { |
| ep = exfat_get_dentry(sb, &clu, i, &bh); |
| if (!ep) |
| return -EIO; |
| entry_type = exfat_get_entry_type(ep); |
| brelse(bh); |
| |
| if (entry_type == TYPE_UNUSED) |
| return count; |
| if (entry_type != TYPE_DIR) |
| continue; |
| count++; |
| } |
| |
| if (clu.flags == ALLOC_NO_FAT_CHAIN) { |
| if (--clu.size > 0) |
| clu.dir++; |
| else |
| clu.dir = EXFAT_EOF_CLUSTER; |
| } else { |
| if (exfat_get_next_cluster(sb, &(clu.dir))) |
| return -EIO; |
| } |
| } |
| |
| return count; |
| } |
