diff options
Diffstat (limited to 'fs/exfat/dir.c')
| -rw-r--r-- | fs/exfat/dir.c | 1238 |
1 files changed, 1238 insertions, 0 deletions
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c new file mode 100644 index 000000000000..4b91afb0f051 --- /dev/null +++ b/fs/exfat/dir.c @@ -0,0 +1,1238 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. + */ + +#include <linux/slab.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_dentry *ep; + struct exfat_entry_set_cache *es; + + es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES, &ep); + if (!es) + return; + + if (es->num_entries < 3) + goto free_es; + + ep += 2; + + /* + * 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++, ep++) { + /* end of name entry */ + if (exfat_get_entry_type(ep) != TYPE_EXTEND) + goto free_es; + + exfat_extract_uni_name(ep, uniname); + uniname += EXFAT_FILE_NAME_LEN; + } + +free_es: + kfree(es); +} + +/* read a directory entry from the opened directory */ +static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry) +{ + int i, dentries_per_clu, dentries_per_clu_bits = 0; + unsigned int type, clu_offset; + sector_t sector; + 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 = ei->rwoffset & 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); + + 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) { + i = dentry & (dentries_per_clu - 1); + + for ( ; i < dentries_per_clu; i++, dentry++) { + ep = exfat_get_dentry(sb, &clu, i, &bh, §or); + 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; + } + + 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_ms); + 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_ms); + 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, &dir, dentry, + 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, NULL); + if (!ep) + return -EIO; + dir_entry->size = + le64_to_cpu(ep->dentry.stream.valid_size); + brelse(bh); + + ei->hint_bmap.off = dentry >> dentries_per_clu_bits; + ei->hint_bmap.clu = clu.dir; + + ei->rwoffset = ++dentry; + 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'; + ei->rwoffset = 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: + ei->rwoffset = EXFAT_B_TO_DEN(cpos); + + if (cpos >= i_size_read(inode)) + goto end_of_dir; + + err = exfat_readdir(inode, &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; + } + + cpos = EXFAT_DEN_TO_B(ei->rwoffset); + + if (!nb->lfn[0]) + goto end_of_dir; + + i_pos = ((loff_t)ei->start_clu << 32) | + ((ei->rwoffset - 1) & 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, + .fsync = generic_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); + 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++) { + ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); + if (*uniname == 0x0) + break; + uniname++; + } +} + +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); + sector_t sector; + 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, §or); + 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_ms); + 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_ms); + 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(sb, bh, IS_DIRSYNC(inode)); + brelse(bh); + + ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); + 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(sb, 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; + sector_t sector; + unsigned short chksum; + struct exfat_dentry *ep, *fep; + struct buffer_head *fbh, *bh; + + fep = exfat_get_dentry(sb, p_dir, entry, &fbh, §or); + if (!fep) + return -EIO; + + num_entries = fep->dentry.file.num_ext + 1; + chksum = exfat_calc_chksum_2byte(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY); + + for (i = 1; i < num_entries; i++) { + ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, NULL); + if (!ep) { + ret = -EIO; + goto release_fbh; + } + chksum = exfat_calc_chksum_2byte(ep, DENTRY_SIZE, chksum, + CS_DEFAULT); + brelse(bh); + } + + fep->dentry.file.checksum = cpu_to_le16(chksum); + exfat_update_bh(sb, 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; + sector_t sector; + 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, §or); + if (!ep) + return -EIO; + + ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); + exfat_update_bh(sb, bh, sync); + brelse(bh); + + ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); + 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(sb, bh, sync); + brelse(bh); + + for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { + ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or); + if (!ep) + return -EIO; + + exfat_init_name_entry(ep, uniname); + exfat_update_bh(sb, 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; + sector_t sector; + 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, §or); + if (!ep) + return -EIO; + + exfat_set_entry_type(ep, TYPE_DELETED); + exfat_update_bh(sb, bh, IS_DIRSYNC(inode)); + brelse(bh); + } + + return 0; +} + +int exfat_update_dir_chksum_with_entry_set(struct super_block *sb, + struct exfat_entry_set_cache *es, int sync) +{ + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct buffer_head *bh; + sector_t sec = es->sector; + unsigned int off = es->offset; + int chksum_type = CS_DIR_ENTRY, i, num_entries = es->num_entries; + unsigned int buf_off = (off - es->offset); + unsigned int remaining_byte_in_sector, copy_entries, clu; + unsigned short chksum = 0; + + for (i = 0; i < num_entries; i++) { + chksum = exfat_calc_chksum_2byte(&es->entries[i], DENTRY_SIZE, + chksum, chksum_type); + chksum_type = CS_DEFAULT; + } + + es->entries[0].dentry.file.checksum = cpu_to_le16(chksum); + + while (num_entries) { + /* write per sector base */ + remaining_byte_in_sector = (1 << sb->s_blocksize_bits) - off; + copy_entries = min_t(int, + EXFAT_B_TO_DEN(remaining_byte_in_sector), + num_entries); + bh = sb_bread(sb, sec); + if (!bh) + goto err_out; + memcpy(bh->b_data + off, + (unsigned char *)&es->entries[0] + buf_off, + EXFAT_DEN_TO_B(copy_entries)); + exfat_update_bh(sb, bh, sync); + brelse(bh); + num_entries -= copy_entries; + + if (num_entries) { + /* get next sector */ + if (exfat_is_last_sector_in_cluster(sbi, sec)) { + clu = exfat_sector_to_cluster(sbi, sec); + if (es->alloc_flag == ALLOC_NO_FAT_CHAIN) + clu++; + else if (exfat_get_next_cluster(sb, &clu)) + goto err_out; + sec = exfat_cluster_to_sector(sbi, clu); + } else { + sec++; + } + off = 0; + buf_off += EXFAT_DEN_TO_B(copy_entries); + } + } + + return 0; +err_out: + return -EIO; +} + +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; +} + +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_msg(sb, KERN_ERR, + "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, + sector_t *sector) +{ + unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); + int off; + sector_t sec; + + if (p_dir->dir == DIR_DELETED) { + exfat_msg(sb, KERN_ERR, "abnormal access to deleted dentry\n"); + 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; + + if (sector) + *sector = sec; + 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; + } +} + +/* + * Returns a set of dentries for a file or dir. + * + * Note that this is a copy (dump) of dentries so that user should + * call write_entry_set() 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. + * out: + * file_ep: will point the first dentry(= file dentry) on success + * 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, + struct exfat_dentry **file_ep) +{ + int ret; + unsigned int off, byte_offset, clu = 0; + unsigned int entry_type; + sector_t sec; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct exfat_entry_set_cache *es; + struct exfat_dentry *ep, *pos; + unsigned char num_entries; + enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; + struct buffer_head *bh; + + if (p_dir->dir == DIR_DELETED) { + exfat_msg(sb, KERN_ERR, "access to deleted dentry\n"); + return NULL; + } + + byte_offset = EXFAT_DEN_TO_B(entry); + ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu); + if (ret) + return NULL; + + /* byte offset in cluster */ + byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi); + + /* byte offset in sector */ + off = EXFAT_BLK_OFFSET(byte_offset, sb); + + /* 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) + return NULL; + + ep = (struct exfat_dentry *)(bh->b_data + off); + entry_type = exfat_get_entry_type(ep); + + if (entry_type != TYPE_FILE && entry_type != TYPE_DIR) + goto release_bh; + + num_entries = type == ES_ALL_ENTRIES ? + ep->dentry.file.num_ext + 1 : type; + es = kmalloc(struct_size(es, entries, num_entries), GFP_KERNEL); + if (!es) + goto release_bh; + + es->num_entries = num_entries; + es->sector = sec; + es->offset = off; + es->alloc_flag = p_dir->flags; + + pos = &es->entries[0]; + + while (num_entries) { + if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) + goto free_es; + + /* copy dentry */ + memcpy(pos, ep, sizeof(struct exfat_dentry)); + + if (--num_entries == 0) + break; + + if (((off + DENTRY_SIZE) & (sb->s_blocksize - 1)) < + (off & (sb->s_blocksize - 1))) { + /* get the next sector */ + if (exfat_is_last_sector_in_cluster(sbi, sec)) { + if (es->alloc_flag == 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++; + } + + brelse(bh); + bh = sb_bread(sb, sec); + if (!bh) + goto free_es; + off = 0; + ep = (struct exfat_dentry *)bh->b_data; + } else { + ep++; + off += DENTRY_SIZE; + } + pos++; + } + + if (file_ep) + *file_ep = &es->entries[0]; + brelse(bh); + return es; + +free_es: + kfree(es); +release_bh: + brelse(bh); + return NULL; +} + +enum { + DIRENT_STEP_FILE, + DIRENT_STEP_STRM, + DIRENT_STEP_NAME, + DIRENT_STEP_SECD, +}; + +/* + * return values: + * >= 0 : return dir entiry position with the name in dir + * -EEXIST : (root dir, ".") it is the root dir itself + * -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) +{ + 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, NULL); + 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) { + memcpy(&ei->hint_femp, + &candi_empty, + sizeof(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; + 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) { + unsigned short 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, NULL); + 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, NULL); + 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; +} |