[PATCH v12 04/13] exfat: add directory operations

Namjae Jeon
2020-01-20T12:45:00Z

This adds the implementation of directory operations for exfat.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
---
fs/exfat/dir.c | 1238 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 1238 insertions(+)
create mode 100644 fs/exfat/dir.c

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, &sector);
+ 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, &sector);
+ 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, &sector);
+ 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, &sector);
+ 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, &sector);
+ 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, &sector);
+ 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, &sector);
+ 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, &sector);
+ 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;
+}
--
2.17.1