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linux/fs/exfat/dir.c
Yuezhang Mo e298c8a818 exfat: hint the empty entry which at the end of cluster chain 
After traversing all directory entries, hint the empty directory
entry no matter whether or not there are enough empty directory
entries.

After this commit, hint the empty directory entries like this:

1. Hint the deleted directory entries if enough;
2. Hint the deleted and unused directory entries which at the
   end of the cluster chain no matter whether enough or not(Add
   by this commit);
3. If no any empty directory entries, hint the empty directory
   entries in the new cluster(Add by this commit).

This avoids repeated traversal of directory entries, reduces CPU
usage, and improves the performance of creating files and
directories(especially on low-performance CPUs).

Test create 5000 files in a class 4 SD card on imx6q-sabrelite
with:

for ((i=0;i<5;i++)); do
   sync
   time (for ((j=1;j<=1000;j++)); do touch file$((i*1000+j)); done)
done

The more files, the more performance improvements.

            Before   After    Improvement
   1~1000   25.360s  22.168s  14.40%
1001~2000   38.242s  28.72ss  33.15%
2001~3000   49.134s  35.037s  40.23%
3001~4000   62.042s  41.624s  49.05%
4001~5000   73.629s  46.772s  57.42%

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2022-12-12 11:02:48 +09:00

1218 lines
29 KiB
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// 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 *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
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(file, 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;
}
static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp)
{
hint_femp->eidx = EXFAT_HINT_NONE;
hint_femp->count = 0;
}
static inline void exfat_set_empty_hint(struct exfat_inode_info *ei,
struct exfat_hint_femp *candi_empty, struct exfat_chain *clu,
int dentry, int num_entries, int entry_type)
{
if (ei->hint_femp.eidx == EXFAT_HINT_NONE ||
ei->hint_femp.eidx > dentry) {
int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode));
if (candi_empty->count == 0) {
candi_empty->cur = *clu;
candi_empty->eidx = dentry;
}
if (entry_type == TYPE_UNUSED)
candi_empty->count += total_entries - dentry;
else
candi_empty->count++;
if (candi_empty->count == num_entries ||
candi_empty->count + candi_empty->eidx == total_entries)
ei->hint_femp = *candi_empty;
}
}
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;
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;
}
exfat_reset_empty_hint(&ei->hint_femp);
rewind:
order = 0;
step = DIRENT_STEP_FILE;
exfat_reset_empty_hint(&candi_empty);
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;
exfat_set_empty_hint(ei, &candi_empty, &clu,
dentry, num_entries,
entry_type);
brelse(bh);
if (entry_type == TYPE_UNUSED)
goto not_found;
continue;
}
exfat_reset_empty_hint(&candi_empty);
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;
goto rewind;
}
/*
* set the EXFAT_EOF_CLUSTER flag to avoid search
* from the beginning again when allocated a new cluster
*/
if (ei->hint_femp.eidx == EXFAT_HINT_NONE) {
ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER;
ei->hint_femp.eidx = p_dir->size * dentries_per_clu;
ei->hint_femp.count = 0;
}
/* 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;
}
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