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Message-ID: <PUZPR04MB6316A9B8063E7A88FB61DFD8810F9@PUZPR04MB6316.apcprd04.prod.outlook.com>
Date: Thu, 24 Nov 2022 06:40:35 +0000
From: "Yuezhang.Mo@...y.com" <Yuezhang.Mo@...y.com>
To: "linkinjeon@...nel.org" <linkinjeon@...nel.org>,
"sj1557.seo@...sung.com" <sj1557.seo@...sung.com>
CC: "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"Andy.Wu@...y.com" <Andy.Wu@...y.com>,
"Wataru.Aoyama@...y.com" <Wataru.Aoyama@...y.com>
Subject: [PATCH v2 3/5] exfat: move exfat_entry_set_cache from heap to stack
The size of struct exfat_entry_set_cache is only 56 bytes on
64-bit system, and allocating from stack is more efficient than
allocating from heap.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@...y.com>
Reviewed-by: Andy Wu <Andy.Wu@...y.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@...y.com>
---
fs/exfat/dir.c | 35 +++++++++++++++--------------------
fs/exfat/exfat_fs.h | 5 +++--
fs/exfat/inode.c | 13 ++++++-------
fs/exfat/namei.c | 11 +++++------
4 files changed, 29 insertions(+), 35 deletions(-)
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 03e9c9e3966e..a3fb609dd129 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -33,10 +33,9 @@ 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;
+ struct exfat_entry_set_cache es;
- es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES);
- if (!es)
+ if (exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES))
return;
/*
@@ -45,8 +44,8 @@ static void exfat_get_uniname_from_ext_entry(struct super_block *sb,
* 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);
+ 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)
@@ -56,7 +55,7 @@ static void exfat_get_uniname_from_ext_entry(struct super_block *sb,
uniname += EXFAT_FILE_NAME_LEN;
}
- exfat_free_dentry_set(es, false);
+ exfat_free_dentry_set(&es, false);
}
/* read a directory entry from the opened directory */
@@ -619,7 +618,6 @@ int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync)
if (IS_DYNAMIC_ES(es))
kfree(es->bh);
- kfree(es);
return err;
}
@@ -816,14 +814,14 @@ struct exfat_dentry *exfat_get_dentry_cached(
* 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 exfat_get_dentry_set(struct exfat_entry_set_cache *es,
+ 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;
@@ -831,17 +829,15 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
if (p_dir->dir == DIR_DELETED) {
exfat_err(sb, "access to deleted dentry");
- return NULL;
+ return -EIO;
}
byte_offset = EXFAT_DEN_TO_B(entry);
ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu);
if (ret)
- return NULL;
+ return ret;
- es = kzalloc(sizeof(*es), GFP_KERNEL);
- if (!es)
- return NULL;
+ memset(es, 0, sizeof(*es));
es->sb = sb;
es->modified = false;
@@ -859,7 +855,7 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
bh = sb_bread(sb, sec);
if (!bh)
- goto free_es;
+ return -EIO;
es->bh[es->num_bh++] = bh;
ep = exfat_get_dentry_cached(es, 0);
@@ -875,8 +871,7 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_KERNEL);
if (!es->bh) {
brelse(bh);
- kfree(es);
- return NULL;
+ return -ENOMEM;
}
es->bh[0] = bh;
}
@@ -905,11 +900,11 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
goto free_es;
}
- return es;
+ return 0;
free_es:
exfat_free_dentry_set(es, false);
- return NULL;
+ return -EIO;
}
static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp)
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 82395ae80dba..2ffe5792b1a9 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -490,8 +490,9 @@ struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
struct exfat_chain *p_dir, int entry, struct buffer_head **bh);
struct exfat_dentry *exfat_get_dentry_cached(struct exfat_entry_set_cache *es,
int num);
-struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
- struct exfat_chain *p_dir, int entry, unsigned int type);
+int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
+ struct super_block *sb, struct exfat_chain *p_dir, int entry,
+ unsigned int type);
int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync);
int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index 5590a1e83126..cdcf037a304f 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -21,7 +21,7 @@ int __exfat_write_inode(struct inode *inode, int sync)
{
unsigned long long on_disk_size;
struct exfat_dentry *ep, *ep2;
- struct exfat_entry_set_cache *es = NULL;
+ struct exfat_entry_set_cache es;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
@@ -42,11 +42,10 @@ int __exfat_write_inode(struct inode *inode, int sync)
exfat_set_volume_dirty(sb);
/* get the directory entry of given file or directory */
- es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES);
- if (!es)
+ if (exfat_get_dentry_set(&es, sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES))
return -EIO;
- ep = exfat_get_dentry_cached(es, 0);
- ep2 = exfat_get_dentry_cached(es, 1);
+ ep = exfat_get_dentry_cached(&es, 0);
+ ep2 = exfat_get_dentry_cached(&es, 1);
ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));
@@ -83,8 +82,8 @@ int __exfat_write_inode(struct inode *inode, int sync)
ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
}
- exfat_update_dir_chksum_with_entry_set(es);
- return exfat_free_dentry_set(es, sync);
+ exfat_update_dir_chksum_with_entry_set(&es);
+ return exfat_free_dentry_set(&es, sync);
}
int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index 99e00a36c029..8d72527dfb78 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -604,7 +604,7 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(dir);
struct exfat_dentry *ep, *ep2;
- struct exfat_entry_set_cache *es;
+ struct exfat_entry_set_cache es;
/* for optimized dir & entry to prevent long traverse of cluster chain */
struct exfat_hint hint_opt;
@@ -644,11 +644,10 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
if (cdir.flags & ALLOC_NO_FAT_CHAIN)
cdir.size -= dentry / sbi->dentries_per_clu;
dentry = hint_opt.eidx;
- es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES);
- if (!es)
+ if (exfat_get_dentry_set(&es, sb, &cdir, dentry, ES_2_ENTRIES))
return -EIO;
- ep = exfat_get_dentry_cached(es, 0);
- ep2 = exfat_get_dentry_cached(es, 1);
+ ep = exfat_get_dentry_cached(&es, 0);
+ ep2 = exfat_get_dentry_cached(&es, 1);
info->type = exfat_get_entry_type(ep);
info->attr = le16_to_cpu(ep->dentry.file.attr);
@@ -677,7 +676,7 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
ep->dentry.file.access_time,
ep->dentry.file.access_date,
0);
- exfat_free_dentry_set(es, false);
+ exfat_free_dentry_set(&es, false);
if (ei->start_clu == EXFAT_FREE_CLUSTER) {
exfat_fs_error(sb,
--
2.25.1
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