This is a note to let you know that I've just added the patch titled
exfat: move exfat_entry_set_cache from heap to stack
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
exfat-move-exfat_entry_set_cache-from-heap-to-stack.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6c290ca5ee81f3322bcc3c5a7879a0e100405040
Author: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
Date: Thu Nov 17 11:37:13 2022 +0800
exfat: move exfat_entry_set_cache from heap to stack
[ Upstream commit 20914ff6dd56dd6b548bf5dd90bff09ef89999e4 ]
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@xxxxxxxx>
Reviewed-by: Andy Wu <Andy.Wu@xxxxxxxx>
Reviewed-by: Aoyama Wataru <wataru.aoyama@xxxxxxxx>
Reviewed-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Stable-dep-of: d42334578eba ("exfat: check if filename entries exceeds max filename length")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 185aa13945d3d..d2be36ddc18a5 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -32,10 +32,9 @@ 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;
/*
@@ -44,8 +43,8 @@ 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)
@@ -55,7 +54,7 @@ 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 */
@@ -613,7 +612,6 @@ 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;
}
@@ -813,14 +811,14 @@ 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;
@@ -828,17 +826,15 @@ 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;
@@ -856,7 +852,7 @@ 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);
@@ -872,8 +868,7 @@ 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;
}
@@ -902,11 +897,11 @@ 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;
}
enum {
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 11e579a2598d8..6ecc7a51b4d18 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -470,8 +470,9 @@ struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
sector_t *sector);
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 4bd73820a4ac0..7f70284da530f 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -21,7 +21,7 @@ static 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 @@ static 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));
@@ -76,8 +75,8 @@ static int __exfat_write_inode(struct inode *inode, int sync)
ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size);
ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
- 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 bd00afc5e4c16..10062b5282bd0 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -595,7 +595,7 @@ 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;
@@ -635,11 +635,10 @@ 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);
@@ -668,7 +667,7 @@ 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,
