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@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>

diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 03e9c9e..a3fb609 100644 (file)
--- 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 82395ae..2ffe579 100644 (file)
--- 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 5590a1e..cdcf037 100644 (file)
--- 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 99e00a3..8d72527 100644 (file)
--- 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,