From 4728c613cf274107cc88cf5228ef8e2caf1d27ca Mon Sep 17 00:00:00 2001
From: Hyeongseok Kim <hyeongseok@gmail.com>
Date: Thu, 18 Mar 2021 15:23:56 +0900
Subject: [PATCH] exfat: improve write performance when dirsync enabled

Degradation of write speed caused by frequent disk access for cluster
bitmap update on every cluster allocation could be improved by
selective syncing bitmap buffer. Change to flush bitmap buffer only
for the directory related operations.

Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
---
 balloc.c   | 4 ++--
 dir.c      | 2 +-
 exfat_fs.h | 4 ++--
 fatent.c   | 4 ++--
 inode.c    | 3 ++-
 namei.c    | 2 +-
 6 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/balloc.c b/balloc.c
index ad990217d3d0..c6807392183e 100644
--- a/balloc.c
+++ b/balloc.c
@@ -145,7 +145,7 @@ void exfat_free_bitmap(struct exfat_sb_info *sbi)
 	kfree(sbi->vol_amap);
 }
 
-int exfat_set_bitmap(struct inode *inode, unsigned int clu)
+int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync)
 {
 	int i, b;
 	unsigned int ent_idx;
@@ -158,7 +158,7 @@ int exfat_set_bitmap(struct inode *inode, unsigned int clu)
 	b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
 
 	set_bit_le(b, sbi->vol_amap[i]->b_data);
-	exfat_update_bh(sbi->vol_amap[i], IS_DIRSYNC(inode));
+	exfat_update_bh(sbi->vol_amap[i], sync);
 	return 0;
 }
 
diff --git a/dir.c b/dir.c
index e671094f57ae..ba91062d8004 100644
--- a/dir.c
+++ b/dir.c
@@ -321,7 +321,7 @@ int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu)
 
 	exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN);
 
-	ret = exfat_alloc_cluster(inode, 1, clu);
+	ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode));
 	if (ret)
 		return ret;
 
diff --git a/exfat_fs.h b/exfat_fs.h
index 0260b9f20790..f38a061e082b 100644
--- a/exfat_fs.h
+++ b/exfat_fs.h
@@ -402,7 +402,7 @@ int exfat_clear_volume_dirty(struct super_block *sb);
 #define exfat_get_next_cluster(sb, pclu) exfat_ent_get(sb, *(pclu), pclu)
 
 int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
-		struct exfat_chain *p_chain);
+		struct exfat_chain *p_chain, bool sync_bmap);
 int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain);
 int exfat_ent_get(struct super_block *sb, unsigned int loc,
 		unsigned int *content);
@@ -421,7 +421,7 @@ int exfat_count_num_clusters(struct super_block *sb,
 /* balloc.c */
 int exfat_load_bitmap(struct super_block *sb);
 void exfat_free_bitmap(struct exfat_sb_info *sbi);
-int exfat_set_bitmap(struct inode *inode, unsigned int clu);
+int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync);
 void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync);
 unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu);
 int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count);
diff --git a/fatent.c b/fatent.c
index 74f3092a277d..c0a9cc9ac6e2 100644
--- a/fatent.c
+++ b/fatent.c
@@ -328,7 +328,7 @@ release_bhs:
 }
 
 int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
-		struct exfat_chain *p_chain)
+		struct exfat_chain *p_chain, bool sync_bmap)
 {
 	int ret = -ENOSPC;
 	unsigned int num_clusters = 0, total_cnt;
@@ -396,7 +396,7 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
 		}
 
 		/* update allocation bitmap */
-		if (exfat_set_bitmap(inode, new_clu)) {
+		if (exfat_set_bitmap(inode, new_clu, sync_bmap)) {
 			ret = -EIO;
 			goto free_cluster;
 		}
diff --git a/inode.c b/inode.c
index 02ddbd3df7bb..2d9a01a6fa94 100644
--- a/inode.c
+++ b/inode.c
@@ -181,7 +181,8 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
 			return -EIO;
 		}
 
-		ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu);
+		ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu,
+				inode_needs_sync(inode));
 		if (ret)
 			return ret;
 
diff --git a/namei.c b/namei.c
index 3b45cc6e0113..a68e56ecd644 100644
--- a/namei.c
+++ b/namei.c
@@ -367,7 +367,7 @@ static int exfat_find_empty_entry(struct inode *inode,
 		exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags);
 
 		/* allocate a cluster */
-		ret = exfat_alloc_cluster(inode, 1, &clu);
+		ret = exfat_alloc_cluster(inode, 1, &clu, IS_DIRSYNC(inode));
 		if (ret)
 			return ret;