f2fs: decrease maximum flush retry count in f2fs_enable_checkpoint()

It's rare case that sync_inodes_sb() always skips to flush some drity
datas, so it's enough to give extra three more chances to flush data.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Author: chaseyu

fs/f2fs/f2fs.h

@@ -699,6 +699,8 @@ enum {
 
 #define DEFAULT_RETRY_IO_COUNT	8	/* maximum retry read IO or flush count */
 
+#define MAX_FLUSH_RETRY_COUNT	3	/* maximum flush retry count in f2fs_enable_checkpoint() */
+
 /* IO/non-IO congestion wait timeout value, default: 1 jiffies */
 #define	DEFAULT_SCHEDULE_TIMEOUT	1
 

fs/f2fs/super.c

@@ -2687,7 +2687,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)
 
 static int f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)
 {
-	int retry = DEFAULT_RETRY_IO_COUNT;
+	int retry = MAX_FLUSH_RETRY_COUNT;
 	long long start, writeback, end;
 	int ret;
 	struct f2fs_lock_context lc;