exfat: remove count used cluster from exfat_statfs()

The callback function statfs() is called only after the file
system is mounted. During the process of mounting the exFAT
file system, the number of used clusters has been counted, so
the condition "sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED"
is always false and should be deleted.

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

Author: YuezhangMo

fs/exfat/exfat_fs.h

@@ -14,8 +14,6 @@
 
 #define EXFAT_ROOT_INO		1
 
-#define EXFAT_CLUSTERS_UNTRACKED (~0u)
-
 /*
  * exfat error flags
  */

fs/exfat/super.c

@@ -67,15 +67,6 @@ static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);
 
-	if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
-		mutex_lock(&sbi->s_lock);
-		if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
-			mutex_unlock(&sbi->s_lock);
-			return -EIO;
-		}
-		mutex_unlock(&sbi->s_lock);
-	}
-
 	buf->f_type = sb->s_magic;
 	buf->f_bsize = sbi->cluster_size;
 	buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
@@ -531,7 +522,6 @@ static int exfat_read_boot_sector(struct super_block *sb)
 	sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
 	sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);
 	sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
-	sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
 
 	/* check consistencies */
 	if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits <