1 files changed, 28 insertions, 44 deletions

diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index bd57844414aa..3a9ec75ab452 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -36,46 +36,18 @@ static void exfat_put_super(struct super_block *sb)
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 
 	mutex_lock(&sbi->s_lock);
+	exfat_clear_volume_dirty(sb);
 	exfat_free_bitmap(sbi);
 	brelse(sbi->boot_bh);
 	mutex_unlock(&sbi->s_lock);
 }
 
-static int exfat_sync_fs(struct super_block *sb, int wait)
-{
-	struct exfat_sb_info *sbi = EXFAT_SB(sb);
-	int err = 0;
-
-	if (unlikely(exfat_forced_shutdown(sb)))
-		return 0;
-
-	if (!wait)
-		return 0;
-
-	/* If there are some dirty buffers in the bdev inode */
-	mutex_lock(&sbi->s_lock);
-	sync_blockdev(sb->s_bdev);
-	if (exfat_clear_volume_dirty(sb))
-		err = -EIO;
-	mutex_unlock(&sbi->s_lock);
-	return err;
-}
-
 static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	struct super_block *sb = dentry->d_sb;
 	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 */
@@ -228,7 +200,6 @@ static const struct super_operations exfat_sops = {
 	.write_inode	= exfat_write_inode,
 	.evict_inode	= exfat_evict_inode,
 	.put_super	= exfat_put_super,
-	.sync_fs	= exfat_sync_fs,
 	.statfs		= exfat_statfs,
 	.show_options	= exfat_show_options,
 	.shutdown	= exfat_shutdown,
@@ -370,13 +341,12 @@ static void exfat_hash_init(struct super_block *sb)
 		INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
 }
 
-static int exfat_read_root(struct inode *inode)
+static int exfat_read_root(struct inode *inode, struct exfat_chain *root_clu)
 {
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
-	struct exfat_chain cdir;
-	int num_subdirs, num_clu = 0;
+	int num_subdirs;
 
 	exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
 	ei->entry = -1;
@@ -389,12 +359,9 @@ static int exfat_read_root(struct inode *inode)
 	ei->hint_stat.clu = sbi->root_dir;
 	ei->hint_femp.eidx = EXFAT_HINT_NONE;
 
-	exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
-	if (exfat_count_num_clusters(sb, &cdir, &num_clu))
-		return -EIO;
-	i_size_write(inode, num_clu << sbi->cluster_size_bits);
+	i_size_write(inode, EXFAT_CLU_TO_B(root_clu->size, sbi));
 
-	num_subdirs = exfat_count_dir_entries(sb, &cdir);
+	num_subdirs = exfat_count_dir_entries(sb, root_clu);
 	if (num_subdirs < 0)
 		return -EIO;
 	set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
@@ -531,7 +498,6 @@ 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 <
@@ -608,7 +574,8 @@ static int exfat_verify_boot_region(struct super_block *sb)
 }
 
 /* mount the file system volume */
-static int __exfat_fill_super(struct super_block *sb)
+static int __exfat_fill_super(struct super_block *sb,
+		struct exfat_chain *root_clu)
 {
 	int ret;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
@@ -625,6 +592,18 @@ static int __exfat_fill_super(struct super_block *sb)
 		goto free_bh;
 	}
 
+	/*
+	 * Call exfat_count_num_cluster() before searching for up-case and
+	 * bitmap directory entries to avoid infinite loop if they are missing
+	 * and the cluster chain includes a loop.
+	 */
+	exfat_chain_set(root_clu, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
+	ret = exfat_count_num_clusters(sb, root_clu, &root_clu->size);
+	if (ret) {
+		exfat_err(sb, "failed to count the number of clusters in root");
+		goto free_bh;
+	}
+
 	ret = exfat_create_upcase_table(sb);
 	if (ret) {
 		exfat_err(sb, "failed to load upcase table");
@@ -657,6 +636,7 @@ static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
 	struct exfat_sb_info *sbi = sb->s_fs_info;
 	struct exfat_mount_options *opts = &sbi->options;
 	struct inode *root_inode;
+	struct exfat_chain root_clu;
 	int err;
 
 	if (opts->allow_utime == (unsigned short)-1)
@@ -675,7 +655,7 @@ static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
 	sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
 	sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
 
-	err = __exfat_fill_super(sb);
+	err = __exfat_fill_super(sb, &root_clu);
 	if (err) {
 		exfat_err(sb, "failed to recognize exfat type");
 		goto check_nls_io;
@@ -710,7 +690,7 @@ static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	root_inode->i_ino = EXFAT_ROOT_INO;
 	inode_set_iversion(root_inode, 1);
-	err = exfat_read_root(root_inode);
+	err = exfat_read_root(root_inode, &root_clu);
 	if (err) {
 		exfat_err(sb, "failed to initialize root inode");
 		goto put_inode;
@@ -761,10 +741,14 @@ static void exfat_free(struct fs_context *fc)
 
 static int exfat_reconfigure(struct fs_context *fc)
 {
+	struct super_block *sb = fc->root->d_sb;
 	fc->sb_flags |= SB_NODIRATIME;
 
-	/* volume flag will be updated in exfat_sync_fs */
-	sync_filesystem(fc->root->d_sb);
+	sync_filesystem(sb);
+	mutex_lock(&EXFAT_SB(sb)->s_lock);
+	exfat_clear_volume_dirty(sb);
+	mutex_unlock(&EXFAT_SB(sb)->s_lock);
+
 	return 0;
 }