ntfs3: free the sbi in ->kill_sb

As a rule of thumb everything allocated to the fs_context and moved into
the super_block should be freed by ->kill_sb so that the teardown
handling doesn't need to be duplicated between the fill_super error
path and put_super.  Implement an ntfs3-specific kill_sb method to do
that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Message-Id: <20230809220545.1308228-14-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/ntfs3/super.c

@@ -625,10 +625,6 @@ static void ntfs_put_super(struct super_block *sb)
 
 	/* Mark rw ntfs as clear, if possible. */
 	ntfs_set_state(sbi, NTFS_DIRTY_CLEAR);
-
-	put_mount_options(sbi->options);
-	ntfs3_free_sbi(sbi);
-	sb->s_fs_info = NULL;
 }
 
 static int ntfs_statfs(struct dentry *dentry, struct kstatfs *buf)
@@ -1562,15 +1558,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
 put_inode_out:
 	iput(inode);
 out:
-	/*
-	 * Free resources here.
-	 * ntfs_fs_free will be called with fc->s_fs_info = NULL
-	 */
-	put_mount_options(sbi->options);
-	ntfs3_free_sbi(sbi);
-	sb->s_fs_info = NULL;
 	kfree(boot2);
-
 	return err;
 }
 
@@ -1726,13 +1714,24 @@ static int ntfs_init_fs_context(struct fs_context *fc)
 	return -ENOMEM;
 }
 
+static void ntfs3_kill_sb(struct super_block *sb)
+{
+	struct ntfs_sb_info *sbi = sb->s_fs_info;
+
+	kill_block_super(sb);
+
+	if (sbi->options)
+		put_mount_options(sbi->options);
+	ntfs3_free_sbi(sbi);
+}
+
 // clang-format off
 static struct file_system_type ntfs_fs_type = {
 	.owner			= THIS_MODULE,
 	.name			= "ntfs3",
 	.init_fs_context	= ntfs_init_fs_context,
 	.parameters		= ntfs_fs_parameters,
-	.kill_sb		= kill_block_super,
+	.kill_sb		= ntfs3_kill_sb,
 	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
 };
 // clang-format on