Unverified Commit d55f90e9 authored by Christian Brauner's avatar Christian Brauner
Browse files

ntfs3: enforce read-only when used as legacy ntfs driver 



Ensure that ntfs3 is mounted read-only when it is used to provide the
legacy ntfs driver.

Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 74871791

fs/ntfs3/ntfs_fs.h

+2 −0
Original line number Diff line number Diff line
@@ -1154,4 +1154,6 @@ static inline void le64_sub_cpu(__le64 *var, u64 val) 
	*var = cpu_to_le64(le64_to_cpu(*var) - val);

}



bool is_legacy_ntfs(struct super_block *sb);



#endif /* _LINUX_NTFS3_NTFS_FS_H */

fs/ntfs3/super.c

+32 −4
Original line number Diff line number Diff line
@@ -408,6 +408,12 @@ static int ntfs_fs_reconfigure(struct fs_context *fc) 
	struct ntfs_mount_options *new_opts = fc->fs_private;

	int ro_rw;



	/* If ntfs3 is used as legacy ntfs enforce read-only mode. */

	if (is_legacy_ntfs(sb)) {

		fc->sb_flags |= SB_RDONLY;

		goto out;

	}



	ro_rw = sb_rdonly(sb) && !(fc->sb_flags & SB_RDONLY);

	if (ro_rw && (sbi->flags & NTFS_FLAGS_NEED_REPLAY)) {

		errorf(fc,
@@ -427,8 +433,6 @@ static int ntfs_fs_reconfigure(struct fs_context *fc) 
			fc,

			"ntfs3: Cannot use different iocharset when remounting!");



	sync_filesystem(sb);



	if (ro_rw && (sbi->volume.flags & VOLUME_FLAG_DIRTY) &&

	    !new_opts->force) {

		errorf(fc,
@@ -436,6 +440,8 @@ static int ntfs_fs_reconfigure(struct fs_context *fc) 
		return -EINVAL;

	}



out:

	sync_filesystem(sb);

	swap(sbi->options, fc->fs_private);



	return 0;
@@ -1613,6 +1619,8 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc) 
	}

#endif



	if (is_legacy_ntfs(sb))

		sb->s_flags |= SB_RDONLY;

	return 0;



put_inode_out:
@@ -1730,7 +1738,7 @@ static const struct fs_context_operations ntfs_context_ops = { 
 * This will called when mount/remount. We will first initialize

 * options so that if remount we can use just that.

 */

static int ntfs_init_fs_context(struct fs_context *fc)

static int __ntfs_init_fs_context(struct fs_context *fc)

{

	struct ntfs_mount_options *opts;

	struct ntfs_sb_info *sbi;
@@ -1778,6 +1786,11 @@ static int ntfs_init_fs_context(struct fs_context *fc) 
	return -ENOMEM;

}



static int ntfs_init_fs_context(struct fs_context *fc)

{

	return __ntfs_init_fs_context(fc);

}



static void ntfs3_kill_sb(struct super_block *sb)

{

	struct ntfs_sb_info *sbi = sb->s_fs_info;
@@ -1800,10 +1813,20 @@ static struct file_system_type ntfs_fs_type = { 
};



#if IS_ENABLED(CONFIG_NTFS_FS)

static int ntfs_legacy_init_fs_context(struct fs_context *fc)

{

	int ret;



	ret = __ntfs_init_fs_context(fc);

	/* If ntfs3 is used as legacy ntfs enforce read-only mode. */

	fc->sb_flags |= SB_RDONLY;

	return ret;

}



static struct file_system_type ntfs_legacy_fs_type = {

	.owner			= THIS_MODULE,

	.name			= "ntfs",

	.init_fs_context	= ntfs_init_fs_context,

	.init_fs_context	= ntfs_legacy_init_fs_context,

	.parameters		= ntfs_fs_parameters,

	.kill_sb		= ntfs3_kill_sb,

	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
@@ -1821,9 +1844,14 @@ static inline void unregister_as_ntfs_legacy(void) 
{

	unregister_filesystem(&ntfs_legacy_fs_type);

}

bool is_legacy_ntfs(struct super_block *sb)

{

	return sb->s_type == &ntfs_legacy_fs_type;

}

#else

static inline void register_as_ntfs_legacy(void) {}

static inline void unregister_as_ntfs_legacy(void) {}

bool is_legacy_ntfs(struct super_block *sb) { return false; }

#endif