Unverified Commit 11a51d8c authored by Christian Brauner's avatar Christian Brauner
Browse files

fs: add vfs_cmd_reconfigure() 



Split the steps to reconfigure a superblock into a tiny helper instead
of open-coding it in the switch.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarAleksa Sarai <cyphar@cyphar.com>
Message-Id: <20230802-vfs-super-exclusive-v2-3-95dc4e41b870@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent dae8b08d

fs/fsopen.c

+29 −18
Original line number Diff line number Diff line
@@ -242,6 +242,34 @@ static int vfs_cmd_create(struct fs_context *fc) 
	return 0;

}



static int vfs_cmd_reconfigure(struct fs_context *fc)

{

	struct super_block *sb;

	int ret;



	if (fc->phase != FS_CONTEXT_RECONF_PARAMS)

		return -EBUSY;



	fc->phase = FS_CONTEXT_RECONFIGURING;



	sb = fc->root->d_sb;

	if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) {

		fc->phase = FS_CONTEXT_FAILED;

		return -EPERM;

	}



	down_write(&sb->s_umount);

	ret = reconfigure_super(fc);

	up_write(&sb->s_umount);

	if (ret) {

		fc->phase = FS_CONTEXT_FAILED;

		return ret;

	}



	vfs_clean_context(fc);

	return 0;

}



/*

 * Check the state and apply the configuration.  Note that this function is

 * allowed to 'steal' the value by setting param->xxx to NULL before returning.
@@ -249,7 +277,6 @@ static int vfs_cmd_create(struct fs_context *fc) 
static int vfs_fsconfig_locked(struct fs_context *fc, int cmd,

			       struct fs_parameter *param)

{

	struct super_block *sb;

	int ret;



	ret = finish_clean_context(fc);
@@ -259,21 +286,7 @@ static int vfs_fsconfig_locked(struct fs_context *fc, int cmd, 
	case FSCONFIG_CMD_CREATE:

		return vfs_cmd_create(fc);

	case FSCONFIG_CMD_RECONFIGURE:

		if (fc->phase != FS_CONTEXT_RECONF_PARAMS)

			return -EBUSY;

		fc->phase = FS_CONTEXT_RECONFIGURING;

		sb = fc->root->d_sb;

		if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) {

			ret = -EPERM;

			break;

		}

		down_write(&sb->s_umount);

		ret = reconfigure_super(fc);

		up_write(&sb->s_umount);

		if (ret)

			break;

		vfs_clean_context(fc);

		return 0;

		return vfs_cmd_reconfigure(fc);

	default:

		if (fc->phase != FS_CONTEXT_CREATE_PARAMS &&

		    fc->phase != FS_CONTEXT_RECONF_PARAMS)
@@ -281,8 +294,6 @@ static int vfs_fsconfig_locked(struct fs_context *fc, int cmd, 


		return vfs_parse_fs_param(fc, param);

	}

	fc->phase = FS_CONTEXT_FAILED;

	return ret;

}



/**