Unverified Commit dae8b08d authored by Christian Brauner's avatar Christian Brauner
Browse files

fs: add vfs_cmd_create() 



Split the steps to create a superblock into a tiny helper. This will
make the next patch easier to follow.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
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-v2-2-95dc4e41b870@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent e062abae

fs/fsopen.c

+34 −17
Original line number Diff line number Diff line
@@ -209,38 +209,55 @@ SYSCALL_DEFINE3(fspick, int, dfd, const char __user *, path, unsigned int, flags 
	return ret;

}



/*

 * 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.

 */

static int vfs_fsconfig_locked(struct fs_context *fc, int cmd,

			       struct fs_parameter *param)

static int vfs_cmd_create(struct fs_context *fc)

{

	struct super_block *sb;

	int ret;



	ret = finish_clean_context(fc);

	if (ret)

		return ret;

	switch (cmd) {

	case FSCONFIG_CMD_CREATE:

	if (fc->phase != FS_CONTEXT_CREATE_PARAMS)

		return -EBUSY;



	if (!mount_capable(fc))

		return -EPERM;



	fc->phase = FS_CONTEXT_CREATING;



	ret = vfs_get_tree(fc);

		if (ret)

			break;

	if (ret) {

		fc->phase = FS_CONTEXT_FAILED;

		return ret;

	}



	sb = fc->root->d_sb;

	ret = security_sb_kern_mount(sb);

	if (unlikely(ret)) {

		fc_drop_locked(fc);

			break;

		fc->phase = FS_CONTEXT_FAILED;

		return ret;

	}



	/* vfs_get_tree() callchains will have grabbed @s_umount */

	up_write(&sb->s_umount);

	fc->phase = FS_CONTEXT_AWAITING_MOUNT;

	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.

 */

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);

	if (ret)

		return ret;

	switch (cmd) {

	case FSCONFIG_CMD_CREATE:

		return vfs_cmd_create(fc);

	case FSCONFIG_CMD_RECONFIGURE:

		if (fc->phase != FS_CONTEXT_RECONF_PARAMS)

			return -EBUSY;