Re: [PATCH 0/3] fs_parser: handle parameters that can be empty and don't have a value

[Christian Brauner]

> Unfortunately, the two filesystems that use this flag (ext4 and overlayfs)
> aren't prepared to have the parameter value set to NULL.  Patches #2 and #3
> fix this.

Both ext4 and overlayfs define

#define fsparam_string_empty(NAME, OPT) \
        __fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)

Please add that to include/linux/fs_parser.h so that it can be used by both.