Hi Neil,
> Some filesystems cannot be exported without an fsid or uuid.
> tmpfs is the main example.
> When mountd (or exportd) creates nfsv4 pseudo-root exports for the path
> leading down to an export point it exports each directory without any
> fsid or uuid. If one of these directories is on tmp, that will fail.
^ nit: you probably
mean tmpfs
> The net result is that exporting a subdirectory of a tmpfs filesystem
> will not work over NFSv4 as the parents within the filesystem cannot be
> exported. It will either fail, or fall-back to NFSv3 (depending on the
> version of the mount.nfs program).
> To fix this we need to provide an fsid or uuid for these pseudo-root
> exports. This patch does that by creating an RFC-4122 V5 compatible
> UUID based on an arbitrary seed and the path to the export.
> To check if an export needs a uuid, text_export() is moved from exportfs
> to libexport.a, modified slightly and renamed to export_test().
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
Reported-by: Petr Vorel <pvorel@xxxxxxx>
Reviewed-by: Petr Vorel <pvorel@xxxxxxx>
Tested-by: Petr Vorel <pvorel@xxxxxxx>
LGTM, thanks for fixing it.
...
> --- a/support/include/exportfs.h
> +++ b/support/include/exportfs.h
> @@ -173,5 +173,6 @@ struct export_features {
> struct export_features *get_export_features(void);
> void fix_pseudoflavor_flags(struct exportent *ep);
> char *exportent_realpath(struct exportent *eep);
> +int export_test(struct exportent *eep, int with_fsid);
> #endif /* EXPORTFS_H */
> diff --git a/utils/exportd/Makefile.am b/utils/exportd/Makefile.am
> index eb521f15032d..c95bdee76d3f 100644
> --- a/utils/exportd/Makefile.am
> +++ b/utils/exportd/Makefile.am
> @@ -16,7 +16,7 @@ exportd_SOURCES = exportd.c
> exportd_LDADD = ../../support/export/libexport.a \
> ../../support/nfs/libnfs.la \
> ../../support/misc/libmisc.a \
> - $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD)
> + $(OPTLIBS) $(LIBBLKID) $(LIBPTHREAD) -luuid
I wonder if configure.ac should have libuuid check as it's now mandatory, e.g.:
AC_CHECK_LIB[uuid], uuid_parse, [LIBUUID="-luuid"], AC_MSG_ERROR([libuuid needed]))
Kind regards,
Petr
