On Wed, Apr 19, 2023 at 11:29:55AM +0800, Gao Xiang wrote:
> Newer glibc such as glibc 2.36 also defines 'struct mount_attr'
> in addition to <linux/mount.h>. It will report as below when
> compiling with old linux kernel headers (without idmapped mounts,
> such as kernel-headers 5.10.134) but with newer glibc (here checked
> with glibc 2.36.6):
>
> [CC] detached_mounts_propagation
> In file included from detached_mounts_propagation.c:29:
> vfs/missing.h:115:8: error: redefinition of 'struct mount_attr'
> 115 | struct mount_attr {
> | ^~~~~~~~~~
> In file included from detached_mounts_propagation.c:23:
> /usr/include/sys/mount.h:210:8: note: originally defined here
> 210 | struct mount_attr
> | ^~~~~~~~~~
> gmake[3]: *** [Makefile:102: detached_mounts_propagation] Error 1
> gmake[2]: *** [include/buildrules:31: src] Error 2
> make[1]: *** [Makefile:51: default] Error 2
> make: *** [Makefile:49: default] Error 2
>
> Cc: Christian Brauner <brauner@xxxxxxxxxx>
> Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
> ---
This header mount.h mess is a neverending nightmare...
>
> Not quite look into that, but at a quick glance of tester reports
> it seems the cases.
>
> configure.ac | 5 ++++-
> src/detached_mounts_propagation.c | 1 -
> src/vfs/missing.h | 1 +
> 3 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/configure.ac b/configure.ac
> index 4687d8a3..517b4c18 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -74,7 +74,10 @@ AC_HAVE_FIEXCHANGE
>
> AC_CHECK_FUNCS([renameat2])
> AC_CHECK_FUNCS([reallocarray])
> -AC_CHECK_TYPES([struct mount_attr], [], [], [[#include <linux/mount.h>]])
> +AC_CHECK_TYPES([struct mount_attr], [], [], [[
> +#include <linux/mount.h>
> +#include <sys/mount.h>
I think we should only rely on sys/mount.h. linux/mount.h and
sys/mount.h are incompatible because linux/mount.h might have a #define
where sys/mount.h has an enum.
