Re: [libvirt] [PATCH 1/2] cgroup: fix including sys/mount.h for OpenBSD
Martin Kletzander wrote:
On Fri, Jan 08, 2016 at 10:36:07PM +0300, Roman Bogorodskiy wrote:
>From: Jasper Lievisse Adriaanse <jasper(a)openbsd.org>
>
>Include sys/param.h along with sys/mount.h to fix compilation on
>OpenBSD.
>
>Signed-off-by: Roman Bogorodskiy <bogorodskiy(a)gmail.com>
>---
> src/util/vircgroup.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
>diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
>index e39c4d1..e8e0875 100644
>--- a/src/util/vircgroup.c
>+++ b/src/util/vircgroup.c
>@@ -27,7 +27,8 @@
> #if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R
> # include <mntent.h>
> #endif
>-#if defined HAVE_SYS_MOUNT_H
>+#if defined HAVE_SYS_PARAM_H && defined HAVE_SYS_MOUNT_H
>+# include <sys/param.h>
> # include <sys/mount.h>
Wouldn't this cause an error for systems that have sys/mount.h and need
it for the mount() call, but don't have sys/param.h ?
That's an interesting question.
A check for sys/mount.h was added with the initial implementation of the
mount() using code in commit 1da631e. The mount() call currently is used
only on platforms with cgroups available (i.e. Linux).
Moreover, HAVE_SYS_MOUNT_H does not play any role in cgroups detection:
#if defined(__linux__) && defined(HAVE_GETMNTENT_R) && \
defined(_DIRENT_HAVE_D_TYPE) && defined(_SC_CLK_TCK)
# define VIR_CGROUP_SUPPORTED
#endif
So, sys/mount.h and mount() are only needed on Linux anyway, and I'm
wondering if we actually can just do something like this:
#if defined HAVE_SYS_MOUNT_H && defined HAVE_GETMNTENT_R
# include <sys/mount.h>
#endif
as if we don't have HAVE_GETMNTENT_R define, we will not have
VIR_CGROUP_SUPPORTED, and therefore we'll not need the mount() call.
I've tested it on FreeBSD and OpenBSD and it builds fine. Unfortunately,
cannot test it on Linux at this moment.
Roman Bogorodskiy