Re: [Qemu-devel] qemu-kvm build issue on RHEL5.1

[Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>]

(Add CC to kvm@vger)

(2010/10/12 10:52), Hao, Xudong wrote:
> Hi, 
> Currently qemu-kvm build fail on RHEL5 with gcc 4.1.2, build can pass on Fedora11 with gcc 4.4.1, can anybody look on RHEL5 system?
> 
> Gcc: 4.1.2
> system: RHEL5.1
> qemu-kvm: 85566812a4f8cae721fea0224e05a7e75c08c5dd
> 
> ...
>   LINK  qemu-img
>   LINK  qemu-io
>   CC    libhw64/virtio-9p-local.o
> cc1: warnings being treated as errors
> /home/source/qemu-kvm/hw/virtio-9p-local.c: In function 'local_utimensat':
> /home/source/qemu-kvm/hw/virtio-9p-local.c:479: warning: implicit declaration of function 'utimensat'
> /home/source/qemu-kvm/hw/virtio-9p-local.c:479: warning: nested extern declaration of 'utimensat'
> make[1]: *** [virtio-9p-local.o] Error 1
> make: *** [subdir-libhw64] Error 2
> 
> 
> Best Regards,
> Xudong Hao

It seems that this issue is caused by the old glibc.
Though I don't know well about virtio-9p and suppose there
should be better fix, I confirmed that following change
removed the warnings.

Thanks,
H.Seto

=====

[PATCH] virtio-9p: fix build on !CONFIG_UTIMENSAT

This removes following warnings on RHEL5, which has utimensat syscall
but has old glibc that doesn't have support for it:

hw/virtio-9p-local.c: In function 'local_utimensat':
hw/virtio-9p-local.c:479: warning: implicit declaration of function 'utimensat'
hw/virtio-9p-local.c:479: warning: nested extern declaration of 'utimensat'

and

hw/virtio-9p.c: In function 'v9fs_setattr_post_chmod':
hw/virtio-9p.c:1410: error: 'UTIME_NOW' undeclared (first use in this function)
hw/virtio-9p.c:1410: error: (Each undeclared identifier is reported only once
hw/virtio-9p.c:1410: error: for each function it appears in.)
hw/virtio-9p.c:1413: error: 'UTIME_OMIT' undeclared (first use in this function)
hw/virtio-9p.c: In function 'v9fs_wstat_post_chmod':
hw/virtio-9p.c:2905: error: 'UTIME_OMIT' undeclared (first use in this function)

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
---
 hw/virtio-9p-local.c |    8 ++++++++
 hw/virtio-9p.c       |    9 +++++++++
 2 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c
index 57f9243..e075c27 100644
--- a/hw/virtio-9p-local.c
+++ b/hw/virtio-9p-local.c
@@ -18,6 +18,9 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <attr/xattr.h>
+#ifndef CONFIG_UTIMENSAT
+#include <syscall.h>
+#endif
 
 static const char *rpath(FsContext *ctx, const char *path)
 {
@@ -476,7 +479,12 @@ static int local_chown(FsContext *fs_ctx, const char *path, FsCred *credp)
 static int local_utimensat(FsContext *s, const char *path,
 		       const struct timespec *buf)
 {
+#ifndef CONFIG_UTIMENSAT
+    return syscall(SYS_utimensat, AT_FDCWD, rpath(s, path), buf,
+                   AT_SYMLINK_NOFOLLOW);
+#else
     return utimensat(AT_FDCWD, rpath(s, path), buf, AT_SYMLINK_NOFOLLOW);
+#endif
 }
 
 static int local_remove(FsContext *ctx, const char *path)
diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
index 32fa3bc..efe5c51 100644
--- a/hw/virtio-9p.c
+++ b/hw/virtio-9p.c
@@ -1393,6 +1393,15 @@ out:
     qemu_free(vs);
 }
 
+#ifndef CONFIG_UTIMENSAT
+#ifndef UTIME_NOW
+# define UTIME_NOW	((1l << 30) - 1l)
+#endif
+#ifndef UTIME_OMIT
+# define UTIME_OMIT	((1l << 30) - 2l)
+#endif
+#endif
+
 static void v9fs_setattr_post_chmod(V9fsState *s, V9fsSetattrState *vs, int err)
 {
     if (err == -1) {
-- 
1.7.3.1