[libvirt] [PATCH] qemu: Make virFileFindHugeTLBFS fault tolerant

[Martin Kletzander]

On Wed, Aug 06, 2014 at 10:44:55AM +0200, Michal Privoznik wrote:
>Since commit be0782e1 we are parsing /proc/meminfo to find out the
>default huge page size. However, if the host we are running at does
>not support any huge pages (e.g. CONFIG_HUGETLB_PAGE is turned off),
>we will not successfully parse the meminfo file and hence the whole
>qemu driver init process fails. Moreover, the default huge page size
>is needed if and only if there's at least one hugetlbfs mount point.
>So the fix consists of moving the virFileGetDefaultHugepageSize
>function call after the first hugetlbfs mount point is found.
>
>With this fix, we fail to start with one or more hugetlbfs mounts and
>malformed meminfo file, but that's expected (how can one mount
>hugetlbfs without kernel supporting huge pages?). Workaround in that
>case is to umount all the hugetlbfs mounts.
>
>Reported-by: Jim Fehlig <jfehlig at suse.com>
>Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>---
> src/util/virfile.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>

ACK,

Martin

>diff --git a/src/util/virfile.c b/src/util/virfile.c
>index 9863fd0..f9efc65 100644
>--- a/src/util/virfile.c
>+++ b/src/util/virfile.c
>@@ -2990,10 +2990,7 @@ virFileFindHugeTLBFS(virHugeTLBFSPtr *ret_fs,
>     char mntbuf[1024];
>     virHugeTLBFSPtr fs = NULL;
>     size_t nfs = 0;
>-    unsigned long long default_hugepagesz;
>-
>-    if (virFileGetDefaultHugepageSize(&default_hugepagesz) < 0)
>-        goto cleanup;
>+    unsigned long long default_hugepagesz = 0;
>
>     if (!(f = setmntent(PROC_MOUNTS, "r"))) {
>         virReportSystemError(errno,
>@@ -3019,6 +3016,10 @@ virFileFindHugeTLBFS(virHugeTLBFSPtr *ret_fs,
>         if (virFileGetHugepageSize(tmp->mnt_dir, &tmp->size) < 0)
>             goto cleanup;
>
>+        if (!default_hugepagesz &&
>+            virFileGetDefaultHugepageSize(&default_hugepagesz) < 0)
>+            goto cleanup;
>+
>         tmp->deflt = tmp->size == default_hugepagesz;
>     }
>
>--
>1.8.5.5
>
>--
>libvir-list mailing list
>libvir-list at redhat.com
>https://www.redhat.com/mailman/listinfo/libvir-list
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20140806/58b4fdfa/attachment-0001.sig>