Re: [libvirt] [PATCH] Fix starting domains when kernel has no cgroups support

On Fri, May 10, 2013 at 12:40:40PM -0600, Jim Fehlig wrote: > Found that I was unable to start existing domains after updating > to a kernel with no cgroups support > > # zgrep CGROUP /proc/config.gz > # CONFIG_CGROUPS is not set > # virsh start test > error: Failed to start domain test > error: Unable to initialize /machine cgroup: Cannot allocate memory > > virCgroupPartitionNeedsEscaping() correctly returns errno (ENOENT) when > attempting to open /proc/cgroups on such a system, but it was being > dropped in virCgroupSetPartitionSuffix(). > > Change virCgroupSetPartitionSuffix() to propogate errors returned by > its callees. Also check for ENOENT in qemuInitCgroup() when determining > if cgroups support is available. > --- > src/qemu/qemu_cgroup.c | 3 ++- > src/util/vircgroup.c | 19 +++++++++++++------ > 2 files changed, 15 insertions(+), 7 deletions(-) > > diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c > index 9c45b76..40777aa 100644 > --- a/src/qemu/qemu_cgroup.c > +++ b/src/qemu/qemu_cgroup.c > @@ -414,7 +414,8 @@ int qemuInitCgroup(virQEMUDriverPtr driver, > if (rc != 0) { > if (rc == -ENXIO || > rc == -EPERM || > - rc == -EACCES) { /* No cgroups mounts == success */ > + rc == -EACCES || > + rc == -ENOENT) { /* No cgroups mounts == success */ > VIR_DEBUG("No cgroups present/configured/accessible, ignoring error"); > goto done; > } > diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c > index 473d2fc..ef619dc 100644 > --- a/src/util/vircgroup.c > +++ b/src/util/vircgroup.c > @@ -1167,14 +1167,14 @@ static int virCgroupPartitionEscape(char **path) > return 0; > } > > -static char *virCgroupSetPartitionSuffix(const char *path) > +static int virCgroupSetPartitionSuffix(const char *path, char **res) > You're changing the signature, but I don't see you changing any callers to adapt.