Re: [libvirt] [PATCH v2 1/2] host-validate: Be more careful when checking for cgroup support

Simply checking whether the cgroup name appears somewhere inside /proc/self/cgroup is enough most of the time, but there are some corner cases that require a more mindful parsing. As a bonus, after the rewrite 'line' is no longer leaked. --- tools/virt-host-validate-common.c | 49 +++++++++++++++++++++++++++++++++------ 1 file changed, 42 insertions(+), 7 deletions(-) diff --git a/tools/virt-host-validate-common.c b/tools/virt-host-validate-common.c index 8ebf73e..56c6b56 100644 --- a/tools/virt-host-validate-common.c +++ b/tools/virt-host-validate-common.c @@ -265,18 +265,53 @@ static int virHostValidateCGroupSupport(const char *hvname, goto error; while ((ret = getline(&line, &len, fp)) >= 0 && !matched) { - char *tmp = strstr(line, cg_name); - if (!tmp) + char **cgroups; + char *start; + char *end; + size_t ncgroups; + size_t i; + + /* Each line in this file looks like + * + * 4:cpu,cpuacct:/machine.slice/machine-qemu\x2dtest.scope/emulator + *

+ * Since multiple cgroups can be part of the same line and some cgroup + * names can appear as part of other cgroup names (eg. 'cpu' is a + * prefix for both 'cpuacct' and 'cpuset'), it's not enough to simply + * check whether the cgroup name is present somewhere inside the file

+ */ + + /* Look for the first colon. + * The part we're interested in starts right after it */ + if (!(start = strchr(line, ':'))) {

+ VIR_FREE(line); continue;