}
/*
- * reads the vmid from /proc/<pid>/cmdline
- * after the '-id' argument
+ * parses the vmid from the qemu.slice entry of /proc/<pid>/cgroup
*/
static unsigned long
get_vmid_from_pid(pid_t pid)
{
char filename[32] = { 0 };
- int len = snprintf(filename, sizeof(filename), "/proc/%d/cmdline", pid);
+ int len = snprintf(filename, sizeof(filename), "/proc/%d/cgroup", pid);
if (len < 0) {
fprintf(stderr, "error during snprintf for %d: %s\n", pid,
strerror(errno));
}
unsigned long vmid = 0;
- ssize_t rc = 0;
char *buf = NULL;
size_t buflen = 0;
- while ((rc = getdelim(&buf, &buflen, '\0', fp)) >= 0) {
- if (!strcmp(buf, "-id")) {
- break;
+
+ while (getline(&buf, &buflen, fp) >= 0) {
+ char *cgroup_path = strrchr(buf, ':');
+ if (!cgroup_path) {
+ fprintf(stderr, "unexpected cgroup entry %s\n", buf);
+ continue;
}
- }
+ cgroup_path++;
- if (rc < 0) {
- goto err;
- }
+ if (strncmp(cgroup_path, "/qemu.slice/", 12)) {
+ continue;
+ }
- if (getdelim(&buf, &buflen, '\0', fp) >= 0) {
- if (buf[0] == '-' || buf[0] == '\0') {
- fprintf(stderr, "invalid vmid %s\n", buf);
- goto ret;
+ char *vmid_start = strrchr(buf, '/');
+ if (!vmid_start) {
+ fprintf(stderr, "unexpected cgroup entry %s\n", buf);
+ continue;
+ }
+ vmid_start++;
+
+ if (vmid_start[0] == '-' || vmid_start[0] == '\0') {
+ fprintf(stderr, "invalid vmid in cgroup entry %s\n", buf);
+ continue;
}
errno = 0;
char *endptr = NULL;
- vmid = strtoul(buf, &endptr, 10);
- if (errno != 0) {
+ vmid = strtoul(vmid_start, &endptr, 10);
+ if (!endptr || strncmp(endptr, ".scope", 6)) {
+ fprintf(stderr, "unexpected cgroup entry %s\n", buf);
vmid = 0;
- goto err;
- } else if (*endptr != '\0') {
- fprintf(stderr, "invalid vmid %s\n", buf);
+ continue;
+ }
+ if (errno != 0) {
+ fprintf(stderr, "error parsing vmid for %d: %s\n", pid, strerror(errno));
vmid = 0;
}
goto ret;
}
-err:
- fprintf(stderr, "error parsing vmid for %d: %s\n", pid, strerror(errno));
+ if (errno) {
+ fprintf(stderr, "error parsing vmid for %d: %s\n", pid, strerror(errno));
+ } else {
+ fprintf(stderr, "error parsing vmid for %d: no matching qemu.slice cgroup entry\n", pid);
+ }
ret:
free(buf);