The virCgroupKill method kills all PIDs found in a cgroup The virCgroupKillRecursively method does this recursively for child cgroups. The virCgroupKillPainfully method does a recursive kill several times in a row until everything has really died --- src/libvirt_private.syms | 3 + src/util/cgroup.c | 229 ++++++++++++++++++++++++++++++++++++++++++++++ src/util/cgroup.h | 4 + 3 files changed, 236 insertions(+), 0 deletions(-) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 797a670..989b3eb 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -74,6 +74,9 @@ virCgroupGetMemoryHardLimit; virCgroupGetMemorySoftLimit; virCgroupGetMemoryUsage; virCgroupGetSwapHardLimit; +virCgroupKill; +virCgroupKillRecursive; +virCgroupKillPainfully; virCgroupMounted; virCgroupRemove; virCgroupSetBlkioWeight; diff --git a/src/util/cgroup.c b/src/util/cgroup.c index b71eef9..2c7efb4 100644 --- a/src/util/cgroup.c +++ b/src/util/cgroup.c @@ -23,6 +23,7 @@ #include <stdbool.h> #include <sys/stat.h> #include <sys/types.h> +#include <signal.h> #include <libgen.h> #include <dirent.h> @@ -32,6 +33,7 @@ #include "cgroup.h" #include "logging.h" #include "files.h" +#include "hash.h" #define CGROUP_MAX_VAL 512 @@ -258,6 +260,19 @@ static int virCgroupPathOfController(virCgroupPtr group, const char *key, char **path) { + if (controller == -1) { + int i; + for (i = 0 ; i < VIR_CGROUP_CONTROLLER_LAST ; i++) { + if (group->controllers[i].mountPoint && + group->controllers[i].placement) { + controller = i; + break; + } + } + } + if (controller == -1) + return -ENOSYS; + if (group->controllers[controller].mountPoint == NULL) return -ENOENT; @@ -1291,3 +1306,217 @@ int virCgroupGetFreezerState(virCgroupPtr group, char **state) VIR_CGROUP_CONTROLLER_CPU, "freezer.state", state); } + +static int virCgroupKillInternal(virCgroupPtr group, int signum, virHashTablePtr pids) +{ + int rc; + int killedAny = 0; + char *keypath = NULL; + bool done = false; + VIR_DEBUG("group=%p path=%s signum=%d pids=%p", group, group->path, signum, pids); + + rc = virCgroupPathOfController(group, -1, "tasks", &keypath); + if (rc != 0) { + VIR_DEBUG("No path of %s, tasks", group->path); + return rc; + } + + /* PIDs may be forking as we kill them, so loop + * until there are no new PIDs found + */ + while (!done) { + done = true; + FILE *fp; + if (!(fp = fopen(keypath, "r"))) { + rc = -errno; + VIR_DEBUG("Failed to read %s: %m\n", keypath); + goto cleanup; + } else { + while (!feof(fp)) { + unsigned long pid; + if (fscanf(fp, "%lu", &pid) != 1) { + if (feof(fp)) + break; + rc = -errno; + break; + } + if (virHashLookup(pids, (void*)pid)) + continue; + + VIR_DEBUG("pid=%lu", pid); + if (kill((pid_t)pid, signum) < 0) { + if (errno != ESRCH) { + rc = -errno; + goto cleanup; + } + /* Leave RC == 0 since we didn't kill one */ + } else { + killedAny = 1; + done = false; + } + + virHashAddEntry(pids, (void*)pid, (void*)1); + } + fclose(fp); + } + } + + rc = killedAny ? 1 : 0; + +cleanup: + VIR_FREE(keypath); + + return rc; +} + + +static unsigned long virCgroupPidCode(const void *name) +{ + return (unsigned long)name; +} +static bool virCgroupPidEqual(const void *namea, const void *nameb) +{ + return namea == nameb; +} +static void *virCgroupPidCopy(const void *name) +{ + return (void*)name; +} + +/* + * Returns + * < 0 : errno that occurred + * 0 : no PIDs killed + * 1 : at least one PID killed + */ +int virCgroupKill(virCgroupPtr group, int signum) +{ + VIR_DEBUG("group=%p path=%s signum=%d", group, group->path, signum); + int rc; + /* The 'tasks' file in cgroups can contain duplicated + * pids, so we use a hash to track which we've already + * killed. + */ + virHashTablePtr pids = virHashCreateFull(100, + NULL, + virCgroupPidCode, + virCgroupPidEqual, + virCgroupPidCopy, + NULL); + + rc = virCgroupKillInternal(group, signum, pids); + + virHashFree(pids); + + return rc; +} + + +static int virCgroupKillRecursiveInternal(virCgroupPtr group, int signum, virHashTablePtr pids, bool dormdir) +{ + int rc; + int killedAny = 0; + char *keypath = NULL; + DIR *dp; + virCgroupPtr subgroup = NULL; + struct dirent *ent; + VIR_DEBUG("group=%p path=%s signum=%d pids=%p", group, group->path, signum, pids); + + rc = virCgroupPathOfController(group, -1, "", &keypath); + if (rc != 0) { + VIR_DEBUG("No path of %s, tasks", group->path); + return rc; + } + + if ((rc = virCgroupKillInternal(group, signum, pids)) != 0) + return rc; + + VIR_DEBUG("Iterate over children of %s", keypath); + if (!(dp = opendir(keypath))) { + rc = -errno; + return rc; + } + + while ((ent = readdir(dp))) { + char *subpath; + + if (STREQ(ent->d_name, ".")) + continue; + if (STREQ(ent->d_name, "..")) + continue; + if (ent->d_type != DT_DIR) + continue; + + VIR_DEBUG("Process subdir %s", ent->d_name); + if (virAsprintf(&subpath, "%s/%s", group->path, ent->d_name) < 0) { + rc = -ENOMEM; + goto cleanup; + } + + if ((rc = virCgroupNew(subpath, &subgroup)) != 0) + goto cleanup; + + if ((rc = virCgroupKillRecursiveInternal(subgroup, signum, pids, true)) < 0) + goto cleanup; + if (rc == 1) + killedAny = 1; + + if (dormdir) + virCgroupRemove(subgroup); + + virCgroupFree(&subgroup); + } + + rc = killedAny; + +cleanup: + virCgroupFree(&subgroup); + closedir(dp); + + return rc; +} + +int virCgroupKillRecursive(virCgroupPtr group, int signum) +{ + int rc; + VIR_DEBUG("group=%p path=%s signum=%d", group, group->path, signum); + virHashTablePtr pids = virHashCreateFull(100, + NULL, + virCgroupPidCode, + virCgroupPidEqual, + virCgroupPidCopy, + NULL); + + rc = virCgroupKillRecursiveInternal(group, signum, pids, false); + + virHashFree(pids); + + return rc; +} + + +int virCgroupKillPainfully(virCgroupPtr group) +{ + int i; + int rc; + VIR_DEBUG("cgroup=%p path=%s", group, group->path); + for (i = 0 ; i < 15 ; i++) { + int signum; + if (i == 0) + signum = SIGTERM; + else if (i == 8) + signum = SIGKILL; + else + signum = 0; /* Just check for existance */ + + rc = virCgroupKillRecursive(group, signum); + VIR_DEBUG("Iteration %d rc=%d", i, rc); + /* If rc == -1 we hit error, if 0 we ran out of PIDs */ + if (rc <= 0) + break; + + usleep(200 * 1000); + } + VIR_DEBUG("Complete %d", rc); + return rc; +} diff --git a/src/util/cgroup.h b/src/util/cgroup.h index f1bdd0f..d468cb3 100644 --- a/src/util/cgroup.h +++ b/src/util/cgroup.h @@ -90,4 +90,8 @@ int virCgroupRemove(virCgroupPtr group); void virCgroupFree(virCgroupPtr *group); bool virCgroupMounted(virCgroupPtr cgroup, int controller); +int virCgroupKill(virCgroupPtr group, int signum); +int virCgroupKillRecursive(virCgroupPtr group, int signum); +int virCgroupKillPainfully(virCgroupPtr group); + #endif /* CGROUP_H */ -- 1.7.4