[libvirt] [RFC PATCH 2/4] lxc: Add save/restore helper functions
Radostin Stoyanov
rstoyanov1 at gmail.com
Wed Apr 11 11:29:13 UTC 2018
Add helper functions for checkpoint/restore of linux containers using
CRIU.
Signed-off-by: Radostin Stoyanov <rstoyanov1 at gmail.com>
---
po/POTFILES.in | 1 +
src/lxc/Makefile.inc.am | 4 +
src/lxc/lxc_criu.c | 253 ++++++++++++++++++++++++++++++++++++++++++++++++
src/lxc/lxc_criu.h | 36 +++++++
4 files changed, 294 insertions(+)
create mode 100644 src/lxc/lxc_criu.c
create mode 100644 src/lxc/lxc_criu.h
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 0dcd1cab2..a6d3a5743 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -106,6 +106,7 @@ src/lxc/lxc_fuse.c
src/lxc/lxc_hostdev.c
src/lxc/lxc_native.c
src/lxc/lxc_process.c
+src/lxc/lxc_criu.c
src/network/bridge_driver.c
src/network/bridge_driver_linux.c
src/network/leaseshelper.c
diff --git a/src/lxc/Makefile.inc.am b/src/lxc/Makefile.inc.am
index 8dd2e9ea9..fbdc87b24 100644
--- a/src/lxc/Makefile.inc.am
+++ b/src/lxc/Makefile.inc.am
@@ -42,6 +42,8 @@ LXC_DRIVER_SOURCES = \
lxc/lxc_native.h \
lxc/lxc_driver.c \
lxc/lxc_driver.h \
+ lxc/lxc_criu.c \
+ lxc/lxc_criu.h \
$(NULL)
LXC_CONTROLLER_SOURCES = \
@@ -58,6 +60,8 @@ LXC_CONTROLLER_SOURCES = \
lxc/lxc_fuse.c \
lxc/lxc_fuse.h \
lxc/lxc_controller.c \
+ lxc/lxc_criu.c \
+ lxc/lxc_criu.h \
$(NULL)
diff --git a/src/lxc/lxc_criu.c b/src/lxc/lxc_criu.c
new file mode 100644
index 000000000..b45f9b9f3
--- /dev/null
+++ b/src/lxc/lxc_criu.c
@@ -0,0 +1,253 @@
+/*
+ * Copyright (C) 2016 Katerina Koukiou
+ *
+ * lxc_criu.c: Helper functions for checkpoint/restore of linux containers
+ *
+ * Authors:
+ * Katerina Koukiou <k.koukiou at gmail.com>
+ * Radostin Stoyanov <r.stoyanov.14 at aberdeen.ac.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+
+#include "virobject.h"
+#include "virerror.h"
+#include "virlog.h"
+#include "virfile.h"
+#include "vircommand.h"
+#include "virstring.h"
+#include "viralloc.h"
+
+#include "lxc_domain.h"
+#include "lxc_driver.h"
+#include "lxc_criu.h"
+
+#define VIR_FROM_THIS VIR_FROM_LXC
+
+VIR_LOG_INIT("lxc.lxc_criu");
+
+#ifdef CRIU
+
+int lxcCriuDump(virLXCDriverPtr driver ATTRIBUTE_UNUSED,
+ virDomainObjPtr vm,
+ const char *checkpointdir)
+{
+ int fd;
+ int ret = -1;
+ pid_t initpid;
+ virCommandPtr cmd;
+ struct stat sb;
+ char *path = NULL;
+ char *tty_info_path = NULL;
+ char *ttyinfo = NULL;
+ int status;
+
+ initpid = ((virLXCDomainObjPrivatePtr) vm->privateData)->initpid;
+
+ if (virFileMakePath(checkpointdir) < 0) {
+ virReportSystemError(errno, _("Failed to mkdir %s"), checkpointdir);
+ return -1;
+ }
+
+ fd = open(checkpointdir, O_DIRECTORY);
+ if (fd < 0) {
+ virReportSystemError(errno,
+ _("Failed to open directory %s"), checkpointdir);
+ return -1;
+ }
+
+ cmd = virCommandNew(CRIU);
+ virCommandAddArg(cmd, "dump");
+ virCommandAddArg(cmd, "--tree");
+ virCommandAddArgFormat(cmd, "%d", initpid);
+ virCommandAddArgList(cmd,
+ "--images-dir", checkpointdir,
+ "--tcp-established",
+ "--log-file", "dump.log",
+ "-v4",
+ "--file-locks",
+ "--link-remap",
+ "--force-irmap",
+ "--manage-cgroups=full",
+ "--enable-fs", "hugetlbfs",
+ "--enable-fs", "tracefs",
+ "--external", "mnt[]{:ms}",
+ "--external", "mnt[/proc/meminfo]:fuse",
+ "--external", "mnt[/dev/console]:console",
+ "--external", "mnt[/dev/tty1]:tty1",
+ NULL
+ );
+
+ /* The master pair of the /dev/pts device lives outside from what is dumped
+ * inside the libvirt-lxc process. Add the slave pair as an external tty
+ * otherwise criu will fail.
+ */
+ if (virAsprintf(&path, "/proc/%d/root/dev/pts/0", initpid) < 0)
+ goto cleanup;
+
+ if (stat(path, &sb) < 0) {
+ virReportSystemError(errno, _("Unable to stat %s"), path);
+ goto cleanup;
+ }
+
+ if (virAsprintf(&tty_info_path, "%s/tty.info", checkpointdir) < 0)
+ goto cleanup;
+
+ if (virAsprintf(&ttyinfo, "tty[%llx:%llx]",
+ (long long unsigned) sb.st_rdev,
+ (long long unsigned) sb.st_dev) < 0)
+ goto cleanup;
+
+ if (virFileWriteStr(tty_info_path, ttyinfo, 0600) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Failed to write tty info to %s"), tty_info_path);
+ goto cleanup;
+ }
+
+ virCommandAddArg(cmd, "--external");
+ virCommandAddArgFormat(cmd, "tty[%llx:%llx]",
+ (long long unsigned) sb.st_rdev,
+ (long long unsigned) sb.st_dev);
+
+ virCommandAddEnvString(cmd, "PATH=/bin:/sbin");
+
+ VIR_DEBUG("About to checkpoint domain %s (pid = %d)",
+ vm->def->name, initpid);
+ virCommandRawStatus(cmd);
+ if (virCommandRun(cmd, &status) < 0)
+ goto cleanup;
+
+ ret = 0;
+
+ cleanup:
+ VIR_FORCE_CLOSE(fd);
+ VIR_FREE(path);
+ VIR_FREE(tty_info_path);
+ VIR_FREE(ttyinfo);
+ virCommandFree(cmd);
+
+ return (ret < 0) ? ret : status;
+}
+
+
+int lxcCriuRestore(virDomainDefPtr def, int restorefd,
+ int ttyfd)
+{
+ int ret = -1;
+ virCommandPtr cmd;
+ char *ttyinfo = NULL;
+ char *inheritfd = NULL;
+ char *tty_info_path = NULL;
+ char *checkpointfd = NULL;
+ char *checkpointdir = NULL;
+ virDomainFSDefPtr root;
+ gid_t *groups = NULL;
+ int ngroups;
+
+ cmd = virCommandNew(CRIU);
+ virCommandAddArg(cmd, "restore");
+
+ if (virAsprintf(&checkpointfd, "/proc/self/fd/%d", restorefd) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("Failed to write checkpoint dir path"));
+ goto cleanup;
+ }
+
+ if (virFileResolveLink(checkpointfd, &checkpointdir) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("Failed to readlink checkpoint dir path"));
+ goto cleanup;
+ }
+
+ virCommandAddArgList(cmd,
+ "--pidfile", "pidfile",
+ "--restore-detached",
+ "--restore-sibling",
+ "--tcp-established",
+ "--file-locks",
+ "--link-remap",
+ "--manage-cgroups=full",
+ "--enable-fs", "hugetlbfs",
+ "--enable-fs", "tracefs",
+ "--images-dir", checkpointdir,
+ "--log-file", "restore.log",
+ "-v4",
+ "--external", "mnt[]{:ms}",
+ "--external", "mnt[fuse]:/proc/meminfo",
+ "--external", "mnt[console]:/dev/console",
+ "--external", "mnt[tty1]:/dev/tty1",
+ NULL
+ );
+
+ /* Restore external tty from tty.info file */
+ if (virAsprintf(&tty_info_path, "%s/tty.info", checkpointdir) < 0)
+ goto cleanup;
+
+ if (virFileReadAll(tty_info_path, 1024, &ttyinfo) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Failed to read tty info from %s"), tty_info_path);
+ goto cleanup;
+ }
+ if (virAsprintf(&inheritfd, "fd[%d]:%s", ttyfd, ttyinfo) < 0)
+ goto cleanup;
+
+ virCommandAddArgList(cmd, "--inherit-fd", inheritfd, NULL);
+
+ root = virDomainGetFilesystemForTarget(def, "/");
+ virCommandAddArgList(cmd, "--root", root->src->path, NULL);
+
+ virCommandAddEnvString(cmd, "PATH=/bin:/sbin");
+
+ if ((ngroups = virGetGroupList(virCommandGetUID(cmd), virCommandGetGID(cmd), &groups)) < 0)
+ goto cleanup;
+
+ /* If virCommandExec returns here we have an error */
+ ignore_value(virCommandExec(cmd, groups, ngroups));
+
+ ret = -1;
+
+ cleanup:
+ VIR_FREE(tty_info_path);
+ VIR_FREE(ttyinfo);
+ VIR_FREE(inheritfd);
+ VIR_FREE(checkpointdir);
+ VIR_FREE(checkpointfd);
+ virCommandFree(cmd);
+
+ return ret;
+}
+#else
+int lxcCriuDump(virLXCDriverPtr driver ATTRIBUTE_UNUSED,
+ virDomainObjPtr vm ATTRIBUTE_UNUSED,
+ const char *checkpointdir ATTRIBUTE_UNUSED)
+{
+ virReportUnsupportedError();
+ return -1;
+}
+
+int lxcCriuRestore(virDomainDefPtr def ATTRIBUTE_UNUSED,
+ int fd ATTRIBUTE_UNUSED,
+ int ttyfd ATTRIBUTE_UNUSED)
+{
+ virReportUnsupportedError();
+ return -1;
+}
+#endif
diff --git a/src/lxc/lxc_criu.h b/src/lxc/lxc_criu.h
new file mode 100644
index 000000000..aadc3ac34
--- /dev/null
+++ b/src/lxc/lxc_criu.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2016 Katerina Koukiou
+ *
+ * lxc_criu.h: Helper functions for checkpoint/restore of linux containers
+ *
+ * Authors:
+ * Katerina Koukiou <k.koukiou at gmail.com>
+ * Radostin Stoyanov <r.stoyanov.14 at aberdeen.ac.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LXC_CRIU_H
+# define LXC_CRIU_H
+
+# include "virobject.h"
+
+int lxcCriuDump(virLXCDriverPtr driver,
+ virDomainObjPtr vm,
+ const char *checkpointdir);
+
+int lxcCriuRestore(virDomainDefPtr def, int fd,
+ int ttyfd);
+#endif /* LXC_CRIU_H */
--
2.14.3
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