[libvirt] [PATCH v6 2/6] add fuse support for libvirt lxc
Gao feng
gaofeng at cn.fujitsu.com
Mon Nov 5 05:23:52 UTC 2012
this patch addes fuse support for libvirt lxc.
we can use fuse filesystem to generate sysinfo dynamically,
So we can isolate /proc/meminfo,cpuinfo and so on through
fuse filesystem.
we mount fuse filesystem for every container.
the mount name is libvirt,mount point is
localstatedir/run/libvirt/lxc/containername.
Signed-off-by: Gao feng <gaofeng at cn.fujitsu.com>
---
po/POTFILES.in | 1 +
src/Makefile.am | 9 ++-
src/lxc/lxc_cgroup.c | 1 +
src/lxc/lxc_container.h | 3 +
src/lxc/lxc_controller.c | 26 ++++++++
src/lxc/lxc_fuse.c | 157 ++++++++++++++++++++++++++++++++++++++++++++++
src/lxc/lxc_fuse.h | 40 ++++++++++++
src/lxc/lxc_process.c | 1 +
8 files changed, 236 insertions(+), 2 deletions(-)
create mode 100644 src/lxc/lxc_fuse.c
create mode 100644 src/lxc/lxc_fuse.h
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 9768528..0199d6f 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -50,6 +50,7 @@ src/locking/lock_driver_sanlock.c
src/locking/lock_manager.c
src/locking/sanlock_helper.c
src/lxc/lxc_cgroup.c
+src/lxc/lxc_fuse.c
src/lxc/lxc_container.c
src/lxc/lxc_conf.c
src/lxc/lxc_controller.c
diff --git a/src/Makefile.am b/src/Makefile.am
index 187663f..e7b2bd6 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -413,6 +413,7 @@ LXC_DRIVER_SOURCES = \
lxc/lxc_domain.c lxc/lxc_domain.h \
lxc/lxc_monitor.c lxc/lxc_monitor.h \
lxc/lxc_process.c lxc/lxc_process.h \
+ lxc/lxc_fuse.c lxc/lxc_fuse.h \
lxc/lxc_driver.c lxc/lxc_driver.h
LXC_CONTROLLER_SOURCES = \
@@ -421,6 +422,7 @@ LXC_CONTROLLER_SOURCES = \
lxc/lxc_conf.c lxc/lxc_conf.h \
lxc/lxc_container.c lxc/lxc_container.h \
lxc/lxc_cgroup.c lxc/lxc_cgroup.h \
+ lxc/lxc_fuse.c lxc/lxc_fuse.h \
lxc/lxc_controller.c
SECURITY_DRIVER_APPARMOR_HELPER_SOURCES = \
@@ -911,8 +913,9 @@ endif
libvirt_driver_lxc_impl_la_CFLAGS = \
$(LIBNL_CFLAGS) \
+ $(FUSE_CFLAGS) \
-I$(top_srcdir)/src/conf $(AM_CFLAGS)
-libvirt_driver_lxc_impl_la_LIBADD = $(CAPNG_LIBS) $(LIBNL_LIBS)
+libvirt_driver_lxc_impl_la_LIBADD = $(CAPNG_LIBS) $(LIBNL_LIBS) $(FUSE_LIBS)
if HAVE_LIBBLKID
libvirt_driver_lxc_impl_la_CFLAGS += $(BLKID_CFLAGS)
libvirt_driver_lxc_impl_la_LIBADD += $(BLKID_LIBS)
@@ -1672,6 +1675,7 @@ libvirt_lxc_SOURCES = \
libvirt_lxc_LDFLAGS = $(WARN_CFLAGS) $(AM_LDFLAGS)
libvirt_lxc_LDADD = \
$(NUMACTL_LIBS) \
+ $(FUSE_LIBS) \
libvirt-net-rpc-server.la \
libvirt-net-rpc.la \
libvirt_security_manager.la \
@@ -1690,7 +1694,8 @@ endif
libvirt_lxc_CFLAGS = \
-I$(top_srcdir)/src/conf \
$(AM_CFLAGS) \
- $(LIBNL_CFLAGS)
+ $(LIBNL_CFLAGS) \
+ $(FUSE_CFLAGS)
if HAVE_LIBBLKID
libvirt_lxc_CFLAGS += $(BLKID_CFLAGS)
libvirt_lxc_LDADD += $(BLKID_LIBS)
diff --git a/src/lxc/lxc_cgroup.c b/src/lxc/lxc_cgroup.c
index bdfaa54..9a5ba1a 100644
--- a/src/lxc/lxc_cgroup.c
+++ b/src/lxc/lxc_cgroup.c
@@ -163,6 +163,7 @@ static int virLXCCgroupSetupDeviceACL(virDomainDefPtr def,
{'c', LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_URANDOM},
{'c', LXC_DEV_MAJ_TTY, LXC_DEV_MIN_TTY},
{'c', LXC_DEV_MAJ_TTY, LXC_DEV_MIN_PTMX},
+ {'c', LXC_DEV_MAJ_FUSE, LXC_DEV_MIN_FUSE},
{0, 0, 0}};
rc = virCgroupDenyAllDevices(cgroup);
diff --git a/src/lxc/lxc_container.h b/src/lxc/lxc_container.h
index b1adacb..c8c70e0 100644
--- a/src/lxc/lxc_container.h
+++ b/src/lxc/lxc_container.h
@@ -46,6 +46,9 @@ enum {
# define LXC_DEV_MAJ_PTY 136
+# define LXC_DEV_MAJ_FUSE 10
+# define LXC_DEV_MIN_FUSE 229
+
int lxcContainerSendContinue(int control);
int lxcContainerWaitForContinue(int control);
diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c
index a41c903..f0d28f8 100644
--- a/src/lxc/lxc_controller.c
+++ b/src/lxc/lxc_controller.c
@@ -60,6 +60,7 @@
#include "lxc_container.h"
#include "lxc_cgroup.h"
#include "lxc_protocol.h"
+#include "lxc_fuse.h"
#include "virnetdev.h"
#include "virnetdevveth.h"
#include "memory.h"
@@ -1245,6 +1246,28 @@ cleanup:
return ret;
}
+static int
+virLXCControllerSetupFuse(virLXCControllerPtr ctrl)
+{
+ int try = 0;
+ virThread thread;
+ if (virThreadCreate(&thread, true, lxcRegisterFuse,
+ (void *)ctrl->def) < 0)
+ return -1;
+ /*
+ * because libvirt_lxc may use fuse filesystem before fuse being
+ * mounted by the thread. so wait 3 seconds in libvirt_lxc. if fuse
+ * is not mounted in 3 seconds, libvirt_lxc will exit.
+ */
+ while (try++ < 2) {
+ if (lxcRegisterFuseSuccess())
+ return 0;
+
+ sleep(1);
+ }
+
+ return -1;
+}
static int
virLXCControllerSetupConsoles(virLXCControllerPtr ctrl,
@@ -1388,6 +1411,9 @@ virLXCControllerRun(virLXCControllerPtr ctrl)
if (virLXCControllerSetupDevPTS(ctrl) < 0)
goto cleanup;
+ if (virLXCControllerSetupFuse(ctrl) < 0)
+ goto cleanup;
+
if (virLXCControllerSetupConsoles(ctrl, containerTTYPaths) < 0)
goto cleanup;
diff --git a/src/lxc/lxc_fuse.c b/src/lxc/lxc_fuse.c
new file mode 100644
index 0000000..42107d7
--- /dev/null
+++ b/src/lxc/lxc_fuse.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2012 Fujitsu Limited.
+ *
+ * lxc_fuse.c: fuse filesystem support for libvirt lxc
+ *
+ * Authors:
+ * Gao feng <gaofeng at cn.fujitsu.com>
+ *
+ * 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 <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <mntent.h>
+
+#include "lxc_fuse.h"
+#include "virterror_internal.h"
+#include "logging.h"
+
+#define VIR_FROM_THIS VIR_FROM_LXC
+
+#if HAVE_FUSE
+
+static int lxcProcGetattr(const char *path, struct stat *stbuf)
+{
+ int res = 0;
+
+ memset(stbuf, 0, sizeof(struct stat));
+
+ if (STREQ(path, "/")) {
+ stbuf->st_mode = S_IFDIR | 0755;
+ stbuf->st_nlink = 2;
+ } else {
+ res = -ENOENT;
+ }
+
+ return res;
+}
+
+static int lxcProcReaddir(const char *path, void *buf,
+ fuse_fill_dir_t filler,
+ off_t offset ATTRIBUTE_UNUSED,
+ struct fuse_file_info *fi ATTRIBUTE_UNUSED)
+{
+ if (!STREQ(path, "/"))
+ return -ENOENT;
+
+ filler(buf, ".", NULL, 0);
+ filler(buf, "..", NULL, 0);
+
+ return 0;
+}
+
+static int lxcProcOpen(const char *path ATTRIBUTE_UNUSED,
+ struct fuse_file_info *fi ATTRIBUTE_UNUSED)
+{
+ return -ENOENT;
+}
+
+static int lxcProcRead(const char *path ATTRIBUTE_UNUSED,
+ char *buf ATTRIBUTE_UNUSED,
+ size_t size ATTRIBUTE_UNUSED,
+ off_t offset ATTRIBUTE_UNUSED,
+ struct fuse_file_info *fi ATTRIBUTE_UNUSED)
+{
+ return -ENOENT;
+}
+
+static struct fuse_operations lxcProcOper = {
+ .getattr = lxcProcGetattr,
+ .readdir = lxcProcReaddir,
+ .open = lxcProcOpen,
+ .read = lxcProcRead,
+};
+
+void lxcRegisterFuse(void *opaque)
+{
+ int argc = 4;
+ char *argv[argc];
+ char *path = NULL;
+ virDomainDefPtr def = opaque;
+
+ if (virAsprintf(&path, "%s/%s/", LXC_STATE_DIR, def->name) < 0) {
+ virReportOOMError();
+ goto cleanup;
+ }
+
+ if (virFileMakePath(path) < 0) {
+ virReportSystemError(errno, _("Cannot create %s"), path);
+ goto cleanup;
+ }
+
+ argv[0] = (char *)"libvirt";
+ argv[1] = path;
+ argv[2] = (char *)"-odirect_io";
+ argv[3] = (char *)"-f";
+
+ if (fuse_main(argc, argv, &lxcProcOper, def) < 0)
+ virReportSystemError(errno, "%s", _("Cannot start fuse"));
+
+cleanup:
+ VIR_FREE(path);
+ return;
+}
+
+int lxcRegisterFuseSuccess(void)
+{
+ FILE *procmnt = NULL;
+ struct mntent mntent;
+ char mntbuf[1024];
+ int ret = 0;
+
+ if (!(procmnt = setmntent("/proc/mounts", "r"))) {
+ virReportSystemError(errno, "%s",
+ _("Failed to read /proc/mounts"));
+ return ret;
+ }
+
+ while (getmntent_r(procmnt, &mntent, mntbuf, sizeof(mntbuf)) != NULL) {
+ VIR_DEBUG("Got %s\n",mntent.mnt_fsname);
+ if (STRNEQ(mntent.mnt_fsname, "libvirt"))
+ continue;
+
+ ret = 1;
+ break;
+ }
+
+ endmntent(procmnt);
+ return ret;
+}
+
+#else
+void lxcRegisterFuse(void *opaque ATTRIBUTE_UNUSED)
+{
+}
+
+int lxcRegisterFuseSuccess(void)
+{
+ return 1;
+}
+#endif
diff --git a/src/lxc/lxc_fuse.h b/src/lxc/lxc_fuse.h
new file mode 100644
index 0000000..5b3689e
--- /dev/null
+++ b/src/lxc/lxc_fuse.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2012 Fujitsu Limited.
+ *
+ * lxc_fuse.c: fuse filesystem support for libvirt lxc
+ *
+ * Authors:
+ * Gao feng <gaofeng at cn.fujitsu.com>
+ *
+ * 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_FUSE_H
+#define LXC_FUSE_H
+
+#define FUSE_USE_VERSION 26
+
+#include <config.h>
+#if HAVE_FUSE
+#include <fuse.h>
+#endif
+
+#include "lxc_conf.h"
+#include "util.h"
+#include "memory.h"
+
+extern void lxcRegisterFuse(void *opaque);
+extern int lxcRegisterFuseSuccess(void);
+#endif
diff --git a/src/lxc/lxc_process.c b/src/lxc/lxc_process.c
index 079bc3a..a9a0984 100644
--- a/src/lxc/lxc_process.c
+++ b/src/lxc/lxc_process.c
@@ -28,6 +28,7 @@
#include "lxc_process.h"
#include "lxc_domain.h"
#include "lxc_container.h"
+#include "lxc_fuse.h"
#include "datatypes.h"
#include "virfile.h"
#include "virpidfile.h"
--
1.7.7.6
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