[libvirt] [PATCH V8 2/6] add fuse support for libvirt lxc
Richard W.M. Jones
rjones at redhat.com
Mon Nov 12 08:43:59 UTC 2012
On Mon, Nov 12, 2012 at 03:02:24PM +0800, Gao feng wrote:
> 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 | 20 +++++
> src/lxc/lxc_fuse.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++
> src/lxc/lxc_fuse.h | 50 +++++++++++
> src/lxc/lxc_process.c | 1 +
> 8 files changed, 285 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 1f32263..4b8e6c0 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)
> @@ -1678,6 +1681,7 @@ libvirt_lxc_SOURCES = \
> libvirt_lxc_LDFLAGS = $(WARN_CFLAGS) $(AM_LDFLAGS)
> libvirt_lxc_LDADD = \
> $(NUMACTL_LIBS) \
> + $(FUSE_LIBS) \
> libvirt-net-rpc-server.la \
> libvirt-net-rpc.la \
> libvirt_security_manager.la \
> @@ -1696,7 +1700,8 @@ endif
> libvirt_lxc_CFLAGS = \
> -I$(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..b993fe5 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"
> @@ -127,6 +128,8 @@ struct _virLXCController {
> virNetServerProgramPtr prog;
> bool inShutdown;
> int timerShutdown;
> +
> + virLXCFusePtr fuse;
> };
>
> #include "lxc_controller_dispatch.h"
> @@ -236,6 +239,13 @@ static void virLXCControllerConsoleClose(virLXCControllerConsolePtr console)
> }
>
>
> +static void
> +virLXCControllerFreeFuse(virLXCControllerPtr ctrl)
> +{
> + return lxcFreeFuse(&ctrl->fuse);
> +}
> +
> +
> static void virLXCControllerFree(virLXCControllerPtr ctrl)
> {
> size_t i;
> @@ -266,6 +276,7 @@ static void virLXCControllerFree(virLXCControllerPtr ctrl)
> virEventRemoveTimeout(ctrl->timerShutdown);
>
> virObjectUnref(ctrl->server);
> + virLXCControllerFreeFuse(ctrl);
>
> VIR_FREE(ctrl);
> }
> @@ -1247,6 +1258,12 @@ cleanup:
>
>
> static int
> +virLXCControllerSetupFuse(virLXCControllerPtr ctrl)
> +{
> + return lxcSetupFuse(&ctrl->fuse, ctrl->def);
> +}
> +
> +static int
> virLXCControllerSetupConsoles(virLXCControllerPtr ctrl,
> char **containerTTYPaths)
> {
> @@ -1388,6 +1405,9 @@ 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..6d621ee
> --- /dev/null
> +++ b/src/lxc/lxc_fuse.c
> @@ -0,0 +1,202 @@
> +/*
> + * 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,
> +};
> +
> +static void lxcFuseDestroy(virLXCFusePtr fuse)
> +{
> + virMutexLock(&fuse->lock);
> + fuse_unmount(fuse->mountpoint, fuse->ch);
> + fuse_destroy(fuse->fuse);
> + fuse->fuse = NULL;
> + virMutexUnlock(&fuse->lock);
> +}
> +
> +static void lxcFuseRun(void *opaque)
> +{
> + virLXCFusePtr fuse = opaque;
> +
> + if (fuse_loop(fuse->fuse) < 0)
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("fuse_loop failed"));
> +
> + lxcFuseDestroy(fuse);
> +}
> +
> +int lxcSetupFuse(virLXCFusePtr *f, virDomainDefPtr def)
> +{
> + int ret = -1;
> + struct fuse_args args = FUSE_ARGS_INIT(0, NULL);
> + virLXCFusePtr fuse = NULL;
> +
> + if (VIR_ALLOC(fuse) < 0)
> + goto cleanup;
> +
> + fuse->def = def;
> +
> + if (virMutexInit(&fuse->lock) < 0)
> + goto cleanup2;
> +
> + if (virAsprintf(&fuse->mountpoint, "%s/%s/", LXC_STATE_DIR,
> + def->name) < 0) {
> + virReportOOMError();
> + goto cleanup1;
> + }
> +
> + if (virFileMakePath(fuse->mountpoint) < 0) {
> + virReportSystemError(errno, _("Cannot create %s"),
> + fuse->mountpoint);
> + goto cleanup1;
> + }
> +
> + /* process name is libvirt_lxc */
> + if (fuse_opt_add_arg(&args, "libvirt_lxc") == -1 ||
> + fuse_opt_add_arg(&args, "-odirect_io") == -1 ||
> + fuse_opt_add_arg(&args, "-ofsname=libvirt") == -1)
> + goto cleanup1;
> +
> + fuse->ch = fuse_mount(fuse->mountpoint, &args);
> + if (fuse->ch == NULL)
> + goto cleanup1;
> +
> + fuse->fuse = fuse_new(fuse->ch, &args, &lxcProcOper,
> + sizeof(lxcProcOper), fuse->def);
> + if (fuse->fuse == NULL) {
> + fuse_unmount(fuse->mountpoint, fuse->ch);
> + goto cleanup1;
> + }
> +
> + if (virThreadCreate(&fuse->thread, true, lxcFuseRun,
> + (void *)fuse) < 0) {
> + lxcFuseDestroy(fuse);
> + goto cleanup1;
> + }
> +
> + ret = 0;
> +cleanup:
> + fuse_opt_free_args(&args);
> + *f = fuse;
> + return ret;
> +cleanup1:
> + VIR_FREE(fuse->mountpoint);
> + virMutexDestroy(&fuse->lock);
> +cleanup2:
> + VIR_FREE(fuse);
> + goto cleanup;
> +}
> +
> +void lxcFreeFuse(virLXCFusePtr *f)
> +{
> + virLXCFusePtr fuse = *f;
> + /* lxcFuseRun thread create success */
> + if (fuse) {
> + /* exit fuse_loop, lxcFuseRun thread may try to destroy
> + * fuse->fuse at the same time,so add a lock here. */
> + virMutexLock(&fuse->lock);
> + if (fuse->fuse)
> + fuse_exit(fuse->fuse);
> + virMutexUnlock(&fuse->lock);
> +
> + virThreadJoin(&fuse->thread);
> +
> + VIR_FREE(fuse->mountpoint);
> + VIR_FREE(*f);
> + }
> +}
> +#else
> +int lxcSetupFuse(virLXCFusePtr *f ATTRIBUTE_UNUSED,
> + virDomainDefPtr def ATTRIBUTE_UNUSED)
> +{
> + return 0;
> +}
> +
> +void lxcFreeFuse(virLXCFusePtr *f ATTRIBUTE_UNUSED)
> +{
> +}
> +#endif
> diff --git a/src/lxc/lxc_fuse.h b/src/lxc/lxc_fuse.h
> new file mode 100644
> index 0000000..f2d2cbb
> --- /dev/null
> +++ b/src/lxc/lxc_fuse.h
> @@ -0,0 +1,50 @@
> +/*
> + * 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"
> +
> +struct virLXCFuse {
> + virDomainDefPtr def;
> + virThread thread;
> + char *mountpoint;
> + struct fuse *fuse;
> + struct fuse_chan *ch;
> + virMutex lock;
> +};
> +typedef struct virLXCFuse *virLXCFusePtr;
> +
> +extern int lxcSetupFuse(virLXCFusePtr *f, virDomainDefPtr def);
> +extern void lxcFreeFuse(virLXCFusePtr *f);
> +#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
Yes, this seems better than having the busy wait. ACK.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines. Supports shell scripting,
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