[libvirt] [PATCH v6 2/6] add fuse support for libvirt lxc

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(a)cn.fujitsu.com&gt; --- 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