[libvirt] [RFC] [PATCH v2 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 Lxc-containename-fuse. Signed-off-by: Gao feng <gaofeng(a)cn.fujitsu.com&gt; --- po/POTFILES.in | 1 + src/Makefile.am | 9 ++- src/lxc/lxc_controller.c | 10 +++ src/lxc/lxc_fuse.c | 152 ++++++++++++++++++++++++++++++++++++++++++++++ src/lxc/lxc_fuse.h | 40 ++++++++++++ src/lxc/lxc_process.c | 2 + 6 files changed, 212 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 7587c61..dedf83e 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -43,6 +43,7 @@ src/libvirt-qemu.c src/locking/lock_driver_sanlock.c src/locking/lock_manager.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 a9f8d94..5282a06 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -353,12 +353,14 @@ LXC_DRIVER_SOURCES = \ lxc/lxc_cgroup.c lxc/lxc_cgroup.h \ lxc/lxc_domain.c lxc/lxc_domain.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 = \ 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 = \ @@ -827,8 +829,9 @@ 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) @@ -1536,6 +1539,7 @@ 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_driver_security.la \ @@ -1553,7 +1557,8 @@ libvirt_lxc_LDADD += $(APPARMOR_LIBS) endif libvirt_lxc_CFLAGS = \ -I$(top_srcdir)/src/conf \ - $(AM_CFLAGS) + $(AM_CFLAGS) \ + $(FUSE_CFLAGS) if HAVE_LIBBLKID libvirt_lxc_CFLAGS += $(BLKID_CFLAGS) libvirt_lxc_LDADD += $(BLKID_LIBS) diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c index 4777d51..ff3bb6d 100644 --- a/src/lxc/lxc_controller.c +++ b/src/lxc/lxc_controller.c @@ -59,6 +59,7 @@ #include "lxc_conf.h" #include "lxc_container.h" #include "lxc_cgroup.h" +#include "lxc_fuse.h" #include "virnetdev.h" #include "virnetdevveth.h" #include "memory.h" @@ -1329,6 +1330,7 @@ int main(int argc, char *argv[]) char *name = NULL; size_t nveths = 0; char **veths = NULL; + virThread thread; int handshakeFd = -1; int bg = 0; const struct option options[] = { @@ -1516,6 +1518,14 @@ int main(int argc, char *argv[]) } } + rc = virThreadCreate(&thread, true, lxcRegisterFuse, + (void *)ctrl->def); + if (rc < 0) { + virReportSystemError(-rc, "%s", + _("Create Fuse filesystem failed")); + goto cleanup; + } + rc = virLXCControllerRun(ctrl); cleanup: diff --git a/src/lxc/lxc_fuse.c b/src/lxc/lxc_fuse.c new file mode 100644 index 0000000..3ffe82d --- /dev/null +++ b/src/lxc/lxc_fuse.c @@ -0,0 +1,152 @@ +/* + * 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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <config.h> +#include <fcntl.h> +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <sys/mount.h> + +#include "virterror_internal.h" +#include "lxc_fuse.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 *DomainDef) +{ + int argc = 4; + char *argv[argc]; + char *path = NULL; + char *name = NULL; + virDomainDefPtr def = (virDomainDefPtr) DomainDef; + + if (virAsprintf(&name, "Lxc-%s-fuse", def->name) < 0) { + virReportOOMError(); + goto cleanup; + } + + 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] = name; + 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\n")); + +cleanup: + VIR_FREE(name); + VIR_FREE(path); + return; +} + +void lxcUnregisterFuse(virDomainDefPtr def) +{ + char *path = NULL; + + if (virAsprintf(&path, "%s/%s/", LXC_STATE_DIR, def->name) < 0) { + virReportOOMError(); + return; + } + + if (umount(path) < 0) + virReportSystemError(errno, "%s", + _("umount fuse filesystem failed\n")); + + VIR_FREE(path); +} + +#else +void lxcRegisterFuse(void *DomainDef ATTRIBUTE_UNUSED) +{ +} + +void lxcUnregisterFuse(virDomainDefPtr def ATTRIBUTE_UNUSED) +{ +} +#endif diff --git a/src/lxc/lxc_fuse.h b/src/lxc/lxc_fuse.h new file mode 100644 index 0000000..d60c238 --- /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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#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 *DomainDef); +extern void lxcUnregisterFuse(virDomainDefPtr def); +#endif diff --git a/src/lxc/lxc_process.c b/src/lxc/lxc_process.c index 12f6ae6..341a2b8 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" @@ -542,6 +543,7 @@ int lxcVmTerminate(lxc_driver_t *driver, return -1; } + lxcUnregisterFuse(vm->def); virSecurityManagerRestoreAllLabel(driver->securityManager, vm->def, false); virSecurityManagerReleaseLabel(driver->securityManager, vm->def); -- 1.7.7.6