From 893647671b052cba67f2241bb910df56f3191f2e Mon Sep 17 00:00:00 2001 From: Jiri Denemark Date: Tue, 18 Sep 2012 13:41:26 +0200 Subject: [PATCH] locking: Implement lock failure action in sanlock driver While the changes to sanlock driver should be stable, the actual implementation of sanlock_helper is supposed to be replaced in the future. However, before we can implement a better sanlock_helper, we need an administrative interface to libvirtd so that the helper can just pass a "leases lost" event to the particular libvirt driver and everything else will be taken care of internally. This approach will also allow libvirt to pass such event to applications and use appropriate reasons when changing domain states. The temporary implementation handles all actions directly by calling appropriate libvirt APIs (which among other things means that it needs to know the credentials required to connect to libvirtd). --- docs/locking.html.in | 24 ++++++ libvirt.spec.in | 1 + po/POTFILES.in | 1 + src/Makefile.am | 11 +++ src/locking/lock_driver_sanlock.c | 115 ++++++++++++++++++++++--- src/locking/sanlock_helper.c | 138 ++++++++++++++++++++++++++++++ 6 files changed, 277 insertions(+), 13 deletions(-) create mode 100644 src/locking/sanlock_helper.c diff --git a/docs/locking.html.in b/docs/locking.html.in index 0d039dabc3..6d7b5174a4 100644 --- a/docs/locking.html.in +++ b/docs/locking.html.in @@ -208,5 +208,29 @@ </pool> +

Domain configuration

+ +

+ In case sanlock loses access to disk locks for some reason, it will + kill all domains that lost their locks. This default behavior may + be changed using + on_lockfailure + element in domain XML. When this element is present, sanlock + will call sanlock_helper (provided by libvirt) with + the specified action. This helper binary will connect to libvirtd + and thus it may need to authenticate if libvirtd was configured to + require that on the read-write UNIX socket. To provide the + appropriate credentials to sanlock_helper, a + client authentication + file needs to contain something like the following: +

+ 
+[auth-libvirt-localhost]
+credentials=sanlock
+
+[credentials-sanlock]
+authname=login
+password=password
+
diff --git a/libvirt.spec.in b/libvirt.spec.in index e3d0a2d48a..318fe92503 100644 --- a/libvirt.spec.in +++ b/libvirt.spec.in @@ -1788,6 +1788,7 @@ rm -f $RPM_BUILD_ROOT%{_sysconfdir}/sysctl.d/libvirtd %dir %attr(0700, root, root) %{_localstatedir}/lib/libvirt/sanlock %{_sbindir}/virt-sanlock-cleanup %{_mandir}/man8/virt-sanlock-cleanup.8* +%attr(0755, root, root) %{_libexecdir}/libvirt_sanlock_helper %endif %files client -f %{name}.lang diff --git a/po/POTFILES.in b/po/POTFILES.in index 2538225979..815e992705 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -47,6 +47,7 @@ src/libvirt.c src/libvirt-qemu.c src/locking/lock_driver_sanlock.c src/locking/lock_manager.c +src/locking/sanlock_helper.c src/lxc/lxc_cgroup.c src/lxc/lxc_container.c src/lxc/lxc_conf.c diff --git a/src/Makefile.am b/src/Makefile.am index 0aefc024ee..4f19bcfe07 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -142,6 +142,8 @@ DRIVER_SOURCES = \ LOCK_DRIVER_SANLOCK_SOURCES = \ locking/lock_driver_sanlock.c +LOCK_DRIVER_SANLOCK_HELPER_SOURCES = \ + locking/sanlock_helper.c NETDEV_CONF_SOURCES = \ conf/netdev_bandwidth_conf.h conf/netdev_bandwidth_conf.c \ @@ -1649,6 +1651,15 @@ endif EXTRA_DIST += $(STORAGE_HELPER_DISK_SOURCES) +if HAVE_SANLOCK +libexec_PROGRAMS += libvirt_sanlock_helper + +libvirt_sanlock_helper_SOURCES = $(LOCK_DRIVER_SANLOCK_HELPER_SOURCES) +libvirt_sanlock_helper_CFLAGS = -I$(top_srcdir)/src/conf $(AM_CFLAGS) +libvirt_sanlock_helper_LDFLAGS = $(WARN_LDFLAGS) $(AM_LDFLAGS) +libvirt_sanlock_helper_LDADD = libvirt.la +endif + if WITH_LXC if WITH_LIBVIRTD libexec_PROGRAMS += libvirt_lxc diff --git a/src/locking/lock_driver_sanlock.c b/src/locking/lock_driver_sanlock.c index 8c0ac8c636..a218432fd2 100644 --- a/src/locking/lock_driver_sanlock.c +++ b/src/locking/lock_driver_sanlock.c @@ -50,6 +50,7 @@ #define VIR_FROM_THIS VIR_FROM_LOCKING #define VIR_LOCK_MANAGER_SANLOCK_AUTO_DISK_LOCKSPACE "__LIBVIRT__DISKS__" +#define VIR_LOCK_MANAGER_SANLOCK_KILLPATH LIBEXECDIR "/libvirt_sanlock_helper" /* * temporary fix for the case where the sanlock devel package is @@ -75,8 +76,9 @@ struct _virLockManagerSanlockDriver { static virLockManagerSanlockDriver *driver = NULL; struct _virLockManagerSanlockPrivate { + const char *vm_uri; char vm_name[SANLK_NAME_LEN]; - char vm_uuid[VIR_UUID_BUFLEN]; + unsigned char vm_uuid[VIR_UUID_BUFLEN]; unsigned int vm_id; unsigned int vm_pid; unsigned int flags; @@ -383,6 +385,8 @@ static int virLockManagerSanlockNew(virLockManagerPtr lock, priv->vm_pid = param->value.ui; } else if (STREQ(param->key, "id")) { priv->vm_id = param->value.ui; + } else if (STREQ(param->key, "uri")) { + priv->vm_uri = param->value.cstr; } } @@ -683,10 +687,86 @@ static int virLockManagerSanlockAddResource(virLockManagerPtr lock, return 0; } +static int +virLockManagerSanlockRegisterKillscript(int sock, + const char *vmuri, + const char *uuidstr, + virDomainLockFailureAction action) +{ + virBuffer buf = VIR_BUFFER_INITIALIZER; + char *path; + char *args = NULL; + int ret = -1; + int rv; + + if (action > VIR_DOMAIN_LOCK_FAILURE_IGNORE) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Failure action %s is not supported by sanlock"), + virDomainLockFailureTypeToString(action)); + goto cleanup; + } + + virBufferEscape(&buf, '\\', "\\ ", "%s", vmuri); + virBufferAddLit(&buf, " "); + virBufferEscape(&buf, '\\', "\\ ", "%s", uuidstr); + virBufferAddLit(&buf, " "); + virBufferEscape(&buf, '\\', "\\ ", "%s", + virDomainLockFailureTypeToString(action)); + + if (virBufferError(&buf)) { + virBufferFreeAndReset(&buf); + virReportOOMError(); + goto cleanup; + } + + /* Unfortunately, sanlock_killpath() does not use const for either + * path or args even though it will just copy them into its own + * buffers. + */ + path = (char *) VIR_LOCK_MANAGER_SANLOCK_KILLPATH; + args = virBufferContentAndReset(&buf); + + VIR_DEBUG("Register sanlock killpath: %s %s", path, args); + + /* sanlock_killpath() would just crop the strings */ + if (strlen(path) >= SANLK_HELPER_PATH_LEN) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Sanlock helper path is longer than %d: '%s'"), + SANLK_HELPER_PATH_LEN - 1, path); + goto cleanup; + } + if (strlen(args) >= SANLK_HELPER_ARGS_LEN) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Sanlock helper arguments are longer than %d:" + " '%s'"), + SANLK_HELPER_ARGS_LEN - 1, args); + goto cleanup; + } + + if ((rv = sanlock_killpath(sock, 0, path, args)) < 0) { + if (rv <= -200) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Failed to register lock failure action:" + " error %d"), rv); + } else { + virReportSystemError(-rv, "%s", + _("Failed to register lock failure" + " action")); + } + goto cleanup; + } + + ret = 0; + +cleanup: + VIR_FREE(args); + return ret; +} + static int virLockManagerSanlockAcquire(virLockManagerPtr lock, const char *state, unsigned int flags, - virDomainLockFailureAction action ATTRIBUTE_UNUSED, + virDomainLockFailureAction action, int *fd) { virLockManagerSanlockPrivatePtr priv = lock->privateData; @@ -741,23 +821,32 @@ static int virLockManagerSanlockAcquire(virLockManagerPtr lock, res_count = priv->res_count; } - VIR_DEBUG("Register sanlock %d", flags); /* We only initialize 'sock' if we are in the real * child process and we need it to be inherited * * If sock==-1, then sanlock auto-open/closes a * temporary sock */ - if (priv->vm_pid == getpid() && - (sock = sanlock_register()) < 0) { - if (sock <= -200) - virReportError(VIR_ERR_INTERNAL_ERROR, - _("Failed to open socket to sanlock daemon: error %d"), - sock); - else - virReportSystemError(-sock, "%s", - _("Failed to open socket to sanlock daemon")); - goto error; + if (priv->vm_pid == getpid()) { + VIR_DEBUG("Register sanlock %d", flags); + if ((sock = sanlock_register()) < 0) { + if (sock <= -200) + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Failed to open socket to sanlock daemon: error %d"), + sock); + else + virReportSystemError(-sock, "%s", + _("Failed to open socket to sanlock daemon")); + goto error; + } + + if (action != VIR_DOMAIN_LOCK_FAILURE_DEFAULT) { + char uuidstr[VIR_UUID_STRING_BUFLEN]; + virUUIDFormat(priv->vm_uuid, uuidstr); + if (virLockManagerSanlockRegisterKillscript(sock, priv->vm_uri, + uuidstr, action) < 0) + goto error; + } } if (!(flags & VIR_LOCK_MANAGER_ACQUIRE_REGISTER_ONLY)) { diff --git a/src/locking/sanlock_helper.c b/src/locking/sanlock_helper.c new file mode 100644 index 0000000000..a73b49ca41 --- /dev/null +++ b/src/locking/sanlock_helper.c @@ -0,0 +1,138 @@ +#include +#include +#include +#include + +#include "configmake.h" +#include "internal.h" +#include "conf.h" +#include "memory.h" +#include "domain_conf.h" + + +static int +getArgs(int argc, + char **argv, + const char **uri, + const char **uuid, + virDomainLockFailureAction *action) +{ + int act; + + if (argc != 4) { + fprintf(stderr, _("%s uri uuid action\n"), argv[0]); + return -1; + } + + *uri = argv[1]; + *uuid = argv[2]; + + act = virDomainLockFailureTypeFromString(argv[3]); + if (act < 0) { + fprintf(stderr, _("invalid failure action: '%s'\n"), argv[3]); + return -1; + } + *action = act; + + return 0; +} + + +static int +authCallback(virConnectCredentialPtr cred ATTRIBUTE_UNUSED, + unsigned int ncred ATTRIBUTE_UNUSED, + void *cbdata ATTRIBUTE_UNUSED) +{ + return -1; +} + + +int +main(int argc, char **argv) +{ + const char *uri; + const char *uuid; + virDomainLockFailureAction action; + char *xml = NULL; + virConnectPtr conn = NULL; + virDomainPtr dom = NULL; + int ret = EXIT_FAILURE; + + int authTypes[] = { + VIR_CRED_AUTHNAME, + VIR_CRED_ECHOPROMPT, + VIR_CRED_PASSPHRASE, + VIR_CRED_NOECHOPROMPT, + }; + virConnectAuth auth = { + .credtype = authTypes, + .ncredtype = ARRAY_CARDINALITY(authTypes), + .cb = authCallback, + }; + + if (setlocale(LC_ALL, "") == NULL || + bindtextdomain(PACKAGE, LOCALEDIR) == NULL || + textdomain(PACKAGE) == NULL) { + fprintf(stderr, _("%s: initialization failed\n"), argv[0]); + exit(EXIT_FAILURE); + } + + if (getArgs(argc, argv, &uri, &uuid, &action) < 0) + goto cleanup; + + if (!(conn = virConnectOpenAuth(uri, &auth, 0)) || + !(dom = virDomainLookupByUUIDString(conn, uuid))) + goto cleanup; + + switch (action) { + case VIR_DOMAIN_LOCK_FAILURE_POWEROFF: + if (virDomainDestroy(dom) == 0 || + virDomainIsActive(dom) == 0) + ret = EXIT_SUCCESS; + break; + + case VIR_DOMAIN_LOCK_FAILURE_RESTART: + if (virDomainIsPersistent(dom)) { + if ((virDomainDestroy(dom) == 0 || + virDomainIsActive(dom) == 0) && + virDomainCreate(dom) == 0) + ret = EXIT_SUCCESS; + } else { + xml = virDomainGetXMLDesc(dom, + VIR_DOMAIN_XML_SECURE | + VIR_DOMAIN_XML_INACTIVE); + + if (!xml || + (virDomainDestroy(dom) < 0 && + virDomainIsActive(dom) != 0)) + goto cleanup; + virDomainFree(dom); + if ((dom = virDomainCreateXML(conn, xml, 0))) + ret = EXIT_SUCCESS; + } + break; + + case VIR_DOMAIN_LOCK_FAILURE_PAUSE: + if (virDomainSuspend(dom) == 0) + ret = EXIT_SUCCESS; + break; + + case VIR_DOMAIN_LOCK_FAILURE_IGNORE: + ret = EXIT_SUCCESS; + break; + + default: + fprintf(stderr, _("unsupported failure action: '%s'\n"), + virDomainLockFailureTypeToString(action)); + break; + } + +cleanup: + if (dom) + virDomainFree(dom); + if (conn) + virConnectClose(conn); + VIR_FREE(xml); + + return ret; +} -- 2.39.5