[libvirt] [PATCH 3/3] libxl: provide integration with lock manager

Daniel P. Berrange berrange at redhat.com
Tue Apr 21 10:04:33 UTC 2015


On Fri, Apr 17, 2015 at 03:36:22PM -0600, Jim Fehlig wrote:
> Provide integration with libvirt's lock manager in the libxl driver.
> 
> Signed-off-by: Jim Fehlig <jfehlig at suse.com>
> ---
>  src/Makefile.am                      | 12 +++++++++
>  src/libxl/libvirtd_libxl.aug         |  2 ++
>  src/libxl/libxl.conf                 | 10 ++++++++
>  src/libxl/libxl_conf.c               | 14 +++++++++++
>  src/libxl/libxl_conf.h               |  6 +++++
>  src/libxl/libxl_domain.c             | 47 ++++++++++++++++++++++++++++++++++--
>  src/libxl/libxl_domain.h             |  1 +
>  src/libxl/libxl_driver.c             | 25 +++++++++++++++++++
>  src/libxl/libxl_migration.c          |  6 +++++
>  src/libxl/test_libvirtd_libxl.aug.in |  1 +
>  10 files changed, 122 insertions(+), 2 deletions(-)
> 
> diff --git a/src/Makefile.am b/src/Makefile.am
> index 9a5f16c..1438174 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -2246,6 +2246,12 @@ BUILT_SOURCES += locking/qemu-lockd.conf
>  DISTCLEANFILES += locking/qemu-lockd.conf
>  endif WITH_QEMU
>  
> +if WITH_LIBXL
> +nodist_conf_DATA += locking/libxl-lockd.conf
> +BUILT_SOURCES += locking/libxl-lockd.conf
> +DISTCLEANFILES += locking/libxl-lockd.conf
> +endif WITH_LIBXL
> +
>  locking/%-lockd.conf: $(srcdir)/locking/lockd.conf
>  	$(AM_V_GEN)$(MKDIR_P) locking ; \
>  	cp $< $@
> @@ -2431,6 +2437,12 @@ nodist_conf_DATA += locking/qemu-sanlock.conf
>  BUILT_SOURCES += locking/qemu-sanlock.conf
>  DISTCLEANFILES += locking/qemu-sanlock.conf
>  endif WITH_QEMU
> +
> +if WITH_LIBXL
> +nodist_conf_DATA += locking/libxl-sanlock.conf
> +BUILT_SOURCES += locking/libxl-sanlock.conf
> +DISTCLEANFILES += locking/libxl-sanlock.conf
> +endif WITH_LIBXL
>  else ! WITH_SANLOCK
>  EXTRA_DIST += $(LOCK_DRIVER_SANLOCK_SOURCES)
>  endif ! WITH_SANLOCK
> diff --git a/src/libxl/libvirtd_libxl.aug b/src/libxl/libvirtd_libxl.aug
> index f225954..d5aa150 100644
> --- a/src/libxl/libvirtd_libxl.aug
> +++ b/src/libxl/libvirtd_libxl.aug
> @@ -25,9 +25,11 @@ module Libvirtd_libxl =
>  
>     (* Config entry grouped by function - same order as example config *)
>     let autoballoon_entry = bool_entry "autoballoon"
> +   let lock_entry = str_entry "lock_manager"
>  
>     (* Each entry in the config is one of the following ... *)
>     let entry = autoballoon_entry
> +             | lock_entry
>  
>     let comment = [ label "#comment" . del /#[ \t]*/ "# " .  store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ]
>     let empty = [ label "#empty" . eol ]
> diff --git a/src/libxl/libxl.conf b/src/libxl/libxl.conf
> index c104d40..ba3de7a 100644
> --- a/src/libxl/libxl.conf
> +++ b/src/libxl/libxl.conf
> @@ -10,3 +10,13 @@
>  # autoballoon setting.
>  #
>  #autoballoon = 1
> +
> +
> +# In order to prevent accidentally starting two domains that
> +# share one writable disk, libvirt offers two approaches for
> +# locking files: sanlock and virtlockd.  sanlock is an external
> +# project which libvirt integrates with via the libvirt-lock-sanlock
> +# package.  virtlockd is a libvirt implementation that is enabled with
> +# "lockd".  Accepted values are "sanlock" and "lockd".
> +#
> +#lock_manager = "lockd"
> diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
> index 6ea2889..503e8a4 100644
> --- a/src/libxl/libxl_conf.c
> +++ b/src/libxl/libxl_conf.c
> @@ -102,6 +102,7 @@ libxlDriverConfigDispose(void *obj)
>      VIR_FREE(cfg->libDir);
>      VIR_FREE(cfg->saveDir);
>      VIR_FREE(cfg->autoDumpDir);
> +    VIR_FREE(cfg->lockManagerName);
>  }
>  
>  
> @@ -1495,6 +1496,7 @@ int libxlDriverConfigLoadFile(libxlDriverConfigPtr cfg,
>                                const char *filename)
>  {
>      virConfPtr conf = NULL;
> +    virConfValuePtr p;
>      int ret = -1;
>  
>      /* Check the file is readable before opening it, otherwise
> @@ -1512,6 +1514,18 @@ int libxlDriverConfigLoadFile(libxlDriverConfigPtr cfg,
>      if (libxlGetAutoballoonConf(cfg, conf) < 0)
>          goto cleanup;
>  
> +    if ((p = virConfGetValue(conf, "lock_manager"))) {
> +        if (p->type != VIR_CONF_STRING) {
> +            virReportError(VIR_ERR_INTERNAL_ERROR,
> +                           "%s",
> +                           _("Unexpected type for 'lock_manager' setting"));
> +            goto cleanup;
> +        }
> +
> +        if (VIR_STRDUP(cfg->lockManagerName, p->str) < 0)
> +            goto cleanup;
> +    }
> +
>      ret = 0;
>  
>   cleanup:
> diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h
> index 5ba1a71..0a1c0db 100644
> --- a/src/libxl/libxl_conf.h
> +++ b/src/libxl/libxl_conf.h
> @@ -38,6 +38,7 @@
>  # include "virobject.h"
>  # include "virchrdev.h"
>  # include "virhostdev.h"
> +# include "locking/lock_manager.h"
>  
>  # define LIBXL_DRIVER_NAME "xenlight"
>  # define LIBXL_VNC_PORT_MIN  5900
> @@ -98,6 +99,8 @@ struct _libxlDriverConfig {
>       * memory for new domains from domain0. */
>      bool autoballoon;
>  
> +    char *lockManagerName;
> +
>      /* Once created, caps are immutable */
>      virCapsPtr caps;
>  
> @@ -144,6 +147,9 @@ struct _libxlDriverPrivate {
>  
>      /* Immutable pointer, lockless APIs*/
>      virSysinfoDefPtr hostsysinfo;
> +
> +    /* Immutable pointer. lockless access */
> +    virLockManagerPluginPtr lockManager;
>  };
>  
>  # define LIBXL_SAVE_MAGIC "libvirt-xml\n \0 \r"
> diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c
> index 77d46d0..70247f5 100644
> --- a/src/libxl/libxl_domain.c
> +++ b/src/libxl/libxl_domain.c
> @@ -34,6 +34,7 @@
>  #include "virlog.h"
>  #include "virstring.h"
>  #include "virtime.h"
> +#include "locking/domain_lock.h"
>  
>  #define VIR_FROM_THIS VIR_FROM_LIBXL
>  
> @@ -217,12 +218,36 @@ libxlDomainObjPrivateFree(void *data)
>  {
>      libxlDomainObjPrivatePtr priv = data;
>  
> +    VIR_FREE(priv->lockState);
>      virObjectUnref(priv);
>  }
>  
> +static int
> +libxlDomainObjPrivateXMLParse(xmlXPathContextPtr ctxt, void *data)
> +{
> +    libxlDomainObjPrivatePtr priv = data;
> +
> +    priv->lockState = virXPathString("string(./lockstate)", ctxt);
> +
> +    return 0;
> +}
> +
> +static int
> +libxlDomainObjPrivateXMLFormat(virBufferPtr buf, void *data)
> +{
> +    libxlDomainObjPrivatePtr priv = data;
> +
> +    if (priv->lockState)
> +        virBufferAsprintf(buf, "<lockstate>%s</lockstate>\n", priv->lockState);
> +
> +    return 0;
> +}
> +
>  virDomainXMLPrivateDataCallbacks libxlDomainXMLPrivateDataCallbacks = {
>      .alloc = libxlDomainObjPrivateAlloc,
>      .free = libxlDomainObjPrivateFree,
> +    .parse = libxlDomainObjPrivateXMLParse,
> +    .format = libxlDomainObjPrivateXMLFormat,
>  };
>  
>  
> @@ -668,6 +693,11 @@ libxlDomainCleanup(libxlDriverPrivatePtr driver,
>      virHostdevReAttachDomainDevices(hostdev_mgr, LIBXL_DRIVER_NAME,
>                                      vm->def, VIR_HOSTDEV_SP_PCI, NULL);
>  
> +    VIR_FREE(priv->lockState);
> +    if (virDomainLockProcessPause(driver->lockManager, vm, &priv->lockState) < 0)
> +        VIR_WARN("Unable to release lease on %s", vm->def->name);
> +    VIR_DEBUG("Preserving lock state '%s'", NULLSTR(priv->lockState));

I see a few calls to ProcessPause, but I'm not seeing any to ProcessResume,
so I think you might have missed a few places needing hooks.


Regards,
Daniel
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