Re: [libvirt] [PATCH] Add support for guest bind mounts with LXC

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; Currently you can configure LXC to bind a host directory to a guest directory, but not to bind a guest directory to a guest directory. While the guest container init could do this itself, allowing it in the libvirt XML means a stricter SELinux policy can be written --- src/conf/domain_conf.c | 7 +++++-- src/conf/domain_conf.h | 11 ++++++----- src/lxc/lxc_container.c | 7 +++++++ 3 files changed, 18 insertions(+), 7 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index a653fe6..8ce122e 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -263,7 +263,8 @@ VIR_ENUM_IMPL(virDomainFS, VIR_DOMAIN_FS_TYPE_LAST, "block", "file", "template", - "ram") + "ram", + "bind") VIR_ENUM_IMPL(virDomainFSDriverType, VIR_DOMAIN_FS_DRIVER_TYPE_LAST, "default", @@ -4260,7 +4261,8 @@ virDomainFSDefParseXML(xmlNodePtr node, if (!source && xmlStrEqual(cur->name, BAD_CAST "source")) { - if (def->type == VIR_DOMAIN_FS_TYPE_MOUNT) + if (def->type == VIR_DOMAIN_FS_TYPE_MOUNT || + def->type == VIR_DOMAIN_FS_TYPE_BIND) source = virXMLPropString(cur, "dir"); else if (def->type == VIR_DOMAIN_FS_TYPE_FILE) source = virXMLPropString(cur, "file"); @@ -11335,6 +11337,7 @@ virDomainFSDefFormat(virBufferPtr buf, switch (def->type) { case VIR_DOMAIN_FS_TYPE_MOUNT: + case VIR_DOMAIN_FS_TYPE_BIND: virBufferEscapeString(buf, " <source dir='%s'/>\n", def->src); break; diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index b8d9c87..bdb1f75 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -656,11 +656,12 @@ struct _virDomainControllerDef { /* Two types of disk backends */ enum virDomainFSType { - VIR_DOMAIN_FS_TYPE_MOUNT, /* Better named 'bind' */ - VIR_DOMAIN_FS_TYPE_BLOCK, - VIR_DOMAIN_FS_TYPE_FILE, - VIR_DOMAIN_FS_TYPE_TEMPLATE, - VIR_DOMAIN_FS_TYPE_RAM, + VIR_DOMAIN_FS_TYPE_MOUNT, /* Mounts (binds) a host dir on a guest dir */ + VIR_DOMAIN_FS_TYPE_BLOCK, /* Mounts a host block dev on a guest dir */ + VIR_DOMAIN_FS_TYPE_FILE, /* Loopback mounts a host file on a guest dir */ + VIR_DOMAIN_FS_TYPE_TEMPLATE, /* Expands a OS template to a guest dir */ + VIR_DOMAIN_FS_TYPE_RAM, /* Mount a RAM filesystem on a guest dir */ + VIR_DOMAIN_FS_TYPE_BIND, /* Binds a guest dir to another guest dir */ VIR_DOMAIN_FS_TYPE_LAST }; diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index b69255e..bf67ba1 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -1025,7 +1025,14 @@ static int lxcContainerMountFS(virDomainFSDefPtr fs, if (lxcContainerMountFSTmpfs(fs) < 0) return -1; break; + case VIR_DOMAIN_FS_TYPE_BIND: + if (lxcContainerMountFSBind(fs, "") < 0) + return -1; + break; case VIR_DOMAIN_FS_TYPE_FILE: + /* We do actually support this, but the lxc controller + * should have associated the file with a loopback + * device and changed this to TYPE_BLOCK for us */ lxcError(VIR_ERR_INTERNAL_ERROR, _("Unexpected filesystem type %s"), virDomainFSTypeToString(fs->type));