1:38 p.m.
On 08/14/2018 07:19 AM, Michal Privoznik wrote:
Fortunately, we have qemu wrappers so it's sufficient to put
lock/unlock call only there.
Kind of sparse... Maybe a few words related to what benefit locking the
metadata provides. There is a danger in all this too if the unlock does
fail since metadata locks are wait type locks any subsequent lock will wait.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/qemu/qemu_security.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 107 insertions(+)
diff --git a/src/qemu/qemu_security.c b/src/qemu/qemu_security.c
index af3be42854..527563947c 100644
--- a/src/qemu/qemu_security.c
+++ b/src/qemu/qemu_security.c
@@ -26,6 +26,7 @@
#include "qemu_domain.h"
#include "qemu_security.h"
#include "virlog.h"
+#include "locking/domain_lock.h"
#define VIR_FROM_THIS VIR_FROM_QEMU
@@ -39,6 +40,12 @@ qemuSecuritySetAllLabel(virQEMUDriverPtr driver,
{
int ret = -1;
qemuDomainObjPrivatePtr priv = vm->privateData;
+ bool locked = false;
+
+ if (virDomainLockMetadataLock(driver->lockManager, vm) < 0)
+ goto cleanup;
+
+ locked = true;
if (qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT) &&
virSecurityManagerTransactionStart(driver->securityManager) < 0)
@@ -55,9 +62,17 @@ qemuSecuritySetAllLabel(virQEMUDriverPtr driver,
vm->pid) < 0)
goto cleanup;
+ locked = false;
Technically not true yet. Also , I think two such attempts with the
second eliciting the VIR_WARN is perfectly reasonable (IOW: on failure
of the following goto cleanup with locked == true, try again, and spew
that message).
This repeats a few times, but I'll note just once.
+
+ if (virDomainLockMetadataUnlock(driver->lockManager, vm) < 0)
+ goto cleanup;
+
ret = 0;
cleanup:
virSecurityManagerTransactionAbort(driver->securityManager);
+ if (locked &&
+ virDomainLockMetadataUnlock(driver->lockManager, vm) < 0)
+ VIR_WARN("unable to release metadata lock");
Should we add the @stdin_path and @vm->pid and/or vm->name here? It may
help some day. Similar comments for other new VIR_WARN's, but the
parameters change...
return ret;
}
@@ -68,6 +83,10 @@ qemuSecurityRestoreAllLabel(virQEMUDriverPtr driver,
bool migrated)
{
qemuDomainObjPrivatePtr priv = vm->privateData;
+ bool unlock = true;
+
+ if (virDomainLockMetadataLock(driver->lockManager, vm) < 0)
+ unlock = false;
/* In contrast to qemuSecuritySetAllLabel, do not use
* secdriver transactions here. This function is called from
@@ -79,6 +98,10 @@ qemuSecurityRestoreAllLabel(virQEMUDriverPtr driver,
vm->def,
migrated,
priv->chardevStdioLogd);
+
+ if (unlock &&
+ virDomainLockMetadataUnlock(driver->lockManager, vm) < 0)
+ VIR_WARN("unable to release metadata lock");
}
@@ -88,6 +111,12 @@ qemuSecuritySetDiskLabel(virQEMUDriverPtr driver,
virDomainDiskDefPtr disk)
{
int ret = -1;
+ bool locked = false;
+
+ if (virDomainLockMetadataDiskLock(driver->lockManager, vm, disk) < 0)
+ goto cleanup;
+
+ locked = true;
if (qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT) &&
virSecurityManagerTransactionStart(driver->securityManager) < 0)
@@ -103,9 +132,17 @@ qemuSecuritySetDiskLabel(virQEMUDriverPtr driver,
vm->pid) < 0)
goto cleanup;
+ locked = false;
+
+ if (virDomainLockMetadataDiskUnlock(driver->lockManager, vm, disk) < 0)
+ goto cleanup;
+
ret = 0;
cleanup:
virSecurityManagerTransactionAbort(driver->securityManager);
+ if (locked &&
+ virDomainLockMetadataDiskUnlock(driver->lockManager, vm, disk) < 0)
+ VIR_WARN("unable to release disk metadata lock");
return ret;
}
@@ -116,6 +153,12 @@ qemuSecurityRestoreDiskLabel(virQEMUDriverPtr driver,
virDomainDiskDefPtr disk)
{
int ret = -1;
+ bool locked = false;
+
+ if (virDomainLockMetadataDiskLock(driver->lockManager, vm, disk) < 0)
+ goto cleanup;
+
+ locked = true;
if (qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT) &&
virSecurityManagerTransactionStart(driver->securityManager) < 0)
@@ -131,9 +174,17 @@ qemuSecurityRestoreDiskLabel(virQEMUDriverPtr driver,
vm->pid) < 0)
goto cleanup;
+ locked = false;
+
+ if (virDomainLockMetadataDiskUnlock(driver->lockManager, vm, disk) < 0)
+ goto cleanup;
+
ret = 0;
cleanup:
virSecurityManagerTransactionAbort(driver->securityManager);
+ if (locked &&
+ virDomainLockMetadataDiskUnlock(driver->lockManager, vm, disk) < 0)
+ VIR_WARN("unable to release disk metadata lock");
return ret;
}
@@ -144,6 +195,12 @@ qemuSecuritySetImageLabel(virQEMUDriverPtr driver,
virStorageSourcePtr src)
{
int ret = -1;
+ bool locked = false;
+
+ if (virDomainLockMetadataImageLock(driver->lockManager, vm, src) < 0)
+ goto cleanup;
+
+ locked = true;
if (qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT) &&
virSecurityManagerTransactionStart(driver->securityManager) < 0)
@@ -159,9 +216,17 @@ qemuSecuritySetImageLabel(virQEMUDriverPtr driver,
vm->pid) < 0)
goto cleanup;
+ locked = false;
+
+ if (virDomainLockMetadataImageUnlock(driver->lockManager, vm, src) < 0)
+ goto cleanup;
+
ret = 0;
cleanup:
virSecurityManagerTransactionAbort(driver->securityManager);
+ if (locked &&
+ virDomainLockMetadataImageUnlock(driver->lockManager, vm, src) < 0)
+ VIR_WARN("unable to release image metadata lock");
return ret;
}
@@ -172,6 +237,12 @@ qemuSecurityRestoreImageLabel(virQEMUDriverPtr driver,
virStorageSourcePtr src)
{
int ret = -1;
+ bool locked = false;
+
+ if (virDomainLockMetadataImageLock(driver->lockManager, vm, src) < 0)
+ goto cleanup;
+
+ locked = true;
if (qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT) &&
virSecurityManagerTransactionStart(driver->securityManager) < 0)
@@ -187,9 +258,17 @@ qemuSecurityRestoreImageLabel(virQEMUDriverPtr driver,
vm->pid) < 0)
goto cleanup;
+ locked = false;
+
+ if (virDomainLockMetadataImageUnlock(driver->lockManager, vm, src) < 0)
+ goto cleanup;
+
ret = 0;
cleanup:
virSecurityManagerTransactionAbort(driver->securityManager);
+ if (locked &&
+ virDomainLockMetadataImageUnlock(driver->lockManager, vm, src) < 0)
+ VIR_WARN("unable to release image metadata lock");
return ret;
}
Just below here is HostdevLabel processing... For a SCSI host device
that would seem to cover the type of resource described in the cover
letter to patch6 - at least for iSCSI LUNs (and of course vHBA LUNs).
Need to look at the hostdev->mode and hostdev->source.subsys.type and
dig into the subsys.u.scsi to get to the src->path.
Other than that nothing else sticks out to me.
John
@@ -258,6 +337,12 @@ qemuSecuritySetMemoryLabel(virQEMUDriverPtr
driver,
virDomainMemoryDefPtr mem)
{
int ret = -1;
+ bool locked = false;
+
+ if (virDomainLockMetadataMemLock(driver->lockManager, vm, mem) < 0)
+ goto cleanup;
+
+ locked = true;
if (qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT) &&
virSecurityManagerTransactionStart(driver->securityManager) < 0)
@@ -273,9 +358,17 @@ qemuSecuritySetMemoryLabel(virQEMUDriverPtr driver,
vm->pid) < 0)
goto cleanup;
+ locked = false;
+
+ if (virDomainLockMetadataMemUnlock(driver->lockManager, vm, mem) < 0)
+ goto cleanup;
+
ret = 0;
cleanup:
virSecurityManagerTransactionAbort(driver->securityManager);
+ if (locked &&
+ virDomainLockMetadataMemUnlock(driver->lockManager, vm, mem) < 0)
+ VIR_WARN("unable to release memory metadata lock");
return ret;
}
@@ -286,6 +379,12 @@ qemuSecurityRestoreMemoryLabel(virQEMUDriverPtr driver,
virDomainMemoryDefPtr mem)
{
int ret = -1;
+ bool locked = false;
+
+ if (virDomainLockMetadataMemLock(driver->lockManager, vm, mem) < 0)
+ goto cleanup;
+
+ locked = true;
if (qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT) &&
virSecurityManagerTransactionStart(driver->securityManager) < 0)
@@ -301,9 +400,17 @@ qemuSecurityRestoreMemoryLabel(virQEMUDriverPtr driver,
vm->pid) < 0)
goto cleanup;
+ locked = false;
+
+ if (virDomainLockMetadataMemUnlock(driver->lockManager, vm, mem) < 0)
+ goto cleanup;
+
ret = 0;
cleanup:
virSecurityManagerTransactionAbort(driver->securityManager);
+ if (locked &&
+ virDomainLockMetadataMemUnlock(driver->lockManager, vm, mem) < 0)
+ VIR_WARN("unable to release memory metadata lock");
return ret;
}