The BSOD occurred because the FilterAttach routine released the switch context, while there were IRPs in processing.
The solution was to add a reference count in the switch context to prevent premature deallocation of the switch context structure. Signed-off-by: Sorin Vinturis <svintu...@cloudbasesolutions.com> Reported-by: Alin Gabriel Serdean <aserd...@cloudbasesolutions.com> Reported-at: https://github.com/openvswitch/ovs-issues/issues/58 --- datapath-windows/ovsext/Datapath.c | 10 +++++---- datapath-windows/ovsext/Switch.c | 44 ++++++++++++++++++++++++++++++++++++++ datapath-windows/ovsext/Switch.h | 12 ++++++++++- 3 files changed, 61 insertions(+), 5 deletions(-) diff --git a/datapath-windows/ovsext/Datapath.c b/datapath-windows/ovsext/Datapath.c index 8eb13f1..8b561a3 100644 --- a/datapath-windows/ovsext/Datapath.c +++ b/datapath-windows/ovsext/Datapath.c @@ -699,10 +699,9 @@ OvsDeviceControl(PDEVICE_OBJECT deviceObject, outputBufferLen = irpSp->Parameters.DeviceIoControl.OutputBufferLength; inputBuffer = irp->AssociatedIrp.SystemBuffer; - /* Check if the extension is enabled. */ - if (NULL == gOvsSwitchContext) { - status = STATUS_DEVICE_NOT_READY; - goto done; + if (!OvsAcquireSwitchContext(gOvsSwitchContext)) { + status = STATUS_NOT_FOUND; + goto exit; } /* Concurrent netlink operations are not supported. */ @@ -874,6 +873,9 @@ OvsDeviceControl(PDEVICE_OBJECT deviceObject, status = InvokeNetlinkCmdHandler(&usrParamsCtx, nlFamilyOps, &replyLen); done: + OvsReleaseSwitchContext(gOvsSwitchContext); + +exit: KeMemoryBarrier(); instance->inUse = 0; diff --git a/datapath-windows/ovsext/Switch.c b/datapath-windows/ovsext/Switch.c index a228d8e..8366944 100644 --- a/datapath-windows/ovsext/Switch.c +++ b/datapath-windows/ovsext/Switch.c @@ -420,6 +420,9 @@ OvsInitSwitchContext(POVS_SWITCH_CONTEXT switchContext) switchContext->isActivateFailed = FALSE; switchContext->dpNo = OVS_DP_NUMBER; ovsTimeIncrementPerTick = KeQueryTimeIncrement() / 10000; + + switchContext->refCount = 1; + OVS_LOG_TRACE("Exit: Succesfully initialized switchContext: %p", switchContext); return NDIS_STATUS_SUCCESS; @@ -428,6 +431,12 @@ OvsInitSwitchContext(POVS_SWITCH_CONTEXT switchContext) static VOID OvsUninitSwitchContext(POVS_SWITCH_CONTEXT switchContext) { + OvsReleaseSwitchContext(switchContext); +} + +VOID +OvsDeleteSwitchContext(POVS_SWITCH_CONTEXT switchContext) +{ OVS_LOG_TRACE("Enter: Delete switchContext:%p", switchContext); /* We need to do cleanup for tunnel port here. */ @@ -447,9 +456,44 @@ OvsUninitSwitchContext(POVS_SWITCH_CONTEXT switchContext) switchContext->pidHashArray = NULL; OvsDeleteFlowTable(&switchContext->datapath); OvsCleanupBufferPool(switchContext); + switchContext->refCount = 0; OVS_LOG_TRACE("Exit: Delete switchContext: %p", switchContext); } +VOID +OvsReleaseSwitchContext(POVS_SWITCH_CONTEXT switchContext) +{ + if (1 == InterlockedCompareExchange( + (LONG volatile *)&switchContext->refCount, 0, 1)) { + OvsDeleteSwitchContext(switchContext); + } + else { + InterlockedDecrement((LONG volatile *)&switchContext->refCount); + } +} + +BOOLEAN +OvsAcquireSwitchContext(POVS_SWITCH_CONTEXT switchContext) +{ + BOOLEAN ret = FALSE; + + do { + if (NULL == switchContext) { + break; + } + + if (0 == InterlockedCompareExchange( + (LONG volatile *)&switchContext->refCount, 0, 0)) { + break; + } + + InterlockedIncrement((LONG volatile *)&switchContext->refCount); + ret = TRUE; + } while (!ret); + + return ret; +} + /* * -------------------------------------------------------------------------- * This function activates the switch by initializing it with all the runtime diff --git a/datapath-windows/ovsext/Switch.h b/datapath-windows/ovsext/Switch.h index 7960072..25db636 100644 --- a/datapath-windows/ovsext/Switch.h +++ b/datapath-windows/ovsext/Switch.h @@ -179,6 +179,12 @@ typedef struct _OVS_SWITCH_CONTEXT volatile LONG pendingOidCount; OVS_NBL_POOL ovsPool; + + /* + * Reference count used to prevent premature deallocation of the switch + * context. + */ + INT32 refCount; } OVS_SWITCH_CONTEXT, *POVS_SWITCH_CONTEXT; @@ -202,7 +208,6 @@ OvsAcquireDatapathWrite(OVS_DATAPATH *datapath, dispatch ? NDIS_RWL_AT_DISPATCH_LEVEL : 0); } - static __inline VOID OvsReleaseDatapath(OVS_DATAPATH *datapath, LOCK_STATE_EX *lockState) @@ -211,6 +216,11 @@ OvsReleaseDatapath(OVS_DATAPATH *datapath, NdisReleaseRWLock(datapath->lock, lockState); } +BOOLEAN +OvsAcquireSwitchContext(POVS_SWITCH_CONTEXT switchContext); + +VOID +OvsReleaseSwitchContext(POVS_SWITCH_CONTEXT switchContext); PVOID OvsGetExternalVport(); -- 1.9.0.msysgit.0 _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
