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 to prevent premature deallocation of the global switch context structure, gOvsSwitchContext. 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 Acked-by: Eitan Eliahu <elia...@vmware.com> --- datapath-windows/ovsext/Datapath.c | 12 ++++++-- datapath-windows/ovsext/Switch.c | 56 ++++++++++++++++++++++++++++++++++++++ datapath-windows/ovsext/Switch.h | 6 +++- 3 files changed, 71 insertions(+), 3 deletions(-) diff --git a/datapath-windows/ovsext/Datapath.c b/datapath-windows/ovsext/Datapath.c index 8eb13f1..b692225 100644 --- a/datapath-windows/ovsext/Datapath.c +++ b/datapath-windows/ovsext/Datapath.c @@ -701,8 +701,13 @@ OvsDeviceControl(PDEVICE_OBJECT deviceObject, /* Check if the extension is enabled. */ if (NULL == gOvsSwitchContext) { - status = STATUS_DEVICE_NOT_READY; - goto done; + status = STATUS_NOT_FOUND; + goto exit; + } + + if (!OvsAcquireSwitchContext()) { + status = STATUS_NOT_FOUND; + goto exit; } /* Concurrent netlink operations are not supported. */ @@ -874,6 +879,9 @@ 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..94565a6 100644 --- a/datapath-windows/ovsext/Switch.c +++ b/datapath-windows/ovsext/Switch.c @@ -42,6 +42,12 @@ extern PNDIS_SPIN_LOCK gOvsCtrlLock; extern NDIS_HANDLE gOvsExtDriverHandle; extern NDIS_HANDLE gOvsExtDriverObject; +/* + * Reference count used to prevent premature deallocation of the global switch + * context structure, gOvsSwitchContext. + */ +volatile LONG gOvsSwitchContextRefCount = 1; + static NDIS_STATUS OvsCreateSwitch(NDIS_HANDLE ndisFilterHandle, POVS_SWITCH_CONTEXT *switchContextOut); static NDIS_STATUS OvsInitSwitchContext(POVS_SWITCH_CONTEXT switchContext); @@ -420,6 +426,7 @@ OvsInitSwitchContext(POVS_SWITCH_CONTEXT switchContext) switchContext->isActivateFailed = FALSE; switchContext->dpNo = OVS_DP_NUMBER; ovsTimeIncrementPerTick = KeQueryTimeIncrement() / 10000; + OVS_LOG_TRACE("Exit: Succesfully initialized switchContext: %p", switchContext); return NDIS_STATUS_SUCCESS; @@ -428,6 +435,12 @@ 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. */ @@ -450,6 +463,49 @@ OvsUninitSwitchContext(POVS_SWITCH_CONTEXT switchContext) OVS_LOG_TRACE("Exit: Delete switchContext: %p", switchContext); } +VOID +OvsReleaseSwitchContext(POVS_SWITCH_CONTEXT switchContext) +{ + LONG ref = 0; + LONG newRef = 0; + LONG icxRef = 0; + + do { + ref = gOvsSwitchContextRefCount; + newRef = (0 == ref) ? 0 : ref - 1; + icxRef = InterlockedCompareExchange(&gOvsSwitchContextRefCount, + newRef, + ref); + } while (icxRef != ref); + + if (ref == 1) { + OvsDeleteSwitchContext(switchContext); + } +} + +BOOLEAN +OvsAcquireSwitchContext(VOID) +{ + LONG ref = 0; + LONG newRef = 0; + LONG icxRef = 0; + BOOLEAN ret = FALSE; + + do { + ref = gOvsSwitchContextRefCount; + newRef = (0 == ref) ? 0 : ref + 1; + icxRef = InterlockedCompareExchange(&gOvsSwitchContextRefCount, + newRef, + ref); + } while (icxRef != ref); + + if (ref != 0) { + ret = TRUE; + } + + 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..6ec34e1 100644 --- a/datapath-windows/ovsext/Switch.h +++ b/datapath-windows/ovsext/Switch.h @@ -202,7 +202,6 @@ OvsAcquireDatapathWrite(OVS_DATAPATH *datapath, dispatch ? NDIS_RWL_AT_DISPATCH_LEVEL : 0); } - static __inline VOID OvsReleaseDatapath(OVS_DATAPATH *datapath, LOCK_STATE_EX *lockState) @@ -211,6 +210,11 @@ OvsReleaseDatapath(OVS_DATAPATH *datapath, NdisReleaseRWLock(datapath->lock, lockState); } +BOOLEAN +OvsAcquireSwitchContext(VOID); + +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
