scsi: lpfc: fix oops/BUG in lpfc_sli_ringtxcmpl_put()
The BUG_ON() recently introduced in lpfc_sli_ringtxcmpl_put() is hit in
the lpfc_els_abort() > lpfc_sli_issue_abort_iotag() >
lpfc_sli_abort_iotag_issue() function path [similar names], due to
'piocb->vport == NULL':
BUG_ON(!piocb || !piocb->vport);
This happens because lpfc_sli_abort_iotag_issue() doesn't set the
'abtsiocbp->vport' pointer -- but this is not the problem.
Previously, lpfc_sli_ringtxcmpl_put() accessed 'piocb->vport' only if
'piocb->iocb.ulpCommand' is neither CMD_ABORT_XRI_CN nor
CMD_CLOSE_XRI_CN, which are the only possible values for
lpfc_sli_abort_iotag_issue():
So, this function path would not have hit this possible NULL pointer
dereference before.
In order to fix this regression, move the second part of the BUG_ON()
check prior to the pointer dereference that it does check for.
For reference, this is the stack trace observed. The problem happened
because an unsolicited event was received - a PLOGI was received after
our PLOGI was issued but not yet complete, so the discovery state
machine goes on to sw-abort our PLOGI.