scsi: lpfc: Fix crash after handling a pci error

[ Upstream commit b6d777585593426b62a560be0f6d0bc0b20a0731 ]

Injecting EEH on a 32GB card is causing kernel oops

The pci error handler is doing an IO flush and the offline code is also
doing an IO flush. When the 1st flush is complete the hdwq is destroyed
(freed), yet the second flush accesses the hdwq and crashes.

Added a check in lpfc_sli4_fush_io_rings to check both the HBA_IOQ_FLUSH
flag and the hdwq pointer to see if it is already set and not already
freed.

Link: https://lore.kernel.org/r/20200322181304.37655-6-jsmart2021@gmail.com
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 1692ce913b7f0c4401be214a7cd235391fdce13a..a951e1c8165ed146fb430a799c7295c051b8feec 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -4013,6 +4013,11 @@ lpfc_sli_flush_io_rings(struct lpfc_hba *phba)
        struct lpfc_iocbq *piocb, *next_iocb;
 
        spin_lock_irq(&phba->hbalock);
+       if (phba->hba_flag & HBA_IOQ_FLUSH ||
+           !phba->sli4_hba.hdwq) {
+               spin_unlock_irq(&phba->hbalock);
+               return;
+       }
        /* Indicate the I/O queues are flushed */
        phba->hba_flag |= HBA_IOQ_FLUSH;
        spin_unlock_irq(&phba->hbalock);