[PATCH v3 03/14] lpfc: Fix kernel oops when unmapping scsi dma buffers for an aborted cmd

[Justin Tee <justintee8345@gmail.com>]

A kernel oops at dma_unmap_sg_attrs may occur due to a race between an
aborted scsi I/O completion and a scsi error handler issued TUR using the
same repurposed scsi_cmnd structure.

The LPFC_DRIVER_ABORTED cmd_flag is set when inflight I/Os are aborted
via lpfc_sli_abort_taskmgmt, and this flag is not cleared until after
scsi_done is called.  The inflight I/O test is changed to check scsi I/O
for either LFPC_IO_ON_TXCMPLQ or LPFC_DRIVER_ABORTED.  If either cmd_flag
is set, then the I/O should still be counted.

Signed-off-by: Justin Tee <justintee8345@gmail.com>
---
 drivers/scsi/lpfc/lpfc_sli.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 62a30a92b792..10db07771ccf 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -12725,8 +12725,12 @@ lpfc_sli_sum_iocb(struct lpfc_vport *vport, uint16_t tgt_id, uint64_t lun_id,
 
 		if (!iocbq || iocbq->vport != vport)
 			continue;
-		if (!(iocbq->cmd_flag & LPFC_IO_FCP) ||
-		    !(iocbq->cmd_flag & LPFC_IO_ON_TXCMPLQ))
+		/* Only count FCP i/o */
+		if (!(iocbq->cmd_flag & LPFC_IO_FCP))
+			continue;
+		/* Count i/o whilst LLDD retains an interest in the scsi_cmnd */
+		if (!(iocbq->cmd_flag &
+				(LPFC_IO_ON_TXCMPLQ | LPFC_DRIVER_ABORTED)))
 			continue;
 
 		/* Include counting outstanding aborts */
-- 
2.38.0