On 01/24/2018 11:45 PM, James Smart wrote:
> During link bounce testing in a point-to-point topology, the
> host may enter a soft lockup on the lpfc_worker thread:
> Call Trace:
> lpfc_work_done+0x1f3/0x1390 [lpfc]
> lpfc_do_work+0x16f/0x180 [lpfc]
> kthread+0xc7/0xe0
> ret_from_fork+0x3f/0x70
>
> The driver was simultaneously setting a combination of flags
> that caused lpfc_do_work()to effectively spin between slow path
> work and new event data, causing the lockup.
>
> Ensure in the typical wq completions, that new event data flags
> are set if the slow path flag is running. The slow path will
> eventually reschedule the wq handling.
>
> Signed-off-by: Dick Kennedy <dick.kennedy@xxxxxxxxxxxx>
> Signed-off-by: James Smart <james.smart@xxxxxxxxxxxx>
> ---
> drivers/scsi/lpfc/lpfc_hbadisc.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
> index b159a5c4e388..9265906d956e 100644
> --- a/drivers/scsi/lpfc/lpfc_hbadisc.c
> +++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
> @@ -696,8 +696,9 @@ lpfc_work_done(struct lpfc_hba *phba)
> phba->hba_flag & HBA_SP_QUEUE_EVT)) {
> if (pring->flag & LPFC_STOP_IOCB_EVENT) {
> pring->flag |= LPFC_DEFERRED_RING_EVENT;
> - /* Set the lpfc data pending flag */
> - set_bit(LPFC_DATA_READY, &phba->data_flags);
> + /* Preserve legacy behavior. */
> + if (!(phba->hba_flag & HBA_SP_QUEUE_EVT))
> + set_bit(LPFC_DATA_READY, &phba->data_flags);
> } else {
> if (phba->link_state >= LPFC_LINK_UP ||
> phba->link_flag & LS_MDS_LOOPBACK) {
>
_Actually_ lpfc_do_work() and friends could be replace with a workqueue ...
But anyway.
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
