4.14-stable review patch. If anyone has any objections, please let me know.
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From: James Smart jsmart2021@gmail.com
[ Upstream commit ca7fb76e091f889cfda1287c07a9358f73832b39 ]
On io completion, the driver is taking an adapter wide lock and nulling the scsi command back pointer. The nulling of the back pointer is to signify the io was completed and the scsi_done() routine was called. However, the routine makes no check to see if the abort routine had done the same thing and possibly nulled the pointer. Thus it may doubly-complete the io.
Make the following mods:
- Check to make sure forward progress (call scsi_done()) only happens if the command pointer was non-null.
- As the taking of the lock, which is adapter wide, is very costly on a system under load, null the pointer using an xchg operation rather than under lock.
Signed-off-by: Dick Kennedy dick.kennedy@broadcom.com Signed-off-by: James Smart james.smart@broadcom.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/scsi/lpfc/lpfc_scsi.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
--- a/drivers/scsi/lpfc/lpfc_scsi.c +++ b/drivers/scsi/lpfc/lpfc_scsi.c @@ -4149,9 +4149,17 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba
lpfc_scsi_unprep_dma_buf(phba, lpfc_cmd);
- spin_lock_irqsave(&phba->hbalock, flags); - lpfc_cmd->pCmd = NULL; - spin_unlock_irqrestore(&phba->hbalock, flags); + /* If pCmd was set to NULL from abort path, do not call scsi_done */ + if (xchg(&lpfc_cmd->pCmd, NULL) == NULL) { + lpfc_printf_vlog(vport, KERN_INFO, LOG_FCP, + "0711 FCP cmd already NULL, sid: 0x%06x, " + "did: 0x%06x, oxid: 0x%04x\n", + vport->fc_myDID, + (pnode) ? pnode->nlp_DID : 0, + phba->sli_rev == LPFC_SLI_REV4 ? + lpfc_cmd->cur_iocbq.sli4_xritag : 0xffff); + return; + }
/* The sdev is not guaranteed to be valid post scsi_done upcall. */ cmd->scsi_done(cmd);