From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Wagner Subject: [PATCH 1/3] csiostor: fix completion usage Date: Tue, 13 Sep 2016 10:58:48 +0200 Message-ID: <1473757130-14751-2-git-send-email-wagi@monom.org> References: <1473757130-14751-1-git-send-email-wagi@monom.org> Return-path: In-Reply-To: <1473757130-14751-1-git-send-email-wagi@monom.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-scsi@vger.kernel.org Cc: "James E.J. Bottomley" , "Martin K. Petersen" , Matthew Wilcox , linux-kernel@vger.kernel.org, Daniel Wagner List-Id: linux-scsi@vger.kernel.org From: Daniel Wagner The (re)initialzing of the completion object should be done before we trigger the transfer. Doing this after triggering the hardware opens up a race window. Without the timeout we would problaly even deadlock. Use also reinit_completion because we initalize the whole data structure in csio_scscim_init(). There is only one waiter for the completion, therefore there is no need to use complete_all(). Let's make that clear by using complete() instead of complete_all(). The usage pattern of the completion is: waiter context waker context csio_eh_abort_handler() reinit_completion() wait_for_completion_timeout() csio_scsi_err_handler() complete() Signed-off-by: Daniel Wagner --- drivers/scsi/csiostor/csio_scsi.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/csiostor/csio_scsi.c b/drivers/scsi/csiostor/csio_scsi.c index c2a6f9f..89a52b9 100644 --- a/drivers/scsi/csiostor/csio_scsi.c +++ b/drivers/scsi/csiostor/csio_scsi.c @@ -1721,7 +1721,7 @@ csio_scsi_err_handler(struct csio_hw *hw, struct csio_ioreq *req) /* Wake up waiting threads */ csio_scsi_cmnd(req) = NULL; - complete_all(&req->cmplobj); + complete(&req->cmplobj); } /* @@ -1945,6 +1945,7 @@ csio_eh_abort_handler(struct scsi_cmnd *cmnd) ready = csio_is_lnode_ready(ln); tmo = CSIO_SCSI_ABRT_TMO_MS; + reinit_completion(&ioreq->cmplobj); spin_lock_irq(&hw->lock); rv = csio_do_abrt_cls(hw, ioreq, (ready ? SCSI_ABORT : SCSI_CLOSE)); spin_unlock_irq(&hw->lock); @@ -1964,8 +1965,6 @@ csio_eh_abort_handler(struct scsi_cmnd *cmnd) goto inval_scmnd; } - /* Wait for completion */ - init_completion(&ioreq->cmplobj); wait_for_completion_timeout(&ioreq->cmplobj, msecs_to_jiffies(tmo)); /* FW didnt respond to abort within our timeout */ -- 2.7.4