From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753235AbeDJMiv (ORCPT ); Tue, 10 Apr 2018 08:38:51 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:34827 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753198AbeDJMis (ORCPT ); Tue, 10 Apr 2018 08:38:48 -0400 X-Google-Smtp-Source: AIpwx4+2I3UT43Gn/69o8SmQlA0naAefoCv/AsJi1LHn/aVAlkssoV5uOJW9baPlmBGgvCV6SEFS2A== From: Jia-Ju Bai To: Kai.Makisara@kolumbus.fi, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH 2/2] scsi: st: Replace GFP_ATOMIC with GFP_KERNEL in new_tape_buffer Date: Tue, 10 Apr 2018 20:38:42 +0800 Message-Id: <1523363922-31330-1-git-send-email-baijiaju1990@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org new_tape_buffer() is never called in atomic context. new_tape_buffer() is only called by st_probe(), which is only set as ".probe" in struct scsi_driver. Despite never getting called from atomic context, new_tape_buffer() calls kzalloc() with GFP_ATOMIC, which does not sleep for allocation. GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL, which can sleep and improve the possibility of sucessful allocation. This is found by a static analysis tool named DCNS written by myself. And I also manually check it. Signed-off-by: Jia-Ju Bai --- drivers/scsi/st.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 94e402e..b987f6d 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -3878,7 +3878,7 @@ static struct st_buffer *new_tape_buffer(int need_dma, int max_sg) { struct st_buffer *tb; - tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC); + tb = kzalloc(sizeof(struct st_buffer), GFP_KERNEL); if (!tb) { printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n"); return NULL; @@ -3889,7 +3889,7 @@ static struct st_buffer *new_tape_buffer(int need_dma, int max_sg) tb->buffer_size = 0; tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *), - GFP_ATOMIC); + GFP_KERNEL); if (!tb->reserved_pages) { kfree(tb); return NULL; -- 1.9.1