From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: [PATCH] sg: reset 'res_in_use' after unlinking reserved array Date: Mon, 24 Apr 2017 10:26:36 +0200 Message-ID: <1493022396-107620-1-git-send-email-hare@suse.de> Return-path: Received: from mx2.suse.de ([195.135.220.15]:32962 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1166636AbdDXI0j (ORCPT ); Mon, 24 Apr 2017 04:26:39 -0400 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Martin K. Petersen" Cc: Christoph Hellwig , James Bottomley , Johannes Thumshirn , linux-scsi@vger.kernel.org, Hannes Reinecke , Hannes Reinecke Once the reserved page array is unused we can reset the 'res_in_use' state; here we can do a lazy update without holding the mutex as we only need to check against concurrent access, not concurrent release. Fixes: 1bc0eb0 ("scsi: sg: protect accesses to 'reserved' page array") Signed-off-by: Hannes Reinecke --- drivers/scsi/sg.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 8147147..06503c1 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -2056,6 +2056,8 @@ static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned lon req_schp->page_order = 0; req_schp->sglist_len = 0; srp->res_used = 0; + /* Called without mutex lock to avoid deadlock */ + sfp->res_in_use = 0; } static Sg_request * -- 1.8.5.6