From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Duncan Subject: Re: [PATCH] st: remove st_mutex Date: Mon, 10 Sep 2012 15:24:38 -0700 Message-ID: <504E68A6.2070102@suse.com> References: <504E62D2.8030904@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.nue.novell.com ([195.135.221.5]:37386 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752416Ab2IJWYq (ORCPT ); Mon, 10 Sep 2012 18:24:46 -0400 In-Reply-To: <504E62D2.8030904@suse.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org Cc: James Bottomley , =?ISO-8859-1?Q?Kai_M=E4kisara?= , Jeff Mahoney Please disregard this patch -- I have the meta-data wrong. I'll resubmit. On 09/10/2012 02:59 PM, Lee Duncan wrote: > This patch is based on the "misc" branch of the SCSI tree > and the 5-patch series for st sent by Jeff Mahoney 8/18/2012 > and Ack-ed by Kai on 8/20. > > From: Jeff Mahoney > > The st_mutex was created when the BKL was removed, and > prevents simultaneous st_open calls. It is better to > protect just the necessary data. > > Signed-off-by: Jeff Mahoney > Reviewed-by: Lee Duncan > --- > drivers/scsi/st.c | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > > diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c > index ceca095..98156a9 100644 > --- a/drivers/scsi/st.c > +++ b/drivers/scsi/st.c > @@ -75,7 +75,6 @@ static const char *verstr = "20101219"; > #include "st_options.h" > #include "st.h" > > -static DEFINE_MUTEX(st_mutex); > static int buffer_kbs; > static int max_sg_segs; > static int try_direct_io = TRY_DIRECT_IO; > @@ -1185,7 +1184,6 @@ static int st_open(struct inode *inode, struct > file *filp) > int dev = TAPE_NR(inode); > char *name; > > - mutex_lock(&st_mutex); > /* > * We really want to do nonseekable_open(inode, filp); here, but some > * versions of tar incorrectly call lseek on tapes and bail out if that > @@ -1194,7 +1192,6 @@ static int st_open(struct inode *inode, struct > file *filp) > filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE); > > if (!(STp = scsi_tape_get(dev))) { > - mutex_unlock(&st_mutex); > return -ENXIO; > } > > @@ -1205,7 +1202,6 @@ static int st_open(struct inode *inode, struct > file *filp) > if (STp->in_use) { > spin_unlock(&st_use_lock); > scsi_tape_put(STp); > - mutex_unlock(&st_mutex); > DEB( printk(ST_DEB_MSG "%s: Device already in use.\n", name); ) > return (-EBUSY); > } > @@ -1259,16 +1255,16 @@ static int st_open(struct inode *inode, struct > file *filp) > retval = (-EIO); > goto err_out; > } > - mutex_unlock(&st_mutex); > return 0; > > err_out: > normalize_buffer(STp->buffer); > + spin_lock(&st_use_lock); > STp->in_use = 0; > + spin_unlock(&st_use_lock); > scsi_tape_put(STp); > if (resumed) > scsi_autopm_put_device(STp->device); > - mutex_unlock(&st_mutex); > return retval; > > } > -- Lee Duncan SUSE Labs