Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753136Ab3JaJmK (ORCPT ); Thu, 31 Oct 2013 05:42:10 -0400 Received: from mail-ie0-f178.google.com ([209.85.223.178]:54612 "EHLO mail-ie0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750882Ab3JaJmH (ORCPT ); Thu, 31 Oct 2013 05:42:07 -0400 MIME-Version: 1.0 In-Reply-To: <1a9bd106783c1209626074deaf7fe1126530742f.1383138164.git.rashika.kheria@gmail.com> References: <3d7e050910ca994862e7880b4bd3681267681b56.1383138164.git.rashika.kheria@gmail.com> <20131019110539.GA25167@gmail.com> <1a9bd106783c1209626074deaf7fe1126530742f.1383138164.git.rashika.kheria@gmail.com> Date: Thu, 31 Oct 2013 17:42:06 +0800 Message-ID: Subject: Re: [PATCH v8 2/3] Staging: zram: Fix decrement of variable by calling bdput() From: Weijie Yang To: Rashika Kheria Cc: opw-kernel@googlegroups.com, Minchan Kim , Greg Kroah-Hartman , Jiang Liu , Nitin Gupta , Jerome Marchand , linux-kernel@vger.kernel.org, stable@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2634 Lines: 84 Hello, Rashika On Wed, Oct 30, 2013 at 9:10 PM, Rashika Kheria wrote: > As suggested by Jerome Marchand "The code in reset_store get the block device > (bdget_disk()) but it does not put it (bdput()) when it's done using it. > The usage count is therefore incremented but never decremented." > > This patch also puts bdput() for all error cases. > > Cc: stable@vger.kernel.org > Signed-off-by: Rashika Kheria > --- > > This revision fixes the following issues of the previous revision- > Proper error handling > > drivers/staging/zram/zram_drv.c | 25 ++++++++++++++++++------- > 1 file changed, 18 insertions(+), 7 deletions(-) > > diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c > index 012ba15..0bc2835 100644 > --- a/drivers/staging/zram/zram_drv.c > +++ b/drivers/staging/zram/zram_drv.c > @@ -648,25 +648,36 @@ static ssize_t reset_store(struct device *dev, > zram = dev_to_zram(dev); > bdev = bdget_disk(zram->disk, 0); > > - if (!bdev) > - return -ENOMEM; > + if (!bdev) { > + ret = -ENOMEM; > + goto out; > + } If bdev is NULL, just return -ENOMEM; DO NOT goto out; or you will get a NULL point reference in bdput(bdev); > /* Do not reset an active device! */ > - if (bdev->bd_holders) > - return -EBUSY; > + if (bdev->bd_holders) { > + ret = -EBUSY; > + goto out; > + } > > ret = kstrtou16(buf, 10, &do_reset); > if (ret) > - return ret; > + goto out; > > - if (!do_reset) > - return -EINVAL; > + if (!do_reset) { > + ret = -EINVAL; > + goto out; > + } > > /* Make sure all pending I/O is finished */ > fsync_bdev(bdev); > + bdput(bdev); > > zram_reset_device(zram, true); > return len; > + > +out: > + bdput(bdev); > + return ret; > } > > static void __zram_make_request(struct zram *zram, struct bio *bio, int rw) > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/