From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751901AbdJYAqS (ORCPT ); Tue, 24 Oct 2017 20:46:18 -0400 Received: from mail-pf0-f193.google.com ([209.85.192.193]:43777 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751670AbdJYAqN (ORCPT ); Tue, 24 Oct 2017 20:46:13 -0400 X-Google-Smtp-Source: ABhQp+RwkGOxkRVfZ/yD2mGu41sqlYjscRJIM+hlWetDIsq/TN0y2uJTwsfZ/Qpp9uKyxkjwG1blqg== Subject: Re: [PATCH] block: Invalidate cache on discard v2 To: Omar Sandoval , Dmitry Monakhov Cc: linux-kernel@vger.kernel.org, hch@lst.de, Nishita Borkar , linux-block@vger.kernel.org References: <1490210965-28861-1-git-send-email-dmonakhov@openvz.org> <20171024213353.GA13084@vader.DHCP.thefacebook.com> From: Jens Axboe Message-ID: Date: Tue, 24 Oct 2017 18:46:09 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <20171024213353.GA13084@vader.DHCP.thefacebook.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/24/2017 03:33 PM, Omar Sandoval wrote: > On Wed, Mar 22, 2017 at 11:29:25PM +0400, Dmitry Monakhov wrote: >> It is reasonable drop page cache on discard, otherwise that pages may >> be written by writeback second later, so thin provision devices will >> not be happy. This seems to be a security leak in case of secure discard case. >> >> Also add check for queue_discard flag on early stage. >> >> Signed-off-by: Dmitry Monakhov >> Reviewed-by: Christoph Hellwig >> >> --- >> block/ioctl.c | 14 ++++++++++---- >> 1 file changed, 10 insertions(+), 4 deletions(-) >> >> diff --git a/block/ioctl.c b/block/ioctl.c >> index 7b88820..336610d 100644 >> --- a/block/ioctl.c >> +++ b/block/ioctl.c >> @@ -202,10 +202,16 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, >> { >> uint64_t range[2]; >> uint64_t start, len; >> + struct request_queue *q = bdev_get_queue(bdev); >> + struct address_space *mapping = bdev->bd_inode->i_mapping; >> + >> >> if (!(mode & FMODE_WRITE)) >> return -EBADF; >> >> + if (!blk_queue_discard(q)) >> + return -EOPNOTSUPP; >> + >> if (copy_from_user(range, (void __user *)arg, sizeof(range))) >> return -EFAULT; >> >> @@ -216,12 +222,12 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, >> return -EINVAL; >> if (len & 511) >> return -EINVAL; >> - start >>= 9; >> - len >>= 9; >> >> - if (start + len > (i_size_read(bdev->bd_inode) >> 9)) >> + if (start + len > i_size_read(bdev->bd_inode)) >> return -EINVAL; >> - return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags); >> + truncate_inode_pages_range(mapping, start, start + len); >> + return blkdev_issue_discard(bdev, start >> 9, len >> 9, >> + GFP_KERNEL, flags); >> } >> >> static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, >> -- >> 2.9.3 >> > > Hey, Jens, Dmitry didn't send this patch to linux-block so looks like > you missed it. Christoph reviewed it and Nishita sent up a blktest for > it so we should probably pull it in. Definitely missed it, block patches should be cc'ed linux-block always or I will never see them. Especially if I'm not cc'ed either. I've applied it for 4.15. -- Jens Axboe