Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965820AbcCOTnV (ORCPT ); Tue, 15 Mar 2016 15:43:21 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:16633 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750919AbcCOTnT (ORCPT ); Tue, 15 Mar 2016 15:43:19 -0400 Subject: [PATCH 1/3] block: invalidate the page cache when issuing BLKZEROOUT. From: "Darrick J. Wong" To: axboe@kernel.dk, torvalds@linux-foundation.org, darrick.wong@oracle.com Cc: bfields@fieldses.org, tytso@mit.edu, akpm@linux-foundation.org, martin.petersen@oracle.com, linux-api@vger.kernel.org, david@fromorbit.com, linux-kernel@vger.kernel.org, shane.seymour@hpe.com, hch@infradead.org, linux-fsdevel@vger.kernel.org, jlayton@poochiereds.net, Christoph Hellwig Date: Tue, 15 Mar 2016 12:42:29 -0700 Message-ID: <20160315194229.30093.75656.stgit@birch.djwong.org> In-Reply-To: <20160315194221.30093.70506.stgit@birch.djwong.org> References: <20160315194221.30093.70506.stgit@birch.djwong.org> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1937 Lines: 67 Invalidate the page cache (as a regular O_DIRECT write would do) to avoid returning stale cache contents at a later time. v5: Refactor the 4.4 refactoring of the ioctl code into separate functions. Split the page invalidation and the new ioctl into separate patches. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- block/ioctl.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index d8996bb..c6eb462 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -226,7 +226,9 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, unsigned long arg) { uint64_t range[2]; - uint64_t start, len; + struct address_space *mapping; + uint64_t start, end, len; + int ret; if (!(mode & FMODE_WRITE)) return -EBADF; @@ -236,18 +238,33 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, start = range[0]; len = range[1]; + end = start + len - 1; if (start & 511) return -EINVAL; if (len & 511) return -EINVAL; - start >>= 9; - len >>= 9; - - if (start + len > (i_size_read(bdev->bd_inode) >> 9)) + if (end >= (uint64_t)i_size_read(bdev->bd_inode)) + return -EINVAL; + if (end < start) return -EINVAL; - return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false); + /* Invalidate the page cache, including dirty pages */ + mapping = bdev->bd_inode->i_mapping; + truncate_inode_pages_range(mapping, start, end); + + ret = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL, + false); + if (ret) + return ret; + + /* + * Invalidate again; if someone wandered in and dirtied a page, + * the caller will be given -EBUSY. + */ + return invalidate_inode_pages2_range(mapping, + start >> PAGE_CACHE_SHIFT, + end >> PAGE_CACHE_SHIFT); } static int put_ushort(unsigned long arg, unsigned short val)