From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp04.au.ibm.com ([202.81.31.146]:59499 "EHLO e23smtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759320AbcAUK10 (ORCPT ); Thu, 21 Jan 2016 05:27:26 -0500 Received: from localhost by e23smtp04.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 21 Jan 2016 20:27:23 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id A7C7C2CE8054 for ; Thu, 21 Jan 2016 21:27:21 +1100 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u0LARDFa38928634 for ; Thu, 21 Jan 2016 21:27:21 +1100 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u0LAQmTr014808 for ; Thu, 21 Jan 2016 21:26:49 +1100 From: Chandan Rajendra To: linux-btrfs@vger.kernel.org Cc: Chandan Rajendra , jbacik@fb.com, clm@fb.com, bo.li.liu@oracle.com, dsterba@suse.cz, chandan@mykolab.com Subject: [PATCH V10 12/12] Btrfs: btrfs_ioctl_clone: Truncate complete page after performing clone operation Date: Thu, 21 Jan 2016 15:56:04 +0530 Message-Id: <1453371964-4917-13-git-send-email-chandan@linux.vnet.ibm.com> In-Reply-To: <1453371964-4917-1-git-send-email-chandan@linux.vnet.ibm.com> References: <1453371964-4917-1-git-send-email-chandan@linux.vnet.ibm.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: In subpagesize-blocksize scenario, the "destination offset" argument passed to the btrfs_ioctl_clone() can be aligned to sectorsize but may not be necessarily aligned to the machine's page size. In such cases, truncate_inode_pages_range() ends up zeroing out the partial page and future read operations will return incorrect data. Hence this commit explicitly rounds down the "destination offset" to the machine's page size. Signed-off-by: Chandan Rajendra --- fs/btrfs/ioctl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 8bbecda..4e11059 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3914,8 +3914,9 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, * Truncate page cache pages so that future reads will see the cloned * data immediately and not the previous data. */ - truncate_inode_pages_range(&inode->i_data, destoff, - PAGE_CACHE_ALIGN(destoff + len) - 1); + truncate_inode_pages_range(&inode->i_data, + round_down(destoff, PAGE_CACHE_SIZE), + round_up(destoff + len, PAGE_CACHE_SIZE) - 1); out_unlock: if (!same_inode) btrfs_double_inode_unlock(src, inode); -- 2.1.0