From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:53124 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751802AbcJBN0K (ORCPT ); Sun, 2 Oct 2016 09:26:10 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u92DNCV9060670 for ; Sun, 2 Oct 2016 09:26:10 -0400 Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx0b-001b2d01.pphosted.com with ESMTP id 25t99m4q7q-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 02 Oct 2016 09:26:09 -0400 Received: from localhost by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 2 Oct 2016 07:26:09 -0600 From: Chandan Rajendra To: clm@fb.com, jbacik@fb.com, dsterba@suse.com Cc: Chandan Rajendra , linux-btrfs@vger.kernel.org Subject: [PATCH V21 16/19] Btrfs: subpage-blocksize: btrfs_clone: Flush dirty blocks of a page that do not map the clone range Date: Sun, 2 Oct 2016 18:54:25 +0530 In-Reply-To: <1475414668-25954-1-git-send-email-chandan@linux.vnet.ibm.com> References: <1475414668-25954-1-git-send-email-chandan@linux.vnet.ibm.com> Message-Id: <1475414668-25954-17-git-send-email-chandan@linux.vnet.ibm.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: After cloning the required extents, we truncate all the pages that map the file range being cloned. In subpage-blocksize scenario, we could have dirty blocks before and/or after the clone range in the leading/trailing pages. Truncating these pages would lead to data loss. Hence this commit forces such dirty blocks to be flushed to disk before performing the clone operation. Signed-off-by: Chandan Rajendra --- fs/btrfs/ioctl.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index cf13029..0fdc0a0 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3914,6 +3914,7 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src, int ret; u64 len = olen; u64 bs = root->fs_info->sb->s_blocksize; + u64 dest_end; int same_inode = src == inode; /* @@ -3974,6 +3975,21 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src, goto out_unlock; } + if ((round_down(destoff, PAGE_SIZE) < inode->i_size) && + !IS_ALIGNED(destoff, PAGE_SIZE)) { + ret = filemap_write_and_wait_range(inode->i_mapping, + round_down(destoff, PAGE_SIZE), + destoff - 1); + } + + dest_end = destoff + len - 1; + if ((dest_end < inode->i_size) && + !IS_ALIGNED(dest_end + 1, PAGE_SIZE)) { + ret = filemap_write_and_wait_range(inode->i_mapping, + dest_end + 1, + round_up(dest_end, PAGE_SIZE)); + } + if (destoff > inode->i_size) { ret = btrfs_cont_expand(inode, inode->i_size, destoff); if (ret) -- 2.5.5