From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2120.oracle.com ([156.151.31.85]:46358 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751897AbeAXCSF (ORCPT ); Tue, 23 Jan 2018 21:18:05 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w0O27GAH066399 for ; Wed, 24 Jan 2018 02:18:05 GMT Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2120.oracle.com with ESMTP id 2fpgyjg1ge-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Wed, 24 Jan 2018 02:18:05 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w0O2I5tP030001 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Wed, 24 Jan 2018 02:18:05 GMT Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w0O2I4Ra012150 for ; Wed, 24 Jan 2018 02:18:05 GMT Subject: [PATCH 01/11] xfs: reflink should break pnfs leases before sharing blocks From: "Darrick J. Wong" Date: Tue, 23 Jan 2018 18:18:03 -0800 Message-ID: <151676028366.12349.7219306586282315379.stgit@magnolia> In-Reply-To: <151676027743.12349.3845769501491774512.stgit@magnolia> References: <151676027743.12349.3845769501491774512.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org From: Darrick J. Wong Before we share blocks between files, we need to break the pnfs leases on the layout before we start slicing and dicing the block map. Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_reflink.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 47aea2e..f89a725 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -1245,6 +1245,50 @@ xfs_reflink_remap_blocks( } /* + * Grab the exclusive iolock for a data copy from src to dest, making + * sure to abide vfs locking order (lowest pointer value goes first) and + * breaking the pnfs layout leases on dest before proceeding. The loop + * is needed because we cannot call the blocking break_layout() with the + * src iolock held, and therefore have to back out both locks. + */ +static int +xfs_iolock_two_inodes_and_break_layout( + struct inode *src, + struct inode *dest) +{ + bool src_first = src < dest; + bool src_last = src > dest; + int error; + +retry: + if (src_first) { + inode_lock(src); + inode_lock_nested(dest, I_MUTEX_NONDIR2); + } else { + inode_lock(dest); + } + + error = break_layout(dest, false); + if (error == -EWOULDBLOCK) { + inode_unlock(dest); + if (src_first) + inode_unlock(src); + error = break_layout(dest, true); + if (error) + return error; + goto retry; + } else if (error) { + inode_unlock(dest); + if (src_first) + inode_unlock(src); + return error; + } + if (src_last) + inode_lock_nested(src, I_MUTEX_NONDIR2); + return 0; +} + +/* * Link a range of blocks from one file to another. */ int @@ -1274,7 +1318,9 @@ xfs_reflink_remap_range( return -EIO; /* Lock both files against IO */ - lock_two_nondirectories(inode_in, inode_out); + ret = xfs_iolock_two_inodes_and_break_layout(inode_in, inode_out); + if (ret) + return ret; if (same_inode) xfs_ilock(src, XFS_MMAPLOCK_EXCL); else