From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2120.oracle.com ([156.151.31.85]:48606 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726458AbfBXUbR (ORCPT ); Sun, 24 Feb 2019 15:31:17 -0500 Subject: [PATCH 2/2] xfs: rework breaking of shared extents in xfs_file_iomap_begin From: "Darrick J. Wong" Date: Sun, 24 Feb 2019 12:31:05 -0800 Message-ID: <155104026500.24373.14839198455533713908.stgit@magnolia> In-Reply-To: <155104025871.24373.7462613353398620970.stgit@magnolia> References: <155104025871.24373.7462613353398620970.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, bfoster@redhat.com From: Darrick J. Wong Rework the data flow in xfs_file_iomap_begin where we decide if we have to break shared extents. Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_iomap.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index a376fb2d4b94..a3043b1bcd9a 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -982,7 +982,7 @@ xfs_file_iomap_begin( * been done up front, so we don't need to do them here. */ if (xfs_is_cow_inode(ip)) { - struct xfs_bmbt_irec orig = imap; + struct xfs_bmbt_irec cmap; bool convert_now = (flags & IOMAP_DIRECT); /* if zeroing doesn't need COW allocation, then we are done. */ @@ -991,7 +991,8 @@ xfs_file_iomap_begin( goto out_found; /* may drop and re-acquire the ilock */ - error = xfs_reflink_allocate_cow(ip, &imap, &shared, &lockmode, + cmap = imap; + error = xfs_reflink_allocate_cow(ip, &cmap, &shared, &lockmode, convert_now); if (error) goto out_unlock; @@ -1001,10 +1002,12 @@ xfs_file_iomap_begin( * previous block (if there was any) so that the higher level * write code can perform read-modify-write operations. For * direct I/O code, which must be block aligned we need to - * report the newly allocated address. + * report the newly allocated address. If the data fork has + * a hole, copy the COW fork mapping to avoid allocating to + * the data fork. */ - if (!convert_now && orig.br_startblock != HOLESTARTBLOCK) - imap = orig; + if (convert_now || imap.br_startblock == HOLESTARTBLOCK) + imap = cmap; end_fsb = imap.br_startoff + imap.br_blockcount; length = XFS_FSB_TO_B(mp, end_fsb) - offset;