From patchwork Fri Feb 1 14:32:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Foster X-Patchwork-Id: 10792843 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E13F513BF for ; Fri, 1 Feb 2019 14:33:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C816032229 for ; Fri, 1 Feb 2019 14:33:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BC52532233; Fri, 1 Feb 2019 14:33:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 21A573222D for ; Fri, 1 Feb 2019 14:33:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728616AbfBAOc7 (ORCPT ); Fri, 1 Feb 2019 09:32:59 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33298 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727944AbfBAOc7 (ORCPT ); Fri, 1 Feb 2019 09:32:59 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ED66E394D3F for ; Fri, 1 Feb 2019 14:32:58 +0000 (UTC) Received: from bfoster.bos.redhat.com (dhcp-41-66.bos.redhat.com [10.18.41.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id A85285D9D1 for ; Fri, 1 Feb 2019 14:32:58 +0000 (UTC) From: Brian Foster To: linux-xfs@vger.kernel.org Subject: [PATCH v4 5/6] xfs: create delalloc bmapi wrapper for full extent allocation Date: Fri, 1 Feb 2019 09:32:55 -0500 Message-Id: <20190201143256.43232-6-bfoster@redhat.com> In-Reply-To: <20190201143256.43232-1-bfoster@redhat.com> References: <20190201143256.43232-1-bfoster@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 01 Feb 2019 14:32:58 +0000 (UTC) Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The writeback delalloc conversion code is racy with respect to changes in the currently cached file mapping. This stems from the fact that the bmapi allocation code requires a file range to allocate and the writeback conversion code assumes the range of the currently cached mapping is still valid with respect to the fork. It may not be valid, however, because the ilock is cycled (potentially multiple times) between the time the cached mapping was populated and the delalloc conversion occurs. To facilitate a solution to this problem, create a new xfs_bmapi_delalloc() wrapper to xfs_bmapi_write() that takes a file (FSB) offset and attempts to allocate whatever delalloc extent backs the offset. Use a new bmapi flag to cause xfs_bmapi_write() to set the range based on the extent backing the bno parameter unless bno lands in a hole. If bno does land in a hole, fall back to the current behavior (which may result in an error or quietly skipping holes in the specified range depending on other parameters). This patch does not change behavior. [hch: Rename helper function and tweak interface.] Signed-off-by: Brian Foster Signed-off-by: Christoph Hellwig Reviewed-by: Christoph Hellwig --- fs/xfs/libxfs/xfs_bmap.c | 59 +++++++++++++++++++++++++++++++++++++--- fs/xfs/libxfs/xfs_bmap.h | 4 +++ 2 files changed, 59 insertions(+), 4 deletions(-) diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 4c73927819c2..c629004d9a4c 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -4286,10 +4286,6 @@ xfs_bmapi_write( goto error0; } - n = 0; - end = bno + len; - obno = bno; - if (!xfs_iext_lookup_extent(ip, ifp, bno, &bma.icur, &bma.got)) eof = true; if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev)) @@ -4299,6 +4295,26 @@ xfs_bmapi_write( bma.total = total; bma.datatype = 0; + /* + * The reval flag means the caller wants to allocate the entire delalloc + * extent backing bno where bno may not necessarily match the startoff. + * Now that we've looked up the extent, reset the range to map based on + * the extent in the file. If we're in a hole, this may be an error so + * don't adjust anything. + */ + if ((flags & XFS_BMAPI_REVALRANGE) && + !eof && bno >= bma.got.br_startoff) { + ASSERT(flags & XFS_BMAPI_DELALLOC); + bno = bma.got.br_startoff; + len = bma.got.br_blockcount; +#ifdef DEBUG + orig_bno = bno; + orig_len = len; +#endif + } + n = 0; + end = bno + len; + obno = bno; while (bno < end && n < *nmap) { bool need_alloc = false, wasdelay = false; @@ -4455,6 +4471,41 @@ xfs_bmapi_write( return error; } +/* + * Convert an existing delalloc extent to real blocks based on file offset. This + * attempts to allocate the entire delalloc extent and may require multiple + * invocations to allocate the target offset if a large enough physical extent + * is not available. + */ +int +xfs_bmapi_convert_delalloc( + struct xfs_trans *tp, + struct xfs_inode *ip, + xfs_fileoff_t offset_fsb, + int whichfork, + struct xfs_bmbt_irec *imap) +{ + int flags = XFS_BMAPI_DELALLOC; + int nimaps = 1; + int error; + int total = XFS_EXTENTADD_SPACE_RES(ip->i_mount, + XFS_DATA_FORK); + + if (whichfork == XFS_COW_FORK) + flags |= XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC; + + /* + * The reval flag means to allocate the entire extent; pass a dummy + * length of 1. + */ + flags |= XFS_BMAPI_REVALRANGE; + error = xfs_bmapi_write(tp, ip, offset_fsb, 1, flags, total, imap, + &nimaps); + if (!error && !nimaps) + error = -EFSCORRUPTED; + return error; +} + int xfs_bmapi_remap( struct xfs_trans *tp, diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h index b4ff710d7250..75586d56f7a5 100644 --- a/fs/xfs/libxfs/xfs_bmap.h +++ b/fs/xfs/libxfs/xfs_bmap.h @@ -107,6 +107,8 @@ struct xfs_extent_free_item /* Do not update the rmap btree. Used for reconstructing bmbt from rmapbt. */ #define XFS_BMAPI_NORMAP 0x2000 +#define XFS_BMAPI_REVALRANGE 0x4000 + #define XFS_BMAPI_FLAGS \ { XFS_BMAPI_ENTIRE, "ENTIRE" }, \ { XFS_BMAPI_METADATA, "METADATA" }, \ @@ -227,6 +229,8 @@ int xfs_bmapi_reserve_delalloc(struct xfs_inode *ip, int whichfork, xfs_fileoff_t off, xfs_filblks_t len, xfs_filblks_t prealloc, struct xfs_bmbt_irec *got, struct xfs_iext_cursor *cur, int eof); +int xfs_bmapi_convert_delalloc(struct xfs_trans *, struct xfs_inode *, + xfs_fileoff_t, int, struct xfs_bmbt_irec *); static inline void xfs_bmap_add_free(