From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A08D3C433DB for ; Wed, 24 Feb 2021 21:35:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4366464F0A for ; Wed, 24 Feb 2021 21:35:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233920AbhBXVfK (ORCPT ); Wed, 24 Feb 2021 16:35:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:49824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231717AbhBXVfK (ORCPT ); Wed, 24 Feb 2021 16:35:10 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8C73864F08; Wed, 24 Feb 2021 21:34:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614202469; bh=u3qakhSCCECT7aroazzGe5wMi81aHVfeumTT794rtZg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=luuPyc9imohJ8vsS3Tec/HVPgGHbSuJWa84nWXL6b0ZXEUvG32AWSg17H0gDJXVOt DskKIOt331TCbQyKX/ISjIF0beaG+LtJkwwHdewHq3PhpJeGcOphDsM+S9BIPH0z3N 9nRGS2bvf90nS/rvWiuO8//Am7ScNZVTNrATqYoOv0DNZiyiKeyMdaqOm3mNtLSmzT yVHq67bTP4hTqqpfzFd+I1P6COG9KsJFc6Az00CUADKWmwY7umTa6rKMBN7W8Bz8Wg UUpUDJwcaWV2etE+EZXF9N0/A79CsZJmvVdURHC3ult2jCH8LOaMVUWSu/MhnKiMvx kEadi+El0cqPA== Date: Wed, 24 Feb 2021 13:34:28 -0800 From: "Darrick J. Wong" To: Dave Chinner Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH 2/3] xfs: xfs_buf_item_size_segment() needs to pass segment offset Message-ID: <20210224213428.GZ7272@magnolia> References: <20210223044636.3280862-1-david@fromorbit.com> <20210223044636.3280862-3-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210223044636.3280862-3-david@fromorbit.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Tue, Feb 23, 2021 at 03:46:35PM +1100, Dave Chinner wrote: > From: Dave Chinner > > Otherwise it doesn't correctly calculate the number of vectors > in a logged buffer that has a contiguous map that gets split into > multiple regions because the range spans discontigous memory. > > Probably never been hit in practice - we don't log contiguous ranges > on unmapped buffers (inode clusters). > > Signed-off-by: Dave Chinner Subtle. Reviewed-by: Darrick J. Wong --D > --- > fs/xfs/xfs_buf_item.c | 38 +++++++++++++++++++------------------- > 1 file changed, 19 insertions(+), 19 deletions(-) > > diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c > index 0628a65d9c55..91dc7d8c9739 100644 > --- a/fs/xfs/xfs_buf_item.c > +++ b/fs/xfs/xfs_buf_item.c > @@ -55,6 +55,18 @@ xfs_buf_log_format_size( > (blfp->blf_map_size * sizeof(blfp->blf_data_map[0])); > } > > +static inline bool > +xfs_buf_item_straddle( > + struct xfs_buf *bp, > + uint offset, > + int next_bit, > + int last_bit) > +{ > + return xfs_buf_offset(bp, offset + (next_bit << XFS_BLF_SHIFT)) != > + (xfs_buf_offset(bp, offset + (last_bit << XFS_BLF_SHIFT)) + > + XFS_BLF_CHUNK); > +} > + > /* > * Return the number of log iovecs and space needed to log the given buf log > * item segment. > @@ -67,6 +79,7 @@ STATIC void > xfs_buf_item_size_segment( > struct xfs_buf_log_item *bip, > struct xfs_buf_log_format *blfp, > + uint offset, > int *nvecs, > int *nbytes) > { > @@ -101,12 +114,8 @@ xfs_buf_item_size_segment( > */ > if (next_bit == -1) { > break; > - } else if (next_bit != last_bit + 1) { > - last_bit = next_bit; > - (*nvecs)++; > - } else if (xfs_buf_offset(bp, next_bit * XFS_BLF_CHUNK) != > - (xfs_buf_offset(bp, last_bit * XFS_BLF_CHUNK) + > - XFS_BLF_CHUNK)) { > + } else if (next_bit != last_bit + 1 || > + xfs_buf_item_straddle(bp, offset, next_bit, last_bit)) { > last_bit = next_bit; > (*nvecs)++; > } else { > @@ -141,8 +150,10 @@ xfs_buf_item_size( > int *nbytes) > { > struct xfs_buf_log_item *bip = BUF_ITEM(lip); > + struct xfs_buf *bp = bip->bli_buf; > int i; > int bytes; > + uint offset = 0; > > ASSERT(atomic_read(&bip->bli_refcount) > 0); > if (bip->bli_flags & XFS_BLI_STALE) { > @@ -184,8 +195,9 @@ xfs_buf_item_size( > */ > bytes = 0; > for (i = 0; i < bip->bli_format_count; i++) { > - xfs_buf_item_size_segment(bip, &bip->bli_formats[i], > + xfs_buf_item_size_segment(bip, &bip->bli_formats[i], offset, > nvecs, &bytes); > + offset += BBTOB(bp->b_maps[i].bm_len); > } > > /* > @@ -212,18 +224,6 @@ xfs_buf_item_copy_iovec( > nbits * XFS_BLF_CHUNK); > } > > -static inline bool > -xfs_buf_item_straddle( > - struct xfs_buf *bp, > - uint offset, > - int next_bit, > - int last_bit) > -{ > - return xfs_buf_offset(bp, offset + (next_bit << XFS_BLF_SHIFT)) != > - (xfs_buf_offset(bp, offset + (last_bit << XFS_BLF_SHIFT)) + > - XFS_BLF_CHUNK); > -} > - > static void > xfs_buf_item_format_segment( > struct xfs_buf_log_item *bip, > -- > 2.28.0 >