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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 B6FE1C4320A for ; Tue, 17 Aug 2021 23:48:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A03EB60F39 for ; Tue, 17 Aug 2021 23:48:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236651AbhHQXtF (ORCPT ); Tue, 17 Aug 2021 19:49:05 -0400 Received: from mail110.syd.optusnet.com.au ([211.29.132.97]:52538 "EHLO mail110.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235450AbhHQXtE (ORCPT ); Tue, 17 Aug 2021 19:49:04 -0400 Received: from dread.disaster.area (pa49-195-182-146.pa.nsw.optusnet.com.au [49.195.182.146]) by mail110.syd.optusnet.com.au (Postfix) with ESMTPS id 512FC10B8CE; Wed, 18 Aug 2021 09:48:29 +1000 (AEST) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1mG8ol-001vaB-Hy; Wed, 18 Aug 2021 09:48:27 +1000 Date: Wed, 18 Aug 2021 09:48:27 +1000 From: Dave Chinner To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH 3/3] xfs: rename buffer cache index variable b_bn Message-ID: <20210817234827.GK3657114@dread.disaster.area> References: <20210810052851.42312-1-david@fromorbit.com> <20210810052851.42312-4-david@fromorbit.com> <20210811004632.GA3601443@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210811004632.GA3601443@magnolia> X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=Tu+Yewfh c=1 sm=1 tr=0 a=QpfB3wCSrn/dqEBSktpwZQ==:117 a=QpfB3wCSrn/dqEBSktpwZQ==:17 a=kj9zAlcOel0A:10 a=MhDmnRu9jo8A:10 a=20KFwNOVAAAA:8 a=7-415B0cAAAA:8 a=yd1ExSCD8T7kEV-FtUIA:9 a=SAi89j5P6tp7u05n:21 a=BqFtgtFxinGV1TpL:21 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Tue, Aug 10, 2021 at 05:46:32PM -0700, Darrick J. Wong wrote: > On Tue, Aug 10, 2021 at 03:28:51PM +1000, Dave Chinner wrote: > > From: Dave Chinner > > > > TO stop external users from using b_bn as the disk address of the > > buffer, rename it to b_index to indicate that it is the buffer cache > > index, not the block number of the buffer. Code that needs the disk > > address should use xfs_buf_daddr() to obtain it. > > > > Do the rename and clean up any of the remaining b_bn cruft that is > > left over and is now unused. > > > > Signed-off-by: Dave Chinner > > --- > > fs/xfs/xfs_buf.c | 19 +++++++++++-------- > > fs/xfs/xfs_buf.h | 18 +----------------- > > 2 files changed, 12 insertions(+), 25 deletions(-) > > > > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > > index c1bb6e41595b..6f6c6937baaa 100644 > > --- a/fs/xfs/xfs_buf.c > > +++ b/fs/xfs/xfs_buf.c > > @@ -251,7 +251,7 @@ _xfs_buf_alloc( > > return error; > > } > > > > - bp->b_bn = map[0].bm_bn; > > + bp->b_index = map[0].bm_bn; > > bp->b_length = 0; > > for (i = 0; i < nmaps; i++) { > > bp->b_maps[i].bm_bn = map[i].bm_bn; > > @@ -459,7 +459,7 @@ _xfs_buf_obj_cmp( > > */ > > BUILD_BUG_ON(offsetof(struct xfs_buf_map, bm_bn) != 0); > > > > - if (bp->b_bn != map->bm_bn) > > + if (bp->b_index != map->bm_bn) > > return 1; > > > > if (unlikely(bp->b_length != map->bm_len)) { > > @@ -481,7 +481,7 @@ static const struct rhashtable_params xfs_buf_hash_params = { > > .min_size = 32, /* empty AGs have minimal footprint */ > > .nelem_hint = 16, > > .key_len = sizeof(xfs_daddr_t), > > - .key_offset = offsetof(struct xfs_buf, b_bn), > > + .key_offset = offsetof(struct xfs_buf, b_index), > > I would've called this field b_rhash_key, since "index" is a kind of > vague. Ok. > > @@ -875,7 +877,7 @@ xfs_buf_read_uncached( > > > > /* set up the buffer for a read IO */ > > ASSERT(bp->b_map_count == 1); > > - bp->b_bn = XFS_BUF_DADDR_NULL; /* always null for uncached buffers */ > > + bp->b_index = XFS_BUF_DADDR_NULL; > > bp->b_maps[0].bm_bn = daddr; > > bp->b_flags |= XBF_READ; > > bp->b_ops = ops; > > @@ -1513,7 +1515,7 @@ _xfs_buf_ioapply( > > SHUTDOWN_CORRUPT_INCORE); > > return; > > } > > - } else if (bp->b_bn != XFS_BUF_DADDR_NULL) { > > + } else if (bp->b_index != XFS_BUF_DADDR_NULL) { > > struct xfs_mount *mp = bp->b_mount; > > > > /* > > @@ -1523,7 +1525,8 @@ _xfs_buf_ioapply( > > if (xfs_has_crc(mp)) { > > xfs_warn(mp, > > "%s: no buf ops on daddr 0x%llx len %d", > > - __func__, bp->b_bn, bp->b_length); > > + __func__, xfs_buf_daddr(bp), > > + bp->b_length); > > xfs_hex_dump(bp->b_addr, > > XFS_CORRUPTION_DUMP_LEN); > > dump_stack(); > > @@ -1793,7 +1796,7 @@ xfs_buftarg_drain( > > xfs_buf_alert_ratelimited(bp, > > "XFS: Corruption Alert", > > "Corruption Alert: Buffer at daddr 0x%llx had permanent write failures!", > > - (long long)bp->b_bn); > > + (long long)xfs_buf_daddr(bp)); > > These belong in the previous patch, right? Depends on your POV. This patch cleans up all the internal (mis)uses of b_bn, while the previous patches addressed all the external uses. The mods could be in either, I just chose to split internal/external modification based on the file rather than on the specific (ab)use being corrected.... Cheers, Dave. -- Dave Chinner david@fromorbit.com