From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2130.oracle.com ([156.151.31.86]:46082 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933931AbeFGQCN (ORCPT ); Thu, 7 Jun 2018 12:02:13 -0400 Date: Thu, 7 Jun 2018 09:01:57 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH 2/3] xfs: replace do_mod with native operations Message-ID: <20180607160157.GL25007@magnolia> References: <20180607052751.6541-1-david@fromorbit.com> <20180607052751.6541-3-david@fromorbit.com> <20180607114204.GD7798@bfoster> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180607114204.GD7798@bfoster> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Brian Foster Cc: Dave Chinner , linux-xfs@vger.kernel.org On Thu, Jun 07, 2018 at 07:42:05AM -0400, Brian Foster wrote: > On Thu, Jun 07, 2018 at 03:27:50PM +1000, Dave Chinner wrote: > > From: Dave Chinner > > > > do_mod() is a hold-over from when we have different sizes for file > > offsets and and other internal values for 40 bit XFS filesystems. > > Hence depending on build flags variables passed to do_mod() could > > change size. We no longer support those small format filesystems and > > hence everything is of fixed size theses days, even on 32 bit > > platforms. > > > > As such, we can convert all the do_mod() callers to platform > > optimised modulus operations as defined by linux/math64.h. > > Individual conversions depend on the types of variables being used. > > > > Signed-Off-By: Dave Chinner > > --- > > fs/xfs/libxfs/xfs_bmap.c | 37 +++++++++++++++++++++++-------------- > > fs/xfs/xfs_bmap_util.c | 14 +++++++++----- > > fs/xfs/xfs_inode.c | 2 +- > > fs/xfs/xfs_iomap.h | 4 ++-- > > fs/xfs/xfs_linux.h | 19 ------------------- > > fs/xfs/xfs_log_recover.c | 32 +++++++++++++++++++++++++------- > > fs/xfs/xfs_rtalloc.c | 15 +++++++++++---- > > 7 files changed, 71 insertions(+), 52 deletions(-) > > > ... > > diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c > > index 7d897c58b0c8..4405ff21f9a9 100644 > > --- a/fs/xfs/xfs_log_recover.c > > +++ b/fs/xfs/xfs_log_recover.c > > @@ -1235,6 +1235,25 @@ xlog_verify_head( > > be32_to_cpu((*rhead)->h_size)); > > } > > > > +/* > > + * We need to make sure we handle log wrapping properly, so we can't use teh > > + * calculated logbno directly. Make sure it wraps to teh correct bno inside teh > > + * log. > > + * > > s/teh/the/ > > > + * The log is limited to 32 bit sizes, so we use the appropriate modulus > > + * operation here and cast it back to a 64 bit daddr on return. > > + */ > > +static inline xfs_daddr_t > > +xlog_wrap_logbno( > > + struct xlog *log, > > + xfs_daddr_t bno) > > +{ > > + int mod; > > + > > + div_s64_rem(bno, log->l_logBBsize, &mod); > > + return mod; > > +} > > + > > /* > > * Check whether the head of the log points to an unmount record. In other > > * words, determine whether the log is clean. If so, update the in-core state > ... > > diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c > > index 80bbfe604ce0..776502a5dcb7 100644 > > --- a/fs/xfs/xfs_rtalloc.c > > +++ b/fs/xfs/xfs_rtalloc.c > ... > > @@ -1262,8 +1266,11 @@ xfs_rtpick_extent( > > resid = seq - (1ULL << log2); > > b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >> > > (log2 + 1); > > - if (b >= mp->m_sb.sb_rextents) > > - b = do_mod(b, mp->m_sb.sb_rextents); > > + if (b >= mp->m_sb.sb_rextents) { > > + xfs_rtblock_t mod; > > + div64_u64_rem(b, mp->m_sb.sb_rextents, &mod); > > + b = mod; > > + } > > Shouldn't we be able to do 'div64_u64_rem(b, mp->m_sb.sb_rextents, &b)' > here? Otherwise looks fine: I think Dave is trying to avoid aliasing the arguments in case div64_u64_rem ever gets turned into a horrible macro (or over-optimized by gcc) --D > > Reviewed-by: Brian Foster > > > if (b + len > mp->m_sb.sb_rextents) > > b = mp->m_sb.sb_rextents - len; > > } > > -- > > 2.17.0 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html