On Tue, Apr 27, 2021 at 09:12:01AM +0800, Gao Xiang wrote: > From: Dave Chinner <dchinner@xxxxxxxxxx> > > Keep the mount superblock counters up to date for !lazysbcount > filesystems so that when we log the superblock they do not need > updating in any way because they are already correct. > > It's found by what Zorro reported: > 1. mkfs.xfs -f -l lazy-count=0 -m crc=0 $dev > 2. mount $dev $mnt > 3. fsstress -d $mnt -p 100 -n 1000 (maybe need more or less io load) > 4. umount $mnt > 5. xfs_repair -n $dev > and I've seen no problem with this patch. > > Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> > Reported-by: Zorro Lang <zlang@xxxxxxxxxx> > Reviewed-by: Gao Xiang <hsiangkao@xxxxxxxxxx> > Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxx> > --- Could you provide a bit more detail on the problem in the commit log? >From the description and code change, it seems like there is some problem with doing the percpu aggregation in xfs_log_sb() on !lazysbcount filesystems. Therefore this patch reserves that behavior for lazysbcount, and instead enables per-transaction updates in the !lazysbcount specific cleanup path. Am I following that correctly? Brian > > As per discussion earilier [1], use the way Dave suggested instead. > Also update the line to > mp->m_sb.sb_fdblocks += tp->t_fdblocks_delta + tp->t_res_fdblocks_delta; > so it can fix the case above. > > with XFS debug off, xfstests auto testcases fail on my loop-device-based > testbed with this patch and Darrick's [2]: > > generic/095 generic/300 generic/600 generic/607 xfs/073 xfs/148 xfs/273 > xfs/293 xfs/491 xfs/492 xfs/495 xfs/503 xfs/505 xfs/506 xfs/514 xfs/515 > > MKFS_OPTIONS="-mcrc=0 -llazy-count=0" > > and these testcases above still fail without these patches or with > XFS debug on, so I've seen no regression due to this patch. > > [1] https://lore.kernel.org/r/20210422030102.GA63242@xxxxxxxxxxxxxxxxxxx/ > [2] https://lore.kernel.org/r/20210425154634.GZ3122264@magnolia/ > > fs/xfs/libxfs/xfs_sb.c | 16 +++++++++++++--- > fs/xfs/xfs_trans.c | 3 +++ > 2 files changed, 16 insertions(+), 3 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c > index 60e6d255e5e2..dfbbcbd448c1 100644 > --- a/fs/xfs/libxfs/xfs_sb.c > +++ b/fs/xfs/libxfs/xfs_sb.c > @@ -926,9 +926,19 @@ xfs_log_sb( > struct xfs_mount *mp = tp->t_mountp; > struct xfs_buf *bp = xfs_trans_getsb(tp); > > - mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount); > - mp->m_sb.sb_ifree = percpu_counter_sum(&mp->m_ifree); > - mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks); > + /* > + * Lazy sb counters don't update the in-core superblock so do that now. > + * If this is at unmount, the counters will be exactly correct, but at > + * any other time they will only be ballpark correct because of > + * reservations that have been taken out percpu counters. If we have an > + * unclean shutdown, this will be corrected by log recovery rebuilding > + * the counters from the AGF block counts. > + */ > + if (xfs_sb_version_haslazysbcount(&mp->m_sb)) { > + mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount); > + mp->m_sb.sb_ifree = percpu_counter_sum(&mp->m_ifree); > + mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks); > + } > > xfs_sb_to_disk(bp->b_addr, &mp->m_sb); > xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF); > diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c > index bcc978011869..1e37aa8eca5a 100644 > --- a/fs/xfs/xfs_trans.c > +++ b/fs/xfs/xfs_trans.c > @@ -629,6 +629,9 @@ xfs_trans_unreserve_and_mod_sb( > > /* apply remaining deltas */ > spin_lock(&mp->m_sb_lock); > + mp->m_sb.sb_fdblocks += tp->t_fdblocks_delta + tp->t_res_fdblocks_delta; > + mp->m_sb.sb_icount += idelta; > + mp->m_sb.sb_ifree += ifreedelta; > mp->m_sb.sb_frextents += rtxdelta; > mp->m_sb.sb_dblocks += tp->t_dblocks_delta; > mp->m_sb.sb_agcount += tp->t_agcount_delta; > -- > 2.27.0 >
