On Tue, Apr 27, 2021 at 09:13:18PM +0800, Gao Xiang wrote: > On Tue, Apr 27, 2021 at 08:46:25AM -0400, Brian Foster wrote: > > 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? > > This patch inherited from Dave's patch [1] (and I added reproduable > steps), > https://lore.kernel.org/r/20210422014446.GZ63242@xxxxxxxxxxxxxxxxxxx > > More details see my original patch v2: > https://lore.kernel.org/r/20210420110855.2961626-1-hsiangkao@xxxxxxxxxx > Ok, thanks. So the bit about xfs_log_sb() is to avoid an incorrect overwrite of the in-core sb counters from the percpu counters on !lazysbcount. The xfs_trans_apply_sb_deltas() function already applies the transaction deltas to the on-disk superblock buffer, so the change to xfs_trans_unreserve_and_mod_sb() is basically to apply those same deltas to the in-core superblock so they are consistent in the !lazysbcount case... yes? If I'm following that correctly, this looks good to me: Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx> > Thanks, > Gao Xiang > > > > > 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 > > > > > >
