On Wed, Nov 07, 2018 at 08:55:08AM -0800, Darrick J. Wong wrote:
> On Wed, Nov 07, 2018 at 05:31:14PM +1100, Dave Chinner wrote:
> > From: Dave Chinner <dchinner@xxxxxxxxxx>
> >
> > The last AG may be very small comapred to all other AGs, and hence
> > AG reservations based on the superblock AG size may actually consume
> > more space than the AG actually has. This results on assert failures
> > like:
> >
> > XFS: Assertion failed: xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved + xfs_perag_resv(pag, XFS_AG_RESV_RMAPBT)->ar_reserved <= pag->pagf_freeblks + pag->pagf_flcount, file: fs/xfs/libxfs/xfs_ag_resv.c, line: 319
> > [ 48.932891] xfs_ag_resv_init+0x1bd/0x1d0
> > [ 48.933853] xfs_fs_reserve_ag_blocks+0x37/0xb0
> > [ 48.934939] xfs_mountfs+0x5b3/0x920
> > [ 48.935804] xfs_fs_fill_super+0x462/0x640
> > [ 48.936784] ? xfs_test_remount_options+0x60/0x60
> > [ 48.937908] mount_bdev+0x178/0x1b0
> > [ 48.938751] mount_fs+0x36/0x170
> > [ 48.939533] vfs_kern_mount.part.43+0x54/0x130
> > [ 48.940596] do_mount+0x20e/0xcb0
> > [ 48.941396] ? memdup_user+0x3e/0x70
> > [ 48.942249] ksys_mount+0xba/0xd0
> > [ 48.943046] __x64_sys_mount+0x21/0x30
> > [ 48.943953] do_syscall_64+0x54/0x170
> > [ 48.944835] entry_SYSCALL_64_after_hwframe+0x49/0xbe
> >
> > Hence we need to ensure the finobt per-ag space reservations take
> > into account the size of the last AG rather than treat it like all
> > the other full size AGs.
> >
> > Note that both refcountbt and rmapbt already take the size of the AG
> > into account via reading the AGF length directly.
> >
> > Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> > ---
> > fs/xfs/libxfs/xfs_ialloc_btree.c | 17 +++++++++++++----
> > 1 file changed, 13 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
> > index 86c50208a143..62014780d5e4 100644
> > --- a/fs/xfs/libxfs/xfs_ialloc_btree.c
> > +++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
> > @@ -538,15 +538,24 @@ xfs_inobt_rec_check_count(
> >
> > static xfs_extlen_t
> > xfs_inobt_max_size(
> > - struct xfs_mount *mp)
> > + struct xfs_mount *mp,
> > + xfs_agnumber_t agno)
> > {
> > + uint32_t agblocks = mp->m_sb.sb_agblocks;
> > +
> > /* Bail out if we're uninitialized, which can happen in mkfs. */
> > if (mp->m_inobt_mxr[0] == 0)
> > return 0;
> >
> > + /* last AG can be a runt */
> > + if (agno == mp->m_sb.sb_agcount - 1) {
> > + div_u64_rem(mp->m_sb.sb_dblocks, mp->m_sb.sb_agblocks,
> > + &agblocks);
> > + }
>
> Why not: agblocks = xfs_ag_block_count(mp, agno); ?
>
forgot about that function :)
Will fix.
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
