On Sat 19-10-19 15:19:33, Theodore Y. Ts'o wrote: > Hi Jan, > > I've tried applying this patch set against 5.4-rc3, and I'm finding a > easily reproducible failure using: > > kvm-xfstests -c ext3conv ext4/039 > > It is the BUG_ON in fs/jbd2/commit.c, around line 570: > > J_ASSERT(commit_transaction->t_nr_buffers <= > atomic_read(&commit_transaction->t_outstanding_credits)); > > The failure (with the obvious debugging printk added) is: > > ext4/039 [15:13:16][ 6.747101] run fstests ext4/039 at 2019-10 > -19 15:13:16 > [ 7.018766] Mounted ext4 file system at /vdc supports timestamps until 2038 ( > 0x7fffffff) > [ 8.227631] JBD2: t_nr_buffers 226, t_outstanding_credits=223 > [ 8.229215] ------------[ cut here ]------------ > [ 8.230249] kernel BUG at fs/jbd2/commit.c:573! > ... > > The full log is attached (although the stack trace isn't terribly > interesting, since this is being run out of kjournald2). Thanks! Somehow this escaped my testing although I thought I have run ext3 configuration... Anyway we are reserving too few space in this case - with some debugging added: [ 80.296029] t_buffers: 222, t_outstanding_credits: 219, t_revoke_written: 23, t_revoke_reserved: 12, t_revoke_records_written 11432, t_revoke_records_reserved 11432, revokes_per_block: 1020 Which is really puzzling because it would suggest that revokes_per_block is actually wrong. Digging more into this. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
