Re: [patch 003/152] jbd: fix commit of ordered data buffers

[Badari Pulavarty <pbadari@us.ibm.com>]

On Fri, 2006-09-29 at 11:02 +0200, Jan Kara wrote:
...
> > >+		}
> > >+		/* Someone already cleaned up the buffer? */
> > >+		if (!buffer_jbd(bh)
> > >+			|| jh->b_transaction != commit_transaction
> > >+			|| jh->b_jlist != BJ_SyncData) {
> > >+			jbd_unlock_bh_state(bh);
> > >+			if (locked)
> > >+				unlock_buffer(bh);
> > >+			BUFFER_TRACE(bh, "already cleaned up");
> > >+			put_bh(bh);
> > >+			continue;
>    ---> Here the buffer was refiled by someone else

I am little concerned about this particular code. We know that
some one else will do the unfile/remove - but we will keep
spinning on it till that happens. Isn't it ? Why don't we
skip it and move to next one ?

We are seeing few following message while running tests and
wondering if your patch is causing it ..

BUG: spinlock lockup on CPU#1, scp/30189, c00000000fb503d8 (Not tainted)
Call Trace:
[C000000018FDB320] [C0000000000102E0] .show_stack+0x68/0x1b0 (unreliable)
[C000000018FDB3C0] [C0000000001734F4] ._raw_spin_lock+0x138/0x184
[C000000018FDB460] [C00000000025AD24] ._spin_lock+0x10/0x24
[C000000018FDB4E0] [D000000000172E14] .journal_dirty_data+0xa4/0x2c0 [jbd]
[C000000018FDB580] [D000000000205BAC] .ext3_journal_dirty_data+0x28/0x70 [ext3]
[C000000018FDB610] [D0000000002048BC] .walk_page_buffers+0xb0/0x134 [ext3]
[C000000018FDB6D0] [D000000000208280] .ext3_ordered_commit_write+0x74/0x114 
[ext
3]
[C000000018FDB780] [C00000000007E710] .generic_file_buffered_write+0x51c/0x794
[C000000018FDB930] 
[C00000000007ECB8] .__generic_file_aio_write_nolock+0x330/0x3
bc
[C000000018FDBA20] [C00000000007EDBC] .generic_file_aio_write+0x78/0x104
[C000000018FDBAE0] [D000000000202EFC] .ext3_file_write+0x2c/0xd4 [ext3]
[C000000018FDBB70] [C0000000000A8090] .do_sync_write+0xd4/0x130
[C000000018FDBCF0] [C0000000000A8E14] .vfs_write+0x118/0x200
[C000000018FDBD90] [C0000000000A9584] .sys_write+0x4c/0x8c
[C000000018FDBE30] [C000000000008434] syscall_exit+0x0/0x40

Thanks,
Badari