On Wed, Oct 12, 2016 at 10:42:46AM -0400, Chris Mason wrote: > On 10/12/2016 10:40 AM, Dave Jones wrote: > > On Wed, Oct 12, 2016 at 09:47:17AM -0400, Dave Jones wrote: > > > On Tue, Oct 11, 2016 at 11:54:09AM -0400, Chris Mason wrote: > > > > > > > > > > > > On 10/11/2016 10:45 AM, Dave Jones wrote: > > > > > This is from Linus' current tree, with Al's iovec fixups on top. > > > > > > > > > > ------------[ cut here ]------------ > > > > > WARNING: CPU: 1 PID: 3673 at lib/list_debug.c:33 > > __list_add+0x89/0xb0 > > > > > list_add corruption. prev->next should be next (ffffe8ffff806648), > > but was ffffc9000067fcd8. (prev=ffff880503878b80). > > > > > CPU: 1 PID: 3673 Comm: trinity-c0 Not tainted 4.8.0-think+ #13 > > > > > ffffc90000d87458 ffffffff8d32007c ffffc90000d874a8 > > 0000000000000000 > > > > > ffffc90000d87498 ffffffff8d07a6c1 0000002100000246 > > ffff88050388e880 > > > > > > I hit this again overnight, it's the same trace, the only difference > > > being slightly different addresses in the list pointers: > > > > > > [42572.777196] list_add corruption. prev->next should be next > > (ffffe8ffff806648), but was ffffc90000647cd8. (prev=ffff880503a0ba00). > > > > > > I'm actually a little surprised that ->next was the same across two > > > reboots on two different kernel builds. That might be a sign this is > > > more repeatable than I'd thought, even if it does take hours of runtime > > > right now to trigger it. I'll try and narrow the scope of what trinity > > > is doing to see if I can make it happen faster. > > > > .. and of course the first thing that happens is a completely different > > btrfs trace.. > > > > > > WARNING: CPU: 1 PID: 21706 at fs/btrfs/transaction.c:489 > > start_transaction+0x40a/0x440 [btrfs] > > CPU: 1 PID: 21706 Comm: trinity-c16 Not tainted 4.8.0-think+ #14 > > ffffc900019076a8 ffffffffb731ff3c 0000000000000000 0000000000000000 > > ffffc900019076e8 ffffffffb707a6c1 000001e9f5806ce0 ffff8804f74c4d98 > > 0000000000000801 ffff880501cfa2a8 000000000000008a 000000000000008a > > This isn't even IO. Uuughhhh. We're going to need a fast enough test > that we can bisect.
Progress... I've found that this combination of syscalls.. ./trinity -C64 -q -l off -a64 --enable-fds=testfile -c fsync -c fsetxattr -c lremovexattr -c pwritev2 hits one of these two bugs in a few minutes runtime. Just the xattr syscalls + fsync isn't enough, neither is just pwrite + fsync. Mix them together though, and something goes awry. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html