On Tue, Feb 05, 2013 at 10:53:00AM -0500, valdis.kletni...@vt.edu wrote: > On Thu, 31 Jan 2013 16:37:27 -0800, Kent Overstreet said: > > On Thu, Jan 31, 2013 at 01:59:52PM -0800, Andrew Morton wrote: > > > Did this get fixed? > > > With the patches I sent you, yes - not seeing a new linux-next tree yet? > > Well, it's a mixed bag at my end. Finally got a chance to do some more > testing, and: > > 1) next-20130128 didn't show anything in dmesg, but my VirtualBox Windows 7 > images appear to livelock on the way up - the Windows throbber would keep > going, but it never made any actual progress towards booting. (Part of the > delay was fixing a next-20121224 environment, and then discovering it > took Windows *two* reboot cycles to get its act back together after getting > into that hung state). > > 2_ next-20130128 plus the following 3 patches: > > Subject: [PATCH 1/3] aio: Fix a null pointer deref in batch_complete_aio > Subject: [PATCH 3/3] aio-use-cancellation-list-lazily-fix > Subject: [PATCH 2/3] aio-kill-ki_retry-fix-fix
The "smoosh struct kiocb" patch also needs to be dropped. That causes aio_rw_vect_retry() to check ki_nbytes/ki_left after they've been overwritten by aio_complete(), which causes it to return an error when it shouldn't have, which causes aio_run_iocb() to double complete the iocb causing put_reqs_available() to be called twice and the count screwed up. > VirtualBox appears to be functional (I did 2 complete boot/shutdown > sequences of both a 32-bit and 64-bit Win7 Enterprise image). *HOWEVER*, > I saw 3 of these in dmesg: > > [ 668.278624] WARNING: at fs/aio.c:348 put_ioctx+0x1c0/0x241() > > [ 668.278652] Call Trace: > [ 668.278660] [<ffffffff8102ed10>] warn_slowpath_common+0x7c/0x96 > [ 668.278665] [<ffffffff8102edc9>] warn_slowpath_null+0x15/0x17 > [ 668.278669] [<ffffffff8114c562>] put_ioctx+0x1c0/0x241 > [ 668.278673] [<ffffffff8114d42a>] sys_io_destroy+0x4c/0x5c > [ 668.278679] [<ffffffff8160c112>] system_call_fastpath+0x16/0x1b > > and the code there says: > > WARN_ON(atomic_read(&ctx->reqs_available) > ctx->nr); > > which leaves me wondering exactly how we exited the while loop > just above - is the intention that it loop until reqs_available == ctx->nr > exactly? Looks like if 'avail' is anything other than exactly 1 in > that while loop, we can be at a state where reqs_avail == (ctx->nr -1), > get 'avail=2', do the atomic_add, fall out of the loop, and trigger > the WARN_ON. > > Damned if I see how that can happen though.... > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
