On Sat, Jan 15, 2011 at 3:08 AM, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > Hi Nick- > > On Jan 13, 2011, at 8:29 PM, Nick Piggin wrote: > >> Hi Trond, >> >> I'm getting use after frees in aio code in NFS > > Can you describe how to reproduce this? It was with the aio-dio stress code from xfstests, #207 I think or 208. Running it for a short time and then ^C ing it would tend to trigger it. I'll have to get you more details after I come back from travelling in a week's time. > >> [ 2703.396766] Call Trace: >> [ 2703.396858] [<ffffffff8100b057>] ? native_sched_clock+0x27/0x80 >> [ 2703.396959] [<ffffffff8108509e>] ? put_lock_stats+0xe/0x40 >> [ 2703.397058] [<ffffffff81088348>] ? lock_release_holdtime+0xa8/0x140 >> [ 2703.397159] [<ffffffff8108a2a5>] lock_acquire+0x95/0x1b0 >> [ 2703.397260] [<ffffffff811627db>] ? aio_put_req+0x2b/0x60 >> [ 2703.397361] [<ffffffff81039701>] ? get_parent_ip+0x11/0x50 >> [ 2703.397464] [<ffffffff81612a31>] _raw_spin_lock_irq+0x41/0x80 >> [ 2703.397564] [<ffffffff811627db>] ? aio_put_req+0x2b/0x60 >> [ 2703.397662] [<ffffffff811627db>] aio_put_req+0x2b/0x60 >> [ 2703.397761] [<ffffffff811647fe>] do_io_submit+0x2be/0x7c0 >> [ 2703.397895] [<ffffffff81164d0b>] sys_io_submit+0xb/0x10 >> [ 2703.397995] [<ffffffff8100307b>] system_call_fastpath+0x16/0x1b >> >> Adding some tracing, it is due to nfs completing the request then >> returning something other than -EIOCBQUEUED, so aio.c >> also completes the request. > > Is this with reads, writes, or both? Are the I/O requests smaller than, equal to, or larger than rsize or wsize? > > We have a related bug report: hitting the BUG at fs/aio.c:552 (OEL5) and similar for more recent kernels. Looks like dreq refcounting is faulty somehow. I only saw it with writes. The request was being completed in nfs direct write path when I added some tracing. It was very easy to reproduce, I just didn't have time to bisect it, but I can do that when I get back if you don't have it solved by then. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
