Date: Fri, 25 Jan 2013 18:09:50 +0100 From: Christian Gusenbauer <c47g@gmx.at> To: pyunyh@gmail.com Cc: freebsd-fs@freebsd.org, Konstantin Belousov <kostikbel@gmail.com>, net@freebsd.org, John Baldwin <jhb@freebsd.org>, yongari@freebsd.org Subject: Re: 9.1-stable crashes while copying data from a NFS mounted directory Message-ID: <201301251809.50929.c47g@gmx.at> In-Reply-To: <20130125045048.GB1429@michelle.cdnetworks.com> References: <201301241805.57623.c47g@gmx.at> <20130125043043.GA1429@michelle.cdnetworks.com> <20130125045048.GB1429@michelle.cdnetworks.com>
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On Friday 25 January 2013 05:50:48 YongHyeon PYUN wrote:
> On Fri, Jan 25, 2013 at 01:30:43PM +0900, YongHyeon PYUN wrote:
> > On Thu, Jan 24, 2013 at 05:21:50PM -0500, John Baldwin wrote:
> > > On Thursday, January 24, 2013 4:22:12 pm Konstantin Belousov wrote:
> > > > On Thu, Jan 24, 2013 at 09:50:52PM +0100, Christian Gusenbauer wrote:
> > > > > On Thursday 24 January 2013 20:37:09 Konstantin Belousov wrote:
> > > > > > On Thu, Jan 24, 2013 at 07:50:49PM +0100, Christian Gusenbauer
wrote:
> > > > > > > On Thursday 24 January 2013 19:07:23 Konstantin Belousov wrote:
> > > > > > > > On Thu, Jan 24, 2013 at 08:03:59PM +0200, Konstantin Belousov
wrote:
> > > > > > > > > On Thu, Jan 24, 2013 at 06:05:57PM +0100, Christian
Gusenbauer wrote:
> > > > > > > > > > Hi!
> > > > > > > > > >
> > > > > > > > > > I'm using 9.1 stable svn revision 245605 and I get the
> > > > > > > > > > panic below if I execute the following commands (as
> > > > > > > > > > single user):
> > > > > > > > > >
> > > > > > > > > > # swapon -a
> > > > > > > > > > # dumpon /dev/ada0s3b
> > > > > > > > > > # mount -u /
> > > > > > > > > > # ifconfig age0 inet 192.168.2.2 mtu 6144 up
> > > > > > > > > > # mount -t nfs -o rsize=32768 data:/multimedia /mnt
> > > > > > > > > > # cp /mnt/Movies/test/a.m2ts /tmp
> > > > > > > > > >
> > > > > > > > > > then the system panics almost immediately. I'll attach
> > > > > > > > > > the stack trace.
> > > > > > > > > >
> > > > > > > > > > Note, that I'm using jumbo frames (6144 byte) on a 1Gbit
> > > > > > > > > > network, maybe that's the cause for the panic, because
> > > > > > > > > > the bcopy (see stack frame #15) fails.
> > > > > > > > > >
> > > > > > > > > > Any clues?
> > > > > > > > >
> > > > > > > > > I tried a similar operation with the nfs mount of
> > > > > > > > > rsize=32768 and mtu 6144, but the machine runs HEAD and em
> > > > > > > > > instead of age. I was unable to reproduce the panic on the
> > > > > > > > > copy of the 5GB file from nfs mount.
> > > > > > >
> > > > > > > Hmmm, I did a quick test. If I do not change the MTU, so just
> > > > > > > configuring age0 with
> > > > > > >
> > > > > > > # ifconfig age0 inet 192.168.2.2 up
> > > > > > >
> > > > > > > then I can copy all files from the mounted directory without
> > > > > > > any problems, too. So it's probably age0 related?
> > > > > >
> > > > > > From your backtrace and the buffer printout, I see somewhat
> > > > > > strange thing. The buffer data address is 0xffffff8171418000,
> > > > > > while kernel faulted at the attempt to write at
> > > > > > 0xffffff8171413000, which is is lower then the buffer data
> > > > > > pointer, at the attempt to bcopy to the buffer.
> > > > > >
> > > > > > The other data suggests that there were no overflow of the data
> > > > > > from the server response. So it might be that mbuf_len(mp)
> > > > > > returned negative number ? I am not sure is it possible at all.
> > > > > >
> > > > > > Try this debugging patch, please. You need to add INVARIANTS etc
> > > > > > to the kernel config.
> > > > > >
> > > > > > diff --git a/sys/fs/nfs/nfs_commonsubs.c
> > > > > > b/sys/fs/nfs/nfs_commonsubs.c index efc0786..9a6bda5 100644
> > > > > > --- a/sys/fs/nfs/nfs_commonsubs.c
> > > > > > +++ b/sys/fs/nfs/nfs_commonsubs.c
> > > > > > @@ -218,6 +218,7 @@ nfsm_mbufuio(struct nfsrv_descript *nd,
> > > > > > struct uio *uiop, int siz) }
> > > > > >
> > > > > > mbufcp = NFSMTOD(mp, caddr_t);
> > > > > > len = mbuf_len(mp);
> > > > > >
> > > > > > + KASSERT(len > 0, ("len %d", len));
> > > > > >
> > > > > > }
> > > > > > xfer = (left > len) ? len : left;
> > > > > >
> > > > > > #ifdef notdef
> > > > > >
> > > > > > @@ -239,6 +240,8 @@ nfsm_mbufuio(struct nfsrv_descript *nd,
> > > > > > struct uio *uiop, int siz) uiop->uio_resid -= xfer;
> > > > > >
> > > > > > }
> > > > > > if (uiop->uio_iov->iov_len <= siz) {
> > > > > >
> > > > > > + KASSERT(uiop->uio_iovcnt > 1, ("uio_iovcnt %d",
> > > > > > + uiop->uio_iovcnt));
> > > > > >
> > > > > > uiop->uio_iovcnt--;
> > > > > > uiop->uio_iov++;
> > > > > >
> > > > > > } else {
> > > > > >
> > > > > > I thought that server have returned too long response, but it
> > > > > > seems to be not the case from your data. Still, I think the
> > > > > > patch below might be due.
> > > > > >
> > > > > > diff --git a/sys/fs/nfsclient/nfs_clrpcops.c
> > > > > > b/sys/fs/nfsclient/nfs_clrpcops.c index be0476a..a89b907 100644
> > > > > > --- a/sys/fs/nfsclient/nfs_clrpcops.c
> > > > > > +++ b/sys/fs/nfsclient/nfs_clrpcops.c
> > > > > > @@ -1444,7 +1444,7 @@ nfsrpc_readrpc(vnode_t vp, struct uio
> > > > > > *uiop, struct ucred *cred, NFSM_DISSECT(tl, u_int32_t *,
> > > > > > NFSX_UNSIGNED);
> > > > > >
> > > > > > eof = fxdr_unsigned(int, *tl);
> > > > > >
> > > > > > }
> > > > > >
> > > > > > - NFSM_STRSIZ(retlen, rsize);
> > > > > > + NFSM_STRSIZ(retlen, len);
> > > > > >
> > > > > > error = nfsm_mbufuio(nd, uiop, retlen);
> > > > > > if (error)
> > > > > >
> > > > > > goto nfsmout;
> > > > >
> > > > > I applied your patches and now I get a
> > > > >
> > > > > panic: len -4
> > > > > cpuid = 1
> > > > > KDB: enter: panic
> > > > > Dumping 377 out of 6116
> > > > > MB:..5%..13%..22%..34%..43%..51%..64%..73%..81%..94%
> > > >
> > > > This means that the age driver either produced corrupted mbuf chain,
> > > > or filled wrong negative value into the mbuf len field. I am quite
> > > > certain that the issue is in the driver.
> > > >
> > > > I added the net@ to Cc:, hopefully you could get help there.
> > >
> > > And I've cc'd Pyun who has written most of this driver and is likely
> > > the one most familiar with its handling of jumbo frames.
> >
> > Try attached one and let me know how it goes.
> > Note, I don't have age(4) anymore so it wasn't tested at all.
>
> Sorry, ignore previous patch and use this one(age.diff2) instead.
Thanks for the patch! I ignored the first and applied only the second one, but
unfortunately that did not change anything. I still get the "panic: len -4"
:-(.
Ciao,
Christian.
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