9.1-stable crashes while copying data from a NFS mounted directory
Konstantin Belousov
kostikbel at gmail.com
Thu Jan 24 21:22:20 UTC 2013
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.
>
> #0 doadump (textdump=0)
> at /spare/tmp/src-stable9/sys/kern/kern_shutdown.c:265
> 265 if (textdump && textdump_pending) {
> (kgdb) #0 doadump (textdump=0)
> at /spare/tmp/src-stable9/sys/kern/kern_shutdown.c:265
> #1 0xffffffff802a7490 in db_dump (dummy=<value optimized out>,
> dummy2=<value optimized out>, dummy3=<value optimized out>,
> dummy4=<value optimized out>)
> at /spare/tmp/src-stable9/sys/ddb/db_command.c:538
> #2 0xffffffff802a6a7e in db_command (last_cmdp=0xffffffff808ca140,
> cmd_table=<value optimized out>, dopager=1)
> at /spare/tmp/src-stable9/sys/ddb/db_command.c:449
> #3 0xffffffff802a6cd0 in db_command_loop ()
> at /spare/tmp/src-stable9/sys/ddb/db_command.c:502
> #4 0xffffffff802a8e29 in db_trap (type=<value optimized out>,
> code=<value optimized out>)
> at /spare/tmp/src-stable9/sys/ddb/db_main.c:231
> #5 0xffffffff803bf548 in kdb_trap (type=3, code=0, tf=0xffffff81b2ba1080)
> at /spare/tmp/src-stable9/sys/kern/subr_kdb.c:649
> #6 0xffffffff80594c28 in trap (frame=0xffffff81b2ba1080)
> at /spare/tmp/src-stable9/sys/amd64/amd64/trap.c:579
> #7 0xffffffff8057e06f in calltrap ()
> at /spare/tmp/src-stable9/sys/amd64/amd64/exception.S:228
> #8 0xffffffff803beffb in kdb_enter (why=0xffffffff8060ebcf "panic",
> msg=0x80 <Address 0x80 out of bounds>) at cpufunc.h:63
> #9 0xffffffff80389391 in panic (fmt=<value optimized out>)
> at /spare/tmp/src-stable9/sys/kern/kern_shutdown.c:627
> #10 0xffffffff81e5bab2 in nfsm_mbufuio (nd=0xffffff81b2ba1340, uiop=0x7cf,
> siz=18)
> at /spare/tmp/src-stable9/sys/modules/nfscommon/../../fs/nfs/nfs_commonsubs.c:202
> #11 0xffffffff81e195c1 in nfsrpc_read (vp=0xfffffe0006c94dc8,
> uiop=0xffffff81b2ba15c0, cred=<value optimized out>,
> p=0xfffffe0006aa6490, nap=0xffffff81b2ba14a0,
> attrflagp=0xffffff81b2ba156c, stuff=0x0)
> at /spare/tmp/src-stable9/sys/modules/nfscl/../../fs/nfsclient/nfs_clrpcops.c:1343
> #12 0xffffffff81e3bd80 in ncl_readrpc (vp=0xfffffe0006c94dc8,
> uiop=0xffffff81b2ba15c0, cred=<value optimized out>)
> at /spare/tmp/src-stable9/sys/modules/nfscl/../../fs/nfsclient/nfs_clvnops.c:1366
> #13 0xffffffff81e3086b in ncl_doio (vp=0xfffffe0006c94dc8,
> bp=0xffffff816f8f4120, cr=0xfffffe0002d58e00, td=0xfffffe0006aa6490,
> called_from_strategy=0)
> at /spare/tmp/src-stable9/sys/modules/nfscl/../../fs/nfsclient/nfs_clbio.c:1605
> #14 0xffffffff81e3254f in ncl_bioread (vp=0xfffffe0006c94dc8,
> uio=0xffffff81b2ba1ad0, ioflag=<value optimized out>,
> cred=0xfffffe0002d58e00)
> at /spare/tmp/src-stable9/sys/modules/nfscl/../../fs/nfsclient/nfs_clbio.c:541
> #15 0xffffffff80434ae8 in vn_read (fp=0xfffffe0006abda50,
> uio=0xffffff81b2ba1ad0, active_cred=<value optimized out>,
> flags=<value optimized out>, td=<value optimized out>) at vnode_if.h:384
> #16 0xffffffff8043206e in vn_io_fault (fp=0xfffffe0006abda50,
> uio=0xffffff81b2ba1ad0, active_cred=0xfffffe0002d58e00, flags=0,
> td=0xfffffe0006aa6490) at /spare/tmp/src-stable9/sys/kern/vfs_vnops.c:903
> #17 0xffffffff803d7ac1 in dofileread (td=0xfffffe0006aa6490, fd=3,
> fp=0xfffffe0006abda50, auio=0xffffff81b2ba1ad0,
> offset=<value optimized out>, flags=0) at file.h:287
> #18 0xffffffff803d7e1c in kern_readv (td=0xfffffe0006aa6490, fd=3,
> auio=0xffffff81b2ba1ad0)
> at /spare/tmp/src-stable9/sys/kern/sys_generic.c:250
> #19 0xffffffff803d7f34 in sys_read (td=<value optimized out>,
> uap=<value optimized out>)
> at /spare/tmp/src-stable9/sys/kern/sys_generic.c:166
> #20 0xffffffff80593cb3 in amd64_syscall (td=0xfffffe0006aa6490, traced=0)
> at subr_syscall.c:135
> #21 0xffffffff8057e357 in Xfast_syscall ()
> at /spare/tmp/src-stable9/sys/amd64/amd64/exception.S:387
> #22 0x00000008009245fc in ?? ()
> Previous frame inner to this frame (corrupt stack?)
> (kgdb)
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