linux/net
Trond Myklebust beb0f0a9fb kernel panic when mount NFSv4
On Tue, 2010-12-14 at 16:58 +0800, Mi Jinlong wrote:
> Hi,
>
> When testing NFSv4 at RHEL6 with kernel 2.6.32, I got a kernel panic
> at NFS client's __rpc_create_common function.
>
> The panic place is:
>   rpc_mkpipe
>     __rpc_lookup_create()          <=== find pipefile *idmap*
>     __rpc_mkpipe()                 <=== pipefile is *idmap*
>       __rpc_create_common()
>        ******  BUG_ON(!d_unhashed(dentry)); ******    *panic*
>
> It means that the dentry's d_flags have be set DCACHE_UNHASHED,
> but it should not be set here.
>
> Is someone known this bug? or give me some idea?
>
> A reproduce program is append, but it can't reproduce the bug every time.
> the export is: "/nfsroot       *(rw,no_root_squash,fsid=0,insecure)"
>
> And the panic message is append.
>
> ============================================================================
> #!/bin/sh
>
> LOOPTOTAL=768
> LOOPCOUNT=0
> ret=0
>
> while [ $LOOPCOUNT -ne $LOOPTOTAL ]
> do
> 	((LOOPCOUNT += 1))
> 	service nfs restart
> 	/usr/sbin/rpc.idmapd
> 	mount -t nfs4 127.0.0.1:/ /mnt|| return 1;
> 	ls -l /var/lib/nfs/rpc_pipefs/nfs/*/
> 	umount /mnt
> 	echo $LOOPCOUNT
> done
>
> ===============================================================================
> Code: af 60 01 00 00 89 fa 89 f0 e8 64 cf 89 f0 e8 5c 7c 64 cf 31 c0 8b 5c 24 10 8b
> 74 24 14 8b 7c 24 18 8b 6c 24 1c 83 c4 20 c3 <0f> 0b eb fc 8b 46 28 c7 44 24 08 20
> de ee f0 c7 44 24 04 56 ea
> EIP:[<f0ee92ea>] __rpc_create_common+0x8a/0xc0 [sunrpc] SS:ESP 0068:eccb5d28
> ---[ end trace 8f5606cd08928ed2]---
> Kernel panic - not syncing: Fatal exception
> Pid:7131, comm: mount.nfs4 Tainted: G     D   -------------------2.6.32 #1
> Call Trace:
>  [<c080ad18>] ? panic+0x42/0xed
>  [<c080e42c>] ? oops_end+0xbc/0xd0
>  [<c040b090>] ? do_invalid_op+0x0/0x90
>  [<c040b10f>] ? do_invalid_op+0x7f/0x90
>  [<f0ee92ea>] ? __rpc_create_common+0x8a/0xc0[sunrpc]
>  [<f0edc433>] ? rpc_free_task+0x33/0x70[sunrpc]
>  [<f0ed6508>] ? prc_call_sync+0x48/0x60[sunrpc]
>  [<f0ed656e>] ? rpc_ping+0x4e/0x60[sunrpc]
>  [<f0ed6eaf>] ? rpc_create+0x38f/0x4f0[sunrpc]
>  [<c080d80b>] ? error_code+0x73/0x78
>  [<f0ee92ea>] ? __rpc_create_common+0x8a/0xc0[sunrpc]
>  [<c0532bda>] ? d_lookup+0x2a/0x40
>  [<f0ee94b1>] ? rpc_mkpipe+0x111/0x1b0[sunrpc]
>  [<f10a59f4>] ? nfs_create_rpc_client+0xb4/0xf0[nfs]
>  [<f10d6c6d>] ? nfs_fscache_get_client_cookie+0x1d/0x50[nfs]
>  [<f10d3fcb>] ? nfs_idmap_new+0x7b/0x140[nfs]
>  [<c05e76aa>] ? strlcpy+0x3a/0x60
>  [<f10a60ca>] ? nfs4_set_client+0xea/0x2b0[nfs]
>  [<f10a6d0c>] ? nfs4_create_server+0xac/0x1b0[nfs]
>  [<c04f1400>] ? krealloc+0x40/0x50
>  [<f10b0e8b>] ? nfs4_remote_get_sb+0x6b/0x250[nfs]
>  [<c04f14ec>] ? kstrdup+0x3c/0x60
>  [<c0520739>] ? vfs_kern_mount+0x69/0x170
>  [<f10b1a3c>] ? nfs_do_root_mount+0x6c/0xa0[nfs]
>  [<f10b1b47>] ? nfs4_try_mount+0x37/0xa0[nfs]
>  [<f10afe6d>] ? nfs4_validate_text_mount_data+-x7d/0xf0[nfs]
>  [<f10b1c42>] ? nfs4_get_sb+0x92/0x2f0
>  [<c0520739>] ? vfs_kern_mount+0x69/0x170
>  [<c05366d2>] ? get_fs_type+0x32/0xb0
>  [<c052089f>] ? do_kern_mount+0x3f/0xe0
>  [<c053954f>] ? do_mount+0x2ef/0x740
>  [<c0537740>] ? copy_mount_options+0xb0/0x120
>  [<c0539a0e>] ? sys_mount+0x6e/0xa0

Hi,

Does the following patch fix the problem?

Cheers
  Trond

--------------------------
SUNRPC: Fix a BUG in __rpc_create_common

From: Trond Myklebust <Trond.Myklebust@netapp.com>

Mi Jinlong reports:

When testing NFSv4 at RHEL6 with kernel 2.6.32, I got a kernel panic
at NFS client's __rpc_create_common function.

The panic place is:
  rpc_mkpipe
      __rpc_lookup_create()          <=== find pipefile *idmap*
      __rpc_mkpipe()                 <=== pipefile is *idmap*
        __rpc_create_common()
         ******  BUG_ON(!d_unhashed(dentry)); ****** *panic*

The test is wrong: we can find ourselves with a hashed negative dentry here
if the idmapper tried to look up the file before we got round to creating
it.

Just replace the BUG_ON() with a d_drop(dentry).

Reported-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-04 13:10:38 -05:00
..
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802
8021q
appletalk
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ax25 net: ax25: fix information leak to userland 2010-11-10 10:14:33 -08:00
bluetooth Bluetooth: Fix not returning proper error in SCO 2010-11-22 18:23:18 -02:00
bridge
caif
can can-bcm: fix minor heap overflow 2010-11-12 14:07:14 -08:00
ceph Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-11-29 14:36:33 -08:00
core net: fix skb_defer_rx_timestamp() 2010-12-10 16:20:56 -08:00
dcb
dccp dccp: fix error in updating the GAR 2010-11-28 11:29:27 -08:00
decnet DECnet: don't leak uninitialized stack byte 2010-11-28 11:32:30 -08:00
dns_resolver
dsa
econet econet: Fix crash in aun_incoming(). 2010-12-08 20:51:15 -08:00
ethernet
ieee802154
ipv4 tcp: protect sysctl_tcp_cookie_size reads 2010-12-08 12:34:09 -08:00
ipv6 ipv6: fix nl group when advertising a new link 2010-12-10 12:49:36 -08:00
ipx
irda Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-11-19 15:25:59 -08:00
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l2tp l2tp: Fix modalias of l2tp_ip 2010-12-08 12:13:43 -08:00
lapb
llc llc: fix a device refcount imbalance 2010-12-08 09:58:44 -08:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-12-14 17:33:40 -08:00
netfilter netfilter: fix IP_VS dependencies 2010-11-18 13:14:33 -08:00
netlabel
netlink
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packet net: Fix header size check for GSO case in recvmsg (af_packet) 2010-11-12 11:06:46 -08:00
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rds rds: Integer overflow in RDS cmsg handling 2010-11-17 12:20:52 -08:00
rfkill
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sched classifier: report statistics for basic classifier 2010-11-08 12:17:05 -08:00
sctp SCTP: Fix SCTP_SET_PEER_PRIMARY_ADDR to accpet v4mapped address 2010-12-10 15:29:49 -08:00
sunrpc kernel panic when mount NFSv4 2011-01-04 13:10:38 -05:00
tipc net: tipc: fix information leak to userland 2010-11-09 09:25:46 -08:00
unix af_unix: limit recursion level 2010-11-29 09:45:15 -08:00
wanrouter
wimax
wireless cfg80211: fix can_beacon_sec_chan, reenable HT40 2010-11-18 11:35:05 -05:00
x25 x25: decrement netdev reference counts on unload 2010-12-08 12:13:44 -08:00
xfrm xfrm: Fix xfrm_state_migrate leak 2010-12-09 20:35:27 -08:00
compat.c
Kconfig
Makefile
nonet.c
socket.c net: Document the kernel_recvmsg() function 2010-12-10 11:13:18 -08:00
sysctl_net.c
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