* WARNING: at fs/sysfs/sysfs.h:195 (during boot)
@ 2011-11-13 19:24 Markus Trippelsdorf
2011-11-16 0:39 ` Greg KH
0 siblings, 1 reply; 4+ messages in thread
From: Markus Trippelsdorf @ 2011-11-13 19:24 UTC (permalink / raw)
To: linux-kernel; +Cc: Greg Kroah-Hartman
I'm seeing this for the fist time:
...
XFS (sda): Mounting Filesystem
XFS (sda): Ending clean mount
ATL1E 0000:02:00.0: irq 40 for MSI/MSI-X
ATL1E 0000:02:00.0: eth0: NIC Link is Up <100 Mbps Full Duplex>
ATL1E 0000:02:00.0: eth0: NIC Link is Up <100 Mbps Full Duplex>
udevd[888]: starting version 171
------------[ cut here ]------------
WARNING: at fs/sysfs/sysfs.h:195 sysfs_get_inode+0x136/0x140()
Hardware name: System Product Name
Pid: 945, comm: udevadm Not tainted 3.2.0-rc1-00252-g8f042aa #49
Call Trace:
[<ffffffff81072795>] warn_slowpath_common+0x75/0xb0
[<ffffffff81072895>] warn_slowpath_null+0x15/0x20
[<ffffffff81167b26>] sysfs_get_inode+0x136/0x140
[<ffffffff811695df>] sysfs_lookup+0x6f/0x110
[<ffffffff8111b739>] d_alloc_and_lookup+0x39/0x80
[<ffffffff8111ca93>] do_lookup+0x283/0x390
[<ffffffff8111d954>] path_lookupat+0x114/0x6d0
[<ffffffff8111b946>] ? getname_flags+0x36/0x230
[<ffffffff8111df3b>] do_path_lookup+0x2b/0x70
[<ffffffff8111e3a8>] user_path_at_empty+0x58/0xb0
[<ffffffff81169d4c>] ? sysfs_put_link+0x1c/0x20
[<ffffffff81120ac4>] ? generic_readlink+0x84/0xa0
[<ffffffff8111e40c>] user_path_at+0xc/0x10
[<ffffffff811161e0>] vfs_fstatat+0x30/0x70
[<ffffffff8112d94b>] ? mntput_no_expire+0x2b/0xe0
[<ffffffff81116236>] vfs_stat+0x16/0x20
[<ffffffff81116305>] sys_newstat+0x15/0x30
[<ffffffff8111642e>] ? sys_readlinkat+0x7e/0xb0
[<ffffffff814d2c7b>] system_call_fastpath+0x16/0x1b
---[ end trace 2226f614d7765573 ]---
Adding 2097148k swap on /var/tmp/swap/swapfile. Priority:-1 extents:2 across:2634672k
fs/sysfs/sysfs.h:195:
WARN_ON(!atomic_read(&sd->s_count));
--
Markus
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: WARNING: at fs/sysfs/sysfs.h:195 (during boot)
2011-11-13 19:24 WARNING: at fs/sysfs/sysfs.h:195 (during boot) Markus Trippelsdorf
@ 2011-11-16 0:39 ` Greg KH
2011-11-16 2:14 ` Eric W. Biederman
0 siblings, 1 reply; 4+ messages in thread
From: Greg KH @ 2011-11-16 0:39 UTC (permalink / raw)
To: Markus Trippelsdorf, Eric W. Biederman; +Cc: linux-kernel
On Sun, Nov 13, 2011 at 08:24:17PM +0100, Markus Trippelsdorf wrote:
> I'm seeing this for the fist time:
>
> ...
> XFS (sda): Mounting Filesystem
> XFS (sda): Ending clean mount
> ATL1E 0000:02:00.0: irq 40 for MSI/MSI-X
> ATL1E 0000:02:00.0: eth0: NIC Link is Up <100 Mbps Full Duplex>
> ATL1E 0000:02:00.0: eth0: NIC Link is Up <100 Mbps Full Duplex>
> udevd[888]: starting version 171
> ------------[ cut here ]------------
> WARNING: at fs/sysfs/sysfs.h:195 sysfs_get_inode+0x136/0x140()
> Hardware name: System Product Name
> Pid: 945, comm: udevadm Not tainted 3.2.0-rc1-00252-g8f042aa #49
> Call Trace:
> [<ffffffff81072795>] warn_slowpath_common+0x75/0xb0
> [<ffffffff81072895>] warn_slowpath_null+0x15/0x20
> [<ffffffff81167b26>] sysfs_get_inode+0x136/0x140
> [<ffffffff811695df>] sysfs_lookup+0x6f/0x110
> [<ffffffff8111b739>] d_alloc_and_lookup+0x39/0x80
> [<ffffffff8111ca93>] do_lookup+0x283/0x390
> [<ffffffff8111d954>] path_lookupat+0x114/0x6d0
> [<ffffffff8111b946>] ? getname_flags+0x36/0x230
> [<ffffffff8111df3b>] do_path_lookup+0x2b/0x70
> [<ffffffff8111e3a8>] user_path_at_empty+0x58/0xb0
> [<ffffffff81169d4c>] ? sysfs_put_link+0x1c/0x20
> [<ffffffff81120ac4>] ? generic_readlink+0x84/0xa0
> [<ffffffff8111e40c>] user_path_at+0xc/0x10
> [<ffffffff811161e0>] vfs_fstatat+0x30/0x70
> [<ffffffff8112d94b>] ? mntput_no_expire+0x2b/0xe0
> [<ffffffff81116236>] vfs_stat+0x16/0x20
> [<ffffffff81116305>] sys_newstat+0x15/0x30
> [<ffffffff8111642e>] ? sys_readlinkat+0x7e/0xb0
> [<ffffffff814d2c7b>] system_call_fastpath+0x16/0x1b
> ---[ end trace 2226f614d7765573 ]---
> Adding 2097148k swap on /var/tmp/swap/swapfile. Priority:-1 extents:2 across:2634672k
>
> fs/sysfs/sysfs.h:195:
> WARN_ON(!atomic_read(&sd->s_count));
Odd, is it reproducable?
Eric, any ideas?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: WARNING: at fs/sysfs/sysfs.h:195 (during boot)
2011-11-16 0:39 ` Greg KH
@ 2011-11-16 2:14 ` Eric W. Biederman
2011-11-16 6:38 ` Markus Trippelsdorf
0 siblings, 1 reply; 4+ messages in thread
From: Eric W. Biederman @ 2011-11-16 2:14 UTC (permalink / raw)
To: Greg KH; +Cc: Markus Trippelsdorf, linux-kernel
Greg KH <gregkh@suse.de> writes:
> On Sun, Nov 13, 2011 at 08:24:17PM +0100, Markus Trippelsdorf wrote:
>> I'm seeing this for the fist time:
>>
>> ...
>> XFS (sda): Mounting Filesystem
>> XFS (sda): Ending clean mount
>> ATL1E 0000:02:00.0: irq 40 for MSI/MSI-X
>> ATL1E 0000:02:00.0: eth0: NIC Link is Up <100 Mbps Full Duplex>
>> ATL1E 0000:02:00.0: eth0: NIC Link is Up <100 Mbps Full Duplex>
>> udevd[888]: starting version 171
>> ------------[ cut here ]------------
>> WARNING: at fs/sysfs/sysfs.h:195 sysfs_get_inode+0x136/0x140()
>> Hardware name: System Product Name
>> Pid: 945, comm: udevadm Not tainted 3.2.0-rc1-00252-g8f042aa #49
>> Call Trace:
>> [<ffffffff81072795>] warn_slowpath_common+0x75/0xb0
>> [<ffffffff81072895>] warn_slowpath_null+0x15/0x20
>> [<ffffffff81167b26>] sysfs_get_inode+0x136/0x140
>> [<ffffffff811695df>] sysfs_lookup+0x6f/0x110
>> [<ffffffff8111b739>] d_alloc_and_lookup+0x39/0x80
>> [<ffffffff8111ca93>] do_lookup+0x283/0x390
>> [<ffffffff8111d954>] path_lookupat+0x114/0x6d0
>> [<ffffffff8111b946>] ? getname_flags+0x36/0x230
>> [<ffffffff8111df3b>] do_path_lookup+0x2b/0x70
>> [<ffffffff8111e3a8>] user_path_at_empty+0x58/0xb0
>> [<ffffffff81169d4c>] ? sysfs_put_link+0x1c/0x20
>> [<ffffffff81120ac4>] ? generic_readlink+0x84/0xa0
>> [<ffffffff8111e40c>] user_path_at+0xc/0x10
>> [<ffffffff811161e0>] vfs_fstatat+0x30/0x70
>> [<ffffffff8112d94b>] ? mntput_no_expire+0x2b/0xe0
>> [<ffffffff81116236>] vfs_stat+0x16/0x20
>> [<ffffffff81116305>] sys_newstat+0x15/0x30
>> [<ffffffff8111642e>] ? sys_readlinkat+0x7e/0xb0
>> [<ffffffff814d2c7b>] system_call_fastpath+0x16/0x1b
>> ---[ end trace 2226f614d7765573 ]---
>> Adding 2097148k swap on /var/tmp/swap/swapfile. Priority:-1 extents:2 across:2634672k
>>
>> fs/sysfs/sysfs.h:195:
>> WARN_ON(!atomic_read(&sd->s_count));
>
> Odd, is it reproducable?
>
> Eric, any ideas?
So this indicates we found a sysfs_dirent in a directory with a
reference count of 0.
If this isn't caused by a bitflip. My guess would be something off in
the new sysfs directory handling.
Off the top of my head I don't know how the new sysfs directory
handling could have caused this. But I expect it would take
a fair amount of directory modification to cause this. Everything
is serialized under the sysfs_mutex so it should be really hard
to trigger race conditions. I am scratching my head.
Eric
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: WARNING: at fs/sysfs/sysfs.h:195 (during boot)
2011-11-16 2:14 ` Eric W. Biederman
@ 2011-11-16 6:38 ` Markus Trippelsdorf
0 siblings, 0 replies; 4+ messages in thread
From: Markus Trippelsdorf @ 2011-11-16 6:38 UTC (permalink / raw)
To: Eric W. Biederman; +Cc: Greg KH, linux-kernel
On 2011.11.15 at 18:14 -0800, Eric W. Biederman wrote:
> Greg KH <gregkh@suse.de> writes:
>
> > On Sun, Nov 13, 2011 at 08:24:17PM +0100, Markus Trippelsdorf wrote:
> >> I'm seeing this for the fist time:
> >>
> >> ...
> >> XFS (sda): Mounting Filesystem
> >> XFS (sda): Ending clean mount
> >> ATL1E 0000:02:00.0: irq 40 for MSI/MSI-X
> >> ATL1E 0000:02:00.0: eth0: NIC Link is Up <100 Mbps Full Duplex>
> >> ATL1E 0000:02:00.0: eth0: NIC Link is Up <100 Mbps Full Duplex>
> >> udevd[888]: starting version 171
> >> ------------[ cut here ]------------
> >> WARNING: at fs/sysfs/sysfs.h:195 sysfs_get_inode+0x136/0x140()
> >> Hardware name: System Product Name
> >> Pid: 945, comm: udevadm Not tainted 3.2.0-rc1-00252-g8f042aa #49
> >> Call Trace:
> >> [<ffffffff81072795>] warn_slowpath_common+0x75/0xb0
> >> [<ffffffff81072895>] warn_slowpath_null+0x15/0x20
> >> [<ffffffff81167b26>] sysfs_get_inode+0x136/0x140
> >> [<ffffffff811695df>] sysfs_lookup+0x6f/0x110
> >> [<ffffffff8111b739>] d_alloc_and_lookup+0x39/0x80
> >> [<ffffffff8111ca93>] do_lookup+0x283/0x390
> >> [<ffffffff8111d954>] path_lookupat+0x114/0x6d0
> >> [<ffffffff8111b946>] ? getname_flags+0x36/0x230
> >> [<ffffffff8111df3b>] do_path_lookup+0x2b/0x70
> >> [<ffffffff8111e3a8>] user_path_at_empty+0x58/0xb0
> >> [<ffffffff81169d4c>] ? sysfs_put_link+0x1c/0x20
> >> [<ffffffff81120ac4>] ? generic_readlink+0x84/0xa0
> >> [<ffffffff8111e40c>] user_path_at+0xc/0x10
> >> [<ffffffff811161e0>] vfs_fstatat+0x30/0x70
> >> [<ffffffff8112d94b>] ? mntput_no_expire+0x2b/0xe0
> >> [<ffffffff81116236>] vfs_stat+0x16/0x20
> >> [<ffffffff81116305>] sys_newstat+0x15/0x30
> >> [<ffffffff8111642e>] ? sys_readlinkat+0x7e/0xb0
> >> [<ffffffff814d2c7b>] system_call_fastpath+0x16/0x1b
> >> ---[ end trace 2226f614d7765573 ]---
> >> Adding 2097148k swap on /var/tmp/swap/swapfile. Priority:-1 extents:2 across:2634672k
> >>
> >> fs/sysfs/sysfs.h:195:
> >> WARN_ON(!atomic_read(&sd->s_count));
> >
> > Odd, is it reproducable?
> >
> > Eric, any ideas?
>
> So this indicates we found a sysfs_dirent in a directory with a
> reference count of 0.
>
> If this isn't caused by a bitflip. My guess would be something off in
> the new sysfs directory handling.
>
> Off the top of my head I don't know how the new sysfs directory
> handling could have caused this. But I expect it would take
> a fair amount of directory modification to cause this. Everything
> is serialized under the sysfs_mutex so it should be really hard
> to trigger race conditions. I am scratching my head.
Please note that the WARNING above appears to be the benign
manifestation of the underlying bug. There is also a more malignant
form that manifests itself in a kernel OOPS during startup. This
happened two times thus far on my machine. The oops had sysfs entries
all over the call-traces. Unfortunately I didn't take a photo.
Neither the WARNING nor the OOPS are easily reproducible.
A bit-flip is very unlikely because this machine uses ECC memory and
there is nothing in the logs.
--
Markus
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-11-16 6:38 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2011-11-13 19:24 WARNING: at fs/sysfs/sysfs.h:195 (during boot) Markus Trippelsdorf
2011-11-16 0:39 ` Greg KH
2011-11-16 2:14 ` Eric W. Biederman
2011-11-16 6:38 ` Markus Trippelsdorf
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