samba - Feb 2023 - Hanging, uninterruptible smbd-process in "D"-state

On 2/1/23 10:18, Rainer Krienke via samba wrote:
> Since the process is in state "D" its not killable and the only
> solution is a reboot of the samba server itself which of course is an
> "ugly" solution.
as for "D" state: ask the the kernel, that's out of Samba's
control. You
can start with a /proc/PID/stack to find out where in the kernel the 
process is stuck, my guess would be somewhere in the NFS code.

As pointed out by Rowland, resharing NFS should be avoided by all means. 
It will work initially and then it will bite you hard at some point. :)

-slow

-- 
Ralph Boehme, Samba Team                 https://samba.org/
SerNet Samba Team Lead      https://sernet.de/en/team-samba

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Hi,

tanks for the answer. Since /proc/<PID>/stack is a stack the topmost 
element should be the task where it got stuck which is: 
rwsem_down_write_slowpath which waits for getting a write lock semaphore:

cat /proc/10193/stack
[<0>] rwsem_down_write_slowpath+0x2e2/0x620
[<0>] nfs_rmdir+0x117/0x1b0 [nfs]
[<0>] vfs_rmdir+0x7c/0x1b0
[<0>] do_rmdir+0x216/0x230
[<0>] do_syscall_64+0x5b/0x80
[<0>] entry_SYSCALL_64_after_hwframe+0x61/0xcb

The strange is that all of a sudden this setup (nfsserver+samba-client) 
fails, where it has worked for 10 years without any trouble.

Thanks
Rainer

Am 01.02.23 um 11:38 schrieb Ralph Boehme via samba:
> On 2/1/23 10:18, Rainer Krienke via samba wrote:
>> Since the process is in state "D" its not killable and the
only
>> solution is a reboot of the samba server itself which of course is an
>> "ugly" solution.
> 
> as for "D" state: ask the the kernel, that's out of
Samba's control. You
> can start with a /proc/PID/stack to find out where in the kernel the 
> process is stuck, my guess would be somewhere in the NFS code.
> 
> As pointed out by Rowland, resharing NFS should be avoided by all means. 
> It will work initially and then it will bite you hard at some point. :)
> 
> -slow
> 
> 
-- 
Rainer Krienke, Uni Koblenz, IT-Services, A22, Universitaetsstrasse 1
56070 Koblenz, Tel: +49261287 1312 Fax +49261287 100 1312
Web: http://userpages.uni-koblenz.de/~krienke
PGP: http://userpages.uni-koblenz.de/~krienke/mypgp.html