Re: [PATCH] NFSD: Decrease nfsd_users in nfsd_startup_generic fail

[Kinglong Mee <kinglongmee@gmail.com>]

On 7/30/2014 22:16, J. Bruce Fields wrote:
> Thanks!
> 
> On Wed, Jul 30, 2014 at 09:26:05PM +0800, Kinglong Mee wrote:
>> If nfsd_startup_generic fail, nfsd_users isn't decreased right now.
> 
> Looks like that should only fail in out of memory cases?

Yes, it is.
I found this problem through reviewing code.

> 
>> NFSD restarts will return 0 at the first nfsd_users checking,
>> after that, nfs4_state_start_net() will meet a bad laundry_wq
>> (I meet NULL), after nfsd4_grace timeout, the kernel will crash.
> 
> So this was introduced with 4539f14981ce02d48b212786a41c8bcfb62851b4
> "nfsd: replace boolean nfsd_up flag by users counter".

Yes, I forget adding it.

thanks,
Kinglong Mee

>> Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
>> ---
>>  fs/nfsd/nfssvc.c | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
>> index 5d026dc..752d56b 100644
>> --- a/fs/nfsd/nfssvc.c
>> +++ b/fs/nfsd/nfssvc.c
>> @@ -221,7 +221,8 @@ static int nfsd_startup_generic(int nrservs)
>>  	 */
>>  	ret = nfsd_racache_init(2*nrservs);
>>  	if (ret)
>> -		return ret;
>> +		goto dec_users;
>> +
>>  	ret = nfs4_state_start();
>>  	if (ret)
>>  		goto out_racache;
>> @@ -229,6 +230,8 @@ static int nfsd_startup_generic(int nrservs)
>>  
>>  out_racache:
>>  	nfsd_racache_shutdown();
>> +dec_users:
>> +	nfsd_users--;
>>  	return ret;
>>  }
>>  
>> -- 
>> 1.9.3
>>
>