Re: [PATCH 1/3] NFSv4: Fix a slot leak in nfs40_sequence_done

Trond Myklebust
2014-01-30T17:03:23Z

On Jan 30, 2014, at 12:02, Chuck Lever <chuck.lever@oracle.com> wrote:

>
> On Jan 30, 2014, at 8:55 AM, Trond Myklebust <trond.myklebust@primarydata.com> wrote:
>
>>
>> On Jan 30, 2014, at 11:49, Chuck Lever <chuck.lever@oracle.com> wrote:
>>
>>>
>>> On Jan 29, 2014, at 9:36 AM, Trond Myklebust <trond.myklebust@primarydata.com> wrote:
>>>
>>>> The check for whether or not we sent an RPC call in nfs40_sequence_done
>>>> is insufficient to decide whether or not we are holding a session slot,
>>>> and thus should not be used to decide when to free that slot.
>>>>
>>>> This patch replaces the RPC_WAS_SENT() test with the correct test for
>>>> whether or not slot == NULL.
>>>>
>>>> Cc: Chuck Lever <chuck.lever@oracle.com>
>>>> Cc: stable@vger.kernel.org # 3.12+
>>>> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
>>>> ---
>>>> fs/nfs/nfs4proc.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
>>>> index ae00c3ed733f..493e9cce1f11 100644
>>>> --- a/fs/nfs/nfs4proc.c
>>>> +++ b/fs/nfs/nfs4proc.c
>>>> @@ -539,7 +539,7 @@ static int nfs40_sequence_done(struct rpc_task *task,
>>>> struct nfs4_slot *slot = res->sr_slot;
>>>> struct nfs4_slot_table *tbl;
>>>>
>>>> - if (!RPC_WAS_SENT(task))
>>>> + if (slot == NULL)
>>>> goto out;
>>>
>>> When CONFIG_NFS_V4_1 is enabled, nfs4_sequence_done() already does the slot == NULL test, though the other nfs40_sequence_done() call sites do not. This patch should clean that up?
>>
>> Unfortunately we can’t touch nfs4_sequence_done: it wants to test for whether or not a NFSv4.1 session exists, which requires it to look at slot->table->session. :-(
>
> Move the slot == NULL check to all nfs40_sequence_done() call sites? <shrug>

No...

--
Trond Myklebust
Linux NFS client maintainer