On Thu, Sep 17, 2015 at 9:34 AM, Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> wrote: > On Tue, Sep 15, 2015 at 12:52 PM, Olga Kornievskaia <aglo@xxxxxxxxx> wrote: >> On Tue, Sep 15, 2015 at 11:49 AM, Trond Myklebust >> <trond.myklebust@xxxxxxxxxxxxxxx> wrote: >>> On Tue, Sep 15, 2015 at 10:27 AM, Olga Kornievskaia <aglo@xxxxxxxxx> wrote: >>>> On Tue, Sep 15, 2015 at 9:39 AM, Trond Myklebust >>>> <trond.myklebust@xxxxxxxxxxxxxxx> wrote: >>>>> On Mon, Sep 14, 2015 at 7:54 PM, Olga Kornievskaia <aglo@xxxxxxxxx> wrote: >>>>>> A test case is as the description says: >>>>>> open(foobar, O_WRONLY); >>>>>> sleep() --> reboot the server >>>>>> close(foobar) >>>>>> >>>>>> The bug is because in nfs4state.c in nfs4_reclaim_open_state() a few >>>>>> line before going to restart, there is >>>>>> clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &state->flags). >>>>>> >>>>>> NFS4CLNT_RECLAIM_NOGRACE is a flag for the client states not open >>>>>> owner states. Value of NFS4CLNT_RECLAIM_NOGRACE is 4 which is the >>>>>> value of NFS_O_WRONLY_STATE in nfs4_state->flags. So clearing it wipes >>>>>> out state and when we go to close it, “call_close” doesn’t get set as >>>>>> state flag is not set and CLOSE doesn’t go on the wire. >>>>>> >>>>>> That line was introduced to fix an infinite loop for OPEN recovery >>>>>> upon receiving a BAD_STATEID error: commit e8d975e73. I have tested >>>>>> injecting BAD_STATEID error using the patch below and the code >>>>>> recovers without problems. However, I'm not sure the clearing of the >>>>>> bit is needed any more. I have tested for infinite loop by reverting >>>>>> the patch and didn't hit the infinite loop. >>>>>> >>>>>> diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c >>>>>> index da73bc4..5db3246 100644 >>>>>> --- a/fs/nfs/nfs4state.c >>>>>> +++ b/fs/nfs/nfs4state.c >>>>>> @@ -1481,7 +1481,7 @@ restart: >>>>>> spin_unlock(&state->state_lock); >>>>>> } >>>>>> nfs4_put_open_state(state); >>>>>> - clear_bit(NFS4CLNT_RECLAIM_NOGRACE, >>>>>> + clear_bit(NFS_STATE_RECLAIM_NOGRACE, >>>>>> &state->flags); >>>>>> spin_lock(&sp->so_lock); >>>>>> goto restart; >>>>> >>>>> That's an obvious typo. Thanks for spotting it! >>>>> >>>>> As for whether or not the bit clear is needed at all, I think it is >>>>> for NFSv4 on older kernels. On newer kernels, we do have the NFSv4 >>>>> state recovery drain the slot table (just like we've always done for >>>>> NFSv4.1) and so I agree that those kernels probably won't be >>>>> afflicted. >>>>> >>>> >>>> Thanks Trond. Do you need me to resubmit it without the last paragraph >>>> or is the patch ok as is? >>>> >>> >>> I can easily remove that paragraph when applying the patch, if you >>> agree that it is superfluous. >> >> Thanks. Works for me. >> > > May I also add a signed-off-by line from you? I can't really apply > this (or any other patches) without it. Of course. > > Cheers > Trond > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
