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. 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
