On 06/17/2010 07:31 PM, Boaz Harrosh wrote:
>
> On a recall, a client may return NFS4ERR_DELAY to indicate
> that it is busy with the layout and wants to be poled.
>
> TODO: If the client is stuck he would probably be cleaned
> at expire client. But it is possible that the client
> is active/renewing but would not acknowledge the
> recall. We should take a time stamp on first recall
> and expire the client if a lease time has passed.
>
> Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
So I was still crashing on callbacks all during bakethon even
with this patch and Benny's fixes. (See below)
> ---
> fs/nfsd/nfs4callback.c | 6 ++++++
> 1 files changed, 6 insertions(+), 0 deletions(-)
>
> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
> index e1faad4..8374ebd 100644
> --- a/fs/nfsd/nfs4callback.c
> +++ b/fs/nfsd/nfs4callback.c
> @@ -1044,6 +1044,12 @@ static void nfsd4_cb_layout_done(struct rpc_task *task, void *calldata)
> */
> expire_client_lock(clp);
> break;
> + case -NFS4ERR_DELAY:
> + /* Pole the client until it's done with the layout */
> + rpc_delay(task, HZ/100); /* 10 mili-seconds */
> + task->tk_status = 0;
> + rpc_restart_call(task);
When using rpc_restart_call here I get an hard crash at:
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index f3b5015..7529f9a 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -514,6 +514,7 @@ decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *res,
u32 dummy;
__be32 *p;
+ BUG_ON(!res);
if (res->cbs_minorversion == 0)
return 0;
[BUG_ON added for demonstration]
The below code would fix it. (Obviously)
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index f3b5015..7529f9a 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -869,9 +870,6 @@ static void nfsd4_cb_done_sequence(struct rpc_task *task,
rpc_wake_up_next(&clp->cl_cb_waitq);
dprintk("%s: freed slot, new seqid=%d\n", __func__,
clp->cl_cb_seq_nr);
-
- /* We're done looking into the sequence information */
- task->tk_msg.rpc_resp = NULL;
}
}
This is because when the second rpc, that was retried above in nfsd4_cb_layout_done()
has a NULL ->rpc_resp. (Which is the struct nfsd4_cb_sequence *res parameter to
decode_cb_sequence on reply from server).
Now this above nfsd4_cb_layout_done() is new pNFS code, but the same problem (crash) should apply
when a retry is attempted in nfsd4_cb_recall_done(). So this hunk should go into current tree.
(and stable)
The code was introduced by this patch:
0421b5c55acd0e88920cb9a5bcea6ed738186853
From: Ricardo Labiaga <Ricardo.Labiaga@xxxxxxxxxx>
Subject: [PATCH] nfsd41: Backchannel: Implement cb_recall over NFSv4.1
I guess it was never tested with error on callback and retry attempt.
Ricardo what was the original intention of the line above (plus the comment)
[I'll send an official patch to Bruce as well]
Thanks
Boaz
> + break;
> case -NFS4ERR_NOMATCHING_LAYOUT:
> nomatching_layout(clr);
> }
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