| Message ID | 170629112969.20612.8526400738389878628.stgit@manet.1015granger.net (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | NFSD backchannel fixes | expand |
On Fri, 2024-01-26 at 12:45 -0500, Chuck Lever wrote: > From: Chuck Lever <chuck.lever@oracle.com> > > As part of managing a client disconnect, NFSD closes down and > replaces the backchannel rpc_clnt. > > If a callback operation is pending when the backchannel rpc_clnt is > shut down, currently nfsd4_run_cb_work() just discards that > callback. But there are multiple cases to deal with here: > > o The client's lease is getting destroyed. Throw the CB away. > > o The client disconnected. It might be forcing a retransmit of > CB operations, or it could have disconnected for other reasons. > Reschedule the CB so it is retransmitted when the client > reconnects. > > Since callback operations can now be rescheduled, ensure that > cb_ops->prepare can be called only once by moving the > cb_ops->prepare paragraph down to just before the rpc_call_async() > call. > > Fixes: 2bbfed98a4d8 ("nfsd: Fix races between nfsd4_cb_release() and nfsd4_shutdown_callback()") > Signed-off-by: Chuck Lever <chuck.lever@oracle.com> > --- > fs/nfsd/nfs4callback.c | 32 +++++++++++++++++++++++--------- > 1 file changed, 23 insertions(+), 9 deletions(-) > > diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c > index 1ed2512b3648..389d05985c52 100644 > --- a/fs/nfsd/nfs4callback.c > +++ b/fs/nfsd/nfs4callback.c > @@ -890,6 +890,13 @@ static bool nfsd4_queue_cb(struct nfsd4_callback *cb) > return queue_delayed_work(callback_wq, &cb->cb_work, 0); > } > > +static void nfsd4_queue_cb_delayed(struct nfsd4_callback *cb, > + unsigned long msecs) > +{ > + queue_delayed_work(callback_wq, &cb->cb_work, > + msecs_to_jiffies(msecs)); > +} > + > static void nfsd41_cb_inflight_begin(struct nfs4_client *clp) > { > atomic_inc(&clp->cl_cb_inflight); > @@ -1375,20 +1382,21 @@ nfsd4_run_cb_work(struct work_struct *work) > struct rpc_clnt *clnt; > int flags; > > - if (cb->cb_need_restart) { > - cb->cb_need_restart = false; > - } else { > - if (cb->cb_ops && cb->cb_ops->prepare) > - cb->cb_ops->prepare(cb); > - } > - > if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK) > nfsd4_process_cb_update(cb); > > clnt = clp->cl_cb_client; > if (!clnt) { > - /* Callback channel broken, or client killed; give up: */ > - nfsd41_destroy_cb(cb); > + if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) > + nfsd41_destroy_cb(cb); > + else { > + /* > + * XXX: Ideally, we could wait for the client to > + * reconnect, but I haven't figured out how > + * to do that yet. > + */ > + nfsd4_queue_cb_delayed(cb, 25); > + } > return; > } > > @@ -1401,6 +1409,12 @@ nfsd4_run_cb_work(struct work_struct *work) > return; > } > > + if (cb->cb_need_restart) { > + cb->cb_need_restart = false; > + } else { > + if (cb->cb_ops && cb->cb_ops->prepare) > + cb->cb_ops->prepare(cb); > + } > cb->cb_msg.rpc_cred = clp->cl_cb_cred; > flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN; > rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags, > > > Reviewed-by: Jeff Layton <jlayton@kernel.org>
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index 1ed2512b3648..389d05985c52 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -890,6 +890,13 @@ static bool nfsd4_queue_cb(struct nfsd4_callback *cb) return queue_delayed_work(callback_wq, &cb->cb_work, 0); } +static void nfsd4_queue_cb_delayed(struct nfsd4_callback *cb, + unsigned long msecs) +{ + queue_delayed_work(callback_wq, &cb->cb_work, + msecs_to_jiffies(msecs)); +} + static void nfsd41_cb_inflight_begin(struct nfs4_client *clp) { atomic_inc(&clp->cl_cb_inflight); @@ -1375,20 +1382,21 @@ nfsd4_run_cb_work(struct work_struct *work) struct rpc_clnt *clnt; int flags; - if (cb->cb_need_restart) { - cb->cb_need_restart = false; - } else { - if (cb->cb_ops && cb->cb_ops->prepare) - cb->cb_ops->prepare(cb); - } - if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK) nfsd4_process_cb_update(cb); clnt = clp->cl_cb_client; if (!clnt) { - /* Callback channel broken, or client killed; give up: */ - nfsd41_destroy_cb(cb); + if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) + nfsd41_destroy_cb(cb); + else { + /* + * XXX: Ideally, we could wait for the client to + * reconnect, but I haven't figured out how + * to do that yet. + */ + nfsd4_queue_cb_delayed(cb, 25); + } return; } @@ -1401,6 +1409,12 @@ nfsd4_run_cb_work(struct work_struct *work) return; } + if (cb->cb_need_restart) { + cb->cb_need_restart = false; + } else { + if (cb->cb_ops && cb->cb_ops->prepare) + cb->cb_ops->prepare(cb); + } cb->cb_msg.rpc_cred = clp->cl_cb_cred; flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN; rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,