nfsd: New helper nfsd4_cb_sequence_done() for processing more cb errors

According to Christoph's advice, this patch introduce a new helper
nfsd4_cb_sequence_done() for processing more callback errors, following
the example of the client's nfs41_sequence_done().

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index a49201835a970b77a6c767cab55b8f755d9ffa21..e7f50c4081d60c404a642fa18d8a17be97bfe83f 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -435,12 +435,12 @@ static int decode_cb_sequence4resok(struct xdr_stream *xdr,
         */
        status = 0;
 out:
-       if (status)
-               nfsd4_mark_cb_fault(cb->cb_clp, status);
+       cb->cb_seq_status = status;
        return status;
 out_overflow:
        print_overflow_msg(__func__, xdr);
-       return -EIO;
+       status = -EIO;
+       goto out;
 }
 
 static int decode_cb_sequence4res(struct xdr_stream *xdr,
@@ -451,11 +451,10 @@ static int decode_cb_sequence4res(struct xdr_stream *xdr,
        if (cb->cb_minorversion == 0)
                return 0;
 
-       status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_status);
-       if (unlikely(status || cb->cb_status))
+       status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
+       if (unlikely(status || cb->cb_seq_status))
                return status;
 
-       cb->cb_update_seq_nr = true;
        return decode_cb_sequence4resok(xdr, cb);
 }
 
@@ -527,7 +526,7 @@ static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
 
        if (cb != NULL) {
                status = decode_cb_sequence4res(xdr, cb);
-               if (unlikely(status || cb->cb_status))
+               if (unlikely(status || cb->cb_seq_status))
                        return status;
        }
 
@@ -617,7 +616,7 @@ static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
 
        if (cb) {
                status = decode_cb_sequence4res(xdr, cb);
-               if (unlikely(status || cb->cb_status))
+               if (unlikely(status || cb->cb_seq_status))
                        return status;
        }
        return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
@@ -876,7 +875,11 @@ static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
        u32 minorversion = clp->cl_minorversion;
 
        cb->cb_minorversion = minorversion;
-       cb->cb_update_seq_nr = false;
+       /*
+        * cb_seq_status is only set in decode_cb_sequence4res,
+        * and so will remain 1 if an rpc level failure occurs.
+        */
+       cb->cb_seq_status = 1;
        cb->cb_status = 0;
        if (minorversion) {
                if (!nfsd41_cb_get_slot(clp, task))
@@ -885,15 +888,30 @@ static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
        rpc_call_start(task);
 }
 
-static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
+static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
 {
-       struct nfsd4_callback *cb = calldata;
        struct nfs4_client *clp = cb->cb_clp;
+       struct nfsd4_session *session = clp->cl_cb_session;
+       bool ret = true;
 
-       dprintk("%s: minorversion=%d\n", __func__,
-               clp->cl_minorversion);
+       if (!clp->cl_minorversion) {
+               /*
+                * If the backchannel connection was shut down while this
+                * task was queued, we need to resubmit it after setting up
+                * a new backchannel connection.
+                *
+                * Note that if we lost our callback connection permanently
+                * the submission code will error out, so we don't need to
+                * handle that case here.
+                */
+               if (task->tk_flags & RPC_TASK_KILLED)
+                       goto need_restart;
+
+               return true;
+       }
 
-       if (clp->cl_minorversion) {
+       switch (cb->cb_seq_status) {
+       case 0:
                /*
                 * No need for lock, access serialized in nfsd4_cb_prepare
                 *
@@ -901,29 +919,63 @@ static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
                 * If CB_SEQUENCE returns an error, then the state of the slot
                 * (sequence ID, cached reply) MUST NOT change.
                 */
-               if (cb->cb_update_seq_nr)
-                       ++clp->cl_cb_session->se_cb_seq_nr;
-
-               clear_bit(0, &clp->cl_cb_slot_busy);
-               rpc_wake_up_next(&clp->cl_cb_waitq);
-               dprintk("%s: freed slot, new seqid=%d\n", __func__,
-                       clp->cl_cb_session->se_cb_seq_nr);
+               ++session->se_cb_seq_nr;
+               break;
+       case -ESERVERFAULT:
+               ++session->se_cb_seq_nr;
+       case 1:
+       case -NFS4ERR_BADSESSION:
+               nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
+               ret = false;
+               break;
+       case -NFS4ERR_DELAY:
+               if (!rpc_restart_call(task))
+                       goto out;
+
+               rpc_delay(task, 2 * HZ);
+               return false;
+       case -NFS4ERR_BADSLOT:
+               goto retry_nowait;
+       case -NFS4ERR_SEQ_MISORDERED:
+               if (session->se_cb_seq_nr != 1) {
+                       session->se_cb_seq_nr = 1;
+                       goto retry_nowait;
+               }
+               break;
+       default:
+               dprintk("%s: unprocessed error %d\n", __func__,
+                       cb->cb_seq_status);
        }
 
-       /*
-        * If the backchannel connection was shut down while this
-        * task was queued, we need to resubmit it after setting up
-        * a new backchannel connection.
-        *
-        * Note that if we lost our callback connection permanently
-        * the submission code will error out, so we don't need to
-        * handle that case here.
-        */
-       if (task->tk_flags & RPC_TASK_KILLED) {
-               task->tk_status = 0;
-               cb->cb_need_restart = true;
+       clear_bit(0, &clp->cl_cb_slot_busy);
+       rpc_wake_up_next(&clp->cl_cb_waitq);
+       dprintk("%s: freed slot, new seqid=%d\n", __func__,
+               clp->cl_cb_session->se_cb_seq_nr);
+
+       if (task->tk_flags & RPC_TASK_KILLED)
+               goto need_restart;
+out:
+       return ret;
+retry_nowait:
+       if (rpc_restart_call_prepare(task))
+               ret = false;
+       goto out;
+need_restart:
+       task->tk_status = 0;
+       cb->cb_need_restart = true;
+       return false;
+}
+
+static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
+{
+       struct nfsd4_callback *cb = calldata;
+       struct nfs4_client *clp = cb->cb_clp;
+
+       dprintk("%s: minorversion=%d\n", __func__,
+               clp->cl_minorversion);
+
+       if (!nfsd4_cb_sequence_done(task, cb))
                return;
-       }
 
        if (cb->cb_status) {
                WARN_ON_ONCE(task->tk_status);
@@ -1099,8 +1151,8 @@ void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
        cb->cb_msg.rpc_resp = cb;
        cb->cb_ops = ops;
        INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
+       cb->cb_seq_status = 1;
        cb->cb_status = 0;
-       cb->cb_update_seq_nr = false;
        cb->cb_need_restart = false;
 }
 

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 4874ce515fc10024a5bda53e16511b43a8a5f603..583ffc13cae27d165be052609f37dc7428b54dcc 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -67,8 +67,8 @@ struct nfsd4_callback {
        struct rpc_message cb_msg;
        struct nfsd4_callback_ops *cb_ops;
        struct work_struct cb_work;
+       int cb_seq_status;
        int cb_status;
-       bool cb_update_seq_nr;
        bool cb_need_restart;
 };