nfsd: give up on CB_LAYOUTRECALLs after two lease periods

Have the CB_LAYOUTRECALL code treat NFS4_OK and NFS4ERR_DELAY returns
equivalently. Change the code to periodically resend CB_LAYOUTRECALLS
until the ls_layouts list is empty or the client returns a different
error code.

If we go for two lease periods without the list being emptied or the
client sending a hard error, then we give up and clean out the list
anyway.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 25 insertions, 10 deletions

diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
index fec49febb75b..76c13b0228b1 100644
--- a/fs/nfsd/nfs4layouts.c
+++ b/fs/nfsd/nfs4layouts.c
@@ -623,24 +623,39 @@ nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
 {
         struct nfs4_layout_stateid *ls =
                 container_of(cb, struct nfs4_layout_stateid, ls_recall);
+        struct nfsd_net *nn;
+        ktime_t now, cutoff;
         LIST_HEAD(reaplist);
 
+
         switch (task->tk_status) {
         case 0:
-                return 1;
+        case -NFS4ERR_DELAY:
+                /*
+                 * Anything left? If not, then call it done. Note that we don't
+                 * take the spinlock since this is an optimization and nothing
+                 * should get added until the cb counter goes to zero.
+                 */
+                if (list_empty(&ls->ls_layouts))
+                        return 1;
+
+                /* Poll the client until it's done with the layout */
+                now = ktime_get();
+                nn = net_generic(ls->ls_stid.sc_client->net, nfsd_net_id);
+
+                /* Client gets 2 lease periods to return it */
+                cutoff = ktime_add_ns(task->tk_start,
+                                         nn->nfsd4_lease * NSEC_PER_SEC * 2);
+
+                if (ktime_before(now, cutoff)) {
+                        rpc_delay(task, HZ/100); /* 10 mili-seconds */
+                        return 0;
+                }
+                /* Fallthrough */
         case -NFS4ERR_NOMATCHING_LAYOUT:
                 trace_layout_recall_done(&ls->ls_stid.sc_stateid);
                 task->tk_status = 0;
                 return 1;
-        case -NFS4ERR_DELAY:
-                /* Poll the client until it's done with the layout */
-                /* FIXME: cap number of retries.
-                 * The pnfs standard states that we need to only expire
-                 * the client after at-least "lease time" .eg lease-time * 2
-                 * when failing to communicate a recall
-                 */
-                rpc_delay(task, HZ/100); /* 10 mili-seconds */
-                return 0;
         default:
                 /*
                  * Unknown error or non-responding client, we'll need to fence.