nfs41: implement cb_recall_slot

Drain the fore channel and reset the max_slots to the new value.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 8406cacd3240..9164758c1ace 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1249,6 +1249,12 @@ static int nfs4_reclaim_lease(struct nfs_client *clp)
 }
 
 #ifdef CONFIG_NFS_V4_1
+void nfs41_handle_recall_slot(struct nfs_client *clp)
+{
+        set_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state);
+        nfs4_schedule_state_recovery(clp);
+}
+
 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
 {
         if (!flags)
@@ -1299,9 +1305,38 @@ out:
         return status;
 }
 
+static int nfs4_recall_slot(struct nfs_client *clp)
+{
+        struct nfs4_slot_table *fc_tbl = &clp->cl_session->fc_slot_table;
+        struct nfs4_channel_attrs *fc_attrs = &clp->cl_session->fc_attrs;
+        struct nfs4_slot *new, *old;
+        int i;
+
+        nfs4_begin_drain_session(clp);
+        new = kmalloc(fc_tbl->target_max_slots * sizeof(struct nfs4_slot),
+                      GFP_KERNEL);
+        if (!new)
+                return -ENOMEM;
+
+        spin_lock(&fc_tbl->slot_tbl_lock);
+        for (i = 0; i < fc_tbl->target_max_slots; i++)
+                new[i].seq_nr = fc_tbl->slots[i].seq_nr;
+        old = fc_tbl->slots;
+        fc_tbl->slots = new;
+        fc_tbl->max_slots = fc_tbl->target_max_slots;
+        fc_tbl->target_max_slots = 0;
+        fc_attrs->max_reqs = fc_tbl->max_slots;
+        spin_unlock(&fc_tbl->slot_tbl_lock);
+
+        kfree(old);
+        nfs4_end_drain_session(clp);
+        return 0;
+}
+
 #else /* CONFIG_NFS_V4_1 */
 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
 static int nfs4_end_drain_session(struct nfs_client *clp) { return 0; }
+static int nfs4_recall_slot(struct nfs_client *clp) { return 0; }
 #endif /* CONFIG_NFS_V4_1 */
 
 /* Set NFS4CLNT_LEASE_EXPIRED for all v4.0 errors and for recoverable errors
@@ -1398,6 +1433,15 @@ static void nfs4_state_manager(struct nfs_client *clp)
                         nfs_client_return_marked_delegations(clp);
                         continue;
                 }
+                /* Recall session slots */
+                if (test_and_clear_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state)
+                   && nfs4_has_session(clp)) {
+                        status = nfs4_recall_slot(clp);
+                        if (status < 0)
+                                goto out_error;
+                        continue;
+                }
+
 
                 nfs4_clear_state_manager_bit(clp);
                 /* Did we race with an attempt to give us more work? */