NFSv4.1 dereference a disconnected data server client record

When the last DS io is processed, the data server client record will be
freed.

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

1 files changed, 22 insertions, 0 deletions

diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index d4d2032c1992..bf49b78db1b3 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -149,6 +149,28 @@ _data_server_lookup_locked(const struct list_head *dsaddrs)
 }
 
 /*
+ * Lookup DS by nfs_client pointer. Zero data server client pointer
+ */
+void nfs4_ds_disconnect(struct nfs_client *clp)
+{
+        struct nfs4_pnfs_ds *ds;
+        struct nfs_client *found = NULL;
+
+        dprintk("%s clp %p\n", __func__, clp);
+        spin_lock(&nfs4_ds_cache_lock);
+        list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
+                if (ds->ds_clp && ds->ds_clp == clp) {
+                        found = ds->ds_clp;
+                        ds->ds_clp = NULL;
+                }
+        spin_unlock(&nfs4_ds_cache_lock);
+        if (found) {
+                set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
+                nfs_put_client(clp);
+        }
+}
+
+/*
  * Create an rpc connection to the nfs4_pnfs_ds data server
  * Currently only supports IPv4 and IPv6 addresses
  */