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>

3 files changed, 24 insertions, 0 deletions

diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index eb8eb00f3b52..eaaca897305c 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -196,6 +196,7 @@ static int filelayout_async_handle_error(struct rpc_task *task,
                         _pnfs_return_layout(state->inode);
                 filelayout_mark_devid_invalid(devid);
                 rpc_wake_up(&tbl->slot_tbl_waitq);
+                nfs4_ds_disconnect(clp);
                 /* fall through */
         default:
                 dprintk("%s Retry through MDS. Error %d\n", __func__,
diff --git a/fs/nfs/nfs4filelayout.h b/fs/nfs/nfs4filelayout.h
index 3259be60da92..95562ad43e12 100644
--- a/fs/nfs/nfs4filelayout.h
+++ b/fs/nfs/nfs4filelayout.h
@@ -146,5 +146,6 @@ extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
 extern void nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
 struct nfs4_file_layout_dsaddr *
 get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id, gfp_t gfp_flags);
+void nfs4_ds_disconnect(struct nfs_client *clp);
 
 #endif /* FS_NFS_NFS4FILELAYOUT_H */
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
  */