cifs: handle when server starts supporting multichannel

When the user mounts with multichannel option, but the
server does not support it, there can be a time in future
where it can be supported.

With this change, such a case is handled.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>

diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index eed8dbb6b2fbe3e4dcf69376f52a6407d3b1f7f9..00ad41633e26bb0dbd6bf0538e7dc2c49e345f55 100644 (file)
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -132,6 +132,7 @@ extern int SendReceiveBlockingLock(const unsigned int xid,
                        struct smb_hdr *in_buf,
                        struct smb_hdr *out_buf,
                        int *bytes_returned);
+
 void
 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
                                      bool all_channels);

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index b514b41cc9f034b77e330b9fcfd739404af02ecc..1490547ec4937c9e985e0d24af7ef483d405a372 100644 (file)
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -132,6 +132,9 @@ static void smb2_query_server_interfaces(struct work_struct *work)
        free_xid(xid);
 
        if (rc) {
+               if (rc == -EOPNOTSUPP)
+                       return;
+
                cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
                                __func__, rc);
        }

diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index b7665155f4e2cf625f104498e168c522f1ce5133..0d4351e430695ec90f1d2331f26dc90963bd2233 100644 (file)
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -163,6 +163,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
        int rc = 0;
        struct nls_table *nls_codepage = NULL;
        struct cifs_ses *ses;
+       int xid;
 
        /*
         * SMB2s NegProt, SessSetup, Logoff do not have tcon yet so
@@ -307,17 +308,44 @@ skip_sess_setup:
                tcon->need_reopen_files = true;
 
        rc = cifs_tree_connect(0, tcon, nls_codepage);
-       mutex_unlock(&ses->session_mutex);
 
        cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
        if (rc) {
                /* If sess reconnected but tcon didn't, something strange ... */
+               mutex_unlock(&ses->session_mutex);
                cifs_dbg(VFS, "reconnect tcon failed rc = %d\n", rc);
                goto out;
        }
 
+       if (!rc &&
+           (server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
+               mutex_unlock(&ses->session_mutex);
+
+               /*
+                * query server network interfaces, in case they change
+                */
+               xid = get_xid();
+               rc = SMB3_request_interfaces(xid, tcon, false);
+               free_xid(xid);
+
+               if (rc)
+                       cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
+                                __func__, rc);
+
+               if (ses->chan_max > ses->chan_count &&
+                   !SERVER_IS_CHAN(server)) {
+                       if (ses->chan_count == 1)
+                               cifs_server_dbg(VFS, "supports multichannel now\n");
+
+                       cifs_try_adding_channels(ses);
+               }
+       } else {
+               mutex_unlock(&ses->session_mutex);
+       }
+
        if (smb2_command != SMB2_INTERNAL_CMD)
-               mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
+               if (mod_delayed_work(cifsiod_wq, &server->reconnect, 0))
+                       cifs_put_tcp_session(server, false);
 
        atomic_inc(&tconInfoReconnectCount);
 out: