smb3: display network namespace in debug information

commit 7b38f6ddc97bf572c3422d3175e8678dd95502fa upstream.

We recently had problems where a network namespace was deleted
causing hard to debug reconnect problems.  To help deal with
configuration issues like this it is useful to dump the network
namespace to better debug what happened.

So add this to information displayed in /proc/fs/cifs/DebugData for
the server (and channels if mounted with multichannel). For example:

   Local Users To Server: 1 SecMode: 0x1 Req On Wire: 0 Net namespace: 4026531840

This can be easily compared with what is displayed for the
processes on the system. For example /proc/1/ns/net in this case
showed the same thing (see below), and we can see that the namespace
is still valid in this example.

   'net:[4026531840]'

Cc: stable@vger.kernel.org
Acked-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/smb/client/cifs_debug.c b/fs/smb/client/cifs_debug.c
index ed0f71137584f3150cbbc9a0a8b258d435dca8fe..d14e88e14fb2e276c04e44230d8909fb91ce802a 100644 (file)
--- a/fs/smb/client/cifs_debug.c
+++ b/fs/smb/client/cifs_debug.c
@@ -153,6 +153,11 @@ cifs_dump_channel(struct seq_file *m, int i, struct cifs_chan *chan)
                   in_flight(server),
                   atomic_read(&server->in_send),
                   atomic_read(&server->num_waiters));
+#ifdef CONFIG_NET_NS
+       if (server->net)
+               seq_printf(m, " Net namespace: %u ", server->net->ns.inum);
+#endif /* NET_NS */
+
 }
 
 static inline const char *smb_speed_to_str(size_t bps)
@@ -429,10 +434,15 @@ skip_rdma:
                                server->reconnect_instance,
                                server->srv_count,
                                server->sec_mode, in_flight(server));
+#ifdef CONFIG_NET_NS
+               if (server->net)
+                       seq_printf(m, " Net namespace: %u ", server->net->ns.inum);
+#endif /* NET_NS */
 
                seq_printf(m, "\nIn Send: %d In MaxReq Wait: %d",
                                atomic_read(&server->in_send),
                                atomic_read(&server->num_waiters));
+
                if (server->leaf_fullpath) {
                        seq_printf(m, "\nDFS leaf full path: %s",
                                   server->leaf_fullpath);