Revert "cifs: reconnect work should have reference on server struct"

[ Upstream commit 823342524868168bf681f135d01b4ae10f5863ec ]

This reverts commit 19a4b9d6c372cab6a3b2c9a061a236136fe95274.

This earlier commit was making an assumption that each mod_delayed_work
called for the reconnect work would result in smb2_reconnect_server
being called twice. This assumption turns out to be untrue. So reverting
this change for now.

I will submit a follow-up patch to fix the actual problem in a different
way.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: 78e727e58e54 ("cifs: update iface_last_update on each query-and-update")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index f43f51f..2a30245 100644 (file)
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -401,13 +401,7 @@ static int __cifs_reconnect(struct TCP_Server_Info *server,
                        spin_unlock(&server->srv_lock);
                        cifs_swn_reset_server_dstaddr(server);
                        cifs_server_unlock(server);
-
-                       /* increase ref count which reconnect work will drop */
-                       spin_lock(&cifs_tcp_ses_lock);
-                       server->srv_count++;
-                       spin_unlock(&cifs_tcp_ses_lock);
-                       if (mod_delayed_work(cifsiod_wq, &server->reconnect, 0))
-                               cifs_put_tcp_session(server, false);
+                       mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
                }
        } while (server->tcpStatus == CifsNeedReconnect);
 
@@ -537,13 +531,7 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
                spin_unlock(&server->srv_lock);
                cifs_swn_reset_server_dstaddr(server);
                cifs_server_unlock(server);
-
-               /* increase ref count which reconnect work will drop */
-               spin_lock(&cifs_tcp_ses_lock);
-               server->srv_count++;
-               spin_unlock(&cifs_tcp_ses_lock);
-               if (mod_delayed_work(cifsiod_wq, &server->reconnect, 0))
-                       cifs_put_tcp_session(server, false);
+               mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
        } while (server->tcpStatus == CifsNeedReconnect);
 
        mutex_lock(&server->refpath_lock);
@@ -1630,19 +1618,16 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
 
        cancel_delayed_work_sync(&server->echo);
 
-       if (from_reconnect) {
+       if (from_reconnect)
                /*
                 * Avoid deadlock here: reconnect work calls
                 * cifs_put_tcp_session() at its end. Need to be sure
                 * that reconnect work does nothing with server pointer after
                 * that step.
                 */
-               if (cancel_delayed_work(&server->reconnect))
-                       cifs_put_tcp_session(server, from_reconnect);
-       } else {
-               if (cancel_delayed_work_sync(&server->reconnect))
-                       cifs_put_tcp_session(server, from_reconnect);
-       }
+               cancel_delayed_work(&server->reconnect);
+       else
+               cancel_delayed_work_sync(&server->reconnect);
 
        spin_lock(&server->srv_lock);
        server->tcpStatus = CifsExiting;

diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index f197798..da752f4 100644 (file)
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -3981,6 +3981,12 @@ void smb2_reconnect_server(struct work_struct *work)
                }
                spin_unlock(&ses->chan_lock);
        }
+       /*
+        * Get the reference to server struct to be sure that the last call of
+        * cifs_put_tcon() in the loop below won't release the server pointer.
+        */
+       if (tcon_exist || ses_exist)
+               server->srv_count++;
 
        spin_unlock(&cifs_tcp_ses_lock);
 
@@ -4028,17 +4034,13 @@ void smb2_reconnect_server(struct work_struct *work)
 
 done:
        cifs_dbg(FYI, "Reconnecting tcons and channels finished\n");
-       if (resched) {
+       if (resched)
                queue_delayed_work(cifsiod_wq, &server->reconnect, 2 * HZ);
-               mutex_unlock(&pserver->reconnect_mutex);
-
-               /* no need to put tcp session as we're retrying */
-               return;
-       }
        mutex_unlock(&pserver->reconnect_mutex);
 
        /* now we can safely release srv struct */
-       cifs_put_tcp_session(server, true);
+       if (tcon_exist || ses_exist)
+               cifs_put_tcp_session(server, 1);
 }
 
 int
@@ -4058,12 +4060,7 @@ SMB2_echo(struct TCP_Server_Info *server)
            server->ops->need_neg(server)) {
                spin_unlock(&server->srv_lock);
                /* No need to send echo on newly established connections */
-               spin_lock(&cifs_tcp_ses_lock);
-               server->srv_count++;
-               spin_unlock(&cifs_tcp_ses_lock);
-               if (mod_delayed_work(cifsiod_wq, &server->reconnect, 0))
-                       cifs_put_tcp_session(server, false);
-
+               mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
                return rc;
        }
        spin_unlock(&server->srv_lock);