cifs: Introduce helpers for finding TCP connection

Add helpers for finding TCP connections that are good candidates for
being used by DFS refresh worker.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
index 49c5f04..e889608 100644 (file)
--- a/fs/cifs/dfs_cache.c
+++ b/fs/cifs/dfs_cache.c
@@ -1305,6 +1305,30 @@ static char *get_dfs_root(const char *path)
        return npath;
 }
 
+static inline void put_tcp_server(struct TCP_Server_Info *server)
+{
+       cifs_put_tcp_session(server, 0);
+}
+
+static struct TCP_Server_Info *get_tcp_server(struct smb_vol *vol)
+{
+       struct TCP_Server_Info *server;
+
+       server = cifs_find_tcp_session(vol);
+       if (IS_ERR_OR_NULL(server))
+               return NULL;
+
+       spin_lock(&GlobalMid_Lock);
+       if (server->tcpStatus != CifsGood) {
+               spin_unlock(&GlobalMid_Lock);
+               put_tcp_server(server);
+               return NULL;
+       }
+       spin_unlock(&GlobalMid_Lock);
+
+       return server;
+}
+
 /* Find root SMB session out of a DFS link path */
 static struct cifs_ses *find_root_ses(struct vol_info *vi,
                                      struct cifs_tcon *tcon,
@@ -1347,13 +1371,8 @@ static struct cifs_ses *find_root_ses(struct vol_info *vi,
                goto out;
        }
 
-       server = cifs_find_tcp_session(&vol);
-       if (IS_ERR_OR_NULL(server)) {
-               ses = ERR_PTR(-EHOSTDOWN);
-               goto out;
-       }
-       if (server->tcpStatus != CifsGood) {
-               cifs_put_tcp_session(server, 0);
+       server = get_tcp_server(&vol);
+       if (!server) {
                ses = ERR_PTR(-EHOSTDOWN);
                goto out;
        }
@@ -1451,19 +1470,18 @@ static void refresh_cache_worker(struct work_struct *work)
        mutex_lock(&vol_lock);
 
        list_for_each_entry(vi, &vol_list, list) {
-               server = cifs_find_tcp_session(&vi->smb_vol);
-               if (IS_ERR_OR_NULL(server))
+               server = get_tcp_server(&vi->smb_vol);
+               if (!server)
                        continue;
-               if (server->tcpStatus != CifsGood)
-                       goto next;
+
                get_tcons(server, &list);
                list_for_each_entry_safe(tcon, ntcon, &list, ulist) {
                        refresh_tcon(vi, tcon);
                        list_del_init(&tcon->ulist);
                        cifs_put_tcon(tcon);
                }
-next:
-               cifs_put_tcp_session(server, 0);
+
+               put_tcp_server(server);
        }
        queue_delayed_work(dfscache_wq, &refresh_task, cache_ttl * HZ);
        mutex_unlock(&vol_lock);