[PATCH v3 06/11] cifs: Introduce helpers for finding TCP connection

Paulo Alcantara (SUSE)
2019-11-27T00:37:22Z

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>
---
fs/cifs/dfs_cache.c | 44 +++++++++++++++++++++++++++++++-------------
1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
index 49c5f045270f..e889608e5e13 100644
--- 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);
--
2.24.0