smb: client: get rid of TCP_Server_Info::refpath_lock

TCP_Server_Info::leaf_fullpath is allocated in cifs_get_tcp_session()
and never changed afterwards, so there is no need to serialize its
access.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index c747b6f9baca23fc976f3617d80c33d167ee8848..49ffc040f736c7b9715afe099ea0cfcfdd33c595 100644 (file)
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -811,18 +811,9 @@ struct TCP_Server_Info {
        bool use_swn_dstaddr;
        struct sockaddr_storage swn_dstaddr;
 #endif
-       struct mutex refpath_lock; /* protects leaf_fullpath */
        /*
-        * leaf_fullpath: Canonical DFS referral path related to this
-        *                connection.
-        *                It is used in DFS cache refresher, reconnect and may
-        *                change due to nested DFS links.
-        *
-        * Protected by @refpath_lock and @srv_lock.  The @refpath_lock is
-        * mostly used for not requiring a copy of @leaf_fullpath when getting
-        * cached or new DFS referrals (which might also sleep during I/O).
-        * While @srv_lock is held for making string and NULL comparisons against
-        * both fields as in mount(2) and cache refresh.
+        * Canonical DFS referral path used in cifs_reconnect() for failover as
+        * well as in DFS cache refresher.
         *
         * format: \\HOST\SHARE[\OPTIONAL PATH]
         */

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 73d07d95d4354fab4571803b7405c45de0875e7b..1053ef8915fbbcd6d161b0637b39f932aadc0517 100644 (file)
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -492,7 +492,7 @@ static int reconnect_target_locked(struct TCP_Server_Info *server,
 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 {
        struct dfs_cache_tgt_iterator *target_hint = NULL;
-
+       const char *ref_path = server->leaf_fullpath + 1;
        DFS_CACHE_TGT_LIST(tl);
        int num_targets = 0;
        int rc = 0;
@@ -505,10 +505,8 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
         * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
         * refreshing the referral, so, in this case, default it to 1.
         */
-       mutex_lock(&server->refpath_lock);
-       if (!dfs_cache_noreq_find(server->leaf_fullpath + 1, NULL, &tl))
+       if (!dfs_cache_noreq_find(ref_path, NULL, &tl))
                num_targets = dfs_cache_get_nr_tgts(&tl);
-       mutex_unlock(&server->refpath_lock);
        if (!num_targets)
                num_targets = 1;
 
@@ -552,9 +550,7 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
                mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
        } while (server->tcpStatus == CifsNeedReconnect);
 
-       mutex_lock(&server->refpath_lock);
-       dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, target_hint);
-       mutex_unlock(&server->refpath_lock);
+       dfs_cache_noreq_update_tgthint(ref_path, target_hint);
        dfs_cache_free_tgts(&tl);
 
        /* Need to set up echo worker again once connection has been established */
@@ -569,13 +565,8 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
 
 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 {
-       mutex_lock(&server->refpath_lock);
-       if (!server->leaf_fullpath) {
-               mutex_unlock(&server->refpath_lock);
+       if (!server->leaf_fullpath)
                return __cifs_reconnect(server, mark_smb_session);
-       }
-       mutex_unlock(&server->refpath_lock);
-
        return reconnect_dfs_server(server);
 }
 #else
@@ -1754,9 +1745,6 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
        INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
        INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
        mutex_init(&tcp_ses->reconnect_mutex);
-#ifdef CONFIG_CIFS_DFS_UPCALL
-       mutex_init(&tcp_ses->refpath_lock);
-#endif
        memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
               sizeof(tcp_ses->srcaddr));
        memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,

diff --git a/fs/smb/client/dfs_cache.c b/fs/smb/client/dfs_cache.c
index 72527623f4330b7d71a993050d6d8d14fb011fd1..5022bb1f122a1088beceef8fd7ab7fd8ff514f23 100644 (file)
--- a/fs/smb/client/dfs_cache.c
+++ b/fs/smb/client/dfs_cache.c
@@ -1141,13 +1141,11 @@ static char *get_ses_refpath(struct cifs_ses *ses)
        struct TCP_Server_Info *server = ses->server;
        char *path = ERR_PTR(-ENOENT);
 
-       mutex_lock(&server->refpath_lock);
        if (server->leaf_fullpath) {
-               path = kstrdup(server->leaf_fullpath + 1, GFP_ATOMIC);
+               path = kstrdup(server->leaf_fullpath + 1, GFP_KERNEL);
                if (!path)
                        path = ERR_PTR(-ENOMEM);
        }
-       mutex_unlock(&server->refpath_lock);
        return path;
 }