smb3: do not try to cache root directory if dir leases not supported

commit 3c6e65e679182d55779ef6f8582f0945af4319b0 upstream.

To servers which do not support directory leases (e.g. Samba)
it is wasteful to try to open_shroot (ie attempt to cache the
root directory handle).  Skip attempt to open_shroot when
server does not indicate support for directory leases.

Cuts the number of requests on mount from 17 to 15, and
cuts the number of requests on stat of the root directory
from 4 to 3.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org> # v5.1+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a61abde09ffe1f612b5d7bd23c8ef9773117c178..f4ecc13b02c0a50694f6e27a3074dd52b2373009 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3594,7 +3594,10 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
         */
        tcon->retry = volume_info->retry;
        tcon->nocase = volume_info->nocase;
-       tcon->nohandlecache = volume_info->nohandlecache;
+       if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
+               tcon->nohandlecache = volume_info->nohandlecache;
+       else
+               tcon->nohandlecache = 1;
        tcon->nodelete = volume_info->nodelete;
        tcon->local_lease = volume_info->local_lease;
        INIT_LIST_HEAD(&tcon->pending_opens);