From: Steve French <stfrench@microsoft.com>
Date: Wed, 21 Oct 2020 00:15:42 -0500
Subject: [PATCH] smb3: do not try to cache root directory if dir leases not
 supported
Git-commit: 3c6e65e679182d55779ef6f8582f0945af4319b0
References: bsc#1190317
Patch-mainline: v5.10-rc1

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+
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
 fs/cifs/connect.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index d096cfda56eb..3a9980bf0d6e 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3608,7 +3608,10 @@ 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);
-- 
2.33.0