[PATCH v3 02/19] cifs: abort open_cached_dir if we don't request leases

[nspmangalore@gmail.com]

From: Shyam Prasad N <sprasad@microsoft.com>

It is possible that SMB2_open_init may not set lease context based
on the requested oplock level. This can happen when leases have been
temporarily or permanently disabled. When this happens, we will have
open_cached_dir making an open without lease context and the response
will anyway be rejected by open_cached_dir (thereby forcing a close to
discard this open). That's unnecessary two round-trips to the server.

This change adds a check before making the open request to the server
to make sure that SMB2_open_init did add the expected lease context
to the open in open_cached_dir.

Cc: <stable@vger.kernel.org>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
---
 fs/smb/client/cached_dir.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index 04bb95091f498..64e22c064fa0a 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -286,6 +286,14 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 			    &rqst[0], &oplock, &oparms, utf16_path);
 	if (rc)
 		goto oshr_free;
+
+	if (oplock != SMB2_OPLOCK_LEVEL_II) {
+		rc = -EINVAL;
+		cifs_dbg(FYI, "%s: Oplock level %d not suitable for cached directory\n",
+			 __func__, oplock);
+		goto oshr_free;
+	}
+
 	smb2_set_next_command(tcon, &rqst[0]);
 
 	memset(&qi_iov, 0, sizeof(qi_iov));
-- 
2.43.0