[PATCH 4.19 309/346] SMB3: avoid confusing warning message on mount to Azure

Greg Kroah-Hartman
2020-12-28T13:34:45Z

From: Steve French <stfrench@microsoft.com>

commit ebcd6de98754d9b6a5f89d7835864b1c365d432f upstream.

Mounts to Azure cause an unneeded warning message in dmesg
"CIFS: VFS: parse_server_interfaces: incomplete interface info"

Azure rounds up the size (by 8 additional bytes, to a
16 byte boundary) of the structure returned on the query
of the server interfaces at mount time. This is permissible
even though different than other servers so do not log a warning
if query network interfaces response is only rounded up by 8
bytes or fewer.

CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/cifs/smb2ops.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -366,7 +366,8 @@ parse_server_interfaces(struct network_i
goto out;
}

- if (bytes_left || p->Next)
+ /* Azure rounds the buffer size up 8, to a 16 byte boundary */
+ if ((bytes_left > 8) || p->Next)
cifs_dbg(VFS, "%s: incomplete interface info\n", __func__);