cifsd: Do not use 0 or 0xFFFFFFFF for TreeID

Returning TreeID=0 is valid behaviour according to [MS-SMB2] 2.2.1.2:

  TreeId (4 bytes): Uniquely identifies the tree connect for the command.
  This MUST be 0 for the SMB2 TREE_CONNECT Request. The TreeId can be
  any unsigned 32-bit integer that is received from a previous
  SMB2 TREE_CONNECT Response. TreeId SHOULD be set to 0 for the
  following commands:
   [...]

However, some client implementations reject it as invalid. Windows10
assigns ids starting from 1, and samba4 returns a random uint32_t
which suggests there may be other clients that consider it is
invalid behaviour.

Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifsd/mgmt/ksmbd_ida.c b/fs/cifsd/mgmt/ksmbd_ida.c
index 3dbc27c..54194d9 100644 (file)
--- a/fs/cifsd/mgmt/ksmbd_ida.c
+++ b/fs/cifsd/mgmt/ksmbd_ida.c
@@ -14,9 +14,7 @@ int ksmbd_acquire_smb2_tid(struct ida *ida)
 {
        int id;
 
-       id = __acquire_id(ida, 0, 0);
-       if (id == 0xFFFF)
-               id = __acquire_id(ida, 0, 0);
+       id = __acquire_id(ida, 1, 0xFFFFFFFF);
 
        return id;
 }