xen: xenbus: Catch closing of non existent transactions

Users of the xenbus functions should never close a non existent
transaction (for example by trying to closing the same transaction
twice) but better catch it in xs_request_exit() than to corrupt the
reference counter.

Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
This commit is contained in:
Simon Gaiser 2018-03-15 03:43:21 +01:00 committed by Boris Ostrovsky
parent 2a22ee6c3a
commit b93008d1ac

View file

@ -140,7 +140,9 @@ void xs_request_exit(struct xb_req_data *req)
spin_lock(&xs_state_lock);
xs_state_users--;
if ((req->type == XS_TRANSACTION_START && req->msg.type == XS_ERROR) ||
req->type == XS_TRANSACTION_END)
(req->type == XS_TRANSACTION_END &&
!WARN_ON_ONCE(req->msg.type == XS_ERROR &&
!strcmp(req->body, "ENOENT"))))
xs_state_users--;
spin_unlock(&xs_state_lock);