From: Alexander Aring aahringo@redhat.com
commit 7a931477bff1c7548aa8492bccf600f5f29452b1 upstream.
This patch clears the DLM_IFL_CB_PENDING_BIT flag which will be set when there is callback work queued when there was no callback to dequeue. It is a buggy case and should never happen, that's why there is a WARN_ON(). However if the case happens we are prepared to somehow recover from it.
Cc: stable@vger.kernel.org Fixes: 61bed0baa4db ("fs: dlm: use a non-static queue for callbacks") Signed-off-by: Alexander Aring aahringo@redhat.com Signed-off-by: David Teigland teigland@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/dlm/ast.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c index 700ff2e0515a..ff0ef4653535 100644 --- a/fs/dlm/ast.c +++ b/fs/dlm/ast.c @@ -181,10 +181,12 @@ void dlm_callback_work(struct work_struct *work)
spin_lock(&lkb->lkb_cb_lock); rv = dlm_dequeue_lkb_callback(lkb, &cb); - spin_unlock(&lkb->lkb_cb_lock); - - if (WARN_ON_ONCE(rv == DLM_DEQUEUE_CALLBACK_EMPTY)) + if (WARN_ON_ONCE(rv == DLM_DEQUEUE_CALLBACK_EMPTY)) { + clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags); + spin_unlock(&lkb->lkb_cb_lock); goto out; + } + spin_unlock(&lkb->lkb_cb_lock);
for (;;) { castfn = lkb->lkb_astfn;