On Fri, 2019-04-05 at 08:54 -0700, Trond Myklebust wrote: > If there are multiple callbacks queued, waiting for the callback > slot when the callback gets shut down, then they all currently > end up acting as if they hold the slot, and call > nfsd4_cb_sequence_done() resulting in interesting side-effects. > > In addition, the 'retry_nowait' path in nfsd4_cb_sequence_done() > causes a loop back to nfsd4_cb_prepare() without first freeing the > slot, which causes a deadlock when nfsd41_cb_get_slot() gets called > a second time. > > This patch therefore adds a boolean to track whether or not the > callback did pick up the slot, so that it can do the right thing > in these 2 cases. > > Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> > --- > v2: try to restart the callback if we hit nfsd4_cb_sequence_done() > without a slot. > > Hi Bruce, Should this patch perhaps be considered for stable? The callback slot leak is permanent (or at least for the lifetime of the nfs4_client). Cheers Trond -- Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx
