6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jeff Layton jlayton@kernel.org
commit b9382e29ca538b879645899ce45d652a304e2ed2 upstream.
nfsd_file_dispose_list_delayed can be called from the filecache laundrette, which is shut down after the nfsd threads are shut down and the nfsd_serv pointer is cleared. If nn->nfsd_serv is NULL then there are no threads to wake.
Ensure that the nn->nfsd_serv pointer is non-NULL before calling svc_wake_up in nfsd_file_dispose_list_delayed. This is safe since the svc_serv is not freed until after the filecache laundrette is cancelled.
Reported-by: Salvatore Bonaccorso carnil@debian.org Closes: https://bugs.debian.org/1093734 Fixes: ffb402596147 ("nfsd: Don't leave work of closing files to a work queue") Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton jlayton@kernel.org Reviewed-by: NeilBrown neilb@suse.de Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfsd/filecache.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
--- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -445,11 +445,20 @@ nfsd_file_dispose_list_delayed(struct li struct nfsd_file, nf_gc); struct nfsd_net *nn = net_generic(nf->nf_net, nfsd_net_id); struct nfsd_fcache_disposal *l = nn->fcache_disposal; + struct svc_serv *serv;
spin_lock(&l->lock); list_move_tail(&nf->nf_gc, &l->freeme); spin_unlock(&l->lock); - svc_wake_up(nn->nfsd_serv); + + /* + * The filecache laundrette is shut down after the + * nn->nfsd_serv pointer is cleared, but before the + * svc_serv is freed. + */ + serv = nn->nfsd_serv; + if (serv) + svc_wake_up(serv); } }