Commit f456458e authored Apr 22, 2019 by Jeff Layton Committed by J. Bruce Fields Apr 22, 2019

nfsd: wake blocked file lock waiters before sending callback

When a blocked NFS lock is "awoken" we send a callback to the server and
then wake any hosts waiting on it. If a client attempts to get a lock
and then drops off the net, we could end up waiting for a long time
until we end up waking locks blocked on that request.

So, wake any other waiting lock requests before sending the callback.
Do this by calling locks_delete_block in a new "prepare" phase for
CB_NOTIFY_LOCK callbacks.

URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363


Fixes: 16306a61 ("fs/locks: always delete_block after waiting.")
Reported-by: Slawomir Pryczek <slawek1211@gmail.com>
Cc: Neil Brown <neilb@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

parent 6aaafc43

fs/nfsd/nfs4state.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -298,6 +298,14 @@ remove_blocked_locks(struct nfs4_lockowner *lo)
		}
		}

		static void
		nfsd4_cb_notify_lock_prepare(struct nfsd4_callback *cb)
		{
		struct nfsd4_blocked_lock *nbl = container_of(cb,
		struct nfsd4_blocked_lock, nbl_cb);
		locks_delete_block(&nbl->nbl_lock);
		}

		static int
		nfsd4_cb_notify_lock_done(struct nfsd4_callback cb, struct rpc_task task)
		{
		@@ -325,6 +333,7 @@ nfsd4_cb_notify_lock_release(struct nfsd4_callback *cb)
		}

		static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops = {
		.prepare = nfsd4_cb_notify_lock_prepare,
		.done = nfsd4_cb_notify_lock_done,
		.release = nfsd4_cb_notify_lock_release,
		};

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