From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 095693A1A21 for ; Sat, 5 Sep 2026 20:05:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788638733; cv=none; b=Fs2J0pX4gZ2L8r/oEFzpHk15Baw9eicxoBAGf0zDM3B3ZxNkbiA4hTVjdz3+SC5gk3fQKe7gntklCF71ckDCfRjheALv4YeCMViZd5s6PyxQhlX5i+oYCykBvDdcFfqiEx9tQXXX3NOl69ATdJ6YiSuzx5dA9FUat1kgyixlmQY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788638733; c=relaxed/simple; bh=Hj2uCzdrEY6dbu/iKeFR8w783HpvNQ8rSEJjYk8rTJA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sMYM2ADN2Sx4Ewe6sZnk7jJbYmcV5wQtD4I14clf8TjMz8/AtUjkGDR/pzZCACPLLjwhmJypFiU0wqtADHhj8cJ1KSCYoocDhrYiIT1i558BxlNtFCGsBmRVeDJ/P232UNmjICa99gayOMIr1qccQqMZfIhWP2ud/o9AIcDFc98= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bQ42uf8p; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bQ42uf8p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67D1D1F00A3A; Sat, 5 Sep 2026 20:05:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788638731; bh=qvGydiVf1+3yJFJsDnzDWk7PrBfrSpxBcbgJYKjAeSc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bQ42uf8pQmuQE1lVry2XfXSya4hGz8C+mkihMlGP+DMrK06mdZlfv40/nH2U4G34a dxhfHZxQ3D7E9/G7JWfPMytEf6zUggxFi6c1yMYjvwVIf/ktA3LY0CTgX3uvINvWMZ 0MV8wXpjJciMUJzOTk2upodshmN4XeWI7ZKgpn5eb0fTdcBJmtx1zZGmVClf4JCXKI 2ZfCIXDJF9XzuDoGe+YsFRnp4nOY7odsC8HS3218JvOSdhh0G3pQGFnlCUl3GwNdTp yrqQGXpg1q6kN233FO1mIvDMOGl3Hp4vYcEOsPuMCMTtffnY3DjyR8B4Ic96rEp/Y1 5+LlHULLZw8vQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Jeff Layton , Chuck Lever , Sasha Levin Subject: [PATCH 6.6.y 4/7] nfsd: handle NFS4ERR_BADSLOT on CB_SEQUENCE better Date: Sat, 5 Sep 2026 16:05:24 -0400 Message-ID: <20260905200527.607284-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260905200527.607284-1-sashal@kernel.org> References: <2026090302-liquefy-backrest-fcbf@gregkh> <20260905200527.607284-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jeff Layton [ Upstream commit 999595a651a87f4285c53710b5f600d6a141f526 ] Currently it just restarts the call, without getting a new slot. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever Stable-dep-of: 01c5d5f58a5d ("nfsd: RCU-protect cl_cb_session to fix use-after-free on session teardown") Signed-off-by: Sasha Levin --- fs/nfsd/nfs4callback.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index f131c7dbbb194..8d63fc429f9ae 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1202,6 +1202,13 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback rpc_delay(task, 2 * HZ); return false; case -NFS4ERR_BADSLOT: + /* + * BADSLOT means that the client and server are out of sync + * as to the backchannel parameters. Mark the backchannel faulty + * and restart the RPC, but leak the slot so no one uses it. + */ + nfsd4_mark_cb_fault(cb->cb_clp); + cb->cb_held_slot = -1; goto retry_nowait; case -NFS4ERR_SEQ_MISORDERED: if (session->se_cb_seq_nr != 1) { -- 2.53.0