From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793831254; b=ZJRSv7OWq91rftRQluCuCDwNh5njkuCYCROmH4bQKEuq9NuOksBKV+Ev3txcPIJ6qcHS 7sJiksW93DUlN6h5ZPZBeDjRTxzKohoaoj3ekYsIUL69iCHdjZPJkXo+uhzgcv2E1IhP7 W93/c41CJx7m4OXOr5CSN/v2Dfaeqn4c7QvVeeXOWIKgUWe+3pEt1+KYMB9KWJp/n8Hcy 1qaDdu7x8YZK1DxJCeKy8MDmdP1VGvEEpXM9//7DR/+CP7FvRsTvVR6g+3ma8+BDJom4L JxwGvPlWqVHkbeD7hyU9A49sKwugYJDUimtWvY75YLbtfSjAlw5b0Zh6UZd3Igt9pFg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831254; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=C4iN2i7whsB2R52uuhoXaN+c1J/Zwt70UjYeZqAzFwY=; b=OFG3BZOykfn2YhTE5c+NJIBtlnuZU4Hg0M+LOkT8qLoIEyoDgSm7Bo7sqLAHo7n0z67M 8QAwxgViyFCwFfbrz/Hh7A4OqcOwXMi4imEED4VHJeXUftc+dpFYNZhQb1zWXjAtPk8KD bUcpeAqQ9nvkjOgNkowWnzUWwzk4oKHgOnpkMXtHMMdqDJpyD6YrXICDY04eFo0giYj24 0pLYV1DHMFjlNoXFC+6V5If01Ug4AdVuKP0t6CG6Hs9iimSeD9nABomKm2GepJPoUHHrp kcW8lxlmTKjY1G5RMLNjgEBjAuDOkKL9liih+5KeZeLH+gvsf94Gw2vRZMf74YQ6Glw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=WdyFSAhd; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A0E2606A33E; Wed, 4 Nov 2026 22:27:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=WdyFSAhd Received: by smtp.kernel.org (Postfix) with ESMTPSA id B76081F0093A; Wed, 4 Nov 2026 22:27:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793831254; bh=C4iN2i7whsB2R52uuhoXaN+c1J/Zwt70UjYeZqAzFwY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WdyFSAhdM6nnyDu80F1lnRrbYjqBh1sLeq5BwECZQsKPpcWYItql3LMgw3EJaYgOZ 8VQCayEkUNHos+JZgveUkYJVT6DMGcFybeaKCzNQzN82avKq9IkafYvETh7pGbB7my 6NgzKD/vl7J6oeNTKzANqlP8kuC4OtwswKvsYRfw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jeff Layton , Chuck Lever , Sasha Levin Subject: [PATCH 6.18 0554/1005] nfsd: use test_and_clear_bit for somebody_reclaimed to prevent lost update Date: Wed, 4 Nov 2026 16:04:47 -0500 Message-ID: <20261104211059.412643986@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Layton [ Upstream commit 0a5a548861ab09e79a6b3062ac17e410323af3cd ] clients_still_reclaiming() uses separate test_bit() and clear_bit() calls on NFSD_NET_SOMEBODY_RECLAIMED. A concurrent set_bit() from the OPEN or LOCK reclaim path arriving between the test and clear is silently lost, causing the next laundromat tick to end grace prematurely. Replace with test_and_clear_bit() to make the read-and-clear atomic. Fixes: 8c67a210c90c ("nfsd: convert nfsd_net boolean flags to unsigned long flags word") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260611-nfsd-testing-v2-13-5b90e276f2d9@kernel.org Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- fs/nfsd/nfs4state.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index f5671861ef7e7..e56f072d2e5de 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6856,9 +6856,8 @@ static bool clients_still_reclaiming(struct nfsd_net *nn) if (atomic_read(&nn->nr_reclaim_complete) == size) return false; } - if (!test_bit(NFSD_NET_SOMEBODY_RECLAIMED, &nn->flags)) + if (!test_and_clear_bit(NFSD_NET_SOMEBODY_RECLAIMED, &nn->flags)) return false; - clear_bit(NFSD_NET_SOMEBODY_RECLAIMED, &nn->flags); /* * If we've given them *two* lease times to reclaim, and they're * still not done, give up: -- 2.53.0