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 3C6351891A9 for ; Fri, 11 Sep 2026 00:34:15 +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=1789086858; cv=none; b=qZ/SJT8VN9IU1D6H+udw1kPkuShG0yAUEeksbw+VjTOqmF+nBHyJxxQjH8rYAMVRNMa9jURw3rc9XtOLwsMXuuuxpmcjr50GI2vToSx2vc61HXqDqzoGCNggvdw5N2+V5T9y34j3R6HtvGPaCIN3rDnfinZbwonbWNUwpbPEHIY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789086858; c=relaxed/simple; bh=7ctE6MOjll48+D25s0ViMyw/p4TWh4mqiU3c7iuD7/4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nV7fezUgJmMThodXiU3qG908mwpi9jk/ma/Lzyo0sIx1kx4afL+JNp79RVR/SVFUn1NPAgFH0ltmZhHYFyhm269rCLN15cE7f+He1mhsBMdKwVBq6zUhNn+QogIt7ooANt4eCI1otjK4/xP1FLjcucr/L20W9FAqWdPinPG/cz4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NSzH29ZC; 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="NSzH29ZC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D2531F0089A; Fri, 11 Sep 2026 00:34:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789086854; bh=UAMvTsbABiGRVoOaSRfq6lSNQgfHd4jeox7utp0alTM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NSzH29ZC9H1lc6zX43fInWIfSfdCBXkXPmMDGszVKBMA+noUn0XGQUMVwz5MciJYH 8sFcKrm/yf9BkxiEC4fe/bnEDqNdwU3IkH5sciIyRRzGRE/L4zYLnL0WgrHTTJJGie 6anOxbh14ZzWJ/UWYjCBbEsrvrssjQemdag4KiczUSQD75jJfBz7sWJihiROOm+prk q3HoILE7I++UBwGnx5AZJCONSygKv8OWLXmaG7tt3wiSP0AZTZSwCibkGr54v9wXQA iAuhXge26KYxERzbq6qa3D9n+2r/O+WNHB1AWtaI8bTt9kt6O2lZNgThBAQux23Fj0 JYKxC9LgFmk8g== From: Sasha Levin To: stable@vger.kernel.org Cc: Li Chen , "Michael S. Tsirkin" , Sasha Levin Subject: [PATCH 6.18.y 4/6] nvdimm: virtio_pmem: always wake -ENOSPC waiters Date: Thu, 10 Sep 2026 20:34:08 -0400 Message-ID: <20260911003410.3483414-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260911003410.3483414-1-sashal@kernel.org> References: <2026090938-reliance-nearly-8ed8@gregkh> <20260911003410.3483414-1-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: Li Chen [ Upstream commit 811808761e19fdea1c25b7c76734b8945f758f27 ] virtio_pmem_host_ack() reclaims virtqueue descriptors with virtqueue_get_buf(). The -ENOSPC waiter wakeup is tied to completing the returned token. If token completion is skipped for any reason, reclaimed descriptors may not wake a waiter and the submitter may sleep forever waiting for a free slot. Always wake one -ENOSPC waiter for each virtqueue completion before touching the returned token. Signed-off-by: Li Chen Signed-off-by: Michael S. Tsirkin Message-ID: <20260630092338.2094628-7-me@linux.beauty> Stable-dep-of: e57140944b5a ("nvdimm: virtio_pmem: refcount requests for token lifetime") Signed-off-by: Sasha Levin --- drivers/nvdimm/nd_virtio.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/nvdimm/nd_virtio.c b/drivers/nvdimm/nd_virtio.c index dc6babb9742d4..0ef8a7820fea2 100644 --- a/drivers/nvdimm/nd_virtio.c +++ b/drivers/nvdimm/nd_virtio.c @@ -15,26 +15,33 @@ struct virtio_pmem_flush_work { struct bio *bio; }; +static void virtio_pmem_wake_one_waiter(struct virtio_pmem *vpmem) +{ + struct virtio_pmem_request *req_buf; + + if (list_empty(&vpmem->req_list)) + return; + + req_buf = list_first_entry(&vpmem->req_list, + struct virtio_pmem_request, list); + req_buf->wq_buf_avail = true; + wake_up(&req_buf->wq_buf); + list_del(&req_buf->list); +} + /* The interrupt handler */ void virtio_pmem_host_ack(struct virtqueue *vq) { struct virtio_pmem *vpmem = vq->vdev->priv; - struct virtio_pmem_request *req_data, *req_buf; + struct virtio_pmem_request *req_data; unsigned long flags; unsigned int len; spin_lock_irqsave(&vpmem->pmem_lock, flags); while ((req_data = virtqueue_get_buf(vq, &len)) != NULL) { + virtio_pmem_wake_one_waiter(vpmem); req_data->done = true; wake_up(&req_data->host_acked); - - if (!list_empty(&vpmem->req_list)) { - req_buf = list_first_entry(&vpmem->req_list, - struct virtio_pmem_request, list); - req_buf->wq_buf_avail = true; - wake_up(&req_buf->wq_buf); - list_del(&req_buf->list); - } } spin_unlock_irqrestore(&vpmem->pmem_lock, flags); } -- 2.53.0