From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-op-o15.zoho.com (sender4-op-o15.zoho.com [136.143.188.15]) (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 D5EA440BCDA; Tue, 9 Jun 2026 12:08:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.15 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781006898; cv=pass; b=jcp4oFZnB23Er16ohiRI3gJA/6+yjuuLv1PvvHDxrXUEYFgXWj6ba+qLKHsOfti33ewf8Xjvk+4DiKvU6VB2wKbSsfj+GCKBs+j30lnwF2kUZ7IJZs7JAa/dCgxUQs51oZJIY7B3Hi7+JqAgVoudWyaavzQMXzRp2TDTTJpvOQM= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781006898; c=relaxed/simple; bh=GnBkHB2tsKfOTSBG+XpIVJrTWoi3EyC6RCw9K5pXf/Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C5IZluhRjfYfE3ev4/yGCCu4wkFWgcywT5fQ3QC9IFO5lUe6OC87Z/8AGHRguSSXuHLxtxCKj8UjQZ7+dv8h3lP6htegzcROFBxua48NZvHCeUrqDcWEWYPcax5xUQhw0bKa+UuGM6NJLp+/qyZ5MX+rjc+xYbTh6O5M9nABC7U= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.beauty; spf=pass smtp.mailfrom=linux.beauty; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b=gYEx9tWk; arc=pass smtp.client-ip=136.143.188.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.beauty Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.beauty Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b="gYEx9tWk" ARC-Seal: i=1; a=rsa-sha256; t=1781006880; cv=none; d=zohomail.com; s=zohoarc; b=O/qvyAqrW+dQ1Kop74v0Xm88JRX0qF/AuBdG+EHe55MhDKSTI3TgMZ8KTtLGojmZh6MxnS+OXV51W1z17XL6bBtObgPkPutkfBF7CHDuQziq9LZesXqH1ZrjfWGXg803ZFhx2rDx7ec6vUAsrdgH+BlOsXmMOGefEMLgTvPauts= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1781006880; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=79C1DXTtv5mIJ7drNEJRTgyEFf08rMj3no/LbB3sb3I=; b=hSZQ+mbDJ81XTY5ZQah9jOhHD3M9evvngtn+KZPw9e9xZAoGVVswX3N5s2yEziTKzBIVAfC9GwEaO+vRjlKKPInJvbF8wQnHGgtVOMyR1DRRvjWEiYsf2rnBxPAitm2jAYO6PTOs2XobE3OD/tWv89q7zjDgWy7wZYhJ+ABsHZc= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=linux.beauty; spf=pass smtp.mailfrom=me@linux.beauty; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1781006880; s=zmail; d=linux.beauty; i=me@linux.beauty; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:In-Reply-To:References:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=79C1DXTtv5mIJ7drNEJRTgyEFf08rMj3no/LbB3sb3I=; b=gYEx9tWk1NNnsoZ0klsu87jLlfYkMPSB74Iacv+RS2zokoQQrcoge6GmDgWe7X+D EMIsEieR7GubYhEK+e//Ocn8glbZgZvyxhuyrTpNNdHlWE+RO9pwiObQA1LTLgRr+eH SApfma+ac/smT2JksRHOEPjr3Y4x9894WM3AQT8Y= Received: by mx.zohomail.com with SMTPS id 1781006878827833.794050155962; Tue, 9 Jun 2026 05:07:58 -0700 (PDT) From: Li Chen To: Pankaj Gupta , Dan Williams , Vishal Verma , Dave Jiang , Ira Weiny , Alison Schofield , virtualization@lists.linux.dev, nvdimm@lists.linux.dev Cc: linux-kernel@vger.kernel.org, Li Chen Subject: [PATCH v4 3/7] nvdimm: virtio_pmem: always wake -ENOSPC waiters Date: Tue, 9 Jun 2026 20:07:17 +0800 Message-ID: <20260609120726.1714780-4-me@linux.beauty> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260609120726.1714780-1-me@linux.beauty> References: <20260609120726.1714780-1-me@linux.beauty> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-ZohoMailClient: External 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 --- v2->v3: - Split out the waiter wakeup ordering change from READ_ONCE()/WRITE_ONCE() updates (now patch 4/7), per Pankaj's suggestion. v3->v4: - Rebased onto v7.1-rc7 and renumbered after the flush error patches. 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 081370aac6317..16ee5a47b9938 100644 --- a/drivers/nvdimm/nd_virtio.c +++ b/drivers/nvdimm/nd_virtio.c @@ -9,26 +9,33 @@ #include "virtio_pmem.h" #include "nd.h" +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); } -- 2.52.0