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 CCB2F3B4EBC; Wed, 17 Jun 2026 12:25:44 +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=1781699147; cv=pass; b=pc4FYl5JWkcsj9gLG9CgSBK4qX5UTa1coB+2obwjsfA4d+rkC3UISst+Jxah8R7bLu1z0lJu5cLFvFJqYeBBo8pGKuwsbmGaF+XybS3IPbmFngklBlSNaAWBrK/4oIwyeee0utmE0TjZKePyfIp+WWbXSk/RvldTQAy0vEbCNK0= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781699147; c=relaxed/simple; bh=GnBkHB2tsKfOTSBG+XpIVJrTWoi3EyC6RCw9K5pXf/Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Nvk0bV6fPvN+MWyJJWXYn0ynQXyS8ZRgjk1jt7nrF6LktkDTKb/ReJPnOBWU83R3s2BJgRSpHr31X9OD4vUVMeef0QZkg9g/oCvMYhPrNtMLvYS+cK4OV4cYFfuf9K2b/nZCPv9Am7WnNbNd5LmB50f7UhYBJkVduw9yG0rj80Q= 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=gYqJuCH4; 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="gYqJuCH4" ARC-Seal: i=1; a=rsa-sha256; t=1781699118; cv=none; d=zohomail.com; s=zohoarc; b=ispkE79M77tq0kS+OrOhhv2ZaL+6dy4oumPqOvTc0x4FjHF2aAkLOolB//8dOQrVLYsUAzW7f0F3QX8OJtKuQhuYdM1maRe4bVY3gzwQ4bXu3Yt1u9kaGjaIMPjHRpZRKAvQ5talJ/s/Xxk9k6b78LautrJajZg2LgAHFL0Fdcg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1781699118; 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=Dc+naFy0bsonvBsJn4qN18tx+ZsCovwRzyu1yOoJdtPv+S2np30QKeU82zJLU+s75yfoihbfFpnqyv98iyJwtHIn5FJSMBzHvqbURTInDNdKv13JJMzZa+KRPHExYc2UhPiyJ5XYSanGBIwDZ3oJPepNJ0jT58Moyt0AjhboXKY= 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=1781699118; 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=gYqJuCH4GYX3YQ6RMsUii/yeBimQJcEEqjBWwHmsRzZwhLSgHuA+bSSb1AAot89q syayYEAlO1JZdfE3VA2Yut77tY7NrqGJRlh0lz/lFGSqxKEAY2Yp49KhdAygwFktNvK R5cCtxW1YcMcmCVUvCmsu9Dnsu6TUA3FymPcE0ws= Received: by mx.zohomail.com with SMTPS id 17816991162441001.8892699418471; Wed, 17 Jun 2026 05:25:16 -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 v5 4/8] nvdimm: virtio_pmem: always wake -ENOSPC waiters Date: Wed, 17 Jun 2026 20:24:36 +0800 Message-ID: <20260617122442.2118957-5-me@linux.beauty> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260617122442.2118957-1-me@linux.beauty> References: <20260617122442.2118957-1-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