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 8CC273EDE6A; Tue, 30 Jun 2026 09:24:47 +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=1782811488; cv=pass; b=dDNXwF2zebF29j6Ezm9hBKo3uC+phfI8GpyWTMCZdBdHai4razDVt0FKFwgXvYdz3UAUG0uYUkUNiCo8UyfFyLBb3EOaYJ7zA+vQZshpd0i2rUFL2rpFs/O7ZcdhQCXC+omhsWlp8AQhBXENyWjLF5bJKJ1Ax0HuHDifhIt/ko8= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782811488; c=relaxed/simple; bh=hd18FWLb1hcER0eGN0CDNYzR1McHOJM564y1QUlWJmQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DtewIB7jO1HX7fQDctqTdM3rA3JQSFVTC72HJwvu53NDWHKjXwiXIudTLMrZ2zSXYcn+jabBY3PcghGIvMEKcH927NU+BecU4uNVtY4XAEgwntUS9wajcjQ18HhByWxlbIfQbgEOzE8ZmiflhF1GjNiXPg3ThGBRy45TWT6ub4I= 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=RR2K/AEH; 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="RR2K/AEH" ARC-Seal: i=1; a=rsa-sha256; t=1782811458; cv=none; d=zohomail.com; s=zohoarc; b=j6vtgyyidvpfh4yzjBIDMs5mOJAKY75BgwtRI2LDH/HA0UPV9N3EVykPW/cIpkSrcfTl08cxZkyw9sgK0DLocqXW7D3jbzgkB6vL8HEPBgecJSz2TVLBexGQ9bQ8Dq/VoljQCoQNawZCwA/ylQyITiceJ2TngW4YPzxWLqwCB3g= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1782811458; 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=cV4ALsu3V/Afm3yHy+Bf/CmLmsd/Z4GOKtaXkbRgoWk=; b=GjdsKrYjH905os0InRouB9nPwKhtti4oMsjHdbjLVYWryMI1fiMna2m8bMJo0D/n1r++7LpCJiBC7rP2tEP2mOmsfVWAloNI0tasqZITxqtiGWCDKkTtvk7Bd25tyKlmBBxFVeh26SkI0mo+c3vnHLmOcMGg/38ILqgoE7c+LTk= 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=1782811458; 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=cV4ALsu3V/Afm3yHy+Bf/CmLmsd/Z4GOKtaXkbRgoWk=; b=RR2K/AEHiJ4oSAvOUtieRYacbkQ9uu9kx0b1u0GQLhDoiqJwDrVoWNJf5P48M2ef ERUiyQKPlWWNSYKl+ySKiHyrkDLBS5ahMlC8PFbPTB/VZ5nPXzRWB4YDxSpLHTo5O4z FdS0owk7i1tGqQ0bSlpTeXrn9Q8B872/zHVkGJp0= Received: by mx.zohomail.com with SMTPS id 1782811455428174.18424278975897; Tue, 30 Jun 2026 02:24:15 -0700 (PDT) From: Li Chen To: Pankaj Gupta , Vishal Verma , Dave Jiang , Alison Schofield , virtualization@lists.linux.dev, nvdimm@lists.linux.dev Cc: linux-kernel@vger.kernel.org, Li Chen Subject: [PATCH v7 06/12] nvdimm: virtio_pmem: always wake -ENOSPC waiters Date: Tue, 30 Jun 2026 17:23:31 +0800 Message-ID: <20260630092338.2094628-7-me@linux.beauty> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260630092338.2094628-1-me@linux.beauty> References: <20260630092338.2094628-1-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 a35044afddf34..fcb26a595d7c6 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); } -- 2.52.0