From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A2CFC0650F for ; Mon, 1 Jul 2019 06:21:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6DBF2145D for ; Mon, 1 Jul 2019 06:21:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="iKEi8d7g" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727778AbfGAGV0 (ORCPT ); Mon, 1 Jul 2019 02:21:26 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:48624 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727750AbfGAGVJ (ORCPT ); Mon, 1 Jul 2019 02:21:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=IzZcWaqQrWGdZeOcxQugf7n/YqC01MqphcLxaz0+wR0=; b=iKEi8d7gceCqjmsj3y6uTQglI6 NtyilHlo/Z3cOVWCQphycuVqQ9ZQEAaUmLuPbPaLq8x+TUQ4nPQItVtJhEJtMCQJXUZZyE10291/3 /dabnPYnGrVGTga/rAs5SVW+jf9uVsAeL5AaxVeQdjMWxlyZygrHjfY498GAHgBJlLG/qdbo7Qntr l/rPVwz9p2HuKbtcYVxPcUdGtLeSCQZMVE6Ev8BYFiKy+/6rYLpa5KX6wp4Uhe+17QegQ7nBpRiaR MLNX+XmpbzcP/dTJzryRXIqgDprZnE9ZupEE72sMJwkCLSY4so6Z5irk7JglSSP6q8vxZyFsiEJ/m AzaC/mig==; Received: from [46.140.178.35] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hhpgX-0003Jv-Ab; Mon, 01 Jul 2019 06:21:05 +0000 From: Christoph Hellwig To: Dan Williams , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jason Gunthorpe , Ben Skeggs Cc: Ira Weiny , linux-mm@kvack.org, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 19/22] mm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot} Date: Mon, 1 Jul 2019 08:20:17 +0200 Message-Id: <20190701062020.19239-20-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190701062020.19239-1-hch@lst.de> References: <20190701062020.19239-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org We should not have two different error codes for the same condition. In addition this really complicates the code due to the special handling of EAGAIN that drops the mmap_sem due to the FAULT_FLAG_ALLOW_RETRY logic in the core vm. Signed-off-by: Christoph Hellwig --- mm/hmm.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/mm/hmm.c b/mm/hmm.c index c85ed7d4e2ce..d125df698e2b 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -974,7 +974,7 @@ long hmm_range_snapshot(struct hmm_range *range) do { /* If range is no longer valid force retry. */ if (!range->valid) - return -EAGAIN; + return -EBUSY; vma = find_vma(hmm->mm, start); if (vma == NULL || (vma->vm_flags & device_vma)) @@ -1069,10 +1069,8 @@ long hmm_range_fault(struct hmm_range *range, bool block) do { /* If range is no longer valid force retry. */ - if (!range->valid) { - up_read(&hmm->mm->mmap_sem); - return -EAGAIN; - } + if (!range->valid) + return -EBUSY; vma = find_vma(hmm->mm, start); if (vma == NULL || (vma->vm_flags & device_vma)) -- 2.20.1