From patchwork Wed Nov 16 10:26:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13044810 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B52DC433FE for ; Wed, 16 Nov 2022 10:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232045AbiKPKi6 (ORCPT ); Wed, 16 Nov 2022 05:38:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230031AbiKPKgW (ORCPT ); Wed, 16 Nov 2022 05:36:22 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15C0A1571C for ; Wed, 16 Nov 2022 02:28:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668594532; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AXY/UyjjpCuDyNIViwtXXXaWlWVq5fOjr9nC+t8u+wk=; b=bpmJTPzf1VnkDmm2BM3gxvRChC4ZpYwv2cFDFVRGRvkYFXR3WQw3fxu0Yq/fVZui9JENsC t2OhDgm+ZBKH6qLVfDyXeeyPbgrXj/l39+P6AfvoKFqMKVQWWUj52nHcjTwKKMcN7g7Tzd vR8gNy2CoNW034zt/oc7XKdDRz03asM= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-325-nf3OqAa0Mp2NEpiQ4Fl_4w-1; Wed, 16 Nov 2022 05:28:47 -0500 X-MC-Unique: nf3OqAa0Mp2NEpiQ4Fl_4w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 43CBC1C0A10F; Wed, 16 Nov 2022 10:28:45 +0000 (UTC) Received: from t480s.fritz.box (unknown [10.39.193.216]) by smtp.corp.redhat.com (Postfix) with ESMTP id C3F5B2028E8F; Wed, 16 Nov 2022 10:28:37 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, Linus Torvalds , Andrew Morton , Jason Gunthorpe , John Hubbard , Peter Xu , Greg Kroah-Hartman , Andrea Arcangeli , Hugh Dickins , Nadav Amit , Vlastimil Babka , Matthew Wilcox , Mike Kravetz , Muchun Song , Shuah Khan , Lucas Stach , David Airlie , Oded Gabbay , Arnd Bergmann , Christoph Hellwig , Alex Williamson , David Hildenbrand , Christian Benvenuti , Nelson Escobar , Leon Romanovsky Subject: [PATCH mm-unstable v1 11/20] RDMA/usnic: remove FOLL_FORCE usage Date: Wed, 16 Nov 2022 11:26:50 +0100 Message-Id: <20221116102659.70287-12-david@redhat.com> In-Reply-To: <20221116102659.70287-1-david@redhat.com> References: <20221116102659.70287-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Precedence: bulk List-ID: GUP now supports reliable R/O long-term pinning in COW mappings, such that we break COW early. MAP_SHARED VMAs only use the shared zeropage so far in one corner case (DAXFS file with holes), which can be ignored because GUP does not support long-term pinning in fsdax (see check_vma_flags()). Consequently, FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM is no longer required for reliable R/O long-term pinning: FOLL_LONGTERM is sufficient. So stop using FOLL_FORCE, which is really only for ptrace access. Cc: Christian Benvenuti Cc: Nelson Escobar Cc: Jason Gunthorpe Cc: Leon Romanovsky Signed-off-by: David Hildenbrand Reviewed-by: Jason Gunthorpe --- drivers/infiniband/hw/usnic/usnic_uiom.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c index 67923ced6e2d..c301b3be9f30 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c @@ -85,6 +85,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, int dmasync, struct usnic_uiom_reg *uiomr) { struct list_head *chunk_list = &uiomr->chunk_list; + unsigned int gup_flags = FOLL_LONGTERM; struct page **page_list; struct scatterlist *sg; struct usnic_uiom_chunk *chunk; @@ -96,7 +97,6 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, int off; int i; dma_addr_t pa; - unsigned int gup_flags; struct mm_struct *mm; /* @@ -131,8 +131,8 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, goto out; } - gup_flags = FOLL_WRITE; - gup_flags |= (writable) ? 0 : FOLL_FORCE; + if (writable) + gup_flags |= FOLL_WRITE; cur_base = addr & PAGE_MASK; ret = 0; @@ -140,8 +140,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, ret = pin_user_pages(cur_base, min_t(unsigned long, npages, PAGE_SIZE / sizeof(struct page *)), - gup_flags | FOLL_LONGTERM, - page_list, NULL); + gup_flags, page_list, NULL); if (ret < 0) goto out;