From patchwork Wed Dec 4 21:36:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11273633 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C47C5138C for ; Wed, 4 Dec 2019 21:36:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2037206DF for ; Wed, 4 Dec 2019 21:36:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="eCFl7oV6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728030AbfLDVgG (ORCPT ); Wed, 4 Dec 2019 16:36:06 -0500 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:3151 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728011AbfLDVgF (ORCPT ); Wed, 4 Dec 2019 16:36:05 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 04 Dec 2019 13:36:01 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Wed, 04 Dec 2019 13:36:05 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Wed, 04 Dec 2019 13:36:05 -0800 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 4 Dec 2019 21:36:04 +0000 Received: from hqnvemgw03.nvidia.com (10.124.88.68) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Wed, 4 Dec 2019 21:36:04 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by hqnvemgw03.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Wed, 04 Dec 2019 13:36:04 -0800 From: John Hubbard To: Andrew Morton , Jason Gunthorpe , Leon Romanovsky , Christoph Hellwig CC: Ira Weiny , , , LKML , John Hubbard , Christoph Hellwig Subject: [PATCH v2 1/2] mm/gup: allow FOLL_FORCE for get_user_pages_fast() Date: Wed, 4 Dec 2019 13:36:02 -0800 Message-ID: <20191204213603.464373-2-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191204213603.464373-1-jhubbard@nvidia.com> References: <20191204213603.464373-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1575495361; bh=D5FKf6o88yrnam68mO83xEuXphYTA3McnnbS0GFu5aA=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=eCFl7oV6N1zFHWhmaXu9MCkZmrub7KXbOYWLH/D/jUkygF0DtjswPT2qe+aARAZFH jalNYGfDUmDPJZcLuaNkfZQs5g8cxMa8gn/wgOSGkjteGuJH6rxi6NZuRw1Vlaqb2E 7uzMo7yCYyx1ZuotG2ThIsFANYlKuS2hdorpsuhz/r8JOAo/QWLOsWH+ytGPxUtk/8 Ge1jG58RtT9eRllOlBhF4qIJXXoZlK8xvAZ47WoMzWeGx9KoUM3NYZ65MgiySrtka4 w41lEaiz0oliyAhaKRxPeLlCM2bWfLxMhWhwnoW+cxAjJU3TqbQlXWqq9wKural0c/ P45ahLYmbnzlA== Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Commit 817be129e6f2 ("mm: validate get_user_pages_fast flags") allowed only FOLL_WRITE and FOLL_LONGTERM to be passed to get_user_pages_fast(). This, combined with the fact that get_user_pages_fast() falls back to "slow gup", which *does* accept FOLL_FORCE, leads to an odd situation: if you need FOLL_FORCE, you cannot call get_user_pages_fast(). There does not appear to be any reason for filtering out FOLL_FORCE. There is nothing in the _fast() implementation that requires that we avoid writing to the pages. So it appears to have been an oversight. Fix by allowing FOLL_FORCE to be set for get_user_pages_fast(). Fixes: 817be129e6f2 ("mm: validate get_user_pages_fast flags") Cc: Christoph Hellwig Signed-off-by: John Hubbard Reviewed-by: Leon Romanovsky --- mm/gup.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/gup.c b/mm/gup.c index 7646bf993b25..5244b8090440 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2415,7 +2415,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, unsigned long addr, len, end; int nr = 0, ret = 0; - if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM))) + if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM | + FOLL_FORCE))) return -EINVAL; start = untagged_addr(start) & PAGE_MASK; From patchwork Wed Dec 4 21:36:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11273643 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D0D066C1 for ; Wed, 4 Dec 2019 21:36:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF0E221826 for ; Wed, 4 Dec 2019 21:36:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="ptXEQ04x" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727982AbfLDVgM (ORCPT ); Wed, 4 Dec 2019 16:36:12 -0500 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:3166 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728011AbfLDVgI (ORCPT ); Wed, 4 Dec 2019 16:36:08 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 04 Dec 2019 13:36:03 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Wed, 04 Dec 2019 13:36:07 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Wed, 04 Dec 2019 13:36:07 -0800 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 4 Dec 2019 21:36:04 +0000 Received: from hqnvemgw03.nvidia.com (10.124.88.68) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Wed, 4 Dec 2019 21:36:04 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by hqnvemgw03.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Wed, 04 Dec 2019 13:36:04 -0800 From: John Hubbard To: Andrew Morton , Jason Gunthorpe , Leon Romanovsky , Christoph Hellwig CC: Ira Weiny , , , LKML , John Hubbard , Christoph Hellwig , Jan Kara , Jason Gunthorpe Subject: [PATCH v2 2/2] IB/umem: use get_user_pages_fast() to pin DMA pages Date: Wed, 4 Dec 2019 13:36:03 -0800 Message-ID: <20191204213603.464373-3-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191204213603.464373-1-jhubbard@nvidia.com> References: <20191204213603.464373-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1575495363; bh=wK/7Zcr9JkY1oVaBb+a1odFvVDUbZPXG7o4esu8lpZI=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=ptXEQ04xcPn8GdBQs2rp1XVY1OuF77GjHPSFFgY17UMuAVXRuuciVJqui9dCSv87B yCbOSxw7VjnSJQGnrVsT1Xq5Wqzv4+IqtS9m8ZPYl8LmZw6MkaTA5hLyDoM0xHXNPO Av16EWu/XC/kClF+whWx+5CFr/TIxNY7i2Se1qYu2a6jWWeRXdqPqg3uus4rEBVfaS i+8V/puwLz7IlHI2zyKxfZlWG0cjzbtmv0aDISe02uxsmQUApNlguxclaR436XBAyk 7gYqtM6Sg/CovzDx0g3o8qQgztOvXDyXdmH1W1G4A4gb863I1mfGx+WrBqJHiFIclE Pb9Y3ZnPvGwUQ== Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org And get rid of the mmap_sem calls, as part of that. Note that get_user_pages_fast() will, if necessary, fall back to __gup_longterm_unlocked(), which takes the mmap_sem as needed. Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Jason Gunthorpe Reviewed-by: Ira Weiny Signed-off-by: John Hubbard Reviewed-by: Leon Romanovsky --- drivers/infiniband/core/umem.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 7a3b99597ead..214e87aa609d 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -266,16 +266,13 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, sg = umem->sg_head.sgl; while (npages) { - down_read(&mm->mmap_sem); - ret = get_user_pages(cur_base, - min_t(unsigned long, npages, - PAGE_SIZE / sizeof (struct page *)), - gup_flags | FOLL_LONGTERM, - page_list, NULL); - if (ret < 0) { - up_read(&mm->mmap_sem); + ret = get_user_pages_fast(cur_base, + min_t(unsigned long, npages, + PAGE_SIZE / + sizeof(struct page *)), + gup_flags | FOLL_LONGTERM, page_list); + if (ret < 0) goto umem_release; - } cur_base += ret * PAGE_SIZE; npages -= ret; @@ -283,8 +280,6 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, sg = ib_umem_add_sg_table(sg, page_list, ret, dma_get_max_seg_size(context->device->dma_device), &umem->sg_nents); - - up_read(&mm->mmap_sem); } sg_mark_end(sg);