From patchwork Fri Jan 6 14:11:03 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 9501143 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6D9666070F for ; Fri, 6 Jan 2017 14:17:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 724B0284CB for ; Fri, 6 Jan 2017 14:17:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 66F98284D4; Fri, 6 Jan 2017 14:17:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.4 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0BF23284CB for ; Fri, 6 Jan 2017 14:17:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932901AbdAFOM1 (ORCPT ); Fri, 6 Jan 2017 09:12:27 -0500 Received: from mail-wj0-f195.google.com ([209.85.210.195]:34414 "EHLO mail-wj0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755138AbdAFOLW (ORCPT ); Fri, 6 Jan 2017 09:11:22 -0500 Received: by mail-wj0-f195.google.com with SMTP id qs7so42686521wjc.1; Fri, 06 Jan 2017 06:11:21 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=gnb1VwvPz5U6+zxamM6jIBO7bOp3xQNtiPm/8RpE7i4=; b=TR7RUbohCdILJZAfc1tgo+Wg7JvguoeiZo08mqD/oldXVIkoweUPvmTIa24Ptn7UAu UNcZ87bxHJtd2ONj9uqKZiALkBokaj7kFU+zYy9Lahq+8MUPNgEzEDCicFex6DddiZ6O g/cZDOEvsBHm3IEd8Yp9/YtjQ+vLfMv9YgVJieW5e82MRv/MyubgBzbZyKgPr49MDFMP arqIUQpn42+Ad9cKGOk4HUerZPOAF46PzGc6oVFqHPWWpMSF9jcE58DELXquVue078un 83/9ipeR6VDxud7a4ylb8/LyA+yRqbCAtBv9AXjyWOziS/g/k/Q+UyASVTs1xXhNL//b FSHg== X-Gm-Message-State: AIkVDXI3FrkhOtOb+8kywR+m3v7XdQTbeJCDjTvX1r6PWd+yqp0c/gqtCHZKq8BNiZ3/cg== X-Received: by 10.223.172.168 with SMTP id o37mr1156083wrc.21.1483711880233; Fri, 06 Jan 2017 06:11:20 -0800 (PST) Received: from tiehlicka.suse.cz ([213.151.95.130]) by smtp.gmail.com with ESMTPSA id b15sm3592642wma.5.2017.01.06.06.11.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 06 Jan 2017 06:11:19 -0800 (PST) From: Michal Hocko To: , Cc: Andrew Morton , Dave Chinner , djwong@kernel.org, "Theodore Ts'o" , Chris Mason , David Sterba , Jan Kara , ceph-devel@vger.kernel.org, cluster-devel@redhat.com, linux-nfs@vger.kernel.org, logfs@logfs.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mtd@lists.infradead.org, reiserfs-devel@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, linux-f2fs-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, LKML , Michal Hocko Subject: [PATCH 4/8] xfs: use memalloc_nofs_{save, restore} instead of memalloc_noio* Date: Fri, 6 Jan 2017 15:11:03 +0100 Message-Id: <20170106141107.23953-5-mhocko@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170106141107.23953-1-mhocko@kernel.org> References: <20170106141107.23953-1-mhocko@kernel.org> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Michal Hocko kmem_zalloc_large and _xfs_buf_map_pages use memalloc_noio_{save,restore} API to prevent from reclaim recursion into the fs because vmalloc can invoke unconditional GFP_KERNEL allocations and these functions might be called from the NOFS contexts. The memalloc_noio_save will enforce GFP_NOIO context which is even weaker than GFP_NOFS and that seems to be unnecessary. Let's use memalloc_nofs_{save,restore} instead as it should provide exactly what we need here - implicit GFP_NOFS context. Changes since v1 - s@memalloc_noio_restore@memalloc_nofs_restore@ in _xfs_buf_map_pages as per Brian Foster Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong --- fs/xfs/kmem.c | 10 +++++----- fs/xfs/xfs_buf.c | 8 ++++---- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c index a76a05dae96b..d69ed5e76621 100644 --- a/fs/xfs/kmem.c +++ b/fs/xfs/kmem.c @@ -65,7 +65,7 @@ kmem_alloc(size_t size, xfs_km_flags_t flags) void * kmem_zalloc_large(size_t size, xfs_km_flags_t flags) { - unsigned noio_flag = 0; + unsigned nofs_flag = 0; void *ptr; gfp_t lflags; @@ -80,14 +80,14 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t flags) * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering * the filesystem here and potentially deadlocking. */ - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) - noio_flag = memalloc_noio_save(); + if (flags & KM_NOFS) + nofs_flag = memalloc_nofs_save(); lflags = kmem_flags_convert(flags); ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) - memalloc_noio_restore(noio_flag); + if (flags & KM_NOFS) + memalloc_nofs_restore(nofs_flag); return ptr; } diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 7f0a01f7b592..8cb8dd4cdfd8 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -441,17 +441,17 @@ _xfs_buf_map_pages( bp->b_addr = NULL; } else { int retried = 0; - unsigned noio_flag; + unsigned nofs_flag; /* * vm_map_ram() will allocate auxillary structures (e.g. * pagetables) with GFP_KERNEL, yet we are likely to be under * GFP_NOFS context here. Hence we need to tell memory reclaim - * that we are in such a context via PF_MEMALLOC_NOIO to prevent + * that we are in such a context via PF_MEMALLOC_NOFS to prevent * memory reclaim re-entering the filesystem here and * potentially deadlocking. */ - noio_flag = memalloc_noio_save(); + nofs_flag = memalloc_nofs_save(); do { bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, -1, PAGE_KERNEL); @@ -459,7 +459,7 @@ _xfs_buf_map_pages( break; vm_unmap_aliases(); } while (retried++ <= 1); - memalloc_noio_restore(noio_flag); + memalloc_nofs_restore(nofs_flag); if (!bp->b_addr) return -ENOMEM;