From patchwork Thu Dec 15 14:07:11 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 9476217 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 EA64A60826 for ; Thu, 15 Dec 2016 14:09:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CA9FC2878E for ; Thu, 15 Dec 2016 14:09:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BF2AC2878C; Thu, 15 Dec 2016 14:09:51 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI 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 5572428785 for ; Thu, 15 Dec 2016 14:09:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757997AbcLOOH7 (ORCPT ); Thu, 15 Dec 2016 09:07:59 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35184 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757846AbcLOOH4 (ORCPT ); Thu, 15 Dec 2016 09:07:56 -0500 Received: by mail-wm0-f67.google.com with SMTP id a20so6738661wme.2; Thu, 15 Dec 2016 06:07:55 -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=0Gv9RYH4E8NTReXSOY5SdbNURf7fxuFqTSlyv3Q95Ys=; b=Bgv0VoO4O3pu4Ggelx3B8Dz51csxTy8KTfIQzDG9TpzR7ZiL9Catx6sBGfsKYTUDaW A6wu7E0Fr37mjKN7xxyLtFyFV4PTdmF6C3DWArBglFlvVx0kXPLk1azpqZyKqymPVfkR Pe5aj36yxUJncjRAQ3H42ENyL0qBOsuCAMjv3GM5R1sOGzWZRGSR+lRIX9E8kqqiIJ1q PnGc1diyR6iEIJCmIdmABfv/SsaPmXlo8r56KY8pS7+wruCBBtL8BMWCTqwMXsaHu5Le Sra4ciyGZb8yEejRpDy7d+vyMhQ9clgD8/2h4MxStOMUrcU/TwO9O9nhtRy6VI+Ve0lr te4w== X-Gm-Message-State: AIkVDXJ2vcA4FeNxr2+lVm/D3Y1+ZhR8mqlHXc3/nktAdIhU9k11neTnKly/sT2e26/ojw== X-Received: by 10.28.142.16 with SMTP id q16mr1560159wmd.35.1481810874532; Thu, 15 Dec 2016 06:07:54 -0800 (PST) Received: from tiehlicka.suse.cz ([213.151.95.130]) by smtp.gmail.com with ESMTPSA id d8sm12646880wmi.21.2016.12.15.06.07.53 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 Dec 2016 06:07:54 -0800 (PST) From: Michal Hocko To: , Cc: Andrew Morton , Dave Chinner , "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 5/9] xfs: use memalloc_nofs_{save, restore} instead of memalloc_noio* Date: Thu, 15 Dec 2016 15:07:11 +0100 Message-Id: <20161215140715.12732-6-mhocko@kernel.org> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161215140715.12732-1-mhocko@kernel.org> References: <20161215140715.12732-1-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. Signed-off-by: Michal Hocko --- 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 f31ae592dcae..5c6f9bd4d8be 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_noio_restore(nofs_flag); if (!bp->b_addr) return -ENOMEM;