From patchwork Thu Dec 15 14:07:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 706107 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3tfb0T1Frjz9sdn for ; Fri, 16 Dec 2016 01:09:13 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935521AbcLOOIB (ORCPT ); Thu, 15 Dec 2016 09:08:01 -0500 Received: from mail-wj0-f193.google.com ([209.85.210.193]:35355 "EHLO mail-wj0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752070AbcLOOH6 (ORCPT ); Thu, 15 Dec 2016 09:07:58 -0500 Received: by mail-wj0-f193.google.com with SMTP id he10so9971263wjc.2; Thu, 15 Dec 2016 06:07:56 -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=iCrd59CY6vcMR5vto/NhMy6HL3IOWf8SeReYVHp3lgY=; b=tz1jBY9Eq9Ov3BohehxNw9B4P7F1u6VZc+cNEfV3CfJ86yezJAndbiJtujT82nLJkb TuOj2NUZLUOlUhNb1jceQ1OzGr/XMSiiiaAVnoa1RcR9R/CG8bgemC7Kiiv3sthoOvzO H41icl4TQ6TvPBV0CcS9U+YRAuXrcQS0CTfRyTpww+ineeYCfR0vDj/SyUifl8S942xc ozeD74P4qfLz8MTL6o0TEqqXi6LXv8v8FR4iu8ReEx/+t4BuY/Hq0iII4Pnsw+zJXsJu IvX4d6llOzoRHAUE2+F4ecGAeU1LC23TUtNyRIVZ5/lgGcKnXOnJgW6CgN6Nbgne62XL 8oPQ== X-Gm-Message-State: AIkVDXLc52Q+1oyEA9FJbBBdmIlX9+3wQzXDkc6CmuMOzpNMr0Tm10Ebw9cPYw4qdUbNVw== X-Received: by 10.194.95.194 with SMTP id dm2mr1561400wjb.207.1481810875546; Thu, 15 Dec 2016 06:07:55 -0800 (PST) Received: from tiehlicka.suse.cz ([213.151.95.130]) by smtp.gmail.com with ESMTPSA id d8sm12646880wmi.21.2016.12.15.06.07.54 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 Dec 2016 06:07:55 -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 6/9] jbd2: mark the transaction context with the scope GFP_NOFS context Date: Thu, 15 Dec 2016 15:07:12 +0100 Message-Id: <20161215140715.12732-7-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-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Michal Hocko now that we have memalloc_nofs_{save,restore} api we can mark the whole transaction context as implicitly GFP_NOFS. All allocations will automatically inherit GFP_NOFS this way. This means that we do not have to mark any of those requests with GFP_NOFS and moreover all the ext4_kv[mz]alloc(GFP_NOFS) are also safe now because even the hardcoded GFP_KERNEL allocations deep inside the vmalloc will be NOFS now. Signed-off-by: Michal Hocko Reviewed-by: Jan Kara --- fs/jbd2/transaction.c | 11 +++++++++++ include/linux/jbd2.h | 2 ++ 2 files changed, 13 insertions(+) diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index e1652665bd93..35a5d3d76182 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -388,6 +388,11 @@ static int start_this_handle(journal_t *journal, handle_t *handle, rwsem_acquire_read(&journal->j_trans_commit_map, 0, 0, _THIS_IP_); jbd2_journal_free_transaction(new_transaction); + /* + * Make sure that no allocations done while the transaction is + * open is going to recurse back to the fs layer. + */ + handle->saved_alloc_context = memalloc_nofs_save(); return 0; } @@ -466,6 +471,7 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks, trace_jbd2_handle_start(journal->j_fs_dev->bd_dev, handle->h_transaction->t_tid, type, line_no, nblocks); + return handle; } EXPORT_SYMBOL(jbd2__journal_start); @@ -1760,6 +1766,11 @@ int jbd2_journal_stop(handle_t *handle) if (handle->h_rsv_handle) jbd2_journal_free_reserved(handle->h_rsv_handle); free_and_exit: + /* + * scope of th GFP_NOFS context is over here and so we can + * restore the original alloc context. + */ + memalloc_nofs_restore(handle->saved_alloc_context); jbd2_free_handle(handle); return err; } diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index dfaa1f4dcb0c..606b6bce3a5b 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -491,6 +491,8 @@ struct jbd2_journal_handle unsigned long h_start_jiffies; unsigned int h_requested_credits; + + unsigned int saved_alloc_context; };