From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A4FFC43382 for ; Wed, 26 Sep 2018 14:47:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0881F214FA for ; Wed, 26 Sep 2018 14:47:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="JxxhkhKv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0881F214FA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728204AbeIZVA0 (ORCPT ); Wed, 26 Sep 2018 17:00:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:59224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726915AbeIZVA0 (ORCPT ); Wed, 26 Sep 2018 17:00:26 -0400 Received: from localhost.localdomain (unknown [180.109.255.143]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 48EF220843; Wed, 26 Sep 2018 14:47:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1537973228; bh=9rVpzRlXWSV+keEy5ZQMwhTSMdXjnII8meLc5Q087Ts=; h=From:To:Cc:Subject:Date:From; b=JxxhkhKvGEC9pNjIg35V6z7D09Lb/T7QlvxrVduZN2rHt5X5ANByizIMtp41dwYLj sS2JLtU2kyWUKhoZstvn+6q9PPsOUccAgND9YQ03zktH7JjRkQ4f441TLeS/QwiCP9 nLhVXHByOIrqnjuw4VPi0LeqdiUtFw/H22EyTCiE= From: Chao Yu To: jaegeuk@kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu Subject: [PATCH] f2fs: refactor ->page_mkwrite() flow Date: Wed, 26 Sep 2018 22:45:52 +0800 Message-Id: <20180926144552.3302-1-chao@kernel.org> X-Mailer: git-send-email 2.18.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chao Yu Thread A Thread B - f2fs_vm_page_mkwrite - f2fs_setattr - down_write(i_mmap_sem) - truncate_setsize - f2fs_truncate - up_write(i_mmap_sem) - f2fs_reserve_block reserve NEW_ADDR - skip dirty page due to truncation 1. we don't need to rserve new block address for a truncated page. 2. dn.data_blkaddr is used out of node page lock coverage. Refactor ->page_mkwrite() flow to fix above issues: - use __do_map_lock() to avoid racing checkpoint() - lock data page in prior to dnode page - cover f2fs_reserve_block with i_mmap_sem lock - access dn.data_blkaddr under dnode lock Signed-off-by: Chao Yu --- fs/f2fs/file.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 6f02c8daff76..fcb4788b48aa 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -47,7 +47,7 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) struct page *page = vmf->page; struct inode *inode = file_inode(vmf->vma->vm_file); struct f2fs_sb_info *sbi = F2FS_I_SB(inode); - struct dnode_of_data dn; + struct dnode_of_data dn = { .node_changed = false }; int err; if (unlikely(f2fs_cp_error(sbi))) { @@ -59,19 +59,6 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) f2fs_bug_on(sbi, f2fs_has_inline_data(inode)); - /* block allocation */ - f2fs_lock_op(sbi); - set_new_dnode(&dn, inode, NULL, NULL, 0); - err = f2fs_reserve_block(&dn, page->index); - if (err) { - f2fs_unlock_op(sbi); - goto out; - } - f2fs_put_dnode(&dn); - f2fs_unlock_op(sbi); - - f2fs_balance_fs(sbi, dn.node_changed); - file_update_time(vmf->vma->vm_file); down_read(&F2FS_I(inode)->i_mmap_sem); lock_page(page); @@ -108,12 +95,24 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) /* fill the page */ f2fs_wait_on_page_writeback(page, DATA, false); + /* block allocation */ + __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true); + set_new_dnode(&dn, inode, NULL, NULL, 0); + err = f2fs_reserve_block(&dn, page->index); + if (err) + goto out_unlock; + /* wait for GCed page writeback via META_MAPPING */ f2fs_wait_on_block_writeback(inode, dn.data_blkaddr); + f2fs_put_dnode(&dn); +out_unlock: + __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false); out_sem: up_read(&F2FS_I(inode)->i_mmap_sem); -out: + + f2fs_balance_fs(sbi, dn.node_changed); + sb_end_pagefault(inode->i_sb); f2fs_update_time(sbi, REQ_TIME); err: -- 2.18.0