Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754075AbdG3KMg (ORCPT ); Sun, 30 Jul 2017 06:12:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:42860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753739AbdG3KMe (ORCPT ); Sun, 30 Jul 2017 06:12:34 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF38622BCD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=chao@kernel.org Subject: Re: [PATCH] f2fs: provide f2fs_balance_fs to __write_data_page for dentry pages To: Jaegeuk Kim , Yunlong Song Cc: yuchao0@huawei.com, sylinux@163.com, miaoxie@huawei.com, bintian.wang@huawei.com, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org References: <1501334365-123333-1-git-send-email-yunlong.song@huawei.com> <20170730073154.GA13058@jaegeuk-macbookpro.roam.corp.google.com> From: Chao Yu Message-ID: Date: Sun, 30 Jul 2017 18:11:48 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170730073154.GA13058@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6449 Lines: 187 Hi Jaegeuk, On 2017/7/30 15:31, Jaegeuk Kim wrote: > On 07/29, Yunlong Song wrote: >> f2fs_balance_fs of dentry pages is skipped in __write_data_page due to deadlock >> of gc_mutex in write_checkpoint flow. This patch enables f2fs_balance_fs for >> normal dentry page writeback to ensure there are always enough free segments. > > Sorry, by the way, why do we need to do this? I subtly thought that dirty node > pages can be produce by redirtied inodes from what we've not covered through > filesystem calls. But, in dentry pages, we're controlling the number of dirty > pages, and calling f2fs_balance_fs in each directory operations. IMO, writebacking dentry page can redirty dnode page which may be clean previously, so it will be more safe to call f2fs_balance_fs to make sure dirty metadatas of filesystem didn't exceed the threshold. Thanks, > > Chao? > > Thanks, > >> >> Reported-by: Chao Yu >> Signed-off-by: Yunlong Song >> --- >> fs/f2fs/checkpoint.c | 2 +- >> fs/f2fs/data.c | 67 +++++++++++++++++++++++++++++++++++++++++++++------- >> fs/f2fs/f2fs.h | 1 + >> 3 files changed, 61 insertions(+), 9 deletions(-) >> >> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c >> index 3c84a25..2882878 100644 >> --- a/fs/f2fs/checkpoint.c >> +++ b/fs/f2fs/checkpoint.c >> @@ -904,7 +904,7 @@ int sync_dirty_inodes(struct f2fs_sb_info *sbi, enum inode_type type) >> if (inode) { >> unsigned long cur_ino = inode->i_ino; >> >> - filemap_fdatawrite(inode->i_mapping); >> + f2fs_filemap_fdatawrite(inode->i_mapping, is_dir); >> iput(inode); >> /* We need to give cpu to another writers. */ >> if (ino == cur_ino) { >> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >> index aefc2a5..ed7efa5 100644 >> --- a/fs/f2fs/data.c >> +++ b/fs/f2fs/data.c >> @@ -1475,7 +1475,7 @@ int do_write_data_page(struct f2fs_io_info *fio) >> } >> >> static int __write_data_page(struct page *page, bool *submitted, >> - struct writeback_control *wbc) >> + struct writeback_control *wbc, bool do_balance) >> { >> struct inode *inode = page->mapping->host; >> struct f2fs_sb_info *sbi = F2FS_I_SB(inode); >> @@ -1578,7 +1578,7 @@ static int __write_data_page(struct page *page, bool *submitted, >> } >> >> unlock_page(page); >> - if (!S_ISDIR(inode->i_mode)) >> + if (do_balance) >> f2fs_balance_fs(sbi, need_balance_fs); >> >> if (unlikely(f2fs_cp_error(sbi))) { >> @@ -1602,7 +1602,7 @@ static int __write_data_page(struct page *page, bool *submitted, >> static int f2fs_write_data_page(struct page *page, >> struct writeback_control *wbc) >> { >> - return __write_data_page(page, NULL, wbc); >> + return __write_data_page(page, NULL, wbc, true); >> } >> >> /* >> @@ -1611,7 +1611,7 @@ static int f2fs_write_data_page(struct page *page, >> * warm/hot data page. >> */ >> static int f2fs_write_cache_pages(struct address_space *mapping, >> - struct writeback_control *wbc) >> + struct writeback_control *wbc, bool do_balance) >> { >> int ret = 0; >> int done = 0; >> @@ -1701,7 +1701,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping, >> if (!clear_page_dirty_for_io(page)) >> goto continue_unlock; >> >> - ret = __write_data_page(page, &submitted, wbc); >> + ret = __write_data_page(page, &submitted, wbc, do_balance); >> if (unlikely(ret)) { >> /* >> * keep nr_to_write, since vfs uses this to >> @@ -1756,8 +1756,8 @@ static int f2fs_write_cache_pages(struct address_space *mapping, >> return ret; >> } >> >> -static int f2fs_write_data_pages(struct address_space *mapping, >> - struct writeback_control *wbc) >> +static int _f2fs_write_data_pages(struct address_space *mapping, >> + struct writeback_control *wbc, bool do_balance) >> { >> struct inode *inode = mapping->host; >> struct f2fs_sb_info *sbi = F2FS_I_SB(inode); >> @@ -1794,7 +1794,7 @@ static int f2fs_write_data_pages(struct address_space *mapping, >> goto skip_write; >> >> blk_start_plug(&plug); >> - ret = f2fs_write_cache_pages(mapping, wbc); >> + ret = f2fs_write_cache_pages(mapping, wbc, do_balance); >> blk_finish_plug(&plug); >> >> if (wbc->sync_mode == WB_SYNC_ALL) >> @@ -1813,6 +1813,57 @@ static int f2fs_write_data_pages(struct address_space *mapping, >> return 0; >> } >> >> +static int f2fs_write_data_pages(struct address_space *mapping, >> + struct writeback_control *wbc) >> +{ >> + return _f2fs_write_data_pages(mapping, wbc, true); >> +} >> + >> +/* >> + * This function was copied from do_writepages from mm/page-writeback.c. >> + * The major change is changing writepages to _f2fs_write_data_pages. >> + */ >> +static int f2fs_do_writepages(struct address_space *mapping, >> + struct writeback_control *wbc, bool is_dir) >> +{ >> + int ret; >> + >> + if (wbc->nr_to_write <= 0) >> + return 0; >> + while (1) { >> + ret = _f2fs_write_data_pages(mapping, wbc, !is_dir); >> + if ((ret != -ENOMEM) || (wbc->sync_mode != WB_SYNC_ALL)) >> + break; >> + cond_resched(); >> + congestion_wait(BLK_RW_ASYNC, HZ/50); >> + } >> + return ret; >> +} >> + >> +/* >> + * This function was copied from __filemap_fdatawrite_range from >> + * mm/filemap.c. The major change is changing do_writepages to >> + * f2fs_do_writepages. >> + */ >> +int f2fs_filemap_fdatawrite(struct address_space *mapping, bool is_dir) >> +{ >> + int ret; >> + struct writeback_control wbc = { >> + .sync_mode = WB_SYNC_ALL, >> + .nr_to_write = LONG_MAX, >> + .range_start = 0, >> + .range_end = LLONG_MAX, >> + }; >> + >> + if (!mapping_cap_writeback_dirty(mapping)) >> + return 0; >> + >> + wbc_attach_fdatawrite_inode(&wbc, mapping->host); >> + ret = f2fs_do_writepages(mapping, &wbc, is_dir); >> + wbc_detach_inode(&wbc); >> + return ret; >> +} >> + >> static void f2fs_write_failed(struct address_space *mapping, loff_t to) >> { >> struct inode *inode = mapping->host; >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >> index 9280283..ea9bebb 100644 >> --- a/fs/f2fs/f2fs.h >> +++ b/fs/f2fs/f2fs.h >> @@ -2572,6 +2572,7 @@ void f2fs_invalidate_page(struct page *page, unsigned int offset, >> int f2fs_migrate_page(struct address_space *mapping, struct page *newpage, >> struct page *page, enum migrate_mode mode); >> #endif >> +int f2fs_filemap_fdatawrite(struct address_space *mapping, bool is_dir); >> >> /* >> * gc.c >> -- >> 1.8.5.2