From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752766AbdKCDqU (ORCPT ); Thu, 2 Nov 2017 23:46:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:42578 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752071AbdKCDqT (ORCPT ); Thu, 2 Nov 2017 23:46:19 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6ECC321911 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=jaegeuk@kernel.org Date: Thu, 2 Nov 2017 20:46:18 -0700 From: Jaegeuk Kim To: Yunlong Song Cc: chao@kernel.org, yuchao0@huawei.com, yunlong.song@icloud.com, miaoxie@huawei.com, bintian.wang@huawei.com, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] f2fs: fix out-of-free problem caused by atomic write Message-ID: <20171103034618.GD11335@jaegeuk-macbookpro.roam.corp.google.com> References: <1509027715-80477-1-git-send-email-yunlong.song@huawei.com> <1509368658-60355-1-git-send-email-yunlong.song@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1509368658-60355-1-git-send-email-yunlong.song@huawei.com> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/30, Yunlong Song wrote: > f2fs_balance_fs only actives once in the commit_inmem_pages, but there > are more than one page to commit, so all the other pages will miss the > check. This will lead to out-of-free problem when commit a very large > file. However, we cannot do f2fs_balance_fs for each inmem page, since > this will break atomicity. As a result, we should collect prefree > segments if needed and stop atomic commit when there are not enough > available blocks to write atomic pages. > > Signed-off-by: Yunlong Song > --- > fs/f2fs/f2fs.h | 1 + > fs/f2fs/segment.c | 29 ++++++++++++++++++++++++++++- > 2 files changed, 29 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 13a96b8..04ce48f 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -610,6 +610,7 @@ struct f2fs_inode_info { > struct list_head inmem_pages; /* inmemory pages managed by f2fs */ > struct task_struct *inmem_task; /* store inmemory task */ > struct mutex inmem_lock; /* lock for inmemory pages */ > + unsigned long inmem_blocks; /* inmemory blocks */ > struct extent_tree *extent_tree; /* cached extent_tree entry */ > struct rw_semaphore dio_rwsem[2];/* avoid racing between dio and gc */ > struct rw_semaphore i_mmap_sem; > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 46dfbca..813c110 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -210,6 +210,7 @@ void register_inmem_page(struct inode *inode, struct page *page) > list_add_tail(&fi->inmem_ilist, &sbi->inode_list[ATOMIC_FILE]); > spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); > inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES); > + fi->inmem_blocks++; > mutex_unlock(&fi->inmem_lock); > > trace_f2fs_register_inmem_page(page, INMEM); > @@ -221,6 +222,7 @@ static int __revoke_inmem_pages(struct inode *inode, > struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > struct inmem_pages *cur, *tmp; > int err = 0; > + struct f2fs_inode_info *fi = F2FS_I(inode); > > list_for_each_entry_safe(cur, tmp, head, list) { > struct page *page = cur->page; > @@ -263,6 +265,7 @@ static int __revoke_inmem_pages(struct inode *inode, > list_del(&cur->list); > kmem_cache_free(inmem_entry_slab, cur); > dec_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES); > + fi->inmem_blocks--; > } > return err; > } > @@ -302,6 +305,10 @@ void drop_inmem_pages(struct inode *inode) > if (!list_empty(&fi->inmem_ilist)) > list_del_init(&fi->inmem_ilist); > spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); > + if (fi->inmem_blocks) { > + f2fs_bug_on(sbi, 1); > + fi->inmem_blocks = 0; > + } > mutex_unlock(&fi->inmem_lock); > > clear_inode_flag(inode, FI_ATOMIC_FILE); > @@ -326,6 +333,7 @@ void drop_inmem_page(struct inode *inode, struct page *page) > > f2fs_bug_on(sbi, !cur || cur->page != page); > list_del(&cur->list); > + fi->inmem_blocks--; > mutex_unlock(&fi->inmem_lock); > > dec_page_count(sbi, F2FS_INMEM_PAGES); > @@ -410,11 +418,26 @@ int commit_inmem_pages(struct inode *inode) > > INIT_LIST_HEAD(&revoke_list); > f2fs_balance_fs(sbi, true); > + if (prefree_segments(sbi) > + && has_not_enough_free_secs(sbi, 0, > + fi->inmem_blocks / BLKS_PER_SEC(sbi))) { > + struct cp_control cpc; > + > + cpc.reason = __get_cp_reason(sbi); > + err = write_checkpoint(sbi, &cpc); > + if (err) > + goto drop; > + } > f2fs_lock_op(sbi); > > set_inode_flag(inode, FI_ATOMIC_COMMIT); > > mutex_lock(&fi->inmem_lock); > + if ((sbi->user_block_count - valid_user_blocks(sbi)) < What does this mean? We already allocated blocks successfully? > + fi->inmem_blocks) { > + err = -ENOSPC; > + goto drop; > + } > err = __commit_inmem_pages(inode, &revoke_list); > if (err) { > int ret; > @@ -429,7 +452,7 @@ int commit_inmem_pages(struct inode *inode) > ret = __revoke_inmem_pages(inode, &revoke_list, false, true); > if (ret) > err = ret; > - > +drop: > /* drop all uncommitted pages */ > __revoke_inmem_pages(inode, &fi->inmem_pages, true, false); > } > @@ -437,6 +460,10 @@ int commit_inmem_pages(struct inode *inode) > if (!list_empty(&fi->inmem_ilist)) > list_del_init(&fi->inmem_ilist); > spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); > + if (fi->inmem_blocks) { > + f2fs_bug_on(sbi, 1); > + fi->inmem_blocks = 0; > + } > mutex_unlock(&fi->inmem_lock); > > clear_inode_flag(inode, FI_ATOMIC_COMMIT); > -- > 1.8.5.2