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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B11CFC4360C for ; Sun, 29 Sep 2019 02:22:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 890562082F for ; Sun, 29 Sep 2019 02:22:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728889AbfI2CWZ (ORCPT ); Sat, 28 Sep 2019 22:22:25 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:2054 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728569AbfI2CWZ (ORCPT ); Sat, 28 Sep 2019 22:22:25 -0400 Received: from DGGEMM401-HUB.china.huawei.com (unknown [172.30.72.53]) by Forcepoint Email with ESMTP id 81C8489247855DFBD3EF; Sun, 29 Sep 2019 10:22:21 +0800 (CST) Received: from dggeme762-chm.china.huawei.com (10.3.19.108) by DGGEMM401-HUB.china.huawei.com (10.3.20.209) with Microsoft SMTP Server (TLS) id 14.3.439.0; Sun, 29 Sep 2019 10:22:21 +0800 Received: from architecture4 (10.140.130.215) by dggeme762-chm.china.huawei.com (10.3.19.108) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Sun, 29 Sep 2019 10:22:11 +0800 Date: Sun, 29 Sep 2019 10:20:52 +0800 From: Gao Xiang To: CC: Chao Yu , Jaegeuk Kim , , Subject: Re: [f2fs-dev] [PATCH] f2fs: fix comment of f2fs_evict_inode Message-ID: <20190929021939.GA136917@architecture4> References: <20190925093050.118921-1-yuchao0@huawei.com> <20190927183150.GA54001@jaegeuk-macbookpro.roam.corp.google.com> <8c54adaf-163f-fcbe-7731-0c18b12410e0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <8c54adaf-163f-fcbe-7731-0c18b12410e0@huawei.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Originating-IP: [10.140.130.215] X-ClientProxiedBy: dggeme701-chm.china.huawei.com (10.1.199.97) To dggeme762-chm.china.huawei.com (10.3.19.108) X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 29, 2019 at 08:53:05AM +0800, Chao Yu wrote: > Hi Jaegeuk, > > On 2019/9/28 2:31, Jaegeuk Kim wrote: > > Hi Chao, > > > > On 09/25, Chao Yu wrote: > >> evict() should be called once i_count is zero, rather than i_nlinke > >> is zero. > >> > >> Reported-by: Gao Xiang > >> Signed-off-by: Chao Yu > >> --- > >> fs/f2fs/inode.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c > >> index db4fec30c30d..8262f4a483d3 100644 > >> --- a/fs/f2fs/inode.c > >> +++ b/fs/f2fs/inode.c > >> @@ -632,7 +632,7 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc) > >> } > >> > >> /* > >> - * Called at the last iput() if i_nlink is zero > > > > I don't think this comment is wrong. You may be able to add on top of this. > > It actually misleads the developer or user. > > How do you think of: > > "Called at the last iput() if i_count is zero, and will release all meta/data > blocks allocated in the inode if i_nlink is zero" (sigh... side note: I just took some time to check the original meaning out of curiosity. AFAIK, the above word was added in Linux-2.1.45 [1] due to ext2_delete_inode behavior, which is called when i_nlink == 0, and .delete_inode was gone in 2010 (commit 72edc4d0873b merge ext2 delete_inode and clear_inode, switch to ->evict_inode()), it may be helpful to understand the story so I write here for later folks reference. And it's also good to just kill it. ) + +/* + * Called at the last iput() if i_nlink is zero. + */ +void ext2_delete_inode (struct inode * inode) +{ + if (inode->i_ino == EXT2_ACL_IDX_INO || inode->i_ino == EXT2_ACL_DATA_INO) return; inode->u.ext2_i.i_dtime = CURRENT_TIME; - inode->i_dirt = 1; + mark_inode_dirty(inode); ext2_update_inode(inode, IS_SYNC(inode)); inode->i_size = 0; if (inode->i_blocks) @@ -248,7 +258,7 @@ if (IS_SYNC(inode) || inode->u.ext2_i.i_osync) ext2_sync_inode (inode); else - inode->i_dirt = 1; + mark_inode_dirty(inode); return result; } +void iput(struct inode *inode) { - struct inode * inode = get_empty_inode(); + if (inode) { + struct super_operations *op = NULL; - PIPE_BASE(*inode) = (char*)__get_free_page(GFP_USER); - if (!(PIPE_BASE(*inode))) { - iput(inode); - return NULL; + if (inode->i_sb && inode->i_sb->s_op) + op = inode->i_sb->s_op; + if (op && op->put_inode) + op->put_inode(inode); + + spin_lock(&inode_lock); + if (!--inode->i_count) { + if (!inode->i_nlink) { + list_del(&inode->i_hash); + INIT_LIST_HEAD(&inode->i_hash); + if (op && op->delete_inode) { + void (*delete)(struct inode *) = op->delete_inode; + spin_unlock(&inode_lock); + delete(inode); + spin_lock(&inode_lock); + } + } + if (list_empty(&inode->i_hash)) { + list_del(&inode->i_list); + list_add(&inode->i_list, &inode_unused); + } + } + spin_unlock(&inode_lock); } [1] https://www.kernel.org/pub/linux/kernel/v2.1/patch-2.1.45.xz Thanks, Gao Xiang > > Thanks, > > > > >> + * Called at the last iput() if i_count is zero > >> */ > >> void f2fs_evict_inode(struct inode *inode) > >> { > >> -- > >> 2.18.0.rc1 > > . > > > > > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel