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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 45169C4332D for ; Mon, 15 Mar 2021 09:48:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0907964E90 for ; Mon, 15 Mar 2021 09:48:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229591AbhCOJsI (ORCPT ); Mon, 15 Mar 2021 05:48:08 -0400 Received: from mx2.suse.de ([195.135.220.15]:60690 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229624AbhCOJrr (ORCPT ); Mon, 15 Mar 2021 05:47:47 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id BCC60AC1D; Mon, 15 Mar 2021 09:47:45 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id CE6971E423D; Mon, 15 Mar 2021 10:47:44 +0100 (CET) Date: Mon, 15 Mar 2021 10:47:44 +0100 From: Jan Kara To: "zhangyi (F)" Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-block@vger.kernel.org, jack@suse.cz, tytso@mit.edu, viro@zeniv.linux.org.uk, hch@infradead.org, axboe@kernel.dk, mcgrof@kernel.org, keescook@chromium.org, yzaikin@google.com Subject: Re: [RFC PATCH 1/3] block_dump: remove block_dump feature in mark_inode_dirty() Message-ID: <20210315094744.GA3227@quack2.suse.cz> References: <20210313030146.2882027-1-yi.zhang@huawei.com> <20210313030146.2882027-2-yi.zhang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210313030146.2882027-2-yi.zhang@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sat 13-03-21 11:01:44, zhangyi (F) wrote: > block_dump is an old debugging interface, one of it's functions is used > to print the information about who write which file on disk. If we > enable block_dump through /proc/sys/vm/block_dump and turn on debug log > level, we can gather information about write process name, target file > name and disk from kernel message. This feature is realized in > block_dump___mark_inode_dirty(), it print above information into kernel > message directly when marking inode dirty, so it is noisy and can easily > trigger log storm. At the same time, get the dentry refcount is also not > safe, we found it will lead to deadlock on ext4 file system with > data=journal mode. > > After tracepoints has been introduced into the kernel, we got a > tracepoint in __mark_inode_dirty(), which is a better replacement of > block_dump___mark_inode_dirty(). The only downside is that it only trace > the inode number and not a file name, but it probably doesn't matter > because the original printed file name in block_dump is not accurate in > some cases, and we can still find it through the inode number and device > id. So this patch delete the dirting inode part of block_dump feature. > > Signed-off-by: zhangyi (F) Looks good to me. Feel free to add: Reviewed-by: Jan Kara Honza > --- > fs/fs-writeback.c | 25 ------------------------- > 1 file changed, 25 deletions(-) > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index e91980f49388..7c46d1588a19 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -2205,28 +2205,6 @@ int dirtytime_interval_handler(struct ctl_table *table, int write, > return ret; > } > > -static noinline void block_dump___mark_inode_dirty(struct inode *inode) > -{ > - if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) { > - struct dentry *dentry; > - const char *name = "?"; > - > - dentry = d_find_alias(inode); > - if (dentry) { > - spin_lock(&dentry->d_lock); > - name = (const char *) dentry->d_name.name; > - } > - printk(KERN_DEBUG > - "%s(%d): dirtied inode %lu (%s) on %s\n", > - current->comm, task_pid_nr(current), inode->i_ino, > - name, inode->i_sb->s_id); > - if (dentry) { > - spin_unlock(&dentry->d_lock); > - dput(dentry); > - } > - } > -} > - > /** > * __mark_inode_dirty - internal function to mark an inode dirty > * > @@ -2296,9 +2274,6 @@ void __mark_inode_dirty(struct inode *inode, int flags) > (dirtytime && (inode->i_state & I_DIRTY_INODE))) > return; > > - if (unlikely(block_dump)) > - block_dump___mark_inode_dirty(inode); > - > spin_lock(&inode->i_lock); > if (dirtytime && (inode->i_state & I_DIRTY_INODE)) > goto out_unlock_inode; > -- > 2.25.4 > -- Jan Kara SUSE Labs, CR