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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32C4FC6FD18 for ; Wed, 19 Apr 2023 06:29:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232287AbjDSG3Y (ORCPT ); Wed, 19 Apr 2023 02:29:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232242AbjDSG3F (ORCPT ); Wed, 19 Apr 2023 02:29:05 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 797D5B774 for ; Tue, 18 Apr 2023 23:28:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0870363B72 for ; Wed, 19 Apr 2023 06:28:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F635C433EF; Wed, 19 Apr 2023 06:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681885716; bh=985/Kh3t1ZuC33aqHLJddpQN44KiQbFNY0oeobBOvOY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=UCuMd2kWq7lnS3b/8L76RDxr3quWOCJnAaMOBzRrnIBatf+HhJVzCNZWl2XLCDYw5 Pa9Q0+XRBo0phjqWcZ9dTaZ5l4gmWxTrSSkOFaTgrZ59g6OPCQeJKkQ5KWyiM25O6n KOrKXTKWLpw4TcjhmFgHPsiclrrtXE2ALtGFOvlAps7cIY1SJT1AN8IEgMwwmi6zBm oKwCkbw20bzWNHEgUVbPZ+f3+fhgrwakSFYKkJkKfh3LKEEWz0p5tOXCSdJ2qC3aI+ wkDtN5Lfe6/04b20GREdHiWCeiig/UeE1dXajukVS5NmBhkh4JA7RKOypw/MsbHz3m tk7SlmerkOqWw== Message-ID: <91a05857-c916-cae5-d61d-bbec6f1ae052@kernel.org> Date: Wed, 19 Apr 2023 14:28:33 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Subject: Re: [PATCH 1/1] f2fs: allocate trace path buffer from names_cache Content-Language: en-US To: Jaegeuk Kim Cc: Wu Bo , linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, wubo.oduw@gmail.com References: <20230414104308.6591-1-bo.wu@vivo.com> From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/4/19 0:07, Jaegeuk Kim wrote: > On 04/18, Chao Yu wrote: >> On 2023/4/14 18:43, Wu Bo wrote: >>> It would be better to use the dedicated slab to store path. >>> >>> Signed-off-by: Wu Bo >>> --- >>> fs/f2fs/file.c | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >>> index 15dabeac4690..27137873958f 100644 >>> --- a/fs/f2fs/file.c >>> +++ b/fs/f2fs/file.c >>> @@ -4361,7 +4361,7 @@ static void f2fs_trace_rw_file_path(struct kiocb *iocb, size_t count, int rw) >>> struct inode *inode = file_inode(iocb->ki_filp); >>> char *buf, *path; >>> - buf = f2fs_kmalloc(F2FS_I_SB(inode), PATH_MAX, GFP_KERNEL); >>> + buf = __getname(); >> >> How about: >> >> buf = f2fs_kmem_cache_alloc(names_cachep, GFP_KERNEL, NULL, F2FS_I_SB(inode)); > > This looks like a hack using names_cachep? names_cachep was exported in fs.h. > Using f2fs_kmem_cache_alloc is able to inject malloc error. > But here is a trace event, is it ok to inject error in a trace path? Yes, the fail path handling is very simple, so it's fine to leave it as it is. Reviewed-by: Chao Yu Thanks, > >> >>> if (!buf) >>> return; >>> path = dentry_path_raw(file_dentry(iocb->ki_filp), buf, PATH_MAX); >>> @@ -4374,7 +4374,7 @@ static void f2fs_trace_rw_file_path(struct kiocb *iocb, size_t count, int rw) >>> trace_f2fs_dataread_start(inode, iocb->ki_pos, count, >>> current->pid, path, current->comm); >>> free_buf: >>> - kfree(buf); >>> + __putname(buf); >> >> kmem_cache_free(names_cachep, buf); >> >> Thanks, >> >>> } >>> static ssize_t f2fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)