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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT 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 8085DC48BE5 for ; Wed, 23 Jun 2021 05:50:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A9C861186 for ; Wed, 23 Jun 2021 05:50:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229920AbhFWFwu (ORCPT ); Wed, 23 Jun 2021 01:52:50 -0400 Received: from foss.arm.com ([217.140.110.172]:57944 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229726AbhFWFwu (ORCPT ); Wed, 23 Jun 2021 01:52:50 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 95C2CED1; Tue, 22 Jun 2021 22:50:32 -0700 (PDT) Received: from entos-ampere-02.shanghai.arm.com (entos-ampere-02.shanghai.arm.com [10.169.214.103]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 656BF3F694; Tue, 22 Jun 2021 22:50:27 -0700 (PDT) From: Jia He To: Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes , Jonathan Corbet , Alexander Viro , Linus Torvalds Cc: "Peter Zijlstra (Intel)" , Eric Biggers , "Ahmed S. Darwish" , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Matthew Wilcox , Christoph Hellwig , nd@arm.com, Jia He Subject: [PATCH v2 0/4] make '%pD' print the full path of file Date: Wed, 23 Jun 2021 13:50:07 +0800 Message-Id: <20210623055011.22916-1-justin.he@arm.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Background ========== Linus suggested printing the full path of file instead of printing the components as '%pd'. Typically, there is no need for printk specifiers to take any real locks (ie mount_lock or rename_lock). So I introduce a new helper d_path_unsafe() which is similar to d_path() except it doesn't take any seqlock/spinlock. This series is based on Al Viro's d_path() cleanup patches [1] which lifted the inner lockless loop into a new helper. Test ==== The cases I tested: 1. print '%pD' with full path of ext4 file 2. mount a ext4 filesystem upon a ext4 filesystem, and print the file with '%pD' 3. all test_print selftests, including the new '%14pD' '%-14pD' 4. kasprintf TODO ==== I plan to do the followup work after '%pD' behavior is changed. - s390/hmcdrv: remove the redundant directory path in printing string. - fs/iomap: simplify the iomap_swapfile_fail() with '%pD'. - simplify the string printing when file_path() is invoked(in some cases, not all). - change the previous '%pD[2,3,4]' to '%pD' Changelog ========= v2: - refine the commit msg/comments (Andy) - pass the validator check by "make C=1 W=1" - add the R-b for patch 4/4 from Andy v1: https://lkml.org/lkml/2021/6/22/680 - remove the RFC tag - refine the commit msg/comments(by Petr, Andy) - make using_scratch_space a new parameter of the test case RFCv4: - don't support spec.precision anymore for '%pD' - add Rasmus's patch into this series RFCv3: - implement new d_path_unsafe to use [buf, end] instead of stack space for filling bytes (by Matthew) - add new test cases for '%pD' - drop patch "hmcdrv: remove the redundant directory path" before removing rfc. RFCv2: - implement new d_path_fast based on Al Viro's patches - add check_pointer check (by Petr) - change the max full path size to 256 in stack space RFCv1: https://lkml.org/lkml/2021/5/8/122 Link: https://lkml.org/lkml/2021/5/18/1260 [1] Jia He (3): fs: introduce helper d_path_unsafe() lib/vsprintf.c: make '%pD' print the full path of file lib/test_printf.c: add test cases for '%pD' Rasmus Villemoes (1): lib/test_printf.c: split write-beyond-buffer check in two Documentation/core-api/printk-formats.rst | 5 +- fs/d_path.c | 122 ++++++++++++++++++++-- include/linux/dcache.h | 1 + lib/test_printf.c | 54 ++++++++-- lib/vsprintf.c | 40 ++++++- 5 files changed, 199 insertions(+), 23 deletions(-) -- 2.17.1