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 28E28C43331 for ; Sat, 9 Nov 2019 12:59:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D270521848 for ; Sat, 9 Nov 2019 12:59:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726565AbfKIM7i (ORCPT ); Sat, 9 Nov 2019 07:59:38 -0500 Received: from mx2.suse.de ([195.135.220.15]:42860 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726267AbfKIM7h (ORCPT ); Sat, 9 Nov 2019 07:59:37 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id DAB3AB023; Sat, 9 Nov 2019 12:59:34 +0000 (UTC) Date: Sat, 9 Nov 2019 13:59:33 +0100 From: Michal =?iso-8859-1?Q?Such=E1nek?= To: Sourabh Jain Cc: mpe@ellerman.id.au, corbet@lwn.net, mahesh@linux.vnet.ibm.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, hbathini@linux.ibm.com Subject: Re: [PATCH v3 2/4] powerpc/fadump: reorganize /sys/kernel/fadump_* sysfs files Message-ID: <20191109125933.GF1384@kitsune.suse.cz> References: <20191109122339.20484-1-sourabhjain@linux.ibm.com> <20191109122339.20484-3-sourabhjain@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191109122339.20484-3-sourabhjain@linux.ibm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 09, 2019 at 05:53:37PM +0530, Sourabh Jain wrote: > As the number of FADump sysfs files increases it is hard to manage all of > them inside /sys/kernel directory. It's better to have all the FADump > related sysfs files in a dedicated directory /sys/kernel/fadump. But in > order to maintain the backward compatibility the /sys/kernel/fadump_* > sysfs files are replicated inside /sys/kernel/fadump/ and eventually get > removed in future. > > As the FADump sysfs files are now part of dedicated directory there is no > need to prefix their name with fadump_, hence sysfs file names are also > updated. For example fadump_enabled sysfs file is now referred as enabled. > > Also consolidate ABI documentation for all the FADump sysfs files in a > single file Documentation/ABI/testing/sysfs-kernel-fadump. > > Signed-off-by: Sourabh Jain > --- > Documentation/ABI/testing/sysfs-kernel-fadump | 41 +++++++++++++++++++ > arch/powerpc/kernel/fadump.c | 38 +++++++++++++++++ > arch/powerpc/platforms/powernv/opal-core.c | 10 +++-- > 3 files changed, 86 insertions(+), 3 deletions(-) > create mode 100644 Documentation/ABI/testing/sysfs-kernel-fadump > > diff --git a/Documentation/ABI/testing/sysfs-kernel-fadump b/Documentation/ABI/testing/sysfs-kernel-fadump > new file mode 100644 > index 000000000000..a77f1a5ba389 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-kernel-fadump > @@ -0,0 +1,41 @@ > +What: /sys/kernel/fadump/* > +Date: Nov 2019 > +Contact: linuxppc-dev@lists.ozlabs.org > +Description: > + The /sys/kernel/fadump/* is a collection of FADump sysfs > + file provide information about the configuration status > + of Firmware Assisted Dump (FADump). > + > +What: /sys/kernel/fadump/enabled > +Date: Nov 2019 > +Contact: linuxppc-dev@lists.ozlabs.org > +Description: read only > + Primarily used to identify whether the FADump is enabled in > + the kernel or not. > +User: Kdump service > + > +What: /sys/kernel/fadump/registered > +Date: Nov 2019 > +Contact: linuxppc-dev@lists.ozlabs.org > +Description: read/write > + Helps to control the dump collect feature from userspace. > + Setting 1 to this file enables the system to collect the > + dump and 0 to disable it. > +User: Kdump service > + > +What: /sys/kernel/fadump/release_mem > +Date: Nov 2019 > +Contact: linuxppc-dev@lists.ozlabs.org > +Description: write only > + This is a special sysfs file and only available when > + the system is booted to capture the vmcore using FADump. > + It is used to release the memory reserved by FADump to > + save the crash dump. > + > +What: /sys/kernel/fadump/release_opalcore > +Date: Nov 2019 > +Contact: linuxppc-dev@lists.ozlabs.org > +Description: write only > + The sysfs file is available when the system is booted to > + collect the dump on OPAL based machine. It used to release > + the memory used to collect the opalcore. > diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c > index ed59855430b9..a9591def0c84 100644 > --- a/arch/powerpc/kernel/fadump.c > +++ b/arch/powerpc/kernel/fadump.c > @@ -1418,6 +1418,9 @@ static int fadump_region_show(struct seq_file *m, void *private) > return 0; > } > > +struct kobject *fadump_kobj; > +EXPORT_SYMBOL_GPL(fadump_kobj); > + > static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, > 0200, NULL, > fadump_release_memory_store); > @@ -1428,6 +1431,16 @@ static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, > 0644, fadump_register_show, > fadump_register_store); > > +static struct kobj_attribute release_attr = __ATTR(release_mem, > + 0200, NULL, > + fadump_release_memory_store); > +static struct kobj_attribute enable_attr = __ATTR(enabled, > + 0444, fadump_enabled_show, > + NULL); > +static struct kobj_attribute register_attr = __ATTR(registered, > + 0644, fadump_register_show, > + fadump_register_store); > + > DEFINE_SHOW_ATTRIBUTE(fadump_region); > > static void fadump_init_files(void) > @@ -1435,6 +1448,11 @@ static void fadump_init_files(void) > struct dentry *debugfs_file; > int rc = 0; > > + fadump_kobj = kobject_create_and_add("fadump", kernel_kobj); > + if (!fadump_kobj) { > + pr_err("failed to create fadump kobject\n"); > + return; > + } > rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); > if (rc) > printk(KERN_ERR "fadump: unable to create sysfs file" > @@ -1458,6 +1476,26 @@ static void fadump_init_files(void) > printk(KERN_ERR "fadump: unable to create sysfs file" > " fadump_release_mem (%d)\n", rc); > } > + /* Replicating the following sysfs attributes under FADump kobject. > + * > + * - fadump_enabled -> enabled > + * - fadump_registered -> registered > + * - fadump_release_mem -> release_mem > + */ > + rc = sysfs_create_file(fadump_kobj, &enable_attr.attr); > + if (rc) > + pr_err("unable to create enabled sysfs file (%d)\n", > + rc); > + rc = sysfs_create_file(fadump_kobj, ®ister_attr.attr); > + if (rc) > + pr_err("unable to create registered sysfs file (%d)\n", > + rc); > + if (fw_dump.dump_active) { > + rc = sysfs_create_file(fadump_kobj, &release_attr.attr); > + if (rc) > + pr_err("unable to create release_mem sysfs file (%d)\n", > + rc); > + } > return; > } Hello, wouldn't it make more sense to create the files in the new location and add a symlink at the old location? Also your error messages aren't really readeable. Without the fadump_ prefix it's not clear what's going on here. Perhaps quoting the file name and saying fadump somewhere in the message would be useful. Thanks Michal