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=-10.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 55BCDC433EA for ; Mon, 13 Jul 2020 15:40:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1D6BE20771 for ; Mon, 13 Jul 2020 15:40:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="p5NtX2gb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1D6BE20771 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 933348D0009; Mon, 13 Jul 2020 11:40:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8E40F8D0005; Mon, 13 Jul 2020 11:40:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7ABA68D0009; Mon, 13 Jul 2020 11:40:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0234.hostedemail.com [216.40.44.234]) by kanga.kvack.org (Postfix) with ESMTP id 5E7ED8D0005 for ; Mon, 13 Jul 2020 11:40:20 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id B80BA33C4 for ; Mon, 13 Jul 2020 15:40:19 +0000 (UTC) X-FDA: 77033464158.25.door55_5616f3426ee9 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id EA4381804E531 for ; Mon, 13 Jul 2020 15:39:56 +0000 (UTC) X-HE-Tag: door55_5616f3426ee9 X-Filterd-Recvd-Size: 5107 Received: from mail-ed1-f65.google.com (mail-ed1-f65.google.com [209.85.208.65]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Mon, 13 Jul 2020 15:39:55 +0000 (UTC) Received: by mail-ed1-f65.google.com with SMTP id h28so14121420edz.0 for ; Mon, 13 Jul 2020 08:39:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=du57OarKMFj2//aqQNh8usAhJGOEHYQoIDCsSqzfRrA=; b=p5NtX2gb+X8NBTzJ3q4wi1YSieEG+HNt+0otz/H/s/4MmLGrJII8dW/W0UVEpeW0Hg qC3dEPnVuhhvBwHhOLmT0GIL1CYUYMo9ubUoSer6T64yW74mkvzKKDKlZDVr19K+cYri LtlbMnBKoOcwmDXe/2csa9LQ7/dQV+rttec6lQsYqYKQLaZDSoi1NaLa2MvaowwAoBYv FeI+RRFcbGjItkCjE4SunsxqoBYnRp76pca1wVuHw/7y67Q/sHjhAzl/ezQtIiTEEG4j yQVjwihttrowt+w804UNoet1fmlmsFKNkFYmUigdIXnkpiItEwYkP2N/ahsYzcyDUeNq Dsyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=du57OarKMFj2//aqQNh8usAhJGOEHYQoIDCsSqzfRrA=; b=jiWOa8TnZwat4bL+/rGqUQBN+c6pT7KMFioN6WruP6Z6vKm+vd1UjJXwD1entpD740 DtvoJGSemgHQfphrQpaxoDStkSXDJnShztisP9SImvTdhhGe9k/DkvccwV7E85z/ItdN zV3KWc1XUTYDR4CDzE+8hNt1gSvNNjMPgkW0HxeuaozS8iYjOKwm0lNUveFqmMljOjxs QfmNLVVvMPcfeV6NcLherpNBceFXQOr1jqz3Ar95cpCcR8RMYVHhyiDcBzSfNh/tYu/I ntZZYmYfq7r2WSBIhOzj0cgszgtIpiQG3X22bvpy692dJmGw8BFI4zUK2SSvLveBBY+V lOiw== X-Gm-Message-State: AOAM533PAh61l++O/NOPIGE/NfGGLp7g057atNJ4h/hJhBjDFLynZbi3 Ug4tBvss3FUgUEjbIsPNqz9hzaNtR7IZw2AkMuTkIg== X-Google-Smtp-Source: ABdhPJwvCxFFHwbU4mztcnMn5QN22D7JN5cZqYOUrLmDBOAdReDdsMY67wCR/9JL04AtkGrUTxK3CfgbBEbrs6JuO2k= X-Received: by 2002:aa7:c24d:: with SMTP id y13mr95634335edo.123.1594654794604; Mon, 13 Jul 2020 08:39:54 -0700 (PDT) MIME-Version: 1.0 References: <159457116473.754248.7879464730875147365.stgit@dwillia2-desk3.amr.corp.intel.com> <159457125753.754248.6000936585361264069.stgit@dwillia2-desk3.amr.corp.intel.com> <20200712170945.GA194499@kroah.com> In-Reply-To: <20200712170945.GA194499@kroah.com> From: Dan Williams Date: Mon, 13 Jul 2020 08:39:43 -0700 Message-ID: Subject: Re: [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs To: Greg Kroah-Hartman Cc: linux-nvdimm , "Rafael J. Wysocki" , Peter Zijlstra , Vishal L Verma , Dave Hansen , Ard Biesheuvel , Linux MM , Linux Kernel Mailing List , Linux ACPI , Christoph Hellwig , Joao Martins Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: EA4381804E531 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, Jul 12, 2020 at 10:09 AM Greg Kroah-Hartman wrote: > > On Sun, Jul 12, 2020 at 09:27:37AM -0700, Dan Williams wrote: > > Use sysfs_streq() in device_find_child_by_name() to allow it to use a > > sysfs input string that might contain a trailing newline. > > > > The other "device by name" interfaces, > > {bus,driver,class}_find_device_by_name(), already account for sysfs > > strings. > > > > Cc: Greg Kroah-Hartman > > Cc: "Rafael J. Wysocki" > > Signed-off-by: Dan Williams > > --- > > drivers/base/core.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/base/core.c b/drivers/base/core.c > > index 67d39a90b45c..5d31b962c898 100644 > > --- a/drivers/base/core.c > > +++ b/drivers/base/core.c > > @@ -3078,7 +3078,7 @@ struct device *device_find_child_by_name(struct device *parent, > > > > klist_iter_init(&parent->p->klist_children, &i); > > while ((child = next_device(&i))) > > - if (!strcmp(dev_name(child), name) && get_device(child)) > > + if (sysfs_streq(dev_name(child), name) && get_device(child)) > > Who wants to call this function with a name passed from userspace? > > Not objecting to it, just curious... > The series that incorporates this patch adds a partitioning mechanism to "device-dax region" devices with an: "echo 1 > regionX/create" to create a new partition / sub-instance of a region, and... "echo $devname > regionX/delete" to delete. Where $devname is searched in the child devices of regionX to trigger device_del(). This arrangement avoids one of the design mistakes of libnvdimm which uses a sysfs attribute of the device to delete itself. Parent-device triggered deletion rather than self-deletion avoids those locking entanglements.