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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 2EB1BC2D0A3 for ; Sun, 1 Nov 2020 22:13:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7FAC722260 for ; Sun, 1 Nov 2020 22:13:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7FAC722260 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B60186B005C; Sun, 1 Nov 2020 17:13:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B11596B005D; Sun, 1 Nov 2020 17:13:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A01586B0068; Sun, 1 Nov 2020 17:13:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0041.hostedemail.com [216.40.44.41]) by kanga.kvack.org (Postfix) with ESMTP id 746A76B005C for ; Sun, 1 Nov 2020 17:13:56 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0A4023625 for ; Sun, 1 Nov 2020 22:13:56 +0000 (UTC) X-FDA: 77437252872.26.rake53_0a05980272aa Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id D8F471804B660 for ; Sun, 1 Nov 2020 22:13:55 +0000 (UTC) X-HE-Tag: rake53_0a05980272aa X-Filterd-Recvd-Size: 2994 Received: from smtprelay.hostedemail.com (smtprelay0193.hostedemail.com [216.40.44.193]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Sun, 1 Nov 2020 22:13:55 +0000 (UTC) Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay01.hostedemail.com (Postfix) with ESMTP id 51BFF100E7B42; Sun, 1 Nov 2020 22:13:55 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: wash01_230fb5d272aa X-Filterd-Recvd-Size: 1888 Received: from XPS-9350.home (unknown [47.151.133.149]) (Authenticated sender: joe@perches.com) by omf02.hostedemail.com (Postfix) with ESMTPA; Sun, 1 Nov 2020 22:13:53 +0000 (UTC) Message-ID: <2abb3c694107764dea1e118566eb3c6c331404fc.camel@perches.com> Subject: Re: [PATCH 4/5] mm: shmem: Convert shmem_enabled_show to use sysfs_emit_at From: Joe Perches To: Matthew Wilcox , Greg Kroah-Hartman Cc: Hugh Dickins , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Sun, 01 Nov 2020 14:13:52 -0800 In-Reply-To: <20201101220604.GI27442@casper.infradead.org> References: <20201101204834.GF27442@casper.infradead.org> <616b92af9378e9f9697555074bba1e377450477f.camel@perches.com> <20201101211910.GG27442@casper.infradead.org> <20201101220604.GI27442@casper.infradead.org> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.38.1-1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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, 2020-11-01 at 22:06 +0000, Matthew Wilcox wrote: > Oh, ugh, sysfs_emit() should be able to work on a buffer that isn't > page aligned. Greg, how about this? >=20 > +++ b/fs/sysfs/file.c > @@ -722,13 +722,13 @@ int sysfs_emit(char *buf, const char *fmt, ...) > =A0{ > =A0=A0=A0=A0=A0=A0=A0=A0va_list args; > =A0=A0=A0=A0=A0=A0=A0=A0int len; > + int start =3D offset_in_page(buf); I thought of that originally and didn't want to implement it that way as it allows sysfs_emit to be used on non-page aligned buffers. Using two functions makes sure the buf is always page aligned and so buf should never defectively be passed in unaligned.