From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 7A5906B005A for ; Tue, 29 Sep 2009 18:52:59 -0400 (EDT) Message-ID: <4AC291B9.4060204@librato.com> Date: Tue, 29 Sep 2009 19:01:13 -0400 From: Oren Laadan MIME-Version: 1.0 Subject: Re: [PATCH v18 49/80] c/r: support for UTS namespace References: <1253749920-18673-1-git-send-email-orenl@librato.com> <1253749920-18673-50-git-send-email-orenl@librato.com> <200909292213.21266@blacky.localdomain> In-Reply-To: <200909292213.21266@blacky.localdomain> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: "Nikita V. Youshchenko" Cc: Andrew Morton , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, Serge Hallyn , Ingo Molnar , Pavel Emelyanov , Dan Smith , Oren Laadan List-ID: Nikita V. Youshchenko wrote: >> +static struct uts_namespace *do_restore_uts_ns(struct ckpt_ctx *ctx) >> ... >> +#ifdef CONFIG_UTS_NS >> + uts_ns = create_uts_ns(); >> + if (!uts_ns) { >> + uts_ns = ERR_PTR(-ENOMEM); >> + goto out; >> + } >> + down_read(&uts_sem); >> + name = &uts_ns->name; >> + memcpy(name->sysname, h->sysname, sizeof(name->sysname)); >> + memcpy(name->nodename, h->nodename, sizeof(name->nodename)); >> + memcpy(name->release, h->release, sizeof(name->release)); >> + memcpy(name->version, h->version, sizeof(name->version)); >> + memcpy(name->machine, h->machine, sizeof(name->machine)); >> + memcpy(name->domainname, h->domainname, sizeof(name->domainname)); >> + up_read(&uts_sem); > > Could you please explain what for is this down_read() / up_read() ? > You operate only on local objects: 'name' points to just-created > uts_ns, 'h' is also local data. Nothing more than symmetry with checkpoint code, and a pedagogical aspect... Can be replaced by a suitable comment. Oren. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org