From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [PATCH v18 49/80] c/r: support for UTS namespace Date: Tue, 29 Sep 2009 13:51:26 -0500 Message-ID: <20090929185126.GB13297@us.ibm.com> References: <1253749920-18673-1-git-send-email-orenl@librato.com> <1253749920-18673-50-git-send-email-orenl@librato.com> <200909292213.21266@blacky.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <200909292213.21266-vlktAfmDCSZSq9BJjBFyUp/QNRX+jHPU@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Nikita V. Youshchenko" Cc: Oren Laadan , Andrew Morton , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ingo Molnar , Pavel Emelyanov , Dan Smith , Oren Laadan List-Id: linux-api@vger.kernel.org Quoting Nikita V. Youshchenko (yoush-/llMDZXAvAOHXe+LvDLADg@public.gmane.org): > > +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. Yup, good point, that looks unnecessary. thanks, -serge -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html