Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753493Ab2HOKwa (ORCPT ); Wed, 15 Aug 2012 06:52:30 -0400 Received: from charlotte.tuxdriver.com ([70.61.120.58]:39291 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750724Ab2HOKw2 (ORCPT ); Wed, 15 Aug 2012 06:52:28 -0400 Date: Wed, 15 Aug 2012 06:52:06 -0400 From: Neil Horman To: John Fastabend Cc: viro@ZenIV.linux.org.uk, netdev@vger.kernel.org, davem@davemloft.net, linux-kernel@vger.kernel.org, joe@perches.com Subject: Re: [net PATCH v3 1/3] net: netprio: fix files lock and remove useless d_path bits Message-ID: <20120815105206.GA23811@hmsreliant.think-freely.org> References: <20120814223424.3551.21608.stgit@jf-dev1-dcblab> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120814223424.3551.21608.stgit@jf-dev1-dcblab> User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Score: -2.9 (--) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2395 Lines: 78 On Tue, Aug 14, 2012 at 03:34:24PM -0700, John Fastabend wrote: > Add lock to prevent a race with a file closing and also remove > useless and ugly sscanf code. The extra code was never needed > and the case it supposedly protected against is in fact handled > correctly by sock_from_file as pointed out by Al Viro. > > CC: Neil Horman > Reported-by: Al Viro > Signed-off-by: John Fastabend > --- > > net/core/netprio_cgroup.c | 22 ++++------------------ > 1 files changed, 4 insertions(+), 18 deletions(-) > > diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c > index ed0c043..f65dba3 100644 > --- a/net/core/netprio_cgroup.c > +++ b/net/core/netprio_cgroup.c > @@ -277,12 +277,6 @@ out_free_devname: > void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) > { > struct task_struct *p; > - char *tmp = kzalloc(sizeof(char) * PATH_MAX, GFP_KERNEL); > - > - if (!tmp) { > - pr_warn("Unable to attach cgrp due to alloc failure!\n"); > - return; > - } > > cgroup_taskset_for_each(p, cgrp, tset) { > unsigned int fd; > @@ -296,32 +290,24 @@ void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) > continue; > } > > - rcu_read_lock(); > + spin_lock(&files->file_lock); > fdt = files_fdtable(files); > for (fd = 0; fd < fdt->max_fds; fd++) { > - char *path; > struct file *file; > struct socket *sock; > - unsigned long s; > - int rv, err = 0; > + int err; > > file = fcheck_files(files, fd); > if (!file) > continue; > > - path = d_path(&file->f_path, tmp, PAGE_SIZE); > - rv = sscanf(path, "socket:[%lu]", &s); > - if (rv <= 0) > - continue; > - > sock = sock_from_file(file, &err); > - if (!err) > + if (sock) > sock_update_netprioidx(sock->sk, p); > } > - rcu_read_unlock(); > + spin_unlock(&files->file_lock); > task_unlock(p); > } > - kfree(tmp); > } > > static struct cftype ss_files[] = { > > Acked-by: Neil Horman It looks good to me. Al, could you please lend your review here too? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/