From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757278AbYEQOxh (ORCPT ); Sat, 17 May 2008 10:53:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754999AbYEQOxa (ORCPT ); Sat, 17 May 2008 10:53:30 -0400 Received: from dsl093-193-175.stl1.dsl.speakeasy.net ([66.93.193.175]:60891 "EHLO hades.sngx.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754724AbYEQOx3 (ORCPT ); Sat, 17 May 2008 10:53:29 -0400 Message-ID: <482EF192.4070707@sngx.net> Date: Sat, 17 May 2008 09:54:10 -0500 From: James Cammarata User-Agent: Thunderbird 2.0.0.14 (X11/20080505) MIME-Version: 1.0 To: Eric Dumazet CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH updated] net: add ability to clear per-interface network statistics via procfs References: <482DA5B6.1020606@sngx.net> <482DB46A.8020103@cosmosbay.com> In-Reply-To: <482DB46A.8020103@cosmosbay.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > 1) Every call to get_proc_net() should be paired with a call to > put_net(), or else you leak struct net. My mistake, I will add this and resubmit. > 2) I am not sure this is the right way to do this... Did you consider to > extend ethtool instead ? Yes, I did consider that. My reasoning for adding it to procfs is that each driver defines their own ethtool interface, so it was much simpler to add it here, with a lot less code changes and broader support. --- --- linux-2.6.25.4/net/core/dev.c 2008-05-15 10:00:12.000000000 -0500 +++ linux-2.6.25.4-jcammara/net/core/dev.c 2008-05-17 09:50:22.000000000 -0500 @@ -2455,2 +2455,80 @@ +/** + * proc_net_dev_write - handle writes to /proc/net/dev + * @file: not used + * @buf: buffer to write + * @length: length of buf, at most PAGE_SIZE + * @ppos: not used + * + * Description: this provides a mechanism to clear statistics on a + * per-interface basis + * "echo 'net clear-stats ifdev' >/proc/net/dev" + * with "ifdev" replaced by the device name you wish to clear. + * + */ +static ssize_t proc_net_dev_write(struct file *file, const char __user *buf, + size_t length, loff_t *ppos) +{ + char *buffer, *p; + char devname[IFNAMSIZ]; + struct net *net; + struct net_device *dev; + int err; + + if (!buf || length > PAGE_SIZE) + return -EINVAL; + + buffer = (char *)__get_free_page(GFP_KERNEL); + if (!buffer) + return -ENOMEM; + + err = -EFAULT; + if (copy_from_user(buffer, buf, length)) + goto out; + + err = -EINVAL; + if (length < PAGE_SIZE) + buffer[length] = '\0'; + else if (buffer[PAGE_SIZE-1]) + goto out; + + err = -ENXIO; + net = get_proc_net(file->f_dentry->d_inode); + if (!net) + goto out; + + /* + * Usage: echo "net clear-stats ifdev" >/proc/net/dev + * with "ifdev" replaced by the device name you wish to clear. + */ + if (!strncmp("net clear-stats",buffer,15)) { + p = buffer + 16; + if(sscanf(p,"%16s",devname)>0) { + dev = dev_get_by_name(net,devname); + if (dev) { + if (dev->get_stats) { + struct net_device_stats *stats = + dev->get_stats(dev); + memset(stats,0, + sizeof(struct net_device_stats)); + } + dev_put(dev); + } + } + } + + /* + * convert success returns so that we return the + * number of bytes consumed. + */ + if (!err) + err = length; + + out: + if(net) + put_net(net); + free_page((unsigned long)buffer); + return err; +} + static void *softnet_seq_start(struct seq_file *seq, loff_t *pos) @@ -2498,2 +2576,3 @@ .read = seq_read, + .write = proc_net_dev_write, .llseek = seq_lseek,