Messages in this thread | | | Date | Fri, 16 May 2008 13:03:09 -0700 (PDT) | Subject | Re: [PATCH updated] net: add ability to clear per-interface network statistics via procfs | From | David Miller <> |
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From: Eric Dumazet <dada1@cosmosbay.com> Date: Fri, 16 May 2008 18:20:58 +0200
netdev CC:'d, people please... Eric, you in particular know better :-)))
> James Cammarata a écrit : > > From: James Cammarata <jimi@sngx.net> > > > > Added the ability to write to /proc/net/dev in order to clear the > > interface counters for a given interface. The ability to zero out > > counters (especially the error counters) is extremely useful when > > troubleshooting interface issues. Now diffed against 2.6.25.4, and > > added some sanity checking. > > > Hello James > > 1) Every call to get_proc_net() should be paired with a call to > put_net(), or else you leak struct net. > > 2) I am not sure this is the right way to do this... Did you consider to > extend ethtool instead ? > > > Syntax: > > echo 'net clear-stats ifdev' > /proc/net/dev > > Where "ifdev" is the device name you wish to clear. > > > > This code is based mainly on the code found in drivers/scsi/scsi_proc.c > > > > Signed-off-by: James Cammarata <jimi@sngx.net> > > --- > > > > --- 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 2008-05-16 > > 07:02:48.000000000 -0500 > > @@ -2455,2 +2455,78 @@ > > > > +/** > > + * 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; > > + > Here probably, you should add > > put_net(net); > > > + out: > > + free_page((unsigned long)buffer); > > + return err; > > +} > > + > > static void *softnet_seq_start(struct seq_file *seq, loff_t *pos) > > @@ -2498,2 +2574,3 @@ > > .read = seq_read, > > + .write = proc_net_dev_write, > > .llseek = seq_lseek, > > > > > > > > > -- > 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/ -- 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/
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