forked from luck/tmp_suning_uos_patched
[NET]: Factor out __dev_alloc_name from dev_alloc_name
When forcibly changing the network namespace of a device I need something that can generate a name for the device in the new namespace without overwriting the old name. __dev_alloc_name provides me that functionality. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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@ -739,9 +739,10 @@ int dev_valid_name(const char *name)
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}
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/**
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* dev_alloc_name - allocate a name for a device
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* @dev: device
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* __dev_alloc_name - allocate a name for a device
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* @net: network namespace to allocate the device name in
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* @name: name format string
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* @buf: scratch buffer and result name string
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*
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* Passed a format string - eg "lt%d" it will try and find a suitable
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* id. It scans list of devices to build up a free map, then chooses
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@ -752,18 +753,13 @@ int dev_valid_name(const char *name)
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* Returns the number of the unit assigned or a negative errno code.
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*/
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int dev_alloc_name(struct net_device *dev, const char *name)
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static int __dev_alloc_name(struct net *net, const char *name, char *buf)
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{
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int i = 0;
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char buf[IFNAMSIZ];
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const char *p;
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const int max_netdevices = 8*PAGE_SIZE;
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long *inuse;
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struct net_device *d;
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struct net *net;
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BUG_ON(!dev->nd_net);
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net = dev->nd_net;
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p = strnchr(name, IFNAMSIZ-1, '%');
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if (p) {
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@ -787,7 +783,7 @@ int dev_alloc_name(struct net_device *dev, const char *name)
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continue;
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/* avoid cases where sscanf is not exact inverse of printf */
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snprintf(buf, sizeof(buf), name, i);
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snprintf(buf, IFNAMSIZ, name, i);
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if (!strncmp(buf, d->name, IFNAMSIZ))
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set_bit(i, inuse);
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}
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@ -796,11 +792,9 @@ int dev_alloc_name(struct net_device *dev, const char *name)
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free_page((unsigned long) inuse);
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}
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snprintf(buf, sizeof(buf), name, i);
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if (!__dev_get_by_name(net, buf)) {
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strlcpy(dev->name, buf, IFNAMSIZ);
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snprintf(buf, IFNAMSIZ, name, i);
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if (!__dev_get_by_name(net, buf))
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return i;
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}
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/* It is possible to run out of possible slots
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* when the name is long and there isn't enough space left
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@ -809,6 +803,34 @@ int dev_alloc_name(struct net_device *dev, const char *name)
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return -ENFILE;
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}
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/**
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* dev_alloc_name - allocate a name for a device
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* @dev: device
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* @name: name format string
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*
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* Passed a format string - eg "lt%d" it will try and find a suitable
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* id. It scans list of devices to build up a free map, then chooses
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* the first empty slot. The caller must hold the dev_base or rtnl lock
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* while allocating the name and adding the device in order to avoid
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* duplicates.
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* Limited to bits_per_byte * page size devices (ie 32K on most platforms).
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* Returns the number of the unit assigned or a negative errno code.
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*/
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int dev_alloc_name(struct net_device *dev, const char *name)
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{
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char buf[IFNAMSIZ];
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struct net *net;
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int ret;
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BUG_ON(!dev->nd_net);
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net = dev->nd_net;
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ret = __dev_alloc_name(net, name, buf);
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if (ret >= 0)
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strlcpy(dev->name, buf, IFNAMSIZ);
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return ret;
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}
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/**
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* dev_change_name - change name of a device
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