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net: Remove all_adj_list and its references
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Only direct adjacencies are maintained. All upper or lower devices can
be learned via the new walk API which recursively walks the adj_list for
upper devices or lower devices.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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David Ahern authored and David S. Miller committed Oct 18, 2016
1 parent cf2d674 commit f1170fd
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Showing 2 changed files with 18 additions and 230 deletions.
25 changes: 0 additions & 25 deletions include/linux/netdevice.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1456,7 +1456,6 @@ enum netdev_priv_flags {
* @ptype_specific: Device-specific, protocol-specific packet handlers
*
* @adj_list: Directly linked devices, like slaves for bonding
* @all_adj_list: All linked devices, *including* neighbours
* @features: Currently active device features
* @hw_features: User-changeable features
*
Expand Down Expand Up @@ -1675,11 +1674,6 @@ struct net_device {
struct list_head lower;
} adj_list;

struct {
struct list_head upper;
struct list_head lower;
} all_adj_list;

netdev_features_t features;
netdev_features_t hw_features;
netdev_features_t wanted_features;
Expand Down Expand Up @@ -3771,13 +3765,6 @@ struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev,
updev; \
updev = netdev_upper_get_next_dev_rcu(dev, &(iter)))

/* iterate through upper list, must be called under RCU read lock */
#define netdev_for_each_all_upper_dev_rcu(dev, updev, iter) \
for (iter = &(dev)->all_adj_list.upper, \
updev = netdev_all_upper_get_next_dev_rcu(dev, &(iter)); \
updev; \
updev = netdev_all_upper_get_next_dev_rcu(dev, &(iter)))

int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
int (*fn)(struct net_device *upper_dev,
void *data),
Expand Down Expand Up @@ -3817,18 +3804,6 @@ struct net_device *netdev_all_lower_get_next(struct net_device *dev,
struct net_device *netdev_all_lower_get_next_rcu(struct net_device *dev,
struct list_head **iter);

#define netdev_for_each_all_lower_dev(dev, ldev, iter) \
for (iter = (dev)->all_adj_list.lower.next, \
ldev = netdev_all_lower_get_next(dev, &(iter)); \
ldev; \
ldev = netdev_all_lower_get_next(dev, &(iter)))

#define netdev_for_each_all_lower_dev_rcu(dev, ldev, iter) \
for (iter = (dev)->all_adj_list.lower.next, \
ldev = netdev_all_lower_get_next_rcu(dev, &(iter)); \
ldev; \
ldev = netdev_all_lower_get_next_rcu(dev, &(iter)))

int netdev_walk_all_lower_dev(struct net_device *dev,
int (*fn)(struct net_device *lower_dev,
void *data),
Expand Down
223 changes: 18 additions & 205 deletions net/core/dev.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5137,6 +5137,13 @@ static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
return NULL;
}

static int __netdev_has_upper_dev(struct net_device *upper_dev, void *data)
{
struct net_device *dev = data;

return upper_dev == dev;
}

/**
* netdev_has_upper_dev - Check if device is linked to an upper device
* @dev: device
Expand All @@ -5151,7 +5158,8 @@ bool netdev_has_upper_dev(struct net_device *dev,
{
ASSERT_RTNL();

return __netdev_find_adj(upper_dev, &dev->all_adj_list.upper);
return netdev_walk_all_upper_dev_rcu(dev, __netdev_has_upper_dev,
upper_dev);
}
EXPORT_SYMBOL(netdev_has_upper_dev);

Expand All @@ -5165,13 +5173,6 @@ EXPORT_SYMBOL(netdev_has_upper_dev);
* The caller must hold rcu lock.
*/

static int __netdev_has_upper_dev(struct net_device *upper_dev, void *data)
{
struct net_device *dev = data;

return upper_dev == dev;
}

bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
struct net_device *upper_dev)
{
Expand All @@ -5191,7 +5192,7 @@ static bool netdev_has_any_upper_dev(struct net_device *dev)
{
ASSERT_RTNL();

return !list_empty(&dev->all_adj_list.upper);
return !list_empty(&dev->adj_list.upper);
}

/**
Expand Down Expand Up @@ -5254,32 +5255,6 @@ struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
}
EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);

/**
* netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next device from the dev's upper list, starting from iter
* position. The caller must hold RCU read lock.
*/
struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *upper;

WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());

upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);

if (&upper->list == &dev->all_adj_list.upper)
return NULL;

*iter = &upper->list;

return upper->dev;
}
EXPORT_SYMBOL(netdev_all_upper_get_next_dev_rcu);

static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
struct list_head **iter)
{
Expand Down Expand Up @@ -5406,31 +5381,6 @@ void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
}
EXPORT_SYMBOL(netdev_lower_get_next);

/**
* netdev_all_lower_get_next - Get the next device from all lower neighbour list
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next netdev_adjacent from the dev's all lower neighbour
* list, starting from iter position. The caller must hold RTNL lock or
* its own locking that guarantees that the neighbour all lower
* list will remain unchanged.
*/
struct net_device *netdev_all_lower_get_next(struct net_device *dev, struct list_head **iter)
{
struct netdev_adjacent *lower;

lower = list_entry(*iter, struct netdev_adjacent, list);

if (&lower->list == &dev->all_adj_list.lower)
return NULL;

*iter = lower->list.next;

return lower->dev;
}
EXPORT_SYMBOL(netdev_all_lower_get_next);

static struct net_device *netdev_next_lower_dev(struct net_device *dev,
struct list_head **iter)
{
Expand Down Expand Up @@ -5474,27 +5424,6 @@ int netdev_walk_all_lower_dev(struct net_device *dev,
}
EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);

/**
* netdev_all_lower_get_next_rcu - Get the next device from all
* lower neighbour list, RCU variant
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next netdev_adjacent from the dev's all lower neighbour
* list, starting from iter position. The caller must hold RCU read lock.
*/
struct net_device *netdev_all_lower_get_next_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *lower;

lower = list_first_or_null_rcu(&dev->all_adj_list.lower,
struct netdev_adjacent, list);

return lower ? lower->dev : NULL;
}
EXPORT_SYMBOL(netdev_all_lower_get_next_rcu);

static struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
struct list_head **iter)
{
Expand Down Expand Up @@ -5722,15 +5651,6 @@ static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
return 0;
}

static int __netdev_adjacent_dev_link(struct net_device *dev,
struct net_device *upper_dev)
{
return __netdev_adjacent_dev_link_lists(dev, upper_dev,
&dev->all_adj_list.upper,
&upper_dev->all_adj_list.lower,
NULL, false);
}

static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
struct net_device *upper_dev,
u16 ref_nr,
Expand All @@ -5741,40 +5661,19 @@ static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
}

static void __netdev_adjacent_dev_unlink(struct net_device *dev,
struct net_device *upper_dev,
u16 ref_nr)
{
__netdev_adjacent_dev_unlink_lists(dev, upper_dev, ref_nr,
&dev->all_adj_list.upper,
&upper_dev->all_adj_list.lower);
}

static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
struct net_device *upper_dev,
void *private, bool master)
{
int ret = __netdev_adjacent_dev_link(dev, upper_dev);

if (ret)
return ret;

ret = __netdev_adjacent_dev_link_lists(dev, upper_dev,
&dev->adj_list.upper,
&upper_dev->adj_list.lower,
private, master);
if (ret) {
__netdev_adjacent_dev_unlink(dev, upper_dev, 1);
return ret;
}

return 0;
return __netdev_adjacent_dev_link_lists(dev, upper_dev,
&dev->adj_list.upper,
&upper_dev->adj_list.lower,
private, master);
}

static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
struct net_device *upper_dev)
{
__netdev_adjacent_dev_unlink(dev, upper_dev, 1);
__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
&dev->adj_list.upper,
&upper_dev->adj_list.lower);
Expand All @@ -5785,7 +5684,6 @@ static int __netdev_upper_dev_link(struct net_device *dev,
void *upper_priv, void *upper_info)
{
struct netdev_notifier_changeupper_info changeupper_info;
struct netdev_adjacent *i, *j, *to_i, *to_j;
int ret = 0;

ASSERT_RTNL();
Expand All @@ -5794,10 +5692,10 @@ static int __netdev_upper_dev_link(struct net_device *dev,
return -EBUSY;

/* To prevent loops, check if dev is not upper device to upper_dev. */
if (__netdev_find_adj(dev, &upper_dev->all_adj_list.upper))
if (netdev_has_upper_dev(upper_dev, dev))
return -EBUSY;

if (__netdev_find_adj(upper_dev, &dev->adj_list.upper))
if (netdev_has_upper_dev(dev, upper_dev))
return -EEXIST;

if (master && netdev_master_upper_dev_get(dev))
Expand All @@ -5819,80 +5717,15 @@ static int __netdev_upper_dev_link(struct net_device *dev,
if (ret)
return ret;

/* Now that we linked these devs, make all the upper_dev's
* all_adj_list.upper visible to every dev's all_adj_list.lower an
* versa, and don't forget the devices itself. All of these
* links are non-neighbours.
*/
list_for_each_entry(i, &dev->all_adj_list.lower, list) {
list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) {
pr_debug("Interlinking %s with %s, non-neighbour\n",
i->dev->name, j->dev->name);
ret = __netdev_adjacent_dev_link(i->dev, j->dev);
if (ret)
goto rollback_mesh;
}
}

/* add dev to every upper_dev's upper device */
list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) {
pr_debug("linking %s's upper device %s with %s\n",
upper_dev->name, i->dev->name, dev->name);
ret = __netdev_adjacent_dev_link(dev, i->dev);
if (ret)
goto rollback_upper_mesh;
}

/* add upper_dev to every dev's lower device */
list_for_each_entry(i, &dev->all_adj_list.lower, list) {
pr_debug("linking %s's lower device %s with %s\n", dev->name,
i->dev->name, upper_dev->name);
ret = __netdev_adjacent_dev_link(i->dev, upper_dev);
if (ret)
goto rollback_lower_mesh;
}

ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER, dev,
&changeupper_info.info);
ret = notifier_to_errno(ret);
if (ret)
goto rollback_lower_mesh;
goto rollback;

return 0;

rollback_lower_mesh:
to_i = i;
list_for_each_entry(i, &dev->all_adj_list.lower, list) {
if (i == to_i)
break;
__netdev_adjacent_dev_unlink(i->dev, upper_dev, i->ref_nr);
}

i = NULL;

rollback_upper_mesh:
to_i = i;
list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) {
if (i == to_i)
break;
__netdev_adjacent_dev_unlink(dev, i->dev, i->ref_nr);
}

i = j = NULL;

rollback_mesh:
to_i = i;
to_j = j;
list_for_each_entry(i, &dev->all_adj_list.lower, list) {
list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) {
if (i == to_i && j == to_j)
break;
__netdev_adjacent_dev_unlink(i->dev, j->dev, i->ref_nr);
}
if (i == to_i)
break;
}

rollback:
__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);

return ret;
Expand Down Expand Up @@ -5949,7 +5782,6 @@ void netdev_upper_dev_unlink(struct net_device *dev,
struct net_device *upper_dev)
{
struct netdev_notifier_changeupper_info changeupper_info;
struct netdev_adjacent *i, *j;
ASSERT_RTNL();

changeupper_info.upper_dev = upper_dev;
Expand All @@ -5961,23 +5793,6 @@ void netdev_upper_dev_unlink(struct net_device *dev,

__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);

/* Here is the tricky part. We must remove all dev's lower
* devices from all upper_dev's upper devices and vice
* versa, to maintain the graph relationship.
*/
list_for_each_entry(i, &dev->all_adj_list.lower, list)
list_for_each_entry(j, &upper_dev->all_adj_list.upper, list)
__netdev_adjacent_dev_unlink(i->dev, j->dev, i->ref_nr);

/* remove also the devices itself from lower/upper device
* list
*/
list_for_each_entry(i, &dev->all_adj_list.lower, list)
__netdev_adjacent_dev_unlink(i->dev, upper_dev, i->ref_nr);

list_for_each_entry(i, &upper_dev->all_adj_list.upper, list)
__netdev_adjacent_dev_unlink(dev, i->dev, i->ref_nr);

call_netdevice_notifiers_info(NETDEV_CHANGEUPPER, dev,
&changeupper_info.info);
}
Expand Down Expand Up @@ -7679,8 +7494,6 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
INIT_LIST_HEAD(&dev->link_watch_list);
INIT_LIST_HEAD(&dev->adj_list.upper);
INIT_LIST_HEAD(&dev->adj_list.lower);
INIT_LIST_HEAD(&dev->all_adj_list.upper);
INIT_LIST_HEAD(&dev->all_adj_list.lower);
INIT_LIST_HEAD(&dev->ptype_all);
INIT_LIST_HEAD(&dev->ptype_specific);
#ifdef CONFIG_NET_SCHED
Expand Down

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