[PATCH v2 net-next 00/11] net: Fix netdev adjacency tracking

STALE3623d

Revision v2 of 2 in this series.

4 messages, 1 author, 2016-10-15 · open the first message on its own page

[PATCH v2 net-next 00/11] net: Fix netdev adjacency tracking

From: David Ahern <hidden>
Date: 2016-10-15 01:29:01

The netdev adjacency tracking is failing to create proper dependencies
for some topologies. For example this topology

        +--------+
        |  myvrf |
        +--------+
          |    |
          |  +---------+
          |  | macvlan |
          |  +---------+
          |    |
      +----------+
      |  bridge  |
      +----------+
          |
      +--------+
      | bond1  |
      +--------+
          |
      +--------+
      |  eth3  |
      +--------+

hits 1 of 2 problems depending on the order of enslavement. The base set of
commands for both cases:

    ip link add bond1 type bond
    ip link set bond1 up
    ip link set eth3 down
    ip link set eth3 master bond1
    ip link set eth3 up

    ip link add bridge type bridge
    ip link set bridge up
    ip link add macvlan link bridge type macvlan
    ip link set macvlan up

    ip link add myvrf type vrf table 1234
    ip link set myvrf up

    ip link set bridge master myvrf

Case 1 enslave macvlan to the vrf before enslaving the bond to the bridge:

    ip link set macvlan master myvrf
    ip link set bond1 master bridge

Attempts to delete the VRF:
    ip link delete myvrf

trigger the BUG in __netdev_adjacent_dev_remove:

[  587.405260] tried to remove device eth3 from myvrf
[  587.407269] ------------[ cut here ]------------
[  587.408918] kernel BUG at /home/dsa/kernel.git/net/core/dev.c:5661!
[  587.411113] invalid opcode: 0000 [#1] SMP
[  587.412454] Modules linked in: macvlan bridge stp llc bonding vrf
[  587.414765] CPU: 0 PID: 726 Comm: ip Not tainted 4.8.0+ #109
[  587.416766] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[  587.420241] task: ffff88013ab6eec0 task.stack: ffffc90000628000
[  587.422163] RIP: 0010:[<ffffffff813cef03>]  [<ffffffff813cef03>] __netdev_adjacent_dev_remove+0x40/0x12c
...
[  587.446053] Call Trace:
[  587.446424]  [<ffffffff813d1542>] __netdev_adjacent_dev_unlink+0x20/0x3c
[  587.447390]  [<ffffffff813d16a3>] netdev_upper_dev_unlink+0xfa/0x15e
[  587.448297]  [<ffffffffa00003a3>] vrf_del_slave+0x13/0x2a [vrf]
[  587.449153]  [<ffffffffa00004a4>] vrf_dev_uninit+0xea/0x114 [vrf]
[  587.450036]  [<ffffffff813d19b0>] rollback_registered_many+0x22b/0x2da
[  587.450974]  [<ffffffff813d1aac>] unregister_netdevice_many+0x17/0x48
[  587.451903]  [<ffffffff813de444>] rtnl_delete_link+0x3c/0x43
[  587.452719]  [<ffffffff813dedcd>] rtnl_dellink+0x180/0x194

When the BUG is converted to a WARN_ON it shows 4 missing adjacencies:
  eth3 - myvrf, mvrf - eth3, bond1 - myvrf and myvrf - bond1

All of those are because the __netdev_upper_dev_link function does not
properly link macvlan lower devices to myvrf when it is enslaved.

The second case just flips the ordering of the enslavements:
    ip link set bond1 master bridge
    ip link set macvlan master myvrf

Then run:
    ip link delete bond1
    ip link delete myvrf

The vrf delete command hangs because myvrf has a reference that has not
been released. In this case the removal code does not account for 2 paths 
between eth3 and myvrf - one from bridge to vrf and the other through the
macvlan.

Rather than try to maintain a linked list of all upper and lower devices
per netdevice, only track the direct neighbors. The remaining stack can
be determined by recursively walking the neighbors.

The existing netdev_for_each_all_upper_dev_rcu,
netdev_for_each_all_lower_dev and netdev_for_each_all_lower_dev_rcu macros
are replaced with APIs that walk the upper and lower device lists. The
new APIs take a callback function and a data arg that is passed to the
callback for each device in the list. Drivers using the old macros are
converted in separate patches to make it easier on reviewers. It is an
API conversion only; no functional change is intended.

DaveM: Given the impact of this bug (both cases requiring a reboot) I
would like to get this backported to at least the 4.8 tree which as I 
understand it has been targeted as the next LTS.

v2
- fixed bond0 references in cover-letter
- fixed definition of netdev_next_lower_dev_rcu to mirror the upper_dev
  version.

David Ahern (11):
  net: Remove refnr arg when inserting link adjacencies
  net: Introduce new api for walking upper and lower devices
  net: bonding: Flip to the new dev walk API
  IB/core: Flip to the new dev walk API
  IB/ipoib: Flip to new dev walk API
  ixgbe: Flip to the new dev walk API
  mlxsw: Flip to the new dev walk API
  rocker: Flip to the new dev walk API
  net: Remove all_adj_list and its references
  net: Add warning if any lower device is still in adjacency list
  net: dev: Improve debug statements for adjacency tracking

 drivers/infiniband/core/core_priv.h            |   9 +-
 drivers/infiniband/core/roce_gid_mgmt.c        |  42 +--
 drivers/infiniband/ulp/ipoib/ipoib_main.c      |  37 ++-
 drivers/net/bonding/bond_alb.c                 |  82 +++---
 drivers/net/bonding/bond_main.c                |  21 +-
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c  | 132 +++++----
 drivers/net/ethernet/mellanox/mlxsw/spectrum.c |  37 ++-
 drivers/net/ethernet/rocker/rocker_main.c      |  31 ++-
 include/linux/netdevice.h                      |  38 ++-
 net/core/dev.c                                 | 356 ++++++++++++-------------
 10 files changed, 433 insertions(+), 352 deletions(-)

-- 
2.1.4

[PATCH net-next 04/11] IB/core: Flip to the new dev walk API

From: David Ahern <hidden>
Date: 2016-10-15 01:29:04

Convert rdma_is_upper_dev_rcu, handle_netdev_upper and
ipoib_get_net_dev_match_addr to the new upper device walk API.
This is just a code conversion; no functional change is intended.

Signed-off-by: David Ahern <redacted>
---
 drivers/infiniband/core/core_priv.h     |  9 +------
 drivers/infiniband/core/roce_gid_mgmt.c | 42 ++++++++++++++++++---------------
 2 files changed, 24 insertions(+), 27 deletions(-)

diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index 19d499dcab76..0c0bea091de8 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h

@@ -127,14 +127,7 @@ void ib_cache_release_one(struct ib_device *device);
 static inline bool rdma_is_upper_dev_rcu(struct net_device *dev,
 					 struct net_device *upper)
 {
-	struct net_device *_upper = NULL;
-	struct list_head *iter;
-
-	netdev_for_each_all_upper_dev_rcu(dev, _upper, iter)
-		if (_upper == upper)
-			break;
-
-	return _upper == upper;
+	return netdev_has_upper_dev_all_rcu(dev, upper);
 }
 
 int addr_init(void);

diff --git a/drivers/infiniband/core/roce_gid_mgmt.c b/drivers/infiniband/core/roce_gid_mgmt.c
index 06556c34606d..db759a68d948 100644
--- a/drivers/infiniband/core/roce_gid_mgmt.c
+++ b/drivers/infiniband/core/roce_gid_mgmt.c

@@ -437,6 +437,28 @@ static void callback_for_addr_gid_device_scan(struct ib_device *device,
 			  &parsed->gid_attr);
 }
 
+struct upper_list {
+	struct list_head list;
+	struct net_device *upper;
+};
+
+static int netdev_upper_walk(struct net_device *upper, void *data)
+{
+	struct upper_list *entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
+	struct list_head *upper_list = (struct list_head *)data;
+
+	if (!entry) {
+		pr_info("roce_gid_mgmt: couldn't allocate entry to delete ndev\n");
+		return 0;
+	}
+
+	list_add_tail(&entry->list, upper_list);
+	dev_hold(upper);
+	entry->upper = upper;
+
+	return 0;
+}
+
 static void handle_netdev_upper(struct ib_device *ib_dev, u8 port,
 				void *cookie,
 				void (*handle_netdev)(struct ib_device *ib_dev,

@@ -444,30 +466,12 @@ static void handle_netdev_upper(struct ib_device *ib_dev, u8 port,
 						      struct net_device *ndev))
 {
 	struct net_device *ndev = (struct net_device *)cookie;
-	struct upper_list {
-		struct list_head list;
-		struct net_device *upper;
-	};
-	struct net_device *upper;
-	struct list_head *iter;
 	struct upper_list *upper_iter;
 	struct upper_list *upper_temp;
 	LIST_HEAD(upper_list);
 
 	rcu_read_lock();
-	netdev_for_each_all_upper_dev_rcu(ndev, upper, iter) {
-		struct upper_list *entry = kmalloc(sizeof(*entry),
-						   GFP_ATOMIC);
-
-		if (!entry) {
-			pr_info("roce_gid_mgmt: couldn't allocate entry to delete ndev\n");
-			continue;
-		}
-
-		list_add_tail(&entry->list, &upper_list);
-		dev_hold(upper);
-		entry->upper = upper;
-	}
+	netdev_walk_all_upper_dev_rcu(ndev, netdev_upper_walk, &upper_list);
 	rcu_read_unlock();
 
 	handle_netdev(ib_dev, port, ndev);

-- 
2.1.4

[PATCH net-next 08/11] rocker: Flip to the new dev walk API

From: David Ahern <hidden>
Date: 2016-10-15 01:29:08

Convert rocker to the new dev walk API. This is just a code conversion;
no functional change is intended.

Signed-off-by: David Ahern <redacted>
---
 drivers/net/ethernet/rocker/rocker_main.c | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/rocker/rocker_main.c b/drivers/net/ethernet/rocker/rocker_main.c
index 5424fb341613..9310adc0bcbb 100644
--- a/drivers/net/ethernet/rocker/rocker_main.c
+++ b/drivers/net/ethernet/rocker/rocker_main.c

@@ -2839,20 +2839,37 @@ static bool rocker_port_dev_check_under(const struct net_device *dev,
 	return true;
 }
 
+struct rocker_walk_data {
+	struct rocker *rocker;
+	struct rocker_port *port;
+};
+
+static int rocker_lower_dev_walk(struct net_device *lower_dev, void *_data)
+{
+	struct rocker_walk_data *data = (struct rocker_walk_data *)_data;
+	int ret = 0;
+
+	if (rocker_port_dev_check_under(lower_dev, data->rocker)) {
+		data->port = netdev_priv(lower_dev);
+		ret = 1;
+	}
+
+	return ret;
+}
+
 struct rocker_port *rocker_port_dev_lower_find(struct net_device *dev,
 					       struct rocker *rocker)
 {
-	struct net_device *lower_dev;
-	struct list_head *iter;
+	struct rocker_walk_data data;
 
 	if (rocker_port_dev_check_under(dev, rocker))
 		return netdev_priv(dev);
 
-	netdev_for_each_all_lower_dev(dev, lower_dev, iter) {
-		if (rocker_port_dev_check_under(lower_dev, rocker))
-			return netdev_priv(lower_dev);
-	}
-	return NULL;
+	data.rocker = rocker;
+	data.port = NULL;
+	netdev_walk_all_lower_dev(dev, rocker_lower_dev_walk, &data);
+
+	return data.port;
 }
 
 static int rocker_netdevice_event(struct notifier_block *unused,

-- 
2.1.4

[PATCH net-next 09/11] net: Remove all_adj_list and its references

From: David Ahern <hidden>
Date: 2016-10-15 01:29:09

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 <redacted>
---
 include/linux/netdevice.h |  25 -----
 net/core/dev.c            | 229 +++++-----------------------------------------
 2 files changed, 21 insertions(+), 233 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a5902d995907..458c87631e7f 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h

@@ -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
  *

@@ -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;

@@ -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),

@@ -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),

diff --git a/net/core/dev.c b/net/core/dev.c
index 1780f94ed25f..a012c7266230 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c

@@ -5137,6 +5137,16 @@ 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 = (struct net_device *)data;
+
+	if (upper_dev == dev)
+		return 1;
+
+	return 0;
+}
+
 /**
  * netdev_has_upper_dev - Check if device is linked to an upper device
  * @dev: device

@@ -5151,7 +5161,8 @@ 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);

@@ -5165,16 +5176,6 @@ 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 = (struct net_device *)data;
-
-	if (upper_dev == dev)
-		return 1;
-
-	return 0;
-}
-
 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
 				  struct net_device *upper_dev)
 {

@@ -5197,7 +5198,7 @@ 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);
 }
 
 /**

@@ -5260,32 +5261,6 @@ 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)
 {

@@ -5412,31 +5387,6 @@ 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)
 {

@@ -5480,27 +5430,6 @@ 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)
 {

@@ -5728,15 +5657,6 @@ 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,

@@ -5747,40 +5667,19 @@ 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);

@@ -5791,7 +5690,6 @@ 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();

@@ -5800,10 +5698,10 @@ 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))

@@ -5825,80 +5723,15 @@ 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;

@@ -5955,7 +5788,6 @@ 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;

@@ -5967,23 +5799,6 @@ 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);
 }

@@ -7685,8 +7500,6 @@ 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

-- 
2.1.4

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