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| author |   Debabrata Banerjee <dbanerje@akamai.com> | 2018-10-18 11:18:26 -0400 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-10-19 17:01:43 -0700 |
| commit | c9fbd71f73094311b31ee703a918e9e0df502cef (patch) | |
| tree | 1f3d85463e83f066e5aa7e335d70382f0fc23dba /drivers | |
| parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net (diff) | |
| download | linux-dev-c9fbd71f73094311b31ee703a918e9e0df502cef.tar.xz linux-dev-c9fbd71f73094311b31ee703a918e9e0df502cef.zip | |
netpoll: allow cleanup to be synchronous
This fixes a problem introduced by:
commit 2cde6acd49da ("netpoll: Fix __netpoll_rcu_free so that it can hold the rtnl lock")
When using netconsole on a bond, __netpoll_cleanup can asynchronously
recurse multiple times, each __netpoll_free_async call can result in
more __netpoll_free_async's. This means there is now a race between
cleanup_work queues on multiple netpoll_info's on multiple devices and
the configuration of a new netpoll. For example if a netconsole is set
to enable 0, reconfigured, and enable 1 immediately, this netconsole
will likely not work.
Given the reason for __netpoll_free_async is it can be called when rtnl
is not locked, if it is locked, we should be able to execute
synchronously. It appears to be locked everywhere it's called from.
Generalize the design pattern from the teaming driver for current
callers of __netpoll_free_async.
CC: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/bonding/bond_main.c | 3 | ||||
| -rw-r--r-- | drivers/net/macvlan.c | 2 | ||||
| -rw-r--r-- | drivers/net/team/team.c | 5 |
3 files changed, 4 insertions, 6 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index ee28ec9e0aba..ffa37adb7681 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -963,7 +963,8 @@ static inline void slave_disable_netpoll(struct slave *slave) return; slave->np = NULL; - __netpoll_free_async(np); + + __netpoll_free(np); } static void bond_poll_controller(struct net_device *bond_dev) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index cfda146f3b3b..fc8d5f1ee1ad 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -1077,7 +1077,7 @@ static void macvlan_dev_netpoll_cleanup(struct net_device *dev) vlan->netpoll = NULL; - __netpoll_free_async(netpoll); + __netpoll_free(netpoll); } #endif /* CONFIG_NET_POLL_CONTROLLER */ diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c index d887016e54b6..db633ae9f784 100644 --- a/drivers/net/team/team.c +++ b/drivers/net/team/team.c @@ -1104,10 +1104,7 @@ static void team_port_disable_netpoll(struct team_port *port) return; port->np = NULL; - /* Wait for transmitting packets to finish before freeing. */ - synchronize_rcu_bh(); - __netpoll_cleanup(np); - kfree(np); + __netpoll_free(np); } #else static int team_port_enable_netpoll(struct team_port *port) |