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| author | Pavel Emelyanov <xemul@openvz.org> | 2008-05-02 17:49:39 -0700 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@redhat.com> | 2008-05-06 12:01:30 -0400 |
| commit | ae68c39819ddf30549652962768a50edae5eec6f (patch) | |
| tree | 0d0ef28152945ad23b72f6cff62a8dfc0345224b | |
| parent | c4ebc66a1a8e3576322a9f47f0d06ec3c96a08d7 (diff) | |
| download | linux-ae68c39819ddf30549652962768a50edae5eec6f.tar.bz2 | |
bonding: Deadlock between bonding_store_bonds and bond_destroy_sysfs.
The sysfs layer has an internal protection, that ensures, that
all the process sitting inside ->sore/->show callback exits
before the appropriate entry is unregistered (the calltraces
are rather big, but I can provide them if required).
On the other hand, bonding takes rtnl_lock in
a) the bonding_store_bonds, i.e. in ->store callback,
b) module exit before calling the sysfs unregister routines.
Thus, the classical AB-BA deadlock may occur. To reproduce run
# while :; do modprobe bonding; rmmod bonding; done
and
# while :; do echo '+bond%d' > /sys/class/net/bonding_masters ; done
in parallel.
The fix is to move the bond_destroy_sysfs out of the rtnl_lock,
but _before_ bond_free_all to make sure no bonding devices exist
after module unload.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
| -rw-r--r-- | drivers/net/bonding/bond_main.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 5509732d3f9d..e41b3e57260c 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -4992,9 +4992,10 @@ err: destroy_workqueue(bond->wq); } + bond_destroy_sysfs(); + rtnl_lock(); bond_free_all(); - bond_destroy_sysfs(); rtnl_unlock(); out: return res; @@ -5006,9 +5007,10 @@ static void __exit bonding_exit(void) unregister_netdevice_notifier(&bond_netdev_notifier); unregister_inetaddr_notifier(&bond_inetaddr_notifier); + bond_destroy_sysfs(); + rtnl_lock(); bond_free_all(); - bond_destroy_sysfs(); rtnl_unlock(); } |