From: Laszlo Attila Toth <[EMAIL PROTECTED]> Date: Fri, 1 Feb 2008 17:07:33 +0100
> The do_setlink() function is protected by rtnl, additional locks are > unnecessary. > and the set_operstate() function is called from protected parts. Locks removed > from both functions. > > The set_operstate() is also called from rtnl_create_link() and from no other > places. > In rtnl_create_link() none of the changes is protected by set_lock_bh() except > inside set_operstate(), different locking scheme is not necessary > for the operstate. > > Signed-off-by: Laszlo Attila Toth <[EMAIL PROTECTED]> The protection using dev_base_lock() is needed. When analyzing cases like this you need to also look at other code paths outside of rtnetlink that access ->operstate and ->link_mode, you obviously didn't do this. For example, net/core/net-sysfs.c takes a read lock on dev_base_lock in order to fetch a stable copy of both netif_running() and dev->operstate at the same time. Similar write locking to protect dev->operstate is made by net/core/link_watch.c:rfc2863_policy(), for the same reason rtnetlink has to make this locking. You therefore cannot remove it. This invalidates your second patch so I'm dropping that as well. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
