David Miller írta:
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.
Thanks for your answer, yes, unfortunatelly I checked only inside
rtnetlink.c
--
Attila
--
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
