From: Arnd Bergmann <arnd@arndb.de>
Date: Thu, 18 Feb 2010 05:45:36 +0000 (+0000)
Subject: macvtap: rework object lifetime rules
X-Git-Tag: v2.6.34-rc1~233^2~151
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=02df55d28c6001a3cdb7a997a34a0b01f01d015e;p=pandora-kernel.git

macvtap: rework object lifetime rules

This reworks the change done by the previous patch
in a more complete way.

The original macvtap code has a number of problems
resulting from the use of RCU for protecting the
access to struct macvtap_queue from open files.

This includes
- need for GFP_ATOMIC allocations for skbs
- potential deadlocks when copy_*_user sleeps
- inability to work with vhost-net

Changing the lifetime of macvtap_queue to always
depend on the open file solves all these. The
RCU reference simply moves one step down to
the reference on the macvlan_dev, which we
only need for nonblocking operations.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

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