]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
snapshot: Use pm_mutex for mutual exclusion
authorRafael J. Wysocki <rjw@sisk.pl>
Wed, 11 Jun 2008 20:09:45 +0000 (22:09 +0200)
committerAndi Kleen <andi@basil.nowhere.org>
Wed, 16 Jul 2008 21:27:03 +0000 (23:27 +0200)
commit25f2f3daadaf0768a61d02ee3ed3d9a21e9dc46c
tree6b17e6d78f562825cc9fc26259f9e5d5f8e80087
parent52d11025dba32bed696eaee1822b26529e764770
snapshot: Use pm_mutex for mutual exclusion

We can avoid taking the BKL in snapshot_ioctl() if pm_mutex is used to prevent
the ioctls from being executed concurrently.

In addition, although it is only possible to open /dev/snapshot once, the task
which has done that may spawn a child that will inherit the open descriptor,
so in theory they can call snapshot_write(), snapshot_read() and
snapshot_release() concurrently.  pm_mutex can also be used for mutual
exclusion in such cases.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>
kernel/power/user.c