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| author | Rafael J. Wysocki <rjw@sisk.pl> | 2008-06-11 22:09:45 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2008-07-16 23:27:03 +0200 |
| commit | 25f2f3daadaf0768a61d02ee3ed3d9a21e9dc46c (patch) | |
| tree | 6b17e6d78f562825cc9fc26259f9e5d5f8e80087 /block/blk.h | |
| parent | snapshot: Push BKL down into ioctl handlers (diff) | |
| download | linux-25f2f3daadaf0768a61d02ee3ed3d9a21e9dc46c.tar.xz linux-25f2f3daadaf0768a61d02ee3ed3d9a21e9dc46c.zip | |
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>
Diffstat (limited to 'block/blk.h')
0 files changed, 0 insertions, 0 deletions