At present there are ~200 usages of device_lock() in the kernel. Some of those usages lead to "goto unlock;" patterns which have proven to be error prone. Define a "device" guard() definition to allow for those to be cleaned up and prevent new ones from appearing.
Link: http://lore.kernel.org/r/657897453dda8_269bd29...@dwillia2-mobl3.amr.corp.intel.com.notmuch Link: http://lore.kernel.org/r/6577b0c2a02df_a04c529...@dwillia2-xfh.jf.intel.com.notmuch Cc: Vishal Verma <vishal.l.ve...@intel.com> Cc: Ira Weiny <ira.we...@intel.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.willi...@intel.com> --- Hi Greg, I wonder if you might include this change in v6.7-rc to ease some patch sets alternately going through my tree and Andrew's tree. Those discussions are linked above. Alternately I can can just take it through my tree with your ack and the other use case can circle back to it in the v6.9 cycle. I considered also defining a __free() helper similar to __free(mutex), but I think "__free(device)" would be a surprising name for something that drops a lock. Also, I like the syntax of guard(device) over something like guard(device_lock) since a 'struct device *' is the argument, not a lock type, but I'm open to your or Peter's thoughts on the naming. include/linux/device.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/device.h b/include/linux/device.h index d7a72a8749ea..6c83294395ac 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1007,6 +1007,8 @@ static inline void device_unlock(struct device *dev) mutex_unlock(&dev->mutex); } +DEFINE_GUARD(device, struct device *, device_lock(_T), device_unlock(_T)) + static inline void device_lock_assert(struct device *dev) { lockdep_assert_held(&dev->mutex);
