the partition. More specifically, we introduce __blkdev_get and __blkdev_put which do exactly what blkdev_{get,put} did, only with an extra "for_part" argument (blkget_{get,put} then call the __ version with a '0' for the extra argument). If for_part is 1, then the blkdev is being get(put) because a partition is being opened(closed) for the first(last) time, and so bd_part_count should be updated (on success). The particular advantage of pushing this function down is that the bd_mutex lock (which is needed to update bd_part_count) is already held at the lower level. Note that this slightly changes the semantics of bd_part_count. Instead of updating it whenever a partition is opened or released, it is now only updated on the first open or last release. This is an adequate semantic as it is only ever tested for "== 0". Having introduced these functions we remove the current bd_part_count updates from do_open (which is really the body of blkdev_get) and call __blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count updates and call __blkget_put(..., 1). This call is moved to the end of __blkdev_put to avoid nested locks of bd_mutex. Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was only really needed to protect bd_part_count, and that is now managed (and protected) within the recursive call. The observation that bd_part_count is central to the locking issues, and the modifications to create __blkdev_put are from Peter Zijlstra. Cc: Ingo Molnar Acked-by: Peter Zijlstra Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds >ã‹›“(x