add hlist_bl_lock/unlock helpers

Now that the whole dcache_hash_bucket crap is gone, go all the way and
also remove the weird locking layering violations for locking the hash
buckets.  Add hlist_bl_lock/unlock helpers to move the locking into the
list abstraction instead of requiring each caller to open code it.
After all allowing for the bit locks is the whole point of these helpers
over the plain hlist variant.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 5bad17d1acde..31f9d75adc5b 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -2,6 +2,7 @@
 #define _LINUX_LIST_BL_H
 
 #include <linux/list.h>
+#include <linux/bit_spinlock.h>
 
 /*
  * Special version of lists, where head of the list has a lock in the lowest
@@ -114,6 +115,16 @@ static inline void hlist_bl_del_init(struct hlist_bl_node *n)
 	}
 }
 
+static inline void hlist_bl_lock(struct hlist_bl_head *b)
+{
+	bit_spin_lock(0, (unsigned long *)b);
+}
+
+static inline void hlist_bl_unlock(struct hlist_bl_head *b)
+{
+	__bit_spin_unlock(0, (unsigned long *)b);
+}
+
 /**
  * hlist_bl_for_each_entry	- iterate over list of given type
  * @tpos:	the type * to use as a loop cursor.