[PATCH] md: define and use safe_put_page for md

md sometimes call put_page on NULL pointers (treating it like kfree).  This is
not safe, so define and use a 'safe_put_page' which checks for NULL.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index e559fb701aa1..12b3203e3419 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -324,5 +324,10 @@ do {									\
         __wait_event_lock_irq(wq, condition, lock, cmd);                \
 } while (0)
 
+static inline void safe_put_page(struct page *p)
+{
+        if (p) put_page(p);
+}
+
 #endif