From ec7756ae1517af483d995f386936d00a4cb1ab7d Mon Sep 17 00:00:00 2001
From: T Makphaibulchoke <tmac@hp.com>
Date: Wed, 25 Jun 2014 22:08:29 -0400
Subject: [PATCH] fs/mbcache: replace __builtin_log2() with ilog2()

Fix compiler error with some gcc version(s) that do not
support __builtin_log2() by replacing __builtin_log2() with
ilog2().

Signed-off-by: T. Makphaibulchoke <tmac@hp.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org>
---
 fs/mbcache.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/mbcache.c b/fs/mbcache.c
index bf166e388f0d..187477ded6b3 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -73,6 +73,7 @@
 #include <linux/mbcache.h>
 #include <linux/init.h>
 #include <linux/blockgroup_lock.h>
+#include <linux/log2.h>
 
 #ifdef MB_CACHE_DEBUG
 # define mb_debug(f...) do { \
@@ -93,7 +94,7 @@
 
 #define MB_CACHE_WRITER ((unsigned short)~0U >> 1)
 
-#define MB_CACHE_ENTRY_LOCK_BITS	__builtin_log2(NR_BG_LOCKS)
+#define MB_CACHE_ENTRY_LOCK_BITS	ilog2(NR_BG_LOCKS)
 #define	MB_CACHE_ENTRY_LOCK_INDEX(ce)			\
 	(hash_long((unsigned long)ce, MB_CACHE_ENTRY_LOCK_BITS))
 
-- 
2.20.1