[PATCH] ext4: Fix mballoc BUG when running compilebench

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

This fix the mballoc bug when running compile bench.
Instead of using direct division even though the arguments
are 32 bits we retain do_div. This would be needed if we
move to 64 bit logical block number.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 fs/ext4/mballoc.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index fe7cf9e..8467b3d 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3089,13 +3089,14 @@ static void ext4_mb_normalize_request(struct ext4_allocation_context *ac,
 		}
 	}
 	if (wind == 0) {
+		__u64 tstart;
 		/* file is quite large, we now preallocate with
 		 * the biggest configured window with regart to
 		 * logical offset */
 		wind = sbi->s_mb_prealloc_table[i - 1];
-		start = ac->ac_o_ex.fe_logical;
-		do_div(start, wind);
-		start = start * wind;
+		tstart = ac->ac_o_ex.fe_logical;
+		do_div(tstart, wind);
+		start = tstart * wind;
 	}
 	size = wind;
 	orig_size = size;
-- 
1.5.3.4.319.gdd817-dirty