[PATCH -V2 4/4] ext4: Init the complete page while building buddy cache

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

We need to init the complete page during buddy cache init
by setting the contents to '1'. This ensures that during
resize when we increment the s_groups_count we don't hit
the erros as below.

EXT4-fs error (device sdb1): ext4_mb_mark_diskspace_used:
	Allocating block 1040385 in system zone of 127 group

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 fs/ext4/mballoc.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 8f33691..01c86f3 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -846,6 +846,8 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
 
 	err = 0;
 	first_block = page->index * blocks_per_page;
+	/* init the page  */
+	memset(page_address(page), 0xff, PAGE_CACHE_SIZE);
 	for (i = 0; i < blocks_per_page; i++) {
 		int group;
 		struct ext4_group_info *grinfo;
-- 
1.6.0.4.735.gea4f