ext4: Use EXT4_GROUP_INFO_NEED_INIT_BIT during resize

The new groups added during resize are flagged as
need_init group. Make sure we properly initialize these
groups. When we have block size < page size and we are adding
new groups the page may still be marked uptodate even though
we haven't initialized the group. While forcing the init
of buddy cache we need to make sure other groups part of the
same page of buddy cache is not using the cache.
group_info->alloc_sem is added to ensure the same.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
cc: stable@kernel.org

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index b5dff1fff1e..a931b6b4f6a 100644
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -20,6 +20,7 @@
 #include <linux/version.h>
 #include <linux/blkdev.h>
 #include <linux/marker.h>
+#include <linux/mutex.h>
 #include "ext4_jbd2.h"
 #include "ext4.h"
 #include "group.h"
@@ -130,6 +131,7 @@ struct ext4_group_info {
 #ifdef DOUBLE_CHECK
         void            *bb_bitmap;
 #endif
+        struct rw_semaphore alloc_sem;
         unsigned short  bb_counters[];
 };
 
@@ -250,6 +252,7 @@ struct ext4_buddy {
         struct super_block *bd_sb;
         __u16 bd_blkbits;
         ext4_group_t bd_group;
+        struct rw_semaphore *alloc_semp;
 };
 #define EXT4_MB_BITMAP(e4b)     ((e4b)->bd_bitmap)
 #define EXT4_MB_BUDDY(e4b)      ((e4b)->bd_buddy)