ext4: use ext4_grpblk_t more extensively

unsigned  short is potentially too small to track blocks within
a group; today it is safe due to restrictions in e2fsprogs but
we have _lo / _hi bits for group blocks with the intent to go
up to 32 bits, so clean this up now.

There are many more places where we use unsigned/int/unsigned int
to contain a group block but this should at least fix all the
short types.

I added a few comments to the struct ext4_group_info definition
as well.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 7 insertions, 4 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 02b22885eb02..41a76e163b99 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1577,15 +1577,18 @@ static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
 struct ext4_group_info {
         unsigned long   bb_state;
         struct rb_root  bb_free_root;
-        unsigned short  bb_first_free;
-        unsigned short  bb_free;
-        unsigned short  bb_fragments;
+        ext4_grpblk_t   bb_first_free;  /* first free block */
+        ext4_grpblk_t   bb_free;        /* total free blocks */
+        ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
         struct          list_head bb_prealloc_list;
 #ifdef DOUBLE_CHECK
         void            *bb_bitmap;
 #endif
         struct rw_semaphore alloc_sem;
-        unsigned short  bb_counters[];
+        ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
+                                         * regions, index is order.
+                                         * bb_counters[3] = 5 means
+                                         * 5 free 8-block regions. */
 };
 
 #define EXT4_GROUP_INFO_NEED_INIT_BIT   0