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>

3 files changed, 19 insertions, 16 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
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 081eaf7fce89..3086b3c65adc 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -623,13 +623,13 @@ static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
 
 /* FIXME!! need more doc */
 static void ext4_mb_mark_free_simple(struct super_block *sb,
-                                void *buddy, unsigned first, int len,
+                                void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
                                         struct ext4_group_info *grp)
 {
         struct ext4_sb_info *sbi = EXT4_SB(sb);
-        unsigned short min;
-        unsigned short max;
-        unsigned short chunk;
+        ext4_grpblk_t min;
+        ext4_grpblk_t max;
+        ext4_grpblk_t chunk;
         unsigned short border;
 
         BUG_ON(len > EXT4_BLOCKS_PER_GROUP(sb));
@@ -663,10 +663,10 @@ void ext4_mb_generate_buddy(struct super_block *sb,
                                 void *buddy, void *bitmap, ext4_group_t group)
 {
         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
-        unsigned short max = EXT4_BLOCKS_PER_GROUP(sb);
-        unsigned short i = 0;
-        unsigned short first;
-        unsigned short len;
+        ext4_grpblk_t max = EXT4_BLOCKS_PER_GROUP(sb);
+        ext4_grpblk_t i = 0;
+        ext4_grpblk_t first;
+        ext4_grpblk_t len;
         unsigned free = 0;
         unsigned fragments = 0;
         unsigned long long period = get_cycles();
@@ -2325,7 +2325,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
         struct ext4_buddy e4b;
         struct sg {
                 struct ext4_group_info info;
-                unsigned short counters[16];
+                ext4_grpblk_t counters[16];
         } sg;
 
         group--;
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index 9db890d4d275..188d3d709b24 100644
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -136,8 +136,8 @@ struct ext4_prealloc_space {
         unsigned                pa_deleted;
         ext4_fsblk_t            pa_pstart;      /* phys. block */
         ext4_lblk_t             pa_lstart;      /* log. block */
-        unsigned short          pa_len;         /* len of preallocated chunk */
-        unsigned short          pa_free;        /* how many blocks are free */
+        ext4_grpblk_t           pa_len;         /* len of preallocated chunk */
+        ext4_grpblk_t           pa_free;        /* how many blocks are free */
         unsigned short          pa_type;        /* pa type. inode or group */
         spinlock_t              *pa_obj_lock;
         struct inode            *pa_inode;      /* hack, for history only */
@@ -152,7 +152,7 @@ struct ext4_free_extent {
         ext4_lblk_t fe_logical;
         ext4_grpblk_t fe_start;
         ext4_group_t fe_group;
-        int fe_len;
+        ext4_grpblk_t fe_len;
 };
 
 /*