GFS2: Change maxlen variables to size_t

This patch changes some variables (especially maxlen in function
gfs2_block_map) from unsigned int to size_t. We need 64-bit arithmetic
for very large files (e.g. 1PB) where the variables otherwise get
shifted to all 0's.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/bmap.c

@@ -359,7 +359,7 @@ static inline void release_metapath(struct metapath *mp)
  * Returns: The length of the extent (minimum of one block)
  */
 
-static inline unsigned int gfs2_extent_length(void *start, unsigned int len, __be64 *ptr, unsigned limit, int *eob)
+static inline unsigned int gfs2_extent_length(void *start, unsigned int len, __be64 *ptr, size_t limit, int *eob)
 {
 	const __be64 *end = (start + len);
 	const __be64 *first = ptr;
@@ -449,7 +449,7 @@ static int gfs2_bmap_alloc(struct inode *inode, const sector_t lblock,
 			   struct buffer_head *bh_map, struct metapath *mp,
 			   const unsigned int sheight,
 			   const unsigned int height,
-			   const unsigned int maxlen)
+			   const size_t maxlen)
 {
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_sbd *sdp = GFS2_SB(inode);
@@ -483,7 +483,8 @@ static int gfs2_bmap_alloc(struct inode *inode, const sector_t lblock,
 	} else {
 		/* Need to allocate indirect blocks */
 		ptrs_per_blk = height > 1 ? sdp->sd_inptrs : sdp->sd_diptrs;
-		dblks = min(maxlen, ptrs_per_blk - mp->mp_list[end_of_metadata]);
+		dblks = min(maxlen, (size_t)(ptrs_per_blk -
+					     mp->mp_list[end_of_metadata]));
 		if (height == ip->i_height) {
 			/* Writing into existing tree, extend tree down */
 			iblks = height - sheight;
@@ -605,7 +606,7 @@ int gfs2_block_map(struct inode *inode, sector_t lblock,
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	unsigned int bsize = sdp->sd_sb.sb_bsize;
-	const unsigned int maxlen = bh_map->b_size >> inode->i_blkbits;
+	const size_t maxlen = bh_map->b_size >> inode->i_blkbits;
 	const u64 *arr = sdp->sd_heightsize;
 	__be64 *ptr;
 	u64 size;