ext4: add ext4_group_t, and change all group variables to this type.

In many places variables for block group are of type int, which limits the
maximum number of block groups to 2^31.  Each block group can have up to
2^15 blocks, with a 4K block size,  and the max filesystem size is limited to
2^31 * (2^15 * 2^12) = 2^58  -- or 256 PB

This patch introduces a new type ext4_group_t, of type unsigned long, to
represent block group numbers in ext4.
All occurrences of block group variables are converted to type ext4_group_t.
Signed-off-by: Avantika Mathur <mathur@us.ibm.com>

fs/ext4/balloc.c

@@ -29,7 +29,7 @@
  * Calculate the block group number and offset, given a block number
  */
 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
-		unsigned long *blockgrpp, ext4_grpblk_t *offsetp)
+		ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp)
 {
 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 	ext4_grpblk_t offset;
@@ -46,7 +46,7 @@ void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
 /* Initializes an uninitialized block bitmap if given, and returns the
  * number of blocks free in the group. */
 unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
-				int block_group, struct ext4_group_desc *gdp)
+		 ext4_group_t block_group, struct ext4_group_desc *gdp)
 {
 	unsigned long start;
 	int bit, bit_max;
@@ -60,7 +60,7 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
 		 * essentially implementing a per-group read-only flag. */
 		if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
 			ext4_error(sb, __FUNCTION__,
-				   "Checksum bad for group %u\n", block_group);
+				  "Checksum bad for group %lu\n", block_group);
 			gdp->bg_free_blocks_count = 0;
 			gdp->bg_free_inodes_count = 0;
 			gdp->bg_itable_unused = 0;
@@ -153,7 +153,7 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
  *			group descriptor
  */
 struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
-					     unsigned int block_group,
+					     ext4_group_t block_group,
 					     struct buffer_head ** bh)
 {
 	unsigned long group_desc;
@@ -164,7 +164,7 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
 	if (block_group >= sbi->s_groups_count) {
 		ext4_error (sb, "ext4_get_group_desc",
 			    "block_group >= groups_count - "
-			    "block_group = %d, groups_count = %lu",
+			    "block_group = %lu, groups_count = %lu",
 			    block_group, sbi->s_groups_count);
 
 		return NULL;
@@ -176,7 +176,7 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
 	if (!sbi->s_group_desc[group_desc]) {
 		ext4_error (sb, "ext4_get_group_desc",
 			    "Group descriptor not loaded - "
-			    "block_group = %d, group_desc = %lu, desc = %lu",
+			    "block_group = %lu, group_desc = %lu, desc = %lu",
 			     block_group, group_desc, offset);
 		return NULL;
 	}
@@ -200,7 +200,7 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
  * Return buffer_head on success or NULL in case of failure.
  */
 struct buffer_head *
-read_block_bitmap(struct super_block *sb, unsigned int block_group)
+read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
 {
 	struct ext4_group_desc * desc;
 	struct buffer_head * bh = NULL;
@@ -227,7 +227,7 @@ read_block_bitmap(struct super_block *sb, unsigned int block_group)
 	if (!bh)
 		ext4_error (sb, __FUNCTION__,
 			    "Cannot read block bitmap - "
-			    "block_group = %d, block_bitmap = %llu",
+			    "block_group = %lu, block_bitmap = %llu",
 			    block_group, bitmap_blk);
 	return bh;
 }
@@ -320,7 +320,7 @@ static void __rsv_window_dump(struct rb_root *root, int verbose,
  */
 static int
 goal_in_my_reservation(struct ext4_reserve_window *rsv, ext4_grpblk_t grp_goal,
-			unsigned int group, struct super_block * sb)
+			ext4_group_t group, struct super_block *sb)
 {
 	ext4_fsblk_t group_first_block, group_last_block;
 
@@ -540,7 +540,7 @@ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
 {
 	struct buffer_head *bitmap_bh = NULL;
 	struct buffer_head *gd_bh;
-	unsigned long block_group;
+	ext4_group_t block_group;
 	ext4_grpblk_t bit;
 	unsigned long i;
 	unsigned long overflow;
@@ -920,9 +920,10 @@ claim_block(spinlock_t *lock, ext4_grpblk_t block, struct buffer_head *bh)
  * ext4_journal_release_buffer(), else we'll run out of credits.
  */
 static ext4_grpblk_t
-ext4_try_to_allocate(struct super_block *sb, handle_t *handle, int group,
-			struct buffer_head *bitmap_bh, ext4_grpblk_t grp_goal,
-			unsigned long *count, struct ext4_reserve_window *my_rsv)
+ext4_try_to_allocate(struct super_block *sb, handle_t *handle,
+			ext4_group_t group, struct buffer_head *bitmap_bh,
+			ext4_grpblk_t grp_goal, unsigned long *count,
+			struct ext4_reserve_window *my_rsv)
 {
 	ext4_fsblk_t group_first_block;
 	ext4_grpblk_t start, end;
@@ -1156,7 +1157,7 @@ static int find_next_reservable_window(
  */
 static int alloc_new_reservation(struct ext4_reserve_window_node *my_rsv,
 		ext4_grpblk_t grp_goal, struct super_block *sb,
-		unsigned int group, struct buffer_head *bitmap_bh)
+		ext4_group_t group, struct buffer_head *bitmap_bh)
 {
 	struct ext4_reserve_window_node *search_head;
 	ext4_fsblk_t group_first_block, group_end_block, start_block;
@@ -1354,7 +1355,7 @@ static void try_to_extend_reservation(struct ext4_reserve_window_node *my_rsv,
  */
 static ext4_grpblk_t
 ext4_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
-			unsigned int group, struct buffer_head *bitmap_bh,
+			ext4_group_t group, struct buffer_head *bitmap_bh,
 			ext4_grpblk_t grp_goal,
 			struct ext4_reserve_window_node * my_rsv,
 			unsigned long *count, int *errp)
@@ -1528,12 +1529,12 @@ ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
 {
 	struct buffer_head *bitmap_bh = NULL;
 	struct buffer_head *gdp_bh;
-	unsigned long group_no;
-	int goal_group;
+	ext4_group_t group_no;
+	ext4_group_t goal_group;
 	ext4_grpblk_t grp_target_blk;	/* blockgroup relative goal block */
 	ext4_grpblk_t grp_alloc_blk;	/* blockgroup-relative allocated block*/
 	ext4_fsblk_t ret_block;		/* filesyetem-wide allocated block */
-	int bgi;			/* blockgroup iteration index */
+	ext4_group_t bgi;			/* blockgroup iteration index */
 	int fatal = 0, err;
 	int performed_allocation = 0;
 	ext4_grpblk_t free_blocks;	/* number of free blocks in a group */
@@ -1544,10 +1545,7 @@ ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
 	struct ext4_reserve_window_node *my_rsv = NULL;
 	struct ext4_block_alloc_info *block_i;
 	unsigned short windowsz = 0;
-#ifdef EXT4FS_DEBUG
-	static int goal_hits, goal_attempts;
-#endif
-	unsigned long ngroups;
+	ext4_group_t ngroups;
 	unsigned long num = *count;
 
 	*errp = -ENOSPC;
@@ -1743,9 +1741,6 @@ ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
 	 * list of some description.  We don't know in advance whether
 	 * the caller wants to use it as metadata or data.
 	 */
-	ext4_debug("allocating block %lu. Goal hits %d of %d.\n",
-			ret_block, goal_hits, goal_attempts);
-
 	spin_lock(sb_bgl_lock(sbi, group_no));
 	if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
 		gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
@@ -1804,8 +1799,8 @@ ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
 {
 	ext4_fsblk_t desc_count;
 	struct ext4_group_desc *gdp;
-	int i;
-	unsigned long ngroups = EXT4_SB(sb)->s_groups_count;
+	ext4_group_t i;
+	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
 #ifdef EXT4FS_DEBUG
 	struct ext4_super_block *es;
 	ext4_fsblk_t bitmap_count;
@@ -1829,7 +1824,7 @@ ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
 			continue;
 
 		x = ext4_count_free(bitmap_bh, sb->s_blocksize);
-		printk("group %d: stored = %d, counted = %lu\n",
+		printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
 			i, le16_to_cpu(gdp->bg_free_blocks_count), x);
 		bitmap_count += x;
 	}
@@ -1853,7 +1848,7 @@ ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
 #endif
 }
 
-static inline int test_root(int a, int b)
+static inline int test_root(ext4_group_t a, int b)
 {
 	int num = b;
 
@@ -1862,7 +1857,7 @@ static inline int test_root(int a, int b)
 	return num == a;
 }
 
-static int ext4_group_sparse(int group)
+static int ext4_group_sparse(ext4_group_t group)
 {
 	if (group <= 1)
 		return 1;
@@ -1880,7 +1875,7 @@ static int ext4_group_sparse(int group)
  *	Return the number of blocks used by the superblock (primary or backup)
  *	in this group.  Currently this will be only 0 or 1.
  */
-int ext4_bg_has_super(struct super_block *sb, int group)
+int ext4_bg_has_super(struct super_block *sb, ext4_group_t group)
 {
 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 				EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) &&
@@ -1889,18 +1884,20 @@ int ext4_bg_has_super(struct super_block *sb, int group)
 	return 1;
 }
 
-static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb, int group)
+static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb,
+					ext4_group_t group)
 {
 	unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
-	unsigned long first = metagroup * EXT4_DESC_PER_BLOCK(sb);
-	unsigned long last = first + EXT4_DESC_PER_BLOCK(sb) - 1;
+	ext4_group_t first = metagroup * EXT4_DESC_PER_BLOCK(sb);
+	ext4_group_t last = first + EXT4_DESC_PER_BLOCK(sb) - 1;
 
 	if (group == first || group == first + 1 || group == last)
 		return 1;
 	return 0;
 }
 
-static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb, int group)
+static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb,
+					ext4_group_t group)
 {
 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 				EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) &&
@@ -1918,7 +1915,7 @@ static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb, int group)
  *	(primary or backup) in this group.  In the future there may be a
  *	different number of descriptor blocks in each group.
  */
-unsigned long ext4_bg_num_gdb(struct super_block *sb, int group)
+unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group)
 {
 	unsigned long first_meta_bg =
 			le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);

fs/ext4/group.h

@@ -14,14 +14,16 @@ extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
 				       struct ext4_group_desc *gdp);
 struct buffer_head *read_block_bitmap(struct super_block *sb,
-				      unsigned int block_group);
+				      ext4_group_t block_group);
 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
-				       struct buffer_head *bh, int group,
+				       struct buffer_head *bh,
+				       ext4_group_t group,
 				       struct ext4_group_desc *desc);
 #define ext4_free_blocks_after_init(sb, group, desc)			\
 		ext4_init_block_bitmap(sb, NULL, group, desc)
 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
-				       struct buffer_head *bh, int group,
+				       struct buffer_head *bh,
+				       ext4_group_t group,
 				       struct ext4_group_desc *desc);
 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
 #endif /* _LINUX_EXT4_GROUP_H */

fs/ext4/ialloc.c

@@ -64,8 +64,8 @@ void mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
 }
 
 /* Initializes an uninitialized inode bitmap */
-unsigned ext4_init_inode_bitmap(struct super_block *sb,
-				struct buffer_head *bh, int block_group,
+unsigned ext4_init_inode_bitmap(struct super_block *sb, struct buffer_head *bh,
+				ext4_group_t block_group,
 				struct ext4_group_desc *gdp)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -75,7 +75,7 @@ unsigned ext4_init_inode_bitmap(struct super_block *sb,
 	/* If checksum is bad mark all blocks and inodes use to prevent
 	 * allocation, essentially implementing a per-group read-only flag. */
 	if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
-		ext4_error(sb, __FUNCTION__, "Checksum bad for group %u\n",
+		ext4_error(sb, __FUNCTION__, "Checksum bad for group %lu\n",
 			   block_group);
 		gdp->bg_free_blocks_count = 0;
 		gdp->bg_free_inodes_count = 0;
@@ -98,7 +98,7 @@ unsigned ext4_init_inode_bitmap(struct super_block *sb,
  * Return buffer_head of bitmap on success or NULL.
  */
 static struct buffer_head *
-read_inode_bitmap(struct super_block * sb, unsigned long block_group)
+read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 {
 	struct ext4_group_desc *desc;
 	struct buffer_head *bh = NULL;
@@ -152,7 +152,7 @@ void ext4_free_inode (handle_t *handle, struct inode * inode)
 	unsigned long ino;
 	struct buffer_head *bitmap_bh = NULL;
 	struct buffer_head *bh2;
-	unsigned long block_group;
+	ext4_group_t block_group;
 	unsigned long bit;
 	struct ext4_group_desc * gdp;
 	struct ext4_super_block * es;
@@ -260,12 +260,12 @@ void ext4_free_inode (handle_t *handle, struct inode * inode)
  * For other inodes, search forward from the parent directory\'s block
  * group to find a free inode.
  */
-static int find_group_dir(struct super_block *sb, struct inode *parent)
+static ext4_group_t find_group_dir(struct super_block *sb, struct inode *parent)
 {
-	int ngroups = EXT4_SB(sb)->s_groups_count;
+	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
 	unsigned int freei, avefreei;
 	struct ext4_group_desc *desc, *best_desc = NULL;
-	int group, best_group = -1;
+	ext4_group_t group, best_group = -1;
 
 	freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);
 	avefreei = freei / ngroups;
@@ -314,12 +314,13 @@ static int find_group_dir(struct super_block *sb, struct inode *parent)
 #define INODE_COST 64
 #define BLOCK_COST 256
 
-static int find_group_orlov(struct super_block *sb, struct inode *parent)
+static ext4_group_t find_group_orlov(struct super_block *sb,
+				      struct inode *parent)
 {
-	int parent_group = EXT4_I(parent)->i_block_group;
+	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_super_block *es = sbi->s_es;
-	int ngroups = sbi->s_groups_count;
+	ext4_group_t ngroups = sbi->s_groups_count;
 	int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 	unsigned int freei, avefreei;
 	ext4_fsblk_t freeb, avefreeb;
@@ -327,7 +328,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
 	unsigned int ndirs;
 	int max_debt, max_dirs, min_inodes;
 	ext4_grpblk_t min_blocks;
-	int group = -1, i;
+	ext4_group_t group = -1, i;
 	struct ext4_group_desc *desc;
 
 	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
@@ -340,7 +341,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
 	if ((parent == sb->s_root->d_inode) ||
 	    (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
 		int best_ndir = inodes_per_group;
-		int best_group = -1;
+		ext4_group_t best_group = -1;
 
 		get_random_bytes(&group, sizeof(group));
 		parent_group = (unsigned)group % ngroups;
@@ -415,12 +416,13 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
 	return -1;
 }
 
-static int find_group_other(struct super_block *sb, struct inode *parent)
+static ext4_group_t find_group_other(struct super_block *sb,
+					struct inode *parent)
 {
-	int parent_group = EXT4_I(parent)->i_block_group;
-	int ngroups = EXT4_SB(sb)->s_groups_count;
+	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
+	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
 	struct ext4_group_desc *desc;
-	int group, i;
+	ext4_group_t group, i;
 
 	/*
 	 * Try to place the inode in its parent directory
@@ -487,7 +489,7 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
 	struct super_block *sb;
 	struct buffer_head *bitmap_bh = NULL;
 	struct buffer_head *bh2;
-	int group;
+	ext4_group_t group;
 	unsigned long ino = 0;
 	struct inode * inode;
 	struct ext4_group_desc * gdp = NULL;
@@ -583,7 +585,7 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
 	    ino > EXT4_INODES_PER_GROUP(sb)) {
 		ext4_error(sb, __FUNCTION__,
 			   "reserved inode or inode > inodes count - "
-			   "block_group = %d, inode=%lu", group,
+			   "block_group = %lu, inode=%lu", group,
 			   ino + group * EXT4_INODES_PER_GROUP(sb));
 		err = -EIO;
 		goto fail;
@@ -777,7 +779,7 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
 {
 	unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
-	unsigned long block_group;
+	ext4_group_t block_group;
 	int bit;
 	struct buffer_head *bitmap_bh = NULL;
 	struct inode *inode = NULL;
@@ -833,7 +835,7 @@ unsigned long ext4_count_free_inodes (struct super_block * sb)
 {
 	unsigned long desc_count;
 	struct ext4_group_desc *gdp;
-	int i;
+	ext4_group_t i;
 #ifdef EXT4FS_DEBUG
 	struct ext4_super_block *es;
 	unsigned long bitmap_count, x;
@@ -879,7 +881,7 @@ unsigned long ext4_count_free_inodes (struct super_block * sb)
 unsigned long ext4_count_dirs (struct super_block * sb)
 {
 	unsigned long count = 0;
-	int i;
+	ext4_group_t i;
 
 	for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 		struct ext4_group_desc *gdp = ext4_get_group_desc (sb, i, NULL);

fs/ext4/inode.c

@@ -2464,7 +2464,8 @@ void ext4_truncate(struct inode *inode)
 static ext4_fsblk_t ext4_get_inode_block(struct super_block *sb,
 		unsigned long ino, struct ext4_iloc *iloc)
 {
-	unsigned long desc, group_desc, block_group;
+	unsigned long desc, group_desc;
+	ext4_group_t block_group;
 	unsigned long offset;
 	ext4_fsblk_t block;
 	struct buffer_head *bh;
@@ -2551,7 +2552,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
 			struct ext4_group_desc *desc;
 			int inodes_per_buffer;
 			int inode_offset, i;
-			int block_group;
+			ext4_group_t block_group;
 			int start;
 
 			block_group = (inode->i_ino - 1) /

fs/ext4/resize.c

@@ -28,7 +28,7 @@ static int verify_group_input(struct super_block *sb,
 	struct ext4_super_block *es = sbi->s_es;
 	ext4_fsblk_t start = ext4_blocks_count(es);
 	ext4_fsblk_t end = start + input->blocks_count;
-	unsigned group = input->group;
+	ext4_group_t group = input->group;
 	ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
 	unsigned overhead = ext4_bg_has_super(sb, group) ?
 		(1 + ext4_bg_num_gdb(sb, group) +
@@ -357,7 +357,7 @@ static int verify_reserved_gdb(struct super_block *sb,
 			       struct buffer_head *primary)
 {
 	const ext4_fsblk_t blk = primary->b_blocknr;
-	const unsigned long end = EXT4_SB(sb)->s_groups_count;
+	const ext4_group_t end = EXT4_SB(sb)->s_groups_count;
 	unsigned three = 1;
 	unsigned five = 5;
 	unsigned seven = 7;
@@ -656,12 +656,12 @@ static void update_backups(struct super_block *sb,
 			   int blk_off, char *data, int size)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	const unsigned long last = sbi->s_groups_count;
+	const ext4_group_t last = sbi->s_groups_count;
 	const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
 	unsigned three = 1;
 	unsigned five = 5;
 	unsigned seven = 7;
-	unsigned group;
+	ext4_group_t group;
 	int rest = sb->s_blocksize - size;
 	handle_t *handle;
 	int err = 0, err2;
@@ -716,7 +716,7 @@ static void update_backups(struct super_block *sb,
 exit_err:
 	if (err) {
 		ext4_warning(sb, __FUNCTION__,
-			     "can't update backup for group %d (err %d), "
+			     "can't update backup for group %lu (err %d), "
 			     "forcing fsck on next reboot", group, err);
 		sbi->s_mount_state &= ~EXT4_VALID_FS;
 		sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
@@ -952,7 +952,7 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
 		      ext4_fsblk_t n_blocks_count)
 {
 	ext4_fsblk_t o_blocks_count;
-	unsigned long o_groups_count;
+	ext4_group_t o_groups_count;
 	ext4_grpblk_t last;
 	ext4_grpblk_t add;
 	struct buffer_head * bh;

fs/ext4/super.c

@@ -1364,7 +1364,7 @@ static int ext4_check_descriptors (struct super_block * sb)
 	struct ext4_group_desc * gdp = NULL;
 	int desc_block = 0;
 	int flexbg_flag = 0;
-	int i;
+	ext4_group_t i;
 
 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
 		flexbg_flag = 1;
@@ -1386,7 +1386,7 @@ static int ext4_check_descriptors (struct super_block * sb)
 		if (block_bitmap < first_block || block_bitmap > last_block)
 		{
 			ext4_error (sb, "ext4_check_descriptors",
-				    "Block bitmap for group %d"
+				    "Block bitmap for group %lu"
 				    " not in group (block %llu)!",
 				    i, block_bitmap);
 			return 0;
@@ -1395,7 +1395,7 @@ static int ext4_check_descriptors (struct super_block * sb)
 		if (inode_bitmap < first_block || inode_bitmap > last_block)
 		{
 			ext4_error (sb, "ext4_check_descriptors",
-				    "Inode bitmap for group %d"
+				    "Inode bitmap for group %lu"
 				    " not in group (block %llu)!",
 				    i, inode_bitmap);
 			return 0;
@@ -1405,17 +1405,16 @@ static int ext4_check_descriptors (struct super_block * sb)
 		    inode_table + sbi->s_itb_per_group - 1 > last_block)
 		{
 			ext4_error (sb, "ext4_check_descriptors",
-				    "Inode table for group %d"
+				    "Inode table for group %lu"
 				    " not in group (block %llu)!",
 				    i, inode_table);
 			return 0;
 		}
 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
 			ext4_error(sb, __FUNCTION__,
-				   "Checksum for group %d failed (%u!=%u)\n", i,
-				   le16_to_cpu(ext4_group_desc_csum(sbi, i,
-								    gdp)),
-				   le16_to_cpu(gdp->bg_checksum));
+				   "Checksum for group %lu failed (%u!=%u)\n",
+				    i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
+				    gdp)), le16_to_cpu(gdp->bg_checksum));
 			return 0;
 		}
 		if (!flexbg_flag)
@@ -1429,7 +1428,6 @@ static int ext4_check_descriptors (struct super_block * sb)
 	return 1;
 }
 
-
 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
  * the superblock) which were deleted from all directories, but held open by
  * a process at the time of a crash.  We walk the list and try to delete these
@@ -1570,7 +1568,7 @@ static ext4_fsblk_t descriptor_loc(struct super_block *sb,
 				ext4_fsblk_t logical_sb_block, int nr)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	unsigned long bg, first_meta_bg;
+	ext4_group_t bg, first_meta_bg;
 	int has_super = 0;
 
 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
@@ -2678,7 +2676,7 @@ static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
 	if (test_opt(sb, MINIX_DF)) {
 		sbi->s_overhead_last = 0;
 	} else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
-		unsigned long ngroups = sbi->s_groups_count, i;
+		ext4_group_t ngroups = sbi->s_groups_count, i;
 		ext4_fsblk_t overhead = 0;
 		smp_rmb();
 

include/linux/ext4_fs.h

@@ -830,7 +830,7 @@ struct ext4_iloc
 {
 	struct buffer_head *bh;
 	unsigned long offset;
-	unsigned long block_group;
+	ext4_group_t block_group;
 };
 
 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
@@ -855,7 +855,7 @@ struct dir_private_info {
 
 /* calculate the first block number of the group */
 static inline ext4_fsblk_t
-ext4_group_first_block_no(struct super_block *sb, unsigned long group_no)
+ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
 {
 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
@@ -886,8 +886,9 @@ extern unsigned int ext4_block_group(struct super_block *sb,
 			ext4_fsblk_t blocknr);
 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
 			ext4_fsblk_t blocknr);
-extern int ext4_bg_has_super(struct super_block *sb, int group);
-extern unsigned long ext4_bg_num_gdb(struct super_block *sb, int group);
+extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
+extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
+			ext4_group_t group);
 extern ext4_fsblk_t ext4_new_block (handle_t *handle, struct inode *inode,
 			ext4_fsblk_t goal, int *errp);
 extern ext4_fsblk_t ext4_new_blocks (handle_t *handle, struct inode *inode,
@@ -900,7 +901,7 @@ extern void ext4_free_blocks_sb (handle_t *handle, struct super_block *sb,
 extern ext4_fsblk_t ext4_count_free_blocks (struct super_block *);
 extern void ext4_check_blocks_bitmap (struct super_block *);
 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
-						    unsigned int block_group,
+						    ext4_group_t block_group,
 						    struct buffer_head ** bh);
 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
 extern void ext4_init_block_alloc_info(struct inode *);

include/linux/ext4_fs_i.h

@@ -30,6 +30,9 @@ typedef unsigned long long ext4_fsblk_t;
 /* data type for file logical block number */
 typedef __u32 ext4_lblk_t;
 
+/* data type for block group number */
+typedef unsigned long ext4_group_t;
+
 struct ext4_reserve_window {
 	ext4_fsblk_t	_rsv_start;	/* First byte reserved */
 	ext4_fsblk_t	_rsv_end;	/* Last byte reserved or 0 */
@@ -92,7 +95,7 @@ struct ext4_inode_info {
 	 * place a file's data blocks near its inode block, and new inodes
 	 * near to their parent directory's inode.
 	 */
-	__u32	i_block_group;
+	ext4_group_t	i_block_group;
 	__u32	i_state;		/* Dynamic state flags for ext4 */
 
 	/* block reservation info */

include/linux/ext4_fs_sb.h

@@ -35,7 +35,7 @@ struct ext4_sb_info {
 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
-	unsigned long s_groups_count;	/* Number of groups in the fs */
+	ext4_group_t s_groups_count;	/* Number of groups in the fs */
 	unsigned long s_overhead_last;  /* Last calculated overhead */
 	unsigned long s_blocks_last;    /* Last seen block count */
 	struct buffer_head * s_sbh;	/* Buffer containing the super block */