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>

1 files changed, 6 insertions, 6 deletions

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index bd8a52bb3999..7090c2d25c76 100644
--- a/fs/ext4/resize.c
+++ b/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;