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, 33 insertions, 36 deletions

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 71ee95e534fd..9568a57c607c 100644
--- a/fs/ext4/balloc.c
+++ b/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 @@ restart:
  */
 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 @@ allocated:
          * 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);