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ext4: add ext4_group_t, and change all group variables to this type.
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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>
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@tytso
Avantika Mathur authored and tytso committed Jan 29, 2008
1 parent bba9074 commit fd2d429
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Showing 9 changed files with 91 additions and 87 deletions.
69 changes: 33 additions & 36 deletions fs/ext4/balloc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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;
}
Expand All @@ -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;
Expand All @@ -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;
}
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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 */
Expand All @@ -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;
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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;
Expand All @@ -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;
}
Expand All @@ -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;

Expand All @@ -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;
Expand All @@ -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) &&
Expand All @@ -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) &&
Expand All @@ -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);
Expand Down
8 changes: 5 additions & 3 deletions fs/ext4/group.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 */
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