diff options
Diffstat (limited to 'include/linux/ext4_fs.h')
| -rw-r--r-- | include/linux/ext4_fs.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h index b61181aadcb..e952c6db969 100644 --- a/include/linux/ext4_fs.h +++ b/include/linux/ext4_fs.h @@ -17,6 +17,7 @@ #define _LINUX_EXT4_FS_H #include <linux/types.h> +#include <linux/blkdev.h> #include <linux/magic.h> /* @@ -750,6 +751,27 @@ ext4_group_first_block_no(struct super_block *sb, unsigned long group_no) #define ERR_BAD_DX_DIR -75000 /* + * This function calculate the block group number and offset, + * given a block number + */ + +static inline void ext4_get_group_no_and_offset(struct super_block * sb, + ext4_fsblk_t blocknr, unsigned long* blockgrpp, + ext4_grpblk_t *offsetp) +{ + struct ext4_super_block *es = EXT4_SB(sb)->s_es; + ext4_grpblk_t offset; + + blocknr = blocknr - le32_to_cpu(es->s_first_data_block); + offset = sector_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)); + if (offsetp) + *offsetp = offset; + if (blockgrpp) + *blockgrpp = blocknr; + +} + +/* * Function prototypes */ @@ -762,6 +784,10 @@ ext4_group_first_block_no(struct super_block *sb, unsigned long group_no) # define NORET_AND noreturn, /* balloc.c */ +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 ext4_fsblk_t ext4_new_block (handle_t *handle, struct inode *inode, |