# 对数据块的分配
“`
#define NEXT_FREE_BLKADDR(sbi, curseg) \
(START_BLOCK(sbi, (curseg)->segno) + (curseg)->next_blkoff)
…..
void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
block_t old_blkaddr, block_t *new_blkaddr,
struct f2fs_summary *sum, int type,
struct f2fs_io_info *fio, bool add_list)
{
struct sit_info *sit_i = SIT_I(sbi);
struct curseg_info *curseg = CURSEG_I(sbi, type);
down_read(&SM_I(sbi)->curseg_lock);
mutex_lock(&curseg->curseg_mutex);
down_write(&sit_i->sentry_lock);
*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
f2fs_wait_discard_bio(sbi, *new_blkaddr);
….
“`