__sync_dirty_buffer
EXPORT_SYMBOL(__sync_dirty_buffer);
return __sync_dirty_buffer(bh, REQ_SYNC);
__sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);
err = __sync_dirty_buffer(nilfs->ns_sbh[0],
int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags);