dbuf_whichblock
uint64_t l1blkid = dbuf_whichblock(dn, 1, offset);
blkid = dbuf_whichblock(dn, 0, offset);
blkid = dbuf_whichblock(dn, 0, offset);
blkid = dbuf_whichblock(dn, 0, offset);
blkid = dbuf_whichblock(dn, 0, offset);
blkid = dbuf_whichblock(dn, level,
nblks = dbuf_whichblock(dn, level, offset + len - 1) -
dbuf_whichblock(dn, level, offset) + 1;
blkid = dbuf_whichblock(dn, level, offset);
blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off),
res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len),
uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
uint64_t dbuf_whichblock(struct dnode *di, int64_t level, uint64_t offset);