Esempi in C++ (Cpp) per dbuf_create_bonus

Esempio n. 1

File: dmu.c Progetto: YaroslavLitvinov/zfs-port

/*
 * returns ENOENT, EIO, or 0.
 */
int
dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
{
	dnode_t *dn;
	dmu_buf_impl_t *db;
	int error;

	error = dnode_hold(os->os, object, FTAG, &dn);
	if (error)
		return (error);

	rw_enter(&dn->dn_struct_rwlock, RW_READER);
	if (dn->dn_bonus == NULL) {
		rw_exit(&dn->dn_struct_rwlock);
		rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
		if (dn->dn_bonus == NULL)
			dbuf_create_bonus(dn);
	}
	db = dn->dn_bonus;
	rw_exit(&dn->dn_struct_rwlock);

	/* as long as the bonus buf is held, the dnode will be held */
	if (refcount_add(&db->db_holds, tag) == 1)
		VERIFY(dnode_add_ref(dn, db));

	dnode_rele(dn, FTAG);

	VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED));

	*dbp = &db->db;
	return (0);
}

Esempio n. 2

File: dmu.c Progetto: yaoyutian/freebsd

/*
 * returns ENOENT, EIO, or 0.
 */
int
dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
{
	dnode_t *dn;
	dmu_buf_impl_t *db;
	int error;

	error = dnode_hold(os, object, FTAG, &dn);
	if (error)
		return (error);

	rw_enter(&dn->dn_struct_rwlock, RW_READER);
	if (dn->dn_bonus == NULL) {
		rw_exit(&dn->dn_struct_rwlock);
		rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
		if (dn->dn_bonus == NULL)
			dbuf_create_bonus(dn);
	}
	db = dn->dn_bonus;

	/* as long as the bonus buf is held, the dnode will be held */
	if (refcount_add(&db->db_holds, tag) == 1) {
		VERIFY(dnode_add_ref(dn, db));
		atomic_inc_32(&dn->dn_dbufs_count);
	}

	/*
	 * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
	 * hold and incrementing the dbuf count to ensure that dnode_move() sees
	 * a dnode hold for every dbuf.
	 */
	rw_exit(&dn->dn_struct_rwlock);

	dnode_rele(dn, FTAG);

	VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH));

	*dbp = &db->db;
	return (0);
}