C++ (Cpp) zvol_log_truncate Examples

Example #1

File: zvol.c Project: Oliverlyn/zfs

static int
zvol_discard(struct bio *bio)
{
	zvol_state_t *zv = bio->bi_bdev->bd_disk->private_data;
	uint64_t start = BIO_BI_SECTOR(bio) << 9;
	uint64_t size = BIO_BI_SIZE(bio);
	uint64_t end = start + size;
	int error;
	rl_t *rl;
	dmu_tx_t *tx;

	ASSERT(zv && zv->zv_open_count > 0);

	if (end > zv->zv_volsize)
		return (SET_ERROR(EIO));

	/*
	 * Align the request to volume block boundaries when REQ_SECURE is
	 * available, but not requested. If we don't, then this will force
	 * dnode_free_range() to zero out the unaligned parts, which is slow
	 * (read-modify-write) and useless since we are not freeing any space
	 * by doing so. Kernels that do not support REQ_SECURE (2.6.32 through
	 * 2.6.35) will not receive this optimization.
	 */
#ifdef REQ_SECURE
	if (!(bio->bi_rw & REQ_SECURE)) {
		start = P2ROUNDUP(start, zv->zv_volblocksize);
		end = P2ALIGN(end, zv->zv_volblocksize);
		size = end - start;
	}
#endif

	if (start >= end)
		return (0);

	rl = zfs_range_lock(&zv->zv_znode, start, size, RL_WRITER);
	tx = dmu_tx_create(zv->zv_objset);
	dmu_tx_mark_netfree(tx);
	error = dmu_tx_assign(tx, TXG_WAIT);
	if (error != 0) {
		dmu_tx_abort(tx);
	} else {
		zvol_log_truncate(zv, tx, start, size, B_TRUE);
		dmu_tx_commit(tx);
		error = dmu_free_long_range(zv->zv_objset,
		    ZVOL_OBJ, start, size);
	}

	zfs_range_unlock(rl);

	return (error);
}

Example #2

File: zvol.c Project: alek-p/zfs

static int
zvol_discard(struct bio *bio)
{
	zvol_state_t *zv = bio->bi_bdev->bd_disk->private_data;
	uint64_t start = BIO_BI_SECTOR(bio) << 9;
	uint64_t size = BIO_BI_SIZE(bio);
	uint64_t end = start + size;
	int error;
	rl_t *rl;
	dmu_tx_t *tx;

	ASSERT(zv && zv->zv_open_count > 0);

	if (end > zv->zv_volsize)
		return (SET_ERROR(EIO));

	/*
	 * Align the request to volume block boundaries when a secure erase is
	 * not required.  This will prevent dnode_free_range() from zeroing out
	 * the unaligned parts which is slow (read-modify-write) and useless
	 * since we are not freeing any space by doing so.
	 */
	if (!bio_is_secure_erase(bio)) {
		start = P2ROUNDUP(start, zv->zv_volblocksize);
		end = P2ALIGN(end, zv->zv_volblocksize);
		size = end - start;
	}

	if (start >= end)
		return (0);

	rl = zfs_range_lock(&zv->zv_range_lock, start, size, RL_WRITER);
	tx = dmu_tx_create(zv->zv_objset);
	dmu_tx_mark_netfree(tx);
	error = dmu_tx_assign(tx, TXG_WAIT);
	if (error != 0) {
		dmu_tx_abort(tx);
	} else {
		zvol_log_truncate(zv, tx, start, size, B_TRUE);
		dmu_tx_commit(tx);
		error = dmu_free_long_range(zv->zv_objset,
		    ZVOL_OBJ, start, size);
	}

	zfs_range_unlock(rl);

	return (error);
}