target: Add sbc_execute_unmap() helper

iblock_execute_unmap() and fd_execute_unmap share a lot of code.
Add sbc_execute_unmap() helper to remove duplicated code for
iblock_execute_unmap() and fd_execute_unmap().

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 85 insertions, 0 deletions

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 60d4b5185f32..bbc5b0ee2bdc 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -596,3 +596,88 @@ u32 sbc_get_device_type(struct se_device *dev)
 	return TYPE_DISK;
 }
 EXPORT_SYMBOL(sbc_get_device_type);
+
+sense_reason_t
+sbc_execute_unmap(struct se_cmd *cmd,
+	sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
+				      sector_t, sector_t),
+	void *priv)
+{
+	struct se_device *dev = cmd->se_dev;
+	unsigned char *buf, *ptr = NULL;
+	sector_t lba;
+	int size;
+	u32 range;
+	sense_reason_t ret = 0;
+	int dl, bd_dl;
+
+	/* We never set ANC_SUP */
+	if (cmd->t_task_cdb[1])
+		return TCM_INVALID_CDB_FIELD;
+
+	if (cmd->data_length == 0) {
+		target_complete_cmd(cmd, SAM_STAT_GOOD);
+		return 0;
+	}
+
+	if (cmd->data_length < 8) {
+		pr_warn("UNMAP parameter list length %u too small\n",
+			cmd->data_length);
+		return TCM_PARAMETER_LIST_LENGTH_ERROR;
+	}
+
+	buf = transport_kmap_data_sg(cmd);
+	if (!buf)
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	dl = get_unaligned_be16(&buf[0]);
+	bd_dl = get_unaligned_be16(&buf[2]);
+
+	size = cmd->data_length - 8;
+	if (bd_dl > size)
+		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
+			cmd->data_length, bd_dl);
+	else
+		size = bd_dl;
+
+	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
+		ret = TCM_INVALID_PARAMETER_LIST;
+		goto err;
+	}
+
+	/* First UNMAP block descriptor starts at 8 byte offset */
+	ptr = &buf[8];
+	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
+		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
+
+	while (size >= 16) {
+		lba = get_unaligned_be64(&ptr[0]);
+		range = get_unaligned_be32(&ptr[8]);
+		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
+				 (unsigned long long)lba, range);
+
+		if (range > dev->dev_attrib.max_unmap_lba_count) {
+			ret = TCM_INVALID_PARAMETER_LIST;
+			goto err;
+		}
+
+		if (lba + range > dev->transport->get_blocks(dev) + 1) {
+			ret = TCM_ADDRESS_OUT_OF_RANGE;
+			goto err;
+		}
+
+		ret = do_unmap_fn(cmd, priv, lba, range);
+		if (ret)
+			goto err;
+
+		ptr += 16;
+		size -= 16;
+	}
+
+err:
+	transport_kunmap_data_sg(cmd);
+	if (!ret)
+		target_complete_cmd(cmd, GOOD);
+	return ret;
+}
+EXPORT_SYMBOL(sbc_execute_unmap);