[PATCH v2 4/7] scsi: target: Add WRITE_ATOMIC_16 handler

[John Garry <john.g.garry@oracle.com>]

From: Mike Christie <michael.christie@oracle.com>

This adds the core LIO code to process the WRITE_ATOMIC_16 command.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
jpg: fix return code from sbc_check_atomic, reformat
Signed-off-by: John Garry <john.g.garry@oracle.com>
---
 drivers/target/target_core_sbc.c  | 49 +++++++++++++++++++++++++++++++
 include/target/target_core_base.h |  1 +
 2 files changed, 50 insertions(+)

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index fe8beb7dbab12..2878cbc3e79df 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -764,6 +764,47 @@ sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 	return 0;
 }
 
+static sense_reason_t
+sbc_check_atomic(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
+{
+	struct se_dev_attrib *attrib = &dev->dev_attrib;
+	u16 boundary, transfer_len;
+	u64 lba;
+
+	lba = transport_lba_64(cdb);
+	boundary = get_unaligned_be16(&cdb[10]);
+	transfer_len = get_unaligned_be16(&cdb[12]);
+
+	if (!attrib->atomic_max_len)
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+
+	if (boundary) {
+		if (transfer_len > attrib->atomic_max_with_boundary)
+			return TCM_INVALID_CDB_FIELD;
+
+		if (boundary > attrib->atomic_max_boundary)
+			return TCM_INVALID_CDB_FIELD;
+	} else {
+		if (transfer_len > attrib->atomic_max_len)
+			return TCM_INVALID_CDB_FIELD;
+	}
+
+	if (attrib->atomic_granularity) {
+		if (transfer_len % attrib->atomic_granularity)
+			return TCM_INVALID_CDB_FIELD;
+
+		if (boundary && boundary % attrib->atomic_granularity)
+			return TCM_INVALID_CDB_FIELD;
+	}
+
+	if (dev->dev_attrib.atomic_alignment) {
+		if (lba % dev->dev_attrib.atomic_alignment)
+			return TCM_INVALID_CDB_FIELD;
+	}
+
+	return 0;
+}
+
 sense_reason_t
 sbc_parse_cdb(struct se_cmd *cmd, struct exec_cmd_ops *ops)
 {
@@ -861,6 +902,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct exec_cmd_ops *ops)
 		break;
 	case WRITE_16:
 	case WRITE_VERIFY_16:
+	case WRITE_ATOMIC_16:
 		sectors = transport_get_sectors_16(cdb);
 		cmd->t_task_lba = transport_lba_64(cdb);
 
@@ -872,6 +914,13 @@ sbc_parse_cdb(struct se_cmd *cmd, struct exec_cmd_ops *ops)
 			return ret;
 
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+		if (cdb[0] == WRITE_ATOMIC_16) {
+			cmd->se_cmd_flags |= SCF_ATOMIC;
+
+			ret = sbc_check_atomic(dev, cmd, cdb);
+			if (ret)
+				return ret;
+		}
 		cmd->execute_cmd = sbc_execute_rw;
 		break;
 	case VARIABLE_LENGTH_CMD:
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 70ece58d30780..56333b5726c8b 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -158,6 +158,7 @@ enum se_cmd_flags_table {
 	SCF_TASK_ATTR_SET			= (1 << 17),
 	SCF_TREAT_READ_AS_NORMAL		= (1 << 18),
 	SCF_TASK_ORDERED_SYNC			= (1 << 19),
+	SCF_ATOMIC				= (1 << 20),
 };
 
 /*
-- 
2.43.5