Commit fde9f50f authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Add sanity checks for DPO/FUA bit usage 



This patch adds a sbc_check_dpofua() function that performs sanity
checks for DPO/FUA command bits.

It introduces checks to fail when either bit is set, but the backend
device is not advertising support for them.

It also moves the existing cmd->se_cmd_flags |= SCF_FUA assignement
into the new helper function.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent afd73f1b

drivers/target/target_core_sbc.c

+46 −10
Original line number Diff line number Diff line
@@ -692,6 +692,29 @@ sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb, 
	return TCM_NO_SENSE;

}



static int

sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)

{

	if (cdb[1] & 0x10) {

		if (!dev->dev_attrib.emulate_dpo) {

			pr_err("Got CDB: 0x%02x with DPO bit set, but device"

			       " does not advertise support for DPO\n", cdb[0]);

			return -EINVAL;

		}

	}

	if (cdb[1] & 0x8) {

		if (!dev->dev_attrib.emulate_fua_write ||

		    !dev->dev_attrib.emulate_write_cache) {

			pr_err("Got CDB: 0x%02x with FUA bit set, but device"

			       " does not advertise support for FUA write\n",

			       cdb[0]);

			return -EINVAL;

		}

		cmd->se_cmd_flags |= SCF_FUA;

	}

	return 0;

}



sense_reason_t

sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)

{
@@ -713,6 +736,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		sectors = transport_get_sectors_10(cdb);

		cmd->t_task_lba = transport_lba_32(cdb);



		if (sbc_check_dpofua(dev, cmd, cdb))

			return TCM_INVALID_CDB_FIELD;



		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);

		if (ret)

			return ret;
@@ -725,6 +751,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		sectors = transport_get_sectors_12(cdb);

		cmd->t_task_lba = transport_lba_32(cdb);



		if (sbc_check_dpofua(dev, cmd, cdb))

			return TCM_INVALID_CDB_FIELD;



		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);

		if (ret)

			return ret;
@@ -737,6 +766,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		sectors = transport_get_sectors_16(cdb);

		cmd->t_task_lba = transport_lba_64(cdb);



		if (sbc_check_dpofua(dev, cmd, cdb))

			return TCM_INVALID_CDB_FIELD;



		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);

		if (ret)

			return ret;
@@ -757,12 +789,13 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		sectors = transport_get_sectors_10(cdb);

		cmd->t_task_lba = transport_lba_32(cdb);



		if (sbc_check_dpofua(dev, cmd, cdb))

			return TCM_INVALID_CDB_FIELD;



		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);

		if (ret)

			return ret;



		if (cdb[1] & 0x8)

			cmd->se_cmd_flags |= SCF_FUA;

		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;

		cmd->execute_rw = ops->execute_rw;

		cmd->execute_cmd = sbc_execute_rw;
@@ -771,12 +804,13 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		sectors = transport_get_sectors_12(cdb);

		cmd->t_task_lba = transport_lba_32(cdb);



		if (sbc_check_dpofua(dev, cmd, cdb))

			return TCM_INVALID_CDB_FIELD;



		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);

		if (ret)

			return ret;



		if (cdb[1] & 0x8)

			cmd->se_cmd_flags |= SCF_FUA;

		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;

		cmd->execute_rw = ops->execute_rw;

		cmd->execute_cmd = sbc_execute_rw;
@@ -785,12 +819,13 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		sectors = transport_get_sectors_16(cdb);

		cmd->t_task_lba = transport_lba_64(cdb);



		if (sbc_check_dpofua(dev, cmd, cdb))

			return TCM_INVALID_CDB_FIELD;



		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);

		if (ret)

			return ret;



		if (cdb[1] & 0x8)

			cmd->se_cmd_flags |= SCF_FUA;

		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;

		cmd->execute_rw = ops->execute_rw;

		cmd->execute_cmd = sbc_execute_rw;
@@ -801,6 +836,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
			return TCM_INVALID_CDB_FIELD;

		sectors = transport_get_sectors_10(cdb);



		if (sbc_check_dpofua(dev, cmd, cdb))

			return TCM_INVALID_CDB_FIELD;



		cmd->t_task_lba = transport_lba_32(cdb);

		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
@@ -810,8 +848,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		cmd->execute_rw = ops->execute_rw;

		cmd->execute_cmd = sbc_execute_rw;

		cmd->transport_complete_callback = &xdreadwrite_callback;

		if (cdb[1] & 0x8)

			cmd->se_cmd_flags |= SCF_FUA;

		break;

	case VARIABLE_LENGTH_CMD:

	{
@@ -820,6 +856,8 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		case XDWRITEREAD_32:

			sectors = transport_get_sectors_32(cdb);



			if (sbc_check_dpofua(dev, cmd, cdb))

				return TCM_INVALID_CDB_FIELD;

			/*

			 * Use WRITE_32 and READ_32 opcodes for the emulated

			 * XDWRITE_READ_32 logic.
@@ -834,8 +872,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
			cmd->execute_rw = ops->execute_rw;

			cmd->execute_cmd = sbc_execute_rw;

			cmd->transport_complete_callback = &xdreadwrite_callback;

			if (cdb[1] & 0x8)

				cmd->se_cmd_flags |= SCF_FUA;

			break;

		case WRITE_SAME_32:

			sectors = transport_get_sectors_32(cdb);

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