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Commit 9b3b8041 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Nicholas Bellinger
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target: split overflow and underflow checks into a helper 



Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 64f1db38

drivers/target/target_core_transport.c

+53 −37
Original line number Diff line number Diff line
@@ -1345,6 +1345,55 @@ static inline void transport_generic_prepare_cdb( 


static int transport_generic_cmd_sequencer(struct se_cmd *, unsigned char *);



static int target_cmd_size_check(struct se_cmd *cmd, unsigned int size)

{

	struct se_device *dev = cmd->se_dev;



	if (cmd->unknown_data_length) {

		cmd->data_length = size;

	} else if (size != cmd->data_length) {

		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"

			" %u does not match SCSI CDB Length: %u for SAM Opcode:"

			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),

				cmd->data_length, size, cmd->t_task_cdb[0]);



		cmd->cmd_spdtl = size;



		if (cmd->data_direction == DMA_TO_DEVICE) {

			pr_err("Rejecting underflow/overflow"

					" WRITE data\n");

			goto out_invalid_cdb_field;

		}

		/*

		 * Reject READ_* or WRITE_* with overflow/underflow for

		 * type SCF_SCSI_DATA_CDB.

		 */

		if (dev->se_sub_dev->se_dev_attrib.block_size != 512)  {

			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"

				" CDB on non 512-byte sector setup subsystem"

				" plugin: %s\n", dev->transport->name);

			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */

			goto out_invalid_cdb_field;

		}



		if (size > cmd->data_length) {

			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;

			cmd->residual_count = (size - cmd->data_length);

		} else {

			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;

			cmd->residual_count = (cmd->data_length - size);

		}

		cmd->data_length = size;

	}



	return 0;



out_invalid_cdb_field:

	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;

	cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;

	return -EINVAL;

}



/*

 * Used by fabric modules containing a local struct se_cmd within their

 * fabric dependent per I/O descriptor.
@@ -2431,6 +2480,7 @@ static int transport_generic_cmd_sequencer( 
	int sector_ret = 0, passthrough;

	u32 sectors = 0, size = 0;

	u16 service_action;

	int ret;



	/*

	 * If we operate in passthrough mode we skip most CDB emulation and
@@ -2929,43 +2979,9 @@ static int transport_generic_cmd_sequencer( 
		goto out_unsupported_cdb;

	}



	if (cmd->unknown_data_length)

		cmd->data_length = size;



	if (size != cmd->data_length) {

		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"

			" %u does not match SCSI CDB Length: %u for SAM Opcode:"

			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),

				cmd->data_length, size, cdb[0]);



		cmd->cmd_spdtl = size;



		if (cmd->data_direction == DMA_TO_DEVICE) {

			pr_err("Rejecting underflow/overflow"

					" WRITE data\n");

			goto out_invalid_cdb_field;

		}

		/*

		 * Reject READ_* or WRITE_* with overflow/underflow for

		 * type SCF_SCSI_DATA_CDB.

		 */

		if (dev->se_sub_dev->se_dev_attrib.block_size != 512)  {

			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"

				" CDB on non 512-byte sector setup subsystem"

				" plugin: %s\n", dev->transport->name);

			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */

			goto out_invalid_cdb_field;

		}



		if (size > cmd->data_length) {

			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;

			cmd->residual_count = (size - cmd->data_length);

		} else {

			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;

			cmd->residual_count = (cmd->data_length - size);

		}

		cmd->data_length = size;

	}

	ret = target_cmd_size_check(cmd, size);

	if (ret)

		return ret;



	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {

		if (sectors > su_dev->se_dev_attrib.fabric_max_sectors) {