target: add struct spc_ops + initial ->execute_rw pointer usage

Remove the execute_cmd method in struct se_subsystem_api, and always use the
one directly in struct se_cmd.  To make life simpler for SBC virtual backends
a struct spc_ops that is passed to sbc_parse_cmd is added.  For now it
only contains an execute_rw member, but more will follow with the subsequent
commits.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_file.c

@@ -375,9 +375,11 @@ static void fd_emulate_sync_cache(struct se_cmd *cmd)
 	}
 }
 
-static int fd_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
-		u32 sgl_nents, enum dma_data_direction data_direction)
+static int fd_execute_rw(struct se_cmd *cmd)
 {
+	struct scatterlist *sgl = cmd->t_data_sg;
+	u32 sgl_nents = cmd->t_data_nents;
+	enum dma_data_direction data_direction = cmd->data_direction;
 	struct se_device *dev = cmd->se_dev;
 	int ret = 0;
 
@@ -550,6 +552,15 @@ static sector_t fd_get_blocks(struct se_device *dev)
 	return div_u64(dev_size, dev->se_sub_dev->se_dev_attrib.block_size);
 }
 
+static struct spc_ops fd_spc_ops = {
+	.execute_rw		= fd_execute_rw,
+};
+
+static int fd_parse_cdb(struct se_cmd *cmd)
+{
+	return sbc_parse_cdb(cmd, &fd_spc_ops);
+}
+
 static struct se_subsystem_api fileio_template = {
 	.name			= "fileio",
 	.owner			= THIS_MODULE,
@@ -561,8 +572,7 @@ static struct se_subsystem_api fileio_template = {
 	.allocate_virtdevice	= fd_allocate_virtdevice,
 	.create_virtdevice	= fd_create_virtdevice,
 	.free_device		= fd_free_device,
-	.parse_cdb		= sbc_parse_cdb,
-	.execute_cmd		= fd_execute_cmd,
+	.parse_cdb		= fd_parse_cdb,
 	.do_sync_cache		= fd_emulate_sync_cache,
 	.check_configfs_dev_params = fd_check_configfs_dev_params,
 	.set_configfs_dev_params = fd_set_configfs_dev_params,

drivers/target/target_core_iblock.c

@@ -514,9 +514,11 @@ static void iblock_submit_bios(struct bio_list *list, int rw)
 	blk_finish_plug(&plug);
 }
 
-static int iblock_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
-		u32 sgl_nents, enum dma_data_direction data_direction)
+static int iblock_execute_rw(struct se_cmd *cmd)
 {
+	struct scatterlist *sgl = cmd->t_data_sg;
+	u32 sgl_nents = cmd->t_data_nents;
+	enum dma_data_direction data_direction = cmd->data_direction;
 	struct se_device *dev = cmd->se_dev;
 	struct iblock_req *ibr;
 	struct bio *bio;
@@ -663,6 +665,15 @@ static void iblock_bio_done(struct bio *bio, int err)
 	iblock_complete_cmd(cmd);
 }
 
+static struct spc_ops iblock_spc_ops = {
+	.execute_rw		= iblock_execute_rw,
+};
+
+static int iblock_parse_cdb(struct se_cmd *cmd)
+{
+	return sbc_parse_cdb(cmd, &iblock_spc_ops);
+}
+
 static struct se_subsystem_api iblock_template = {
 	.name			= "iblock",
 	.owner			= THIS_MODULE,
@@ -674,8 +685,7 @@ static struct se_subsystem_api iblock_template = {
 	.allocate_virtdevice	= iblock_allocate_virtdevice,
 	.create_virtdevice	= iblock_create_virtdevice,
 	.free_device		= iblock_free_device,
-	.parse_cdb		= sbc_parse_cdb,
-	.execute_cmd		= iblock_execute_cmd,
+	.parse_cdb		= iblock_parse_cdb,
 	.do_discard		= iblock_do_discard,
 	.do_sync_cache		= iblock_emulate_sync_cache,
 	.check_configfs_dev_params = iblock_check_configfs_dev_params,

drivers/target/target_core_pscsi.c

@@ -55,6 +55,7 @@
 
 static struct se_subsystem_api pscsi_template;
 
+static int pscsi_execute_cmd(struct se_cmd *cmd);
 static void pscsi_req_done(struct request *, int);
 
 /*	pscsi_attach_hba():
@@ -1081,17 +1082,20 @@ static int pscsi_parse_cdb(struct se_cmd *cmd)
 	case WRITE_16:
 	case WRITE_VERIFY:
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
-		break;
+		/* FALLTHROUGH*/
 	default:
+		cmd->execute_cmd = pscsi_execute_cmd;
 		break;
 	}
 
 	return 0;
 }
 
-static int pscsi_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
-		u32 sgl_nents, enum dma_data_direction data_direction)
+static int pscsi_execute_cmd(struct se_cmd *cmd)
 {
+	struct scatterlist *sgl = cmd->t_data_sg;
+	u32 sgl_nents = cmd->t_data_nents;
+	enum dma_data_direction data_direction = cmd->data_direction;
 	struct pscsi_dev_virt *pdv = cmd->se_dev->dev_ptr;
 	struct pscsi_plugin_task *pt;
 	struct request *req;
@@ -1259,7 +1263,6 @@ static struct se_subsystem_api pscsi_template = {
 	.free_device		= pscsi_free_device,
 	.transport_complete	= pscsi_transport_complete,
 	.parse_cdb		= pscsi_parse_cdb,
-	.execute_cmd		= pscsi_execute_cmd,
 	.check_configfs_dev_params = pscsi_check_configfs_dev_params,
 	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
 	.show_configfs_dev_params = pscsi_show_configfs_dev_params,

drivers/target/target_core_rd.c

@@ -284,9 +284,11 @@ static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 	return NULL;
 }
 
-static int rd_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
-		u32 sgl_nents, enum dma_data_direction data_direction)
+static int rd_execute_rw(struct se_cmd *cmd)
 {
+	struct scatterlist *sgl = cmd->t_data_sg;
+	u32 sgl_nents = cmd->t_data_nents;
+	enum dma_data_direction data_direction = cmd->data_direction;
 	struct se_device *se_dev = cmd->se_dev;
 	struct rd_dev *dev = se_dev->dev_ptr;
 	struct rd_dev_sg_table *table;
@@ -460,6 +462,15 @@ static sector_t rd_get_blocks(struct se_device *dev)
 	return blocks_long;
 }
 
+static struct spc_ops rd_spc_ops = {
+	.execute_rw		= rd_execute_rw,
+};
+
+static int rd_parse_cdb(struct se_cmd *cmd)
+{
+	return sbc_parse_cdb(cmd, &rd_spc_ops);
+}
+
 static struct se_subsystem_api rd_mcp_template = {
 	.name			= "rd_mcp",
 	.transport_type		= TRANSPORT_PLUGIN_VHBA_VDEV,
@@ -468,8 +479,7 @@ static struct se_subsystem_api rd_mcp_template = {
 	.allocate_virtdevice	= rd_allocate_virtdevice,
 	.create_virtdevice	= rd_create_virtdevice,
 	.free_device		= rd_free_device,
-	.parse_cdb		= sbc_parse_cdb,
-	.execute_cmd		= rd_execute_cmd,
+	.parse_cdb		= rd_parse_cdb,
 	.check_configfs_dev_params = rd_check_configfs_dev_params,
 	.set_configfs_dev_params = rd_set_configfs_dev_params,
 	.show_configfs_dev_params = rd_show_configfs_dev_params,

drivers/target/target_core_sbc.c

@@ -395,7 +395,7 @@ static void xdreadwrite_callback(struct se_cmd *cmd)
 	kfree(buf);
 }
 
-int sbc_parse_cdb(struct se_cmd *cmd)
+int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
 {
 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
 	struct se_device *dev = cmd->se_dev;
@@ -409,26 +409,31 @@ int sbc_parse_cdb(struct se_cmd *cmd)
 		sectors = transport_get_sectors_6(cdb);
 		cmd->t_task_lba = transport_lba_21(cdb);
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+		cmd->execute_cmd = ops->execute_rw;
 		break;
 	case READ_10:
 		sectors = transport_get_sectors_10(cdb);
 		cmd->t_task_lba = transport_lba_32(cdb);
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+		cmd->execute_cmd = ops->execute_rw;
 		break;
 	case READ_12:
 		sectors = transport_get_sectors_12(cdb);
 		cmd->t_task_lba = transport_lba_32(cdb);
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+		cmd->execute_cmd = ops->execute_rw;
 		break;
 	case READ_16:
 		sectors = transport_get_sectors_16(cdb);
 		cmd->t_task_lba = transport_lba_64(cdb);
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+		cmd->execute_cmd = ops->execute_rw;
 		break;
 	case WRITE_6:
 		sectors = transport_get_sectors_6(cdb);
 		cmd->t_task_lba = transport_lba_21(cdb);
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+		cmd->execute_cmd = ops->execute_rw;
 		break;
 	case WRITE_10:
 	case WRITE_VERIFY:
@@ -437,6 +442,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
 		if (cdb[1] & 0x8)
 			cmd->se_cmd_flags |= SCF_FUA;
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+		cmd->execute_cmd = ops->execute_rw;
 		break;
 	case WRITE_12:
 		sectors = transport_get_sectors_12(cdb);
@@ -444,6 +450,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
 		if (cdb[1] & 0x8)
 			cmd->se_cmd_flags |= SCF_FUA;
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+		cmd->execute_cmd = ops->execute_rw;
 		break;
 	case WRITE_16:
 		sectors = transport_get_sectors_16(cdb);
@@ -451,6 +458,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
 		if (cdb[1] & 0x8)
 			cmd->se_cmd_flags |= SCF_FUA;
 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+		cmd->execute_cmd = ops->execute_rw;
 		break;
 	case XDWRITEREAD_10:
 		if ((cmd->data_direction != DMA_TO_DEVICE) ||
@@ -464,6 +472,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
 		/*
 		 * Setup BIDI XOR callback to be run after I/O completion.
 		 */
+		cmd->execute_cmd = ops->execute_rw;
 		cmd->transport_complete_callback = &xdreadwrite_callback;
 		if (cdb[1] & 0x8)
 			cmd->se_cmd_flags |= SCF_FUA;
@@ -486,6 +495,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
 			 * Setup BIDI XOR callback to be run during after I/O
 			 * completion.
 			 */
+			cmd->execute_cmd = ops->execute_rw;
 			cmd->transport_complete_callback = &xdreadwrite_callback;
 			if (cdb[1] & 0x8)
 				cmd->se_cmd_flags |= SCF_FUA;

drivers/target/target_core_transport.c

@@ -1865,7 +1865,7 @@ EXPORT_SYMBOL(transport_generic_request_failure);
 
 static void __target_execute_cmd(struct se_cmd *cmd)
 {
-	int error;
+	int error = 0;
 
 	spin_lock_irq(&cmd->t_state_lock);
 	cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
@@ -1873,10 +1873,6 @@ static void __target_execute_cmd(struct se_cmd *cmd)
 
 	if (cmd->execute_cmd)
 		error = cmd->execute_cmd(cmd);
-	else {
-		error = cmd->se_dev->transport->execute_cmd(cmd, cmd->t_data_sg,
-				cmd->t_data_nents, cmd->data_direction);
-	}
 
 	if (error) {
 		spin_lock_irq(&cmd->t_state_lock);

include/target/target_core_backend.h

@@ -26,8 +26,6 @@ struct se_subsystem_api {
 	int (*transport_complete)(struct se_cmd *cmd, struct scatterlist *);
 
 	int (*parse_cdb)(struct se_cmd *cmd);
-	int (*execute_cmd)(struct se_cmd *, struct scatterlist *, u32,
-			enum dma_data_direction);
 	int (*do_discard)(struct se_device *, sector_t, u32);
 	void (*do_sync_cache)(struct se_cmd *);
 	ssize_t (*check_configfs_dev_params)(struct se_hba *,
@@ -42,6 +40,10 @@ struct se_subsystem_api {
 	unsigned char *(*get_sense_buffer)(struct se_cmd *);
 };
 
+struct spc_ops {
+	int (*execute_rw)(struct se_cmd *cmd);
+};
+
 int	transport_subsystem_register(struct se_subsystem_api *);
 void	transport_subsystem_release(struct se_subsystem_api *);
 
@@ -51,7 +53,7 @@ struct se_device *transport_add_device_to_core_hba(struct se_hba *,
 
 void	target_complete_cmd(struct se_cmd *, u8);
 
-int	sbc_parse_cdb(struct se_cmd *cmd);
+int	sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops);
 int	spc_parse_cdb(struct se_cmd *cmd, unsigned int *size);
 
 void	transport_set_vpd_proto_id(struct t10_vpd *, unsigned char *);