target: make the ->get_cdb method optional

The most commonly used file, iblock and rd backends have no use for
a per-task CDB and thus don't need a method to copy it into their
otherwise unused CDB fields.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

7 files changed, 15 insertions, 48 deletions

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 524f41afea48..98aa5836448b 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -609,17 +609,6 @@ static ssize_t fd_show_configfs_dev_params(
         return bl;
 }
 
-/*      fd_get_cdb(): (Part of se_subsystem_api_t template)
- *
- *
- */
-static unsigned char *fd_get_cdb(struct se_task *task)
-{
-        struct fd_request *req = FILE_REQ(task);
-
-        return req->fd_scsi_cdb;
-}
-
 /*      fd_get_device_rev(): (Part of se_subsystem_api_t template)
  *
  *
@@ -667,7 +656,6 @@ static struct se_subsystem_api fileio_template = {
         .check_configfs_dev_params = fd_check_configfs_dev_params,
         .set_configfs_dev_params = fd_set_configfs_dev_params,
         .show_configfs_dev_params = fd_show_configfs_dev_params,
-        .get_cdb                = fd_get_cdb,
         .get_device_rev         = fd_get_device_rev,
         .get_device_type        = fd_get_device_type,
         .get_blocks             = fd_get_blocks,
diff --git a/drivers/target/target_core_file.h b/drivers/target/target_core_file.h
index daebd710b893..59e6e73106c2 100644
--- a/drivers/target/target_core_file.h
+++ b/drivers/target/target_core_file.h
@@ -14,9 +14,7 @@
 
 struct fd_request {
         struct se_task  fd_task;
-        /* SCSI CDB from iSCSI Command PDU */
-        unsigned char   fd_scsi_cdb[TCM_MAX_COMMAND_SIZE];
-} ____cacheline_aligned;
+};
 
 #define FBDF_HAS_PATH           0x01
 #define FBDF_HAS_SIZE           0x02
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 21a3677984fb..bf074c4b7a36 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -618,11 +618,6 @@ fail:
         return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
 }
 
-static unsigned char *iblock_get_cdb(struct se_task *task)
-{
-        return IBLOCK_REQ(task)->ib_scsi_cdb;
-}
-
 static u32 iblock_get_device_rev(struct se_device *dev)
 {
         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
@@ -696,7 +691,6 @@ static struct se_subsystem_api iblock_template = {
         .check_configfs_dev_params = iblock_check_configfs_dev_params,
         .set_configfs_dev_params = iblock_set_configfs_dev_params,
         .show_configfs_dev_params = iblock_show_configfs_dev_params,
-        .get_cdb                = iblock_get_cdb,
         .get_device_rev         = iblock_get_device_rev,
         .get_device_type        = iblock_get_device_type,
         .get_blocks             = iblock_get_blocks,
diff --git a/drivers/target/target_core_iblock.h b/drivers/target/target_core_iblock.h
index 7a76f663385c..5cf1860c10d0 100644
--- a/drivers/target/target_core_iblock.h
+++ b/drivers/target/target_core_iblock.h
@@ -8,7 +8,6 @@
 
 struct iblock_req {
         struct se_task ib_task;
-        unsigned char ib_scsi_cdb[TCM_MAX_COMMAND_SIZE];
         atomic_t ib_bio_cnt;
         atomic_t ib_bio_err_cnt;
 } ____cacheline_aligned;
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index daf95dbe12ec..5158d3846f19 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -691,17 +691,6 @@ static ssize_t rd_show_configfs_dev_params(
         return bl;
 }
 
-/*      rd_get_cdb(): (Part of se_subsystem_api_t template)
- *
- *
- */
-static unsigned char *rd_get_cdb(struct se_task *task)
-{
-        struct rd_request *req = RD_REQ(task);
-
-        return req->rd_scsi_cdb;
-}
-
 static u32 rd_get_device_rev(struct se_device *dev)
 {
         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
@@ -735,7 +724,6 @@ static struct se_subsystem_api rd_mcp_template = {
         .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,
-        .get_cdb                = rd_get_cdb,
         .get_device_rev         = rd_get_device_rev,
         .get_device_type        = rd_get_device_type,
         .get_blocks             = rd_get_blocks,
diff --git a/drivers/target/target_core_rd.h b/drivers/target/target_core_rd.h
index 0d027732cd00..784e56a04100 100644
--- a/drivers/target/target_core_rd.h
+++ b/drivers/target/target_core_rd.h
@@ -22,8 +22,6 @@ void rd_module_exit(void);
 struct rd_request {
         struct se_task  rd_task;
 
-        /* SCSI CDB from iSCSI Command PDU */
-        unsigned char   rd_scsi_cdb[TCM_MAX_COMMAND_SIZE];
         /* Offset from start of page */
         u32             rd_offset;
         /* Starting page in Ramdisk for request */
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 4a787a0ab068..895969650a27 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -3932,7 +3932,6 @@ static int transport_allocate_data_tasks(
         struct scatterlist *sgl,
         unsigned int sgl_nents)
 {
-        unsigned char *cdb = NULL;
         struct se_task *task;
         struct se_device *dev = cmd->se_dev;
         unsigned long flags;
@@ -3959,14 +3958,17 @@ static int transport_allocate_data_tasks(
                 task->task_sectors = min(sectors, dev_max_sectors);
                 task->task_size = task->task_sectors * sector_size;
 
-                cdb = dev->transport->get_cdb(task);
-                BUG_ON(!cdb);
+                if (dev->transport->get_cdb) {
+                        unsigned char *cdb = dev->transport->get_cdb(task);
 
-                memcpy(cdb, cmd->t_task_cdb,
-                       scsi_command_size(cmd->t_task_cdb));
+                        memcpy(cdb, cmd->t_task_cdb,
+                               scsi_command_size(cmd->t_task_cdb));
+
+                        /* Update new cdb with updated lba/sectors */
+                        cmd->transport_split_cdb(task->task_lba,
+                                                 task->task_sectors, cdb);
+                }
 
-                /* Update new cdb with updated lba/sectors */
-                cmd->transport_split_cdb(task->task_lba, task->task_sectors, cdb);
                 /*
                  * This now assumes that passed sg_ents are in PAGE_SIZE chunks
                  * in order to calculate the number per task SGL entries
@@ -4021,7 +4023,6 @@ static int
 transport_allocate_control_task(struct se_cmd *cmd)
 {
         struct se_device *dev = cmd->se_dev;
-        unsigned char *cdb;
         struct se_task *task;
         unsigned long flags;
 
@@ -4029,10 +4030,11 @@ transport_allocate_control_task(struct se_cmd *cmd)
         if (!task)
                 return -ENOMEM;
 
-        cdb = dev->transport->get_cdb(task);
-        BUG_ON(!cdb);
-        memcpy(cdb, cmd->t_task_cdb,
-               scsi_command_size(cmd->t_task_cdb));
+        if (dev->transport->get_cdb) {
+                unsigned char *cdb = dev->transport->get_cdb(task);
+
+                memcpy(cdb, cmd->t_task_cdb, scsi_command_size(cmd->t_task_cdb));
+        }
 
         task->task_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
                                 GFP_KERNEL);