These are two fairly small functions, and merging them gives a much
more readable control flow, and opportunities for more useful comments.
It also moves all code related to resources allocation closer together
and allows to remove a forward declaration for transport_allocate_tasks.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: lio-core/drivers/target/target_core_transport.c
===================================================================
--- lio-core.orig/drivers/target/target_core_transport.c 2011-10-18 12:04:36.673858642 +0200
+++ lio-core/drivers/target/target_core_transport.c 2011-10-18 12:04:39.681853501 +0200
@@ -76,10 +76,6 @@ static void transport_handle_queue_full(
struct se_device *dev);
static void transport_direct_request_timeout(struct se_cmd *cmd);
static void transport_free_dev_tasks(struct se_cmd *cmd);
-static u32 transport_allocate_tasks(struct se_cmd *cmd,
- unsigned long long starting_lba,
- enum dma_data_direction data_direction,
- struct scatterlist *sgl, unsigned int nents);
static int transport_generic_get_mem(struct se_cmd *cmd);
static void transport_put_cmd(struct se_cmd *cmd);
static void transport_remove_cmd_from_queue(struct se_cmd *cmd);
@@ -3646,62 +3642,6 @@ int transport_generic_map_mem_to_cmd(
}
EXPORT_SYMBOL(transport_generic_map_mem_to_cmd);
-static int transport_new_cmd_obj(struct se_cmd *cmd)
-{
- struct se_device *dev = cmd->se_dev;
- int set_counts = 1, rc, task_cdbs;
-
- /*
- * Setup any BIDI READ tasks and memory from
- * cmd->t_mem_bidi_list so the READ struct se_tasks
- * are queued first for the non pSCSI passthrough case.
- */
- if (cmd->t_bidi_data_sg &&
- (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV)) {
- rc = transport_allocate_tasks(cmd,
- cmd->t_task_lba,
- DMA_FROM_DEVICE,
- cmd->t_bidi_data_sg,
- cmd->t_bidi_data_nents);
- if (rc <= 0) {
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->scsi_sense_reason =
- TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- return -EINVAL;
- }
- atomic_inc(&cmd->t_fe_count);
- atomic_inc(&cmd->t_se_count);
- set_counts = 0;
- }
- /*
- * Setup the tasks and memory from cmd->t_mem_list
- * Note for BIDI transfers this will contain the WRITE payload
- */
- task_cdbs = transport_allocate_tasks(cmd,
- cmd->t_task_lba,
- cmd->data_direction,
- cmd->t_data_sg,
- cmd->t_data_nents);
- if (task_cdbs <= 0) {
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->scsi_sense_reason =
- TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- return -EINVAL;
- }
-
- if (set_counts) {
- atomic_inc(&cmd->t_fe_count);
- atomic_inc(&cmd->t_se_count);
- }
-
- cmd->t_task_list_num = task_cdbs;
-
- atomic_set(&cmd->t_task_cdbs_left, task_cdbs);
- atomic_set(&cmd->t_task_cdbs_ex_left, task_cdbs);
- atomic_set(&cmd->t_task_cdbs_timeout_left, task_cdbs);
- return 0;
-}
-
void *transport_kmap_first_data_page(struct se_cmd *cmd)
{
struct scatterlist *sg = cmd->t_data_sg;
@@ -3980,17 +3920,16 @@ static u32 transport_allocate_tasks(
}
-/* transport_generic_new_cmd(): Called from transport_processing_thread()
- *
- * Allocate storage transport resources from a set of values predefined
- * by transport_generic_cmd_sequencer() from the iSCSI Target RX process.
- * Any non zero return here is treated as an "out of resource' op here.
+/*
+ * Allocate any required ressources to execute the command, and either place
+ * it on the execution queue if possible. For writes we might not have the
+ * payload yet, thus notify the fabric via a call to ->write_pending instead.
*/
- /*
- * Generate struct se_task(s) and/or their payloads for this CDB.
- */
int transport_generic_new_cmd(struct se_cmd *cmd)
{
+ struct se_device *dev = cmd->se_dev;
+ int task_cdbs;
+ int set_counts = 1;
int ret = 0;
/*
@@ -4004,16 +3943,49 @@ int transport_generic_new_cmd(struct se_
if (ret < 0)
return ret;
}
+
/*
- * Call transport_new_cmd_obj() to invoke transport_allocate_tasks() for
- * control or data CDB types, and perform the map to backend subsystem
- * code from SGL memory allocated here by transport_generic_get_mem(), or
- * via pre-existing SGL memory setup explictly by fabric module code with
- * transport_generic_map_mem_to_cmd().
+ * Setup any BIDI READ tasks and memory from
+ * cmd->t_mem_bidi_list so the READ struct se_tasks
+ * are queued first for the non pSCSI passthrough case.
*/
- ret = transport_new_cmd_obj(cmd);
- if (ret < 0)
- return ret;
+ if (cmd->t_bidi_data_sg &&
+ (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV)) {
+ ret = transport_allocate_tasks(cmd,
+ cmd->t_task_lba,
+ DMA_FROM_DEVICE,
+ cmd->t_bidi_data_sg,
+ cmd->t_bidi_data_nents);
+ if (ret <= 0)
+ goto out_fail;
+
+ atomic_inc(&cmd->t_fe_count);
+ atomic_inc(&cmd->t_se_count);
+ set_counts = 0;
+ }
+ /*
+ * Setup the tasks and memory from cmd->t_mem_list
+ * Note for BIDI transfers this will contain the WRITE payload
+ */
+ task_cdbs = transport_allocate_tasks(cmd,
+ cmd->t_task_lba,
+ cmd->data_direction,
+ cmd->t_data_sg,
+ cmd->t_data_nents);
+ if (task_cdbs <= 0)
+ goto out_fail;
+
+ if (set_counts) {
+ atomic_inc(&cmd->t_fe_count);
+ atomic_inc(&cmd->t_se_count);
+ }
+
+ cmd->t_task_list_num = task_cdbs;
+
+ atomic_set(&cmd->t_task_cdbs_left, task_cdbs);
+ atomic_set(&cmd->t_task_cdbs_ex_left, task_cdbs);
+ atomic_set(&cmd->t_task_cdbs_timeout_left, task_cdbs);
+
/*
* For WRITEs, let the fabric know its buffer is ready..
* This WRITE struct se_cmd (and all of its associated struct se_task's)
@@ -4031,6 +4003,11 @@ int transport_generic_new_cmd(struct se_
*/
transport_execute_tasks(cmd);
return 0;
+
+out_fail:
+ cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
+ cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+ return -EINVAL;
}
EXPORT_SYMBOL(transport_generic_new_cmd);
--
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