From 4101f0a89d4eb13f04cb0344d59a335b862ca5f9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 24 Apr 2012 00:25:03 -0400 Subject: target: always allocate a single task Simply transport_generic_new_cmd to only allocate a single task. For normal unidirection commands nothing changes except that the code is a lot simpler now. Any BIDI support that used to work will stop now for the next few patches at least. Signed-off-by: Christoph Hellwig Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 157 ++++++++------------------------- 1 file changed, 37 insertions(+), 120 deletions(-) (limited to 'drivers/target') diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 087bbea46cdc..5267198688fe 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1474,29 +1474,6 @@ static inline void transport_generic_prepare_cdb( } } -static struct se_task * -transport_generic_get_task(struct se_cmd *cmd, - enum dma_data_direction data_direction) -{ - struct se_task *task; - struct se_device *dev = cmd->se_dev; - - task = dev->transport->alloc_task(cmd->t_task_cdb); - if (!task) { - pr_err("Unable to allocate struct se_task\n"); - return NULL; - } - - INIT_LIST_HEAD(&task->t_list); - INIT_LIST_HEAD(&task->t_execute_list); - INIT_LIST_HEAD(&task->t_state_list); - init_completion(&task->task_stop_comp); - task->task_se_cmd = cmd; - task->task_data_direction = data_direction; - - return task; -} - static int transport_generic_cmd_sequencer(struct se_cmd *, unsigned char *); /* @@ -3704,68 +3681,6 @@ out: return -ENOMEM; } -/* - * Break up cmd into chunks transport can handle - */ -static int -transport_allocate_data_tasks(struct se_cmd *cmd, - enum dma_data_direction data_direction, - struct scatterlist *cmd_sg, unsigned int sgl_nents) -{ - struct se_device *dev = cmd->se_dev; - struct se_dev_attrib *attr = &dev->se_sub_dev->se_dev_attrib; - sector_t sectors; - struct se_task *task; - unsigned long flags; - - if (transport_cmd_get_valid_sectors(cmd) < 0) - return -EINVAL; - - sectors = DIV_ROUND_UP(cmd->data_length, attr->block_size); - - BUG_ON(cmd->data_length % attr->block_size); - BUG_ON(sectors > attr->max_sectors); - - task = transport_generic_get_task(cmd, data_direction); - if (!task) - return -ENOMEM; - - task->task_sg = cmd_sg; - task->task_sg_nents = sgl_nents; - - spin_lock_irqsave(&cmd->t_state_lock, flags); - list_add_tail(&task->t_list, &cmd->t_task_list); - spin_unlock_irqrestore(&cmd->t_state_lock, flags); - - return 1; -} - -static int -transport_allocate_control_task(struct se_cmd *cmd) -{ - struct se_task *task; - unsigned long flags; - - /* Workaround for handling zero-length control CDBs */ - if ((cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB) && - !cmd->data_length) - return 0; - - task = transport_generic_get_task(cmd, cmd->data_direction); - if (!task) - return -ENOMEM; - - task->task_sg = cmd->t_data_sg; - task->task_sg_nents = cmd->t_data_nents; - - spin_lock_irqsave(&cmd->t_state_lock, flags); - list_add_tail(&task->t_list, &cmd->t_task_list); - spin_unlock_irqrestore(&cmd->t_state_lock, flags); - - /* Success! Return number of tasks allocated */ - return 1; -} - /* * Allocate any required resources to execute the command. For writes we * might not have the payload yet, so notify the fabric via a call to @@ -3774,8 +3689,8 @@ transport_allocate_control_task(struct se_cmd *cmd) int transport_generic_new_cmd(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; - int task_cdbs, task_cdbs_bidi = 0; - int set_counts = 1; + struct se_task *task; + unsigned long flags; int ret = 0; /* @@ -3790,35 +3705,9 @@ int transport_generic_new_cmd(struct se_cmd *cmd) goto out_fail; } - /* - * For BIDI command set up the read tasks first. - */ - if (cmd->t_bidi_data_sg && - dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV) { - BUG_ON(!(cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB)); - - task_cdbs_bidi = transport_allocate_data_tasks(cmd, - DMA_FROM_DEVICE, cmd->t_bidi_data_sg, - cmd->t_bidi_data_nents); - if (task_cdbs_bidi <= 0) - goto out_fail; - - atomic_inc(&cmd->t_fe_count); - atomic_inc(&cmd->t_se_count); - set_counts = 0; - } - - if (cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) { - task_cdbs = transport_allocate_data_tasks(cmd, - cmd->data_direction, cmd->t_data_sg, - cmd->t_data_nents); - } else { - task_cdbs = transport_allocate_control_task(cmd); - } - - if (task_cdbs < 0) - goto out_fail; - else if (!task_cdbs && (cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB)) { + /* Workaround for handling zero-length control CDBs */ + if ((cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB) && + !cmd->data_length) { spin_lock_irq(&cmd->t_state_lock); cmd->t_state = TRANSPORT_COMPLETE; cmd->transport_state |= CMD_T_ACTIVE; @@ -3836,12 +3725,40 @@ int transport_generic_new_cmd(struct se_cmd *cmd) return 0; } - if (set_counts) { - atomic_inc(&cmd->t_fe_count); - atomic_inc(&cmd->t_se_count); + if (cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) { + struct se_dev_attrib *attr = &dev->se_sub_dev->se_dev_attrib; + + if (transport_cmd_get_valid_sectors(cmd) < 0) + return -EINVAL; + + BUG_ON(cmd->data_length % attr->block_size); + BUG_ON(DIV_ROUND_UP(cmd->data_length, attr->block_size) > + attr->max_sectors); + } + + task = dev->transport->alloc_task(cmd->t_task_cdb); + if (!task) { + pr_err("Unable to allocate struct se_task\n"); + goto out_fail; } - cmd->t_task_list_num = (task_cdbs + task_cdbs_bidi); + INIT_LIST_HEAD(&task->t_list); + INIT_LIST_HEAD(&task->t_execute_list); + INIT_LIST_HEAD(&task->t_state_list); + init_completion(&task->task_stop_comp); + task->task_se_cmd = cmd; + task->task_data_direction = cmd->data_direction; + task->task_sg = cmd->t_data_sg; + task->task_sg_nents = cmd->t_data_nents; + + spin_lock_irqsave(&cmd->t_state_lock, flags); + list_add_tail(&task->t_list, &cmd->t_task_list); + spin_unlock_irqrestore(&cmd->t_state_lock, flags); + + atomic_inc(&cmd->t_fe_count); + atomic_inc(&cmd->t_se_count); + + cmd->t_task_list_num = 1; atomic_set(&cmd->t_task_cdbs_left, cmd->t_task_list_num); atomic_set(&cmd->t_task_cdbs_ex_left, cmd->t_task_list_num); -- cgit v1.2.3