From 07bde79a5c355dbca66ca4318645aa17b4c0d859 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Mon, 13 Jun 2011 14:46:09 -0700 Subject: target: Add SCF_EMULATE_QUEUE_FULL -> transport_handle_queue_full This patch adds SCF_EMULATE_QUEUE_FULL support using -EAGAIN failures via transport_handle_queue_full() to signal queue full in completion path TFO->queue_data_in() and TFO->queue_status() callbacks. This is done using a new se_cmd->transport_qf_callback() to handle the following queue full exception cases within target core: *) TRANSPORT_COMPLETE_OK (for completion path queue full) *) TRANSPORT_COMPLETE_QF_WP (for TRANSPORT_WRITE_PENDING queue full) *) transport_send_check_condition_and_sense() failure paths in transport_generic_request_failure() and transport_generic_complete_ok() All logic is driven using se_device->qf_work_queue -> target_qf_do_work() to to requeue outstanding se_cmd at the head of se_dev->queue_obj->qobj_list for transport_processing_thread() execution. Tested using tcm_qla2xxx with MAX_OUTSTANDING_COMMANDS=128 for FCP READ to trigger the TRANSPORT_COMPLETE_OK queue full cases, and a simulated TFO->write_pending() -EAGAIN failure to trigger TRANSPORT_COMPLETE_QF_WP. Reported-by: Roland Dreier Signed-off-by: Nicholas Bellinger --- include/target/target_core_base.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/target/target_core_base.h') diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 71abc4c5e2b4..cd163dd94cd4 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -99,6 +99,7 @@ enum transport_state_table { TRANSPORT_FREE = 15, TRANSPORT_NEW_CMD_MAP = 16, TRANSPORT_FREE_CMD_INTR = 17, + TRANSPORT_COMPLETE_QF_WP = 18, }; /* Used for struct se_cmd->se_cmd_flags */ @@ -125,6 +126,7 @@ enum se_cmd_flags_table { SCF_PASSTHROUGH_CONTIG_TO_SG = 0x00200000, SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC = 0x00400000, SCF_EMULATE_CDB_ASYNC = 0x01000000, + SCF_EMULATE_QUEUE_FULL = 0x02000000, }; /* struct se_dev_entry->lun_flags and struct se_lun->lun_access */ @@ -466,6 +468,7 @@ struct se_cmd { struct list_head se_delayed_node; struct list_head se_ordered_node; struct list_head se_lun_node; + struct list_head se_qf_node; struct se_device *se_dev; struct se_dev_entry *se_deve; struct se_device *se_obj_ptr; @@ -480,6 +483,8 @@ struct se_cmd { void (*transport_split_cdb)(unsigned long long, u32 *, unsigned char *); void (*transport_wait_for_tasks)(struct se_cmd *, int, int); void (*transport_complete_callback)(struct se_cmd *); + int (*transport_qf_callback)(struct se_cmd *); + unsigned char *t_task_cdb; unsigned char __t_task_cdb[TCM_MAX_COMMAND_SIZE]; unsigned long long t_task_lba; @@ -743,6 +748,7 @@ struct se_device { atomic_t dev_status_thr_count; atomic_t dev_hoq_count; atomic_t dev_ordered_sync; + atomic_t dev_qf_count; struct se_obj dev_obj; struct se_obj dev_access_obj; struct se_obj dev_export_obj; @@ -758,6 +764,7 @@ struct se_device { spinlock_t dev_status_thr_lock; spinlock_t se_port_lock; spinlock_t se_tmr_lock; + spinlock_t qf_cmd_lock; /* Used for legacy SPC-2 reservationsa */ struct se_node_acl *dev_reserved_node_acl; /* Used for ALUA Logical Unit Group membership */ @@ -771,10 +778,12 @@ struct se_device { struct task_struct *process_thread; pid_t process_thread_pid; struct task_struct *dev_mgmt_thread; + struct work_struct qf_work_queue; struct list_head delayed_cmd_list; struct list_head ordered_cmd_list; struct list_head execute_task_list; struct list_head state_task_list; + struct list_head qf_cmd_list; /* Pointer to associated SE HBA */ struct se_hba *se_hba; struct se_subsystem_dev *se_sub_dev; -- cgit v1.2.3-59-g8ed1b