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| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2011-06-13 23:46:09 +0200 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2011-07-22 11:37:45 +0200 |
| commit | 07bde79a5c355dbca66ca4318645aa17b4c0d859 (patch) | |
| tree | e602132193959df436a2f5d325cd3da9984ada4f /include/target | |
| parent | target: Add transport_handle_cdb_direct optimization (diff) | |
| download | linux-07bde79a5c355dbca66ca4318645aa17b4c0d859.tar.xz linux-07bde79a5c355dbca66ca4318645aa17b4c0d859.zip | |
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 <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'include/target')
| -rw-r--r-- | include/target/target_core_base.h | 9 |
1 files changed, 9 insertions, 0 deletions
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; |