tcm: Add TFO->new_cmd_map() and TFO->task_sg_chaining=1
cover tcm: Add TFO->new_cmd_map() and TFO->task_sg_chaining=1
From: Nicholas Bellinger <[email protected]>
Greetings all,
This patch series adds two new features to the TCM v4 data I/O path that will be included in v4.0.0-rc4 for TCM_Loop (included below in patch #5) and other WIP HW target mode drivers.
The first patch adds support for TFO->new_cmd_map() / TRANSPORT_NEW_CMD_MAP which allows fabric modules to use a callback in TCM backstore processing thread context when doing the second stage setup of a new struct se_cmd descriptor.
The second patch adds support for greating a struct se_cmd wide SGL array chain using include/linux/scatterlist.h:sg_chain() from contigiously allocated struct se_task->task_sg[] arrays. This includes the use of a trailing padding SGL within struct se_task->task_sg[] to hold the SGL link to the next struct se_task->task_sg[].
The third and forth patches involve the conversion of two spinlocks which now may used in interrupt context from __transport_get_lun_for_cmd(), and makes them use spin_lock_irq() and spin_unlock_irq() and handles a couple of special cases in target_core_mib.c for reference counting.
And finally the fifth path converts the TCM_Loop virtual SCSI LLD module to use the new TFO->new_cmd_map() / TRANSPORT_NEW_CMD_MAP, and removes the original per struct tcm_loop_hba->tl_hba_qobj. This will give us a nice reduction in context-switches per TCM_Loop I/O now that this patch removes the original per HBA tcm_loop_processing_thread() overhead in TCM_Loop v4 code!
Comments are welcome,
Nicholas Bellinger (6):
tcm: Add support for TRANSPORT_NEW_CMD_MAP
tcm: Add support for struct target_core_fabric_ops->task_sg_chaining tcm/ramdisk: Add special case for TFO->task_sg_chaining=1 with
RAMDISK_DR
tcm: Convert struct se_node_acl->device_list_lock to spin_*lock_irq()
tcm: Convert struct se_device->dev_status_lock to spin_*lock_irq()
tcm_loop: Convert to use new optimized TFO->new_cmd_map() caller
drivers/target/target_core_device.c | 94 +++++--------- drivers/target/target_core_fabric_configfs.c | 8 +- drivers/target/target_core_mib.c | 28 ++++- drivers/target/target_core_rd.c | 45 ++++++- drivers/target/target_core_tpg.c | 18 ++- drivers/target/target_core_transport.c | 160 ++++++++++++++++++++++-- drivers/target/target_core_ua.c | 20 ++-- drivers/target/tcm_loop/tcm_loop_configfs.c | 35 +----- drivers/target/tcm_loop/tcm_loop_core.h | 2 - drivers/target/tcm_loop/tcm_loop_fabric.c | 61 --------- drivers/target/tcm_loop/tcm_loop_fabric.h | 2 - drivers/target/tcm_loop/tcm_loop_fabric_scsi.c | 100 +++++----------- drivers/target/tcm_loop/tcm_loop_fabric_scsi.h | 2 +- include/target/target_core_base.h | 11 ++- include/target/target_core_device.h | 1 - include/target/target_core_fabric_ops.h | 12 ++ include/target/target_core_tpg.h | 1 + include/target/target_core_transport.h | 3 +- 18 files changed, 332 insertions(+), 271 deletions(-)