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| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2011-11-02 21:52:08 -0700 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2011-11-04 07:50:26 +0000 |
| commit | a17f091d1a7c570804cfc2c77701634da88f8ecf (patch) | |
| tree | 50884063148c31cb5ee7b9a3f13bcc41f585cb92 /include/target/target_core_transport.h | |
| parent | 2235007c4d3245c0eca5e49497aafe5a111c00fb (diff) | |
| download | op-kernel-dev-a17f091d1a7c570804cfc2c77701634da88f8ecf.zip op-kernel-dev-a17f091d1a7c570804cfc2c77701634da88f8ecf.tar.gz | |
target: Add generic active I/O shutdown logic
This patch adds the initial pieces of generic active I/O shutdown logic.
This is intended to be a 'opt-in' feature for fabric modules that
includes the following functions to provide a mechinism for fabric
modules to track se_cmd via se_session->sess_cmd_list:
*) target_get_sess_cmd() - Add se_cmd to sess->sess_cmd_list, called
from fabric module incoming I/O path.
*) target_put_sess_cmd() - Check for completion or drop se_cmd from
->sess_cmd_list
*) target_splice_sess_cmd_list() - Splice active I/O list from
->sess_cmd_list to ->sess_wait_list, can called with HW fabric
lock held.
*) target_wait_for_sess_cmds() - Walk ->sess_wait_list waiting on
individual ->cmd_wait_comp. Optional transport_wait_for_tasks()
call.
target_splice_sess_cmd_list() is allowed to be called under HW fabric
lock, and performs the splice into se_sess->sess_wait_list and set
se_cmd->cmd_wait_set. Then target_wait_for_sess_cmds() walks the list
waiting for individual target_put_sess_cmd() fabric callbacks to
complete.
It also adds TFO->check_release_cmd() to split the completion and memory
release calls, where a fabric module uses target_put_sess_cmd() to check
for I/O completion during session shutdown. This is currently pushed out
into fabric modules as current fabric code may sleep here waiting for
TFO->check_stop_free() to complete in main response path, and because
target_wait_for_sess_cmds() calling TFO->release_cmd() to free fabric
descriptor memory directly.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'include/target/target_core_transport.h')
| -rw-r--r-- | include/target/target_core_transport.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/target/target_core_transport.h b/include/target/target_core_transport.h index d1b68c9..c16e943 100644 --- a/include/target/target_core_transport.h +++ b/include/target/target_core_transport.h @@ -164,12 +164,16 @@ extern bool target_stop_task(struct se_task *task, unsigned long *flags); extern int transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *, u32, struct scatterlist *, u32); extern int transport_clear_lun_from_sessions(struct se_lun *); -extern void transport_wait_for_tasks(struct se_cmd *); +extern bool transport_wait_for_tasks(struct se_cmd *); extern int transport_check_aborted_status(struct se_cmd *, int); extern int transport_send_check_condition_and_sense(struct se_cmd *, u8, int); extern void transport_send_task_abort(struct se_cmd *); extern void transport_release_cmd(struct se_cmd *); extern void transport_generic_free_cmd(struct se_cmd *, int); +extern void target_get_sess_cmd(struct se_session *, struct se_cmd *); +extern int target_put_sess_cmd(struct se_session *, struct se_cmd *); +extern void target_splice_sess_cmd_list(struct se_session *); +extern void target_wait_for_sess_cmds(struct se_session *, int); extern void transport_generic_wait_for_cmds(struct se_cmd *, int); extern void transport_do_task_sg_chain(struct se_cmd *); extern void transport_generic_process_write(struct se_cmd *); |
