Looks Good.
Regards,
Quinn Tran
-----Original Message-----
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Date: Saturday, June 3, 2017 at 3:10 PM
To: target-devel <target-devel@xxxxxxxxxxxxxxx>
Cc: linux-scsi <linux-scsi@xxxxxxxxxxxxxxx>, lkml <linux-kernel@xxxxxxxxxxxxxxx>, Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>, "Madhani, Himanshu" <Himanshu.Madhani@xxxxxxxxxx>, "Tran, Quinn" <Quinn.Tran@xxxxxxxxxx>, Mike Christie <mchristi@xxxxxxxxxx>, Hannes Reinecke <hare@xxxxxxxx>, Christoph Hellwig <hch@xxxxxx>
Subject: [PATCH 2/3] target: Add TARGET_SCF_LOOKUP_LUN_FROM_TAG support for ABORT_TASK
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch introduces support in target_submit_tmr() for locating a
unpacked_lun from an existing se_cmd->tag during ABORT_TASK.
When TARGET_SCF_LOOKUP_LUN_FROM_TAG is set, target_submit_tmr()
will do the extra lookup via target_lookup_lun_from_tag() and
subsequently invoke transport_lookup_tmr_lun() so a proper
percpu se_lun->lun_ref is taken before workqueue dispatch into
se_device->tmr_wq happens.
Aside from the extra target_lookup_lun_from_tag(), the existing
code-path remains unchanged.
Cc: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Cc: Quinn Tran <quinn.tran@xxxxxxxxxx>
Cc: Mike Christie <mchristi@xxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 53 ++++++++++++++++++++++++++++------
include/target/target_core_base.h | 3 +-
2 files changed, 46 insertions(+), 10 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 83bfc97..dbb8101 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1592,6 +1592,29 @@ static void target_complete_tmr_failure(struct work_struct *work)
transport_cmd_check_stop_to_fabric(se_cmd);
}
+static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
+ u64 *unpacked_lun)
+{
+ struct se_cmd *se_cmd;
+ unsigned long flags;
+ bool ret = false;
+
+ spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
+ list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
+ if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
+ continue;
+
+ if (se_cmd->tag == tag) {
+ *unpacked_lun = se_cmd->orig_fe_lun;
+ ret = true;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+ return ret;
+}
+
/**
* target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
* for TMR CDBs
@@ -1639,19 +1662,31 @@ int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
core_tmr_release_req(se_cmd->se_tmr_req);
return ret;
}
+ /*
+ * If this is ABORT_TASK with no explicit fabric provided LUN,
+ * go ahead and search active session tags for a match to figure
+ * out unpacked_lun for the original se_cmd.
+ */
+ if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
+ if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
+ goto failure;
+ }
ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
- if (ret) {
- /*
- * For callback during failure handling, push this work off
- * to process context with TMR_LUN_DOES_NOT_EXIST status.
- */
- INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
- schedule_work(&se_cmd->work);
- return 0;
- }
+ if (ret)
+ goto failure;
+
transport_generic_handle_tmr(se_cmd);
return 0;
+
+ /*
+ * For callback during failure handling, push this work off
+ * to process context with TMR_LUN_DOES_NOT_EXIST status.
+ */
+failure:
+ INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
+ schedule_work(&se_cmd->work);
+ return 0;
}
EXPORT_SYMBOL(target_submit_tmr);
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index db2c7b3..a3af69f 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -188,7 +188,8 @@ enum target_sc_flags_table {
TARGET_SCF_BIDI_OP = 0x01,
TARGET_SCF_ACK_KREF = 0x02,
TARGET_SCF_UNKNOWN_SIZE = 0x04,
- TARGET_SCF_USE_CPUID = 0x08,
+ TARGET_SCF_USE_CPUID = 0x08,
+ TARGET_SCF_LOOKUP_LUN_FROM_TAG = 0x10,
};
/* fabric independent task management function values */
--
1.9.1
