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scst: Rework scst_handle_aca()

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Make sure that the code that is in the hot path occurs first.


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7924 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Bart Van Assche
2019-02-12 03:41:16 +00:00
parent e2639613c5
commit 81e904c750
1 changed files with 54 additions and 55 deletions
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scst/src/scst_targ.c
+54 -55
View File
@@ -5042,69 +5042,70 @@ static void scst_handle_aca(struct scst_cmd *cmd)
unsigned long flags;
again:
if (unlikely(order_data->aca_tgt_dev != 0)) {
spin_lock_irqsave(&order_data->sn_lock, flags);
if (order_data->aca_tgt_dev == 0) {
spin_unlock_irqrestore(&order_data->sn_lock, flags);
goto again;
if (likely(!order_data->aca_tgt_dev)) {
if (unlikely(cmd->queue_type == SCST_CMD_QUEUE_ACA)) {
TRACE_MGMT_DBG("Refusing ACA cmd %p, because there's no ACA, tgt_dev %p",
cmd, cmd->tgt_dev);
scst_set_cmd_error(cmd,
SCST_LOAD_SENSE(scst_sense_invalid_message));
scst_set_cmd_abnormal_done_state(cmd);
}
return;
}
if (order_data->aca_tgt_dev == (unsigned long)cmd->tgt_dev) {
if (cmd->queue_type != SCST_CMD_QUEUE_ACA ||
order_data->aca_cmd || cmd->dev->tmf_only) {
TRACE_DBG("Refusing cmd %p, because ACA active (aca_cmd %p, tgt_dev %p)",
cmd, order_data->aca_cmd,
cmd->tgt_dev);
goto out_unlock_aca_active;
} else {
TRACE_MGMT_DBG("ACA cmd %p (tgt_dev %p)",
cmd, cmd->tgt_dev);
order_data->aca_cmd = cmd;
/* allow it */
}
spin_lock_irqsave(&order_data->sn_lock, flags);
if (!order_data->aca_tgt_dev) {
spin_unlock_irqrestore(&order_data->sn_lock, flags);
goto again;
}
if (order_data->aca_tgt_dev == (unsigned long)cmd->tgt_dev) {
if (cmd->queue_type != SCST_CMD_QUEUE_ACA ||
order_data->aca_cmd || cmd->dev->tmf_only) {
TRACE_DBG("Refusing cmd %p, because ACA active (aca_cmd %p, tgt_dev %p)",
cmd, order_data->aca_cmd,
cmd->tgt_dev);
goto out_unlock_aca_active;
} else {
/* Non-faulted I_T nexus */
EXTRACHECKS_BUG_ON(cmd->dev->tst !=
SCST_TST_0_SINGLE_TASK_SET);
if (cmd->queue_type == SCST_CMD_QUEUE_ACA) {
TRACE_MGMT_DBG("Refusing ACA cmd %p from wrong I_T nexus (aca_tgt_dev %ld, cmd->tgt_dev %p)",
cmd, order_data->aca_tgt_dev,
cmd->tgt_dev);
scst_set_cmd_error(cmd,
SCST_LOAD_SENSE(scst_sense_invalid_message));
goto out_unlock_aca_active;
TRACE_MGMT_DBG("ACA cmd %p (tgt_dev %p)",
cmd, cmd->tgt_dev);
order_data->aca_cmd = cmd;
/* allow it */
}
} else {
/* Non-faulted I_T nexus */
EXTRACHECKS_BUG_ON(cmd->dev->tst != SCST_TST_0_SINGLE_TASK_SET);
if (cmd->queue_type == SCST_CMD_QUEUE_ACA) {
TRACE_MGMT_DBG("Refusing ACA cmd %p from wrong I_T nexus (aca_tgt_dev %ld, cmd->tgt_dev %p)",
cmd, order_data->aca_tgt_dev,
cmd->tgt_dev);
scst_set_cmd_error(cmd,
SCST_LOAD_SENSE(scst_sense_invalid_message));
goto out_unlock_aca_active;
} else {
if (cmd->cdb[0] == PERSISTENT_RESERVE_OUT &&
(cmd->cdb[1] & 0x1f) == PR_PREEMPT_AND_ABORT) {
TRACE_MGMT_DBG("Allow PR PREEMPT AND ABORT cmd %p during ACA (tgt_dev %p)",
cmd, cmd->tgt_dev);
/* allow it */
} else {
if (cmd->cdb[0] == PERSISTENT_RESERVE_OUT &&
(cmd->cdb[1] & 0x1f) ==
PR_PREEMPT_AND_ABORT) {
TRACE_MGMT_DBG("Allow PR PREEMPT AND ABORT cmd %p during ACA (tgt_dev %p)",
cmd, cmd->tgt_dev);
/* allow it */
TRACE_DBG("Refusing other IT-nexus cmd %p, because ACA active (tgt_dev %p)",
cmd, cmd->tgt_dev);
if (cmd->cmd_naca) {
goto out_unlock_aca_active;
} else {
TRACE_DBG("Refusing other IT-nexus cmd %p, because ACA active (tgt_dev %p)",
cmd, cmd->tgt_dev);
if (cmd->cmd_naca)
goto out_unlock_aca_active;
else {
spin_unlock_irqrestore(&order_data->sn_lock, flags);
scst_set_cmd_error_status(cmd, SAM_STAT_BUSY);
goto out_bypass_aca;
}
spin_unlock_irqrestore(&order_data->sn_lock, flags);
scst_set_cmd_error_status(cmd, SAM_STAT_BUSY);
goto out_bypass_aca;
}
}
}
cmd->cmd_aca_allowed = 1;
spin_unlock_irqrestore(&order_data->sn_lock, flags);
} else if (unlikely(cmd->queue_type == SCST_CMD_QUEUE_ACA)) {
TRACE_MGMT_DBG("Refusing ACA cmd %p, because there's no ACA, tgt_dev %p",
cmd, cmd->tgt_dev);
scst_set_cmd_error(cmd,
SCST_LOAD_SENSE(scst_sense_invalid_message));
goto out_abnormal;
}
cmd->cmd_aca_allowed = 1;
spin_unlock_irqrestore(&order_data->sn_lock, flags);
return;
out_unlock_aca_active:
@@ -5113,8 +5114,6 @@ out_unlock_aca_active:
out_bypass_aca:
cmd->cmd_aca_allowed = 1; /* for check in scst_pre_xmit_response2() */
out_abnormal:
scst_set_cmd_abnormal_done_state(cmd);
return;
}