From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch adds a new transport_cmd_check_stop() parameter for signaling
when TRANSPORT_WRITE_PENDING needs to be set.
This allows transport_generic_new_cmd() to avoid the extra lock acquire/release
of ->t_state_lock in the fast path for DMA_TO_DEVICE operations ahead of
transport_cmd_check_stop() + se_tfo->write_pending().
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Roland Dreier <roland@xxxxxxxxxx>
Cc: Kent Overstreet <koverstreet@xxxxxxxxxx>
Cc: Or Gerlitz <ogerlitz@xxxxxxxxxxxx>
Cc: Moussa Ba <moussaba@xxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 19 +++++++++----------
1 files changed, 9 insertions(+), 10 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 4a79336..15afa83 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -445,11 +445,15 @@ static void target_remove_from_state_list(struct se_cmd *cmd)
spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}
-static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists)
+static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
+ bool write_pending)
{
unsigned long flags;
spin_lock_irqsave(&cmd->t_state_lock, flags);
+ if (write_pending)
+ cmd->t_state = TRANSPORT_WRITE_PENDING;
+
/*
* Determine if IOCTL context caller in requesting the stopping of this
* command for LUN shutdown purposes.
@@ -514,7 +518,7 @@ static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists)
static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
{
- return transport_cmd_check_stop(cmd, true);
+ return transport_cmd_check_stop(cmd, true, false);
}
static void transport_lun_remove_cmd(struct se_cmd *cmd)
@@ -2116,12 +2120,7 @@ transport_generic_new_cmd(struct se_cmd *cmd)
target_execute_cmd(cmd);
return 0;
}
-
- spin_lock_irq(&cmd->t_state_lock);
- cmd->t_state = TRANSPORT_WRITE_PENDING;
- spin_unlock_irq(&cmd->t_state_lock);
-
- transport_cmd_check_stop(cmd, false);
+ transport_cmd_check_stop(cmd, false, true);
ret = cmd->se_tfo->write_pending(cmd);
if (ret == -EAGAIN || ret == -ENOMEM)
@@ -2325,7 +2324,7 @@ static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
cmd->se_tfo->get_task_tag(cmd));
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- transport_cmd_check_stop(cmd, false);
+ transport_cmd_check_stop(cmd, false, false);
return -EPERM;
}
cmd->transport_state |= CMD_T_LUN_FE_STOP;
@@ -2433,7 +2432,7 @@ check_cond:
spin_unlock_irqrestore(&cmd->t_state_lock,
cmd_flags);
- transport_cmd_check_stop(cmd, false);
+ transport_cmd_check_stop(cmd, false, false);
complete(&cmd->transport_lun_fe_stop_comp);
spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
continue;
--
1.7.2.5
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