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target: Avoid extra t_state_lock access in __target_execute_cmd
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This patch makes target_execute_cmd() set CMD_T_BUSY|CMD_T_SENT while
holding se_cmd->t_state_lock, in order to avoid the extra aquire/release
in __target_execute_cmd().

It also clears these bits in case of a target_handle_task_attr()
failure.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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Nicholas Bellinger committed Jun 20, 2013
1 parent c1c35d5 commit 1a398b9
Showing 1 changed file with 9 additions and 7 deletions.
16 changes: 9 additions & 7 deletions drivers/target/target_core_transport.c
Original file line number Diff line number Diff line change
Expand Up @@ -1580,10 +1580,6 @@ static void __target_execute_cmd(struct se_cmd *cmd)
{
sense_reason_t ret;

spin_lock_irq(&cmd->t_state_lock);
cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
spin_unlock_irq(&cmd->t_state_lock);

if (cmd->execute_cmd) {
ret = cmd->execute_cmd(cmd);
if (ret) {
Expand Down Expand Up @@ -1690,11 +1686,17 @@ void target_execute_cmd(struct se_cmd *cmd)
}

cmd->t_state = TRANSPORT_PROCESSING;
cmd->transport_state |= CMD_T_ACTIVE;
cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
spin_unlock_irq(&cmd->t_state_lock);

if (!target_handle_task_attr(cmd))
__target_execute_cmd(cmd);
if (target_handle_task_attr(cmd)) {
spin_lock_irq(&cmd->t_state_lock);
cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
spin_unlock_irq(&cmd->t_state_lock);
return;
}

__target_execute_cmd(cmd);
}
EXPORT_SYMBOL(target_execute_cmd);

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