Commit c1c35d52 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Remove legacy t_fe_count + avoid t_state_lock access in transport_put_cmd 



This patch removes legacy se_cmd->t_fe_count usage in order to avoid
se_cmd->t_state_lock access within transport_put_cmd() during normal
fast path se_cmd descriptor release.

Also drop the left-over parameter usage within core_tmr_handle_tas_abort()

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: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 0b66818a

drivers/target/target_core_tmr.c

+2 −10
Original line number Diff line number Diff line
@@ -85,13 +85,8 @@ void core_tmr_release_req( 
static void core_tmr_handle_tas_abort(

	struct se_node_acl *tmr_nacl,

	struct se_cmd *cmd,

	int tas,

	int fe_count)

	int tas)

{

	if (!fe_count) {

		transport_cmd_finish_abort(cmd, 1);

		return;

	}

	/*

	 * TASK ABORTED status (TAS) bit support

	*/
@@ -253,7 +248,6 @@ static void core_tmr_drain_state_list( 
	LIST_HEAD(drain_task_list);

	struct se_cmd *cmd, *next;

	unsigned long flags;

	int fe_count;



	/*

	 * Complete outstanding commands with TASK_ABORTED SAM status.
@@ -329,12 +323,10 @@ static void core_tmr_drain_state_list( 
		spin_lock_irqsave(&cmd->t_state_lock, flags);

		target_stop_cmd(cmd, &flags);



		fe_count = atomic_read(&cmd->t_fe_count);



		cmd->transport_state |= CMD_T_ABORTED;

		spin_unlock_irqrestore(&cmd->t_state_lock, flags);



		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);

		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas);

	}

}

drivers/target/target_core_transport.c

+0 −18
Original line number Diff line number Diff line
@@ -1968,21 +1968,6 @@ static int transport_release_cmd(struct se_cmd *cmd) 
 */

static int transport_put_cmd(struct se_cmd *cmd)

{

	unsigned long flags;



	spin_lock_irqsave(&cmd->t_state_lock, flags);

	if (atomic_read(&cmd->t_fe_count) &&

	    !atomic_dec_and_test(&cmd->t_fe_count)) {

		spin_unlock_irqrestore(&cmd->t_state_lock, flags);

		return 0;

	}



	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {

		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;

		target_remove_from_state_list(cmd);

	}

	spin_unlock_irqrestore(&cmd->t_state_lock, flags);



	transport_free_pages(cmd);

	return transport_release_cmd(cmd);

}
@@ -2100,9 +2085,6 @@ transport_generic_new_cmd(struct se_cmd *cmd) 
		if (ret < 0)

			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	}



	atomic_inc(&cmd->t_fe_count);



	/*

	 * If this command is not a write we can execute it right here,

	 * for write buffers we need to notify the fabric driver first

include/target/target_core_base.h

+0 −1
Original line number Diff line number Diff line
@@ -454,7 +454,6 @@ struct se_cmd { 
	unsigned char		*t_task_cdb;

	unsigned char		__t_task_cdb[TCM_MAX_COMMAND_SIZE];

	unsigned long long	t_task_lba;

	atomic_t		t_fe_count;

	unsigned int		transport_state;

#define CMD_T_ABORTED		(1 << 0)

#define CMD_T_ACTIVE		(1 << 1)

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