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Commit f41d4721 authored by Mike Christie's avatar Mike Christie Committed by James Bottomley
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[SCSI] libiscsi: do not take host lock in queuecommand 



iscsi_tcp, ib_iser, cxgb*, be2iscsi and bnx2i do not use
the host lock and do not take the session lock against
a irq, so this patch drops the DEF_SCSI_QCMD use. Instead
we just take the session lock and disable bhs.

Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@suse.de>
parent 1227633a

drivers/scsi/libiscsi.c

+14 −23
Original line number Diff line number Diff line
@@ -505,6 +505,7 @@ static void iscsi_free_task(struct iscsi_task *task) 
	struct iscsi_conn *conn = task->conn;

	struct iscsi_session *session = conn->session;

	struct scsi_cmnd *sc = task->sc;

	int oldstate = task->state;



	ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",

			  task->itt, task->state, task->sc);
@@ -525,10 +526,10 @@ static void iscsi_free_task(struct iscsi_task *task) 
		/* SCSI eh reuses commands to verify us */

		sc->SCp.ptr = NULL;

		/*

		 * queue command may call this to free the task, but

		 * not have setup the sc callback

		 * queue command may call this to free the task, so

		 * it will decide how to return sc to scsi-ml.

		 */

		if (sc->scsi_done)

		if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)

			sc->scsi_done(sc);

	}

}
@@ -572,7 +573,8 @@ static void iscsi_complete_task(struct iscsi_task *task, int state) 
			  task->itt, task->state, task->sc);

	if (task->state == ISCSI_TASK_COMPLETED ||

	    task->state == ISCSI_TASK_ABRT_TMF ||

	    task->state == ISCSI_TASK_ABRT_SESS_RECOV)

	    task->state == ISCSI_TASK_ABRT_SESS_RECOV ||

	    task->state == ISCSI_TASK_REQUEUE_SCSIQ)

		return;

	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);

	task->state = state;
@@ -1600,27 +1602,23 @@ enum { 
	FAILURE_SESSION_NOT_READY,

};



static int iscsi_queuecommand_lck(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))

int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)

{

	struct iscsi_cls_session *cls_session;

	struct Scsi_Host *host;

	struct iscsi_host *ihost;

	int reason = 0;

	struct iscsi_session *session;

	struct iscsi_conn *conn;

	struct iscsi_task *task = NULL;



	sc->scsi_done = done;

	sc->result = 0;

	sc->SCp.ptr = NULL;



	host = sc->device->host;

	ihost = shost_priv(host);

	spin_unlock(host->host_lock);



	cls_session = starget_to_session(scsi_target(sc->device));

	session = cls_session->dd_data;

	spin_lock(&session->lock);

	spin_lock_bh(&session->lock);



	reason = iscsi_session_chkready(cls_session);

	if (reason) {
@@ -1706,25 +1704,21 @@ static int iscsi_queuecommand_lck(struct scsi_cmnd *sc, void (*done)(struct scsi 
	}



	session->queued_cmdsn++;

	spin_unlock(&session->lock);

	spin_lock(host->host_lock);

	spin_unlock_bh(&session->lock);

	return 0;



prepd_reject:

	sc->scsi_done = NULL;

	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);

	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);

reject:

	spin_unlock(&session->lock);

	spin_unlock_bh(&session->lock);

	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",

			  sc->cmnd[0], reason);

	spin_lock(host->host_lock);

	return SCSI_MLQUEUE_TARGET_BUSY;



prepd_fault:

	sc->scsi_done = NULL;

	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);

	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);

fault:

	spin_unlock(&session->lock);

	spin_unlock_bh(&session->lock);

	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",

			  sc->cmnd[0], reason);

	if (!scsi_bidi_cmnd(sc))
@@ -1733,12 +1727,9 @@ static int iscsi_queuecommand_lck(struct scsi_cmnd *sc, void (*done)(struct scsi 
		scsi_out(sc)->resid = scsi_out(sc)->length;

		scsi_in(sc)->resid = scsi_in(sc)->length;

	}

	done(sc);

	spin_lock(host->host_lock);

	sc->scsi_done(sc);

	return 0;

}



DEF_SCSI_QCMD(iscsi_queuecommand)

EXPORT_SYMBOL_GPL(iscsi_queuecommand);



int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)

include/scsi/libiscsi.h

+2 −1
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ enum { 
	ISCSI_TASK_RUNNING,

	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */

	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */

	ISCSI_TASK_REQUEUE_SCSIQ,	/* qcmd requeueing to scsi-ml */

};



struct iscsi_r2t_info {
@@ -341,7 +342,7 @@ extern int iscsi_eh_abort(struct scsi_cmnd *sc); 
extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);

extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);

extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);

extern int iscsi_queuecommand(struct Scsi_Host *h, struct scsi_cmnd *sc);

extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);



/*

 * iSCSI host helpers.