Commit 913e5bf4 authored by Mike Christie's avatar Mike Christie Committed by James Bottomley
Browse files

[SCSI] libiscsi, iser, tcp: remove recv_lock 



The recv lock was defined so the iscsi layer could block
the recv path from processing IO during recovery. It
turns out iser just set a lock to that pointer which was pointless.

We now disconnect the transport connection before doing recovery
so we do not need the recv lock. For iscsi_tcp we still stop
the recv path incase older tools are being used.

This patch also has iscsi_itt_to_ctask user grab the session lock
and has the caller access the task with the lock or get a ref
to it in case the target is broken and sends a tmf success response
then sends data or a response for the command that was supposed to
be affected bty the tmf.

Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 3cf7b233

drivers/infiniband/ulp/iser/iscsi_iser.c

+10 −10
Original line number Diff line number Diff line
@@ -281,9 +281,6 @@ iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx) 
	conn->max_recv_dlength = 128;



	iser_conn = conn->dd_data;

	/* currently this is the only field which need to be initiated */

	rwlock_init(&iser_conn->lock);



	conn->dd_data = iser_conn;

	iser_conn->iscsi_conn = conn;
@@ -342,9 +339,6 @@ iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session, 
	ib_conn->iser_conn = iser_conn;

	iser_conn->ib_conn  = ib_conn;

	iser_conn_get(ib_conn);



	conn->recv_lock = &iser_conn->lock;



	return 0;

}
@@ -355,12 +349,18 @@ iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) 
	struct iscsi_iser_conn *iser_conn = conn->dd_data;

	struct iser_conn *ib_conn = iser_conn->ib_conn;



	/*

	 * Userspace may have goofed up and not bound the connection or

	 * might have only partially setup the connection.

	 */

	if (ib_conn) {

		iscsi_conn_stop(cls_conn, flag);

		/*

		 * There is no unbind event so the stop callback

		 * must release the ref from the bind.

		 */

		iser_conn_put(ib_conn);

	}

	iser_conn->ib_conn = NULL;

}

drivers/infiniband/ulp/iser/iscsi_iser.h

+0 −2
Original line number Diff line number Diff line
@@ -263,8 +263,6 @@ struct iser_conn { 
struct iscsi_iser_conn {

	struct iscsi_conn            *iscsi_conn;/* ptr to iscsi conn */

	struct iser_conn             *ib_conn;   /* iSER IB conn      */



	rwlock_t		     lock;

};



struct iscsi_iser_task {

drivers/infiniband/ulp/iser/iser_initiator.c

+6 −0
Original line number Diff line number Diff line
@@ -558,7 +558,12 @@ void iser_rcv_completion(struct iser_desc *rx_desc, 
	opcode = hdr->opcode & ISCSI_OPCODE_MASK;



	if (opcode == ISCSI_OP_SCSI_CMD_RSP) {

		spin_lock(&conn->iscsi_conn->session->lock);

		task = iscsi_itt_to_ctask(conn->iscsi_conn, hdr->itt);

		if (task)

			__iscsi_get_task(task);

		spin_unlock(&conn->iscsi_conn->session->lock);



		if (!task)

			iser_err("itt can't be matched to task!!! "

				 "conn %p opcode %d itt %d\n",
@@ -568,6 +573,7 @@ void iser_rcv_completion(struct iser_desc *rx_desc, 
			iser_dbg("itt %d task %p\n",hdr->itt, task);

			iser_task->status = ISER_TASK_STATUS_COMPLETED;

			iser_task_rdma_finalize(iser_task);

			iscsi_put_task(task);

		}

	}

	iser_dto_buffs_release(dto);

drivers/scsi/iscsi_tcp.c

+39 −34
Original line number Diff line number Diff line
@@ -741,7 +741,6 @@ static int 
iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)

{

	int rc = 0, opcode, ahslen;

	struct iscsi_session *session = conn->session;

	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;

	struct iscsi_task *task;
@@ -770,17 +769,17 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr) 


	switch(opcode) {

	case ISCSI_OP_SCSI_DATA_IN:

		spin_lock(&conn->session->lock);

		task = iscsi_itt_to_ctask(conn, hdr->itt);

		if (!task)

			return ISCSI_ERR_BAD_ITT;

		if (!task->sc)

			return ISCSI_ERR_NO_SCSI_CMD;



		spin_lock(&conn->session->lock);

			rc = ISCSI_ERR_BAD_ITT;

		else

			rc = iscsi_data_rsp(conn, task);

		if (rc) {

			spin_unlock(&conn->session->lock);

		if (rc)

			return rc;

			break;

		}



		if (tcp_conn->in.datalen) {

			struct iscsi_tcp_task *tcp_task = task->dd_data;

			struct hash_desc *rx_hash = NULL;
@@ -801,15 +800,19 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr) 
				  "datalen=%d)\n", tcp_conn,

				  tcp_task->data_offset,

				  tcp_conn->in.datalen);

			return iscsi_segment_seek_sg(&tcp_conn->in.segment,

			rc = iscsi_segment_seek_sg(&tcp_conn->in.segment,

						   sdb->table.sgl,

						   sdb->table.nents,

						   tcp_task->data_offset,

						   tcp_conn->in.datalen,

						   iscsi_tcp_process_data_in,

						   rx_hash);

			spin_unlock(&conn->session->lock);

			return rc;

		}

		/* fall through */

		rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);

		spin_unlock(&conn->session->lock);

		break;

	case ISCSI_OP_SCSI_CMD_RSP:

		if (tcp_conn->in.datalen) {

			iscsi_tcp_data_recv_prep(tcp_conn);
@@ -818,20 +821,17 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr) 
		rc = iscsi_complete_pdu(conn, hdr, NULL, 0);

		break;

	case ISCSI_OP_R2T:

		spin_lock(&conn->session->lock);

		task = iscsi_itt_to_ctask(conn, hdr->itt);

		if (!task)

			return ISCSI_ERR_BAD_ITT;

		if (!task->sc)

			return ISCSI_ERR_NO_SCSI_CMD;



		if (ahslen)

			rc = ISCSI_ERR_BAD_ITT;

		else if (ahslen)

			rc = ISCSI_ERR_AHSLEN;

		else if (task->sc->sc_data_direction == DMA_TO_DEVICE) {

			spin_lock(&session->lock);

		else if (task->sc->sc_data_direction == DMA_TO_DEVICE)

			rc = iscsi_r2t_rsp(conn, task);

			spin_unlock(&session->lock);

		} else

		else

			rc = ISCSI_ERR_PROTO;

		spin_unlock(&conn->session->lock);

		break;

	case ISCSI_OP_LOGIN_RSP:

	case ISCSI_OP_TEXT_RSP:
@@ -1553,7 +1553,6 @@ iscsi_tcp_release_conn(struct iscsi_conn *conn) 


	spin_lock_bh(&session->lock);

	tcp_conn->sock = NULL;

	conn->recv_lock = NULL;

	spin_unlock_bh(&session->lock);

	sockfd_put(sock);

}
@@ -1578,6 +1577,19 @@ static void 
iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)

{

	struct iscsi_conn *conn = cls_conn->dd_data;

	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;



	/* userspace may have goofed up and not bound us */

	if (!tcp_conn->sock)

		return;

	/*

	 * Make sure our recv side is stopped.

	 * Older tools called conn stop before ep_disconnect

	 * so IO could still be coming in.

	 */

	write_lock_bh(&tcp_conn->sock->sk->sk_callback_lock);

	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);

	write_unlock_bh(&tcp_conn->sock->sk->sk_callback_lock);



	iscsi_conn_stop(cls_conn, flag);

	iscsi_tcp_release_conn(conn);
@@ -1671,13 +1683,6 @@ iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session, 
	sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */

	sk->sk_allocation = GFP_ATOMIC;



	/* FIXME: disable Nagle's algorithm */



	/*

	 * Intercept TCP callbacks for sendfile like receive

	 * processing.

	 */

	conn->recv_lock = &sk->sk_callback_lock;

	iscsi_conn_set_callbacks(conn);

	tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;

	/*

drivers/scsi/libiscsi.c

+86 −66
Original line number Diff line number Diff line
@@ -362,10 +362,11 @@ static void iscsi_complete_command(struct iscsi_task *task) 
	}

}



static void __iscsi_get_task(struct iscsi_task *task)

void __iscsi_get_task(struct iscsi_task *task)

{

	atomic_inc(&task->refcount);

}

EXPORT_SYMBOL_GPL(__iscsi_get_task);



static void __iscsi_put_task(struct iscsi_task *task)

{
@@ -403,9 +404,13 @@ static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task, 
		conn->session->queued_cmdsn--;

	else

		conn->session->tt->cleanup_task(conn, task);

	/*

	 * Check if cleanup_task dropped the lock and the command completed,

	 */

	if (!task->sc)

		return;



	sc->result = err;



	if (!scsi_bidi_cmnd(sc))

		scsi_set_resid(sc, scsi_bufflen(sc));

	else {
@@ -696,6 +701,31 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
	return 0;

}



/**

 * iscsi_itt_to_task - look up task by itt

 * @conn: iscsi connection

 * @itt: itt

 *

 * This should be used for mgmt tasks like login and nops, or if

 * the LDD's itt space does not include the session age.

 *

 * The session lock must be held.

 */

static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)

{

	struct iscsi_session *session = conn->session;

	uint32_t i;



	if (itt == RESERVED_ITT)

		return NULL;



	i = get_itt(itt);

	if (i >= session->cmds_max)

		return NULL;



	return session->cmds[i];

}



/**

 * __iscsi_complete_pdu - complete pdu

 * @conn: iscsi conn
@@ -707,7 +737,7 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
 * queuecommand or send generic. session lock must be held and verify

 * itt must have been called.

 */

static int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,

int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,

			 char *data, int datalen)

{

	struct iscsi_session *session = conn->session;
@@ -758,22 +788,36 @@ static int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
		goto out;

	}



	task = session->cmds[itt];

	switch(opcode) {

	case ISCSI_OP_SCSI_CMD_RSP:

		if (!task->sc) {

			rc = ISCSI_ERR_NO_SCSI_CMD;

	case ISCSI_OP_SCSI_DATA_IN:

		task = iscsi_itt_to_ctask(conn, hdr->itt);

		if (!task)

			return ISCSI_ERR_BAD_ITT;

		break;

	case ISCSI_OP_R2T:

		/*

		 * LLD handles R2Ts if they need to.

		 */

		return 0;

	case ISCSI_OP_LOGOUT_RSP:

	case ISCSI_OP_LOGIN_RSP:

	case ISCSI_OP_TEXT_RSP:

	case ISCSI_OP_SCSI_TMFUNC_RSP:

	case ISCSI_OP_NOOP_IN:

		task = iscsi_itt_to_task(conn, hdr->itt);

		if (!task)

			return ISCSI_ERR_BAD_ITT;

		break;

	default:

		return ISCSI_ERR_BAD_OPCODE;

	}

		BUG_ON((void*)task != task->sc->SCp.ptr);



	switch(opcode) {

	case ISCSI_OP_SCSI_CMD_RSP:

		iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);

		break;

	case ISCSI_OP_SCSI_DATA_IN:

		if (!task->sc) {

			rc = ISCSI_ERR_NO_SCSI_CMD;

			break;

		}

		BUG_ON((void*)task != task->sc->SCp.ptr);

		if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {

			conn->scsirsp_pdus_cnt++;

			iscsi_update_cmdsn(session,
@@ -781,9 +825,6 @@ static int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
			__iscsi_put_task(task);

		}

		break;

	case ISCSI_OP_R2T:

		/* LLD handles this for now */

		break;

	case ISCSI_OP_LOGOUT_RSP:

		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);

		if (datalen) {
@@ -841,6 +882,7 @@ recv_pdu: 
	__iscsi_put_task(task);

	return rc;

}

EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);



int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,

		       char *data, int datalen)
@@ -857,7 +899,6 @@ EXPORT_SYMBOL_GPL(iscsi_complete_pdu); 
int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)

{

	struct iscsi_session *session = conn->session;

	struct iscsi_task *task;

	uint32_t i;



	if (itt == RESERVED_ITT)
@@ -867,8 +908,7 @@ int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt) 
	    (session->age << ISCSI_AGE_SHIFT)) {

		iscsi_conn_printk(KERN_ERR, conn,

				  "received itt %x expected session age (%x)\n",

				  (__force u32)itt,

				  session->age & ISCSI_AGE_MASK);

				  (__force u32)itt, session->age);

		return ISCSI_ERR_BAD_ITT;

	}
@@ -879,42 +919,36 @@ int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt) 
				   "%u.\n", i, session->cmds_max);

		return ISCSI_ERR_BAD_ITT;

	}



	task = session->cmds[i];

	if (task->sc && task->sc->SCp.phase != session->age) {

		iscsi_conn_printk(KERN_ERR, conn,

				  "iscsi: task's session age %d, "

				  "expected %d\n", task->sc->SCp.phase,

				  session->age);

		return ISCSI_ERR_SESSION_FAILED;

	}

	return 0;

}

EXPORT_SYMBOL_GPL(iscsi_verify_itt);



struct iscsi_task *

iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)

/**

 * iscsi_itt_to_ctask - look up ctask by itt

 * @conn: iscsi connection

 * @itt: itt

 *

 * This should be used for cmd tasks.

 *

 * The session lock must be held.

 */

struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)

{

	struct iscsi_session *session = conn->session;

	struct iscsi_task *task;

	uint32_t i;



	if (iscsi_verify_itt(conn, itt))

		return NULL;



	if (itt == RESERVED_ITT)

		return NULL;



	i = get_itt(itt);

	if (i >= session->cmds_max)

		return NULL;



	task = session->cmds[i];

	if (!task->sc)

	task = iscsi_itt_to_task(conn, itt);

	if (!task || !task->sc)

		return NULL;



	if (task->sc->SCp.phase != session->age)

	if (task->sc->SCp.phase != conn->session->age) {

		iscsi_session_printk(KERN_ERR, conn->session,

				  "task's session age %d, expected %d\n",

				  task->sc->SCp.phase, conn->session->age);

		return NULL;

	}



	return task;

}
@@ -1620,16 +1654,20 @@ int iscsi_eh_abort(struct scsi_cmnd *sc) 
	switch (conn->tmf_state) {

	case TMF_SUCCESS:

		spin_unlock_bh(&session->lock);

		/*

		 * stop tx side incase the target had sent a abort rsp but

		 * the initiator was still writing out data.

		 */

		iscsi_suspend_tx(conn);

		/*

		 * clean up task if aborted. grab the recv lock as a writer

		 * we do not stop the recv side because targets have been

		 * good and have never sent us a successful tmf response

		 * then sent more data for the cmd.

		 */

		write_lock_bh(conn->recv_lock);

		spin_lock(&session->lock);

		fail_command(conn, task, DID_ABORT << 16);

		conn->tmf_state = TMF_INITIAL;

		spin_unlock(&session->lock);

		write_unlock_bh(conn->recv_lock);

		iscsi_start_tx(conn);

		goto success_unlocked;

	case TMF_TIMEDOUT:
@@ -1729,13 +1767,11 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc) 
	spin_unlock_bh(&session->lock);



	iscsi_suspend_tx(conn);

	/* need to grab the recv lock then session lock */

	write_lock_bh(conn->recv_lock);



	spin_lock(&session->lock);

	fail_all_commands(conn, sc->device->lun, DID_ERROR);

	conn->tmf_state = TMF_INITIAL;

	spin_unlock(&session->lock);

	write_unlock_bh(conn->recv_lock);



	iscsi_start_tx(conn);

	goto done;
@@ -2256,17 +2292,6 @@ static void iscsi_start_session_recovery(struct iscsi_session *session, 
		return;

	}



	/*

	 * The LLD either freed/unset the lock on us, or userspace called

	 * stop but did not create a proper connection (connection was never

	 * bound or it was unbound then stop was called).

	 */

	if (!conn->recv_lock) {

		spin_unlock_bh(&session->lock);

		mutex_unlock(&session->eh_mutex);

		return;

	}



	/*

	 * When this is called for the in_login state, we only want to clean

	 * up the login task and connection. We do not need to block and set
@@ -2283,11 +2308,6 @@ static void iscsi_start_session_recovery(struct iscsi_session *session, 
	spin_unlock_bh(&session->lock);



	iscsi_suspend_tx(conn);



	write_lock_bh(conn->recv_lock);

	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);

	write_unlock_bh(conn->recv_lock);



	/*

	 * for connection level recovery we should not calculate

	 * header digest. conn->hdr_size used for optimization

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