[SCSI] iscsi_tcp: fix xmittask oops (db37c505) · Commits · 戴 / test

XMSTATE_SOL_HDR could be set when the xmit thread tests it, but there may not be anything on the r2tqueue yet. Move the XMSTATE_SOL_HDR set before the addition to the queue to make sure that when we pull something off it it is valid. This does not add locks around the xmstate test or make that a atmoic_t because this is a fast path and if it is set when we test it we can handle it there without the overhead. Later on we check the xmitqueue for all requests with the session lock so we will not miss it. Signed-off-by:

Mike Christie <michaelc@cs.wisc.edu> Signed-off-by:

James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/iscsi_tcp.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -415,8 +415,8 @@ iscsi_r2t_rsp(struct iscsi_conn conn, struct iscsi_cmd_task ctask)
		iscsi_solicit_data_init(conn, ctask, r2t);

		tcp_ctask->exp_r2tsn = r2tsn + 1;
		tcp_ctask->xmstate \|= XMSTATE_SOL_HDR;
		__kfifo_put(tcp_ctask->r2tqueue, (void)&r2t, sizeof(void));
		tcp_ctask->xmstate \|= XMSTATE_SOL_HDR;
		list_move_tail(&ctask->running, &conn->xmitqueue);

		scsi_queue_work(session->host, &conn->xmitwork);
		@@ -1627,9 +1627,12 @@ static int iscsi_send_sol_pdu(struct iscsi_conn *conn,
		if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
		tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
		tcp_ctask->xmstate \|= XMSTATE_SOL_DATA;
		if (!tcp_ctask->r2t)
		if (!tcp_ctask->r2t) {
		spin_lock_bh(&session->lock);
		__kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
		sizeof(void*));
		spin_unlock_bh(&session->lock);
		}
		send_hdr:
		r2t = tcp_ctask->r2t;
		dtask = &r2t->dtask;

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