Date: Thu, 12 Nov 2009 13:37:41 GMT From: Alexander Motin <mav@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 170543 for review Message-ID: <200911121337.nACDbfSa062404@repoman.freebsd.org>
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http://p4web.freebsd.org/chv.cgi?CH=170543 Change 170543 by mav@mav_mavbook on 2009/11/12 13:37:13 Remove code that 10 years ago was closing race between sim_action() and device/SIM freeze. It just impossible with present CAM locking, but caused some unexpected side effects. Affected files ... .. //depot/projects/scottl-camlock/src/sys/cam/cam_queue.c#6 edit .. //depot/projects/scottl-camlock/src/sys/cam/cam_queue.h#5 edit .. //depot/projects/scottl-camlock/src/sys/cam/cam_xpt.c#127 edit Differences ... ==== //depot/projects/scottl-camlock/src/sys/cam/cam_queue.c#6 (text+ko) ==== @@ -334,7 +334,6 @@ } ccbq->devq_openings = openings; ccbq->dev_openings = openings; - TAILQ_INIT(&ccbq->active_ccbs); return (0); } ==== //depot/projects/scottl-camlock/src/sys/cam/cam_queue.h#5 (text+ko) ==== @@ -60,7 +60,6 @@ int dev_openings; int dev_active; int held; - struct ccb_hdr_tailq active_ccbs; }; struct cam_ed; @@ -209,9 +208,6 @@ cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb) { - TAILQ_INSERT_TAIL(&ccbq->active_ccbs, - &(send_ccb->ccb_h), - xpt_links.tqe); send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX; ccbq->dev_active++; ccbq->dev_openings--; @@ -220,8 +216,7 @@ static __inline void cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb) { - TAILQ_REMOVE(&ccbq->active_ccbs, &done_ccb->ccb_h, - xpt_links.tqe); + ccbq->dev_active--; ccbq->dev_openings++; ccbq->held++; ==== //depot/projects/scottl-camlock/src/sys/cam/cam_xpt.c#127 (text+ko) ==== @@ -3327,9 +3327,7 @@ } mtx_unlock(&xsoftc.xpt_lock); } - devq->active_dev = device; cam_ccbq_remove_ccb(&device->ccbq, work_ccb); - cam_ccbq_send_ccb(&device->ccbq, work_ccb); devq->send_openings--; @@ -3367,8 +3365,6 @@ */ sim = work_ccb->ccb_h.path->bus->sim; (*(sim->sim_action))(sim, work_ccb); - - devq->active_dev = NULL; } devq->send_queue.qfrozen_cnt--; } @@ -4099,45 +4095,18 @@ u_int32_t xpt_freeze_devq(struct cam_path *path, u_int count) { - struct ccb_hdr *ccbh; mtx_assert(path->bus->sim->mtx, MA_OWNED); - path->device->ccbq.queue.qfrozen_cnt += count; - - /* - * Mark the last CCB in the queue as needing - * to be requeued if the driver hasn't - * changed it's state yet. This fixes a race - * where a ccb is just about to be queued to - * a controller driver when it's interrupt routine - * freezes the queue. To completly close the - * hole, controller drives must check to see - * if a ccb's status is still CAM_REQ_INPROG - * just before they queue - * the CCB. See ahc_action/ahc_freeze_devq for - * an example. - */ - ccbh = TAILQ_LAST(&path->device->ccbq.active_ccbs, ccb_hdr_tailq); - if (ccbh && ccbh->status == CAM_REQ_INPROG) - ccbh->status = CAM_REQUEUE_REQ; return (path->device->ccbq.queue.qfrozen_cnt); } u_int32_t xpt_freeze_simq(struct cam_sim *sim, u_int count) { + mtx_assert(sim->mtx, MA_OWNED); - sim->devq->send_queue.qfrozen_cnt += count; - if (sim->devq->active_dev != NULL) { - struct ccb_hdr *ccbh; - - ccbh = TAILQ_LAST(&sim->devq->active_dev->ccbq.active_ccbs, - ccb_hdr_tailq); - if (ccbh && ccbh->status == CAM_REQ_INPROG) - ccbh->status = CAM_REQUEUE_REQ; - } return (sim->devq->send_queue.qfrozen_cnt); }help
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