From c2ba444d1d871d3f6cd3bc5e7d8e19c48c8c02a4 Mon Sep 17 00:00:00 2001 From: Horst Hummel Date: Wed, 1 Feb 2006 03:06:37 -0800 Subject: [PATCH] s390: dasd wait for clear i/o interrupt The sleep_on function clears a running cqr without waiting for the related interrupt. This can lead to a panic at the time the interrupt is processed because the related memory might already be freed. Wait for clear-interrupt and de-queue cqr prior to return. Signed-off-by: Horst Hummel Signed-off-by: Martin Schwidefsky Signed-off-by: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/s390/block/dasd.c | 45 +++++++++++++++++++++++++++++++++------------ 1 file changed, 33 insertions(+), 12 deletions(-) diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 953097c..abdf1ee 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -674,11 +674,8 @@ dasd_term_IO(struct dasd_ccw_req * cqr) rc = ccw_device_clear(device->cdev, (long) cqr); switch (rc) { case 0: /* termination successful */ - if (cqr->retries > 0) { - cqr->retries--; - cqr->status = DASD_CQR_CLEAR; - } else - cqr->status = DASD_CQR_FAILED; + cqr->retries--; + cqr->status = DASD_CQR_CLEAR; cqr->stopclk = get_clock(); DBF_DEV_EVENT(DBF_DEBUG, device, "terminate cqr %p successful", @@ -1307,7 +1304,7 @@ dasd_tasklet(struct dasd_device * device) /* Now call the callback function of requests with final status */ list_for_each_safe(l, n, &final_queue) { cqr = list_entry(l, struct dasd_ccw_req, list); - list_del(&cqr->list); + list_del_init(&cqr->list); if (cqr->callback != NULL) (cqr->callback)(cqr, cqr->callback_data); } @@ -1392,7 +1389,9 @@ _wait_for_wakeup(struct dasd_ccw_req *cqr) device = cqr->device; spin_lock_irq(get_ccwdev_lock(device->cdev)); - rc = cqr->status == DASD_CQR_DONE || cqr->status == DASD_CQR_FAILED; + rc = ((cqr->status == DASD_CQR_DONE || + cqr->status == DASD_CQR_FAILED) && + list_empty(&cqr->list)); spin_unlock_irq(get_ccwdev_lock(device->cdev)); return rc; } @@ -1456,15 +1455,37 @@ dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr) while (!finished) { rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr)); if (rc != -ERESTARTSYS) { - /* Request status is either done or failed. */ - rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0; + /* Request is final (done or failed) */ + rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO; break; } spin_lock_irq(get_ccwdev_lock(device->cdev)); - if (cqr->status == DASD_CQR_IN_IO && - device->discipline->term_IO(cqr) == 0) { - list_del(&cqr->list); + switch (cqr->status) { + case DASD_CQR_IN_IO: + /* terminate runnig cqr */ + if (device->discipline->term_IO) { + cqr->retries = -1; + device->discipline->term_IO(cqr); + /*nished = + * wait (non-interruptible) for final status + * because signal ist still pending + */ + spin_unlock_irq(get_ccwdev_lock(device->cdev)); + wait_event(wait_q, _wait_for_wakeup(cqr)); + spin_lock_irq(get_ccwdev_lock(device->cdev)); + rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO; + finished = 1; + } + break; + case DASD_CQR_QUEUED: + /* request */ + list_del_init(&cqr->list); + rc = -EIO; finished = 1; + break; + default: + /* cqr with 'non-interruptable' status - just wait */ + break; } spin_unlock_irq(get_ccwdev_lock(device->cdev)); } -- cgit v1.1