From e14ac67026b46e94478134df9521682fc6501ac0 Mon Sep 17 00:00:00 2001 From: "scameron@beardog.cca.cpqcorp.net" Date: Thu, 17 Apr 2008 13:19:03 +0200 Subject: [PATCH] cciss: Fix race between disk-adding code and interrupt handler Fix race condition between cciss_init_one(), cciss_update_drive_info(), and cciss_check_queues(). Signed-off-by: Stephen M. Cameron Signed-off-by: Jens Axboe --- drivers/block/cciss.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c index 9c9627e8e334..cf6083a1f928 100644 --- a/drivers/block/cciss.c +++ b/drivers/block/cciss.c @@ -1349,6 +1349,10 @@ static void cciss_update_drive_info(int ctlr, int drv_index) spin_lock_irqsave(CCISS_LOCK(h->ctlr), flags); h->drv[drv_index].busy_configuring = 1; spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags); + + /* deregister_disk sets h->drv[drv_index].queue = NULL */ + /* which keeps the interrupt handler from starting */ + /* the queue. */ ret = deregister_disk(h->gendisk[drv_index], &h->drv[drv_index], 0); h->drv[drv_index].busy_configuring = 0; @@ -1419,6 +1423,10 @@ static void cciss_update_drive_info(int ctlr, int drv_index) blk_queue_hardsect_size(disk->queue, hba[ctlr]->drv[drv_index].block_size); + /* Make sure all queue data is written out before */ + /* setting h->drv[drv_index].queue, as setting this */ + /* allows the interrupt handler to start the queue */ + wmb(); h->drv[drv_index].queue = disk->queue; add_disk(disk); } @@ -3520,10 +3528,17 @@ static int __devinit cciss_init_one(struct pci_dev *pdev, continue; blk_queue_hardsect_size(q, drv->block_size); set_capacity(disk, drv->nr_blocks); - add_disk(disk); j++; } while (j <= hba[i]->highest_lun); + /* Make sure all queue data is written out before */ + /* interrupt handler, triggered by add_disk, */ + /* is allowed to start them. */ + wmb(); + + for (j = 0; j <= hba[i]->highest_lun; j++) + add_disk(hba[i]->gendisk[j]); + return 1; clean4: