Commit e14ac670 authored by scameron@beardog.cca.cpqcorp.net's avatar scameron@beardog.cca.cpqcorp.net Committed by Jens Axboe
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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: default avatarStephen M. Cameron <scameron@beardog.cca.cpqcorp.net>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent f18573ab

drivers/block/cciss.c

+16 −1
Original line number Diff line number Diff line
@@ -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: