Messages in this thread Patch in this message |  | | Date | Thu, 15 May 2003 09:37:31 +0530 | From | Bharata B Rao <> | Subject | Re: 2.5.69-mjb1: undefined reference to `blk_queue_empty' |
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On Wed, May 14, 2003 at 10:32:24AM +0200, Jens Axboe wrote: > > That really has to be locked down as well. For your purpose, I think the > use of elv_queue_empty() is much better even though it really is an > internal function. The problem mainly comes from AS, that can have non > empty queue but still return NULL in elv_next_request(). > > But yes, it needs to be locked. If you have pinned the other CPUs, then > I suppose it should work. But it's still a violation of the locking > rules, and one would get in trouble dropping the queue lock from the io > scheduler elevator_queue_empty_fn. No one does that currently, but... So > please take the lock. >
Ok, Now we try to acquire the lock and refuse to dump if we don't get the lock.
--- 2569+mjb1/drivers/dump/dump_blockdev.c.orig Wed May 14 13:23:36 2003 +++ 2569+mjb1/drivers/dump/dump_blockdev.c Thu May 15 09:26:12 2003 @@ -258,10 +258,19 @@ dump_block_silence(struct dump_dev *dev) { struct dump_blockdev *dump_bdev = DUMP_BDEV(dev); + struct request_queue *q = bdev_get_queue(dump_bdev->bdev); + int ret; + + /* If we can't get request queue lock, refuse to take the dump */ + if (!spin_trylock(q->queue_lock)) + return -EBUSY; + + ret = elv_queue_empty(q); + spin_unlock(q->queue_lock); /* For now we assume we have the device to ourselves */ /* Just a quick sanity check */ - if (!blk_queue_empty(bdev_get_queue(dump_bdev->bdev))) { + if (!ret) { /* i/o in flight - safer to quit */ return -EBUSY; } Regards, Bharata. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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