Re: 2.6.19-rc3-git7: scsi_device_unbusy: inconsistent lock state

From: Mark Lord
Date: Mon Oct 30 2006 - 12:55:09 EST


Jens Axboe wrote:
I looked over them, and cfq_cic_link() should use _irqsave() instead of
_irq() if called without __GFP_WAIT set. That doesn't happen in the
normal io path though, so I'm not sure that is it.

So if the bug is using spin_lock_irq() with interrupts already disabled,
iirc that would trigger a different warning...
..

This seems 100% reproduceable here, so if there's any specific instrumentation
that might be useful, just let me know. Meanwhile I'll try Jen's patch (below).

-ml


diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4bae64e..da9bddf 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1355,6 +1355,7 @@ cfq_cic_link(struct cfq_data *cfqd, stru
struct rb_node **p;
struct rb_node *parent;
struct cfq_io_context *__cic;
+ unsigned long flags;
void *k;
cic->ioc = ioc;
@@ -1384,9 +1385,9 @@ restart:
rb_link_node(&cic->rb_node, parent, p);
rb_insert_color(&cic->rb_node, &ioc->cic_root);
- spin_lock_irq(cfqd->queue->queue_lock);
+ spin_lock_irqsave(cfqd->queue->queue_lock, flags);
list_add(&cic->queue_list, &cfqd->cic_list);
- spin_unlock_irq(cfqd->queue->queue_lock);
+ spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
}
-
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