blk_cbt_release() can be called both from soft irq and from
non-interrupt context, so spin_lock should be used with irqsave.
Example of the call from softirq context (taken from google):
blk_release_queue
kobject_cleanup
kobject_put
blk_put_queue
blkg_free
__blkg_release
rcu_do_batch
rcu_core
rcu_core_si
__do_softirq
blk_cbt_release() is called by the blk_release_queue()
which is the .release() callback of struct kobj_type.
Example of the call from non-irq context:
blk_cbt_release
cbt_ioc_stop (even mutex is taken there => non-irq context)
blk_cbt_ioctl
blkdev_ioctl
block_ioctl
Fixes: acdc18e4d1aa ("cbt: introduce changed block tracking")
Signed-off-by: Konstantin Khorenko <khore...@virtuozzo.com>
---
block/blk-cbt.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/block/blk-cbt.c b/block/blk-cbt.c
index a6e1558835f1..432697f009dc 100644
--- a/block/blk-cbt.c
+++ b/block/blk-cbt.c
@@ -524,15 +524,16 @@ void blk_cbt_release(struct request_queue *q)
{
struct cbt_info *cbt;
int in_use = 0;
+ unsigned long flags;
cbt = q->cbt;
if (!cbt)
return;
- spin_lock(&cbt->lock);
+ spin_lock_irqsave(&cbt->lock, flags);
set_bit(CBT_DEAD, &cbt->flags);
rcu_assign_pointer(q->cbt, NULL);
in_use = cbt->count;
- spin_unlock(&cbt->lock);
+ spin_unlock_irqrestore(&cbt->lock, flags);
if (!in_use)
call_rcu(&cbt->rcu, &cbt_release_callback);
}
--
2.24.3
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