On 01.02.2023 21:22, Nikolay Borisov wrote:
blk_cbt_update_size uses spin_lock_irq to lock the cbt while pages are
being copied and the new cbt is published at q->cbt. This lock is used
to synchronize against blk_cbt_release, which can be called within
softirq context. This function requires unlocking be done with
spin_unlock_irq so that interrupts are properly reenabled. Without
this fix the core on which blk_cbt_update_size run would end up with
interrupts being disabled.
Reviewed-by: Pavel Tikhomirov <ptikhomi...@virtuozzo.com>
Fixes: e69ca16f4135 ("cbt: introduce changed block tracking")
Reported-by: Pavel Tikhomirov <ptikhomi...@virtuozzo.com>
Signed-off-by: Nikolay Borisov <nikolay.bori...@virtuozzo.com>
---
block/blk-cbt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-cbt.c b/block/blk-cbt.c
index 32485c793484..083ed5785031 100644
--- a/block/blk-cbt.c
+++ b/block/blk-cbt.c
@@ -607,7 +607,7 @@ void blk_cbt_update_size(struct block_device *bdev)
}
rcu_assign_pointer(q->cbt, new);
in_use = cbt->count;
- spin_unlock(&cbt->lock);
+ spin_unlock_irq(&cbt->lock);
if (!in_use)
call_rcu(&cbt->rcu, &cbt_release_callback);
err_mtx:
--
Best regards, Tikhomirov Pavel
Software Developer, Virtuozzo.
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