Re: [PATCH] __set_page_dirty uses spin_lock_irqsave instead ofspin_lock_irq

[David Rientjes]

On Tue, 4 Feb 2014, kosaki.motohiro@xxxxxxxxx wrote:

> From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> 
> To use spin_{un}lock_irq is dangerous if caller disabled interrupt.
> During aio buffer migration, we have a possibility to see the
> following call stack.
> 
> aio_migratepage  [disable interrupt]
>   migrate_page_copy
>     clear_page_dirty_for_io
>       set_page_dirty
>         __set_page_dirty_buffers
>           __set_page_dirty
>             spin_lock_irq
> 
> This mean, current aio migration is a deadlockable. spin_lock_irqsave
> is a safer alternative and we should use it.
> 
> Reported-by: David Rientjes rientjes@xxxxxxxxxx>
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx

Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
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