Re: [stable] upstream 3d5fe03a3ea01 -stable backport request

[Sergey Senozhatsky]

On (01/25/16 21:46), Sergey Senozhatsky wrote:
> 
> Hello,
> 
> Please add upstream 'commit 3d5fe03a3ea01 ("zram/zcomp: use
> GFP_NOIO to allocate streams")' to stable releases.
> 

[v3.15+]

	-ss

> 
> :commit 3d5fe03a3ea013060ebba2a811aeb0f23f56aefa
> :Author: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> :
> :    zram/zcomp: use GFP_NOIO to allocate streams
> :    
> :    We can end up allocating a new compression stream with GFP_KERNEL from
> :    within the IO path, which may result is nested (recursive) IO
> :    operations.  That can introduce problems if the IO path in question is a
> :    reclaimer, holding some locks that will deadlock nested IOs.
> :    
> :    Allocate streams and working memory using GFP_NOIO flag, forbidding
> :    recursive IO and FS operations.
> 
> 
> 	-ss
>