Re: [PATCH V3] fuse: Remove __GFP_FS flag to avoid allocator recursing

[ppvk@codeaurora.org]

On 2020-09-24 20:26, ppvk@codeaurora.org wrote:
> On 2020-09-23 18:19, Matthew Wilcox wrote:
>> On Wed, Sep 23, 2020 at 11:27:55AM +0530, Pradeep P V K wrote:
>>> Changes since V2:
>>> - updated memalloc_nofs_save() to allocation paths that potentially
>>>   can cause deadlock.
>> 
>> That's the exact opposite of what I said to do.  Again, the *THREAD*
>> is the thing which must not block, not the *ALLOCATION*.  So you
>> set this flag *ON THE THREAD*, not *WHEN IT DOES AN ALLOCATION*.
>> If that's not clear, please ask again.
> 
> The fuse threads are created and started in external libfuse userspace
> library functions but not in Kernel. The lowest entry point for these 
> threads
> to enter in kernel is fuse_dev_read()/fuse_dev_splice_read().
> 
> So, can we suppose to use memalloc_nofs_save() from
> external userspace library functions ?
> 
> Even if we used, can you confirm, if the context of 
> memalloc_nofs_save()
> can be persist in kernel ?  (when the thread enters into kernel space).
> 
> Also, i didn't see memalloc_nofs_save() been used/called from any
> external userspace library functions.
> 
> 
> Thanks and Regards,
> Pradeep

Friendly Reminder !!