Re: [Cluster-devel] [PATCH] gfs2: Add check for mempool_alloc

[Christoph Hellwig]

On Fri, Apr 01, 2022 at 11:37:55AM +0800, Jiasheng Jiang wrote:
> >> Fixes: e8c92ed76900 ("GFS2: Clean up log write code path")
> >> Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
> > 
> > Please explain how it could fail to start with.
> 
> I think that for safety, the cost of redundant and harmless
> check is acceptable.
> Also, checking after allocation is a good program pattern.
> Therefore, it should be better to check it although it is
> hard to fail.

Please take a look at the implemetation and documentation of
mempool_alloc again.  Thewhole point of that function is that it will
not fail for allocations that can sleep.