Re: [PATCH 05/23] MM: reclaim mustn't enter FS for SWP_FS_OPS swap-space

[Christoph Hellwig]

On Mon, Jan 24, 2022 at 02:48:32PM +1100, NeilBrown wrote:
> If swap-out is using filesystem operations (SWP_FS_OPS), then it is not
> safe to enter the FS for reclaim.
> So only down-grade the requirement for swap pages to __GFP_IO after
> checking that SWP_FS_OPS are not being used.
> 
> This makes the calculation of "may_enter_fs" slightly more complex, so
> move it into a separate function.  with that done, there is little value
> in maintaining the bool variable any more.  So replace the
> may_enter_fs variable with a may_enter_fs() function.  This removes any
> risk for the variable becoming out-of-date.

Looks good,

Reviewed-by: Christoph Hellwig <hch@xxxxxx>