Re: [PATCH 06/12] xfs: remove XFS_TRANS_NOFS

[Christoph Hellwig]

On Tue, Jun 25, 2019 at 08:59:04AM +1000, Dave Chinner wrote:
> On Mon, Jun 24, 2019 at 07:52:47AM +0200, Christoph Hellwig wrote:
> > Instead of a magic flag for xfs_trans_alloc, just ensure all callers
> > that can't relclaim through the file system use memalloc_nofs_save to
> > set the per-task nofs flag.
> 
> I'm thinking that it would be a good idea to add comments to explain
> exactly what the memalloc_nofs_save/restore() are protecting where
> they are used. Right now the XFS_TRANS_NOFS flag is largely
> undocumented, so a reader is left guessing as to why the flag is
> necessary and what contexts it may apply to. Hence I think we should
> fix that while we are changing over to a different GFP_NOFS
> allocation context mechanism....

Sure.