Re: [PATCH v5 15/17] dax: add struct iomap based DAX PMD support

From: Ross Zwisler
Date: Mon Oct 10 2016 - 18:06:26 EST


On Mon, Oct 10, 2016 at 05:59:17PM +0200, Christoph Hellwig wrote:
> On Fri, Oct 07, 2016 at 03:09:02PM -0600, Ross Zwisler wrote:
> > - if (RADIX_DAX_TYPE(entry) == RADIX_DAX_PMD)
> > + if ((unsigned long)entry & RADIX_DAX_PMD)
>
> Please introduce a proper inline helper that mask all the possible type
> bits out of the radix tree entry, and use them wherever you do the
> open cast.

Sure, will do.

> > restart:
> > spin_lock_irq(&mapping->tree_lock);
> > entry = get_unlocked_mapping_entry(mapping, index, &slot);
> > +
> > + if (entry) {
> > + if (size_flag & RADIX_DAX_PMD) {
> > + if (!radix_tree_exceptional_entry(entry) ||
> > + !((unsigned long)entry & RADIX_DAX_PMD)) {
> > + entry = ERR_PTR(-EEXIST);
> > + goto out_unlock;
> > + }
> > + } else { /* trying to grab a PTE entry */
> > + if (radix_tree_exceptional_entry(entry) &&
> > + ((unsigned long)entry & RADIX_DAX_PMD) &&
> > + ((unsigned long)entry &
> > + (RADIX_DAX_HZP|RADIX_DAX_EMPTY))) {
>
> And when we do these cases N times next to each other we should
> have a local variable the valid flag bits of entry.

Okay, will fix.