Re: [PATCH 1/4] ceph: add ceph_folio_snap_context()

[Tal Zussman]

On 8/2/26 6:44 PM, Zi Yan wrote:
> On Sun Aug 2, 2026 at 5:52 PM EDT, Matthew Wilcox wrote:
>> On Sun, Aug 02, 2026 at 12:50:02PM -0400, Tal Zussman wrote:
>>> +static inline struct ceph_snap_context *ceph_folio_snap_context(struct folio *folio)
>>> +{
>>> +	if (folio_test_private(folio))
>>> +		return (void *)folio->private;
>>> +	return NULL;
>>> +}
>>
>> Filesystem folios _ought_to have folio->private as NULL when PG_private
>> is unset and PG_private set when folio->private is non-NULL.  Now, ceph
>> could be doing something Bad (I believe hugetlbfs does not honour this
>> for various reasons), but it looks like it's using
>> folio_attach_private() / folio_detach_private() appropriately.
>>
>> So I think we should just do:
>>
>> static inline
>> struct ceph_snap_context *ceph_folio_snap_context(const struct folio *folio)
>> {
>> 	return folio->private;
>> }
> 
> Yes, please. So I do not need to handle another exceptional user when I
> am trying to remove PG_private[1].
> 

Sounds good, will do.