On 27.03.25 18:22, Zi Yan wrote:
On Thu Mar 27, 2025 at 12:52 PM EDT, Matthew Wilcox wrote:
On Thu, Mar 27, 2025 at 11:04:57AM -0400, Zi Yan wrote:
On Fri Mar 7, 2025 at 8:54 AM EST, Matthew Wilcox (Oracle) wrote:
The writepage callback is going away; filesystems must implement
migrate_folio or else dirty folios will not be migratable.
What is the impact of this? Are there any filesystem that has
a_ops->writepage() without migrate_folio()? I wonder if it could make
the un-migratable problem worse[1] when such FS exists.
As Christoph and I have been going through filesystems removing their
->writepage operations, we've been careful to add ->migrate_folio
callbacks at the same time. But we haven't fixed any out-of-tree
filesystems, and we can't fix the filesystems which will be written in
the future.
So maybe what we should do is WARN_ON_ONCE() for filesystems which
have a ->writepages, but do not have a ->migrate_folio()?
Sounds good to me.
Agreed, that will also make it clear what our expectation towards
filesystems is.
--
Cheers,
David / dhildenb
