On Thu, 10 Apr 2025, Jan Kara wrote:
I'd rather do:
if (atomic) {
spin_lock(&bd_mapping->i_private_lock);
folio_locked = false;
} else {
folio_lock(folio);
}
Fine with me. I just think the trylock for the atomic scenario would have
given greater chances of successful migration, but at a lack of determinism,
of course.
I'd actually love to do something like:
if (atomic) {
if (!folio_trylock(folio))
bail...
} else {
folio_lock(folio);
}
but that may be just too radical this point and would need some serious
testing how frequent the trylock failures are. No point in blocking this
series with it. So just go with the deterministic use of i_private_lock for
atomic users for now.
This acually crossed my mind, but I also considered the scheme a little
too much for this series.
