On Sat, May 30, 2026 at 04:50:35PM +0000, John Groves wrote: > From: John Groves <[email protected]> > > The comment in dax_folio_reset_order() claims that DAX maintains an > invariant where folio->share != 0 only when folio->mapping == NULL, > implying folio->share is zero whenever mapping is non-NULL. This is > misleading because folio->share and folio->index are a union -- for > non-shared folios with mapping != NULL, reading folio->share returns > the file page offset (folio->index), which is typically non-zero. > > Reword the comment to accurately describe the union aliasing: the > assignment clears whichever interpretation of the union word is active > (index for non-shared folios, share for shared folios), which is correct > because the folio is being released in either case. > > No functional change -- the code was already correct, only the > justification was wrong. > > Fixes: 59eb73b98ae0b ("dax: Factor out dax_folio_reset_order() helper") > > Reviewed-by: Jonathan Cameron <[email protected]> > Signed-off-by: John Groves <[email protected]>
Reviewed-by: Alison Schofield <[email protected]>
