On 10 Nov 2025, at 16:16, Lorenzo Stoakes wrote: > OK ignore the past mail, I have managed to repro this locally and have a > fix. > > Turns out the swap code is doing something quite insane... I will send > fix-patches to the series shortly. > > Meanwhile I attach fix-patch! :) > > Cheers, Lorenzo > > ----8<---- > From c705fd85a806f53017df31e6b072c4bfa839e3a2 Mon Sep 17 00:00:00 2001 > From: Lorenzo Stoakes <[email protected]> > Date: Mon, 10 Nov 2025 21:11:52 +0000 > Subject: [PATCH] fix > > Signed-off-by: Lorenzo Stoakes <[email protected]> > --- > include/linux/leafops.h | 4 ++-- > mm/swapfile.c | 12 ++++++++++-- > 2 files changed, 12 insertions(+), 4 deletions(-) > > diff --git a/include/linux/leafops.h b/include/linux/leafops.h > index a464a7e08c76..c4cd36760ea0 100644 > --- a/include/linux/leafops.h > +++ b/include/linux/leafops.h > @@ -56,7 +56,7 @@ static inline softleaf_t softleaf_from_pte(pte_t pte) > { > softleaf_t arch_entry; > > - if (pte_present(pte)) > + if (pte_present(pte) || pte_none(pte)) > return softleaf_mk_none(); > > pte = pte_swp_clear_flags(pte); > @@ -95,7 +95,7 @@ static inline softleaf_t softleaf_from_pmd(pmd_t pmd) > { > softleaf_t arch_entry; > > - if (pmd_present(pmd)) > + if (pmd_present(pmd) || pmd_none(pmd)) > return softleaf_mk_none(); > > if (pmd_swp_soft_dirty(pmd)) > diff --git a/mm/swapfile.c b/mm/swapfile.c > index fd23d9f7ae10..f0dcf261f652 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -3202,9 +3202,17 @@ static int claim_swapfile(struct swap_info_struct *si, > struct inode *inode) > */ > unsigned long generic_max_swapfile_size(void) > { > - const softleaf_t entry = swp_entry(0, ~0UL); > + softleaf_t entry = swp_entry(0, ~0UL); > + const pte_t pte = softleaf_to_pte(entry); > > - return swp_offset(softleaf_from_pte(softleaf_to_pte(entry))) + 1; > + /* > + * Since the PTE can be an invalid swap entry (i.e. the none PTE), we do
So softleaf_from_pte() returns softleaf_mk_none() instead and causes the issue? > + * this manually. > + */ This comment is not aligned, in case you plan to send this patch as is. :) > + entry = __pte_to_swp_entry(pte); > + entry = swp_entry(__swp_type(entry), __swp_offset(entry)); > + > + return swp_offset(entry) + 1; > } > > /* Can be overridden by an architecture for additional checks. */ > -- > 2.51.0 This fix looks good to me. Thanks. Best Regards, Yan, Zi
