Re: [PATCH v3 13/13] mm/huge_memory: add and use has_deposited_pgtable()

["Lorenzo Stoakes (Oracle)" <ljs@kernel.org>]

Hi Andrew,

Could you apply the below fix-patch to resolve an issue with us performing
folio_put() on a folio before checking it again to see if a table was
deposited, as per Sashiko.

This patch resolves the issue by storing whether or not this is the case in
a has_deposit local variable (as used previously) before invoking
zap_huge_pmd_folio(), then using this boolean to determine whether or not
to zap any deposited table.

Thanks, Lorenzo

----8<----
From 009f8abba834b49f8285b03a680dbd04d953a528 Mon Sep 17 00:00:00 2001
From: "Lorenzo Stoakes (Oracle)" <ljs@kernel.org>
Date: Mon, 23 Mar 2026 11:42:01 +0000
Subject: [PATCH] fix

Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
---
 mm/huge_memory.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 610a6184e92c..4585465eda0c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2397,6 +2397,7 @@ bool zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 	struct mm_struct *mm = tlb->mm;
 	struct folio *folio = NULL;
 	bool is_present = false;
+	bool has_deposit;
 	spinlock_t *ptl;
 	pmd_t orig_pmd;

@@ -2420,8 +2421,8 @@ bool zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 	folio = normal_or_softleaf_folio_pmd(vma, addr, orig_pmd, is_present);
 	if (folio)
 		zap_huge_pmd_folio(mm, vma, orig_pmd, folio, is_present);
-
-	if (has_deposited_pgtable(vma, orig_pmd, folio))
+	has_deposit = has_deposited_pgtable(vma, orig_pmd, folio);
+	if (has_deposit)
 		zap_deposited_table(mm, pmd);

 	spin_unlock(ptl);
--
2.53.0