[PATCH 4.19 16/34] mm: page_vma_mapped_walk(): add a level of indentation

Greg Kroah-Hartman
2021-07-09T13:21:43Z

From: Hugh Dickins <hughd@google.com>

[ Upstream commit b3807a91aca7d21c05d5790612e49969117a72b9 ]

page_vma_mapped_walk() cleanup: add a level of indentation to much of
the body, making no functional change in this commit, but reducing the
later diff when this is all converted to a loop.

[hughd@google.com: : page_vma_mapped_walk(): add a level of indentation fix]
Link: https://lkml.kernel.org/r/7f817555-3ce1-c785-e438-87d8efdcaf26@google.com

Link: https://lkml.kernel.org/r/efde211-f3e2-fe54-977-ef481419e7f3@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/page_vma_mapped.c | 105 ++++++++++++++++++++++---------------------
1 file changed, 55 insertions(+), 50 deletions(-)

diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 1fccadd0eb6d..819945678264 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -169,62 +169,67 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
if (pvmw->pte)
goto next_pte;
restart:
- pgd = pgd_offset(mm, pvmw->address);
- if (!pgd_present(*pgd))
- return false;
- p4d = p4d_offset(pgd, pvmw->address);
- if (!p4d_present(*p4d))
- return false;
- pud = pud_offset(p4d, pvmw->address);
- if (!pud_present(*pud))
- return false;
- pvmw->pmd = pmd_offset(pud, pvmw->address);
- /*
- * Make sure the pmd value isn't cached in a register by the
- * compiler and used as a stale value after we've observed a
- * subsequent update.
- */
- pmde = READ_ONCE(*pvmw->pmd);
- if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) {
- pvmw->ptl = pmd_lock(mm, pvmw->pmd);
- pmde = *pvmw->pmd;
- if (likely(pmd_trans_huge(pmde))) {
- if (pvmw->flags & PVMW_MIGRATION)
- return not_found(pvmw);
- if (pmd_page(pmde) != page)
- return not_found(pvmw);
- return true;
- }
- if (!pmd_present(pmde)) {
- swp_entry_t entry;
+ {
+ pgd = pgd_offset(mm, pvmw->address);
+ if (!pgd_present(*pgd))
+ return false;
+ p4d = p4d_offset(pgd, pvmw->address);
+ if (!p4d_present(*p4d))
+ return false;
+ pud = pud_offset(p4d, pvmw->address);
+ if (!pud_present(*pud))
+ return false;

- if (!thp_migration_supported() ||
- !(pvmw->flags & PVMW_MIGRATION))
- return not_found(pvmw);
- entry = pmd_to_swp_entry(pmde);
- if (!is_migration_entry(entry) ||
- migration_entry_to_page(entry) != page)
- return not_found(pvmw);
- return true;
- }
- /* THP pmd was split under us: handle on pte level */
- spin_unlock(pvmw->ptl);
- pvmw->ptl = NULL;
- } else if (!pmd_present(pmde)) {
+ pvmw->pmd = pmd_offset(pud, pvmw->address);
/*
- * If PVMW_SYNC, take and drop THP pmd lock so that we
- * cannot return prematurely, while zap_huge_pmd() has
- * cleared *pmd but not decremented compound_mapcount().
+ * Make sure the pmd value isn't cached in a register by the
+ * compiler and used as a stale value after we've observed a
+ * subsequent update.
*/
- if ((pvmw->flags & PVMW_SYNC) && PageTransCompound(page)) {
- spinlock_t *ptl = pmd_lock(mm, pvmw->pmd);
+ pmde = READ_ONCE(*pvmw->pmd);

- spin_unlock(ptl);
+ if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) {
+ pvmw->ptl = pmd_lock(mm, pvmw->pmd);
+ pmde = *pvmw->pmd;
+ if (likely(pmd_trans_huge(pmde))) {
+ if (pvmw->flags & PVMW_MIGRATION)
+ return not_found(pvmw);
+ if (pmd_page(pmde) != page)
+ return not_found(pvmw);
+ return true;
+ }
+ if (!pmd_present(pmde)) {
+ swp_entry_t entry;
+
+ if (!thp_migration_supported() ||
+ !(pvmw->flags & PVMW_MIGRATION))
+ return not_found(pvmw);
+ entry = pmd_to_swp_entry(pmde);
+ if (!is_migration_entry(entry) ||
+ migration_entry_to_page(entry) != page)
+ return not_found(pvmw);
+ return true;
+ }
+ /* THP pmd was split under us: handle on pte level */
+ spin_unlock(pvmw->ptl);
+ pvmw->ptl = NULL;
+ } else if (!pmd_present(pmde)) {
+ /*
+ * If PVMW_SYNC, take and drop THP pmd lock so that we
+ * cannot return prematurely, while zap_huge_pmd() has
+ * cleared *pmd but not decremented compound_mapcount().
+ */
+ if ((pvmw->flags & PVMW_SYNC) &&
+ PageTransCompound(page)) {
+ spinlock_t *ptl = pmd_lock(mm, pvmw->pmd);
+
+ spin_unlock(ptl);
+ }
+ return false;
}
- return false;
+ if (!map_pte(pvmw))
+ goto next_pte;
}
- if (!map_pte(pvmw))
- goto next_pte;
while (1) {
unsigned long end;

--
2.30.2