if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) ==
(FOLL_PIN | FOLL_GET)))
return ERR_PTR(-EINVAL);
-retry:
if (unlikely(pmd_bad(*pmd)))
return no_page_table(vma, flags);
ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
pte = *ptep;
- if (!pte_present(pte)) {
- swp_entry_t entry;
- /*
- * KSM's break_ksm() relies upon recognizing a ksm page
- * even while it is being migrated, so for that case we
- * need migration_entry_wait().
- */
- if (likely(!(flags & FOLL_MIGRATION)))
- goto no_page;
- if (pte_none(pte))
- goto no_page;
- entry = pte_to_swp_entry(pte);
- if (!is_migration_entry(entry))
- goto no_page;
- pte_unmap_unlock(ptep, ptl);
- migration_entry_wait(mm, pmd, address);
- goto retry;
- }
+ if (!pte_present(pte))
+ goto no_page;
if (pte_protnone(pte) && !gup_can_follow_protnone(flags))
goto no_page;
pmdval = READ_ONCE(*pmd);
if (pmd_none(pmdval))
return no_page_table(vma, flags);
-retry:
- if (!pmd_present(pmdval)) {
- /*
- * Should never reach here, if thp migration is not supported;
- * Otherwise, it must be a thp migration entry.
- */
- VM_BUG_ON(!thp_migration_supported() ||
- !is_pmd_migration_entry(pmdval));
-
- if (likely(!(flags & FOLL_MIGRATION)))
- return no_page_table(vma, flags);
-
- pmd_migration_entry_wait(mm, pmd);
- pmdval = READ_ONCE(*pmd);
- /*
- * MADV_DONTNEED may convert the pmd to null because
- * mmap_lock is held in read mode
- */
- if (pmd_none(pmdval))
- return no_page_table(vma, flags);
- goto retry;
- }
+ if (!pmd_present(pmdval))
+ return no_page_table(vma, flags);
if (pmd_devmap(pmdval)) {
ptl = pmd_lock(mm, pmd);
page = follow_devmap_pmd(vma, address, pmd, flags, &ctx->pgmap);
if (pmd_protnone(pmdval) && !gup_can_follow_protnone(flags))
return no_page_table(vma, flags);
-retry_locked:
ptl = pmd_lock(mm, pmd);
- if (unlikely(pmd_none(*pmd))) {
- spin_unlock(ptl);
- return no_page_table(vma, flags);
- }
if (unlikely(!pmd_present(*pmd))) {
spin_unlock(ptl);
- if (likely(!(flags & FOLL_MIGRATION)))
- return no_page_table(vma, flags);
- pmd_migration_entry_wait(mm, pmd);
- goto retry_locked;
+ return no_page_table(vma, flags);
}
if (unlikely(!pmd_trans_huge(*pmd))) {
spin_unlock(ptl);