diff options
Diffstat (limited to 'mm/page_vma_mapped.c')
| -rw-r--r-- | mm/page_vma_mapped.c | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index ae5cc42aa208..81839a9e74f1 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -13,7 +13,8 @@ static inline bool not_found(struct page_vma_mapped_walk *pvmw) return false; } -static bool map_pte(struct page_vma_mapped_walk *pvmw, spinlock_t **ptlp) +static bool map_pte(struct page_vma_mapped_walk *pvmw, pmd_t *pmdvalp, + spinlock_t **ptlp) { pte_t ptent; @@ -25,6 +26,7 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw, spinlock_t **ptlp) return !!pvmw->pte; } +again: /* * It is important to return the ptl corresponding to pte, * in case *pvmw->pmd changes underneath us; so we need to @@ -32,8 +34,8 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw, spinlock_t **ptlp) * proceeds to loop over next ptes, and finds a match later. * Though, in most cases, page lock already protects this. */ - pvmw->pte = pte_offset_map_nolock(pvmw->vma->vm_mm, pvmw->pmd, - pvmw->address, ptlp); + pvmw->pte = pte_offset_map_rw_nolock(pvmw->vma->vm_mm, pvmw->pmd, + pvmw->address, pmdvalp, ptlp); if (!pvmw->pte) return false; @@ -67,8 +69,13 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw, spinlock_t **ptlp) } else if (!pte_present(ptent)) { return false; } + spin_lock(*ptlp); + if (unlikely(!pmd_same(*pmdvalp, pmdp_get_lockless(pvmw->pmd)))) { + pte_unmap_unlock(pvmw->pte, *ptlp); + goto again; + } pvmw->ptl = *ptlp; - spin_lock(pvmw->ptl); + return true; } @@ -278,7 +285,7 @@ restart: step_forward(pvmw, PMD_SIZE); continue; } - if (!map_pte(pvmw, &ptl)) { + if (!map_pte(pvmw, &pmde, &ptl)) { if (!pvmw->pte) goto restart; goto next_pte; @@ -305,8 +312,13 @@ next_pte: } while (pte_none(ptep_get(pvmw->pte))); if (!pvmw->ptl) { + spin_lock(ptl); + if (unlikely(!pmd_same(pmde, pmdp_get_lockless(pvmw->pmd)))) { + pte_unmap_unlock(pvmw->pte, ptl); + pvmw->pte = NULL; + goto restart; + } pvmw->ptl = ptl; - spin_lock(pvmw->ptl); } goto this_pte; } while (pvmw->address < end); @@ -325,10 +337,10 @@ next_pte: * outside the VMA or not present, returns -EFAULT. * Only valid for normal file or anonymous VMAs. */ -unsigned long page_mapped_in_vma(struct page *page, struct vm_area_struct *vma) +unsigned long page_mapped_in_vma(const struct page *page, + struct vm_area_struct *vma) { - struct folio *folio = page_folio(page); - pgoff_t pgoff = folio->index + folio_page_idx(folio, page); + const struct folio *folio = page_folio(page); struct page_vma_mapped_walk pvmw = { .pfn = page_to_pfn(page), .nr_pages = 1, @@ -336,7 +348,7 @@ unsigned long page_mapped_in_vma(struct page *page, struct vm_area_struct *vma) .flags = PVMW_SYNC, }; - pvmw.address = vma_address(vma, pgoff, 1); + pvmw.address = vma_address(vma, page_pgoff(folio, page), 1); if (pvmw.address == -EFAULT) goto out; if (!page_vma_mapped_walk(&pvmw)) |