diff options
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index d4347ae337fb..14afb5b67dd4 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5560,17 +5560,15 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, } /* - * We can not race with truncation due to holding i_mmap_rwsem. - * i_size is modified when holding i_mmap_rwsem, so check here - * once for faults beyond end of file. + * Use page lock to guard against racing truncation + * before we get page_table_lock. */ - size = i_size_read(mapping->host) >> huge_page_shift(h); - if (idx >= size) - goto out; - new_page = false; page = find_lock_page(mapping, idx); if (!page) { + size = i_size_read(mapping->host) >> huge_page_shift(h); + if (idx >= size) + goto out; /* Check for page in userfault range */ if (userfaultfd_missing(vma)) { ret = hugetlb_handle_userfault(vma, mapping, idx, @@ -5666,6 +5664,10 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, } ptl = huge_pte_lock(h, mm, ptep); + size = i_size_read(mapping->host) >> huge_page_shift(h); + if (idx >= size) + goto backout; + ret = 0; /* If pte changed from under us, retry */ if (!pte_same(huge_ptep_get(ptep), old_pte)) @@ -5774,10 +5776,8 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, /* * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold - * until finished with ptep. This serves two purposes: - * 1) It prevents huge_pmd_unshare from being called elsewhere - * and making the ptep no longer valid. - * 2) It synchronizes us with i_size modifications during truncation. + * until finished with ptep. This prevents huge_pmd_unshare from + * being called elsewhere and making the ptep no longer valid. * * ptep could have already be assigned via huge_pte_offset. That * is OK, as huge_pte_alloc will return the same value unless |