diff options
| -rw-r--r-- | mm/hugetlb.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index dfc940d5221d..8ea35ba6699f 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2476,7 +2476,7 @@ void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, if (!rc) { /* * This indicates there is an entry in the reserve map - * added by alloc_huge_page. We know it was added + * not added by alloc_huge_page. We know it was added * before the alloc_huge_page call, otherwise * HPageRestoreReserve would be set on the page. * Remove the entry so that a subsequent allocation @@ -4660,7 +4660,9 @@ retry_avoidcopy: spin_unlock(ptl); mmu_notifier_invalidate_range_end(&range); out_release_all: - restore_reserve_on_error(h, vma, haddr, new_page); + /* No restore in case of successful pagetable update (Break COW) */ + if (new_page != old_page) + restore_reserve_on_error(h, vma, haddr, new_page); put_page(new_page); out_release_old: put_page(old_page); @@ -4776,7 +4778,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, pte_t new_pte; spinlock_t *ptl; unsigned long haddr = address & huge_page_mask(h); - bool new_page = false; + bool new_page, new_pagecache_page = false; /* * Currently, we are forced to kill the process in the event the @@ -4799,6 +4801,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, goto out; retry: + new_page = false; page = find_lock_page(mapping, idx); if (!page) { /* Check for page in userfault range */ @@ -4842,6 +4845,7 @@ retry: goto retry; goto out; } + new_pagecache_page = true; } else { lock_page(page); if (unlikely(anon_vma_prepare(vma))) { @@ -4926,7 +4930,9 @@ backout: spin_unlock(ptl); backout_unlocked: unlock_page(page); - restore_reserve_on_error(h, vma, haddr, page); + /* restore reserve for newly allocated pages not in page cache */ + if (new_page && !new_pagecache_page) + restore_reserve_on_error(h, vma, haddr, page); put_page(page); goto out; } @@ -5135,6 +5141,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, int ret = -ENOMEM; struct page *page; int writable; + bool new_pagecache_page = false; if (is_continue) { ret = -EFAULT; @@ -5228,6 +5235,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, ret = huge_add_to_page_cache(page, mapping, idx); if (ret) goto out_release_nounlock; + new_pagecache_page = true; } ptl = huge_pte_lockptr(h, dst_mm, dst_pte); @@ -5291,7 +5299,8 @@ out_release_unlock: if (vm_shared || is_continue) unlock_page(page); out_release_nounlock: - restore_reserve_on_error(h, dst_vma, dst_addr, page); + if (!new_pagecache_page) + restore_reserve_on_error(h, dst_vma, dst_addr, page); put_page(page); goto out; } |