diff options
| -rw-r--r-- | mm/hugetlb.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 9519f3f6c1da..c03273807182 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2324,11 +2324,8 @@ retry_avoidcopy: * and just make the page writable */ avoidcopy = (page_mapcount(old_page) == 1); if (avoidcopy) { - if (!trylock_page(old_page)) { - if (PageAnon(old_page)) - page_move_anon_rmap(old_page, vma, address); - } else - unlock_page(old_page); + if (PageAnon(old_page)) + page_move_anon_rmap(old_page, vma, address); set_huge_ptep_writable(vma, address, ptep); return 0; } @@ -2631,10 +2628,16 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, vma, address); } - if (!pagecache_page) { - page = pte_page(entry); + /* + * hugetlb_cow() requires page locks of pte_page(entry) and + * pagecache_page, so here we need take the former one + * when page != pagecache_page or !pagecache_page. + * Note that locking order is always pagecache_page -> page, + * so no worry about deadlock. + */ + page = pte_page(entry); + if (page != pagecache_page) lock_page(page); - } spin_lock(&mm->page_table_lock); /* Check for a racing update before calling hugetlb_cow */ @@ -2661,9 +2664,8 @@ out_page_table_lock: if (pagecache_page) { unlock_page(pagecache_page); put_page(pagecache_page); - } else { - unlock_page(page); } + unlock_page(page); out_mutex: mutex_unlock(&hugetlb_instantiation_mutex); |