diff options
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 26 |
1 files changed, 10 insertions, 16 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 1b84945d655c..08c56aaf72eb 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -28,12 +28,12 @@ * hugetlb_fault_mutex (hugetlbfs specific page fault mutex) * anon_vma->rwsem * mm->page_table_lock or pte_lock - * pgdat->lru_lock (in mark_page_accessed, isolate_lru_page) * swap_lock (in swap_duplicate, swap_info_get) * mmlist_lock (in mmput, drain_mmlist and others) * mapping->private_lock (in __set_page_dirty_buffers) - * mem_cgroup_{begin,end}_page_stat (memcg->move_lock) + * lock_page_memcg move_lock (in __set_page_dirty_buffers) * i_pages lock (widely used) + * lruvec->lru_lock (in lock_page_lruvec_irq) * inode->i_lock (in set_page_dirty's __mark_inode_dirty) * bdi.wb->list_lock (in set_page_dirty's __mark_inode_dirty) * sb_lock (within inode_lock in fs/fs-writeback.c) @@ -1054,8 +1054,14 @@ static void __page_set_anon_rmap(struct page *page, if (!exclusive) anon_vma = anon_vma->root; + /* + * page_idle does a lockless/optimistic rmap scan on page->mapping. + * Make sure the compiler doesn't split the stores of anon_vma and + * the PAGE_MAPPING_ANON type identifier, otherwise the rmap code + * could mistake the mapping for a struct address_space and crash. + */ anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON; - page->mapping = (struct address_space *) anon_vma; + WRITE_ONCE(page->mapping, (struct address_space *) anon_vma); page->index = linear_page_index(vma, address); } @@ -1413,9 +1419,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, /* * If sharing is possible, start and end will be adjusted * accordingly. - * - * If called for a huge page, caller must hold i_mmap_rwsem - * in write mode as it is possible to call huge_pmd_unshare. */ adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); @@ -1462,7 +1465,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, subpage = page - page_to_pfn(page) + pte_pfn(*pvmw.pte); address = pvmw.address; - if (PageHuge(page)) { + if (PageHuge(page) && !PageAnon(page)) { /* * To call huge_pmd_unshare, i_mmap_rwsem must be * held in write mode. Caller needs to explicitly @@ -1536,15 +1539,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, goto discard; } - if (!(flags & TTU_IGNORE_ACCESS)) { - if (ptep_clear_flush_young_notify(vma, address, - pvmw.pte)) { - ret = false; - page_vma_mapped_walk_done(&pvmw); - break; - } - } - /* Nuke the page table entry. */ flush_cache_page(vma, address, pte_pfn(*pvmw.pte)); if (should_defer_flush(mm, flags)) { |