diff options
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/mm/util.c b/mm/util.c index 6cc81e7b8705..917e0e3d0f8e 100644 --- a/mm/util.c +++ b/mm/util.c @@ -297,7 +297,8 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr, ret = security_mmap_file(file, prot, flag); if (!ret) { - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff, &populate); up_write(&mm->mmap_sem); @@ -346,6 +347,29 @@ void *page_rmapping(struct page *page) return __page_rmapping(page); } +/* + * Return true if this page is mapped into pagetables. + * For compound page it returns true if any subpage of compound page is mapped. + */ +bool page_mapped(struct page *page) +{ + int i; + + if (likely(!PageCompound(page))) + return atomic_read(&page->_mapcount) >= 0; + page = compound_head(page); + if (atomic_read(compound_mapcount_ptr(page)) >= 0) + return true; + if (PageHuge(page)) + return false; + for (i = 0; i < hpage_nr_pages(page); i++) { + if (atomic_read(&page[i]._mapcount) >= 0) + return true; + } + return false; +} +EXPORT_SYMBOL(page_mapped); + struct anon_vma *page_anon_vma(struct page *page) { unsigned long mapping; |