Merge tag 'linux-kselftest-4.8-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kerne...

[cascardo/linux.git] / mm / util.c

diff --git a/mm/util.c b/mm/util.c
index 6cc81e7..662cddf 100644 (file)
--- 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;
@@ -375,10 +399,12 @@ struct address_space *page_mapping(struct page *page)
        }
 
        mapping = page->mapping;
-       if ((unsigned long)mapping & PAGE_MAPPING_FLAGS)
+       if ((unsigned long)mapping & PAGE_MAPPING_ANON)
                return NULL;
-       return mapping;
+
+       return (void *)((unsigned long)mapping & ~PAGE_MAPPING_FLAGS);
 }
+EXPORT_SYMBOL(page_mapping);
 
 /* Slow path of page_mapcount() for compound pages */
 int __page_mapcount(struct page *page)
@@ -386,6 +412,12 @@ int __page_mapcount(struct page *page)
        int ret;
 
        ret = atomic_read(&page->_mapcount) + 1;
+       /*
+        * For file THP page->_mapcount contains total number of mapping
+        * of the page: no need to look into compound_mapcount.
+        */
+       if (!PageAnon(page) && !PageHuge(page))
+               return ret;
        page = compound_head(page);
        ret += atomic_read(compound_mapcount_ptr(page)) + 1;
        if (PageDoubleMap(page))
@@ -496,7 +528,7 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
 
        if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) {
                free = global_page_state(NR_FREE_PAGES);
-               free += global_page_state(NR_FILE_PAGES);
+               free += global_node_page_state(NR_FILE_PAGES);
 
                /*
                 * shmem pages shouldn't be counted as free in this
@@ -504,7 +536,7 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
                 * that won't affect the overall amount of available
                 * memory in the system.
                 */
-               free -= global_page_state(NR_SHMEM);
+               free -= global_node_page_state(NR_SHMEM);
 
                free += get_nr_swap_pages();