x86: access_error API cleanup

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / mm / filemap.c

diff --git a/mm/filemap.c b/mm/filemap.c
index 3d4df44e4221d25bb041995813823e00903161e5..33f81252a74420a57189d34c22510d1c1dd5f936 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -612,6 +612,19 @@ void __lock_page_nosync(struct page *page)
                                                        TASK_UNINTERRUPTIBLE);
 }
 
+int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
+                        unsigned int flags)
+{
+       if (!(flags & FAULT_FLAG_ALLOW_RETRY)) {
+               __lock_page(page);
+               return 1;
+       } else {
+               up_read(&mm->mmap_sem);
+               wait_on_page_locked(page);
+               return 0;
+       }
+}
+
 /**
  * find_get_page - find and get a page reference
  * @mapping: the address_space to search
@@ -1539,25 +1552,28 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
                 * waiting for the lock.
                 */
                do_async_mmap_readahead(vma, ra, file, page, offset);
-               lock_page(page);
-
-               /* Did it get truncated? */
-               if (unlikely(page->mapping != mapping)) {
-                       unlock_page(page);
-                       put_page(page);
-                       goto no_cached_page;
-               }
        } else {
                /* No page in the page cache at all */
                do_sync_mmap_readahead(vma, ra, file, offset);
                count_vm_event(PGMAJFAULT);
                ret = VM_FAULT_MAJOR;
 retry_find:
-               page = find_lock_page(mapping, offset);
+               page = find_get_page(mapping, offset);
                if (!page)
                        goto no_cached_page;
        }
 
+       if (!lock_page_or_retry(page, vma->vm_mm, vmf->flags))
+               return ret | VM_FAULT_RETRY;
+
+       /* Did it get truncated? */
+       if (unlikely(page->mapping != mapping)) {
+               unlock_page(page);
+               put_page(page);
+               goto retry_find;
+       }
+       VM_BUG_ON(page->index != offset);
+
        /*
         * We have a locked page in the page cache, now we need to check
         * that it's up-to-date. If not, it is going to be due to an error.