1 files changed, 21 insertions, 0 deletions
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 3fb36d43362..c2e7a7ff008 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -780,3 +780,24 @@ int afs_fsync(struct file *file, struct dentry *dentry, int datasync)
 	_leave(" = %d", ret);
 	return ret;
 }
+
+/*
+ * notification that a previously read-only page is about to become writable
+ * - if it returns an error, the caller will deliver a bus error signal
+ */
+int afs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+{
+	struct afs_vnode *vnode = AFS_FS_I(vma->vm_file->f_mapping->host);
+
+	_enter("{{%x:%u}},{%lx}",
+	       vnode->fid.vid, vnode->fid.vnode, page->index);
+
+	/* wait for the page to be written to the cache before we allow it to
+	 * be modified */
+#ifdef CONFIG_AFS_FSCACHE
+	fscache_wait_on_page_write(vnode->cache, page);
+#endif
+
+	_leave(" = 0");
+	return 0;
+}