diff --git a/wp-admin/admin-functions.php b/wp-admin/admin-functions.php
index de55af2f93..4083458380 100644
--- a/wp-admin/admin-functions.php
+++ b/wp-admin/admin-functions.php
@@ -2016,7 +2016,7 @@ function the_attachment_links( $id = false ) {
 		return false;
 
 	$icon = get_attachment_icon( $post->ID );
-	$attachment_data = get_post_meta( $id, '_wp_attachment_metadata', true );
+	$attachment_data = wp_get_attachment_metadata( $id );
 	$thumb = isset( $attachment_data['thumb'] );
 ?>
 <form id="the-attachment-links">
diff --git a/wp-admin/page.php b/wp-admin/page.php
index 9893b0b389..59742a0e7e 100644
--- a/wp-admin/page.php
+++ b/wp-admin/page.php
@@ -71,13 +71,10 @@ case 'editattachment':
 	$_POST['post_type'] = 'attachment';
 
 	// Update the thumbnail filename
-	$oldmeta = $newmeta = get_post_meta($page_id, '_wp_attachment_metadata', true);
+	$newmeta = wp_get_attachment_metadata( $page_id, true );
 	$newmeta['thumb'] = $_POST['thumb'];
 
-	if ( '' !== $oldmeta )
-		update_post_meta($page_id, '_wp_attachment_metadata', $newmeta, $oldmeta);
-	else
-		add_post_meta($page_id, '_wp_attachment_metadata', $newmeta);
+	wp_update_attachment_metadata( $newmeta );
 
 case 'editpost':
 	$page_ID = (int) $_POST['post_ID'];
diff --git a/wp-admin/post.php b/wp-admin/post.php
index 31d16bdaed..b35ff330f5 100644
--- a/wp-admin/post.php
+++ b/wp-admin/post.php
@@ -78,13 +78,10 @@ case 'editattachment':
 	$_POST['post_type'] = 'attachment';
 
 	// Update the thumbnail filename
-	$oldmeta = $newmeta = get_post_meta($post_id, '_wp_attachment_metadata', true);
+	$newmeta = wp_get_attachment_metadata( $post_id, true );
 	$newmeta['thumb'] = $_POST['thumb'];
 
-	if ( '' !== $oldmeta )
-		update_post_meta($post_id, '_wp_attachment_metadata', $newmeta, $oldmeta);
-	else
-		add_post_meta($post_id, '_wp_attachment_metadata', $newmeta);
+	wp_update_attachment_metadata( $post_id, $newmeta );
 
 case 'editpost':
 	$post_ID = (int) $_POST['post_ID'];
diff --git a/wp-admin/upgrade-functions.php b/wp-admin/upgrade-functions.php
index ac1a130db4..d5537cba34 100644
--- a/wp-admin/upgrade-functions.php
+++ b/wp-admin/upgrade-functions.php
@@ -466,7 +466,7 @@ function upgrade_160() {
 
 			$meta = get_post_meta($object->ID, 'imagedata', true);
 			if ( ! empty($meta['file']) )
-				add_post_meta($object->ID, '_wp_attached_file', $meta['file']);
+				update_attached_file( $object->ID, $meta['file'] );
 		}
 	}
 }
diff --git a/wp-admin/upload-functions.php b/wp-admin/upload-functions.php
index 3900c6e677..11f3b77e1e 100644
--- a/wp-admin/upload-functions.php
+++ b/wp-admin/upload-functions.php
@@ -2,7 +2,7 @@
 function wp_upload_display( $dims = false, $href = '' ) {
 	global $post;
 	$id = get_the_ID();
-	$attachment_data = get_post_meta( $id, '_wp_attachment_metadata', true );
+	$attachment_data = wp_get_attachment_metadata( $id );
 	if ( isset($attachment_data['width']) )
 		list($width,$height) = wp_shrink_dimensions($attachment_data['width'], $attachment_data['height'], 171, 128);
 	ob_start();
@@ -57,7 +57,7 @@ function wp_upload_display( $dims = false, $href = '' ) {
 function wp_upload_view() {
 	global $style, $post_id, $style;
 	$id = get_the_ID();
-	$attachment_data = get_post_meta( $id, '_wp_attachment_metadata', true );
+	$attachment_data = wp_get_attachment_metadata( $id );
 ?>
 	<div id="upload-file">
 		<div id="file-title">
@@ -98,7 +98,7 @@ function wp_upload_form() {
 <?php
 	if ( $id ) :
 		$attachment = get_post_to_edit( $id );
-		$attachment_data = get_post_meta( $id, '_wp_attachment_metadata', true );
+		$attachment_data = wp_get_attachment_metadata( $id );
 ?>
 		<div id="file-title">
 			<h2><?php if ( !isset($attachment_data['width']) && 'inline' != $style )
@@ -229,7 +229,7 @@ function wp_upload_tab_upload_action() {
 			$imagedata['hwstring_small'] = "height='$uheight' width='$uwidth'";
 			$imagedata['file'] = $file;
 
-			add_post_meta($id, '_wp_attachment_metadata', $imagedata);
+			wp_update_attachment_metadata( $id, $imagedata );
 
 			if ( $imagedata['width'] * $imagedata['height'] < 3 * 1024 * 1024 ) {
 				if ( $imagedata['width'] > 128 && $imagedata['width'] >= $imagedata['height'] * 4 / 3 )
@@ -240,13 +240,13 @@ function wp_upload_tab_upload_action() {
 				if ( @file_exists($thumb) ) {
 					$newdata = $imagedata;
 					$newdata['thumb'] = basename($thumb);
-					update_post_meta($id, '_wp_attachment_metadata', $newdata, $imagedata);
+					wp_update_attachment_metadata( $id, $newdata );
 				} else {
 					$error = $thumb;
 				}
 			}
 		} else {
-			add_post_meta($id, '_wp_attachment_metadata', array());
+			wp_update_attachment_metadata( $id, array() );
 		}
 
 		wp_redirect( get_option('siteurl') . "/wp-admin/upload.php?style=$style&tab=browse&action=view&ID=$id&post_id=$post_id");
diff --git a/wp-includes/post-template.php b/wp-includes/post-template.php
index a4a9c6f415..e1d83c5cd5 100644
--- a/wp-includes/post-template.php
+++ b/wp-includes/post-template.php
@@ -353,12 +353,11 @@ function get_attachment_icon($id = 0, $fullsize = false, $max_dims = false) {
 
 	$mime = $post->post_mime_type;
 
-	$imagedata = get_post_meta($post->ID, '_wp_attachment_metadata', true);
+	$imagedata = wp_get_attachment_metadata( $post->ID );
 
-	$file = get_post_meta($post->ID, '_wp_attached_file', true);
+	$file = get_attached_file( $post->ID );
 
 	$exts = array('jpg', 'gif', 'png');
-
 	if ( !$fullsize && !empty($imagedata['thumb'])
 			&& ($thumbfile = str_replace(basename($file), $imagedata['thumb'], $file))
 			&& file_exists($thumbfile) ) {
diff --git a/wp-includes/post.php b/wp-includes/post.php
index 661c38b3b5..ddfe815a5d 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -4,8 +4,25 @@
 // Post functions
 //
 
-function get_attached_file($attachment_id) {
-	return get_post_meta($attachment_id, '_wp_attached_file', true);
+function get_attached_file( $attachment_id, $unfiltered = false ) {
+	$file = get_post_meta( $attachment_id, '_wp_attached_file', true );
+	if ( $unfiltered )
+		return $file;
+	return apply_filters( 'get_attached_file', $file, $attachment_id );
+}
+
+function update_attached_file( $attachment_id, $file ) {
+	if ( !get_post( $attachment_id ) )
+		return false;
+
+	$old_file = get_attached_file( $attachment_id, true );
+
+	$file = apply_filters( 'update_attached_file', $file, $attachment_id );
+
+	if ( $old_file )
+		return update_post_meta( $attachment_id, '_wp_attached_file', $file, $old_file );
+	else
+		return add_post_meta( $attachment_id, '_wp_attached_file', $file );
 }
 
 function &get_children($args = '', $output = OBJECT) {
@@ -1331,7 +1348,7 @@ function wp_insert_attachment($object, $file = false, $post_parent = 0) {
 	wp_set_post_categories($post_ID, $post_category);
 
 	if ( $file )
-		add_post_meta($post_ID, '_wp_attached_file', $file);
+		update_attached_file( $post_ID, $file );
 
 	clean_post_cache($post_ID);
 
@@ -1354,8 +1371,8 @@ function wp_delete_attachment($postid) {
 	if ( 'attachment' != $post->post_type )
 		return false;
 
-	$meta = get_post_meta($postid, '_wp_attachment_metadata', true);
-	$file = get_post_meta($postid, '_wp_attached_file', true);
+	$meta = wp_get_attachment_metadata( $postid );
+	$file = get_attached_file( $postid );
 
 	$wpdb->query("DELETE FROM $wpdb->posts WHERE ID = '$postid'");
 
@@ -1384,4 +1401,27 @@ function wp_delete_attachment($postid) {
 	return $post;
 }
 
+function wp_get_attachment_metadata( $post_id, $unfiltered = false ) {
+	$post_id = (int) $post_id;
+
+	$data = get_post_meta( $post_id, '_wp_attachment_metadata', true );
+	if ( $unfiltered )
+		return $data;
+	return apply_filters( 'wp_get_attachment_metadata', $data, $post_id );
+}
+
+function wp_update_attachment_metadata( $post_id, $data ) {
+	if ( !get_post( $post_id ) )
+		return false;
+
+	$old_data = wp_get_attachment_metadata( $post_id, true );
+
+	$data = apply_filters( 'wp_update_attachment_metadata', $data, $post_id );
+
+	if ( $old_data )
+		return update_post_meta( $post_id, '_wp_attachment_metadata', $data, $old_data );
+	else
+		return add_post_meta( $post_id, '_wp_attachment_metadata', $data );
+}
+
 ?>
diff --git a/xmlrpc.php b/xmlrpc.php
index 60301b4614..61126ae1e9 100644
--- a/xmlrpc.php
+++ b/xmlrpc.php
@@ -871,8 +871,8 @@ class wp_xmlrpc_server extends IXR_Server {
 			'guid' => $upload[ 'url' ]
 		);
 		// Save the data
-		$id = wp_insert_attachment($attachment, $upload[ 'file' ], $post_id);
-		add_post_meta($id, '_wp_attachment_metadata', array());
+		$id = wp_insert_attachment( $attachment, $upload[ 'file' ], $post_id );
+		wp_update_attachment_metadata( $id, array() );
 
 		return apply_filters( 'wp_handle_upload', array( 'file' => $upload[ 'file' ], 'url' => $upload[ 'url' ], 'type' => $type ) );
 	}