Upgrade/Install: Create a temporary backup of plugins and themes before updating.

This aims to make the update process more reliable and ensures that if a plugin or theme update fails, the previous version can be safely restored.

* When updating a plugin or theme, the old version is moved to a temporary backup directory:
 * `wp-content/upgrade/temp-backup/plugins/[plugin-slug]` for plugins
 * `wp-content/upgrade/temp-backup/themes/[theme-slug]` for themes.

* If the update fails, then the temporary backup kept in the `upgrade/temp-backup` directory is restored to its original location.
* If the update succeeds, the temporary backup is deleted.

To further help troubleshoot plugin and theme updates, two new checks were added to the Site Health screen:
* A check to make sure that the `temp-backup` directory is writable.
* A check that there is enough disk space available to safely perform updates.

To avoid confusion: The `temp-backup` directory will NOT be used to "roll back" a plugin to a previous version after a completed update. This directory will simply contain a transient backup of the previous version of a plugin or theme being updated, and as soon as the update process finishes, the directory will be empty.

Props aristath, afragen, pbiron, dd32, poena, TimothyBlynJacobs, audrasjb, mikeschroder, a2hosting, hellofromTonya, KZeni, galbaras, richards1052, Boniu91, mai21, francina, SergeyBiryukov.
See #51857.
Built from https://develop.svn.wordpress.org/trunk@51815


git-svn-id: http://core.svn.wordpress.org/trunk@51422 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/class-plugin-upgrader.php

@@ -229,6 +229,11 @@ class Plugin_Upgrader extends WP_Upgrader {
 					'plugin'      => $plugin,
 					'type'        => 'plugin',
 					'action'      => 'update',
+					'temp_backup' => array(
+						'slug' => dirname( $plugin ),
+						'src'  => WP_PLUGIN_DIR,
+						'dir'  => 'plugins',
+					),
 				),
 			)
 		);
@@ -343,6 +348,11 @@ class Plugin_Upgrader extends WP_Upgrader {
 					'is_multi'          => true,
 					'hook_extra'        => array(
 						'plugin'      => $plugin,
+						'temp_backup' => array(
+							'slug' => dirname( $plugin ),
+							'src'  => WP_PLUGIN_DIR,
+							'dir'  => 'plugins',
+						),
 					),
 				)
 			);

wp-admin/includes/class-theme-upgrader.php

@@ -331,6 +331,11 @@ class Theme_Upgrader extends WP_Upgrader {
 					'theme'       => $theme,
 					'type'        => 'theme',
 					'action'      => 'update',
+					'temp_backup' => array(
+						'slug' => $theme,
+						'src'  => get_theme_root( $theme ),
+						'dir'  => 'themes',
+					),
 				),
 			)
 		);
@@ -444,6 +449,11 @@ class Theme_Upgrader extends WP_Upgrader {
 					'is_multi'          => true,
 					'hook_extra'        => array(
 						'theme'       => $theme,
+						'temp_backup' => array(
+							'slug' => $theme,
+							'src'  => get_theme_root( $theme ),
+							'dir'  => 'themes',
+						),
 					),
 				)
 			);

wp-admin/includes/class-wp-site-health.php

@@ -1882,6 +1882,196 @@ class WP_Site_Health {
 		return $result;
 	}
 
+	/**
+	 * Test available disk space for updates.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @return array The test results.
+	 */
+	public function get_test_available_updates_disk_space() {
+		$available_space       = function_exists( 'disk_free_space' ) ? (int) @disk_free_space( WP_CONTENT_DIR . '/upgrade/' ) : false;
+		$available_space_in_mb = $available_space / MB_IN_BYTES;
+
+		$result = array(
+			'label'       => __( 'Disk space available to safely perform updates' ),
+			'status'      => 'good',
+			'badge'       => array(
+				'label' => __( 'Security' ),
+				'color' => 'blue',
+			),
+			'description' => sprintf(
+				/* translators: %s: Available disk space in MB or GB. */
+				'<p>' . __( '%s available disk space was detected, update routines can be performed safely.' ),
+				size_format( $available_space )
+			),
+			'actions'     => '',
+			'test'        => 'available_updates_disk_space',
+		);
+
+		if ( $available_space_in_mb < 100 ) {
+			$result['description'] = __( 'Available disk space is low, less than 100 MB available.' );
+			$result['status']      = 'recommended';
+		}
+
+		if ( $available_space_in_mb < 20 ) {
+			$result['description'] = __( 'Available disk space is critically low, less than 20 MB available. Proceed with caution, updates may fail.' );
+			$result['status']      = 'critical';
+		}
+
+		if ( ! $available_space ) {
+			$result['description'] = __( 'Could not determine available disk space for updates.' );
+			$result['status']      = 'recommended';
+		}
+
+		return $result;
+	}
+
+	/**
+	 * Test if plugin and theme updates temp-backup directories are writable or can be created.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
+	 *
+	 * @return array The test results.
+	 */
+	public function get_test_update_temp_backup_writable() {
+		global $wp_filesystem;
+
+		$result = array(
+			'label'       => sprintf(
+				/* translators: %s: temp-backup */
+				__( 'Plugin and theme update %s directory is writable' ),
+				'temp-backup'
+			),
+			'status'      => 'good',
+			'badge'       => array(
+				'label' => __( 'Security' ),
+				'color' => 'blue',
+			),
+			'description' => sprintf(
+				/* translators: %s: wp-content/upgrade/temp-backup */
+				'<p>' . __( 'The %s directory used to improve the stability of plugin and theme updates is writable.' ),
+				'<code>wp-content/upgrade/temp-backup</code>'
+			),
+			'actions'     => '',
+			'test'        => 'update_temp_backup_writable',
+		);
+
+		if ( ! $wp_filesystem ) {
+			if ( ! function_exists( 'WP_Filesystem' ) ) {
+				require_once wp_normalize_path( ABSPATH . '/wp-admin/includes/file.php' );
+			}
+			WP_Filesystem();
+		}
+		$wp_content = $wp_filesystem->wp_content_dir();
+
+		$upgrade_dir_exists      = $wp_filesystem->is_dir( "$wp_content/upgrade" );
+		$upgrade_dir_is_writable = $wp_filesystem->is_writable( "$wp_content/upgrade" );
+		$backup_dir_exists       = $wp_filesystem->is_dir( "$wp_content/upgrade/temp-backup" );
+		$backup_dir_is_writable  = $wp_filesystem->is_writable( "$wp_content/upgrade/temp-backup" );
+
+		$plugins_dir_exists      = $wp_filesystem->is_dir( "$wp_content/upgrade/temp-backup/plugins" );
+		$plugins_dir_is_writable = $wp_filesystem->is_writable( "$wp_content/upgrade/temp-backup/plugins" );
+		$themes_dir_exists       = $wp_filesystem->is_dir( "$wp_content/upgrade/temp-backup/themes" );
+		$themes_dir_is_writable  = $wp_filesystem->is_writable( "$wp_content/upgrade/temp-backup/themes" );
+
+		if ( $plugins_dir_exists && ! $plugins_dir_is_writable && $themes_dir_exists && ! $themes_dir_is_writable ) {
+			$result['status']      = 'critical';
+			$result['label']       = sprintf(
+				/* translators: %s: temp-backup */
+				__( 'Plugins and themes %s directories exist but are not writable' ),
+				'temp-backup'
+			);
+			$result['description'] = sprintf(
+				/* translators: 1: wp-content/upgrade/temp-backup/plugins, 2: wp-content/upgrade/temp-backup/themes. */
+				'<p>' . __( 'The %1$s and %2$s directories exist but are not writable. These directories are used to improve the stability of plugin updates. Please make sure the server has write permissions to these directories.' ) . '</p>',
+				'<code>wp-content/upgrade/temp-backup/plugins</code>',
+				'<code>wp-content/upgrade/temp-backup/themes</code>'
+			);
+			return $result;
+		}
+
+		if ( $plugins_dir_exists && ! $plugins_dir_is_writable ) {
+			$result['status']      = 'critical';
+			$result['label']       = sprintf(
+				/* translators: %s: temp-backup */
+				__( 'Plugins %s directory exists but is not writable' ),
+				'temp-backup'
+			);
+			$result['description'] = sprintf(
+				/* translators: %s: wp-content/upgrade/temp-backup/plugins */
+				'<p>' . __( 'The %s directory exists but is not writable. This directory is used to improve the stability of plugin updates. Please make sure the server has write permissions to this directory.' ) . '</p>',
+				'<code>wp-content/upgrade/temp-backup/plugins</code>'
+			);
+			return $result;
+		}
+
+		if ( $themes_dir_exists && ! $themes_dir_is_writable ) {
+			$result['status']      = 'critical';
+			$result['label']       = sprintf(
+				/* translators: %s: temp-backup */
+				__( 'Themes %s directory exists but is not writable' ),
+				'temp-backup'
+			);
+			$result['description'] = sprintf(
+				/* translators: %s: wp-content/upgrade/temp-backup/themes */
+				'<p>' . __( 'The %s directory exists but is not writable. This directory is used to improve the stability of theme updates. Please make sure the server has write permissions to this directory.' ) . '</p>',
+				'<code>wp-content/upgrade/temp-backup/themes</code>'
+			);
+			return $result;
+		}
+
+		if ( ( ! $plugins_dir_exists || ! $themes_dir_exists ) && $backup_dir_exists && ! $backup_dir_is_writable ) {
+			$result['status']      = 'critical';
+			$result['label']       = sprintf(
+				/* translators: %s: temp-backup */
+				__( 'The %s directory exists but is not writable' ),
+				'temp-backup'
+			);
+			$result['description'] = sprintf(
+				/* translators: %s: wp-content/upgrade/temp-backup */
+				'<p>' . __( 'The %s directory exists but is not writable. This directory is used to improve the stability of plugin and theme updates. Please make sure the server has write permissions to this directory.' ) . '</p>',
+				'<code>wp-content/upgrade/temp-backup</code>'
+			);
+			return $result;
+		}
+
+		if ( ! $backup_dir_exists && $upgrade_dir_exists && ! $upgrade_dir_is_writable ) {
+			$result['status']      = 'critical';
+			$result['label']       = sprintf(
+				/* translators: %s: upgrade */
+				__( 'The %s directory exists but is not writable' ),
+				'upgrade'
+			);
+			$result['description'] = sprintf(
+				/* translators: %s: wp-content/upgrade */
+				'<p>' . __( 'The %s directory exists but is not writable. This directory is used for plugin and theme updates. Please make sure the server has write permissions to this directory.' ) . '</p>',
+				'<code>wp-content/upgrade</code>'
+			);
+			return $result;
+		}
+
+		if ( ! $upgrade_dir_exists && ! $wp_filesystem->is_writable( $wp_content ) ) {
+			$result['status']      = 'critical';
+			$result['label']       = sprintf(
+				/* translators: %s: upgrade */
+				__( 'The %s directory cannot be created' ),
+				'upgrade'
+			);
+			$result['description'] = sprintf(
+				/* translators: 1: wp-content/upgrade, 2: wp-content. */
+				'<p>' . __( 'The %1$s directory does not exist, and the server does not have write permissions in %2$s to create it. This directory is used for plugin and theme updates. Please make sure the server has write permissions in %2$s.' ) . '</p>',
+				'<code>wp-content/upgrade</code>',
+				'<code>wp-content</code>'
+			);
+			return $result;
+		}
+
+		return $result;
+	}
+
 	/**
 	 * Test if loopbacks work as expected.
 	 *
@@ -2331,6 +2521,15 @@ class WP_Site_Health {
 					'label' => __( 'Plugin and theme auto-updates' ),
 					'test'  => 'plugin_theme_auto_updates',
 				),
+				'update_temp_backup_writable'  => array(
+					/* translators: %s: temp-backup */
+					'label' => sprintf( __( 'Updates %s directory access' ), 'temp-backup' ),
+					'test'  => 'update_temp_backup_writable',
+				),
+				'available_updates_disk_space' => array(
+					'label' => __( 'Available disk space' ),
+					'test'  => 'available_updates_disk_space',
+				),
 			),
 			'async'  => array(
 				'dotorg_communication' => array(

wp-admin/includes/class-wp-upgrader.php

@@ -133,11 +133,25 @@ class WP_Upgrader {
 	 * This will set the relationship between the skin being used and this upgrader,
 	 * and also add the generic strings to `WP_Upgrader::$strings`.
 	 *
+	 * Additionally, it will schedule a weekly task to clean up the temp-backup directory.
+	 *
 	 * @since 2.8.0
+	 * @since 5.9.0 Added the `schedule_temp_backup_cleanup()` task.
 	 */
 	public function init() {
 		$this->skin->set_upgrader( $this );
 		$this->generic_strings();
+		$this->schedule_temp_backup_cleanup();
+	}
+
+	/**
+	 * Schedule cleanup of the temp-backup directory.
+	 *
+	 * @since 5.9.0
+	 */
+	protected function schedule_temp_backup_cleanup() {
+		wp_schedule_event( time(), 'weekly', 'delete_temp_updater_backups' );
+		add_action( 'delete_temp_updater_backups', array( $this, 'delete_all_temp_backups' ) );
 	}
 
 	/**
@@ -166,6 +180,13 @@ class WP_Upgrader {
 
 		$this->strings['maintenance_start'] = __( 'Enabling Maintenance mode…' );
 		$this->strings['maintenance_end']   = __( 'Disabling Maintenance mode…' );
+
+		/* translators: %s: temp-backup */
+		$this->strings['temp_backup_mkdir_failed'] = sprintf( __( 'Could not create the %s directory.' ), 'temp-backup' );
+		/* translators: %s: temp-backup */
+		$this->strings['temp_backup_move_failed']    = sprintf( __( 'Could not move old version to the %s directory.' ), 'temp-backup' );
+		$this->strings['temp_backup_restore_failed'] = __( 'Could not restore original version.' );
+
 	}
 
 	/**
@@ -313,6 +334,9 @@ class WP_Upgrader {
 		$upgrade_files = $wp_filesystem->dirlist( $upgrade_folder );
 		if ( ! empty( $upgrade_files ) ) {
 			foreach ( $upgrade_files as $file ) {
+				if ( 'temp-backup' === $file['name'] ) {
+					continue;
+				}
 				$wp_filesystem->delete( $upgrade_folder . $file['name'], true );
 			}
 		}
@@ -493,6 +517,13 @@ class WP_Upgrader {
 			return $res;
 		}
 
+		if ( ! empty( $args['hook_extra']['temp_backup'] ) ) {
+			$temp_backup = $this->move_to_temp_backup_dir( $args['hook_extra']['temp_backup'] );
+			if ( is_wp_error( $temp_backup ) ) {
+				return $temp_backup;
+			}
+		}
+
 		// Retain the original source and destinations.
 		$remote_source     = $args['source'];
 		$local_destination = $destination;
@@ -811,6 +842,9 @@ class WP_Upgrader {
 
 		$this->skin->set_result( $result );
 		if ( is_wp_error( $result ) ) {
+			if ( ! empty( $options['hook_extra']['temp_backup'] ) ) {
+				$this->restore_temp_backup( $options['hook_extra']['temp_backup'] );
+			}
 			$this->skin->error( $result );
 
 			if ( ! method_exists( $this->skin, 'hide_process_failed' ) || ! $this->skin->hide_process_failed( $result ) ) {
@@ -823,6 +857,11 @@ class WP_Upgrader {
 
 		$this->skin->after();
 
+		// Clean up the backup kept in the temp-backup directory.
+		if ( ! empty( $options['hook_extra']['temp_backup'] ) ) {
+			$this->delete_temp_backup( $options['hook_extra']['temp_backup'] );
+		}
+
 		if ( ! $options['is_multi'] ) {
 
 			/**
@@ -948,6 +987,154 @@ class WP_Upgrader {
 		return delete_option( $lock_name . '.lock' );
 	}
 
+	/**
+	 * Moves the plugin/theme being updated into a temp-backup directory.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
+	 *
+	 * @param array $args Array of data for the temp-backup. Must include a slug, the source, and directory.
+	 * @return bool|WP_Error
+	 */
+	public function move_to_temp_backup_dir( $args ) {
+		global $wp_filesystem;
+
+		if ( empty( $args['slug'] ) || empty( $args['src'] ) || empty( $args['dir'] ) ) {
+			return false;
+		}
+
+		$dest_dir = $wp_filesystem->wp_content_dir() . 'upgrade/temp-backup/';
+		// Create the temp-backup directory if it doesn't exist.
+		if ( (
+				! $wp_filesystem->is_dir( $dest_dir )
+				&& ! $wp_filesystem->mkdir( $dest_dir )
+			) || (
+				! $wp_filesystem->is_dir( $dest_dir . $args['dir'] . '/' )
+				&& ! $wp_filesystem->mkdir( $dest_dir . $args['dir'] . '/' )
+			)
+		) {
+			return new WP_Error( 'fs_temp_backup_mkdir', $this->strings['temp_backup_mkdir_failed'] );
+		}
+
+		$src  = trailingslashit( $args['src'] ) . $args['slug'];
+		$dest = $dest_dir . $args['dir'] . '/' . $args['slug'];
+
+		// Delete the temp-backup directory if it already exists.
+		if ( $wp_filesystem->is_dir( $dest ) ) {
+			$wp_filesystem->delete( $dest, true );
+		}
+
+		// Move to the temp-backup directory.
+		if ( ! $wp_filesystem->move( $src, $dest, true ) ) {
+			return new WP_Error( 'fs_temp_backup_move', $this->strings['temp_backup_move_failed'] );
+		}
+
+		return true;
+	}
+
+	/**
+	 * Restores the plugin/theme from the temp-backup directory.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
+	 *
+	 * @param array $args Array of data for the temp-backup. Must include a slug, the source, and directory.
+	 * @return bool|WP_Error
+	 */
+	public function restore_temp_backup( $args ) {
+		global $wp_filesystem;
+
+		if ( empty( $args['slug'] ) || empty( $args['src'] ) || empty( $args['dir'] ) ) {
+			return false;
+		}
+
+		$src  = $wp_filesystem->wp_content_dir() . 'upgrade/temp-backup/' . $args['dir'] . '/' . $args['slug'];
+		$dest = trailingslashit( $args['src'] ) . $args['slug'];
+
+		if ( $wp_filesystem->is_dir( $src ) ) {
+			// Cleanup.
+			if ( $wp_filesystem->is_dir( $dest ) && ! $wp_filesystem->delete( $dest, true ) ) {
+				return new WP_Error( 'fs_temp_backup_delete', $this->strings['temp_backup_restore_failed'] );
+			}
+
+			// Move it.
+			if ( ! $wp_filesystem->move( $src, $dest, true ) ) {
+				return new WP_Error( 'fs_temp_backup_delete', $this->strings['temp_backup_restore_failed'] );
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Deletes a temp-backup.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
+	 *
+	 * @param array $args Array of data for the temp-backup. Must include a slug, the source, and directory.
+	 * @return bool
+	 */
+	public function delete_temp_backup( $args ) {
+		global $wp_filesystem;
+
+		if ( empty( $args['slug'] ) || empty( $args['dir'] ) ) {
+			return false;
+		}
+
+		return $wp_filesystem->delete(
+			$wp_filesystem->wp_content_dir() . "upgrade/temp-backup/{$args['dir']}/{$args['slug']}",
+			true
+		);
+	}
+
+	/**
+	 * Deletes all contents of the temp-backup directory.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
+	 */
+	public function delete_all_temp_backups() {
+		/*
+		 * Check if there's a lock, or if currently performing an Ajax request,
+		 * in which case there's a chance we're doing an update.
+		 * Reschedule for an hour from now and exit early.
+		 */
+		if ( get_option( 'core_updater.lock' ) || get_option( 'auto_updater.lock' ) || wp_doing_ajax() ) {
+			wp_schedule_single_event( time() + HOUR_IN_SECONDS, 'delete_temp_updater_backups' );
+			return;
+		}
+
+		add_action(
+			'shutdown',
+			/*
+			 * This action runs on shutdown to make sure there's no plugin updates currently running.
+			 * Using a closure in this case is OK since the action can be removed by removing the parent hook.
+			 */
+			function() {
+				global $wp_filesystem;
+
+				if ( ! $wp_filesystem ) {
+					include_once ABSPATH . '/wp-admin/includes/file.php';
+					WP_Filesystem();
+				}
+
+				$dirlist = $wp_filesystem->dirlist( $wp_filesystem->wp_content_dir() . 'upgrade/temp-backup/' );
+
+				foreach ( array_keys( $dirlist ) as $dir ) {
+					if ( '.' === $dir || '..' === $dir ) {
+						continue;
+					}
+
+					$wp_filesystem->delete( $wp_filesystem->wp_content_dir() . 'upgrade/temp-backup/' . $dir, true );
+				}
+			}
+		);
+	}
 }
 
 /** Plugin_Upgrader class */

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-51814';
+$wp_version = '5.9-alpha-51815';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.