From owner-svn-src-all@freebsd.org Sun Feb 14 19:52:52 2016 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 02850AA8E61; Sun, 14 Feb 2016 19:52:52 +0000 (UTC) (envelope-from pfg@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id C862DDE7; Sun, 14 Feb 2016 19:52:51 +0000 (UTC) (envelope-from pfg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u1EJqoYQ072955; Sun, 14 Feb 2016 19:52:50 GMT (envelope-from pfg@FreeBSD.org) Received: (from pfg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u1EJqoN1072954; Sun, 14 Feb 2016 19:52:50 GMT (envelope-from pfg@FreeBSD.org) Message-Id: <201602141952.u1EJqoN1072954@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: pfg set sender to pfg@FreeBSD.org using -f From: "Pedro F. Giffuni" Date: Sun, 14 Feb 2016 19:52:50 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r295616 - head/sys/fs/ext2fs X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 14 Feb 2016 19:52:52 -0000 Author: pfg Date: Sun Feb 14 19:52:50 2016 New Revision: 295616 URL: https://svnweb.freebsd.org/changeset/base/295616 Log: ext2fs: Remove panics for rename() race conditions. Sync with r84642 from UFS: The panics are inappropriate because the IN_RENAME flag only fixes a few of the huge number of race conditions that can result in the source path becoming invalid even prior to the VOP_RENAME() call. Found accidentally while checking an issue from PVS Static Analysis. MFC after: 3 days Modified: head/sys/fs/ext2fs/ext2_vnops.c Modified: head/sys/fs/ext2fs/ext2_vnops.c ============================================================================== --- head/sys/fs/ext2fs/ext2_vnops.c Sun Feb 14 18:57:40 2016 (r295615) +++ head/sys/fs/ext2fs/ext2_vnops.c Sun Feb 14 19:52:50 2016 (r295616) @@ -985,10 +985,10 @@ abortit: dp = VTOI(fdvp); } else { /* - * From name has disappeared. + * From name has disappeared. IN_RENAME is not sufficient + * to protect against directory races due to timing windows, + * so we can't panic here. */ - if (doingdirectory) - panic("ext2_rename: lost dir entry"); vrele(ap->a_fvp); return (0); } @@ -1003,8 +1003,11 @@ abortit: * rename. */ if (xp != ip) { - if (doingdirectory) - panic("ext2_rename: lost dir entry"); + /* + * From name resolves to a different inode. IN_RENAME is + * not sufficient protection against timing window races + * so we can't panic here. + */ } else { /* * If the source is a directory with a