Date: Thu, 22 Mar 2018 23:47:04 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r331388 - stable/11/cddl/contrib/opensolaris/lib/libzfs/common Message-ID: <201803222347.w2MNl44k095228@repo.freebsd.org>
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Author: mav Date: Thu Mar 22 23:47:04 2018 New Revision: 331388 URL: https://svnweb.freebsd.org/changeset/base/331388 Log: MFC r329659: MFV r316873: 7233 dir_is_empty should open directory with CLOEXEC illumos/illumos-gate@d420209d9c807f782c1d31f5683be74798142198 https://github.com/illumos/illumos-gate/commit/d420209d9c807f782c1d31f5683be74798142198 https://www.illumos.org/issues/7233 This fixes a race where one thread is executing zfs_mount() while another thread forks and execs. If the fork occurs while the directory is open, the child process will inherit (but not necessarily close immediately) the open fd for the directory, preventing the mount. Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: Paul Dagnelie <pcd@delphix.com> Approved by: Richard Lowe <richlowe@richlowe.net> Author: Alex Reece <alex@delphix.com> Modified: stable/11/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Directory Properties: stable/11/ (props changed) Modified: stable/11/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c ============================================================================== --- stable/11/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Thu Mar 22 23:45:46 2018 (r331387) +++ stable/11/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Thu Mar 22 23:47:04 2018 (r331388) @@ -22,7 +22,7 @@ /* * Copyright 2015 Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2014 by Delphix. All rights reserved. + * Copyright (c) 2014, 2015 by Delphix. All rights reserved. * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com> * Copyright 2017 Joyent, Inc. * Copyright 2017 RackTop Systems. @@ -67,6 +67,7 @@ #include <dirent.h> #include <dlfcn.h> #include <errno.h> +#include <fcntl.h> #include <libgen.h> #include <libintl.h> #include <stdio.h> @@ -187,9 +188,16 @@ dir_is_empty(const char *dirname) { DIR *dirp; struct dirent64 *dp; + int dirfd; - if ((dirp = opendir(dirname)) == NULL) + if ((dirfd = openat(AT_FDCWD, dirname, + O_RDONLY | O_NDELAY | O_LARGEFILE | O_CLOEXEC, 0)) < 0) { return (B_TRUE); + } + + if ((dirp = fdopendir(dirfd)) == NULL) { + return (B_TRUE); + } while ((dp = readdir64(dirp)) != NULL) {
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