Date: Tue, 20 Feb 2018 20:17:20 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r329659 - head/cddl/contrib/opensolaris/lib/libzfs/common Message-ID: <201802202017.w1KKHK9B044372@repo.freebsd.org>
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Author: mav Date: Tue Feb 20 20:17:19 2018 New Revision: 329659 URL: https://svnweb.freebsd.org/changeset/base/329659 Log: 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: head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Directory Properties: head/cddl/contrib/opensolaris/ (props changed) head/cddl/contrib/opensolaris/lib/libzfs/ (props changed) Modified: head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c ============================================================================== --- head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Tue Feb 20 20:14:11 2018 (r329658) +++ head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Tue Feb 20 20:17:19 2018 (r329659) @@ -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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