According to fcntl(2) man page, record locks are preserved across an execve(2). This is a regression case for this. Signed-off-by: Xiong Zhou <xzhou@xxxxxxxxxx> --- Thanks Daniel for the report and reproducer! Jeff Layton is fixing this in kernel upstream. .gitignore | 1 + src/Makefile | 2 +- src/t_locks_execve.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++ tests/generic/482 | 70 +++++++++++++++++++++++++++++++++++++++++ tests/generic/482.out | 2 ++ tests/generic/group | 1 + 6 files changed, 161 insertions(+), 1 deletion(-) create mode 100644 src/t_locks_execve.c create mode 100755 tests/generic/482 create mode 100644 tests/generic/482.out diff --git a/.gitignore b/.gitignore index 368d11c..192ca35 100644 --- a/.gitignore +++ b/.gitignore @@ -121,6 +121,7 @@ /src/t_getcwd /src/t_holes /src/t_immutable +/src/t_locks_execve /src/t_mmap_cow_race /src/t_mmap_dio /src/t_mmap_fallocate diff --git a/src/Makefile b/src/Makefile index 0d3feae..6ca5636 100644 --- a/src/Makefile +++ b/src/Makefile @@ -15,7 +15,7 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \ holetest t_truncate_self t_mmap_dio af_unix t_mmap_stale_pmd \ t_mmap_cow_race t_mmap_fallocate fsync-err t_mmap_write_ro \ t_ext4_dax_journal_corruption t_ext4_dax_inline_corruption \ - t_ofd_locks + t_ofd_locks t_locks_execve LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \ preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \ diff --git a/src/t_locks_execve.c b/src/t_locks_execve.c new file mode 100644 index 0000000..a93c6ca --- /dev/null +++ b/src/t_locks_execve.c @@ -0,0 +1,86 @@ +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif +#include <stdio.h> +#include <fcntl.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <pthread.h> +#include <unistd.h> +#include <sys/wait.h> + +static void err_exit(char *op, int errn) +{ + fprintf(stderr, "%s: %s\n", op, strerror(errn)); + exit(errn); +} + +void *thread_fn(void *arg) +{ + /* execve will release threads */ + while(1) sleep(1); + return NULL; +} + +static void checklock(int fd) +{ + pid_t child = fork(); + if (child < 0) + err_exit("fork", errno); + if (child == 0) { + struct flock fl = { + .l_type = F_WRLCK, + .l_whence = SEEK_SET, + .l_start = 0, + .l_len = 1, + }; + + if (fcntl(fd, F_GETLK, &fl) < 0) + err_exit("getlk", errno); + + if (fl.l_type == F_UNLCK) + printf("Lock released\n"); + exit(0); + } + waitpid(child, NULL, 0); +} + +int main(int argc, char **argv) { + + int fd; + /* passing fd in argv[2] in execve */ + if (argc == 3) { + fd = atoi(argv[2]); + checklock(fd); + exit(0); + } + + fd = open(argv[1], O_WRONLY|O_CREAT, 0755); + if (fd < 0) + err_exit("open", errno); + struct flock fl = { + .l_type = F_WRLCK, + .l_whence = SEEK_SET, + .l_start = 0, + .l_len = 1, + }; + if (fcntl(fd, F_SETLK, &fl) < 0) + err_exit("setlk", errno); + + pthread_t th; + pthread_create(&th, NULL, thread_fn, &fd); + + int flags; + if ((flags = fcntl(fd, F_GETFD)) < 0) + err_exit("getfd", errno); + flags &= ~FD_CLOEXEC; + if (fcntl(fd, F_SETFD, flags) < 0) + err_exit("setfd", errno); + + char fdstr[10]; + snprintf(fdstr, sizeof(fdstr), "%d", fd); + char *newargv[] = { argv[0], argv[1], fdstr, NULL }; + execve(argv[0], newargv, NULL); + return 0; +} diff --git a/tests/generic/482 b/tests/generic/482 new file mode 100755 index 0000000..f7cb251 --- /dev/null +++ b/tests/generic/482 @@ -0,0 +1,70 @@ +#! /bin/bash +# FS QA Test 482 +# +# This is testing +# +# "Record locks are not inherited by a child created via fork(2), +# but are preserved across an execve(2)." +# +# from fcntl(2) man page. +# +# Author: "Daniel P. Berrangé" <berrange@xxxxxxxxxx> +# +#----------------------------------------------------------------------- +# Copyright (c) 2018 RedHat Inc. All Rights Reserved. +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU General Public License as +# published by the Free Software Foundation. +# +# This program is distributed in the hope that it would be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write the Free Software Foundation, +# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +#----------------------------------------------------------------------- +# + +seq=`basename $0` +seqres=$RESULT_DIR/$seq +echo "QA output created by $seq" + +here=`pwd` +tmp=/tmp/$$ +status=1 # failure is the default! +trap "_cleanup; exit \$status" 0 1 2 3 15 + +_cleanup() +{ + cd / + rm -f $tmp.* +} + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter + +# remove previous $seqres.full before test +rm -f $seqres.full + +# real QA test starts here + +# Modify as appropriate. +_supported_fs generic +_supported_os Linux +_require_test + +# prepare a 4k testfile in TEST_DIR +$XFS_IO_PROG -f -c "pwrite -S 0xFF 0 4096" \ + $TEST_DIR/t_lock_execve_file >> $seqres.full 2>&1 + +# run test programe +$here/src/t_locks_execve $TEST_DIR/t_lock_execve_file + +# success, all done +echo "Silence is golden" +status=0 +exit diff --git a/tests/generic/482.out b/tests/generic/482.out new file mode 100644 index 0000000..f5e17c8 --- /dev/null +++ b/tests/generic/482.out @@ -0,0 +1,2 @@ +QA output created by 482 +Silence is golden diff --git a/tests/generic/group b/tests/generic/group index e867606..0bf3c1f 100644 --- a/tests/generic/group +++ b/tests/generic/group @@ -484,3 +484,4 @@ 479 auto quick metadata 480 auto quick metadata 481 auto quick log metadata +482 auto lock quick -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe fstests" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html