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lvm2/lib/misc/lvm-exec.c
Mikulas Patocka 3395d72881 Change exit() to _exit() in the child process. exit flushes stdio file buffers,
_exit doesn't. If there were some open files, an error in exec and subsequent
exit() would cause the buffers to be flushed twice.

Example:

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>

int main()
{
	printf("buu");
	if (!fork()) {
		execl("/bin/true-not-exists", "/bin/true", NULL);
		exit(1);
	}
	wait(NULL);
	return 0;
}

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com

---
 daemons/dmeventd/libdevmapper-event.c |    2 +-
 lib/misc/lvm-exec.c                   |    2 +-
 test/harness.c                        |    3 ++-
 tools/dmsetup.c                       |    2 +-
 4 files changed, 5 insertions(+), 4 deletions(-)
2009-07-13 21:26:41 +00:00

93 lines
2.0 KiB
C

/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
*
* This file is part of LVM2.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "lib.h"
#include "device.h"
#include "locking.h"
#include "lvm-exec.h"
#include "toolcontext.h"
#include <unistd.h>
#include <sys/wait.h>
/*
* Create verbose string with list of parameters
*/
static char *_verbose_args(const char *const argv[], char *buf, size_t sz)
{
int pos = 0;
int len;
unsigned i;
buf[0] = '\0';
for (i = 0; argv[i]; i++) {
if ((len = dm_snprintf(buf + pos, sz - pos,
"%s ", argv[i])) < 0)
/* Truncated */
break;
pos += len;
}
return buf;
}
/*
* Execute and wait for external command
*/
int exec_cmd(struct cmd_context *cmd, const char *const argv[])
{
pid_t pid;
int status;
char buf[PATH_MAX * 2];
log_verbose("Executing: %s", _verbose_args(argv, buf, sizeof(buf)));
if ((pid = fork()) == -1) {
log_error("fork failed: %s", strerror(errno));
return 0;
}
if (!pid) {
/* Child */
reset_locking();
dev_close_all();
/* FIXME Fix effect of reset_locking on cache then include this */
/* destroy_toolcontext(cmd); */
/* FIXME Use execve directly */
execvp(argv[0], (char **const) argv);
log_sys_error("execvp", argv[0]);
_exit(errno);
}
/* Parent */
if (wait4(pid, &status, 0, NULL) != pid) {
log_error("wait4 child process %u failed: %s", pid,
strerror(errno));
return 0;
}
if (!WIFEXITED(status)) {
log_error("Child %u exited abnormally", pid);
return 0;
}
if (WEXITSTATUS(status)) {
log_error("%s failed: %u", argv[0], WEXITSTATUS(status));
return 0;
}
return 1;
}