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/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2011 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[],
int *rstatus, int sync_needed)
{
pid_t pid;
int status;
char buf[PATH_MAX * 2];
if (rstatus)
*rstatus = -1;
if (!argv[0]) {
log_error(INTERNAL_ERROR "Missing command.");
return 0;
}
if (sync_needed)
/* Flush ops and reset dm cookie */
if (!sync_local_dev_names(cmd)) {
log_error("Failed to sync local device names before forking.");
return 0;
}
log_verbose("Executing:%s", _verbose_args(argv, buf, sizeof(buf)));
if ((pid = fork()) == -1) {
log_sys_error("fork", "");
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 **) 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)) {
if (rstatus) {
*rstatus = WEXITSTATUS(status);
log_verbose("%s failed: %u", argv[0], *rstatus);
} else
log_error("%s failed: %u", argv[0], WEXITSTATUS(status));
return 0;
}
if (rstatus)
*rstatus = 0;
return 1;
}
static int _reopen_fd_to_null(int fd)
{
int null_fd;
int r = 0;
if ((null_fd = open("/dev/null", O_RDWR)) == -1) {
log_sys_error("open", "/dev/null");
return 0;
}
if (close(fd)) {
log_sys_error("close", "");
goto out;
}
if (dup2(null_fd, fd) == -1) {
log_sys_error("dup2", "");
goto out;
}
r = 1;
out:
if (close(null_fd)) {
log_sys_error("dup2", "");
return 0;
}
return r;
}
FILE *pipe_open(struct cmd_context *cmd, const char *const argv[],
int sync_needed, struct pipe_data *pdata)
{
int pipefd[2];
char buf[PATH_MAX * 2];
if (sync_needed)
/* Flush ops and reset dm cookie */
if (!sync_local_dev_names(cmd)) {
log_error("Failed to sync local device names before forking.");
return 0;
}
if (pipe(pipefd)) {
log_sys_error("pipe", "");
return 0;
}
log_verbose("Piping:%s", _verbose_args(argv, buf, sizeof(buf)));
if ((pdata->pid = fork()) == -1) {
log_sys_error("pipe", "");
return 0;
}
if (pdata->pid == 0) {
/* Child -> writer, convert pipe[0] to STDOUT */
if (!_reopen_fd_to_null(STDIN_FILENO))
stack;
else if (close(pipefd[0 /*read*/]))
log_sys_error("close", "pipe[0]");
else if (close(STDOUT_FILENO))
log_sys_error("close", "STDOUT");
else if (dup2(pipefd[1 /*write*/], STDOUT_FILENO) == -1)
log_sys_error("dup2", "STDOUT");
else if (close(pipefd[1]))
log_sys_error("close", "pipe[1]");
else if (argv[0]) {
execvp(argv[0], (char **) argv);
log_sys_error("execvp", argv[0]);
}
_exit(errno);
}
/* Parent -> reader */
if (close(pipefd[1 /*write*/])) {
log_sys_error("close", "STDOUT");
return NULL;
}
if (!(pdata->fp = fdopen(pipefd[0 /*read*/], "r"))) {
log_sys_error("fdopen", "STDIN");
if (close(pipefd[0]))
log_sys_error("close", "STDIN");
return NULL; /* FIXME: kill */
}
return pdata->fp;
}
int pipe_close(struct pipe_data *pdata)
{
int status;
if (fclose(pdata->fp))
log_sys_error("fclose", "STDIN");
if (waitpid(pdata->pid, &status, 0) != pdata->pid) {
log_sys_error("waitpid", "");
return 0;
}
return (status == 0) ? 1 : 0;
}
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