+++ /dev/null
-// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
-// vim: ts=8 sw=2 smarttab
-/*
- * Ceph - scalable distributed file system
- *
- * Copyright (C) 2011 New Dream Network
- *
- * This is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License version 2.1, as published by the Free Software
- * Foundation. See file COPYING.
- *
- */
-
-#include "common/debug.h"
-#include "common/errno.h"
-#include "common/safe_io.h"
-#include "global/pidfile.h"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#if defined(__FreeBSD__)
-#include <sys/param.h>
-#endif
-
-#include "include/compat.h"
-
-//
-// derr can be used for functions exclusively called from pidfile_write
-//
-// cerr must be used for functions called by pidfile_remove because
-// logging is not functional when it is called. cerr output is lost
-// when the caller is daemonized but it will show if not (-f)
-//
-#define dout_context g_ceph_context
-#define dout_prefix *_dout
-#define dout_subsys ceph_subsys_
-
-struct pidfh {
- int pf_fd;
- char pf_path[PATH_MAX + 1];
- dev_t pf_dev;
- ino_t pf_ino;
-
- pidfh() {
- reset();
- }
- ~pidfh() {
- remove();
- }
-
- bool is_open() {
- return pf_path[0] != '\0' && pf_fd != -1;
- }
- void reset() {
- pf_fd = -1;
- memset(pf_path, 0, sizeof(pf_path));
- pf_dev = 0;
- pf_ino = 0;
- }
- int verify();
- int remove();
- int open(const md_config_t *conf);
- int write();
-};
-
-static pidfh *pfh = nullptr;
-
-int pidfh::verify() {
- // check that the file we opened still is the same
- if (pf_fd == -1)
- return -EINVAL;
- struct stat st;
- if (stat(pf_path, &st) == -1)
- return -errno;
- if (st.st_dev != pf_dev || st.st_ino != pf_ino)
- return -ESTALE;
- return 0;
-}
-
-int pidfh::remove()
-{
- if (!pf_path[0])
- return 0;
-
- int ret;
- if ((ret = verify()) < 0) {
- if (pf_fd != -1) {
- ::close(pf_fd);
- reset();
- }
- return ret;
- }
-
- // seek to the beginning of the file before reading
- ret = ::lseek(pf_fd, 0, SEEK_SET);
- if (ret < 0) {
- std::cerr << __func__ << " lseek failed "
- << cpp_strerror(errno) << std::endl;
- return -errno;
- }
-
- // check that the pid file still has our pid in it
- char buf[32];
- memset(buf, 0, sizeof(buf));
- ssize_t res = safe_read(pf_fd, buf, sizeof(buf));
- ::close(pf_fd);
- if (res < 0) {
- std::cerr << __func__ << " safe_read failed "
- << cpp_strerror(-res) << std::endl;
- return res;
- }
-
- int a = atoi(buf);
- if (a != getpid()) {
- std::cerr << __func__ << " the pid found in the file is "
- << a << " which is different from getpid() "
- << getpid() << std::endl;
- return -EDOM;
- }
- ret = ::unlink(pf_path);
- if (ret < 0) {
- std::cerr << __func__ << " unlink " << pf_path << " failed "
- << cpp_strerror(errno) << std::endl;
- return -errno;
- }
- reset();
- return 0;
-}
-
-int pidfh::open(const md_config_t *conf)
-{
- int len = snprintf(pf_path, sizeof(pf_path),
- "%s", conf->pid_file.c_str());
-
- if (len >= (int)sizeof(pf_path))
- return -ENAMETOOLONG;
-
- int fd;
- fd = ::open(pf_path, O_CREAT|O_RDWR, 0644);
- if (fd < 0) {
- int err = errno;
- derr << __func__ << ": failed to open pid file '"
- << pf_path << "': " << cpp_strerror(err) << dendl;
- reset();
- return -err;
- }
- struct stat st;
- if (fstat(fd, &st) == -1) {
- int err = errno;
- derr << __func__ << ": failed to fstat pid file '"
- << pf_path << "': " << cpp_strerror(err) << dendl;
- ::close(fd);
- reset();
- return -err;
- }
-
- pf_fd = fd;
- pf_dev = st.st_dev;
- pf_ino = st.st_ino;
-
- struct flock l = {
- .l_type = F_WRLCK,
- .l_whence = SEEK_SET,
- .l_start = 0,
- .l_len = 0
- };
- int r = ::fcntl(pf_fd, F_SETLK, &l);
- if (r < 0) {
- derr << __func__ << ": failed to lock pidfile "
- << pf_path << " because another process locked it." << dendl;
- ::close(pf_fd);
- reset();
- return -errno;
- }
- return 0;
-}
-
-int pidfh::write()
-{
- if (!is_open())
- return 0;
-
- char buf[32];
- int len = snprintf(buf, sizeof(buf), "%d\n", getpid());
- if (::ftruncate(pf_fd, 0) < 0) {
- int err = errno;
- derr << __func__ << ": failed to ftruncate the pid file '"
- << pf_path << "': " << cpp_strerror(err) << dendl;
- return -err;
- }
- ssize_t res = safe_write(pf_fd, buf, len);
- if (res < 0) {
- derr << __func__ << ": failed to write to pid file '"
- << pf_path << "': " << cpp_strerror(-res) << dendl;
- return res;
- }
- return 0;
-}
-
-void pidfile_remove()
-{
- if (pfh != nullptr)
- delete pfh;
- pfh = nullptr;
-}
-
-int pidfile_write(const md_config_t *conf)
-{
- if (conf->pid_file.empty()) {
- dout(0) << __func__ << ": ignore empty --pid-file" << dendl;
- return 0;
- }
-
- assert(pfh == nullptr);
-
- pfh = new pidfh();
- if (atexit(pidfile_remove)) {
- derr << __func__ << ": failed to set pidfile_remove function "
- << "to run at exit." << dendl;
- return -EINVAL;
- }
-
- int r = pfh->open(conf);
- if (r != 0) {
- pidfile_remove();
- return r;
- }
-
- r = pfh->write();
- if (r != 0) {
- pidfile_remove();
- return r;
- }
-
- return 0;
-}
Code Review / stor4nfv.git / blobdiff