+++ /dev/null
-/* lxcfs
- *
- * Copyright © 2014-2016 Canonical, Inc
- * Author: Serge Hallyn <serge.hallyn@ubuntu.com>
- *
- * See COPYING file for details.
- */
-
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
-#ifndef FUSE_USE_VERSION
-#define FUSE_USE_VERSION 26
-#endif
-
-#define _FILE_OFFSET_BITS 64
-
-#include <alloca.h>
-#include <dirent.h>
-#include <dlfcn.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <fuse.h>
-#include <libgen.h>
-#include <pthread.h>
-#include <sched.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-#include <unistd.h>
-#include <wait.h>
-#include <linux/sched.h>
-#include <sys/epoll.h>
-#include <sys/mount.h>
-#include <sys/socket.h>
-#include <linux/limits.h>
-
-#include "bindings.h"
-#include "config.h"
-
-void *dlopen_handle;
-
-/* Functions to keep track of number of threads using the library */
-
-static int users_count;
-static pthread_mutex_t user_count_mutex = PTHREAD_MUTEX_INITIALIZER;
-static void lock_mutex(pthread_mutex_t *l)
-{
- int ret;
-
- if ((ret = pthread_mutex_lock(l)) != 0) {
- lxcfs_error("returned:%d %s\n", ret, strerror(ret));
- exit(1);
- }
-}
-
-static void unlock_mutex(pthread_mutex_t *l)
-{
- int ret;
-
- if ((ret = pthread_mutex_unlock(l)) != 0) {
- lxcfs_error("returned:%d %s\n", ret, strerror(ret));
- exit(1);
- }
-}
-
-static void users_lock(void)
-{
- lock_mutex(&user_count_mutex);
-}
-
-static void users_unlock(void)
-{
- unlock_mutex(&user_count_mutex);
-}
-
-static pthread_t loadavg_pid = 0;
-
-/* Returns zero on success */
-static int start_loadavg(void) {
- char *error;
- pthread_t (*load_daemon)(int);
-
- dlerror(); /* Clear any existing error */
-
- load_daemon = (pthread_t (*)(int)) dlsym(dlopen_handle, "load_daemon");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("load_daemon fails:%s\n", error);
- return -1;
- }
- loadavg_pid = load_daemon(1);
- if (loadavg_pid == 0)
- return -1;
-
- return 0;
-}
-
-/* Returns zero on success */
-static int stop_loadavg(void) {
- char *error;
- int (*stop_load_daemon)(pthread_t);
-
- stop_load_daemon = (int (*)(pthread_t)) dlsym(dlopen_handle, "stop_load_daemon");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("stop_load_daemon error: %s\n", error);
- return -1;
- }
-
- if (stop_load_daemon(loadavg_pid) != 0)
- return -1;
-
- return 0;
-}
-
-static volatile sig_atomic_t need_reload;
-
-/* do_reload - reload the dynamic library. Done under
- * lock and when we know the user_count was 0 */
-static void do_reload(void)
-{
- char lxcfs_lib_path[PATH_MAX];
-
- if (loadavg_pid > 0)
- stop_loadavg();
-
- if (dlopen_handle) {
- lxcfs_debug("%s\n", "Closing liblxcfs.so handle.");
- dlclose(dlopen_handle);
- }
-
- /* First try loading using ld.so */
- dlopen_handle = dlopen("liblxcfs.so", RTLD_LAZY);
- if (dlopen_handle) {
- lxcfs_debug("%s\n", "Successfully called dlopen() on liblxcfs.so.");
- goto good;
- }
-
-#ifdef LIBDIR
- /* LIBDIR: autoconf will setup this MACRO. Default value is $PREFIX/lib */
- snprintf(lxcfs_lib_path, PATH_MAX, "%s/lxcfs/liblxcfs.so", LIBDIR);
-#else
- snprintf(lxcfs_lib_path, PATH_MAX, "/usr/local/lib/lxcfs/liblxcfs.so");
-#endif
- dlopen_handle = dlopen(lxcfs_lib_path, RTLD_LAZY);
- if (!dlopen_handle) {
- lxcfs_error("Failed to open liblxcfs.so: %s.\n", dlerror());
- _exit(1);
- }
-
-good:
- if (loadavg_pid > 0)
- start_loadavg();
-
- if (need_reload)
- lxcfs_error("%s\n", "lxcfs: reloaded");
- need_reload = 0;
-}
-
-static void up_users(void)
-{
- users_lock();
- if (users_count == 0 && need_reload)
- do_reload();
- users_count++;
- users_unlock();
-}
-
-static void down_users(void)
-{
- users_lock();
- users_count--;
- users_unlock();
-}
-
-static void reload_handler(int sig)
-{
- need_reload = 1;
-}
-
-/* Functions to run the library methods */
-static int do_cg_getattr(const char *path, struct stat *sb)
-{
- int (*cg_getattr)(const char *path, struct stat *sb);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_getattr = (int (*)(const char *, struct stat *)) dlsym(dlopen_handle, "cg_getattr");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_getattr(path, sb);
-}
-
-static int do_proc_getattr(const char *path, struct stat *sb)
-{
- int (*proc_getattr)(const char *path, struct stat *sb);
- char *error;
- dlerror(); /* Clear any existing error */
- proc_getattr = (int (*)(const char *, struct stat *)) dlsym(dlopen_handle, "proc_getattr");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return proc_getattr(path, sb);
-}
-
-static int do_sys_getattr(const char *path, struct stat *sb)
-{
- int (*sys_getattr)(const char *path, struct stat *sb);
- char *error;
- dlerror(); /* Clear any existing error */
- sys_getattr = (int (*)(const char *, struct stat *)) dlsym(dlopen_handle, "sys_getattr");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return sys_getattr(path, sb);
-}
-
-static int do_cg_read(const char *path, char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi)
-{
- int (*cg_read)(const char *path, char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi);
- char *error;
-
- dlerror(); /* Clear any existing error */
- cg_read = (int (*)(const char *, char *, size_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_read");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_read(path, buf, size, offset, fi);
-}
-
-static int do_proc_read(const char *path, char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi)
-{
- int (*proc_read)(const char *path, char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi);
- char *error;
-
- dlerror(); /* Clear any existing error */
- proc_read = (int (*)(const char *, char *, size_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "proc_read");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return proc_read(path, buf, size, offset, fi);
-}
-
-static int do_sys_read(const char *path, char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi)
-{
- int (*sys_read)(const char *path, char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi);
- char *error;
-
- dlerror(); /* Clear any existing error */
- sys_read = (int (*)(const char *, char *, size_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "sys_read");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return sys_read(path, buf, size, offset, fi);
-}
-
-static int do_cg_write(const char *path, const char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi)
-{
- int (*cg_write)(const char *path, const char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_write = (int (*)(const char *, const char *, size_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_write");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_write(path, buf, size, offset, fi);
-}
-
-static int do_cg_mkdir(const char *path, mode_t mode)
-{
- int (*cg_mkdir)(const char *path, mode_t mode);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_mkdir = (int (*)(const char *, mode_t)) dlsym(dlopen_handle, "cg_mkdir");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_mkdir(path, mode);
-}
-
-static int do_cg_chown(const char *path, uid_t uid, gid_t gid)
-{
- int (*cg_chown)(const char *path, uid_t uid, gid_t gid);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_chown = (int (*)(const char *, uid_t, gid_t)) dlsym(dlopen_handle, "cg_chown");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_chown(path, uid, gid);
-}
-
-static int do_cg_rmdir(const char *path)
-{
- int (*cg_rmdir)(const char *path);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_rmdir = (int (*)(const char *path)) dlsym(dlopen_handle, "cg_rmdir");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_rmdir(path);
-}
-
-static int do_cg_chmod(const char *path, mode_t mode)
-{
- int (*cg_chmod)(const char *path, mode_t mode);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_chmod = (int (*)(const char *, mode_t)) dlsym(dlopen_handle, "cg_chmod");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_chmod(path, mode);
-}
-
-static int do_cg_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset,
- struct fuse_file_info *fi)
-{
- int (*cg_readdir)(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset,
- struct fuse_file_info *fi);
- char *error;
-
- dlerror(); /* Clear any existing error */
- cg_readdir = (int (*)(const char *, void *, fuse_fill_dir_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_readdir");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_readdir(path, buf, filler, offset, fi);
-}
-
-static int do_proc_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset,
- struct fuse_file_info *fi)
-{
- int (*proc_readdir)(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset,
- struct fuse_file_info *fi);
- char *error;
-
- dlerror(); /* Clear any existing error */
- proc_readdir = (int (*)(const char *, void *, fuse_fill_dir_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "proc_readdir");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return proc_readdir(path, buf, filler, offset, fi);
-}
-
-static int do_sys_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset,
- struct fuse_file_info *fi)
-{
- int (*sys_readdir)(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset,
- struct fuse_file_info *fi);
- char *error;
-
- dlerror(); /* Clear any existing error */
- sys_readdir = (int (*)(const char *, void *, fuse_fill_dir_t, off_t, struct fuse_file_info *)) dlsym(dlopen_handle, "sys_readdir");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return sys_readdir(path, buf, filler, offset, fi);
-}
-
-
-static int do_cg_open(const char *path, struct fuse_file_info *fi)
-{
- int (*cg_open)(const char *path, struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_open = (int (*)(const char *, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_open");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_open(path, fi);
-}
-
-static int do_cg_access(const char *path, int mode)
-{
- int (*cg_access)(const char *path, int mode);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_access = (int (*)(const char *, int mode)) dlsym(dlopen_handle, "cg_access");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_access(path, mode);
-}
-
-static int do_proc_open(const char *path, struct fuse_file_info *fi)
-{
- int (*proc_open)(const char *path, struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- proc_open = (int (*)(const char *path, struct fuse_file_info *fi)) dlsym(dlopen_handle, "proc_open");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return proc_open(path, fi);
-}
-
-static int do_proc_access(const char *path, int mode)
-{
- int (*proc_access)(const char *path, int mode);
- char *error;
- dlerror(); /* Clear any existing error */
- proc_access = (int (*)(const char *, int mode)) dlsym(dlopen_handle, "proc_access");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return proc_access(path, mode);
-}
-
-static int do_sys_open(const char *path, struct fuse_file_info *fi)
-{
- int (*sys_open)(const char *path, struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- sys_open = (int (*)(const char *path, struct fuse_file_info *fi)) dlsym(dlopen_handle, "sys_open");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return sys_open(path, fi);
-}
-
-static int do_sys_access(const char *path, int mode)
-{
- int (*sys_access)(const char *path, int mode);
- char *error;
- dlerror(); /* Clear any existing error */
- sys_access = (int (*)(const char *, int mode)) dlsym(dlopen_handle, "sys_access");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return sys_access(path, mode);
-}
-
-
-static int do_cg_release(const char *path, struct fuse_file_info *fi)
-{
- int (*cg_release)(const char *path, struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_release = (int (*)(const char *path, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_release");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_release(path, fi);
-}
-
-static int do_proc_release(const char *path, struct fuse_file_info *fi)
-{
- int (*proc_release)(const char *path, struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- proc_release = (int (*)(const char *path, struct fuse_file_info *)) dlsym(dlopen_handle, "proc_release");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return proc_release(path, fi);
-}
-
-static int do_sys_release(const char *path, struct fuse_file_info *fi)
-{
- int (*sys_release)(const char *path, struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- sys_release = (int (*)(const char *path, struct fuse_file_info *)) dlsym(dlopen_handle, "sys_release");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return sys_release(path, fi);
-}
-
-static int do_cg_opendir(const char *path, struct fuse_file_info *fi)
-{
- int (*cg_opendir)(const char *path, struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_opendir = (int (*)(const char *path, struct fuse_file_info *fi)) dlsym(dlopen_handle, "cg_opendir");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_opendir(path, fi);
-}
-
-static int do_cg_releasedir(const char *path, struct fuse_file_info *fi)
-{
- int (*cg_releasedir)(const char *path, struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- cg_releasedir = (int (*)(const char *path, struct fuse_file_info *)) dlsym(dlopen_handle, "cg_releasedir");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return cg_releasedir(path, fi);
-}
-
-static int do_sys_releasedir(const char *path, struct fuse_file_info *fi)
-{
- int (*sys_releasedir)(const char *path, struct fuse_file_info *fi);
- char *error;
- dlerror(); /* Clear any existing error */
- sys_releasedir = (int (*)(const char *path, struct fuse_file_info *)) dlsym(dlopen_handle, "sys_releasedir");
- error = dlerror();
- if (error != NULL) {
- lxcfs_error("%s\n", error);
- return -1;
- }
-
- return sys_releasedir(path, fi);
-}
-
-/*
- * FUSE ops for /
- * these just delegate to the /proc and /cgroup ops as
- * needed
- */
-
-static int lxcfs_getattr(const char *path, struct stat *sb)
-{
- int ret;
- struct timespec now;
-
- if (strcmp(path, "/") == 0) {
- if (clock_gettime(CLOCK_REALTIME, &now) < 0)
- return -EINVAL;
- sb->st_uid = sb->st_gid = 0;
- sb->st_atim = sb->st_mtim = sb->st_ctim = now;
- sb->st_size = 0;
- sb->st_mode = S_IFDIR | 00755;
- sb->st_nlink = 2;
- return 0;
- }
-
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_getattr(path, sb);
- down_users();
- return ret;
- }
- if (strncmp(path, "/proc", 5) == 0) {
- up_users();
- ret = do_proc_getattr(path, sb);
- down_users();
- return ret;
- }
- if (strncmp(path, "/sys", 4) == 0) {
- up_users();
- ret = do_sys_getattr(path, sb);
- down_users();
- return ret;
- }
- return -ENOENT;
-}
-
-static int lxcfs_opendir(const char *path, struct fuse_file_info *fi)
-{
- int ret;
- if (strcmp(path, "/") == 0)
- return 0;
-
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_opendir(path, fi);
- down_users();
- return ret;
- }
- if (strcmp(path, "/proc") == 0)
- return 0;
- if (strncmp(path, "/sys", 4) == 0)
- return 0;
-
- return -ENOENT;
-}
-
-static int lxcfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset,
- struct fuse_file_info *fi)
-{
- int ret;
- if (strcmp(path, "/") == 0) {
- if (filler(buf, ".", NULL, 0) != 0 ||
- filler(buf, "..", NULL, 0) != 0 ||
- filler(buf, "proc", NULL, 0) != 0 ||
- filler(buf, "sys", NULL, 0) != 0 ||
- filler(buf, "cgroup", NULL, 0) != 0)
- return -ENOMEM;
- return 0;
- }
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_readdir(path, buf, filler, offset, fi);
- down_users();
- return ret;
- }
- if (strcmp(path, "/proc") == 0) {
- up_users();
- ret = do_proc_readdir(path, buf, filler, offset, fi);
- down_users();
- return ret;
- }
-
- if (strncmp(path, "/sys", 4) == 0) {
- up_users();
- ret = do_sys_readdir(path, buf, filler, offset, fi);
- down_users();
- return ret;
- }
-
- return -ENOENT;
-}
-
-static int lxcfs_access(const char *path, int mode)
-{
- int ret;
-
- if (strcmp(path, "/") == 0 && (mode & W_OK) == 0)
- return 0;
-
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_access(path, mode);
- down_users();
- return ret;
- }
- if (strncmp(path, "/proc", 5) == 0) {
- up_users();
- ret = do_proc_access(path, mode);
- down_users();
- return ret;
- }
- if (strncmp(path, "/sys", 4) == 0) {
- up_users();
- ret = do_sys_access(path, mode);
- down_users();
- return ret;
- }
-
-
- return -EACCES;
-}
-
-static int lxcfs_releasedir(const char *path, struct fuse_file_info *fi)
-{
- int ret;
- if (strcmp(path, "/") == 0)
- return 0;
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_releasedir(path, fi);
- down_users();
- return ret;
- }
- if (strcmp(path, "/proc") == 0)
- return 0;
- if (strncmp(path, "/sys", 4) == 0){
- up_users();
- ret = do_sys_releasedir(path, fi);
- down_users();
- return ret;
- }
-
- return -EINVAL;
-}
-
-static int lxcfs_open(const char *path, struct fuse_file_info *fi)
-{
- int ret;
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_open(path, fi);
- down_users();
- return ret;
- }
- if (strncmp(path, "/proc", 5) == 0) {
- up_users();
- ret = do_proc_open(path, fi);
- down_users();
- return ret;
- }
- if (strncmp(path, "/sys", 4) == 0) {
- up_users();
- ret = do_sys_open(path, fi);
- down_users();
- return ret;
- }
-
-
- return -EACCES;
-}
-
-static int lxcfs_read(const char *path, char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi)
-{
- int ret;
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_read(path, buf, size, offset, fi);
- down_users();
- return ret;
- }
- if (strncmp(path, "/proc", 5) == 0) {
- up_users();
- ret = do_proc_read(path, buf, size, offset, fi);
- down_users();
- return ret;
- }
- if (strncmp(path, "/sys", 4) == 0) {
- up_users();
- ret = do_sys_read(path, buf, size, offset, fi);
- down_users();
- return ret;
- }
-
-
- return -EINVAL;
-}
-
-int lxcfs_write(const char *path, const char *buf, size_t size, off_t offset,
- struct fuse_file_info *fi)
-{
- int ret;
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_write(path, buf, size, offset, fi);
- down_users();
- return ret;
- }
-
- return -EINVAL;
-}
-
-static int lxcfs_flush(const char *path, struct fuse_file_info *fi)
-{
- return 0;
-}
-
-static int lxcfs_release(const char *path, struct fuse_file_info *fi)
-{
- int ret;
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_release(path, fi);
- down_users();
- return ret;
- }
- if (strncmp(path, "/proc", 5) == 0) {
- up_users();
- ret = do_proc_release(path, fi);
- down_users();
- return ret;
- }
- if (strncmp(path, "/sys", 4) == 0) {
- up_users();
- ret = do_sys_release(path, fi);
- down_users();
- return ret;
- }
-
-
- return -EINVAL;
-}
-
-static int lxcfs_fsync(const char *path, int datasync, struct fuse_file_info *fi)
-{
- return 0;
-}
-
-int lxcfs_mkdir(const char *path, mode_t mode)
-{
- int ret;
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_mkdir(path, mode);
- down_users();
- return ret;
- }
-
- return -EPERM;
-}
-
-int lxcfs_chown(const char *path, uid_t uid, gid_t gid)
-{
- int ret;
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_chown(path, uid, gid);
- down_users();
- return ret;
- }
-
- if (strncmp(path, "/proc", 5) == 0)
- return -EPERM;
-
- if (strncmp(path, "/sys", 4) == 0)
- return -EPERM;
- return -ENOENT;
-}
-
-/*
- * cat first does a truncate before doing ops->write. This doesn't
- * really make sense for cgroups. So just return 0 always but do
- * nothing.
- */
-int lxcfs_truncate(const char *path, off_t newsize)
-{
- if (strncmp(path, "/cgroup", 7) == 0)
- return 0;
- return -EPERM;
-}
-
-int lxcfs_rmdir(const char *path)
-{
- int ret;
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_rmdir(path);
- down_users();
- return ret;
- }
- return -EPERM;
-}
-
-int lxcfs_chmod(const char *path, mode_t mode)
-{
- int ret;
- if (strncmp(path, "/cgroup", 7) == 0) {
- up_users();
- ret = do_cg_chmod(path, mode);
- down_users();
- return ret;
- }
-
- if (strncmp(path, "/proc", 5) == 0)
- return -EPERM;
-
- if (strncmp(path, "/sys", 4) == 0)
- return -EPERM;
-
- return -ENOENT;
-}
-
-const struct fuse_operations lxcfs_ops = {
- .getattr = lxcfs_getattr,
- .readlink = NULL,
- .getdir = NULL,
- .mknod = NULL,
- .mkdir = lxcfs_mkdir,
- .unlink = NULL,
- .rmdir = lxcfs_rmdir,
- .symlink = NULL,
- .rename = NULL,
- .link = NULL,
- .chmod = lxcfs_chmod,
- .chown = lxcfs_chown,
- .truncate = lxcfs_truncate,
- .utime = NULL,
-
- .open = lxcfs_open,
- .read = lxcfs_read,
- .release = lxcfs_release,
- .write = lxcfs_write,
-
- .statfs = NULL,
- .flush = lxcfs_flush,
- .fsync = lxcfs_fsync,
-
- .setxattr = NULL,
- .getxattr = NULL,
- .listxattr = NULL,
- .removexattr = NULL,
-
- .opendir = lxcfs_opendir,
- .readdir = lxcfs_readdir,
- .releasedir = lxcfs_releasedir,
-
- .fsyncdir = NULL,
- .init = NULL,
- .destroy = NULL,
- .access = lxcfs_access,
- .create = NULL,
- .ftruncate = NULL,
- .fgetattr = NULL,
-};
-
-static void usage()
-{
- fprintf(stderr, "Usage:\n");
- fprintf(stderr, "\n");
- fprintf(stderr, "lxcfs [-f|-d] -u -l -n [-p pidfile] mountpoint\n");
- fprintf(stderr, " -f running foreground by default; -d enable debug output \n");
- fprintf(stderr, " -l use loadavg \n");
- fprintf(stderr, " -u no swap \n");
- fprintf(stderr, " Default pidfile is %s/lxcfs.pid\n", RUNTIME_PATH);
- fprintf(stderr, "lxcfs -h\n");
- fprintf(stderr, "lxcfs -v\n");
- exit(1);
-}
-
-static bool is_help(char *w)
-{
- if (strcmp(w, "-h") == 0 ||
- strcmp(w, "--help") == 0 ||
- strcmp(w, "-help") == 0 ||
- strcmp(w, "help") == 0)
- return true;
- return false;
-}
-
-static bool is_version(char *w)
-{
- if (strcmp(w, "-v") == 0 ||
- strcmp(w, "--version") == 0 ||
- strcmp(w, "-version") == 0 ||
- strcmp(w, "version") == 0)
- return true;
- return false;
-}
-
-bool swallow_arg(int *argcp, char *argv[], char *which)
-{
- int i;
-
- for (i = 1; argv[i]; i++) {
- if (strcmp(argv[i], which) != 0)
- continue;
- for (; argv[i]; i++) {
- argv[i] = argv[i+1];
- }
- (*argcp)--;
- return true;
- }
- return false;
-}
-
-bool swallow_option(int *argcp, char *argv[], char *opt, char **v)
-{
- int i;
-
- for (i = 1; argv[i]; i++) {
- if (!argv[i+1])
- continue;
- if (strcmp(argv[i], opt) != 0)
- continue;
- do {
- *v = strdup(argv[i+1]);
- } while (!*v);
- for (; argv[i+1]; i++) {
- argv[i] = argv[i+2];
- }
- (*argcp) -= 2;
- return true;
- }
- return false;
-}
-
-static int set_pidfile(char *pidfile)
-{
- int fd;
- char buf[50];
- struct flock fl;
-
- fl.l_type = F_WRLCK;
- fl.l_whence = SEEK_SET;
- fl.l_start = 0;
- fl.l_len = 0;
-
- fd = open(pidfile, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
- if (fd == -1) {
- fprintf(stderr, "Could not open pidfile %s: %m\n", pidfile);
- return -1;
- }
-
- if (fcntl(fd, F_SETLK, &fl) == -1) {
- if (errno == EAGAIN || errno == EACCES) {
- fprintf(stderr, "PID file '%s' is already locked.\n", pidfile);
- close(fd);
- return -1;
- }
- fprintf(stderr, "Warning; unable to lock PID file, proceeding.\n");
- }
-
- if (ftruncate(fd, 0) == -1) {
- fprintf(stderr, "Error truncating PID file '%s': %m", pidfile);
- close(fd);
- return -1;
- }
-
- snprintf(buf, 50, "%ld\n", (long) getpid());
- if (write(fd, buf, strlen(buf)) != strlen(buf)) {
- fprintf(stderr, "Error writing to PID file '%s': %m", pidfile);
- close(fd);
- return -1;
- }
-
- return fd;
-}
-
-int main(int argc, char *argv[])
-{
- int ret = EXIT_FAILURE;
- int pidfd = -1;
- char *pidfile = NULL, *saveptr = NULL, *token = NULL, *v = NULL;
- size_t pidfile_len;
- bool debug = false, nonempty = false;
- bool load_use = false;
- /*
- * what we pass to fuse_main is:
- * argv[0] -s [-f|-d] -o allow_other,directio argv[1] NULL
- */
- int nargs = 5, cnt = 0;
- char *newargv[6];
- struct lxcfs_opts *opts;
-
- opts = malloc(sizeof(struct lxcfs_opts));
- if (opts == NULL) {
- fprintf(stderr, "Error allocating memory for options.\n");
- goto out;
- }
- opts->swap_off = false;
- opts->use_pidfd = false;
-
- /* accomodate older init scripts */
- swallow_arg(&argc, argv, "-s");
- swallow_arg(&argc, argv, "-f");
- debug = swallow_arg(&argc, argv, "-d");
- if (swallow_arg(&argc, argv, "-l"))
- load_use = true;
- if (swallow_arg(&argc, argv, "-u"))
- opts->swap_off = true;
-
- if (swallow_arg(&argc, argv, "--pidfd"))
- opts->use_pidfd = true;
-
- if (swallow_option(&argc, argv, "-o", &v)) {
- /* Parse multiple values */
- for (; (token = strtok_r(v, ",", &saveptr)); v = NULL) {
- if (strcmp(token, "allow_other") == 0) {
- /* Noop. this is the default. Always enabled. */
- } else if (strcmp(token, "nonempty") == 0) {
- nonempty = true;
- } else {
- free(v);
- fprintf(stderr, "Warning: unexpected fuse option %s\n", v);
- exit(EXIT_FAILURE);
- }
- }
- free(v);
- v = NULL;
- }
- if (swallow_option(&argc, argv, "-p", &v))
- pidfile = v;
-
- if (argc == 2 && is_version(argv[1])) {
- fprintf(stderr, "%s\n", VERSION);
- exit(EXIT_SUCCESS);
- }
-
- if (argc != 2 || is_help(argv[1]))
- usage();
-
- do_reload();
- if (signal(SIGUSR1, reload_handler) == SIG_ERR) {
- fprintf(stderr, "Error setting USR1 signal handler: %m\n");
- goto out;
- }
-
- newargv[cnt++] = argv[0];
- if (debug)
- newargv[cnt++] = "-d";
- else
- newargv[cnt++] = "-f";
- newargv[cnt++] = "-o";
- if (nonempty)
- newargv[cnt++] = "allow_other,direct_io,entry_timeout=0.5,attr_timeout=0.5,nonempty";
- else
- newargv[cnt++] = "allow_other,direct_io,entry_timeout=0.5,attr_timeout=0.5";
- newargv[cnt++] = argv[1];
- newargv[cnt++] = NULL;
-
- if (!pidfile) {
- pidfile_len = strlen(RUNTIME_PATH) + strlen("/lxcfs.pid") + 1;
- pidfile = alloca(pidfile_len);
- snprintf(pidfile, pidfile_len, "%s/lxcfs.pid", RUNTIME_PATH);
- }
- if ((pidfd = set_pidfile(pidfile)) < 0)
- goto out;
-
- if (load_use && start_loadavg() != 0)
- goto out;
-
- if (!fuse_main(nargs, newargv, &lxcfs_ops, opts))
- ret = EXIT_SUCCESS;
- if (load_use)
- stop_loadavg();
-
-out:
- if (dlopen_handle)
- dlclose(dlopen_handle);
- if (pidfile)
- unlink(pidfile);
- if (pidfd > 0)
- close(pidfd);
- exit(ret);
-}
projects / mirror_lxcfs.git / blobdiff