38 #define FUSE_USE_VERSION 34 
   40 #include <fuse_lowlevel.h> 
   54 #include <sys/xattr.h> 
   56 #include "passthrough_helpers.h" 
   62 #if defined(__GNUC__) && (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 6) && !defined __cplusplus 
   63 _Static_assert(
sizeof(
fuse_ino_t) >= 
sizeof(uintptr_t),
 
   64                "fuse_ino_t too small to hold uintptr_t values!");
 
   66 struct _uintptr_to_must_hold_fuse_ino_t_dummy_struct \
 
   67         { 
unsigned _uintptr_to_must_hold_fuse_ino_t:
 
   68                         ((
sizeof(
fuse_ino_t) >= 
sizeof(uintptr_t)) ? 1 : -1); };
 
   72         struct lo_inode *next; 
 
   73         struct lo_inode *prev; 
 
   87         pthread_mutex_t mutex;
 
   99 static const struct fuse_opt lo_opts[] = {
 
  101           offsetof(
struct lo_data, writeback), 1 },
 
  103           offsetof(
struct lo_data, writeback), 0 },
 
  105           offsetof(
struct lo_data, source), 0 },
 
  107           offsetof(
struct lo_data, flock), 1 },
 
  109           offsetof(
struct lo_data, flock), 0 },
 
  111           offsetof(
struct lo_data, xattr), 1 },
 
  113           offsetof(
struct lo_data, xattr), 0 },
 
  115           offsetof(
struct lo_data, timeout), 0 },
 
  117           offsetof(
struct lo_data, timeout_set), 1 },
 
  119           offsetof(
struct lo_data, cache), CACHE_NEVER },
 
  121           offsetof(
struct lo_data, cache), CACHE_NORMAL },
 
  123           offsetof(
struct lo_data, cache), CACHE_ALWAYS },
 
  128 static void passthrough_ll_help(
void)
 
  131 "    -o writeback           Enable writeback\n" 
  132 "    -o no_writeback        Disable write back\n" 
  133 "    -o source=/home/dir    Source directory to be mounted\n" 
  134 "    -o flock               Enable flock\n" 
  135 "    -o no_flock            Disable flock\n" 
  136 "    -o xattr               Enable xattr\n" 
  137 "    -o no_xattr            Disable xattr\n" 
  138 "    -o timeout=1.0         Caching timeout\n" 
  139 "    -o timeout=0/1         Timeout is set\n" 
  140 "    -o cache=never         Disable cache\n" 
  141 "    -o cache=auto          Auto enable cache\n" 
  142 "    -o cache=always        Cache always\n");
 
  145 static struct lo_data *lo_data(
fuse_req_t req)
 
  153                 return &lo_data(req)->root;
 
  155                 return (
struct lo_inode *) (uintptr_t) ino;
 
  160         return lo_inode(req, ino)->fd;
 
  165         return lo_data(req)->debug != 0;
 
  168 static void lo_init(
void *userdata,
 
  171         struct lo_data *lo = (
struct lo_data*) userdata;
 
  179                         fuse_log(FUSE_LOG_DEBUG, 
"lo_init: activating writeback\n");
 
  184                         fuse_log(FUSE_LOG_DEBUG, 
"lo_init: activating flock locks\n");
 
  189 static void lo_destroy(
void *userdata)
 
  191         struct lo_data *lo = (
struct lo_data*) userdata;
 
  193         while (lo->root.next != &lo->root) {
 
  194                 struct lo_inode* next = lo->root.next;
 
  195                 lo->root.next = next->next;
 
  205         struct lo_data *lo = lo_data(req);
 
  209         res = fstatat(lo_fd(req, ino), 
"", &buf, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
 
  221         struct lo_inode *inode = lo_inode(req, ino);
 
  225         if (valid & FUSE_SET_ATTR_MODE) {
 
  227                         res = fchmod(fi->
fh, attr->st_mode);
 
  229                         sprintf(procname, 
"/proc/self/fd/%i", ifd);
 
  230                         res = chmod(procname, attr->st_mode);
 
  235         if (valid & (FUSE_SET_ATTR_UID | FUSE_SET_ATTR_GID)) {
 
  236                 uid_t uid = (valid & FUSE_SET_ATTR_UID) ?
 
  237                         attr->st_uid : (uid_t) -1;
 
  238                 gid_t gid = (valid & FUSE_SET_ATTR_GID) ?
 
  239                         attr->st_gid : (gid_t) -1;
 
  241                 res = fchownat(ifd, 
"", uid, gid,
 
  242                                AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
 
  246         if (valid & FUSE_SET_ATTR_SIZE) {
 
  248                         res = ftruncate(fi->
fh, attr->st_size);
 
  250                         sprintf(procname, 
"/proc/self/fd/%i", ifd);
 
  251                         res = truncate(procname, attr->st_size);
 
  256         if (valid & (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME)) {
 
  257                 struct timespec tv[2];
 
  261                 tv[0].tv_nsec = UTIME_OMIT;
 
  262                 tv[1].tv_nsec = UTIME_OMIT;
 
  264                 if (valid & FUSE_SET_ATTR_ATIME_NOW)
 
  265                         tv[0].tv_nsec = UTIME_NOW;
 
  266                 else if (valid & FUSE_SET_ATTR_ATIME)
 
  267                         tv[0] = attr->st_atim;
 
  269                 if (valid & FUSE_SET_ATTR_MTIME_NOW)
 
  270                         tv[1].tv_nsec = UTIME_NOW;
 
  271                 else if (valid & FUSE_SET_ATTR_MTIME)
 
  272                         tv[1] = attr->st_mtim;
 
  275                         res = futimens(fi->
fh, tv);
 
  277                         sprintf(procname, 
"/proc/self/fd/%i", ifd);
 
  278                         res = utimensat(AT_FDCWD, procname, tv, 0);
 
  284         return lo_getattr(req, ino, fi);
 
  291 static struct lo_inode *lo_find(
struct lo_data *lo, 
struct stat *st)
 
  294         struct lo_inode *ret = NULL;
 
  296         pthread_mutex_lock(&lo->mutex);
 
  297         for (p = lo->root.next; p != &lo->root; p = p->next) {
 
  298                 if (p->ino == st->st_ino && p->dev == st->st_dev) {
 
  299                         assert(p->refcount > 0);
 
  305         pthread_mutex_unlock(&lo->mutex);
 
  315         struct lo_data *lo = lo_data(req);
 
  316         struct lo_inode *inode;
 
  318         memset(e, 0, 
sizeof(*e));
 
  322         newfd = openat(lo_fd(req, parent), name, O_PATH | O_NOFOLLOW);
 
  326         res = fstatat(newfd, 
"", &e->
attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
 
  330         inode = lo_find(lo_data(req), &e->
attr);
 
  335                 struct lo_inode *prev, *next;
 
  338                 inode = calloc(1, 
sizeof(
struct lo_inode));
 
  344                 inode->ino = e->
attr.st_ino;
 
  345                 inode->dev = e->
attr.st_dev;
 
  347                 pthread_mutex_lock(&lo->mutex);
 
  354                 pthread_mutex_unlock(&lo->mutex);
 
  356         e->
ino = (uintptr_t) inode;
 
  359                 fuse_log(FUSE_LOG_DEBUG, 
"  %lli/%s -> %lli\n",
 
  360                         (
unsigned long long) parent, name, (
unsigned long long) e->
ino);
 
  377                 fuse_log(FUSE_LOG_DEBUG, 
"lo_lookup(parent=%" PRIu64 
", name=%s)\n",
 
  380         err = lo_do_lookup(req, parent, name, &e);
 
  388                              const char *name, mode_t mode, dev_t rdev,
 
  393         struct lo_inode *dir = lo_inode(req, parent);
 
  396         res = mknod_wrapper(dir->fd, name, link, mode, rdev);
 
  402         saverr = lo_do_lookup(req, parent, name, &e);
 
  407                 fuse_log(FUSE_LOG_DEBUG, 
"  %lli/%s -> %lli\n",
 
  408                         (
unsigned long long) parent, name, (
unsigned long long) e.
ino);
 
  418                      const char *name, mode_t mode, dev_t rdev)
 
  420         lo_mknod_symlink(req, parent, name, mode, rdev, NULL);
 
  426         lo_mknod_symlink(req, parent, name, S_IFDIR | mode, 0, NULL);
 
  429 static void lo_symlink(
fuse_req_t req, 
const char *link,
 
  432         lo_mknod_symlink(req, parent, name, S_IFLNK, 0, link);
 
  439         struct lo_data *lo = lo_data(req);
 
  440         struct lo_inode *inode = lo_inode(req, ino);
 
  449         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
  450         res = linkat(AT_FDCWD, procname, lo_fd(req, parent), name,
 
  455         res = fstatat(inode->fd, 
"", &e.
attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
 
  459         pthread_mutex_lock(&lo->mutex);
 
  461         pthread_mutex_unlock(&lo->mutex);
 
  462         e.
ino = (uintptr_t) inode;
 
  465                 fuse_log(FUSE_LOG_DEBUG, 
"  %lli/%s -> %lli\n",
 
  466                         (
unsigned long long) parent, name,
 
  467                         (
unsigned long long) e.
ino);
 
  481         res = unlinkat(lo_fd(req, parent), name, AT_REMOVEDIR);
 
  497         res = renameat(lo_fd(req, parent), name,
 
  498                         lo_fd(req, newparent), newname);
 
  507         res = unlinkat(lo_fd(req, parent), name, 0);
 
  512 static void unref_inode(
struct lo_data *lo, 
struct lo_inode *inode, uint64_t n)
 
  517         pthread_mutex_lock(&lo->mutex);
 
  518         assert(inode->refcount >= n);
 
  519         inode->refcount -= n;
 
  520         if (!inode->refcount) {
 
  521                 struct lo_inode *prev, *next;
 
  528                 pthread_mutex_unlock(&lo->mutex);
 
  533                 pthread_mutex_unlock(&lo->mutex);
 
  539         struct lo_data *lo = lo_data(req);
 
  540         struct lo_inode *inode = lo_inode(req, ino);
 
  543                 fuse_log(FUSE_LOG_DEBUG, 
"  forget %lli %lli -%lli\n",
 
  544                         (
unsigned long long) ino,
 
  545                         (
unsigned long long) inode->refcount,
 
  546                         (
unsigned long long) nlookup);
 
  549         unref_inode(lo, inode, nlookup);
 
  554         lo_forget_one(req, ino, nlookup);
 
  558 static void lo_forget_multi(
fuse_req_t req, 
size_t count,
 
  559                                 struct fuse_forget_data *forgets)
 
  563         for (i = 0; i < count; i++)
 
  564                 lo_forget_one(req, forgets[i].ino, forgets[i].nlookup);
 
  570         char buf[PATH_MAX + 1];
 
  573         res = readlinkat(lo_fd(req, ino), 
"", buf, 
sizeof(buf));
 
  577         if (res == 
sizeof(buf))
 
  587         struct dirent *entry;
 
  593         return (
struct lo_dirp *) (uintptr_t) fi->
fh;
 
  599         struct lo_data *lo = lo_data(req);
 
  603         d = calloc(1, 
sizeof(
struct lo_dirp));
 
  607         fd = openat(lo_fd(req, ino), 
".", O_RDONLY);
 
  611         d->dp = fdopendir(fd);
 
  618         fi->
fh = (uintptr_t) d;
 
  619         if (lo->cache == CACHE_ALWAYS)
 
  635 static int is_dot_or_dotdot(
const char *name)
 
  637         return name[0] == 
'.' && (name[1] == 
'\0' ||
 
  638                                   (name[1] == 
'.' && name[2] == 
'\0'));
 
  644         struct lo_dirp *d = lo_dirp(fi);
 
  652         buf = calloc(1, size);
 
  659         if (offset != d->offset) {
 
  660                 seekdir(d->dp, offset);
 
  671                         d->entry = readdir(d->dp);
 
  681                 nextoff = d->entry->d_off;
 
  682                 name = d->entry->d_name;
 
  686                         if (is_dot_or_dotdot(name)) {
 
  688                                         .
attr.st_ino = d->entry->d_ino,
 
  689                                         .attr.st_mode = d->entry->d_type << 12,
 
  692                                 err = lo_do_lookup(req, ino, name, &e);
 
  702                                 .st_ino = d->entry->d_ino,
 
  703                                 .st_mode = d->entry->d_type << 12,
 
  710                                 lo_forget_one(req, entry_ino, 1);
 
  727     if (err && rem == size)
 
  737         lo_do_readdir(req, ino, size, offset, fi, 0);
 
  743         lo_do_readdir(req, ino, size, offset, fi, 1);
 
  748         struct lo_dirp *d = lo_dirp(fi);
 
  759         struct lo_data *lo = lo_data(req);
 
  764                 fuse_log(FUSE_LOG_DEBUG, 
"lo_create(parent=%" PRIu64 
", name=%s)\n",
 
  767         fd = openat(lo_fd(req, parent), name,
 
  768                     (fi->
flags | O_CREAT) & ~O_NOFOLLOW, mode);
 
  773         if (lo->cache == CACHE_NEVER)
 
  775         else if (lo->cache == CACHE_ALWAYS)
 
  778         err = lo_do_lookup(req, parent, name, &e);
 
  789         int fd = dirfd(lo_dirp(fi)->dp);
 
  802         struct lo_data *lo = lo_data(req);
 
  805                 fuse_log(FUSE_LOG_DEBUG, 
"lo_open(ino=%" PRIu64 
", flags=%d)\n",
 
  810         if (lo->writeback && (fi->
flags & O_ACCMODE) == O_WRONLY) {
 
  811                 fi->
flags &= ~O_ACCMODE;
 
  821         if (lo->writeback && (fi->
flags & O_APPEND))
 
  822                 fi->
flags &= ~O_APPEND;
 
  824         sprintf(buf, 
"/proc/self/fd/%i", lo_fd(req, ino));
 
  825         fd = open(buf, fi->
flags & ~O_NOFOLLOW);
 
  830         if (lo->cache == CACHE_NEVER)
 
  832         else if (lo->cache == CACHE_ALWAYS)
 
  849         res = close(dup(fi->
fh));
 
  859                 res = fdatasync(fi->
fh);
 
  871                 fuse_log(FUSE_LOG_DEBUG, 
"lo_read(ino=%" PRIu64 
", size=%zd, " 
  872                         "off=%lu)\n", ino, size, (
unsigned long) offset);
 
  894                 fuse_log(FUSE_LOG_DEBUG, 
"lo_write(ino=%" PRIu64 
", size=%zd, off=%lu)\n",
 
  895                         ino, out_buf.
buf[0].
size, (
unsigned long) 
off);
 
  907         struct statvfs stbuf;
 
  909         res = fstatvfs(lo_fd(req, ino), &stbuf);
 
  919         int err = EOPNOTSUPP;
 
  922 #ifdef HAVE_FALLOCATE 
  923         err = fallocate(fi->
fh, mode, offset, length);
 
  927 #elif defined(HAVE_POSIX_FALLOCATE) 
  933         err = posix_fallocate(fi->
fh, offset, length);
 
  945         res = flock(fi->
fh, op);
 
  955         struct lo_inode *inode = lo_inode(req, ino);
 
  960         if (!lo_data(req)->xattr)
 
  964                 fuse_log(FUSE_LOG_DEBUG, 
"lo_getxattr(ino=%" PRIu64 
", name=%s size=%zd)\n",
 
  968         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
  971                 value = malloc(size);
 
  975                 ret = getxattr(procname, name, value, size);
 
  984                 ret = getxattr(procname, name, NULL, 0);
 
 1005         struct lo_inode *inode = lo_inode(req, ino);
 
 1010         if (!lo_data(req)->xattr)
 
 1013         if (lo_debug(req)) {
 
 1014                 fuse_log(FUSE_LOG_DEBUG, 
"lo_listxattr(ino=%" PRIu64 
", size=%zd)\n",
 
 1018         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
 1021                 value = malloc(size);
 
 1025                 ret = listxattr(procname, value, size);
 
 1034                 ret = listxattr(procname, NULL, 0);
 
 1052                         const char *value, 
size_t size, 
int flags)
 
 1055         struct lo_inode *inode = lo_inode(req, ino);
 
 1060         if (!lo_data(req)->xattr)
 
 1063         if (lo_debug(req)) {
 
 1064                 fuse_log(FUSE_LOG_DEBUG, 
"lo_setxattr(ino=%" PRIu64 
", name=%s value=%s size=%zd)\n",
 
 1065                         ino, name, value, size);
 
 1068         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
 1070         ret = setxattr(procname, name, value, size, flags);
 
 1071         saverr = ret == -1 ? errno : 0;
 
 1080         struct lo_inode *inode = lo_inode(req, ino);
 
 1085         if (!lo_data(req)->xattr)
 
 1088         if (lo_debug(req)) {
 
 1089                 fuse_log(FUSE_LOG_DEBUG, 
"lo_removexattr(ino=%" PRIu64 
", name=%s)\n",
 
 1093         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
 1095         ret = removexattr(procname, name);
 
 1096         saverr = ret == -1 ? errno : 0;
 
 1102 #ifdef HAVE_COPY_FILE_RANGE 
 1112                 fuse_log(FUSE_LOG_DEBUG, 
"lo_copy_file_range(ino=%" PRIu64 
"/fd=%lu, " 
 1113                                 "off=%lu, ino=%" PRIu64 
"/fd=%lu, " 
 1114                                 "off=%lu, size=%zd, flags=0x%x)\n",
 
 1115                         ino_in, fi_in->
fh, off_in, ino_out, fi_out->
fh, off_out,
 
 1118         res = copy_file_range(fi_in->
fh, &off_in, fi_out->
fh, &off_out, len,
 
 1133         res = lseek(fi->
fh, off, whence);
 
 1142         .destroy        = lo_destroy,
 
 1143         .lookup         = lo_lookup,
 
 1146         .symlink        = lo_symlink,
 
 1148         .unlink         = lo_unlink,
 
 1150         .rename         = lo_rename,
 
 1151         .forget         = lo_forget,
 
 1152         .forget_multi   = lo_forget_multi,
 
 1153         .getattr        = lo_getattr,
 
 1154         .setattr        = lo_setattr,
 
 1155         .readlink       = lo_readlink,
 
 1156         .opendir        = lo_opendir,
 
 1157         .readdir        = lo_readdir,
 
 1158         .readdirplus    = lo_readdirplus,
 
 1159         .releasedir     = lo_releasedir,
 
 1160         .fsyncdir       = lo_fsyncdir,
 
 1161         .create         = lo_create,
 
 1163         .release        = lo_release,
 
 1167         .write_buf      = lo_write_buf,
 
 1168         .statfs         = lo_statfs,
 
 1169         .fallocate      = lo_fallocate,
 
 1171         .getxattr       = lo_getxattr,
 
 1172         .listxattr      = lo_listxattr,
 
 1173         .setxattr       = lo_setxattr,
 
 1174         .removexattr    = lo_removexattr,
 
 1175 #ifdef HAVE_COPY_FILE_RANGE 
 1176         .copy_file_range = lo_copy_file_range,
 
 1181 int main(
int argc, 
char *argv[])
 
 1184         struct fuse_session *se;
 
 1187         struct lo_data lo = { .debug = 0,
 
 1194         pthread_mutex_init(&lo.mutex, NULL);
 
 1195         lo.root.next = lo.root.prev = &lo.root;
 
 1197         lo.cache = CACHE_NORMAL;
 
 1199         if (fuse_parse_cmdline(&args, &opts) != 0)
 
 1201         if (opts.show_help) {
 
 1202                 printf(
"usage: %s [options] <mountpoint>\n\n", argv[0]);
 
 1205                 passthrough_ll_help();
 
 1208         } 
else if (opts.show_version) {
 
 1215         if(opts.mountpoint == NULL) {
 
 1216                 printf(
"usage: %s [options] <mountpoint>\n", argv[0]);
 
 1217                 printf(
"       %s --help\n", argv[0]);
 
 1225         lo.debug = opts.debug;
 
 1226         lo.root.refcount = 2;
 
 1231                 res = lstat(lo.source, &stat);
 
 1233                         fuse_log(FUSE_LOG_ERR, 
"failed to stat source (\"%s\"): %m\n",
 
 1237                 if (!S_ISDIR(stat.st_mode)) {
 
 1238                         fuse_log(FUSE_LOG_ERR, 
"source is not a directory\n");
 
 1243                 lo.source = strdup(
"/");
 
 1245                         fuse_log(FUSE_LOG_ERR, 
"fuse: memory allocation failed\n");
 
 1249         if (!lo.timeout_set) {
 
 1260                         lo.timeout = 86400.0;
 
 1263         } 
else if (lo.timeout < 0) {
 
 1264                 fuse_log(FUSE_LOG_ERR, 
"timeout is negative (%lf)\n",
 
 1269         lo.root.fd = open(lo.source, O_PATH);
 
 1270         if (lo.root.fd == -1) {
 
 1271                 fuse_log(FUSE_LOG_ERR, 
"open(\"%s\", O_PATH): %m\n",
 
 1289         if (opts.singlethread)
 
 1292                 config.clone_fd = opts.clone_fd;
 
 1293                 config.max_idle_threads = opts.max_idle_threads;
 
 1294                 ret = fuse_session_loop_mt(se, &config);
 
 1303         free(opts.mountpoint);
 
 1306         if (lo.root.fd >= 0)
 
int fuse_set_signal_handlers(struct fuse_session *se)
size_t fuse_buf_size(const struct fuse_bufvec *bufv)
#define FUSE_CAP_WRITEBACK_CACHE
#define FUSE_CAP_EXPORT_SUPPORT
ssize_t fuse_buf_copy(struct fuse_bufvec *dst, struct fuse_bufvec *src, enum fuse_buf_copy_flags flags)
const char * fuse_pkgversion(void)
void fuse_remove_signal_handlers(struct fuse_session *se)
int fuse_daemonize(int foreground)
#define FUSE_CAP_FLOCK_LOCKS
void fuse_log(enum fuse_log_level level, const char *fmt,...)
void fuse_session_destroy(struct fuse_session *se)
int fuse_reply_data(fuse_req_t req, struct fuse_bufvec *bufv, enum fuse_buf_copy_flags flags)
int fuse_reply_open(fuse_req_t req, const struct fuse_file_info *fi)
int fuse_reply_err(fuse_req_t req, int err)
int fuse_reply_buf(fuse_req_t req, const char *buf, size_t size)
struct fuse_req * fuse_req_t
size_t fuse_add_direntry_plus(fuse_req_t req, char *buf, size_t bufsize, const char *name, const struct fuse_entry_param *e, off_t off)
int fuse_reply_readlink(fuse_req_t req, const char *link)
int fuse_session_loop(struct fuse_session *se)
int fuse_reply_entry(fuse_req_t req, const struct fuse_entry_param *e)
void fuse_session_unmount(struct fuse_session *se)
void fuse_cmdline_help(void)
void fuse_reply_none(fuse_req_t req)
void fuse_lowlevel_help(void)
struct fuse_session * fuse_session_new(struct fuse_args *args, const struct fuse_lowlevel_ops *op, size_t op_size, void *userdata)
int fuse_reply_statfs(fuse_req_t req, const struct statvfs *stbuf)
int fuse_reply_write(fuse_req_t req, size_t count)
int fuse_session_mount(struct fuse_session *se, const char *mountpoint)
void * fuse_req_userdata(fuse_req_t req)
int fuse_reply_create(fuse_req_t req, const struct fuse_entry_param *e, const struct fuse_file_info *fi)
int fuse_reply_lseek(fuse_req_t req, off_t off)
void fuse_lowlevel_version(void)
size_t fuse_add_direntry(fuse_req_t req, char *buf, size_t bufsize, const char *name, const struct stat *stbuf, off_t off)
int fuse_reply_attr(fuse_req_t req, const struct stat *attr, double attr_timeout)
int fuse_reply_xattr(fuse_req_t req, size_t count)
void fuse_opt_free_args(struct fuse_args *args)
int fuse_opt_parse(struct fuse_args *args, void *data, const struct fuse_opt opts[], fuse_opt_proc_t proc)
#define FUSE_ARGS_INIT(argc, argv)
enum fuse_buf_flags flags
unsigned int cache_readdir
void(* init)(void *userdata, struct fuse_conn_info *conn)