38 #define FUSE_USE_VERSION 34 
   42 #include <fuse_lowlevel.h> 
   56 #include <sys/xattr.h> 
   58 #include "passthrough_helpers.h" 
   64 #if defined(__GNUC__) && (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 6) && !defined __cplusplus 
   65 _Static_assert(
sizeof(
fuse_ino_t) >= 
sizeof(uintptr_t),
 
   66                "fuse_ino_t too small to hold uintptr_t values!");
 
   68 struct _uintptr_to_must_hold_fuse_ino_t_dummy_struct \
 
   69         { 
unsigned _uintptr_to_must_hold_fuse_ino_t:
 
   70                         ((
sizeof(
fuse_ino_t) >= 
sizeof(uintptr_t)) ? 1 : -1); };
 
   74         struct lo_inode *next; 
 
   75         struct lo_inode *prev; 
 
   89         pthread_mutex_t mutex;
 
  101 static const struct fuse_opt lo_opts[] = {
 
  103           offsetof(
struct lo_data, writeback), 1 },
 
  105           offsetof(
struct lo_data, writeback), 0 },
 
  107           offsetof(
struct lo_data, source), 0 },
 
  109           offsetof(
struct lo_data, flock), 1 },
 
  111           offsetof(
struct lo_data, flock), 0 },
 
  113           offsetof(
struct lo_data, xattr), 1 },
 
  115           offsetof(
struct lo_data, xattr), 0 },
 
  117           offsetof(
struct lo_data, timeout), 0 },
 
  119           offsetof(
struct lo_data, timeout_set), 1 },
 
  121           offsetof(
struct lo_data, cache), CACHE_NEVER },
 
  123           offsetof(
struct lo_data, cache), CACHE_NORMAL },
 
  125           offsetof(
struct lo_data, cache), CACHE_ALWAYS },
 
  130 static struct lo_data *lo_data(
fuse_req_t req)
 
  138                 return &lo_data(req)->root;
 
  140                 return (
struct lo_inode *) (uintptr_t) ino;
 
  145         return lo_inode(req, ino)->fd;
 
  150         return lo_data(req)->debug != 0;
 
  153 static void lo_init(
void *userdata,
 
  156         struct lo_data *lo = (
struct lo_data*) userdata;
 
  164                         fuse_log(FUSE_LOG_DEBUG, 
"lo_init: activating writeback\n");
 
  169                         fuse_log(FUSE_LOG_DEBUG, 
"lo_init: activating flock locks\n");
 
  174 static void lo_destroy(
void *userdata)
 
  176         struct lo_data *lo = (
struct lo_data*) userdata;
 
  178         while (lo->root.next != &lo->root) {
 
  179                 struct lo_inode* next = lo->root.next;
 
  180                 lo->root.next = next->next;
 
  190         struct lo_data *lo = lo_data(req);
 
  194         res = fstatat(lo_fd(req, ino), 
"", &buf, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
 
  206         struct lo_inode *inode = lo_inode(req, ino);
 
  210         if (valid & FUSE_SET_ATTR_MODE) {
 
  212                         res = fchmod(fi->
fh, attr->st_mode);
 
  214                         sprintf(procname, 
"/proc/self/fd/%i", ifd);
 
  215                         res = chmod(procname, attr->st_mode);
 
  220         if (valid & (FUSE_SET_ATTR_UID | FUSE_SET_ATTR_GID)) {
 
  221                 uid_t uid = (valid & FUSE_SET_ATTR_UID) ?
 
  222                         attr->st_uid : (uid_t) -1;
 
  223                 gid_t gid = (valid & FUSE_SET_ATTR_GID) ?
 
  224                         attr->st_gid : (gid_t) -1;
 
  226                 res = fchownat(ifd, 
"", uid, gid,
 
  227                                AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
 
  231         if (valid & FUSE_SET_ATTR_SIZE) {
 
  233                         res = ftruncate(fi->
fh, attr->st_size);
 
  235                         sprintf(procname, 
"/proc/self/fd/%i", ifd);
 
  236                         res = truncate(procname, attr->st_size);
 
  241         if (valid & (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME)) {
 
  242                 struct timespec tv[2];
 
  246                 tv[0].tv_nsec = UTIME_OMIT;
 
  247                 tv[1].tv_nsec = UTIME_OMIT;
 
  249                 if (valid & FUSE_SET_ATTR_ATIME_NOW)
 
  250                         tv[0].tv_nsec = UTIME_NOW;
 
  251                 else if (valid & FUSE_SET_ATTR_ATIME)
 
  252                         tv[0] = attr->st_atim;
 
  254                 if (valid & FUSE_SET_ATTR_MTIME_NOW)
 
  255                         tv[1].tv_nsec = UTIME_NOW;
 
  256                 else if (valid & FUSE_SET_ATTR_MTIME)
 
  257                         tv[1] = attr->st_mtim;
 
  260                         res = futimens(fi->
fh, tv);
 
  262                         sprintf(procname, 
"/proc/self/fd/%i", ifd);
 
  263                         res = utimensat(AT_FDCWD, procname, tv, 0);
 
  269         return lo_getattr(req, ino, fi);
 
  276 static struct lo_inode *lo_find(
struct lo_data *lo, 
struct stat *st)
 
  279         struct lo_inode *ret = NULL;
 
  281         pthread_mutex_lock(&lo->mutex);
 
  282         for (p = lo->root.next; p != &lo->root; p = p->next) {
 
  283                 if (p->ino == st->st_ino && p->dev == st->st_dev) {
 
  284                         assert(p->refcount > 0);
 
  290         pthread_mutex_unlock(&lo->mutex);
 
  300         struct lo_data *lo = lo_data(req);
 
  301         struct lo_inode *inode;
 
  303         memset(e, 0, 
sizeof(*e));
 
  307         newfd = openat(lo_fd(req, parent), name, O_PATH | O_NOFOLLOW);
 
  311         res = fstatat(newfd, 
"", &e->
attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
 
  315         inode = lo_find(lo_data(req), &e->
attr);
 
  320                 struct lo_inode *prev, *next;
 
  323                 inode = calloc(1, 
sizeof(
struct lo_inode));
 
  329                 inode->ino = e->
attr.st_ino;
 
  330                 inode->dev = e->
attr.st_dev;
 
  332                 pthread_mutex_lock(&lo->mutex);
 
  339                 pthread_mutex_unlock(&lo->mutex);
 
  341         e->
ino = (uintptr_t) inode;
 
  344                 fuse_log(FUSE_LOG_DEBUG, 
"  %lli/%s -> %lli\n",
 
  345                         (
unsigned long long) parent, name, (
unsigned long long) e->
ino);
 
  362                 fuse_log(FUSE_LOG_DEBUG, 
"lo_lookup(parent=%" PRIu64 
", name=%s)\n",
 
  365         err = lo_do_lookup(req, parent, name, &e);
 
  373                              const char *name, mode_t mode, dev_t rdev,
 
  378         struct lo_inode *dir = lo_inode(req, parent);
 
  381         res = mknod_wrapper(dir->fd, name, link, mode, rdev);
 
  387         saverr = lo_do_lookup(req, parent, name, &e);
 
  392                 fuse_log(FUSE_LOG_DEBUG, 
"  %lli/%s -> %lli\n",
 
  393                         (
unsigned long long) parent, name, (
unsigned long long) e.
ino);
 
  403                      const char *name, mode_t mode, dev_t rdev)
 
  405         lo_mknod_symlink(req, parent, name, mode, rdev, NULL);
 
  411         lo_mknod_symlink(req, parent, name, S_IFDIR | mode, 0, NULL);
 
  414 static void lo_symlink(
fuse_req_t req, 
const char *link,
 
  417         lo_mknod_symlink(req, parent, name, S_IFLNK, 0, link);
 
  424         struct lo_data *lo = lo_data(req);
 
  425         struct lo_inode *inode = lo_inode(req, ino);
 
  434         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
  435         res = linkat(AT_FDCWD, procname, lo_fd(req, parent), name,
 
  440         res = fstatat(inode->fd, 
"", &e.
attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
 
  444         pthread_mutex_lock(&lo->mutex);
 
  446         pthread_mutex_unlock(&lo->mutex);
 
  447         e.
ino = (uintptr_t) inode;
 
  450                 fuse_log(FUSE_LOG_DEBUG, 
"  %lli/%s -> %lli\n",
 
  451                         (
unsigned long long) parent, name,
 
  452                         (
unsigned long long) e.
ino);
 
  466         res = unlinkat(lo_fd(req, parent), name, AT_REMOVEDIR);
 
  482         res = renameat(lo_fd(req, parent), name,
 
  483                         lo_fd(req, newparent), newname);
 
  492         res = unlinkat(lo_fd(req, parent), name, 0);
 
  497 static void unref_inode(
struct lo_data *lo, 
struct lo_inode *inode, uint64_t n)
 
  502         pthread_mutex_lock(&lo->mutex);
 
  503         assert(inode->refcount >= n);
 
  504         inode->refcount -= n;
 
  505         if (!inode->refcount) {
 
  506                 struct lo_inode *prev, *next;
 
  513                 pthread_mutex_unlock(&lo->mutex);
 
  518                 pthread_mutex_unlock(&lo->mutex);
 
  524         struct lo_data *lo = lo_data(req);
 
  525         struct lo_inode *inode = lo_inode(req, ino);
 
  528                 fuse_log(FUSE_LOG_DEBUG, 
"  forget %lli %lli -%lli\n",
 
  529                         (
unsigned long long) ino,
 
  530                         (
unsigned long long) inode->refcount,
 
  531                         (
unsigned long long) nlookup);
 
  534         unref_inode(lo, inode, nlookup);
 
  539         lo_forget_one(req, ino, nlookup);
 
  543 static void lo_forget_multi(
fuse_req_t req, 
size_t count,
 
  544                                 struct fuse_forget_data *forgets)
 
  548         for (i = 0; i < count; i++)
 
  549                 lo_forget_one(req, forgets[i].ino, forgets[i].nlookup);
 
  555         char buf[PATH_MAX + 1];
 
  558         res = readlinkat(lo_fd(req, ino), 
"", buf, 
sizeof(buf));
 
  562         if (res == 
sizeof(buf))
 
  572         struct dirent *entry;
 
  578         return (
struct lo_dirp *) (uintptr_t) fi->
fh;
 
  584         struct lo_data *lo = lo_data(req);
 
  588         d = calloc(1, 
sizeof(
struct lo_dirp));
 
  592         fd = openat(lo_fd(req, ino), 
".", O_RDONLY);
 
  596         d->dp = fdopendir(fd);
 
  603         fi->
fh = (uintptr_t) d;
 
  604         if (lo->cache == CACHE_ALWAYS)
 
  620 static int is_dot_or_dotdot(
const char *name)
 
  622         return name[0] == 
'.' && (name[1] == 
'\0' ||
 
  623                                   (name[1] == 
'.' && name[2] == 
'\0'));
 
  629         struct lo_dirp *d = lo_dirp(fi);
 
  637         buf = calloc(1, size);
 
  644         if (offset != d->offset) {
 
  645                 seekdir(d->dp, offset);
 
  656                         d->entry = readdir(d->dp);
 
  666                 nextoff = d->entry->d_off;
 
  667                 name = d->entry->d_name;
 
  671                         if (is_dot_or_dotdot(name)) {
 
  673                                         .
attr.st_ino = d->entry->d_ino,
 
  674                                         .attr.st_mode = d->entry->d_type << 12,
 
  677                                 err = lo_do_lookup(req, ino, name, &e);
 
  687                                 .st_ino = d->entry->d_ino,
 
  688                                 .st_mode = d->entry->d_type << 12,
 
  695                                 lo_forget_one(req, entry_ino, 1);
 
  712     if (err && rem == size)
 
  722         lo_do_readdir(req, ino, size, offset, fi, 0);
 
  728         lo_do_readdir(req, ino, size, offset, fi, 1);
 
  733         struct lo_dirp *d = lo_dirp(fi);
 
  744         struct lo_data *lo = lo_data(req);
 
  749                 fuse_log(FUSE_LOG_DEBUG, 
"lo_create(parent=%" PRIu64 
", name=%s)\n",
 
  752         fd = openat(lo_fd(req, parent), name,
 
  753                     (fi->
flags | O_CREAT) & ~O_NOFOLLOW, mode);
 
  758         if (lo->cache == CACHE_NEVER)
 
  760         else if (lo->cache == CACHE_ALWAYS)
 
  763         err = lo_do_lookup(req, parent, name, &e);
 
  774         int fd = dirfd(lo_dirp(fi)->dp);
 
  787         struct lo_data *lo = lo_data(req);
 
  790                 fuse_log(FUSE_LOG_DEBUG, 
"lo_open(ino=%" PRIu64 
", flags=%d)\n",
 
  795         if (lo->writeback && (fi->
flags & O_ACCMODE) == O_WRONLY) {
 
  796                 fi->
flags &= ~O_ACCMODE;
 
  806         if (lo->writeback && (fi->
flags & O_APPEND))
 
  807                 fi->
flags &= ~O_APPEND;
 
  809         sprintf(buf, 
"/proc/self/fd/%i", lo_fd(req, ino));
 
  810         fd = open(buf, fi->
flags & ~O_NOFOLLOW);
 
  815         if (lo->cache == CACHE_NEVER)
 
  817         else if (lo->cache == CACHE_ALWAYS)
 
  834         res = close(dup(fi->
fh));
 
  844                 res = fdatasync(fi->
fh);
 
  856                 fuse_log(FUSE_LOG_DEBUG, 
"lo_read(ino=%" PRIu64 
", size=%zd, " 
  857                         "off=%lu)\n", ino, size, (
unsigned long) offset);
 
  879                 fuse_log(FUSE_LOG_DEBUG, 
"lo_write(ino=%" PRIu64 
", size=%zd, off=%lu)\n",
 
  880                         ino, out_buf.
buf[0].
size, (
unsigned long) 
off);
 
  892         struct statvfs stbuf;
 
  894         res = fstatvfs(lo_fd(req, ino), &stbuf);
 
  904         int err = EOPNOTSUPP;
 
  907 #ifdef HAVE_FALLOCATE 
  908         err = fallocate(fi->
fh, mode, offset, length);
 
  912 #elif defined(HAVE_POSIX_FALLOCATE) 
  918         err = posix_fallocate(fi->
fh, offset, length);
 
  930         res = flock(fi->
fh, op);
 
  940         struct lo_inode *inode = lo_inode(req, ino);
 
  945         if (!lo_data(req)->xattr)
 
  949                 fuse_log(FUSE_LOG_DEBUG, 
"lo_getxattr(ino=%" PRIu64 
", name=%s size=%zd)\n",
 
  953         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
  956                 value = malloc(size);
 
  960                 ret = getxattr(procname, name, value, size);
 
  969                 ret = getxattr(procname, name, NULL, 0);
 
  990         struct lo_inode *inode = lo_inode(req, ino);
 
  995         if (!lo_data(req)->xattr)
 
  999                 fuse_log(FUSE_LOG_DEBUG, 
"lo_listxattr(ino=%" PRIu64 
", size=%zd)\n",
 
 1003         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
 1006                 value = malloc(size);
 
 1010                 ret = listxattr(procname, value, size);
 
 1019                 ret = listxattr(procname, NULL, 0);
 
 1037                         const char *value, 
size_t size, 
int flags)
 
 1040         struct lo_inode *inode = lo_inode(req, ino);
 
 1045         if (!lo_data(req)->xattr)
 
 1048         if (lo_debug(req)) {
 
 1049                 fuse_log(FUSE_LOG_DEBUG, 
"lo_setxattr(ino=%" PRIu64 
", name=%s value=%s size=%zd)\n",
 
 1050                         ino, name, value, size);
 
 1053         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
 1055         ret = setxattr(procname, name, value, size, flags);
 
 1056         saverr = ret == -1 ? errno : 0;
 
 1065         struct lo_inode *inode = lo_inode(req, ino);
 
 1070         if (!lo_data(req)->xattr)
 
 1073         if (lo_debug(req)) {
 
 1074                 fuse_log(FUSE_LOG_DEBUG, 
"lo_removexattr(ino=%" PRIu64 
", name=%s)\n",
 
 1078         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
 
 1080         ret = removexattr(procname, name);
 
 1081         saverr = ret == -1 ? errno : 0;
 
 1087 #ifdef HAVE_COPY_FILE_RANGE 
 1097                 fuse_log(FUSE_LOG_DEBUG, 
"lo_copy_file_range(ino=%" PRIu64 
"/fd=%lu, " 
 1098                                 "off=%lu, ino=%" PRIu64 
"/fd=%lu, " 
 1099                                 "off=%lu, size=%zd, flags=0x%x)\n",
 
 1100                         ino_in, fi_in->
fh, off_in, ino_out, fi_out->
fh, off_out,
 
 1103         res = copy_file_range(fi_in->
fh, &off_in, fi_out->
fh, &off_out, len,
 
 1118         res = lseek(fi->
fh, off, whence);
 
 1127         .destroy        = lo_destroy,
 
 1128         .lookup         = lo_lookup,
 
 1131         .symlink        = lo_symlink,
 
 1133         .unlink         = lo_unlink,
 
 1135         .rename         = lo_rename,
 
 1136         .forget         = lo_forget,
 
 1137         .forget_multi   = lo_forget_multi,
 
 1138         .getattr        = lo_getattr,
 
 1139         .setattr        = lo_setattr,
 
 1140         .readlink       = lo_readlink,
 
 1141         .opendir        = lo_opendir,
 
 1142         .readdir        = lo_readdir,
 
 1143         .readdirplus    = lo_readdirplus,
 
 1144         .releasedir     = lo_releasedir,
 
 1145         .fsyncdir       = lo_fsyncdir,
 
 1146         .create         = lo_create,
 
 1148         .release        = lo_release,
 
 1152         .write_buf      = lo_write_buf,
 
 1153         .statfs         = lo_statfs,
 
 1154         .fallocate      = lo_fallocate,
 
 1156         .getxattr       = lo_getxattr,
 
 1157         .listxattr      = lo_listxattr,
 
 1158         .setxattr       = lo_setxattr,
 
 1159         .removexattr    = lo_removexattr,
 
 1160 #ifdef HAVE_COPY_FILE_RANGE 
 1161         .copy_file_range = lo_copy_file_range,
 
 1166 int main(
int argc, 
char *argv[])
 
 1169         struct fuse_session *se;
 
 1172         struct lo_data lo = { .debug = 0,
 
 1179         pthread_mutex_init(&lo.mutex, NULL);
 
 1180         lo.root.next = lo.root.prev = &lo.root;
 
 1182         lo.cache = CACHE_NORMAL;
 
 1186         if (opts.show_help) {
 
 1187                 printf(
"usage: %s [options] <mountpoint>\n\n", argv[0]);
 
 1192         } 
else if (opts.show_version) {
 
 1199         if(opts.mountpoint == NULL) {
 
 1200                 printf(
"usage: %s [options] <mountpoint>\n", argv[0]);
 
 1201                 printf(
"       %s --help\n", argv[0]);
 
 1209         lo.debug = opts.debug;
 
 1210         lo.root.refcount = 2;
 
 1215                 res = lstat(lo.source, &stat);
 
 1217                         fuse_log(FUSE_LOG_ERR, 
"failed to stat source (\"%s\"): %m\n",
 
 1221                 if (!S_ISDIR(stat.st_mode)) {
 
 1222                         fuse_log(FUSE_LOG_ERR, 
"source is not a directory\n");
 
 1229         if (!lo.timeout_set) {
 
 1240                         lo.timeout = 86400.0;
 
 1243         } 
else if (lo.timeout < 0) {
 
 1244                 fuse_log(FUSE_LOG_ERR, 
"timeout is negative (%lf)\n",
 
 1249         lo.root.fd = open(lo.source, O_PATH);
 
 1250         if (lo.root.fd == -1) {
 
 1251                 fuse_log(FUSE_LOG_ERR, 
"open(\"%s\", O_PATH): %m\n",
 
 1269         if (opts.singlethread)
 
 1272                 config.clone_fd = opts.clone_fd;
 
 1273                 config.max_idle_threads = opts.max_idle_threads;
 
 1274                 ret = fuse_session_loop_mt(se, &config);
 
 1283         free(opts.mountpoint);
 
 1286         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)
int fuse_parse_cmdline(struct fuse_args *args, struct fuse_cmdline_opts *opts)
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)