38#define FUSE_USE_VERSION 34 
   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!");
 
   66struct _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;
 
   99static 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 },
 
  128static 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");
 
  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;
 
  168static 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");
 
  189static 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);
 
  291static 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);
 
  429static 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);
 
  512static 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);
 
  558static 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)
 
  635static 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;
 
  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,
 
 1181int 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)
void * fuse_req_userdata(fuse_req_t req)
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)
struct fuse_session * fuse_session_new(struct fuse_args *args, const struct fuse_lowlevel_ops *op, size_t op_size, void *userdata)
void fuse_reply_none(fuse_req_t req)
void fuse_lowlevel_help(void)
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)
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)