38 #define FUSE_USE_VERSION 31    57 #include <sys/xattr.h>    63 #if defined(__GNUC__) && (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 6) && !defined __cplusplus    64 _Static_assert(
sizeof(
fuse_ino_t) >= 
sizeof(uintptr_t),
    65                "fuse_ino_t too small to hold uintptr_t values!");
    67 struct _uintptr_to_must_hold_fuse_ino_t_dummy_struct \
    68         { 
unsigned _uintptr_to_must_hold_fuse_ino_t:
    69                         ((
sizeof(
fuse_ino_t) >= 
sizeof(uintptr_t)) ? 1 : -1); };
    73         struct lo_inode *next; 
    74         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                         fprintf(stderr, 
"lo_init: activating writeback\n");
   169                         fprintf(stderr, 
"lo_init: activating flock locks\n");
   179         struct lo_data *lo = lo_data(req);
   183         res = fstatat(lo_fd(req, ino), 
"", &buf, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
   190 static int utimensat_empty_nofollow(
struct lo_inode *inode,
   191                                     const struct timespec *tv)
   196         if (inode->is_symlink) {
   197                 res = utimensat(inode->fd, 
"", tv,
   198                                 AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
   199                 if (res == -1 && errno == EINVAL) {
   205         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
   207         return utimensat(AT_FDCWD, procname, tv, 0);
   215         struct lo_inode *inode = lo_inode(req, ino);
   219         if (valid & FUSE_SET_ATTR_MODE) {
   221                         res = fchmod(fi->
fh, attr->st_mode);
   223                         sprintf(procname, 
"/proc/self/fd/%i", ifd);
   224                         res = chmod(procname, attr->st_mode);
   229         if (valid & (FUSE_SET_ATTR_UID | FUSE_SET_ATTR_GID)) {
   230                 uid_t uid = (valid & FUSE_SET_ATTR_UID) ?
   231                         attr->st_uid : (uid_t) -1;
   232                 gid_t gid = (valid & FUSE_SET_ATTR_GID) ?
   233                         attr->st_gid : (gid_t) -1;
   235                 res = fchownat(ifd, 
"", uid, gid,
   236                                AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
   240         if (valid & FUSE_SET_ATTR_SIZE) {
   242                         res = ftruncate(fi->
fh, attr->st_size);
   244                         sprintf(procname, 
"/proc/self/fd/%i", ifd);
   245                         res = truncate(procname, attr->st_size);
   250         if (valid & (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME)) {
   251                 struct timespec tv[2];
   255                 tv[0].tv_nsec = UTIME_OMIT;
   256                 tv[1].tv_nsec = UTIME_OMIT;
   258                 if (valid & FUSE_SET_ATTR_ATIME_NOW)
   259                         tv[0].tv_nsec = UTIME_NOW;
   260                 else if (valid & FUSE_SET_ATTR_ATIME)
   261                         tv[0] = attr->st_atim;
   263                 if (valid & FUSE_SET_ATTR_MTIME_NOW)
   264                         tv[1].tv_nsec = UTIME_NOW;
   265                 else if (valid & FUSE_SET_ATTR_MTIME)
   266                         tv[1] = attr->st_mtim;
   269                         res = futimens(fi->
fh, tv);
   271                         res = utimensat_empty_nofollow(inode, tv);
   276         return lo_getattr(req, ino, fi);
   283 static struct lo_inode *lo_find(
struct lo_data *lo, 
struct stat *st)
   286         struct lo_inode *ret = NULL;
   288         pthread_mutex_lock(&lo->mutex);
   289         for (p = lo->root.next; p != &lo->root; p = p->next) {
   290                 if (p->ino == st->st_ino && p->dev == st->st_dev) {
   291                         assert(p->refcount > 0);
   297         pthread_mutex_unlock(&lo->mutex);
   307         struct lo_data *lo = lo_data(req);
   308         struct lo_inode *inode;
   310         memset(e, 0, 
sizeof(*e));
   314         newfd = openat(lo_fd(req, parent), name, O_PATH | O_NOFOLLOW);
   318         res = fstatat(newfd, 
"", &e->
attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
   322         inode = lo_find(lo_data(req), &e->
attr);
   327                 struct lo_inode *prev, *next;
   330                 inode = calloc(1, 
sizeof(
struct lo_inode));
   334                 inode->is_symlink = S_ISLNK(e->
attr.st_mode);
   337                 inode->ino = e->
attr.st_ino;
   338                 inode->dev = e->
attr.st_dev;
   340                 pthread_mutex_lock(&lo->mutex);
   347                 pthread_mutex_unlock(&lo->mutex);
   349         e->
ino = (uintptr_t) inode;
   352                 fprintf(stderr, 
"  %lli/%s -> %lli\n",
   353                         (
unsigned long long) parent, name, (
unsigned long long) e->
ino);
   370                 fprintf(stderr, 
"lo_lookup(parent=%" PRIu64 
", name=%s)\n",
   373         err = lo_do_lookup(req, parent, name, &e);
   381                              const char *name, mode_t mode, dev_t rdev,
   387         struct lo_inode *inode;
   388         struct lo_inode *dir = lo_inode(req, parent);
   392         inode = calloc(1, 
sizeof(
struct lo_inode));
   397                 res = mkdirat(dir->fd, name, mode);
   398         else if (S_ISLNK(mode))
   399                 res = symlinkat(link, dir->fd, name);
   401                 res = mknodat(dir->fd, name, mode, rdev);
   406         saverr = lo_do_lookup(req, parent, name, &e);
   411                 fprintf(stderr, 
"  %lli/%s -> %lli\n",
   412                         (
unsigned long long) parent, name, (
unsigned long long) e.
ino);
   425                      const char *name, mode_t mode, dev_t rdev)
   427         lo_mknod_symlink(req, parent, name, mode, rdev, NULL);
   433         lo_mknod_symlink(req, parent, name, S_IFDIR | mode, 0, NULL);
   436 static void lo_symlink(
fuse_req_t req, 
const char *link,
   439         lo_mknod_symlink(req, parent, name, S_IFLNK, 0, link);
   442 static int linkat_empty_nofollow(
struct lo_inode *inode, 
int dfd,
   448         if (inode->is_symlink) {
   449                 res = linkat(inode->fd, 
"", dfd, name, AT_EMPTY_PATH);
   450                 if (res == -1 && (errno == ENOENT || errno == EINVAL)) {
   457         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
   459         return linkat(AT_FDCWD, procname, dfd, name, AT_SYMLINK_FOLLOW);
   466         struct lo_data *lo = lo_data(req);
   467         struct lo_inode *inode = lo_inode(req, ino);
   475         res = linkat_empty_nofollow(inode, lo_fd(req, parent), name);
   479         res = fstatat(inode->fd, 
"", &e.
attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
   483         pthread_mutex_lock(&lo->mutex);
   485         pthread_mutex_unlock(&lo->mutex);
   486         e.
ino = (uintptr_t) inode;
   489                 fprintf(stderr, 
"  %lli/%s -> %lli\n",
   490                         (
unsigned long long) parent, name,
   491                         (
unsigned long long) e.
ino);
   505         res = unlinkat(lo_fd(req, parent), name, AT_REMOVEDIR);
   521         res = renameat(lo_fd(req, parent), name,
   522                         lo_fd(req, newparent), newname);
   531         res = unlinkat(lo_fd(req, parent), name, 0);
   536 static void unref_inode(
struct lo_data *lo, 
struct lo_inode *inode, uint64_t n)
   541         pthread_mutex_lock(&lo->mutex);
   542         assert(inode->refcount >= n);
   543         inode->refcount -= n;
   544         if (!inode->refcount) {
   545                 struct lo_inode *prev, *next;
   552                 pthread_mutex_unlock(&lo->mutex);
   557                 pthread_mutex_unlock(&lo->mutex);
   563         struct lo_data *lo = lo_data(req);
   564         struct lo_inode *inode = lo_inode(req, ino);
   567                 fprintf(stderr, 
"  forget %lli %lli -%lli\n",
   568                         (
unsigned long long) ino,
   569                         (
unsigned long long) inode->refcount,
   570                         (
unsigned long long) nlookup);
   573         unref_inode(lo, inode, nlookup);
   578         lo_forget_one(req, ino, nlookup);
   582 static void lo_forget_multi(
fuse_req_t req, 
size_t count,
   583                                 struct fuse_forget_data *forgets)
   587         for (i = 0; i < count; i++)
   588                 lo_forget_one(req, forgets[i].ino, forgets[i].nlookup);
   594         char buf[PATH_MAX + 1];
   597         res = readlinkat(lo_fd(req, ino), 
"", buf, 
sizeof(buf));
   601         if (res == 
sizeof(buf))
   612         struct dirent *entry;
   618         return (
struct lo_dirp *) (uintptr_t) fi->
fh;
   624         struct lo_data *lo = lo_data(req);
   625         struct lo_dirp *d = calloc(1, 
sizeof(
struct lo_dirp));
   629         d->fd = openat(lo_fd(req, ino), 
".", O_RDONLY);
   633         d->dp = fdopendir(d->fd);
   640         fi->
fh = (uintptr_t) d;
   641         if (lo->cache == CACHE_ALWAYS)
   657 static int is_dot_or_dotdot(
const char *name)
   659         return name[0] == 
'.' && (name[1] == 
'\0' ||
   660                                   (name[1] == 
'.' && name[2] == 
'\0'));
   666         struct lo_dirp *d = lo_dirp(fi);
   674         buf = calloc(1, size);
   681         if (offset != d->offset) {
   682                 seekdir(d->dp, offset);
   693                         d->entry = readdir(d->dp);
   703                 nextoff = d->entry->d_off;
   704                 name = d->entry->d_name;
   708                         if (is_dot_or_dotdot(name)) {
   710                                         .
attr.st_ino = d->entry->d_ino,
   711                                         .attr.st_mode = d->entry->d_type << 12,
   714                                 err = lo_do_lookup(req, ino, name, &e);
   724                                 .st_ino = d->entry->d_ino,
   725                                 .st_mode = d->entry->d_type << 12,
   732                                 lo_forget_one(req, entry_ino, 1);
   749     if (err && rem == size)
   759         lo_do_readdir(req, ino, size, offset, fi, 0);
   765         lo_do_readdir(req, ino, size, offset, fi, 1);
   770         struct lo_dirp *d = lo_dirp(fi);
   785                 fprintf(stderr, 
"lo_create(parent=%" PRIu64 
", name=%s)\n",
   788         fd = openat(lo_fd(req, parent), name,
   789                     (fi->
flags | O_CREAT) & ~O_NOFOLLOW, mode);
   795         err = lo_do_lookup(req, parent, name, &e);
   806         int fd = dirfd(lo_dirp(fi)->dp);
   819         struct lo_data *lo = lo_data(req);
   822                 fprintf(stderr, 
"lo_open(ino=%" PRIu64 
", flags=%d)\n",
   827         if (lo->writeback && (fi->
flags & O_ACCMODE) == O_WRONLY) {
   828                 fi->
flags &= ~O_ACCMODE;
   838         if (lo->writeback && (fi->
flags & O_APPEND))
   839                 fi->
flags &= ~O_APPEND;
   841         sprintf(buf, 
"/proc/self/fd/%i", lo_fd(req, ino));
   842         fd = open(buf, fi->
flags & ~O_NOFOLLOW);
   847         if (lo->cache == CACHE_NEVER)
   849         else if (lo->cache == CACHE_ALWAYS)
   866         res = close(dup(fi->
fh));
   876                 res = fdatasync(fi->
fh);
   888                 fprintf(stderr, 
"lo_read(ino=%" PRIu64 
", size=%zd, "   889                         "off=%lu)\n", ino, size, (
unsigned long) offset);
   911                 fprintf(stderr, 
"lo_write(ino=%" PRIu64 
", size=%zd, off=%lu)\n",
   912                         ino, out_buf.
buf[0].
size, (
unsigned long) off);
   924         struct statvfs stbuf;
   926         res = fstatvfs(lo_fd(req, ino), &stbuf);
   944         err = posix_fallocate(fi->
fh, offset, length);
   955         res = flock(fi->
fh, op);
   965         struct lo_inode *inode = lo_inode(req, ino);
   970         if (!lo_data(req)->xattr)
   974                 fprintf(stderr, 
"lo_getxattr(ino=%" PRIu64 
", name=%s size=%zd)\n",
   978         if (inode->is_symlink) {
   984         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
   987                 value = malloc(size);
   991                 ret = getxattr(procname, name, value, size);
  1000                 ret = getxattr(procname, name, NULL, 0);
  1021         struct lo_inode *inode = lo_inode(req, ino);
  1026         if (!lo_data(req)->xattr)
  1029         if (lo_debug(req)) {
  1030                 fprintf(stderr, 
"lo_listxattr(ino=%" PRIu64 
", size=%zd)\n",
  1034         if (inode->is_symlink) {
  1040         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
  1043                 value = malloc(size);
  1047                 ret = listxattr(procname, value, size);
  1056                 ret = listxattr(procname, NULL, 0);
  1074                         const char *value, 
size_t size, 
int flags)
  1077         struct lo_inode *inode = lo_inode(req, ino);
  1082         if (!lo_data(req)->xattr)
  1085         if (lo_debug(req)) {
  1086                 fprintf(stderr, 
"lo_setxattr(ino=%" PRIu64 
", name=%s value=%s size=%zd)\n",
  1087                         ino, name, value, size);
  1090         if (inode->is_symlink) {
  1096         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
  1098         ret = setxattr(procname, name, value, size, flags);
  1099         saverr = ret == -1 ? errno : 0;
  1108         struct lo_inode *inode = lo_inode(req, ino);
  1113         if (!lo_data(req)->xattr)
  1116         if (lo_debug(req)) {
  1117                 fprintf(stderr, 
"lo_removexattr(ino=%" PRIu64 
", name=%s)\n",
  1121         if (inode->is_symlink) {
  1127         sprintf(procname, 
"/proc/self/fd/%i", inode->fd);
  1129         ret = removexattr(procname, name);
  1130         saverr = ret == -1 ? errno : 0;
  1136 #ifdef HAVE_COPY_FILE_RANGE  1146                 fprintf(stderr, 
"lo_copy_file_range(ino=%" PRIu64 
"/fd=%lu, "  1147                                 "off=%lu, ino=%" PRIu64 
"/fd=%lu, "  1148                                 "off=%lu, size=%zd, flags=0x%x)\n",
  1149                         ino_in, fi_in->
fh, off_in, ino_out, fi_out->
fh, off_out,
  1152         res = copy_file_range(fi_in->
fh, &off_in, fi_out->
fh, &off_out, len,
  1163         .lookup         = lo_lookup,
  1166         .symlink        = lo_symlink,
  1168         .unlink         = lo_unlink,
  1170         .rename         = lo_rename,
  1171         .forget         = lo_forget,
  1172         .forget_multi   = lo_forget_multi,
  1173         .getattr        = lo_getattr,
  1174         .setattr        = lo_setattr,
  1175         .readlink       = lo_readlink,
  1176         .opendir        = lo_opendir,
  1177         .readdir        = lo_readdir,
  1178         .readdirplus    = lo_readdirplus,
  1179         .releasedir     = lo_releasedir,
  1180         .fsyncdir       = lo_fsyncdir,
  1181         .create         = lo_create,
  1183         .release        = lo_release,
  1187         .write_buf      = lo_write_buf,
  1188         .statfs         = lo_statfs,
  1189         .fallocate      = lo_fallocate,
  1191         .getxattr       = lo_getxattr,
  1192         .listxattr      = lo_listxattr,
  1193         .setxattr       = lo_setxattr,
  1194         .removexattr    = lo_removexattr,
  1195 #ifdef HAVE_COPY_FILE_RANGE  1196         .copy_file_range = lo_copy_file_range,
  1200 int main(
int argc, 
char *argv[])
  1203         struct fuse_session *se;
  1204         struct fuse_cmdline_opts opts;
  1205         struct lo_data lo = { .debug = 0,
  1212         pthread_mutex_init(&lo.mutex, NULL);
  1213         lo.root.next = lo.root.prev = &lo.root;
  1215         lo.cache = CACHE_NORMAL;
  1219         if (opts.show_help) {
  1220                 printf(
"usage: %s [options] <mountpoint>\n\n", argv[0]);
  1225         } 
else if (opts.show_version) {
  1232         if(opts.mountpoint == NULL) {
  1233                 printf(
"usage: %s [options] <mountpoint>\n", argv[0]);
  1234                 printf(
"       %s --help\n", argv[0]);
  1242         lo.debug = opts.debug;
  1243         lo.root.refcount = 2;
  1248                 res = lstat(lo.source, &stat);
  1250                         err(1, 
"failed to stat source (\"%s\")", lo.source);
  1251                 if (!S_ISDIR(stat.st_mode))
  1252                         errx(1, 
"source is not a directory");
  1257         lo.root.is_symlink = 
false;
  1258         if (!lo.timeout_set) {
  1269                         lo.timeout = 86400.0;
  1272         } 
else if (lo.timeout < 0) {
  1273                 errx(1, 
"timeout is negative (%lf)", lo.timeout);
  1276         lo.root.fd = open(lo.source, O_PATH);
  1277         if (lo.root.fd == -1)
  1278                 err(1, 
"open(\"%s\", O_PATH)", lo.source);
  1293         if (opts.singlethread)
  1296                 ret = fuse_session_loop_mt(se, opts.clone_fd);
  1304         free(opts.mountpoint);
  1307         if (lo.root.fd >= 0)
 void fuse_session_destroy(struct fuse_session *se)
int fuse_reply_err(fuse_req_t req, int err)
struct fuse_session * fuse_session_new(struct fuse_args *args, const struct fuse_lowlevel_ops *op, size_t op_size, void *userdata)
int fuse_session_loop(struct fuse_session *se)
void fuse_lowlevel_help(void)
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_data(fuse_req_t req, struct fuse_bufvec *bufv, enum fuse_buf_copy_flags flags)
int fuse_daemonize(int foreground)
int fuse_session_mount(struct fuse_session *se, const char *mountpoint)
int fuse_opt_parse(struct fuse_args *args, void *data, const struct fuse_opt opts[], fuse_opt_proc_t proc)
struct fuse_req * fuse_req_t
size_t fuse_add_direntry(fuse_req_t req, char *buf, size_t bufsize, const char *name, const struct stat *stbuf, off_t off)
void * fuse_req_userdata(fuse_req_t req)
#define FUSE_CAP_EXPORT_SUPPORT
int fuse_parse_cmdline(struct fuse_args *args, struct fuse_cmdline_opts *opts)
int fuse_reply_xattr(fuse_req_t req, size_t count)
void fuse_cmdline_help(void)
int fuse_reply_entry(fuse_req_t req, const struct fuse_entry_param *e)
int fuse_set_signal_handlers(struct fuse_session *se)
void fuse_remove_signal_handlers(struct fuse_session *se)
void fuse_lowlevel_version(void)
void fuse_reply_none(fuse_req_t req)
void fuse_opt_free_args(struct fuse_args *args)
int fuse_reply_attr(fuse_req_t req, const struct stat *attr, double attr_timeout)
void fuse_session_unmount(struct fuse_session *se)
enum fuse_buf_flags flags
int fuse_reply_statfs(fuse_req_t req, const struct statvfs *stbuf)
#define FUSE_CAP_FLOCK_LOCKS
int fuse_reply_create(fuse_req_t req, const struct fuse_entry_param *e, const struct fuse_file_info *fi)
int fuse_reply_write(fuse_req_t req, size_t count)
#define FUSE_CAP_WRITEBACK_CACHE
int fuse_reply_open(fuse_req_t req, const struct fuse_file_info *fi)
const char * fuse_pkgversion(void)
#define FUSE_ARGS_INIT(argc, argv)
size_t fuse_buf_size(const struct fuse_bufvec *bufv)
ssize_t fuse_buf_copy(struct fuse_bufvec *dst, struct fuse_bufvec *src, enum fuse_buf_copy_flags flags)
int fuse_reply_readlink(fuse_req_t req, const char *link)
int fuse_reply_buf(fuse_req_t req, const char *buf, size_t size)
void(* init)(void *userdata, struct fuse_conn_info *conn)