Module: Mountfd::Native

Defined in:
ext/mountfd/mountfd.c

Defined Under Namespace

Classes: Handle

Class Method Summary collapse

Class Method Details

.fsconfig(handle, command, key, value, aux) ⇒ Object 



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# File 'ext/mountfd/mountfd.c', line 184

static VALUE native_fsconfig(VALUE self, VALUE handle, VALUE command, VALUE key,
                             VALUE value, VALUE aux)
{
#ifdef __linux__
    int fd = fd_from(handle);
    unsigned int cmd = NUM2UINT(command);
    int raw_aux = NUM2INT(aux);
    const char *key_ptr;
    const void *value_ptr;
    if (!NIL_P(key)) StringValueCStr(key);
    if (!NIL_P(value)) {
        if (cmd == FSCONFIG_SET_BINARY) StringValue(value);
        else StringValueCStr(value);
    }
    if (cmd == FSCONFIG_SET_BINARY &&
        (raw_aux < 0 || (NIL_P(value) ? raw_aux != 0 : raw_aux > RSTRING_LEN(value))))
        rb_raise(rb_eArgError, "binary fsconfig length must be between zero and the value size");
    key_ptr = NIL_P(key) ? NULL : RSTRING_PTR(key);
    if (NIL_P(value)) value_ptr = NULL;
    else value_ptr = RSTRING_PTR(value);
    if (syscall(SYS_fsconfig, fd, cmd, key_ptr, value_ptr, raw_aux) < 0) {
        int error = errno;
        RB_GC_GUARD(key);
        RB_GC_GUARD(value);
        errno = error;
        mountfd_syscall_failed("fsconfig");
    }
    RB_GC_GUARD(key);
    RB_GC_GUARD(value);
    return Qnil;
#else
    unavailable(); return Qnil;
#endif
}

.fsmount(handle, flags, attrs) ⇒ Object 



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# File 'ext/mountfd/mountfd.c', line 219

static VALUE native_fsmount(VALUE self, VALUE handle, VALUE flags, VALUE attrs)
{
#ifdef __linux__
    int context_fd = fd_from(handle);
    unsigned int raw_flags = NUM2UINT(flags);
    unsigned int raw_attrs = NUM2UINT(attrs);
    int fd = (int)syscall(SYS_fsmount, context_fd, raw_flags, raw_attrs);
    if (fd < 0) mountfd_syscall_failed("fsmount");
    return mountfd_wrap_fd(fd);
#else
    unavailable(); return Qnil;
#endif
}

.fsopen(fsname, flags) ⇒ Object 



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# File 'ext/mountfd/mountfd.c', line 169

static VALUE native_fsopen(VALUE self, VALUE fsname, VALUE flags)
{
#ifdef __linux__
    unsigned int raw_flags = NUM2UINT(flags);
    const char *name = StringValueCStr(fsname);
    int fd = (int)syscall(SYS_fsopen, name, raw_flags);
    RB_GC_GUARD(fsname);
    if (fd < 0) mountfd_syscall_failed("fsopen");
    set_nonblocking_or_close(fd);
    return mountfd_wrap_fd(fd);
#else
    unavailable(); return Qnil;
#endif
}

.fspick(dfd, path, flags) ⇒ Object 



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# File 'ext/mountfd/mountfd.c', line 233

static VALUE native_fspick(VALUE self, VALUE dfd, VALUE path, VALUE flags)
{
#ifdef __linux__
    int directory_fd = NUM2INT(dfd);
    unsigned int raw_flags = NUM2UINT(flags);
    const char *raw_path = StringValueCStr(path);
    int fd = (int)syscall(SYS_fspick, directory_fd, raw_path, raw_flags);
    RB_GC_GUARD(path);
    if (fd < 0) mountfd_syscall_failed("fspick");
    set_nonblocking_or_close(fd);
    return mountfd_wrap_fd(fd);
#else
    unavailable(); return Qnil;
#endif
}

.linux? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'ext/mountfd/mountfd.c', line 137

static VALUE native_linux_p(VALUE self)
{
#ifdef __linux__
    return Qtrue;
#else
    return Qfalse;
#endif
}

.mount_setattr(dfd, path, flags, attr_set, attr_clr, propagation, userns_fd) ⇒ Object 



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# File 'ext/mountfd/mountfd.c', line 291

static VALUE native_mount_setattr(VALUE self, VALUE dfd, VALUE path, VALUE flags,
                                  VALUE attr_set, VALUE attr_clr, VALUE propagation,
                                  VALUE userns_fd)
{
#ifdef __linux__
    int directory_fd = fd_from(dfd);
    unsigned int raw_flags = NUM2UINT(flags);
    uint64_t raw_set = NUM2ULL(attr_set);
    uint64_t raw_clr = NUM2ULL(attr_clr);
    uint64_t raw_propagation = NUM2ULL(propagation);
    int has_idmap = (raw_set & MOUNT_ATTR_IDMAP) != 0;
    if ((raw_clr & MOUNT_ATTR_IDMAP) != 0)
        rb_raise(rb_eArgError, "an idmapped mount cannot be cleared");
    if ((has_idmap && NIL_P(userns_fd)) || (!has_idmap && !NIL_P(userns_fd)))
        rb_raise(rb_eArgError, "MOUNT_ATTR_IDMAP and a user namespace fd must be provided together");
    struct mount_attr attr = {
        raw_set, raw_clr, raw_propagation,
        NIL_P(userns_fd) ? 0 : (uint64_t)fd_from(userns_fd)
    };
    const char *raw_path = StringValueCStr(path);
    if (syscall(SYS_mount_setattr, directory_fd, raw_path, raw_flags,
                &attr, MOUNT_ATTR_SIZE_VER0) < 0) {
        int error = errno;
        RB_GC_GUARD(path);
        errno = error;
        mountfd_syscall_failed("mount_setattr");
    }
    RB_GC_GUARD(path);
    return Qnil;
#else
    unavailable(); return Qnil;
#endif
}

.move_mount(from_dfd, from_path, to_dfd, to_path, flags) ⇒ Object 



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# File 'ext/mountfd/mountfd.c', line 264

static VALUE native_move_mount(VALUE self, VALUE from_dfd, VALUE from_path,
                               VALUE to_dfd, VALUE to_path, VALUE flags)
{
#ifdef __linux__
    int source_fd = fd_from(from_dfd);
    int target_fd = NUM2INT(to_dfd);
    unsigned int raw_flags = NUM2UINT(flags);
    const char *source_path, *target_path;
    StringValueCStr(from_path);
    StringValueCStr(to_path);
    source_path = RSTRING_PTR(from_path);
    target_path = RSTRING_PTR(to_path);
    if (syscall(SYS_move_mount, source_fd, source_path, target_fd, target_path, raw_flags) < 0) {
        int error = errno;
        RB_GC_GUARD(from_path);
        RB_GC_GUARD(to_path);
        errno = error;
        mountfd_syscall_failed("move_mount");
    }
    RB_GC_GUARD(from_path);
    RB_GC_GUARD(to_path);
    return Qnil;
#else
    unavailable(); return Qnil;
#endif
}

.open_tree(dfd, path, flags) ⇒ Object 



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# File 'ext/mountfd/mountfd.c', line 249

static VALUE native_open_tree(VALUE self, VALUE dfd, VALUE path, VALUE flags)
{
#ifdef __linux__
    int directory_fd = NUM2INT(dfd);
    unsigned int raw_flags = NUM2UINT(flags);
    const char *raw_path = StringValueCStr(path);
    int fd = (int)syscall(SYS_open_tree, directory_fd, raw_path, raw_flags);
    RB_GC_GUARD(path);
    if (fd < 0) mountfd_syscall_failed("open_tree");
    return mountfd_wrap_fd(fd);
#else
    unavailable(); return Qnil;
#endif
}

.read_diagnostics(handle) ⇒ Object 



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# File 'ext/mountfd/mountfd.c', line 343

static VALUE native_read_diagnostics(VALUE self, VALUE handle)
{
#ifdef __linux__
    char buffer[4096];
    int fd = fd_from(handle);
    VALUE output = rb_str_new(NULL, 0);
    ssize_t length;
    for (;;) {
        length = read(fd, buffer, sizeof(buffer));
        if (length > 0) rb_str_cat(output, buffer, length);
        else if (length < 0 && errno == EINTR) continue;
        else break;
    }
    if (length < 0 && errno != EAGAIN && errno != EWOULDBLOCK && errno != ENODATA)
        rb_sys_fail("read(fs_context)");
    return output;
#else
    unavailable(); return Qnil;
#endif
}

.syscall_available?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'ext/mountfd/mountfd.c', line 146

static VALUE native_syscall_available(VALUE self, VALUE name)
{
#ifdef __linux__
    const char *value = StringValueCStr(name);
    long result;
    if (strcmp(value, "fsopen") == 0) {
        result = syscall(SYS_fsopen, "__mountfd_probe__", FSOPEN_CLOEXEC);
        if (result >= 0) mountfd_close((int)result);
    } else if (strcmp(value, "mount_setattr") == 0) {
        result = syscall(SYS_mount_setattr, -1, "", 0, NULL, 0);
    } else if (strcmp(value, "statmount") == 0) {
        result = syscall(SYS_statmount, NULL, NULL, 0, 0);
    } else if (strcmp(value, "listmount") == 0) {
        result = syscall(SYS_listmount, NULL, NULL, 0, 0);
    } else {
        rb_raise(rb_eArgError, "unknown syscall: %s", value);
    }
    return result >= 0 || errno != ENOSYS ? Qtrue : Qfalse;
#else
    return Qfalse;
#endif
}

.umount2(path, flags) ⇒ Object 



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# File 'ext/mountfd/mountfd.c', line 325

static VALUE native_umount2(VALUE self, VALUE path, VALUE flags)
{
#ifdef __linux__
    int raw_flags = NUM2INT(flags);
    const char *raw_path = StringValueCStr(path);
    if (umount2(raw_path, raw_flags) < 0) {
        int error = errno;
        RB_GC_GUARD(path);
        errno = error;
        mountfd_syscall_failed("umount2");
    }
    RB_GC_GUARD(path);
    return Qnil;
#else
    unavailable(); return Qnil;
#endif
}