src/core/device.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2010 Lennart Poettering
   8 ***/
   9
  10 #include "unit.h"
  11
  12 typedef struct Device Device;
  13
  14 /* A mask specifying where we have seen the device currently. This is a bitmask because the device might show up
  15  * asynchronously from each other at various places. For example, in very common case a device might already be mounted
  16  * before udev finished probing it (think: a script setting up a loopback block device, formatting it and mounting it
  17  * in quick succession). Hence we need to track precisely where it is already visible and where not. */
  18 typedef enum DeviceFound {
  19         DEVICE_NOT_FOUND   = 0,
  20         DEVICE_FOUND_UDEV  = 1U << 1, /* The device has shown up in the udev database */
  21         DEVICE_FOUND_MOUNT = 1U << 2, /* The device has shown up in /proc/self/mountinfo */
  22         DEVICE_FOUND_SWAP  = 1U << 3, /* The device has shown up in /proc/swaps */
  23         DEVICE_FOUND_MASK  = DEVICE_FOUND_UDEV|DEVICE_FOUND_MOUNT|DEVICE_FOUND_SWAP,
  24 } DeviceFound;
  25
  26 struct Device {
  27         Unit meta;
  28
  29         char *sysfs;
  30
  31         /* In order to be able to distinguish dependencies on different device nodes we might end up creating multiple
  32          * devices for the same sysfs path. We chain them up here. */
  33         LIST_FIELDS(struct Device, same_sysfs);
  34
  35         DeviceState state, deserialized_state;
  36         DeviceFound found, deserialized_found, enumerated_found;
  37
  38         bool bind_mounts;
  39 };
  40
  41 extern const UnitVTable device_vtable;
  42
  43 void device_found_node(Manager *m, const char *node, DeviceFound found, DeviceFound mask);
  44 bool device_shall_be_bound_by(Unit *device, Unit *u);
  45
  46 DEFINE_CAST(DEVICE, Device);