src/core/device.h

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