From 628c89cc68ab96fce2de7ebba5933725d147aecc Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 27 Feb 2015 21:55:08 +0100 Subject: core: rework device state logic This change introduces a new state "tentative" for device units. Device units are considered "plugged" when udev announced them, "dead" when they are not available in the kernel, and "tentative" when they are referenced in /proc/self/mountinfo or /proc/swaps but not (yet) announced via udev. This should fix a race when device nodes (like loop devices) are created and immediately mounted. Previously, systemd might end up seeing the mount unit before the device, and would thus pull down the mount because its BindTo dependency on the device would not be fulfilled. --- src/core/device.h | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'src/core/device.h') diff --git a/src/core/device.h b/src/core/device.h index 906508530d..9f46e08953 100644 --- a/src/core/device.h +++ b/src/core/device.h @@ -28,20 +28,28 @@ typedef struct Device Device; * simplifies the state engine greatly */ typedef enum DeviceState { DEVICE_DEAD, - DEVICE_PLUGGED, + DEVICE_TENTATIVE, /* mounted or swapped, but not (yet) announced by udev */ + DEVICE_PLUGGED, /* announced by udev */ _DEVICE_STATE_MAX, _DEVICE_STATE_INVALID = -1 } DeviceState; +typedef enum DeviceFound { + DEVICE_NOT_FOUND = 0, + DEVICE_FOUND_UDEV = 1, + DEVICE_FOUND_MOUNT = 2, + DEVICE_FOUND_SWAP = 4, +} DeviceFound; + struct Device { Unit meta; char *sysfs; + DeviceFound found; /* In order to be able to distinguish dependencies on different device nodes we might end up creating multiple devices for the same sysfs path. We chain them up here. */ - LIST_FIELDS(struct Device, same_sysfs); DeviceState state; @@ -51,3 +59,5 @@ extern const UnitVTable device_vtable; const char* device_state_to_string(DeviceState i) _const_; DeviceState device_state_from_string(const char *s) _pure_; + +int device_found_node(Manager *m, const char *node, bool add, DeviceFound found, bool now); -- cgit v1.2.3-54-g00ecf