device_rename(9) [centos man page]

DEVICE_RENAME(9)					   Device drivers infrastructure					  DEVICE_RENAME(9)

NAME

       device_rename - renames a device

SYNOPSIS

       int device_rename(struct device * dev, const char * new_name);

ARGUMENTS

       dev
	   the pointer to the struct device to be renamed

       new_name
	   the new name of the device

DESCRIPTION

       It is the responsibility of the caller to provide mutual exclusion between two different calls of device_rename on the same device to
       ensure that new_name is valid and won't conflict with other devices.

NOTE

       Don't call this function. Currently, the networking layer calls this function, but that will change. The following text from Kay Sievers
       offers

SOME INSIGHT

       Renaming devices is racy at many levels, symlinks and other stuff are not replaced atomically, and you get a "move" uevent, but it's not
       easy to connect the event to the old and new device. Device nodes are not renamed at all, there isn't even support for that in the kernel
       now.

       In the meantime, during renaming, your target name might be taken by another driver, creating conflicts. Or the old name is taken directly
       after you renamed it -- then you get events for the same DEVPATH, before you even see the "move" event. It's just a mess, and nothing new
       should ever rely on kernel device renaming. Besides that, it's not even implemented now for other things than (driver-core wise very
       simple) network devices.

       We are currently about to change network renaming in udev to completely disallow renaming of devices in the same namespace as the kernel
       uses, because we can't solve the problems properly, that arise with swapping names of multiple interfaces without races. Means, renaming of
       eth[0-9]* will only be allowed to some other name than eth[0-9]*, for the aforementioned reasons.

       Make up a "real" name in the driver before you register anything, or add some other attributes for userspace to find the device, or use
       udev to add symlinks -- but never rename kernel devices later, it's a complete mess. We don't even want to get into that and try to
       implement the missing pieces in the core. We really have other pieces to fix in the driver core mess. :)

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014							  DEVICE_RENAME(9)

SYSTEMD.DEVICE(5)						  systemd.device						 SYSTEMD.DEVICE(5)

NAME

       systemd.device - systemd device configuration files

SYNOPSIS

       systemd.device

DESCRIPTION

       A unit configuration file whose name ends in .device encodes information about a device unit as exposed in the sysfs/udev(7) device tree.

       This unit type has no specific options. See systemd.unit(5) for the common options of all unit configuration files. The common
       configuration items are configured in the generic [Unit] and [Install] sections. A separate [Device] section does not exist, since no
       device-specific options may be configured.

       systemd will automatically create dynamic device units for all kernel devices that are marked with the "systemd" udev tag (by default all
       block and network devices, and a few others). This may be used to define dependencies between devices and other units.

       Device units are named after the /sys and /dev paths they control. Example: the device /dev/sda5 is exposed in systemd as dev-sda5.device.
       For details about the escaping logic used to convert a file system path to a unit name see systemd.unit(5).

THE UDEV DATABASE

       The settings of device units may either be configured via unit files, or directly from the udev database (which is recommended). The
       following udev properties are understood by systemd:

       SYSTEMD_WANTS=
	   Adds dependencies of type Wants from this unit to all listed units. This may be used to activate arbitrary units, when a specific
	   device becomes available. Note that this and the other tags are not taken into account unless the device is tagged with the "systemd"
	   string in the udev database, because otherwise the device is not exposed as systemd unit.

       SYSTEMD_ALIAS=
	   Adds an additional alias name to the device unit. This must be an absolute path that is automatically transformed into a unit name.
	   (See above.)

       SYSTEMD_READY=
	   If set to 0 systemd will consider this device unplugged even if it shows up in the udev tree. If this property is unset or set to 1 the
	   device will be considered plugged the moment it shows up in the udev tree. This property has no influence on the behaviour when a
	   device disappears from the udev tree. This option is useful to support devices that initially show up in an uninitialized state in the
	   tree, and for which a changed event is generated the moment they are fully set up.

       ID_MODEL_FROM_DATABASE=, ID_MODEL=
	   If set, this property is used as description string for the device unit.

SEE ALSO

       systemd(1), systemctl(8), systemd.unit(5), udev(7)

AUTHOR

       Lennart Poettering <lennart@poettering.net>
	   Developer

systemd 							    10/07/2013							 SYSTEMD.DEVICE(5)