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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)

Check Out this Related Man Page

INTRO(4)						   BSD Kernel Interfaces Manual 						  INTRO(4)

NAME
intro -- introduction to devices and device drivers DESCRIPTION
This section contains information related to devices, device drivers and miscellaneous hardware. The device abstraction Device is a term used mostly for hardware-related stuff that belongs to the system, like disks, printers, or a graphics display with its key- board. There are also so-called pseudo-devices where a device driver emulates the behaviour of a device in software without any particular underlying hardware. A typical example for the latter class is /dev/mem, a loophole where the physical memory can be accessed using the reg- ular file access semantics. The device abstraction generally provides a common set of system calls layered on top of them, which are dispatched to the corresponding device driver by the upper layers of the kernel. The set of system calls available for devices is chosen from open(2), close(2), read(2), write(2), ioctl(2), select(2), and mmap(2). Not all drivers implement all system calls, for example, calling mmap(2) on terminal devices is likely to be not useful at all. Accessing Devices Most of the devices in a UNIX-like operating system are accessed through so-called device nodes, sometimes also called special files. They are usually located under the directory /dev in the file system hierarchy (see also hier(7)). Note that this could lead to an inconsistent state, where either there are device nodes that do not have a configured driver associated with them, or there may be drivers that have successfully probed for their devices, but cannot be accessed since the corresponding device node is still missing. In the first case, any attempt to reference the device through the device node will result in an error, returned by the upper layers of the kernel, usually ENXIO. In the second case, the device node needs to be created before the driver and its device will be usable. Some devices come in two flavors: block and character devices, or to use better terms, buffered and unbuffered (raw) devices. The tradi- tional names are reflected by the letters 'b' and 'c' as the file type identification in the output of 'ls -l'. Buffered devices are being accessed through the buffer cache of the operating system, and they are solely intended to layer a file system on top of them. They are nor- mally implemented for disks and disk-like devices only and, for historical reasons, for tape devices. Raw devices are available for all drivers, including those that also implement a buffered device. For the latter group of devices, the dif- ferentiation is conventionally done by prepending the letter 'r' to the path name of the device node, for example /dev/rda0 denotes the raw device for the first SCSI disk, while /dev/da0 is the corresponding device node for the buffered device. Unbuffered devices should be used for all actions that are not related to file system operations, even if the device in question is a disk device. This includes making backups of entire disk partitions, or to raw floppy disks (i.e., those used like tapes). Access restrictions to device nodes are usually subject to the regular file permissions of the device node entry, instead of being enforced directly by the drivers in the kernel. Drivers without device nodes Drivers for network devices do not use device nodes in order to be accessed. Their selection is based on other decisions inside the kernel, and instead of calling open(2), use of a network device is generally introduced by using the system call socket(2). Configuring a driver into the kernel For each kernel, there is a configuration file that is used as a base to select the facilities and drivers for that kernel, and to tune sev- eral options. See config(8) for a detailed description of the files involved. The individual manual pages in this section provide a sample line for the configuration file in their synopsis portion. See also the sample config file /sys/i386/conf/LINT (for the i386 architecture). SEE ALSO
close(2), ioctl(2), mmap(2), open(2), read(2), select(2), socket(2), write(2), devfs(5), hier(7), config(8) HISTORY
This manual page first appeared in FreeBSD 2.1. AUTHORS
This man page has been written by Jorg Wunsch with initial input by David E. O'Brien. BSD
January 20, 1996 BSD
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