Vectors in Linux

Gins · 08-07-2005, 02:56 PM

Block devices also support being accessed like files. The mechanisms used to provide the correct set of file operations for the opened block special file are very much the same as for character devices. Linux maintains the set of registered block devices as the blkdevs vector. It, like the chrdevs vector, is indexed using the device's major device number. Its entries are also device_struct data structures. Unlike character devices, there are classes of block devices. SCSI devices are one such class and IDE devices are another. It is the class that registers itself with the Linux kernel and provides file operations to the kernel. The device drivers for a class of block device provide class specific interfaces to the class. So, for example, a SCSI device driver has to provide interfaces to the SCSI subsystem which the SCSI subsystem uses to provide file operations for this device to the kernel.

Every block device driver must provide an interface to the buffer cache as well as the normal file operations interface. Each block device driver fills in its entry in the blk_dev vector

What are the 'blkdevs' vector and 'chrdevs' vector? Is it a file? Where do I find it?

XavierP · 08-07-2005, 04:12 PM

http://www.tldp.org/LDP/tlk/dd/drivers.html may be a good start point for you.

Gins · 08-07-2005, 04:25 PM

XavierP

Thanks for the reply. The crux of my question is on the word vector. What is it? Is it a file?
Where do I find it?

Tinkster · 08-07-2005, 04:42 PM

It's a kernel "structure" (in quotes because it's not
what a structure in C usually would be) that holds
information about devices that are registered with
the kernel... you'll find it in /usr/src/linux somewhere ;}

Cheers,
Tink

Gins · 08-07-2005, 04:53 PM

Thanks Tinkster.