understanding of sysfs.

[greg@kroah.com (Greg KH)]

On Mon, May 29, 2017 at 10:58:09AM +0530, Madhu K wrote:
> 
> 
> On Tue, May 23, 2017 at 2:53 PM, Greg KH <greg@kroah.com> wrote:
> 
>     On Tue, May 23, 2017 at 12:58:07PM +0530, Madhu K wrote:
>     > Hi Greg,
>     >
>     > Thanks for your response.
>     >
>     >
>     > On Tue, May 23, 2017 at 12:04 PM, Greg KH <greg@kroah.com> wrote:
>     >
>     >? ? ?On Tue, May 23, 2017 at 11:58:31AM +0530, Madhu K wrote:
>     >? ? ?> Hi All,
>     >? ? ?>
>     >? ? ?> why there is no character device entry present in /sys/class? where
>     as
>     >? ? ?block
>     >? ? ?> and net device entries are present.
>     >
>     >? ? ?I see character devices there, but not the device nodes.? I don't see
>     >? ? ?block device nodes there either.
>     >
>     >
>     > If I am wrong please correct me, there is a folder called block in /sys/
>     class.
>     > is block not containing block device nodes??
> 
>     Nope, look closer :)
> 
> 
> I checked the block folder, the entries which are present in /sys/class/block
> are softlink to /sys/devices nodes.

What do you exactly mean by "nodes"?  /sys/class/block/ points to the
block device "class devices" in the kernel device hierarchy, just like
the other /sys/class/* entries point to other class devices.

> what i understand from this is, all block net and char node entries
> are present in /sys/devices. Am i correct?

Again, what do you mean by a "node"?  Did you read the documentation
about sysfs and the driver model?

thanks,

greg k-h