Xen devel - Sep 2006 - [PATCH 0/2] clean up blktap and change to use a dynamic major

The following two patches are to clean up blktap.c and to make it use a 
dynamic major instead of a hardcoded one.

The first patch does two things:

1. cleans up the style to be more compatible with the Linux Style

2. gets rid of the private data structure used in filp->private_data

The private data structure only has one item and that is the idx (index 
into the tapfds descriptors).  This is allocated on open of the device 
and freed on close.  The idx element always is the same as the minor 
number.  Instead of using this (which would not be accepted into the 
kernel), I got rid of the private structure completely and instead I 
have filp->private_data point to the descriptor itself.  This cleans up 
the code a bit.


The second patch changes the blktap to use a dynamic major.  Instead of 
a hardcoded 254, the number is dynamic, and the blktapctrl now reads 
/proc/devices to find the number to use to create the node.

NOTE:  Currently and after this patch, the blktapctrl daemon creates the 
device node. This is not the way Linux should work, and this needs to be 
done by udev.  That update should be next (after I learn how udev works :)

-- Steve

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This patch cleans up the blktap.c code to make it form to the Linux 
coding style a little better.

It also removes the private data structure that is only used to store 
the index of the tabfds descriptor.  Instead the filp->private_data now 
points to the descriptor itself.

-- Steve

Signed-off-by: Steven Rostedt <srostedt@redhat.com>



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blktap currently uses a hardcoded major of 254 for the device.  This is 
not robust in anyway and needs to be dynamic.

Note: it is better not to have the daemon create the node, and have udev 
create it instead. But since the daemon currently creates the node 
anyway, it is still the way this is done.  That change needs to be made 
at another time.

-- Steve

Signed-off-by: Steven Rostedt <srostedt@redhat.com>



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Applied, thank you.  Great clean-up.

a.

On 9/27/06, Steven Rostedt <srostedt@redhat.com>
wrote:
> This patch cleans up the blktap.c code to make it form to the Linux
> coding style a little better.
>
> It also removes the private data structure that is only used to store
> the index of the tabfds descriptor.  Instead the filp->private_data now
> points to the descriptor itself.
>
> -- Steve
>
> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
>
>
>
>
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Applied, thank you.

On 9/27/06, Steven Rostedt <srostedt@redhat.com>
wrote:
> blktap currently uses a hardcoded major of 254 for the device.  This is
> not robust in anyway and needs to be dynamic.
>
> Note: it is better not to have the daemon create the node, and have udev
> create it instead. But since the daemon currently creates the node
> anyway, it is still the way this is done.  That change needs to be made
> at another time.
>
> -- Steve
>
> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
>
>
>
>
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