Help understanding block layer sample in LDD3

François fser at code-libre.org
Fri Jul 29 06:45:11 EDT 2016


On Fri, Jul 29, 2016 at 03:58:28PM +0530, Pranay Srivastava wrote:
> 
> I don't see req->buffer. Which version you are using?

You're absolutely right. Both [1] and [2] seems to be outdated.
I'm currently compiling and testing most of my code on a 3.19 on a 14.04 LTS ubuntu in a VM, 
rather than the actual kernel. It's simpler for me to work that way.

[1] https://github.com/martinezjavier/ldd3/blob/master/sbull/sbull.c#L119
[2] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/block/biodoc.txt

[...]
> 
> If this is a memory backed block driver, then perhaps you can handle
> multiple requests[?]. I don't think you need
> to actually break up the same request into multiple requests.

Actually, it is a shared memory based. Hence, a request might larger than the available room in 
the shared memory. This case has to be handled.

Thanks for your input!

-- 
François



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