Re: [Nbd] [PATCH] Only send one reply on oversize writes

[Alex Bligh <alex@...872...>]

Wouter,

--On 28 May 2011 12:12:14 +0200 Wouter Verhelst <w@...112...> wrote:

> What about a hash table instead? There's a GHashTable in libglib-2.0,
> which we're already using.

That looks promising.

> That would also allow reusing the original
> handle number, which would make it slightly easier to match against
> what's in the transaction log.

That won't work. Consider the original sequence
	Request		Reply
	H1
	H2
			H2
			H1
	H1
			H1

where H1 gets reused. I could (in fact probably would) replay this as
	Request		Reply
	H1
	H2
	H1
			H2
			H1
			H1

in which case there are 2 H1s in flight, and I won't be able to match
up the replies.

I could however use (e.g.) the seek offset as the handle, and store
the original handle.

--
Alex Bligh