Ceph » Linux kernel client

There is an osd request field "r_num_pages" that's used
to record the number of pages supplied with the request.
For page-oriented requests this makes perfect sense.

But for bio requests it doesn't. The length of space
available in the complete bio chain is instead what
should be recorded.

I hit this because the r_num_pages field is checked
when data is coming back on a read request. The osd
client fails saying, in effect, we don't have enough
pages ready to receive the data.

For now I'll just assign a value that works for the
bio case.