Re: [Qemu-devel] [PATCH for-4.0 v3 0/6] NBD server alignment improvement

[Richard W.M. Jones]

I tested this version of qemu against the nbdkit test suite and it
passed.

It also fixes the problem with qemu-img convert:

  $ ./nbdkit -U - memory size=511 --run 'qemu-img convert $nbd /var/tmp/out'

There are a couple of issues though (I don't think you'll think they
are bugs).

Firstly it rounds up the size to 512 bytes.  eg. /var/tmp/out above is
512 bytes, and qemu-img info shows the virtual size as 512 bytes.

Secondly I still can't open the INT64_MAX image which as you will
recall has a 511 byte tail:

  $ ./nbdkit -U - memory size=$((2**63 - 1)) --run 'qemu-img info $nbd'
  qemu-img: Could not open 'nbd:unix:/tmp/nbdkitTimYSJ/socket': Could not read 
image for determining its format: File too large

... yet the 2^63-512 image can be opened (same as before):

  $ ./nbdkit -U - memory size=$((2**63 - 512)) --run 'qemu-img info $nbd'
  image: nbd+unix://?socket=/tmp/nbdkitHSAzNz/socket
  file format: raw
  virtual size: -8388607T (9223372036854775296 bytes)
  disk size: unavailable

I've just noticed that the virtual size negative (also in upstream
qemu).  That looks like a bug too ...

Rich.

-- 
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