On 05.12.2013 18:41, Max Reitz wrote:
[…]
Second, if specifying a reference to an existing device should really
be supported, bdrv_open() should ideally not call bdrv_file_open()
anymore, but a function bdrv_find_ref() instead which resolves a
BlockdevRef structure (for simplicity, it appears to be easier to use
a QDict equivalent to a BlockdevRef instead of the latter itself
(since that results in many effectively redundant conversions to and
from those representations)). However, bdrv_file_open() supports
parsing protocol filenames, which bdrv_find_ref() would not. As a
result, it is probably best to call bdrv_find_ref() from
bdrv_file_open() instead and leave bdrv_open() generally the way it is
right now – yes, this is a question. ;-) (“Do you agree?”)
I noticed only just now that the current design does not seem to allow
nesting of files (i.e., driver=blkdebug-qmp, file.driver=qcow2,
file.file.driver=file). Perhaps I do have to call bdrv_find_ref() in
bdrv_open() and only resort to bdrv_file_open() if a filename that must
be parsed was given...?
Max
