Am 22.07.2014 um 22:58 hat Max Reitz geschrieben:
Currently, qemu-img does not allow setting the cache mode for source
images. However, it reads images generally only once, therefore a full
writeback cache unnecessarily clutters the host cache. In case the user
finds this undesirable, there has to be a way of disabling that cache.
This series first introduces such a way for check, compare, convert and
rebase and then (while at it) adds a cache mode switch to amend (which
was missing so far).
Peter already tried to add a BDRV_O_SEQUENTIAL mode to qemu-img convert.
If we want to add such a mode (which in my opinion would be the logical
consequence of this series), we may want to make it just another cache
mode which can be selected by the user.
I would prefer if we used -t in all places where only one image is
used, so that I don't have to remember that supposedly check -r has only
an input image, whereas amend has only an output image. But that's
probably a matter of taste...
If you don't want to change it, the implementation looks okay:
Reviewed-by: Kevin Wolf <address@hidden>