tree 037e6362b3c5af9d43308305cd707c7dc1c63f27
parent 84f94a9a82487639bc87d5f09f938c9f6a61f79a
author Max Reitz <mreitz@redhat.com> 1386079072 +0100
committer Stefan Hajnoczi <stefanha@redhat.com> 1386152959 +0100

block: Close backing file early in bdrv_img_create

Leaving the backing file open although it is not needed anymore can
cause problems if it is opened through a block driver which allows
exclusive access only and if the create function of the block driver
used for the top image (the one being created) tries to close and reopen
the image file (which will include opening the backing file a second
time).

In particular, this will happen with a backing file opened through
qemu-nbd and using qcow2 as the top image file format (which reopens the
image to flush it to disk).

In addition, the BlockDriverState in bdrv_img_create() is used for the
backing file only; it should therefore be made local to the respective
block.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>