Stefan Hajnoczi <stefa...@redhat.com> writes: > Linux block devices can be set read-only with "blockdev --setro > <device>". The same thing can be done for LVM volumes using "lvchange > --permission r <volume>". This read-only setting is independent of > device node permissions. Therefore the device can still be opened > O_RDWR but actual writes will fail. > > This results in odd behavior for QEMU. bdrv_open() is supposed to fail > if a read-only image is being opened with BDRV_O_RDWR. By not failing > for Linux block devices, the guest boots up but every write produces an > I/O error. > > This patch checks whether the block device is read-only so that Linux > block devices behave like regular files. > > Reported-by: Sibiao Luo <s...@redhat.com> > Suggested-by: Paolo Bonzini <pbonz...@redhat.com> > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Reviewed-by: Markus Armbruster <arm...@redhat.com>
