blockdev: warn when copy_on_read=on and readonly=on

If the image is read-only then it's not possible to copy read data into
it.  Therefore copy-on-read is automatically disabled for read-only
images.

Up until now this behavior was silent, add a warning so the user knows
why copy-on-read is not working.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2012-06-27 18:03:13 +01:00 committed by Kevin Wolf
parent 206e6d8551
commit 04d4abe96c
1 changed files with 4 additions and 0 deletions

View File

@ -609,6 +609,10 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
if (ro && copy_on_read) {
error_report("warning: disabling copy_on_read on readonly drive");
}
ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
if (ret < 0) {
error_report("could not open disk image %s: %s",