From 04d4abe96ca07b851fb74125390b1b626126aa86 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 27 Jun 2012 18:03:13 +0100 Subject: [PATCH] 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 Signed-off-by: Kevin Wolf --- blockdev.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/blockdev.c b/blockdev.c index 9e0a72a269..a85a429aef 100644 --- a/blockdev.c +++ b/blockdev.c @@ -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",