The device is exported with erroneous values and can't be read.
Before the patch:
$ sudo nbd-client localhost -p 10809 /dev/nbd0 -name floppy0
Negotiation: ..size = 17592186044415MB
bs=1024, sz=18446744073709547520 bytes
$ sudo mount /dev/nbd0 /mnt/tmp/
mount: block device /dev/nbd0 is write-protected, mounting read-only
mount: /dev/nbd0: can't read superblock
After the patch:
(qemu) nbd_server_add ide0-hd0
(qemu) nbd_server_add floppy0
Device 'floppy0' has no medium
Signed-off-by: Hani Benhabiles <h...@linux.com>
---
blockdev-nbd.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 922cf56..a700d52 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -91,6 +91,10 @@ void qmp_nbd_server_add(const char *device, bool
has_writable, bool writable,
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
+ if (!bdrv_is_inserted(bs)) {
+ error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
+ return;
+ }
if (!has_writable) {
writable = false;
--
1.8.3.2
