nbd: Don't export a block device with no medium.

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 <kroosec@gmail.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Hani Benhabiles 2014-05-18 11:50:04 +01:00 committed by Paolo Bonzini
parent d4cba13bdf
commit 60fe4fac22

View file

@ -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;