From 60fe4fac22895576973e317d7148b084c31cc64c Mon Sep 17 00:00:00 2001 From: Hani Benhabiles Date: Sun, 18 May 2014 11:50:04 +0100 Subject: 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 Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini --- blockdev-nbd.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'blockdev-nbd.c') diff --git a/blockdev-nbd.c b/blockdev-nbd.c index b60b66d66c..18dc528761 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; -- cgit v1.2.1