From 2a2c61156e6049f7cd16e219be1da24f18d1b92b Mon Sep 17 00:00:00 2001
From: Eduardo Habkost <ehabkost@redhat.com>
Date: Fri, 18 Dec 2009 19:23:43 -0200
Subject: [PATCH 2/2] monitor: allow device to be ejected if no disk is inserted

RH-Author: Eduardo Habkost <ehabkost@redhat.com>
Message-id: <20091218192343.GI6538@blackpad.lan.raisama.net>
Patchwork-id: 5807
O-Subject: [RHEL-5.5 KVM PATCH] monitor: allow device to be ejected if no
	disk is inserted
Bugzilla: 539250
RH-Acked-by: Markus Armbruster <armbru@redhat.com>
RH-Acked-by: Juan Quintela <quintela@redhat.com>
RH-Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
RH-Acked-by: Naphtali Sprei <nsprei@redhat.com>

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=539250

Upstream status:
    submitted and entered staging tree last week, but had to be rebased
    due to conflicts with the monitor QMP changes.

    A new rebased version was submitted today.
    (http://article.gmane.org/gmane.comp.emulators.qemu/59813)

This changes the monitor eject_device() function to not check for
bdrv_is_inserted().

Example run where the bug manifests itself:

(output of 'info block' is stripped to include only the CD-ROM device)

  QEMU 0.11.50 monitor - type 'help' for more information
  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 [not inserted]
  (qemu) change ide1-cd0 /mnt/common/images/smalldisk1.img
  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 file=/mnt/common/images/smalldisk1.img ro=0 drv=raw encrypted=0
  (qemu) eject ide1-cd0
  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 [not inserted]

When using a file, eject works as expected. But when using a host cdrom device:

  (qemu) change ide1-cd0 /dev/cdrom
  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 file=/dev/cdrom ro=0 drv=host_cdrom encrypted=0
  (qemu) eject ide1-cd0
  (qemu) info block
  ide1-cd0: type=cdrom removable=1 locked=0 file=/dev/cdrom ro=0 drv=host_cdrom encrypted=0

Eject didn't work because the is_inserted() check fails.

I have no clue why the code had the is_inserted() check, as it doesn't matter
if there is a disk present at the host drive, when the user wants the virtual
device to be disconnected from the host device.

The is_inserted() has another side effect: a memory leak if the "change"
command is used multiple times, as do_change() calls eject_device() before
re-opening the block device, but bdrv_close() is never called.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 qemu/monitor.c |   20 +++++++++-----------
 1 files changed, 9 insertions(+), 11 deletions(-)

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 qemu/monitor.c |   20 +++++++++-----------
 1 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/qemu/monitor.c b/qemu/monitor.c
index ee33bfc..1ab6ac6 100644
--- a/qemu/monitor.c
+++ b/qemu/monitor.c
@@ -504,19 +504,17 @@ static void do_quit(void)
 
 static int eject_device(BlockDriverState *bs, int force)
 {
-    if (bdrv_is_inserted(bs)) {
-        if (!force) {
-            if (!bdrv_is_removable(bs)) {
-                term_printf("device is not removable\n");
-                return -1;
-            }
-            if (bdrv_is_locked(bs)) {
-                term_printf("device is locked\n");
-                return -1;
-            }
+    if (!force) {
+        if (!bdrv_is_removable(bs)) {
+            term_printf("device is not removable\n");
+            return -1;
+        }
+        if (bdrv_is_locked(bs)) {
+            term_printf("device is locked\n");
+            return -1;
         }
-        bdrv_close(bs);
     }
+    bdrv_close(bs);
     return 0;
 }
 
-- 
1.6.3.rc4.29.g8146