commit d6fcdf06d9fc7d72151cc2069dc5c1adf5c21707
author Jeff Cody <jcody@redhat.com> Fri Apr 07 16:55:27 2017 -0400
committer Jeff Cody <jcody@redhat.com> Mon Apr 24 15:09:33 2017 -0400
tree 540436244a6886cb53b4e2cd9beb10f67526b6a1
parent e2b8247a322cd92945785edf25f09e6b3e8285f9

block: honor BDRV_O_ALLOW_RDWR when clearing bs->read_only

The BDRV_O_ALLOW_RDWR flag allows / prohibits the changing of
the BDS 'read_only' state, but there are a few places where it
is ignored.  In the bdrv_set_read_only() helper, make sure to
honor the flag.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: be2e5fb2d285cbece2b6d06bed54a6f56520d251.1491597120.git.jcody@redhat.com

block.c

diff --git a/block.c b/block.c
index 67ae35a..4752fee 100644
--- a/block.c
+++ b/block.c
@@ -201,6 +201,13 @@
         return -EINVAL;
     }
 
+    /* Do not clear read_only if it is prohibited */
+    if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR)) {
+        error_setg(errp, "Node '%s' is read only",
+                   bdrv_get_device_or_node_name(bs));
+        return -EPERM;
+    }
+
     bs->read_only = read_only;
     return 0;
 }