[Qemu-devel] [RFC Patch 1/3]Qemu: Enhance "info block" to display cache setting

[Supriya Kannery <supriyak@linux.vnet.ibm.com>]

Enhance "info block" to display cache setting

Example:
(qemu) info block
ide0-hd0: type=hd removable=0 file=../rhel6-32.qcow2 ro=0 drv=qcow2 
encrypted=0

Enhanced to include "cache" setting:
(qemu) info block
ide0-hd0: type=hd removable=0 cache=none file=../rhel6-32.qcow2 ro=0 
drv=qcow2 encrypted=0

Signed-off-by: Supriya Kannery <supriyak@in.ibm.com>
Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>

---
 block.c |   18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

Index: qemu/block.c
===================================================================
--- qemu.orig/block.c
+++ qemu/block.c
@@ -1713,6 +1713,19 @@ static void bdrv_print_dict(QObject *obj
         monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
     }
 
+    if (qdict_haskey(bs_dict, "open_flags")) {
+        int open_flags = qdict_get_int(bs_dict, "open_flags");
+        if (open_flags & BDRV_O_NOCACHE) {
+            monitor_printf(mon, " cache=none");
+        } else if (open_flags & BDRV_O_CACHE_WB) {
+            if (open_flags & BDRV_O_NO_FLUSH)
+                monitor_printf(mon, " cache=unsafe");
+            else
+                monitor_printf(mon, " cache=writeback");
+        } else
+            monitor_printf(mon, " cache=writethrough");
+    }
+
     if (qdict_haskey(bs_dict, "inserted")) {
         QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
 
@@ -1762,9 +1775,10 @@ void bdrv_info(Monitor *mon, QObject **r
         }
 
         bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
-                                    "'removable': %i, 'locked': %i }",
+                                    "'removable': %i, 'locked': %i, "
+                                    "'open_flags': %d }",
                                     bs->device_name, type, bs->removable,
-                                    bs->locked);
+                                    bs->locked, bs->open_flags);
 
         if (bs->drv) {
             QObject *obj;