[Qemu-devel] [RFC][PATCH 2/2] Extend monitor command 'info block' to display cache settings for block devices.

[Prerna Saxena <prerna@linux.vnet.ibm.com>]

(qemu)info block
SAMPLE output :
ide0-hd0: type=hd removable=0 cache=none file=/tmp/abc.img ro=0
drv=qcow2 encrypted=0

---
 block.c |   22 ++++++++++++++++++++--
 1 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/block.c b/block.c
index f7d91a2..c717888 100644
--- a/block.c
+++ b/block.c
@@ -1707,6 +1707,23 @@ static void bdrv_print_dict(QObject *obj, void *opaque)
         monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
     }
 
+    if (qdict_haskey(bs_dict, "open_flags") &&
+        !strcmp(qdict_get_str(bs_dict, "type"), "hd")) {
+        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"));
 
@@ -1756,9 +1773,10 @@ void bdrv_info(Monitor *mon, QObject **ret_data)
         }
 
         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;
-- 
1.7.2.3



-- 
Prerna Saxena

Linux Technology Centre,
IBM Systems and Technology Lab,
Bangalore, India