[Qemu-devel] [PATCH 2/2] block: Extend info blockstats monitor command

[Kevin Wolf <kwolf@redhat.com>]

Now the high watermark and statistics of the underlying images are exposed via
QMP, but they are missing in the user monitor. This patch changes the user
monitor to provide the same functionality.

Note that it's not possible to maintain compatibility with older clients that
try to parse the output of this command. They need to use QMP for a stable API.

The new info blockstats output looks like this (and yes, the example shows that
read/write statistics are broken currently, they ignore synchronous I/O):

(qemu) info blockstats
ide0-hd0:
  qcow2         rd_bytes=814592 rd_ops=1591
                wr_bytes=0 wr_ops=0 wr_highest_offset=0

  file          rd_bytes=814592 rd_ops=1591
                wr_bytes=0 wr_ops=0 wr_highest_offset=0

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c |   35 +++++++++++++++++++++--------------
 qdict.c |    2 +-
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/block.c b/block.c
index b75cef2..b22325e 100644
--- a/block.c
+++ b/block.c
@@ -1517,19 +1517,25 @@ static void bdrv_stats_iter(QObject *data, void *opaque)
     qdict = qobject_to_qdict(data);
     monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
 
-    qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
-    monitor_printf(mon, " rd_bytes=%" PRId64
-                        " wr_bytes=%" PRId64
-                        " rd_operations=%" PRId64
-                        " wr_operations=%" PRId64
-                        "\n",
-                        qdict_get_int(qdict, "rd_bytes"),
-                        qdict_get_int(qdict, "wr_bytes"),
-                        qdict_get_int(qdict, "rd_operations"),
-                        qdict_get_int(qdict, "wr_operations"));
-    if (qdict_haskey(qdict, "parent")) {
-        QObject *parent = qdict_get(qdict, "parent");
-        bdrv_stats_iter(parent, mon);
+    while (qdict) {
+        QDict *stats = qobject_to_qdict(qdict_get(qdict, "stats"));
+
+        monitor_printf(mon, "\n  %-12s  rd_bytes=%" PRId64
+                            " rd_ops=%" PRId64
+                            "\n  %-12s  wr_bytes=%" PRId64
+                            " wr_ops=%" PRId64
+                            " wr_highest_offset=%" PRId64
+                            "\n",
+                            qdict_get_str(qdict, "format"),
+                            qdict_get_int(stats, "rd_bytes"),
+                            qdict_get_int(stats, "rd_operations"),
+                            "",
+                            qdict_get_int(stats, "wr_bytes"),
+                            qdict_get_int(stats, "wr_operations"),
+                            qdict_get_int(stats, "wr_highest_offset"));
+
+
+        qdict = qobject_to_qdict(qdict_get(qdict, "parent"));
     }
 }
 
@@ -1547,7 +1553,7 @@ static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
         parent = bdrv_info_stats_bs(bs->file);
     }
 
-    res = qobject_from_jsonf("{ 'device': %s, 'stats': {"
+    res = qobject_from_jsonf("{ 'device': %s, 'format': %s, 'stats': {"
                              "'rd_bytes': %" PRId64 ","
                              "'wr_bytes': %" PRId64 ","
                              "'rd_operations': %" PRId64 ","
@@ -1555,6 +1561,7 @@ static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
                              "'wr_highest_offset': %" PRId64
                              "} }",
                              bs->device_name,
+                             bs->drv ? bs->drv->format_name : "none",
                              bs->rd_bytes, bs->wr_bytes,
                              bs->rd_ops, bs->wr_ops,
                              bs->wr_highest_sector * 512);
diff --git a/qdict.c b/qdict.c
index aae57bf..32491db 100644
--- a/qdict.c
+++ b/qdict.c
@@ -46,7 +46,7 @@ QDict *qdict_new(void)
  */
 QDict *qobject_to_qdict(const QObject *obj)
 {
-    if (qobject_type(obj) != QTYPE_QDICT)
+    if (!obj || qobject_type(obj) != QTYPE_QDICT)
         return NULL;
 
     return container_of(obj, QDict, base);
-- 
1.6.6.1