Emitted whenever the watermark value set by the Monitor
'block_watermark' command is reached.
This value is not permanently stored and it's automatically
set to zero when the event is emitted.
Signed-off-by: Luiz Capitulino <lcapitul...@redhat.com>
---
QMP/qmp-events.txt | 26 ++++++++++++++++++++++++++
block/qcow2-refcount.c | 20 ++++++++++++++++++++
monitor.c | 3 +++
monitor.h | 1 +
4 files changed, 50 insertions(+), 0 deletions(-)
diff --git a/QMP/qmp-events.txt b/QMP/qmp-events.txt
index a94e9b4..f1fe3aa 100644
--- a/QMP/qmp-events.txt
+++ b/QMP/qmp-events.txt
@@ -26,6 +26,32 @@ Example:
Note: If action is "stop", a STOP event will eventually follow the
BLOCK_IO_ERROR event.
+BLOCK_WATERMARK
+---------------
+
+Emitted when the watermark value for a device is reached.
+
+Data:
+
+- "device": device name (json-string)
+- "type": watermark type (json-string, only "high" currently)
+- "mark": current device's high watermark value (json-int)
+- "allocation": current allocation (json-int)
+
+Example:
+
+{ "event": "BLOCK_WATERMARK",
+ "data": { "device": "ide0-hd0",
+ "ide0-hd0",
+ "mark": 1048576,
+ "allocation": 1376256 },
+ "timestamp": { "seconds": 1268170711, "microseconds": 698676 } }
+
+Note: (1) The watermark value is set by the 'block_watermark' Monitor's command
+ (2) The device's watermark value is set to zero when the event is
+ emitted. Thus, this event is emitted only once.
+ (3) Currently only the high watermark value is supported
+
RESET
-----
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 9cb38c8..684e0ff 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -23,6 +23,8 @@
*/
#include "qemu-common.h"
+#include "qjson.h"
+#include "monitor.h"
#include "block_int.h"
#include "block/qcow2.h"
@@ -531,6 +533,17 @@ static int update_cluster_refcount(BlockDriverState *bs,
/* cluster allocation functions */
+static void watermark_mon_event(const BlockDriverState *bs, int64_t ha)
+{
+ QObject *data;
+
+ data = qobject_from_jsonf("{ 'device': %s, 'type': 'high', "
+ "'allocation': %" PRId64 ", 'mark': %" PRId64
"}",
+ bs->device_name, ha, bs->high_watermark);
+
+ monitor_protocol_event(QEVENT_BLOCK_WATERMARK, data);
+ qobject_decref(data);
+}
/* return < 0 if error */
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
@@ -552,6 +565,13 @@ retry:
#endif
if (s->highest_alloc < s->free_cluster_index) {
s->highest_alloc = s->free_cluster_index;
+ if (bs->high_watermark) {
+ uint64_t ha = (s->highest_alloc << s->cluster_bits);
+ if (ha >= bs->high_watermark) {
+ watermark_mon_event(bs, ha);
+ bs->high_watermark = 0;
+ }
+ }
}
return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
}
diff --git a/monitor.c b/monitor.c
index 595bd62..3f74994 100644
--- a/monitor.c
+++ b/monitor.c
@@ -423,6 +423,9 @@ void monitor_protocol_event(MonitorEvent event, QObject
*data)
case QEVENT_BLOCK_IO_ERROR:
event_name = "BLOCK_IO_ERROR";
break;
+ case QEVENT_BLOCK_WATERMARK:
+ event_name = "BLOCK_WATERMARK";
+ break;
case QEVENT_RTC_CHANGE:
event_name = "RTC_CHANGE";
break;
diff --git a/monitor.h b/monitor.h
index e5f2d2b..e767990 100644
--- a/monitor.h
+++ b/monitor.h
@@ -23,6 +23,7 @@ typedef enum MonitorEvent {
QEVENT_VNC_INITIALIZED,
QEVENT_VNC_DISCONNECTED,
QEVENT_BLOCK_IO_ERROR,
+ QEVENT_BLOCK_WATERMARK,
QEVENT_RTC_CHANGE,
QEVENT_WATCHDOG,
QEVENT_MAX,
--
1.7.0.1
