[PATCH v3 0/2] throttling for BLOCK_IO_ERROR

[PATCH v3 0/2] throttling for BLOCK_IO_ERROR

[Vladimir Sementsov-Ogievskiy]

v2: switch to qom-path as discriminator, for this, add patch 01.

Leonid Kaplan (1):
  block-backend: per-device throttling of BLOCK_IO_ERROR reports

Vladimir Sementsov-Ogievskiy (1):
  qapi: add qom-path to BLOCK_IO_ERROR event

 block/block-backend.c | 21 +++++++++++++++++----
 monitor/monitor.c     |  7 +++++--
 qapi/block-core.json  |  9 +++++++--
 3 files changed, 29 insertions(+), 8 deletions(-)

-- 
2.34.1

[PATCH v3 1/2] qapi: add qom-path to BLOCK_IO_ERROR event

[Vladimir Sementsov-Ogievskiy]

We need something more reliable than "device" (which absent in modern
interfaces) and "node-name" (which may absent, and actually don't
specify the device, which is a source of error) to make a per-device
throttling for the event in the following commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 block/block-backend.c | 21 +++++++++++++++++----
 qapi/block-core.json  |  7 +++++--
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index db6f9b92a3..9b70f44aec 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1028,22 +1028,34 @@ DeviceState *blk_get_attached_dev(BlockBackend *blk)
     return blk->dev;
 }
 
-/* Return the qdev ID, or if no ID is assigned the QOM path, of the block
- * device attached to the BlockBackend. */
-char *blk_get_attached_dev_id(BlockBackend *blk)
+static char *blk_get_attached_dev_id_or_path(BlockBackend *blk, bool want_id)
 {
     DeviceState *dev = blk->dev;
     IO_CODE();
 
     if (!dev) {
         return g_strdup("");
-    } else if (dev->id) {
+    } else if (want_id && dev->id) {
         return g_strdup(dev->id);
     }
 
     return object_get_canonical_path(OBJECT(dev)) ?: g_strdup("");
 }
 
+/*
+ * Return the qdev ID, or if no ID is assigned the QOM path, of the block
+ * device attached to the BlockBackend.
+ */
+char *blk_get_attached_dev_id(BlockBackend *blk)
+{
+    return blk_get_attached_dev_id_or_path(blk, true);
+}
+
+static char *blk_get_attached_dev_path(BlockBackend *blk)
+{
+    return blk_get_attached_dev_id_or_path(blk, false);
+}
+
 /*
  * Return the BlockBackend which has the device model @dev attached if it
  * exists, else null.
@@ -2140,6 +2152,7 @@ static void send_qmp_error_event(BlockBackend *blk,
 
     optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE;
     qapi_event_send_block_io_error(blk_name(blk),
+                                   blk_get_attached_dev_path(blk),
                                    bs ? bdrv_get_node_name(bs) : NULL, optype,
                                    action, blk_iostatus_is_enabled(blk),
                                    error == ENOSPC, strerror(error));
diff --git a/qapi/block-core.json b/qapi/block-core.json
index c3b0a2376b..b3743022be 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -5580,6 +5580,8 @@
 #
 # Emitted when a disk I/O error occurs
 #
+# @qom-path: path to the device object in the QOM tree (since 9.2)
+#
 # @device: device name.  This is always present for compatibility
 #     reasons, but it can be empty ("") if the image does not have a
 #     device name associated.
@@ -5610,7 +5612,8 @@
 # .. qmp-example::
 #
 #     <- { "event": "BLOCK_IO_ERROR",
-#          "data": { "device": "ide0-hd1",
+#          "data": { "qom-path": "/machine/unattached/device[0]",
+#                    "device": "ide0-hd1",
 #                    "node-name": "#block212",
 #                    "operation": "write",
 #                    "action": "stop",
@@ -5618,7 +5621,7 @@
 #          "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
 ##
 { 'event': 'BLOCK_IO_ERROR',
-  'data': { 'device': 'str', '*node-name': 'str',
+  'data': { 'qom-path': 'str', 'device': 'str', '*node-name': 'str',
             'operation': 'IoOperationType',
             'action': 'BlockErrorAction', '*nospace': 'bool',
             'reason': 'str' } }
-- 
2.34.1

[PATCH v3 2/2] block-backend: per-device throttling of BLOCK_IO_ERROR reports

[Vladimir Sementsov-Ogievskiy]

From: Leonid Kaplan <xeor@yandex-team.ru>

BLOCK_IO_ERROR events comes from guest, so we must throttle them.
We still want per-device throttling, so let's use device id as a key.

Signed-off-by: Leonid Kaplan <xeor@yandex-team.ru>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 monitor/monitor.c    | 7 +++++--
 qapi/block-core.json | 2 ++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/monitor/monitor.c b/monitor/monitor.c
index db52a9c7ef..56786c0ccc 100644
--- a/monitor/monitor.c
+++ b/monitor/monitor.c
@@ -308,6 +308,7 @@ int error_printf_unless_qmp(const char *fmt, ...)
 static MonitorQAPIEventConf monitor_qapi_event_conf[QAPI_EVENT__MAX] = {
     /* Limit guest-triggerable events to 1 per second */
     [QAPI_EVENT_RTC_CHANGE]        = { 1000 * SCALE_MS },
+    [QAPI_EVENT_BLOCK_IO_ERROR]    = { 1000 * SCALE_MS },
     [QAPI_EVENT_WATCHDOG]          = { 1000 * SCALE_MS },
     [QAPI_EVENT_BALLOON_CHANGE]    = { 1000 * SCALE_MS },
     [QAPI_EVENT_QUORUM_REPORT_BAD] = { 1000 * SCALE_MS },
@@ -493,7 +494,8 @@ static unsigned int qapi_event_throttle_hash(const void *key)
         hash += g_str_hash(qdict_get_str(evstate->data, "node-name"));
     }
 
-    if (evstate->event == QAPI_EVENT_MEMORY_DEVICE_SIZE_CHANGE) {
+    if (evstate->event == QAPI_EVENT_MEMORY_DEVICE_SIZE_CHANGE ||
+        evstate->event == QAPI_EVENT_BLOCK_IO_ERROR) {
         hash += g_str_hash(qdict_get_str(evstate->data, "qom-path"));
     }
 
@@ -519,7 +521,8 @@ static gboolean qapi_event_throttle_equal(const void *a, const void *b)
                        qdict_get_str(evb->data, "node-name"));
     }
 
-    if (eva->event == QAPI_EVENT_MEMORY_DEVICE_SIZE_CHANGE) {
+    if (eva->event == QAPI_EVENT_MEMORY_DEVICE_SIZE_CHANGE ||
+        eva->event == QAPI_EVENT_BLOCK_IO_ERROR) {
         return !strcmp(qdict_get_str(eva->data, "qom-path"),
                        qdict_get_str(evb->data, "qom-path"));
     }
diff --git a/qapi/block-core.json b/qapi/block-core.json
index b3743022be..835f90b118 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -5607,6 +5607,8 @@
 # .. note:: If action is "stop", a STOP event will eventually follow
 #    the BLOCK_IO_ERROR event.
 #
+# .. note:: This event is rate-limited.
+#
 # Since: 0.13
 #
 # .. qmp-example::
-- 
2.34.1

Re: [PATCH v3 0/2] throttling for BLOCK_IO_ERROR

[Kevin Wolf]

Am 02.10.2024 um 17:18 hat Vladimir Sementsov-Ogievskiy geschrieben:
> v2: switch to qom-path as discriminator, for this, add patch 01.
> 
> Leonid Kaplan (1):
>   block-backend: per-device throttling of BLOCK_IO_ERROR reports
> 
> Vladimir Sementsov-Ogievskiy (1):
>   qapi: add qom-path to BLOCK_IO_ERROR event

Thanks, applied to the block branch.

Kevin