From 1a2b98f958fb770b70fa5a244e86c93655400858 Mon Sep 17 00:00:00 2001
From: Luiz Capitulino <lcapitulino@redhat.com>
Date: Thu, 4 Nov 2010 13:51:42 -0200
Subject: [RHEL6 qemu-kvm PATCH 2/2] QMP: Improve debuggability of the BLOCK_IO_ERROR event
RH-Author: Luiz Capitulino <lcapitulino@redhat.com>
Message-id: <20101104115142.7dafa97a@doriath>
Patchwork-id: 13201
O-Subject: [PATCH v2 RHEL6.0.z/RHEL6.1] QMP: Improve debuggability of the
BLOCK_IO_ERROR event
Bugzilla: 624607
RH-Acked-by: Markus Armbruster <armbru@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Juan Quintela <quintela@redhat.com>
BZ: 624607
Upstream: N/A
We have a vendor extension in the BLOCK_IO_ERROR event which adds
a 'reason' field, which contains a stringfied errno (Please, check
commit a635efd74e to learn why this was needed).
However, it turns out that this information is not enough for
debugging.
Based on a suggestion from Kevin Wolf, this commit adds a new
json-object member to the event, containing the errno value and an
error string from strerror(). Additionally, an error message is
printed to stderr.
All this new information is meant for human debugging only and should
not be used by libvirt (as stated in the event's documentation entry).
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
v2:
- Add errno and error string (as a json-object)
- Update event example in QMP/qmp-events.txt
QMP/qmp-events.txt | 10 +++++++++-
block.c | 16 ++++++++++++++++
2 files changed, 25 insertions(+), 1 deletions(-)
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
QMP/qmp-events.txt | 10 +++++++++-
block.c | 16 ++++++++++++++++
2 files changed, 25 insertions(+), 1 deletions(-)
diff --git a/QMP/qmp-events.txt b/QMP/qmp-events.txt
index 46f8b63..aa815f7 100644
--- a/QMP/qmp-events.txt
+++ b/QMP/qmp-events.txt
@@ -20,6 +20,11 @@ Data:
"eperm": errno EPERM
"enospc": errno ENOSPC
"eother": any other errno (other than EIO, EPERM, ENOSPC)
+- "__com.redhat_debug_info": RHEL6 extension containing debug information for
+ humans, applications should NOT read any
+ information from this member (json-object):
+ - "errno": errno value (json-int)
+ - "message": error message returned by strerror() (json-string)
Example:
@@ -27,7 +32,10 @@ Example:
"data": { "device": "ide0-hd1",
"operation": "write",
"action": "stop",
- "__com.redhat_reason": "enospc" },
+ "__com.redhat_reason": "enospc",
+ "__com.redhat_debug_info": {
+ "message": "No space left on device",
+ "errno": 28 } }
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
Note: If action is "stop", a STOP event will eventually follow the
diff --git a/block.c b/block.c
index 74b7180..d09addd 100644
--- a/block.c
+++ b/block.c
@@ -1431,6 +1431,18 @@ static void bdrv_put_rhel6_reason(QDict *event, int error)
qdict_put(event, BDRV_REASON_KEY, qstring_from_str(reason));
}
+#define BDRV_DEBUG_KEY RFQDN_REDHAT "debug_info"
+
+/* RHEL6 vendor extension */
+static void bdrv_put_rhel6_debug_info(QDict *event, int error)
+{
+ QObject *info;
+
+ info = qobject_from_jsonf("{ 'errno': %d, 'message': %s }", error,
+ strerror(error));
+ qdict_put_obj(event, BDRV_DEBUG_KEY, info);
+}
+
void bdrv_mon_event(const BlockDriverState *bdrv,
BlockMonEventAction action, int error, int is_read)
{
@@ -1451,11 +1463,15 @@ void bdrv_mon_event(const BlockDriverState *bdrv,
abort();
}
+ fprintf(stderr, "block I/O error in device '%s': %s (%d)\n",
+ bdrv->device_name, strerror(error), error);
+
data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
bdrv->device_name,
action_str,
is_read ? "read" : "write");
bdrv_put_rhel6_reason(qobject_to_qdict(data), error);
+ bdrv_put_rhel6_debug_info(qobject_to_qdict(data), error);
monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
qobject_decref(data);
--
1.7.3.2