From 1a2fe5a329ffe4b89dcd5c27c8f53ff87a28702b Mon Sep 17 00:00:00 2001
From: Luiz Capitulino <lcapitulino@redhat.com>
Date: Wed, 9 Jul 2014 14:31:51 +0200
Subject: qmp: add error reason to the BLOCK_IO_ERROR event

Message-id: <1404916312-27953-3-git-send-email-lcapitulino@redhat.com>
Patchwork-id: 59729
O-Subject: [RHEV7.1 qemu-kvm-rhev PATCH 2/3] qmp: add error reason to the BLOCK_IO_ERROR event
Bugzilla: 1116772
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Eric Blake <eblake@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

This commit forward ports the following RHEL-7.0 commit to RHEL-7.1:

  commit 771a3a333eb0c9299a69a78ddb9c4181850b827d
  Author: Laszlo Ersek <lersek@redhat.com>
  Date:   Thu Nov 21 16:27:18 2013 +0100

  error reason in BLOCK_IO_ERROR / BLOCK_JOB_ERROR events (RHEL 6->7 fwd)

I had to redo the work because now events use the QAPI, but it
was straightforward.

There's one significant difference though: this commit does not
extend the BLOCK_JOB_ERROR event as did the RHEL-7.0 commit. The
reason is that this extension was supposed to be used only by vdsm
and I don't think there's a requirement to have the extension
in BLOCK_JOB_ERROR too. Let's not spread it.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

diff --git a/block.c b/block.c
index 8cf519b..aab65d9 100644
--- a/block.c
+++ b/block.c
@@ -3596,6 +3596,21 @@ BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int e
     }
 }
 
+/* https://bugzilla.redhat.com/show_bug.cgi?id=1116772 */
+static RHEL7BlockErrorReason get_rhel7_error_reason(int error)
+{
+	switch (error) {
+	case ENOSPC:
+        return RHEL7_BLOCK_ERROR_REASON_ENOSPC;
+	case EPERM:
+        return RHEL7_BLOCK_ERROR_REASON_EPERM;
+	case EIO:
+        return RHEL7_BLOCK_ERROR_REASON_EIO;
+	default:
+        return RHEL7_BLOCK_ERROR_REASON_EOTHER;
+    }
+}
+
 /* This is done by device models because, while the block layer knows
  * about the error, it does not know whether an operation comes from
  * the device or the block layer (from a job, for example).
@@ -3603,7 +3618,10 @@ BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int e
 void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action,
                        bool is_read, int error)
 {
+    RHEL7BlockErrorReason res;
+
     assert(error >= 0);
+    res = get_rhel7_error_reason(error);
 
     if (action == BLOCK_ERROR_ACTION_STOP) {
         /* First set the iostatus, so that "info block" returns an iostatus
@@ -3624,13 +3642,13 @@ void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action,
         qapi_event_send_block_io_error(bdrv_get_device_name(bs),
                                        is_read ? IO_OPERATION_TYPE_READ :
                                        IO_OPERATION_TYPE_WRITE,
-                                       action, &error_abort);
+                                       action, res, &error_abort);
         qemu_system_vmstop_request(RUN_STATE_IO_ERROR);
     } else {
         qapi_event_send_block_io_error(bdrv_get_device_name(bs),
                                        is_read ? IO_OPERATION_TYPE_READ :
                                        IO_OPERATION_TYPE_WRITE,
-                                       action, &error_abort);
+                                       action, res, &error_abort);
     }
 }
 
diff --git a/docs/qmp/qmp-events.txt b/docs/qmp/qmp-events.txt
index d759d19..40c2917 100644
--- a/docs/qmp/qmp-events.txt
+++ b/docs/qmp/qmp-events.txt
@@ -63,13 +63,20 @@ Data:
     "ignore": error has been ignored
     "report": error has been reported to the device
     "stop": the VM is going to stop because of the error
+- "__com.redhat_reason": error reason, this is a RHEL7 extension, it's one of
+  the following (json-string):
+    "eio": errno EIO
+	"eperm": errno EPERM
+	"enospc": errno ENOSPC
+	"eother": any other errno (other than EIO, EPERM, ENOSPC)
 
 Example:
 
 { "event": "BLOCK_IO_ERROR",
     "data": { "device": "ide0-hd1",
               "operation": "write",
-              "action": "stop" },
+              "action": "stop",
+              "__com.redhat_reason": "enospc" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
 
 Note: If action is "stop", a STOP event will eventually follow the
diff --git a/qapi/block-core.json b/qapi/block-core.json
index e378653..404059b 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1496,6 +1496,13 @@
 { 'enum': 'BlockErrorAction',
   'data': [ 'ignore', 'report', 'stop' ] }
 
+##
+# @RHEL7BlockErrorReason
+#
+# Block I/O error reason
+##
+{ 'enum': 'RHEL7BlockErrorReason',
+  'data': [ 'enospc', 'eperm', 'eio', 'eother' ] }
 
 ##
 # @BLOCK_IMAGE_CORRUPTED
@@ -1533,6 +1540,8 @@
 #
 # @action: action that has been taken
 #
+# @__com.redhat_reason: error reason (RHEL7 vendor extension)
+#
 # Note: If action is "stop", a STOP event will eventually follow the
 # BLOCK_IO_ERROR event
 #
@@ -1540,7 +1549,8 @@
 ##
 { 'event': 'BLOCK_IO_ERROR',
   'data': { 'device': 'str', 'operation': 'IoOperationType',
-            'action': 'BlockErrorAction' } }
+            'action': 'BlockErrorAction',
+            '__com.redhat_reason': 'RHEL7BlockErrorReason' } }
 
 ##
 # @BLOCK_JOB_COMPLETED