block/export: Add BLOCK_EXPORT_DELETED event

Clients may want to know when an export has finally disappeard
(block-export-del returns earlier than that in the general case), so add
a QAPI event for it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200924152717.287415-22-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2020-09-24 17:27:07 +02:00
parent 3c3bc462ad
commit 1a9f7a804f
5 changed files with 27 additions and 2 deletions

View File

@ -19,6 +19,7 @@
#include "block/nbd.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-block-export.h"
#include "qapi/qapi-events-block-export.h"
#include "qemu/id.h"
static const BlockExportDriver *blk_exp_drivers[] = {
@ -113,6 +114,7 @@ static void blk_exp_delete_bh(void *opaque)
assert(exp->refcount == 0);
QLIST_REMOVE(exp, next);
exp->drv->delete(exp);
qapi_event_send_block_export_deleted(exp->id);
g_free(exp->id);
g_free(exp);

View File

@ -233,3 +233,15 @@
##
{ 'command': 'block-export-del',
'data': { 'id': 'str', '*mode': 'BlockExportRemoveMode' } }
##
# @BLOCK_EXPORT_DELETED:
#
# Emitted when a block export is removed and its id can be reused.
#
# @id: Block export id.
#
# Since: 5.2
##
{ 'event': 'BLOCK_EXPORT_DELETED',
'data': { 'id': 'str' } }

View File

@ -81,10 +81,17 @@ $QEMU_IO_PROG -f raw -r -c 'read -P 42 0 64k' \
"nbd+unix:///drv?socket=$SOCK_DIR/nbd" 2>&1 \
| _filter_qemu_io | _filter_nbd
# The order of 'return' and the BLOCK_EXPORT_DELETED event is undefined. Just
# wait until we've twice seen one of them. Filter the 'return' line out so that
# the output is defined.
_send_qemu_cmd $QEMU_HANDLE \
"{ 'execute': 'eject',
'arguments': { 'device': 'drv' }}" \
'return'
'return\|BLOCK_EXPORT_DELETED' |
grep -v 'return'
_send_qemu_cmd $QEMU_HANDLE '' 'return\|BLOCK_EXPORT_DELETED' |
grep -v 'return'
$QEMU_IO_PROG -f raw -r -c close \
"nbd+unix:///drv?socket=$SOCK_DIR/nbd" 2>&1 \

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@ -11,7 +11,7 @@ wrote 65536/65536 bytes at offset 0
read 65536/65536 bytes at offset 0
64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
{ 'execute': 'eject', 'arguments': { 'device': 'drv' }}
{"return": {}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_EXPORT_DELETED", "data": {"id": "drv"}}
qemu-io: can't open device nbd+unix:///drv?socket=SOCK_DIR/nbd: Requested export not available
server reported: export 'drv' not present
{ 'execute': 'quit' }

View File

@ -102,8 +102,10 @@ read 2097152/2097152 bytes at offset 2097152
{"execute":"nbd-server-remove", "arguments":{"name":"n"}}
{"return": {}}
{"execute":"nbd-server-remove", "arguments":{"name":"n2"}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_EXPORT_DELETED", "data": {"id": "n"}}
{"return": {}}
{"execute":"nbd-server-remove", "arguments":{"name":"n2"}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_EXPORT_DELETED", "data": {"id": "n2"}}
{"error": {"class": "GenericError", "desc": "Export 'n2' is not found"}}
{"execute":"nbd-server-stop"}
{"return": {}}
@ -183,8 +185,10 @@ read 2097152/2097152 bytes at offset 2097152
{"execute":"nbd-server-remove", "arguments":{"name":"n"}}
{"return": {}}
{"execute":"nbd-server-remove", "arguments":{"name":"n2"}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_EXPORT_DELETED", "data": {"id": "n"}}
{"return": {}}
{"execute":"nbd-server-remove", "arguments":{"name":"n2"}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_EXPORT_DELETED", "data": {"id": "n2"}}
{"error": {"class": "GenericError", "desc": "Export 'n2' is not found"}}
{"execute":"nbd-server-stop"}
{"return": {}}