[RFC PATCH 3/6] Convert query-block/info_block to coroutine

[Fabiano Rosas <farosas@suse.de>]

From: Lin Ma <lma@suse.com>

Sometimes the query-block performs time-consuming I/O(say waiting for
the fstat of NFS complete), So let's make this QMP handler runs in a
coroutine.

The following patch moves the fstat() into a thread pool.

Signed-off-by: Lin Ma <lma@suse.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 block/monitor/block-hmp-cmds.c | 2 +-
 block/qapi.c                   | 2 +-
 hmp-commands-info.hx           | 1 +
 include/block/block-hmp-cmds.h | 2 +-
 qapi/block-core.json           | 2 +-
 5 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
index ca2599de44..4b704010bc 100644
--- a/block/monitor/block-hmp-cmds.c
+++ b/block/monitor/block-hmp-cmds.c
@@ -738,7 +738,7 @@ static void print_block_info(Monitor *mon, BlockInfo *info,
     }
 }
 
-void hmp_info_block(Monitor *mon, const QDict *qdict)
+void coroutine_fn hmp_info_block(Monitor *mon, const QDict *qdict)
 {
     BlockInfoList *block_list, *info;
     BlockDeviceInfoList *blockdev_list, *blockdev;
diff --git a/block/qapi.c b/block/qapi.c
index 79bf80c503..ae6cd1c2ff 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -667,7 +667,7 @@ bdrv_query_bds_stats(BlockDriverState *bs, bool blk_level)
     return s;
 }
 
-BlockInfoList *qmp_query_block(Error **errp)
+BlockInfoList *coroutine_fn qmp_query_block(Error **errp)
 {
     BlockInfoList *head = NULL, **p_next = &head;
     BlockBackend *blk;
diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
index 47d63d26db..996895f417 100644
--- a/hmp-commands-info.hx
+++ b/hmp-commands-info.hx
@@ -65,6 +65,7 @@ ERST
         .help       = "show info of one block device or all block devices "
                       "(-n: show named nodes; -v: show details)",
         .cmd        = hmp_info_block,
+        .coroutine  = true,
     },
 
 SRST
diff --git a/include/block/block-hmp-cmds.h b/include/block/block-hmp-cmds.h
index 71113cd7ef..6d9152318f 100644
--- a/include/block/block-hmp-cmds.h
+++ b/include/block/block-hmp-cmds.h
@@ -48,7 +48,7 @@ void hmp_eject(Monitor *mon, const QDict *qdict);
 
 void hmp_qemu_io(Monitor *mon, const QDict *qdict);
 
-void hmp_info_block(Monitor *mon, const QDict *qdict);
+void coroutine_fn hmp_info_block(Monitor *mon, const QDict *qdict);
 void hmp_info_blockstats(Monitor *mon, const QDict *qdict);
 void hmp_info_block_jobs(Monitor *mon, const QDict *qdict);
 void hmp_info_snapshots(Monitor *mon, const QDict *qdict);
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 98d9116dae..da95fe456c 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -838,7 +838,7 @@
 #    }
 ##
 { 'command': 'query-block', 'returns': ['BlockInfo'],
-  'allow-preconfig': true }
+  'allow-preconfig': true, 'coroutine': true }
 
 ##
 # @BlockDeviceTimedStats:
-- 
2.35.3