[Qemu-devel] [PATCH 3/4] block: Use bdrv_get_backing_file_depth()

[Luiz Capitulino <lcapitulino@redhat.com>]

From: Benoît Canet <benoit.canet@gmail.com>

Use the dedicated counting function in qmp_query_block in order to
propagate the backing file depth to HMP and add backing_file_depth
to qmp-commands.hx

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 block.c          | 3 +++
 qapi-schema.json | 9 ++++++---
 qmp-commands.hx  | 2 ++
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/block.c b/block.c
index 1206bba..24323c1 100644
--- a/block.c
+++ b/block.c
@@ -2450,6 +2450,9 @@ BlockInfoList *qmp_query_block(Error **errp)
                 info->value->inserted->backing_file = g_strdup(bs->backing_file);
             }
 
+            info->value->inserted->backing_file_depth =
+                bdrv_get_backing_file_depth(bs);
+
             if (bs->io_limits_enabled) {
                 info->value->inserted->bps =
                                bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL];
diff --git a/qapi-schema.json b/qapi-schema.json
index bc55ed2..b58f5cd 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -398,6 +398,8 @@
 #
 # @backing_file: #optional the name of the backing file (for copy-on-write)
 #
+# @backing_file_depth: number of files in the backing file chain (since: 1.2)
+#
 # @encrypted: true if the backing device is encrypted
 #
 # @bps: total throughput limit in bytes per second is specified
@@ -418,9 +420,10 @@
 ##
 { 'type': 'BlockDeviceInfo',
   'data': { 'file': 'str', 'ro': 'bool', 'drv': 'str',
-            '*backing_file': 'str', 'encrypted': 'bool',
-            'bps': 'int', 'bps_rd': 'int', 'bps_wr': 'int',
-            'iops': 'int', 'iops_rd': 'int', 'iops_wr': 'int'} }
+            '*backing_file': 'str', 'backing_file_depth': 'int',
+            'encrypted': 'bool', 'bps': 'int', 'bps_rd': 'int',
+            'bps_wr': 'int', 'iops': 'int', 'iops_rd': 'int',
+            'iops_wr': 'int'} }
 
 ##
 # @BlockDeviceIoStatus:
diff --git a/qmp-commands.hx b/qmp-commands.hx
index e3cf3c5..ac46638 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1317,6 +1317,7 @@ Each json-object contain the following:
                                 "nbd", "parallels", "qcow", "qcow2", "raw",
                                 "tftp", "vdi", "vmdk", "vpc", "vvfat"
          - "backing_file": backing file name (json-string, optional)
+         - "backing_file_depth": number of files in the backing file chain (json-int)
          - "encrypted": true if encrypted, false otherwise (json-bool)
          - "bps": limit total bytes per second (json-int)
          - "bps_rd": limit read bytes per second (json-int)
@@ -1345,6 +1346,7 @@ Example:
                "drv":"qcow2",
                "encrypted":false,
                "file":"disks/test.img",
+               "backing_file_depth":0,
                "bps":1000000,
                "bps_rd":0,
                "bps_wr":0,
-- 
1.7.11.2.249.g31c7954.dirty