rbd/info: add snapshot count in rbd info

Signed-off-by: Zheng Yin <zhengyin@huayun.com>

src/test/cli-integration/rbd/formatted-output.t

@@ -59,6 +59,7 @@ For now, use a more inclusive regex.
   \tsize 1GiB in 256 objects (esc)
   \torder 22 (4MiB objects) (esc)
   [^^]+ (re)
+  \tblock_name_prefix: rb.0.*  (glob)
   \tformat: 1 (esc)
   $ rbd info foo --format json | python -mjson.tool | sed 's/,$/, /'
   {
@@ -69,7 +70,8 @@ For now, use a more inclusive regex.
       "object_size": 4194304, 
       "objects": 256, 
       "order": 22, 
-      "size": 1073741824
+      "size": 1073741824, 
+      "snapshot_count": 1
   }
 The version of xml_pp included in ubuntu precise always prints a 'warning'
 whenever it is run. grep -v to ignore it, but still work on other distros.
@@ -81,6 +83,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>256</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>1</snapshot_count>
     <block_name_prefix>rb.0.*</block_name_prefix> (glob)
     <format>1</format>
   </image>
@@ -89,6 +92,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
   \tsize 1GiB in 256 objects (esc)
   \torder 22 (4MiB objects) (esc)
   [^^]+ (re)
+  \tblock_name_prefix: rb.0.*  (glob)
   \tformat: 1 (esc)
   \tprotected: False (esc)
   $ rbd info foo@snap --format json | python -mjson.tool | sed 's/,$/, /'
@@ -101,7 +105,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
       "objects": 256, 
       "order": 22, 
       "protected": "false", 
-      "size": 1073741824
+      "size": 1073741824, 
+      "snapshot_count": 1
   }
   $ rbd info foo@snap --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -111,6 +116,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>256</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>1</snapshot_count>
     <block_name_prefix>rb.0*</block_name_prefix> (glob)
     <format>1</format>
     <protected>false</protected>
@@ -119,6 +125,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
   rbd image 'bar':
   \tsize 1GiB in 256 objects (esc)
   \torder 22 (4MiB objects) (esc)
+  \tsnapshot_count: 2 (esc)
   \tid:* (glob)
   [^^]+ (re)
   \tformat: 2 (esc)
@@ -145,7 +152,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
       "objects": 256, 
       "op_features": [], 
       "order": 22, 
-      "size": 1073741824
+      "size": 1073741824, 
+      "snapshot_count": 2
   }
   $ rbd info bar --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -155,6 +163,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>256</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>2</snapshot_count>
     <block_name_prefix>rbd_data.*</block_name_prefix> (glob)
     <format>2</format>
     <features>
@@ -172,6 +181,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
   rbd image 'bar':
   \tsize 512MiB in 128 objects (esc)
   \torder 22 (4MiB objects) (esc)
+  \tsnapshot_count: 2 (esc)
   \tid:* (glob)
   [^^]+ (re)
   \tformat: 2 (esc)
@@ -200,7 +210,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
       "op_features": [], 
       "order": 22, 
       "protected": "true", 
-      "size": 536870912
+      "size": 536870912, 
+      "snapshot_count": 2
   }
   $ rbd info bar@snap --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -210,6 +221,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>128</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>2</snapshot_count>
     <block_name_prefix>rbd_data.*</block_name_prefix> (glob)
     <format>2</format>
     <features>
@@ -228,6 +240,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
   rbd image 'bar':
   \tsize 1GiB in 256 objects (esc)
   \torder 22 (4MiB objects) (esc)
+  \tsnapshot_count: 2 (esc)
   \tid:* (glob)
   [^^]+ (re)
   \tformat: 2 (esc)
@@ -256,7 +269,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
       "op_features": [], 
       "order": 22, 
       "protected": "false", 
-      "size": 1073741824
+      "size": 1073741824, 
+      "snapshot_count": 2
   }
   $ rbd info bar@snap2 --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -266,6 +280,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>256</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>2</snapshot_count>
     <block_name_prefix>rbd_data.*</block_name_prefix> (glob)
     <format>2</format>
     <features>
@@ -284,6 +299,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
   rbd image 'baz':
   \tsize 2GiB in 512 objects (esc)
   \torder 22 (4MiB objects) (esc)
+  \tsnapshot_count: 0 (esc)
   \tid:* (glob)
   [^^]+ (re)
   \tformat: 2 (esc)
@@ -306,7 +322,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
       "objects": 512, 
       "op_features": [], 
       "order": 22, 
-      "size": 2147483648
+      "size": 2147483648, 
+      "snapshot_count": 0
   }
   $ rbd info baz --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -316,6 +333,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>512</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>0</snapshot_count>
     <block_name_prefix>rbd_data.*</block_name_prefix> (glob)
     <format>2</format>
     <features>
@@ -329,6 +347,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
   rbd image 'quux':
   \tsize 1MiB in 1 objects (esc)
   \torder 22 (4MiB objects) (esc)
+  \tsnapshot_count: 0 (esc)
   [^^]+ (re)
   \tformat: 1 (esc)
   $ rbd info quux --format json | python -mjson.tool | sed 's/,$/, /'
@@ -340,7 +359,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
       "object_size": 4194304, 
       "objects": 1, 
       "order": 22, 
-      "size": 1048576
+      "size": 1048576, 
+      "snapshot_count": 0
   }
   $ rbd info quux --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -350,13 +370,15 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>1</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>0</snapshot_count>
     <block_name_prefix>rb.0.*</block_name_prefix> (glob)
     <format>1</format>
   </image>
   $ rbd info rbd_other/child
   rbd image 'child':
   \tsize 512MiB in 128 objects (esc)
   \torder 22 (4MiB objects) (esc)
+  \tsnapshot_count: 1 (esc)
   \tid:* (glob)
   [^^]+ (re)
   \tformat: 2 (esc)
@@ -382,7 +404,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
       "objects": 128, 
       "op_features": [], 
       "order": 22, 
-      "size": 536870912
+      "size": 536870912, 
+      "snapshot_count": 1
   }
   $ rbd info rbd_other/child --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -392,6 +415,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>128</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>1</snapshot_count>
     <block_name_prefix>rbd_data.*</block_name_prefix> (glob)
     <format>2</format>
     <features>
@@ -408,6 +432,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
   rbd image 'child':
   \tsize 512MiB in 128 objects (esc)
   \torder 22 (4MiB objects) (esc)
+  \tsnapshot_count: 1 (esc)
   \tid:* (glob)
   [^^]+ (re)
   \tformat: 2 (esc)
@@ -443,7 +468,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
           "snapshot": "snap"
       }, 
       "protected": "false", 
-      "size": 536870912
+      "size": 536870912, 
+      "snapshot_count": 1
   }
   $ rbd info rbd_other/child@snap --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -453,6 +479,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>128</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>1</snapshot_count>
     <block_name_prefix>rbd_data.*</block_name_prefix> (glob)
     <format>2</format>
     <features>
@@ -476,6 +503,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
   rbd image 'deep-flatten-child':
   \tsize 512MiB in 128 objects (esc)
   \torder 22 (4MiB objects) (esc)
+  \tsnapshot_count: 1 (esc)
   \tid:* (glob)
   [^^]+ (re)
   \tformat: 2 (esc)
@@ -502,7 +530,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
       "objects": 128, 
       "op_features": [], 
       "order": 22, 
-      "size": 536870912
+      "size": 536870912, 
+      "snapshot_count": 1
   }
   $ rbd info rbd_other/deep-flatten-child --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -512,6 +541,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>128</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>1</snapshot_count>
     <block_name_prefix>rbd_data.*</block_name_prefix> (glob)
     <format>2</format>
     <features>
@@ -529,6 +559,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
   rbd image 'deep-flatten-child':
   \tsize 512MiB in 128 objects (esc)
   \torder 22 (4MiB objects) (esc)
+  \tsnapshot_count: 1 (esc)
   \tid:* (glob)
   [^^]+ (re)
   \tformat: 2 (esc)
@@ -557,7 +588,8 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
       "op_features": [], 
       "order": 22, 
       "protected": "false", 
-      "size": 536870912
+      "size": 536870912, 
+      "snapshot_count": 1
   }
   $ rbd info rbd_other/deep-flatten-child@snap --format xml | xml_pp 2>&1 | grep -v '^new version at /usr/bin/xml_pp'
   <image>
@@ -567,6 +599,7 @@ whenever it is run. grep -v to ignore it, but still work on other distros.
     <objects>128</objects>
     <order>22</order>
     <object_size>4194304</object_size>
+    <snapshot_count>1</snapshot_count>
     <block_name_prefix>rbd_data.*</block_name_prefix> (glob)
     <format>2</format>
     <features>

src/tools/rbd/action/Info.cc

@@ -82,13 +82,18 @@ static int do_show_info(librados::IoCtx &io_ctx, librbd::Image& image,
   uint64_t overlap, features, flags, snap_limit;
   bool snap_protected = false;
   librbd::mirror_image_info_t mirror_image;
+  std::vector<librbd::snap_info_t> snaps;
   int r;
 
   std::string imgname;
   r = image.get_name(&imgname);
   if (r < 0)
     return r;
 
+  r = image.snap_list(snaps);
+  if (r < 0)
+    return r;
+
   r = image.stat(info, sizeof(info));
   if (r < 0)
     return r;
@@ -197,6 +202,7 @@ static int do_show_info(librados::IoCtx &io_ctx, librbd::Image& image,
     f->dump_unsigned("objects", info.num_objs);
     f->dump_int("order", info.order);
     f->dump_unsigned("object_size", info.obj_size);
+    f->dump_int("snapshot_count", snaps.size());
     if (!data_pool.empty()) {
       f->dump_string("data_pool", data_pool);
     }
@@ -209,6 +215,8 @@ static int do_show_info(librados::IoCtx &io_ctx, librbd::Image& image,
               << std::endl
               << "\torder " << info.order
               << " (" << byte_u_t(info.obj_size) << " objects)"
+              << std::endl
+              << "\tsnapshot_count: " << snaps.size()
               << std::endl;
     if (!imgid.empty()) {
       std::cout << "\tid: " << imgid << std::endl;