qcow2: introduce icount field for snapshots

This patch introduces the icount field for saving within the snapshot.
It is required for navigation between the snapshots in record/replay mode.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Acked-by: Kevin Wolf <kwolf@redhat.com>

--

v7 changes:
 - also fix the test which checks qcow2 snapshot extra data
Message-Id: <160174518284.12451.2301137308458777398.stgit@pasha-ThinkPad-X280>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 43 insertions, 23 deletions

diff --git a/tests/qemu-iotests/261 b/tests/qemu-iotests/261
index ddcb04f285..848ffa760d 100755
--- a/tests/qemu-iotests/261
+++ b/tests/qemu-iotests/261
@@ -91,7 +91,10 @@ print_snapshot_table()
         if [ $extra_len -ge 16 ]; then
             echo "    Disk size: $(peek_file_be "$1" $((extra_ofs + 8)) 8)"
         fi
-        if [ $extra_len -gt 16 ]; then
+        if [ $extra_len -ge 24 ]; then
+            echo "    Icount: $(peek_file_be "$1" $((extra_ofs + 16)) 8)"
+        fi
+        if [ $extra_len -gt 24 ]; then
             echo '    Unknown extra data:' \
                 "$(peek_file_raw "$1" $((extra_ofs + 16)) $((extra_len - 16)) \
                    | tr -d '\0')"
@@ -198,12 +201,12 @@ truncate -s 0 "$TEST_DIR/sn0-extra"
 truncate -s $(($(snapshot_table_entry_size "$TEST_DIR/sn0-pre") - 40)) \
     "$TEST_DIR/sn0-post"
 
-# Set sn1's extra data size to 42
-poke_file "$TEST_DIR/sn1-pre" 36 '\x00\x00\x00\x2a'
-truncate -s 42 "$TEST_DIR/sn1-extra"
-poke_file "$TEST_DIR/sn1-extra" 16 'very important data'
+# Set sn1's extra data size to 50
+poke_file "$TEST_DIR/sn1-pre" 36 '\x00\x00\x00\x32'
+truncate -s 50 "$TEST_DIR/sn1-extra"
+poke_file "$TEST_DIR/sn1-extra" 24 'very important data'
 # Grow sn1-post to pad
-truncate -s $(($(snapshot_table_entry_size "$TEST_DIR/sn1-pre") - 82)) \
+truncate -s $(($(snapshot_table_entry_size "$TEST_DIR/sn1-pre") - 90)) \
     "$TEST_DIR/sn1-post"
 
 # Set sn2's extra data size to 8
diff --git a/tests/qemu-iotests/261.out b/tests/qemu-iotests/261.out
index 2600354566..612433ae40 100644
--- a/tests/qemu-iotests/261.out
+++ b/tests/qemu-iotests/261.out
@@ -12,9 +12,10 @@ Snapshots in TEST_DIR/t.IMGFMT.v2.orig:
   [1]
     ID: 2
     Name: sn1
-    Extra data size: 42
+    Extra data size: 50
     VM state size: 0
     Disk size: 67108864
+    Icount: 0
     Unknown extra data: very important data
   [2]
     ID: 3
@@ -29,22 +30,25 @@ Snapshots in TEST_DIR/t.IMGFMT.v3.orig:
   [0]
     ID: 1
     Name: sn0
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
   [1]
     ID: 2
     Name: sn1
-    Extra data size: 42
+    Extra data size: 50
     VM state size: 0
     Disk size: 67108864
+    Icount: 0
     Unknown extra data: very important data
   [2]
     ID: 3
     Name: sn2
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
 
 === Repair botched v3 ===
 
@@ -61,22 +65,25 @@ Snapshots in TEST_DIR/t.IMGFMT:
   [0]
     ID: 1
     Name: sn0
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
   [1]
     ID: 2
     Name: sn1
-    Extra data size: 42
+    Extra data size: 50
     VM state size: 0
     Disk size: 67108864
+    Icount: 0
     Unknown extra data: very important data
   [2]
     ID: 3
     Name: sn2
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
 
 === Add new snapshot ===
 
@@ -85,28 +92,32 @@ Snapshots in TEST_DIR/t.IMGFMT:
   [0]
     ID: 1
     Name: sn0
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
   [1]
     ID: 2
     Name: sn1
-    Extra data size: 42
+    Extra data size: 50
     VM state size: 0
     Disk size: 67108864
+    Icount: 0
     Unknown extra data: very important data
   [2]
     ID: 3
     Name: sn2
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
   [3]
     ID: 4
     Name: sn3
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 0
 
 === Remove different snapshots ===
 
@@ -116,16 +127,18 @@ Snapshots in TEST_DIR/t.IMGFMT:
   [0]
     ID: 2
     Name: sn1
-    Extra data size: 42
+    Extra data size: 50
     VM state size: 0
     Disk size: 67108864
+    Icount: 0
     Unknown extra data: very important data
   [1]
     ID: 3
     Name: sn2
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
 
 --- sn1 ---
 No errors were found on the image.
@@ -133,15 +146,17 @@ Snapshots in TEST_DIR/t.IMGFMT:
   [0]
     ID: 1
     Name: sn0
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
   [1]
     ID: 3
     Name: sn2
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
 
 --- sn2 ---
 No errors were found on the image.
@@ -149,15 +164,17 @@ Snapshots in TEST_DIR/t.IMGFMT:
   [0]
     ID: 1
     Name: sn0
-    Extra data size: 16
+    Extra data size: 24
     VM state size: 0
     Disk size: 67108864
+    Icount: 18446744073709551615
   [1]
     ID: 2
     Name: sn1
-    Extra data size: 42
+    Extra data size: 50
     VM state size: 0
     Disk size: 67108864
+    Icount: 0
     Unknown extra data: very important data
 
 === Reject too much unknown extra data ===