qcow2: List autoclear bit names in header

The feature table is supposed to advertise the name of all feature
bits that we support; however, we forgot to update the table for
autoclear bits.  While at it, move the table to read-only memory in
code, and tweak the qcow2 spec to name the second autoclear bit.
Update iotests that are affected by the longer header length.

Fixes: 88ddffae
Fixes: 93c24936Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200324174233.1622067-3-eblake@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>
(cherry picked from commit bb40ebce)
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

block/qcow2.c

@@ -2822,7 +2822,7 @@ int qcow2_update_header(BlockDriverState *bs)
 
     /* Feature table */
     if (s->qcow_version >= 3) {
-        Qcow2Feature features[] = {
+        static const Qcow2Feature features[] = {
             {
                 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
                 .bit  = QCOW2_INCOMPAT_DIRTY_BITNR,
@@ -2843,6 +2843,16 @@ int qcow2_update_header(BlockDriverState *bs)
                 .bit  = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
                 .name = "lazy refcounts",
             },
+            {
+                .type = QCOW2_FEAT_TYPE_AUTOCLEAR,
+                .bit  = QCOW2_AUTOCLEAR_BITMAPS_BITNR,
+                .name = "bitmaps",
+            },
+            {
+                .type = QCOW2_FEAT_TYPE_AUTOCLEAR,
+                .bit  = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
+                .name = "raw external data",
+            },
         };
 
         ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE,

docs/interop/qcow2.txt

@@ -138,7 +138,8 @@ in the description of a field.
                                 bit is unset, the bitmaps extension data must be
                                 considered inconsistent.
 
-                    Bit 1:      If this bit is set, the external data file can
+                    Bit 1:      Raw external data bit
+                                If this bit is set, the external data file can
                                 be read as a consistent standalone raw image
                                 without looking at the qcow2 metadata.
 

tests/qemu-iotests/031.out

@@ -117,7 +117,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 Header extension:
@@ -150,7 +150,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 Header extension:
@@ -164,7 +164,7 @@ No errors were found on the image.
 
 magic                     0x514649fb
 version                   3
-backing_file_offset       0x178
+backing_file_offset       0x1d8
 backing_file_size         0x17
 cluster_bits              16
 size                      67108864
@@ -188,7 +188,7 @@ data                      'host_device'
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 Header extension:

tests/qemu-iotests/036.out

@@ -58,7 +58,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 
@@ -86,7 +86,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 *** done

tests/qemu-iotests/061.out

@@ -26,7 +26,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 magic                     0x514649fb
@@ -84,7 +84,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 magic                     0x514649fb
@@ -140,7 +140,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 ERROR cluster 5 refcount=0 reference=1
@@ -195,7 +195,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 magic                     0x514649fb
@@ -264,7 +264,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 read 65536/65536 bytes at offset 44040192
@@ -298,7 +298,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 ERROR cluster 5 refcount=0 reference=1
@@ -327,7 +327,7 @@ header_length             104
 
 Header extension:
 magic                     0x6803f857
-length                    192
+length                    288
 data                      <binary>
 
 read 131072/131072 bytes at offset 0