vmdk: Implement .bdrv_get_info()

This will return cluster_size and needs_compressed_writes to caller, if all the
extents have the same value (or there's only one extent). Otherwise return
-ENOTSUP.

cluster_size is only reported for sparse formats.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

block/vmdk.c

@@ -2076,6 +2076,26 @@ static ImageInfoSpecific *vmdk_get_specific_info(BlockDriverState *bs)
     return spec_info;
 }
 
+static int vmdk_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+    int i;
+    BDRVVmdkState *s = bs->opaque;
+    assert(s->num_extents);
+    bdi->needs_compressed_writes = s->extents[0].compressed;
+    if (!s->extents[0].flat) {
+        bdi->cluster_size = s->extents[0].cluster_sectors << BDRV_SECTOR_BITS;
+    }
+    /* See if we have multiple extents but they have different cases */
+    for (i = 1; i < s->num_extents; i++) {
+        if (bdi->needs_compressed_writes != s->extents[i].compressed ||
+            (bdi->cluster_size && bdi->cluster_size !=
+                s->extents[i].cluster_sectors << BDRV_SECTOR_BITS)) {
+            return -ENOTSUP;
+        }
+    }
+    return 0;
+}
+
 static QEMUOptionParameter vmdk_create_options[] = {
     {
         .name = BLOCK_OPT_SIZE,
@@ -2132,6 +2152,7 @@ static BlockDriver bdrv_vmdk = {
     .bdrv_has_zero_init           = vmdk_has_zero_init,
     .bdrv_get_specific_info       = vmdk_get_specific_info,
     .bdrv_refresh_limits          = vmdk_refresh_limits,
+    .bdrv_get_info                = vmdk_get_info,
 
     .create_options               = vmdk_create_options,
 };

tests/qemu-iotests/059.out

@@ -2050,6 +2050,7 @@ qemu-img: Could not open 'TEST_DIR/t.IMGFMT': File truncated, expecting at least
 image: TEST_DIR/iotest-version3.IMGFMT
 file format: IMGFMT
 virtual size: 1.0G (1073741824 bytes)
+cluster_size: 65536
 
 === Testing 4TB monolithicFlat creation and IO ===
 Formatting 'TEST_DIR/iotest-version3.IMGFMT', fmt=IMGFMT size=4398046511104