block: add BDRV_BLOCK_COMPRESSED flag for bdrv_block_status()

Functions qcow2_get_host_offset(), get_cluster_offset(), vmdk_co_block_status() explicitly report compressed cluster types when data is compressed. However, this information is never passed further. Let's make use of it by adding new BDRV_BLOCK_COMPRESSED flag for bdrv_block_status(), so that caller may know that the data range is compressed. In particular, we're going to use this flag to tweak "qemu-img map" output. This new flag is only being utilized by qcow, qcow2 and vmdk formats, as only those support compression. Reviewed-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Hanna Czenczek <hreitz@redhat.com> Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com> Message-ID: <20230907210226.953821-2-andrey.drobyshev@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu · Sep 20, 2023 · 2848289 · 2848289
1 parent 9def608
commit 2848289
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Showing 4 changed files with 12 additions and 1 deletion.
diff --git a/block/qcow.c b/block/qcow.c
@@ -549,7 +549,10 @@ qcow_co_block_status(BlockDriverState *bs, bool want_zero,
     if (!cluster_offset) {
         return 0;
     }
-    if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypto) {
+    if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
+        return BDRV_BLOCK_DATA | BDRV_BLOCK_COMPRESSED;
+    }
+    if (s->crypto) {
         return BDRV_BLOCK_DATA;
     }
     *map = cluster_offset | index_in_cluster;

diff --git a/block/qcow2.c b/block/qcow2.c
@@ -2162,6 +2162,9 @@ qcow2_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
     {
         status |= BDRV_BLOCK_RECURSE;
     }
+    if (type == QCOW2_SUBCLUSTER_COMPRESSED) {
+        status |= BDRV_BLOCK_COMPRESSED;
+    }
     return status;
 }
 

diff --git a/block/vmdk.c b/block/vmdk.c
@@ -1783,6 +1783,8 @@ vmdk_co_block_status(BlockDriverState *bs, bool want_zero,
             if (extent->flat) {
                 ret |= BDRV_BLOCK_RECURSE;
             }
+        } else {
+            ret |= BDRV_BLOCK_COMPRESSED;
         }
         *file = extent->file->bs;
         break;

diff --git a/include/block/block-common.h b/include/block/block-common.h
@@ -291,6 +291,8 @@ typedef enum {
  *                       layer rather than any backing, set by block layer
  * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
  *                 layer, set by block layer
+ * BDRV_BLOCK_COMPRESSED: the underlying data is compressed; only valid for
+ *                        the formats supporting compression: qcow, qcow2
  *
  * Internal flags:
  * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
@@ -326,6 +328,7 @@ typedef enum {
 #define BDRV_BLOCK_ALLOCATED    0x10
 #define BDRV_BLOCK_EOF          0x20
 #define BDRV_BLOCK_RECURSE      0x40
+#define BDRV_BLOCK_COMPRESSED   0x80
 
 typedef QTAILQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;