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>

diff --git a/block/qcow.c b/block/qcow.c
index 577bd70..d56d24a 100644 (file)
--- 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
index 071004b..af43d59 100644 (file)
--- 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
index 78baa04..e90649c 100644 (file)
--- 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
index 3bbc5d9..2d2af72 100644 (file)
--- 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;