[PULL,15/37] block: Move BlockAcctStats into BlockBackend

diff --git a/block.c b/block.c
index 25c4fd8..dbce7bc 100644
--- a/block.c
+++ b/block.c
@@ -4153,14 +4153,3 @@  void bdrv_refresh_filename(BlockDriverState *bs)
         QDECREF(json);
     }
 }
-
-/* This accessor function purpose is to allow the device models to access the
- * BlockAcctStats structure embedded inside a BlockDriverState without being
- * aware of the BlockDriverState structure layout.
- * It will go away when the BlockAcctStats structure will be moved inside
- * the device models.
- */
-BlockAcctStats *bdrv_get_stats(BlockDriverState *bs)
-{
-    return &bs->stats;
-}
diff --git a/block/block-backend.c b/block/block-backend.c
index 7bc2eb1..a52037b 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -34,6 +34,9 @@  struct BlockBackend {
 
     /* the block size for which the guest device expects atomicity */
     int guest_block_size;
+
+    /* I/O stats (display with "info blockstats"). */
+    BlockAcctStats stats;
 };
 
 typedef struct BlockBackendAIOCB {
@@ -892,7 +895,7 @@  void blk_io_unplug(BlockBackend *blk)
 
 BlockAcctStats *blk_get_stats(BlockBackend *blk)
 {
-    return bdrv_get_stats(blk->bs);
+    return &blk->stats;
 }
 
 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
diff --git a/block/io.c b/block/io.c
index b80044b..2fd7a1d 100644
--- a/block/io.c
+++ b/block/io.c
@@ -23,6 +23,7 @@ 
  */
 
 #include "trace.h"
+#include "sysemu/block-backend.h"
 #include "block/blockjob.h"
 #include "block/block_int.h"
 #include "block/throttle-groups.h"
@@ -1905,7 +1906,10 @@  static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
         }
     }
 
-    block_acct_merge_done(&bs->stats, BLOCK_ACCT_WRITE, num_reqs - outidx - 1);
+    if (bs->blk) {
+        block_acct_merge_done(blk_get_stats(bs->blk), BLOCK_ACCT_WRITE,
+                              num_reqs - outidx - 1);
+    }
 
     return outidx + 1;
 }
diff --git a/block/qapi.c b/block/qapi.c
index 0360126..7c8209b 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -344,16 +344,20 @@  static BlockStats *bdrv_query_stats(const BlockDriverState *bs,
     }
 
     s->stats = g_malloc0(sizeof(*s->stats));
-    s->stats->rd_bytes = bs->stats.nr_bytes[BLOCK_ACCT_READ];
-    s->stats->wr_bytes = bs->stats.nr_bytes[BLOCK_ACCT_WRITE];
-    s->stats->rd_operations = bs->stats.nr_ops[BLOCK_ACCT_READ];
-    s->stats->wr_operations = bs->stats.nr_ops[BLOCK_ACCT_WRITE];
-    s->stats->rd_merged = bs->stats.merged[BLOCK_ACCT_READ];
-    s->stats->wr_merged = bs->stats.merged[BLOCK_ACCT_WRITE];
-    s->stats->flush_operations = bs->stats.nr_ops[BLOCK_ACCT_FLUSH];
-    s->stats->wr_total_time_ns = bs->stats.total_time_ns[BLOCK_ACCT_WRITE];
-    s->stats->rd_total_time_ns = bs->stats.total_time_ns[BLOCK_ACCT_READ];
-    s->stats->flush_total_time_ns = bs->stats.total_time_ns[BLOCK_ACCT_FLUSH];
+    if (bs->blk) {
+        BlockAcctStats *stats = blk_get_stats(bs->blk);
+
+        s->stats->rd_bytes = stats->nr_bytes[BLOCK_ACCT_READ];
+        s->stats->wr_bytes = stats->nr_bytes[BLOCK_ACCT_WRITE];
+        s->stats->rd_operations = stats->nr_ops[BLOCK_ACCT_READ];
+        s->stats->wr_operations = stats->nr_ops[BLOCK_ACCT_WRITE];
+        s->stats->rd_merged = stats->merged[BLOCK_ACCT_READ];
+        s->stats->wr_merged = stats->merged[BLOCK_ACCT_WRITE];
+        s->stats->flush_operations = stats->nr_ops[BLOCK_ACCT_FLUSH];
+        s->stats->wr_total_time_ns = stats->total_time_ns[BLOCK_ACCT_WRITE];
+        s->stats->rd_total_time_ns = stats->total_time_ns[BLOCK_ACCT_READ];
+        s->stats->flush_total_time_ns = stats->total_time_ns[BLOCK_ACCT_FLUSH];
+    }
 
     s->stats->wr_highest_offset = bs->wr_highest_offset;
 
diff --git a/include/block/block.h b/include/block/block.h
index 8a6f001..a39cfe3 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -621,6 +621,4 @@  void bdrv_io_plug(BlockDriverState *bs);
 void bdrv_io_unplug(BlockDriverState *bs);
 void bdrv_flush_io_queue(BlockDriverState *bs);
 
-BlockAcctStats *bdrv_get_stats(BlockDriverState *bs);
-
 #endif
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 35d4c19..aa00aea 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -399,9 +399,6 @@  struct BlockDriverState {
     unsigned       pending_reqs[2];
     QLIST_ENTRY(BlockDriverState) round_robin;
 
-    /* I/O stats (display with "info blockstats"). */
-    BlockAcctStats stats;
-
     /* Offset after the highest byte written to */
     uint64_t wr_highest_offset;