[Qemu-devel] [PATCH 21/24] qcow2-bitmap: refcounts

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Calculate refcounts for qcow2 bitmaps. It is needed for qcow2's qemu-img
check implementation.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2-bitmap.c   | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++
 block/qcow2-refcount.c |  6 ++++
 block/qcow2.h          |  3 ++
 3 files changed, 85 insertions(+)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 94a7bc5421..590a0fcc8e 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1233,3 +1233,79 @@ common_errp:
                name, bdrv_get_device_or_node_name(bs), reason);
     return false;
 }
+
+int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
+                                  void **refcount_table,
+                                  int64_t *refcount_table_size)
+{
+    int ret;
+    BDRVQcow2State *s = bs->opaque;
+    Qcow2BitmapList *bm_list;
+    Qcow2Bitmap *bm;
+
+    if (s->nb_bitmaps == 0) {
+        return 0;
+    }
+
+    ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, refcount_table_size,
+                                   s->bitmap_directory_offset,
+                                   s->bitmap_directory_size);
+    if (ret < 0) {
+        return ret;
+    }
+
+    bm_list = bitmap_list_load(bs, s->bitmap_directory_offset,
+                               s->bitmap_directory_size, NULL);
+    if (bm_list == NULL) {
+        res->corruptions++;
+        return -EINVAL;
+    }
+
+    QSIMPLEQ_FOREACH(bm, bm_list, entry) {
+        uint64_t *bitmap_table = NULL;
+        int i;
+
+        ret = qcow2_inc_refcounts_imrt(bs, res,
+                                       refcount_table, refcount_table_size,
+                                       bm->table.offset,
+                                       bm->table.size * sizeof(uint64_t));
+        if (ret < 0) {
+            goto out;
+        }
+
+        ret = bitmap_table_load(bs, &bm->table, &bitmap_table);
+        if (ret < 0) {
+            res->corruptions++;
+            goto out;
+        }
+
+        for (i = 0; i < bm->table.size; ++i) {
+            uint64_t entry = bitmap_table[i];
+            uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK;
+
+            if (check_table_entry(entry, s->cluster_size) < 0) {
+                res->corruptions++;
+                continue;
+            }
+
+            if (offset == 0) {
+                continue;
+            }
+
+            ret = qcow2_inc_refcounts_imrt(bs, res,
+                                           refcount_table, refcount_table_size,
+                                           offset, s->cluster_size);
+            if (ret < 0) {
+                g_free(bitmap_table);
+                goto out;
+            }
+        }
+
+        g_free(bitmap_table);
+    }
+
+out:
+    bitmap_list_free(bm_list);
+
+    return ret;
+}
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 14a736d245..cdb74ba4de 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1846,6 +1846,12 @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
         return ret;
     }
 
+    /* bitmaps */
+    ret = qcow2_check_bitmaps_refcounts(bs, res, refcount_table, nb_clusters);
+    if (ret < 0) {
+        return ret;
+    }
+
     return check_refblocks(bs, res, fix, rebuild, refcount_table, nb_clusters);
 }
 
diff --git a/block/qcow2.h b/block/qcow2.h
index 0a3708d890..eaad34a527 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -624,5 +624,8 @@ bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
                                       const char *name,
                                       uint32_t granularity,
                                       Error **errp);
+int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
+                                  void **refcount_table,
+                                  int64_t *refcount_table_size);
 
 #endif
-- 
2.11.0