[Qemu-devel] [PATCH v3 8/9] block/qcow2-bitmap: fix reopening bitmaps to RW

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

Currently reopening bitmaps to RW can't work, as qcow2 needs write
access to file child, to mark bitmaps in-image with IN_USE flag.

The possibility to write-access file child during reopen-RW was
implemented several patches ago with help of
.bdrv_need_rw_file_child_during_reopen_rw handler. Let's use
this new API to fix bitmaps reopening.

Add corresponding test-cases to 260 iotest.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/qcow2.h              |  1 +
 block/qcow2-bitmap.c       |  6 ++++++
 block/qcow2.c              |  1 +
 tests/qemu-iotests/260     |  2 ++
 tests/qemu-iotests/260.out | 35 +++++++++++++++++++++++++++++++++++
 5 files changed, 45 insertions(+)

diff --git a/block/qcow2.h b/block/qcow2.h
index a67e6a7d7c..3bfdaa7957 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -730,6 +730,7 @@ void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
 void qcow2_cache_discard(Qcow2Cache *c, void *table);
 
 /* qcow2-bitmap.c functions */
+bool qcow2_has_bitmaps(BlockDriverState *bs);
 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
                                   void **refcount_table,
                                   int64_t *refcount_table_size);
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index e276a95154..ed02588626 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1102,6 +1102,12 @@ Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
     return list;
 }
 
+bool qcow2_has_bitmaps(BlockDriverState *bs)
+{
+    BDRVQcow2State *s = bs->opaque;
+    return s->nb_bitmaps;
+}
+
 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp)
 {
     BDRVQcow2State *s = bs->opaque;
diff --git a/block/qcow2.c b/block/qcow2.c
index 5c1187e2f9..1d9fb3ae98 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -5232,6 +5232,7 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_reopen_bitmaps_rw = qcow2_reopen_bitmaps_rw,
     .bdrv_can_store_new_dirty_bitmap = qcow2_can_store_new_dirty_bitmap,
     .bdrv_remove_persistent_dirty_bitmap = qcow2_remove_persistent_dirty_bitmap,
+    .bdrv_need_rw_file_child_during_reopen_rw = qcow2_has_bitmaps,
 };
 
 static void bdrv_qcow2_init(void)
diff --git a/tests/qemu-iotests/260 b/tests/qemu-iotests/260
index 51288b8ee7..d8fcf4567a 100755
--- a/tests/qemu-iotests/260
+++ b/tests/qemu-iotests/260
@@ -83,3 +83,5 @@ def test(persistent, restart):
 
 
 test(persistent=False, restart=False)
+test(persistent=True, restart=False)
+test(persistent=True, restart=True)
diff --git a/tests/qemu-iotests/260.out b/tests/qemu-iotests/260.out
index 5239d27c46..2f0d98d036 100644
--- a/tests/qemu-iotests/260.out
+++ b/tests/qemu-iotests/260.out
@@ -15,3 +15,38 @@ check that no bitmaps are in snapshot: not found
 {"data": {"device": "drive0", "len": 65536, "offset": 65536, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 check bitmap after commit: name=bitmap0 dirty-clusters=2
 check updated bitmap: name=bitmap0 dirty-clusters=3
+
+Testcase persistent without restart
+
+{"execute": "block-dirty-bitmap-add", "arguments": {"name": "bitmap0", "node": "drive0", "persistent": true}}
+{"return": {}}
+initial bitmap: name=bitmap0 dirty-clusters=1
+{"execute": "blockdev-snapshot-sync", "arguments": {"device": "drive0", "format": "qcow2", "snapshot-file": "TEST_DIR/PID-top"}}
+{"return": {}}
+check that no bitmaps are in snapshot: not found
+{"execute": "block-commit", "arguments": {"device": "drive0", "top": "TEST_DIR/PID-top"}}
+{"return": {}}
+{"data": {"device": "drive0", "len": 65536, "offset": 65536, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_READY", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"execute": "block-job-complete", "arguments": {"device": "drive0"}}
+{"return": {}}
+{"data": {"device": "drive0", "len": 65536, "offset": 65536, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+check bitmap after commit: name=bitmap0 dirty-clusters=2
+check updated bitmap: name=bitmap0 dirty-clusters=3
+
+Testcase persistent with restart
+
+{"execute": "block-dirty-bitmap-add", "arguments": {"name": "bitmap0", "node": "drive0", "persistent": true}}
+{"return": {}}
+initial bitmap: name=bitmap0 dirty-clusters=1
+{"execute": "blockdev-snapshot-sync", "arguments": {"device": "drive0", "format": "qcow2", "snapshot-file": "TEST_DIR/PID-top"}}
+{"return": {}}
+check that no bitmaps are in snapshot: not found
+... Restart ...
+{"execute": "block-commit", "arguments": {"device": "drive0", "top": "TEST_DIR/PID-top"}}
+{"return": {}}
+{"data": {"device": "drive0", "len": 65536, "offset": 65536, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_READY", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"execute": "block-job-complete", "arguments": {"device": "drive0"}}
+{"return": {}}
+{"data": {"device": "drive0", "len": 65536, "offset": 65536, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+check bitmap after commit: name=bitmap0 dirty-clusters=2
+check updated bitmap: name=bitmap0 dirty-clusters=3
-- 
2.18.0