Merge remote-tracking branch 'remotes/ericb/tags/pull-bitmaps-2021-02-12' into staging

bitmaps patches for 2021-02-12

- add 'transform' member to manipulate bitmaps across migration
- work towards better error handling during bdrv_open

# gpg: Signature made Fri 12 Feb 2021 23:19:39 GMT
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-bitmaps-2021-02-12:
  block: use return status of bdrv_append()
  block: return status from bdrv_append and friends
  qemu-iotests: 300: Add test case for modifying persistence of bitmap
  migration: dirty-bitmap: Allow control of bitmap persistence
  migration: dirty-bitmap: Use struct for alias map inner members

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 15 insertions, 20 deletions

diff --git a/block/backup-top.c b/block/backup-top.c
index 6e7e7bf340..d1253e1aa6 100644
--- a/block/backup-top.c
+++ b/block/backup-top.c
@@ -191,7 +191,8 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
                                          BlockCopyState **bcs,
                                          Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_GUARD();
+    int ret;
     BDRVBackupTopState *state;
     BlockDriverState *top;
     bool appended = false;
@@ -224,9 +225,9 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
     bdrv_drained_begin(source);
 
     bdrv_ref(top);
-    bdrv_append(top, source, &local_err);
-    if (local_err) {
-        error_prepend(&local_err, "Cannot append backup-top filter: ");
+    ret = bdrv_append(top, source, errp);
+    if (ret < 0) {
+        error_prepend(errp, "Cannot append backup-top filter: ");
         goto fail;
     }
     appended = true;
@@ -236,19 +237,18 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
      * we want.
      */
     state->active = true;
-    bdrv_child_refresh_perms(top, top->backing, &local_err);
-    if (local_err) {
-        error_prepend(&local_err,
-                      "Cannot set permissions for backup-top filter: ");
+    ret = bdrv_child_refresh_perms(top, top->backing, errp);
+    if (ret < 0) {
+        error_prepend(errp, "Cannot set permissions for backup-top filter: ");
         goto fail;
     }
 
     state->cluster_size = cluster_size;
     state->bcs = block_copy_state_new(top->backing, state->target,
                                       cluster_size, perf->use_copy_range,
-                                      write_flags, &local_err);
-    if (local_err) {
-        error_prepend(&local_err, "Cannot create block-copy-state: ");
+                                      write_flags, errp);
+    if (!state->bcs) {
+        error_prepend(errp, "Cannot create block-copy-state: ");
         goto fail;
     }
     *bcs = state->bcs;
@@ -266,7 +266,6 @@ fail:
     }
 
     bdrv_drained_end(source);
-    error_propagate(errp, local_err);
 
     return NULL;
 }
diff --git a/block/commit.c b/block/commit.c
index 71db7ba747..dd9ba87349 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -254,7 +254,6 @@ void commit_start(const char *job_id, BlockDriverState *bs,
     BlockDriverState *iter;
     BlockDriverState *commit_top_bs = NULL;
     BlockDriverState *filtered_base;
-    Error *local_err = NULL;
     int64_t base_size, top_size;
     uint64_t base_perms, iter_shared_perms;
     int ret;
@@ -312,10 +311,9 @@ void commit_start(const char *job_id, BlockDriverState *bs,
 
     commit_top_bs->total_sectors = top->total_sectors;
 
-    bdrv_append(commit_top_bs, top, &local_err);
-    if (local_err) {
+    ret = bdrv_append(commit_top_bs, top, errp);
+    if (ret < 0) {
         commit_top_bs = NULL;
-        error_propagate(errp, local_err);
         goto fail;
     }
 
diff --git a/block/mirror.c b/block/mirror.c
index 9faffe4707..1803c6988b 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1569,7 +1569,6 @@ static BlockJob *mirror_start_job(
     BlockDriverState *mirror_top_bs;
     bool target_is_backing;
     uint64_t target_perms, target_shared_perms;
-    Error *local_err = NULL;
     int ret;
 
     if (granularity == 0) {
@@ -1618,12 +1617,11 @@ static BlockJob *mirror_start_job(
      * it alive until block_job_create() succeeds even if bs has no parent. */
     bdrv_ref(mirror_top_bs);
     bdrv_drained_begin(bs);
-    bdrv_append(mirror_top_bs, bs, &local_err);
+    ret = bdrv_append(mirror_top_bs, bs, errp);
     bdrv_drained_end(bs);
 
-    if (local_err) {
+    if (ret < 0) {
         bdrv_unref(mirror_top_bs);
-        error_propagate(errp, local_err);
         return NULL;
     }