[PULL 5/5] block: use return status of bdrv_append()

[Eric Blake <eblake@redhat.com>]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Now bdrv_append returns status and we can drop all the local_err things
around it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20210202124956.63146-3-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block.c                     |  6 ++----
 block/backup-top.c          | 23 +++++++++++------------
 block/commit.c              |  6 ++----
 block/mirror.c              |  6 ++----
 blockdev.c                  |  6 +++---
 tests/test-bdrv-graph-mod.c |  6 +++---
 6 files changed, 23 insertions(+), 30 deletions(-)

diff --git a/block.c b/block.c
index fdb0261cb324..c682c3e3b96b 100644
--- a/block.c
+++ b/block.c
@@ -3118,7 +3118,6 @@ static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
     int64_t total_size;
     QemuOpts *opts = NULL;
     BlockDriverState *bs_snapshot = NULL;
-    Error *local_err = NULL;
     int ret;

     /* if snapshot, we create a temporary backing file and open it
@@ -3165,9 +3164,8 @@ static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
      * order to be able to return one, we have to increase
      * bs_snapshot's refcount here */
     bdrv_ref(bs_snapshot);
-    bdrv_append(bs_snapshot, bs, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    ret = bdrv_append(bs_snapshot, bs, errp);
+    if (ret < 0) {
         bs_snapshot = NULL;
         goto out;
     }
diff --git a/block/backup-top.c b/block/backup-top.c
index 6e7e7bf34047..d1253e1aa63f 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 71db7ba7472e..dd9ba87349e3 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 8e1ad6eceb57..fad270193888 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1560,7 +1560,6 @@ 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) {
@@ -1609,12 +1608,11 @@ 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;
     }

diff --git a/blockdev.c b/blockdev.c
index b250b9b95957..cd438e60e35a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1432,6 +1432,7 @@ typedef struct ExternalSnapshotState {
 static void external_snapshot_prepare(BlkActionState *common,
                                       Error **errp)
 {
+    int ret;
     int flags = 0;
     QDict *options = NULL;
     Error *local_err = NULL;
@@ -1591,9 +1592,8 @@ static void external_snapshot_prepare(BlkActionState *common,
      * can fail, so we need to do it in .prepare; undoing it for abort is
      * always possible. */
     bdrv_ref(state->new_bs);
-    bdrv_append(state->new_bs, state->old_bs, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    ret = bdrv_append(state->new_bs, state->old_bs, errp);
+    if (ret < 0) {
         goto out;
     }
     state->overlay_appended = true;
diff --git a/tests/test-bdrv-graph-mod.c b/tests/test-bdrv-graph-mod.c
index 8cff13830e3e..c4f7d1603924 100644
--- a/tests/test-bdrv-graph-mod.c
+++ b/tests/test-bdrv-graph-mod.c
@@ -101,7 +101,7 @@ static BlockDriverState *pass_through_node(const char *name)
  */
 static void test_update_perm_tree(void)
 {
-    Error *local_err = NULL;
+    int ret;

     BlockBackend *root = blk_new(qemu_get_aio_context(),
                                  BLK_PERM_WRITE | BLK_PERM_CONSISTENT_READ,
@@ -114,8 +114,8 @@ static void test_update_perm_tree(void)
     bdrv_attach_child(filter, bs, "child", &child_of_bds,
                       BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, &error_abort);

-    bdrv_append(filter, bs, &local_err);
-    error_free_or_abort(&local_err);
+    ret = bdrv_append(filter, bs, NULL);
+    g_assert_cmpint(ret, <, 0);

     blk_unref(root);
 }
-- 
2.30.1