error: Avoid unnecessary error_propagate() after error_setg()

Replace

    error_setg(&err, ...);
    error_propagate(errp, err);

by

    error_setg(errp, ...);

Related pattern:

    if (...) {
        error_setg(&err, ...);
        goto out;
    }
    ...
 out:
    error_propagate(errp, err);
    return;

When all paths to label out are that way, replace by

    if (...) {
        error_setg(errp, ...);
        return;
    }

and delete the label along with the error_propagate().

When we have at most one other path that actually needs to propagate,
and maybe one at the end that where propagation is unnecessary, e.g.

    foo(..., &err);
    if (err) {
        goto out;
    }
    ...
    bar(..., &err);
 out:
    error_propagate(errp, err);
    return;

move the error_propagate() to where it's needed, like

    if (...) {
        foo(..., &err);
        error_propagate(errp, err);
        return;
    }
    ...
    bar(..., errp);
    return;

and transform the error_setg() as above.

In some places, the transformation results in obviously unnecessary
error_propagate().  The next few commits will eliminate them.

Bonus: the elimination of gotos will make later patches in this series
easier to review.

Candidates for conversion tracked down with this Coccinelle script:

    @@
    identifier err, errp;
    expression list args;
    @@
    -    error_setg(&err, args);
    +    error_setg(errp, args);
         ... when != err
         error_propagate(errp, err);

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-34-armbru@redhat.com>

1 files changed, 5 insertions, 6 deletions

diff --git a/block/replication.c b/block/replication.c
index 5701eeb..b844a09 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -105,7 +105,7 @@ static int replication_open(BlockDriverState *bs, QDict *options,
 
     mode = qemu_opt_get(opts, REPLICATION_MODE);
     if (!mode) {
-        error_setg(&local_err, "Missing the option mode");
+        error_setg(errp, "Missing the option mode");
         goto fail;
     }
 
@@ -113,7 +113,8 @@ static int replication_open(BlockDriverState *bs, QDict *options,
         s->mode = REPLICATION_MODE_PRIMARY;
         top_id = qemu_opt_get(opts, REPLICATION_TOP_ID);
         if (top_id) {
-            error_setg(&local_err, "The primary side does not support option top-id");
+            error_setg(errp,
+                       "The primary side does not support option top-id");
             goto fail;
         }
     } else if (!strcmp(mode, "secondary")) {
@@ -121,11 +122,11 @@ static int replication_open(BlockDriverState *bs, QDict *options,
         top_id = qemu_opt_get(opts, REPLICATION_TOP_ID);
         s->top_id = g_strdup(top_id);
         if (!s->top_id) {
-            error_setg(&local_err, "Missing the option top-id");
+            error_setg(errp, "Missing the option top-id");
             goto fail;
         }
     } else {
-        error_setg(&local_err,
+        error_setg(errp,
                    "The option mode's value should be primary or secondary");
         goto fail;
     }
@@ -136,8 +137,6 @@ static int replication_open(BlockDriverState *bs, QDict *options,
 
 fail:
     qemu_opts_del(opts);
-    error_propagate(errp, local_err);
-
     return ret;
 }