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, 4 insertions, 5 deletions

diff --git a/block/vxhs.c b/block/vxhs.c
index 237df4f185..fecaeb82c9 100644
--- a/block/vxhs.c
+++ b/block/vxhs.c
@@ -326,14 +326,14 @@ static int vxhs_open(BlockDriverState *bs, QDict *options,
     /* vdisk-id is the disk UUID */
     vdisk_id_opt = qemu_opt_get(opts, VXHS_OPT_VDISK_ID);
     if (!vdisk_id_opt) {
-        error_setg(&local_err, QERR_MISSING_PARAMETER, VXHS_OPT_VDISK_ID);
+        error_setg(errp, QERR_MISSING_PARAMETER, VXHS_OPT_VDISK_ID);
         ret = -EINVAL;
         goto out;
     }
 
     /* vdisk-id may contain a leading '/' */
     if (strlen(vdisk_id_opt) > UUID_FMT_LEN + 1) {
-        error_setg(&local_err, "vdisk-id cannot be more than %d characters",
+        error_setg(errp, "vdisk-id cannot be more than %d characters",
                    UUID_FMT_LEN);
         ret = -EINVAL;
         goto out;
@@ -352,14 +352,14 @@ static int vxhs_open(BlockDriverState *bs, QDict *options,
 
     server_host_opt = qemu_opt_get(tcp_opts, VXHS_OPT_HOST);
     if (!server_host_opt) {
-        error_setg(&local_err, QERR_MISSING_PARAMETER,
+        error_setg(errp, QERR_MISSING_PARAMETER,
                    VXHS_OPT_SERVER"."VXHS_OPT_HOST);
         ret = -EINVAL;
         goto out;
     }
 
     if (strlen(server_host_opt) > MAXHOSTNAMELEN) {
-        error_setg(&local_err, "server.host cannot be more than %d characters",
+        error_setg(errp, "server.host cannot be more than %d characters",
                    MAXHOSTNAMELEN);
         ret = -EINVAL;
         goto out;
@@ -412,7 +412,6 @@ out:
 
     if (ret < 0) {
         vxhs_unref();
-        error_propagate(errp, local_err);
         g_free(s->vdisk_hostinfo.host);
         g_free(s->vdisk_guid);
         g_free(s->tlscredsid);