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, 7 insertions, 9 deletions

diff --git a/block/quorum.c b/block/quorum.c
index beb3b6dbcc..5d52e605db 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -910,13 +910,12 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
     /* count how many different children are present */
     s->num_children = qdict_array_entries(options, "children.");
     if (s->num_children < 0) {
-        error_setg(&local_err, "Option children is not a valid array");
+        error_setg(errp, "Option children is not a valid array");
         ret = -EINVAL;
         goto exit;
     }
     if (s->num_children < 1) {
-        error_setg(&local_err,
-                   "Number of provided children must be 1 or more");
+        error_setg(errp, "Number of provided children must be 1 or more");
         ret = -EINVAL;
         goto exit;
     }
@@ -929,7 +928,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
 
     s->threshold = qemu_opt_get_number(opts, QUORUM_OPT_VOTE_THRESHOLD, 0);
     /* and validate it against s->num_children */
-    ret = quorum_valid_threshold(s->threshold, s->num_children, &local_err);
+    ret = quorum_valid_threshold(s->threshold, s->num_children, errp);
     if (ret < 0) {
         goto exit;
     }
@@ -942,7 +941,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
                               -EINVAL, NULL);
     }
     if (ret < 0) {
-        error_setg(&local_err, "Please set read-pattern as fifo or quorum");
+        error_setg(errp, "Please set read-pattern as fifo or quorum");
         goto exit;
     }
     s->read_pattern = ret;
@@ -950,7 +949,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
     if (s->read_pattern == QUORUM_READ_PATTERN_QUORUM) {
         s->is_blkverify = qemu_opt_get_bool(opts, QUORUM_OPT_BLKVERIFY, false);
         if (s->is_blkverify && (s->num_children != 2 || s->threshold != 2)) {
-            error_setg(&local_err, "blkverify=on can only be set if there are "
+            error_setg(errp, "blkverify=on can only be set if there are "
                        "exactly two files and vote-threshold is 2");
             ret = -EINVAL;
             goto exit;
@@ -959,7 +958,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
         s->rewrite_corrupted = qemu_opt_get_bool(opts, QUORUM_OPT_REWRITE,
                                                  false);
         if (s->rewrite_corrupted && s->is_blkverify) {
-            error_setg(&local_err,
+            error_setg(errp,
                        "rewrite-corrupted=on cannot be used with blkverify=on");
             ret = -EINVAL;
             goto exit;
@@ -979,6 +978,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
                                          &child_of_bds, BDRV_CHILD_DATA, false,
                                          &local_err);
         if (local_err) {
+            error_propagate(errp, local_err);
             ret = -EINVAL;
             goto close_exit;
         }
@@ -1004,8 +1004,6 @@ close_exit:
     g_free(opened);
 exit:
     qemu_opts_del(opts);
-    /* propagate error */
-    error_propagate(errp, local_err);
     return ret;
 }