[RFC v5 055/126] virtio-blk: introduce ERRP_AUTO_PROPAGATE

[Vladimir Sementsov-Ogievskiy]

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_AUTO_PROPAGATE macro.
Otherwise, this info will not be added when errp == &fatal_err
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix such cases.

If we want to check error after errp-function call, we need to
introduce local_err and than propagate it to errp. Instead, use
ERRP_AUTO_PROPAGATE macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_AUTO_PROPAGATE leaves errp as is if it's not NULL or
   &error_fatel, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

This commit (together with its neighbors) was generated by

for f in $(git grep -l errp \*.[ch]); do \
    spatch --sp-file scripts/coccinelle/auto-propagated-errp.cocci \
    --macro-file scripts/cocci-macro-file.h --in-place --no-show-diff $f; \
done;

then fix a bit of compilation problems: coccinelle for some reason
leaves several
f() {
    ...
    goto out;
    ...
    out:
}
patterns, with "out:" at function end.

then
./python/commit-per-subsystem.py MAINTAINERS "$(< auto-msg)"

(auto-msg was a file with this commit message)

Still, for backporting it may be more comfortable to use only the first
command and then do one huge commit.

Reported-by: Kevin Wolf <address@hidden>
Reported-by: Greg Kurz <address@hidden>
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
 hw/block/dataplane/virtio-blk.c | 1 +
 hw/block/virtio-blk.c           | 7 +++----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 119906a5fe..f8a1e70886 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -85,6 +85,7 @@ bool virtio_blk_data_plane_create(VirtIODevice *vdev, 
VirtIOBlkConf *conf,
                                   VirtIOBlockDataPlane **dataplane,
                                   Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     VirtIOBlockDataPlane *s;
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index ed2ddebd2b..788d346727 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -1113,10 +1113,10 @@ static const BlockDevOps virtio_block_ops = {
 
 static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOBlock *s = VIRTIO_BLK(dev);
     VirtIOBlkConf *conf = &s->conf;
-    Error *err = NULL;
     unsigned i;
 
     if (!conf->conf.blk) {
@@ -1188,9 +1188,8 @@ static void virtio_blk_device_realize(DeviceState *dev, 
Error **errp)
     for (i = 0; i < conf->num_queues; i++) {
         virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output);
     }
-    virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err);
-    if (err != NULL) {
-        error_propagate(errp, err);
+    virtio_blk_data_plane_create(vdev, conf, &s->dataplane, errp);
+    if (*errp) {
         virtio_cleanup(vdev);
         return;
     }
-- 
2.21.0