[RFC v5 097/126] VDI: 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>
---
 block/vdi.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/block/vdi.c b/block/vdi.c
index 806ba7f53c..0f2e0723f9 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -371,11 +371,11 @@ static int vdi_probe(const uint8_t *buf, int buf_size, 
const char *filename)
 static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
                     Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     BDRVVdiState *s = bs->opaque;
     VdiHeader header;
     size_t bmap_size;
     int ret;
-    Error *local_err = NULL;
     QemuUUID uuid_link, uuid_parent;
 
     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
@@ -496,9 +496,8 @@ static int vdi_open(BlockDriverState *bs, QDict *options, 
int flags,
     error_setg(&s->migration_blocker, "The vdi format used by node '%s' "
                "does not support live migration",
                bdrv_get_device_or_node_name(bs));
-    ret = migrate_add_blocker(s->migration_blocker, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    ret = migrate_add_blocker(s->migration_blocker, errp);
+    if (*errp) {
         error_free(s->migration_blocker);
         goto fail_free_bmap;
     }
@@ -735,6 +734,7 @@ nonallocating_write:
 static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options,
                                          size_t block_size, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     BlockdevCreateOptionsVdi *vdi_opts;
     int ret = 0;
     uint64_t bytes = 0;
@@ -899,13 +899,13 @@ static int coroutine_fn 
vdi_co_create(BlockdevCreateOptions *create_options,
 static int coroutine_fn vdi_co_create_opts(const char *filename, QemuOpts 
*opts,
                                            Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     QDict *qdict = NULL;
     BlockdevCreateOptions *create_options = NULL;
     BlockDriverState *bs_file = NULL;
     uint64_t block_size = DEFAULT_CLUSTER_SIZE;
     bool is_static = false;
     Visitor *v;
-    Error *local_err = NULL;
     int ret;
 
     /* Parse options and convert legacy syntax.
@@ -956,11 +956,10 @@ static int coroutine_fn vdi_co_create_opts(const char 
*filename, QemuOpts *opts,
         ret = -EINVAL;
         goto done;
     }
-    visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
+    visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
     visit_free(v);
 
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (*errp) {
         ret = -EINVAL;
         goto done;
     }
-- 
2.21.0