bug: copy progress reporting of backends which run multiple COPYs

pg_stat_progress_copy was added in v14 (8a4f618e7, 9d2d45700).

But if a command JOINs file_fdw tables, the progress report gets bungled
up. This will warn/assert during file_fdw tests.

diff --git a/src/backend/utils/activity/backend_progress.c b/src/backend/utils/activity/backend_progress.c
index 6743e68cef6..7abcb4f60db 100644
--- a/src/backend/utils/activity/backend_progress.c
+++ b/src/backend/utils/activity/backend_progress.c
@@ -10,6 +10,7 @@
*/
#include "postgres.h"

+#include "commands/progress.h"
#include "port/atomics.h" /* for memory barriers */
#include "utils/backend_progress.h"
#include "utils/backend_status.h"
@@ -105,6 +106,20 @@ pgstat_progress_end_command(void)
if (beentry->st_progress_command == PROGRESS_COMMAND_INVALID)
return;

+// This currently fails file_fdw tests, since pgstat_progress evidently fails
+// to support simultaneous copy commands, as happens during JOIN.
+ /* bytes progress is not available in all cases */
+ if (beentry->st_progress_command == PROGRESS_COMMAND_COPY &&
+ beentry->st_progress_param[PROGRESS_COPY_BYTES_TOTAL] > 0)
+ {
+ volatile int64 *a = beentry->st_progress_param;
+ if (a[PROGRESS_COPY_BYTES_PROCESSED] > a[PROGRESS_COPY_BYTES_TOTAL])
+ elog(WARNING, "PROGRESS_COPY_BYTES_PROCESSED %ld %ld",
+ a[PROGRESS_COPY_BYTES_PROCESSED],
+ a[PROGRESS_COPY_BYTES_TOTAL]);
+ // Assert(a[PROGRESS_COPY_BYTES_PROCESSED] <= a[PROGRESS_COPY_BYTES_TOTAL]);
+ }
+
PGSTAT_BEGIN_WRITE_ACTIVITY(beentry);
beentry->st_progress_command = PROGRESS_COMMAND_INVALID;
beentry->st_progress_command_target = InvalidOid;