pg_upgrade: Report full disk better

Previously, pg_upgrade would abort copy_file() on a short write without
setting errno, which the caller would report as an error with the
message "Success".  We assume ENOSPC in that case, as we do elsewhere in
the code.  Also set errno in some other error cases in copy_file() to
avoid bogus "Success" error messages.

This was broken in 6b711cf37c228749b6a8cef50e16e3c587d18dd4, so 9.2 and
before are OK.

1 files changed, 9 insertions, 0 deletions

diff --git a/contrib/pg_upgrade/file.c b/contrib/pg_upgrade/file.c
index dfeb79f255d..c198e91ce15 100644
--- a/contrib/pg_upgrade/file.c
+++ b/contrib/pg_upgrade/file.c
@@ -136,16 +136,22 @@ copy_file(const char *srcfile, const char *dstfile, bool force)
 	int			save_errno = 0;
 
 	if ((srcfile == NULL) || (dstfile == NULL))
+	{
+		errno = EINVAL;
 		return -1;
+	}
 
 	if ((src_fd = open(srcfile, O_RDONLY, 0)) < 0)
 		return -1;
 
 	if ((dest_fd = open(dstfile, O_RDWR | O_CREAT | (force ? 0 : O_EXCL), S_IRUSR | S_IWUSR)) < 0)
 	{
+		save_errno = errno;
+
 		if (src_fd != 0)
 			close(src_fd);
 
+		errno = save_errno;
 		return -1;
 	}
 
@@ -170,6 +176,9 @@ copy_file(const char *srcfile, const char *dstfile, bool force)
 
 		if (write(dest_fd, buffer, nbytes) != nbytes)
 		{
+			/* if write didn't set errno, assume problem is no disk space */
+			if (errno == 0)
+				errno = ENOSPC;
 			save_errno = errno;
 			ret = -1;
 			break;