selftests/coredump: ignore ENOSPC errors

If we crash multiple processes at the same time we may run out of space.
Just ignore those errors. They're not actually all that relevant for the
test.

Link: https://patch.msgid.link/[e-mail]
Reviewed-by: Alexander Mikhalitsyn <[e-mail]>
Signed-off-by: Christian Brauner <[e-mail]>

tools/testing/selftests/coredump/coredump_socket_protocol_test.c

···
 
 			bytes_write = write(fd_core_file, buffer, bytes_read);
 			if (bytes_read != bytes_write) {
+				if (bytes_write < 0 && errno == ENOSPC)
+					continue;
 				fprintf(stderr, "socket_request_kernel: write to core file failed (read=%zd, write=%zd): %m\n",
 					bytes_read, bytes_write);
 				goto out;
···
 
 				bytes_write = write(fd_core_file, buffer, bytes_read);
 				if (bytes_read != bytes_write) {
+					if (bytes_write < 0 && errno == ENOSPC)
+						continue;
 					fprintf(stderr, "write failed for fd %d: %m\n", fd_core_file);
 					goto out;
 				}

tools/testing/selftests/coredump/coredump_socket_test.c

···
 
 			bytes_write = write(fd_core_file, buffer, bytes_read);
 			if (bytes_read != bytes_write) {
-				fprintf(stderr, "socket test: write to core file failed (read=%zd, write=%zd): %m\n",
-					bytes_read, bytes_write);
+				if (bytes_write < 0 && errno == ENOSPC)
+					continue;
+				fprintf(stderr, "socket test: write to core file failed (read=%zd, write=%zd): %m\n", bytes_read, bytes_write);
 				goto out;
 			}
 		}

tools/testing/selftests/coredump/coredump_test_helpers.c

···
 					goto done;
 				ssize_t bytes_write = write(fd_core_file, buffer, bytes_read);
 				if (bytes_write != bytes_read) {
+					if (bytes_write < 0 && errno == ENOSPC)
+						continue;
 					fprintf(stderr, "Worker: write() failed (read=%zd, write=%zd): %m\n",
 						bytes_read, bytes_write);
 					goto out;