scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

3 files changed, 155 insertions, 0 deletions

diff --git a/samples/fanotify/.gitignore b/samples/fanotify/.gitignore
new file mode 100644
index 000000000..d74593e8b
--- /dev/null
+++ b/samples/fanotify/.gitignore
@@ -0,0 +1 @@
+fs-monitor
diff --git a/samples/fanotify/Makefile b/samples/fanotify/Makefile
new file mode 100644
index 000000000..e20db1bdd
--- /dev/null
+++ b/samples/fanotify/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+userprogs-always-y += fs-monitor
+
+userccflags += -I usr/include -Wall
+
diff --git a/samples/fanotify/fs-monitor.c b/samples/fanotify/fs-monitor.c
new file mode 100644
index 000000000..28c0a652f
--- /dev/null
+++ b/samples/fanotify/fs-monitor.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2021, Collabora Ltd.
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <err.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/fanotify.h>
+#include <sys/types.h>
+#include <unistd.h>
+#ifndef __GLIBC__
+#include <asm-generic/int-ll64.h>
+#endif
+
+#ifndef FAN_FS_ERROR
+#define FAN_FS_ERROR		0x00008000
+#define FAN_EVENT_INFO_TYPE_ERROR	5
+
+struct fanotify_event_info_error {
+	struct fanotify_event_info_header hdr;
+	__s32 error;
+	__u32 error_count;
+};
+#endif
+
+#ifndef FILEID_INO32_GEN
+#define FILEID_INO32_GEN	1
+#endif
+
+#ifndef FILEID_INVALID
+#define	FILEID_INVALID		0xff
+#endif
+
+static void print_fh(struct file_handle *fh)
+{
+	int i;
+	uint32_t *h = (uint32_t *) fh->f_handle;
+
+	printf("\tfh: ");
+	for (i = 0; i < fh->handle_bytes; i++)
+		printf("%hhx", fh->f_handle[i]);
+	printf("\n");
+
+	printf("\tdecoded fh: ");
+	if (fh->handle_type == FILEID_INO32_GEN)
+		printf("inode=%u gen=%u\n", h[0], h[1]);
+	else if (fh->handle_type == FILEID_INVALID && !fh->handle_bytes)
+		printf("Type %d (Superblock error)\n", fh->handle_type);
+	else
+		printf("Type %d (Unknown)\n", fh->handle_type);
+
+}
+
+static void handle_notifications(char *buffer, int len)
+{
+	struct fanotify_event_metadata *event =
+		(struct fanotify_event_metadata *) buffer;
+	struct fanotify_event_info_header *info;
+	struct fanotify_event_info_error *err;
+	struct fanotify_event_info_fid *fid;
+	int off;
+
+	for (; FAN_EVENT_OK(event, len); event = FAN_EVENT_NEXT(event, len)) {
+
+		if (event->mask != FAN_FS_ERROR) {
+			printf("unexpected FAN MARK: %llx\n",
+							(unsigned long long)event->mask);
+			goto next_event;
+		}
+
+		if (event->fd != FAN_NOFD) {
+			printf("Unexpected fd (!= FAN_NOFD)\n");
+			goto next_event;
+		}
+
+		printf("FAN_FS_ERROR (len=%d)\n", event->event_len);
+
+		for (off = sizeof(*event) ; off < event->event_len;
+		     off += info->len) {
+			info = (struct fanotify_event_info_header *)
+				((char *) event + off);
+
+			switch (info->info_type) {
+			case FAN_EVENT_INFO_TYPE_ERROR:
+				err = (struct fanotify_event_info_error *) info;
+
+				printf("\tGeneric Error Record: len=%d\n",
+				       err->hdr.len);
+				printf("\terror: %d\n", err->error);
+				printf("\terror_count: %d\n", err->error_count);
+				break;
+
+			case FAN_EVENT_INFO_TYPE_FID:
+				fid = (struct fanotify_event_info_fid *) info;
+
+				printf("\tfsid: %x%x\n",
+#if defined(__GLIBC__)
+				       fid->fsid.val[0], fid->fsid.val[1]);
+#else
+				       fid->fsid.__val[0], fid->fsid.__val[1]);
+#endif
+				print_fh((struct file_handle *) &fid->handle);
+				break;
+
+			default:
+				printf("\tUnknown info type=%d len=%d:\n",
+				       info->info_type, info->len);
+			}
+		}
+next_event:
+		printf("---\n\n");
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int fd;
+
+	char buffer[BUFSIZ];
+
+	if (argc < 2) {
+		printf("Missing path argument\n");
+		return 1;
+	}
+
+	fd = fanotify_init(FAN_CLASS_NOTIF|FAN_REPORT_FID, O_RDONLY);
+	if (fd < 0)
+		errx(1, "fanotify_init");
+
+	if (fanotify_mark(fd, FAN_MARK_ADD|FAN_MARK_FILESYSTEM,
+			  FAN_FS_ERROR, AT_FDCWD, argv[1])) {
+		errx(1, "fanotify_mark");
+	}
+
+	while (1) {
+		int n = read(fd, buffer, BUFSIZ);
+
+		if (n < 0)
+			errx(1, "read");
+
+		handle_notifications(buffer, n);
+	}
+
+	return 0;
+}