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>

1 files changed, 274 insertions, 0 deletions

diff --git a/samples/vfs/mountinfo.c b/samples/vfs/mountinfo.c
new file mode 100644
index 000000000..bc78275ca
--- /dev/null
+++ b/samples/vfs/mountinfo.c
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/*
+ * Use pidfds, nsfds, listmount() and statmount() mimic the
+ * contents of /proc/self/mountinfo.
+ */
+#define _GNU_SOURCE
+#define __SANE_USERSPACE_TYPES__
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <alloca.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <errno.h>
+
+#include "samples-vfs.h"
+
+/* max mounts per listmount call */
+#define MAXMOUNTS		1024
+
+/* size of struct statmount (including trailing string buffer) */
+#define STATMOUNT_BUFSIZE	4096
+
+static bool ext_format;
+
+#ifndef __NR_pidfd_open
+#define __NR_pidfd_open -1
+#endif
+
+/*
+ * There are no bindings in glibc for listmount() and statmount() (yet),
+ * make our own here.
+ */
+static int statmount(__u64 mnt_id, __u64 mnt_ns_id, __u64 mask,
+		     struct statmount *buf, size_t bufsize,
+		     unsigned int flags)
+{
+	struct mnt_id_req req = {
+		.size = MNT_ID_REQ_SIZE_VER0,
+		.mnt_id = mnt_id,
+		.param = mask,
+	};
+
+	if (mnt_ns_id) {
+		req.size = MNT_ID_REQ_SIZE_VER1;
+		req.mnt_ns_id = mnt_ns_id;
+	}
+
+	return syscall(__NR_statmount, &req, buf, bufsize, flags);
+}
+
+static ssize_t listmount(__u64 mnt_id, __u64 mnt_ns_id, __u64 last_mnt_id,
+			 __u64 list[], size_t num, unsigned int flags)
+{
+	struct mnt_id_req req = {
+		.size = MNT_ID_REQ_SIZE_VER0,
+		.mnt_id = mnt_id,
+		.param = last_mnt_id,
+	};
+
+	if (mnt_ns_id) {
+		req.size = MNT_ID_REQ_SIZE_VER1;
+		req.mnt_ns_id = mnt_ns_id;
+	}
+
+	return syscall(__NR_listmount, &req, list, num, flags);
+}
+
+static void show_mnt_attrs(__u64 flags)
+{
+	printf("%s", flags & MOUNT_ATTR_RDONLY ? "ro" : "rw");
+
+	if (flags & MOUNT_ATTR_NOSUID)
+		printf(",nosuid");
+	if (flags & MOUNT_ATTR_NODEV)
+		printf(",nodev");
+	if (flags & MOUNT_ATTR_NOEXEC)
+		printf(",noexec");
+
+	switch (flags & MOUNT_ATTR__ATIME) {
+	case MOUNT_ATTR_RELATIME:
+		printf(",relatime");
+		break;
+	case MOUNT_ATTR_NOATIME:
+		printf(",noatime");
+		break;
+	case MOUNT_ATTR_STRICTATIME:
+		/* print nothing */
+		break;
+	}
+
+	if (flags & MOUNT_ATTR_NODIRATIME)
+		printf(",nodiratime");
+	if (flags & MOUNT_ATTR_NOSYMFOLLOW)
+		printf(",nosymfollow");
+	if (flags & MOUNT_ATTR_IDMAP)
+		printf(",idmapped");
+}
+
+static void show_propagation(struct statmount *sm)
+{
+	if (sm->mnt_propagation & MS_SHARED)
+		printf(" shared:%llu", sm->mnt_peer_group);
+	if (sm->mnt_propagation & MS_SLAVE) {
+		printf(" master:%llu", sm->mnt_master);
+		if (sm->propagate_from && sm->propagate_from != sm->mnt_master)
+			printf(" propagate_from:%llu", sm->propagate_from);
+	}
+	if (sm->mnt_propagation & MS_UNBINDABLE)
+		printf(" unbindable");
+}
+
+static void show_sb_flags(__u64 flags)
+{
+	printf("%s", flags & MS_RDONLY ? "ro" : "rw");
+	if (flags & MS_SYNCHRONOUS)
+		printf(",sync");
+	if (flags & MS_DIRSYNC)
+		printf(",dirsync");
+	if (flags & MS_MANDLOCK)
+		printf(",mand");
+	if (flags & MS_LAZYTIME)
+		printf(",lazytime");
+}
+
+static int dump_mountinfo(__u64 mnt_id, __u64 mnt_ns_id)
+{
+	int ret;
+	struct statmount *buf = alloca(STATMOUNT_BUFSIZE);
+	const __u64 mask = STATMOUNT_SB_BASIC | STATMOUNT_MNT_BASIC |
+			   STATMOUNT_PROPAGATE_FROM | STATMOUNT_FS_TYPE |
+			   STATMOUNT_MNT_ROOT | STATMOUNT_MNT_POINT |
+			   STATMOUNT_MNT_OPTS | STATMOUNT_FS_SUBTYPE |
+			   STATMOUNT_SB_SOURCE;
+
+	ret = statmount(mnt_id, mnt_ns_id, mask, buf, STATMOUNT_BUFSIZE, 0);
+	if (ret < 0) {
+		perror("statmount");
+		return 1;
+	}
+
+	if (ext_format)
+		printf("0x%llx 0x%llx 0x%llx ", mnt_ns_id, mnt_id, buf->mnt_parent_id);
+
+	printf("%u %u %u:%u %s %s ", buf->mnt_id_old, buf->mnt_parent_id_old,
+				   buf->sb_dev_major, buf->sb_dev_minor,
+				   &buf->str[buf->mnt_root],
+				   &buf->str[buf->mnt_point]);
+	show_mnt_attrs(buf->mnt_attr);
+	show_propagation(buf);
+
+	printf(" - %s", &buf->str[buf->fs_type]);
+	if (buf->mask & STATMOUNT_FS_SUBTYPE)
+		printf(".%s", &buf->str[buf->fs_subtype]);
+	if (buf->mask & STATMOUNT_SB_SOURCE)
+		printf(" %s ", &buf->str[buf->sb_source]);
+	else
+		printf(" :none ");
+
+	show_sb_flags(buf->sb_flags);
+	if (buf->mask & STATMOUNT_MNT_OPTS)
+		printf(",%s", &buf->str[buf->mnt_opts]);
+	printf("\n");
+	return 0;
+}
+
+static int dump_mounts(__u64 mnt_ns_id)
+{
+	__u64 mntid[MAXMOUNTS];
+	__u64 last_mnt_id = 0;
+	ssize_t count;
+	int i;
+
+	/*
+	 * Get a list of all mntids in mnt_ns_id. If it returns MAXMOUNTS
+	 * mounts, then go again until we get everything.
+	 */
+	do {
+		count = listmount(LSMT_ROOT, mnt_ns_id, last_mnt_id, mntid, MAXMOUNTS, 0);
+		if (count < 0 || count > MAXMOUNTS) {
+			errno = count < 0 ? errno : count;
+			perror("listmount");
+			return 1;
+		}
+
+		/* Walk the returned mntids and print info about each */
+		for (i = 0; i < count; ++i) {
+			int ret = dump_mountinfo(mntid[i], mnt_ns_id);
+
+			if (ret != 0)
+				return ret;
+		}
+		/* Set up last_mnt_id to pick up where we left off */
+		last_mnt_id = mntid[count - 1];
+	} while (count == MAXMOUNTS);
+	return 0;
+}
+
+static void usage(const char * const prog)
+{
+	printf("Usage:\n");
+	printf("%s [-e] [-p pid] [-r] [-h]\n", prog);
+	printf("    -e: extended format\n");
+	printf("    -h: print usage message\n");
+	printf("    -p: get mount namespace from given pid\n");
+	printf("    -r: recursively print all mounts in all child namespaces\n");
+}
+
+int main(int argc, char * const *argv)
+{
+	struct mnt_ns_info mni = { .size = MNT_NS_INFO_SIZE_VER0 };
+	int pidfd, mntns, ret, opt;
+	pid_t pid = getpid();
+	bool recursive = false;
+
+	while ((opt = getopt(argc, argv, "ehp:r")) != -1) {
+		switch (opt) {
+		case 'e':
+			ext_format = true;
+			break;
+		case 'h':
+			usage(argv[0]);
+			return 0;
+		case 'p':
+			pid = atoi(optarg);
+			break;
+		case 'r':
+			recursive = true;
+			break;
+		}
+	}
+
+	/* Get a pidfd for pid */
+	pidfd = syscall(__NR_pidfd_open, pid, 0);
+	if (pidfd < 0) {
+		perror("pidfd_open");
+		return 1;
+	}
+
+	/* Get the mnt namespace for pidfd */
+	mntns = ioctl(pidfd, PIDFD_GET_MNT_NAMESPACE, NULL);
+	if (mntns < 0) {
+		perror("PIDFD_GET_MNT_NAMESPACE");
+		return 1;
+	}
+	close(pidfd);
+
+	/* get info about mntns. In particular, the mnt_ns_id */
+	ret = ioctl(mntns, NS_MNT_GET_INFO, &mni);
+	if (ret < 0) {
+		perror("NS_MNT_GET_INFO");
+		return 1;
+	}
+
+	do {
+		int ret;
+
+		ret = dump_mounts(mni.mnt_ns_id);
+		if (ret)
+			return ret;
+
+		if (!recursive)
+			break;
+
+		/* get the next mntns (and overwrite the old mount ns info) */
+		ret = ioctl(mntns, NS_MNT_GET_NEXT, &mni);
+		close(mntns);
+		mntns = ret;
+	} while (mntns >= 0);
+
+	return 0;
+}