[PATCH v4 1/3] xfs: add memory failure test for dax mode

[Shiyang Ruan <ruansy.fnst@fujitsu.com>]

Make sure memory failure mechanism works when filesystem is mounted with
dax option.

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
 .gitignore                      |   1 +
 src/Makefile                    |   3 +-
 src/t_mmap_cow_memory_failure.c | 157 ++++++++++++++++++++++++++++++++
 tests/xfs/900                   |  50 ++++++++++
 tests/xfs/900.out               |   9 ++
 5 files changed, 219 insertions(+), 1 deletion(-)
 create mode 100644 src/t_mmap_cow_memory_failure.c
 create mode 100755 tests/xfs/900
 create mode 100644 tests/xfs/900.out

diff --git a/.gitignore b/.gitignore
index c1d75b019..ad9f45437 100644
--- a/.gitignore
+++ b/.gitignore
@@ -147,6 +147,7 @@ tags
 /src/t_holes
 /src/t_immutable
 /src/t_mmap_collision
+/src/t_mmap_cow_memory_failure
 /src/t_mmap_cow_race
 /src/t_mmap_dio
 /src/t_mmap_fallocate
diff --git a/src/Makefile b/src/Makefile
index 665edcf9f..5f565e73c 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -18,7 +18,8 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
 	t_ext4_dax_journal_corruption t_ext4_dax_inline_corruption \
 	t_ofd_locks t_mmap_collision mmap-write-concurrent \
 	t_get_file_time t_create_short_dirs t_create_long_dirs t_enospc \
-	t_mmap_writev_overlap checkpoint_journal mmap-rw-fault allocstale
+	t_mmap_writev_overlap checkpoint_journal mmap-rw-fault allocstale \
+	t_mmap_cow_memory_failure
 
 LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
 	preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \
diff --git a/src/t_mmap_cow_memory_failure.c b/src/t_mmap_cow_memory_failure.c
new file mode 100644
index 000000000..bb3fd3fbd
--- /dev/null
+++ b/src/t_mmap_cow_memory_failure.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Fujitsu Limited.  All Rights Reserved. */
+#include <errno.h>
+#include <fcntl.h>
+#include <libgen.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <semaphore.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
+#include <sys/sem.h>
+#include <time.h>
+#include <unistd.h>
+
+sem_t *sem;
+
+void sigbus_handler(int signal)
+{
+	printf("Process is killed by signal: %d\n", signal);
+	sem_post(sem);
+}
+
+void mmap_read_file(char *filename, off_t offset, size_t size)
+{
+	int fd;
+	char *map, *dummy;
+	struct timespec ts;
+
+	fd = open(filename, O_RDWR);
+	map = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, offset);
+	dummy = malloc(size);
+
+	/* make sure page fault happens */
+	memcpy(dummy, map, size);
+
+	/* ready */
+	sem_post(sem);
+
+	usleep(200000);
+
+	clock_gettime(CLOCK_REALTIME, &ts);
+	ts.tv_sec += 3;
+	/* wait for injection done */
+	sem_timedwait(sem, &ts);
+
+	free(dummy);
+	munmap(map, size);
+	close(fd);
+}
+
+void mmap_read_file_then_poison(char *filename, off_t offset, size_t size,
+		off_t poisonOffset, size_t poisonSize)
+{
+	int fd, error;
+	char *map, *dummy;
+
+	/* wait for parent preparation done */
+	sem_wait(sem);
+
+	fd = open(filename, O_RDWR);
+	map = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, offset);
+	dummy = malloc(size);
+
+	/* make sure page fault happens */
+	memcpy(dummy, map, size);
+
+	printf("Inject poison...\n");
+	error = madvise(map + poisonOffset, poisonSize, MADV_HWPOISON);
+	if (error)
+		printf("madvise() has fault: %d, errno: %d\n", error, errno);
+
+	free(dummy);
+	munmap(map, size);
+	close(fd);
+}
+
+int main(int argc, char *argv[])
+{
+	char *pReadFile = NULL, *pPoisonFile = NULL;
+	size_t mmapSize, poisonSize;
+	off_t mmapOffset = 0, poisonOffset = 0;
+	long pagesize = sysconf(_SC_PAGESIZE);
+	int c;
+	pid_t pid;
+
+	if (pagesize < 1) {
+		fprintf(stderr, "sysconf(_SC_PAGESIZE): failed to get page size\n");
+		abort();
+	}
+
+	/* default mmap / poison size, in unit of System Page Size */
+	mmapSize = poisonSize = pagesize;
+
+	while ((c = getopt(argc, argv, "o::s::O::S::R:P:")) != -1) {
+		switch (c) {
+		/* mmap offset */
+		case 'o':
+			mmapOffset = atoi(optarg) * pagesize;
+			break;
+		/* mmap size */
+		case 's':
+			mmapSize = atoi(optarg) * pagesize;
+			break;
+		/* madvice offset */
+		case 'O':
+			poisonOffset = atoi(optarg) * pagesize;
+			break;
+		/* madvice size */
+		case 'S':
+			poisonSize = atoi(optarg) * pagesize;
+			break;
+		/* filename for mmap read */
+		case 'R':
+			pReadFile = optarg;
+			break;
+		/* filename for poison read */
+		case 'P':
+			pPoisonFile = optarg;
+			break;
+		default:
+			printf("Unknown option: %c\n", c);
+			exit(1);
+		}
+	}
+
+	if (!pReadFile || !pPoisonFile) {
+		printf("Usage: \n"
+		       "  %s [-o mmapOffset] [-s mmapSize] [-O mmapOffset] [-S mmapSize] -R readFile -P poisonFile\n"
+		       "  (offset and size are both in unit of System Page Size: %ld)\n",
+				basename(argv[0]), pagesize);
+		exit(0);
+	}
+	if (poisonSize < mmapSize)
+		mmapSize = poisonSize;
+
+	/* fork and mmap files */
+	pid = fork();
+	if (pid == 0) {
+		/* handle SIGBUS */
+		signal(SIGBUS, sigbus_handler);
+		sem = sem_open("sync", O_CREAT, 0666, 0);
+
+		/* mread & do memory failure on poison file */
+		mmap_read_file_then_poison(pPoisonFile, mmapOffset, mmapSize,
+				poisonOffset, poisonSize);
+
+		sem_close(sem);
+	} else {
+		sem = sem_open("sync", O_CREAT, 0666, 0);
+
+		/* mread read file, wait for child process to be killed */
+		mmap_read_file(pReadFile, mmapOffset, mmapSize);
+		sem_close(sem);
+	}
+	exit(0);
+}
diff --git a/tests/xfs/900 b/tests/xfs/900
new file mode 100755
index 000000000..def1ab51e
--- /dev/null
+++ b/tests/xfs/900
@@ -0,0 +1,50 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2022 Fujitsu Limited.  All Rights Reserved.
+#
+# FS QA Test No. 900
+#
+# Test memory failure mechanism when dax enabled
+#
+. ./common/preamble
+_begin_fstest auto quick dax
+
+# Import common functions.
+. ./common/filter
+. ./common/reflink
+
+# real QA test starts here
+_require_check_dmesg
+_require_scratch_reflink
+_require_cp_reflink
+_require_xfs_scratch_rmapbt
+_require_scratch_dax_mountopt "dax"
+_require_test_program "t_mmap_cow_memory_failure"
+
+echo "Format and mount"
+_scratch_mkfs > $seqres.full 2>&1
+_scratch_mount "-o dax" >> $seqres.full 2>&1
+
+testdir=$SCRATCH_MNT/test-$seq
+mkdir $testdir
+
+echo "Create the original files"
+filesize=65536
+_pwrite_byte 0x61 0 $filesize $testdir/testfile >> $seqres.full
+_scratch_cycle_mount "dax"
+
+echo "Inject memory failure (1 page)"
+# create two processes:
+#  process1: mread 1 page to cause page fault, and wait
+#  process2: mread 1 page to cause page fault, then inject poison on this page
+$here/src/t_mmap_cow_memory_failure -s1 -S1 -R $testdir/testfile -P $testdir/testfile
+
+echo "Inject memory failure (2 pages)"
+$here/src/t_mmap_cow_memory_failure -s2 -S2 -R $testdir/testfile -P $testdir/testfile
+
+_check_dmesg_for "Sending SIGBUS to t_mmap_cow_memo" || echo "Memory failure didn't kill the process"
+_check_dmesg_for "recovery action for dax page: Recovered" || echo "Failured page didn't recovered"
+
+# success, all done
+status=0
+exit
diff --git a/tests/xfs/900.out b/tests/xfs/900.out
new file mode 100644
index 000000000..f974e59f1
--- /dev/null
+++ b/tests/xfs/900.out
@@ -0,0 +1,9 @@
+QA output created by 900
+Format and mount
+Create the original files
+Inject memory failure (1 page)
+Inject poison...
+Process is killed by signal: 7
+Inject memory failure (2 pages)
+Inject poison...
+Process is killed by signal: 7
-- 
2.37.1