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From:   Leah Rumancik <leah.rumancik@gmail.com>
To:     fstests@vger.kernel.org, linux-ext4@vger.kernel.org
Cc:     Leah Rumancik <leah.rumancik@gmail.com>
Subject: [PATCH] ext4/310: test journal checkpoint ioctl
Date:   Wed, 19 May 2021 14:47:51 +0000
Message-Id: <20210519144751.466933-1-leah.rumancik@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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Test journal checkpointing and journal erasing via
EXT4_IOC_CHECKPOINT with flag EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT set.

Signed-off-by: Leah Rumancik <leah.rumancik@gmail.com>
---
 src/Makefile             |   3 +-
 src/checkpoint_journal.c |  95 ++++++++++++++++++++++++++++++++
 tests/ext4/310           | 114 +++++++++++++++++++++++++++++++++++++++
 tests/ext4/310.out       |   2 +
 tests/ext4/group         |   1 +
 5 files changed, 214 insertions(+), 1 deletion(-)
 create mode 100644 src/checkpoint_journal.c
 create mode 100644 tests/ext4/310
 create mode 100644 tests/ext4/310.out

diff --git a/src/Makefile b/src/Makefile
index cc0b9579..e0e7006b 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -17,7 +17,8 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
 	t_mmap_cow_race t_mmap_fallocate fsync-err t_mmap_write_ro \
 	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_get_file_time t_create_short_dirs t_create_long_dirs t_enospc \
+	checkpoint_journal
 
 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/checkpoint_journal.c b/src/checkpoint_journal.c
new file mode 100644
index 00000000..0347e0c0
--- /dev/null
+++ b/src/checkpoint_journal.c
@@ -0,0 +1,95 @@
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <linux/fs.h>
+#include <getopt.h>
+
+/*
+ * checkpoint_journal.c
+ *
+ * Flush journal log and checkpoint journal for ext4 file system and
+ * optionally, issue discard or zeroout for the journal log blocks.
+ *
+ * Arguments:
+ * 1) mount point for device
+ * 2) flags (optional)
+ *	set --erase=discard to enable discarding journal blocks
+ *	set --erase=zeroout to enable zero-filling journal blocks
+ *	set --dry-run flag to only perform input checking
+ */
+
+#if defined(__linux__) && !defined(EXT4_IOC_CHECKPOINT)
+#define EXT4_IOC_CHECKPOINT	_IOW('f', 43, __u32)
+#endif
+
+
+#if defined(__linux__) && !defined(EXT4_IOC_CHECKPOINT_FLAG_DISCARD)
+#define EXT4_IOC_CHECKPOINT_FLAG_DISCARD		1
+#define EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT		2
+#define EXT4_IOC_CHECKPOINT_FLAG_DRY_RUN		4
+#endif
+
+
+int main(int argc, char** argv) {
+	int fd, c, ret = 0, option_index = 0;
+	char* rpath;
+	unsigned int flags = 0;
+
+	static struct option long_options[] =
+	{
+		{"dry-run", no_argument, 0, 'd'},
+		{"erase", required_argument, 0, 'e'},
+		{0, 0, 0, 0}
+	};
+
+	/* get optional flags */
+	while ((c = getopt_long(argc, argv, "de:", long_options,
+				&option_index)) != -1) {
+		switch (c) {
+		case 'd':
+			flags |= EXT4_IOC_CHECKPOINT_FLAG_DRY_RUN;
+			break;
+		case 'e':
+			if (strcmp(optarg, "discard") == 0) {
+				flags |= EXT4_IOC_CHECKPOINT_FLAG_DISCARD;
+			} else if (strcmp(optarg, "zeroout") == 0) {
+				flags |= EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT;
+			} else {
+				fprintf(stderr, "Error: invalid erase option\n");
+				return 1;
+			}
+			break;
+		default:
+			return 1;
+		}
+	}
+
+	if (optind != argc - 1) {
+		fprintf(stderr, "Error: invalid number of arguments\n");
+		return 1;
+	}
+
+	/* get fd to file system */
+	rpath = realpath(argv[optind], NULL);
+	fd = open(rpath, O_RDONLY);
+	free(rpath);
+
+	if (fd == -1) {
+		fprintf(stderr, "Error: unable to open device %s: %s\n",
+			argv[optind], strerror(errno));
+		return 1;
+	}
+
+	ret = ioctl(fd, EXT4_IOC_CHECKPOINT, &flags);
+
+	if (ret)
+		fprintf(stderr, "checkpoint ioctl returned error: %s\n", strerror(errno));
+
+	close(fd);
+	return ret;
+}
+
diff --git a/tests/ext4/310 b/tests/ext4/310
new file mode 100644
index 00000000..3693cb29
--- /dev/null
+++ b/tests/ext4/310
@@ -0,0 +1,114 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2021 Google, Inc. All Rights Reserved.
+#
+# FS QA Test No. 310
+#
+# Test checkpoint and zeroout of journal via ioctl EXT4_IOC_CHECKPOINT
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+status=1       # failure is the default!
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+_supported_fs ext4
+
+_require_scratch
+_require_command "$DEBUGFS_PROG" debugfs
+
+checkpoint_journal=$here/src/checkpoint_journal
+_require_test_program "checkpoint_journal"
+
+# convert output from stat<journal_inode> to list of block numbers
+get_journal_extents() {
+	inode_info=$($DEBUGFS_PROG $SCRATCH_DEV -R "stat <8>" 2>> $seqres.full)
+	echo -e "\nJournal info:" >> $seqres.full
+	echo "$inode_info" >> $seqres.full
+
+	extents_line=$(echo "$inode_info" | awk '/EXTENTS:/{ print NR; exit }')
+	get_extents=$(echo "$inode_info" | sed -n "$(($extents_line + 1))"p)
+
+	# get just the physical block numbers
+	get_extents=$(echo "$get_extents" |  perl -pe 's|\(.*?\):||g' | sed -e 's/, /\n/g' | perl -pe 's|(\d+)-(\d+)|\1 \2|g')
+
+	echo "$get_extents"
+}
+
+
+# checks all extents are zero'd out except for the superblock
+# arg 1: extents (output of get_journal_extents())
+check_extents() {
+	echo -e "\nChecking extents:" >> $seqres.full
+	echo "$1" >> $seqres.full
+
+	super_block="true"
+	echo "$1" | while IFS= read line; do
+		start_block=$(echo $line | cut -f1 -d' ')
+		end_block=$(echo $line | cut -f2 -d' ' -s)
+
+		# if first block of journal, shouldn't be wiped
+		if [ "$super_block" == "true" ]; then
+			super_block="false"
+
+			#if super block only block in this extent, skip extent
+			if [ -z "$end_block" ]; then
+				continue;
+			fi
+			start_block=$(($start_block + 1))
+		fi
+
+		if [ ! -z "$end_block" ]; then
+			blocks=$(($end_block - $start_block + 1))
+		else
+			blocks=1
+		fi
+
+		check=$(od $SCRATCH_DEV --skip-bytes=$(($start_block * $blocksize)) --read-bytes=$(($blocks * $blocksize)) -An -v | sed -e 's/[0 \t\n\r]//g')
+
+		[ ! -z "$check" ] && echo "error" && break
+	done
+}
+
+testdir="${SCRATCH_MNT}/testdir"
+
+_scratch_mkfs_sized $((64 * 1024 * 1024)) >> $seqres.full 2>&1
+_scratch_mount >> $seqres.full 2>&1
+blocksize=$(_get_block_size $SCRATCH_MNT)
+mkdir $testdir
+
+# check if ioctl present, skip test if not present
+$checkpoint_journal $SCRATCH_MNT --dry-run || _notrun "journal checkpoint ioctl not present on device"
+
+# create some files to add some entries to journal
+for i in {1..100}; do
+	touch $testdir/$i
+done
+
+# make sure these files get to the journal
+sync --file-system $testdir/1
+
+# call ioctl to checkpoint and zero-fill journal blocks
+$checkpoint_journal $SCRATCH_MNT --erase=zeroout || _fail "ioctl returned error"
+
+extents=$(get_journal_extents)
+
+# check journal blocks zeroed out
+ret=$(check_extents "$extents")
+[ "$ret" = "error" ] && _fail "Journal was not zero-filled"
+
+_scratch_unmount >> $seqres.full 2>&1
+
+echo "Done."
+
+status=0
+exit
diff --git a/tests/ext4/310.out b/tests/ext4/310.out
new file mode 100644
index 00000000..e52f7345
--- /dev/null
+++ b/tests/ext4/310.out
@@ -0,0 +1,2 @@
+QA output created by 310
+Done.
diff --git a/tests/ext4/group b/tests/ext4/group
index e7ad3c24..622590a9 100644
--- a/tests/ext4/group
+++ b/tests/ext4/group
@@ -60,3 +60,4 @@
 307 auto ioctl rw defrag
 308 auto ioctl rw prealloc quick defrag
 309 auto quick dir
+310 auto ioctl quick
-- 
2.31.1.751.gd2f1c929bd-goog