[PATCH v4] xfs: test inode allocation state missmatch corruption

[Zorro Lang <zlang@redhat.com>]

There's a situation where the directory structure and the inobt
thinks the inode is free, but the inode on disk thinks it is still
in use. XFS should detect it and prevent the kernel from oopsing
on lookup.

Signed-off-by: Zorro Lang <zlang@redhat.com>
---

Hi,

Sorry, it's been long time since I last sent v3 of this case... For bringing
your memory, please check below link:
V3 review history: https://marc.info/?t=152986575600003&r=1&w=2
V2 review history: https://marc.info/?t=152605514200002&r=1&w=2

As Darrick suggested to cover v5 filesystems testing last time, I did below
changes:
1) Remove "-m crc=0" mkfs option, but add "-m finobt=0"
2) Use "ikeep" mount option if test on V5.
3) Remove a useless dmesg filter from filter_dmesg()
4) Use _require_no_xfs_debug
5) Use _require_xfs_mkfs_finobt

About the problem:
  "Does this test leave the scratch fs mounted but shut down if the kernel hasn't been patched?"
I have to say "yes, it does". I have no idea about how we deal with this issue,
feel free to remind me if I missed some discussion:)

Thanks,
Zorro


 tests/xfs/999     | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/xfs/999.out |   2 +
 tests/xfs/group   |   1 +
 3 files changed, 116 insertions(+)
 create mode 100755 tests/xfs/999
 create mode 100644 tests/xfs/999.out

diff --git a/tests/xfs/999 b/tests/xfs/999
new file mode 100755
index 00000000..785a84d0
--- /dev/null
+++ b/tests/xfs/999
@@ -0,0 +1,113 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2018 Red Hat Inc.  All Rights Reserved.
+#
+# FS QA Test No. 999
+#
+# Test a corruption when the directory structure and the inobt thinks the inode
+# is free, but the inode on disk thinks it is still in use.
+#
+# This case test same bug (upstream linux commit ee457001ed6c) as xfs/132, but
+# through different code path.
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs xfs
+_supported_os Linux
+_require_scratch_nocheck
+_require_xfs_mkfs_finobt
+
+# Skip the verifier "xfs_check_agi_freecount()" which verify the number of free
+# inodes in the AGI is correct, when XFS_DEBUG is enabled
+_require_no_xfs_debug
+
+filter_dmesg()
+{
+	local warn1="Internal error xfs_trans_cancel.*fs/xfs/xfs_trans\.c.*"
+
+	sed -e "s#$warn1#Intentional error in xfs_trans_cancel#"
+}
+
+# If enable free inode B+tree, this case will fail on xfs_dialloc_ag_update_inobt,
+# that's not what we want to test. Due to finobt feature is not necessary for this
+# test, so disable it directly.
+_scratch_mkfs_xfs -m finobt=0 | _filter_mkfs 2>$tmp.mkfs >> $seqres.full
+
+# On V5 filesystem, this case can't trigger bug because it doesn't read inodes
+# we are allocating from disk - it simply overwrites them with new inode
+# information. So use ikeep mount option to stop that.
+source $tmp.mkfs
+mount_opt=""
+if [ $_fs_has_crcs -eq 1 ]; then
+	mount_opt="-o ikeep"
+fi
+
+blksz=$(_scratch_xfs_get_sb_field blocksize)
+agcount=$(_scratch_xfs_get_sb_field agcount)
+
+_scratch_mount $mount_opt
+# Create a directory for later allocation in same AG (AG 0, due to this's an
+# empty XFS for now)
+mkdir $SCRATCH_MNT/dir
+
+# Allocate 1 block for testfile
+$XFS_IO_PROG -fc "pwrite 0 $blksz" -c fsync $SCRATCH_MNT/dir/testfile >> $seqres.full
+inum=`stat -c %i $SCRATCH_MNT/dir/testfile`
+_scratch_unmount
+
+# Find the AG which contains testfile
+agi=`_scratch_xfs_db -c "convert inode $inum agno" | sed -e 's/^.*(\([0-9]*\).*$/\1/g'`
+
+# Due to we only allocate 1 block for testfile, and this's the only one data
+# block we use. So we use single level inobt, So the ${agi}->root->recs[1]
+# should be the only one record points the chunk which contains testfile's
+# inode.
+# An exmaple of inode record is as below:
+#   recs[1] = [startino,freecount,free] 1:[1024,59,0xffffffffffffffe0]
+freecount=$(_scratch_xfs_get_metadata_field "recs[1].freecount" \
+					    "agi $agi" "addr root")
+fmask=$(_scratch_xfs_get_metadata_field "recs[1].free" "agi $agi" "addr root")
+
+# fmask shift right 1 bit, and freecount++, to mark testfile inode as free in
+# inobt. (But the inode itself isn't freed, it still has allocated block)
+freecount="$((freecount + 1))"
+fmask="$((fmask / 2))"
+_scratch_xfs_set_metadata_field "recs[1].freecount" "$freecount" \
+				"agi $agi" "addr root" >/dev/null
+_scratch_xfs_set_metadata_field "recs[1].free" "$fmask" \
+				"agi $agi" "addr root" >/dev/null
+
+# Mount again and create a new inode cover that inode we just 'freed' from inobt
+_scratch_mount $mount_opt
+$XFS_IO_PROG -fc "pwrite 0 $blksz" -c fsync $SCRATCH_MNT/dir/newfile 2>&1 | \
+	grep -i "Structure needs cleaning" | _filter_scratch
+
+# filter a intentional internal errors
+_check_dmesg filter_dmesg
+
+# success, all done
+status=0
+exit
diff --git a/tests/xfs/999.out b/tests/xfs/999.out
new file mode 100644
index 00000000..cb8d9e34
--- /dev/null
+++ b/tests/xfs/999.out
@@ -0,0 +1,2 @@
+QA output created by 999
+SCRATCH_MNT/dir/newfile: Structure needs cleaning
diff --git a/tests/xfs/group b/tests/xfs/group
index 976a12c2..f9178d3b 100644
--- a/tests/xfs/group
+++ b/tests/xfs/group
@@ -487,3 +487,4 @@
 487 dangerous_fuzzers dangerous_norepair
 488 dangerous_fuzzers dangerous_norepair
 489 dangerous_fuzzers dangerous_norepair
+999 auto quick
-- 
2.14.4