[PATCH v9 3/5] btrfs: test btrfs specific fsverity corruption

[Boris Burkov <boris@bur.io>]

There are some btrfs specific fsverity scenarios that don't map
neatly onto the tests in generic/574 like holes, inline extents,
and preallocated extents. Cover those in a btrfs specific test.

This test relies on the btrfs implementation of fsverity in the patch:
btrfs: initial fsverity support

and on btrfs-corrupt-block for corruption in the patches titled:
btrfs-progs: corrupt generic item data with btrfs-corrupt-block
btrfs-progs: expand corrupt_file_extent in btrfs-corrupt-block

Signed-off-by: Boris Burkov <boris@bur.io>
---
 tests/btrfs/290     | 168 ++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/290.out |  25 +++++++
 2 files changed, 193 insertions(+)
 create mode 100755 tests/btrfs/290
 create mode 100644 tests/btrfs/290.out

diff --git a/tests/btrfs/290 b/tests/btrfs/290
new file mode 100755
index 00000000..f9acd55a
--- /dev/null
+++ b/tests/btrfs/290
@@ -0,0 +1,168 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2021 Facebook, Inc. All Rights Reserved.
+#
+# FS QA Test 290
+#
+# Test btrfs support for fsverity.
+# This test extends the generic fsverity testing by corrupting inline extents,
+# preallocated extents, holes, and the Merkle descriptor in a btrfs-aware way.
+#
+. ./common/preamble
+_begin_fstest auto quick verity
+
+# Import common functions.
+. ./common/filter
+. ./common/verity
+
+# real QA test starts here
+_supported_fs btrfs
+_require_scratch_verity
+_require_scratch_nocheck
+_require_odirect
+_require_xfs_io_command "falloc"
+_require_xfs_io_command "pread"
+_require_xfs_io_command "pwrite"
+_require_btrfs_corrupt_block
+
+get_ino() {
+	local file=$1
+	stat -c "%i" $file
+}
+
+validate() {
+	local f=$1
+	local sz=$(_get_filesize $f)
+	# buffered io
+	echo $(basename $f)
+	$XFS_IO_PROG -rc "pread -q 0 $sz" $f 2>&1 | _filter_scratch
+	# direct io
+	$XFS_IO_PROG -rdc "pread -q 0 $sz" $f 2>&1 | _filter_scratch
+}
+
+# corrupt the data portion of an inline extent
+corrupt_inline() {
+	local f=$SCRATCH_MNT/inl
+	$XFS_IO_PROG -fc "pwrite -q -S 0x58 0 42" $f
+	local ino=$(get_ino $f)
+	_fsv_enable $f
+	_scratch_unmount
+	# inline data starts at disk_bytenr
+	# overwrite the first u64 with random bogus junk
+	$BTRFS_CORRUPT_BLOCK_PROG -i $ino -x 0 -f disk_bytenr $SCRATCH_DEV > /dev/null 2>&1
+	_scratch_mount
+	validate $f
+}
+
+# preallocate a file, then corrupt it by changing it to a regular file
+corrupt_prealloc_to_reg() {
+	local f=$SCRATCH_MNT/prealloc
+	$XFS_IO_PROG -fc "falloc 0 12k" $f
+	local ino=$(get_ino $f)
+	_fsv_enable $f
+	_scratch_unmount
+	# set extent type from prealloc (2) to reg (1)
+	$BTRFS_CORRUPT_BLOCK_PROG -i $ino -x 0 -f type -v 1 $SCRATCH_DEV >/dev/null 2>&1
+	_scratch_mount
+	validate $f
+}
+
+# corrupt a regular file by changing the type to preallocated
+corrupt_reg_to_prealloc() {
+	local f=$SCRATCH_MNT/reg
+	$XFS_IO_PROG -fc "pwrite -q -S 0x58 0 12288" $f
+	local ino=$(get_ino $f)
+	_fsv_enable $f
+	_scratch_unmount
+	# set type from reg (1) to prealloc (2)
+	$BTRFS_CORRUPT_BLOCK_PROG -i $ino -x 0 -f type -v 2 $SCRATCH_DEV >/dev/null 2>&1
+	_scratch_mount
+	validate $f
+}
+
+# corrupt a file by punching a hole
+corrupt_punch_hole() {
+	local f=$SCRATCH_MNT/punch
+	$XFS_IO_PROG -fc "pwrite -q -S 0x58 0 12288" $f
+	local ino=$(get_ino $f)
+	# make a new extent in the middle, sync so the writes don't coalesce
+	$XFS_IO_PROG -c sync $SCRATCH_MNT
+	$XFS_IO_PROG -fc "pwrite -q -S 0x59 4096 4096" $f
+	_fsv_enable $f
+	_scratch_unmount
+	# change disk_bytenr to 0, representing a hole
+	$BTRFS_CORRUPT_BLOCK_PROG -i $ino -x 4096 -f disk_bytenr -v 0 $SCRATCH_DEV > /dev/null 2>&1
+	_scratch_mount
+	validate $f
+}
+
+# plug hole
+corrupt_plug_hole() {
+	local f=$SCRATCH_MNT/plug
+	$XFS_IO_PROG -fc "pwrite -q -S 0x58 0 12288" $f
+	local ino=$(get_ino $f)
+	$XFS_IO_PROG -fc "falloc 4k 4k" $f
+	_fsv_enable $f
+	_scratch_unmount
+	# change disk_bytenr to some value, plugging the hole
+	$BTRFS_CORRUPT_BLOCK_PROG -i $ino -x 4096 -f disk_bytenr -v 13639680 $SCRATCH_DEV > /dev/null 2>&1
+	_scratch_mount
+	validate $f
+}
+
+# corrupt the fsverity descriptor item indiscriminately (causes EINVAL)
+corrupt_verity_descriptor() {
+	local f=$SCRATCH_MNT/desc
+	$XFS_IO_PROG -fc "pwrite -q -S 0x58 0 12288" $f
+	local ino=$(get_ino $f)
+	_fsv_enable $f
+	_scratch_unmount
+	# key for the descriptor item is <inode, BTRFS_VERITY_DESC_ITEM_KEY, 1>,
+	# 88 is X. So we write 5 Xs to the start of the descriptor
+	$BTRFS_CORRUPT_BLOCK_PROG -r 5 -I $ino,36,1 -v 88 -o 0 -b 5 $SCRATCH_DEV > /dev/null 2>&1
+	_scratch_mount
+	validate $f
+}
+
+# specifically target the root hash in the descriptor (causes EIO)
+corrupt_root_hash() {
+	local f=$SCRATCH_MNT/roothash
+	$XFS_IO_PROG -fc "pwrite -q -S 0x58 0 12288" $f
+	local ino=$(get_ino $f)
+	_fsv_enable $f
+	_scratch_unmount
+	$BTRFS_CORRUPT_BLOCK_PROG -r 5 -I $ino,36,1 -v 88 -o 16 -b 1 $SCRATCH_DEV > /dev/null 2>&1
+	_scratch_mount
+	validate $f
+}
+
+# corrupt the Merkle tree data itself
+corrupt_merkle_tree() {
+	local f=$SCRATCH_MNT/merkle
+	$XFS_IO_PROG -fc "pwrite -q -S 0x58 0 12288" $f
+	local ino=$(get_ino $f)
+	_fsv_enable $f
+	_scratch_unmount
+	# key for the descriptor item is <inode, BTRFS_VERITY_MERKLE_ITEM_KEY, 0>,
+	# 88 is X. So we write 5 Xs to somewhere in the middle of the first
+	# merkle item
+	$BTRFS_CORRUPT_BLOCK_PROG -r 5 -I $ino,37,0 -v 88 -o 100 -b 5 $SCRATCH_DEV > /dev/null 2>&1
+	_scratch_mount
+	validate $f
+}
+
+# real QA test starts here
+_scratch_mkfs >/dev/null
+_scratch_mount
+
+corrupt_inline
+corrupt_prealloc_to_reg
+corrupt_reg_to_prealloc
+corrupt_punch_hole
+corrupt_plug_hole
+corrupt_verity_descriptor
+corrupt_root_hash
+corrupt_merkle_tree
+
+status=0
+exit
diff --git a/tests/btrfs/290.out b/tests/btrfs/290.out
new file mode 100644
index 00000000..056b114b
--- /dev/null
+++ b/tests/btrfs/290.out
@@ -0,0 +1,25 @@
+QA output created by 290
+inl
+pread: Input/output error
+pread: Input/output error
+prealloc
+pread: Input/output error
+pread: Input/output error
+reg
+pread: Input/output error
+pread: Input/output error
+punch
+pread: Input/output error
+pread: Input/output error
+plug
+pread: Input/output error
+pread: Input/output error
+desc
+SCRATCH_MNT/desc: Invalid argument
+SCRATCH_MNT/desc: Invalid argument
+roothash
+pread: Input/output error
+pread: Input/output error
+merkle
+pread: Input/output error
+pread: Input/output error
-- 
2.35.1