[PATCH v9 0/5] tests for btrfs fsverity

[PATCH v9 0/5] tests for btrfs fsverity

[Boris Burkov]

This patchset provides tests for fsverity support in btrfs.

It includes modifications for generic tests to pass with btrfs as well
as new tests.

--
v9:
- use nodatasum for btrfs corruption tests.
- modify eof block corruption test to allow all zeroes rather than
  requiring an error.
v8:
- reorganize to have a patch for enabling generic tests followed by the
  patches with new and specific tests.
- fix some rebasing miscues from v7.
- fix a chunk of space characters instead of a tab in the new requires
  function.
v7:
- add a new patch to make the new corruption requires more clear
- require corruption in generic/576
- require only btrfs_corrupt_block in btrfs/290
- add missing xfs_io requirements in btrfs/290
- remove unneeded zero byte check from btrfs corruption function
- fix sloppy extras in generic/690
v6:
- refactor "requires" for verity corruption tests so that other verity
  tests can run on btrfs even without the corruption command available.
  Also, explictly require xfs_io fiemap for all corruption tests.
- simplify and clarify "non-trivial EFBIG" calculation and documentation
  per suggestions by Eric Biggers.
- remove unnecessary adjustment to max file size in the new EFBIG test;
  the bug it worked around has been fixed.
v5:
- more idiomatic requires structure for making efbig test generic
- make efbig test use truncate instead of pwrite for making a big file
- improve documentation for efbig test approximation
- fix underscores vs dashes in btrfs_requires_corrupt_block
- improvements in missing/redundant requires invocations
- move orphan test image file to $TEST_DIR
- make orphan test replay/snapshot device size depend on log device
  instead of hard-coding it.
- rebase (signicant: no more "groups" file; use preamble)
v4:
- mark local variables
- get rid of redundant mounts and syncs
- use '_' in function names correctly
- add a test for the EFBIG case
- reduce usage of requires_btrfs_corrupt_block
- handle variable input when corrupting merkle tree
v3: rebase onto xfstests master branch
v2: pass generic tests, add logwrites test


Boris Burkov (5):
  common/verity: require corruption functionality
  common/verity: support btrfs in generic fsverity tests
  btrfs: test btrfs specific fsverity corruption
  btrfs: test verity orphans with dmlogwrites
  generic: test fs-verity EFBIG scenarios

 common/btrfs          |   5 ++
 common/config         |   1 +
 common/verity         |  45 +++++++++++
 tests/btrfs/290       | 168 ++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/290.out   |  25 +++++++
 tests/btrfs/291       | 161 ++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/291.out   |   2 +
 tests/generic/574     |  40 +++++++++-
 tests/generic/574.out |  12 +--
 tests/generic/576     |   1 +
 tests/generic/690     |  64 ++++++++++++++++
 tests/generic/690.out |   7 ++
 12 files changed, 520 insertions(+), 11 deletions(-)
 create mode 100755 tests/btrfs/290
 create mode 100644 tests/btrfs/290.out
 create mode 100755 tests/btrfs/291
 create mode 100644 tests/btrfs/291.out
 create mode 100755 tests/generic/690
 create mode 100644 tests/generic/690.out

-- 
2.35.1

[PATCH v9 1/5] common/verity: require corruption functionality

[Boris Burkov]

Corrupting ext4 and f2fs relies on xfs_io fiemap. Btrfs corruption
testing will rely on a btrfs specific corruption utility. Add the
ability to require corruption functionality to make this properly
modular. To start, just check for fiemap, as that is needed
universally for _fsv_scratch_corrupt_bytes.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 common/verity     | 6 ++++++
 tests/generic/574 | 1 +
 tests/generic/576 | 1 +
 3 files changed, 8 insertions(+)

diff --git a/common/verity b/common/verity
index 38eea157..d58cad90 100644
--- a/common/verity
+++ b/common/verity
@@ -141,6 +141,12 @@ _require_fsverity_dump_metadata()
 	_fail "Unexpected output from 'fsverity dump_metadata': $(<"$tmpfile")"
 }
 
+# Check for userspace tools needed to corrupt verity data or metadata.
+_require_fsverity_corruption()
+{
+	_require_xfs_io_command "fiemap"
+}
+
 _scratch_mkfs_verity()
 {
 	case $FSTYP in
diff --git a/tests/generic/574 b/tests/generic/574
index 882baa21..17fdea52 100755
--- a/tests/generic/574
+++ b/tests/generic/574
@@ -28,6 +28,7 @@ _cleanup()
 _supported_fs generic
 _require_scratch_verity
 _disable_fsverity_signatures
+_require_fsverity_corruption
 
 _scratch_mkfs_verity &>> $seqres.full
 _scratch_mount
diff --git a/tests/generic/576 b/tests/generic/576
index 82fbdd71..d3e0a2d6 100755
--- a/tests/generic/576
+++ b/tests/generic/576
@@ -28,6 +28,7 @@ _supported_fs generic
 _require_scratch_verity
 _require_scratch_encryption
 _require_command "$KEYCTL_PROG" keyctl
+_require_fsverity_corruption
 _disable_fsverity_signatures
 
 _scratch_mkfs_encrypted_verity &>> $seqres.full
-- 
2.35.1

[PATCH v9 2/5] common/verity: support btrfs in generic fsverity tests

[Boris Burkov]

generic/572-579 have tests for fsverity. Now that btrfs supports
fsverity, make these tests function as well. For a majority of the tests
that pass, simply adding the case to mkfs a btrfs filesystem with no
extra options is sufficient.

However, generic/574 has tests for corrupting the merkle tree itself.
Since btrfs uses a different scheme from ext4 and f2fs for storing this
data, the existing logic for corrupting it doesn't work out of the box.
Adapt it to properly corrupt btrfs merkle items.

576 does not run because btrfs does not support transparent encryption.

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>
---
 common/btrfs          |  5 +++++
 common/config         |  1 +
 common/verity         | 28 ++++++++++++++++++++++++++++
 tests/generic/574     | 39 +++++++++++++++++++++++++++++++++++++--
 tests/generic/574.out | 12 +++---------
 5 files changed, 74 insertions(+), 11 deletions(-)

diff --git a/common/btrfs b/common/btrfs
index 670d9d1f..c3a7dc6e 100644
--- a/common/btrfs
+++ b/common/btrfs
@@ -511,3 +511,8 @@ _btrfs_metadump()
 	$BTRFS_IMAGE_PROG "$device" "$dumpfile"
 	[ -n "$DUMP_COMPRESSOR" ] && $DUMP_COMPRESSOR -f "$dumpfile" &> /dev/null
 }
+
+_require_btrfs_corrupt_block()
+{
+	_require_command "$BTRFS_CORRUPT_BLOCK_PROG" btrfs-corrupt-block
+}
diff --git a/common/config b/common/config
index 479e50d1..67bdf912 100644
--- a/common/config
+++ b/common/config
@@ -296,6 +296,7 @@ export BTRFS_UTIL_PROG=$(type -P btrfs)
 export BTRFS_SHOW_SUPER_PROG=$(type -P btrfs-show-super)
 export BTRFS_CONVERT_PROG=$(type -P btrfs-convert)
 export BTRFS_TUNE_PROG=$(type -P btrfstune)
+export BTRFS_CORRUPT_BLOCK_PROG=$(type -P btrfs-corrupt-block)
 export XFS_FSR_PROG=$(type -P xfs_fsr)
 export MKFS_NFS_PROG="false"
 export MKFS_CIFS_PROG="false"
diff --git a/common/verity b/common/verity
index d58cad90..8cde2737 100644
--- a/common/verity
+++ b/common/verity
@@ -3,6 +3,13 @@
 #
 # Functions for setting up and testing fs-verity
 
+. common/btrfs
+# btrfs will return IO errors on corrupted data with or without fs-verity.
+# to really test fs-verity, use nodatasum.
+if [ "$FSTYP" == "btrfs" ]; then
+	export MOUNT_OPTIONS="-o nodatasum"
+fi
+
 _require_scratch_verity()
 {
 	_require_scratch
@@ -145,6 +152,9 @@ _require_fsverity_dump_metadata()
 _require_fsverity_corruption()
 {
 	_require_xfs_io_command "fiemap"
+	if [ $FSTYP == "btrfs" ]; then
+		_require_btrfs_corrupt_block
+	fi
 }
 
 _scratch_mkfs_verity()
@@ -153,6 +163,9 @@ _scratch_mkfs_verity()
 	ext4|f2fs)
 		_scratch_mkfs -O verity
 		;;
+	btrfs)
+		_scratch_mkfs
+		;;
 	*)
 		_notrun "No verity support for $FSTYP"
 		;;
@@ -314,6 +327,21 @@ _fsv_scratch_corrupt_merkle_tree()
 		(( offset += ($(_get_filesize $file) + 65535) & ~65535 ))
 		_fsv_scratch_corrupt_bytes $file $offset
 		;;
+	btrfs)
+		local ino=$(stat -c '%i' $file)
+		_scratch_unmount
+		local byte=""
+		while read -n 1 byte; do
+			local ascii=$(printf "%d" "'$byte'")
+			# This command will find a Merkle tree item for the inode (-I $ino,37,0)
+			# in the default filesystem tree (-r 5) and corrupt one byte (-b 1) at
+			# $offset (-o $offset) with the ascii representation of the byte we read
+			# (-v $ascii)
+			$BTRFS_CORRUPT_BLOCK_PROG -r 5 -I $ino,37,0 -v $ascii -o $offset -b 1 $SCRATCH_DEV
+			(( offset += 1 ))
+		done
+		_scratch_mount
+		;;
 	*)
 		_fail "_fsv_scratch_corrupt_merkle_tree() unimplemented on $FSTYP"
 		;;
diff --git a/tests/generic/574 b/tests/generic/574
index 17fdea52..680cece3 100755
--- a/tests/generic/574
+++ b/tests/generic/574
@@ -126,6 +126,41 @@ corruption_test()
 	fi
 }
 
+# xfs_io mread's output is parseable by xxd -r, except it has an extra space
+# after the colon. Output the number of non zero characters in the parsed contents.
+filter_mread() {
+	sed 's/:  /: /' | xxd -r | sed 's/\x0//g' | wc -c
+}
+
+# this expects to see stdout + stderr passed through filter_sigbus and filter_mread.
+# Outputs "OK" on a bus error or 0 non-zero characters counted by mread.
+filter_eof_block() {
+	sed 's/^Bus error$/OK/' | sed 's/^0$/OK/'
+}
+
+# some filesystems return zeros in the last block past EOF, regardless of
+# their contents. Handle those with a special test that accepts either zeros
+# or SIGBUS on an mmap+read of that block.
+corrupt_eof_block_test() {
+	local file_len=$1
+	local zap_len=$2
+	local page_aligned_eof=$(round_up_to_page_boundary $file_len)
+	local eof_page_start=$((page_aligned_eof - $(get_page_size)))
+	local corrupt_func=_fsv_scratch_corrupt_bytes
+	_fsv_scratch_begin_subtest "Corruption test: EOF block"
+	setup_zeroed_file $file_len false
+	cmp $fsv_file $fsv_orig_file
+	echo "Corrupting bytes..."
+	head -c $zap_len /dev/zero | tr '\0' X \
+		| $corrupt_func $fsv_file $((file_len + 1))
+
+	echo "Validating corruption or zeros (reading eof block via mmap)..."
+	bash -c "trap '' SIGBUS; $XFS_IO_PROG -r $fsv_file \
+		-c 'mmap -r $eof_page_start $(get_page_size)' \
+		-c 'mread -v $eof_page_start $(get_page_size)'" \
+		|& filter_mread | filter_sigbus | filter_eof_block
+}
+
 # Note: these tests just overwrite some bytes without checking their original
 # values.  Therefore, make sure to overwrite at least 5 or so bytes, to make it
 # nearly guaranteed that there will be a change -- even when the test file is
@@ -137,8 +172,8 @@ corruption_test 131072 65536 65536
 corruption_test 131072 131067 5
 
 # Non-zeroed bytes in the final partial block beyond EOF should cause reads to
-# fail too.  Such bytes would be visible via mmap().
-corruption_test 130999 131000 72
+# fail too.  Such bytes could be visible via mmap().
+corrupt_eof_block_test 130999 72
 
 # Merkle tree corruption.
 corruption_test 200000 100 10 true
diff --git a/tests/generic/574.out b/tests/generic/574.out
index 3c08d3e8..51bbd17b 100644
--- a/tests/generic/574.out
+++ b/tests/generic/574.out
@@ -56,17 +56,11 @@ Bus error
 Validating corruption (reading just corrupted part via mmap)...
 Bus error
 
-# Corruption test: file_len=130999 zap_offset=131000 zap_len=72
+# Corruption test: EOF block
 f5cca0d7fbb8b02bc6118a9954d5d306  SCRATCH_MNT/file.fsv
 Corrupting bytes...
-Validating corruption (reading full file)...
-md5sum: SCRATCH_MNT/file.fsv: Input/output error
-Validating corruption (direct I/O)...
-dd: error reading 'SCRATCH_MNT/file.fsv': Input/output error
-Validating corruption (reading full file via mmap)...
-Bus error
-Validating corruption (reading just corrupted part via mmap)...
-Bus error
+Validating corruption or zeros (reading eof block via mmap)...
+OK
 
 # Corruption test: file_len=200000 zap_offset=100 (in Merkle tree) zap_len=10
 4a1e4325031b13f933ac4f1db9ecb63f  SCRATCH_MNT/file.fsv
-- 
2.35.1

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

[Boris Burkov]

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

[PATCH v9 4/5] btrfs: test verity orphans with dmlogwrites

[Boris Burkov]

The behavior of orphans is most interesting across mounts, interrupted
at arbitrary points during fsverity enable. To cover as many such cases
as possible, use dmlogwrites and dmsnapshot as in
log-writes/replay-individual.sh. At each log entry, we want to assert a
somewhat complicated invariant:

If verity has not yet started: an orphan indicates that verity has
started.
If verity has started: mount should handle the orphan and blow away
verity data: expect 0 merkle items after mounting the snapshot dev. If
we can measure the file, verity has finished.
If verity has finished: the orphan should be gone, so mount should not
blow away merkle items. Expect the same number of merkle items before
and after mounting the snapshot dev.

Note that this relies on grepping btrfs inspect-internal dump-tree.
Until btrfs-progs has the ability to print the new Merkle items, they
will show up as UNKNOWN.36/37.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 tests/btrfs/291     | 161 ++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/291.out |   2 +
 2 files changed, 163 insertions(+)
 create mode 100755 tests/btrfs/291
 create mode 100644 tests/btrfs/291.out

diff --git a/tests/btrfs/291 b/tests/btrfs/291
new file mode 100755
index 00000000..1bb3f1b3
--- /dev/null
+++ b/tests/btrfs/291
@@ -0,0 +1,161 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2021 Facebook, Inc. All Rights Reserved.
+#
+# FS QA Test 291
+#
+# Test btrfs consistency after each FUA while enabling verity on a file
+# This test works by following the pattern in log-writes/replay-individual.sh:
+# 1. run a workload (verity + sync) while logging to the log device
+# 2. replay an entry to the replay device
+# 3. snapshot the replay device to the snapshot device
+# 4. run destructive tests on the snapshot device (e.g. mount with orphans)
+# 5. goto 2
+#
+. ./common/preamble
+_begin_fstest auto verity
+
+# Override the default cleanup function.
+_cleanup()
+{
+	cd /
+	_log_writes_cleanup &> /dev/null
+	rm -f $img
+	$LVM_PROG vgremove -f -y $vgname >>$seqres.full 2>&1
+	losetup -d $loop_dev >>$seqres.full 2>&1
+}
+
+# Import common functions.
+. ./common/filter
+. ./common/attr
+. ./common/dmlogwrites
+. ./common/verity
+
+# real QA test starts here
+_supported_fs btrfs
+
+_require_scratch
+_require_test
+_require_log_writes
+_require_dm_target snapshot
+_require_command $LVM_PROG lvm
+_require_scratch_verity
+_require_btrfs_command inspect-internal dump-tree
+_require_test_program "log-writes/replay-log"
+
+sync_loop() {
+	i=$1
+	[ -z "$i" ] && _fail "sync loop needs a number of iterations"
+	while [ $i -gt 0 ]
+	do
+		$XFS_IO_PROG -c sync $SCRATCH_MNT
+		let i-=1
+	done
+}
+
+dump_tree() {
+	local dev=$1
+	$BTRFS_UTIL_PROG inspect-internal dump-tree $dev
+}
+
+count_item() {
+	local dev=$1
+	local item=$2
+	dump_tree $dev | grep -c $item
+}
+
+_log_writes_init $SCRATCH_DEV
+_log_writes_mkfs
+_log_writes_mount
+
+f=$SCRATCH_MNT/fsv
+MB=$((1024 * 1024))
+img=$TEST_DIR/$$.img
+$XFS_IO_PROG -fc "pwrite -q 0 $((10 * $MB))" $f
+$XFS_IO_PROG -c sync $SCRATCH_MNT
+sync_loop 10 &
+sync_proc=$!
+_fsv_enable $f
+$XFS_IO_PROG -c sync $SCRATCH_MNT
+wait $sync_proc
+
+_log_writes_unmount
+_log_writes_remove
+
+# the snapshot and the replay will each be the size of the log writes dev
+# so we create a loop device of size 2 * logwrites and then split it into
+# replay and snapshot with lvm.
+log_writes_blocks=$(blockdev --getsz $LOGWRITES_DEV)
+replay_bytes=$((512 * $log_writes_blocks))
+img_bytes=$((2 * $replay_bytes))
+
+$XFS_IO_PROG -fc "pwrite -q -S 0 $img_bytes $MB" $img >>$seqres.full 2>&1 || \
+	_fail "failed to create image for loop device"
+loop_dev=$(losetup -f --show $img)
+vgname=vg_replay
+lvname=lv_replay
+replay_dev=/dev/mapper/vg_replay-lv_replay
+snapname=lv_snap
+snap_dev=/dev/mapper/vg_replay-$snapname
+
+$LVM_PROG vgcreate -f $vgname $loop_dev >>$seqres.full 2>&1 || _fail "failed to vgcreate $vgname"
+$LVM_PROG lvcreate -L "$replay_bytes"B -n $lvname $vgname -y >>$seqres.full 2>&1 || \
+	_fail "failed to lvcreate $lvname"
+$UDEV_SETTLE_PROG >>$seqres.full 2>&1
+
+replay_log_prog=$here/src/log-writes/replay-log
+num_entries=$($replay_log_prog --log $LOGWRITES_DEV --num-entries)
+entry=$($replay_log_prog --log $LOGWRITES_DEV --replay $replay_dev --find --end-mark mkfs | cut -d@ -f1)
+$replay_log_prog --log $LOGWRITES_DEV --replay $replay_dev --limit $entry || \
+	_fail "failed to replay to start entry $entry"
+let entry+=1
+
+# state = 0: verity hasn't started
+# state = 1: verity underway
+# state = 2: verity done
+state=0
+while [ $entry -lt $num_entries ];
+do
+	$replay_log_prog --limit 1 --log $LOGWRITES_DEV --replay $replay_dev --start $entry || \
+		_fail "failed to take replay step at entry: $entry"
+
+	$LVM_PROG lvcreate -s -L 4M -n $snapname $vgname/$lvname >>$seqres.full 2>&1 || \
+		_fail "Failed to create snapshot"
+	$UDEV_SETTLE_PROG >>$seqres.full 2>&1
+
+	orphan=$(count_item $snap_dev ORPHAN)
+	if [ $state -eq 0 ]; then
+		[ $orphan -gt 0 ] && state=1
+	fi
+
+	pre_mount=$(count_item $snap_dev UNKNOWN.3[67])
+	_mount $snap_dev $SCRATCH_MNT || _fail "mount failed at entry $entry"
+	fsverity measure $SCRATCH_MNT/fsv >>$seqres.full 2>&1
+	measured=$?
+	umount $SCRATCH_MNT
+	[ $state -eq 1 ] && [ $measured -eq 0 ] && state=2
+	[ $state -eq 2 ] && ([ $measured -eq 0 ] || _fail "verity done, but measurement failed at entry $entry")
+	post_mount=$(count_item $snap_dev UNKNOWN.3[67])
+
+	echo "entry: $entry, state: $state, orphan: $orphan, pre_mount: $pre_mount, post_mount: $post_mount" >> $seqres.full
+
+	if [ $state -eq 1 ]; then
+		[ $post_mount -eq 0 ] || \
+			_fail "mount failed to clear under-construction merkle items pre: $pre_mount, post: $post_mount at entry $entry";
+	fi
+	if [ $state -eq 2 ]; then
+		[ $pre_mount -gt 0 ] || \
+			_fail "expected to have verity items before mount at entry $entry"
+		[ $pre_mount -eq $post_mount ] || \
+			_fail "mount cleared merkle items after verity was enabled $pre_mount vs $post_mount at entry $entry";
+	fi
+
+	let entry+=1
+	$LVM_PROG lvremove $vgname/$snapname -y >>$seqres.full
+done
+
+echo "Silence is golden"
+
+# success, all done
+status=0
+exit
diff --git a/tests/btrfs/291.out b/tests/btrfs/291.out
new file mode 100644
index 00000000..04605c70
--- /dev/null
+++ b/tests/btrfs/291.out
@@ -0,0 +1,2 @@
+QA output created by 291
+Silence is golden
-- 
2.35.1

[PATCH v9 5/5] generic: test fs-verity EFBIG scenarios

[Boris Burkov]

btrfs, ext4, and f2fs cache the Merkle tree past EOF, which restricts
the maximum file size beneath the normal maximum. Test the logic in
those filesystems against files with sizes near the maximum.

To work properly, this does require some understanding of the practical
but not standardized layout of the Merkle tree. This is a bit unpleasant
and could make the test incorrect in the future, if the implementation
changes. On the other hand, it feels quite useful to test this tricky
edge case. It could perhaps be made more generic by adding some ioctls
to let the file system communicate the maximum file size for a verity
file or some information about the storage of the Merkle tree.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 common/verity         | 11 ++++++++
 tests/generic/690     | 64 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/690.out |  7 +++++
 3 files changed, 82 insertions(+)
 create mode 100755 tests/generic/690
 create mode 100644 tests/generic/690.out

diff --git a/common/verity b/common/verity
index 8cde2737..657af8aa 100644
--- a/common/verity
+++ b/common/verity
@@ -347,3 +347,14 @@ _fsv_scratch_corrupt_merkle_tree()
 		;;
 	esac
 }
+
+_require_fsverity_max_file_size_limit()
+{
+	case $FSTYP in
+	btrfs|ext4|f2fs)
+		;;
+	*)
+		_notrun "$FSTYP does not store verity data past EOF; no special file size limit"
+		;;
+	esac
+}
diff --git a/tests/generic/690 b/tests/generic/690
new file mode 100755
index 00000000..afdd95f2
--- /dev/null
+++ b/tests/generic/690
@@ -0,0 +1,64 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2021 Facebook, Inc.  All Rights Reserved.
+#
+# FS QA Test 690
+#
+# fs-verity requires the filesystem to decide how it stores the Merkle tree,
+# which can be quite large.
+# It is convenient to treat the Merkle tree as past EOF, and ext4, f2fs, and
+# btrfs do so in at least some fashion. This leads to an edge case where a
+# large file can be under the file system file size limit, but trigger EFBIG
+# on enabling fs-verity. Test enabling verity on some large files to exercise
+# EFBIG logic for filesystems with fs-verity specific limits.
+#
+. ./common/preamble
+_begin_fstest auto quick verity
+
+
+# Import common functions.
+. ./common/filter
+. ./common/verity
+
+# real QA test starts here
+_supported_fs generic
+_require_test
+_require_math
+_require_scratch_verity
+_require_fsverity_max_file_size_limit
+
+_scratch_mkfs_verity &>> $seqres.full
+_scratch_mount
+
+fsv_file=$SCRATCH_MNT/file.fsv
+
+max_sz=$(_get_max_file_size)
+_fsv_scratch_begin_subtest "way too big: fail on first merkle block"
+truncate -s $max_sz $fsv_file
+_fsv_enable $fsv_file |& _filter_scratch
+
+# The goal of this second test is to make a big enough file that we trip the
+# EFBIG codepath, but not so big that we hit it immediately when writing the
+# first Merkle leaf.
+#
+# The Merkle tree is stored with the leaf node level (L0) last, but it is
+# written first.  To get an interesting overflow, we need the maximum file size
+# (MAX) to be in the middle of L0 -- ideally near the beginning of L0 so that we
+# don't have to write many blocks before getting an error.
+#
+# With SHA-256 and 4K blocks, there are 128 hashes per block.  Thus, ignoring
+# padding, L0 is 1/128 of the file size while the other levels in total are
+# 1/128**2 + 1/128**3 + 1/128**4 + ... = 1/16256 of the file size.  So still
+# ignoring padding, for L0 start exactly at MAX, the file size must be s such
+# that s + s/16256 = MAX, i.e. s = MAX * (16256/16257).  Then to get a file size
+# where MAX occurs *near* the start of L0 rather than *at* the start, we can
+# just subtract an overestimate of the padding: 64K after the file contents,
+# then 4K per level, where the consideration of 8 levels is sufficient.
+sz=$(echo "scale=20; $max_sz * (16256/16257) - 65536 - 4096*8" | $BC -q | cut -d. -f1)
+_fsv_scratch_begin_subtest "still too big: fail on first invalid merkle block"
+truncate -s $sz $fsv_file
+_fsv_enable $fsv_file |& _filter_scratch
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/690.out b/tests/generic/690.out
new file mode 100644
index 00000000..a3e2b9b9
--- /dev/null
+++ b/tests/generic/690.out
@@ -0,0 +1,7 @@
+QA output created by 690
+
+# way too big: fail on first merkle block
+ERROR: FS_IOC_ENABLE_VERITY failed on 'SCRATCH_MNT/file.fsv': File too large
+
+# still too big: fail on first invalid merkle block
+ERROR: FS_IOC_ENABLE_VERITY failed on 'SCRATCH_MNT/file.fsv': File too large
-- 
2.35.1

Re: [PATCH v9 4/5] btrfs: test verity orphans with dmlogwrites

[Josef Bacik]

On Tue, Apr 26, 2022 at 03:40:15PM -0700, Boris Burkov wrote:
> The behavior of orphans is most interesting across mounts, interrupted
> at arbitrary points during fsverity enable. To cover as many such cases
> as possible, use dmlogwrites and dmsnapshot as in
> log-writes/replay-individual.sh. At each log entry, we want to assert a
> somewhat complicated invariant:
> 
> If verity has not yet started: an orphan indicates that verity has
> started.
> If verity has started: mount should handle the orphan and blow away
> verity data: expect 0 merkle items after mounting the snapshot dev. If
> we can measure the file, verity has finished.
> If verity has finished: the orphan should be gone, so mount should not
> blow away merkle items. Expect the same number of merkle items before
> and after mounting the snapshot dev.
> 
> Note that this relies on grepping btrfs inspect-internal dump-tree.
> Until btrfs-progs has the ability to print the new Merkle items, they
> will show up as UNKNOWN.36/37.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>
> ---
>  tests/btrfs/291     | 161 ++++++++++++++++++++++++++++++++++++++++++++
>  tests/btrfs/291.out |   2 +
>  2 files changed, 163 insertions(+)
>  create mode 100755 tests/btrfs/291
>  create mode 100644 tests/btrfs/291.out
> 
> diff --git a/tests/btrfs/291 b/tests/btrfs/291
> new file mode 100755
> index 00000000..1bb3f1b3
> --- /dev/null
> +++ b/tests/btrfs/291
> @@ -0,0 +1,161 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2021 Facebook, Inc. All Rights Reserved.
> +#
> +# FS QA Test 291
> +#
> +# Test btrfs consistency after each FUA while enabling verity on a file
> +# This test works by following the pattern in log-writes/replay-individual.sh:
> +# 1. run a workload (verity + sync) while logging to the log device
> +# 2. replay an entry to the replay device
> +# 3. snapshot the replay device to the snapshot device
> +# 4. run destructive tests on the snapshot device (e.g. mount with orphans)
> +# 5. goto 2
> +#
> +. ./common/preamble
> +_begin_fstest auto verity
> +
> +# Override the default cleanup function.
> +_cleanup()
> +{
> +	cd /
> +	_log_writes_cleanup &> /dev/null
> +	rm -f $img
> +	$LVM_PROG vgremove -f -y $vgname >>$seqres.full 2>&1
> +	losetup -d $loop_dev >>$seqres.full 2>&1
> +}
> +
> +# Import common functions.
> +. ./common/filter
> +. ./common/attr
> +. ./common/dmlogwrites
> +. ./common/verity
> +
> +# real QA test starts here
> +_supported_fs btrfs
> +
> +_require_scratch
> +_require_test
> +_require_log_writes
> +_require_dm_target snapshot
> +_require_command $LVM_PROG lvm
> +_require_scratch_verity
> +_require_btrfs_command inspect-internal dump-tree
> +_require_test_program "log-writes/replay-log"
> +
> +sync_loop() {
> +	i=$1
> +	[ -z "$i" ] && _fail "sync loop needs a number of iterations"
> +	while [ $i -gt 0 ]
> +	do
> +		$XFS_IO_PROG -c sync $SCRATCH_MNT
> +		let i-=1
> +	done
> +}
> +
> +dump_tree() {
> +	local dev=$1
> +	$BTRFS_UTIL_PROG inspect-internal dump-tree $dev
> +}
> +
> +count_item() {
> +	local dev=$1
> +	local item=$2
> +	dump_tree $dev | grep -c $item
> +}
> +
> +_log_writes_init $SCRATCH_DEV
> +_log_writes_mkfs
> +_log_writes_mount
> +
> +f=$SCRATCH_MNT/fsv
> +MB=$((1024 * 1024))
> +img=$TEST_DIR/$$.img
> +$XFS_IO_PROG -fc "pwrite -q 0 $((10 * $MB))" $f
> +$XFS_IO_PROG -c sync $SCRATCH_MNT
> +sync_loop 10 &
> +sync_proc=$!
> +_fsv_enable $f
> +$XFS_IO_PROG -c sync $SCRATCH_MNT
> +wait $sync_proc
> +
> +_log_writes_unmount
> +_log_writes_remove
> +
> +# the snapshot and the replay will each be the size of the log writes dev
> +# so we create a loop device of size 2 * logwrites and then split it into
> +# replay and snapshot with lvm.
> +log_writes_blocks=$(blockdev --getsz $LOGWRITES_DEV)
> +replay_bytes=$((512 * $log_writes_blocks))
> +img_bytes=$((2 * $replay_bytes))
> +
> +$XFS_IO_PROG -fc "pwrite -q -S 0 $img_bytes $MB" $img >>$seqres.full 2>&1 || \
> +	_fail "failed to create image for loop device"
> +loop_dev=$(losetup -f --show $img)

I got bit by this recently, you need

_require_loop

for this test.  Thanks,

Josef

Re: [PATCH v9 1/5] common/verity: require corruption functionality

[Josef Bacik]

On Tue, Apr 26, 2022 at 03:40:12PM -0700, Boris Burkov wrote:
> Corrupting ext4 and f2fs relies on xfs_io fiemap. Btrfs corruption
> testing will rely on a btrfs specific corruption utility. Add the
> ability to require corruption functionality to make this properly
> modular. To start, just check for fiemap, as that is needed
> universally for _fsv_scratch_corrupt_bytes.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

Re: [PATCH v9 2/5] common/verity: support btrfs in generic fsverity tests

[Josef Bacik]

On Tue, Apr 26, 2022 at 03:40:13PM -0700, Boris Burkov wrote:
> generic/572-579 have tests for fsverity. Now that btrfs supports
> fsverity, make these tests function as well. For a majority of the tests
> that pass, simply adding the case to mkfs a btrfs filesystem with no
> extra options is sufficient.
> 
> However, generic/574 has tests for corrupting the merkle tree itself.
> Since btrfs uses a different scheme from ext4 and f2fs for storing this
> data, the existing logic for corrupting it doesn't work out of the box.
> Adapt it to properly corrupt btrfs merkle items.
> 
> 576 does not run because btrfs does not support transparent encryption.
> 
> 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>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

Re: [PATCH v9 1/5] common/verity: require corruption functionality

[Eric Biggers]

On Tue, Apr 26, 2022 at 03:40:12PM -0700, Boris Burkov wrote:
> Corrupting ext4 and f2fs relies on xfs_io fiemap. Btrfs corruption
> testing will rely on a btrfs specific corruption utility. Add the
> ability to require corruption functionality to make this properly
> modular. To start, just check for fiemap, as that is needed
> universally for _fsv_scratch_corrupt_bytes.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>
> ---
>  common/verity     | 6 ++++++
>  tests/generic/574 | 1 +
>  tests/generic/576 | 1 +
>  3 files changed, 8 insertions(+)

Reviewed-by: Eric Biggers <ebiggers@google.com>

- Eric

Re: [PATCH v9 2/5] common/verity: support btrfs in generic fsverity tests

[Eric Biggers]

On Tue, Apr 26, 2022 at 03:40:13PM -0700, Boris Burkov wrote:
> diff --git a/common/verity b/common/verity
> index d58cad90..8cde2737 100644
> --- a/common/verity
> +++ b/common/verity
> @@ -3,6 +3,13 @@
>  #
>  # Functions for setting up and testing fs-verity
>  
> +. common/btrfs
> +# btrfs will return IO errors on corrupted data with or without fs-verity.
> +# to really test fs-verity, use nodatasum.
> +if [ "$FSTYP" == "btrfs" ]; then
> +	export MOUNT_OPTIONS="-o nodatasum"
> +fi

Shouldn't this append to MOUNT_OPTIONS rather than replacing it?

> diff --git a/tests/generic/574 b/tests/generic/574
> index 17fdea52..680cece3 100755
> --- a/tests/generic/574
> +++ b/tests/generic/574
> @@ -126,6 +126,41 @@ corruption_test()
>  	fi
>  }
>  
> +# xfs_io mread's output is parseable by xxd -r, except it has an extra space
> +# after the colon. Output the number of non zero characters in the parsed contents.
> +filter_mread() {
> +	sed 's/:  /: /' | xxd -r | sed 's/\x0//g' | wc -c
> +}
> +
> +# this expects to see stdout + stderr passed through filter_sigbus and filter_mread.
> +# Outputs "OK" on a bus error or 0 non-zero characters counted by mread.
> +filter_eof_block() {
> +	sed 's/^Bus error$/OK/' | sed 's/^0$/OK/'
> +}
> +
> +# some filesystems return zeros in the last block past EOF, regardless of
> +# their contents. Handle those with a special test that accepts either zeros
> +# or SIGBUS on an mmap+read of that block.
> +corrupt_eof_block_test() {
> +	local file_len=$1
> +	local zap_len=$2
> +	local page_aligned_eof=$(round_up_to_page_boundary $file_len)
> +	local eof_page_start=$((page_aligned_eof - $(get_page_size)))
> +	local corrupt_func=_fsv_scratch_corrupt_bytes

The corrupt_func variable is unnecessary.

> +	_fsv_scratch_begin_subtest "Corruption test: EOF block"
> +	setup_zeroed_file $file_len false
> +	cmp $fsv_file $fsv_orig_file
> +	echo "Corrupting bytes..."
> +	head -c $zap_len /dev/zero | tr '\0' X \
> +		| $corrupt_func $fsv_file $((file_len + 1))
> +
> +	echo "Validating corruption or zeros (reading eof block via mmap)..."
> +	bash -c "trap '' SIGBUS; $XFS_IO_PROG -r $fsv_file \
> +		-c 'mmap -r $eof_page_start $(get_page_size)' \
> +		-c 'mread -v $eof_page_start $(get_page_size)'" \
> +		|& filter_mread | filter_sigbus | filter_eof_block
> +}
> +

This actually causes the test to stop checking for the string "Bus error"
because it sends the output through 'xxd -r' first, which turns anything that
isn't valid 'xxd' input into all zeroed bytes, which passes the test.  So
"Bus error" will still pass, but lots of other random strings will pass too.

Also, I don't think we can assume that the xxd program is available, as it's
part of the vim package.  This would be the first use of xxd in xfstests.

Instead, how about dumping the output to a file $tmp.out, then checking if
either of the following is true:

   - The output contains the string "Bus error".
   - The contents of the output matches that of the same xfs_io command executed
     on the same region of a file containing all zeroes.

Also, it might be a bit simpler to use $file_len as the $zap_offset (instead of
$file_len + 1), and just reading $zap_len bytes starting at $file_len.  The
mread doesn't need to be page aligned; only the mmap needs to be, and that can
just be from 0 to page_aligned_eof.  That would also avoid the page/block
ambiguity where the comments are talking about the "EOF block", but the code is
actually reading a whole page.

>  # Non-zeroed bytes in the final partial block beyond EOF should cause reads to
> -# fail too.  Such bytes would be visible via mmap().
> -corruption_test 130999 131000 72
> +# fail too.  Such bytes could be visible via mmap().
> +corrupt_eof_block_test 130999 72

The above comment is now outdated.  Maybe just remove it and improve the comment
above corrupt_eof_block_test().

- Eric

Re: [PATCH v9 5/5] generic: test fs-verity EFBIG scenarios

[Eric Biggers]

On Tue, Apr 26, 2022 at 03:40:16PM -0700, Boris Burkov wrote:
> btrfs, ext4, and f2fs cache the Merkle tree past EOF, which restricts
> the maximum file size beneath the normal maximum. Test the logic in
> those filesystems against files with sizes near the maximum.
> 
> To work properly, this does require some understanding of the practical
> but not standardized layout of the Merkle tree. This is a bit unpleasant
> and could make the test incorrect in the future, if the implementation
> changes. On the other hand, it feels quite useful to test this tricky
> edge case. It could perhaps be made more generic by adding some ioctls
> to let the file system communicate the maximum file size for a verity
> file or some information about the storage of the Merkle tree.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>
> ---
>  common/verity         | 11 ++++++++
>  tests/generic/690     | 64 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/690.out |  7 +++++
>  3 files changed, 82 insertions(+)
>  create mode 100755 tests/generic/690
>  create mode 100644 tests/generic/690.out

Unchanged from v8 which I had given R-b for:

Reviewed-by: Eric Biggers <ebiggers@google.com>

- Eric