diff mbox series

[v13,2/5] common/verity: support btrfs in generic fsverity tests

Message ID 2bbb68b90691a82b8143ba4612ea2cc761e44ecb.1658277755.git.boris@bur.io (mailing list archive)
State Accepted
Headers show
Series tests for btrfs fsverity | expand

Commit Message

Boris Burkov July 20, 2022, 12:49 a.m. UTC
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: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
---
 common/btrfs          |  5 +++++
 common/config         |  1 +
 common/verity         | 31 +++++++++++++++++++++++++++++++
 tests/generic/574     | 37 ++++++++++++++++++++++++++++++++++---
 tests/generic/574.out | 13 ++++---------
 5 files changed, 75 insertions(+), 12 deletions(-)

Comments

Eric Biggers July 25, 2022, 6:41 p.m. UTC | #1
On Tue, Jul 19, 2022 at 05:49:47PM -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: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
> ---
>  common/btrfs          |  5 +++++
>  common/config         |  1 +
>  common/verity         | 31 +++++++++++++++++++++++++++++++
>  tests/generic/574     | 37 ++++++++++++++++++++++++++++++++++---
>  tests/generic/574.out | 13 ++++---------
>  5 files changed, 75 insertions(+), 12 deletions(-)

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

- Eric
diff mbox series

Patch

diff --git a/common/btrfs b/common/btrfs
index 14ad890e..bd2639bf 100644
--- a/common/btrfs
+++ b/common/btrfs
@@ -580,3 +580,8 @@  _btrfs_buffered_read_on_mirror()
 		:
 	done
 }
+
+_require_btrfs_corrupt_block()
+{
+	_require_command "$BTRFS_CORRUPT_BLOCK_PROG" btrfs-corrupt-block
+}
diff --git a/common/config b/common/config
index de3aba15..c30eec6d 100644
--- a/common/config
+++ b/common/config
@@ -297,6 +297,7 @@  export BTRFS_UTIL_PROG=$(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..4c50d2b1 100644
--- a/common/verity
+++ b/common/verity
@@ -3,6 +3,16 @@ 
 #
 # Functions for setting up and testing fs-verity
 
+# btrfs will return IO errors on corrupted data with or without fs-verity.
+# to really test fs-verity, use nodatasum.
+if [ "$FSTYP" == "btrfs" ]; then
+        if [ -z "$MOUNT_OPTIONS" ]; then
+                export MOUNT_OPTIONS="-o nodatasum"
+        else
+                export MOUNT_OPTIONS+=" -o nodatasum"
+        fi
+fi
+
 _require_scratch_verity()
 {
 	_require_scratch
@@ -145,6 +155,9 @@  _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 +166,9 @@  _scratch_mkfs_verity()
 	ext4|f2fs)
 		_scratch_mkfs -O verity
 		;;
+	btrfs)
+		_scratch_mkfs
+		;;
 	*)
 		_notrun "No verity support for $FSTYP"
 		;;
@@ -314,6 +330,21 @@  _fsv_scratch_corrupt_merkle_tree()
 		(( offset += ($(_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..fd4488c9 100755
--- a/tests/generic/574
+++ b/tests/generic/574
@@ -126,6 +126,39 @@  corruption_test()
 	fi
 }
 
+# Reading the last block of the file with mmap is tricky, so we need to be
+# a bit careful. Some filesystems read the last block in full, while others
+# return zeros in the last block past EOF, regardless of the contents on
+# disk. In the former, corruption should be detected and result in SIGBUS,
+# while in the latter we would expect zeros past EOF, but no error.
+corrupt_eof_block_test() {
+	local file_len=$1
+	local zap_len=$2
+	local page_aligned_eof=$(round_up_to_page_boundary $file_len)
+	_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 \
+		| _fsv_scratch_corrupt_bytes $fsv_file $file_len
+
+	echo "Reading eof block via mmap into a temporary file..."
+	bash -c "trap '' SIGBUS; $XFS_IO_PROG -r $fsv_file \
+		-c 'mmap -r 0 $page_aligned_eof' \
+		-c 'mread -v $file_len $zap_len'" \
+		|& filter_sigbus >$tmp.eof_block_read 2>&1
+
+	head -c $file_len /dev/zero > $tmp.zero_cmp_file
+	$XFS_IO_PROG -r $tmp.zero_cmp_file \
+		-c "mmap -r 0 $page_aligned_eof" \
+		-c "mread -v $file_len $zap_len" >$tmp.eof_zero_read
+
+	echo "Checking for SIGBUS or zeros..."
+	grep -q -e '^Bus error$' $tmp.eof_block_read \
+		|| diff $tmp.eof_block_read $tmp.eof_zero_read \
+		&& echo "OK"
+}
+
 # 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
@@ -136,9 +169,7 @@  corruption_test 131072 4091 5
 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
+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..d40d1263 100644
--- a/tests/generic/574.out
+++ b/tests/generic/574.out
@@ -56,17 +56,12 @@  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
+Reading eof block via mmap into a temporary file...
+Checking for SIGBUS or zeros...
+OK
 
 # Corruption test: file_len=200000 zap_offset=100 (in Merkle tree) zap_len=10
 4a1e4325031b13f933ac4f1db9ecb63f  SCRATCH_MNT/file.fsv