btrfs-progs: tests: add test case for init-csum-tree

This new test script will create a fs with the following situations:

- Preallocated extents (no data csum)
- Nodatasum inodes (no data csum)
- Partially written preallocated extents (no data csum for part of the
  extent)
- Regular data extents (with data csum)
- Regular data extents then hole punched (with data csum)
- Preallocated data, then written, then hole punched (with data csum)
- Compressed extents (with data csum)

And make sure after --init-csum-tree (with or without
--init-extent-tree) the result fs can still pass check.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

tests/fsck-tests/052-init-csum-tree/test.sh

@@ -0,0 +1,65 @@
+#!/bin/bash
+#
+# Verify that `btrfs check --init-csum-tree` can handle various nodatasum
+# cases.
+
+source "$TEST_TOP/common"
+
+check_prereq btrfs
+check_global_prereq fallocate
+check_global_prereq dd
+
+setup_root_helper
+prepare_test_dev
+
+run_check_mkfs_test_dev
+
+# Create an inode with nodatasum and some content
+run_check_mount_test_dev -o nodatasum
+
+run_check $SUDO_HELPER dd if=/dev/urandom of="$TEST_MNT/nodatasum_file" \
+	bs=16k count=1 status=noxfer > /dev/null 2>&1
+
+# Revert to default datasum
+run_check $SUDO_HELPER mount -o remount,datasum "$TEST_MNT"
+
+# Then create an inode with datasum, but all preallocated extents
+run_check $SUDO_HELPER fallocate -l 32k "$TEST_MNT/prealloc1"
+
+# Create preallocated extent but partially written
+run_check $SUDO_HELPER fallocate -l 32k "$TEST_MNT/prealloc2"
+run_check $SUDO_HELPER dd if=/dev/urandom of="$TEST_MNT/prealloc2" \
+	bs=16k count=1 conv=notrunc status=noxfer> /dev/null 2>&1
+
+# Then some regular files
+run_check $SUDO_HELPER dd if=/dev/urandom of="$TEST_MNT/regular" \
+	bs=16k count=1 status=noxfer > /dev/null 2>&1
+
+# And some regular files with holes
+run_check $SUDO_HELPER dd if=/dev/urandom of="$TEST_MNT/regular_with_holes" \
+	bs=16k count=1 status=noxfer > /dev/null 2>&1
+run_check $SUDO_HELPER fallocate -p -o 4096 -l 4096 "$TEST_MNT/regular_with_holes"
+
+# And the most complex one, preallocated, written, then hole
+run_check $SUDO_HELPER fallocate  -l 8192 "$TEST_MNT/complex"
+run_check $SUDO_HELPER dd if=/dev/urandom of="$TEST_MNT/compex" \
+	bs=4k count=1 conv=notrunc status=noxfer > /dev/null 2>&1
+sync
+run_check $SUDO_HELPER fallocate -p -l 4096 "$TEST_MNT/regular_with_holes"
+
+# Create some compressed file
+run_check $SUDO_HELPER mount -o remount,compress "$TEST_MNT"
+run_check $SUDO_HELPER dd if=/dev/zero of="$TEST_MNT/compressed" \
+	bs=16k count=4 conv=notrunc status=noxfer> /dev/null 2>&1
+
+# And create a snapshot, every data extent is at least shared twice
+run_check $SUDO_HELPER "$TOP/btrfs" subvolume snapshot "$TEST_MNT" \
+	"$TEST_MNT/snapshot"
+run_check_umount_test_dev
+
+# --init-csum-tree should not fail
+run_check $SUDO_HELPER "$TOP/btrfs" check --force \
+	--init-csum-tree "$TEST_DEV"
+
+# No error should be found
+run_check $SUDO_HELPER "$TOP/btrfs" check "$TEST_DEV"