[PATCH 2/2] btrfs/291: fix state transition logic and add size requirement

This patch fixes two issues in btrfs/291:

1. Add minimum 9GB LOGWRITES_DEV size requirement
   The test creates LVM snapshots at each FUA point during replay,
   requiring significant space. Add _require_logwrites_size check
   to ensure sufficient space is available before running the test.

2. Fix state transition logic for verity enablement
   The original test assumed orphan items would always be created
   during verity enablement (state 0->1 transition). However, in
   some cases verity completes without creating orphan items,
   causing the test to fail with "expected to reach verity done state".

   Fix by transitioning to state 1 when either orphan items exist
   OR merkle items appear, handling both verity enablement paths.
   Also improve state 1 validation to only check for cleared merkle
   items when measurement actually fails.

The test now correctly handles verity enablement with or without
orphan items while maintaining crash consistency validation.

Signed-off-by: Disha Goel <[email protected]>
---
 tests/btrfs/291 | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/tests/btrfs/291 b/tests/btrfs/291
index 122aeaa5..d29dc5dd 100755
--- a/tests/btrfs/291
+++ b/tests/btrfs/291
@@ -37,6 +37,7 @@ _require_scratch
 _require_test
 _require_loop
 _require_log_writes
+_require_logwrites_size $((9 * 1024 * 1024))
 _require_dm_target snapshot
 _require_command $LVM_PROG lvm
 _require_scratch_verity
@@ -129,9 +130,14 @@ do
 	_udev_wait /dev/mapper/$vgname-$snapname
 
 	orphan=$(count_item $snap_dev ORPHAN)
-	[ $state -eq 0 ] && [ $orphan -gt 0 ] && state=1
-
 	pre_mount=$(count_merkle_items $snap_dev)
+
+	if [ $state -eq 0 ]; then
+		if [ $orphan -gt 0 ] || [ $pre_mount -gt 0 ]; then
+			state=1
+		fi
+	fi
+
 	_mount $snap_dev $SCRATCH_MNT || _fail "mount failed at entry $cur"
 	fsverity measure $SCRATCH_MNT/fsv >>$seqres.full 2>&1
 	measured=$?
@@ -143,8 +149,10 @@ do
 	echo "entry: $cur, 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 $cur";
+		if [ $measured -ne 0 ]; then
+			[ $post_mount -eq 0 ] || \
+				_fail "mount failed to clear under-construction merkle items pre: $pre_mount, post: $post_mount at entry $cur";
+		fi
 	fi
 	if [ $state -eq 2 ]; then
 		[ $pre_mount -gt 0 ] || \
-- 
2.45.1