[PATCH] generic/064: allow 50 extents on F2FS after fcollapse

On F2FS, generic/064 fails with "extents mismatched before = 1 after =
50" following multiple fcollapse (collapse range) operations.

To ensure crash consistency and checkpoint integrity, F2FS forbids
in-place SSR (Summary Standalone Replacement) overwrites on valid
checkpointed blocks. When collapse range shifts blocks, F2FS allocates
new data pages in LFS mode (out-of-place log writes). As a result,
sequential collapse range calls rewrite shifted blocks at new log
locations, intentionally leaving the file with 50 extents.

Adjust the extent verification in generic/064 to expect exactly 50
extents on F2FS, while preserving the strict 1-extent requirement for
all other filesystems. Data integrity continues to be verified via byte
comparison.

Signed-off-by: Jaegeuk Kim <[email protected]>
Signed-off-by: Jan Prusakowski <[email protected]>
---
 tests/generic/064 | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tests/generic/064 b/tests/generic/064
index aed13970..b77eccb4 100755
--- a/tests/generic/064
+++ b/tests/generic/064
@@ -59,7 +59,13 @@ for (( j=0; j < $(($BLOCKS/2)); j++ )); do
 done
 
 extent_after=`_count_extents $dest`
-if [ $extent_before -ne $extent_after ]; then
+
+if [ "$FSTYP" == "f2fs" ];
+then
+	if [ $extent_before -ne 1 ] || [ $extent_after -ne 50 ]; then
+		echo "extents mismatched before = $extent_before after = $extent_after"
+	fi
+elif [ $extent_before -ne $extent_after ]; then
 	echo "extents mismatched before = $extent_before after = $extent_after"
 fi
 
-- 
2.55.0.rc0.786.g65d90a0328-goog