test code v1

tests/TC048-readdir-seek.md

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+# Test Case: Readdir Cookies and seekdir Resume
+
+**Test ID**: TC048-readdir-seek
+**Category**: Directory Operations
+**Priority**: Critical
+
+## Objective
+
+Verify every kernel d_off and libc telldir cookie resumes at the next exact
+entry; complete second traversals are not substitutes.
+
+## Procedure
+
+Mount metadata/namei-base.erofs and run:
+
+    ./readdir_probe /tmp/repo22-g3/mnt/wide 128 |
+      tee TC048-probe.out
+
+## Probe Contract
+
+The helper fails on non-increasing cookies, invalid records, duplicate names,
+kernel/libc order or type differences, a restart at the wrong next name, or a
+final cookie that does not reach EOF. Kernel d_off values are validated after
+reopen/lseek; each libc telldir value is passed back to seekdir on the same
+DIR stream that produced it, as required by the API contract.
+
+## Expected Results
+
+The helper exits zero and reports entries=322, d_off_restarts=322,
+seekdir_restarts=322, buffer=128, the type counts, and one FNV-1a name/type
+hash. Record literal output and cleanup.