generic: test creating and removing symlink xattrs

This began as a regression test for the issues identified in "xfs: allow
symlinks with short remote targets".  To summarize, the kernel XFS code
does not convert a remote symlink back to a shortform symlink after
deleting the attr fork.  Recent attempts to tighten validation have
flagged this incorrectly, so we need a regression test to focus on this
dusty corner of the codebase.

However, there's nothing in here that's xfs-specific so it's a generic
test.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zorro Lang <zlang@kernel.org>

diff --git a/tests/generic/754 b/tests/generic/754
new file mode 100755 (executable)
index 0000000..e0dcb86
--- /dev/null
+++ b/tests/generic/754
@@ -0,0 +1,58 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2024 Oracle.  All Rights Reserved.
+#
+# FS QA Test No. 754
+#
+# Test that we can add xattrs to a symbolic link, remove all the xattrs, and
+# that the symbolic link doesn't get corrupted.  This is a regression test for
+# some incorrect checks in the xfs inode verifier.
+#
+. ./common/preamble
+_begin_fstest auto
+
+_supported_fs generic
+_require_scratch
+
+test $FSTYP = "xfs" && \
+       _fixed_by_git_commit kernel XXXXXXXXXXXXX \
+                       "xfs: allow symlinks with short remote targets"
+
+_scratch_mkfs >> $seqres.full
+_scratch_mount >> $seqres.full
+
+SYMLINK_ADD="0123456789ABCDEF01234567890ABCDEF"
+
+# test from 32 to MAXPATHLEN sized symlink. This should make sure that
+# 256-1024 byte version 2 and 3 inodes are covered.
+SYMLINK=""
+for ((SIZE = 32; SIZE < 1024; SIZE += 32)); do
+       SYMLINK_FILE="$SCRATCH_MNT/symlink.$SIZE"
+       SYMLINK="${SYMLINK}${SYMLINK_ADD}"
+       ln -s $SYMLINK $SYMLINK_FILE > /dev/null 2>&1
+
+# add the extended attributes
+       attr  -Rs 1234567890ab $SYMLINK_FILE < /dev/null > /dev/null 2>&1
+       attr  -Rs 1234567890ac $SYMLINK_FILE < /dev/null > /dev/null 2>&1
+       attr  -Rs 1234567890ad $SYMLINK_FILE < /dev/null > /dev/null 2>&1
+# remove the extended attributes
+       attr  -Rr 1234567890ab $SYMLINK_FILE > /dev/null 2>&1
+       attr  -Rr 1234567890ac $SYMLINK_FILE > /dev/null 2>&1
+       attr  -Rr 1234567890ad $SYMLINK_FILE > /dev/null 2>&1
+done
+
+_scratch_cycle_mount
+
+# Now check the symlink target contents
+SYMLINK=""
+for ((SIZE = 32; SIZE < 1024; SIZE += 32)); do
+       SYMLINK_FILE="$SCRATCH_MNT/symlink.$SIZE"
+       SYMLINK="${SYMLINK}${SYMLINK_ADD}"
+
+       target="$(readlink $SYMLINK_FILE)"
+       test "$target" = "$SYMLINK" || echo "$SYMLINK_FILE: target is corrupt"
+done
+
+echo Silence is golden
+status=0
+exit

diff --git a/tests/generic/754.out b/tests/generic/754.out
new file mode 100644 (file)
index 0000000..9e7cda8
--- /dev/null
+++ b/tests/generic/754.out
@@ -0,0 +1,2 @@
+QA output created by 754
+Silence is golden