LU-17660 tests: test symlink file to existing dir

Create a test case to verify LU-17660.

Symlink a file to an existing dir. Expect the symlink entry
under dir. Error if report "cannot overwrite directory".

Fixed in kernels newer than v6.9-rc4-39-gbb32cded3be2 or with
a backported fix.

Signed-off-by: Feng Lei <flei@whamcloud.com>
Test-Parameters: trivial
Test-Parameters: clientdistro=el8.10 testlist=sanity env=ONLY=17p
Test-Parameters: clientdistro=el9.4 testlist=sanity env=ONLY=17p
Test-Parameters: clientdistro=sles15sp5 testlist=sanity env=ONLY=17p
Test-Parameters: clientdistro=sles15sp6 testlist=sanity env=ONLY=17p
Test-Parameters: clientdistro=ubuntu2204 testlist=sanity env=ONLY=17p
Test-Parameters: clientdistro=ubuntu2404 testlist=sanity env=ONLY=17p
Change-Id: I905813c26e78ae3e6df4f88af10ab3f0c596a59b
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56639
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>

diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index 0350bed..e07ea6f 100755 (executable)
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -803,6 +803,26 @@ test_17o() {
 }
 run_test 17o "stat file with incompat LMA feature"
 
+# LU-17660: "cannot overwrite directory" when creating symlink
+test_17p() {
+       touch $DIR/$tfile
+       test_mkdir $DIR/$tdir
+
+       # there is a kernel bug in el9.x series (9.0 - 9.4 as we know till now)
+       # kernel, we need to stat the target dir to cache it first
+       if [[ "$CLIENT_OS_ID_LIKE" =~ "rhel" ]]; then
+               if (( $CLIENT_OS_VERSION_CODE >= $(version_code 9.0) &&
+                     $CLIENT_OS_VERSION_CODE <= $(version_code 9.4) )); then
+                       echo "stat $DIR/$tdir to cache it in el9.0-9.4"
+                       stat $DIR/$tdir
+               fi
+       fi
+
+       strace ln -sf $DIR/$tfile $DIR/$tdir/ ||
+               error "Failed to create symlink $DIR/$tfile under $DIR/$tdir/"
+}
+run_test 17p "symlink overwrite directory error message"
+
 test_18() {
        touch $DIR/$tfile || error "Failed to touch $DIR/$tfile: $?"
        ls $DIR || error "Failed to ls $DIR: $?"