TestFSOps: expect errno 0 but got is a directory

[zhoucheng361]

What happened:
https://github.com/juicedata/juicefs/actions/runs/13323319491/job/37211692074?pr=5573

=== RUN   TestFSOps
    random_test.go:2144: [rapid] failed after 4105 tests: expect errno 0 but got is a directory
        To reproduce, specify -run="TestFSOps" -rapid.failfile="testdata/rapid/TestFSOps/TestFSOps-20250214054809-17988.fail" (or -rapid.seed=8427566)
        Failed test output:
    random_test.go:126: [rapid] draw sid: 0x0
    random_test.go:2144: [rapid] draw action: "Mkdir"
    random_test.go:163: [rapid] draw uid: 0x0
    random_test.go:164: [rapid] draw gid: 0x0
    random_test.go:176: [rapid] draw node: 0x1
    random_test.go:1037: [rapid] draw name: "A"
    random_test.go:1038: [rapid] draw mode: 0x0
    random_test.go:1042: parent ino 1
    random_test.go:1046: dir ino 2
    random_test.go:2144: [rapid] draw action: "Mknod"
    random_test.go:163: [rapid] draw uid: 0x0
    random_test.go:164: [rapid] draw gid: 0x0
    random_test.go:176: [rapid] draw node: 0x1
    random_test.go:1057: [rapid] draw name: "?"
    random_test.go:1061: [rapid] draw type: 0x1
    random_test.go:1062: [rapid] draw mode: 0x0
    random_test.go:2144: [rapid] draw action: "Rename"
    random_test.go:1183: [rapid] draw name: "A"
    random_test.go:163: [rapid] draw uid: 0x0
    random_test.go:164: [rapid] draw gid: 0x0
    random_test.go:176: [rapid] draw node: 0x1
    random_test.go:421: [rapid] draw child: "?"
    random_test.go:163: [rapid] draw uid: 0x0
    random_test.go:164: [rapid] draw gid: 0x0
    random_test.go:176: [rapid] draw node: 0x1
    random_test.go:1221: expect errno 0 but got is a directory
--- FAIL: TestFSOps (39.67s)

What you expected to happen:

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?

Environment:

• JuiceFS version (use juicefs --version) or Hadoop Java SDK version:
• Cloud provider or hardware configuration running JuiceFS:
• OS (e.g cat /etc/os-release):
• Kernel (e.g. uname -a):
• Object storage (cloud provider and region, or self maintained):
• Metadata engine info (version, cloud provider managed or self maintained):
• Network connectivity (JuiceFS to metadata engine, JuiceFS to object storage):
• Others: