| 1 | //go:build linux |
| 2 | |
| 3 | package cgroup |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "errors" |
| 8 | "os" |
| 9 | "os/exec" |
| 10 | "path/filepath" |
| 11 | "strconv" |
| 12 | "syscall" |
| 13 | "testing" |
| 14 | "time" |
| 15 | ) |
| 16 | |
| 17 | // genParentFixture is strictFixture turned into a generation parent: the |
| 18 | // tier on its files, memory.oom.group=0, the record matching. |
| 19 | func genParentFixture(t *testing.T) *Prepared { |
| 20 | t.Helper() |
| 21 | p := strictFixture(t) |
| 22 | p.genParent, p.tier = true, TierDefault |
| 23 | for name, value := range tierExpected(TierDefault, "0") { |
| 24 | if err := strictWrite(p.limits[name], value); err != nil { |
| 25 | t.Fatal(err) |
| 26 | } |
| 27 | p.expected[name] = value |
| 28 | } |
| 29 | return p |
| 30 | } |
| 31 | |
| 32 | func makeGenFixture(t *testing.T, p *Prepared, n uint64, events string) string { |
| 33 | t.Helper() |
| 34 | d := filepath.Join(p.dir.Name(), GenChild(n)) |
| 35 | if err := os.Mkdir(d, 0o700); err != nil { |
| 36 | t.Fatal(err) |
| 37 | } |
| 38 | for name, v := range map[string]string{"cgroup.events": events, "cgroup.kill": "", "memory.max": "", "memory.high": "", "memory.swap.max": "", "memory.oom.group": ""} { |
| 39 | if err := os.WriteFile(filepath.Join(d, name), []byte(v), 0o600); err != nil { |
| 40 | t.Fatal(err) |
| 41 | } |
| 42 | } |
| 43 | return d |
| 44 | } |
| 45 | |
| 46 | func TestPrepareGenWritesTheFullTier(t *testing.T) { |
| 47 | p := genParentFixture(t) |
| 48 | d := makeGenFixture(t, p, 1, "populated 0\n") |
| 49 | child, err := p.PrepareGen(1, TierDefault) |
| 50 | if err != nil { |
| 51 | t.Fatal(err) |
| 52 | } |
| 53 | defer child.Close() |
| 54 | want := tierExpected(TierDefault, "1") |
| 55 | for name, value := range want { |
| 56 | if got := readFixture(t, filepath.Join(d, name)); got != value { |
| 57 | t.Errorf("g1/%s = %q, want %q", name, got, value) |
| 58 | } |
| 59 | } |
| 60 | if want["memory.max"] != "536870912" || want["memory.oom.group"] != "1" { |
| 61 | t.Fatalf("tierExpected = %v", want) |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | func TestPrepareGenReservesPerChild(t *testing.T) { |
| 66 | p := genParentFixture(t) |
| 67 | makeGenFixture(t, p, 1, "populated 0\n") |
| 68 | makeGenFixture(t, p, 2, "populated 0\n") |
| 69 | g1, err := p.PrepareGen(1, TierDefault) |
| 70 | if err != nil { |
| 71 | t.Fatal(err) |
| 72 | } |
| 73 | defer g1.Close() |
| 74 | if again, err := p.PrepareGen(1, TierDefault); !errors.Is(err, ErrStrictState) || again != nil { |
| 75 | t.Fatalf("second reservation of g1: %v", err) |
| 76 | } |
| 77 | g2, err := p.PrepareGen(2, TierDefault) |
| 78 | if err != nil { |
| 79 | t.Fatalf("g2 beside a live g1: %v", err) |
| 80 | } |
| 81 | defer g2.Close() |
| 82 | if _, err := p.PrepareGen(0, TierDefault); !errors.Is(err, ErrStrictRefused) { |
| 83 | t.Errorf("generation 0: %v", err) |
| 84 | } |
| 85 | if _, err := p.PrepareGen(3, Limit{MemoryMax: 64 << 20}); !errors.Is(err, ErrStrictRefused) { |
| 86 | t.Errorf("a limit that is not a tier: %v", err) |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | func TestPrepareGenAndSetParentLimitRefuseAPlainHostGroup(t *testing.T) { |
| 91 | p := strictFixture(t) |
| 92 | if _, err := p.PrepareGen(1, TierDefault); !errors.Is(err, ErrStrictState) { |
| 93 | t.Errorf("PrepareGen on a leaf host group: %v", err) |
| 94 | } |
| 95 | if err := p.SetParentLimit(TierDefault); !errors.Is(err, ErrStrictState) { |
| 96 | t.Errorf("SetParentLimit on a leaf host group: %v", err) |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | func TestGenerationParentRefusesAProcess(t *testing.T) { |
| 101 | p := genParentFixture(t) |
| 102 | if err := p.Start(exec.Command("/bin/true")); !errors.Is(err, ErrStrictState) { |
| 103 | t.Fatalf("a generation parent accepted a process: %v", err) |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | // The parent's record moves with the limit it raises, so a child's Start |
| 108 | // passes limitsOK after a raise; a limit set by anyone else fails it. |
| 109 | func TestSetParentLimitRecordsWhatItWrites(t *testing.T) { |
| 110 | p := genParentFixture(t) |
| 111 | makeGenFixture(t, p, 1, "populated 0\n") |
| 112 | makeGenFixture(t, p, 2, "populated 0\n") |
| 113 | child, err := p.PrepareGen(1, TierDefault) |
| 114 | if err != nil { |
| 115 | t.Fatal(err) |
| 116 | } |
| 117 | defer child.Close() |
| 118 | if err := p.SetParentLimit(OverlapLimit(TierDefault, TierDefault)); err != nil { |
| 119 | t.Fatal(err) |
| 120 | } |
| 121 | if got := readFixture(t, filepath.Join(p.dir.Name(), "memory.max")); got != "1073741824" { |
| 122 | t.Fatalf("parent memory.max = %q", got) |
| 123 | } |
| 124 | // The fixture's start answers ENOSYS: reaching it means every check passed. |
| 125 | child.start = func(*exec.Cmd) error { return syscall.ENOSYS } |
| 126 | if err := child.Start(exec.Command("/bin/true")); !errors.Is(err, ErrStrictUnsupported) { |
| 127 | t.Fatalf("child start after an API raise: %v, want it to reach the spawn", err) |
| 128 | } |
| 129 | // strictWrite does not truncate a fixture file: "9" over "1073741824" |
| 130 | // leaves "9073741824", a limit this API never set. |
| 131 | if err := strictWrite(p.limits["memory.max"], "9"); err != nil { |
| 132 | t.Fatal(err) |
| 133 | } |
| 134 | other, err := p.PrepareGen(2, TierDefault) |
| 135 | if err != nil { |
| 136 | t.Fatal(err) |
| 137 | } |
| 138 | defer other.Close() |
| 139 | if err := other.Start(exec.Command("/bin/true")); !errors.Is(err, ErrStrictRefused) { |
| 140 | t.Fatalf("child start under a limit the API did not set: %v", err) |
| 141 | } |
| 142 | if err := p.SetParentLimit(TierDefault); !errors.Is(err, ErrStrictRefused) { |
| 143 | t.Fatalf("SetParentLimit papered over a foreign limit: %v", err) |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | // Review focus 4: a release that changes tier. |
| 148 | func TestSetParentLimitAcceptsATierChange(t *testing.T) { |
| 149 | p := genParentFixture(t) |
| 150 | if err := p.SetParentLimit(OverlapLimit(TierDefault, TierChildren)); err != nil { |
| 151 | t.Fatalf("512M + 1G: %v", err) |
| 152 | } |
| 153 | if got := readFixture(t, filepath.Join(p.dir.Name(), "memory.max")); got != strconv.FormatInt(1536<<20, 10) { |
| 154 | t.Fatalf("parent memory.max = %q", got) |
| 155 | } |
| 156 | if err := p.SetParentLimit(Limit{MemoryMax: 64 << 20}); !errors.Is(err, ErrStrictRefused) { |
| 157 | t.Fatalf("a limit that is no tier sum: %v", err) |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | func TestGenerationKillAndEmptyTouchesOnlyItsChild(t *testing.T) { |
| 162 | p := genParentFixture(t) |
| 163 | d1 := makeGenFixture(t, p, 1, "populated 1\n") |
| 164 | d2 := makeGenFixture(t, p, 2, "populated 0\n") |
| 165 | g1, err := p.PrepareGen(1, TierDefault) |
| 166 | if err == nil { |
| 167 | t.Fatal("PrepareGen pinned a populated group") |
| 168 | } |
| 169 | _ = g1 |
| 170 | if err := os.WriteFile(filepath.Join(d1, "cgroup.events"), []byte("populated 0\n"), 0o600); err != nil { |
| 171 | t.Fatal(err) |
| 172 | } |
| 173 | if g1, err = p.PrepareGen(1, TierDefault); err != nil { |
| 174 | t.Fatal(err) |
| 175 | } |
| 176 | defer g1.Close() |
| 177 | g2, err := p.PrepareGen(2, TierDefault) |
| 178 | if err != nil { |
| 179 | t.Fatal(err) |
| 180 | } |
| 181 | ctx, cancel := context.WithTimeout(t.Context(), time.Second) |
| 182 | defer cancel() |
| 183 | if err := g2.KillAndEmpty(ctx); err != nil { |
| 184 | t.Fatal(err) |
| 185 | } |
| 186 | for dir, want := range map[string]string{d2: "1", d1: "", p.dir.Name(): ""} { |
| 187 | if got := readFixture(t, filepath.Join(dir, "cgroup.kill")); got != want { |
| 188 | t.Errorf("%s/cgroup.kill = %q, want %q", dir, got, want) |
| 189 | } |
| 190 | } |
| 191 | // CloseRemove: refused while populated; once empty it closes and frees |
| 192 | // the reservation even when rmdir fails (a fixture dir holds files). |
| 193 | if err := os.WriteFile(filepath.Join(d2, "cgroup.events"), []byte("populated 1\n"), 0o600); err != nil { |
| 194 | t.Fatal(err) |
| 195 | } |
| 196 | if err := g2.CloseRemove(); !errors.Is(err, ErrStrictRefused) { |
| 197 | t.Fatalf("CloseRemove of a populated child: %v", err) |
| 198 | } |
| 199 | if err := os.WriteFile(filepath.Join(d2, "cgroup.events"), []byte("populated 0\n"), 0o600); err != nil { |
| 200 | t.Fatal(err) |
| 201 | } |
| 202 | if err := g2.CloseRemove(); err == nil { |
| 203 | t.Fatal("rmdir of a fixture dir holding files reported success") |
| 204 | } |
| 205 | if _, err := g2.Populated(); !errors.Is(err, ErrStrictState) { |
| 206 | t.Fatalf("handle still open after CloseRemove: %v", err) |
| 207 | } |
| 208 | strictReservations.Lock() |
| 209 | held := strictReservations.held[g2.identity] |
| 210 | strictReservations.Unlock() |
| 211 | if held { |
| 212 | t.Fatal("reservation not released by CloseRemove") |
| 213 | } |
| 214 | // The directory survived its failed rmdir, but it took cgroup.kill, so |
| 215 | // it is never pinned for a spawn again (amadan #272). |
| 216 | if again, err := p.PrepareGen(2, TierDefault); !errors.Is(err, ErrStrictRefused) { |
| 217 | if again != nil { |
| 218 | again.Close() |
| 219 | } |
| 220 | t.Fatalf("re-pin of a killed generation child: %v, want ErrStrictRefused", err) |
| 221 | } |
| 222 | } |
| 223 | |
amadan