mathiasandClaude Opus 5.5
b6f7dac46e
Option 1 of #157, slice 2. readExcerpt (brain_context), api.ReadNote (brain_get / read-after-write) and notes.ReadScoped (brain_read) read the Syncthing-shared brain by path. Under a symlink swap race each leaked an outside file hundreds of thousands of times in 1.5s, including brain_read, whose Lstat check was raced by the reopen-by-name; a FIFO blocked os.ReadFile. - All three read through brainfs (os.Root, regular files only, non-blocking open, type check on the handle). - brainfs.ReadRegularMax checks a size limit on the opened handle; notes keeps its ErrTooLarge. - New internal/brainfs/brainfstest: the shared swap-race harness (symlink and held-writer FIFO swappers, awaited before TempDir cleanup; AssertNoLeak / AssertNoHang) for this and later slices. Tests red first: each reader under a symlink-swap race and a held-writer FIFO race, plus static checks. Flipped: readExcerpt back to os.ReadFile is red. Refs #157 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
106 lines
3.6 KiB
Go
106 lines
3.6 KiB
Go
package brainfs
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import (
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"errors"
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"os"
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"path/filepath"
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"syscall"
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"testing"
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"time"
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"github.com/stretchr/testify/assert"
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"github.com/stretchr/testify/require"
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)
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// The handle check is what stops a FIFO swapped in after the Lstat. A FIFO
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// with no writer reads EOF at once, so a race test could not see the check
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// missing; here a writer holds the FIFO open, as any local process can, and
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// readOpened must refuse it promptly (PR #161 review).
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func TestReadOpenedRefusesAFIFOHeldOpenByAWriter(t *testing.T) {
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dir := t.TempDir()
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fifo := filepath.Join(dir, "p.md")
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require.NoError(t, syscall.Mkfifo(fifo, 0o644))
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w, err := os.OpenFile(fifo, os.O_RDWR, 0)
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require.NoError(t, err)
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defer func() { _ = w.Close() }()
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b, err := Open(dir)
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require.NoError(t, err)
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defer func() { _ = b.Close() }()
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done := make(chan error, 1)
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go func() { _, err := b.readOpened("p.md"); done <- err }()
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select {
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case err := <-done:
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assert.True(t, errors.Is(err, ErrNotRegular), "got %v", err)
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case <-time.After(2 * time.Second):
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t.Fatal("readOpened blocked on a FIFO with a writer")
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}
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}
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func TestReadRegularRefusesSymlinksAndReadsRegularFiles(t *testing.T) {
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dir := t.TempDir()
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require.NoError(t, os.WriteFile(filepath.Join(dir, "ok.md"), []byte("ok"), 0o644))
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outside := filepath.Join(t.TempDir(), "s.md")
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require.NoError(t, os.WriteFile(outside, []byte("secret"), 0o644))
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require.NoError(t, os.Symlink(outside, filepath.Join(dir, "link.md")))
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b, err := Open(dir)
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require.NoError(t, err)
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defer func() { _ = b.Close() }()
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got, err := b.ReadRegular("ok.md")
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require.NoError(t, err)
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assert.Equal(t, "ok", string(got))
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_, err = b.ReadRegular("link.md")
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assert.True(t, errors.Is(err, ErrNotRegular), "got %v", err)
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_, err = b.ReadRegular("../" + filepath.Base(outside))
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assert.Error(t, err)
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}
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func TestRelAcceptsPathsInsideAndRefusesEscapes(t *testing.T) {
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dir := t.TempDir()
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b, err := Open(dir)
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require.NoError(t, err)
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defer func() { _ = b.Close() }()
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for in, want := range map[string]string{
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filepath.Join(dir, "wiki", "x.md"): "wiki/x.md",
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filepath.Join(dir, "..foo", "x"): "..foo/x",
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dir: ".",
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} {
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got, err := b.Rel(in)
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require.NoError(t, err, in)
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assert.Equal(t, want, got, in)
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}
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for _, bad := range []string{filepath.Join(dir, "..", "x"), dir + "-evil/x", "/etc/passwd", filepath.Join(dir, "wiki", "..", "..", "x")} {
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_, err := b.Rel(bad)
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assert.Error(t, err, bad)
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}
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}
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func TestWalkRegularYieldsOnlyRegularFiles(t *testing.T) {
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dir := t.TempDir()
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require.NoError(t, os.MkdirAll(filepath.Join(dir, "a"), 0o755))
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require.NoError(t, os.WriteFile(filepath.Join(dir, "a", "n.md"), []byte("n"), 0o644))
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require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(dir, "a", "dirlink")))
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require.NoError(t, os.Symlink(filepath.Join(dir, "a", "n.md"), filepath.Join(dir, "a", "filelink.md")))
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require.NoError(t, syscall.Mkfifo(filepath.Join(dir, "a", "p.md"), 0o644))
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b, err := Open(dir)
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require.NoError(t, err)
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defer func() { _ = b.Close() }()
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var got []string
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require.NoError(t, b.WalkRegular(".", func(rel string) error { got = append(got, rel); return nil }, nil))
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assert.Equal(t, []string{"a/n.md"}, got)
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}
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func TestReadRegularMaxRefusesAFileOverTheLimit(t *testing.T) {
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dir := t.TempDir()
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require.NoError(t, os.WriteFile(filepath.Join(dir, "big.md"), make([]byte, 100), 0o644))
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b, err := Open(dir)
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require.NoError(t, err)
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defer func() { _ = b.Close() }()
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_, err = b.ReadRegularMax("big.md", 99)
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assert.True(t, errors.Is(err, ErrTooLarge), "got %v", err)
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got, err := b.ReadRegularMax("big.md", 100)
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require.NoError(t, err)
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assert.Len(t, got, 100)
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}
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