test(api): race the pdf/docmark temp-copy path too

PR #156 round 4: TextIn's pdf/docmark branch copies the file through the
root to a temp file, and pointing the extractor back at the raw/ path by
name stayed green (race tests used only r.md); a stub docmark then got
the outside file's bytes 34k times in 4s.

TestDocmarkExtractionLeaksNothingUnderASymlinkSwapRace races a symlink
into raw/r.docx through ReadIngestFile while a fake docmark counts the
sentinel in every document it receives. Flipped: the by-name revert is
red.

Refs #153

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ingestion/cmd/server/jwt_validator.go

@@ -1,25 +0,0 @@
-package main
-
-import (
-	"context"
-	"log/slog"
-
-	chassisauth "git.d-ma.be/mathias/mcp-chassis/auth"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/startupretry"
-)
-
-// buildJWTValidator runs OIDC discovery under policy, so a 502 from an auth
-// upstream that is not serving yet on a cold boot is retried instead of
-// exiting (#83). It honours ctx between attempts.
-func buildJWTValidator(
-	ctx context.Context, logger *slog.Logger, issuer, audience string, policy startupretry.Policy,
-) (*chassisauth.JWTValidator, error) {
-	return startupretry.Do(ctx, policy, func(ctx context.Context) (*chassisauth.JWTValidator, error) {
-		v, err := chassisauth.NewJWTValidator(ctx, issuer, audience)
-		if err != nil {
-			logger.Warn("oidc discovery not ready, retrying", "err", err)
-		}
-		return v, err
-	})
-}

ingestion/cmd/server/jwt_validator_test.go

@@ -1,86 +0,0 @@
-package main
-
-import (
-	"context"
-	"io"
-	"log/slog"
-	"net/http"
-	"net/http/httptest"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/startupretry"
-)
-
-// fakeIssuer answers OIDC discovery with 502 for the first fail requests, as
-// ingress does while dex is not yet serving on a cold boot (#83), then with a
-// real discovery document and an empty JWKS.
-func fakeIssuer(t *testing.T, fail int32) (*httptest.Server, *atomic.Int32) {
-	t.Helper()
-	var discoveries atomic.Int32
-	mux := http.NewServeMux()
-	var srv *httptest.Server
-	mux.HandleFunc("/.well-known/openid-configuration", func(w http.ResponseWriter, _ *http.Request) {
-		if discoveries.Add(1) <= fail {
-			w.WriteHeader(http.StatusBadGateway)
-			return
-		}
-		w.Header().Set("Content-Type", "application/json")
-		_, _ = io.WriteString(w, `{"issuer":"`+srv.URL+`","jwks_uri":"`+srv.URL+`/keys"}`)
-	})
-	mux.HandleFunc("/keys", func(w http.ResponseWriter, _ *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		_, _ = io.WriteString(w, `{"keys":[]}`)
-	})
-	srv = httptest.NewServer(mux)
-	t.Cleanup(srv.Close)
-	return srv, &discoveries
-}
-
-var fastPolicy = startupretry.Policy{Attempts: 8, Base: time.Millisecond, Max: 5 * time.Millisecond}
-
-func TestBuildJWTValidatorRetriesDiscovery502sThenSucceeds(t *testing.T) {
-	srv, discoveries := fakeIssuer(t, 3)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	v, err := buildJWTValidator(ctx, slog.New(slog.DiscardHandler), srv.URL, "brain", fastPolicy)
-	require.NoError(t, err)
-	assert.NotNil(t, v)
-	assert.Equal(t, int32(4), discoveries.Load(), "three 502s, then the successful discovery")
-}
-
-func TestBuildJWTValidatorGivesUpAfterTheBudgetWithTheLastError(t *testing.T) {
-	srv, discoveries := fakeIssuer(t, 1000)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	_, err := buildJWTValidator(ctx, slog.New(slog.DiscardHandler), srv.URL, "brain", fastPolicy)
-	require.Error(t, err)
-	assert.Contains(t, err.Error(), "status 502")
-	assert.Equal(t, int32(8), discoveries.Load(), "bounded: exactly the attempt budget")
-}
-
-func TestBuildJWTValidatorStopsRetryingWhenTheContextIsCancelled(t *testing.T) {
-	srv, _ := fakeIssuer(t, 1000)
-	ctx, cancel := context.WithCancel(context.Background())
-	slow := startupretry.Policy{Attempts: 8, Base: time.Hour, Max: time.Hour}
-
-	done := make(chan error, 1)
-	go func() {
-		_, err := buildJWTValidator(ctx, slog.New(slog.DiscardHandler), srv.URL, "brain", slow)
-		done <- err
-	}()
-	time.Sleep(50 * time.Millisecond)
-	cancel()
-	select {
-	case err := <-done:
-		assert.ErrorIs(t, err, context.Canceled)
-	case <-time.After(3 * time.Second):
-		t.Fatal("did not return after the context was cancelled")
-	}
-}

ingestion/cmd/server/main.go

@@ -33,7 +33,6 @@ import (
 	"github.com/mathiasbq/hyperguild/ingestion/internal/reranker"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/search"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/startupretry"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/symlinkguard"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/vectorstore"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/watcher"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/webhook"
@@ -174,8 +173,7 @@ func alertingWarnings(getenv func(string) string) []string {
 	var out []string
 	if getenv("BRAIN_NTFY_URL") == "" {
 		out = append(out, "alerting DISABLED: BRAIN_NTFY_URL unset — "+
-			"brain_edit_root governance rewrites, capture audit degradation and the "+
+			"brain_edit_root governance rewrites and capture audit degradation will not notify")
-			"brain symlink tripwire (hyperguild#157) will not notify")
 	}
 	return out
 }
@@ -241,10 +239,6 @@ func main() {
 	}
 
 	brainDir := envOr("INGEST_BRAIN_DIR", "../brain")
-	if err := startupSymlinkCheck(brainDir); err != nil {
-		logger.Error("brain symlink tripwire", "err", err)
-		os.Exit(1)
-	}
 	port := envOr("INGEST_PORT", "3300")
 
 	llmURL := envOr("INGEST_LLM_URL", "http://iguana:4000/v1")
@@ -366,8 +360,6 @@ func main() {
 	}
 
 	ctx := context.Background()
-	// hyperguild#157: report a symlink that appears in the brain while running.
-	go symlinkguard.Watch(ctx, brainDir, symlinkScanInterval(os.Getenv), buildNotifier())
 
 	// Built before the watcher, the graph backfill and session ingestion, and
 	// retried rather than fatal (#83). Two separate reasons:
@@ -381,9 +373,15 @@ func main() {
 	//
 	// The budget stays bounded: retrying forever would turn a misconfiguration
 	// into a process that looks alive and never serves.
-	jwtValidator, err := buildJWTValidator(ctx, logger,
+	jwtValidator, err := startupretry.Do(ctx,
-		os.Getenv("DEX_ISSUER_URL"), os.Getenv("MCP_AUDIENCE"),
+		startupretry.Policy{Attempts: 8, Base: time.Second, Max: 30 * time.Second},
-		startupretry.Policy{Attempts: 8, Base: time.Second, Max: 30 * time.Second})
+		func(ctx context.Context) (*chassisauth.JWTValidator, error) {
+			v, err := chassisauth.NewJWTValidator(ctx, os.Getenv("DEX_ISSUER_URL"), os.Getenv("MCP_AUDIENCE"))
+			if err != nil {
+				logger.Warn("oidc discovery not ready, retrying", "err", err)
+			}
+			return v, err
+		})
 	if err != nil {
 		logger.Error("build jwt validator", "err", err)
 		os.Exit(1)

ingestion/cmd/server/symlink_check.go

@@ -1,39 +0,0 @@
-package main
-
-import (
-	"errors"
-	"fmt"
-	"os"
-	"strconv"
-	"time"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/symlinkguard"
-)
-
-// startupSymlinkCheck is the hyperguild#157 tripwire at boot: a symlink in the
-// brain dir would let brain readers serve a file from outside the brain, so
-// the server does not start until it is removed. A directory the scan cannot
-// read could hide one, so it refuses on that too. A missing brain dir (first
-// boot) is the only case it lets pass.
-func startupSymlinkCheck(brainDir string) error {
-	r, err := symlinkguard.Scan(brainDir)
-	if err != nil {
-		if errors.Is(err, os.ErrNotExist) {
-			return nil
-		}
-		return fmt.Errorf("refusing to start: cannot scan the brain dir %s (hyperguild#157): %w", brainDir, err)
-	}
-	if !r.Clean() {
-		return fmt.Errorf("refusing to start: brain dir %s has %s (hyperguild#157); fix them first", brainDir, r)
-	}
-	return nil
-}
-
-// symlinkScanInterval reads BRAIN_SYMLINK_SCAN_INTERVAL (seconds), falling
-// back to the default on an unset, non-numeric or non-positive value.
-func symlinkScanInterval(getenv func(string) string) time.Duration {
-	if s, err := strconv.Atoi(getenv("BRAIN_SYMLINK_SCAN_INTERVAL")); err == nil && s > 0 {
-		return time.Duration(s) * time.Second
-	}
-	return symlinkguard.DefaultInterval
-}

ingestion/cmd/server/symlink_check_test.go

@@ -1,65 +0,0 @@
-package main
-
-import (
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// hyperguild#157: the server refuses to start while a symlink exists in the
-// brain dir, or while any part of it cannot be scanned (which could hide
-// one); a missing brain dir is the only thing it lets pass.
-func TestStartupSymlinkCheckRefusesABrainWithASymlink(t *testing.T) {
-	brain := t.TempDir()
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "planted")))
-	err := startupSymlinkCheck(brain)
-	require.Error(t, err)
-	assert.Contains(t, err.Error(), "planted")
-}
-
-func TestStartupSymlinkCheckRefusesABrainWithAnUnreadableDir(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root reads mode-000 directories")
-	}
-	brain := t.TempDir()
-	locked := filepath.Join(brain, "aaa")
-	require.NoError(t, os.MkdirAll(locked, 0o755))
-	require.NoError(t, os.Chmod(locked, 0o000))
-	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })
-	err := startupSymlinkCheck(brain)
-	require.Error(t, err)
-	assert.Contains(t, err.Error(), "aaa")
-}
-
-func TestStartupSymlinkCheckPassesACleanOrMissingBrain(t *testing.T) {
-	brain := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(brain, "n.md"), []byte("x"), 0o644))
-	assert.NoError(t, startupSymlinkCheck(brain))
-	assert.NoError(t, startupSymlinkCheck(filepath.Join(brain, "missing")))
-}
-
-func TestSymlinkScanIntervalFallsBackOnNonPositive(t *testing.T) {
-	for _, v := range []string{"0", "-5", "", "junk"} {
-		got := symlinkScanInterval(func(string) string { return v })
-		assert.Positive(t, got, "env %q", v)
-	}
-}
-
-func TestAlertingWarningsNamesTheSymlinkTripwire(t *testing.T) {
-	w := strings.Join(alertingWarnings(func(string) string { return "" }), " ")
-	assert.Contains(t, w, "symlink tripwire")
-}
-
-func TestStartupSymlinkCheckRefusesAnUnlistableBrainRoot(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root lists mode-0100 directories")
-	}
-	brain := t.TempDir()
-	require.NoError(t, os.Chmod(brain, 0o100))
-	t.Cleanup(func() { _ = os.Chmod(brain, 0o755) })
-	assert.Error(t, startupSymlinkCheck(brain))
-}

ingestion/go.mod

@@ -34,9 +34,9 @@ require (
 	github.com/rogpeppe/go-internal v1.15.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
-	golang.org/x/net v0.55.0 // indirect
+	golang.org/x/net v0.26.0 // indirect
 	golang.org/x/oauth2 v0.21.0 // indirect
-	golang.org/x/term v0.43.0 // indirect
+	golang.org/x/term v0.28.0 // indirect
 	golang.org/x/time v0.3.0 // indirect
 	google.golang.org/protobuf v1.34.2 // indirect
 	gopkg.in/evanphx/json-patch.v4 v4.12.0 // indirect
@@ -66,9 +66,9 @@ require (
 	github.com/lestrrat-go/option v1.0.1 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/segmentio/asm v1.2.0 // indirect
-	golang.org/x/crypto v0.51.0 // indirect
+	golang.org/x/crypto v0.32.0 // indirect
-	golang.org/x/sync v0.21.0 // indirect
+	golang.org/x/sync v0.17.0 // indirect
-	golang.org/x/sys v0.45.0 // indirect
+	golang.org/x/sys v0.31.0 // indirect
-	golang.org/x/text v0.39.0 // indirect
+	golang.org/x/text v0.29.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1
 )

ingestion/go.sum

@@ -117,42 +117,42 @@ github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9dec
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.51.0 h1:IBPXwPfKxY7cWQZ38ZCIRPI50YLeevDLlLnyC5wRGTI=
+golang.org/x/crypto v0.32.0 h1:euUpcYgM8WcP71gNpTqQCn6rC2t6ULUPiOzfWaXVVfc=
-golang.org/x/crypto v0.51.0/go.mod h1:8AdwkbraGNABw2kOX6YFPs3WM22XqI4EXEd8g+x7Oc8=
+golang.org/x/crypto v0.32.0/go.mod h1:ZnnJkOaASj8g0AjIduWNlq2NRxL0PlBrbKVyZ6V/Ugc=
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
-golang.org/x/net v0.55.0 h1:bcvxaJn3e1U6InsFWt1JUq1aSjnRxLzT2rtD2KfkDF8=
+golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
-golang.org/x/net v0.55.0/go.mod h1:L5U2KuzuOe1lY7Z+aWVIKK6qEeJXnXV9yzGA+WCHJww=
+golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
 golang.org/x/oauth2 v0.21.0 h1:tsimM75w1tF/uws5rbeHzIWxEqElMehnc+iW793zsZs=
 golang.org/x/oauth2 v0.21.0/go.mod h1:XYTD2NtWslqkgxebSiOHnXEap4TF09sJSc7H1sXbhtI=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.21.0 h1:HLII4xRRTtCRkxYp4HNFF0Js/Og6q2i++KXbg0gHCwM=
+golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
-golang.org/x/sync v0.21.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
+golang.org/x/sync v0.17.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.45.0 h1:dO4czNzziLiiXplLQgBCEpCvXQ3dnkn0SdaZSYdQ+FY=
+golang.org/x/sys v0.31.0 h1:ioabZlmFYtWhL+TRYpcnNlLwhyxaM9kWTDEmfnprqik=
-golang.org/x/sys v0.45.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/sys v0.31.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/term v0.43.0 h1:S4RLU2sB31O/NCl+zFN9Aru9A/Cq2aqKpTZJ6B+DwT4=
+golang.org/x/term v0.28.0 h1:/Ts8HFuMR2E6IP/jlo7QVLZHggjKQbhu/7H0LJFr3Gg=
-golang.org/x/term v0.43.0/go.mod h1:lrhlHNdQJHO+1qVYiHfFKVuVioJIheAc3fBSMFYEIsk=
+golang.org/x/term v0.28.0/go.mod h1:Sw/lC2IAUZ92udQNf3WodGtn4k/XoLyZoh8v/8uiwek=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.39.0 h1:UbZz4pLOvn600D6Oh6GGEI6VAmndrEBLv8/6BEXzyus=
+golang.org/x/text v0.29.0 h1:1neNs90w9YzJ9BocxfsQNHKuAT4pkghyXc4nhZ6sJvk=
-golang.org/x/text v0.39.0/go.mod h1:3UwRclnC2g0TU9x8PZiyfOajCd1zaUNHF9cvqcQZ+ZM=
+golang.org/x/text v0.29.0/go.mod h1:7MhJOA9CD2qZyOKYazxdYMF85OwPdEr9jTtBpO7ydH4=
 golang.org/x/time v0.3.0 h1:rg5rLMjNzMS1RkNLzCG38eapWhnYLFYXDXj2gOlr8j4=
 golang.org/x/time v0.3.0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20200619180055-7c47624df98f/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20210106214847-113979e3529a/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
-golang.org/x/tools v0.47.0 h1:7Kn5x/d1svx/PzryTsqeoZN4TZwqeH5pGWjefhLi/1Q=
+golang.org/x/tools v0.36.0 h1:kWS0uv/zsvHEle1LbV5LE8QujrxB3wfQyxHfhOk0Qkg=
-golang.org/x/tools v0.47.0/go.mod h1:dFHnyTvFWY212G+h7ZY4Vsp/K3U4/7W9TyVaAul8uCA=
+golang.org/x/tools v0.36.0/go.mod h1:WBDiHKJK8YgLHlcQPYQzNCkUxUypCaa5ZegCVutKm+s=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

ingestion/internal/api/raw_race_test.go

@@ -8,7 +8,6 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
-	"sync"
 	"sync/atomic"
 	"syscall"
 	"testing"
@@ -26,18 +25,6 @@ import (
 
 const raceSentinel = "SENTINEL-153-RACE"
 
-// startSwapper runs fn until the test ends, and waits for it to exit before
-// t.TempDir's cleanup removes the directory it writes into (hyperguild#162:
-// an unawaited swapper raced the cleanup, "directory not empty").
-func startSwapper(t *testing.T, fn func(stop *atomic.Bool)) {
-	t.Helper()
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() { defer wg.Done(); fn(&stop) }()
-	t.Cleanup(func() { stop.Store(true); wg.Wait() })
-}
-
 func swap(raw, outside string, fifo bool, stop *atomic.Bool) {
 	tgt := filepath.Join(raw, "r.md")
 	for i := 0; !stop.Load(); i++ {
@@ -89,7 +76,9 @@ func readers(brain, raw string) string {
 
 func TestRawReadersLeakNothingUnderASymlinkSwapRace(t *testing.T) {
 	brain, raw, outside := raceBrain(t)
-	startSwapper(t, func(stop *atomic.Bool) { swap(raw, outside, false, stop) })
+	var stop atomic.Bool
+	go swap(raw, outside, false, &stop)
+	defer stop.Store(true)
 	leaks, iters := 0, 0
 	for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); iters++ {
 		leaks += strings.Count(readers(brain, raw), raceSentinel)
@@ -102,7 +91,8 @@ func TestRawReadersLeakNothingUnderASymlinkSwapRace(t *testing.T) {
 
 func TestRawReadersDoNotHangUnderAFIFOSwapRace(t *testing.T) {
 	brain, raw, outside := raceBrain(t)
-	startSwapper(t, func(stop *atomic.Bool) { swap(raw, outside, true, stop) })
+	var stop atomic.Bool
+	go swap(raw, outside, true, &stop)
 	var iters atomic.Int64
 	done := make(chan struct{})
 	go func() {
@@ -114,7 +104,9 @@ func TestRawReadersDoNotHangUnderAFIFOSwapRace(t *testing.T) {
 	}()
 	select {
 	case <-done:
+		stop.Store(true)
 	case <-time.After(6 * time.Second):
+		stop.Store(true)
 		// Unblock the stuck open so the test process can exit.
 		if f, err := os.OpenFile(filepath.Join(raw, "r.md"), os.O_WRONLY|syscall.O_NONBLOCK, 0); err == nil {
 			_ = f.Close()
@@ -155,7 +147,8 @@ func TestDocmarkExtractionLeaksNothingUnderASymlinkSwapRace(t *testing.T) {
 	if err := os.WriteFile(tgt, []byte("inside docx bytes"), 0o644); err != nil {
 		t.Fatal(err)
 	}
-	startSwapper(t, func(stop *atomic.Bool) {
+	var stop atomic.Bool
+	go func() {
 		for i := 0; !stop.Load(); i++ {
 			tmp := filepath.Join(raw, ".swapdocx")
 			_ = os.Remove(tmp)
@@ -166,7 +159,8 @@ func TestDocmarkExtractionLeaksNothingUnderASymlinkSwapRace(t *testing.T) {
 			}
 			_ = os.Rename(tmp, tgt)
 		}
-	})
+	}()
+	defer stop.Store(true)
 	iters := 0
 	for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); iters++ {
 		_, _ = api.ReadIngestFile(brain, tgt)

ingestion/internal/api/readnote_root_test.go

@@ -1,43 +0,0 @@
-package api_test
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/api"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-)
-
-// hyperguild#157 slice 2: ReadNote (brain_get, read-after-write) read by
-// path; it now reads through brainfs.
-func TestReadNoteRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "leak.md")))
-	_, body, _, err := api.ReadNote(brain, "wiki/w/facts/leak.md")
-	assert.Error(t, err)
-	assert.NotContains(t, body, brainfstest.Sentinel)
-
-	p := filepath.Join(facts, "r.md")
-	require.NoError(t, os.WriteFile(p, []byte("---\nx: y\n---\ninside"), 0o644))
-	fm, body, _, err := api.ReadNote(brain, "wiki/w/facts/r.md")
-	require.NoError(t, err)
-	assert.Equal(t, "y", fm["x"])
-	assert.Contains(t, body, "inside")
-	read := func() string {
-		fm, body, _, _ := api.ReadNote(brain, "wiki/w/facts/r.md")
-		s := body
-		for k, v := range fm {
-			s += k + v
-		}
-		return s
-	}
-	brainfstest.AssertNoLeak(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, read)
-	brainfstest.AssertNoHang(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, 6*time.Second, func() { _ = read() })
-}

ingestion/internal/api/update.go

@@ -4,7 +4,6 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"fmt"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 	"os"
 	"path/filepath"
 	"strings"
@@ -175,17 +174,11 @@ func UpdateNote(brainDir string, opts UpdateNoteOptions) (relPath, contentHash,
 // write primitive behind brain_get: the hash it returns equals the hash
 // brain_write / brain_update returned for the same bytes.
 func ReadNote(brainDir, relPath string) (fm map[string]string, body, contentHash string, err error) {
-	rel, _, err := resolveWithin(brainDir, relPath)
+	_, abs, err := resolveWithin(brainDir, relPath)
 	if err != nil {
 		return nil, "", "", err
 	}
-	// Through the brain root, regular files only (hyperguild#157).
+	raw, err := os.ReadFile(abs)
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return nil, "", "", fmt.Errorf("read note: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
-	raw, err := bfs.ReadRegular(rel)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return nil, "", "", fmt.Errorf("note %q does not exist", relPath)

ingestion/internal/audit/ntfy.go

@@ -49,19 +49,7 @@ func (n *NtfyNotifier) Notify(ctx context.Context, msg string) error {
 	}
 	defer func() { _ = resp.Body.Close() }()
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		return &RejectedError{Status: resp.StatusCode}
+		return fmt.Errorf("ntfy notify: status %d", resp.StatusCode)
 	}
 	return nil
 }
-
-// RejectedError is a non-2xx ntfy response.
-type RejectedError struct{ Status int }
-
-func (e *RejectedError) Error() string { return fmt.Sprintf("ntfy notify: status %d", e.Status) }
-
-// Permanent reports whether resending the same message cannot succeed: a 4xx
-// other than 429 (rate limited). Callers may drop such a message; anything
-// else (5xx, 429, transport errors) is an outage and must be retried.
-func (e *RejectedError) Permanent() bool {
-	return e.Status >= 400 && e.Status < 500 && e.Status != http.StatusTooManyRequests
-}

ingestion/internal/audit/ntfy_rejected_test.go

@@ -1,27 +0,0 @@
-package audit
-
-import (
-	"context"
-	"errors"
-	"net/http"
-	"net/http/httptest"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// A non-2xx ntfy response is a *RejectedError, and only a client-side refusal
-// other than rate limiting is permanent: callers may drop a message on a
-// permanent rejection and must retry the rest (hyperguild#157, PR #160).
-func TestNotifyClassifiesRejectionsAsPermanentOrNot(t *testing.T) {
-	for status, permanent := range map[int]bool{413: true, 400: true, 403: true, 429: false, 500: false, 503: false} {
-		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(status) }))
-		err := NewNtfyNotifier(srv.URL, "").Notify(context.Background(), "m")
-		srv.Close()
-		var rej *RejectedError
-		require.True(t, errors.As(err, &rej), "status %d: %v", status, err)
-		assert.Equal(t, status, rej.Status)
-		assert.Equal(t, permanent, rej.Permanent(), "status %d", status)
-	}
-}

ingestion/internal/brainfs/brainfs.go

@@ -1,230 +0,0 @@
-// Package brainfs reads the brain directory through an os.Root (hyperguild#157).
-// The brain dir is a Syncthing sendreceive folder and Syncthing syncs
-// symlinks; a reader that walks and reads by path follows a planted symlink
-// out of the brain, and blocks forever on a planted FIFO. Readers that go
-// through a Brain only ever read regular files inside the brain: os.Root
-// refuses to leave the root even if an entry is swapped mid-read, and every
-// open is non-blocking with the type checked on the opened handle.
-package brainfs
-
-import (
-	"errors"
-	"fmt"
-	"io"
-	"io/fs"
-	"os"
-	"path"
-	"path/filepath"
-	"strings"
-	"syscall"
-)
-
-// ErrNotRegular is returned for an entry that is not a regular file.
-var ErrNotRegular = errors.New("not a regular file")
-
-// ErrTooLarge is returned by ReadRegularMax for a file over the limit.
-var ErrTooLarge = errors.New("file too large")
-
-// Brain is an open brain directory.
-type Brain struct {
-	root *os.Root
-	dir  string
-}
-
-// Open opens brainDir (which may itself be a mount symlink) as a root.
-func Open(brainDir string) (*Brain, error) {
-	r, err := os.OpenRoot(brainDir)
-	if err != nil {
-		return nil, fmt.Errorf("open brain root: %w", err)
-	}
-	return &Brain{root: r, dir: brainDir}, nil
-}
-
-// Close releases the root.
-func (b *Brain) Close() error { return b.root.Close() }
-
-// Rel converts a path under the brain dir to a root-relative path.
-func (b *Brain) Rel(path string) (string, error) {
-	rel, err := filepath.Rel(b.dir, path)
-	if err != nil {
-		return "", err
-	}
-	if rel == ".." || len(rel) > 2 && rel[:3] == ".."+string(filepath.Separator) {
-		return "", fmt.Errorf("%s is outside the brain dir", path)
-	}
-	return filepath.ToSlash(rel), nil
-}
-
-// Lstat stats a brain-relative path through the root without following a
-// final symlink.
-func (b *Brain) Lstat(rel string) (fs.FileInfo, error) {
-	return b.root.Lstat(filepath.ToSlash(rel))
-}
-
-// realDir returns ErrNotRegular unless every component of rel is a real
-// directory. A swap after the check is not caught (accepted residual,
-// hyperguild#157).
-func (b *Brain) realDir(rel string) error {
-	if rel == "." {
-		return nil
-	}
-	prefix := ""
-	for _, part := range strings.Split(rel, "/") {
-		prefix = path.Join(prefix, part)
-		fi, err := b.root.Lstat(prefix)
-		if err != nil {
-			return err
-		}
-		if !fi.IsDir() {
-			return fmt.Errorf("%s: walk root component %s is not a directory: %w", rel, prefix, ErrNotRegular)
-		}
-	}
-	return nil
-}
-
-// ReadDirRegular lists the regular files directly in a brain-relative
-// directory, by name. Every component of relDir must be a real directory
-// (ErrNotRegular otherwise); symlinks, FIFOs, devices and subdirectories in
-// it are left out.
-func (b *Brain) ReadDirRegular(relDir string) ([]string, error) {
-	relDir = filepath.ToSlash(relDir)
-	if err := b.realDir(relDir); err != nil {
-		return nil, err
-	}
-	ents, err := fs.ReadDir(b.root.FS(), relDir)
-	if err != nil {
-		return nil, err
-	}
-	var names []string
-	for _, e := range ents {
-		if e.Type().IsRegular() {
-			names = append(names, e.Name())
-		}
-	}
-	return names, nil
-}
-
-// ReadRegular reads a brain-relative path, refusing anything that is not a
-// regular file, both before the open and on the opened handle.
-func (b *Brain) ReadRegular(rel string) ([]byte, error) {
-	fi, err := b.root.Lstat(rel)
-	if err != nil {
-		return nil, err
-	}
-	if !fi.Mode().IsRegular() {
-		return nil, fmt.Errorf("%s: %w", rel, ErrNotRegular)
-	}
-	return b.readOpenedMax(rel, -1, fi)
-}
-
-// readOpened opens rel non-blocking and reads it only if the OPENED handle is
-// a regular file. This is the check that matters under a race: an entry
-// swapped for a FIFO after the Lstat, with a writer holding it open, would
-// otherwise park io.ReadAll forever (PR #161 review: removing it hung search
-// after 16 iterations).
-//
-// Accepted residual, as in api/rawroot.go: a HARD link to an outside file is
-// a regular file and is read. Syncthing syncs contents, not links, so a peer
-// cannot create one; fs.protected_hardlinks=1 and the pod's secrets are on a
-// different filesystem from the brain volume, so a local caller cannot link
-// them in. Refusing Nlink > 1 is the next step if either changes.
-func (b *Brain) readOpened(rel string) ([]byte, error) { return b.readOpenedMax(rel, -1, nil) }
-
-// ReadRegularMax is ReadRegular with a size limit, checked on the opened
-// handle before reading (max < 0 means no limit).
-func (b *Brain) ReadRegularMax(rel string, max int64) ([]byte, error) {
-	fi, err := b.root.Lstat(rel)
-	if err != nil {
-		return nil, err
-	}
-	if !fi.Mode().IsRegular() {
-		return nil, fmt.Errorf("%s: %w", rel, ErrNotRegular)
-	}
-	return b.readOpenedMax(rel, max, fi)
-}
-
-// readOpenedMax opens rel and reads it if the opened handle is a regular file
-// and, when lfi is set, the same file the caller Lstat-ed: os.Root follows an
-// in-root final symlink even with O_NOFOLLOW, so a symlink to another brain
-// file swapped in between the Lstat and the open is refused only here.
-func (b *Brain) readOpenedMax(rel string, max int64, lfi fs.FileInfo) ([]byte, error) {
-	f, err := b.root.OpenFile(rel, os.O_RDONLY|syscall.O_NONBLOCK, 0)
-	if err != nil {
-		return nil, err
-	}
-	defer func() { _ = f.Close() }()
-	hfi, err := f.Stat()
-	if err != nil {
-		return nil, err
-	}
-	if !hfi.Mode().IsRegular() {
-		return nil, fmt.Errorf("%s: %w", rel, ErrNotRegular)
-	}
-	if lfi != nil && !os.SameFile(lfi, hfi) {
-		return nil, fmt.Errorf("%s: changed while opening: %w", rel, ErrNotRegular)
-	}
-	if max >= 0 && hfi.Size() > max {
-		return nil, fmt.Errorf("%s is %d bytes (limit %d): %w", rel, hfi.Size(), max, ErrTooLarge)
-	}
-	var r io.Reader = f
-	if wrapAfterStat != nil {
-		r = wrapAfterStat(r)
-	}
-	if max < 0 {
-		return io.ReadAll(r)
-	}
-	// The handle's size can grow after the check; bound the read itself.
-	data, err := io.ReadAll(io.LimitReader(r, max+1))
-	if err != nil {
-		return nil, err
-	}
-	if int64(len(data)) > max {
-		return nil, fmt.Errorf("%s grew past %d bytes while read: %w", rel, max, ErrTooLarge)
-	}
-	return data, nil
-}
-
-// wrapAfterStat is a test seam: it runs between the size check and the read,
-// and wraps the reader the read consumes. A package global: brainfs tests
-// must not use t.Parallel.
-var wrapAfterStat func(io.Reader) io.Reader
-
-// WalkRegular walks a brain-relative directory through the root and calls fn
-// for each regular file. Directories are descended; symlinks, FIFOs and
-// devices found by the walk are skipped. A walk root with any component that
-// is not a real directory goes to onErr as ErrNotRegular and nothing is
-// yielded. An entry error is passed to onErr and the walk continues; a nil
-// onErr ignores it.
-//
-// Accepted residual (hyperguild#157): a directory swapped for a symlink
-// between the listing and the read is followed. os.Root still keeps the read
-// inside the brain, but not inside relDir.
-func (b *Brain) WalkRegular(relDir string, fn func(rel string) error, onErr func(rel string, err error)) error {
-	relDir = filepath.ToSlash(relDir)
-	// fs.WalkDir stats its root with a follow, and os.Root allows a symlink
-	// that stays inside the brain: knowledge -> . would alias the whole
-	// brain. Require every component of the root to be a real directory
-	// (Lstat checks only the last one).
-	err := b.realDir(relDir)
-	if err != nil {
-		if onErr != nil {
-			onErr(relDir, err)
-		}
-		return nil
-	}
-	return fs.WalkDir(b.root.FS(), relDir, func(p string, d fs.DirEntry, err error) error {
-		if err != nil {
-			if onErr != nil {
-				onErr(p, err)
-			}
-			if d != nil && d.IsDir() {
-				return fs.SkipDir
-			}
-			return nil
-		}
-		if d.IsDir() || !d.Type().IsRegular() {
-			return nil
-		}
-		return fn(p)
-	})
-}

ingestion/internal/brainfs/brainfs_test.go

@@ -1,264 +0,0 @@
-package brainfs
-
-import (
-	"errors"
-	"io"
-	"io/fs"
-	"os"
-	"path/filepath"
-	"sync"
-	"sync/atomic"
-	"syscall"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// The handle check is what stops a FIFO swapped in after the Lstat. A FIFO
-// with no writer reads EOF at once, so a race test could not see the check
-// missing; here a writer holds the FIFO open, as any local process can, and
-// readOpened must refuse it promptly (PR #161 review).
-func TestReadOpenedRefusesAFIFOHeldOpenByAWriter(t *testing.T) {
-	dir := t.TempDir()
-	fifo := filepath.Join(dir, "p.md")
-	require.NoError(t, syscall.Mkfifo(fifo, 0o644))
-	w, err := os.OpenFile(fifo, os.O_RDWR, 0)
-	require.NoError(t, err)
-	defer func() { _ = w.Close() }()
-
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-
-	done := make(chan error, 1)
-	go func() { _, err := b.readOpened("p.md"); done <- err }()
-	select {
-	case err := <-done:
-		assert.True(t, errors.Is(err, ErrNotRegular), "got %v", err)
-	case <-time.After(2 * time.Second):
-		t.Fatal("readOpened blocked on a FIFO with a writer")
-	}
-}
-
-func TestReadRegularRefusesSymlinksAndReadsRegularFiles(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "ok.md"), []byte("ok"), 0o644))
-	outside := filepath.Join(t.TempDir(), "s.md")
-	require.NoError(t, os.WriteFile(outside, []byte("secret"), 0o644))
-	require.NoError(t, os.Symlink(outside, filepath.Join(dir, "link.md")))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	got, err := b.ReadRegular("ok.md")
-	require.NoError(t, err)
-	assert.Equal(t, "ok", string(got))
-	_, err = b.ReadRegular("link.md")
-	assert.True(t, errors.Is(err, ErrNotRegular), "got %v", err)
-	_, err = b.ReadRegular("../" + filepath.Base(outside))
-	assert.Error(t, err)
-}
-
-func TestRelAcceptsPathsInsideAndRefusesEscapes(t *testing.T) {
-	dir := t.TempDir()
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	for in, want := range map[string]string{
-		filepath.Join(dir, "wiki", "x.md"): "wiki/x.md",
-		filepath.Join(dir, "..foo", "x"):   "..foo/x",
-		dir:                                ".",
-	} {
-		got, err := b.Rel(in)
-		require.NoError(t, err, in)
-		assert.Equal(t, want, got, in)
-	}
-	for _, bad := range []string{filepath.Join(dir, "..", "x"), dir + "-evil/x", "/etc/passwd", filepath.Join(dir, "wiki", "..", "..", "x")} {
-		_, err := b.Rel(bad)
-		assert.Error(t, err, bad)
-	}
-}
-
-func TestWalkRegularYieldsOnlyRegularFiles(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "a"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "a", "n.md"), []byte("n"), 0o644))
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(dir, "a", "dirlink")))
-	require.NoError(t, os.Symlink(filepath.Join(dir, "a", "n.md"), filepath.Join(dir, "a", "filelink.md")))
-	require.NoError(t, syscall.Mkfifo(filepath.Join(dir, "a", "p.md"), 0o644))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	var got []string
-	require.NoError(t, b.WalkRegular(".", func(rel string) error { got = append(got, rel); return nil }, nil))
-	assert.Equal(t, []string{"a/n.md"}, got)
-}
-
-func TestReadRegularMaxRefusesAFileOverTheLimit(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "big.md"), make([]byte, 100), 0o644))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	_, err = b.ReadRegularMax("big.md", 99)
-	assert.True(t, errors.Is(err, ErrTooLarge), "got %v", err)
-	got, err := b.ReadRegularMax("big.md", 100)
-	require.NoError(t, err)
-	assert.Len(t, got, 100)
-}
-
-func TestReadRegularMaxRefusesAndStopsReadingAFileThatGrowsPastTheLimit(t *testing.T) {
-	dir := t.TempDir()
-	p := filepath.Join(dir, "grow.md")
-	require.NoError(t, os.WriteFile(p, make([]byte, 10), 0o644))
-	consumed := &countingReader{}
-	wrapAfterStat = func(r io.Reader) io.Reader {
-		f, err := os.OpenFile(p, os.O_WRONLY|os.O_APPEND, 0)
-		require.NoError(t, err)
-		_, err = f.Write(make([]byte, 1000))
-		require.NoError(t, err)
-		require.NoError(t, f.Close())
-		consumed.r = r
-		return consumed
-	}
-	t.Cleanup(func() { wrapAfterStat = nil })
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	got, err := b.ReadRegularMax("grow.md", 100)
-	assert.True(t, errors.Is(err, ErrTooLarge), "got %v", err)
-	assert.Nil(t, got)
-	assert.LessOrEqual(t, consumed.n, 101, "read past max+1 bytes")
-}
-
-type countingReader struct {
-	r io.Reader
-	n int
-}
-
-func (c *countingReader) Read(p []byte) (int, error) {
-	n, err := c.r.Read(p)
-	c.n += n
-	return n, err
-}
-
-func TestLstatDoesNotFollowSymlinksAndRefusesEscapes(t *testing.T) {
-	dir := t.TempDir()
-	outside := filepath.Join(t.TempDir(), "o.md")
-	require.NoError(t, os.WriteFile(outside, []byte("o"), 0o644))
-	require.NoError(t, os.Symlink(outside, filepath.Join(dir, "l.md")))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	fi, err := b.Lstat("l.md")
-	require.NoError(t, err)
-	assert.Equal(t, fs.ModeSymlink, fi.Mode().Type())
-	_, err = b.Lstat("../" + filepath.Base(filepath.Dir(outside)) + "/o.md")
-	assert.Error(t, err)
-}
-
-func TestWalkRegularReportsASymlinkedWalkRootAndYieldsNothing(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "real"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "real", "n.md"), []byte("n"), 0o644))
-	require.NoError(t, os.Symlink("real", filepath.Join(dir, "alias")))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	var got []string
-	var errs []error
-	require.NoError(t, b.WalkRegular("alias", func(rel string) error { got = append(got, rel); return nil },
-		func(_ string, err error) { errs = append(errs, err) }))
-	assert.Empty(t, got)
-	require.Len(t, errs, 1)
-	assert.ErrorIs(t, errs[0], ErrNotRegular)
-}
-
-func TestWalkRegularReportsASymlinkedIntermediateComponentOfTheWalkRoot(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "real", "sub"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "real", "sub", "n.md"), []byte("n"), 0o644))
-	require.NoError(t, os.Symlink("real", filepath.Join(dir, "alias")))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	var got []string
-	var errs []error
-	require.NoError(t, b.WalkRegular("alias/sub", func(rel string) error { got = append(got, rel); return nil },
-		func(_ string, err error) { errs = append(errs, err) }))
-	assert.Empty(t, got)
-	require.Len(t, errs, 1)
-	assert.ErrorIs(t, errs[0], ErrNotRegular)
-}
-
-func TestReadDirRegularListsOnlyRegularFilesAndRefusesSymlinkedComponents(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "a", "b", "sub"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "a", "b", "n.md"), []byte("n"), 0o644))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "other.md"), []byte("o"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join("..", "..", "other.md"), filepath.Join(dir, "a", "b", "l.md")))
-	require.NoError(t, syscall.Mkfifo(filepath.Join(dir, "a", "b", "f.md"), 0o644))
-	require.NoError(t, os.Symlink("a", filepath.Join(dir, "alias")))
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "x"), 0o755))
-	require.NoError(t, os.Symlink(filepath.Join("..", "a"), filepath.Join(dir, "x", "mid")))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-
-	names, err := b.ReadDirRegular("a/b")
-	require.NoError(t, err)
-	assert.Equal(t, []string{"n.md"}, names)
-	for _, rel := range []string{"alias/b", "x/mid/b"} {
-		_, err := b.ReadDirRegular(rel)
-		assert.ErrorIs(t, err, ErrNotRegular, rel)
-	}
-}
-
-// A final component swapped for a symlink to another regular file in the
-// brain between the Lstat and the open: os.Root follows in-root links, so
-// only comparing the two (os.SameFile) refuses it.
-func TestReadRegularNeverReturnsAnInBrainFileSwappedInBehindASymlink(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "s.md"), []byte("zqsamefilesentinel"), 0o644))
-	p := filepath.Join(dir, "r.md")
-	require.NoError(t, os.WriteFile(p, []byte("inside"), 0o644))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		tmp := p + ".swap"
-		for i := 0; !stop.Load(); i++ {
-			_ = os.Remove(tmp)
-			if i%2 == 0 {
-				_ = os.WriteFile(tmp, []byte("inside"), 0o644)
-			} else {
-				_ = os.Symlink("s.md", tmp)
-			}
-			_ = os.Rename(tmp, p)
-		}
-	}()
-	leaks, ok := 0, 0
-	for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); {
-		got, err := b.ReadRegular("r.md")
-		if err == nil {
-			ok++
-		}
-		if string(got) == "zqsamefilesentinel" {
-			leaks++
-		}
-		got, _ = b.ReadRegularMax("r.md", 1<<20)
-		if string(got) == "zqsamefilesentinel" {
-			leaks++
-		}
-	}
-	stop.Store(true)
-	wg.Wait()
-	assert.Zero(t, leaks)
-	assert.Positive(t, ok, "positive control: the regular file is read")
-}

ingestion/internal/brainfs/brainfstest/brainfstest.go

@@ -1,141 +0,0 @@
-// Package brainfstest is the shared harness for hyperguild#157's swap-race
-// tests: it keeps swapping a regular note, a symlink to an outside file, or a
-// FIFO (with a writer held open) into a path while a reader under test loops.
-// It observes two things: no sentinel byte from the outside file reaches the
-// reader's output, and the reader returns within a timeout. It does not cover
-// hard links, other paths into the reader, or races it does not generate.
-package brainfstest
-
-import (
-	"fmt"
-	"os"
-	"path/filepath"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"syscall"
-	"testing"
-	"time"
-)
-
-// Sentinel marks the outside file's contents.
-const Sentinel = "zqbrainfssentinelonefiftyseven"
-
-// outsideContent carries Sentinel in every field a reader might extract: the
-// frontmatter title and aliases, a heading, a wikilink and the body.
-const outsideContent = "---\ntitle: " + Sentinel + "\naliases:\n  - " + Sentinel + "\n---\n# " + Sentinel +
-	"\n\n" + Sentinel + " [[" + Sentinel + "]]\n"
-
-// Outside writes a file outside any brain dir containing Sentinel.
-func Outside(t *testing.T) string {
-	t.Helper()
-	p := filepath.Join(t.TempDir(), "secret.md")
-	if err := os.WriteFile(p, []byte(outsideContent), 0o644); err != nil {
-		t.Fatal(err)
-	}
-	return p
-}
-
-var swapSeq atomic.Int64
-
-// StartSwap renames, in a loop, a regular note (content inside) and either
-// a symlink to outside or a FIFO into path, until the test ends. FIFOs get a
-// writer held open until the swapper exits, so a reader that skips the
-// handle check parks forever instead of reading EOF. The swapper is stopped
-// and awaited before t.TempDir cleanup.
-func StartSwap(t *testing.T, path, inside, outside string, fifo bool) {
-	t.Helper()
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		// A name of its own: swappers on one path share a test, and one
-		// opening another's FIFO for write would block forever.
-		tmp := fmt.Sprintf("%s.swap%d", path, swapSeq.Add(1))
-		// A relative link: os.Root refuses every absolute link on its own, so
-		// an absolute in-brain target would test nothing.
-		link := outside
-		if rel, err := filepath.Rel(filepath.Dir(path), outside); err == nil {
-			link = rel
-		}
-		var writers []*os.File
-		defer func() {
-			for _, w := range writers {
-				_ = w.Close()
-			}
-		}()
-		for i := 0; !stop.Load(); i++ {
-			_ = os.Remove(tmp)
-			switch {
-			case i%2 == 0:
-				_ = os.WriteFile(tmp, []byte(inside), 0o644)
-			case fifo:
-				if err := syscall.Mkfifo(tmp, 0o644); err == nil {
-					if w, err := os.OpenFile(tmp, os.O_RDWR, 0); err == nil {
-						writers = append(writers, w)
-					}
-				}
-			default:
-				_ = os.Symlink(link, tmp)
-			}
-			_ = os.Rename(tmp, path)
-		}
-	}()
-	t.Cleanup(func() { stop.Store(true); wg.Wait() })
-}
-
-// WriteSentinelAt writes a file carrying Sentinel at p (creating its
-// directory), for an in-brain symlink target.
-func WriteSentinelAt(t *testing.T, p string) string {
-	t.Helper()
-	if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(p, []byte(outsideContent), 0o644); err != nil {
-		t.Fatal(err)
-	}
-	return p
-}
-
-// AssertNoLeak loops read for d while a symlink swapper runs on path, and
-// fails if any output contains Sentinel. The symlink points outside the
-// brain; os.Root refuses that on its own, so pair it with AssertNoLeakFrom
-// and an in-brain target.
-func AssertNoLeak(t *testing.T, path, inside string, d time.Duration, read func() string) {
-	t.Helper()
-	AssertNoLeakFrom(t, path, inside, Outside(t), d, read)
-}
-
-// AssertNoLeakFrom is AssertNoLeak with the symlink pointing at target, e.g.
-// a file elsewhere in the brain written with WriteSentinelAt.
-func AssertNoLeakFrom(t *testing.T, path, inside, target string, d time.Duration, read func() string) {
-	t.Helper()
-	StartSwap(t, path, inside, target, false)
-	leaks, iters := 0, 0
-	for deadline := time.Now().Add(d); time.Now().Before(deadline); iters++ {
-		leaks += strings.Count(read(), Sentinel)
-	}
-	if leaks > 0 {
-		t.Fatalf("outside file leaked %d times in %d iterations", leaks, iters)
-	}
-}
-
-// AssertNoHang loops read for d while a FIFO swapper (held writers) runs on
-// path, and fails if a read does not return within timeout.
-func AssertNoHang(t *testing.T, path, inside string, d, timeout time.Duration, read func()) {
-	t.Helper()
-	StartSwap(t, path, inside, Outside(t), true)
-	done := make(chan struct{})
-	go func() {
-		for deadline := time.Now().Add(d); time.Now().Before(deadline); {
-			read()
-		}
-		close(done)
-	}()
-	select {
-	case <-done:
-	case <-time.After(timeout):
-		t.Fatal("reader hung on a swapped-in FIFO with a writer held open")
-	}
-}

ingestion/internal/graphsync/graphsync.go

@@ -12,14 +12,10 @@ package graphsync
 
 import (
 	"context"
-	"errors"
 	"fmt"
-	"io/fs"
+	"os"
-	"path"
 	"path/filepath"
-	"strings"
 
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/graph"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/graphstore"
 )
@@ -50,25 +46,8 @@ func IndexDoc(ctx context.Context, store Store, brainDir, relPath string) error
 	if relPath == "" {
 		return nil
 	}
-	// Callers pass caller-supplied paths (brain_tunnel, brain_update): index
+	abs := filepath.Join(brainDir, filepath.FromSlash(relPath))
-	// only a clean path under wiki/ or knowledge/.
+	content, err := os.ReadFile(abs)
-	if path.Clean(relPath) != relPath || !filepath.IsLocal(relPath) ||
-		(!strings.HasPrefix(relPath, "wiki/") && !strings.HasPrefix(relPath, "knowledge/")) {
-		return fmt.Errorf("index %q: not a clean wiki/ or knowledge/ path", relPath)
-	}
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return fmt.Errorf("open brain: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
-	return indexDoc(ctx, store, bfs, relPath)
-}
-
-// indexDoc reads relPath through the brain root, regular files only
-// (hyperguild#157): the brain is a Syncthing folder, and os.ReadFile
-// followed a synced symlink into the graph and blocked on a FIFO.
-func indexDoc(ctx context.Context, store Store, bfs *brainfs.Brain, relPath string) error {
-	content, err := bfs.ReadRegular(relPath)
 	if err != nil {
 		return fmt.Errorf("read %q: %w", relPath, err)
 	}
@@ -98,34 +77,33 @@ func BackfillFromBrainDir(ctx context.Context, store Store, brainDir string) (in
 	if store == nil {
 		return 0, nil
 	}
-	bfs, err := brainfs.Open(brainDir)
+	roots := []string{"wiki", "knowledge"}
-	if err != nil {
+	for _, root := range roots {
-		return 0, fmt.Errorf("open brain: %w", err)
+		base := filepath.Join(brainDir, root)
-	}
+		if _, err := os.Stat(base); os.IsNotExist(err) {
-	defer func() { _ = bfs.Close() }()
-	for _, root := range []string{"wiki", "knowledge"} {
-		if _, err := bfs.Lstat(root); errors.Is(err, fs.ErrNotExist) {
 			continue
 		}
-		// Any walk error, including a root that is a symlink, aborts.
+		err := filepath.WalkDir(base, func(path string, d os.DirEntry, walkErr error) error {
-		var walkErr error
+			if walkErr != nil {
-		err := bfs.WalkRegular(root, func(rel string) error {
+				return walkErr
-			if path.Ext(rel) != ".md" {
+			}
+			if d.IsDir() {
 				return nil
 			}
-			if err := indexDoc(ctx, store, bfs, rel); err != nil {
+			if filepath.Ext(path) != ".md" {
+				return nil
+			}
+			rel, relErr := filepath.Rel(brainDir, path)
+			if relErr != nil {
+				return fmt.Errorf("rel %q: %w", path, relErr)
+			}
+			rel = filepath.ToSlash(rel)
+			if err := IndexDoc(ctx, store, brainDir, rel); err != nil {
 				return fmt.Errorf("index %q: %w", rel, err)
 			}
 			indexed++
 			return nil
-		}, func(rel string, err error) {
-			if walkErr == nil {
-				walkErr = fmt.Errorf("%s: %w", rel, err)
-			}
 		})
-		if err == nil {
-			err = walkErr
-		}
 		if err != nil {
 			return indexed, fmt.Errorf("walk %s: %w", root, err)
 		}

ingestion/internal/graphsync/graphsync_root_test.go

@@ -1,92 +0,0 @@
-package graphsync
-
-import (
-	"context"
-	"fmt"
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-)
-
-func (f *fakeStore) dump() string {
-	f.mu.Lock()
-	defer f.mu.Unlock()
-	return fmt.Sprintf("%+v %+v", f.upserts, f.replaces)
-}
-
-// hyperguild#157 slice 4: IndexDoc and BackfillFromBrainDir read notes with
-// os.ReadFile, so a symlinked note put the target's title and wikilinks into
-// the graph, and a FIFO hung the read.
-func TestIndexDocRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(facts, "ok.md"), []byte("---\ntitle: zqinside\n---\nbody [[other]]\n"), 0o644))
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "leak.md")))
-
-	store := newFakeStore()
-	require.NoError(t, IndexDoc(context.Background(), store, brain, "wiki/w/facts/ok.md"))
-	assert.Contains(t, store.dump(), "zqinside", "positive control: a regular note is indexed")
-	assert.Error(t, IndexDoc(context.Background(), store, brain, "wiki/w/facts/leak.md"))
-	// A link to a file elsewhere in the brain: os.Root allows it, only the
-	// regular-file check refuses it.
-	inBrain := brainfstest.WriteSentinelAt(t, filepath.Join(brain, "raw", "s.md"))
-	require.NoError(t, os.Symlink(filepath.Join("..", "..", "..", "raw", "s.md"), filepath.Join(facts, "inlink.md")))
-	assert.Error(t, IndexDoc(context.Background(), store, brain, "wiki/w/facts/inlink.md"))
-	assert.NotContains(t, store.dump(), brainfstest.Sentinel)
-
-	p := filepath.Join(facts, "r.md")
-	read := func() string {
-		s := newFakeStore()
-		_ = IndexDoc(context.Background(), s, brain, "wiki/w/facts/r.md")
-		return s.dump()
-	}
-	brainfstest.AssertNoLeak(t, p, "---\ntitle: zqinside\n---\n", 1500*time.Millisecond, read)
-	brainfstest.AssertNoLeakFrom(t, p, "---\ntitle: zqinside\n---\n", inBrain, 1500*time.Millisecond, read)
-	brainfstest.AssertNoHang(t, p, "---\ntitle: zqinside\n---\n", 1500*time.Millisecond, 6*time.Second, func() { _ = read() })
-}
-
-func TestBackfillSkipsSymlinkedNotesAndAbortsOnASymlinkedRoot(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(facts, "ok.md"), []byte("---\ntitle: zqinside\n---\n"), 0o644))
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "leak.md")))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "raw"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(brain, "raw", "r.md"), []byte("---\ntitle: zqrawonly\n---\n"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join("..", "..", "..", "raw", "r.md"), filepath.Join(facts, "inlink.md")))
-	require.NoError(t, os.Symlink(".", filepath.Join(brain, "knowledge")))
-
-	store := newFakeStore()
-	_, err := BackfillFromBrainDir(context.Background(), store, brain)
-	assert.Error(t, err, "a symlinked root aborts the backfill")
-	assert.NotContains(t, store.dump(), brainfstest.Sentinel)
-	assert.NotContains(t, store.dump(), "zqrawonly")
-
-	require.NoError(t, os.Remove(filepath.Join(brain, "knowledge")))
-	store = newFakeStore()
-	n, err := BackfillFromBrainDir(context.Background(), store, brain)
-	require.NoError(t, err)
-	assert.Equal(t, 1, n, "only the regular note is indexed")
-	assert.Contains(t, store.dump(), "zqinside")
-	assert.NotContains(t, store.dump(), brainfstest.Sentinel)
-}
-
-// IndexDoc gets caller-supplied paths (brain_tunnel, brain_update): only a
-// clean path under wiki/ or knowledge/ is indexed.
-func TestIndexDocRefusesPathsOutsideWikiAndKnowledgeAndUncleanPaths(t *testing.T) {
-	brain := t.TempDir()
-	brainfstest.WriteSentinelAt(t, filepath.Join(brain, "raw", "secret.md"))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki", "w"), 0o755))
-	for _, p := range []string{"raw/secret.md", "wiki/w/../../raw/secret.md", "./raw/secret.md", "/raw/secret.md"} {
-		store := newFakeStore()
-		assert.Error(t, IndexDoc(context.Background(), store, brain, p), p)
-		assert.NotContains(t, store.dump(), brainfstest.Sentinel, p)
-	}
-}

ingestion/internal/mcp/readexcerpt_root_test.go

@@ -1,34 +0,0 @@
-package mcp
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-)
-
-// hyperguild#157 slice 2: readExcerpt (brain_context) read by path, so a
-// symlink in the Syncthing-shared brain put an outside file in context, and
-// a FIFO hung it. It now reads through brainfs.
-func TestReadExcerptRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "leak.md")))
-	assert.NotContains(t, readExcerpt(brain, "wiki/w/facts/leak.md", 500), brainfstest.Sentinel)
-
-	p := filepath.Join(facts, "r.md")
-	require.NoError(t, os.WriteFile(p, []byte("---\nx: y\n---\ninside"), 0o644))
-	assert.Equal(t, "inside", readExcerpt(brain, "wiki/w/facts/r.md", 500))
-	brainfstest.AssertNoLeak(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, func() string {
-		return readExcerpt(brain, "wiki/w/facts/r.md", 500)
-	})
-	brainfstest.AssertNoHang(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, 6*time.Second, func() {
-		_ = readExcerpt(brain, "wiki/w/facts/r.md", 500)
-	})
-}

ingestion/internal/mcp/tools_context.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
+	"os"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -181,13 +181,8 @@ func readExcerpt(brainDir, relPath string, maxLen int) string {
 	if relPath == "" {
 		return ""
 	}
-	// Through the brain root, regular files only (hyperguild#157).
+	full := filepath.Join(brainDir, filepath.FromSlash(relPath))
-	bfs, err := brainfs.Open(brainDir)
+	content, err := os.ReadFile(full)
-	if err != nil {
-		return ""
-	}
-	defer func() { _ = bfs.Close() }()
-	content, err := bfs.ReadRegular(filepath.ToSlash(relPath))
 	if err != nil {
 		return ""
 	}

ingestion/internal/notes/edit.go

@@ -5,7 +5,6 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 	"os"
 	"path/filepath"
 	"strings"
@@ -72,18 +71,14 @@ func ReadScoped(brainDir, path string, scope Scope) ([]byte, error) {
 }
 
 func readContained(t Target) ([]byte, error) {
-	// Through the brain root, regular files only, size checked on the opened
+	fi, err := os.Stat(t.Abs)
-	// handle (hyperguild#157): Resolve's Lstat could be raced by a swap, and
-	// os.ReadFile blocked on a FIFO.
-	bfs, err := brainfs.Open(t.Brain)
 	if err != nil {
-		return nil, fmt.Errorf("notes: %w", err)
+		return nil, fmt.Errorf("notes: stat %s: %w", t.Rel, err)
 	}
-	defer func() { _ = bfs.Close() }()
+	if fi.Size() > maxNoteBytes {
-	b, err := bfs.ReadRegularMax(t.Rel, maxNoteBytes)
+		return nil, fmt.Errorf("%w: %s is %d bytes (limit %d)", ErrTooLarge, t.Rel, fi.Size(), maxNoteBytes)
-	if errors.Is(err, brainfs.ErrTooLarge) {
-		return nil, fmt.Errorf("%w: %s (limit %d)", ErrTooLarge, t.Rel, maxNoteBytes)
 	}
+	b, err := os.ReadFile(t.Abs)
 	if err != nil {
 		return nil, fmt.Errorf("notes: read %s: %w", t.Rel, err)
 	}

ingestion/internal/notes/path.go

@@ -60,7 +60,6 @@ var (
 type Target struct {
 	Rel string // brain-relative, cleaned
 	Abs string // absolute, symlink-checked
-	Brain string // the brain root Rel is relative to
 }
 
 // Resolve canonicalises path, then checks it against the scope's allowlist,
@@ -110,7 +109,7 @@ func Resolve(brainDir, path string, scope Scope) (Target, error) {
 		return Target{}, err
 	}
 
-	return Target{Rel: clean, Abs: abs, Brain: brainDir}, nil
+	return Target{Rel: clean, Abs: abs}, nil
 }
 
 // allow enforces the scope's allowlist. The two scopes are DISJOINT, not

ingestion/internal/notes/read_root_test.go

@@ -1,40 +0,0 @@
-package notes
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-)
-
-// hyperguild#157 slice 2: ReadScoped (brain_read) Lstat-checked the final
-// component, then reopened by name with os.ReadFile: a swap after the check
-// was followed, and a FIFO blocked the read. It now reads through brainfs.
-func TestReadScopedRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	p := filepath.Join(facts, "r.md")
-	read := func() string {
-		b, _ := ReadScoped(brain, "wiki/w/facts/r.md", ScopeNotes)
-		return string(b)
-	}
-	require.NoError(t, os.WriteFile(p, []byte("inside"), 0o644))
-	assert.Equal(t, "inside", read())
-	brainfstest.AssertNoLeak(t, p, "inside", 1500*time.Millisecond, read)
-	brainfstest.AssertNoHang(t, p, "inside", 1500*time.Millisecond, 6*time.Second, func() { _ = read() })
-}
-
-func TestReadScopedRefusesANoteOverMaxNoteBytes(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(facts, "big.md"), make([]byte, maxNoteBytes+1), 0o644))
-	_, err := ReadScoped(brain, "wiki/w/facts/big.md", ScopeNotes)
-	assert.ErrorIs(t, err, ErrTooLarge)
-}

ingestion/internal/search/brainroot_test.go

@@ -1,174 +0,0 @@
-package search
-
-import (
-	"os"
-	"path/filepath"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"syscall"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// hyperguild#157 option 1: search walked and read the brain by path, so a
-// symlink anywhere in the Syncthing-shared brain dir (wiki/<w>/<h>/leak.md ->
-// /any/file) put the target's contents in brain_query results (reproduced in
-// the PR #156 review). Search now walks and reads through an os.Root on the
-// brain dir and only reads regular files.
-
-const sentinel157 = "zqsentinelonefiftyseven"
-
-func searchBrain(t *testing.T) (brain, facts, outside string) {
-	t.Helper()
-	brain = t.TempDir()
-	facts = filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "knowledge"), 0o755))
-	outside = filepath.Join(t.TempDir(), "secret.md")
-	require.NoError(t, os.WriteFile(outside, []byte("# secret\n\n"+sentinel157), 0o644))
-	return brain, facts, outside
-}
-
-func leaked(rs []Result) int {
-	n := 0
-	for _, r := range rs {
-		n += strings.Count(r.Excerpt+r.Title, sentinel157)
-	}
-	return n
-}
-
-func TestQueryDoesNotFollowASymlinkInTheWiki(t *testing.T) {
-	brain, facts, outside := searchBrain(t)
-	require.NoError(t, os.Symlink(outside, filepath.Join(facts, "leak.md")))
-	require.NoError(t, os.WriteFile(filepath.Join(facts, "real.md"), []byte("# real\n\nzqrealnote"), 0o644))
-	rs, err := Query(brain, QueryOptions{Query: sentinel157, Limit: 10})
-	require.NoError(t, err)
-	assert.Zero(t, leaked(rs))
-	rs, err = Query(brain, QueryOptions{Query: "zqrealnote", Limit: 10})
-	require.NoError(t, err)
-	assert.Len(t, rs, 1, "regular notes are still found")
-}
-
-func TestQueryDoesNotFollowASymlinkedDirectory(t *testing.T) {
-	brain, _, outside := searchBrain(t)
-	require.NoError(t, os.Symlink(filepath.Dir(outside), filepath.Join(brain, "wiki", "linked")))
-	rs, err := Query(brain, QueryOptions{Query: sentinel157, Limit: 10})
-	require.NoError(t, err)
-	assert.Zero(t, leaked(rs))
-}
-
-// A search root that is a symlink staying inside the brain (wiki/<w> -> ..)
-// was followed by fs.WalkDir, aliasing raw/ and root files into results
-// (PR #166 review). The root is now Lstat-checked and skipped.
-func TestQueryDoesNotFollowASymlinkedWingRootInsideTheBrain(t *testing.T) {
-	brain, _, _ := searchBrain(t)
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "raw"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(brain, "raw", "r.md"), []byte("# r\n\nzqrawonly"), 0o644))
-	require.NoError(t, os.Symlink("..", filepath.Join(brain, "wiki", "alias")))
-	rs, err := Query(brain, QueryOptions{Query: "zqrawonly", Wing: "alias", Limit: 10})
-	require.NoError(t, err)
-	assert.Empty(t, rs)
-}
-
-// With a hall the search root is wiki/<wing>/<hall>; a symlinked <wing> with
-// a real <hall> directory under its target was followed (PR #166 round 2).
-func TestQueryDoesNotFollowASymlinkedWingUnderAWingAndHallRoot(t *testing.T) {
-	brain, _, _ := searchBrain(t)
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "raw", "facts"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(brain, "raw", "facts", "r.md"), []byte("# r\n\nzqrawhall"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join("..", "raw"), filepath.Join(brain, "wiki", "alias")))
-	rs, err := Query(brain, QueryOptions{Query: "zqrawhall", Wing: "alias", Hall: "facts", Limit: 10})
-	require.NoError(t, err)
-	assert.Empty(t, rs)
-}
-
-// swapInto keeps renaming a regular note, and either a symlink to outside or
-// a FIFO, into path. Each FIFO has a writer held open (as any local process
-// can): a FIFO with no writer reads EOF at once, which would let a reader
-// that skips the handle check pass (PR #161 round 2: with a held writer, a
-// bypass of readOpened hung Query after 5 iterations).
-// startSwap runs swapInto until the test ends and waits for it before
-// t.TempDir's cleanup (hyperguild#162).
-func startSwap(t *testing.T, path, outside string, fifo bool) {
-	t.Helper()
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() { defer wg.Done(); swapInto(path, outside, fifo, &stop) }()
-	t.Cleanup(func() { stop.Store(true); wg.Wait() })
-}
-
-func swapInto(path, outside string, fifo bool, stop *atomic.Bool) {
-	tmp := path + ".swap"
-	// Writers stay open until the swapper exits, so a reader parked on a
-	// FIFO stays parked (closing one would hand the reader EOF and hide the
-	// hang). Past the fd limit, new FIFOs simply have no writer.
-	var writers []*os.File
-	defer func() {
-		for _, w := range writers {
-			_ = w.Close()
-		}
-	}()
-	for i := 0; !stop.Load(); i++ {
-		_ = os.Remove(tmp)
-		switch {
-		case i%2 == 0:
-			_ = os.WriteFile(tmp, []byte("# r\n\nzqinside "+"zqracenote"), 0o644)
-		case fifo:
-			if err := syscall.Mkfifo(tmp, 0o644); err == nil {
-				if w, err := os.OpenFile(tmp, os.O_RDWR, 0); err == nil {
-					writers = append(writers, w)
-				}
-			}
-		default:
-			_ = os.Symlink(outside, tmp)
-		}
-		_ = os.Rename(tmp, path)
-	}
-}
-
-func TestQueryLeaksNothingUnderASymlinkSwapRace(t *testing.T) {
-	brain, facts, outside := searchBrain(t)
-	startSwap(t, filepath.Join(facts, "r.md"), outside, false)
-	leaks, iters := 0, 0
-	for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); iters++ {
-		rs, _ := Query(brain, QueryOptions{Query: sentinel157, Limit: 10})
-		leaks += leaked(rs)
-	}
-	if leaks > 0 {
-		t.Fatalf("outside file leaked %d times in %d iterations", leaks, iters)
-	}
-}
-
-func TestQueryDoesNotHangUnderAFIFOSwapRace(t *testing.T) {
-	brain, facts, outside := searchBrain(t)
-	startSwap(t, filepath.Join(facts, "r.md"), outside, true)
-	done := make(chan struct{})
-	go func() {
-		for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); {
-			_, _ = Query(brain, QueryOptions{Query: "zqracenote", Limit: 10})
-		}
-		close(done)
-	}()
-	select {
-	case <-done:
-	case <-time.After(6 * time.Second):
-		if f, err := os.OpenFile(filepath.Join(facts, "r.md"), os.O_WRONLY|syscall.O_NONBLOCK, 0); err == nil {
-			_ = f.Close()
-		}
-		t.Fatal("search hung on a swapped-in FIFO")
-	}
-}
-
-// hydrate (vector-only hits) reads by relative path; it must refuse a symlink.
-func TestHydrateRefusesASymlink(t *testing.T) {
-	brain, facts, outside := searchBrain(t)
-	require.NoError(t, os.Symlink(outside, filepath.Join(facts, "leak.md")))
-	r, err := hydrate(brain, "wiki/w/facts/leak.md")
-	assert.Error(t, err)
-	assert.NotContains(t, r.Excerpt, sentinel157)
-}

ingestion/internal/search/search.go

@@ -5,7 +5,6 @@ import (
 	"bufio"
 	"context"
 	"fmt"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 	sharedfm "github.com/mathiasbq/hyperguild/ingestion/internal/frontmatter"
 	"log/slog"
 	"os"
@@ -120,30 +119,20 @@ func QueryContext(ctx context.Context, brainDir string, opts QueryOptions) ([]Re
 		return nil, err
 	}
 
-	// Walk and read through an os.Root on the brain dir, regular files only
-	// (hyperguild#157): a symlink planted in the Syncthing-shared brain must
-	// not put an outside file in results, nor a FIFO hang the query.
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return nil, fmt.Errorf("search: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
-
 	var results []Result
 	for _, dir := range roots {
 		if _, statErr := os.Stat(dir); os.IsNotExist(statErr) {
 			continue
 		}
-		relDir, relErr := bfs.Rel(dir)
+		err := filepath.WalkDir(dir, func(path string, d os.DirEntry, err error) error {
-		if relErr != nil {
+			if err != nil {
-			return nil, fmt.Errorf("search: %w", relErr)
+				slog.Warn("search: skipping path", "path", path, "err", err)
-		}
-		err := bfs.WalkRegular(relDir, func(relPath string) error {
-			if !strings.HasSuffix(relPath, ".md") {
 				return nil
 			}
-			path := filepath.Join(brainDir, filepath.FromSlash(relPath))
+			if d.IsDir() || !strings.HasSuffix(path, ".md") {
-			content, err := bfs.ReadRegular(relPath)
+				return nil
+			}
+			content, err := os.ReadFile(path)
 			if err != nil {
 				slog.Warn("search: skipping unreadable file", "path", path, "err", err)
 				return nil
@@ -166,7 +155,7 @@ func QueryContext(ctx context.Context, brainDir string, opts QueryOptions) ([]Re
 			origin, writtenBy := extractProvenance(string(content))
 			results = append(results, Result{
 				Path:    rel,
-				Title:   extractTitle(string(content), filepath.Base(relPath)),
+				Title:   extractTitle(string(content), d.Name()),
 				Excerpt: excerpt(string(content), 300),
 				Score:   score,
 				Wing:    wing,
@@ -177,8 +166,6 @@ func QueryContext(ctx context.Context, brainDir string, opts QueryOptions) ([]Re
 				WrittenBy: writtenBy,
 			})
 			return nil
-		}, func(p string, err error) {
-			slog.Warn("search: skipping path", "path", p, "err", err)
 		})
 		if err != nil {
 			return nil, err
@@ -288,13 +275,8 @@ func pathInScope(relPath, wing, hall string) bool {
 // excerpt, wing, and hall populated. Used for paths that surface only
 // via vector search.
 func hydrate(brainDir, relPath string) (Result, error) {
-	// Through the brain root, regular files only (hyperguild#157).
+	full := filepath.Join(brainDir, filepath.FromSlash(relPath))
-	bfs, err := brainfs.Open(brainDir)
+	content, err := os.ReadFile(full)
-	if err != nil {
-		return Result{}, err
-	}
-	defer func() { _ = bfs.Close() }()
-	content, err := bfs.ReadRegular(filepath.ToSlash(relPath))
 	if err != nil {
 		return Result{}, err
 	}

ingestion/internal/symlinkguard/symlinkguard.go

@@ -1,264 +0,0 @@
-// Package symlinkguard is the hyperguild#157 tripwire. The brain directory is
-// a Syncthing sendreceive folder and Syncthing syncs symlinks; several brain
-// readers (search, vectorstore, context, graph) follow a symlink out of the
-// brain and would index or return whatever it points to. Until every reader
-// reads through an os.Root, a symlink inside the brain, or a directory the
-// scan cannot read (which could hide one), is an incident: the server refuses
-// to start on one (main), and Watch reports one that appears while it runs.
-package symlinkguard
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"io/fs"
-	"log/slog"
-	"os"
-	"path/filepath"
-	"sort"
-	"strconv"
-	"strings"
-	"time"
-)
-
-// DefaultInterval is used when Watch is given a non-positive interval.
-const DefaultInterval = 30 * time.Second
-
-// Alert bounds (PR #160 review): the planter chooses the paths, so neither an
-// alert's size nor the queue may grow with what was planted.
-const (
-	maxPathsPerAlert = 10 // further paths are counted, not listed
-	maxPending       = 5  // queued alerts; the rest become one summary
-)
-
-// Notifier is the out-of-band alert sink (audit.Notifier satisfies it).
-type Notifier interface {
-	Notify(ctx context.Context, msg string) error
-}
-
-// Result is what a scan found: symlinks, and directories it could not read
-// (each of which could hide a symlink). Paths are brain-relative.
-type Result struct {
-	Symlinks   []string
-	Unreadable []string
-}
-
-// Clean reports whether the scan found nothing to act on.
-func (r Result) Clean() bool { return len(r.Symlinks) == 0 && len(r.Unreadable) == 0 }
-
-// String describes the findings for a log line or alert. Paths are quoted, so
-// a name containing a newline cannot blur two findings together.
-func (r Result) String() string {
-	q := r.quoted
-	var parts []string
-	if len(r.Symlinks) > 0 {
-		parts = append(parts, fmt.Sprintf("%d symlink(s): %s", len(r.Symlinks), q(r.Symlinks)))
-	}
-	if len(r.Unreadable) > 0 {
-		parts = append(parts, fmt.Sprintf("%d unreadable dir(s): %s", len(r.Unreadable), q(r.Unreadable)))
-	}
-	return strings.Join(parts, "; ")
-}
-
-// quoted joins at most maxPathsPerAlert paths, each strconv-quoted, and
-// counts the rest.
-func (Result) quoted(xs []string) string {
-	shown := xs
-	if len(shown) > maxPathsPerAlert {
-		shown = shown[:maxPathsPerAlert]
-	}
-	out := make([]string, len(shown))
-	for i, x := range shown {
-		out[i] = strconv.Quote(x)
-	}
-	s := strings.Join(out, ", ")
-	if extra := len(xs) - len(shown); extra > 0 {
-		s += fmt.Sprintf(" and %d more", extra)
-	}
-	return s
-}
-
-// Scan walks the brain dir and reports every symlink in it and every
-// directory it could not read, continuing past both. Only the ROOT .git is
-// skipped (it is brain-sync's, and no reader walks it); a nested .git is
-// scanned like any other directory. brainDir itself may be a symlink (a
-// volume mount); it is resolved first. The error is non-nil when the root
-// cannot be resolved (wrapping os.ErrNotExist when it is missing) or cannot be
-// listed.
-func Scan(brainDir string) (Result, error) {
-	root, err := filepath.EvalSymlinks(brainDir)
-	if err != nil {
-		return Result{}, fmt.Errorf("resolve brain dir: %w", err)
-	}
-	var r Result
-	rootGit := filepath.Join(root, ".git")
-	walkErr := filepath.WalkDir(root, func(p string, d fs.DirEntry, err error) error {
-		rel, _ := filepath.Rel(root, p)
-		rel = filepath.ToSlash(rel)
-		if err != nil {
-			if p == root {
-				return err
-			}
-			r.Unreadable = append(r.Unreadable, rel)
-			if d != nil && d.IsDir() {
-				return filepath.SkipDir
-			}
-			return nil
-		}
-		if d.IsDir() && p == rootGit {
-			return filepath.SkipDir
-		}
-		if d.Type()&os.ModeSymlink != 0 {
-			r.Symlinks = append(r.Symlinks, rel)
-		}
-		return nil
-	})
-	sort.Strings(r.Symlinks)
-	sort.Strings(r.Unreadable)
-	if walkErr != nil {
-		// Only the root's own error reaches here (deeper errors are recorded
-		// as Unreadable). A root that cannot be listed cannot be shown clean
-		// (PR #159 round 2: discarding this reported clean while search
-		// served a planted symlink).
-		return r, fmt.Errorf("scan brain dir: %w", walkErr)
-	}
-	return r, nil
-}
-
-// Watch rescans every interval (DefaultInterval if non-positive) until ctx
-// ends. Every symlink found is removed (the link, never its target:
-// hyperguild#157 decision), so one is readable for at most one interval.
-// Each removal is an alert; a persistent finding (a link it could not remove,
-// an unreadable dir, a scan error) alerts once per distinct state. Alerts
-// queue until Notify succeeds (see alertQueue): an outage delays them, and
-// any that do not fit the bounded queue, or are undeliverable, are counted in
-// a summary that is never dropped, so every incident is delivered or counted.
-func Watch(ctx context.Context, brainDir string, interval time.Duration, n Notifier) {
-	if interval <= 0 {
-		interval = DefaultInterval
-	}
-	t := time.NewTicker(interval)
-	defer t.Stop()
-	q := &alertQueue{}
-	reported := ""
-	for {
-		select {
-		case <-ctx.Done():
-			return
-		case <-t.C:
-		}
-		r, err := Scan(brainDir)
-		key := ""
-		if err != nil {
-			key = "cannot scan the brain dir: " + err.Error()
-		} else {
-			removed, failed := removeSymlinks(brainDir, r.Symlinks)
-			if len(removed) > 0 {
-				slog.Error("brain symlink tripwire removed symlinks", "count", len(removed))
-				q.push(fmt.Sprintf("brain symlink tripwire (hyperguild#157): removed %d symlink(s) from the brain dir: %s",
-					len(removed), Result{}.quoted(removed)))
-			}
-			key = Result{Symlinks: failed, Unreadable: r.Unreadable}.String()
-		}
-		if key != reported {
-			reported = key
-			if key != "" {
-				slog.Error("brain symlink tripwire", "finding", key)
-				q.push("brain symlink tripwire (hyperguild#157): " + key +
-					". Readers may follow symlinks out of the brain; fix them.")
-			}
-		}
-		q.flush(ctx, n)
-	}
-}
-
-// alertQueue holds alerts until Notify accepts them. It is bounded (at most
-// maxPending queued) and loses nothing from the record: every overflow and
-// every dropped message increments suppressed, sent as a summary that is
-// retried every tick and never dropped.
-//
-// A message is dropped only when the notifier rejects it permanently (an
-// error with Permanent() == true, e.g. ntfy 413). Every other failure is an
-// outage, and nothing is dropped however long it lasts (PR #160 round 2:
-// dropping after N raw failures lost the only incident of a long outage).
-// Each flush tries every queued message, so one undeliverable message cannot
-// block the others.
-type alertQueue struct {
-	items      []string
-	suppressed int
-}
-
-func (q *alertQueue) push(msg string) {
-	if len(q.items) >= maxPending {
-		q.suppressed++
-		return
-	}
-	q.items = append(q.items, msg)
-}
-
-func (q *alertQueue) flush(ctx context.Context, n Notifier) {
-	if n == nil {
-		q.items, q.suppressed = nil, 0
-		return
-	}
-	kept := q.items[:0]
-	for _, msg := range q.items {
-		err := n.Notify(ctx, msg)
-		switch {
-		case err == nil:
-		case permanent(err):
-			slog.Error("symlink tripwire alert rejected permanently; counted in the summary", "err", err)
-			q.suppressed++
-		default:
-			slog.Warn("symlink tripwire notify failed; will retry", "err", err)
-			kept = append(kept, msg)
-		}
-	}
-	q.items = kept
-	if q.suppressed > 0 {
-		msg := fmt.Sprintf("brain symlink tripwire (hyperguild#157): %d further alert(s) were suppressed or undeliverable; check the ingestion logs", q.suppressed)
-		if err := n.Notify(ctx, msg); err == nil {
-			q.suppressed = 0
-		}
-	}
-}
-
-// permanent reports whether err says the message itself can never be sent.
-func permanent(err error) bool {
-	var p interface{ Permanent() bool }
-	return errors.As(err, &p) && p.Permanent()
-}
-
-// removeSymlinks unlinks each brain-relative symlink through an os.Root on
-// the brain dir, after re-checking it is still a symlink. Removing a symlink
-// never touches its target. It returns what was removed and what was not.
-func removeSymlinks(brainDir string, rels []string) (removed, failed []string) {
-	if len(rels) == 0 {
-		return nil, nil
-	}
-	resolved, err := filepath.EvalSymlinks(brainDir)
-	if err != nil {
-		return nil, rels
-	}
-	root, err := os.OpenRoot(resolved)
-	if err != nil {
-		return nil, rels
-	}
-	defer func() { _ = root.Close() }()
-	for _, rel := range rels {
-		fi, err := root.Lstat(rel)
-		if err != nil || fi.Mode()&os.ModeSymlink == 0 {
-			failed = append(failed, rel)
-			continue
-		}
-		// root.Remove, not os.RemoveAll: if the link is swapped for a
-		// non-empty directory after the Lstat, Remove refuses rather than
-		// deleting it recursively, and it cannot act outside the root.
-		if err := root.Remove(rel); err != nil {
-			failed = append(failed, rel)
-			continue
-		}
-		removed = append(removed, rel)
-	}
-	return removed, failed
-}

ingestion/internal/symlinkguard/symlinkguard_test.go

@@ -1,498 +0,0 @@
-package symlinkguard
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"os"
-	"path/filepath"
-	"strconv"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// hyperguild#157: the brain dir is a Syncthing sendreceive folder and
-// Syncthing syncs symlinks; several readers follow them out of the brain.
-// Until every reader goes through an os.Root, a symlink anywhere in the brain,
-// or a directory the scan cannot read (which could hide one), is an incident.
-
-func TestScanReportsSymlinksAtEveryDepthIncludingNestedGit(t *testing.T) {
-	brain := t.TempDir()
-	outside := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki", "w", "facts", ".git"), 0o755))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, ".git", "objects"), 0o755))
-	require.NoError(t, os.Symlink(filepath.Join(outside, "f"), filepath.Join(brain, "wiki", "w", "facts", "leak.md")))
-	require.NoError(t, os.Symlink(outside, filepath.Join(brain, "wiki", "dirlink")))
-	// PR #159 review: only the ROOT .git is skipped; a nested .git is not
-	// special to the brain readers, which walk into it.
-	require.NoError(t, os.Symlink(filepath.Join(outside, "g"), filepath.Join(brain, "wiki", "w", "facts", ".git", "leak.md")))
-	require.NoError(t, os.Symlink(outside, filepath.Join(brain, ".git", "objects", "alt")))
-
-	r, err := Scan(brain)
-	require.NoError(t, err)
-	assert.ElementsMatch(t, []string{"wiki/w/facts/leak.md", "wiki/dirlink", "wiki/w/facts/.git/leak.md"}, r.Symlinks)
-	assert.Empty(t, r.Unreadable)
-}
-
-// PR #159 review: WalkDir stopped at the first unreadable directory and the
-// startup check passed, while search (which keeps walking) served a planted
-// symlink. Scan now records the unreadable dir and keeps going.
-func TestScanReportsUnreadableDirsAndKeepsWalkingPastThem(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root reads mode-000 directories")
-	}
-	brain := t.TempDir()
-	locked := filepath.Join(brain, "aaa")
-	require.NoError(t, os.MkdirAll(locked, 0o755))
-	require.NoError(t, os.Chmod(locked, 0o000))
-	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "zzz-planted")))
-
-	r, err := Scan(brain)
-	require.NoError(t, err)
-	assert.Equal(t, []string{"aaa"}, r.Unreadable)
-	assert.Equal(t, []string{"zzz-planted"}, r.Symlinks, "the walk continues past the unreadable dir")
-}
-
-func TestScanResolvesASymlinkedRootAndReportsSymlinkedEntriesInsideIt(t *testing.T) {
-	real := t.TempDir()
-	link := filepath.Join(t.TempDir(), "brain")
-	require.NoError(t, os.Symlink(real, link))
-	require.NoError(t, os.WriteFile(filepath.Join(real, "n.md"), []byte("x"), 0o644))
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(real, "inner")))
-	r, err := Scan(link)
-	require.NoError(t, err)
-	assert.Equal(t, []string{"inner"}, r.Symlinks)
-}
-
-func TestScanOfAMissingRootIsErrNotExist(t *testing.T) {
-	_, err := Scan(filepath.Join(t.TempDir(), "nope"))
-	assert.True(t, errors.Is(err, os.ErrNotExist), "got %v", err)
-}
-
-type recNotifier struct {
-	mu   sync.Mutex
-	msgs []string
-	fail int // fail the first N calls
-}
-
-func (r *recNotifier) Notify(_ context.Context, m string) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	r.msgs = append(r.msgs, m)
-	if r.fail > 0 {
-		r.fail--
-		return errors.New("ntfy down")
-	}
-	return nil
-}
-
-func (r *recNotifier) count() int { r.mu.Lock(); defer r.mu.Unlock(); return len(r.msgs) }
-
-func TestWatchNotifiesOncePerDistinctSetAndAgainForANewSet(t *testing.T) {
-	brain := t.TempDir()
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-
-	time.Sleep(50 * time.Millisecond)
-	assert.Zero(t, n.count(), "a clean brain raises nothing")
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "first")))
-	require.Eventually(t, func() bool { return n.count() == 1 }, 2*time.Second, 10*time.Millisecond)
-	time.Sleep(60 * time.Millisecond)
-	assert.Equal(t, 1, n.count(), "the same set is reported once, not every tick")
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "second")))
-	require.Eventually(t, func() bool { return n.count() == 2 }, 2*time.Second, 10*time.Millisecond)
-}
-
-// PR #159 review: last was recorded before Notify, so an alert lost to an
-// ntfy outage was never retried while the symlink stayed.
-func TestWatchRetriesAnAlertThatFailedToSend(t *testing.T) {
-	brain := t.TempDir()
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "planted")))
-	n := &recNotifier{fail: 2}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.Eventually(t, func() bool { return n.count() == 3 }, 2*time.Second, 10*time.Millisecond)
-	time.Sleep(60 * time.Millisecond)
-	assert.Equal(t, 3, n.count(), "after one successful send, no more")
-}
-
-func TestWatchAlertsOnAnUnreadableDir(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root reads mode-000 directories")
-	}
-	brain := t.TempDir()
-	locked := filepath.Join(brain, "locked")
-	require.NoError(t, os.MkdirAll(locked, 0o755))
-	require.NoError(t, os.Chmod(locked, 0o000))
-	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.Eventually(t, func() bool { return n.count() == 1 }, 2*time.Second, 10*time.Millisecond)
-	assert.Contains(t, n.msgs[0], "locked")
-}
-
-// PR #159 review: a non-positive interval panicked time.NewTicker inside the
-// goroutine and crashlooped the server.
-func TestWatchToleratesANonPositiveInterval(t *testing.T) {
-	brain := t.TempDir()
-	ctx, cancel := context.WithCancel(context.Background())
-	done := make(chan struct{})
-	go func() { Watch(ctx, brain, 0, nil); close(done) }()
-	cancel()
-	select {
-	case <-done:
-	case <-time.After(2 * time.Second):
-		t.Fatal("Watch did not return on cancel")
-	}
-}
-
-// PR #159 round 2: a brain root that can be entered but not listed (mode
-// 0100) made WalkDir fail at the root; the error was discarded and Scan
-// reported clean, while search (which goes straight into wiki/) still served
-// a planted symlink. A root that cannot be listed is now an error.
-func TestScanOfAnUnlistableRootIsAnError(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root lists mode-0100 directories")
-	}
-	brain := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki"), 0o755))
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "wiki", "leak.md")))
-	require.NoError(t, os.Chmod(brain, 0o100))
-	t.Cleanup(func() { _ = os.Chmod(brain, 0o755) })
-	_, err := Scan(brain)
-	require.Error(t, err)
-	assert.False(t, errors.Is(err, os.ErrNotExist), "an unlistable root is not a missing root")
-}
-
-// The same set that disappears and comes back is reported again.
-func TestWatchReportsASetAgainAfterItWasCleared(t *testing.T) {
-	brain := t.TempDir()
-	link := filepath.Join(brain, "planted")
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.NoError(t, os.Symlink(t.TempDir(), link))
-	require.Eventually(t, func() bool { return n.count() == 1 }, 2*time.Second, 10*time.Millisecond)
-	// The tripwire removed it; planting it again is a new event.
-	require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 10*time.Millisecond)
-	require.NoError(t, os.Symlink(t.TempDir(), link))
-	require.Eventually(t, func() bool { return n.count() == 2 }, 2*time.Second, 10*time.Millisecond)
-}
-
-// hyperguild#157 decision: the runtime tripwire removes a symlink it finds
-// (the link, never its target), so it is readable for at most one interval
-// instead of until a human acts, and the alert says what was removed.
-func TestWatchRemovesAnOutsideFileLinkButNotItsTargetOrRegularFiles(t *testing.T) {
-	brain := t.TempDir()
-	outside := filepath.Join(t.TempDir(), "target.md")
-	require.NoError(t, os.WriteFile(outside, []byte("keep me"), 0o644))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki"), 0o755))
-	link := filepath.Join(brain, "wiki", "leak.md")
-	require.NoError(t, os.Symlink(outside, link))
-	regular := filepath.Join(brain, "wiki", "note.md")
-	require.NoError(t, os.WriteFile(regular, []byte("note"), 0o644))
-
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-
-	require.Eventually(t, func() bool {
-		_, err := os.Lstat(link)
-		return os.IsNotExist(err)
-	}, 2*time.Second, 10*time.Millisecond, "the symlink is removed")
-	require.Eventually(t, func() bool { return n.count() >= 1 }, 2*time.Second, 10*time.Millisecond)
-	b, err := os.ReadFile(outside)
-	require.NoError(t, err)
-	assert.Equal(t, "keep me", string(b), "the target is untouched")
-	b, err = os.ReadFile(regular)
-	require.NoError(t, err)
-	assert.Equal(t, "note", string(b), "regular files are untouched")
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	assert.Contains(t, n.msgs[0], "removed")
-	assert.Contains(t, n.msgs[0], "wiki/leak.md")
-}
-
-func TestDefaultIntervalIsThirtySeconds(t *testing.T) {
-	assert.Equal(t, 30*time.Second, DefaultInterval)
-}
-
-// PR #160 review: the Lstat re-check and the os.Root confinement in
-// removeSymlinks had no test. Anything that is not a symlink inside the brain
-// is reported failed and nothing is deleted.
-func TestRemoveSymlinksRefusesNonSymlinksEscapesAndPathsThroughLinks(t *testing.T) {
-	brain := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki", "real"), 0o755))
-	regular := filepath.Join(brain, "wiki", "note.md")
-	require.NoError(t, os.WriteFile(regular, []byte("note"), 0o644))
-	inLinked := filepath.Join(brain, "wiki", "real", "x.md")
-	require.NoError(t, os.WriteFile(inLinked, []byte("x"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join(brain, "wiki", "real"), filepath.Join(brain, "wiki", "linkdir")))
-	outside := filepath.Join(filepath.Dir(brain), "outside-157.md")
-	require.NoError(t, os.WriteFile(outside, []byte("o"), 0o644))
-	t.Cleanup(func() { _ = os.Remove(outside) })
-
-	removed, failed := removeSymlinks(brain, []string{
-		"wiki/note.md", "wiki/linkdir/x.md", "../outside-157.md", "wiki/missing.md",
-	})
-	assert.Empty(t, removed)
-	assert.ElementsMatch(t, []string{"wiki/note.md", "wiki/linkdir/x.md", "../outside-157.md", "wiki/missing.md"}, failed)
-	for _, p := range []string{regular, inLinked, outside} {
-		_, err := os.Stat(p)
-		assert.NoError(t, err, "%s must not be deleted", p)
-	}
-}
-
-// Dir targets and in-brain targets survive too, not only an outside file.
-func TestWatchRemovesDirAndInBrainLinksButNotTheirTargets(t *testing.T) {
-	brain := t.TempDir()
-	outsideDir := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(outsideDir, "keep.md"), []byte("keep"), 0o644))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki"), 0o755))
-	inBrain := filepath.Join(brain, "wiki", "target.md")
-	require.NoError(t, os.WriteFile(inBrain, []byte("t"), 0o644))
-	require.NoError(t, os.Symlink(outsideDir, filepath.Join(brain, "wiki", "dirlink")))
-	require.NoError(t, os.Symlink(inBrain, filepath.Join(brain, "wiki", "inlink.md")))
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, nil)
-	require.Eventually(t, func() bool {
-		r, err := Scan(brain)
-		return err == nil && len(r.Symlinks) == 0
-	}, 2*time.Second, 10*time.Millisecond)
-	for _, p := range []string{filepath.Join(outsideDir, "keep.md"), inBrain} {
-		_, err := os.Stat(p)
-		assert.NoError(t, err, "%s must survive", p)
-	}
-}
-
-// PR #160 review: the planter chooses the paths. An alert names at most
-// maxPathsPerAlert of them and counts the rest, so its size stays bounded.
-func TestWatchAlertNamesBoundedPathsAndCountsTheRest(t *testing.T) {
-	brain := t.TempDir()
-	for i := 0; i < 50; i++ {
-		require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, strings.Repeat("n", 100)+strconv.Itoa(i))))
-	}
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.Eventually(t, func() bool { return n.count() >= 1 }, 2*time.Second, 10*time.Millisecond)
-	n.mu.Lock()
-	msg := n.msgs[0]
-	n.mu.Unlock()
-	assert.Contains(t, msg, "removed 50 symlink(s)")
-	assert.Contains(t, msg, "and 40 more")
-	assert.Less(t, len(msg), 2500, "alert size is bounded regardless of how many links were planted")
-}
-
-// rejectNotifier refuses every message containing a marker, forever.
-type rejectNotifier struct {
-	recNotifier
-	reject string
-}
-
-// permanentErr is a rejection the notifier says can never succeed (like ntfy 413).
-type permanentErr struct{}
-
-func (permanentErr) Error() string   { return "413 payload too large" }
-func (permanentErr) Permanent() bool { return true }
-
-func (r *rejectNotifier) Notify(ctx context.Context, m string) error {
-	if strings.Contains(m, r.reject) {
-		r.mu.Lock()
-		r.msgs = append(r.msgs, "REJECTED")
-		r.mu.Unlock()
-		return permanentErr{}
-	}
-	return r.recNotifier.Notify(ctx, m)
-}
-
-// PR #160 review: one message the server will never accept blocked every
-// later alert forever (head-of-line). It is dropped after maxAttempts.
-func TestWatchDropsAMessageThatNeverSendsSoLaterAlertsFlow(t *testing.T) {
-	brain := t.TempDir()
-	n := &rejectNotifier{reject: "POISON"}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "POISON")))
-	time.Sleep(30 * time.Millisecond)
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "later")))
-	require.Eventually(t, func() bool {
-		n.mu.Lock()
-		defer n.mu.Unlock()
-		for _, m := range n.msgs {
-			if strings.Contains(m, "later") {
-				return true
-			}
-		}
-		return false
-	}, 3*time.Second, 10*time.Millisecond, "a later alert is delivered despite a poison message")
-}
-
-// toggleNotifier fails while down is set.
-type toggleNotifier struct {
-	recNotifier
-	down atomic.Bool
-}
-
-func (r *toggleNotifier) Notify(ctx context.Context, m string) error {
-	if r.down.Load() {
-		return errors.New("ntfy down")
-	}
-	return r.recNotifier.Notify(ctx, m)
-}
-
-// PR #160 review: an outage queued one message per removal, unbounded. The
-// queue holds at most maxPending messages; the rest become one summary.
-func TestWatchQueueIsBoundedDuringAnOutage(t *testing.T) {
-	brain := t.TempDir()
-	n := &toggleNotifier{}
-	n.down.Store(true)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 5*time.Millisecond, n)
-	for i := 0; i < 30; i++ {
-		link := filepath.Join(brain, "p"+strconv.Itoa(i))
-		require.NoError(t, os.Symlink(t.TempDir(), link))
-		require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 2*time.Millisecond)
-	}
-	n.down.Store(false)
-	require.Eventually(t, func() bool { return n.count() >= 1 }, 2*time.Second, 5*time.Millisecond)
-	time.Sleep(100 * time.Millisecond)
-	assert.LessOrEqual(t, n.count(), maxPending+1, "queued alerts plus at most one suppression summary")
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	found := false
-	for _, m := range n.msgs {
-		if strings.Contains(m, "suppressed") {
-			found = true
-		}
-	}
-	assert.True(t, found, "suppressed alerts are counted in a summary")
-}
-
-// Within the bound, every alert queued during an outage is delivered after
-// it, each naming its own removal (PR #160 review: truncating the queue after
-// the first send stayed green).
-func TestWatchDeliversEveryQueuedAlertAfterAShortOutage(t *testing.T) {
-	brain := t.TempDir()
-	n := &toggleNotifier{}
-	n.down.Store(true)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 5*time.Millisecond, n)
-	for _, name := range []string{"qa", "qb", "qc"} {
-		link := filepath.Join(brain, name)
-		require.NoError(t, os.Symlink(t.TempDir(), link))
-		require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 2*time.Millisecond)
-	}
-	n.down.Store(false)
-	require.Eventually(t, func() bool { return n.count() == 3 }, 2*time.Second, 5*time.Millisecond)
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	for i, name := range []string{"qa", "qb", "qc"} {
-		assert.Contains(t, n.msgs[i], strconv.Quote(name))
-	}
-}
-
-// PR #160 round 2: dropping after N failures could not tell a poison message
-// from an outage, so a 15-minute outage silently lost the only incident. A
-// message is only dropped when it keeps failing while others send; through
-// an outage nothing is dropped, however long.
-func TestWatchLosesNoAlertThroughALongOutage(t *testing.T) {
-	brain := t.TempDir()
-	n := &toggleNotifier{}
-	n.down.Store(true)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 2*time.Millisecond, n)
-	link := filepath.Join(brain, "only-incident")
-	require.NoError(t, os.Symlink(t.TempDir(), link))
-	require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 2*time.Millisecond)
-	time.Sleep(200 * time.Millisecond) // ~100 ticks of outage, far past any attempt limit
-	n.down.Store(false)
-	require.Eventually(t, func() bool { return n.count() >= 1 }, 2*time.Second, 5*time.Millisecond)
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	assert.Contains(t, n.msgs[0], strconv.Quote("only-incident"))
-}
-
-// Every removal is either delivered or counted in the suppression summary:
-// none disappears from the record (round 2: 74 of 300 were in neither).
-func TestWatchAccountsForEveryRemovalDuringAnOutage(t *testing.T) {
-	brain := t.TempDir()
-	n := &toggleNotifier{}
-	n.down.Store(true)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 2*time.Millisecond, n)
-	const plants = 25
-	for i := 0; i < plants; i++ {
-		link := filepath.Join(brain, "acct"+strconv.Itoa(i))
-		require.NoError(t, os.Symlink(t.TempDir(), link))
-		require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 1*time.Millisecond)
-	}
-	n.down.Store(false)
-	require.Eventually(t, func() bool {
-		n.mu.Lock()
-		defer n.mu.Unlock()
-		for _, m := range n.msgs {
-			if strings.Contains(m, "suppressed") {
-				return true
-			}
-		}
-		return false
-	}, 2*time.Second, 5*time.Millisecond)
-	time.Sleep(50 * time.Millisecond)
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	delivered, counted := 0, 0
-	for _, m := range n.msgs {
-		if strings.Contains(m, "removed 1 symlink(s)") {
-			delivered++
-		}
-		if i := strings.Index(m, "): "); i >= 0 && strings.Contains(m, "suppressed") {
-			_, _ = fmt.Sscanf(m[i+3:], "%d", &counted)
-		}
-	}
-	assert.Equal(t, plants, delivered+counted, "delivered %d + counted %d must equal %d removals", delivered, counted, plants)
-}
-
-// A poison message is still dropped (others send while it fails), and the
-// drop is counted in the summary.
-func TestWatchDropsAPoisonMessageAndCountsIt(t *testing.T) {
-	brain := t.TempDir()
-	n := &rejectNotifier{reject: "POISON"}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 5*time.Millisecond, n)
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "POISON")))
-	time.Sleep(20 * time.Millisecond)
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "fine")))
-	require.Eventually(t, func() bool {
-		n.mu.Lock()
-		defer n.mu.Unlock()
-		for _, m := range n.msgs {
-			if strings.Contains(m, "1 further alert(s)") {
-				return true
-			}
-		}
-		return false
-	}, 3*time.Second, 5*time.Millisecond, "the dropped poison alert is counted in a summary")
-}

ingestion/internal/vectorstore/sync.go

@@ -2,15 +2,12 @@ package vectorstore
 
 import (
 	"context"
-	"errors"
 	"fmt"
-	"io/fs"
 	"log/slog"
-	"path"
+	"os"
+	"path/filepath"
 	"strings"
 	"time"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 )
 
 // Embedder produces dense vectors. The embed package's Client satisfies
@@ -93,38 +90,31 @@ func Sync(ctx context.Context, brainDir string, store Store, embedder Embedder)
 	}
 	seenParents := make(map[string]struct{})
 
-	// Through the brain root, regular files only (hyperguild#157): the brain
-	// is a Syncthing folder, and os.ReadFile followed a synced symlink into
-	// the embeddings and blocked on a FIFO.
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return res, fmt.Errorf("open brain: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
-
 	for _, sub := range scanDirs {
-		if _, err := bfs.Lstat(sub); errors.Is(err, fs.ErrNotExist) {
+		root := filepath.Join(brainDir, sub)
+		if _, err := os.Stat(root); os.IsNotExist(err) {
 			continue
 		}
-		// Any other walk error, including a scan root that is a symlink,
+
-		// aborts the run below.
+		err = filepath.WalkDir(root, func(path string, d os.DirEntry, err error) error {
-		var walkErr error
+			if err != nil {
-		onErr := func(rel string, err error) {
+				return err
-			if walkErr == nil {
-				walkErr = fmt.Errorf("%s: %w", rel, err)
 			}
-		}
+			if d.IsDir() || !strings.HasSuffix(path, ".md") || d.Name() == "_index.md" {
-		err = bfs.WalkRegular(sub, func(relSlash string) error {
-			if !strings.HasSuffix(relSlash, ".md") || path.Base(relSlash) == "_index.md" {
 				return nil
 			}
+			rel, err := filepath.Rel(brainDir, path)
+			if err != nil {
+				return err
+			}
+			relSlash := filepath.ToSlash(rel)
 			seenParents[relSlash] = struct{}{}
 
 			if ps, ok := parents[relSlash]; ok {
 				// File already has chunks in the store. Re-embed only when
 				// the file has been edited since the oldest chunk was
 				// written. Tolerate clock skew with a sub-second grace.
-				info, statErr := bfs.Lstat(relSlash)
+				info, statErr := d.Info()
 				if statErr != nil {
 					res.Errors = append(res.Errors, fmt.Errorf("stat %s: %w", relSlash, statErr))
 					return nil
@@ -142,7 +132,7 @@ func Sync(ctx context.Context, brainDir string, store Store, embedder Embedder)
 				}
 			}
 
-			content, readErr := bfs.ReadRegular(relSlash)
+			content, readErr := os.ReadFile(path)
 			if readErr != nil {
 				res.Errors = append(res.Errors, fmt.Errorf("read %s: %w", relSlash, readErr))
 				return nil
@@ -161,12 +151,7 @@ func Sync(ctx context.Context, brainDir string, store Store, embedder Embedder)
 				res.Added++
 			}
 			return nil
-		}, onErr)
+		})
-		if err == nil {
-			err = walkErr
-		}
-		// Abort before the delete pass: an incomplete walk would leave
-		// seenParents short and delete chunks of files that still exist.
 		if err != nil {
 			return res, fmt.Errorf("walk %s: %w", sub, err)
 		}

ingestion/internal/vectorstore/sync_root_test.go

@@ -1,126 +0,0 @@
-package vectorstore_test
-
-import (
-	"context"
-	"os"
-	"path/filepath"
-	"strings"
-	"sync"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/vectorstore"
-)
-
-// recordingEmbedder keeps every text it was asked to embed.
-type recordingEmbedder struct {
-	mu    sync.Mutex
-	texts []string
-}
-
-func (e *recordingEmbedder) Embed(_ context.Context, text string) ([]float32, error) {
-	e.mu.Lock()
-	defer e.mu.Unlock()
-	e.texts = append(e.texts, text)
-	return []float32{1}, nil
-}
-
-func (e *recordingEmbedder) all() string {
-	e.mu.Lock()
-	defer e.mu.Unlock()
-	return strings.Join(e.texts, "\n")
-}
-
-// hyperguild#157 slice 3: Sync walked wiki/ and knowledge/ and read each .md
-// with os.ReadFile, so a symlinked note had its target embedded and served by
-// semantic search, and a FIFO stalled the sync.
-func TestSyncRefusesSymlinkedNotesAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/facts/ok.md", "inside note")
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(brain, "wiki", "w", "facts", "leak.md")))
-
-	emb := &recordingEmbedder{}
-	store := &stubStore{}
-	_, err := vectorstore.Sync(context.Background(), brain, store, emb)
-	require.NoError(t, err)
-	assert.Contains(t, emb.all(), "inside note", "positive control: the regular note is embedded")
-	assert.NotContains(t, emb.all(), brainfstest.Sentinel)
-	for p := range store.upserts {
-		assert.NotContains(t, p, "leak.md")
-	}
-
-	p := filepath.Join(brain, "knowledge", "r.md")
-	require.NoError(t, os.MkdirAll(filepath.Dir(p), 0o755))
-	sync := func() string {
-		e := &recordingEmbedder{}
-		_, _ = vectorstore.Sync(context.Background(), brain, &stubStore{}, e)
-		return e.all()
-	}
-	brainfstest.AssertNoLeak(t, p, "inside", 1500*time.Millisecond, sync)
-	brainfstest.AssertNoHang(t, p, "inside", 1500*time.Millisecond, 6*time.Second, func() { _ = sync() })
-}
-
-// Chunks embedded from a symlinked note before this fix are deleted: the
-// note is no longer seen, so the delete pass drops its rows.
-func TestSyncDeletesChunksOfASymlinkedNote(t *testing.T) {
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/facts/ok.md", "inside note")
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(brain, "wiki", "w", "facts", "leak.md")))
-	store := &stubStore{known: map[string]time.Time{
-		"wiki/w/facts/leak.md#0001": {},
-		"wiki/w/facts/ok.md#0001":   {},
-	}}
-	_, err := vectorstore.Sync(context.Background(), brain, store, &recordingEmbedder{})
-	require.NoError(t, err)
-	assert.Equal(t, []string{"wiki/w/facts/leak.md#0001"}, store.deletes)
-}
-
-// A walk error aborts Sync before the delete pass, so chunks of files the
-// walk could not see are kept.
-func TestSyncAbortsBeforeDeletingWhenASubdirIsUnreadable(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root ignores directory permissions")
-	}
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/facts/ok.md", "inside note")
-	locked := filepath.Join(brain, "wiki", "w")
-	require.NoError(t, os.Chmod(locked, 0o000))
-	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })
-	store := &stubStore{known: map[string]time.Time{"wiki/w/facts/ok.md#0001": {}}}
-	_, err := vectorstore.Sync(context.Background(), brain, store, &recordingEmbedder{})
-	assert.Error(t, err)
-	assert.Empty(t, store.deletes)
-}
-
-// A scan root that is a symlink inside the brain (knowledge -> .) was
-// followed by fs.WalkDir, aliasing raw/, sessions/ and root files into the
-// index. Sync now aborts on it, before embedding or deleting anything.
-func TestSyncAbortsOnASymlinkedScanRoot(t *testing.T) {
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/a.md", "wiki note")
-	writeNote(t, brain, "sessions/s1.md", "session note")
-	require.NoError(t, os.Symlink(".", filepath.Join(brain, "knowledge")))
-	emb := &recordingEmbedder{}
-	store := &stubStore{known: map[string]time.Time{"wiki/w/a.md#0001": {}}}
-	_, err := vectorstore.Sync(context.Background(), brain, store, emb)
-	assert.Error(t, err)
-	assert.NotContains(t, emb.all(), "session note")
-	for p := range store.upserts {
-		assert.False(t, strings.HasPrefix(p, "knowledge/"), "upserted %s", p)
-	}
-	assert.Empty(t, store.deletes)
-}
-
-// A missing scan root is skipped; the other root still syncs.
-func TestSyncSkipsAMissingScanRoot(t *testing.T) {
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/a.md", "wiki note")
-	emb := &recordingEmbedder{}
-	_, err := vectorstore.Sync(context.Background(), brain, &stubStore{}, emb)
-	require.NoError(t, err)
-	assert.Contains(t, emb.all(), "wiki note")
-}

ingestion/internal/watcher/watcher_test.go

@@ -8,7 +8,6 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
-	"sync"
 	"sync/atomic"
 	"syscall"
 	"testing"
@@ -344,12 +343,7 @@ func TestProcessDir_DoesNotHangUnderAFIFOSwapRace(t *testing.T) {
 	brainDir := setupBrainDir(t)
 	raw := filepath.Join(brainDir, "raw")
 	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	// Awaited before t.TempDir's cleanup (hyperguild#162).
-	t.Cleanup(func() { stop.Store(true); wg.Wait() })
 	go func() {
-		defer wg.Done()
 		for i := 0; !stop.Load(); i++ {
 			tmp := filepath.Join(raw, ".swap")
 			_ = os.Remove(tmp)

ingestion/internal/wiki/index.go

@@ -7,7 +7,6 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/textutil"
 )
 
@@ -17,11 +16,6 @@ func RebuildIndex(brainDir, date string) error {
 	if err != nil {
 		return fmt.Errorf("load inventory: %w", err)
 	}
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return fmt.Errorf("open brain: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
 
 	total := len(inv[PageTypeConcept]) + len(inv[PageTypeEntity]) + len(inv[PageTypeSource])
 	var sb strings.Builder
@@ -40,7 +34,7 @@ func RebuildIndex(brainDir, date string) error {
 		label := strings.ToUpper(string(pt)[:1]) + string(pt)[1:]
 		fmt.Fprintf(&sb, "## %s\n\n", label)
 		for _, e := range entries {
-			summary := pageFirstSentence(bfs, e)
+			summary := pageFirstSentence(brainDir, e)
 			if summary != "" {
 				fmt.Fprintf(&sb, "- [[%s|%s]] — %s\n", e.Slug, e.Title, summary)
 			} else {
@@ -54,10 +48,9 @@ func RebuildIndex(brainDir, date string) error {
 	return os.WriteFile(dest, []byte(sb.String()), 0o644)
 }
 
-// pageFirstSentence reads the page through the brain root, regular files
+func pageFirstSentence(brainDir string, e Entry) string {
-// only (hyperguild#157).
+	path := filepath.Join(brainDir, "wiki", string(e.Type), e.Slug+".md")
-func pageFirstSentence(bfs *brainfs.Brain, e Entry) string {
+	content, err := os.ReadFile(path)
-	content, err := bfs.ReadRegular("wiki/" + string(e.Type) + "/" + e.Slug + ".md")
 	if err != nil {
 		return ""
 	}

ingestion/internal/wiki/inventory.go

@@ -3,45 +3,36 @@ package wiki
 
 import (
 	"bufio"
-	"bytes"
-	"errors"
 	"fmt"
-	"io/fs"
+	"os"
+	"path/filepath"
 	"strings"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 )
 
 // LoadInventory walks brain/wiki/ and returns all pages grouped by type.
-// Missing subdirectories are silently skipped. Pages are listed and read
+// Missing subdirectories are silently skipped.
-// through the brain root, regular files only (hyperguild#157); a type
-// directory that is a symlink is an error.
 func LoadInventory(brainDir string) (map[PageType][]Entry, error) {
 	result := map[PageType][]Entry{
 		PageTypeConcept: {},
 		PageTypeEntity:  {},
 		PageTypeSource:  {},
 	}
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return nil, fmt.Errorf("open brain: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
 	for pt := range result {
-		dir := "wiki/" + string(pt)
+		dir := filepath.Join(brainDir, "wiki", string(pt))
-		names, err := bfs.ReadDirRegular(dir)
+		entries, err := os.ReadDir(dir)
-		if errors.Is(err, fs.ErrNotExist) {
+		if os.IsNotExist(err) {
 			continue
 		}
 		if err != nil {
 			return nil, fmt.Errorf("read dir %s: %w", dir, err)
 		}
-		for _, name := range names {
+		for _, e := range entries {
-			if !strings.HasSuffix(name, ".md") {
+			if e.IsDir() || !strings.HasSuffix(e.Name(), ".md") {
 				continue
 			}
-			slug := strings.TrimSuffix(name, ".md")
+			slug := strings.TrimSuffix(e.Name(), ".md")
-			title, aliases := readFrontmatter(bfs, dir+"/"+name, slug)
+			path := filepath.Join(dir, e.Name())
+			title, aliases := readFrontmatter(path, slug)
 			result[pt] = append(result[pt], Entry{Slug: slug, Title: title, Aliases: aliases, Type: pt})
 		}
 	}
@@ -50,14 +41,15 @@ func LoadInventory(brainDir string) (map[PageType][]Entry, error) {
 
 // readFrontmatter extracts title and aliases from YAML frontmatter.
 // Falls back to slug for title and empty aliases on any error.
-func readFrontmatter(bfs *brainfs.Brain, rel, fallbackSlug string) (title string, aliases []string) {
+func readFrontmatter(path, fallbackSlug string) (title string, aliases []string) {
 	title = fallbackSlug
-	content, err := bfs.ReadRegular(rel)
+	f, err := os.Open(path)
 	if err != nil {
 		return
 	}
+	defer f.Close() //nolint:errcheck
 
-	scanner := bufio.NewScanner(bytes.NewReader(content))
+	scanner := bufio.NewScanner(f)
 	inFM := false
 	inAliases := false
 	for scanner.Scan() {

ingestion/internal/wiki/root_test.go

@@ -1,79 +0,0 @@
-package wiki
-
-import (
-	"fmt"
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-)
-
-// hyperguild#157 slice 4: LoadInventory listed wiki/<type>/ with os.ReadDir
-// and opened each .md by path, so a symlinked page put the target's title and
-// aliases into the inventory (and the LLM prompts built from it), and a FIFO
-// hung it. RebuildIndex read first sentences the same way.
-func TestLoadInventoryRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	dir := filepath.Join(brain, "wiki", "concepts")
-	require.NoError(t, os.MkdirAll(dir, 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "ok.md"), []byte("---\ntitle: zqinside\n---\n"), 0o644))
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(dir, "leak.md")))
-	inBrain := brainfstest.WriteSentinelAt(t, filepath.Join(brain, "raw", "s.md"))
-	require.NoError(t, os.Symlink(filepath.Join("..", "..", "raw", "s.md"), filepath.Join(dir, "inlink.md")))
-
-	inv, err := LoadInventory(brain)
-	require.NoError(t, err)
-	got := fmt.Sprintf("%+v", inv)
-	assert.Contains(t, got, "zqinside", "positive control")
-	assert.NotContains(t, got, brainfstest.Sentinel)
-	assert.NotContains(t, got, "leak", "a symlinked page is not listed")
-	assert.NotContains(t, got, "inlink", "a page linked to another brain file is not listed")
-
-	p := filepath.Join(dir, "r.md")
-	read := func() string {
-		inv, _ := LoadInventory(brain)
-		return fmt.Sprintf("%+v", inv)
-	}
-	brainfstest.AssertNoLeak(t, p, "---\ntitle: zqinside\n---\n", 1500*time.Millisecond, read)
-	brainfstest.AssertNoLeakFrom(t, p, "---\ntitle: zqinside\n---\n", inBrain, 1500*time.Millisecond, read)
-	brainfstest.AssertNoHang(t, p, "---\ntitle: zqinside\n---\n", 1500*time.Millisecond, 6*time.Second, func() { _ = read() })
-}
-
-func TestLoadInventoryReturnsErrNotRegularForASymlinkedTypeDir(t *testing.T) {
-	brain := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki"), 0o755))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "raw"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(brain, "raw", "r.md"), []byte("---\ntitle: zqrawonly\n---\n"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join("..", "raw"), filepath.Join(brain, "wiki", "concepts")))
-	inv, err := LoadInventory(brain)
-	require.ErrorIs(t, err, brainfs.ErrNotRegular)
-	assert.NotContains(t, fmt.Sprintf("%+v", inv), "zqrawonly")
-}
-
-func TestRebuildIndexDoesNotReadAPageSwappedForASymlink(t *testing.T) {
-	brain := t.TempDir()
-	dir := filepath.Join(brain, "wiki", "concepts")
-	require.NoError(t, os.MkdirAll(dir, 0o755))
-	p := filepath.Join(dir, "r.md")
-	require.NoError(t, os.WriteFile(p, []byte("---\ntitle: R\n---\nzqinside sentence.\n"), 0o644))
-	require.NoError(t, RebuildIndex(brain, "2026-10-04"))
-	idx, err := os.ReadFile(filepath.Join(brain, "wiki", "index.md"))
-	require.NoError(t, err)
-	require.Contains(t, string(idx), "zqinside", "positive control: the summary is read")
-
-	read := func() string {
-		_ = RebuildIndex(brain, "2026-10-04")
-		b, _ := os.ReadFile(filepath.Join(brain, "wiki", "index.md"))
-		return string(b)
-	}
-	brainfstest.AssertNoLeak(t, p, "---\ntitle: R\n---\nzqinside sentence.\n", 1500*time.Millisecond, read)
-	inBrain := brainfstest.WriteSentinelAt(t, filepath.Join(brain, "raw", "s.md"))
-	brainfstest.AssertNoLeakFrom(t, p, "---\ntitle: R\n---\nzqinside sentence.\n", inBrain, 1500*time.Millisecond, read)
-	brainfstest.AssertNoHang(t, p, "---\ntitle: R\n---\nzqinside sentence.\n", 1500*time.Millisecond, 6*time.Second, func() { _ = read() })
-}