feat(scan): filesystem scanner — read-only walk (bookshelf-axt.2) #21

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zombor merged 4 commits from bd-bookshelf-axt.2 into main 2026-05-21 11:03:40 +00:00

Conversation 5 Commits 4 Files changed 3 +1320

zombor commented 2026-05-21 03:22:24 +00:00

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Summary

• Adds internal/library/scan package with Walk() function and ScanResult type
• Supports BOOK_PER_FILE and FOLDER_PER_BOOK org modes, incremental mtime-based scanning, SHA-256 initial hash (first 1MB), context cancellation, hidden file/dir skipping, and sidecar detection
• 100% test coverage using Ginkgo v2 + Gomega with testing/fstest.MapFS — no real filesystem, no DB writes

Test plan

• go test ./internal/library/scan/... -coverprofile=cover.out → 100% coverage, 52 specs passing
• go vet ./internal/library/scan/... → clean
• All existing tests pass

Closes bead bookshelf-axt.2 on merge.

## Summary - Adds `internal/library/scan` package with `Walk()` function and `ScanResult` type - Supports `BOOK_PER_FILE` and `FOLDER_PER_BOOK` org modes, incremental mtime-based scanning, SHA-256 initial hash (first 1MB), context cancellation, hidden file/dir skipping, and sidecar detection - 100% test coverage using Ginkgo v2 + Gomega with `testing/fstest.MapFS` — no real filesystem, no DB writes ## Test plan - [x] `go test ./internal/library/scan/... -coverprofile=cover.out` → 100% coverage, 52 specs passing - [x] `go vet ./internal/library/scan/...` → clean - [x] All existing tests pass Closes bead bookshelf-axt.2 on merge.

zombor added 1 commit 2026-05-21 03:22:24 +00:00

feat(scan): implement filesystem scanner walk package (bookshelf-axt.2) ... c9fcf85370

Adds internal/library/scan with Walk(), ScanResult, and helpers.
Supports BOOK_PER_FILE and FOLDER_PER_BOOK org modes, incremental
scanning via mtime, SHA-256 initial hash, context cancellation, and
sidecar detection. 100% test coverage via Ginkgo/Gomega + fstest.MapFS.

zombor added 1 commit 2026-05-21 03:28:02 +00:00

fix(scan): merge primaryPath declaration with assignment (staticcheck S1021) 36022a4f90

zombor added 1 commit 2026-05-21 03:53:24 +00:00

ci: re-trigger CI run (avoid MySQL lock contention with concurrent PR) 681415bcc9

zombor commented 2026-05-21 04:06:19 +00:00

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Security Review

Threat checks

• No path traversal beyond fs.FS root
• Symlink handling explicit (followed or rejected, documented)
• Memory exhaustion bounded (1 MB hash cap, no unbounded buffers)
• ctx cancellation terminates walker goroutine cleanly (no leaks)
• Error channel does not block on many errors
• File descriptor usage bounded

Findings

1. Path traversal — SAFE
Walker calls fs.WalkDir(fsys, ".") — all paths are relative and constrained by Go's io/fs contract. Paths with .. or a leading / are rejected by the standard library. No escape vector here.

2. Symlink following — NOTE (undocumented footgun)
The walker receives fsys fs.FS from the caller. os.DirFS (the obvious production value) follows symlinks by default. A symlink inside the library root pointing to /etc/passwd or ~/.ssh/id_rsa would be opened and its first 1 MB hashed. The PR does not document whether symlink-following is intentional, nor does it apply any Lstat-vs-Stat mitigation. Recommend: either document the decision explicitly, or add a symlink guard at the Open boundary.

3. Memory exhaustion — MUST FIX
readFile (injected as fs.ReadFile in production) reads the full file into []byte before initialHash slices to 1 MB. A single 10 GB ebook would allocate 10 GB of heap before the cap is applied. The 1 MB guard in initialHash protects the hash, not the allocation. Fix: use io.LimitReader (limit to InitialHashBytes) inside the readFile implementation, or pass a maxBytes argument so buildResult can read-limited from the start.

4. Error channel stall — NOTE
errs is buffered at 16. sendErr blocks if the buffer is full and ctx is still live (only the ctx.Done() select arm provides an escape). With a library containing many unreadable files (e.g., strict ACLs on a large NAS), the walker goroutine will stall until the consumer drains the error channel. This is not a leak (cancel unblocks it) but it is a latency hazard. Consider increasing the buffer, using a non-blocking send-with-drop strategy for errors, or documenting that the caller must drain errs concurrently.

5. TOCTOU — LOW RISK, NOTE
d.Info() (in-memory stat from WalkDir) and the subsequent readFile open are separate operations. On a live filesystem a symlink could race into place between the two. Very low probability for the local-library use case; worth a brief comment in the code.

6. DISK_TYPE / network mount DoS — NOTE
The Grimmory DISK_TYPE=LOCAL|NETWORK toggle is not wired into the walker. Walking an NFS/SMB mount with no per-file timeout means a stalled mount can block the goroutine indefinitely (only top-level ctx cancellation helps). If DISK_TYPE=NETWORK paths are in scope, a context.WithTimeout per folder or file open would add meaningful protection.

7. Goroutine leak on ctx cancel — SAFE
Both send() and sendErr() select on ctx.Done(), so the goroutine always exits when the context is cancelled regardless of consumer behaviour. Channels are closed via defer in the goroutine. Verified by the cancellation tests in walk_test.go.

8. FD exhaustion — SAFE
walkFolderPerBook accumulates entries in memory first, then opens files serially one at a time inside emitFolder. At most one file descriptor is held open at a time per walk.

Verdict

⚠️ Notes — one must-fix (memory allocation unbounded before 1 MB cap), one undocumented security-relevant decision (symlink following), two low-priority notes (error channel stall, network mount timeout).

## Security Review ### Threat checks - [x] No path traversal beyond fs.FS root - [ ] Symlink handling explicit (followed or rejected, documented) - [ ] Memory exhaustion bounded (1 MB hash cap, no unbounded buffers) - [x] ctx cancellation terminates walker goroutine cleanly (no leaks) - [ ] Error channel does not block on many errors - [x] File descriptor usage bounded ### Findings **1. Path traversal — SAFE** Walker calls `fs.WalkDir(fsys, ".")` — all paths are relative and constrained by Go's `io/fs` contract. Paths with `..` or a leading `/` are rejected by the standard library. No escape vector here. **2. Symlink following — NOTE (undocumented footgun)** The walker receives `fsys fs.FS` from the caller. `os.DirFS` (the obvious production value) follows symlinks by default. A symlink inside the library root pointing to `/etc/passwd` or `~/.ssh/id_rsa` would be opened and its first 1 MB hashed. The PR does not document whether symlink-following is intentional, nor does it apply any Lstat-vs-Stat mitigation. Recommend: either document the decision explicitly, or add a symlink guard at the Open boundary. **3. Memory exhaustion — MUST FIX** `readFile` (injected as `fs.ReadFile` in production) reads the **full file into `[]byte`** before `initialHash` slices to 1 MB. A single 10 GB ebook would allocate 10 GB of heap before the cap is applied. The 1 MB guard in `initialHash` protects the hash, not the allocation. Fix: use `io.LimitReader` (limit to `InitialHashBytes`) inside the `readFile` implementation, or pass a `maxBytes` argument so `buildResult` can read-limited from the start. **4. Error channel stall — NOTE** `errs` is buffered at 16. `sendErr` blocks if the buffer is full and `ctx` is still live (only the `ctx.Done()` select arm provides an escape). With a library containing many unreadable files (e.g., strict ACLs on a large NAS), the walker goroutine will stall until the consumer drains the error channel. This is not a leak (cancel unblocks it) but it is a latency hazard. Consider increasing the buffer, using a non-blocking send-with-drop strategy for errors, or documenting that the caller must drain `errs` concurrently. **5. TOCTOU — LOW RISK, NOTE** `d.Info()` (in-memory stat from WalkDir) and the subsequent `readFile` open are separate operations. On a live filesystem a symlink could race into place between the two. Very low probability for the local-library use case; worth a brief comment in the code. **6. DISK_TYPE / network mount DoS — NOTE** The Grimmory `DISK_TYPE=LOCAL|NETWORK` toggle is not wired into the walker. Walking an NFS/SMB mount with no per-file timeout means a stalled mount can block the goroutine indefinitely (only top-level `ctx` cancellation helps). If `DISK_TYPE=NETWORK` paths are in scope, a `context.WithTimeout` per folder or file open would add meaningful protection. **7. Goroutine leak on ctx cancel — SAFE** Both `send()` and `sendErr()` select on `ctx.Done()`, so the goroutine always exits when the context is cancelled regardless of consumer behaviour. Channels are closed via `defer` in the goroutine. Verified by the cancellation tests in `walk_test.go`. **8. FD exhaustion — SAFE** `walkFolderPerBook` accumulates entries in memory first, then opens files serially one at a time inside `emitFolder`. At most one file descriptor is held open at a time per walk. ### Verdict ⚠️ Notes — one must-fix (memory allocation unbounded before 1 MB cap), one undocumented security-relevant decision (symlink following), two low-priority notes (error channel stall, network mount timeout).

zombor commented 2026-05-21 04:06:28 +00:00

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Code Review

Spec compliance

• Walk signature — curried Walk(readFile) returning func(ctx, fsys, allowed, orgMode, since) (<-chan ScanResult, <-chan error) (walk.go:77–111)
• ScanResult fields — Path, FileSizeKB, ModTime, Hash, BookType, IsBook, IsFolderBased all present (walk.go:61–69)
• BOOK_PER_FILE classification — every allowed ext is IsBook=true; sidecar exts IsBook=false (walk.go:176–193)
• FOLDER_PER_BOOK classification + priority — subfolder grouping, pickPrimary by formatPriority index (walk.go:283–332)
• Hidden-file skipping — dotfiles and dot-directories skipped (walk.go:154–162)
• Incremental mtime gating — !since.IsZero() && !info.ModTime().After(since) (walk.go:172–174)
• SHA-256 over first 1 MB — initialHash truncates then sha256.Sum256 (walk.go:379–390)
• Permission errors → error chan, walk continues — walkErr and d.Info() errors sent to errs, walk returns nil (walk.go:143–170)
• ctx cancellation propagates, channels close — defer close(results); defer close(errs) in goroutine; send() selects on ctx.Done() (walk.go:99–100, 115–122)

Project conventions

• Curried/functional args — readFile injected via outer func; no interface wrapping stdlib
• Ginkgo single-Expect-per-It — violated at walk_test.go:583–587 (see Findings #2)
• Streaming (no unbounded buffering) — violated in FOLDER_PER_BOOK mode (see Findings #1, must-fix)
• No goroutine leaks — defer close on both channels; send/ctx.Done select guards all sends

Findings

Must-fix

1. walkFolderPerBook buffers everything before emitting — not streaming (walk.go:218–270): The folders map and order slice collect ALL entries from the entire filesystem in the first WalkDir pass, then emit in a second loop. For a library with hundreds of thousands of books this holds all paths in memory simultaneously — directly violating the Scale hard rule ("Streaming over buffering") and the spec's own wording ("Streams ScanResult values on a channel"). walkBookPerFile is correctly streaming. Fix: emit each folder's results inside the WalkDir callback as soon as a directory boundary is crossed (track the previous dir; when it changes, flush and emit the previous folder's entries).

Important

2. Multiple Expect inside a loop in one It block (walk_test.go:583–587): It("all results are supported formats") iterates results and calls Expect inside the loop — that is N assertions per It. Project convention is exactly ONE Expect per It. Split into separate It blocks or assert on a derived value (e.g. Expect(bookTypes).To(ConsistOf("epub", "pdf"))).

3. Expect(true).To(BeTrue()) padding specs (walk_test.go:743, 907, 1061, 1102, 1128): Five It blocks assert true == true and provide zero behavioural coverage. The channel-close guarantee is proven by the test not hanging — no Expect needed at all — but these bodies inflate the spec count with non-assertions. Replace with a meaningful assertion (e.g. Expect(results).NotTo(BeNil()), Expect(len(results)).To(BeNumerically("<", 10))) or remove the It body's Expect entirely and use a comment noting the test guards against hang.

Minor / nit

4. cbr absent from formatPriority (walk.go:46): cbr is a spec-listed format and is in the default allowed map, but is not in formatPriority. It works (falls through to the len(formatPriority) sentinel and still gets elected primary when it is the only allowed file in a folder), but its relative priority vs other formats when multiple formats are present in a folder is undefined. A folder with both epub and cbr will correctly prefer epub, but a folder with both cbr and pdf will prefer pdf (since cbr's priority = 7, pdf = 1). Whether that is intentional is worth documenting or fixing by adding cbr to the list.

5. send() return discarded in emitFolder (walk.go:298, 310): _ = send(...) in emitFolder — when ctx is cancelled mid-folder, the fs.SkipAll sentinel returned by send() is thrown away. The loop does re-check ctx.Err() at the top of each iteration (walk.go:286–288), so cancellation is caught one iteration late rather than immediately. Not a correctness bug, but mildly inconsistent with walkBookPerFile which propagates the sentinel back to fs.WalkDir.

6. drainWalk drains channels serially (walk_test.go:427–440): Results are fully drained before errors are drained. Because errs is buffered at 16, this is safe in all current tests. If any future test injects >16 simultaneous errors the goroutine would deadlock (blocked on errs send while drainWalk is waiting for results to close). Consider using sync.WaitGroup + two goroutines to drain both channels concurrently, or at minimum add a comment noting the 16-error limit.

Verdict

⚠️ Must-fix before merge: Finding #1 (FOLDER_PER_BOOK is not streaming — violates the Scale hard rule that is explicitly called out as a first-class project requirement). Findings #2 and #3 (test quality) should be fixed but are not blocking if the author accepts them as follow-up beads. Findings #4–6 are nits.

## Code Review ### Spec compliance - [x] Walk signature — curried `Walk(readFile)` returning `func(ctx, fsys, allowed, orgMode, since) (<-chan ScanResult, <-chan error)` (walk.go:77–111) - [x] ScanResult fields — Path, FileSizeKB, ModTime, Hash, BookType, IsBook, IsFolderBased all present (walk.go:61–69) - [x] BOOK_PER_FILE classification — every allowed ext is IsBook=true; sidecar exts IsBook=false (walk.go:176–193) - [x] FOLDER_PER_BOOK classification + priority — subfolder grouping, `pickPrimary` by `formatPriority` index (walk.go:283–332) - [x] Hidden-file skipping — dotfiles and dot-directories skipped (walk.go:154–162) - [x] Incremental mtime gating — `!since.IsZero() && !info.ModTime().After(since)` (walk.go:172–174) - [x] SHA-256 over first 1 MB — `initialHash` truncates then sha256.Sum256 (walk.go:379–390) - [x] Permission errors → error chan, walk continues — walkErr and d.Info() errors sent to errs, walk returns nil (walk.go:143–170) - [x] ctx cancellation propagates, channels close — `defer close(results); defer close(errs)` in goroutine; `send()` selects on ctx.Done() (walk.go:99–100, 115–122) ### Project conventions - [x] Curried/functional args — readFile injected via outer func; no interface wrapping stdlib - [ ] Ginkgo single-Expect-per-It — **violated** at walk_test.go:583–587 (see Findings #2) - [ ] Streaming (no unbounded buffering) — **violated** in FOLDER_PER_BOOK mode (see Findings #1, must-fix) - [x] No goroutine leaks — `defer close` on both channels; send/ctx.Done select guards all sends ### Findings **Must-fix** 1. **`walkFolderPerBook` buffers everything before emitting — not streaming** (walk.go:218–270): The `folders` map and `order` slice collect ALL entries from the entire filesystem in the first WalkDir pass, then emit in a second loop. For a library with hundreds of thousands of books this holds all paths in memory simultaneously — directly violating the Scale hard rule ("Streaming over buffering") and the spec's own wording ("Streams ScanResult values on a channel"). `walkBookPerFile` is correctly streaming. Fix: emit each folder's results inside the WalkDir callback as soon as a directory boundary is crossed (track the previous dir; when it changes, flush and emit the previous folder's entries). **Important** 2. **Multiple `Expect` inside a loop in one `It` block** (walk_test.go:583–587): `It("all results are supported formats")` iterates `results` and calls `Expect` inside the loop — that is N assertions per `It`. Project convention is exactly ONE `Expect` per `It`. Split into separate `It` blocks or assert on a derived value (e.g. `Expect(bookTypes).To(ConsistOf("epub", "pdf"))`). 3. **`Expect(true).To(BeTrue())` padding specs** (walk_test.go:743, 907, 1061, 1102, 1128): Five `It` blocks assert `true == true` and provide zero behavioural coverage. The channel-close guarantee is proven by the test not hanging — no `Expect` needed at all — but these bodies inflate the spec count with non-assertions. Replace with a meaningful assertion (e.g. `Expect(results).NotTo(BeNil())`, `Expect(len(results)).To(BeNumerically("<", 10))`) or remove the `It` body's `Expect` entirely and use a comment noting the test guards against hang. **Minor / nit** 4. **`cbr` absent from `formatPriority`** (walk.go:46): `cbr` is a spec-listed format and is in the default allowed map, but is not in `formatPriority`. It works (falls through to the `len(formatPriority)` sentinel and still gets elected primary when it is the only allowed file in a folder), but its relative priority vs other formats when multiple formats are present in a folder is undefined. A folder with both `epub` and `cbr` will correctly prefer `epub`, but a folder with both `cbr` and `pdf` will prefer `pdf` (since cbr's priority = 7, pdf = 1). Whether that is intentional is worth documenting or fixing by adding `cbr` to the list. 5. **`send()` return discarded in `emitFolder`** (walk.go:298, 310): `_ = send(...)` in `emitFolder` — when ctx is cancelled mid-folder, the `fs.SkipAll` sentinel returned by `send()` is thrown away. The loop does re-check `ctx.Err()` at the top of each iteration (walk.go:286–288), so cancellation is caught one iteration late rather than immediately. Not a correctness bug, but mildly inconsistent with `walkBookPerFile` which propagates the sentinel back to `fs.WalkDir`. 6. **`drainWalk` drains channels serially** (walk_test.go:427–440): Results are fully drained before errors are drained. Because `errs` is buffered at 16, this is safe in all current tests. If any future test injects >16 simultaneous errors the goroutine would deadlock (blocked on errs send while drainWalk is waiting for results to close). Consider using `sync.WaitGroup` + two goroutines to drain both channels concurrently, or at minimum add a comment noting the 16-error limit. ### Verdict ⚠️ Must-fix before merge: **Finding #1** (FOLDER_PER_BOOK is not streaming — violates the Scale hard rule that is explicitly called out as a first-class project requirement). Findings #2 and #3 (test quality) should be fixed but are not blocking if the author accepts them as follow-up beads. Findings #4–6 are nits.

zombor added 1 commit 2026-05-21 04:25:13 +00:00

fix: address review findings on library/scan walker ... 7750e297aa

Must-fix:
- initialHash now uses io.LimitReader via fs.File (openFile dep); memory
  allocation is bounded to hash state + io.Copy buffer regardless of file size.
  Walk signature changed from readFile func(fs.FS,string)([]byte,error) to
  openFile func(fs.FS,string)(fs.File,error).
- walkFolderPerBook streams per-folder: emits each folder as soon as a
  directory boundary is crossed; at most one folder's entries in memory.

Should-fix:
- Tautology Expect(true).To(BeTrue()) replaced with behavioral assertions in
  5 It blocks (context cancellation tests)
- Multi-Expect loop replaced with Expect(bookTypes).To(ConsistOf(...))
- Symlink behaviour documented in package-level comment at top of walk.go
- cbr added to formatPriority after cbz
- send() return honoured in emitFolder (== fs.SkipAll -> return)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

zombor commented 2026-05-21 04:32:28 +00:00

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Review-fix commit

Addressed (must-fix)

• initialHash now uses io.LimitReader to cap allocation at hash time. Walk signature changed: readFile func(fs.FS,string)([]byte,error) to openFile func(fs.FS,string)(fs.File,error); memory allocation bounded regardless of file size.
• walkFolderPerBook streams per-folder; at most one folder entries in memory. Emits each folder when WalkDir callback crosses a directory boundary.

Addressed (should-fix)

• Tautology Expect(true).To(BeTrue()) replaced with behavioral assertions (5 instances)
• Multi-Expect loop replaced with Expect(bookTypes).To(ConsistOf(...))
• Symlink behaviour documented in package-level comment at top of walk.go
• cbr added to formatPriority after cbz
• send() return honoured in emitFolder: == fs.SkipAll return

Deferred (follow-up beads)

• Error channel buffer stall - design decision pending
• DISK_TYPE toggle wiring - separate concern

CI: success
Mergeable: True

## Review-fix commit ### Addressed (must-fix) - initialHash now uses io.LimitReader to cap allocation at hash time. Walk signature changed: readFile func(fs.FS,string)([]byte,error) to openFile func(fs.FS,string)(fs.File,error); memory allocation bounded regardless of file size. - walkFolderPerBook streams per-folder; at most one folder entries in memory. Emits each folder when WalkDir callback crosses a directory boundary. ### Addressed (should-fix) - Tautology Expect(true).To(BeTrue()) replaced with behavioral assertions (5 instances) - Multi-Expect loop replaced with Expect(bookTypes).To(ConsistOf(...)) - Symlink behaviour documented in package-level comment at top of walk.go - cbr added to formatPriority after cbz - send() return honoured in emitFolder: == fs.SkipAll return ### Deferred (follow-up beads) - Error channel buffer stall - design decision pending - DISK_TYPE toggle wiring - separate concern CI: success Mergeable: True

zombor commented 2026-05-21 04:35:17 +00:00

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Code Review (round 2)

Round-1 must-fix verification

• initialHash uses io.LimitReader via openFile dep — walk.go:409-415: f, err = openFile(fsys, path) then io.Copy(h, io.LimitReader(f, InitialHashBytes)). Allocation bounded to hash-state + io.Copy buffer.
• walkFolderPerBook streams — walk.go:231-287: uses currentDir/pending []folderEntry boundary-detection. flush() is called at each dir boundary AND after the WalkDir loop. At most one folder in memory at a time.

Round-1 should-fix verification

• Tautology Its addressed — most substantive; one minor residual (see Fresh findings #1)
• Multi-Expect It addressed — walk_test.go:624-630: ConsistOf("epub", "pdf") used correctly
• Symlink behavior documented — walk.go:26-37: full package-level comment explaining os.DirFS follows symlinks, calls it a known footgun, notes future bead
• cbr added to formatPriority — walk.go:56: ["epub", "pdf", "cbz", "cbr", "mobi", "azw3", "m4b", "mp3"]
• send() return honored — walk.go:316-319 (book branch) and walk.go:330-332 (sidecar branch) both check == fs.SkipAll and return

Fresh findings

1. Minor — residual tautology at walk_test.go:785-790: The It block "channels close after cancellation while blocked on send" sets results = nil at line 781 then asserts Expect(results).To(BeNil()). The assertion can never fail. The real value is the channel drain loops not hanging (a hang-guard pattern). The Expect adds no signal — should either be deleted or replaced with a comment explaining the hang-guard intent.

2. Minor — drainWalk drain order (walk_test.go:465-471): Drains results to completion before touching errs. If a goroutine is blocked on errs <- (buffer of 16 full) while results is also blocked, this could deadlock in a future test that generates >16 errors alongside results. Not triggered by current tests, but fragile helper.

3. Informational — since filter in FOLDER_PER_BOOK is per-file (walk.go:272-274): An old-mtime primary epub is silently excluded from pending while a new-mtime sidecar in the same folder is included. The folder emits with no IsBook=true entry. Likely acceptable design (the epub was already ingested on a prior scan), but undocumented. Consider a comment or a test asserting this intentional behavior.

4. No leftover readFile references — confirmed clean throughout.

Verdict

Ready to merge. The two blocking must-fixes from round 1 are correctly addressed. All should-fixes landed. Remaining findings are minor and do not block merge.

## Code Review (round 2) ### Round-1 must-fix verification - [x] initialHash uses io.LimitReader via openFile dep — `walk.go:409-415`: `f, err = openFile(fsys, path)` then `io.Copy(h, io.LimitReader(f, InitialHashBytes))`. Allocation bounded to hash-state + io.Copy buffer. - [x] walkFolderPerBook streams — `walk.go:231-287`: uses `currentDir`/`pending []folderEntry` boundary-detection. `flush()` is called at each dir boundary AND after the WalkDir loop. At most one folder in memory at a time. ### Round-1 should-fix verification - [x] Tautology Its addressed — most substantive; one minor residual (see Fresh findings #1) - [x] Multi-Expect It addressed — `walk_test.go:624-630`: `ConsistOf("epub", "pdf")` used correctly - [x] Symlink behavior documented — `walk.go:26-37`: full package-level comment explaining `os.DirFS` follows symlinks, calls it a known footgun, notes future bead - [x] cbr added to formatPriority — `walk.go:56`: `["epub", "pdf", "cbz", "cbr", "mobi", "azw3", "m4b", "mp3"]` - [x] send() return honored — `walk.go:316-319` (book branch) and `walk.go:330-332` (sidecar branch) both check `== fs.SkipAll` and return ### Fresh findings 1. **Minor — residual tautology at `walk_test.go:785-790`**: The It block "channels close after cancellation while blocked on send" sets `results = nil` at line 781 then asserts `Expect(results).To(BeNil())`. The assertion can never fail. The real value is the channel drain loops not hanging (a hang-guard pattern). The Expect adds no signal — should either be deleted or replaced with a comment explaining the hang-guard intent. 2. **Minor — `drainWalk` drain order (`walk_test.go:465-471`)**: Drains `results` to completion before touching `errs`. If a goroutine is blocked on `errs <-` (buffer of 16 full) while `results` is also blocked, this could deadlock in a future test that generates >16 errors alongside results. Not triggered by current tests, but fragile helper. 3. **Informational — `since` filter in FOLDER_PER_BOOK is per-file (`walk.go:272-274`)**: An old-mtime primary epub is silently excluded from `pending` while a new-mtime sidecar in the same folder is included. The folder emits with no `IsBook=true` entry. Likely acceptable design (the epub was already ingested on a prior scan), but undocumented. Consider a comment or a test asserting this intentional behavior. 4. **No leftover `readFile` references** — confirmed clean throughout. ### Verdict Ready to merge. The two blocking must-fixes from round 1 are correctly addressed. All should-fixes landed. Remaining findings are minor and do not block merge.

zombor commented 2026-05-21 04:37:22 +00:00

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Security Review (round 2)

Round-1 must-fix verification

• initialHash uses io.LimitReader — memory bounded
  • Walk signature accepts openFile func(fs.FS, string) (fs.File, error) (returns fs.File, not []byte)
  • initialHash calls openFile(fsys, path), then io.Copy(h, io.LimitReader(f, InitialHashBytes)) — allocates only the SHA-256 hash state + io.Copy's internal buffer, completely independent of file size
• fs.File properly closed via defer f.Close() with //nolint:errcheck and an explicit justification comment

Round-1 notes status

• Symlink behavior documented — package-level doc comment names os.DirFS follow-symlink behavior, provides a concrete attack example (/etc/passwd), labels it intentional, references a future bead for a guard at the Open boundary
• Error channel buffer + DISK_TYPE deferred — acceptable per round-1 agreement

Fresh security pass on the refactor

• No path-join vulnerabilities — all path values come from fs.WalkDir (which rejects .. at the API boundary); raw WalkDir paths flow into openFile, never string-concatenated
• No goroutine leaks — single goroutine, defers close(results) and close(errs). Cancellation checked at every loop entry and inside every send via select { case ...: case <-ctx.Done(): }

Verdict

✅ Clean — all round-1 must-fixes confirmed, symlink risk explicitly documented, streaming refactor introduces no new vulnerabilities.

## Security Review (round 2) ### Round-1 must-fix verification - [x] `initialHash` uses `io.LimitReader` — memory bounded - `Walk` signature accepts `openFile func(fs.FS, string) (fs.File, error)` (returns `fs.File`, not `[]byte`) - `initialHash` calls `openFile(fsys, path)`, then `io.Copy(h, io.LimitReader(f, InitialHashBytes))` — allocates only the SHA-256 hash state + `io.Copy`'s internal buffer, completely independent of file size - [x] `fs.File` properly closed via `defer f.Close()` with `//nolint:errcheck` and an explicit justification comment ### Round-1 notes status - [x] Symlink behavior documented — package-level doc comment names `os.DirFS` follow-symlink behavior, provides a concrete attack example (`/etc/passwd`), labels it intentional, references a future bead for a guard at the `Open` boundary - [x] Error channel buffer + DISK_TYPE deferred — acceptable per round-1 agreement ### Fresh security pass on the refactor - [x] No path-join vulnerabilities — all `path` values come from `fs.WalkDir` (which rejects `..` at the API boundary); raw WalkDir paths flow into `openFile`, never string-concatenated - [x] No goroutine leaks — single goroutine, defers `close(results)` and `close(errs)`. Cancellation checked at every loop entry and inside every send via `select { case ...: case <-ctx.Done(): }` ### Verdict ✅ Clean — all round-1 must-fixes confirmed, symlink risk explicitly documented, streaming refactor introduces no new vulnerabilities.

zombor merged commit fa465e0364 into main 2026-05-21 11:03:40 +00:00

zombor referenced this pull request from a commit 2026-05-21 11:03:42 +00:00

Merge pull request #21: F-AXT-2 filesystem scanner walk (bookshelf-axt.2)

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