task a8: move all binaries under ./cmd/<name>/main.go

Relocates the two non-canonical main packages so every binary in the repo
lives at ./cmd/<BINARY>/main.go:

- tools/filewriter/ -> cmd/filewriter/
- integrationtests/cmd/ioworkload/ (20 files) -> cmd/ioworkload/

Consumers updated:
- Magefile.go: workloadSourcePath now ./cmd/ioworkload
- integrationtests/README.md: structure note points at ../cmd/ioworkload

Files moved with git mv so git log --follow history is preserved.
cmd/ior/main.go was already canonical and is untouched.

Verified: mage build produces the ior binary; go build ./cmd/...
builds filewriter and ioworkload; go test ./cmd/ioworkload passes;
go vet ./cmd/filewriter ./cmd/ioworkload is clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

1 files changed, 0 insertions, 193 deletions

diff --git a/integrationtests/cmd/ioworkload/scenario_unlink.go b/integrationtests/cmd/ioworkload/scenario_unlink.go
deleted file mode 100644
index ea73b10..0000000
--- a/integrationtests/cmd/ioworkload/scenario_unlink.go
+++ /dev/null
@@ -1,193 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"path/filepath"
-	"runtime"
-	"syscall"
-	"unsafe"
-)
-
-// unlinkBasic creates a file and unlinks it via raw SYS_UNLINK.
-// We use the raw syscall because Go's syscall.Unlink wraps unlinkat on amd64.
-func unlinkBasic() error {
-	dir, cleanup, err := makeTempDir("unlink-basic")
-	if err != nil {
-		return err
-	}
-	defer cleanup()
-
-	path := filepath.Join(dir, "unlinkme.txt")
-	fd, err := syscall.Open(path, syscall.O_RDWR|syscall.O_CREAT, 0o644)
-	if err != nil {
-		return fmt.Errorf("open: %w", err)
-	}
-	if err := syscall.Close(fd); err != nil {
-		return fmt.Errorf("close: %w", err)
-	}
-
-	pathBytes, err := syscall.BytePtrFromString(path)
-	if err != nil {
-		return fmt.Errorf("path bytes: %w", err)
-	}
-	_, _, errno := syscall.Syscall(syscall.SYS_UNLINK, uintptr(unsafe.Pointer(pathBytes)), 0, 0)
-	runtime.KeepAlive(pathBytes)
-	if errno != 0 {
-		return fmt.Errorf("unlink: %w", errno)
-	}
-	return nil
-}
-
-// unlinkUnlinkat creates a file and unlinks it via unlinkat(2).
-func unlinkUnlinkat() error {
-	dir, cleanup, err := makeTempDir("unlink-unlinkat")
-	if err != nil {
-		return err
-	}
-	defer cleanup()
-
-	path := filepath.Join(dir, "unlinkat-file.txt")
-	fd, err := syscall.Open(path, syscall.O_RDWR|syscall.O_CREAT, 0o644)
-	if err != nil {
-		return fmt.Errorf("open: %w", err)
-	}
-	if err := syscall.Close(fd); err != nil {
-		return fmt.Errorf("close: %w", err)
-	}
-
-	dirFD, err := syscall.Open(dir, syscall.O_RDONLY|syscall.O_DIRECTORY, 0)
-	if err != nil {
-		return fmt.Errorf("open dir: %w", err)
-	}
-	defer syscall.Close(dirFD)
-
-	nameBytes, err := syscall.BytePtrFromString("unlinkat-file.txt")
-	if err != nil {
-		return fmt.Errorf("name bytes: %w", err)
-	}
-	_, _, errno := syscall.Syscall(syscall.SYS_UNLINKAT, uintptr(dirFD), uintptr(unsafe.Pointer(nameBytes)), 0)
-	runtime.KeepAlive(nameBytes)
-	if errno != 0 {
-		return fmt.Errorf("unlinkat: %w", errno)
-	}
-	return nil
-}
-
-// unlinkRmdir creates a directory and removes it via raw SYS_RMDIR.
-// We use the raw syscall because Go's syscall.Rmdir wraps unlinkat on amd64.
-func unlinkRmdir() error {
-	dir, cleanup, err := makeTempDir("unlink-rmdir")
-	if err != nil {
-		return err
-	}
-	defer cleanup()
-
-	// Retry with fresh paths to avoid a single one-shot syscall that can race
-	// tracepoint attach during parallel integration test startup.
-	for i := 0; i < 5; i++ {
-		subDir := filepath.Join(dir, fmt.Sprintf("rmdir-me-%d", i))
-		if err := syscall.Mkdir(subDir, 0o755); err != nil {
-			return fmt.Errorf("mkdir: %w", err)
-		}
-
-		pathBytes, err := syscall.BytePtrFromString(subDir)
-		if err != nil {
-			return fmt.Errorf("path bytes: %w", err)
-		}
-		_, _, errno := syscall.Syscall(syscall.SYS_RMDIR, uintptr(unsafe.Pointer(pathBytes)), 0, 0)
-		runtime.KeepAlive(pathBytes)
-		if errno != 0 {
-			return fmt.Errorf("rmdir: %w", errno)
-		}
-	}
-	return nil
-}
-
-// unlinkEnoent attempts to unlink a nonexistent file via raw SYS_UNLINK.
-// The syscall fails with ENOENT, but ior captures the tracepoint on entry.
-func unlinkEnoent() error {
-	dir, cleanup, err := makeTempDir("unlink-enoent")
-	if err != nil {
-		return err
-	}
-	defer cleanup()
-
-	path := filepath.Join(dir, "unlink-enoent-missing.txt")
-	pathBytes, err := syscall.BytePtrFromString(path)
-	if err != nil {
-		return fmt.Errorf("path bytes: %w", err)
-	}
-	for i := 0; i < 5; i++ {
-		_, _, errno := syscall.Syscall(syscall.SYS_UNLINK, uintptr(unsafe.Pointer(pathBytes)), 0, 0)
-		runtime.KeepAlive(pathBytes)
-		if errno == 0 {
-			return fmt.Errorf("expected ENOENT, but unlink succeeded")
-		}
-	}
-	return nil
-}
-
-// unlinkRmdirNotempty attempts to rmdir a non-empty directory via raw SYS_RMDIR.
-// The syscall fails with ENOTEMPTY, but ior captures the tracepoint on entry.
-func unlinkRmdirNotempty() error {
-	dir, cleanup, err := makeTempDir("unlink-rmdir-notempty")
-	if err != nil {
-		return err
-	}
-	defer cleanup()
-
-	subDir := filepath.Join(dir, "rmdir-notempty")
-	if err := syscall.Mkdir(subDir, 0o755); err != nil {
-		return fmt.Errorf("mkdir: %w", err)
-	}
-
-	// Create a file inside so the directory is non-empty.
-	filePath := filepath.Join(subDir, "blocker.txt")
-	fd, err := syscall.Open(filePath, syscall.O_RDWR|syscall.O_CREAT, 0o644)
-	if err != nil {
-		return fmt.Errorf("create blocker: %w", err)
-	}
-	if err := syscall.Close(fd); err != nil {
-		return fmt.Errorf("close blocker: %w", err)
-	}
-
-	pathBytes, err := syscall.BytePtrFromString(subDir)
-	if err != nil {
-		return fmt.Errorf("path bytes: %w", err)
-	}
-	_, _, errno := syscall.Syscall(syscall.SYS_RMDIR, uintptr(unsafe.Pointer(pathBytes)), 0, 0)
-	runtime.KeepAlive(pathBytes)
-	if errno == 0 {
-		return fmt.Errorf("expected ENOTEMPTY, but rmdir succeeded")
-	}
-	return nil
-}
-
-// unlinkUnlinkatEnoent attempts to unlinkat a nonexistent file.
-// The syscall fails with ENOENT, but ior captures the tracepoint on entry.
-func unlinkUnlinkatEnoent() error {
-	dir, cleanup, err := makeTempDir("unlink-unlinkat-enoent")
-	if err != nil {
-		return err
-	}
-	defer cleanup()
-
-	dirFD, err := syscall.Open(dir, syscall.O_RDONLY|syscall.O_DIRECTORY, 0)
-	if err != nil {
-		return fmt.Errorf("open dir: %w", err)
-	}
-	defer syscall.Close(dirFD)
-
-	nameBytes, err := syscall.BytePtrFromString("unlinkat-enoent-missing.txt")
-	if err != nil {
-		return fmt.Errorf("name bytes: %w", err)
-	}
-	for i := 0; i < 5; i++ {
-		_, _, errno := syscall.Syscall(syscall.SYS_UNLINKAT, uintptr(dirFD), uintptr(unsafe.Pointer(nameBytes)), 0)
-		runtime.KeepAlive(nameBytes)
-		if errno == 0 {
-			return fmt.Errorf("expected ENOENT, but unlinkat succeeded")
-		}
-	}
-	return nil
-}