containerd/vendor/github.com/hanwen/go-fuse/v2/fuse/request.go
Brad Davidson 890953d3c6
Enable btrfs/fuse-overlayfs/stargz snapshotter plugins
Signed-off-by: Brad Davidson <brad.davidson@rancher.com>
2025-05-06 22:38:41 +00:00

287 lines
6.5 KiB
Go

// Copyright 2016 the Go-FUSE Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package fuse
import (
"bytes"
"fmt"
"log"
"reflect"
"strings"
"time"
"unsafe"
)
var sizeOfOutHeader = unsafe.Sizeof(OutHeader{})
var zeroOutBuf [outputHeaderSize]byte
type request struct {
inflightIndex int
cancel chan struct{}
// written under Server.interruptMu
interrupted bool
// inHeader + opcode specific data
inputBuf []byte
// outHeader + opcode specific data.
outputBuf []byte
// Unstructured input (filenames, data for WRITE call)
inPayload []byte
// Output data.
status Status
// Unstructured output. Only one of these is non-nil.
outPayload []byte
fdData *readResultFd
// In case of read, keep read result here so we can call
// Done() on it.
readResult ReadResult
// Start timestamp for timing info.
startTime time.Time
}
// requestAlloc holds the request, plus I/O buffers, which are
// reused across requests.
type requestAlloc struct {
request
// Request storage. For large inputs and outputs, use data
// obtained through bufferpool.
bufferPoolInputBuf []byte
bufferPoolOutputBuf []byte
// For small pieces of data, we use the following inlines
// arrays:
//
// Output header and structured data.
outBuf [outputHeaderSize]byte
// Input, if small enough to fit here.
smallInputBuf [128]byte
}
func (r *request) inHeader() *InHeader {
return (*InHeader)(r.inData())
}
func (r *request) outHeader() *OutHeader {
return (*OutHeader)(unsafe.Pointer(&r.outputBuf[0]))
}
func (r *request) clear() {
r.inputBuf = nil
r.outputBuf = nil
r.inPayload = nil
r.status = OK
r.outPayload = nil
r.fdData = nil
r.startTime = time.Time{}
r.readResult = nil
}
func asType(ptr unsafe.Pointer, typ interface{}) interface{} {
return reflect.NewAt(reflect.ValueOf(typ).Type(), ptr).Interface()
}
func typSize(typ interface{}) uintptr {
return reflect.ValueOf(typ).Type().Size()
}
func (r *request) InputDebug() string {
val := ""
hdr := r.inHeader()
h := getHandler(hdr.Opcode)
if h != nil && h.InType != nil {
val = Print(asType(r.inData(), h.InType))
}
names := ""
if h.FileNames == 1 {
names = fmt.Sprintf("%q", r.filename())
} else if h.FileNames == 2 {
n1, n2 := r.filenames()
names = fmt.Sprintf("%q %q", n1, n2)
} else if l := len(r.inPayload); l > 0 {
dots := ""
if l > 8 {
l = 8
dots = "..."
}
names = fmt.Sprintf("%q%s %db", r.inPayload[:l], dots, len(r.inPayload))
}
return fmt.Sprintf("rx %d: %s n%d %s%s p%d",
hdr.Unique, operationName(hdr.Opcode), hdr.NodeId,
val, names, hdr.Caller.Pid)
}
func (r *request) OutputDebug() string {
var dataStr string
h := getHandler(r.inHeader().Opcode)
if h != nil && h.OutType != nil && len(r.outputBuf) > int(sizeOfOutHeader) {
dataStr = Print(asType(r.outData(), h.OutType))
}
max := 1024
if len(dataStr) > max {
dataStr = dataStr[:max] + " ...trimmed"
}
flatStr := ""
if r.outPayloadSize() > 0 {
if h != nil && h.FileNameOut {
s := strings.TrimRight(string(r.outPayload), "\x00")
flatStr = fmt.Sprintf(" %q", s)
} else {
spl := ""
if r.fdData != nil {
spl = " (fd data)"
} else {
l := len(r.outPayload)
s := ""
if l > 8 {
l = 8
s = "..."
}
spl = fmt.Sprintf(" %q%s", r.outPayload[:l], s)
}
flatStr = fmt.Sprintf(" %db data%s", r.outPayloadSize(), spl)
}
}
extraStr := dataStr + flatStr
if extraStr != "" {
extraStr = ", " + extraStr
}
return fmt.Sprintf("tx %d: %v%s",
r.inHeader().Unique, r.status, extraStr)
}
// setInput returns true if it takes ownership of the argument, false if not.
func (r *requestAlloc) setInput(input []byte) bool {
if len(input) < len(r.smallInputBuf) {
copy(r.smallInputBuf[:], input)
r.inputBuf = r.smallInputBuf[:len(input)]
return false
}
r.inputBuf = input
r.bufferPoolInputBuf = input[:cap(input)]
return true
}
func (r *request) inData() unsafe.Pointer {
return unsafe.Pointer(&r.inputBuf[0])
}
func parseRequest(in []byte, kernelSettings *InitIn) (h *operationHandler, inSize, outSize, payloadSize int, errno Status) {
inSize = int(unsafe.Sizeof(InHeader{}))
if len(in) < inSize {
errno = EIO
return
}
inData := unsafe.Pointer(&in[0])
hdr := (*InHeader)(inData)
h = getHandler(hdr.Opcode)
if h == nil {
log.Printf("Unknown opcode %d", hdr.Opcode)
errno = ENOSYS
return
}
if h.InputSize > 0 {
inSize = int(h.InputSize)
}
if hdr.Opcode == _OP_RENAME && kernelSettings.supportsRenameSwap() {
inSize = int(unsafe.Sizeof(RenameIn{}))
}
if hdr.Opcode == _OP_INIT && inSize > len(in) {
// Minor version 36 extended the size of InitIn struct
inSize = len(in)
}
if len(in) < inSize {
log.Printf("Short read for %v: %q", h.Name, in)
errno = EIO
return
}
switch hdr.Opcode {
case _OP_READDIR, _OP_READDIRPLUS, _OP_READ:
payloadSize = int(((*ReadIn)(inData)).Size)
case _OP_GETXATTR, _OP_LISTXATTR:
payloadSize = int(((*GetXAttrIn)(inData)).Size)
}
outSize = int(h.OutputSize)
return
}
func (r *request) outData() unsafe.Pointer {
return unsafe.Pointer(&r.outputBuf[sizeOfOutHeader])
}
func (r *request) filename() string {
return string(r.inPayload[:len(r.inPayload)-1])
}
func (r *request) filenames() (string, string) {
i1 := bytes.IndexByte(r.inPayload, 0)
s1 := string(r.inPayload[:i1])
s2 := string(r.inPayload[i1+1 : len(r.inPayload)-1])
return s1, s2
}
// serializeHeader serializes the response header. The header points
// to an internal buffer of the receiver.
func (r *request) serializeHeader(outPayloadSize int) {
var dataLength uintptr
h := getHandler(r.inHeader().Opcode)
if h != nil {
dataLength = h.OutputSize
}
if r.status > OK {
// only do this for positive status; negative status
// is used for notification.
dataLength = 0
outPayloadSize = 0
}
// [GET|LIST]XATTR is two opcodes in one: get/list xattr size (return
// structured GetXAttrOut, no flat data) and get/list xattr data
// (return no structured data, but only flat data)
if r.inHeader().Opcode == _OP_GETXATTR || r.inHeader().Opcode == _OP_LISTXATTR {
if (*GetXAttrIn)(r.inData()).Size != 0 {
dataLength = 0
}
}
o := r.outHeader()
o.Unique = r.inHeader().Unique
o.Status = int32(-r.status)
o.Length = uint32(
int(sizeOfOutHeader) + int(dataLength) + outPayloadSize)
r.outputBuf = r.outputBuf[:dataLength+sizeOfOutHeader]
if r.outPayload != nil {
r.outPayload = r.outPayload[:outPayloadSize]
}
}
func (r *request) outPayloadSize() int {
if r.fdData != nil {
return r.fdData.Size()
}
return len(r.outPayload)
}