v2api: rename "File2" to just "File"

Rename the symbols and the files.

1 files changed, 0 insertions, 443 deletions

diff --git a/internal/fusefrontend/file2.go b/internal/fusefrontend/file2.go
deleted file mode 100644
index 0de325c..0000000
--- a/internal/fusefrontend/file2.go
+++ /dev/null
@@ -1,443 +0,0 @@
-package fusefrontend
-
-// FUSE operations on file handles
-
-import (
-	"bytes"
-	"context"
-	"encoding/hex"
-	"fmt"
-	"io"
-	"log"
-	"os"
-	"sync"
-	"syscall"
-
-	"github.com/hanwen/go-fuse/v2/fs"
-	"github.com/hanwen/go-fuse/v2/fuse"
-
-	"github.com/rfjakob/gocryptfs/internal/contentenc"
-	"github.com/rfjakob/gocryptfs/internal/inomap"
-	"github.com/rfjakob/gocryptfs/internal/openfiletable"
-	"github.com/rfjakob/gocryptfs/internal/serialize_reads"
-	"github.com/rfjakob/gocryptfs/internal/stupidgcm"
-	"github.com/rfjakob/gocryptfs/internal/syscallcompat"
-	"github.com/rfjakob/gocryptfs/internal/tlog"
-)
-
-// File2 implements the go-fuse v2 API (github.com/hanwen/go-fuse/v2/fs)
-type File2 struct {
-	fd *os.File
-	// Has Release() already been called on this file? This also means that the
-	// wlock entry has been freed, so let's not crash trying to access it.
-	// Due to concurrency, Release can overtake other operations. These will
-	// return EBADF in that case.
-	released bool
-	// fdLock prevents the fd to be closed while we are in the middle of
-	// an operation.
-	// Every FUSE entrypoint should RLock(). The only user of Lock() is
-	// Release(), which closes the fd and sets "released" to true.
-	fdLock sync.RWMutex
-	// Content encryption helper
-	contentEnc *contentenc.ContentEnc
-	// Device and inode number uniquely identify the backing file
-	qIno inomap.QIno
-	// Entry in the open file table
-	fileTableEntry *openfiletable.Entry
-	// Store where the last byte was written
-	lastWrittenOffset int64
-	// The opCount is used to judge whether "lastWrittenOffset" is still
-	// guaranteed to be correct.
-	lastOpCount uint64
-	// Parent filesystem
-	rootNode *RootNode
-}
-
-// NewFile returns a new go-fuse File instance.
-func NewFile2(fd *os.File, rn *RootNode, st *syscall.Stat_t) *File2 {
-	qi := inomap.QInoFromStat(st)
-	e := openfiletable.Register(qi)
-
-	return &File2{
-		fd:             fd,
-		contentEnc:     rn.contentEnc,
-		qIno:           qi,
-		fileTableEntry: e,
-		rootNode:       rn,
-	}
-}
-
-// intFd - return the backing file descriptor as an integer.
-func (f *File2) intFd() int {
-	return int(f.fd.Fd())
-}
-
-// readFileID loads the file header from disk and extracts the file ID.
-// Returns io.EOF if the file is empty.
-func (f *File2) readFileID() ([]byte, error) {
-	// We read +1 byte to determine if the file has actual content
-	// and not only the header. A header-only file will be considered empty.
-	// This makes File ID poisoning more difficult.
-	readLen := contentenc.HeaderLen + 1
-	buf := make([]byte, readLen)
-	n, err := f.fd.ReadAt(buf, 0)
-	if err != nil {
-		if err == io.EOF && n != 0 {
-			tlog.Warn.Printf("readFileID %d: incomplete file, got %d instead of %d bytes",
-				f.qIno.Ino, n, readLen)
-			f.rootNode.reportMitigatedCorruption(fmt.Sprint(f.qIno.Ino))
-		}
-		return nil, err
-	}
-	buf = buf[:contentenc.HeaderLen]
-	h, err := contentenc.ParseHeader(buf)
-	if err != nil {
-		return nil, err
-	}
-	return h.ID, nil
-}
-
-// createHeader creates a new random header and writes it to disk.
-// Returns the new file ID.
-// The caller must hold fileIDLock.Lock().
-func (f *File2) createHeader() (fileID []byte, err error) {
-	h := contentenc.RandomHeader()
-	buf := h.Pack()
-	// Prevent partially written (=corrupt) header by preallocating the space beforehand
-	if !f.rootNode.args.NoPrealloc {
-		err = syscallcompat.EnospcPrealloc(f.intFd(), 0, contentenc.HeaderLen)
-		if err != nil {
-			if !syscallcompat.IsENOSPC(err) {
-				tlog.Warn.Printf("ino%d: createHeader: prealloc failed: %s\n", f.qIno.Ino, err.Error())
-			}
-			return nil, err
-		}
-	}
-	// Actually write header
-	_, err = f.fd.WriteAt(buf, 0)
-	if err != nil {
-		return nil, err
-	}
-	return h.ID, err
-}
-
-// doRead - read "length" plaintext bytes from plaintext offset "off" and append
-// to "dst".
-// Arguments "length" and "off" do not have to be block-aligned.
-//
-// doRead reads the corresponding ciphertext blocks from disk, decrypts them and
-// returns the requested part of the plaintext.
-//
-// Called by Read() for normal reading,
-// by Write() and Truncate() via doWrite() for Read-Modify-Write.
-func (f *File2) doRead(dst []byte, off uint64, length uint64) ([]byte, syscall.Errno) {
-	// Get the file ID, either from the open file table, or from disk.
-	var fileID []byte
-	f.fileTableEntry.IDLock.Lock()
-	if f.fileTableEntry.ID != nil {
-		// Use the cached value in the file table
-		fileID = f.fileTableEntry.ID
-	} else {
-		// Not cached, we have to read it from disk.
-		var err error
-		fileID, err = f.readFileID()
-		if err != nil {
-			f.fileTableEntry.IDLock.Unlock()
-			if err == io.EOF {
-				// Empty file
-				return nil, 0
-			}
-			buf := make([]byte, 100)
-			n, _ := f.fd.ReadAt(buf, 0)
-			buf = buf[:n]
-			hexdump := hex.EncodeToString(buf)
-			tlog.Warn.Printf("doRead %d: corrupt header: %v\nFile hexdump (%d bytes): %s",
-				f.qIno.Ino, err, n, hexdump)
-			return nil, syscall.EIO
-		}
-		// Save into the file table
-		f.fileTableEntry.ID = fileID
-	}
-	f.fileTableEntry.IDLock.Unlock()
-	if fileID == nil {
-		log.Panicf("fileID=%v", fileID)
-	}
-	// Read the backing ciphertext in one go
-	blocks := f.contentEnc.ExplodePlainRange(off, length)
-	alignedOffset, alignedLength := blocks[0].JointCiphertextRange(blocks)
-	skip := blocks[0].Skip
-	tlog.Debug.Printf("doRead: off=%d len=%d -> off=%d len=%d skip=%d\n",
-		off, length, alignedOffset, alignedLength, skip)
-
-	ciphertext := f.rootNode.contentEnc.CReqPool.Get()
-	ciphertext = ciphertext[:int(alignedLength)]
-	n, err := f.fd.ReadAt(ciphertext, int64(alignedOffset))
-	if err != nil && err != io.EOF {
-		tlog.Warn.Printf("read: ReadAt: %s", err.Error())
-		return nil, fs.ToErrno(err)
-	}
-	// The ReadAt came back empty. We can skip all the decryption and return early.
-	if n == 0 {
-		f.rootNode.contentEnc.CReqPool.Put(ciphertext)
-		return dst, 0
-	}
-	// Truncate ciphertext buffer down to actually read bytes
-	ciphertext = ciphertext[0:n]
-
-	firstBlockNo := blocks[0].BlockNo
-	tlog.Debug.Printf("ReadAt offset=%d bytes (%d blocks), want=%d, got=%d", alignedOffset, firstBlockNo, alignedLength, n)
-
-	// Decrypt it
-	plaintext, err := f.contentEnc.DecryptBlocks(ciphertext, firstBlockNo, fileID)
-	f.rootNode.contentEnc.CReqPool.Put(ciphertext)
-	if err != nil {
-		if f.rootNode.args.ForceDecode && err == stupidgcm.ErrAuth {
-			// We do not have the information which block was corrupt here anymore,
-			// but DecryptBlocks() has already logged it anyway.
-			tlog.Warn.Printf("doRead %d: off=%d len=%d: returning corrupt data due to forcedecode",
-				f.qIno.Ino, off, length)
-		} else {
-			curruptBlockNo := firstBlockNo + f.contentEnc.PlainOffToBlockNo(uint64(len(plaintext)))
-			tlog.Warn.Printf("doRead %d: corrupt block #%d: %v", f.qIno.Ino, curruptBlockNo, err)
-			return nil, syscall.EIO
-		}
-	}
-
-	// Crop down to the relevant part
-	var out []byte
-	lenHave := len(plaintext)
-	lenWant := int(skip + length)
-	if lenHave > lenWant {
-		out = plaintext[skip:lenWant]
-	} else if lenHave > int(skip) {
-		out = plaintext[skip:lenHave]
-	}
-	// else: out stays empty, file was smaller than the requested offset
-
-	out = append(dst, out...)
-	f.rootNode.contentEnc.PReqPool.Put(plaintext)
-
-	return out, 0
-}
-
-// Read - FUSE call
-func (f *File2) Read(ctx context.Context, buf []byte, off int64) (resultData fuse.ReadResult, errno syscall.Errno) {
-	if len(buf) > fuse.MAX_KERNEL_WRITE {
-		// This would crash us due to our fixed-size buffer pool
-		tlog.Warn.Printf("Read: rejecting oversized request with EMSGSIZE, len=%d", len(buf))
-		return nil, syscall.EMSGSIZE
-	}
-	f.fdLock.RLock()
-	defer f.fdLock.RUnlock()
-
-	f.fileTableEntry.ContentLock.RLock()
-	defer f.fileTableEntry.ContentLock.RUnlock()
-
-	tlog.Debug.Printf("ino%d: FUSE Read: offset=%d length=%d", f.qIno.Ino, off, len(buf))
-	if f.rootNode.args.SerializeReads {
-		serialize_reads.Wait(off, len(buf))
-	}
-	out, errno := f.doRead(buf[:0], uint64(off), uint64(len(buf)))
-	if f.rootNode.args.SerializeReads {
-		serialize_reads.Done()
-	}
-	if errno != 0 {
-		return nil, errno
-	}
-	tlog.Debug.Printf("ino%d: Read: errno=%d, returning %d bytes", f.qIno.Ino, errno, len(out))
-	return fuse.ReadResultData(out), errno
-}
-
-// doWrite - encrypt "data" and write it to plaintext offset "off"
-//
-// Arguments do not have to be block-aligned, read-modify-write is
-// performed internally as necessary
-//
-// Called by Write() for normal writing,
-// and by Truncate() to rewrite the last file block.
-//
-// Empty writes do nothing and are allowed.
-func (f *File2) doWrite(data []byte, off int64) (uint32, syscall.Errno) {
-	fileWasEmpty := false
-	// Get the file ID, create a new one if it does not exist yet.
-	var fileID []byte
-	// The caller has exclusively locked ContentLock, which blocks all other
-	// readers and writers. No need to take IDLock.
-	if f.fileTableEntry.ID != nil {
-		fileID = f.fileTableEntry.ID
-	} else {
-		// If the file ID is not cached, read it from disk
-		var err error
-		fileID, err = f.readFileID()
-		// Write a new file header if the file is empty
-		if err == io.EOF {
-			fileID, err = f.createHeader()
-			fileWasEmpty = true
-		}
-		if err != nil {
-			return 0, fs.ToErrno(err)
-		}
-		f.fileTableEntry.ID = fileID
-	}
-	// Handle payload data
-	dataBuf := bytes.NewBuffer(data)
-	blocks := f.contentEnc.ExplodePlainRange(uint64(off), uint64(len(data)))
-	toEncrypt := make([][]byte, len(blocks))
-	for i, b := range blocks {
-		blockData := dataBuf.Next(int(b.Length))
-		// Incomplete block -> Read-Modify-Write
-		if b.IsPartial() {
-			// Read
-			oldData, errno := f.doRead(nil, b.BlockPlainOff(), f.contentEnc.PlainBS())
-			if errno != 0 {
-				tlog.Warn.Printf("ino%d fh%d: RMW read failed: errno=%d", f.qIno.Ino, f.intFd(), errno)
-				return 0, errno
-			}
-			// Modify
-			blockData = f.contentEnc.MergeBlocks(oldData, blockData, int(b.Skip))
-			tlog.Debug.Printf("len(oldData)=%d len(blockData)=%d", len(oldData), len(blockData))
-		}
-		tlog.Debug.Printf("ino%d: Writing %d bytes to block #%d",
-			f.qIno.Ino, len(blockData), b.BlockNo)
-		// Write into the to-encrypt list
-		toEncrypt[i] = blockData
-	}
-	// Encrypt all blocks
-	ciphertext := f.contentEnc.EncryptBlocks(toEncrypt, blocks[0].BlockNo, f.fileTableEntry.ID)
-	// Preallocate so we cannot run out of space in the middle of the write.
-	// This prevents partially written (=corrupt) blocks.
-	var err error
-	cOff := int64(blocks[0].BlockCipherOff())
-	if !f.rootNode.args.NoPrealloc {
-		err = syscallcompat.EnospcPrealloc(f.intFd(), cOff, int64(len(ciphertext)))
-		if err != nil {
-			if !syscallcompat.IsENOSPC(err) {
-				tlog.Warn.Printf("ino%d fh%d: doWrite: prealloc failed: %v", f.qIno.Ino, f.intFd(), err)
-			}
-			if fileWasEmpty {
-				// Kill the file header again
-				f.fileTableEntry.ID = nil
-				err2 := syscall.Ftruncate(f.intFd(), 0)
-				if err2 != nil {
-					tlog.Warn.Printf("ino%d fh%d: doWrite: rollback failed: %v", f.qIno.Ino, f.intFd(), err2)
-				}
-			}
-			return 0, fs.ToErrno(err)
-		}
-	}
-	// Write
-	_, err = f.fd.WriteAt(ciphertext, cOff)
-	// Return memory to CReqPool
-	f.rootNode.contentEnc.CReqPool.Put(ciphertext)
-	if err != nil {
-		tlog.Warn.Printf("ino%d fh%d: doWrite: WriteAt off=%d len=%d failed: %v",
-			f.qIno.Ino, f.intFd(), cOff, len(ciphertext), err)
-		return 0, fs.ToErrno(err)
-	}
-	return uint32(len(data)), 0
-}
-
-// isConsecutiveWrite returns true if the current write
-// directly (in time and space) follows the last write.
-// This is an optimisation for streaming writes on NFS where a
-// Stat() call is very expensive.
-// The caller must "wlock.lock(f.devIno.ino)" otherwise this check would be racy.
-func (f *File2) isConsecutiveWrite(off int64) bool {
-	opCount := openfiletable.WriteOpCount()
-	return opCount == f.lastOpCount+1 && off == f.lastWrittenOffset+1
-}
-
-// Write - FUSE call
-//
-// If the write creates a hole, pads the file to the next block boundary.
-func (f *File2) Write(ctx context.Context, data []byte, off int64) (uint32, syscall.Errno) {
-	if len(data) > fuse.MAX_KERNEL_WRITE {
-		// This would crash us due to our fixed-size buffer pool
-		tlog.Warn.Printf("Write: rejecting oversized request with EMSGSIZE, len=%d", len(data))
-		return 0, syscall.EMSGSIZE
-	}
-	f.fdLock.RLock()
-	defer f.fdLock.RUnlock()
-	if f.released {
-		// The file descriptor has been closed concurrently
-		tlog.Warn.Printf("ino%d fh%d: Write on released file", f.qIno.Ino, f.intFd())
-		return 0, syscall.EBADF
-	}
-	f.fileTableEntry.ContentLock.Lock()
-	defer f.fileTableEntry.ContentLock.Unlock()
-	tlog.Debug.Printf("ino%d: FUSE Write: offset=%d length=%d", f.qIno.Ino, off, len(data))
-	// If the write creates a file hole, we have to zero-pad the last block.
-	// But if the write directly follows an earlier write, it cannot create a
-	// hole, and we can save one Stat() call.
-	if !f.isConsecutiveWrite(off) {
-		errno := f.writePadHole(off)
-		if errno != 0 {
-			return 0, errno
-		}
-	}
-	n, errno := f.doWrite(data, off)
-	if errno != 0 {
-		f.lastOpCount = openfiletable.WriteOpCount()
-		f.lastWrittenOffset = off + int64(len(data)) - 1
-	}
-	return n, errno
-}
-
-// Release - FUSE call, close file
-func (f *File2) Release(ctx context.Context) syscall.Errno {
-	f.fdLock.Lock()
-	if f.released {
-		log.Panicf("ino%d fh%d: double release", f.qIno.Ino, f.intFd())
-	}
-	f.released = true
-	openfiletable.Unregister(f.qIno)
-	f.fd.Close()
-	f.fdLock.Unlock()
-	return 0
-}
-
-// Flush - FUSE call
-func (f *File2) Flush(ctx context.Context) syscall.Errno {
-	f.fdLock.RLock()
-	defer f.fdLock.RUnlock()
-
-	// Since Flush() may be called for each dup'd fd, we don't
-	// want to really close the file, we just want to flush. This
-	// is achieved by closing a dup'd fd.
-	newFd, err := syscall.Dup(f.intFd())
-
-	if err != nil {
-		return fs.ToErrno(err)
-	}
-	err = syscall.Close(newFd)
-	return fs.ToErrno(err)
-}
-
-// Fsync FUSE call
-func (f *File2) Fsync(ctx context.Context, flags uint32) (errno syscall.Errno) {
-	f.fdLock.RLock()
-	defer f.fdLock.RUnlock()
-
-	return fs.ToErrno(syscall.Fsync(f.intFd()))
-}
-
-// Getattr FUSE call (like stat)
-func (f *File2) Getattr(ctx context.Context, a *fuse.AttrOut) syscall.Errno {
-	f.fdLock.RLock()
-	defer f.fdLock.RUnlock()
-
-	tlog.Debug.Printf("file.GetAttr()")
-	st := syscall.Stat_t{}
-	err := syscall.Fstat(f.intFd(), &st)
-	if err != nil {
-		return fs.ToErrno(err)
-	}
-	f.rootNode.inoMap.TranslateStat(&st)
-	a.FromStat(&st)
-	a.Size = f.contentEnc.CipherSizeToPlainSize(a.Size)
-	if f.rootNode.args.ForceOwner != nil {
-		a.Owner = *f.rootNode.args.ForceOwner
-	}
-
-	return 0
-}