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v2api: File2: implement Release, Read, Write, Fsync, Flush, Allocate

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Fortunately, this just means fixing up the function
signatures.
This commit is contained in:
Jakob Unterwurzacher 2020-07-12 12:59:01 +02:00
parent d539a4c214
commit 6196a5b5fe
5 changed files with 89 additions and 87 deletions
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78
internal/fusefrontend/file2.go
View File

@ -25,6 +25,7 @@ import (
"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
@ -129,7 +130,7 @@ func (f *File2) createHeader() (fileID []byte, err error) {
//
// 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, fuse.Status) {
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()
@ -144,7 +145,7 @@ func (f *File2) doRead(dst []byte, off uint64, length uint64) ([]byte, fuse.Stat
f.fileTableEntry.IDLock.Unlock()
if err == io.EOF {
// Empty file
return nil, fuse.OK
return nil, 0
}
buf := make([]byte, 100)
n, _ := f.fd.ReadAt(buf, 0)
@ -152,7 +153,7 @@ func (f *File2) doRead(dst []byte, off uint64, length uint64) ([]byte, fuse.Stat
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, fuse.EIO
return nil, syscall.EIO
}
// Save into the file table
f.fileTableEntry.ID = fileID
@ -173,12 +174,12 @@ func (f *File2) doRead(dst []byte, off uint64, length uint64) ([]byte, fuse.Stat
n, err := f.fd.ReadAt(ciphertext, int64(alignedOffset))
if err != nil && err != io.EOF {
tlog.Warn.Printf("read: ReadAt: %s", err.Error())
return nil, fuse.ToStatus(err)
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, fuse.OK
return dst, 0
}
// Truncate ciphertext buffer down to actually read bytes
ciphertext = ciphertext[0:n]
@ -198,7 +199,7 @@ func (f *File2) doRead(dst []byte, off uint64, length uint64) ([]byte, fuse.Stat
} 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, fuse.EIO
return nil, syscall.EIO
}
}
@ -216,15 +217,15 @@ func (f *File2) doRead(dst []byte, off uint64, length uint64) ([]byte, fuse.Stat
out = append(dst, out...)
f.rootNode.contentEnc.PReqPool.Put(plaintext)
return out, fuse.OK
return out, 0
}
// Read - FUSE call
func (f *File2) Read(buf []byte, off int64) (resultData fuse.ReadResult, code fuse.Status) {
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, fuse.Status(syscall.EMSGSIZE)
return nil, syscall.EMSGSIZE
}
f.fdLock.RLock()
defer f.fdLock.RUnlock()
@ -236,15 +237,15 @@ func (f *File2) Read(buf []byte, off int64) (resultData fuse.ReadResult, code fu
if f.rootNode.args.SerializeReads {
serialize_reads.Wait(off, len(buf))
}
out, status := f.doRead(buf[:0], uint64(off), uint64(len(buf)))
out, errno := f.doRead(buf[:0], uint64(off), uint64(len(buf)))
if f.rootNode.args.SerializeReads {
serialize_reads.Done()
}
if status != fuse.OK {
return nil, status
if errno != 0 {
return nil, errno
}
tlog.Debug.Printf("ino%d: Read: status %v, returning %d bytes", f.qIno.Ino, status, len(out))
return fuse.ReadResultData(out), status
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"
@ -256,7 +257,7 @@ func (f *File2) Read(buf []byte, off int64) (resultData fuse.ReadResult, code fu
// 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, fuse.Status) {
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
@ -274,7 +275,7 @@ func (f *File2) doWrite(data []byte, off int64) (uint32, fuse.Status) {
fileWasEmpty = true
}
if err != nil {
return 0, fuse.ToStatus(err)
return 0, fs.ToErrno(err)
}
f.fileTableEntry.ID = fileID
}
@ -287,10 +288,10 @@ func (f *File2) doWrite(data []byte, off int64) (uint32, fuse.Status) {
// Incomplete block -> Read-Modify-Write
if b.IsPartial() {
// Read
oldData, status := f.doRead(nil, b.BlockPlainOff(), f.contentEnc.PlainBS())
if status != fuse.OK {
tlog.Warn.Printf("ino%d fh%d: RMW read failed: %s", f.qIno.Ino, f.intFd(), status.String())
return 0, status
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))
@ -321,7 +322,7 @@ func (f *File2) doWrite(data []byte, off int64) (uint32, fuse.Status) {
tlog.Warn.Printf("ino%d fh%d: doWrite: rollback failed: %v", f.qIno.Ino, f.intFd(), err2)
}
}
return 0, fuse.ToStatus(err)
return 0, fs.ToErrno(err)
}
}
// Write
@ -331,9 +332,9 @@ func (f *File2) doWrite(data []byte, off int64) (uint32, fuse.Status) {
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, fuse.ToStatus(err)
return 0, fs.ToErrno(err)
}
return uint32(len(data)), fuse.OK
return uint32(len(data)), 0
}
// isConsecutiveWrite returns true if the current write
@ -349,18 +350,18 @@ func (f *File2) isConsecutiveWrite(off int64) bool {
// Write - FUSE call
//
// If the write creates a hole, pads the file to the next block boundary.
func (f *File2) Write(data []byte, off int64) (uint32, fuse.Status) {
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, fuse.Status(syscall.EMSGSIZE)
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, fuse.EBADF
return 0, syscall.EBADF
}
f.fileTableEntry.ContentLock.Lock()
defer f.fileTableEntry.ContentLock.Unlock()
@ -369,21 +370,21 @@ func (f *File2) Write(data []byte, off int64) (uint32, fuse.Status) {
// 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) {
status := f.writePadHole(off)
if !status.Ok() {
return 0, status
errno := f.writePadHole(off)
if errno != 0 {
return 0, errno
}
}
n, status := f.doWrite(data, off)
if status.Ok() {
n, errno := f.doWrite(data, off)
if errno != 0 {
f.lastOpCount = openfiletable.WriteOpCount()
f.lastWrittenOffset = off + int64(len(data)) - 1
}
return n, status
return n, errno
}
// Release - FUSE call, close file
func (f *File2) Release() {
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())
@ -392,10 +393,11 @@ func (f *File2) Release() {
openfiletable.Unregister(f.qIno)
f.fd.Close()
f.fdLock.Unlock()
return 0
}
// Flush - FUSE call
func (f *File2) Flush() fuse.Status {
func (f *File2) Flush(ctx context.Context) syscall.Errno {
f.fdLock.RLock()
defer f.fdLock.RUnlock()
@ -405,18 +407,18 @@ func (f *File2) Flush() fuse.Status {
newFd, err := syscall.Dup(f.intFd())
if err != nil {
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
err = syscall.Close(newFd)
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
// Fsync FUSE call
func (f *File2) Fsync(flags int) (code fuse.Status) {
func (f *File2) Fsync(ctx context.Context, flags uint32) (errno syscall.Errno) {
f.fdLock.RLock()
defer f.fdLock.RUnlock()
return fuse.ToStatus(syscall.Fsync(f.intFd()))
return fs.ToErrno(syscall.Fsync(f.intFd()))
}
// Getattr FUSE call (like stat)

60
internal/fusefrontend/file2_allocate_truncate.go
View File

@ -4,10 +4,11 @@ package fusefrontend
// i.e. ftruncate and fallocate
import (
"context"
"log"
"syscall"
"github.com/hanwen/go-fuse/v2/fuse"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/rfjakob/gocryptfs/internal/syscallcompat"
"github.com/rfjakob/gocryptfs/internal/tlog"
@ -26,19 +27,19 @@ import (
// complicated and hard to get right.
//
// Other modes (hole punching, zeroing) are not supported.
func (f *File2) Allocate(off uint64, sz uint64, mode uint32) fuse.Status {
func (f *File2) Allocate(ctx context.Context, off uint64, sz uint64, mode uint32) syscall.Errno {
if mode != FALLOC_DEFAULT && mode != FALLOC_FL_KEEP_SIZE {
f := func() {
tlog.Info.Printf("fallocate: only mode 0 (default) and 1 (keep size) are supported")
}
allocateWarnOnce.Do(f)
return fuse.Status(syscall.EOPNOTSUPP)
return syscall.EOPNOTSUPP
}
f.fdLock.RLock()
defer f.fdLock.RUnlock()
if f.released {
return fuse.EBADF
return syscall.EBADF
}
f.fileTableEntry.ContentLock.Lock()
defer f.fileTableEntry.ContentLock.Unlock()
@ -57,23 +58,23 @@ func (f *File2) Allocate(off uint64, sz uint64, mode uint32) fuse.Status {
tlog.Debug.Printf("Allocate off=%d sz=%d mode=%x cipherOff=%d cipherSz=%d\n",
off, sz, mode, cipherOff, cipherSz)
if err != nil {
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
if mode == FALLOC_FL_KEEP_SIZE {
// The user did not want to change the apparent size. We are done.
return fuse.OK
return 0
}
// Step (2): Grow the apparent file size
// We need the old file size to determine if we are growing the file at all.
newPlainSz := off + sz
oldPlainSz, err := f.statPlainSize()
if err != nil {
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
if newPlainSz <= oldPlainSz {
// The new size is smaller (or equal). Fallocate with mode = 0 never
// truncates a file, so we are done.
return fuse.OK
return 0
}
// The file grows. The space has already been allocated in (1), so what is
// left to do is to pad the first and last block and call truncate.
@ -82,13 +83,13 @@ func (f *File2) Allocate(off uint64, sz uint64, mode uint32) fuse.Status {
}
// truncate - called from Setattr.
func (f *File2) truncate(newSize uint64) fuse.Status {
func (f *File2) truncate(newSize uint64) (errno syscall.Errno) {
f.fdLock.RLock()
defer f.fdLock.RUnlock()
if f.released {
// The file descriptor has been closed concurrently.
tlog.Warn.Printf("ino%d fh%d: Truncate on released file", f.qIno.Ino, f.intFd())
return fuse.EBADF
return syscall.EBADF
}
f.fileTableEntry.ContentLock.Lock()
defer f.fileTableEntry.ContentLock.Unlock()
@ -98,17 +99,17 @@ func (f *File2) truncate(newSize uint64) fuse.Status {
err = syscall.Ftruncate(int(f.fd.Fd()), 0)
if err != nil {
tlog.Warn.Printf("ino%d fh%d: Ftruncate(fd, 0) returned error: %v", f.qIno.Ino, f.intFd(), err)
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
// Truncate to zero kills the file header
f.fileTableEntry.ID = nil
return fuse.OK
return 0
}
// We need the old file size to determine if we are growing or shrinking
// the file
oldSize, err := f.statPlainSize()
if err != nil {
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
oldB := float32(oldSize) / float32(f.contentEnc.PlainBS())
@ -117,7 +118,7 @@ func (f *File2) truncate(newSize uint64) fuse.Status {
// File size stays the same - nothing to do
if newSize == oldSize {
return fuse.OK
return 0
}
// File grows
if newSize > oldSize {
@ -131,25 +132,24 @@ func (f *File2) truncate(newSize uint64) fuse.Status {
lastBlockLen := newSize - plainOff
var data []byte
if lastBlockLen > 0 {
var status fuse.Status
data, status = f.doRead(nil, plainOff, lastBlockLen)
if status != fuse.OK {
data, errno = f.doRead(nil, plainOff, lastBlockLen)
if errno != 0 {
tlog.Warn.Printf("Truncate: shrink doRead returned error: %v", err)
return status
return errno
}
}
// Truncate down to the last complete block
err = syscall.Ftruncate(int(f.fd.Fd()), int64(cipherOff))
if err != nil {
tlog.Warn.Printf("Truncate: shrink Ftruncate returned error: %v", err)
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
// Append partial block
if lastBlockLen > 0 {
_, status := f.doWrite(data, int64(plainOff))
return status
}
return fuse.OK
return 0
}
// statPlainSize stats the file and returns the plaintext size
@ -167,7 +167,7 @@ func (f *File2) statPlainSize() (uint64, error) {
// truncateGrowFile extends a file using seeking or ftruncate performing RMW on
// the first and last block as necessary. New blocks in the middle become
// file holes unless they have been fallocate()'d beforehand.
func (f *File2) truncateGrowFile(oldPlainSz uint64, newPlainSz uint64) fuse.Status {
func (f *File2) truncateGrowFile(oldPlainSz uint64, newPlainSz uint64) syscall.Errno {
if newPlainSz <= oldPlainSz {
log.Panicf("BUG: newSize=%d <= oldSize=%d", newPlainSz, oldPlainSz)
}
@ -179,17 +179,17 @@ func (f *File2) truncateGrowFile(oldPlainSz uint64, newPlainSz uint64) fuse.Stat
// Write a single zero to the last byte and let doWrite figure out the RMW.
if n1 == n2 {
buf := make([]byte, 1)
_, status := f.doWrite(buf, int64(newEOFOffset))
return status
_, errno := f.doWrite(buf, int64(newEOFOffset))
return errno
}
}
// The truncate creates at least one new block.
//
// Make sure the old last block is padded to the block boundary. This call
// is a no-op if it is already block-aligned.
status := f.zeroPad(oldPlainSz)
if !status.Ok() {
return status
errno := f.zeroPad(oldPlainSz)
if errno != 0 {
return errno
}
// The new size is block-aligned. In this case we can do everything ourselves
// and avoid the call to doWrite.
@ -198,7 +198,7 @@ func (f *File2) truncateGrowFile(oldPlainSz uint64, newPlainSz uint64) fuse.Stat
if oldPlainSz == 0 {
id, err := f.createHeader()
if err != nil {
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
f.fileTableEntry.ID = id
}
@ -207,11 +207,11 @@ func (f *File2) truncateGrowFile(oldPlainSz uint64, newPlainSz uint64) fuse.Stat
if err != nil {
tlog.Warn.Printf("Truncate: grow Ftruncate returned error: %v", err)
}
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
// The new size is NOT aligned, so we need to write a partial block.
// Write a single zero to the last byte and let doWrite figure it out.
buf := make([]byte, 1)
_, status = f.doWrite(buf, int64(newEOFOffset))
return status
_, errno = f.doWrite(buf, int64(newEOFOffset))
return errno
}

12
internal/fusefrontend/file2_api_check.go
View File

@ -7,17 +7,17 @@ import (
// Check that we have implemented the fs.File* interfaces
var _ = (fs.FileGetattrer)((*File2)(nil))
var _ = (fs.FileSetattrer)((*File2)(nil))
/* TODO
var _ = (fs.FileHandle)((*File2)(nil))
var _ = (fs.FileReleaser)((*File2)(nil))
var _ = (fs.FileReader)((*File2)(nil))
var _ = (fs.FileWriter)((*File2)(nil))
var _ = (fs.FileFsyncer)((*File2)(nil))
var _ = (fs.FileFlusher)((*File2)(nil))
var _ = (fs.FileAllocater)((*File2)(nil))
/* TODO
var _ = (fs.FileHandle)((*File2)(nil))
var _ = (fs.FileGetlker)((*File2)(nil))
var _ = (fs.FileSetlker)((*File2)(nil))
var _ = (fs.FileSetlkwer)((*File2)(nil))
var _ = (fs.FileLseeker)((*File2)(nil))
var _ = (fs.FileFlusher)((*File2)(nil))
var _ = (fs.FileFsyncer)((*File2)(nil))
var _ = (fs.FileAllocater)((*File2)(nil))
*/

24
internal/fusefrontend/file2_holes.go
View File

@ -6,19 +6,19 @@ import (
"runtime"
"syscall"
"github.com/hanwen/go-fuse/v2/fuse"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
// Will a write to plaintext offset "targetOff" create a file hole in the
// ciphertext? If yes, zero-pad the last ciphertext block.
func (f *File2) writePadHole(targetOff int64) fuse.Status {
func (f *File2) writePadHole(targetOff int64) syscall.Errno {
// Get the current file size.
fi, err := f.fd.Stat()
if err != nil {
tlog.Warn.Printf("checkAndPadHole: Fstat failed: %v", err)
return fuse.ToStatus(err)
return fs.ToErrno(err)
}
plainSize := f.contentEnc.CipherSizeToPlainSize(uint64(fi.Size()))
// Appending a single byte to the file (equivalent to writing to
@ -29,31 +29,31 @@ func (f *File2) writePadHole(targetOff int64) fuse.Status {
// The write goes into an existing block or (if the last block was full)
// starts a new one directly after the last block. Nothing to do.
if targetBlock <= nextBlock {
return fuse.OK
return 0
}
// The write goes past the next block. nextBlock has
// to be zero-padded to the block boundary and (at least) nextBlock+1
// will contain a file hole in the ciphertext.
status := f.zeroPad(plainSize)
if status != fuse.OK {
return status
errno := f.zeroPad(plainSize)
if errno != 0 {
return errno
}
return fuse.OK
return 0
}
// Zero-pad the file of size plainSize to the next block boundary. This is a no-op
// if the file is already block-aligned.
func (f *File2) zeroPad(plainSize uint64) fuse.Status {
func (f *File2) zeroPad(plainSize uint64) syscall.Errno {
lastBlockLen := plainSize % f.contentEnc.PlainBS()
if lastBlockLen == 0 {
// Already block-aligned
return fuse.OK
return 0
}
missing := f.contentEnc.PlainBS() - lastBlockLen
pad := make([]byte, missing)
tlog.Debug.Printf("zeroPad: Writing %d bytes\n", missing)
_, status := f.doWrite(pad, int64(plainSize))
return status
_, errno := f.doWrite(pad, int64(plainSize))
return errno
}
// SeekData calls the lseek syscall with SEEK_DATA. It returns the offset of the

2
internal/fusefrontend/node.go
View File

@ -286,7 +286,7 @@ func (n *Node) Setattr(ctx context.Context, f fs.FileHandle, in *fuse.SetAttrIn,
return errno
}
f2 = f.(*File2)
defer f2.Release()
defer f2.Release(ctx)
}
return f2.Setattr(ctx, in, out)
}