hardcoresushi/libgocryptfs
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fusefronted: move Truncate() and Allocate() to their own file

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These are large complicated implementations that will share some
code.
This commit is contained in:
Jakob Unterwurzacher 2016-07-02 15:33:48 +02:00
parent 7b22b426b9
commit 04ad063515
4 changed files with 125 additions and 112 deletions
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2
internal/contentenc/intrablock.go
View File

@ -4,7 +4,7 @@ package contentenc
type intraBlock struct {
BlockNo uint64 // Block number in file
Skip uint64 // Offset into block plaintext
Length uint64 // Length of data from this block
Length uint64 // Length of plaintext data in this block
fs *ContentEnc
}

2
internal/contentenc/offsets.go
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@ -76,7 +76,7 @@ func (be *ContentEnc) ExplodePlainRange(offset uint64, length uint64) []intraBlo
nextBlock.BlockNo = be.PlainOffToBlockNo(offset)
nextBlock.Skip = offset - be.BlockNoToPlainOff(nextBlock.BlockNo)
// Minimum of remaining data and remaining space in the block
// Minimum of remaining plaintext data and remaining space in the block
nextBlock.Length = MinUint64(length, be.plainBS-nextBlock.Skip)
blocks = append(blocks, nextBlock)

110
internal/fusefrontend/file.go
View File

@ -354,103 +354,6 @@ func (f *file) Fsync(flags int) (code fuse.Status) {
return fuse.ToStatus(syscall.Fsync(int(f.fd.Fd())))
}
// Truncate - FUSE call
func (f *file) Truncate(newSize uint64) fuse.Status {
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.ino, f.intFd())
return fuse.EBADF
}
wlock.lock(f.ino)
defer wlock.unlock(f.ino)
var err error
// Common case first: Truncate to zero
if newSize == 0 {
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.ino, f.intFd(), err)
return fuse.ToStatus(err)
}
// Truncate to zero kills the file header
f.header = nil
return fuse.OK
}
// We need the old file size to determine if we are growing or shrinking
// the file
fi, err := f.fd.Stat()
if err != nil {
tlog.Warn.Printf("ino%d fh%d: Truncate: Fstat failed: %v", f.ino, f.intFd(), err)
return fuse.ToStatus(err)
}
oldSize := f.contentEnc.CipherSizeToPlainSize(uint64(fi.Size()))
{
oldB := float32(oldSize) / float32(f.contentEnc.PlainBS())
newB := float32(newSize) / float32(f.contentEnc.PlainBS())
tlog.Debug.Printf("ino%d: FUSE Truncate from %.2f to %.2f blocks (%d to %d bytes)", f.ino, oldB, newB, oldSize, newSize)
}
// File size stays the same - nothing to do
if newSize == oldSize {
return fuse.OK
}
// File grows
if newSize > oldSize {
// File was empty, create new header
if oldSize == 0 {
err = f.createHeader()
if err != nil {
return fuse.ToStatus(err)
}
}
// New blocks to add
addBlocks := f.contentEnc.ExplodePlainRange(oldSize, newSize-oldSize)
if len(addBlocks) >= 2 {
f.zeroPad(oldSize)
}
lastBlock := addBlocks[len(addBlocks)-1]
if lastBlock.IsPartial() {
off := lastBlock.BlockPlainOff()
_, status := f.doWrite(make([]byte, lastBlock.Length), int64(off+lastBlock.Skip))
return status
} else {
off := lastBlock.BlockCipherOff()
err = syscall.Ftruncate(f.intFd(), int64(off+f.contentEnc.CipherBS()))
if err != nil {
tlog.Warn.Printf("Truncate: grow Ftruncate returned error: %v", err)
}
return fuse.ToStatus(err)
}
} else {
// File shrinks
blockNo := f.contentEnc.PlainOffToBlockNo(newSize)
cipherOff := f.contentEnc.BlockNoToCipherOff(blockNo)
plainOff := f.contentEnc.BlockNoToPlainOff(blockNo)
lastBlockLen := newSize - plainOff
var data []byte
if lastBlockLen > 0 {
var status fuse.Status
data, status = f.doRead(plainOff, lastBlockLen)
if status != fuse.OK {
tlog.Warn.Printf("Truncate: shrink doRead returned error: %v", err)
return status
}
}
// 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)
}
// Append partial block
if lastBlockLen > 0 {
_, status := f.doWrite(data, int64(plainOff))
return status
}
return fuse.OK
}
}
func (f *file) Chmod(mode uint32) fuse.Status {
f.fdLock.RLock()
defer f.fdLock.RUnlock()
@ -484,19 +387,6 @@ func (f *file) GetAttr(a *fuse.Attr) fuse.Status {
return fuse.OK
}
// Only warn once
var allocateWarnOnce sync.Once
// Allocate - FUSE call, fallocate(2)
// This is not implemented yet in gocryptfs, but it is neither in EncFS. This
// suggests that the user demand is low.
func (f *file) Allocate(off uint64, sz uint64, mode uint32) fuse.Status {
allocateWarnOnce.Do(func() {
tlog.Warn.Printf("fallocate(2) is not supported, returning ENOSYS - see https://github.com/rfjakob/gocryptfs/issues/1")
})
return fuse.ENOSYS
}
const _UTIME_OMIT = ((1 << 30) - 2)
func (f *file) Utimens(a *time.Time, m *time.Time) fuse.Status {

123
internal/fusefrontend/file_allocate_truncate.go Normal file
View File

@ -0,0 +1,123 @@
package fusefrontend
// FUSE operations Truncate and Allocate on file handles
// i.e. ftruncate and fallocate
import (
"sync"
"syscall"
"github.com/hanwen/go-fuse/fuse"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
// Only warn once
var allocateWarnOnce sync.Once
// Allocate - FUSE call, fallocate(2)
// This is not implemented yet in gocryptfs, but it is neither in EncFS. This
// suggests that the user demand is low.
func (f *file) Allocate(off uint64, sz uint64, mode uint32) fuse.Status {
allocateWarnOnce.Do(func() {
tlog.Warn.Printf("fallocate(2) is not supported, returning ENOSYS - see https://github.com/rfjakob/gocryptfs/issues/1")
})
return fuse.ENOSYS
}
// Truncate - FUSE call
func (f *file) Truncate(newSize uint64) fuse.Status {
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.ino, f.intFd())
return fuse.EBADF
}
wlock.lock(f.ino)
defer wlock.unlock(f.ino)
var err error
// Common case first: Truncate to zero
if newSize == 0 {
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.ino, f.intFd(), err)
return fuse.ToStatus(err)
}
// Truncate to zero kills the file header
f.header = nil
return fuse.OK
}
// We need the old file size to determine if we are growing or shrinking
// the file
fi, err := f.fd.Stat()
if err != nil {
tlog.Warn.Printf("ino%d fh%d: Truncate: Fstat failed: %v", f.ino, f.intFd(), err)
return fuse.ToStatus(err)
}
oldSize := f.contentEnc.CipherSizeToPlainSize(uint64(fi.Size()))
{
oldB := float32(oldSize) / float32(f.contentEnc.PlainBS())
newB := float32(newSize) / float32(f.contentEnc.PlainBS())
tlog.Debug.Printf("ino%d: FUSE Truncate from %.2f to %.2f blocks (%d to %d bytes)", f.ino, oldB, newB, oldSize, newSize)
}
// File size stays the same - nothing to do
if newSize == oldSize {
return fuse.OK
}
// File grows
if newSize > oldSize {
// File was empty, create new header
if oldSize == 0 {
err = f.createHeader()
if err != nil {
return fuse.ToStatus(err)
}
}
// New blocks to add
addBlocks := f.contentEnc.ExplodePlainRange(oldSize, newSize-oldSize)
if len(addBlocks) >= 2 {
f.zeroPad(oldSize)
}
lastBlock := addBlocks[len(addBlocks)-1]
if lastBlock.IsPartial() {
off := lastBlock.BlockPlainOff()
_, status := f.doWrite(make([]byte, lastBlock.Length), int64(off+lastBlock.Skip))
return status
} else {
off := lastBlock.BlockCipherOff()
err = syscall.Ftruncate(f.intFd(), int64(off+f.contentEnc.CipherBS()))
if err != nil {
tlog.Warn.Printf("Truncate: grow Ftruncate returned error: %v", err)
}
return fuse.ToStatus(err)
}
} else {
// File shrinks
blockNo := f.contentEnc.PlainOffToBlockNo(newSize)
cipherOff := f.contentEnc.BlockNoToCipherOff(blockNo)
plainOff := f.contentEnc.BlockNoToPlainOff(blockNo)
lastBlockLen := newSize - plainOff
var data []byte
if lastBlockLen > 0 {
var status fuse.Status
data, status = f.doRead(plainOff, lastBlockLen)
if status != fuse.OK {
tlog.Warn.Printf("Truncate: shrink doRead returned error: %v", err)
return status
}
}
// 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)
}
// Append partial block
if lastBlockLen > 0 {
_, status := f.doWrite(data, int64(plainOff))
return status
}
return fuse.OK
}
}