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-rw-r--r--internal/fusefrontend/file.go54
-rw-r--r--internal/fusefrontend/file_allocate_truncate.go16
-rw-r--r--internal/fusefrontend/open_file_table.go101
-rw-r--r--internal/openfiletable/open_file_table.go111
4 files changed, 146 insertions, 136 deletions
diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go
index ab35a59..92b1496 100644
--- a/internal/fusefrontend/file.go
+++ b/internal/fusefrontend/file.go
@@ -8,7 +8,6 @@ import (
"log"
"os"
"sync"
- "sync/atomic"
"syscall"
"time"
@@ -16,6 +15,7 @@ import (
"github.com/hanwen/go-fuse/fuse/nodefs"
"github.com/rfjakob/gocryptfs/internal/contentenc"
+ "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"
@@ -40,9 +40,9 @@ type file struct {
// Content encryption helper
contentEnc *contentenc.ContentEnc
// Device and inode number uniquely identify the backing file
- devIno DevInoStruct
- // Entry in the open file map
- fileTableEntry *openFileEntryT
+ qIno openfiletable.QIno
+ // Entry in the open file table
+ fileTableEntry *openfiletable.Entry
// go-fuse nodefs.loopbackFile
loopbackFile nodefs.File
// Store where the last byte was written
@@ -66,15 +66,15 @@ func NewFile(fd *os.File, writeOnly bool, fs *FS) (nodefs.File, fuse.Status) {
tlog.Warn.Printf("NewFile: Fstat on fd %d failed: %v\n", fd.Fd(), err)
return nil, fuse.ToStatus(err)
}
- di := DevInoFromStat(&st)
- t := openFileMap.register(di)
+ qi := openfiletable.QInoFromStat(&st)
+ e := openfiletable.Register(qi)
return &file{
fd: fd,
writeOnly: writeOnly,
contentEnc: fs.contentEnc,
- devIno: di,
- fileTableEntry: t,
+ qIno: qi,
+ fileTableEntry: e,
loopbackFile: nodefs.NewLoopbackFile(fd),
fs: fs,
File: nodefs.NewDefaultFile(),
@@ -106,7 +106,7 @@ func (f *file) readFileID() ([]byte, error) {
if err != nil {
if err == io.EOF && n != 0 {
tlog.Warn.Printf("ino%d: readFileID: incomplete file, got %d instead of %d bytes",
- f.devIno.ino, n, readLen)
+ f.qIno.Ino, n, readLen)
}
return nil, err
}
@@ -128,7 +128,7 @@ func (f *file) createHeader() (fileID []byte, err error) {
if !f.fs.args.NoPrealloc {
err = syscallcompat.EnospcPrealloc(int(f.fd.Fd()), 0, contentenc.HeaderLen)
if err != nil {
- tlog.Warn.Printf("ino%d: createHeader: prealloc failed: %s\n", f.devIno.ino, err.Error())
+ tlog.Warn.Printf("ino%d: createHeader: prealloc failed: %s\n", f.qIno.Ino, err.Error())
return nil, err
}
}
@@ -200,10 +200,10 @@ func (f *file) doRead(off uint64, length uint64) ([]byte, fuse.Status) {
// We do not have the information which block was corrupt here anymore,
// but DecryptBlocks() has already logged it anyway.
tlog.Warn.Printf("ino%d: doRead off=%d len=%d: returning corrupt data due to forcedecode",
- f.devIno.ino, off, length)
+ f.qIno.Ino, off, length)
} else {
curruptBlockNo := firstBlockNo + f.contentEnc.PlainOffToBlockNo(uint64(len(plaintext)))
- tlog.Warn.Printf("ino%d: doRead: corrupt block #%d: %v", f.devIno.ino, curruptBlockNo, err)
+ tlog.Warn.Printf("ino%d: doRead: corrupt block #%d: %v", f.qIno.Ino, curruptBlockNo, err)
return nil, fuse.EIO
}
}
@@ -227,10 +227,10 @@ func (f *file) Read(buf []byte, off int64) (resultData fuse.ReadResult, code fus
f.fdLock.RLock()
defer f.fdLock.RUnlock()
- tlog.Debug.Printf("ino%d: FUSE Read: offset=%d length=%d", f.devIno.ino, len(buf), off)
+ tlog.Debug.Printf("ino%d: FUSE Read: offset=%d length=%d", f.qIno.Ino, len(buf), off)
if f.writeOnly {
- tlog.Warn.Printf("ino%d: Tried to read from write-only file", f.devIno.ino)
+ tlog.Warn.Printf("ino%d: Tried to read from write-only file", f.qIno.Ino)
return nil, fuse.EBADF
}
@@ -245,13 +245,13 @@ func (f *file) Read(buf []byte, off int64) (resultData fuse.ReadResult, code fus
}
if status == fuse.EIO {
- tlog.Warn.Printf("ino%d: Read: returning EIO, offset=%d, length=%d", f.devIno.ino, len(buf), off)
+ tlog.Warn.Printf("ino%d: Read: returning EIO, offset=%d, length=%d", f.qIno.Ino, len(buf), off)
}
if status != fuse.OK {
return nil, status
}
- tlog.Debug.Printf("ino%d: Read: status %v, returning %d bytes", f.devIno.ino, status, len(out))
+ tlog.Debug.Printf("ino%d: Read: status %v, returning %d bytes", f.qIno.Ino, status, len(out))
return fuse.ReadResultData(out), status
}
@@ -302,7 +302,7 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) {
var oldData []byte
oldData, status = f.doRead(o, f.contentEnc.PlainBS())
if status != fuse.OK {
- tlog.Warn.Printf("ino%d fh%d: RMW read failed: %s", f.devIno.ino, f.intFd(), status.String())
+ tlog.Warn.Printf("ino%d fh%d: RMW read failed: %s", f.qIno.Ino, f.intFd(), status.String())
return 0, status
}
// Modify
@@ -312,7 +312,7 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) {
// Encrypt
blockData = f.contentEnc.EncryptBlock(blockData, b.BlockNo, fileID)
tlog.Debug.Printf("ino%d: Writing %d bytes to block #%d",
- f.devIno.ino, uint64(len(blockData))-f.contentEnc.BlockOverhead(), b.BlockNo)
+ f.qIno.Ino, uint64(len(blockData))-f.contentEnc.BlockOverhead(), b.BlockNo)
// Store output data in the writeChain
writeChain[i] = blockData
numOutBytes += len(blockData)
@@ -330,7 +330,7 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) {
if !f.fs.args.NoPrealloc {
err = syscallcompat.EnospcPrealloc(int(f.fd.Fd()), int64(cOff), int64(writeBuf.Len()))
if err != nil {
- tlog.Warn.Printf("ino%d fh%d: doWrite: prealloc failed: %s", f.devIno.ino, f.intFd(), err.Error())
+ tlog.Warn.Printf("ino%d fh%d: doWrite: prealloc failed: %s", f.qIno.Ino, f.intFd(), err.Error())
return 0, fuse.ToStatus(err)
}
}
@@ -349,7 +349,7 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) {
// Stat() call is very expensive.
// The caller must "wlock.lock(f.devIno.ino)" otherwise this check would be racy.
func (f *file) isConsecutiveWrite(off int64) bool {
- opCount := atomic.LoadUint64(&openFileMap.opCount)
+ opCount := openfiletable.WriteLockCount()
return opCount == f.lastOpCount+1 && off == f.lastWrittenOffset+1
}
@@ -363,12 +363,12 @@ func (f *file) Write(data []byte, off int64) (uint32, fuse.Status) {
// The file descriptor has been closed concurrently, which also means
// the wlock has been freed. Exit here so we don't crash trying to access
// it.
- tlog.Warn.Printf("ino%d fh%d: Write on released file", f.devIno.ino, f.intFd())
+ tlog.Warn.Printf("ino%d fh%d: Write on released file", f.qIno.Ino, f.intFd())
return 0, fuse.EBADF
}
- f.fileTableEntry.writeLock.Lock()
- defer f.fileTableEntry.writeLock.Unlock()
- tlog.Debug.Printf("ino%d: FUSE Write: offset=%d length=%d", f.devIno.ino, off, len(data))
+ f.fileTableEntry.WriteLock.Lock()
+ defer f.fileTableEntry.WriteLock.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.
@@ -380,7 +380,7 @@ func (f *file) Write(data []byte, off int64) (uint32, fuse.Status) {
}
n, status := f.doWrite(data, off)
if status.Ok() {
- f.lastOpCount = atomic.LoadUint64(&openFileMap.opCount)
+ f.lastOpCount = openfiletable.WriteLockCount()
f.lastWrittenOffset = off + int64(len(data)) - 1
}
return n, status
@@ -390,13 +390,13 @@ func (f *file) Write(data []byte, off int64) (uint32, fuse.Status) {
func (f *file) Release() {
f.fdLock.Lock()
if f.released {
- log.Panicf("ino%d fh%d: double release", f.devIno.ino, f.intFd())
+ log.Panicf("ino%d fh%d: double release", f.qIno.Ino, f.intFd())
}
f.fd.Close()
f.released = true
f.fdLock.Unlock()
- openFileMap.unregister(f.devIno)
+ openfiletable.Unregister(f.qIno)
}
// Flush - FUSE call
diff --git a/internal/fusefrontend/file_allocate_truncate.go b/internal/fusefrontend/file_allocate_truncate.go
index ae3dd41..acde76f 100644
--- a/internal/fusefrontend/file_allocate_truncate.go
+++ b/internal/fusefrontend/file_allocate_truncate.go
@@ -50,8 +50,8 @@ func (f *file) Allocate(off uint64, sz uint64, mode uint32) fuse.Status {
if f.released {
return fuse.EBADF
}
- f.fileTableEntry.writeLock.Lock()
- defer f.fileTableEntry.writeLock.Unlock()
+ f.fileTableEntry.WriteLock.Lock()
+ defer f.fileTableEntry.WriteLock.Unlock()
blocks := f.contentEnc.ExplodePlainRange(off, sz)
firstBlock := blocks[0]
@@ -97,17 +97,17 @@ func (f *file) Truncate(newSize uint64) fuse.Status {
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.devIno.ino, f.intFd())
+ tlog.Warn.Printf("ino%d fh%d: Truncate on released file", f.qIno.Ino, f.intFd())
return fuse.EBADF
}
- f.fileTableEntry.writeLock.Lock()
- defer f.fileTableEntry.writeLock.Unlock()
+ f.fileTableEntry.WriteLock.Lock()
+ defer f.fileTableEntry.WriteLock.Unlock()
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.devIno.ino, f.intFd(), err)
+ tlog.Warn.Printf("ino%d fh%d: Ftruncate(fd, 0) returned error: %v", f.qIno.Ino, f.intFd(), err)
return fuse.ToStatus(err)
}
// Truncate to zero kills the file header
@@ -125,7 +125,7 @@ func (f *file) Truncate(newSize uint64) fuse.Status {
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.devIno.ino, oldB, newB, oldSize, newSize)
+ tlog.Debug.Printf("ino%d: FUSE Truncate from %.2f to %.2f blocks (%d to %d bytes)", f.qIno.Ino, oldB, newB, oldSize, newSize)
// File size stays the same - nothing to do
if newSize == oldSize {
@@ -168,7 +168,7 @@ func (f *file) Truncate(newSize uint64) fuse.Status {
func (f *file) statPlainSize() (uint64, error) {
fi, err := f.fd.Stat()
if err != nil {
- tlog.Warn.Printf("ino%d fh%d: statPlainSize: %v", f.devIno.ino, f.intFd(), err)
+ tlog.Warn.Printf("ino%d fh%d: statPlainSize: %v", f.qIno.Ino, f.intFd(), err)
return 0, err
}
cipherSz := uint64(fi.Size())
diff --git a/internal/fusefrontend/open_file_table.go b/internal/fusefrontend/open_file_table.go
deleted file mode 100644
index 053298d..0000000
--- a/internal/fusefrontend/open_file_table.go
+++ /dev/null
@@ -1,101 +0,0 @@
-package fusefrontend
-
-import (
- "sync"
- "sync/atomic"
- "syscall"
-)
-
-// DevInoStruct uniquely identifies a backing file through device number and
-// inode number.
-type DevInoStruct struct {
- dev uint64
- ino uint64
-}
-
-// DevInoFromStat fills a new DevInoStruct with the passed Stat_t info
-func DevInoFromStat(st *syscall.Stat_t) DevInoStruct {
- // Explicit cast to uint64 to prevent build problems on 32-bit platforms
- return DevInoStruct{
- dev: uint64(st.Dev),
- ino: uint64(st.Ino),
- }
-}
-
-func init() {
- openFileMap.entries = make(map[DevInoStruct]*openFileEntryT)
-}
-
-// wlock - serializes write accesses to each file (identified by inode number)
-// Writing partial blocks means we have to do read-modify-write cycles. We
-// really don't want concurrent writes there.
-// Concurrent full-block writes could actually be allowed, but are not to
-// keep the locking simple.
-var openFileMap openFileMapT
-
-// wlockMap - usage:
-// 1) register
-// 2) lock ... unlock ...
-// 3) unregister
-type openFileMapT struct {
- // opCount counts writeLock.Lock() calls. As every operation that modifies a file should
- // call it, this effectively serves as a write-operation counter.
- // The variable is accessed without holding any locks so atomic operations
- // must be used. It must be the first element of the struct to guarantee
- // 64-bit alignment.
- opCount uint64
- // Protects map access
- sync.Mutex
- entries map[DevInoStruct]*openFileEntryT
-}
-
-type opCountMutex struct {
- sync.Mutex
- // Points to the opCount variable of the parent openFileMapT
- opCount *uint64
-}
-
-func (o *opCountMutex) Lock() {
- o.Mutex.Lock()
- atomic.AddUint64(o.opCount, 1)
-}
-
-// refCntMutex - mutex with reference count
-type openFileEntryT struct {
- // Reference count
- refCnt int
- // Write lock for this inode
- writeLock *opCountMutex
- // ID is the file ID in the file header.
- ID []byte
- IDLock sync.RWMutex
-}
-
-// register creates an entry for "ino", or incrementes the reference count
-// if the entry already exists.
-func (w *openFileMapT) register(di DevInoStruct) *openFileEntryT {
- w.Lock()
- defer w.Unlock()
-
- r := w.entries[di]
- if r == nil {
- o := opCountMutex{opCount: &w.opCount}
- r = &openFileEntryT{writeLock: &o}
- w.entries[di] = r
- }
- r.refCnt++
- return r
-}
-
-// unregister decrements the reference count for "di" and deletes the entry if
-// the reference count has reached 0.
-func (w *openFileMapT) unregister(di DevInoStruct) {
- w.Lock()
- defer w.Unlock()
-
- r := w.entries[di]
- r.refCnt--
- if r.refCnt == 0 {
- delete(w.entries, di)
- }
-}
diff --git a/internal/openfiletable/open_file_table.go b/internal/openfiletable/open_file_table.go
new file mode 100644
index 0000000..7cd401e
--- /dev/null
+++ b/internal/openfiletable/open_file_table.go
@@ -0,0 +1,111 @@
+// Package openfiletable maintains a table of currently opened files, identified
+// by the device number + inode number pair. This table is used by fusefrontend
+// to centrally store the current file ID and to lock files against concurrent
+// writes.
+package openfiletable
+
+import (
+ "sync"
+ "sync/atomic"
+ "syscall"
+)
+
+// QIno = Qualified Inode number.
+// Uniquely identifies a backing file through the device number,
+// inode number pair.
+type QIno struct {
+ // Stat_t.{Dev,Ino} is uint64 on 32- and 64-bit Linux
+ Dev uint64
+ Ino uint64
+}
+
+// QInoFromStat fills a new QIno struct with the passed Stat_t info.
+func QInoFromStat(st *syscall.Stat_t) QIno {
+ return QIno{
+ // There are some architectures that use 32-bit values here
+ // (darwin, freebsd-32, maybe others). Add and explicit cast to make
+ // this function work everywhere.
+ Dev: uint64(st.Dev),
+ Ino: uint64(st.Ino),
+ }
+}
+
+// wlock - serializes write accesses to each file (identified by inode number)
+// Writing partial blocks means we have to do read-modify-write cycles. We
+// really don't want concurrent writes there.
+// Concurrent full-block writes could actually be allowed, but are not to
+// keep the locking simple.
+var t table
+
+func init() {
+ t.entries = make(map[QIno]*Entry)
+}
+
+type table struct {
+ // writeLockCount counts entry.writeLock.Lock() calls. As every operation that
+ // modifies a file should
+ // call it, this effectively serves as a write-operation counter.
+ // The variable is accessed without holding any locks so atomic operations
+ // must be used. It must be the first element of the struct to guarantee
+ // 64-bit alignment.
+ writeLockCount uint64
+ // Protects map access
+ sync.Mutex
+ // Table entries
+ entries map[QIno]*Entry
+}
+
+// Entry is an entry in the open file table
+type Entry struct {
+ // Reference count
+ refCount int
+ // Write lock for this inode
+ WriteLock countingMutex
+ // ID is the file ID in the file header.
+ ID []byte
+ IDLock sync.RWMutex
+}
+
+// Register creates an open file table entry for "qi" (or incrementes the
+// reference count if the entry already exists) and returns the entry.
+func Register(qi QIno) *Entry {
+ t.Lock()
+ defer t.Unlock()
+
+ e := t.entries[qi]
+ if e == nil {
+ e = &Entry{}
+ t.entries[qi] = e
+ }
+ e.refCount++
+ return e
+}
+
+// Unregister decrements the reference count for "qi" and deletes the entry from
+// the open file table if the reference count reaches 0.
+func Unregister(qi QIno) {
+ t.Lock()
+ defer t.Unlock()
+
+ e := t.entries[qi]
+ e.refCount--
+ if e.refCount == 0 {
+ delete(t.entries, qi)
+ }
+}
+
+// countingMutex incrementes t.writeLockCount on each Lock() call.
+type countingMutex struct {
+ sync.Mutex
+}
+
+func (c *countingMutex) Lock() {
+ c.Mutex.Lock()
+ atomic.AddUint64(&t.writeLockCount, 1)
+}
+
+// WriteLockCount returns the write lock counter value. This value is encremented
+// each time writeLock.Lock() on a file table entry is called.
+func WriteLockCount() uint64 {
+ return atomic.LoadUint64(&t.writeLockCount)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 12:00:12 +0000