diff options
Diffstat (limited to 'internal/fusefrontend/file.go')
| -rw-r--r-- | internal/fusefrontend/file.go | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go index 8d0ba01..9bd05e6 100644 --- a/internal/fusefrontend/file.go +++ b/internal/fusefrontend/file.go @@ -14,6 +14,8 @@ import ( "sync" "syscall" + "golang.org/x/sys/unix" + "github.com/hanwen/go-fuse/v2/fs" "github.com/hanwen/go-fuse/v2/fuse" @@ -91,6 +93,13 @@ func (f *File) readFileID() ([]byte, error) { // and not only the header. A header-only file will be considered empty. // This makes File ID poisoning more difficult. readLen := contentenc.HeaderLen + 1 + if f.rootNode.args.SharedStorage { + // With -sharedstorage, we consider a header-only file as valid, because + // another gocryptfs process may have either: + // 1) just created the header, and not written further data yet. + // 2) truncated the file down to just the header. + readLen = contentenc.HeaderLen + } buf := make([]byte, readLen) n, err := f.fd.ReadAt(buf, 0) if err != nil { @@ -267,18 +276,25 @@ func (f *File) doWrite(data []byte, off int64) (uint32, syscall.Errno) { // // If the file ID is not cached, read it from disk if f.fileTableEntry.ID == nil { + if err := f.LockSharedStorage(unix.F_WRLCK, 0, contentenc.HeaderLen); err != nil { + return 0, fs.ToErrno(err) + } 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 + // Having the unlock three times is ugly. But every other way I tried is even uglier. + f.LockSharedStorage(unix.F_UNLCK, 0, contentenc.HeaderLen) } else if err != nil { // Other errors mean readFileID() found a corrupt header tlog.Warn.Printf("doWrite %d: corrupt header: %v", f.qIno.Ino, err) + f.LockSharedStorage(unix.F_UNLCK, 0, contentenc.HeaderLen) return 0, syscall.EIO } if err != nil { + f.LockSharedStorage(unix.F_UNLCK, 0, contentenc.HeaderLen) return 0, fs.ToErrno(err) } f.fileTableEntry.ID = fileID |