package fusefrontend // Mkdir and Rmdir import ( "fmt" "os" "path/filepath" "syscall" "github.com/hanwen/go-fuse/fuse" "github.com/rfjakob/gocryptfs/internal/toggledlog" "github.com/rfjakob/gocryptfs/internal/cryptocore" "github.com/rfjakob/gocryptfs/internal/nametransform" ) func (fs *FS) Mkdir(relPath string, mode uint32, context *fuse.Context) (code fuse.Status) { if fs.isFiltered(relPath) { return fuse.EPERM } encPath, err := fs.getBackingPath(relPath) if err != nil { return fuse.ToStatus(err) } if !fs.args.DirIV { return fuse.ToStatus(os.Mkdir(encPath, os.FileMode(mode))) } // We need write and execute permissions to create gocryptfs.diriv origMode := mode mode = mode | 0300 // The new directory may take the place of an older one that is still in the cache fs.nameTransform.DirIVCache.Clear() // Create directory fs.dirIVLock.Lock() defer fs.dirIVLock.Unlock() err = os.Mkdir(encPath, os.FileMode(mode)) if err != nil { return fuse.ToStatus(err) } // Create gocryptfs.diriv inside err = nametransform.WriteDirIV(encPath) if err != nil { // This should not happen toggledlog.Warn.Printf("Mkdir: WriteDirIV failed: %v", err) err2 := syscall.Rmdir(encPath) if err2 != nil { toggledlog.Warn.Printf("Mkdir: Rmdir rollback failed: %v", err2) } return fuse.ToStatus(err) } // Set permissions back to what the user wanted if origMode != mode { err = os.Chmod(encPath, os.FileMode(origMode)) if err != nil { toggledlog.Warn.Printf("Mkdir: Chmod failed: %v", err) } } return fuse.OK } func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) { encPath, err := fs.getBackingPath(name) if err != nil { return fuse.ToStatus(err) } if !fs.args.DirIV { return fuse.ToStatus(syscall.Rmdir(encPath)) } // If the directory is not empty besides gocryptfs.diriv, do not even // attempt the dance around gocryptfs.diriv. fd, err := os.Open(encPath) if perr, ok := err.(*os.PathError); ok && perr.Err == syscall.EACCES { // We need permission to read and modify the directory toggledlog.Debug.Printf("Rmdir: handling EACCESS") fi, err2 := os.Stat(encPath) if err2 != nil { toggledlog.Debug.Printf("Rmdir: Stat: %v", err2) return fuse.ToStatus(err2) } origMode := fi.Mode() newMode := origMode | 0700 err2 = os.Chmod(encPath, newMode) if err2 != nil { toggledlog.Debug.Printf("Rmdir: Chmod failed: %v", err2) return fuse.ToStatus(err) } defer func() { if code != fuse.OK { // Undo the chmod if removing the directory failed err3 := os.Chmod(encPath, origMode) if err3 != nil { toggledlog.Warn.Printf("Rmdir: Chmod rollback failed: %v", err2) } } }() // Retry open fd, err = os.Open(encPath) } if err != nil { toggledlog.Debug.Printf("Rmdir: Open: %v", err) return fuse.ToStatus(err) } list, err := fd.Readdirnames(10) fd.Close() if err != nil { toggledlog.Debug.Printf("Rmdir: Readdirnames: %v", err) return fuse.ToStatus(err) } if len(list) > 1 { return fuse.ToStatus(syscall.ENOTEMPTY) } else if len(list) == 0 { toggledlog.Warn.Printf("Rmdir: gocryptfs.diriv missing, allowing deletion") return fuse.ToStatus(syscall.Rmdir(encPath)) } // Move "gocryptfs.diriv" to the parent dir as "gocryptfs.diriv.rmdir.XYZ" dirivPath := filepath.Join(encPath, nametransform.DirIVFilename) parentDir := filepath.Dir(encPath) tmpName := fmt.Sprintf("gocryptfs.diriv.rmdir.%d", cryptocore.RandUint64()) tmpDirivPath := filepath.Join(parentDir, tmpName) toggledlog.Debug.Printf("Rmdir: Renaming %s to %s", nametransform.DirIVFilename, tmpDirivPath) // The directory is in an inconsistent state between rename and rmdir. Protect against // concurrent readers. fs.dirIVLock.Lock() defer fs.dirIVLock.Unlock() err = os.Rename(dirivPath, tmpDirivPath) if err != nil { toggledlog.Warn.Printf("Rmdir: Renaming %s to %s failed: %v", nametransform.DirIVFilename, tmpDirivPath, err) return fuse.ToStatus(err) } // Actual Rmdir err = syscall.Rmdir(encPath) if err != nil { // This can happen if another file in the directory was created in the // meantime, undo the rename err2 := os.Rename(tmpDirivPath, dirivPath) if err2 != nil { toggledlog.Warn.Printf("Rmdir: Rename rollback failed: %v", err2) } return fuse.ToStatus(err) } // Delete "gocryptfs.diriv.rmdir.INODENUMBER" err = syscall.Unlink(tmpDirivPath) if err != nil { toggledlog.Warn.Printf("Rmdir: Could not clean up %s: %v", tmpName, err) } // The now-deleted directory may have been in the DirIV cache. Clear it. fs.nameTransform.DirIVCache.Clear() return fuse.OK }