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package pathfs_frontend
// 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
}
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