syscallcompat: don't retry Close()

After Close() returns, the fd is dead, even if we
received EINTR. Don't retry, we could shoot down
an unrelated fd that received the same fd number.
libgocryptfs
Jakob Unterwurzacher 2 years ago
parent af4c1fb7a3
commit ec3eaf0b87
  1. 14
      internal/fusefrontend/file.go
  2. 27
      internal/syscallcompat/eintr.go

@ -391,9 +391,9 @@ func (f *File) Release(ctx context.Context) syscall.Errno {
}
f.released = true
openfiletable.Unregister(f.qIno)
f.fd.Close()
err := f.fd.Close()
f.fdLock.Unlock()
return 0
return fs.ToErrno(err)
}
// Flush - FUSE call
@ -401,15 +401,7 @@ func (f *File) Flush(ctx context.Context) syscall.Errno {
f.fdLock.RLock()
defer f.fdLock.RUnlock()
// Since Flush() may be called for each dup'd fd, we don't
// want to really close the file, we just want to flush. This
// is achieved by closing a dup'd fd.
newFd, err := syscall.Dup(f.intFd())
if err != nil {
return fs.ToErrno(err)
}
err = syscallcompat.Close(newFd)
err := syscallcompat.Flush(f.intFd())
return fs.ToErrno(err)
}

@ -11,6 +11,9 @@ import (
//
// This is needed because CIFS throws lots of EINTR errors:
// https://github.com/rfjakob/gocryptfs/issues/483
//
// Don't use retryEINTR() with syscall.Close()!
// See https://code.google.com/p/chromium/issues/detail?id=269623 .
func retryEINTR(op func() error) error {
for {
err := op()
@ -40,9 +43,25 @@ func Open(path string, mode int, perm uint32) (fd int, err error) {
return fd, err
}
// Close wraps syscall.Close.
// Flush is a helper for the FUSE command FLUSH.
// Retries on EINTR.
func Close(fd int) (err error) {
err = retryEINTR(func() error { return syscall.Close(fd) })
return err
func Flush(fd int) error {
for {
// Flushing is achieved by closing a dup'd fd.
newFd, err := syscall.Dup(fd)
if err == syscall.EINTR {
continue
}
if err != nil {
return err
}
err = syscall.Close(newFd)
// Even if we get EINTR here, newFd is dead - see
// https://code.google.com/p/chromium/issues/detail?id=269623 .
// We have to make a new one with Dup(), so continue at the top.
if err == syscall.EINTR {
continue
}
return err
}
}

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