On Mon, 6 Dec 2021 11:16:30 +0100
Corinna Vinschen wrote:
> > For example, RtlEqualUnicodeString() compares \??\UNC\VBoxSrv\tmp and
> > \??\UNC\VBoxSrv\tmp\, then it fails.
> > [...]
> > + if (wcsstr (fpbuf, L"\\\\?\\UNC\\") == fpbuf)
> > + goto file_not_symlink;
> > +
>
> Isn't that a bit intrusive? Wouldn't it also fix the issue if we
> just overwrite a trailing '\\' with '\0', like this?
>
> diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
> index baf04ce89a08..b76e5b0466cf 100644
> --- a/winsup/cygwin/path.cc
> +++ b/winsup/cygwin/path.cc
> @@ -3492,8 +3492,14 @@ restart:
> {
> UNICODE_STRING fpath;
>
> - RtlInitCountedUnicodeString (&fpath, fpbuf, ret * sizeof (WCHAR));
> + /* If incoming path has no trailing backslash, but final path
> + has one, drop trailing backslash from final path so the
> + below string comparison has a chance to succeed. */
> + if (upath.Buffer[(upath.Length - 1) / sizeof (WCHAR)] != L'\\'
> + && fpbuf[ret - 1] == L'\\')
> + fpbuf[--ret] = L'\0';
> fpbuf[1] = L'?'; /* \\?\ --> \??\ */
> + RtlInitCountedUnicodeString (&fpath, fpbuf, ret * sizeof (WCHAR));
> if (!RtlEqualUnicodeString (&upath, &fpath, !!ci_flag))
> {
> issymlink = true;
First, I think the same. However, with this patch, it sometimes causes
hang for a few seconds around the code:
else if (isvirtual_dev (dev))
{
/* FIXME: Calling build_fhandler here is not the right way to
handle this. */
fhandler_virtual *fh = (fhandler_virtual *)
build_fh_dev (dev, path_copy);
virtual_ftype_t file_type;
if (!fh)
file_type = virt_none;
else
{
file_type = fh->exists ();
if (file_type == virt_symlink
|| file_type == virt_fdsymlink)
{
fh->fill_filebuf ();
symlen = sym.set (fh->get_filebuf ());
}
with path_copy of "//VBoxSrv". I am not sure why.
In addition,
https://cygwin.com/pipermail/cygwin/2021-December/250103.html
still needs fix.
So I proposed the patch which stops to treat UNC path as symlink.
--
Takashi Yano <takashi.y...@nifty.ne.jp>
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