Add winsymlinks:sys, to explicitly select always using plain files
containing a magic cookie to represent a symlink.
---
winsup/cygwin/environ.cc | 2 ++
winsup/cygwin/globals.cc | 3 ++-
winsup/cygwin/path.cc | 3 ++-
winsup/doc/cygwinenv.xml | 20 +++++++++++++++++++-
winsup/doc/pathnames.xml | 29 +++++++++++++++++++----------
5 files changed, 44 insertions(+), 13 deletions(-)
diff --git a/winsup/cygwin/environ.cc b/winsup/cygwin/environ.cc
index 3a03657db..a14b47953 100644
--- a/winsup/cygwin/environ.cc
+++ b/winsup/cygwin/environ.cc
@@ -82,6 +82,8 @@ set_winsymlinks (const char *buf)
allow_winsymlinks = WSYM_lnk;
else if (ascii_strncasematch (buf, "lnk", 3))
allow_winsymlinks = WSYM_lnk;
+ else if (ascii_strncasematch (buf, "sys", 3))
+ allow_winsymlinks = WSYM_sysfile;
/* Make sure to try native symlinks only on systems supporting them. */
else if (ascii_strncasematch (buf, "native", 6))
allow_winsymlinks = ascii_strcasematch (buf + 6, "strict")
diff --git a/winsup/cygwin/globals.cc b/winsup/cygwin/globals.cc
index 066026421..48fb312de 100644
--- a/winsup/cygwin/globals.cc
+++ b/winsup/cygwin/globals.cc
@@ -57,7 +57,8 @@ enum winsym_t
WSYM_lnk,
WSYM_native,
WSYM_nativestrict,
- WSYM_nfs
+ WSYM_nfs,
+ WSYM_sysfile,
};
exit_states NO_COPY exit_state;
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index cd029c5b4..baf04ce89 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -2071,6 +2071,7 @@ symlink_worker (const char *oldpath, path_conv
&win32_newpath, bool isdevice)
/* On FSes not supporting reparse points, or in case of an error
creating the WSL symlink, fall back to creating the plain old
SYSTEM file symlink. */
+ wsym_type = WSYM_sysfile;
break;
default:
break;
@@ -2211,7 +2212,7 @@ symlink_worker (const char *oldpath, path_conv
&win32_newpath, bool isdevice)
* sizeof (WCHAR);
cp += *plen;
}
- else
+ else /* wsym_type == WSYM_sysfile */
{
/* Default technique creating a symlink. */
buf = tp.t_get ();
diff --git a/winsup/doc/cygwinenv.xml b/winsup/doc/cygwinenv.xml
index a52b6ac19..649084dfa 100644
--- a/winsup/doc/cygwinenv.xml
+++ b/winsup/doc/cygwinenv.xml
@@ -76,11 +76,17 @@ in addition to the normal UNIX argv list. Defaults to not
set.</para>
</listitem>
<listitem>
-<para><envar>winsymlinks:{lnk,native,nativestrict}</envar> - if set to just
+<para><envar>winsymlinks:{lnk,native,nativestrict,sys}</envar></para>
+
+<itemizedlist mark="square">
+<listitem>
+<para>If set to just
<literal>winsymlinks</literal> or <literal>winsymlinks:lnk</literal>,
Cygwin creates symlinks as Windows shortcuts with a special header and
the R/O attribute set.</para>
+</listitem>
+<listitem>
<para>If set to <literal>winsymlinks:native</literal> or
<literal>winsymlinks:nativestrict</literal>, Cygwin creates symlinks as
native Windows symlinks on filesystems and OS versions supporting them.</para>
@@ -92,9 +98,21 @@ some reason, it will fall back to creating Cygwin default
symlinks
with <literal>winsymlinks:native</literal>, while with
<literal>winsymlinks:nativestrict</literal> the <literal>symlink(2)</literal>
system call will immediately fail.</para>
+</listitem>
+
+<listitem>
+<para>If set to <literal>winsymlinks:sys</literal>, Cygwin creates symlinks as
+plain files with the <literal>system</literal> attribute, containing a magic
+cookie followed by the path to which the link points.</para>
+</listitem>
+</itemizedlist>
+
+<para>Note that this setting has no effect where Cygwin knows that the
+filesystem only supports a creating symlinks in a specific way.</para>
<para>For more information on symbolic links, see
<xref linkend="pathnames-symlinks"></xref>.</para>
+
</listitem>
<listitem>
diff --git a/winsup/doc/pathnames.xml b/winsup/doc/pathnames.xml
index 2966bdabf..1ab45c130 100644
--- a/winsup/doc/pathnames.xml
+++ b/winsup/doc/pathnames.xml
@@ -389,16 +389,25 @@ ways.</para>
<itemizedlist mark="bullet">
<listitem>
-<para>The default symlinks created by Cygwin are either special reparse
-points shared with WSL on Windows 10, or plain files containing a magic
-cookie followed by the path to which the link points. The reparse point
-is used on NTFS, the plain file on almost any other filesystem.</para>
-
-<note><para>Symlinks created by really old Cygwin releases (prior to
-Cygwin 1.7.0) are usually readable. However, you could run into problems
-if you're now using another character set than the one you used when
-creating these symlinks (see <xref linkend="setup-locale-problems"></xref>).
-</para></note>
+ <para>The default symlinks created by Cygwin are:</para>
+
+ <itemizedlist mark="square">
+ <listitem>
+ <para>special reparse points shared with WSL (on NTFS on Windows 10 1607
+ or later)</para>
+ </listitem>
+ <listitem>
+ <para>plain files with the <literal>system</literal> attribute,
containing
+ a magic cookie followed by the path to which the link points.
+ </para>
+ <note><para>Symlinks of this type created by really old Cygwin releases
+ (prior to Cygwin 1.7.0) are usually readable. However, you could run
into
+ problems if you're now using another character set than the one you used
+ when creating these symlinks (see <xref
+ linkend="setup-locale-problems"></xref>).
+ </para></note>
+ </listitem>
+ </itemizedlist>
</listitem>
<listitem>
--
2.32.0
