libutil, libstore: move bindPath to libstore linux platform bits

it's only used for linux sandbox setup, and can't be used elsewhere anyway.

Change-Id: I3560e141e5250cf9e72dc1576f87384a8e01f446

lix/libstore/build/local-derivation-goal.cc

@@ -29,7 +29,6 @@
 #include "lix/libutil/namespaces.hh"
 #include "lix/libutil/types.hh"
 #include "lix/libutil/unix-domain-socket.hh"
-#include "lix/libutil/mount.hh"
 #include "lix/libutil/strings.hh"
 #include "lix/libutil/thread-name.hh"
 #include "lix/libstore/platform/linux.hh"

lix/libstore/platform/linux.cc

@@ -9,7 +9,6 @@
 #include "lix/libutil/file-system.hh"
 #include "lix/libutil/finally.hh"
 #include "lix/libstore/gc-store.hh"
-#include "lix/libutil/mount.hh"
 #include "lix/libutil/processes.hh"
 #include "lix/libutil/result.hh"
 #include "lix/libutil/signals.hh"
@@ -1234,6 +1233,40 @@ std::string LinuxLocalDerivationGoal::rewriteResolvConf(std::string fromHost)
     return std::regex_replace(fromHost, lineRegex, "") + nsInSandbox;
 }
 
+static void bindPath(const Path & source, const Path & target, bool optional = false)
+{
+    debug("bind mounting '%1%' to '%2%'", source, target);
+
+    auto bindMount = [&]() {
+        if (sys::mount(source, target, "", MS_BIND | MS_REC, 0) == -1) {
+            throw SysError("bind mount from '%1%' to '%2%' failed", source, target);
+        }
+    };
+
+    auto maybeSt = maybeLstat(source);
+    if (!maybeSt) {
+        if (optional) {
+            return;
+        } else {
+            throw SysError("getting attributes of path '%1%'", source);
+        }
+    }
+    auto st = *maybeSt;
+
+    if (S_ISDIR(st.st_mode)) {
+        createDirs(target);
+        bindMount();
+    } else if (S_ISLNK(st.st_mode)) {
+        // Symlinks can (apparently) not be bind-mounted, so just copy it
+        createDirs(dirOf(target));
+        copyFile(source, target, {});
+    } else {
+        createDirs(dirOf(target));
+        writeFile(target, "");
+        bindMount();
+    }
+}
+
 bool LinuxLocalDerivationGoal::prepareChildSetup()
 {
     // Set the NO_NEW_PRIVS prctl flag.

lix/libutil/meson.build

@@ -31,7 +31,6 @@ liblix_sources += files(
   'logging-rpc.cc',
   'logging.cc',
   'monitor-fd.cc',
-  'mount.cc',
   'namespaces.cc',
   'position.cc',
   'print-elided.cc',
@@ -114,7 +113,6 @@ libutil_headers = files(
   'lru-cache.hh',
   'manually-drop.hh',
   'monitor-fd.hh',
-  'mount.hh',
   'namespaces.hh',
   'notifying-counter.hh',
   'pool.hh',

lix/libutil/mount.cc

@@ -1,45 +0,0 @@
-#include "lix/libutil/mount.hh"
-#include "c-calls.hh"
-#include "lix/libutil/error.hh"
-#include "lix/libutil/file-system.hh"
-#include "lix/libutil/logging.hh"
-#if __linux__
-#include <sys/mount.h>
-
-namespace nix {
-
-void bindPath(const Path & source, const Path & target, bool optional, CopyFileFlags flags)
-{
-    debug("bind mounting '%1%' to '%2%'", source, target);
-
-    auto bindMount = [&]() {
-        if (sys::mount(source, target, "", MS_BIND | MS_REC, 0) == -1) {
-            throw SysError("bind mount from '%1%' to '%2%' failed", source, target);
-        }
-    };
-
-    auto maybeSt = maybeLstat(source);
-    if (!maybeSt) {
-        if (optional)
-            return;
-        else
-            throw SysError("getting attributes of path '%1%'", source);
-    }
-    auto st = *maybeSt;
-
-    if (S_ISDIR(st.st_mode)) {
-        createDirs(target);
-        bindMount();
-    } else if (S_ISLNK(st.st_mode)) {
-        // Symlinks can (apparently) not be bind-mounted, so just copy it
-        createDirs(dirOf(target));
-        copyFile(source, target, flags);
-    } else {
-        createDirs(dirOf(target));
-        writeFile(target, "");
-        bindMount();
-    }
-}
-}
-
-#endif

lix/libutil/mount.hh

@@ -1,23 +0,0 @@
-#pragma once
-///@file
-
-#include "lix/libutil/types.hh"
-#include "lix/libutil/file-system.hh"
-
-#if __linux__
-namespace nix {
-
-/**
- * Bind-mount file or directory from `source` to `destination`.
- * If source does not exist this will fail unless `optional` is set
- *
- * If `source` is a symlink, it will perform a copy instead of a bind mount
- * because symlinks cannot be bind mounted on all versions of the Linux kernel.
- *
- * If a copy is performed, extra flags to the copy can be passed using `flags`.
- */
-void bindPath(
-    const Path & source, const Path & target, bool optional = false, CopyFileFlags flags = {}
-);
-}
-#endif