Clear any immutable bits in the Nix store

Doing this once makes subsequent operations like garbage collecting
more efficient since we don't have to call makeMutable() first.

src/libutil/Makefile.am

@@ -1,12 +1,12 @@
 pkglib_LTLIBRARIES = libutil.la
 
 libutil_la_SOURCES = util.cc hash.cc serialise.cc \
-  archive.cc xml-writer.cc immutable.cc
+  archive.cc xml-writer.cc
 
 libutil_la_LIBADD = ../boost/format/libformat.la
 
 pkginclude_HEADERS = util.hh hash.hh serialise.hh \
-  archive.hh xml-writer.hh types.hh immutable.hh
+  archive.hh xml-writer.hh types.hh
 
 if !HAVE_OPENSSL
 libutil_la_SOURCES += \

src/libutil/immutable.cc

@@ -1,49 +0,0 @@
-#include "config.h"
-
-#include "immutable.hh"
-#include "util.hh"
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-
-#if HAVE_LINUX_FS_H
-#include <linux/fs.h>
-#include <sys/ioctl.h>
-#include <errno.h>
-#endif
-
-namespace nix {
-
-
-void makeMutable(const Path & path)
-{
-#if defined(FS_IOC_SETFLAGS) && defined(FS_IOC_GETFLAGS) && defined(FS_IMMUTABLE_FL)
-
-    /* Don't even try if we're not root.  One day we should support
-       the CAP_LINUX_IMMUTABLE capability. */
-    if (getuid() != 0) return;
-
-    /* The O_NOFOLLOW is important to prevent us from changing the
-       mutable bit on the target of a symlink (which would be a
-       security hole). */
-    AutoCloseFD fd = open(path.c_str(), O_RDONLY | O_NOFOLLOW);
-    if (fd == -1) {
-        if (errno == ELOOP) return; // it's a symlink
-        throw SysError(format("opening file `%1%'") % path);
-    }
-
-    unsigned int flags = 0, old;
-
-    /* Silently ignore errors getting/setting the immutable flag so
-       that we work correctly on filesystems that don't support it. */
-    if (ioctl(fd, FS_IOC_GETFLAGS, &flags)) return;
-    old = flags;
-    flags &= ~FS_IMMUTABLE_FL;
-    if (old == flags) return;
-    if (ioctl(fd, FS_IOC_SETFLAGS, &flags)) return;
-#endif
-}
-
-
-}

src/libutil/immutable.hh

@@ -1,10 +0,0 @@
-#pragma once
-
-#include <types.hh>
-
-namespace nix {
-
-/* Make the given path mutable. */
-void makeMutable(const Path & path);
-
-}

src/libutil/util.cc

@@ -13,7 +13,6 @@
 #include <limits.h>
 
 #include "util.hh"
-#include "immutable.hh"
 
 
 extern char * * environ;
@@ -305,8 +304,6 @@ static void _deletePath(const Path & path, unsigned long long & bytesFreed)
 
     struct stat st = lstat(path);
 
-    if (S_ISDIR(st.st_mode) || S_ISREG(st.st_mode)) makeMutable(path);
-
     if (!S_ISDIR(st.st_mode) && st.st_nlink == 1)
         bytesFreed += st.st_blocks * 512;