From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Peter Jones <pjones@redhat.com>

Date: Wed, 3 Sep 2014 10:38:00 -0400

Subject: [PATCH] Make editenv chase symlinks including those across devices.

This lets us make /boot/grub2/grubenv a symlink to

/boot/efi/EFI/fedora/grubenv even though they're different mount points,

which allows /usr/bin/grub2-editenv to be the same across platforms

(i.e. UEFI vs BIOS).

Signed-off-by: Peter Jones <pjones@redhat.com>

Reviewed-by: Adam Jackson <ajax@redhat.com>

---

 Makefile.util.def |  9 +++++++++

 util/editenv.c    | 46 ++++++++++++++++++++++++++++++++++++++++++++--

 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/Makefile.util.def b/Makefile.util.def

index c7b775bce..d08713b55 100644

--- a/Makefile.util.def

+++ b/Makefile.util.def

@@ -231,8 +231,17 @@ program = {

   common = util/grub-editenv.c;

   common = util/editenv.c;

+  common = util/grub-install-common.c;

   common = grub-core/osdep/init.c;

+  common = grub-core/osdep/compress.c;

+  extra_dist = grub-core/osdep/unix/compress.c;

+  extra_dist = grub-core/osdep/basic/compress.c;

+  common = util/mkimage.c;

+  common = grub-core/osdep/config.c;

+  common = util/config.c;

+  common = util/resolve.c;

+  ldadd = '$(LIBLZMA)';

   ldadd = libgrubmods.a;

   ldadd = libgrubgcry.a;

   ldadd = libgrubkern.a;

diff --git a/util/editenv.c b/util/editenv.c

index c6f8d2298..d8d1dad6a 100644

--- a/util/editenv.c

+++ b/util/editenv.c

@@ -37,6 +37,7 @@ grub_util_create_envblk_file (const char *name)

   FILE *fp;

   char *buf;

   char *namenew;

+  char *rename_target = xstrdup(name);

   buf = xmalloc (DEFAULT_ENVBLK_SIZE);

@@ -59,7 +60,48 @@ grub_util_create_envblk_file (const char *name)

   free (buf);

   fclose (fp);

-  if (grub_util_rename (namenew, name) < 0)

-    grub_util_error (_("cannot rename the file %s to %s"), namenew, name);

+  ssize_t size = 1;

+  while (1)

+    {

+      char *linkbuf;

+      ssize_t retsize;

+

+      linkbuf = xmalloc(size+1);

+      retsize = grub_util_readlink (rename_target, linkbuf, size);

+      if (retsize < 0 && (errno == ENOENT || errno == EINVAL))

+	{

+	  free (linkbuf);

+	  break;

+	}

+      else if (retsize < 0)

+	{

+	  grub_util_error (_("cannot rename the file %s to %s: %m"), namenew, name);

+	  free (linkbuf);

+	  free (namenew);

+	  return;

+	}

+      else if (retsize == size)

+	{

+	  free(linkbuf);

+	  size += 128;

+	  continue;

+	}

+

+      free (rename_target);

+      linkbuf[retsize] = '\0';

+      rename_target = linkbuf;

+    }

+

+  int rc = grub_util_rename (namenew, rename_target);

+  if (rc < 0 && errno == EXDEV)

+    {

+      rc = grub_install_copy_file (namenew, rename_target, 1);

+      grub_util_unlink (namenew);

+    }

+

+  if (rc < 0)

+    grub_util_error (_("cannot rename the file %s to %s: %m"), namenew, name);

+

   free (namenew);

+  free (rename_target);

 }