From: Peter Jones <pjo...@redhat.com>
The grub-editenv create command will wrongly overwrite /boot/grub2/grubenv
with a regular file if grubenv is a symbolic link. But instead, it should
create a new file in the path the symlink points to.
This lets /boot/grub2/grubenv be a symlink to /boot/efi/EFI/fedora/grubenv
even when they're different mount points, which allows grub2-editenv to be
the same across platforms (i.e. UEFI vs BIOS).
For example, in Fedora the GRUB EFI builds have prefix set to /EFI/fedora
(on the EFI System Partition), but for BIOS machine it'll be /boot/grub2
(which may or may not be its own mountpoint).
With this patch, on EFI machines we can make /boot/grub2/grubenv a symlink
to /boot/efi/EFI/fedora/grubenv, and the same copy of grub-set-default will
work on both kinds of systems.
Windows doesn't implement a readlink primitive, so the current behaviour is
maintained for this operating system.
Signed-off-by: Peter Jones <pjo...@redhat.com>
Signed-off-by: Jonathan Lebon <jle...@redhat.com>
Reviewed-by: Adam Jackson <a...@redhat.com>
Signed-off-by: Javier Martinez Canillas <javi...@redhat.com>
---
Changes in v4:
- Only attempt following symlinks in operating sytems other than Windows.
Changes in v3:
- A couple of style cleanups.
Changes in v2:
- Address issues pointed out by Daniel Kiper in the previous version.
Makefile.util.def | 11 ++++++++
util/editenv.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 76 insertions(+)
diff --git a/Makefile.util.def b/Makefile.util.def
index 969d32f0097..733a397cb2b 100644
--- a/Makefile.util.def
+++ b/Makefile.util.def
@@ -240,8 +240,19 @@ 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 = util/grub-mkimage32.c;
+ common = util/grub-mkimage64.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 eb2d0c03a98..d53d4d6c68e 100644
--- a/util/editenv.c
+++ b/util/editenv.c
@@ -28,6 +28,9 @@
#include <errno.h>
#include <string.h>
+#if !defined(_WIN32)
+#include <libgen.h>
+#endif
#define DEFAULT_ENVBLK_SIZE 1024
@@ -37,6 +40,11 @@ grub_util_create_envblk_file (const char *name)
FILE *fp;
char *buf;
char *namenew;
+#if !defined(_WIN32)
+ ssize_t size = 1;
+ char *rename_target = xstrdup (name);
+ int rc;
+#endif
buf = xmalloc (DEFAULT_ENVBLK_SIZE);
@@ -60,7 +68,64 @@ grub_util_create_envblk_file (const char *name)
free (buf);
fclose (fp);
+#if defined(_WIN32)
if (grub_util_rename (namenew, name) < 0)
grub_util_error (_("cannot rename the file %s to %s"), namenew, name);
+#else
+ 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)
+ {
+ free (linkbuf);
+ grub_util_error (_("cannot rename the file %s to %s: %m"), namenew,
name);
+ }
+ else if (retsize == size)
+ {
+ free (linkbuf);
+ size += 128;
+ continue;
+ }
+
+ linkbuf[retsize] = '\0';
+ if (linkbuf[0] == '/')
+ {
+ free (rename_target);
+ rename_target = linkbuf;
+ }
+ else
+ {
+ char *dbuf = xstrdup (rename_target);
+ const char *dir = dirname (dbuf);
+
+ free (rename_target);
+ rename_target = xasprintf ("%s/%s", dir, linkbuf);
+ free (dbuf);
+ free (linkbuf);
+ }
+ }
+
+ 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);
+ }
+
+ free (rename_target);
+
+ if (rc < 0)
+ grub_util_error (_("cannot rename the file %s to %s: %m"), namenew, name);
+#endif
+
free (namenew);
}
--
2.23.0
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