From ea0df4e9530965c4ec04982656f27e074aeefac8 Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Sat, 11 Dec 2010 15:01:33 +0100
Subject: [PATCH] ZFS mtime support

---
 grub-core/fs/zfs/zfs.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/grub-core/fs/zfs/zfs.c b/grub-core/fs/zfs/zfs.c
index cafe915c5..327e99a90 100644
--- a/grub-core/fs/zfs/zfs.c
+++ b/grub-core/fs/zfs/zfs.c
@@ -2565,6 +2565,29 @@ zfs_uuid (grub_device_t device, char **uuid)
   return GRUB_ERR_NONE;
 }
 
+static grub_err_t 
+zfs_mtime (grub_device_t device, grub_int32_t *mt)
+{
+  struct grub_zfs_data *data;
+  grub_zfs_endian_t ub_endian = UNKNOWN_ENDIAN;
+  uberblock_t *ub;
+
+  *mt = 0;
+
+  data = zfs_mount (device);
+  if (! data)
+    return grub_errno;
+
+  ub = &(data->current_uberblock);
+  ub_endian = (grub_zfs_to_cpu64 (ub->ub_magic, 
+				  LITTLE_ENDIAN) == UBERBLOCK_MAGIC 
+	       ? LITTLE_ENDIAN : BIG_ENDIAN);
+
+  *mt = grub_zfs_to_cpu64 (ub->ub_timestamp, ub_endian);
+  zfs_unmount (data);
+  return GRUB_ERR_NONE;
+}
+
 /*
  * zfs_open() locates a file in the rootpool by following the
  * MOS and places the dnode of the file in the memory address DNODE.
@@ -2934,7 +2957,7 @@ static struct grub_fs grub_zfs_fs = {
   .close = grub_zfs_close,
   .label = zfs_label,
   .uuid = zfs_uuid,
-  .mtime = 0,
+  .mtime = zfs_mtime,
   .next = 0
 };