Adding upstream version 2.06.upstream/2.06upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1241 insertions, 0 deletions

diff --git a/grub-core/fs/nilfs2.c b/grub-core/fs/nilfs2.c
new file mode 100644
index 0000000..3c248a9
--- /dev/null
+++ b/grub-core/fs/nilfs2.c
@@ -0,0 +1,1241 @@
+/* 
+ *  nilfs2.c - New Implementation of Log filesystem 
+ *
+ *  Written by Jiro SEKIBA <jir@unicus.jp>
+ *
+ *  Copyright (C) 2003,2004,2005,2007,2008,2010  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+/* Filetype information as used in inodes.  */
+#define FILETYPE_INO_MASK	0170000
+#define FILETYPE_INO_REG	0100000
+#define FILETYPE_INO_DIRECTORY	0040000
+#define FILETYPE_INO_SYMLINK	0120000
+
+#include <grub/err.h>
+#include <grub/file.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+#include <grub/disk.h>
+#include <grub/dl.h>
+#include <grub/types.h>
+#include <grub/fshelp.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+#define NILFS_INODE_BMAP_SIZE	7
+
+#define NILFS_SUPORT_REV	2
+
+/* Magic value used to identify an nilfs2 filesystem.  */
+#define	NILFS2_SUPER_MAGIC	0x3434
+/* nilfs btree node flag.  */
+#define NILFS_BTREE_NODE_ROOT   0x01
+
+/* nilfs btree node level. */
+#define NILFS_BTREE_LEVEL_DATA          0
+#define NILFS_BTREE_LEVEL_NODE_MIN      (NILFS_BTREE_LEVEL_DATA + 1)
+
+/* nilfs 1st super block posission from beginning of the partition
+   in 512 block size */
+#define NILFS_1ST_SUPER_BLOCK	2
+/* nilfs 2nd super block posission from beginning of the partition
+   in 512 block size */
+#define NILFS_2ND_SUPER_BLOCK(devsize)	(((devsize >> 3) - 1) << 3)
+
+#define LOG_INODE_SIZE 7
+struct grub_nilfs2_inode
+{
+  grub_uint64_t i_blocks;
+  grub_uint64_t i_size;
+  grub_uint64_t i_ctime;
+  grub_uint64_t i_mtime;
+  grub_uint32_t i_ctime_nsec;
+  grub_uint32_t i_mtime_nsec;
+  grub_uint32_t i_uid;
+  grub_uint32_t i_gid;
+  grub_uint16_t i_mode;
+  grub_uint16_t i_links_count;
+  grub_uint32_t i_flags;
+  grub_uint64_t i_bmap[NILFS_INODE_BMAP_SIZE];
+#define i_device_code	i_bmap[0]
+  grub_uint64_t i_xattr;
+  grub_uint32_t i_generation;
+  grub_uint32_t i_pad;
+};
+
+struct grub_nilfs2_super_root
+{
+  grub_uint32_t sr_sum;
+  grub_uint16_t sr_bytes;
+  grub_uint16_t sr_flags;
+  grub_uint64_t sr_nongc_ctime;
+  struct grub_nilfs2_inode sr_dat;
+  struct grub_nilfs2_inode sr_cpfile;
+  struct grub_nilfs2_inode sr_sufile;
+};
+
+struct grub_nilfs2_super_block
+{
+  grub_uint32_t s_rev_level;
+  grub_uint16_t s_minor_rev_level;
+  grub_uint16_t s_magic;
+  grub_uint16_t s_bytes;
+  grub_uint16_t s_flags;
+  grub_uint32_t s_crc_seed;
+  grub_uint32_t s_sum;
+  grub_uint32_t s_log_block_size;
+  grub_uint64_t s_nsegments;
+  grub_uint64_t s_dev_size;
+  grub_uint64_t s_first_data_block;
+  grub_uint32_t s_blocks_per_segment;
+  grub_uint32_t s_r_segments_percentage;
+  grub_uint64_t s_last_cno;
+  grub_uint64_t s_last_pseg;
+  grub_uint64_t s_last_seq;
+  grub_uint64_t s_free_blocks_count;
+  grub_uint64_t s_ctime;
+  grub_uint64_t s_mtime;
+  grub_uint64_t s_wtime;
+  grub_uint16_t s_mnt_count;
+  grub_uint16_t s_max_mnt_count;
+  grub_uint16_t s_state;
+  grub_uint16_t s_errors;
+  grub_uint64_t s_lastcheck;
+  grub_uint32_t s_checkinterval;
+  grub_uint32_t s_creator_os;
+  grub_uint16_t s_def_resuid;
+  grub_uint16_t s_def_resgid;
+  grub_uint32_t s_first_ino;
+  grub_uint16_t s_inode_size;
+  grub_uint16_t s_dat_entry_size;
+  grub_uint16_t s_checkpoint_size;
+  grub_uint16_t s_segment_usage_size;
+  grub_uint8_t s_uuid[16];
+  char s_volume_name[80];
+  grub_uint32_t s_c_interval;
+  grub_uint32_t s_c_block_max;
+  grub_uint32_t s_reserved[192];
+};
+
+struct grub_nilfs2_dir_entry
+{
+  grub_uint64_t inode;
+  grub_uint16_t rec_len;
+#define MAX_NAMELEN 255
+  grub_uint8_t name_len;
+  grub_uint8_t file_type;
+#if 0				/* followed by file name. */
+  char name[NILFS_NAME_LEN];
+  char pad;
+#endif
+} GRUB_PACKED;
+
+enum
+{
+  NILFS_FT_UNKNOWN,
+  NILFS_FT_REG_FILE,
+  NILFS_FT_DIR,
+  NILFS_FT_CHRDEV,
+  NILFS_FT_BLKDEV,
+  NILFS_FT_FIFO,
+  NILFS_FT_SOCK,
+  NILFS_FT_SYMLINK,
+  NILFS_FT_MAX
+};
+
+struct grub_nilfs2_finfo
+{
+  grub_uint64_t fi_ino;
+  grub_uint64_t fi_cno;
+  grub_uint32_t fi_nblocks;
+  grub_uint32_t fi_ndatablk;
+};
+
+struct grub_nilfs2_binfo_v
+{
+  grub_uint64_t bi_vblocknr;
+  grub_uint64_t bi_blkoff;
+};
+
+struct grub_nilfs2_binfo_dat
+{
+  grub_uint64_t bi_blkoff;
+  grub_uint8_t bi_level;
+  grub_uint8_t bi_pad[7];
+};
+
+union grub_nilfs2_binfo
+{
+  struct grub_nilfs2_binfo_v bi_v;
+  struct grub_nilfs2_binfo_dat bi_dat;
+};
+
+struct grub_nilfs2_segment_summary
+{
+  grub_uint32_t ss_datasum;
+  grub_uint32_t ss_sumsum;
+  grub_uint32_t ss_magic;
+  grub_uint16_t ss_bytes;
+  grub_uint16_t ss_flags;
+  grub_uint64_t ss_seq;
+  grub_uint64_t ss_create;
+  grub_uint64_t ss_next;
+  grub_uint32_t ss_nblocks;
+  grub_uint32_t ss_nfinfo;
+  grub_uint32_t ss_sumbytes;
+  grub_uint32_t ss_pad;
+};
+
+struct grub_nilfs2_btree_node
+{
+  grub_uint8_t bn_flags;
+  grub_uint8_t bn_level;
+  grub_uint16_t bn_nchildren;
+  grub_uint32_t bn_pad;
+  grub_uint64_t keys[0];
+};
+
+struct grub_nilfs2_palloc_group_desc
+{
+  grub_uint32_t pg_nfrees;
+};
+
+#define LOG_SIZE_GROUP_DESC 2
+
+#define LOG_NILFS_DAT_ENTRY_SIZE 5
+struct grub_nilfs2_dat_entry
+{
+  grub_uint64_t de_blocknr;
+  grub_uint64_t de_start;
+  grub_uint64_t de_end;
+  grub_uint64_t de_rsv;
+};
+
+struct grub_nilfs2_snapshot_list
+{
+  grub_uint64_t ssl_next;
+  grub_uint64_t ssl_prev;
+};
+
+struct grub_nilfs2_cpfile_header
+{
+  grub_uint64_t ch_ncheckpoints;
+  grub_uint64_t ch_nsnapshots;
+  struct grub_nilfs2_snapshot_list ch_snapshot_list;
+};
+
+struct grub_nilfs2_checkpoint
+{
+  grub_uint32_t cp_flags;
+  grub_uint32_t cp_checkpoints_count;
+  struct grub_nilfs2_snapshot_list cp_snapshot_list;
+  grub_uint64_t cp_cno;
+  grub_uint64_t cp_create;
+  grub_uint64_t cp_nblk_inc;
+  grub_uint64_t cp_inodes_count;
+  grub_uint64_t cp_blocks_count;
+  struct grub_nilfs2_inode cp_ifile_inode;
+};
+
+
+#define NILFS_BMAP_LARGE	0x1
+#define NILFS_BMAP_SIZE	(NILFS_INODE_BMAP_SIZE * sizeof(grub_uint64_t))
+
+/* nilfs extra padding for nonroot btree node. */
+#define NILFS_BTREE_NODE_EXTRA_PAD_SIZE (sizeof(grub_uint64_t))
+#define NILFS_BTREE_ROOT_SIZE	NILFS_BMAP_SIZE
+#define NILFS_BTREE_ROOT_NCHILDREN_MAX \
+ ((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) / \
+  (sizeof(grub_uint64_t) + sizeof(grub_uint64_t)) )
+
+
+struct grub_fshelp_node
+{
+  struct grub_nilfs2_data *data;
+  struct grub_nilfs2_inode inode;
+  grub_uint64_t ino;
+  int inode_read;
+};
+
+struct grub_nilfs2_data
+{
+  struct grub_nilfs2_super_block sblock;
+  struct grub_nilfs2_super_root sroot;
+  struct grub_nilfs2_inode ifile;
+  grub_disk_t disk;
+  struct grub_nilfs2_inode *inode;
+  struct grub_fshelp_node diropen;
+};
+
+/* Log2 size of nilfs2 block in 512 blocks.  */
+#define LOG2_NILFS2_BLOCK_SIZE(data)			\
+	(grub_le_to_cpu32 (data->sblock.s_log_block_size) + 1)
+
+/* Log2 size of nilfs2 block in bytes.  */
+#define LOG2_BLOCK_SIZE(data)					\
+	(grub_le_to_cpu32 (data->sblock.s_log_block_size) + 10)
+
+/* The size of an nilfs2 block in bytes.  */
+#define NILFS2_BLOCK_SIZE(data)		(1 << LOG2_BLOCK_SIZE (data))
+
+static grub_uint64_t
+grub_nilfs2_dat_translate (struct grub_nilfs2_data *data, grub_uint64_t key);
+static grub_dl_t my_mod;
+
+
+
+static inline unsigned long
+grub_nilfs2_log_palloc_entries_per_group (struct grub_nilfs2_data *data)
+{
+  return LOG2_BLOCK_SIZE (data) + 3;
+}
+
+static inline grub_uint64_t
+grub_nilfs2_palloc_group (struct grub_nilfs2_data *data,
+			  grub_uint64_t nr, grub_uint64_t * offset)
+{
+  *offset = nr & ((1 << grub_nilfs2_log_palloc_entries_per_group (data)) - 1);
+  return nr >> grub_nilfs2_log_palloc_entries_per_group (data);
+}
+
+static inline grub_uint32_t
+grub_nilfs2_palloc_log_groups_per_desc_block (struct grub_nilfs2_data *data)
+{
+  return LOG2_BLOCK_SIZE (data) - LOG_SIZE_GROUP_DESC;
+
+  COMPILE_TIME_ASSERT (sizeof (struct grub_nilfs2_palloc_group_desc)
+		       == (1 << LOG_SIZE_GROUP_DESC));
+}
+
+static inline grub_uint32_t
+grub_nilfs2_log_entries_per_block_log (struct grub_nilfs2_data *data,
+				       unsigned long log_entry_size)
+{
+  return LOG2_BLOCK_SIZE (data) - log_entry_size;
+}
+
+
+static inline grub_uint32_t
+grub_nilfs2_blocks_per_group_log (struct grub_nilfs2_data *data,
+				  unsigned long log_entry_size)
+{
+  return (1 << (grub_nilfs2_log_palloc_entries_per_group (data)
+		- grub_nilfs2_log_entries_per_block_log (data,
+							 log_entry_size))) + 1;
+}
+
+static inline grub_uint32_t
+grub_nilfs2_blocks_per_desc_block_log (struct grub_nilfs2_data *data,
+				       unsigned long log_entry_size)
+{
+  return(grub_nilfs2_blocks_per_group_log (data, log_entry_size)
+	 << grub_nilfs2_palloc_log_groups_per_desc_block (data)) + 1;
+}
+
+static inline grub_uint32_t
+grub_nilfs2_palloc_desc_block_offset_log (struct grub_nilfs2_data *data,
+					  unsigned long group,
+					  unsigned long log_entry_size)
+{
+  grub_uint32_t desc_block =
+    group >> grub_nilfs2_palloc_log_groups_per_desc_block (data);
+  return desc_block * grub_nilfs2_blocks_per_desc_block_log (data,
+							     log_entry_size);
+}
+
+static inline grub_uint32_t
+grub_nilfs2_palloc_bitmap_block_offset (struct grub_nilfs2_data *data,
+					unsigned long group,
+					unsigned long log_entry_size)
+{
+  unsigned long desc_offset = group
+    & ((1 << grub_nilfs2_palloc_log_groups_per_desc_block (data)) - 1);
+
+  return grub_nilfs2_palloc_desc_block_offset_log (data, group, log_entry_size)
+    + 1
+    + desc_offset * grub_nilfs2_blocks_per_group_log (data, log_entry_size);
+}
+
+static inline grub_uint32_t
+grub_nilfs2_palloc_entry_offset_log (struct grub_nilfs2_data *data,
+				     grub_uint64_t nr,
+				     unsigned long log_entry_size)
+{
+  unsigned long group;
+  grub_uint64_t group_offset;
+
+  group = grub_nilfs2_palloc_group (data, nr, &group_offset);
+
+  return grub_nilfs2_palloc_bitmap_block_offset (data, group,
+						 log_entry_size) + 1 +
+    (group_offset >> grub_nilfs2_log_entries_per_block_log (data,
+							    log_entry_size));
+
+}
+
+static inline struct grub_nilfs2_btree_node *
+grub_nilfs2_btree_get_root (struct grub_nilfs2_inode *inode)
+{
+  return (struct grub_nilfs2_btree_node *) &inode->i_bmap[0];
+}
+
+static inline int
+grub_nilfs2_btree_get_level (struct grub_nilfs2_btree_node *node)
+{
+  return node->bn_level;
+}
+
+static inline grub_uint64_t *
+grub_nilfs2_btree_node_dkeys (struct grub_nilfs2_btree_node *node)
+{
+  return (node->keys +
+	  ((node->bn_flags & NILFS_BTREE_NODE_ROOT) ?
+	   0 : (NILFS_BTREE_NODE_EXTRA_PAD_SIZE / sizeof (grub_uint64_t))));
+}
+
+static inline grub_uint64_t
+grub_nilfs2_btree_node_get_key (struct grub_nilfs2_btree_node *node,
+				int index)
+{
+  return grub_le_to_cpu64 (*(grub_nilfs2_btree_node_dkeys (node) + index));
+}
+
+static inline int
+grub_nilfs2_btree_node_nchildren_max (struct grub_nilfs2_data *data,
+				      struct grub_nilfs2_btree_node *node)
+{
+  int node_children_max = ((NILFS2_BLOCK_SIZE (data) -
+			    sizeof (struct grub_nilfs2_btree_node) -
+			    NILFS_BTREE_NODE_EXTRA_PAD_SIZE) /
+			   (sizeof (grub_uint64_t) + sizeof (grub_uint64_t)));
+
+  return (node->bn_flags & NILFS_BTREE_NODE_ROOT) ? 3 : node_children_max;
+}
+
+static inline int
+grub_nilfs2_btree_node_lookup (struct grub_nilfs2_data *data,
+			       struct grub_nilfs2_btree_node *node,
+			       grub_uint64_t key, int *indexp)
+{
+  grub_uint64_t nkey;
+  int index = 0, low, high, s;
+
+  low = 0;
+
+  high = grub_le_to_cpu16 (node->bn_nchildren) - 1;
+  if (high >= grub_nilfs2_btree_node_nchildren_max (data, node))
+    {
+      grub_error (GRUB_ERR_BAD_FS, "too many children");
+      *indexp = index;
+      return 0;
+    }
+
+  s = 0;
+  while (low <= high)
+    {
+      index = (low + high) / 2;
+      nkey = grub_nilfs2_btree_node_get_key (node, index);
+      if (nkey == key)
+	{
+	  *indexp = index;
+	  return 1;
+	}
+      else if (nkey < key)
+	{
+	  low = index + 1;
+	  s = -1;
+	}
+      else
+	{
+	  high = index - 1;
+	  s = 1;
+	}
+    }
+
+  if (node->bn_level > NILFS_BTREE_LEVEL_NODE_MIN)
+    {
+      if (s > 0 && index > 0)
+	index--;
+    }
+  else if (s < 0)
+    index++;
+
+  *indexp = index;
+  return s == 0;
+}
+
+static inline grub_uint64_t *
+grub_nilfs2_btree_node_dptrs (struct grub_nilfs2_data *data,
+			      struct grub_nilfs2_btree_node *node)
+{
+  return (grub_uint64_t *) (grub_nilfs2_btree_node_dkeys (node) +
+			    grub_nilfs2_btree_node_nchildren_max (data,
+								  node));
+}
+
+static inline grub_uint64_t
+grub_nilfs2_btree_node_get_ptr (struct grub_nilfs2_data *data,
+				struct grub_nilfs2_btree_node *node,
+				int index)
+{
+  return
+    grub_le_to_cpu64 (*(grub_nilfs2_btree_node_dptrs (data, node) + index));
+}
+
+static inline int
+grub_nilfs2_btree_get_nonroot_node (struct grub_nilfs2_data *data,
+				    grub_uint64_t ptr, void *block)
+{
+  grub_disk_t disk = data->disk;
+  unsigned int nilfs2_block_count = (1 << LOG2_NILFS2_BLOCK_SIZE (data));
+
+  return grub_disk_read (disk, ptr * nilfs2_block_count, 0,
+			 NILFS2_BLOCK_SIZE (data), block);
+}
+
+static grub_uint64_t
+grub_nilfs2_btree_lookup (struct grub_nilfs2_data *data,
+			  struct grub_nilfs2_inode *inode,
+			  grub_uint64_t key, int need_translate)
+{
+  struct grub_nilfs2_btree_node *node;
+  void *block;
+  grub_uint64_t ptr;
+  int level, found = 0, index;
+
+  block = grub_malloc (NILFS2_BLOCK_SIZE (data));
+  if (!block)
+    return -1;
+
+  node = grub_nilfs2_btree_get_root (inode);
+  level = grub_nilfs2_btree_get_level (node);
+
+  found = grub_nilfs2_btree_node_lookup (data, node, key, &index);
+
+  if (grub_errno != GRUB_ERR_NONE)
+    goto fail;
+
+  ptr = grub_nilfs2_btree_node_get_ptr (data, node, index);
+  if (need_translate)
+    ptr = grub_nilfs2_dat_translate (data, ptr);
+
+  for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--)
+    {
+      grub_nilfs2_btree_get_nonroot_node (data, ptr, block);
+      if (grub_errno)
+	{
+	  goto fail;
+	}
+      node = (struct grub_nilfs2_btree_node *) block;
+
+      if (node->bn_level != level)
+	{
+	  grub_error (GRUB_ERR_BAD_FS, "btree level mismatch\n");
+	  goto fail;
+	}
+
+      if (!found)
+	found = grub_nilfs2_btree_node_lookup (data, node, key, &index);
+      else
+	index = 0;
+
+      if (index < grub_nilfs2_btree_node_nchildren_max (data, node) &&
+	  grub_errno == GRUB_ERR_NONE)
+	{
+	  ptr = grub_nilfs2_btree_node_get_ptr (data, node, index);
+	  if (need_translate)
+	    ptr = grub_nilfs2_dat_translate (data, ptr);
+	}
+      else
+	{
+	  grub_error (GRUB_ERR_BAD_FS, "btree corruption\n");
+	  goto fail;
+	}
+    }
+
+  grub_free (block);
+
+  if (!found)
+    return -1;
+
+  return ptr;
+ fail:
+  grub_free (block);
+  return -1;
+}
+
+static inline grub_uint64_t
+grub_nilfs2_direct_lookup (struct grub_nilfs2_inode *inode, grub_uint64_t key)
+{
+  if (1 + key > 6)
+    {
+      grub_error (GRUB_ERR_BAD_FS, "key is too large");
+      return 0xffffffffffffffff;
+    }
+  return grub_le_to_cpu64 (inode->i_bmap[1 + key]);
+}
+
+static inline grub_uint64_t
+grub_nilfs2_bmap_lookup (struct grub_nilfs2_data *data,
+			 struct grub_nilfs2_inode *inode,
+			 grub_uint64_t key, int need_translate)
+{
+  struct grub_nilfs2_btree_node *root = grub_nilfs2_btree_get_root (inode);
+  if (root->bn_flags & NILFS_BMAP_LARGE)
+    return grub_nilfs2_btree_lookup (data, inode, key, need_translate);
+  else
+    {
+      grub_uint64_t ptr;
+      ptr = grub_nilfs2_direct_lookup (inode, key);
+      if (ptr != ((grub_uint64_t) 0xffffffffffffffff) && need_translate)
+	ptr = grub_nilfs2_dat_translate (data, ptr);
+      return ptr;
+    }
+}
+
+static grub_uint64_t
+grub_nilfs2_dat_translate (struct grub_nilfs2_data *data, grub_uint64_t key)
+{
+  struct grub_nilfs2_dat_entry entry;
+  grub_disk_t disk = data->disk;
+  grub_uint64_t pptr;
+  grub_uint64_t blockno, offset;
+  unsigned int nilfs2_block_count = (1 << LOG2_NILFS2_BLOCK_SIZE (data));
+
+  blockno = grub_nilfs2_palloc_entry_offset_log (data, key,
+						 LOG_NILFS_DAT_ENTRY_SIZE);
+
+  offset = ((key * sizeof (struct grub_nilfs2_dat_entry))
+	    & ((1 << LOG2_BLOCK_SIZE (data)) - 1));
+
+  pptr = grub_nilfs2_bmap_lookup (data, &data->sroot.sr_dat, blockno, 0);
+  if (pptr == (grub_uint64_t) - 1)
+    {
+      grub_error (GRUB_ERR_BAD_FS, "btree lookup failure");
+      return -1;
+    }
+
+  grub_disk_read (disk, pptr * nilfs2_block_count, offset,
+		  sizeof (struct grub_nilfs2_dat_entry), &entry);
+
+  return grub_le_to_cpu64 (entry.de_blocknr);
+}
+
+
+static grub_disk_addr_t
+grub_nilfs2_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
+{
+  struct grub_nilfs2_data *data = node->data;
+  struct grub_nilfs2_inode *inode = &node->inode;
+  grub_uint64_t pptr = -1;
+
+  pptr = grub_nilfs2_bmap_lookup (data, inode, fileblock, 1);
+  if (pptr == (grub_uint64_t) - 1)
+    {
+      grub_error (GRUB_ERR_BAD_FS, "btree lookup failure");
+      return -1;
+    }
+
+  return pptr;
+}
+
+/* Read LEN bytes from the file described by DATA starting with byte
+   POS.  Return the amount of read bytes in READ.  */
+static grub_ssize_t
+grub_nilfs2_read_file (grub_fshelp_node_t node,
+		       grub_disk_read_hook_t read_hook, void *read_hook_data,
+		       grub_off_t pos, grub_size_t len, char *buf)
+{
+  return grub_fshelp_read_file (node->data->disk, node,
+				read_hook, read_hook_data,
+				pos, len, buf, grub_nilfs2_read_block,
+				grub_le_to_cpu64 (node->inode.i_size),
+				LOG2_NILFS2_BLOCK_SIZE (node->data), 0);
+
+}
+
+static grub_err_t
+grub_nilfs2_read_checkpoint (struct grub_nilfs2_data *data,
+			     grub_uint64_t cpno,
+			     struct grub_nilfs2_checkpoint *cpp)
+{
+  grub_uint64_t blockno;
+  grub_uint64_t offset;
+  grub_uint64_t pptr;
+  grub_disk_t disk = data->disk;
+  unsigned int nilfs2_block_count = (1 << LOG2_NILFS2_BLOCK_SIZE (data));
+
+  /* Assume sizeof(struct grub_nilfs2_cpfile_header) < 
+     sizeof(struct grub_nilfs2_checkpoint).
+   */
+  blockno = grub_divmod64 (cpno, NILFS2_BLOCK_SIZE (data) /
+                          sizeof (struct grub_nilfs2_checkpoint), &offset);
+  
+  pptr = grub_nilfs2_bmap_lookup (data, &data->sroot.sr_cpfile, blockno, 1);
+  if (pptr == (grub_uint64_t) - 1)
+    {
+      return grub_error (GRUB_ERR_BAD_FS, "btree lookup failure");
+    }
+
+  return grub_disk_read (disk, pptr * nilfs2_block_count,
+			 offset * sizeof (struct grub_nilfs2_checkpoint),
+			 sizeof (struct grub_nilfs2_checkpoint), cpp);
+}
+
+static inline grub_err_t
+grub_nilfs2_read_last_checkpoint (struct grub_nilfs2_data *data,
+				  struct grub_nilfs2_checkpoint *cpp)
+{
+  return grub_nilfs2_read_checkpoint (data,
+				      grub_le_to_cpu64 (data->
+							sblock.s_last_cno),
+				      cpp);
+}
+
+/* Read the inode INO for the file described by DATA into INODE.  */
+static grub_err_t
+grub_nilfs2_read_inode (struct grub_nilfs2_data *data,
+			grub_uint64_t ino, struct grub_nilfs2_inode *inodep)
+{
+  grub_uint64_t blockno;
+  grub_uint64_t offset;
+  grub_uint64_t pptr;
+  grub_disk_t disk = data->disk;
+  unsigned int nilfs2_block_count = (1 << LOG2_NILFS2_BLOCK_SIZE (data));
+
+  blockno = grub_nilfs2_palloc_entry_offset_log (data, ino,
+						 LOG_INODE_SIZE);
+
+  offset = ((sizeof (struct grub_nilfs2_inode) * ino)
+	    & ((1 << LOG2_BLOCK_SIZE (data)) - 1));
+  pptr = grub_nilfs2_bmap_lookup (data, &data->ifile, blockno, 1);
+  if (pptr == (grub_uint64_t) - 1)
+    {
+      return grub_error (GRUB_ERR_BAD_FS, "btree lookup failure");
+    }
+
+  return grub_disk_read (disk, pptr * nilfs2_block_count, offset,
+			 sizeof (struct grub_nilfs2_inode), inodep);
+}
+
+static int
+grub_nilfs2_valid_sb (struct grub_nilfs2_super_block *sbp)
+{
+  if (grub_le_to_cpu16 (sbp->s_magic) != NILFS2_SUPER_MAGIC)
+    return 0;
+
+  if (grub_le_to_cpu32 (sbp->s_rev_level) != NILFS_SUPORT_REV)
+    return 0;
+
+  /* 20 already means 1GiB blocks. We don't want to deal with blocks overflowing int32. */
+  if (grub_le_to_cpu32 (sbp->s_log_block_size) > 20)
+    return 0;
+
+  return 1;
+}
+
+static grub_err_t
+grub_nilfs2_load_sb (struct grub_nilfs2_data *data)
+{
+  grub_disk_t disk = data->disk;
+  struct grub_nilfs2_super_block sb2;
+  grub_uint64_t partition_size;
+  int valid[2];
+  int swp = 0;
+  grub_err_t err;
+
+  /* Read first super block. */
+  err = grub_disk_read (disk, NILFS_1ST_SUPER_BLOCK, 0,
+			sizeof (struct grub_nilfs2_super_block), &data->sblock);
+  if (err)
+    return err;
+  /* Make sure if 1st super block is valid.  */
+  valid[0] = grub_nilfs2_valid_sb (&data->sblock);
+
+  if (valid[0])
+    partition_size = (grub_le_to_cpu64 (data->sblock.s_dev_size)
+		      >> GRUB_DISK_SECTOR_BITS);
+  else
+    partition_size = grub_disk_native_sectors (disk);
+  if (partition_size != GRUB_DISK_SIZE_UNKNOWN)
+    {
+      /* Read second super block. */
+      err = grub_disk_read (disk, NILFS_2ND_SUPER_BLOCK (partition_size), 0,
+			    sizeof (struct grub_nilfs2_super_block), &sb2);
+      if (err)
+	{
+	  valid[1] = 0;
+	  grub_errno = GRUB_ERR_NONE;
+	}
+      else
+	/* Make sure if 2nd super block is valid.  */
+	valid[1] = grub_nilfs2_valid_sb (&sb2);
+    }
+  else
+    /* 2nd super block may not exist, so it's invalid. */
+    valid[1] = 0;
+
+  if (!valid[0] && !valid[1])
+    return grub_error (GRUB_ERR_BAD_FS, "not a nilfs2 filesystem");
+
+  swp = valid[1] && (!valid[0] ||
+		     grub_le_to_cpu64 (data->sblock.s_last_cno) <
+		     grub_le_to_cpu64 (sb2.s_last_cno));
+
+  /* swap if first super block is invalid or older than second one. */
+  if (swp)
+    grub_memcpy (&data->sblock, &sb2,
+		 sizeof (struct grub_nilfs2_super_block));
+
+  return GRUB_ERR_NONE;
+}
+
+static struct grub_nilfs2_data *
+grub_nilfs2_mount (grub_disk_t disk)
+{
+  struct grub_nilfs2_data *data;
+  struct grub_nilfs2_segment_summary ss;
+  struct grub_nilfs2_checkpoint last_checkpoint;
+  grub_uint64_t last_pseg;
+  grub_uint32_t nblocks;
+  unsigned int nilfs2_block_count;
+
+  data = grub_malloc (sizeof (struct grub_nilfs2_data));
+  if (!data)
+    return 0;
+
+  data->disk = disk;
+
+  /* Read the superblock.  */
+  grub_nilfs2_load_sb (data);
+  if (grub_errno)
+    goto fail;
+
+  nilfs2_block_count = (1 << LOG2_NILFS2_BLOCK_SIZE (data));
+
+  /* Read the last segment summary. */
+  last_pseg = grub_le_to_cpu64 (data->sblock.s_last_pseg);
+  grub_disk_read (disk, last_pseg * nilfs2_block_count, 0,
+		  sizeof (struct grub_nilfs2_segment_summary), &ss);
+
+  if (grub_errno)
+    goto fail;
+
+  /* Read the super root block. */
+  nblocks = grub_le_to_cpu32 (ss.ss_nblocks);
+  grub_disk_read (disk, (last_pseg + (nblocks - 1)) * nilfs2_block_count, 0,
+		  sizeof (struct grub_nilfs2_super_root), &data->sroot);
+
+  if (grub_errno)
+    goto fail;
+
+  grub_nilfs2_read_last_checkpoint (data, &last_checkpoint);
+
+  if (grub_errno)
+    goto fail;
+
+  grub_memcpy (&data->ifile, &last_checkpoint.cp_ifile_inode,
+	       sizeof (struct grub_nilfs2_inode));
+
+  data->diropen.data = data;
+  data->diropen.ino = 2;
+  data->diropen.inode_read = 1;
+  data->inode = &data->diropen.inode;
+
+  grub_nilfs2_read_inode (data, 2, data->inode);
+
+  return data;
+
+fail:
+  if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
+    grub_error (GRUB_ERR_BAD_FS, "not a nilfs2 filesystem");
+
+  grub_free (data);
+  return 0;
+}
+
+static char *
+grub_nilfs2_read_symlink (grub_fshelp_node_t node)
+{
+  char *symlink;
+  struct grub_fshelp_node *diro = node;
+
+  if (!diro->inode_read)
+    {
+      grub_nilfs2_read_inode (diro->data, diro->ino, &diro->inode);
+      if (grub_errno)
+	return 0;
+    }
+
+  symlink = grub_malloc (grub_le_to_cpu64 (diro->inode.i_size) + 1);
+  if (!symlink)
+    return 0;
+
+  grub_nilfs2_read_file (diro, 0, 0, 0,
+			 grub_le_to_cpu64 (diro->inode.i_size), symlink);
+  if (grub_errno)
+    {
+      grub_free (symlink);
+      return 0;
+    }
+
+  symlink[grub_le_to_cpu64 (diro->inode.i_size)] = '\0';
+  return symlink;
+}
+
+static int
+grub_nilfs2_iterate_dir (grub_fshelp_node_t dir,
+			 grub_fshelp_iterate_dir_hook_t hook, void *hook_data)
+{
+  grub_off_t fpos = 0;
+  struct grub_fshelp_node *diro = (struct grub_fshelp_node *) dir;
+
+  if (!diro->inode_read)
+    {
+      grub_nilfs2_read_inode (diro->data, diro->ino, &diro->inode);
+      if (grub_errno)
+	return 0;
+    }
+
+  /* Iterate files.  */
+  while (fpos < grub_le_to_cpu64 (diro->inode.i_size))
+    {
+      struct grub_nilfs2_dir_entry dirent;
+
+      grub_nilfs2_read_file (diro, 0, 0, fpos,
+			     sizeof (struct grub_nilfs2_dir_entry),
+			     (char *) &dirent);
+      if (grub_errno)
+	return 0;
+
+      if (dirent.rec_len == 0)
+	return 0;
+
+      if (dirent.name_len != 0)
+	{
+	  char filename[MAX_NAMELEN + 1];
+	  struct grub_fshelp_node *fdiro;
+	  enum grub_fshelp_filetype type = GRUB_FSHELP_UNKNOWN;
+
+	  grub_nilfs2_read_file (diro, 0, 0,
+				 fpos + sizeof (struct grub_nilfs2_dir_entry),
+				 dirent.name_len, filename);
+	  if (grub_errno)
+	    return 0;
+
+	  fdiro = grub_malloc (sizeof (struct grub_fshelp_node));
+	  if (!fdiro)
+	    return 0;
+
+	  fdiro->data = diro->data;
+	  fdiro->ino = grub_le_to_cpu64 (dirent.inode);
+
+	  filename[dirent.name_len] = '\0';
+
+	  if (dirent.file_type != NILFS_FT_UNKNOWN)
+	    {
+	      fdiro->inode_read = 0;
+
+	      if (dirent.file_type == NILFS_FT_DIR)
+		type = GRUB_FSHELP_DIR;
+	      else if (dirent.file_type == NILFS_FT_SYMLINK)
+		type = GRUB_FSHELP_SYMLINK;
+	      else if (dirent.file_type == NILFS_FT_REG_FILE)
+		type = GRUB_FSHELP_REG;
+	    }
+	  else
+	    {
+	      /* The filetype can not be read from the dirent, read
+	         the inode to get more information.  */
+	      grub_nilfs2_read_inode (diro->data,
+				      grub_le_to_cpu64 (dirent.inode),
+				      &fdiro->inode);
+	      if (grub_errno)
+		{
+		  grub_free (fdiro);
+		  return 0;
+		}
+
+	      fdiro->inode_read = 1;
+
+	      if ((grub_le_to_cpu16 (fdiro->inode.i_mode)
+		   & FILETYPE_INO_MASK) == FILETYPE_INO_DIRECTORY)
+		type = GRUB_FSHELP_DIR;
+	      else if ((grub_le_to_cpu16 (fdiro->inode.i_mode)
+			& FILETYPE_INO_MASK) == FILETYPE_INO_SYMLINK)
+		type = GRUB_FSHELP_SYMLINK;
+	      else if ((grub_le_to_cpu16 (fdiro->inode.i_mode)
+			& FILETYPE_INO_MASK) == FILETYPE_INO_REG)
+		type = GRUB_FSHELP_REG;
+	    }
+
+	  if (hook (filename, type, fdiro, hook_data))
+	    return 1;
+	}
+
+      fpos += grub_le_to_cpu16 (dirent.rec_len);
+    }
+
+  return 0;
+}
+
+/* Open a file named NAME and initialize FILE.  */
+static grub_err_t
+grub_nilfs2_open (struct grub_file *file, const char *name)
+{
+  struct grub_nilfs2_data *data = NULL;
+  struct grub_fshelp_node *fdiro = 0;
+
+  grub_dl_ref (my_mod);
+
+  data = grub_nilfs2_mount (file->device->disk);
+  if (!data)
+    goto fail;
+
+  grub_fshelp_find_file (name, &data->diropen, &fdiro,
+			 grub_nilfs2_iterate_dir, grub_nilfs2_read_symlink,
+			 GRUB_FSHELP_REG);
+  if (grub_errno)
+    goto fail;
+
+  if (!fdiro->inode_read)
+    {
+      grub_nilfs2_read_inode (data, fdiro->ino, &fdiro->inode);
+      if (grub_errno)
+	goto fail;
+    }
+
+  grub_memcpy (data->inode, &fdiro->inode, sizeof (struct grub_nilfs2_inode));
+  grub_free (fdiro);
+
+  file->size = grub_le_to_cpu64 (data->inode->i_size);
+  file->data = data;
+  file->offset = 0;
+
+  return 0;
+
+fail:
+  if (fdiro != &data->diropen)
+    grub_free (fdiro);
+  grub_free (data);
+
+  grub_dl_unref (my_mod);
+
+  return grub_errno;
+}
+
+static grub_err_t
+grub_nilfs2_close (grub_file_t file)
+{
+  grub_free (file->data);
+
+  grub_dl_unref (my_mod);
+
+  return GRUB_ERR_NONE;
+}
+
+/* Read LEN bytes data from FILE into BUF.  */
+static grub_ssize_t
+grub_nilfs2_read (grub_file_t file, char *buf, grub_size_t len)
+{
+  struct grub_nilfs2_data *data = (struct grub_nilfs2_data *) file->data;
+
+  return grub_nilfs2_read_file (&data->diropen,
+				file->read_hook, file->read_hook_data,
+				file->offset, len, buf);
+}
+
+/* Context for grub_nilfs2_dir.  */
+struct grub_nilfs2_dir_ctx
+{
+  grub_fs_dir_hook_t hook;
+  void *hook_data;
+  struct grub_nilfs2_data *data;
+};
+
+/* Helper for grub_nilfs2_dir.  */
+static int
+grub_nilfs2_dir_iter (const char *filename, enum grub_fshelp_filetype filetype,
+		      grub_fshelp_node_t node, void *data)
+{
+  struct grub_nilfs2_dir_ctx *ctx = data;
+  struct grub_dirhook_info info;
+
+  grub_memset (&info, 0, sizeof (info));
+  if (!node->inode_read)
+    {
+      grub_nilfs2_read_inode (ctx->data, node->ino, &node->inode);
+      if (!grub_errno)
+	node->inode_read = 1;
+      grub_errno = GRUB_ERR_NONE;
+    }
+  if (node->inode_read)
+    {
+      info.mtimeset = 1;
+      info.mtime = grub_le_to_cpu64 (node->inode.i_mtime);
+    }
+
+  info.dir = ((filetype & GRUB_FSHELP_TYPE_MASK) == GRUB_FSHELP_DIR);
+  grub_free (node);
+  return ctx->hook (filename, &info, ctx->hook_data);
+}
+
+static grub_err_t
+grub_nilfs2_dir (grub_device_t device, const char *path,
+		 grub_fs_dir_hook_t hook, void *hook_data)
+{
+  struct grub_nilfs2_dir_ctx ctx = {
+    .hook = hook,
+    .hook_data = hook_data
+  };
+  struct grub_fshelp_node *fdiro = 0;
+
+  grub_dl_ref (my_mod);
+
+  ctx.data = grub_nilfs2_mount (device->disk);
+  if (!ctx.data)
+    goto fail;
+
+  grub_fshelp_find_file (path, &ctx.data->diropen, &fdiro,
+			 grub_nilfs2_iterate_dir, grub_nilfs2_read_symlink,
+			 GRUB_FSHELP_DIR);
+  if (grub_errno)
+    goto fail;
+
+  grub_nilfs2_iterate_dir (fdiro, grub_nilfs2_dir_iter, &ctx);
+
+fail:
+  if (fdiro != &ctx.data->diropen)
+    grub_free (fdiro);
+  grub_free (ctx.data);
+
+  grub_dl_unref (my_mod);
+
+  return grub_errno;
+}
+
+static grub_err_t
+grub_nilfs2_label (grub_device_t device, char **label)
+{
+  struct grub_nilfs2_data *data;
+  grub_disk_t disk = device->disk;
+
+  grub_dl_ref (my_mod);
+
+  data = grub_nilfs2_mount (disk);
+  if (data)
+    *label = grub_strndup (data->sblock.s_volume_name,
+			   sizeof (data->sblock.s_volume_name));
+  else
+    *label = NULL;
+
+  grub_dl_unref (my_mod);
+
+  grub_free (data);
+
+  return grub_errno;
+}
+
+static grub_err_t
+grub_nilfs2_uuid (grub_device_t device, char **uuid)
+{
+  struct grub_nilfs2_data *data;
+  grub_disk_t disk = device->disk;
+
+  grub_dl_ref (my_mod);
+
+  data = grub_nilfs2_mount (disk);
+  if (data)
+    {
+      *uuid =
+	grub_xasprintf
+	("%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+	 data->sblock.s_uuid[0], data->sblock.s_uuid[1],
+	 data->sblock.s_uuid[2], data->sblock.s_uuid[3],
+	 data->sblock.s_uuid[4], data->sblock.s_uuid[5],
+	 data->sblock.s_uuid[6], data->sblock.s_uuid[7],
+	 data->sblock.s_uuid[8], data->sblock.s_uuid[9],
+	 data->sblock.s_uuid[10], data->sblock.s_uuid[11],
+	 data->sblock.s_uuid[12], data->sblock.s_uuid[13],
+	 data->sblock.s_uuid[14], data->sblock.s_uuid[15]);
+    }
+  else
+    *uuid = NULL;
+
+  grub_dl_unref (my_mod);
+
+  grub_free (data);
+
+  return grub_errno;
+}
+
+/* Get mtime.  */
+static grub_err_t
+grub_nilfs2_mtime (grub_device_t device, grub_int64_t * tm)
+{
+  struct grub_nilfs2_data *data;
+  grub_disk_t disk = device->disk;
+
+  grub_dl_ref (my_mod);
+
+  data = grub_nilfs2_mount (disk);
+  if (!data)
+    *tm = 0;
+  else
+    *tm = (grub_int32_t) grub_le_to_cpu64 (data->sblock.s_wtime);
+
+  grub_dl_unref (my_mod);
+
+  grub_free (data);
+
+  return grub_errno;
+}
+
+
+
+static struct grub_fs grub_nilfs2_fs = {
+  .name = "nilfs2",
+  .fs_dir = grub_nilfs2_dir,
+  .fs_open = grub_nilfs2_open,
+  .fs_read = grub_nilfs2_read,
+  .fs_close = grub_nilfs2_close,
+  .fs_label = grub_nilfs2_label,
+  .fs_uuid = grub_nilfs2_uuid,
+  .fs_mtime = grub_nilfs2_mtime,
+#ifdef GRUB_UTIL
+  .reserved_first_sector = 1,
+  .blocklist_install = 0,
+#endif
+  .next = 0
+};
+
+GRUB_MOD_INIT (nilfs2)
+{
+  COMPILE_TIME_ASSERT ((1 << LOG_NILFS_DAT_ENTRY_SIZE)
+		       == sizeof (struct
+				  grub_nilfs2_dat_entry));
+  COMPILE_TIME_ASSERT (1 << LOG_INODE_SIZE
+		       == sizeof (struct grub_nilfs2_inode));
+  grub_fs_register (&grub_nilfs2_fs);
+  my_mod = mod;
+}
+
+GRUB_MOD_FINI (nilfs2)
+{
+  grub_fs_unregister (&grub_nilfs2_fs);
+}