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(* 'df' command for virtual domains.
(C) Copyright 2007 Richard W.M. Jones, Red Hat Inc.
http://libvirt.org/
This program 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 2 of the License, or
(at your option) any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Support for EXT2/EXT3 filesystems.
*)
open Unix
open Printf
open Virt_df_gettext.Gettext
open Virt_df
let superblock_offset = 1024L
let probe_ext2 dev =
(* Load the superblock. *)
let bits = dev#read_bitstring superblock_offset 1024 in
(* The structure is straight from /usr/include/linux/ext3_fs.h *)
bitmatch bits with
| s_inodes_count : 32 : littleendian; (* Inodes count *)
s_blocks_count : 32 : littleendian; (* Blocks count *)
s_r_blocks_count : 32 : littleendian; (* Reserved blocks count *)
s_free_blocks_count : 32 : littleendian; (* Free blocks count *)
s_free_inodes_count : 32 : littleendian; (* Free inodes count *)
s_first_data_block : 32 : littleendian; (* First Data Block *)
s_log_block_size : 32 : littleendian; (* Block size *)
s_log_frag_size : 32 : littleendian; (* Fragment size *)
s_blocks_per_group : 32 : littleendian; (* # Blocks per group *)
s_frags_per_group : 32 : littleendian; (* # Fragments per group *)
s_inodes_per_group : 32 : littleendian; (* # Inodes per group *)
s_mtime : 32 : littleendian; (* Mount time *)
s_wtime : 32 : littleendian; (* Write time *)
s_mnt_count : 16 : littleendian; (* Mount count *)
s_max_mnt_count : 16 : littleendian; (* Maximal mount count *)
0xef53 : 16 : littleendian; (* Magic signature *)
s_state : 16 : littleendian; (* File system state *)
s_errors : 16 : littleendian; (* Behaviour when detecting errors *)
s_minor_rev_level : 16 : littleendian; (* minor revision level *)
s_lastcheck : 32 : littleendian; (* time of last check *)
s_checkinterval : 32 : littleendian; (* max. time between checks *)
s_creator_os : 32 : littleendian; (* OS *)
s_rev_level : 32 : littleendian; (* Revision level *)
s_def_resuid : 16 : littleendian; (* Default uid for reserved blocks *)
s_def_resgid : 16 : littleendian; (* Default gid for reserved blocks *)
s_first_ino : 32 : littleendian; (* First non-reserved inode *)
s_inode_size : 16 : littleendian; (* size of inode structure *)
s_block_group_nr : 16 : littleendian; (* block group # of this superblock *)
s_feature_compat : 32 : littleendian; (* compatible feature set *)
s_feature_incompat : 32 : littleendian; (* incompatible feature set *)
s_feature_ro_compat : 32 : littleendian; (* readonly-compatible feature set *)
s_uuid : 128 : bitstring; (* 128-bit uuid for volume *)
s_volume_name : 128 : bitstring; (* volume name XXX string *)
s_last_mounted : 512 : bitstring; (* directory where last mounted XXX string *)
s_algorithm_usage_bitmap : 32 : littleendian; (* For compression *)
s_prealloc_blocks : 8; (* Nr of blocks to try to preallocate*)
s_prealloc_dir_blocks : 8; (* Nr to preallocate for dirs *)
s_reserved_gdt_blocks : 16 : littleendian; (* Per group desc for online growth *)
s_journal_uuid : 128 : bitstring; (* uuid of journal superblock *)
s_journal_inum : 32 : littleendian; (* inode number of journal file *)
s_journal_dev : 32 : littleendian; (* device number of journal file *)
s_last_orphan : 32 : littleendian; (* start of list of inodes to delete *)
s_hash_seed0 : 32 : littleendian; (* HTREE hash seed *)
s_hash_seed1 : 32 : littleendian;
s_hash_seed2 : 32 : littleendian;
s_hash_seed3 : 32 : littleendian;
s_def_hash_version : 8; (* Default hash version to use *)
s_reserved_char_pad : 8;
s_reserved_word_pad : 16 : littleendian;
s_default_mount_opts : 32 : littleendian;
s_first_meta_bg : 32 : littleendian; (* First metablock block group *)
s_reserved : 6080 : bitstring -> (* Padding to the end of the block *)
(* Work out the block size in bytes. *)
let s_log_block_size = Int32.to_int s_log_block_size in
let block_size = 1024L in
let block_size = Int64.shift_left block_size s_log_block_size in
(* Number of groups. *)
let s_groups_count =
Int64.of_int32 (
(s_blocks_count -* s_first_data_block -* 1l)
/* s_blocks_per_group +* 1l
) in
(*
(* Number of group descriptors per block. *)
let s_inodes_per_block = s_blocksize /
let s_desc_per_block = block_size / s_inodes_per_block in
let db_count =
(s_groups_count +^ s_desc_per_block -^ 1L)
/^ s_desc_per_block
*)
(* Calculate the block overhead (used by superblocks, inodes, etc.)
* See fs/ext2/super.c.
*)
let overhead = Int64.of_int32 s_first_data_block in
let overhead = (* XXX *) overhead in
{
fs_name = s_ "Linux ext2/3";
fs_block_size = block_size;
fs_blocks_total = Int64.of_int32 s_blocks_count -^ overhead;
fs_is_swap = false;
fs_blocks_reserved = Int64.of_int32 s_r_blocks_count;
fs_blocks_avail = Int64.of_int32 s_free_blocks_count;
fs_blocks_used =
Int64.of_int32 s_blocks_count -^ overhead
-^ Int64.of_int32 s_free_blocks_count;
fs_inodes_total = Int64.of_int32 s_inodes_count;
fs_inodes_reserved = 0L; (* XXX? *)
fs_inodes_avail = Int64.of_int32 s_free_inodes_count;
fs_inodes_used = Int64.of_int32 s_inodes_count
(*-^ 0L*)
-^ Int64.of_int32 s_free_inodes_count;
}
| _ ->
raise Not_found (* Not an EXT2/3 superblock. *)
(* Register with main code. *)
let () = filesystem_type_register "ext2" probe_ext2
|
