1 (* 'df' command for virtual domains.
4 * Support for EXT2/EXT3 filesystems.
10 (* Int64 operators for convenience. *)
13 let ( *^ ) = Int64.mul
16 let sector_size = Virt_df.sector_size
17 let read_int32_le = Virt_df.read_int32_le
19 let probe_ext2 target part_type fd start size =
20 LargeFile.lseek fd ((start+^2L) *^ sector_size) SEEK_SET;
21 let str = String.create 128 in
22 if read fd str 0 128 <> 128 then
23 failwith "error reading ext2/ext3 magic"
25 if str.[56] != '\x53' || str.[57] != '\xEF' then (
26 Virt_df.ProbeFailed "partition marked EXT2/3 but no valid filesystem"
28 (* Refer to <linux/ext2_fs.h> *)
29 let s_inodes_count = read_int32_le str 0 in
30 let s_blocks_count = read_int32_le str 4 in
31 let s_r_blocks_count = read_int32_le str 8 in
32 let s_free_blocks_count = read_int32_le str 12 in
33 let s_free_inodes_count = read_int32_le str 16 in
34 let s_first_data_block = read_int32_le str 20 in
35 let s_log_block_size = read_int32_le str 24 in
36 (*let s_log_frag_size = read_int32_le str 28 in*)
37 let s_blocks_per_group = read_int32_le str 32 in
39 (* Work out the block size in bytes. *)
40 let s_log_block_size = Int64.to_int s_log_block_size in
41 let block_size = 1024L in
42 let block_size = Int64.shift_left block_size s_log_block_size in
44 (* Number of groups. *)
46 (s_blocks_count -^ s_first_data_block -^ 1L)
47 /^ s_blocks_per_group +^ 1L in
50 (* Number of group descriptors per block. *)
51 let s_inodes_per_block = s_blocksize /
52 let s_desc_per_block = block_size / s_inodes_per_block in
54 (s_groups_count +^ s_desc_per_block -^ 1L)
58 (* Calculate the block overhead (used by superblocks, inodes, etc.)
59 * See fs/ext2/super.c.
61 let overhead = s_first_data_block in
62 let overhead = (* XXX *) overhead in
66 Virt_df.fs_name = "Linux ext2/3";
67 fs_block_size = block_size;
68 fs_blocks_total = s_blocks_count -^ overhead;
69 fs_blocks_reserved = s_r_blocks_count;
70 fs_blocks_avail = s_free_blocks_count;
71 fs_blocks_used = s_blocks_count -^ overhead -^ s_free_blocks_count;
72 fs_inodes_total = s_inodes_count;
73 fs_inodes_reserved = 0L; (* XXX? *)
74 fs_inodes_avail = s_free_inodes_count;
75 fs_inodes_used = s_inodes_count (*-^ 0L*) -^ s_free_inodes_count;
80 (* Register with main code. *)
83 [ 0x83 ] (* Partition type. *)