1 (* 'df' command for virtual domains.
3 * Support for EXT2/EXT3 filesystems.
9 (* Int64 operators for convenience. *)
12 let ( *^ ) = Int64.mul
15 let sector_size = Virt_df.sector_size
16 let read_int32_le = Virt_df.read_int32_le
18 let probe_ext2 target part_type fd start size =
19 LargeFile.lseek fd ((start+^2L) *^ sector_size) SEEK_SET;
20 let str = String.create 128 in
21 if read fd str 0 128 <> 128 then
22 failwith "error reading ext2/ext3 magic"
24 if str.[56] != '\x53' || str.[57] != '\xEF' then (
25 Virt_df.ProbeFailed "partition marked EXT2/3 but no valid filesystem"
27 (* Refer to <linux/ext2_fs.h> *)
28 let s_inodes_count = read_int32_le str 0 in
29 let s_blocks_count = read_int32_le str 4 in
30 let s_r_blocks_count = read_int32_le str 8 in
31 let s_free_blocks_count = read_int32_le str 12 in
32 let s_free_inodes_count = read_int32_le str 16 in
33 let s_first_data_block = read_int32_le str 20 in
34 let s_log_block_size = read_int32_le str 24 in
35 (*let s_log_frag_size = read_int32_le str 28 in*)
36 let s_blocks_per_group = read_int32_le str 32 in
38 (* Work out the block size in bytes. *)
39 let s_log_block_size = Int64.to_int s_log_block_size in
40 let block_size = 1024L in
41 let block_size = Int64.shift_left block_size s_log_block_size in
43 (* Number of groups. *)
45 (s_blocks_count -^ s_first_data_block -^ 1L)
46 /^ s_blocks_per_group +^ 1L in
49 (* Number of group descriptors per block. *)
50 let s_inodes_per_block = s_blocksize /
51 let s_desc_per_block = block_size / s_inodes_per_block in
53 (s_groups_count +^ s_desc_per_block -^ 1L)
57 (* Calculate the block overhead (used by superblocks, inodes, etc.)
58 * See fs/ext2/super.c.
60 let overhead = s_first_data_block in
61 let overhead = (* XXX *) overhead in
65 Virt_df.fs_name = "Linux ext2/3";
66 fs_block_size = block_size;
67 fs_blocks_total = s_blocks_count -^ overhead;
68 fs_blocks_reserved = s_r_blocks_count;
69 fs_blocks_avail = s_free_blocks_count;
70 fs_blocks_used = s_blocks_count -^ overhead -^ s_free_blocks_count;
71 fs_inodes_total = s_inodes_count;
72 fs_inodes_reserved = 0L; (* XXX? *)
73 fs_inodes_avail = s_free_inodes_count;
74 fs_inodes_used = s_inodes_count (*-^ 0L*) -^ s_free_inodes_count;
79 (* Register with main code. *)
82 [ 0x83 ] (* Partition type. *)