Source file device_number.ml
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type bus_type =
| Xen
| Scsi
| Ide
type spec = bus_type * int * int
type t = spec
let to_debug_string = function
| (Xen, disk, partition) -> Printf.sprintf "Xen(%d, %d)" disk partition
| (Scsi, disk, partition) -> Printf.sprintf "Scsi(%d, %d)" disk partition
| (Ide, disk, partition) -> Printf.sprintf "Ide(%d, %d)" disk partition
let (<|) = (lsl)
let (>|) = (lsr)
let int_of_string x = try int_of_string x with _ -> failwith (Printf.sprintf "int_of_string [%s]" x)
let use_deprecated_ide_encoding = true
let make (x: spec) : t =
let max_xen = ((1 <| 20) - 1), 15 in
let max_scsi = 15, 15 in
let max_ide = if use_deprecated_ide_encoding then 19, 63 else 3, 63 in
let assert_in_range description (disk_limit, partition_limit) (disk, partition) =
if disk < 0 || (disk > disk_limit)
then failwith (Printf.sprintf "%s disk number out of range 0 <= %d <= %d" description disk disk_limit);
if partition < 0 || partition > partition_limit
then failwith (Printf.sprintf "%s partition number out of range 0 <= %d <= %d" description partition partition_limit) in
begin match x with
| Xen, disk, partition -> assert_in_range "xen" max_xen (disk, partition)
| Scsi, disk, partition -> assert_in_range "scsi" max_scsi (disk, partition)
| Ide, disk, partition -> assert_in_range "ide" max_ide (disk, partition)
end;
x
let spec (x: t) : spec = x
let (||) = (lor)
let standard_ide_table = [ 3; 22 ]
let deprecated_ide_table = standard_ide_table @ [ 33; 34; 56; 57; 88; 89; 90; 91 ]
let to_xenstore_int = function
| Xen, disk, partition when disk < 16 -> (202 <| 8) || (disk <| 4) || partition
| Xen, disk, partition -> (1 <| 28) || (disk <| 8) || partition
| Scsi, disk, partition -> (8 <| 8) || (disk <| 4) || partition
| Ide, disk, partition ->
let m = List.nth deprecated_ide_table (disk / 2) in
let n = disk - (disk / 2) * 2 in
(m <| 8) || (n <| 6) || partition
let of_xenstore_int x =
let (&&) = (land) in
if (x && (1 <| 28)) <> 0
then Xen, (x >| 8) && ((1 <| 20) - 1), x && ((1 <| 8) - 1)
else match x >| 8 with
| 202 -> Xen, (x >| 4) && ((1 <| 4) - 1), x && ((1 <| 4) - 1)
| 8 -> Scsi, (x >| 4) && ((1 <| 4) - 1), x && ((1 <| 4) - 1)
| n ->
let idx = snd(List.fold_left (fun (i, res) e -> i+1, if e = n then i else res) (0, -1) deprecated_ide_table) in
if idx < 0
then failwith (Printf.sprintf "Unknown device number: %d" x);
Ide, ((x >| 6) && ((1 <| 2) - 1)) + idx * 2, x && ((1 <| 6) - 1)
type xenstore_key = int
let to_xenstore_key x = to_xenstore_int x
let of_xenstore_key x = of_xenstore_int x
(** Return an integer encoded as a linux device suffix *)
let rec string_of_int26 x =
let high, low = x / 26 - 1, x mod 26 + 1 in
let high' = if high = -1 then "" else string_of_int26 high in
let low' = String.make 1 (char_of_int (low + (int_of_char 'a') - 1)) in
high' ^ low'
module String = struct
include String
let fold_right f string accu =
let accu = ref accu in
for i = length string - 1 downto 0 do
accu := f string.[i] !accu
done;
!accu
let explode string =
fold_right (fun h t -> h :: t) string []
let implode list =
concat "" (List.map (String.make 1) list)
end
(** Convert a linux device string back into an integer *)
let int26_of_string x =
let ints = List.map (fun c -> int_of_char c - (int_of_char 'a') + 1) (String.explode x) in
List.fold_left (fun acc x -> acc * 26 + x) 0 ints - 1
let to_linux_device =
let p x = if x = 0 then "" else string_of_int x in
function
| Xen, disk, part -> Printf.sprintf "xvd%s%s" (string_of_int26 disk) (p part)
| Scsi, disk, part -> Printf.sprintf "sd%s%s" (string_of_int26 disk) (p part)
| Ide, disk, part -> Printf.sprintf "hd%s%s" (string_of_int26 disk) (p part)
let of_linux_device x =
let letter c = 'a' <= c && (c <= 'z') in
let digit c = '0' <= c && (c <= '9') in
let take f x =
let rec inner f acc = function
| x :: xs ->
if f x then inner f (x :: acc) xs else List.rev acc, x :: xs
| [] -> List.rev acc, [] in
inner f [] x in
let parse_b26_int x =
let d, p = take letter x in
let d' = int26_of_string (String.implode d) in
let p' = if p = [] then 0 else int_of_string (String.implode p) in
d', p' in
let parse_int_p_int x =
let d, rest = take digit x in
match rest with
| 'p' :: rest ->
let p, _ = take digit rest in
int_of_string (String.implode d), int_of_string (String.implode p)
| [] ->
int_of_string (String.implode d), 0
| _ ->
failwith
(Printf.sprintf "expected digit+ p digit+ got: %s" (String.implode x)) in
match String.explode x with
| 'x' :: 'v' :: 'd' :: rest ->
let disk, partition = parse_b26_int rest in
Xen, disk, partition
| 's' :: 'd' :: rest ->
let disk, partition = parse_b26_int rest in
Scsi, disk, partition
| 'h' :: 'd' :: rest ->
let disk, partition = parse_b26_int rest in
Ide, disk, partition
| 'd' :: rest ->
let disk, partition = parse_int_p_int rest in
Xen, disk, partition
| _ -> failwith (Printf.sprintf "Failed to parse device name: %s" x)
type disk_number = int
let to_disk_number = function
| Xen, disk, _ -> disk
| Scsi, disk, _ -> disk
| Ide, disk, _ -> disk
let of_disk_number hvm n =
if hvm && (n < 16)
then Ide, n, 0
else Xen, n, 0
let of_string hvm name =
try
of_disk_number hvm (int_of_string name)
with _ ->
of_linux_device name