From 3844c0e3ba0eb0e07b7ecabe7794def7dd622c2b Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Thu, 1 Jan 1970 00:00:00 +0000
Subject: [PATCH] Associate opaque plugin ID with each major structure.

---
 lib/README                   | 18 +++++++-----------
 lib/diskimage.ml             | 39 ++++++++++++++++++++++++++-------------
 lib/diskimage.mli            | 14 +++++++++-----
 lib/diskimage_ext2.ml        |  5 +++--
 lib/diskimage_ext2.mli       |  3 ++-
 lib/diskimage_linux_swap.ml  |  6 ++++--
 lib/diskimage_linux_swap.mli |  3 ++-
 lib/diskimage_lvm2.ml        |  6 +++---
 lib/diskimage_lvm2.mli       |  6 ++++--
 lib/diskimage_mbr.ml         |  6 ++++--
 lib/diskimage_mbr.mli        |  3 ++-
 lib/diskimage_utils.ml       | 22 ++++------------------
 lib/diskimage_utils.mli      |  9 ++++-----
 virt-df/virt_df_main.ml      |  8 ++++++--
 14 files changed, 80 insertions(+), 68 deletions(-)

diff --git a/lib/README b/lib/README
index 6ee34fc..602df03 100644
--- a/lib/README
+++ b/lib/README
@@ -18,7 +18,13 @@ what is going on inside the source.
 
 The main program consists of two modules:
 
- - diskimage.ml / diskimage.mli (module name: Diskimage)
+ - diskimage.ml / diskimage.mli
+
+   This is the library.  It loads the domain descriptions, calls out
+   to the plug-ins to probe for disks / partitions / filesystems /
+   etc., and finally returns the results.
+
+ - diskimage_utils.ml / diskimage_utils.mli (module name: Diskimage_utils)
 
    This has evolved into a library of miscellaneous functions
    and values which are included throughout the rest of the
@@ -28,16 +34,6 @@ The main program consists of two modules:
    Start by reading diskimage.mli which contains the full types
    and plenty of documentation.
 
- - diskimage_main.ml
-
-   This is the program.  It reads the command line arguments,
-   loads the domain descriptions, calls out to the plug-ins
-   to probe for disks / partitions / filesystems / etc., and
-   finally prints the results.
-
-   The file consists of basically one large program that
-   does all of the above in sequence.
-
 Everything else in this directory is a plug-in specialized for probing
 a particular filesystem, partition scheme or type of LVM.  The
 plug-ins at time of writing are:
diff --git a/lib/diskimage.ml b/lib/diskimage.ml
index fbbec4b..30a7a39 100644
--- a/lib/diskimage.ml
+++ b/lib/diskimage.ml
@@ -24,24 +24,38 @@ open Unix
 include Diskimage_utils
 
 let partition_types = [
-  "MBR", Diskimage_mbr.probe_mbr;
+  Diskimage_mbr.plugin_id,
+    ("MBR", Diskimage_mbr.probe);
 ]
 
 let filesystem_types = [
-  "ext2", Diskimage_ext2.probe_ext2;
-  "linux_swap", Diskimage_linux_swap.probe_swap;
+  Diskimage_ext2.plugin_id,
+    ("Linux ext2/3", Diskimage_ext2.probe);
+  Diskimage_linux_swap.plugin_id,
+    ("Linux swap", Diskimage_linux_swap.probe);
 ]
 
 let lvm_types = [
-  "LVM", (Diskimage_lvm2.probe_pv, Diskimage_lvm2.list_lvs);
+  Diskimage_lvm2.plugin_id,
+    ("Linux LVM2", Diskimage_lvm2.probe, Diskimage_lvm2.list);
 ]
 
+let name_of_parts id =
+  let name, _ = List.assoc id partition_types in
+  name
+let name_of_filesystem id =
+  let name, _ = List.assoc id filesystem_types in
+  name
+let name_of_lvm id =
+  let name, _, _ = List.assoc id lvm_types in
+  name
+
 (* Probe a device for partitions.  Returns [Some parts] or [None]. *)
 let probe_for_partitions dev =
   if !debug then eprintf "probing for partitions on %s ...\n%!" dev#name;
   let rec loop = function
     | [] -> None
-    | (parts_name, probe_fn) :: rest ->
+    | (parts_plugin_id, (_, probe_fn)) :: rest ->
 	try Some (probe_fn dev)
 	with Not_found -> loop rest
   in
@@ -49,10 +63,9 @@ let probe_for_partitions dev =
   if !debug then (
     match r with
     | None -> eprintf "no partitions found on %s\n%!" dev#name
-    | Some { parts_name = name; parts = parts } ->
-	eprintf "found %d %s partitions on %s:\n"
-	  (List.length parts) name dev#name;
-	List.iter (fun p -> eprintf "\t%s\n%!" (string_of_partition p)) parts
+    | Some { parts_plugin_id = name; parts = parts } ->
+	eprintf "found %d %s partitions on %s\n"
+	  (List.length parts) name dev#name
   );
   r
 
@@ -61,7 +74,7 @@ let probe_for_filesystem dev =
   if !debug then eprintf "probing for a filesystem on %s ...\n%!" dev#name;
   let rec loop = function
     | [] -> None
-    | (fs_name, probe_fn) :: rest ->
+    | (fs_name, (_, probe_fn)) :: rest ->
 	try Some (probe_fn dev)
 	with Not_found -> loop rest
   in
@@ -71,7 +84,7 @@ let probe_for_filesystem dev =
     | None -> eprintf "no filesystem found on %s\n%!" dev#name
     | Some fs ->
 	eprintf "found a filesystem on %s:\n" dev#name;
-	eprintf "\t%s\n%!" (string_of_filesystem fs)
+	eprintf "\t%s\n%!" fs.fs_plugin_id
   );
   r
 
@@ -80,7 +93,7 @@ let probe_for_pv dev =
   if !debug then eprintf "probing if %s is a PV ...\n%!" dev#name;
   let rec loop = function
     | [] -> None
-    | (lvm_name, (probe_fn, _)) :: rest ->
+    | (lvm_name, (_, probe_fn, _)) :: rest ->
 	try Some (probe_fn lvm_name dev)
 	with Not_found -> loop rest
   in
@@ -94,7 +107,7 @@ let probe_for_pv dev =
   r
 
 let list_lvs lvm_name devs =
-  let _, list_lvs_fn = List.assoc lvm_name lvm_types in
+  let _, _, list_lvs_fn = List.assoc lvm_name lvm_types in
   list_lvs_fn devs
 
 (* Create machine description. *)
diff --git a/lib/diskimage.mli b/lib/diskimage.mli
index b0ecd8d..113c99b 100644
--- a/lib/diskimage.mli
+++ b/lib/diskimage.mli
@@ -138,7 +138,7 @@ and disk_content =
     ]
 
 and partitions = {
-  parts_name : string;			(** Name of partitioning scheme. *)
+  parts_plugin_id : parts_plugin_id;	(** Partitioning scheme. *)
   parts : partition list;		(** Partitions. *)
 }
 and partition = {
@@ -157,7 +157,7 @@ and partition_content =
     ]
 
 and filesystem = {
-  fs_name : string;			(** Name of filesystem. *)
+  fs_plugin_id : fs_plugin_id;		(** Filesystem type. *)
   fs_block_size : int64;		(** Block size (bytes). *)
   fs_blocks_total : int64;		(** Total blocks. *)
   fs_is_swap : bool;			(** If swap, following not valid. *)
@@ -181,11 +181,15 @@ and lv = {
 }
     (** Physical and logical volumes as used by LVM plug-ins. *)
 
+and parts_plugin_id
+and fs_plugin_id
 and lvm_plugin_id
+  (** Opaque IDs used to refer to the plug-ins. *)
 
-val string_of_partition : partition -> string
-val string_of_filesystem : filesystem -> string
-  (** Convert a partition or filesystem struct to a string (for debugging). *)
+val name_of_parts : parts_plugin_id -> string
+val name_of_filesystem : fs_plugin_id -> string
+val name_of_lvm : lvm_plugin_id -> string
+  (** Convert plug-in IDs to printable strings. *)
 
 (** {2 Scanning functions} *)
 
diff --git a/lib/diskimage_ext2.ml b/lib/diskimage_ext2.ml
index 0457597..1b70977 100644
--- a/lib/diskimage_ext2.ml
+++ b/lib/diskimage_ext2.ml
@@ -24,9 +24,10 @@ open Printf
 
 open Diskimage_utils
 
+let plugin_id = "ext2"
 let superblock_offset = 1024L
 
-let probe_ext2 dev =
+let probe dev =
   (* Load the superblock. *)
   let bits = dev#read_bitstring superblock_offset 1024 in
 
@@ -113,7 +114,7 @@ let probe_ext2 dev =
    let overhead = (* XXX *) overhead in
 
    {
-     fs_name = "Linux ext2/3";
+     fs_plugin_id = plugin_id;
      fs_block_size = block_size;
      fs_blocks_total = Int64.of_int32 s_blocks_count -^ overhead;
      fs_is_swap = false;
diff --git a/lib/diskimage_ext2.mli b/lib/diskimage_ext2.mli
index 8d93189..df0c1fd 100644
--- a/lib/diskimage_ext2.mli
+++ b/lib/diskimage_ext2.mli
@@ -19,4 +19,5 @@
 
 (**/**)
 
-val probe_ext2 : Diskimage_utils.device -> Diskimage_utils.filesystem
+val plugin_id : string
+val probe : Diskimage_utils.device -> Diskimage_utils.filesystem
diff --git a/lib/diskimage_linux_swap.ml b/lib/diskimage_linux_swap.ml
index f4af9c2..8f15651 100644
--- a/lib/diskimage_linux_swap.ml
+++ b/lib/diskimage_linux_swap.ml
@@ -22,7 +22,9 @@
 
 open Diskimage_utils
 
-let probe_swap dev =
+let plugin_id = "linux_swap"
+
+let probe dev =
   (* Load the "superblock" (ie. first 0x1000 bytes). *)
   let bits = dev#read_bitstring 0L 0x1000 in
 
@@ -33,7 +35,7 @@ let probe_swap dev =
       "SWAPSPACE2" : 80 : string
     } ->
     {
-      fs_name = "Linux swap";
+      fs_plugin_id = plugin_id;
       fs_block_size = 4096L;		(* XXX *)
       fs_blocks_total = dev#size /^ 4096L;
 
diff --git a/lib/diskimage_linux_swap.mli b/lib/diskimage_linux_swap.mli
index 75bc517..df0c1fd 100644
--- a/lib/diskimage_linux_swap.mli
+++ b/lib/diskimage_linux_swap.mli
@@ -19,4 +19,5 @@
 
 (**/**)
 
-val probe_swap : Diskimage_utils.device -> Diskimage_utils.filesystem
+val plugin_id : string
+val probe : Diskimage_utils.device -> Diskimage_utils.filesystem
diff --git a/lib/diskimage_lvm2.ml b/lib/diskimage_lvm2.ml
index f8ce5ec..e14c14e 100644
--- a/lib/diskimage_lvm2.ml
+++ b/lib/diskimage_lvm2.ml
@@ -26,7 +26,7 @@ open ExtList
 open Diskimage_utils
 open Diskimage_lvm2_metadata
 
-let plugin_name = "LVM2"
+let plugin_id = "LVM2"
 
 let sector_size = 512
 let sector_size64 = 512L
@@ -88,7 +88,7 @@ end
 
 (*----------------------------------------------------------------------*)
 (* Probe to see if it's an LVM2 PV. *)
-let rec probe_pv lvm_plugin_id dev =
+let rec probe lvm_plugin_id dev =
   try
     let uuid, _ = read_pv_label dev in
     if !debug then
@@ -173,7 +173,7 @@ and read_metadata dev offset32 len32 =
  * (as devices) and return them.  Note that we don't try to detect
  * what is on these LVs - that will be done in the main code.
  *)
-let rec list_lvs devs =
+let rec list devs =
   (* Read the UUID and metadata (again) from each device to end up with
    * an assoc list of PVs, keyed on the UUID.
    *)
diff --git a/lib/diskimage_lvm2.mli b/lib/diskimage_lvm2.mli
index 88e40e4..be84be6 100644
--- a/lib/diskimage_lvm2.mli
+++ b/lib/diskimage_lvm2.mli
@@ -19,7 +19,9 @@
 
 (**/**)
 
-val probe_pv :
+val plugin_id : string
+
+val probe :
   Diskimage_utils.lvm_plugin_id -> Diskimage_utils.device ->
   Diskimage_utils.pv
-val list_lvs : Diskimage_utils.device list -> Diskimage_utils.lv list
+val list : Diskimage_utils.device list -> Diskimage_utils.lv list
diff --git a/lib/diskimage_mbr.ml b/lib/diskimage_mbr.ml
index bd02f65..91ec20f 100644
--- a/lib/diskimage_mbr.ml
+++ b/lib/diskimage_mbr.ml
@@ -26,6 +26,8 @@ open ExtList
 
 open Diskimage_utils
 
+let plugin_id = "mbr"
+
 let sector_size = 512
 let sector_size64 = 512L
 
@@ -56,7 +58,7 @@ end
 
     @raise Not_found if it is not an MBR.
  *)
-let rec probe_mbr dev =
+let rec probe dev =
   (* Read the first sector. *)
   let bits =
     try dev#read_bitstring 0L sector_size
@@ -87,7 +89,7 @@ let rec probe_mbr dev =
       let extendeds = List.concat extendeds in
       primaries @ extendeds
 *)
-      { parts_name = "MBR"; parts = primaries }
+      { parts_plugin_id = plugin_id; parts = primaries }
 
   | { _ } ->
       raise Not_found			(* not an MBR *)
diff --git a/lib/diskimage_mbr.mli b/lib/diskimage_mbr.mli
index 4ba5e27..ebce91a 100644
--- a/lib/diskimage_mbr.mli
+++ b/lib/diskimage_mbr.mli
@@ -19,4 +19,5 @@
 
 (**/**)
 
-val probe_mbr : Diskimage_utils.device -> Diskimage_utils.partitions
+val plugin_id : string
+val probe : Diskimage_utils.device -> Diskimage_utils.partitions
diff --git a/lib/diskimage_utils.ml b/lib/diskimage_utils.ml
index 9290af3..a98e75e 100644
--- a/lib/diskimage_utils.ml
+++ b/lib/diskimage_utils.ml
@@ -110,7 +110,7 @@ and disk_content =
 (* Partitions. *)
 
 and partitions = {
-  parts_name : string;			(* Name of partitioning scheme. *)
+  parts_plugin_id : parts_plugin_id;	(* Partitioning scheme. *)
   parts : partition list		(* Partitions. *)
 }
 and partition = {
@@ -128,7 +128,7 @@ and partition_content =
 
 (* Filesystems (also swap devices). *)
 and filesystem = {
-  fs_name : string;			(* Name of filesystem. *)
+  fs_plugin_id : fs_plugin_id;		(* Filesystem. *)
   fs_block_size : int64;		(* Block size (bytes). *)
   fs_blocks_total : int64;		(* Total blocks. *)
   fs_is_swap : bool;			(* If swap, following not valid. *)
@@ -152,24 +152,10 @@ and lv = {
   lv_dev : device;			(* Logical volume device. *)
 }
 
+and parts_plugin_id = string
+and fs_plugin_id = string
 and lvm_plugin_id = string
 
-(* Convert partition, filesystem types to printable strings for debugging. *)
-let string_of_partition
-    { part_status = status; part_type = typ; part_dev = dev } =
-  sprintf "%s: %s partition type %d"
-    dev#name
-    (match status with
-     | Bootable -> "bootable"
-     | Nonbootable -> "nonbootable"
-     | Malformed -> "malformed"
-     | NullEntry -> "empty")
-    typ
-
-let string_of_filesystem { fs_name = name; fs_is_swap = swap } =
-  if not swap then name
-  else name ^ " [swap]"
-
 (* Convert a UUID (containing '-' chars) to canonical form. *)
 let canonical_uuid uuid =
   let uuid' = String.make 32 ' ' in
diff --git a/lib/diskimage_utils.mli b/lib/diskimage_utils.mli
index 91f43e0..07ad079 100644
--- a/lib/diskimage_utils.mli
+++ b/lib/diskimage_utils.mli
@@ -72,7 +72,7 @@ and disk_content =
     ]
 
 and partitions = {
-  parts_name : string;
+  parts_plugin_id : parts_plugin_id;
   parts : partition list;
 }
 and partition = {
@@ -90,7 +90,7 @@ and partition_content =
     ]
 
 and filesystem = {
-  fs_name : string;
+  fs_plugin_id : fs_plugin_id;
   fs_block_size : int64;
   fs_blocks_total : int64;
   fs_is_swap : bool;
@@ -111,11 +111,10 @@ and lv = {
   lv_dev : device;
 }
 
+and parts_plugin_id = string
+and fs_plugin_id = string
 and lvm_plugin_id = string
 
-val string_of_partition : partition -> string
-val string_of_filesystem : filesystem -> string
-
 (** {2 Internal functions used by the plug-ins} *)
 
 val canonical_uuid : string -> string
diff --git a/virt-df/virt_df_main.ml b/virt-df/virt_df_main.ml
index cd51c88..21f2db0 100644
--- a/virt-df/virt_df_main.ml
+++ b/virt-df/virt_df_main.ml
@@ -338,7 +338,7 @@ OPTIONS" in
     printf "%-32s " name;
 
     let {
-      Diskimage.fs_name = fs_name;
+      Diskimage.fs_plugin_id = fs_plugin_id;
       fs_block_size = fs_block_size;
       fs_blocks_total = fs_blocks_total;
       fs_is_swap = fs_is_swap;
@@ -351,6 +351,8 @@ OPTIONS" in
       fs_inodes_used = fs_inodes_used
     } = fs in
 
+    let fs_name = Diskimage.name_of_filesystem fs_plugin_id in
+
     if fs_is_swap then (
       (* Swap partition. *)
       if not !human then
@@ -396,7 +398,7 @@ OPTIONS" in
     let name = printable_name machine ?disk ?partno dev in
 
     let {
-      Diskimage.fs_name = fs_name;
+      Diskimage.fs_plugin_id = fs_plugin_id;
       fs_block_size = fs_block_size;
       fs_blocks_total = fs_blocks_total;
       fs_is_swap = fs_is_swap;
@@ -409,6 +411,8 @@ OPTIONS" in
       fs_inodes_used = fs_inodes_used
     } = fs in
 
+    let fs_name = Diskimage.name_of_filesystem fs_plugin_id in
+
     let row =
       if fs_is_swap then
 	(* Swap partition. *)
-- 
1.8.3.1