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authorRichard W.M. Jones <rjones@redhat.com>2008-04-15 22:31:24 +0100
committerRichard W.M. Jones <rjones@redhat.com>2008-04-15 22:31:24 +0100
commit291265b7171d332d2969e07ac189d876e3d7f26d (patch)
treefa42349916e7d69d32b9a3148dfb5e07d03c3690
parentb06f8da33e1e87a64ec785e248e47e47fee9073f (diff)
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Almost complete VG & LV metadata parsing.
-rw-r--r--virt-df/virt_df_lvm2.ml140
1 files changed, 130 insertions, 10 deletions
diff --git a/virt-df/virt_df_lvm2.ml b/virt-df/virt_df_lvm2.ml
index fcf1fd2..af58f97 100644
--- a/virt-df/virt_df_lvm2.ml
+++ b/virt-df/virt_df_lvm2.ml
@@ -21,6 +21,8 @@
*)
open Printf
+open ExtList
+
open Virt_df_gettext.Gettext
open Virt_df
@@ -114,29 +116,147 @@ let rec list_lvs devs =
(* Read the UUID and metadata (again) from each device to end up with
* an assoc list of PVs, keyed on the UUID.
*)
- let pvs = List.map read_pv_label devs in
+ let pvs = List.map (
+ fun dev ->
+ let uuid, metadata = read_pv_label dev in
+ (uuid, (metadata, dev))
+ ) devs in
(* Parse the metadata using the external lexer/parser. *)
let pvs = List.map (
- fun (uuid, metadata) ->
- eprintf "parsing: %s\n<<<<\n" metadata;
- uuid, Virt_df_lvm2_lexer.parse_lvm2_metadata_from_string metadata
+ fun (uuid, (metadata, dev)) ->
+ uuid, (Virt_df_lvm2_lexer.parse_lvm2_metadata_from_string metadata,
+ dev)
) pvs in
- (* Print the parsed metadata. *)
+ (* Print the parsed metadata.
List.iter (
- fun (uuid, metadata) ->
+ fun (uuid, (metadata, dev)) ->
eprintf "metadata for UUID %s:\n" uuid;
output_metadata stderr metadata
) pvs;
+ *)
- []
-
-
+ (* Scan for volume groups. The first entry in the metadata
+ * appears to be the volume group name. This gives us a
+ * list of VGs and the metadata for each underlying PV.
+ *)
+ let vgnames =
+ List.filter_map (
+ function
+ | pvuuid, (((vgname, Metadata vgmeta) :: _), dev) ->
+ Some (vgname, (pvuuid, vgmeta))
+ | _ -> None
+ ) pvs in
+
+ let cmp ((a:string),_) ((b:string),_) = compare a b in
+ let vgnames = List.sort ~cmp vgnames in
+ let vgs = group_by vgnames in
+
+ (* Note that the metadata is supposed to be duplicated
+ * identically across all PVs (for redundancy purposes).
+ * In theory we should check this and use the 'seqno'
+ * field to find the latest metadata if it doesn't match,
+ * but in fact we don't check this.
+ *)
+ let vgs = List.map (
+ fun (vgname, metas) ->
+ let pvuuids = List.map fst metas in
+ let _, vgmeta = List.hd metas in (* just pick any metadata *)
+ vgname, (pvuuids, vgmeta)) vgs in
+ (* Print the VGs. *)
+ if debug then
+ List.iter (
+ fun (vgname, (pvuuids, vgmeta)) ->
+ eprintf "VG %s is on PVs: %s\n%!" vgname (String.concat "," pvuuids)
+ ) vgs;
+ (* Some useful getter functions. If these can't get a value
+ * from the metadata or if the type is wrong they raise Not_found.
+ *)
+ let rec get_int64 field meta =
+ match List.assoc field meta with
+ | Int i -> i
+ | _ -> raise Not_found
+ and get_int field meta min max =
+ match List.assoc field meta with
+ | Int i when Int64.of_int min <= i && i <= Int64.of_int max ->
+ Int64.to_int i
+ | _ -> raise Not_found
+ and get_string field meta =
+ match List.assoc field meta with
+ | String s -> s
+ | _ -> raise Not_found
+ and get_meta field meta =
+ match List.assoc field meta with
+ | Metadata md -> md
+ | _ -> raise Not_found in
+ in
+
+ (* Scan for logical volumes. Each VG contains several LVs.
+ * This gives us a list of LVs within each VG (hence extends
+ * the vgs variable).
+ *)
+ let vgs = List.map (
+ fun (vgname, (pvuuids, vgmeta)) ->
+ let lvs =
+ try
+ let extent_size = get_int "extent_size" vgmeta 0 (256*1024) in
+ let lvs = get_meta "logical_volumes" vgmeta in
+ let lvs = List.filter_map (
+ function
+ | lvname, Metadata lvmeta ->
+ (try
+ let segment_count = get_int "segment_count" lvmeta 0 1024 in
+
+ (* Get the segments for this LV. *)
+ let segments = range 1 (segment_count+1) in
+ let segments =
+ List.map
+ (fun i -> get_meta ("segment" ^ string_of_int i) lvmeta)
+ segments in
+
+ let segments =
+ List.map (
+ fun segmeta ->
+ let start_extent =
+ get_int64 "start_extent" segmeta in
+ let extent_count =
+ get_int64 "extent_count" segmeta in
+ let segtype = get_string "type" segmeta in
+ if segtype <> "striped" then raise Not_found;
+ let stripe_count =
+ get_int "stripe_count" segmeta 0 1024 in
+ (* let stripes = in *)
+
+ (start_extent, extent_count, stripe_count)
+ ) segments in
+
+ Some (lvname, (lvmeta, segments))
+ with
+ (* Something went wrong with segments - omit this LV. *)
+ Not_found -> None)
+ | _ -> None
+ ) lvs in
+
+ lvs
+ with
+ Not_found ->
+ (* Something went wrong - assume no LVs found. *)
+ [] in
+ (vgname, (pvuuids, vgmeta, lvs))
+ ) vgs in
+
+ (* Print the LVs. *)
+ if debug then
+ List.iter (
+ fun (vgname, (pvuuids, vgmeta, lvs)) ->
+ let lvnames = List.map fst lvs in
+ eprintf "VG %s contains LVs: %s\n%!" vgname (String.concat ", " lvnames)
+ ) vgs;
-
+ []
(* Register with main code. *)
let () =