From: Richard W.M. Jones <"Richard W.M. Jones "> Date: Tue, 15 Apr 2008 21:31:24 +0000 (+0100) Subject: Almost complete VG & LV metadata parsing. X-Git-Tag: 1.0.4~24^2~12 X-Git-Url: http://git.annexia.org/?a=commitdiff_plain;h=291265b7171d332d2969e07ac189d876e3d7f26d;p=virt-top.git Almost complete VG & LV metadata parsing. --- 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 () =