2 * Copyright (C) 2010 Red Hat Inc.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 module C = Libvirt.Connect
24 module Cond = Condition
25 module D = Libvirt.Domain
29 type 'a callback = 'a -> unit
34 | Connect of string option * domain list callback
35 | Open_domain of string * inspection_data callback
36 | Open_images of (string * string option) list * inspection_data callback
37 | Read_directory of source * string * direntry list callback
45 and inspection_data = {
46 insp_all_filesystems : (string * string) list;
47 insp_oses : inspection_os list;
54 insp_filesystems : string array;
55 insp_hostname : string;
56 insp_major_version : int;
57 insp_minor_version : int;
58 insp_mountpoints : (string * string) list;
59 insp_package_format : string;
60 insp_package_management : string;
61 insp_product_name : string;
63 insp_windows_systemroot : string option;
66 and source = OS of inspection_os | Volume of string
70 dent_stat : Guestfs.stat;
74 let rec string_of_command = function
75 | Exit_thread -> "Exit_thread"
76 | Connect (Some name, _) -> sprintf "Connect %s" name
77 | Connect (None, _) -> "Connect NULL"
78 | Open_domain (name, _) -> sprintf "Open_domain %s" name
79 | Open_images (images, _) ->
80 sprintf "Open_images %s" (string_of_images images)
81 | Read_directory (OS { insp_root = root }, dir, _) ->
82 sprintf "Read_directory (OS %s, %s)" root dir
83 | Read_directory (Volume dev, dir, _) ->
84 sprintf "Read_directory (Volume %s, %s)" dev dir
86 and string_of_images images =
91 | fn, Some format -> sprintf "%s (%s)" fn format)
94 let no_callback _ = ()
96 let failure_hook = ref (fun _ -> ())
97 let busy_hook = ref (fun _ -> ())
98 let idle_hook = ref (fun _ -> ())
100 let set_failure_hook cb = failure_hook := cb
101 let set_busy_hook cb = busy_hook := cb
102 let set_idle_hook cb = idle_hook := cb
104 (* Execute a function, while holding a mutex. If the function
105 * fails, ensure we release the mutex before rethrowing the
110 let r = try Left (f ()) with exn -> Right exn in
114 | Right exn -> raise exn
116 (* The queue of commands, and a lock and condition to protect it. *)
118 let q_discard = ref false
119 let q_lock = M.create ()
120 let q_cond = Cond.create ()
122 (* Send a command message to the slave thread. *)
123 let send_to_slave ?fail cmd =
124 debug "sending message %s to slave thread ..." (string_of_command cmd);
127 Q.push (fail, cmd) q;
131 let discard_command_queue () =
135 (* Discard the currently running command. *)
139 let connect ?fail uri cb = send_to_slave ?fail (Connect (uri, cb))
140 let open_domain ?fail name cb = send_to_slave ?fail (Open_domain (name, cb))
141 let open_images ?fail images cb = send_to_slave ?fail (Open_images (images, cb))
142 let read_directory ?fail src path cb =
143 send_to_slave ?fail (Read_directory (src, path, cb))
145 (*----- Slave thread starts here -----*)
147 (* Set this to true to exit the thread. *)
150 (* Handles. These are not protected by locks because only the slave
151 * thread has access to them.
156 (* Run the callback unless someone set the q_discard flag while
157 * we were running the command.
159 let callback_if_not_discarded (cb : 'a callback) (arg : 'a) =
160 let discard = with_lock q_lock (fun () -> !q_discard) in
162 GtkThread.async cb arg
164 (* Call 'f ()' with source mounted read-only. Ensure that everything
165 * is unmounted even if an exception is thrown.
167 let with_mount_ro g src (f : unit -> 'a) : 'a =
168 Std.finally (fun () -> g#umount_all ()) (
170 (* Do the mount - could be OS or single volume. *)
172 | Volume dev -> g#mount_ro dev "/";
173 | OS { insp_mountpoints = mps } ->
174 (* Sort the mountpoint keys by length, shortest first. *)
175 let cmp (a,_) (b,_) = compare (String.length a) (String.length b) in
176 let mps = List.sort ~cmp mps in
177 (* Mount the filesystems. *)
179 fun (mp, dev) -> g#mount_ro dev mp
186 debug "top of slave loop";
188 (* Get the next command. *)
192 while Q.is_empty q do Cond.wait q_cond q_lock done;
197 debug "slave processing command %s ..." (string_of_command cmd);
200 GtkThread.async !busy_hook ();
203 (* If the user provided an override ?fail parameter to the
204 * original call, call that, else call the global hook.
207 | Some cb -> GtkThread.async cb exn
208 | None -> GtkThread.async !failure_hook exn
211 (* If there are no more commands in the queue, run the idle hook. *)
212 let empty = with_lock q_lock (fun () -> Q.is_empty q) in
213 if empty then GtkThread.async !idle_hook ();
215 if !quit then Thread.exit ();
218 and execute_command = function
223 | Connect (name, cb) ->
225 conn := Some (C.connect_readonly ?name ());
227 let conn = get_conn () in
228 let doms = D.get_domains conn [D.ListAll] in
229 let doms = List.map (
231 { dom_id = D.get_id d;
232 dom_name = D.get_name d;
233 dom_state = (D.get_info d).D.state }
235 let cmp { dom_name = n1 } { dom_name = n2 } = compare n1 n2 in
236 let doms = List.sort ~cmp doms in
237 callback_if_not_discarded cb doms
239 | Open_domain (name, cb) ->
240 let conn = get_conn () in
241 let dom = D.lookup_by_name conn name in
242 let xml = D.get_xml_desc dom in
243 let images = get_disk_images_from_xml xml in
244 open_disk_images images cb
246 | Open_images (images, cb) ->
247 open_disk_images images cb
249 | Read_directory (src, dir, cb) ->
251 let names, stats, links =
252 with_mount_ro g src (
254 let names = g#ls dir in (* sorted and without . and .. *)
255 let names = Array.to_list names in
256 let stats = lstatlist_wrapper g dir names in
257 let links = readlinklist_wrapper g dir names in
261 let n = List.length names in
262 n = List.length stats && n = List.length links
264 let entries = List.combine (List.combine names stats) links in
265 let entries = List.map (
266 fun ((name, stat), link) ->
267 { dent_name = name; dent_stat = stat; dent_link = link }
269 callback_if_not_discarded cb entries
271 (* Expect to be connected, and return the current libvirt connection. *)
275 | None -> failwith "not connected to libvirt"
280 | None -> failwith "no domain or disk image is open"
282 (* Close all libvirt and libguestfs handles. *)
284 (match !conn with Some conn -> C.close conn | None -> ());
289 (match !g with Some g -> g#close () | None -> ());
292 and get_disk_images_from_xml xml =
293 let xml = Xml.parse_string xml in
295 (* Return the device nodes. *)
298 | Xml.Element ("domain", _, children) ->
302 | Xml.Element ("devices", _, devices) -> Some devices
307 failwith "get_xml_desc didn't return <domain/>" in
309 (* Look for <source attr_name=attr_val/> and return attr_val. *)
310 let rec source_of attr_name = function
312 | Xml.Element ("source", attrs, _) :: rest ->
313 (try Some (List.assoc attr_name attrs)
314 with Not_found -> source_of attr_name rest)
315 | _ :: rest -> source_of attr_name rest
318 (* Look for <driver type=attr_val/> and return attr_val. *)
319 let rec format_of = function
321 | Xml.Element ("driver", attrs, _) :: rest ->
322 (try Some (List.assoc "type" attrs)
323 with Not_found -> format_of rest)
324 | _ :: rest -> format_of rest
327 (* Look for <disk> nodes and return the sources (block devices) of those. *)
331 | Xml.Element ("disk", attrs, disks) ->
334 let typ = List.assoc "type" attrs in
335 if typ = "file" then source_of "file" disks
336 else if typ = "block" then source_of "dev" disks
343 let format = format_of disks in
344 Some (filename, format)
350 (* The common code for Open_domain and Open_images which opens the
351 * libguestfs handle, adds the disks, and launches the appliance.
353 and open_disk_images images cb =
354 debug "opening disk image %s" (string_of_images images);
357 let g' = new Guestfs.guestfs () in
361 (* Uncomment the next line to pass the verbose flag from the command
362 * line through to libguestfs. This is not generally necessary since
363 * we are not so interested in debugging libguestfs problems at this
364 * level, and the user can always set LIBGUESTFS_DEBUG=1 if they need
367 (* g#set_verbose (verbose ());*)
372 g#add_drive_opts ~readonly:true filename
373 | filename, Some format ->
374 g#add_drive_opts ~readonly:true ~format filename
379 (* Get list of filesystems. *)
380 let fses = g#list_filesystems () in
382 (* Perform inspection. This can fail, ignore errors. *)
384 try Array.to_list (g#inspect_os ())
387 debug "inspection failed (error ignored): %s" msg;
390 let oses = List.map (
393 insp_arch = g#inspect_get_arch root;
394 insp_distro = g#inspect_get_distro root;
395 insp_filesystems = g#inspect_get_filesystems root;
396 insp_hostname = g#inspect_get_hostname root;
397 insp_major_version = g#inspect_get_major_version root;
398 insp_minor_version = g#inspect_get_minor_version root;
399 insp_mountpoints = g#inspect_get_mountpoints root;
400 insp_package_format = g#inspect_get_package_format root;
401 insp_package_management = g#inspect_get_package_management root;
402 insp_product_name = g#inspect_get_product_name root;
403 insp_type = g#inspect_get_type root;
404 insp_windows_systemroot =
405 try Some (g#inspect_get_windows_systemroot root)
406 with Guestfs.Error _ -> None
410 insp_all_filesystems = fses;
413 callback_if_not_discarded cb data
415 (* guestfs_lstatlist has a "hidden" limit of the protocol message size.
416 * Call this function, but split the list of names into chunks.
418 and lstatlist_wrapper g dir = function
421 let names', names = List.take 1000 names, List.drop 1000 names in
422 let xs = g#lstatlist dir (Array.of_list names') in
423 let xs = Array.to_list xs in
424 xs @ lstatlist_wrapper g dir names
426 (* Same as above for guestfs_readlinklist. *)
427 and readlinklist_wrapper g dir = function
430 let names', names = List.take 1000 names, List.drop 1000 names in
431 let xs = g#readlinklist dir (Array.of_list names') in
432 let xs = Array.to_list xs in
433 xs @ readlinklist_wrapper g dir names
435 (* Start up one slave thread. *)
436 let slave_thread = Thread.create loop ()
438 (* Note the following function is called from the main thread. *)
440 discard_command_queue ();
441 ignore (send_to_slave Exit_thread);
442 Thread.join slave_thread