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Merged
merged 1 commit into from
Jun 2, 2015
+54 −49
Merged

xenvmd: Host.connect should be idempotent #114

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103 changes: 54 additions & 49 deletions xenvmd/xenvmd.ml
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Original file line number Diff line number Diff line change
Expand Up @@ -253,58 +253,63 @@ module VolumeManager = struct
let toLVM = toLVM name in
let fromLVM = fromLVM name in
let freeLVM = freeLVM name in
( try
Lwt.return (Lvm.Vg.LVs.find_by_name freeLVM (Vg_IO.metadata_of vg).Lvm.Vg.lvs).Lvm.Lv.id
with _ ->
fail Xenvm_interface.HostNotCreated ) >>= fun freeLVMid ->
( match Vg_IO.find vg toLVM with
| Some lv -> return lv
| None -> assert false ) >>= fun v ->
Vg_IO.Volume.connect v
>>= function
| `Error _ -> fail (Failure (Printf.sprintf "Failed to open %s" toLVM))
| `Ok disk ->
ToLVM.attach ~name ~disk ()
>>= fun to_LVM ->
ToLVM.state to_LVM
>>= fun state ->
debug "ToLVM queue is currently %s" (match state with `Running -> "Running" | `Suspended -> "Suspended");
ToLVM.resume to_LVM
>>= fun () ->
( match Vg_IO.find vg fromLVM with
| Some lv -> return lv
| None -> assert false ) >>= fun v ->
Vg_IO.Volume.connect v
>>= function
| `Error _ -> fail (Failure (Printf.sprintf "Failed to open %s" fromLVM))
| `Ok disk ->
FromLVM.attach ~name ~disk ()
>>= fun (initial_state, from_LVM) ->
( if initial_state = `Suspended then begin
debug "The FromLVM queue was already suspended: resending the free blocks";
( match Vg_IO.find vg freeLVM with
| Some lv -> return lv
| None -> assert false ) >>= fun lv ->
let allocation = Lvm.Lv.to_allocation (Vg_IO.Volume.metadata_of lv) in
FromLVM.push from_LVM allocation
>>= fun pos ->
FromLVM.advance from_LVM pos
>>= fun () ->
debug "Free blocks pushed";
if List.mem_assoc name !to_LVMs then begin
info "Host-specific volumes (%s, %s, %s) already connected" toLVM fromLVM freeLVM;
return ()
end else begin
debug "The FromLVM queue was running: no need to resend the free blocks";
( try
Lwt.return (Lvm.Vg.LVs.find_by_name freeLVM (Vg_IO.metadata_of vg).Lvm.Vg.lvs).Lvm.Lv.id
with _ ->
fail Xenvm_interface.HostNotCreated ) >>= fun freeLVMid ->
( match Vg_IO.find vg toLVM with
| Some lv -> return lv
| None -> assert false ) >>= fun v ->
Vg_IO.Volume.connect v
>>= function
| `Error _ -> fail (Failure (Printf.sprintf "Failed to open %s" toLVM))
| `Ok disk ->
ToLVM.attach ~name ~disk ()
>>= fun to_LVM ->
ToLVM.state to_LVM
>>= fun state ->
debug "ToLVM queue is currently %s" (match state with `Running -> "Running" | `Suspended -> "Suspended");
ToLVM.resume to_LVM
>>= fun () ->
( match Vg_IO.find vg fromLVM with
| Some lv -> return lv
| None -> assert false ) >>= fun v ->
Vg_IO.Volume.connect v
>>= function
| `Error _ -> fail (Failure (Printf.sprintf "Failed to open %s" fromLVM))
| `Ok disk ->
FromLVM.attach ~name ~disk ()
>>= fun (initial_state, from_LVM) ->
( if initial_state = `Suspended then begin
debug "The FromLVM queue was already suspended: resending the free blocks";
( match Vg_IO.find vg freeLVM with
| Some lv -> return lv
| None -> assert false ) >>= fun lv ->
let allocation = Lvm.Lv.to_allocation (Vg_IO.Volume.metadata_of lv) in
FromLVM.push from_LVM allocation
>>= fun pos ->
FromLVM.advance from_LVM pos
>>= fun () ->
debug "Free blocks pushed";
return ()
end else begin
debug "The FromLVM queue was running: no need to resend the free blocks";
return ()
end )
>>= fun () ->
debug "querying state";
FromLVM.state from_LVM
>>= fun state ->
debug "FromLVM queue is currently %s" (match state with `Running -> "Running" | `Suspended -> "Suspended");
to_LVMs := (name, to_LVM) :: !to_LVMs;
from_LVMs := (name, from_LVM) :: !from_LVMs;
free_LVs := (name, (freeLVM,freeLVMid)) :: !free_LVs;
return ()
end )
>>= fun () ->
debug "querying state";
FromLVM.state from_LVM
>>= fun state ->
debug "FromLVM queue is currently %s" (match state with `Running -> "Running" | `Suspended -> "Suspended");
to_LVMs := (name, to_LVM) :: !to_LVMs;
from_LVMs := (name, from_LVM) :: !from_LVMs;
free_LVs := (name, (freeLVM,freeLVMid)) :: !free_LVs;
return ()
end

(* Hold this mutex when actively flushing from the ToLVM queues *)
let flush_m = Lwt_mutex.create ()
Expand Down