Libguestfs - Aug 2015 - [PATCH 2/4] v2v: consolidate virtio-win file copying

Libguestfs supports passing an ISO image as a source of virtio windows
drivers to v2v.

That support, however, looks too heavy-weight: in order to access those
drivers, a separate guestfs handle is created (and thus a new emulator
process is started), which runs until v2v completes.

This series attempts to make it simpler and lighter-weight, by making
the relevant code more local, and by hot-adding the image into the main
guestfs handle.

Roman Kagan (4):
  v2v: drop useless forced gc
  v2v: consolidate virtio-win file copying
  v2v: copy virtio drivers without guestfs handle leak
  v2v: reuse main guestfs for virtio win drivers iso

 v2v/convert_windows.ml | 184 ++++++++++++++++++++--------------------
 v2v/utils.ml           | 224 ++++++++++++++++---------------------------------
 v2v/v2v.ml             |   8 --
 3 files changed, 163 insertions(+), 253 deletions(-)

-- 
2.4.3

Forced gc meant, according to the comment, to prevent the leak of the
auxiliary guestfs handle (and thus an extra qemu instance) to the data
copy stage of the v2v conversion, doesn't actually achieve its goal:
it's easy to check that in reality that extra qemu instance survives
till the end of v2v execution.

So drop it; an alternative scheme will be proposed in the followup
patches.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
 v2v/v2v.ml | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/v2v/v2v.ml b/v2v/v2v.ml
index 242f129..7c47ea0 100644
--- a/v2v/v2v.ml
+++ b/v2v/v2v.ml
@@ -320,14 +320,6 @@ let rec main ()    if verbose () then
     printf "%s%!" (string_of_target_buses target_buses);
 
-  (* Force a GC here, to ensure that we're using the minimum resources
-   * as we go into the copy stage.  The particular reason is that
-   * Windows conversion may have opened a second libguestfs handle
-   * pointing to the virtio-win ISO, which is only closed when the
-   * handle is GC'd.
-   *)
-  Gc.compact ();
-
   let delete_target_on_exit = ref true in
 
   let targets -- 
2.4.3

Copy the appropriate driver files from the virtio-win storage into
%SYSTEMROOT%\Drivers\VirtIO once they are discovered, and stick to using
those copies later on.

This way the knowledge of where the drivers come from originally is
consolidated in one place, so the lifetime of the associated entities
becomes easier to control (to be implemented in followup patches).

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
 v2v/convert_windows.ml | 128 ++++++++++++++++++++++---------------------------
 1 file changed, 56 insertions(+), 72 deletions(-)

diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
index 9e83df8..26609f2 100644
--- a/v2v/convert_windows.ml
+++ b/v2v/convert_windows.ml
@@ -231,12 +231,9 @@ echo uninstalling Xen PV driver
     with
       Not_found -> ()
 
-  and install_virtio_drivers root current_cs -    (* Copy the virtio drivers to
the guest. *)
-    let driverdir = sprintf "%s/Drivers/VirtIO" systemroot in
-    g#mkdir_p driverdir;
+  and copy_virtio_drivers driverdir +    (* Copy the matching drivers to the
driverdir. *)
 
-    (* Load the list of drivers available. *)
     let drivers = find_virtio_win_drivers virtio_win in
 
     (* Filter out only drivers matching the current guest. *)
@@ -260,73 +257,60 @@ echo uninstalling Xen PV driver
       flush stdout
     );
 
-    match drivers with
-    | [] ->
-       warning (f_"there are no virtio drivers available for this version
of Windows (%d.%d %s %s).  virt-v2v looks for drivers in %s\n\nThe guest will be
configured to use slower emulated devices.")
-               inspect.i_major_version inspect.i_minor_version
-               inspect.i_arch inspect.i_product_variant
-               virtio_win;
-       ( IDE, RTL8139, Cirrus )
-
-    | drivers ->
-       (* Can we install the block driver? *)
-       let block : guestcaps_block_type -         try
-           let viostor_sys_file -             List.find
-               (fun { vwd_filename = filename } -> filename =
"viostor.sys")
-               drivers in
-           (* Get the actual file contents of the .sys file. *)
-           let content = viostor_sys_file.vwd_get_contents () in
-           let target = sprintf "%s/system32/drivers/viostor.sys"
systemroot in
-           let target = g#case_sensitive_path target in
-           g#write target content;
-           add_viostor_to_critical_device_database root current_cs;
-           Virtio_blk
-         with Not_found ->
-           warning (f_"there is no viostor (virtio block device) driver
for this version of Windows (%d.%d %s).  virt-v2v looks for this driver in
%s\n\nThe guest will be configured to use a slower emulated device.")
-                   inspect.i_major_version inspect.i_minor_version
-                   inspect.i_arch virtio_win;
-           IDE in
-
-       (* Can we install the virtio-net driver? *)
-       let net : guestcaps_net_type -         if not (List.exists
-                   (fun { vwd_filename = filename } -> filename =
"netkvm.inf")
-                   drivers) then (
-           warning (f_"there is no virtio network driver for this version
of Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will
be configured to use a slower emulated device.")
-                   inspect.i_major_version inspect.i_minor_version
-                   inspect.i_arch virtio_win;
-           RTL8139
-         )
-         else
-           (* It will be installed at firstboot. *)
-           Virtio_net in
-
-       (* Can we install the QXL driver? *)
-       let video : guestcaps_video_type -         if not (List.exists
-                   (fun { vwd_filename = filename } -> filename =
"qxl.inf")
-                   drivers) then (
-           warning (f_"there is no QXL driver for this version of Windows
(%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will be
configured to use standard VGA.")
-                   inspect.i_major_version inspect.i_minor_version
-                   inspect.i_arch virtio_win;
-           Cirrus
-         )
-         else
-           (* It will be installed at firstboot. *)
-           QXL in
-
-       (* Copy all the drivers to the driverdir.  They will be
-        * installed at firstboot.
-        *)
-       List.iter (
-         fun driver ->
-           let content = driver.vwd_get_contents () in
-           g#write (driverdir // driver.vwd_filename) content
-       ) drivers;
-
-       (block, net, video)
+    List.iter (
+      fun driver ->
+        let content = driver.vwd_get_contents () in
+        g#write (driverdir // driver.vwd_filename) content
+    ) drivers
+
+  and install_virtio_drivers root current_cs +    (* Copy the virtio drivers to
the guest. *)
+    let driverdir = sprintf "%s/Drivers/VirtIO" systemroot in
+    g#mkdir_p driverdir;
+
+    copy_virtio_drivers driverdir;
+
+    (* Can we install the block driver? *)
+    let block : guestcaps_block_type +      let source = driverdir //
"viostor.sys" in
+      if (g#exists source) then (
+        let target = sprintf "%s/system32/drivers/viostor.sys"
systemroot in
+        let target = g#case_sensitive_path target in
+        g#cp source target;
+        add_viostor_to_critical_device_database root current_cs;
+        Virtio_blk
+      ) else (
+        warning (f_"there is no viostor (virtio block device) driver for
this version of Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe
guest will be configured to use a slower emulated device.")
+                inspect.i_major_version inspect.i_minor_version
+                inspect.i_arch virtio_win;
+        IDE
+      ) in
+
+    (* Can we install the virtio-net driver? *)
+    let net : guestcaps_net_type +      if not (g#exists (driverdir //
"netkvm.inf")) then (
+        warning (f_"there is no virtio network driver for this version of
Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will be
configured to use a slower emulated device.")
+                inspect.i_major_version inspect.i_minor_version
+                inspect.i_arch virtio_win;
+        RTL8139
+      )
+      else
+        (* It will be installed at firstboot. *)
+        Virtio_net in
+
+    (* Can we install the QXL driver? *)
+    let video : guestcaps_video_type +      if not (g#exists (driverdir //
"qxl.inf")) then (
+        warning (f_"there is no QXL driver for this version of Windows
(%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will be
configured to use standard VGA.")
+                inspect.i_major_version inspect.i_minor_version
+                inspect.i_arch virtio_win;
+        Cirrus
+      )
+      else
+        (* It will be installed at firstboot. *)
+        QXL in
+
+    (block, net, video)
 
   and add_viostor_to_critical_device_database root current_cs      let {
i_major_version = major; i_minor_version = minor;
-- 
2.4.3

Refactor copying of virtio windows drivers into the guest so that the
matching of the drivers to the guest os flavor and copying the files
happens one next to the other in a single function, and no guestfs
handle (nor any other irrelevant info) is leaked outside.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
 v2v/convert_windows.ml |  77 ++++++++++-------
 v2v/utils.ml           | 224 ++++++++++++++++---------------------------------
 2 files changed, 118 insertions(+), 183 deletions(-)

diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
index 26609f2..b6e6c62 100644
--- a/v2v/convert_windows.ml
+++ b/v2v/convert_windows.ml
@@ -233,35 +233,54 @@ echo uninstalling Xen PV driver
 
   and copy_virtio_drivers driverdir      (* Copy the matching drivers to the
driverdir. *)
-
-    let drivers = find_virtio_win_drivers virtio_win in
-
-    (* Filter out only drivers matching the current guest. *)
-    let drivers -      List.filter (
-        fun { vwd_os_arch = arch;
-              vwd_os_major = os_major; vwd_os_minor = os_minor;
-              vwd_os_variant = os_variant } ->
-        arch = inspect.i_arch &&
-        os_major = inspect.i_major_version &&
-        os_minor = inspect.i_minor_version &&
-        (match os_variant with
-         | Vwd_client -> inspect.i_product_variant = "Client"
-         | Vwd_not_client -> inspect.i_product_variant <>
"Client"
-         | Vwd_any_variant -> true)
-      ) drivers in
-
-    if verbose () then (
-      printf "virtio-win driver files matching this guest:\n";
-      List.iter print_virtio_win_driver_file drivers;
-      flush stdout
-    );
-
-    List.iter (
-      fun driver ->
-        let content = driver.vwd_get_contents () in
-        g#write (driverdir // driver.vwd_filename) content
-    ) drivers
+    if is_directory virtio_win then (
+      let cmd = sprintf "cd %s && find -type f" (quote
virtio_win) in
+      let paths = external_command cmd in
+      List.iter (
+        fun path ->
+          if (match_vio_path_with_os path inspect.i_arch
+              inspect.i_major_version inspect.i_minor_version
+              inspect.i_product_variant) then (
+            let source = virtio_win // path in
+            let target = driverdir // (String.lowercase
+                                        (Filename.basename path)) in
+            if verbose () then
+              printf "Copying virtio driver bits: 'host:%s' ->
'%s'\n"
+                source target;
+
+            g#write target (read_whole_file source)
+          )
+      ) paths
+    )
+    else if is_regular_file virtio_win then (
+      try
+        let g2 = new Guestfs.guestfs () in
+        if trace () then g2#set_trace true;
+        if verbose () then g2#set_verbose true;
+        g2#add_drive_opts virtio_win ~readonly:true;
+        g2#launch ();
+        let vio_root = "/" in
+        g2#mount_ro "/dev/sda" vio_root;
+        let paths = g2#find vio_root in
+        Array.iter (
+          fun path ->
+            let source = vio_root // path in
+            if ((g2#is_file source ~followsymlinks:false) &&
+                (match_vio_path_with_os path inspect.i_arch
+                    inspect.i_major_version inspect.i_minor_version
+                    inspect.i_product_variant)) then
+              let target = driverdir // (String.lowercase
+                                          (Filename.basename path)) in
+              if verbose () then
+                printf "Copying virtio driver bits: '%s:%s' ->
'%s'\n"
+                  virtio_win path target;
+
+              g#write target (g2#read_file source)
+        ) paths;
+        g2#close()
+      with Guestfs.Error msg ->
+        error (f_"%s: cannot open virtio-win ISO file: %s")
virtio_win msg
+    )
 
   and install_virtio_drivers root current_cs      (* Copy the virtio drivers to
the guest. *)
diff --git a/v2v/utils.ml b/v2v/utils.ml
index 4e6befc..7db4448 100644
--- a/v2v/utils.ml
+++ b/v2v/utils.ml
@@ -110,161 +110,77 @@ let find_uefi_firmware guest_arch    in
   loop files
 
-(* Find virtio-win driver files from an unpacked or mounted virtio-win
- * directory, or from a virtio-win.iso file. The location of drivers
-  varies between releases of virtio-win and also across Fedora and
-  RHEL so try to be robust to changes.
- *)
-type virtio_win_driver_file = {
-  (* Base filename, eg. "netkvm.sys".  Always lowercase. *)
-  vwd_filename : string;
-  (* Return the contents of this file. *)
-  vwd_get_contents : unit -> string;
-
-  (* Various fields that classify this driver: *)
-
-  vwd_os_major : int;           (* Windows version. *)
-  vwd_os_minor : int;
-  vwd_os_variant : vwd_os_variant;
-  vwd_os_arch : string;         (* Architecture, eg "i386",
"x86_64". *)
-  vwd_extension : string;       (* File extension (lowercase), eg.
"sys" "inf"*)
-
-  (* Original source of file (for debugging only). *)
-  vwd_original_source : string;
-}
-and vwd_os_variant = Vwd_client | Vwd_not_client | Vwd_any_variant
-
-let print_virtio_win_driver_file vwd -  printf "%s [%d,%d,%s,%s,%s] from
%s\n"
-         vwd.vwd_filename
-         vwd.vwd_os_major vwd.vwd_os_minor
-         (match vwd.vwd_os_variant with
-          | Vwd_client -> "client" | Vwd_not_client ->
"not-client"
-          | Vwd_any_variant -> "any")
-         vwd.vwd_os_arch
-         vwd.vwd_extension
-         vwd.vwd_original_source
-
-let find_virtio_win_drivers virtio_win -  let is_regular_file path = (* NB:
follows symlinks. *)
-    try (Unix.stat path).Unix.st_kind = Unix.S_REG
-    with Unix.Unix_error _ -> false
-  in
-
-  let files -    if is_directory virtio_win then (
-      let cmd = sprintf "cd %s && find -type f" (quote
virtio_win) in
-      let paths = external_command cmd in
-      List.map (
-        fun path ->
-          let abs_path = virtio_win // path in
-          (path, abs_path,
-           Filename.basename path,
-           fun () -> read_whole_file abs_path)
-      ) paths
-    )
-    else if is_regular_file virtio_win then (
-      try
-        let g = new Guestfs.guestfs () in
-        if trace () then g#set_trace true;
-        if verbose () then g#set_verbose true;
-        g#add_drive_opts virtio_win ~readonly:true;
-        g#launch ();
-        g#mount_ro "/dev/sda" "/";
-        let paths = g#find "/" in
-        let paths = Array.to_list paths in
-        let paths = List.map ((^) "/") paths in
-        let paths = List.filter (g#is_file ~followsymlinks:false) paths in
-        List.map (
-          fun path ->
-            let basename -              match last_part_of path '/'
with
-              | Some x -> x
-              | None ->
-                error "v2v/find_virtio_win_drivers: missing '/' in
%s" path in
-            (path, sprintf "%s:%s" virtio_win path,
-             basename,
-             fun () -> g#read_file path)
-        ) paths
-      with Guestfs.Error msg ->
-        error (f_"%s: cannot open virtio-win ISO file: %s")
virtio_win msg
-    )
-    else [] in
+let is_regular_file path = (* NB: follows symlinks. *)
+  try (Unix.stat path).Unix.st_kind = Unix.S_REG
+  with Unix.Unix_error _ -> false
 
-  let files -    filter_map (
-      fun (path, original_source, basename, get_contents) ->
-        try
-          (* Lowercased path, since the ISO may contain upper or lowercase
-           * path elements.  XXX This won't work if paths contain
non-ASCII.
-           *)
-          let lc_path = String.lowercase path in
-          let lc_basename = String.lowercase basename in
-
-          let extension -            match last_part_of lc_basename '.'
with
-            | Some x -> x
-            | None ->
-              error "v2v/find_virtio_win_drivers: missing '.' in
%s"
-                lc_basename in
-
-          (* Skip files without specific extensions. *)
-          if extension <> "cat" && extension <>
"inf" &&
-               extension <> "pdb" && extension <>
"sys" then
-            raise Not_found;
-
-          (* Using the full path, work out what version of Windows
-           * this driver is for.  Paths can be things like:
-           * "NetKVM/2k12R2/amd64/netkvm.sys" or
-           * "./drivers/amd64/Win2012R2/netkvm.sys".
-           * Note we check lowercase paths.
-           *)
-          let pathelem elem = string_find lc_path ("/" ^ elem ^
"/") >= 0 in
-          let arch -            if pathelem "x86" || pathelem
"i386" then "i386"
-            else if pathelem "amd64" then "x86_64"
-            else raise Not_found in
-          let os_major, os_minor, os_variant -            if pathelem
"xp" || pathelem "winxp" then
-              (5, 1, Vwd_any_variant)
-            else if pathelem "2k3" || pathelem "win2003"
then
-              (5, 2, Vwd_any_variant)
-            else if pathelem "vista" then
-              (6, 0, Vwd_client)
-            else if pathelem "2k8" || pathelem "win2008"
then
-              (6, 0, Vwd_not_client)
-            else if pathelem "w7" || pathelem "win7" then
-              (6, 1, Vwd_client)
-            else if pathelem "2k8r2" || pathelem
"win2008r2" then
-              (6, 1, Vwd_not_client)
-            else if pathelem "w8" || pathelem "win8" then
-              (6, 2, Vwd_client)
-            else if pathelem "2k12" || pathelem "win2012"
then
-              (6, 2, Vwd_not_client)
-            else if pathelem "w8.1" || pathelem "win8.1"
then
-              (6, 3, Vwd_client)
-            else if pathelem "2k12r2" || pathelem
"win2012r2" then
-              (6, 3, Vwd_not_client)
-            else if pathelem "w10" || pathelem "win10" then
-              (10, 0, Vwd_client)
-            else
-              raise Not_found in
-
-          Some {
-            vwd_filename = lc_basename;
-            vwd_get_contents = get_contents;
-            vwd_os_major = os_major;
-            vwd_os_minor = os_minor;
-            vwd_os_variant = os_variant;
-            vwd_os_arch = arch;
-            vwd_extension = extension;
-            vwd_original_source = original_source;
-          }
-
-        with Not_found -> None
-    ) files in
-
-  files
+(* Given a path of a file relative to the root of the directory tree with
+ * virtio-win drivers, figure out if it's suitable for the specific Windows
+ * flavor.
+ *)
+let match_vio_path_with_os path arch os_major os_minor os_variant +  try
+    (* Lowercased path, since the ISO may contain upper or lowercase path
+     * elements.  XXX This won't work if paths contain non-ASCII.
+     *)
+    let lc_path = String.lowercase path in
+    let lc_basename = Filename.basename path in
+
+    let extension +      match last_part_of lc_basename '.' with
+      | Some x -> x
+      | None -> raise Not_found
+    in
+
+    (* Skip files without specific extensions. *)
+    let extensions = ["cat"; "inf"; "pdb";
"sys"] in
+    if (not (List.mem extension extensions)) then raise Not_found;
+
+    (* Using the full path, work out what version of Windows
+     * this driver is for.  Paths can be things like:
+     * "NetKVM/2k12R2/amd64/netkvm.sys" or
+     * "./drivers/amd64/Win2012R2/netkvm.sys".
+     * Note we check lowercase paths.
+     *)
+    let pathelem elem = string_find lc_path ("/" ^ elem ^
"/") >= 0 in
+    let p_arch +      if pathelem "x86" || pathelem "i386"
then "i386"
+      else if pathelem "amd64" then "x86_64"
+      else raise Not_found in
+
+    let is_client os_variant = os_variant = "Client"
+    and not_client os_variant = os_variant <> "Client"
+    and any_variant os_variant = true in
+    let p_os_major, p_os_minor, match_os_variant +      if pathelem
"xp" || pathelem "winxp" then
+        (5, 1, any_variant)
+      else if pathelem "2k3" || pathelem "win2003" then
+        (5, 2, any_variant)
+      else if pathelem "vista" then
+        (6, 0, is_client)
+      else if pathelem "2k8" || pathelem "win2008" then
+        (6, 0, not_client)
+      else if pathelem "w7" || pathelem "win7" then
+        (6, 1, is_client)
+      else if pathelem "2k8r2" || pathelem "win2008r2" then
+        (6, 1, not_client)
+      else if pathelem "w8" || pathelem "win8" then
+        (6, 2, is_client)
+      else if pathelem "2k12" || pathelem "win2012" then
+        (6, 2, not_client)
+      else if pathelem "w8.1" || pathelem "win8.1" then
+        (6, 3, is_client)
+      else if pathelem "2k12r2" || pathelem "win2012r2"
then
+        (6, 3, not_client)
+      else if pathelem "w10" || pathelem "win10" then
+        (10, 0, is_client)
+      else
+        raise Not_found in
+
+    arch = p_arch && os_major = p_os_major && os_minor =
p_os_minor &&
+      match_os_variant os_variant
+
+  with Not_found -> false
 
 let compare_app2_versions app1 app2    let i = compare app1.Guestfs.app2_epoch
app2.Guestfs.app2_epoch in
-- 
2.4.3

If we're given a ISO image as the source of virtio windows drivers,
reuse the same guestfs handle that is open for accessing the guest being
inspected, rather than creating a new one.  This is lighter-weight and
more convenient, and, given the support for hot-inserting/ejecting an
ISO image in libguestfs, appears no less reliable.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
 v2v/convert_windows.ml | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
index b6e6c62..51bbd8c 100644
--- a/v2v/convert_windows.ml
+++ b/v2v/convert_windows.ml
@@ -254,18 +254,15 @@ echo uninstalling Xen PV driver
     )
     else if is_regular_file virtio_win then (
       try
-        let g2 = new Guestfs.guestfs () in
-        if trace () then g2#set_trace true;
-        if verbose () then g2#set_verbose true;
-        g2#add_drive_opts virtio_win ~readonly:true;
-        g2#launch ();
-        let vio_root = "/" in
-        g2#mount_ro "/dev/sda" vio_root;
-        let paths = g2#find vio_root in
+        let label = "viowin" in
+        g#add_drive_opts virtio_win ~readonly:true ~label:label;
+        let vio_root = (g#mkdtemp (driverdir // "isoXXXXXX")) in
+        g#mount_ro ("/dev/disk/guestfs" // label) vio_root;
+        let paths = g#find vio_root in
         Array.iter (
           fun path ->
             let source = vio_root // path in
-            if ((g2#is_file source ~followsymlinks:false) &&
+            if ((g#is_file source ~followsymlinks:false) &&
                 (match_vio_path_with_os path inspect.i_arch
                     inspect.i_major_version inspect.i_minor_version
                     inspect.i_product_variant)) then
@@ -275,9 +272,11 @@ echo uninstalling Xen PV driver
                 printf "Copying virtio driver bits: '%s:%s' ->
'%s'\n"
                   virtio_win path target;
 
-              g#write target (g2#read_file source)
+              g#cp source target
         ) paths;
-        g2#close()
+        g#umount vio_root;
+        g#remove_drive label;
+        g#rmdir vio_root
       with Guestfs.Error msg ->
         error (f_"%s: cannot open virtio-win ISO file: %s")
virtio_win msg
     )
-- 
2.4.3

On Mon, Aug 10, 2015 at 06:55:30PM +0300, Roman Kagan
wrote:
> Copy the appropriate driver files from the virtio-win storage into
> %SYSTEMROOT%\Drivers\VirtIO once they are discovered, and stick to using
> those copies later on.
> 
> This way the knowledge of where the drivers come from originally is
> consolidated in one place, so the lifetime of the associated entities
> becomes easier to control (to be implemented in followup patches).
> 
> Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
> ---
>  v2v/convert_windows.ml | 128
++++++++++++++++++++++---------------------------
>  1 file changed, 56 insertions(+), 72 deletions(-)
> 
> diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
> index 9e83df8..26609f2 100644
> --- a/v2v/convert_windows.ml
> +++ b/v2v/convert_windows.ml
> @@ -231,12 +231,9 @@ echo uninstalling Xen PV driver
>      with
>        Not_found -> ()
>  
> -  and install_virtio_drivers root current_cs > -    (* Copy the virtio
drivers to the guest. *)
> -    let driverdir = sprintf "%s/Drivers/VirtIO" systemroot in
> -    g#mkdir_p driverdir;
> +  and copy_virtio_drivers driverdir > +    (* Copy the matching drivers
to the driverdir. *)
>  
> -    (* Load the list of drivers available. *)
>      let drivers = find_virtio_win_drivers virtio_win in
>  
>      (* Filter out only drivers matching the current guest. *)
> @@ -260,73 +257,60 @@ echo uninstalling Xen PV driver
>        flush stdout
>      );
>  
> -    match drivers with
> -    | [] ->
> -       warning (f_"there are no virtio drivers available for this
version of Windows (%d.%d %s %s).  virt-v2v looks for drivers in %s\n\nThe guest
will be configured to use slower emulated devices.")
> -               inspect.i_major_version inspect.i_minor_version
> -               inspect.i_arch inspect.i_product_variant
> -               virtio_win;
> -       ( IDE, RTL8139, Cirrus )
> -
> -    | drivers ->
> -       (* Can we install the block driver? *)
> -       let block : guestcaps_block_type > -         try
> -           let viostor_sys_file > -             List.find
> -               (fun { vwd_filename = filename } -> filename =
"viostor.sys")
> -               drivers in
> -           (* Get the actual file contents of the .sys file. *)
> -           let content = viostor_sys_file.vwd_get_contents () in
> -           let target = sprintf
"%s/system32/drivers/viostor.sys" systemroot in
> -           let target = g#case_sensitive_path target in
> -           g#write target content;
> -           add_viostor_to_critical_device_database root current_cs;
> -           Virtio_blk
> -         with Not_found ->
> -           warning (f_"there is no viostor (virtio block device)
driver for this version of Windows (%d.%d %s).  virt-v2v looks for this driver
in %s\n\nThe guest will be configured to use a slower emulated device.")
> -                   inspect.i_major_version inspect.i_minor_version
> -                   inspect.i_arch virtio_win;
> -           IDE in
> -
> -       (* Can we install the virtio-net driver? *)
> -       let net : guestcaps_net_type > -         if not (List.exists
> -                   (fun { vwd_filename = filename } -> filename =
"netkvm.inf")
> -                   drivers) then (
> -           warning (f_"there is no virtio network driver for this
version of Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe
guest will be configured to use a slower emulated device.")
> -                   inspect.i_major_version inspect.i_minor_version
> -                   inspect.i_arch virtio_win;
> -           RTL8139
> -         )
> -         else
> -           (* It will be installed at firstboot. *)
> -           Virtio_net in
> -
> -       (* Can we install the QXL driver? *)
> -       let video : guestcaps_video_type > -         if not (List.exists
> -                   (fun { vwd_filename = filename } -> filename =
"qxl.inf")
> -                   drivers) then (
> -           warning (f_"there is no QXL driver for this version of
Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will be
configured to use standard VGA.")
> -                   inspect.i_major_version inspect.i_minor_version
> -                   inspect.i_arch virtio_win;
> -           Cirrus
> -         )
> -         else
> -           (* It will be installed at firstboot. *)
> -           QXL in
> -
> -       (* Copy all the drivers to the driverdir.  They will be
> -        * installed at firstboot.
> -        *)
> -       List.iter (
> -         fun driver ->
> -           let content = driver.vwd_get_contents () in
> -           g#write (driverdir // driver.vwd_filename) content
> -       ) drivers;
> -
> -       (block, net, video)
> +    List.iter (
> +      fun driver ->
> +        let content = driver.vwd_get_contents () in
> +        g#write (driverdir // driver.vwd_filename) content
> +    ) drivers
> +
> +  and install_virtio_drivers root current_cs > +    (* Copy the virtio
drivers to the guest. *)
> +    let driverdir = sprintf "%s/Drivers/VirtIO" systemroot in
> +    g#mkdir_p driverdir;
> +
> +    copy_virtio_drivers driverdir;
> +
> +    (* Can we install the block driver? *)
> +    let block : guestcaps_block_type > +      let source = driverdir //
"viostor.sys" in
> +      if (g#exists source) then (
> +        let target = sprintf "%s/system32/drivers/viostor.sys"
systemroot in
> +        let target = g#case_sensitive_path target in
> +        g#cp source target;
> +        add_viostor_to_critical_device_database root current_cs;
> +        Virtio_blk
> +      ) else (
> +        warning (f_"there is no viostor (virtio block device) driver
for this version of Windows (%d.%d %s).  virt-v2v looks for this driver in
%s\n\nThe guest will be configured to use a slower emulated device.")
> +                inspect.i_major_version inspect.i_minor_version
> +                inspect.i_arch virtio_win;
> +        IDE
> +      ) in
> +
> +    (* Can we install the virtio-net driver? *)
> +    let net : guestcaps_net_type > +      if not (g#exists (driverdir
// "netkvm.inf")) then (
> +        warning (f_"there is no virtio network driver for this
version of Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe
guest will be configured to use a slower emulated device.")
> +                inspect.i_major_version inspect.i_minor_version
> +                inspect.i_arch virtio_win;
> +        RTL8139
> +      )
> +      else
> +        (* It will be installed at firstboot. *)
> +        Virtio_net in
> +
> +    (* Can we install the QXL driver? *)
> +    let video : guestcaps_video_type > +      if not (g#exists
(driverdir // "qxl.inf")) then (
> +        warning (f_"there is no QXL driver for this version of
Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will be
configured to use standard VGA.")
> +                inspect.i_major_version inspect.i_minor_version
> +                inspect.i_arch virtio_win;
> +        Cirrus
> +      )
> +      else
> +        (* It will be installed at firstboot. *)
> +        QXL in
> +
> +    (block, net, video)
>  
>    and add_viostor_to_critical_device_database root current_cs >     
let { i_major_version = major; i_minor_version = minor;
> -- 
> 2.4.3
This looks good to me (once I used the 'git diff -w' option to show
the true changes).

So likely ACK.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/

On Mon, Aug 10, 2015 at 06:55:31PM +0300, Roman Kagan
wrote:
> Refactor copying of virtio windows drivers into the guest so that the
> matching of the drivers to the guest os flavor and copying the files
> happens one next to the other in a single function, and no guestfs
> handle (nor any other irrelevant info) is leaked outside.
> 
> Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
> ---
>  v2v/convert_windows.ml |  77 ++++++++++-------
>  v2v/utils.ml           | 224
++++++++++++++++---------------------------------
>  2 files changed, 118 insertions(+), 183 deletions(-)
> 
> diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
> index 26609f2..b6e6c62 100644
> --- a/v2v/convert_windows.ml
> +++ b/v2v/convert_windows.ml
> @@ -233,35 +233,54 @@ echo uninstalling Xen PV driver
>  
>    and copy_virtio_drivers driverdir >      (* Copy the matching drivers
to the driverdir. *)
> -
> -    let drivers = find_virtio_win_drivers virtio_win in
> -
> -    (* Filter out only drivers matching the current guest. *)
> -    let drivers > -      List.filter (
> -        fun { vwd_os_arch = arch;
> -              vwd_os_major = os_major; vwd_os_minor = os_minor;
> -              vwd_os_variant = os_variant } ->
> -        arch = inspect.i_arch &&
> -        os_major = inspect.i_major_version &&
> -        os_minor = inspect.i_minor_version &&
> -        (match os_variant with
> -         | Vwd_client -> inspect.i_product_variant = "Client"
> -         | Vwd_not_client -> inspect.i_product_variant <>
"Client"
> -         | Vwd_any_variant -> true)
> -      ) drivers in
> -
> -    if verbose () then (
> -      printf "virtio-win driver files matching this guest:\n";
> -      List.iter print_virtio_win_driver_file drivers;
> -      flush stdout
> -    );
> -
> -    List.iter (
> -      fun driver ->
> -        let content = driver.vwd_get_contents () in
> -        g#write (driverdir // driver.vwd_filename) content
> -    ) drivers
> +    if is_directory virtio_win then (
> +      let cmd = sprintf "cd %s && find -type f" (quote
virtio_win) in
> +      let paths = external_command cmd in
> +      List.iter (
> +        fun path ->
> +          if (match_vio_path_with_os path inspect.i_arch
> +              inspect.i_major_version inspect.i_minor_version
> +              inspect.i_product_variant) then (
> +            let source = virtio_win // path in
> +            let target = driverdir // (String.lowercase
> +                                        (Filename.basename path)) in
> +            if verbose () then
> +              printf "Copying virtio driver bits: 'host:%s'
-> '%s'\n"
> +                source target;
> +
> +            g#write target (read_whole_file source)
> +          )
> +      ) paths
> +    )
> +    else if is_regular_file virtio_win then (
> +      try
> +        let g2 = new Guestfs.guestfs () in
> +        if trace () then g2#set_trace true;
> +        if verbose () then g2#set_verbose true;
> +        g2#add_drive_opts virtio_win ~readonly:true;
> +        g2#launch ();
> +        let vio_root = "/" in
> +        g2#mount_ro "/dev/sda" vio_root;
> +        let paths = g2#find vio_root in
> +        Array.iter (
> +          fun path ->
> +            let source = vio_root // path in
> +            if ((g2#is_file source ~followsymlinks:false) &&
> +                (match_vio_path_with_os path inspect.i_arch
> +                    inspect.i_major_version inspect.i_minor_version
> +                    inspect.i_product_variant)) then
> +              let target = driverdir // (String.lowercase
> +                                          (Filename.basename path)) in
> +              if verbose () then
> +                printf "Copying virtio driver bits: '%s:%s'
-> '%s'\n"
> +                  virtio_win path target;
> +
> +              g#write target (g2#read_file source)
> +        ) paths;
> +        g2#close()
> +      with Guestfs.Error msg ->
> +        error (f_"%s: cannot open virtio-win ISO file: %s")
virtio_win msg
> +    )
>  
>    and install_virtio_drivers root current_cs >      (* Copy the virtio
drivers to the guest. *)
> diff --git a/v2v/utils.ml b/v2v/utils.ml
> index 4e6befc..7db4448 100644
> --- a/v2v/utils.ml
> +++ b/v2v/utils.ml
> @@ -110,161 +110,77 @@ let find_uefi_firmware guest_arch >    in
>    loop files
>  
> -(* Find virtio-win driver files from an unpacked or mounted virtio-win
> - * directory, or from a virtio-win.iso file. The location of drivers
> -  varies between releases of virtio-win and also across Fedora and
> -  RHEL so try to be robust to changes.
> - *)
> -type virtio_win_driver_file = {
> -  (* Base filename, eg. "netkvm.sys".  Always lowercase. *)
> -  vwd_filename : string;
> -  (* Return the contents of this file. *)
> -  vwd_get_contents : unit -> string;
> -
> -  (* Various fields that classify this driver: *)
> -
> -  vwd_os_major : int;           (* Windows version. *)
> -  vwd_os_minor : int;
> -  vwd_os_variant : vwd_os_variant;
> -  vwd_os_arch : string;         (* Architecture, eg "i386",
"x86_64". *)
> -  vwd_extension : string;       (* File extension (lowercase), eg.
"sys" "inf"*)
> -
> -  (* Original source of file (for debugging only). *)
> -  vwd_original_source : string;
> -}
> -and vwd_os_variant = Vwd_client | Vwd_not_client | Vwd_any_variant
> -
> -let print_virtio_win_driver_file vwd > -  printf "%s
[%d,%d,%s,%s,%s] from %s\n"
> -         vwd.vwd_filename
> -         vwd.vwd_os_major vwd.vwd_os_minor
> -         (match vwd.vwd_os_variant with
> -          | Vwd_client -> "client" | Vwd_not_client ->
"not-client"
> -          | Vwd_any_variant -> "any")
> -         vwd.vwd_os_arch
> -         vwd.vwd_extension
> -         vwd.vwd_original_source
> -
> -let find_virtio_win_drivers virtio_win > -  let is_regular_file path =
(* NB: follows symlinks. *)
> -    try (Unix.stat path).Unix.st_kind = Unix.S_REG
> -    with Unix.Unix_error _ -> false
> -  in
> -
> -  let files > -    if is_directory virtio_win then (
> -      let cmd = sprintf "cd %s && find -type f" (quote
virtio_win) in
> -      let paths = external_command cmd in
> -      List.map (
> -        fun path ->
> -          let abs_path = virtio_win // path in
> -          (path, abs_path,
> -           Filename.basename path,
> -           fun () -> read_whole_file abs_path)
> -      ) paths
> -    )
> -    else if is_regular_file virtio_win then (
> -      try
> -        let g = new Guestfs.guestfs () in
> -        if trace () then g#set_trace true;
> -        if verbose () then g#set_verbose true;
> -        g#add_drive_opts virtio_win ~readonly:true;
> -        g#launch ();
> -        g#mount_ro "/dev/sda" "/";
> -        let paths = g#find "/" in
> -        let paths = Array.to_list paths in
> -        let paths = List.map ((^) "/") paths in
> -        let paths = List.filter (g#is_file ~followsymlinks:false) paths in
> -        List.map (
> -          fun path ->
> -            let basename > -              match last_part_of path
'/' with
> -              | Some x -> x
> -              | None ->
> -                error "v2v/find_virtio_win_drivers: missing
'/' in %s" path in
> -            (path, sprintf "%s:%s" virtio_win path,
> -             basename,
> -             fun () -> g#read_file path)
> -        ) paths
> -      with Guestfs.Error msg ->
> -        error (f_"%s: cannot open virtio-win ISO file: %s")
virtio_win msg
> -    )
> -    else [] in
> +let is_regular_file path = (* NB: follows symlinks. *)
> +  try (Unix.stat path).Unix.st_kind = Unix.S_REG
> +  with Unix.Unix_error _ -> false
>  
> -  let files > -    filter_map (
> -      fun (path, original_source, basename, get_contents) ->
> -        try
> -          (* Lowercased path, since the ISO may contain upper or lowercase
> -           * path elements.  XXX This won't work if paths contain
non-ASCII.
> -           *)
> -          let lc_path = String.lowercase path in
> -          let lc_basename = String.lowercase basename in
> -
> -          let extension > -            match last_part_of lc_basename
'.' with
> -            | Some x -> x
> -            | None ->
> -              error "v2v/find_virtio_win_drivers: missing '.'
in %s"
> -                lc_basename in
> -
> -          (* Skip files without specific extensions. *)
> -          if extension <> "cat" && extension
<> "inf" &&
> -               extension <> "pdb" && extension
<> "sys" then
> -            raise Not_found;
> -
> -          (* Using the full path, work out what version of Windows
> -           * this driver is for.  Paths can be things like:
> -           * "NetKVM/2k12R2/amd64/netkvm.sys" or
> -           * "./drivers/amd64/Win2012R2/netkvm.sys".
> -           * Note we check lowercase paths.
> -           *)
> -          let pathelem elem = string_find lc_path ("/" ^ elem ^
"/") >= 0 in
> -          let arch > -            if pathelem "x86" ||
pathelem "i386" then "i386"
> -            else if pathelem "amd64" then "x86_64"
> -            else raise Not_found in
> -          let os_major, os_minor, os_variant > -            if pathelem
"xp" || pathelem "winxp" then
> -              (5, 1, Vwd_any_variant)
> -            else if pathelem "2k3" || pathelem
"win2003" then
> -              (5, 2, Vwd_any_variant)
> -            else if pathelem "vista" then
> -              (6, 0, Vwd_client)
> -            else if pathelem "2k8" || pathelem
"win2008" then
> -              (6, 0, Vwd_not_client)
> -            else if pathelem "w7" || pathelem "win7"
then
> -              (6, 1, Vwd_client)
> -            else if pathelem "2k8r2" || pathelem
"win2008r2" then
> -              (6, 1, Vwd_not_client)
> -            else if pathelem "w8" || pathelem "win8"
then
> -              (6, 2, Vwd_client)
> -            else if pathelem "2k12" || pathelem
"win2012" then
> -              (6, 2, Vwd_not_client)
> -            else if pathelem "w8.1" || pathelem
"win8.1" then
> -              (6, 3, Vwd_client)
> -            else if pathelem "2k12r2" || pathelem
"win2012r2" then
> -              (6, 3, Vwd_not_client)
> -            else if pathelem "w10" || pathelem "win10"
then
> -              (10, 0, Vwd_client)
> -            else
> -              raise Not_found in
> -
> -          Some {
> -            vwd_filename = lc_basename;
> -            vwd_get_contents = get_contents;
> -            vwd_os_major = os_major;
> -            vwd_os_minor = os_minor;
> -            vwd_os_variant = os_variant;
> -            vwd_os_arch = arch;
> -            vwd_extension = extension;
> -            vwd_original_source = original_source;
> -          }
> -
> -        with Not_found -> None
> -    ) files in
> -
> -  files
> +(* Given a path of a file relative to the root of the directory tree with
> + * virtio-win drivers, figure out if it's suitable for the specific
Windows
> + * flavor.
> + *)
> +let match_vio_path_with_os path arch os_major os_minor os_variant > + 
try
> +    (* Lowercased path, since the ISO may contain upper or lowercase path
> +     * elements.  XXX This won't work if paths contain non-ASCII.
> +     *)
> +    let lc_path = String.lowercase path in
> +    let lc_basename = Filename.basename path in
> +
> +    let extension > +      match last_part_of lc_basename '.'
with
> +      | Some x -> x
> +      | None -> raise Not_found
> +    in
> +
> +    (* Skip files without specific extensions. *)
> +    let extensions = ["cat"; "inf"; "pdb";
"sys"] in
> +    if (not (List.mem extension extensions)) then raise Not_found;
> +
> +    (* Using the full path, work out what version of Windows
> +     * this driver is for.  Paths can be things like:
> +     * "NetKVM/2k12R2/amd64/netkvm.sys" or
> +     * "./drivers/amd64/Win2012R2/netkvm.sys".
> +     * Note we check lowercase paths.
> +     *)
> +    let pathelem elem = string_find lc_path ("/" ^ elem ^
"/") >= 0 in
> +    let p_arch > +      if pathelem "x86" || pathelem
"i386" then "i386"
> +      else if pathelem "amd64" then "x86_64"
> +      else raise Not_found in
> +
> +    let is_client os_variant = os_variant = "Client"
> +    and not_client os_variant = os_variant <> "Client"
> +    and any_variant os_variant = true in
> +    let p_os_major, p_os_minor, match_os_variant > +      if pathelem
"xp" || pathelem "winxp" then
> +        (5, 1, any_variant)
> +      else if pathelem "2k3" || pathelem "win2003"
then
> +        (5, 2, any_variant)
> +      else if pathelem "vista" then
> +        (6, 0, is_client)
> +      else if pathelem "2k8" || pathelem "win2008"
then
> +        (6, 0, not_client)
> +      else if pathelem "w7" || pathelem "win7" then
> +        (6, 1, is_client)
> +      else if pathelem "2k8r2" || pathelem "win2008r2"
then
> +        (6, 1, not_client)
> +      else if pathelem "w8" || pathelem "win8" then
> +        (6, 2, is_client)
> +      else if pathelem "2k12" || pathelem "win2012"
then
> +        (6, 2, not_client)
> +      else if pathelem "w8.1" || pathelem "win8.1"
then
> +        (6, 3, is_client)
> +      else if pathelem "2k12r2" || pathelem
"win2012r2" then
> +        (6, 3, not_client)
> +      else if pathelem "w10" || pathelem "win10" then
> +        (10, 0, is_client)
> +      else
> +        raise Not_found in
> +
> +    arch = p_arch && os_major = p_os_major && os_minor =
p_os_minor &&
> +      match_os_variant os_variant
> +
> +  with Not_found -> false
>  
>  let compare_app2_versions app1 app2 >    let i = compare
app1.Guestfs.app2_epoch app2.Guestfs.app2_epoch in
And this looks good too.  It's basically just a code move.

Difficult patch to follow, even with -w (not your fault of course - if
only we had better tools!)

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

On Mon, Aug 10, 2015 at 06:55:28PM +0300, Roman Kagan
wrote:
> Libguestfs supports passing an ISO image as a source of virtio windows
> drivers to v2v.
> 
> That support, however, looks too heavy-weight: in order to access those
> drivers, a separate guestfs handle is created (and thus a new emulator
> process is started), which runs until v2v completes.
> 
> This series attempts to make it simpler and lighter-weight, by making
> the relevant code more local, and by hot-adding the image into the main
> guestfs handle.
> 
> Roman Kagan (4):
>   v2v: drop useless forced gc
>   v2v: consolidate virtio-win file copying
>   v2v: copy virtio drivers without guestfs handle leak
>   v2v: reuse main guestfs for virtio win drivers iso
> 
>  v2v/convert_windows.ml | 184 ++++++++++++++++++++--------------------
>  v2v/utils.ml           | 224
++++++++++++++++---------------------------------
>  v2v/v2v.ml             |   8 --
>  3 files changed, 163 insertions(+), 253 deletions(-)
I just realized that, although (at least two of) these patches got
"likely ACK", they are not in the libguestfs tree.

The patches still apply to master as of today.

Is there anything I can do to get them merged?

Thanks,
Roman.

On Thu, Oct 01, 2015 at 06:04:03PM +0300, Roman Kagan
wrote:
> On Mon, Aug 10, 2015 at 06:55:28PM +0300, Roman Kagan wrote:
> > Libguestfs supports passing an ISO image as a source of virtio windows
> > drivers to v2v.
> > 
> > That support, however, looks too heavy-weight: in order to access
those
> > drivers, a separate guestfs handle is created (and thus a new emulator
> > process is started), which runs until v2v completes.
> > 
> > This series attempts to make it simpler and lighter-weight, by making
> > the relevant code more local, and by hot-adding the image into the
main
> > guestfs handle.
> > 
> > Roman Kagan (4):
> >   v2v: drop useless forced gc
> >   v2v: consolidate virtio-win file copying
> >   v2v: copy virtio drivers without guestfs handle leak
> >   v2v: reuse main guestfs for virtio win drivers iso
> > 
> >  v2v/convert_windows.ml | 184 ++++++++++++++++++++--------------------
> >  v2v/utils.ml           | 224
++++++++++++++++---------------------------------
> >  v2v/v2v.ml             |   8 --
> >  3 files changed, 163 insertions(+), 253 deletions(-)
> 
> I just realized that, although (at least two of) these patches got
> "likely ACK", they are not in the libguestfs tree.
> 
> The patches still apply to master as of today.
> 
> Is there anything I can do to get them merged?
What happened was I wanted to look at why the inner handle never got
GC'd.  And I did have a look at that, couldn't work out for the life
of me why, and gave up.

I'm going to look at the two patches again, so give me a bit.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v

On Thu, Oct 01, 2015 at 06:04:03PM +0300, Roman Kagan
wrote:
> On Mon, Aug 10, 2015 at 06:55:28PM +0300, Roman Kagan wrote:
> > Libguestfs supports passing an ISO image as a source of virtio windows
> > drivers to v2v.
> > 
> > That support, however, looks too heavy-weight: in order to access
those
> > drivers, a separate guestfs handle is created (and thus a new emulator
> > process is started), which runs until v2v completes.
> > 
> > This series attempts to make it simpler and lighter-weight, by making
> > the relevant code more local, and by hot-adding the image into the
main
> > guestfs handle.
> > 
> > Roman Kagan (4):
> >   v2v: drop useless forced gc
> >   v2v: consolidate virtio-win file copying
> >   v2v: copy virtio drivers without guestfs handle leak
> >   v2v: reuse main guestfs for virtio win drivers iso
> > 
> >  v2v/convert_windows.ml | 184 ++++++++++++++++++++--------------------
> >  v2v/utils.ml           | 224
++++++++++++++++---------------------------------
> >  v2v/v2v.ml             |   8 --
> >  3 files changed, 163 insertions(+), 253 deletions(-)
> 
> I just realized that, although (at least two of) these patches got
> "likely ACK", they are not in the libguestfs tree.
> 
> The patches still apply to master as of today.
> 
> Is there anything I can do to get them merged?
Actually better to post them again so I can review them again.

I spotted a few problems

- There's a missing pair of parentheses around the then clause in:

         g2#mount_ro "/dev/sda" vio_root;
         let paths = g2#find vio_root in
         Array.iter (
           fun path ->
             let source = vio_root // path in
             if ((g2#is_file source ~followsymlinks:false) &&
                 (match_vio_path_with_os path inspect.i_arch
                     inspect.i_major_version inspect.i_minor_version
                     inspect.i_product_variant)) then
                                                     ^^^

  which makes me think this code can't possibly work.

- Calling String.lowercase is unsafe (because the function is just
  broken in OCaml) and unnecessary.  Just remove it.

- (Stylistic) You don't need parentheses around if conditionals.

- (Stylistic) You don't need parentheses around the arguments of &&

- (Stylistic) You don't need parentheses around the arguments of //

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://libguestfs.org

Libguestfs supports passing an ISO image as a source of virtio windows
drivers to v2v.

That support, however, looks too heavy-weight: in order to access those
drivers, a separate guestfs handle is created (and thus a new emulator
process is started), which runs until v2v triggers garbage collection.

This series attempts to make it simpler and lighter-weight, by making
the relevant code more local, and by hot-adding the image into the main
guestfs handle if supported by the backend.

Roman Kagan (4):
  v2v: consolidate virtio-win file copying
  v2v: copy virtio drivers without guestfs handle leak
  v2v: drop useless forced gc
  v2v: reuse main guestfs for virtio win drivers iso

---
changes since v1:
 - rebased to latest master (in particular, updated usage of string
   functions)
 - add missing and remove excessive parentheses
 - reorder patches
 - preserve support for backends with no hot-add capability

 v2v/convert_windows.ml | 206 ++++++++++++++++++++++++++---------------------
 v2v/utils.ml           | 212 +++++++++++++++----------------------------------
 v2v/v2v.ml             |   8 --
 3 files changed, 179 insertions(+), 247 deletions(-)

-- 
2.4.3

Copy the appropriate driver files from the virtio-win storage into
%SYSTEMROOT%\Drivers\VirtIO once they are discovered, and stick to using
those copies later on.

This way the knowledge of where the drivers come from originally is
consolidated in one place, so the lifetime of the associated entities
becomes easier to control (to be implemented in followup patches).

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
changes since v1:
 - former patch #2

 v2v/convert_windows.ml | 128 ++++++++++++++++++++++---------------------------
 1 file changed, 56 insertions(+), 72 deletions(-)

diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
index d1aef36..55213aa 100644
--- a/v2v/convert_windows.ml
+++ b/v2v/convert_windows.ml
@@ -271,12 +271,9 @@ echo uninstalling Xen PV driver
     with
       Not_found -> ()
 
-  and install_virtio_drivers root current_cs -    (* Copy the virtio drivers to
the guest. *)
-    let driverdir = sprintf "%s/Drivers/VirtIO" systemroot in
-    g#mkdir_p driverdir;
+  and copy_virtio_drivers driverdir +    (* Copy the matching drivers to the
driverdir. *)
 
-    (* Load the list of drivers available. *)
     let drivers = find_virtio_win_drivers virtio_win in
 
     (* Filter out only drivers matching the current guest. *)
@@ -300,73 +297,60 @@ echo uninstalling Xen PV driver
       flush stdout
     );
 
-    match drivers with
-    | [] ->
-       warning (f_"there are no virtio drivers available for this version
of Windows (%d.%d %s %s).  virt-v2v looks for drivers in %s\n\nThe guest will be
configured to use slower emulated devices.")
-               inspect.i_major_version inspect.i_minor_version
-               inspect.i_arch inspect.i_product_variant
-               virtio_win;
-       ( IDE, RTL8139, Cirrus )
-
-    | drivers ->
-       (* Can we install the block driver? *)
-       let block : guestcaps_block_type -         try
-           let viostor_sys_file -             List.find
-               (fun { vwd_filename = filename } -> filename =
"viostor.sys")
-               drivers in
-           (* Get the actual file contents of the .sys file. *)
-           let content = viostor_sys_file.vwd_get_contents () in
-           let target = sprintf "%s/system32/drivers/viostor.sys"
systemroot in
-           let target = g#case_sensitive_path target in
-           g#write target content;
-           add_viostor_to_critical_device_database root current_cs;
-           Virtio_blk
-         with Not_found ->
-           warning (f_"there is no viostor (virtio block device) driver
for this version of Windows (%d.%d %s).  virt-v2v looks for this driver in
%s\n\nThe guest will be configured to use a slower emulated device.")
-                   inspect.i_major_version inspect.i_minor_version
-                   inspect.i_arch virtio_win;
-           IDE in
-
-       (* Can we install the virtio-net driver? *)
-       let net : guestcaps_net_type -         if not (List.exists
-                   (fun { vwd_filename = filename } -> filename =
"netkvm.inf")
-                   drivers) then (
-           warning (f_"there is no virtio network driver for this version
of Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will
be configured to use a slower emulated device.")
-                   inspect.i_major_version inspect.i_minor_version
-                   inspect.i_arch virtio_win;
-           RTL8139
-         )
-         else
-           (* It will be installed at firstboot. *)
-           Virtio_net in
-
-       (* Can we install the QXL driver? *)
-       let video : guestcaps_video_type -         if not (List.exists
-                   (fun { vwd_filename = filename } -> filename =
"qxl.inf")
-                   drivers) then (
-           warning (f_"there is no QXL driver for this version of Windows
(%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will be
configured to use standard VGA.")
-                   inspect.i_major_version inspect.i_minor_version
-                   inspect.i_arch virtio_win;
-           Cirrus
-         )
-         else
-           (* It will be installed at firstboot. *)
-           QXL in
-
-       (* Copy all the drivers to the driverdir.  They will be
-        * installed at firstboot.
-        *)
-       List.iter (
-         fun driver ->
-           let content = driver.vwd_get_contents () in
-           g#write (driverdir // driver.vwd_filename) content
-       ) drivers;
-
-       (block, net, video)
+    List.iter (
+      fun driver ->
+        let content = driver.vwd_get_contents () in
+        g#write (driverdir // driver.vwd_filename) content
+    ) drivers
+
+  and install_virtio_drivers root current_cs +    (* Copy the virtio drivers to
the guest. *)
+    let driverdir = sprintf "%s/Drivers/VirtIO" systemroot in
+    g#mkdir_p driverdir;
+
+    copy_virtio_drivers driverdir;
+
+    (* Can we install the block driver? *)
+    let block : guestcaps_block_type +      let source = driverdir //
"viostor.sys" in
+      if (g#exists source) then (
+        let target = sprintf "%s/system32/drivers/viostor.sys"
systemroot in
+        let target = g#case_sensitive_path target in
+        g#cp source target;
+        add_viostor_to_critical_device_database root current_cs;
+        Virtio_blk
+      ) else (
+        warning (f_"there is no viostor (virtio block device) driver for
this version of Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe
guest will be configured to use a slower emulated device.")
+                inspect.i_major_version inspect.i_minor_version
+                inspect.i_arch virtio_win;
+        IDE
+      ) in
+
+    (* Can we install the virtio-net driver? *)
+    let net : guestcaps_net_type +      if not (g#exists (driverdir //
"netkvm.inf")) then (
+        warning (f_"there is no virtio network driver for this version of
Windows (%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will be
configured to use a slower emulated device.")
+                inspect.i_major_version inspect.i_minor_version
+                inspect.i_arch virtio_win;
+        RTL8139
+      )
+      else
+        (* It will be installed at firstboot. *)
+        Virtio_net in
+
+    (* Can we install the QXL driver? *)
+    let video : guestcaps_video_type +      if not (g#exists (driverdir //
"qxl.inf")) then (
+        warning (f_"there is no QXL driver for this version of Windows
(%d.%d %s).  virt-v2v looks for this driver in %s\n\nThe guest will be
configured to use standard VGA.")
+                inspect.i_major_version inspect.i_minor_version
+                inspect.i_arch virtio_win;
+        Cirrus
+      )
+      else
+        (* It will be installed at firstboot. *)
+        QXL in
+
+    (block, net, video)
 
   and add_viostor_to_critical_device_database root current_cs      let {
i_major_version = major; i_minor_version = minor;
-- 
2.4.3

Refactor copying of virtio windows drivers into the guest so that the
matching of the drivers to the guest os flavor and copying the files
happens one next to the other in a single function, and no guestfs
handle (nor any other irrelevant info) is leaked outside.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
changes since v1:
 - former patch #3
 - updated usage of string functions

 v2v/convert_windows.ml |  78 +++++++++++-------
 v2v/utils.ml           | 212 +++++++++++++++----------------------------------
 2 files changed, 113 insertions(+), 177 deletions(-)

diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
index 55213aa..cfa5474 100644
--- a/v2v/convert_windows.ml
+++ b/v2v/convert_windows.ml
@@ -273,35 +273,55 @@ echo uninstalling Xen PV driver
 
   and copy_virtio_drivers driverdir      (* Copy the matching drivers to the
driverdir. *)
-
-    let drivers = find_virtio_win_drivers virtio_win in
-
-    (* Filter out only drivers matching the current guest. *)
-    let drivers -      List.filter (
-        fun { vwd_os_arch = arch;
-              vwd_os_major = os_major; vwd_os_minor = os_minor;
-              vwd_os_variant = os_variant } ->
-        arch = inspect.i_arch &&
-        os_major = inspect.i_major_version &&
-        os_minor = inspect.i_minor_version &&
-        (match os_variant with
-         | Vwd_client -> inspect.i_product_variant = "Client"
-         | Vwd_not_client -> inspect.i_product_variant <>
"Client"
-         | Vwd_any_variant -> true)
-      ) drivers in
-
-    if verbose () then (
-      printf "virtio-win driver files matching this guest:\n";
-      List.iter print_virtio_win_driver_file drivers;
-      flush stdout
-    );
-
-    List.iter (
-      fun driver ->
-        let content = driver.vwd_get_contents () in
-        g#write (driverdir // driver.vwd_filename) content
-    ) drivers
+    if is_directory virtio_win then (
+      let cmd = sprintf "cd %s && find -type f" (quote
virtio_win) in
+      let paths = external_command cmd in
+      List.iter (
+        fun path ->
+          if (match_vio_path_with_os path inspect.i_arch
+              inspect.i_major_version inspect.i_minor_version
+              inspect.i_product_variant) then (
+            let source = virtio_win // path in
+            let target = driverdir // (String.lowercase_ascii
+                                        (Filename.basename path)) in
+            if verbose () then
+              printf "Copying virtio driver bits: 'host:%s' ->
'%s'\n"
+                source target;
+
+            g#write target (read_whole_file source)
+          )
+      ) paths
+    )
+    else if is_regular_file virtio_win then (
+      try
+        let g2 = new Guestfs.guestfs () in
+        if trace () then g2#set_trace true;
+        if verbose () then g2#set_verbose true;
+        g2#add_drive_opts virtio_win ~readonly:true;
+        g2#launch ();
+        let vio_root = "/" in
+        g2#mount_ro "/dev/sda" vio_root;
+        let paths = g2#find vio_root in
+        Array.iter (
+          fun path ->
+            let source = vio_root // path in
+            if (g2#is_file source ~followsymlinks:false) &&
+               (match_vio_path_with_os path inspect.i_arch
+                inspect.i_major_version inspect.i_minor_version
+                inspect.i_product_variant) then (
+              let target = driverdir // (String.lowercase_ascii
+                                          (Filename.basename path)) in
+              if verbose () then
+                printf "Copying virtio driver bits: '%s:%s' ->
'%s'\n"
+                  virtio_win path target;
+
+              g#write target (g2#read_file source)
+            )
+        ) paths;
+        g2#close()
+      with Guestfs.Error msg ->
+        error (f_"%s: cannot open virtio-win ISO file: %s")
virtio_win msg
+    )
 
   and install_virtio_drivers root current_cs      (* Copy the virtio drivers to
the guest. *)
diff --git a/v2v/utils.ml b/v2v/utils.ml
index 2998d90..3d0bec8 100644
--- a/v2v/utils.ml
+++ b/v2v/utils.ml
@@ -159,161 +159,77 @@ let find_uefi_firmware guest_arch    in
   loop files
 
-(* Find virtio-win driver files from an unpacked or mounted virtio-win
- * directory, or from a virtio-win.iso file. The location of drivers
-  varies between releases of virtio-win and also across Fedora and
-  RHEL so try to be robust to changes.
- *)
-type virtio_win_driver_file = {
-  (* Base filename, eg. "netkvm.sys".  Always lowercase. *)
-  vwd_filename : string;
-  (* Return the contents of this file. *)
-  vwd_get_contents : unit -> string;
-
-  (* Various fields that classify this driver: *)
-
-  vwd_os_major : int;           (* Windows version. *)
-  vwd_os_minor : int;
-  vwd_os_variant : vwd_os_variant;
-  vwd_os_arch : string;         (* Architecture, eg "i386",
"x86_64". *)
-  vwd_extension : string;       (* File extension (lowercase), eg.
"sys" "inf"*)
+let is_regular_file path = (* NB: follows symlinks. *)
+  try (Unix.stat path).Unix.st_kind = Unix.S_REG
+  with Unix.Unix_error _ -> false
 
-  (* Original source of file (for debugging only). *)
-  vwd_original_source : string;
-}
-and vwd_os_variant = Vwd_client | Vwd_not_client | Vwd_any_variant
-
-let print_virtio_win_driver_file vwd -  printf "%s [%d,%d,%s,%s,%s] from
%s\n"
-         vwd.vwd_filename
-         vwd.vwd_os_major vwd.vwd_os_minor
-         (match vwd.vwd_os_variant with
-          | Vwd_client -> "client" | Vwd_not_client ->
"not-client"
-          | Vwd_any_variant -> "any")
-         vwd.vwd_os_arch
-         vwd.vwd_extension
-         vwd.vwd_original_source
-
-let find_virtio_win_drivers virtio_win -  let is_regular_file path = (* NB:
follows symlinks. *)
-    try (Unix.stat path).Unix.st_kind = Unix.S_REG
-    with Unix.Unix_error _ -> false
-  in
-
-  let files -    if is_directory virtio_win then (
-      let cmd = sprintf "cd %s && find -type f" (quote
virtio_win) in
-      let paths = external_command cmd in
-      List.map (
-        fun path ->
-          let abs_path = virtio_win // path in
-          (path, abs_path,
-           Filename.basename path,
-           fun () -> read_whole_file abs_path)
-      ) paths
-    )
-    else if is_regular_file virtio_win then (
-      try
-        let g = new Guestfs.guestfs () in
-        g#set_identifier "virtio_win";
-        if trace () then g#set_trace true;
-        if verbose () then g#set_verbose true;
-        g#add_drive_opts virtio_win ~readonly:true;
-        g#launch ();
-        g#mount_ro "/dev/sda" "/";
-        let paths = g#find "/" in
-        let paths = Array.to_list paths in
-        let paths = List.map ((^) "/") paths in
-        let paths = List.filter (g#is_file ~followsymlinks:false) paths in
-        List.map (
-          fun path ->
-            let basename -              match last_part_of path '/'
with
-              | Some x -> x
-              | None ->
-                error "v2v/find_virtio_win_drivers: missing '/' in
%s" path in
-            (path, sprintf "%s:%s" virtio_win path,
-             basename,
-             fun () -> g#read_file path)
-        ) paths
-      with Guestfs.Error msg ->
-        error (f_"%s: cannot open virtio-win ISO file: %s")
virtio_win msg
-    )
-    else [] in
-
-  let files -    filter_map (
-      fun (path, original_source, basename, get_contents) ->
-        try
-          (* Lowercased path, since the ISO may contain upper or lowercase
-           * path elements.
-           *)
-          let lc_path = String.lowercase_ascii path in
-          let lc_basename = String.lowercase_ascii basename in
+(* Given a path of a file relative to the root of the directory tree with
+ * virtio-win drivers, figure out if it's suitable for the specific Windows
+ * flavor.
+ *)
+let match_vio_path_with_os path arch os_major os_minor os_variant +  try
+    (* Lowercased path, since the ISO may contain upper or lowercase path
+     * elements.
+     *)
+    let lc_path = String.lowercase_ascii path in
+    let lc_basename = Filename.basename path in
 
-          let extension -            match last_part_of lc_basename '.'
with
-            | Some x -> x
-            | None -> raise Not_found
-          in
+    let extension +      match last_part_of lc_basename '.' with
+      | Some x -> x
+      | None -> raise Not_found
+    in
 
-          (* Skip files without specific extensions. *)
-          if extension <> "cat" && extension <>
"inf" &&
-               extension <> "pdb" && extension <>
"sys" then
-            raise Not_found;
+    (* Skip files without specific extensions. *)
+    let extensions = ["cat"; "inf"; "pdb";
"sys"] in
+    if (not (List.mem extension extensions)) then raise Not_found;
 
-          (* Using the full path, work out what version of Windows
-           * this driver is for.  Paths can be things like:
-           * "NetKVM/2k12R2/amd64/netkvm.sys" or
-           * "./drivers/amd64/Win2012R2/netkvm.sys".
-           * Note we check lowercase paths.
-           *)
-          let pathelem elem = String.find lc_path ("/" ^ elem ^
"/") >= 0 in
-          let arch -            if pathelem "x86" || pathelem
"i386" then "i386"
-            else if pathelem "amd64" then "x86_64"
-            else raise Not_found in
-          let os_major, os_minor, os_variant -            if pathelem
"xp" || pathelem "winxp" then
-              (5, 1, Vwd_any_variant)
-            else if pathelem "2k3" || pathelem "win2003"
then
-              (5, 2, Vwd_any_variant)
-            else if pathelem "vista" then
-              (6, 0, Vwd_client)
-            else if pathelem "2k8" || pathelem "win2008"
then
-              (6, 0, Vwd_not_client)
-            else if pathelem "w7" || pathelem "win7" then
-              (6, 1, Vwd_client)
-            else if pathelem "2k8r2" || pathelem
"win2008r2" then
-              (6, 1, Vwd_not_client)
-            else if pathelem "w8" || pathelem "win8" then
-              (6, 2, Vwd_client)
-            else if pathelem "2k12" || pathelem "win2012"
then
-              (6, 2, Vwd_not_client)
-            else if pathelem "w8.1" || pathelem "win8.1"
then
-              (6, 3, Vwd_client)
-            else if pathelem "2k12r2" || pathelem
"win2012r2" then
-              (6, 3, Vwd_not_client)
-            else if pathelem "w10" || pathelem "win10" then
-              (10, 0, Vwd_client)
-            else
-              raise Not_found in
+    (* Using the full path, work out what version of Windows
+     * this driver is for.  Paths can be things like:
+     * "NetKVM/2k12R2/amd64/netkvm.sys" or
+     * "./drivers/amd64/Win2012R2/netkvm.sys".
+     * Note we check lowercase paths.
+     *)
+    let pathelem elem = String.find lc_path ("/" ^ elem ^
"/") >= 0 in
+    let p_arch +      if pathelem "x86" || pathelem "i386"
then "i386"
+      else if pathelem "amd64" then "x86_64"
+      else raise Not_found in
 
-          Some {
-            vwd_filename = lc_basename;
-            vwd_get_contents = get_contents;
-            vwd_os_major = os_major;
-            vwd_os_minor = os_minor;
-            vwd_os_variant = os_variant;
-            vwd_os_arch = arch;
-            vwd_extension = extension;
-            vwd_original_source = original_source;
-          }
+    let is_client os_variant = os_variant = "Client"
+    and not_client os_variant = os_variant <> "Client"
+    and any_variant os_variant = true in
+    let p_os_major, p_os_minor, match_os_variant +      if pathelem
"xp" || pathelem "winxp" then
+        (5, 1, any_variant)
+      else if pathelem "2k3" || pathelem "win2003" then
+        (5, 2, any_variant)
+      else if pathelem "vista" then
+        (6, 0, is_client)
+      else if pathelem "2k8" || pathelem "win2008" then
+        (6, 0, not_client)
+      else if pathelem "w7" || pathelem "win7" then
+        (6, 1, is_client)
+      else if pathelem "2k8r2" || pathelem "win2008r2" then
+        (6, 1, not_client)
+      else if pathelem "w8" || pathelem "win8" then
+        (6, 2, is_client)
+      else if pathelem "2k12" || pathelem "win2012" then
+        (6, 2, not_client)
+      else if pathelem "w8.1" || pathelem "win8.1" then
+        (6, 3, is_client)
+      else if pathelem "2k12r2" || pathelem "win2012r2"
then
+        (6, 3, not_client)
+      else if pathelem "w10" || pathelem "win10" then
+        (10, 0, is_client)
+      else
+        raise Not_found in
 
-        with Not_found -> None
-    ) files in
+    arch = p_arch && os_major = p_os_major && os_minor =
p_os_minor &&
+      match_os_variant os_variant
 
-  files
+  with Not_found -> false
 
 let compare_app2_versions app1 app2    let i = compare app1.Guestfs.app2_epoch
app2.Guestfs.app2_epoch in
-- 
2.4.3

Now that virtio driver copying is localized in a single function and the
auxiliary guestfs handle doesn't leak outside of it (and thus an extra
qemu instance doesn't survive beyond that function's runtime)
there's no
need in the forced GC which used to trigger closing of that handle and
termination of that qemu instance.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
changes since v1:
 - former patch #1

 v2v/v2v.ml | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/v2v/v2v.ml b/v2v/v2v.ml
index 4d621b8..fe16131 100644
--- a/v2v/v2v.ml
+++ b/v2v/v2v.ml
@@ -319,14 +319,6 @@ let rec main ()    if verbose () then
     printf "%s%!" (string_of_target_buses target_buses);
 
-  (* Force a GC here, to ensure that we're using the minimum resources
-   * as we go into the copy stage.  The particular reason is that
-   * Windows conversion may have opened a second libguestfs handle
-   * pointing to the virtio-win ISO, which is only closed when the
-   * handle is GC'd.
-   *)
-  Gc.compact ();
-
   let delete_target_on_exit = ref true in
 
   let targets -- 
2.4.3

If we're given an ISO image as the source of virtio windows drivers, and
the backend supports hot-adding drives, reuse the same guestfs handle
that is open for accessing the guest being inspected, rather than
creating a new one (which would run another virtual machine instance and
is fairly resource-intensive).

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
changes since v1:
 - updated usage of string functions
 - add missing and remove excessive parentheses
 - preserve support for backends with no hot-add capability

 v2v/convert_windows.ml | 38 +++++++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
index cfa5474..5fd8bb6 100644
--- a/v2v/convert_windows.ml
+++ b/v2v/convert_windows.ml
@@ -294,13 +294,25 @@ echo uninstalling Xen PV driver
     )
     else if is_regular_file virtio_win then (
       try
-        let g2 = new Guestfs.guestfs () in
-        if trace () then g2#set_trace true;
-        if verbose () then g2#set_verbose true;
-        g2#add_drive_opts virtio_win ~readonly:true;
-        g2#launch ();
-        let vio_root = "/" in
-        g2#mount_ro "/dev/sda" vio_root;
+        let label = "viowin" in
+        let vio_root = "/virtio-win-iso" in
+        let g2 +          (* not all backends support hot-adding drives; create
an extra
+           * guestfs handle in that case *)
+          try
+            g#add_drive_opts virtio_win ~readonly:true ~label:label;
+            g
+          with Guestfs.Error msg -> (
+            let g2 = new Guestfs.guestfs () in
+            if trace () then g2#set_trace true;
+            if verbose () then g2#set_verbose true;
+            g2#add_drive_opts virtio_win ~readonly:true ~label:label;
+            g2#launch ();
+            g2
+          ) in
+
+        g2#mkmountpoint vio_root;
+        g2#mount_ro ("/dev/disk/guestfs" // label) vio_root;
         let paths = g2#find vio_root in
         Array.iter (
           fun path ->
@@ -315,10 +327,18 @@ echo uninstalling Xen PV driver
                 printf "Copying virtio driver bits: '%s:%s' ->
'%s'\n"
                   virtio_win path target;
 
-              g#write target (g2#read_file source)
+              if (g2 == g) then
+                g#cp source target
+              else
+                g#write target (g2#read_file source)
             )
         ) paths;
-        g2#close()
+        g2#umount vio_root;
+        g2#rmmountpoint vio_root;
+        if (g2 == g) then
+          g2#remove_drive label
+        else
+          g2#close()
       with Guestfs.Error msg ->
         error (f_"%s: cannot open virtio-win ISO file: %s")
virtio_win msg
     )
-- 
2.4.3

Libguestfs supports passing an ISO image as a source of virtio windows
drivers to v2v.

This series attempts to make it simpler and better scoped.

Roman Kagan (3):
  v2v: consolidate virtio-win file copying
  v2v: copy virtio drivers without guestfs handle leak
  v2v: drop useless forced gc

---
changes since v2:
 - drop patch 4 (reuse of the master guestfs handle for hot-adding the
   ISO image)
 - more excessive parentheses removed
 - revert the removal of a warning when no virtio drivers matching the
   guest OS are found
 - revert the undesired removal of guestfs handle identifier assignment

changes since v1:
 - rebased to latest master (in particular, updated usage of string
   functions)
 - add missing and remove excessive parentheses
 - reorder patches
 - preserve support for backends with no hot-add capability

 v2v/convert_windows.ml | 192 +++++++++++++++++++++++---------------------
 v2v/utils.ml           | 213 +++++++++++++++----------------------------------
 v2v/v2v.ml             |   8 --
 3 files changed, 167 insertions(+), 246 deletions(-)

-- 
2.4.3