This option allows oVirt to pass a prebuilt qcow2 file to use as the temporary overlay. The file must be qcow2, and must have indisk as a backing file - the code does minimal checks to ensure this is correct. Example usage: qemu-img create -f qcow2 -b indisk overlay.qcow2 virt-sparsify indisk --tmp prebuilt:overlay.qcow2 outdisk Note this only applies in copying mode. --- sparsify/cmdline.ml | 2 +- sparsify/copying.ml | 54 ++++++++++++++++++++++++++++++++-------------- sparsify/virt-sparsify.pod | 27 +++++++++++++++++++++++ 3 files changed, 66 insertions(+), 17 deletions(-) diff --git a/sparsify/cmdline.ml b/sparsify/cmdline.ml index 11e5895..a99c851 100644 --- a/sparsify/cmdline.ml +++ b/sparsify/cmdline.ml @@ -80,7 +80,7 @@ let parse_cmdline () = "-o", Arg.Set_string option, s_"option" ^ " " ^ s_"Add qemu-img options"; "-q", Arg.Set quiet, " " ^ s_"Quiet output"; "--quiet", Arg.Set quiet, ditto; - "--tmp", Arg.Set_string tmp, s_"block|dir" ^ " " ^ s_"Set temporary block device or directory"; + "--tmp", Arg.Set_string tmp, s_"block|dir|prebuilt:file" ^ " " ^ s_"Set temporary block device, directory or prebuilt file"; "-v", Arg.Set verbose, " " ^ s_"Enable debugging messages"; "--verbose", Arg.Set verbose, ditto; "-V", Arg.Unit display_version, " " ^ s_"Display version and exit"; diff --git a/sparsify/copying.ml b/sparsify/copying.ml index 5afb22f..b167b0c 100644 --- a/sparsify/copying.ml +++ b/sparsify/copying.ml @@ -33,7 +33,8 @@ open Cmdline external statvfs_free_space : string -> int64 = "virt_sparsify_statvfs_free_space" -type tmp_place = Directory of string | Block_device of string +type tmp_place = +| Directory of string | Block_device of string | Prebuilt_file of string let run indisk outdisk check_tmpdir compress convert format ignores machine_readable option tmp_param @@ -74,12 +75,26 @@ let run indisk outdisk check_tmpdir compress convert | None -> Directory Filename.temp_dir_name (* $TMPDIR or /tmp *) | Some dir when is_directory dir -> Directory dir | Some dev when is_block_device dev -> Block_device dev + | Some file when string_prefix file "prebuilt:" -> + let file = String.sub file 9 (String.length file - 9) in + if not (Sys.file_exists file) then + error (f_"--tmp prebuilt:file: %s: file does not exist") file; + let g = new G.guestfs () in + if trace then g#set_trace true; + if verbose then g#set_verbose true; + if g#disk_format file <> "qcow2" then + error (f_"--tmp prebuilt:file: %s: file format is not qcow2") file; + if not (g#disk_has_backing_file file) then + error (f_"--tmp prebuilt:file: %s: file does not have backing file") + file; + Prebuilt_file file | Some path -> - error (f_"--tmp parameter must point to a directory or a block device") in + error (f_"--tmp parameter must point to a directory, block device or prebuilt file") in (* Check there is enough space in temporary directory. *) (match tmp_place with - | Block_device _ -> () + | Block_device _ + | Prebuilt_file _ -> () | Directory tmpdir -> (* Get virtual size of the input disk. *) let virtual_size = (new G.guestfs ())#disk_virtual_size indisk in @@ -136,31 +151,38 @@ You can ignore this warning or change it to a hard failure using the | Block_device device -> printf (f_"Create overlay device %s to protect source disk ...\n%!") device + | Prebuilt_file file -> + printf (f_"Using prebuilt file %s as overlay ...\n%!") file ); - let tmp = - match tmp_place with - | Directory temp_dir -> - let tmp = Filename.temp_file ~temp_dir "sparsify" ".qcow2" in - unlink_on_exit tmp; - tmp - - | Block_device device -> device in - - (* Create it with the indisk as the backing file. *) + (* Create 'tmp' with the indisk as the backing file. *) (* XXX Old code used to: * - detect if compat=1.1 was supported * - add lazy_refcounts option *) - let () = + let create tmp = let g = new G.guestfs () in if trace then g#set_trace true; if verbose then g#set_verbose true; g#disk_create ~backingfile:indisk ?backingformat:format ~compat:"1.1" - tmp "qcow2" Int64.minus_one in + tmp "qcow2" Int64.minus_one + in - tmp in + match tmp_place with + | Directory temp_dir -> + let tmp = Filename.temp_file ~temp_dir "sparsify" ".qcow2" in + unlink_on_exit tmp; + create tmp; + tmp + + | Block_device device -> + create device; + device + + | Prebuilt_file file -> + (* Don't create anything, use the prebuilt file as overlay. *) + file in if not quiet then printf (f_"Examine source disk ...\n%!"); diff --git a/sparsify/virt-sparsify.pod b/sparsify/virt-sparsify.pod index bb7dbae..3b6cebd 100644 --- a/sparsify/virt-sparsify.pod +++ b/sparsify/virt-sparsify.pod @@ -262,6 +262,33 @@ L</TMPDIR> environment variable. You cannot use this option and I<--in-place> together. +=item B<--tmp> prebuilt:file + +In copying mode only, the specialized option I<--tmp prebuilt:file> +(where C<prebuilt:> is a literal string) causes virt-sparsify to use +the qcow2 C<file> as temporary space. + +=over 4 + +=item * + +The file B<must> be freshly formatted as qcow2, with indisk as the +backing file. + +=item * + +If you rerun virt-sparsify, you B<must> recreate the file before +each run. + +=item * + +Virt-sparsify does not delete the file. + +=back + +This option is used by oVirt which requires a specially formatted +temporary file. + =item B<-v> =item B<--verbose> -- 1.9.0