Libguestfs - Mar 2016 - [PATCH] mllib: factor out mounting of guest root

Introduce and use a new inspect_mount_root function to mount all the
mountpoints of a root in the guest, replacing the same code doing that
in different tools.

inspect_mount_root_ro is inspect_mount_root with readonly mount option.
---
 builder/builder.ml                   | 10 +---------
 customize/customize_main.ml          |  9 +--------
 get-kernel/get_kernel.ml             |  9 +--------
 mllib/common_utils.ml                | 18 ++++++++++++++++++
 mllib/common_utils.mli               | 11 +++++++++++
 sysprep/main.ml                      | 12 +-----------
 v2v/test-harness/v2v_test_harness.ml |  9 +--------
 7 files changed, 34 insertions(+), 44 deletions(-)

diff --git a/builder/builder.ml b/builder/builder.ml
index 1f9a472..debd7e3 100644
--- a/builder/builder.ml
+++ b/builder/builder.ml
@@ -664,15 +664,7 @@ let main ()    let root      match Array.to_list
(g#inspect_os ()) with
     | [root] ->
-      let mps = g#inspect_get_mountpoints root in
-      let cmp (a,_) (b,_) -        compare (String.length a) (String.length b)
in
-      let mps = List.sort cmp mps in
-      List.iter (
-        fun (mp, dev) ->
-          try g#mount dev mp
-          with G.Error msg -> warning (f_"%s (ignored)") msg
-      ) mps;
+      inspect_mount_root g root;
       root
     | _ ->
       error (f_"no guest operating systems or multiboot OS found in this
disk image\nThis is a failure of the source repository.  Use -v for more
information.")
diff --git a/customize/customize_main.ml b/customize/customize_main.ml
index 13d40bc..55cff2d 100644
--- a/customize/customize_main.ml
+++ b/customize/customize_main.ml
@@ -197,14 +197,7 @@ read the man page virt-customize(1).
         (* Mount up the disks, like guestfish -i.
          * See [ocaml/examples/inspect_vm.ml].
          *)
-        let mps = g#inspect_get_mountpoints root in
-        let cmp (a,_) (b,_) = compare (String.length a) (String.length b) in
-        let mps = List.sort cmp mps in
-        List.iter (
-          fun (mp, dev) ->
-            try g#mount dev mp;
-            with Guestfs.Error msg -> warning (f_"%s (ignored)")
msg
-        ) mps;
+        inspect_mount_root g root;
 
         (* Do the customization. *)
         Customize_run.run g root ops;
diff --git a/get-kernel/get_kernel.ml b/get-kernel/get_kernel.ml
index 6f26ca4..ed88d11 100644
--- a/get-kernel/get_kernel.ml
+++ b/get-kernel/get_kernel.ml
@@ -122,14 +122,7 @@ read the man page virt-get-kernel(1).
 
 let rec do_fetch ~transform_fn ~outputdir g root    (* Mount up the disks. *)
-  let mps = g#inspect_get_mountpoints root in
-  let cmp (a,_) (b,_) = compare (String.length a) (String.length b) in
-  let mps = List.sort cmp mps in
-  List.iter (
-    fun (mp, dev) ->
-      try g#mount_ro dev mp
-      with Guestfs.Error msg -> warning (f_"%s (ignored)") msg
-  ) mps;
+  inspect_mount_root_ro g root;
 
   let files      let typ = g#inspect_get_type root in
diff --git a/mllib/common_utils.ml b/mllib/common_utils.ml
index 6bf99cd..de83dd7 100644
--- a/mllib/common_utils.ml
+++ b/mllib/common_utils.ml
@@ -833,3 +833,21 @@ let read_first_line_from_file filename  let is_regular_file
path = (* NB: follows symlinks. *)
   try (Unix.stat path).Unix.st_kind = Unix.S_REG
   with Unix.Unix_error _ -> false
+
+let inspect_mount_root g ?mount_opts_fn root +  let mps =
g#inspect_get_mountpoints root in
+  let cmp (a,_) (b,_) +    compare (String.length a) (String.length b) in
+  let mps = List.sort cmp mps in
+  List.iter (
+    fun (mp, dev) ->
+      let mountfn +        match mount_opts_fn with
+        | Some fn -> g#mount_options (fn mp)
+        | None -> g#mount in
+      try mountfn dev mp
+      with Guestfs.Error msg -> warning (f_"%s (ignored)") msg
+  ) mps
+
+let inspect_mount_root_ro +  inspect_mount_root ~mount_opts_fn:(fun _ ->
"ro")
diff --git a/mllib/common_utils.mli b/mllib/common_utils.mli
index 7172da9..68b4c1d 100644
--- a/mllib/common_utils.mli
+++ b/mllib/common_utils.mli
@@ -273,3 +273,14 @@ val read_first_line_from_file : string -> string
 
 val is_regular_file : string -> bool
 (** Checks whether the file is a regular file. *)
+
+val inspect_mount_root : Guestfs.guestfs -> ?mount_opts_fn:(string ->
string) -> string -> unit
+(** Mounts all the mount points of the specified root, just like
+    [guestfish -i] does.
+
+    [mount_opts_fn] represents a function providing the mount options
+    for each mount point. *)
+
+val inspect_mount_root_ro : Guestfs.guestfs -> string -> unit
+(** Like [inspect_mount_root], but mounting every mount point as
+    read-only. *)
diff --git a/sysprep/main.ml b/sysprep/main.ml
index 4849311..1441619 100644
--- a/sysprep/main.ml
+++ b/sysprep/main.ml
@@ -227,17 +227,7 @@ read the man page virt-sysprep(1).
         (* Mount up the disks, like guestfish -i.
          * See [ocaml/examples/inspect_vm.ml].
          *)
-        let mps = g#inspect_get_mountpoints root in
-        let cmp (a,_) (b,_) = compare (String.length a) (String.length b) in
-        let mps = List.sort cmp mps in
-        List.iter (
-          fun (mp, dev) ->
-            (* Get mount options for this mountpoint. *)
-            let opts = mount_opts mp in
-
-            try g#mount_options opts dev mp;
-            with Guestfs.Error msg -> warning (f_"%s (ignored)")
msg
-        ) mps;
+        inspect_mount_root ~mount_opts_fn:mount_opts g root;
 
         let side_effects = new Sysprep_operation.filesystem_side_effects in
 
diff --git a/v2v/test-harness/v2v_test_harness.ml
b/v2v/test-harness/v2v_test_harness.ml
index d5b53fa..70ce73e 100644
--- a/v2v/test-harness/v2v_test_harness.ml
+++ b/v2v/test-harness/v2v_test_harness.ml
@@ -86,14 +86,7 @@ let run ~test ?input_disk ?input_xml ?(test_plan =
default_plan) ()        | _ ->
         failwithf "multiple roots found in disk image %s" filename in
 
-    let mps = g#inspect_get_mountpoints root in
-    let cmp (a,_) (b,_) = compare (String.length a) (String.length b) in
-    let mps = List.sort cmp mps in
-    List.iter (
-      fun (mp, dev) ->
-        try g#mount_ro dev mp
-        with G.Error msg -> eprintf "%s (ignored)\n" msg
-    ) mps;
+    inspect_mount_root_ro g root;
 
     g, root
   in
-- 
2.5.0

On Thu, Mar 03, 2016 at 02:30:06PM +0100, Pino Toscano
wrote:
> Introduce and use a new inspect_mount_root function to mount all the
> mountpoints of a root in the guest, replacing the same code doing that
> in different tools.
> 
> inspect_mount_root_ro is inspect_mount_root with readonly mount option.
Simple refactoring, ACK.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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