Fix umount_all command so it unmounts filesystems in the correct order.

[libguestfs.git] / src / generator.ml

diff --git a/src/generator.ml b/src/generator.ml
index d680d42..ae640e2 100755 (executable)
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -1074,6 +1074,20 @@ Some internal mounts are not shown.");
   ("umount_all", (RErr, []), 47, [FishAlias "unmount-all"],
    [InitBasicFS, TestOutputList (
       [["umount_all"];
+       ["mounts"]], []);
+    (* check that umount_all can unmount nested mounts correctly: *)
+    InitEmpty, TestOutputList (
+      [["sfdisk"; "/dev/sda"; "0"; "0"; "0"; ",10 ,20 ,"];
+       ["mkfs"; "ext2"; "/dev/sda1"];
+       ["mkfs"; "ext2"; "/dev/sda2"];
+       ["mkfs"; "ext2"; "/dev/sda3"];
+       ["mount"; "/dev/sda1"; "/"];
+       ["mkdir"; "/mp1"];
+       ["mount"; "/dev/sda2"; "/mp1"];
+       ["mkdir"; "/mp1/mp2"];
+       ["mount"; "/dev/sda3"; "/mp1/mp2"];
+       ["mkdir"; "/mp1/mp2/mp3"];
+       ["umount_all"];
        ["mounts"]], [])],
    "unmount all filesystems",
    "\
@@ -1804,6 +1818,13 @@ let rec string_split sep str =
     s' :: string_split sep s''
   )
 
+let files_equal n1 n2 =
+  let cmd = sprintf "cmp -s %s %s" (Filename.quote n1) (Filename.quote n2) in
+  match Sys.command cmd with
+  | 0 -> true
+  | 1 -> false
+  | i -> failwithf "%s: failed with error code %d" cmd i
+
 let rec find_map f = function
   | [] -> raise Not_found
   | x :: xs ->
@@ -6227,8 +6248,17 @@ let output_to filename =
   let close () =
     close_out !chan;
     chan := stdout;
-    Unix.rename filename_new filename;
-    printf "written %s\n%!" filename;
+
+    (* Is the new file different from the current file? *)
+    if Sys.file_exists filename && files_equal filename filename_new then
+      Unix.unlink filename_new         (* same, so skip it *)
+    else (
+      (* different, overwrite old one *)
+      (try Unix.chmod filename 0o644 with Unix.Unix_error _ -> ());
+      Unix.rename filename_new filename;
+      Unix.chmod filename 0o444;
+      printf "written %s\n%!" filename;
+    )
   in
   close