Re: [PATCH 1/4] Add the ``--no-mount'' option.

[Sergiu Ivanov]

>From 38ee759112cfc93a6e8edbed35d7550e998513e3 Mon Sep 17 00:00:00 2001
From: Sergiu Ivanov <unlimitedscolobb@gmail.com>
Date: Tue, 14 Jul 2009 16:36:05 +0000
Subject: [PATCH 1/4] Add the ``--no-mount'' option.

* mount.c (transparent_mount): New variable.
* mount.h (transparent_mount): Likewise.
* netfs.c (netfs_append_args): Handle the ``--no-mount'' option.
* option.c (argp_common_option): Add the ``--no-mount'' option.
Change the explanation of the ``--mount'' option.
(argp_parse_common_options): Handle the ``--no-mount'' option.
* option.h (OPT_NOMOUNT): New definition.
(OPT_LONG_NOMOUNT): Likewise.
---
 mount.c   |    4 ++++
 mount.h   |    4 ++++
 netfs.c   |   11 ++++++++---
 options.c |    8 +++++++-
 options.h |    2 ++
 5 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/mount.c b/mount.c
index e284fe6..83bd7c3 100644
--- a/mount.c
+++ b/mount.c
@@ -40,6 +40,10 @@ mach_port_t mountee_root;
 
 int mountee_started = 0;
 
+/* Shows the mode in which the current instance of unionmount
+   operates (transparent/non-transparent).  */
+int transparent_mount = 1;
+
 /* Starts the mountee (given by `argz` and `argz_len`), attaches it to
    the node `np` and opens a port `port` to the mountee with
    `flags`.  */
diff --git a/mount.h b/mount.h
index 53679ad..d51fdeb 100644
--- a/mount.h
+++ b/mount.h
@@ -37,6 +37,10 @@ extern mach_port_t mountee_root;
 
 extern int mountee_started;
 
+/* Shows the mode in which the current instance of unionmount
+   operates (transparent/non-transparent).  */
+extern int transparent_mount;
+
 /* Starts the mountee (given by `argz` and `argz_len`), attaches it to
    the node `np` and opens a port `port` to the mountee with
    `flags`.  */
diff --git a/netfs.c b/netfs.c
index 8d2a4ec..00b12bf 100644
--- a/netfs.c
+++ b/netfs.c
@@ -50,7 +50,7 @@ netfs_append_args (char **argz, size_t *argz_len)
 {
   error_t err = 0;
 
-  /* Add the --mount option to the result.  */
+  /* Add the --mount or --no-mount option to the result.  */
   if (mountee_argz)
     {
       char * buf = NULL;
@@ -59,6 +59,10 @@ netfs_append_args (char **argz, size_t *argz_len)
         string form.  */
       char * mountee_cl;
 
+      /* This will be either ``--mount'' or ``--no-mount'' depending
+        on the whether the unionmount is transparent or not.  */
+      char * opt_name;
+
       mountee_cl = malloc (mountee_argz_len);
       if (!mountee_cl)
        return ENOMEM;
@@ -66,8 +70,9 @@ netfs_append_args (char **argz, size_t *argz_len)
       memcpy (mountee_cl, mountee_argz, mountee_argz_len);
       argz_stringify (mountee_cl, mountee_argz_len, ' ');
 
-      if ((err = asprintf (&buf, "%s=\"%s\"", OPT_LONG (OPT_LONG_MOUNT),
-                          mountee_cl)) == -1)
+      opt_name = (transparent_mount ? OPT_LONG (OPT_LONG_MOUNT)
+                 : OPT_LONG (OPT_LONG_NOMOUNT));
+      if ((err = asprintf (&buf, "%s=\"%s\"", opt_name, mountee_cl)) == -1)
        {
          free (mountee_cl);
          return ENOMEM;
diff --git a/options.c b/options.c
index e2e5dcd..4b9a594 100644
--- a/options.c
+++ b/options.c
@@ -56,9 +56,12 @@ static const struct argp_option argp_common_options[] =
       "send debugging messages to stderr" },
     { OPT_LONG_CACHE_SIZE, OPT_CACHE_SIZE, "SIZE", 0,
       "specify the maximum number of nodes in the cache" },
-    { OPT_LONG_MOUNT, OPT_MOUNT, "MOUNTEE", 0,
+    { OPT_LONG_NOMOUNT, OPT_NOMOUNT, "MOUNTEE", 0,
       "use MOUNTEE as translator command line, start the translator,"
       "and add its filesystem"},
+    { OPT_LONG_MOUNT, OPT_MOUNT, "MOUNTEE", 0,
+      "like --no-mount, but make it appear as if MOUNTEE had been set on the "
+      "underlying node directly"},
     { 0, 0, 0, 0, "Runtime options:", 1 },
     { OPT_LONG_STOW, OPT_STOW, "STOWDIR", 0,
       "stow given directory", 1},
@@ -132,6 +135,9 @@ argp_parse_common_options (int key, char *arg, struct 
argp_state *state)
       ulfs_match = 0;
       break;
 
+    case OPT_NOMOUNT:
+      transparent_mount = 0;
+
     case OPT_MOUNT:
       if (mountee_argz)
        error (EXIT_FAILURE, err, "You can specify only one %s option.",
diff --git a/options.h b/options.h
index 95a6ddb..2d80ba1 100644
--- a/options.h
+++ b/options.h
@@ -33,6 +33,7 @@
 #define OPT_PRIORITY   'p'
 #define OPT_STOW       's'
 #define OPT_MOUNT      't'
+#define OPT_NOMOUNT    'n'
 
 /* The long options.  */
 #define OPT_LONG_UNDERLYING "underlying"
@@ -45,6 +46,7 @@
 #define OPT_LONG_PRIORITY   "priority"
 #define OPT_LONG_STOW       "stow"
 #define OPT_LONG_MOUNT      "mount"
+#define OPT_LONG_NOMOUNT    "no-mount"
 
 #define OPT_LONG(o) "--" o
 
-- 
1.6.3.3