Add losetup to NSH

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1243 42af7a65-404d-4744-a932-0658087f49c3

4 files changed, 154 insertions, 9 deletions

diff --git a/nuttx/examples/nsh/README.txt b/nuttx/examples/nsh/README.txt
index 9ea046409..a34b03da9 100644
--- a/nuttx/examples/nsh/README.txt
+++ b/nuttx/examples/nsh/README.txt
@@ -328,6 +328,19 @@ o ifconfig
   if uIP statistics are enabled (CONFIG_NET_STATISTICS), then
   this command will also show the detailed state of uIP.
 
+o losetup [-d <dev-path>] | [[-o <offset>] [-r] <ldev-path> <file-path>]
+
+  Setup or teardown the loop device:
+
+  1. Teardown the setup for the loop device at <dev-path>:
+
+    losetup d <dev-path>
+
+  2. Setup the loop device at <dev-path> to access the file at <file-path>
+     as a block device:
+
+    losetup [-o <offset>] [-r] <dev-path> <file-path>
+
 o ls [-lRs] <dir-path>
 
   Show the contents of the directory at <dir-path>.  NOTE:
@@ -721,6 +734,7 @@ Command Dependencies on Configuration Settings
   get        CONFIG_NET && CONFIG_NET_UDP && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NET_BUFSIZE >= 558  (see note 1)
   help       --
   ifconfig   CONFIG_NET
+  losetup    !CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0
   ls         CONFIG_NFILE_DESCRIPTORS > 0
   mb,mh,mw   ---
   mem        ---
@@ -762,15 +776,15 @@ also allow it to squeeze into very small memory footprints.
   CONFIG_EXAMPLES_NSH_DISABLE_CAT,      CONFIG_EXAMPLES_NSH_DISABLE_CD,      CONFIG_EXAMPLES_NSH_DISABLE_CP,
   CONFIG_EXAMPLES_NSH_DISABLE_DD,       CONFIG_EXAMPLES_NSH_DISABLE_ECHO,    CONFIG_EXAMPLES_NSH_DISABLE_EXEC,
   CONFIG_EXAMPLES_NSH_DISABLE_EXIT,     CONFIG_EXAMPLES_NSH_DISABLE_GET,     CONFIG_EXAMPLES_NSH_DISABLE_HELP,
-  CONFIG_EXAMPLES_NSH_DISABLE_IFCONFIG, CONFIG_EXAMPLES_NSH_DISABLE_LS,      CONFIG_EXAMPLES_NSH_DISABLE_MB,
-  CONFIG_EXAMPLES_NSH_DISABLE_MEM,      CONFIG_EXAMPLES_NSH_DISABLE_MKDIR,   CONFIG_EXAMPLES_NSH_DISABLE_MKFATFS,
-  CONFIG_EXAMPLES_NSH_DISABLE_MKFIFO,   CONFIG_EXAMPLES_NSH_DISABLE_MKRD,    CONFIG_EXAMPLES_NSH_DISABLE_MH,
-  CONFIG_EXAMPLES_NSH_DISABLE_MOUNT,    CONFIG_EXAMPLES_NSH_DISABLE_MW,      CONFIG_EXAMPLES_NSH_DISABLE_PS,
-  CONFIG_EXAMPLES_NSH_DISABLE_PING,     CONFIG_EXAMPLES_NSH_DISABLE_PUT,     CONFIG_EXAMPLES_NSH_DISABLE_PWD,
-  CONFIG_EXAMPLES_NSH_DISABLE_RM,       CONFIG_EXAMPLES_NSH_DISABLE_RMDIR,   CONFIG_EXAMPLES_NSH_DISABLE_SET,
-  CONFIG_EXAMPLES_NSH_DISABLE_SH,       CONFIG_EXAMPLES_NSH_DISABLE_SLEEP,   CONFIG_EXAMPLES_NSH_DISABLE_TEST,
-  CONFIG_EXAMPLES_NSH_DISABLE_UMOUNT,   CONFIG_EXAMPLES_NSH_DISABLE_UNSET,   CONFIG_EXAMPLES_NSH_DISABLE_USLEEP,
-  CONFIG_EXAMPLES_NSH_DISABLE_XD
+  CONFIG_EXAMPLES_NSH_DISABLE_IFCONFIG, CONFIG_EXAMPLES_NSH_DISABLE_LOSETUP, CONFIG_EXAMPLES_NSH_DISABLE_LS,
+  CONFIG_EXAMPLES_NSH_DISABLE_MB,       CONFIG_EXAMPLES_NSH_DISABLE_MEM,     CONFIG_EXAMPLES_NSH_DISABLE_MKDIR,
+  CONFIG_EXAMPLES_NSH_DISABLE_MKFATFS,  CONFIG_EXAMPLES_NSH_DISABLE_MKFIFO,  CONFIG_EXAMPLES_NSH_DISABLE_MKRD,
+  CONFIG_EXAMPLES_NSH_DISABLE_MH,       CONFIG_EXAMPLES_NSH_DISABLE_MOUNT,   CONFIG_EXAMPLES_NSH_DISABLE_MW,
+  CONFIG_EXAMPLES_NSH_DISABLE_PS,       CONFIG_EXAMPLES_NSH_DISABLE_PING,    CONFIG_EXAMPLES_NSH_DISABLE_PUT,
+  CONFIG_EXAMPLES_NSH_DISABLE_PWD,      CONFIG_EXAMPLES_NSH_DISABLE_RM,      CONFIG_EXAMPLES_NSH_DISABLE_RMDIR,
+  CONFIG_EXAMPLES_NSH_DISABLE_SET,      CONFIG_EXAMPLES_NSH_DISABLE_SH,      CONFIG_EXAMPLES_NSH_DISABLE_SLEEP,
+  CONFIG_EXAMPLES_NSH_DISABLE_TEST,     CONFIG_EXAMPLES_NSH_DISABLE_UMOUNT,  CONFIG_EXAMPLES_NSH_DISABLE_UNSET,
+  CONFIG_EXAMPLES_NSH_DISABLE_USLEEP,   CONFIG_EXAMPLES_NSH_DISABLE_XD
 
 NSH-Specific Configuration Settings
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/nuttx/examples/nsh/nsh.h b/nuttx/examples/nsh/nsh.h
index 825ea6554..32a0c934d 100644
--- a/nuttx/examples/nsh/nsh.h
+++ b/nuttx/examples/nsh/nsh.h
@@ -378,6 +378,9 @@ extern int cmd_lbracket(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
 #   endif
 # endif  /* CONFIG_NFILE_STREAMS && !CONFIG_EXAMPLES_NSH_DISABLESCRIPT */
 # ifndef CONFIG_DISABLE_MOUNTPOINT
+#   ifndef CONFIG_EXAMPLES_NSH_DISABLE_LOSETUP
+      extern int cmd_losetup(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
+#   endif
 #   ifndef CONFIG_EXAMPLES_NSH_DISABLE_MKFIFO
       extern int cmd_mkfifo(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv);
 #   endif
diff --git a/nuttx/examples/nsh/nsh_fscmds.c b/nuttx/examples/nsh/nsh_fscmds.c
index 8dcf90372..301abddbb 100644
--- a/nuttx/examples/nsh/nsh_fscmds.c
+++ b/nuttx/examples/nsh/nsh_fscmds.c
@@ -648,6 +648,128 @@ errout:
 #endif
 
 /****************************************************************************
+ * Name: cmd_losetup
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_MOUNTPOINT)
+#ifndef CONFIG_EXAMPLES_NSH_DISABLE_LOSETUP
+int cmd_losetup(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
+{
+  char   *loopdev  = NULL;
+  char   *filepath = NULL;
+  boolean teardown = FALSE;
+  boolean readonly = FALSE;
+  off_t   offset   = 0;
+  int     ret      = ERROR;
+  int     option;
+
+  /* Get the losetup options:  Two forms are supported:
+   *
+   *   losetup -d <loop-device>
+   *   losetup [-o <offset>] [-r] <loop-device> <filename>
+   *
+   * NOTE that the -o and -r options are accepted with the -d option, but
+   * will be ignored.
+   */
+
+  while ((option = getopt(argc, argv, "d:o:r")) != ERROR)
+    {
+      switch (option)
+        {
+        case 'd':
+          loopdev  = nsh_getfullpath(vtbl, optarg);
+          teardown = TRUE;
+          break;
+
+        case 'o':
+          offset = atoi(optarg);
+          break;
+
+        case 'r':
+          readonly = TRUE;
+          break;
+
+        case '?':
+        default:
+          nsh_output(vtbl, g_fmtarginvalid, argv[0]);
+          return ERROR;
+        }
+    }
+
+  /* If this is not a tear down operation, then additional command line
+   * parameters are required.
+   */
+
+  if (!teardown)
+    {
+      /* There must be two arguments on the command line after the options */
+
+      if (optind + 1 < argc)
+        {
+          loopdev = nsh_getfullpath(vtbl, argv[optind]);
+          optind++;
+
+          filepath = nsh_getfullpath(vtbl, argv[optind]);
+          optind++;
+        }
+      else
+        {
+          nsh_output(vtbl, g_fmtargrequired, argv[0]);
+          goto errout_with_paths;
+        }
+    }
+
+  /* There should be nothing else on the command line */
+
+  if (optind < argc)
+   {
+     nsh_output(vtbl, g_fmttoomanyargs, argv[0]);
+     goto errout_with_paths;
+   }
+
+  /* Perform the teardown operation */
+
+  if (teardown)
+    {
+      /* Tear down the loop device. */
+
+      ret = loteardown(loopdev);
+      if (ret < 0)
+        {
+          nsh_output(vtbl, g_fmtcmdfailed, argv[0], "loteardown", NSH_ERRNO_OF(-ret));
+          goto errout_with_paths;
+        }
+    }
+  else
+    {
+      /* Set up the loop device */
+
+      ret = losetup(loopdev, filepath, 512, offset, readonly);
+      if (ret < 0)
+        {
+          nsh_output(vtbl, g_fmtcmdfailed, argv[0], "losetup", NSH_ERRNO_OF(-ret));
+          goto errout_with_paths;
+        }
+    }
+
+  /* Free memory */
+
+errout_with_paths:
+  if (loopdev)
+    {
+      free(loopdev);
+    }
+
+  if (filepath)
+    {
+      free(filepath);
+    }
+  return ret;
+}
+#endif
+#endif
+
+/****************************************************************************
  * Name: cmd_ls
  ****************************************************************************/
 
diff --git a/nuttx/examples/nsh/nsh_main.c b/nuttx/examples/nsh/nsh_main.c
index 14b1afb55..db116b5c0 100644
--- a/nuttx/examples/nsh/nsh_main.c
+++ b/nuttx/examples/nsh/nsh_main.c
@@ -188,6 +188,12 @@ static const struct cmdmap_s g_cmdmap[] =
 # endif
 #endif
 
+#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_MOUNTPOINT)
+# ifndef CONFIG_EXAMPLES_NSH_DISABLE_LOSETUP
+  { "losetup",   cmd_losetup, 3, 6, "[-d <dev-path>] | [[-o <offset>] [-r] <dev-path> <file-path>]" },
+# endif
+#endif
+
 #if CONFIG_NFILE_DESCRIPTORS > 0
 # ifndef CONFIG_EXAMPLES_NSH_DISABLE_LS
   { "ls",       cmd_ls,       1, 5, "[-lRs] <dir-path>" },