bc: convert to "G trick" - this returns bc to zero bss increase

[oweals/busybox.git] / util-linux / freeramdisk.c

diff --git a/util-linux/freeramdisk.c b/util-linux/freeramdisk.c
index 567151455470e00ee6e49f7dcbfe2c2d9d930b1e..6752e49d8926a5b1dba54389b14d3a770057ac02 100644 (file)
--- a/util-linux/freeramdisk.c
+++ b/util-linux/freeramdisk.c
@@ -1,64 +1,80 @@
 /* vi: set sw=4 ts=4: */
 /*
- * freeramdisk implementation for busybox
+ * freeramdisk and fdflush implementations for busybox
  *
  * Copyright (C) 2000 and written by Emanuele Caratti <wiz@iol.it>
- * Adjusted a bit by Erik Andersen <andersee@debian.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Adjusted a bit by Erik Andersen <andersen@codepoet.org>
+ * Unified with fdflush by Tito Ragusa <farmatito@tiscali.it>
  *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
  */
+//config:config FDFLUSH
+//config:      bool "fdflush (1.4 kb)"
+//config:      default y
+//config:      select PLATFORM_LINUX
+//config:      help
+//config:      fdflush is only needed when changing media on slightly-broken
+//config:      removable media drives. It is used to make Linux believe that a
+//config:      hardware disk-change switch has been actuated, which causes Linux to
+//config:      forget anything it has cached from the previous media. If you have
+//config:      such a slightly-broken drive, you will need to run fdflush every time
+//config:      you change a disk. Most people have working hardware and can safely
+//config:      leave this disabled.
+//config:
+//config:config FREERAMDISK
+//config:      bool "freeramdisk (1.4 kb)"
+//config:      default y
+//config:      select PLATFORM_LINUX
+//config:      help
+//config:      Linux allows you to create ramdisks. This utility allows you to
+//config:      delete them and completely free all memory that was used for the
+//config:      ramdisk. For example, if you boot Linux into a ramdisk and later
+//config:      pivot_root, you may want to free the memory that is allocated to the
+//config:      ramdisk. If you have no use for freeing memory from a ramdisk, leave
+//config:      this disabled.
+
+//                     APPLET_ODDNAME:name         main         location     suid_type     help
+//applet:IF_FDFLUSH(   APPLET_ODDNAME(fdflush,     freeramdisk, BB_DIR_BIN,  BB_SUID_DROP, fdflush    ))
+//applet:IF_FREERAMDISK(APPLET_NOEXEC(freeramdisk, freeramdisk, BB_DIR_SBIN, BB_SUID_DROP, freeramdisk))
+
+//kbuild:lib-$(CONFIG_FDFLUSH) += freeramdisk.o
+//kbuild:lib-$(CONFIG_FREERAMDISK) += freeramdisk.o
 
-#include <stdio.h>
-#include <string.h>
-#include <sys/types.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
-#include <errno.h>
-#include "busybox.h"
+//usage:#define freeramdisk_trivial_usage
+//usage:       "DEVICE"
+//usage:#define freeramdisk_full_usage "\n\n"
+//usage:       "Free all memory used by the specified ramdisk"
+//usage:
+//usage:#define freeramdisk_example_usage
+//usage:       "$ freeramdisk /dev/ram2\n"
+//usage:
+//usage:#define fdflush_trivial_usage
+//usage:       "DEVICE"
+//usage:#define fdflush_full_usage "\n\n"
+//usage:       "Force floppy disk drive to detect disk change"
 
+#include <sys/mount.h>
+#include "libbb.h"
 
-/* From linux/fs.h */
-#define BLKFLSBUF  _IO(0x12,97)        /* flush buffer cache */
+/* From <linux/fd.h> */
+#define FDFLUSH  _IO(2,0x4b)
 
-extern int
-freeramdisk_main(int argc, char **argv)
+int freeramdisk_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int freeramdisk_main(int argc UNUSED_PARAM, char **argv)
 {
-       int   f;
+       int fd;
 
-       if (argc != 2 || *argv[1] == '-') {
-               usage(freeramdisk_usage);
-       }
+       fd = xopen(single_argv(argv), O_RDWR);
 
-       if ((f = open(argv[1], O_RDWR)) == -1) {
-               fatalError( "cannot open %s: %s\n", argv[1], strerror(errno));
-       }
-       if (ioctl(f, BLKFLSBUF) < 0) {
-               fatalError( "failed ioctl on %s: %s\n", argv[1], strerror(errno));
-       }
-       /* Don't bother closing.  Exit does
-        * that, so we can save a few bytes */
-       /* close(f); */
-       return EXIT_SUCCESS;
-}
+       // Act like freeramdisk, fdflush, or both depending on configuration.
+       ioctl_or_perror_and_die(fd,
+               ((ENABLE_FREERAMDISK && applet_name[1] == 'r') || !ENABLE_FDFLUSH)
+                               ? BLKFLSBUF
+                               : FDFLUSH,
+               NULL, "%s", argv[1]
+       );
 
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+       if (ENABLE_FEATURE_CLEAN_UP) close(fd);
 
+       return EXIT_SUCCESS;
+}