UBIFS: Add ubifsumount command to unmount an active volume

This new ubifsumount command allows the user to unmount a previously
mounted UBIFS volume.

Signed-off-by: Stefan Roese <sr@denx.de>

common/cmd_ubifs.c

@@ -33,12 +33,17 @@
 #include <config.h>
 #include <command.h>
 
+#include "../fs/ubifs/ubifs.h"
+
 static int ubifs_initialized;
 static int ubifs_mounted;
 
+extern struct super_block *ubifs_sb;
+
 /* Prototypes */
 int ubifs_init(void);
 int ubifs_mount(char *vol_name);
+void ubifs_umount(struct ubifs_info *c);
 int ubifs_ls(char *dir_name);
 int ubifs_load(char *filename, u32 addr, u32 size);
 
@@ -67,6 +72,26 @@ int do_ubifs_mount(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	return 0;
 }
 
+int do_ubifs_umount(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	if (argc != 1)
+		return cmd_usage(cmdtp);
+
+	if (ubifs_initialized == 0) {
+		printf("No UBIFS volume mounted!\n");
+		return -1;
+	}
+
+	if (ubifs_sb)
+		ubifs_umount(ubifs_sb->s_fs_info);
+
+	ubifs_sb = NULL;
+	ubifs_mounted = 0;
+	ubifs_initialized = 0;
+
+	return 0;
+}
+
 int do_ubifs_ls(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	char *filename = "/";
@@ -131,6 +156,12 @@ U_BOOT_CMD(
 	"    - mount 'volume-name' volume"
 );
 
+U_BOOT_CMD(
+	ubifsumount, 1, 0, do_ubifs_umount,
+	"unmount UBIFS volume",
+	"    - unmount current volume"
+);
+
 U_BOOT_CMD(
 	ubifsls, 2, 0, do_ubifs_ls,
 	"list files in a directory",

fs/ubifs/super.c

@@ -824,7 +824,7 @@ out_free:
  * through mounting (error path cleanup function). So it has to make sure the
  * resource was actually allocated before freeing it.
  */
-static void ubifs_umount(struct ubifs_info *c)
+void ubifs_umount(struct ubifs_info *c)
 {
 	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
 		c->vi.vol_id);