Support msc mode automatic switching

Signed-off-by: Cliff Chen <cliff.chen@rock-chips.com>

components/dfs/include/dfs_fs.h

@@ -91,6 +91,7 @@ int dfs_unmount(const char *specialfile);
 int dfs_mkfs(const char *fs_name, const char *device_name);
 int dfs_statfs(const char *path, struct statfs *buffer);
 int dfs_mount_device(rt_device_t dev);
+int dfs_unmount_device(rt_device_t dev);
 
 #ifdef __cplusplus
 }

components/dfs/src/dfs_fs.c

@@ -555,6 +555,54 @@ int dfs_mount_device(rt_device_t dev)
   rt_kprintf("can't find device:%s to be mounted.\n", dev->parent.name);
   return -RT_ERROR;
 }
+
+int dfs_unmount_device(rt_device_t dev)
+{
+    struct dfs_filesystem *iter;
+    struct dfs_filesystem *fs = NULL;
+
+    /* lock filesystem */
+    dfs_lock();
+
+    for (iter = &filesystem_table[0];
+            iter < &filesystem_table[DFS_FILESYSTEMS_MAX]; iter++)
+    {
+        /* check if the PATH is mounted */
+        if ((iter->dev_id->parent.name != NULL)
+            && (strcmp(iter->dev_id->parent.name, dev->parent.name) == 0))
+        {
+            fs = iter;
+            break;
+        }
+    }
+
+    if (fs == NULL ||
+        fs->ops->unmount == NULL ||
+        fs->ops->unmount(fs) < 0)
+    {
+        goto err1;
+    }
+
+    /* close device, but do not check the status of device */
+    if (fs->dev_id != NULL)
+        rt_device_close(fs->dev_id);
+
+    if (fs->path != NULL)
+        rt_free(fs->path);
+
+    /* clear this filesystem table entry */
+    memset(fs, 0, sizeof(struct dfs_filesystem));
+
+    dfs_unlock();
+
+    return 0;
+
+err1:
+    dfs_unlock();
+
+    return -1;
+}
+
 #endif
 
 #ifdef RT_USING_FINSH

components/drivers/usb/usbdevice/class/mstorage.c

@@ -16,6 +16,10 @@
 #include "drivers/usb_device.h"
 #include "mstorage.h"
 
+#ifdef RT_USING_DFS_MNTTABLE
+#include "dfs_fs.h"
+#endif
+
 #ifdef RT_USB_DEVICE_MSTORAGE
 
 enum STAT
@@ -964,6 +968,10 @@ static rt_err_t _function_enable(ufunction_t func)
         return -RT_ERROR;
     }
 
+#ifdef RT_USING_DFS_MNTTABLE
+    dfs_unmount_device(data->disk);
+#endif
+
     if(rt_device_open(data->disk, RT_DEVICE_OFLAG_RDWR) != RT_EOK)
     {
         rt_kprintf("disk open error\n");
@@ -1029,6 +1037,9 @@ static rt_err_t _function_disable(ufunction_t func)
     if(data->disk != RT_NULL)
     {
         rt_device_close(data->disk);
+#ifdef RT_USING_DFS_MNTTABLE
+        dfs_mount_device(data->disk);
+#endif
         data->disk = RT_NULL;
     }