target/linux/generic/patches-3.14/491-ubi-auto-create-ubiblock-device-for-rootfs.patch

   1 From 0f3966579815f889bb2fcb4846152c35f65e79c4 Mon Sep 17 00:00:00 2001
   2 From: Daniel Golle <daniel@makrotopia.org>
   3 Date: Thu, 15 May 2014 21:06:33 +0200
   4 Subject: [PATCH 2/5] ubi: auto-create ubiblock device for rootfs
   5 To: openwrt-devel@lists.openwrt.org
   6
   7 Signed-off-by: Daniel Golle <daniel@makrotopia.org>
   8 ---
   9  drivers/mtd/ubi/block.c | 42 ++++++++++++++++++++++++++++++++++++++++++
  10  1 file changed, 42 insertions(+)
  11
  12 diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
  13 index 8d659e6..2dbe2f4 100644
  14 --- a/drivers/mtd/ubi/block.c
  15 +++ b/drivers/mtd/ubi/block.c
  16 @@ -593,6 +593,44 @@ static int __init ubiblock_create_from_param(void)
  17         return ret;
  18  }
  19
  20 +#define UBIFS_NODE_MAGIC  0x06101831
  21 +static inline int ubi_vol_is_ubifs(struct ubi_volume_desc *desc)
  22 +{
  23 +       int ret;
  24 +       uint32_t magic_of, magic;
  25 +       ret = ubi_read(desc, 0, (char *)&magic_of, 0, 4);
  26 +       if (ret)
  27 +               return 0;
  28 +       magic = le32_to_cpu(magic_of);
  29 +       return magic == UBIFS_NODE_MAGIC;
  30 +}
  31 +
  32 +static void __init ubiblock_create_auto_rootfs(void)
  33 +{
  34 +       int ubi_num, ret, is_ubifs;
  35 +       struct ubi_volume_desc *desc;
  36 +       struct ubi_volume_info vi;
  37 +
  38 +       for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++) {
  39 +               desc = ubi_open_volume_nm(ubi_num, "rootfs", UBI_READONLY);
  40 +               if (IS_ERR(desc))
  41 +                       continue;
  42 +
  43 +               ubi_get_volume_info(desc, &vi);
  44 +               is_ubifs = ubi_vol_is_ubifs(desc);
  45 +               ubi_close_volume(desc);
  46 +               if (is_ubifs)
  47 +                       break;
  48 +
  49 +               ret = ubiblock_create(&vi);
  50 +               if (ret)
  51 +                       ubi_err("block: can't add '%s' volume, err=%d\n",
  52 +                               vi.name, ret);
  53 +               /* always break if we get here */
  54 +               break;
  55 +       }
  56 +}
  57 +
  58  static void ubiblock_remove_all(void)
  59  {
  60         struct ubiblock *next;
  61 @@ -623,6 +661,10 @@ int __init ubiblock_init(void)
  62         if (ret)
  63                 goto err_remove;
  64
  65 +       /* auto-attach "rootfs" volume if existing and non-ubifs */
  66 +       if (config_enabled(CONFIG_MTD_ROOTFS_ROOT_DEV))
  67 +               ubiblock_create_auto_rootfs();
  68 +
  69         /*
  70          * Block devices are only created upon user requests, so we ignore
  71          * existing volumes.
  72 --
  73 1.9.2
  74