f8dc1bcb2886359de7d47972aa40df226d22c0a1
[openwrt/openwrt.git] / target / linux / generic / pending-4.14 / 491-ubi-auto-create-ubiblock-device-for-rootfs.patch
1 From: Daniel Golle <daniel@makrotopia.org>
2 Subject: ubi: auto-create ubiblock device for rootfs
3
4 Signed-off-by: Daniel Golle <daniel@makrotopia.org>
5 ---
6 drivers/mtd/ubi/block.c | 42 ++++++++++++++++++++++++++++++++++++++++++
7 1 file changed, 42 insertions(+)
8
9 --- a/drivers/mtd/ubi/block.c
10 +++ b/drivers/mtd/ubi/block.c
11 @@ -625,6 +625,44 @@ static void __init ubiblock_create_from_
12 }
13 }
14
15 +#define UBIFS_NODE_MAGIC 0x06101831
16 +static inline int ubi_vol_is_ubifs(struct ubi_volume_desc *desc)
17 +{
18 + int ret;
19 + uint32_t magic_of, magic;
20 + ret = ubi_read(desc, 0, (char *)&magic_of, 0, 4);
21 + if (ret)
22 + return 0;
23 + magic = le32_to_cpu(magic_of);
24 + return magic == UBIFS_NODE_MAGIC;
25 +}
26 +
27 +static void __init ubiblock_create_auto_rootfs(void)
28 +{
29 + int ubi_num, ret, is_ubifs;
30 + struct ubi_volume_desc *desc;
31 + struct ubi_volume_info vi;
32 +
33 + for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++) {
34 + desc = ubi_open_volume_nm(ubi_num, "rootfs", UBI_READONLY);
35 + if (IS_ERR(desc))
36 + continue;
37 +
38 + ubi_get_volume_info(desc, &vi);
39 + is_ubifs = ubi_vol_is_ubifs(desc);
40 + ubi_close_volume(desc);
41 + if (is_ubifs)
42 + break;
43 +
44 + ret = ubiblock_create(&vi);
45 + if (ret)
46 + pr_err("UBI error: block: can't add '%s' volume, err=%d\n",
47 + vi.name, ret);
48 + /* always break if we get here */
49 + break;
50 + }
51 +}
52 +
53 static void ubiblock_remove_all(void)
54 {
55 struct ubiblock *next;
56 @@ -655,6 +693,10 @@ int __init ubiblock_init(void)
57 */
58 ubiblock_create_from_param();
59
60 + /* auto-attach "rootfs" volume if existing and non-ubifs */
61 + if (IS_ENABLED(CONFIG_MTD_ROOTFS_ROOT_DEV))
62 + ubiblock_create_auto_rootfs();
63 +
64 /*
65 * Block devices are only created upon user requests, so we ignore
66 * existing volumes.