error!: "/dev/ubi0" is not a character device ?!?

[Arno Steffen]

I just tried the howto (mount an empty UBI volume). But when I want to do
ubimkvol /dev/ubi0 -N test_vol -s 10MiB I get an error message:
libubi: error!: "/dev/ubi0" is not a character device
ubimkvol: error!: error while probing "/dev/ubi0"
          error 22 (Invalid argument)

If I check /dev/ubi0 it is indeed a block device. But this has been
created by ubiattach which I used as howto
What is the problem????

( I tried to set the device as a char-device by

[root at or:/]# ll /dev/ub*
brw-rw----    1 root     root     253,   0 Jan  1 00:46 /dev/ubi0
crw-rw----    1 root     root      10,  63 Jan  1 00:00 /dev/ubi_ctrl
[root at or:/]# rm /dev/ubi0
[root at or:/]# mknod /dev/ubi0 c 253 0

But than I get other error messages:

[root at or:/]# ubimkvol /dev/ubi0 -N test -s 10MiB
UBI error: ubi_io_write: error -5 while writing 512 bytes to PEB
331:512, written 0 bytes
Backtrace:
[<8002d558>] (dump_backtrace+0x0/0x10c) from [<80267dac>] (dump_stack+0x18/0x1c)
 r6:0000014b r5:fffffffb r4:87a19800 r3:00000002
[<80267d94>] (dump_stack+0x0/0x1c) from [<801bb084>] (ubi_io_write+0x308/0x384)
[<801bad7c>] (ubi_io_write+0x0/0x384) from [<801bb228>]
(ubi_io_write_vid_hdr+0x128/0x144)
[<801bb100>] (ubi_io_write_vid_hdr+0x0/0x144) from [<801b9114>]
(ubi_eba_write_leb+0x550/0x758)
 r6:87928400 r5:879dde00 r4:87a19800
[<801b8bc4>] (ubi_eba_write_leb+0x0/0x758) from [<801b1560>]
(ubi_change_vtbl_record+0xf4/0x158)
[<801b146c>] (ubi_change_vtbl_record+0x0/0x158) from [<801b2d74>]
(ubi_create_volume+0x51c/0x6c0)
 r7:87a19800 r6:87a73d2c r5:87928200 r4:879282a0
[<801b2858>] (ubi_create_volume+0x0/0x6c0) from [<801b56f4>]
(ubi_cdev_ioctl+0x1f4/0x96c)
[<801b5500>] (ubi_cdev_ioctl+0x0/0x96c) from [<800b6194>] (vfs_ioctl+0x34/0xb4)
[<800b6160>] (vfs_ioctl+0x0/0xb4) from [<800b6880>] (do_vfs_ioctl+0x56c/0x5b4)
 r6:40986f00 r5:879f73c0 r4:7e85c9d8 r3:87a2e230
[<800b6314>] (do_vfs_ioctl+0x0/0x5b4) from [<800b6908>] (sys_ioctl+0x40/0x64)
[<800b68c8>] (sys_ioctl+0x0/0x64) from [<80029fc0>] (ret_fast_syscall+0x0/0x2c)
 r7:00000036 r6:00000003 r5:7e85cba8 r4:7e85c9d8
UBI warning: ubi_eba_write_leb: failed to write VID header to LEB
2147479551:0, PEB 331
UBI: run torture test for PEB 331