ubi0 error: ubi_open_volume: cannot open device 0, volume 6, error -16

[Zhihao Cheng]

Hi,
> Hi,
> 
> Sorry, for missing the subject last time.
> 
> On Wed, 15 Feb 2023 at 23:06, Pintu Agarwal <pintu.ping at gmail.com> wrote:
>>
>> Hi,
>>
>> We are seeing below "ubi errors" during booting.
>> Although this does not cause any functionality break, I am wondering
>> if there is any way to fix it ?
>> We are using Kernel 4.14 with UBI and squashfs (ubiblock) as volumes,
>> and with systemd.
>>
>> Anybody have experienced the similar logs with ubi/squashfs and
>> figured out a way to avoid it ?
>> It seems like these open volumes are called twice, thus error -16
>> indicates (device or resource busy).
>> Or, are these logs expected because of squashfs or ubiblock ?
>> Or, do we need to add anything related to udev-rules ?
>>
>> {
>> ....
>> [  129.394789] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 6, error -16
>> [  129.486498] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 7, error -16
>> [  129.546582] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 8, error -16
>> [  129.645014] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 9, error -16
>> [  129.676456] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 6, error -16
>> [  129.706655] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 10, error -16
>> [  129.732740] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 7, error -16
>> [  129.811111] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 8, error -16
>> [  129.852308] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 9, error -16
>> [  129.923429] ubi0 error: ubi_open_volume: cannot open device 0,
>> volume 10, error -16
>>
>> }
>>
> 
> I see that the errors are reported by systemd-udevd and other processes.
> Is there a way to fix it by some means ?
> These logs actually consume lots of boot up time...

I guess that systemd-udevd and mtd_probe are racing to open the same 
volume with mode UBI_EXCLUSIVE or UBI_READWRITE, and these error 
messages are in expected. How about temporarily shutting down 
systemd-udevd during booting?