On Wed, 15 Nov 2023, Mike Snitzer wrote:
> On Wed, Nov 15 2023 at 2:01P -0500,
> Aaditya Raj Barnwal <abarnwal@xxxxxxxxxxxxxxxx> wrote:
>
> > Sorry if that statement confused you , It was debugging print
> > that was added to check if the tight while loop has ended or not
> >
> > Code : dm-init.c
> > dm_init_init()
> >
> > wait_for_device_probe();
> > for (i = 0; i < ARRAY_SIZE(waitfor); i++) {
> > if (waitfor[i]) {
> > dev_t dev;
> >
> > DMERR("waiting for device %s ...", waitfor[i]);
> > while ((dev= name_to_dev_t(waitfor[i]) !=0))
> > fsleep(5000);
> > }
> >
> > DMERR("exiting after %s ",waitfor[i]); <<<<<<<<<<<here it was added
> > }
> >
> > if (waitfor[0])
> > DMINFO("all devices available");
> >
> > list_for_each_entry(dev, &devices, list) {
> > if (dm_early_create(&dev->dmi, dev->table,
> > dev->target_args_array))
> > break;
> > }
> >
>
>
> Mikulas wasn't confused. He was pointing out that you have made
> changes to your kernel without sharing what they are.
>
> But your issue is that you configured the dm-mod.waitfor device
> incorrectly. You must wait for the underlying physical device(s) that
> the virtual DM device depends on.
Yes, that's the problem.
> Mike
[ 9.785204][ T9] mmc0: CQHCI version 5.10
[ 9.826746][ T9] mmc0: SDHCI controller on 8804000.sdhci [8804000.sdhci] using ADMA 64-bit
[ 9.835559][ T9] sdhci_msm 8804000.sdhci: mmc0: CQE init: success
[ 9.842578][ T1] device-mapper: init: waiting for device /dev/dm-0 ...
[ 9.849605][ T1] device-mapper: init: exiting after /dev/dm-0 <<<<<got dev/dm-0
[ 9.856689][ T1] device-mapper: init: all devices available
[ 9.863061][ T1] device-mapper: table: 252:0: verity: Data device lookup failed
[ 9.870868][ T1] device-mapper: ioctl: error adding target to table
[ 9.895539][ T37]
I'm wondering about another thing - here it succeeds finding /dev/dm-0 and
immediatelly after that fails loading /dev/dm-0 table with the dm-verity
target.
So, how could we succeed finding /dev/dm-0 before it was created?
I think that you backported that patch incorrectly - instead of
while ((dev= name_to_dev_t(waitfor[i]) !=0)) fsleep(5000);
there should be
while ((dev= name_to_dev_t(waitfor[i]) ==0)) fsleep(5000);
There was a change in the return value of devt_from_devname - in 6.7-rc1,
it returns 0 on success and -ERROR on error. In 5.15.104, it returns 0 on
error and a device nubmer on success.
Mikulas
