Subject: Re: linux-next: build failure after merge of the nvdimm tree

From: Pankaj Gupta <[email-masked]>
Date: Thu, 20 Jun 2019 06:30:19 -0400 (EDT)

> Hi Dan,
> 
> After merging the nvdimm tree, today's linux-next build (i386 defconfig)
> failed like this:
> 
> drivers/md/dm-table.c: In function 'device_synchronous':
> drivers/md/dm-table.c:897:9: error: implicit declaration of function
> 'dax_synchronous'; did you mean 'device_synchronous'?
> [-Werror=implicit-function-declaration]
>   return dax_synchronous(dev->dax_dev);
>          ^~~~~~~~~~~~~~~
>          device_synchronous
> drivers/md/dm-table.c: In function 'dm_table_set_restrictions':
> drivers/md/dm-table.c:1925:4: error: implicit declaration of function
> 'set_dax_synchronous'; did you mean 'device_synchronous'?
> [-Werror=implicit-function-declaration]
>     set_dax_synchronous(t->md->dax_dev);
>     ^~~~~~~~~~~~~~~~~~~
>     device_synchronous
> cc1: some warnings being treated as errors
> 
> Caused by commit
> 
>   38887edec247 ("dm: enable synchronous dax")
> 
> CONFIG_DAX is not set for this build.

Moving 'dax_synchronous' & 'set_dax_synchronous' function declaration
out of CONFIG_DAX should fix this. This will make compiler aware about 
'device_synchronous' function for non DAX archs as well.

Thanks,
Pankaj
 
> 
> I have reverted that commit for today.
> --
> Cheers,
> Stephen Rothwell
>