Re: [Y2038] [PATCH 3/5] fs: nfsd: Replace time_t with u32 in nfsd4_grace

["Ksenija Stanojević" <ksenija.stanojevic@gmail.com>]

On Tue, Nov 3, 2015 at 4:17 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Tuesday 27 October 2015 09:10:45 Ksenija Stanojevic wrote:
>> Replace time_t type and get_seconds function which are not y2038 safe on
>> 32-bit systems. Function ktime_get_seconds use monotonic instead of real
>> time and therefore will not cause overflow.
>>
>> Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
>
> I think this patch needs to be folded into the patch that changes the
> type for nfsd4_lease, as mentioned there.
>
>>       locks_start_grace(net, &nn->nfsd4_manager);
>>       nfsd4_client_tracking_init(net);
>> -     printk(KERN_INFO "NFSD: starting %ld-second grace period (net %p)\n",
>> +     printk(KERN_INFO "NFSD: starting %x-second grace period (net %p)\n",
>>              nn->nfsd4_grace, net);
>>       queue_delayed_work(laundry_wq, &nn->laundromat_work, nn->nfsd4_grace * HZ);
>
>>
>> -     return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%ld\n", *time);
>> +     return scnprintf(buf, (u32)SIMPLE_TRANSACTION_LIMIT, "%x\n", *time);
>>  }
>>
>>  static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size,
>>
>
> You change the format string to print the time as hexadecimal. Is that
> intentional? If there is a reason for doing it, explain it in the changelog,
> otherwise leave it as "%d".
>
> The cast of SIMPLE_TRANSACTION_LIMIT to u32 looks misplaced as well.

I got following warnings with original code and I was trying to fix them:
include/linux/fs.h:2908:61: warning: format ‘%ld’ expects argument of
type ‘long int’, but argument 4 has type ‘u32’ [-Wformat=]
 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct
simple_transaction_argresp))
                                                             ^
fs/nfsd/nfsctl.c:963:24: note: in expansion of macro ‘SIMPLE_TRANSACTION_LIMIT’
  return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%ld\n", *time);

but I see now that changing %ld to %d works as well.

Thanks,
Ksenija