staging/lustre: use 64-bit llite debugfs timestamps

The llite debugfs interface contains timestamps that are computed
from timeval, which overflows in 2038 on 32-bit systems.

This changes the output to use a timespec64 type to avoid the
overflow. I also change the format to print the sub-second portion
as 9 digits (nanoseconds) for clarity, rather than printing six
digits without leading zeroes.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/llite/lproc_llite.c

@@ -1140,20 +1140,20 @@ static void ll_display_extents_info(struct ll_rw_extents_info *io_extents,
 
 static int ll_rw_extents_stats_pp_seq_show(struct seq_file *seq, void *v)
 {
-	struct timeval now;
+	struct timespec64 now;
 	struct ll_sb_info *sbi = seq->private;
 	struct ll_rw_extents_info *io_extents = &sbi->ll_rw_extents_info;
 	int k;
 
-	do_gettimeofday(&now);
+	ktime_get_real_ts64(&now);
 
 	if (!sbi->ll_rw_stats_on) {
 		seq_printf(seq, "disabled\n"
 			   "write anything in this file to activate, then 0 or \"[D/d]isabled\" to deactivate\n");
 		return 0;
 	}
-	seq_printf(seq, "snapshot_time:	 %lu.%lu (secs.usecs)\n",
-		   now.tv_sec, (unsigned long)now.tv_usec);
+	seq_printf(seq, "snapshot_time:	 %llu.%09lu (secs.usecs)\n",
+		   (s64)now.tv_sec, (unsigned long)now.tv_nsec);
 	seq_printf(seq, "%15s %19s       | %20s\n", " ", "read", "write");
 	seq_printf(seq, "%13s   %14s %4s %4s  | %14s %4s %4s\n",
 		   "extents", "calls", "%", "cum%",
@@ -1219,19 +1219,19 @@ LPROC_SEQ_FOPS(ll_rw_extents_stats_pp);
 
 static int ll_rw_extents_stats_seq_show(struct seq_file *seq, void *v)
 {
-	struct timeval now;
+	struct timespec64 now;
 	struct ll_sb_info *sbi = seq->private;
 	struct ll_rw_extents_info *io_extents = &sbi->ll_rw_extents_info;
 
-	do_gettimeofday(&now);
+	ktime_get_real_ts64(&now);
 
 	if (!sbi->ll_rw_stats_on) {
 		seq_printf(seq, "disabled\n"
 			   "write anything in this file to activate, then 0 or \"[D/d]isabled\" to deactivate\n");
 		return 0;
 	}
-	seq_printf(seq, "snapshot_time:	 %lu.%lu (secs.usecs)\n",
-		   now.tv_sec, (unsigned long)now.tv_usec);
+	seq_printf(seq, "snapshot_time:	 %llu.%09lu (secs.usecs)\n",
+		   (u64)now.tv_sec, (unsigned long)now.tv_nsec);
 
 	seq_printf(seq, "%15s %19s       | %20s\n", " ", "read", "write");
 	seq_printf(seq, "%13s   %14s %4s %4s  | %14s %4s %4s\n",
@@ -1396,13 +1396,13 @@ void ll_rw_stats_tally(struct ll_sb_info *sbi, pid_t pid,
 
 static int ll_rw_offset_stats_seq_show(struct seq_file *seq, void *v)
 {
-	struct timeval now;
+	struct timespec64 now;
 	struct ll_sb_info *sbi = seq->private;
 	struct ll_rw_process_info *offset = sbi->ll_rw_offset_info;
 	struct ll_rw_process_info *process = sbi->ll_rw_process_info;
 	int i;
 
-	do_gettimeofday(&now);
+	ktime_get_real_ts64(&now);
 
 	if (!sbi->ll_rw_stats_on) {
 		seq_printf(seq, "disabled\n"
@@ -1411,8 +1411,8 @@ static int ll_rw_offset_stats_seq_show(struct seq_file *seq, void *v)
 	}
 	spin_lock(&sbi->ll_process_lock);
 
-	seq_printf(seq, "snapshot_time:	 %lu.%lu (secs.usecs)\n",
-		   now.tv_sec, (unsigned long)now.tv_usec);
+	seq_printf(seq, "snapshot_time:	 %llu.%09lu (secs.usecs)\n",
+		   (s64)now.tv_sec, (unsigned long)now.tv_nsec);
 	seq_printf(seq, "%3s %10s %14s %14s %17s %17s %14s\n",
 		   "R/W", "PID", "RANGE START", "RANGE END",
 		   "SMALLEST EXTENT", "LARGEST EXTENT", "OFFSET");