gfs2: Make statistics unsigned, suitable for use with do_div()

None of these statistics can meaningfully be negative, and the
numerator for do_div() must have the type u64.  The generic
implementation of do_div() used on some 32-bit architectures asserts
that, resulting in a compiler error in gfs2_rgrp_congested().

Fixes: 0166b19 ("GFS2: Average in only non-zero round-trip times ...")

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glock.c

@@ -1680,17 +1680,17 @@ static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr)
 {
 	struct gfs2_glock *gl = iter_ptr;
 
-	seq_printf(seq, "G: n:%u/%llx rtt:%lld/%lld rttb:%lld/%lld irt:%lld/%lld dcnt: %lld qcnt: %lld\n",
+	seq_printf(seq, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n",
 		   gl->gl_name.ln_type,
 		   (unsigned long long)gl->gl_name.ln_number,
-		   (long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
-		   (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
-		   (long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
-		   (long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
-		   (long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
-		   (long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
-		   (long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
-		   (long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
+		   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT],
+		   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR],
+		   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB],
+		   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB],
+		   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT],
+		   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR],
+		   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT],
+		   (unsigned long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]);
 	return 0;
 }
 
@@ -1727,7 +1727,7 @@ static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
 	loff_t pos = *(loff_t *)iter_ptr;
 	unsigned index = pos >> 3;
 	unsigned subindex = pos & 0x07;
-	s64 value;
+	u64 value;
 	int i;
 
 	if (index == 0 && subindex != 0)
@@ -1743,7 +1743,7 @@ static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr)
 		} else {
 			value = lkstats->lkstats[index - 1].stats[subindex];
 		}
-		seq_printf(seq, " %15lld", (long long)value);
+		seq_printf(seq, " %15llu", (long long)value);
 	}
 	seq_putc(seq, '\n');
 	return 0;

fs/gfs2/incore.h

@@ -244,7 +244,7 @@ enum {
 };
 
 struct gfs2_lkstats {
-	s64 stats[GFS2_NR_LKSTATS];
+	u64 stats[GFS2_NR_LKSTATS];
 };
 
 enum {

fs/gfs2/rgrp.c

@@ -1862,11 +1862,11 @@ static bool gfs2_rgrp_congested(const struct gfs2_rgrpd *rgd, int loops)
 	const struct gfs2_glock *gl = rgd->rd_gl;
 	const struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct gfs2_lkstats *st;
-	s64 r_dcount, l_dcount;
-	s64 l_srttb, a_srttb = 0;
+	u64 r_dcount, l_dcount;
+	u64 l_srttb, a_srttb = 0;
 	s64 srttb_diff;
-	s64 sqr_diff;
-	s64 var;
+	u64 sqr_diff;
+	u64 var;
 	int cpu, nonzero = 0;
 
 	preempt_disable();

fs/gfs2/trace_gfs2.h

@@ -267,14 +267,14 @@ TRACE_EVENT(gfs2_glock_lock_time,
 		__field(	int,	status		)
 		__field(	char,	flags		)
 		__field(	s64,	tdiff		)
-		__field(	s64,	srtt		)
-		__field(	s64,	srttvar		)
-		__field(	s64,	srttb		)
-		__field(	s64,	srttvarb	)
-		__field(	s64,	sirt		)
-		__field(	s64,	sirtvar		)
-		__field(	s64,	dcount		)
-		__field(	s64,	qcount		)
+		__field(	u64,	srtt		)
+		__field(	u64,	srttvar		)
+		__field(	u64,	srttb		)
+		__field(	u64,	srttvarb	)
+		__field(	u64,	sirt		)
+		__field(	u64,	sirtvar		)
+		__field(	u64,	dcount		)
+		__field(	u64,	qcount		)
 	),
 
 	TP_fast_assign(