1 files changed, 60 insertions, 8 deletions

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 81e7bb12aca6..7c863f2c21e0 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -331,12 +331,29 @@ static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
 	fsloc->locations = NULL;
 }
 
+static int export_stats_init(struct export_stats *stats)
+{
+	stats->start_time = ktime_get_seconds();
+	return nfsd_percpu_counters_init(stats->counter, EXP_STATS_COUNTERS_NUM);
+}
+
+static void export_stats_reset(struct export_stats *stats)
+{
+	nfsd_percpu_counters_reset(stats->counter, EXP_STATS_COUNTERS_NUM);
+}
+
+static void export_stats_destroy(struct export_stats *stats)
+{
+	nfsd_percpu_counters_destroy(stats->counter, EXP_STATS_COUNTERS_NUM);
+}
+
 static void svc_export_put(struct kref *ref)
 {
 	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
 	path_put(&exp->ex_path);
 	auth_domain_put(exp->ex_client);
 	nfsd4_fslocs_free(&exp->ex_fslocs);
+	export_stats_destroy(&exp->ex_stats);
 	kfree(exp->ex_uuid);
 	kfree_rcu(exp, ex_rcu);
 }
@@ -692,22 +709,47 @@ static void exp_flags(struct seq_file *m, int flag, int fsid,
 		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
 static void show_secinfo(struct seq_file *m, struct svc_export *exp);
 
+static int is_export_stats_file(struct seq_file *m)
+{
+	/*
+	 * The export_stats file uses the same ops as the exports file.
+	 * We use the file's name to determine the reported info per export.
+	 * There is no rename in nsfdfs, so d_name.name is stable.
+	 */
+	return !strcmp(m->file->f_path.dentry->d_name.name, "export_stats");
+}
+
 static int svc_export_show(struct seq_file *m,
 			   struct cache_detail *cd,
 			   struct cache_head *h)
 {
-	struct svc_export *exp ;
+	struct svc_export *exp;
+	bool export_stats = is_export_stats_file(m);
 
-	if (h ==NULL) {
-		seq_puts(m, "#path domain(flags)\n");
+	if (h == NULL) {
+		if (export_stats)
+			seq_puts(m, "#path domain start-time\n#\tstats\n");
+		else
+			seq_puts(m, "#path domain(flags)\n");
 		return 0;
 	}
 	exp = container_of(h, struct svc_export, h);
 	seq_path(m, &exp->ex_path, " \t\n\\");
 	seq_putc(m, '\t');
 	seq_escape(m, exp->ex_client->name, " \t\n\\");
+	if (export_stats) {
+		seq_printf(m, "\t%lld\n", exp->ex_stats.start_time);
+		seq_printf(m, "\tfh_stale: %lld\n",
+			   percpu_counter_sum_positive(&exp->ex_stats.counter[EXP_STATS_FH_STALE]));
+		seq_printf(m, "\tio_read: %lld\n",
+			   percpu_counter_sum_positive(&exp->ex_stats.counter[EXP_STATS_IO_READ]));
+		seq_printf(m, "\tio_write: %lld\n",
+			   percpu_counter_sum_positive(&exp->ex_stats.counter[EXP_STATS_IO_WRITE]));
+		seq_putc(m, '\n');
+		return 0;
+	}
 	seq_putc(m, '(');
-	if (test_bit(CACHE_VALID, &h->flags) && 
+	if (test_bit(CACHE_VALID, &h->flags) &&
 	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
 		exp_flags(m, exp->ex_flags, exp->ex_fsid,
 			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
@@ -748,6 +790,7 @@ static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
 	new->ex_layout_types = 0;
 	new->ex_uuid = NULL;
 	new->cd = item->cd;
+	export_stats_reset(&new->ex_stats);
 }
 
 static void export_update(struct cache_head *cnew, struct cache_head *citem)
@@ -780,10 +823,15 @@ static void export_update(struct cache_head *cnew, struct cache_head *citem)
 static struct cache_head *svc_export_alloc(void)
 {
 	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
-	if (i)
-		return &i->h;
-	else
+	if (!i)
+		return NULL;
+
+	if (export_stats_init(&i->ex_stats)) {
+		kfree(i);
 		return NULL;
+	}
+
+	return &i->h;
 }
 
 static const struct cache_detail svc_export_cache_template = {
@@ -1245,10 +1293,14 @@ static int e_show(struct seq_file *m, void *p)
 	struct cache_head *cp = p;
 	struct svc_export *exp = container_of(cp, struct svc_export, h);
 	struct cache_detail *cd = m->private;
+	bool export_stats = is_export_stats_file(m);
 
 	if (p == SEQ_START_TOKEN) {
 		seq_puts(m, "# Version 1.1\n");
-		seq_puts(m, "# Path Client(Flags) # IPs\n");
+		if (export_stats)
+			seq_puts(m, "# Path Client Start-time\n#\tStats\n");
+		else
+			seq_puts(m, "# Path Client(Flags) # IPs\n");
 		return 0;
 	}