FreeBSD: Fix up after spa_stats.c move

Moving spa_stats added the additional burden of supporting
KSTAT_TYPE_IO.

spa_state_addr will always return a valid value regardless of
the value of 'n'. On FreeBSD this will cause an infinite loop
as it relies on the raw ops addr routine to indicate that there
is no more data.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10860

Author: mattmacy

module/os/freebsd/spl/spl_kstat.c

@@ -83,6 +83,71 @@ kstat_raw_default_addr(kstat_t *ksp, loff_t n)
 	return (NULL);
 }
 
+static int
+kstat_sysctl(SYSCTL_HANDLER_ARGS)
+{
+	kstat_t *ksp = arg1;
+	kstat_named_t *ksent;
+	uint64_t val;
+
+	ksent = ksp->ks_data;
+	/* Select the correct element */
+	ksent += arg2;
+	/* Update the aggsums before reading */
+	(void) ksp->ks_update(ksp, KSTAT_READ);
+	val = ksent->value.ui64;
+
+	return (sysctl_handle_64(oidp, &val, 0, req));
+}
+
+static int
+kstat_sysctl_string(SYSCTL_HANDLER_ARGS)
+{
+	kstat_t *ksp = arg1;
+	kstat_named_t *ksent = ksp->ks_data;
+	char *val;
+	uint32_t len = 0;
+
+	/* Select the correct element */
+	ksent += arg2;
+	/* Update the aggsums before reading */
+	(void) ksp->ks_update(ksp, KSTAT_READ);
+	val = KSTAT_NAMED_STR_PTR(ksent);
+	len = KSTAT_NAMED_STR_BUFLEN(ksent);
+	val[len-1] = '\0';
+
+	return (sysctl_handle_string(oidp, val, len, req));
+}
+
+static int
+kstat_sysctl_io(SYSCTL_HANDLER_ARGS)
+{
+	struct sbuf *sb;
+	kstat_t *ksp = arg1;
+	kstat_io_t *kip = ksp->ks_data;
+	int rc;
+
+	sb = sbuf_new_auto();
+	if (sb == NULL)
+		return (ENOMEM);
+	/* Update the aggsums before reading */
+	(void) ksp->ks_update(ksp, KSTAT_READ);
+
+	/* though wlentime & friends are signed, they will never be negative */
+	sbuf_printf(sb,
+	    "%-8llu %-8llu %-8u %-8u %-8llu %-8llu "
+	    "%-8llu %-8llu %-8llu %-8llu %-8u %-8u\n",
+	    kip->nread, kip->nwritten,
+	    kip->reads, kip->writes,
+	    kip->wtime, kip->wlentime, kip->wlastupdate,
+	    kip->rtime, kip->rlentime, kip->rlastupdate,
+	    kip->wcnt,  kip->rcnt);
+	rc = sbuf_finish(sb);
+	if (rc == 0)
+		rc = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb));
+	sbuf_delete(sb);
+	return (rc);
+}
 
 static int
 kstat_sysctl_raw(SYSCTL_HANDLER_ARGS)
@@ -235,7 +300,7 @@ __kstat_create(const char *module, int instance, const char *name,
 		free(ksp, M_KSTAT);
 		return (NULL);
 	}
-	if (ksp->ks_type != KSTAT_TYPE_RAW) {
+	if (ksp->ks_type == KSTAT_TYPE_NAMED) {
 		root = SYSCTL_ADD_NODE(&ksp->ks_sysctl_ctx,
 		    SYSCTL_CHILDREN(root),
 		    OID_AUTO, name, CTLFLAG_RW, 0, "");
@@ -253,71 +318,14 @@ __kstat_create(const char *module, int instance, const char *name,
 	return (ksp);
 }
 
-static int
-kstat_sysctl(SYSCTL_HANDLER_ARGS)
+static void
+kstat_install_named(kstat_t *ksp)
 {
-	kstat_t *ksp = arg1;
-	kstat_named_t *ksent;
-	uint64_t val;
-
-	ksent = ksp->ks_data;
-	/* Select the correct element */
-	ksent += arg2;
-	/* Update the aggsums before reading */
-	(void) ksp->ks_update(ksp, KSTAT_READ);
-	val = ksent->value.ui64;
-
-	return (sysctl_handle_64(oidp, &val, 0, req));
-}
-
-static int
-kstat_sysctl_string(SYSCTL_HANDLER_ARGS)
-{
-	kstat_t *ksp = arg1;
-	kstat_named_t *ksent = ksp->ks_data;
-	char *val;
-	uint32_t len = 0;
-
-	/* Select the correct element */
-	ksent += arg2;
-	/* Update the aggsums before reading */
-	(void) ksp->ks_update(ksp, KSTAT_READ);
-	val = KSTAT_NAMED_STR_PTR(ksent);
-	len = KSTAT_NAMED_STR_BUFLEN(ksent);
-	val[len-1] = '\0';
-
-	return (sysctl_handle_string(oidp, val, len, req));
-}
-
-void
-kstat_install(kstat_t *ksp)
-{
-	struct sysctl_oid *root;
 	kstat_named_t *ksent;
 	char *namelast;
 	int typelast;
 
 	ksent = ksp->ks_data;
-	if (ksp->ks_ndata == UINT32_MAX)
-		VERIFY(ksp->ks_type == KSTAT_TYPE_RAW);
-	if (ksp->ks_type == KSTAT_TYPE_RAW) {
-		if (ksp->ks_raw_ops.data) {
-			root = SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
-			    SYSCTL_CHILDREN(ksp->ks_sysctl_root),
-			    OID_AUTO, ksp->ks_name,
-			    CTLTYPE_STRING | CTLFLAG_RD, ksp, 0,
-			    kstat_sysctl_raw, "A", ksp->ks_name);
-		} else {
-			root = SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
-			    SYSCTL_CHILDREN(ksp->ks_sysctl_root),
-			    OID_AUTO, ksp->ks_name,
-			    CTLTYPE_OPAQUE | CTLFLAG_RD, ksp, 0,
-			    kstat_sysctl_raw, "", ksp->ks_name);
-		}
-		VERIFY(root != NULL);
-		ksp->ks_sysctl_root = root;
-		return;
-	}
 
 	VERIFY((ksp->ks_flags & KSTAT_FLAG_VIRTUAL) || ksent != NULL);
 
@@ -387,6 +395,51 @@ kstat_install(kstat_t *ksp)
 		}
 
 	}
+
+}
+
+void
+kstat_install(kstat_t *ksp)
+{
+	struct sysctl_oid *root;
+
+	if (ksp->ks_ndata == UINT32_MAX)
+		VERIFY(ksp->ks_type == KSTAT_TYPE_RAW);
+
+	switch (ksp->ks_type) {
+		case KSTAT_TYPE_NAMED:
+			return (kstat_install_named(ksp));
+			break;
+		case KSTAT_TYPE_RAW:
+			if (ksp->ks_raw_ops.data) {
+				root = SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
+				    SYSCTL_CHILDREN(ksp->ks_sysctl_root),
+				    OID_AUTO, ksp->ks_name,
+				    CTLTYPE_STRING | CTLFLAG_RD, ksp, 0,
+				    kstat_sysctl_raw, "A", ksp->ks_name);
+			} else {
+				root = SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
+				    SYSCTL_CHILDREN(ksp->ks_sysctl_root),
+				    OID_AUTO, ksp->ks_name,
+				    CTLTYPE_OPAQUE | CTLFLAG_RD, ksp, 0,
+				    kstat_sysctl_raw, "", ksp->ks_name);
+			}
+			VERIFY(root != NULL);
+			break;
+		case KSTAT_TYPE_IO:
+			root = SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
+			    SYSCTL_CHILDREN(ksp->ks_sysctl_root),
+			    OID_AUTO, ksp->ks_name,
+			    CTLTYPE_STRING | CTLFLAG_RD, ksp, 0,
+			    kstat_sysctl_io, "A", ksp->ks_name);
+			break;
+		case KSTAT_TYPE_TIMER:
+		case KSTAT_TYPE_INTR:
+		default:
+			panic("unsupported kstat type %d\n", ksp->ks_type);
+	}
+	ksp->ks_sysctl_root = root;
+
 }
 
 void

module/zfs/spa_stats.c

@@ -835,7 +835,9 @@ spa_mmp_history_add(spa_t *spa, uint64_t txg, uint64_t timestamp,
 static void *
 spa_state_addr(kstat_t *ksp, loff_t n)
 {
-	return (ksp->ks_private);	/* return the spa_t */
+	if (n == 0)
+		return (ksp->ks_private);	/* return the spa_t */
+	return (NULL);
 }
 
 static int