svn commit: r355517 - head/sys/vm

[Jeff Roberson]

Author: jeff
Date: Sun Dec  8 01:55:23 2019
New Revision: 355517
URL: https://svnweb.freebsd.org/changeset/base/355517

Log:
  Fix two problems with r355149.  The sysctl name collision code assumed that
  zones would never be freed.  In the case of tmpfs this was not true.  While
  here test for the right bit to disable the keg related sysctls for zones
  that don't have kegs.
  
  Reported by:	pho
  Reviewed by:	rlibby
  Differential Revision:	https://reviews.freebsd.org/D22655

Modified:
  head/sys/vm/uma_core.c

Modified: head/sys/vm/uma_core.c
==============================================================================
--- head/sys/vm/uma_core.c	Sun Dec  8 01:49:53 2019	(r355516)
+++ head/sys/vm/uma_core.c	Sun Dec  8 01:55:23 2019	(r355517)
@@ -1859,14 +1859,13 @@ zone_alloc_counters(uma_zone_t zone, void *unused)
 	zone->uz_fails = counter_u64_alloc(M_WAITOK);
 }
 
-#define	UMA_MAX_DUP	999
 static void
 zone_alloc_sysctl(uma_zone_t zone, void *unused)
 {
 	uma_zone_domain_t zdom;
 	uma_keg_t keg;
 	struct sysctl_oid *oid, *domainoid;
-	int domains, i;
+	int domains, i, cnt;
 	static const char *nokeg = "cache zone";
 	char *c;
 
@@ -1876,10 +1875,11 @@ zone_alloc_sysctl(uma_zone_t zone, void *unused)
 	 * an index.
 	 */
 	if (zone->uz_namecnt != 0) {
-		if (zone->uz_namecnt > UMA_MAX_DUP)
-			zone->uz_namecnt = UMA_MAX_DUP;
-		zone->uz_ctlname = malloc(strlen(zone->uz_name) +
-		    sizeof(__XSTRING(UMA_MAX_DUP)) + 1 , M_UMA, M_WAITOK);
+		/* Count the number of decimal digits and '_' separator. */
+		for (i = 1, cnt = zone->uz_namecnt; cnt != 0; i++)
+			cnt /= 10;
+		zone->uz_ctlname = malloc(strlen(zone->uz_name) + i + 1,
+		    M_UMA, M_WAITOK);
 		sprintf(zone->uz_ctlname, "%s_%d", zone->uz_name,
 		    zone->uz_namecnt);
 	} else
@@ -1912,7 +1912,7 @@ zone_alloc_sysctl(uma_zone_t zone, void *unused)
 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
 	    "keg", CTLFLAG_RD, NULL, "");
 	keg = zone->uz_keg;
-	if ((zone->uz_flags & UMA_ZFLAG_CACHEONLY) == 0) {
+	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0) {
 		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
 		    "name", CTLFLAG_RD, keg->uk_name, "Keg name");
 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
@@ -2018,8 +2018,14 @@ zone_count(uma_zone_t zone, void *arg)
 	struct uma_zone_count *cnt;
 
 	cnt = arg;
+	/*
+	 * Some zones are rapidly created with identical names and
+	 * destroyed out of order.  This can lead to gaps in the count.
+	 * Use one greater than the maximum observed for this name.
+	 */
 	if (strcmp(zone->uz_name, cnt->name) == 0)
-		cnt->count++;
+		cnt->count = MAX(cnt->count,
+		    zone->uz_namecnt + 1);
 }
 
 /*