Hunt bug #25

src/fellow_cache.c

@@ -43,6 +43,8 @@
 
 #include "foreign/vend.h"
 
+#define BUG25_CHECK(fcs) assert(VTAILQ_NEXT(fcs, lru_list) != fcs)
+
 #ifdef TEST_DRIVER
 #define FCERR_INJECT
 #endif
@@ -1139,9 +1141,20 @@ fellow_cache_lru_chgbatch_apply(struct fellow_lru_chgbatch *lcb)
 		TAKE_OBJ_NOTNULL(fcs, &lcb->fcs[lcb->n_rem],
 		    FELLOW_CACHE_SEG_MAGIC);
 		assert(fcs->fco == fco);
+		BUG25_CHECK(fcs);
 		VTAILQ_REMOVE(&lru->lru_head, fcs, lru_list);
 	}
+	fcs = VTAILQ_FIRST(&lcb->add);
+	if (fcs)
+		BUG25_CHECK(fcs);
+	fcs = VTAILQ_FIRST(&lru->lru_head);
+	if (fcs)
+		BUG25_CHECK(fcs);
 	VTAILQ_CONCAT(&lru->lru_head, &lcb->add, lru_list);
+	fcs = VTAILQ_FIRST(&lru->lru_head);
+	if (fcs)
+		BUG25_CHECK(fcs);
+
 	AZ(pthread_mutex_unlock(&lru->lru_mtx));
 	lcb->n_add = 0;
 	AZ(lcb->n_rem);
@@ -1203,13 +1216,17 @@ fellow_cache_lru_chg(struct fellow_lru_chgbatch *lcb,
 		AZ(fcs->lcb_add);
 		AZ(fcs->lcb_remove);
 		fcs->lcb_add = 1;
+		BUG25_CHECK(fcs);
 		VTAILQ_INSERT_TAIL(&lcb->add, fcs, lru_list);
+		BUG25_CHECK(fcs);
 		lcb->n_add++;
 	}
 	else if (fcs->lcb_add) {
 		//DBG("%p -add", fcs);
 		AZ(fcs->lcb_remove);
+		BUG25_CHECK(fcs);
 		VTAILQ_REMOVE(&lcb->add, fcs, lru_list);
+		BUG25_CHECK(fcs);
 		fcs->lcb_add = 0;
 		AN(lcb->n_add);
 		lcb->n_add--;
@@ -3056,7 +3073,9 @@ fellow_cache_lru_seg_evict_locked(
 	fcs->fcs_onlru = 0;
 	AN(lru->n);
 	lru->n--;
+	BUG25_CHECK(fcs);
 	VTAILQ_REMOVE(&lru->lru_head, fcs, lru_list);
+	BUG25_CHECK(fcs);
 	fellow_cache_seg_evict_locked(fcs, alloc);
 }
 
@@ -3167,6 +3186,9 @@ fellow_cache_lru_work(struct worker *wrk, struct fellow_cache_lru *lru)
 	AZ(pthread_mutex_lock(&lru->lru_mtx));
 	//lint -e{850} loop variable modified in body
 	VTAILQ_FOREACH_SAFE(fcs, &lru->lru_head, lru_list, fcss) {
+		BUG25_CHECK(fcs);
+		if (fcss)
+			BUG25_CHECK(fcss);
 		// no use trying the same object again and again
 		if (fcs->fco == fco)
 			continue;
@@ -3180,6 +3202,9 @@ fellow_cache_lru_work(struct worker *wrk, struct fellow_cache_lru *lru)
 		}
 		if (fcs->state == FCS_INCORE) {
 			do {
+				BUG25_CHECK(fcs);
+				if (fcss)
+					BUG25_CHECK(fcss);
 				fellow_cache_lru_seg_evict_locked(fcs,
 				    &alloc, lru);
 				AN(buddy_return_ptr_extent(rets, &alloc));
@@ -3210,6 +3235,8 @@ fellow_cache_lru_work(struct worker *wrk, struct fellow_cache_lru *lru)
 			AN(lru->n);
 			lru->n--;
 			VTAILQ_REMOVE(&lru->lru_head, fcs, lru_list);
+			BUG25_CHECK(fcs);
+
 			AZ(pthread_mutex_unlock(&lru->lru_mtx));
 
 			r = stvfe_mutate(wrk, lru, oc);
@@ -3232,7 +3259,9 @@ fellow_cache_lru_work(struct worker *wrk, struct fellow_cache_lru *lru)
 			AN(fcs->fco_lru_mutate);
 			fcs->fco_lru_mutate = 0;
 
+			BUG25_CHECK(fcs);
 			VTAILQ_INSERT_TAIL(&lru->lru_head, fcs, lru_list);
+			BUG25_CHECK(fcs);
 			lru->n++;
 
 			AZ(pthread_mutex_unlock(&fco->mtx));
@@ -3454,8 +3483,11 @@ fellow_cache_obj_lru_touch(struct fellow_cache_obj *fco)
 		assert(r == EBUSY);
 		return (0);
 	}
+	BUG25_CHECK(fcs);
 	VTAILQ_REMOVE(&lru->lru_head, fcs, lru_list);
+	BUG25_CHECK(fcs);
 	VTAILQ_INSERT_TAIL(&lru->lru_head, fcs, lru_list);
+	BUG25_CHECK(fcs);
 	//lint -e{455} flexelint does not grok trylock
 	AZ(pthread_mutex_unlock(&lru->lru_mtx));