fellow_cache: latch fellow_cache_seglists_load() errors

src/fellow_cache.c

@@ -789,6 +789,16 @@ struct fellow_cache_obj {
 #define FCR_ALLOCFAIL(str) FCR_ALLOCERR(FC_ERRSTR(str))
 #define FCR_IOFAIL(str) FCR_IOERR(FC_ERRSTR(str))
 
+static inline void
+fco_latch_err(struct fellow_cache_obj *fco, struct fellow_cache_res res)
+{
+	assert(res.status != fcr_ok);
+	if (fco->res.status != fcr_ok)
+		return;
+	fco->res = res;
+}
+
+
 const char * const fellow_cache_res_s[FCR_LIM] = {
 	[fcr_ok] = "ok",
 	[fcr_allocerr] = "allocation",
@@ -2144,6 +2154,7 @@ fellow_cache_seglists_load(struct worker *wrk, void *priv)
 
 	struct fellow_lru_chgbatch lcb[1] =
 	    FELLOW_LRU_CHGBATCH_INIT(lcb, fco, 1);
+	struct fellow_cache_res res = FCR_OK(NULL);
 
 	// invalidates fclsp, no use after this point
 	TAKE(mem, fclsp->mem);
@@ -2182,7 +2193,7 @@ fellow_cache_seglists_load(struct worker *wrk, void *priv)
 		fdsl = fdsl_mem.ptr;
 		//if (FC_INJ || fdsl == NULL) {
 		if (fdsl == NULL) {
-			err = FC_ERRSTR("disk seglist fdsl alloc failed");
+			res = FCR_ALLOCFAIL("disk seglist fdsl");
 			goto err;
 		}
 		assert(fdsl_mem.size >= next.size);
@@ -2190,19 +2201,20 @@ fellow_cache_seglists_load(struct worker *wrk, void *priv)
 		ssz = fellow_io_pread_sync(fc->ffd, fdsl, next.size, next.off);
 		//if (FC_INJ || ssz < 0 || (size_t)ssz != next.size) {
 		if (ssz < 0 || (size_t)ssz != next.size) {
-			err = FC_ERRSTR("disk seglist read failed");
+			res = FCR_IOFAIL("disk seglist read");
 			goto err;
 		}
 		err = fellow_disk_seglist_check(fdsl);
-		if (err != NULL)
+		if (err != NULL) {
+			res = FCR_IOFAIL(err);
 			goto err;
-
+		}
 		fcsl_mem = buddy_alloc1_ptr_extent_wait(fc->membuddy, FEP_META,
 		    SEGLIST_SIZE(fcsl, fdsl->nsegs), 0);
 
 		//if (FC_INJ || fcsl_mem.ptr == NULL) {
 		if (fcsl_mem.ptr == NULL) {
-			err = FC_ERRSTR("disk seglist fcsl alloc failed");
+			res = FCR_ALLOCFAIL("disk seglist fcsl");
 			goto err;
 		}
 
@@ -2251,6 +2263,7 @@ fellow_cache_seglists_load(struct worker *wrk, void *priv)
 		fellow_cache_seg_transition_locked(lcb, FCO_FCS(fco),
 		    FCO_STATE(fco), FCO_READFAIL);
 	}
+	fco_latch_err(fco, res);
 	refcnt = fellow_cache_obj_deref_locked(lcb, fc, fco);
 	AZ(pthread_cond_broadcast(&fco->cond));
 	fellow_cache_lru_chgbatch_apply(lcb);
@@ -2259,12 +2272,6 @@ fellow_cache_seglists_load(struct worker *wrk, void *priv)
 		fellow_cache_obj_free(fc, &fco);
 	else
 		AZ(pthread_mutex_unlock(&fco->mtx));
-
-	// XXX where to store?
-	(void)err;
-
-	// XXX handle
-	//INCOMPL();
 }
 
 static void