Tighten DLE array sizing

We should do this right and not over-allocate, this is just confusing.

src/fellow_cache.c

@@ -4037,7 +4037,7 @@ fdr_compar(const void *aa, const void *bb)
 static void
 fellow_busy_log_submit(const struct fellow_busy *fbo)
 {
-	unsigned r = 0, ndle = (fbo->nregion / DLE_REG_NREGION) + 2;
+	unsigned r = 0, ndle = DLE_N_REG(fbo->nregion) + 1;
 	struct fellow_dle *e, dle_obj[1], dles[ndle];
 	struct fellow_cache_obj *fco;
 	const struct fellow_disk_obj *fdo;
@@ -4058,11 +4058,13 @@ fellow_busy_log_submit(const struct fellow_busy *fbo)
 		r = fellow_dle_reg_fill(dles, ndle, fbo->region, fbo->nregion,
 		    DLE_REG_ADD, dle_obj->u.obj.hash);
 
+	assert(r < ndle);
 	e = &dles[r++];
 	e->type = DLEDSK(DLE_OBJ_ADD);
 	memcpy(&e->u.obj, &dle_obj->u.obj, sizeof e->u.obj);
 	e->u.obj.start = fbo->fco->fdb;
 
+	assert(r <= ndle);
 	fellow_log_dle_submit(fbo->fc->ffd, dles, r);
 
 #ifdef XXXDEBUG
@@ -4517,7 +4519,7 @@ fellow_disk_obj_delete_submit(struct fellow_fd *ffd,
     fellow_disk_block start, const uint8_t hash[DIGEST_LEN],
     const struct buddy_off_extent region[FCO_MAX_REGIONS], unsigned n)
 {
-	unsigned r, ndle = (n / DLE_REG_NREGION) + 2;
+	unsigned r, ndle = DLE_N_REG(n) + 1;
 	struct fellow_dle *e, dles[ndle];
 
 	fellow_dle_init(dles, ndle);
@@ -4527,11 +4529,13 @@ fellow_disk_obj_delete_submit(struct fellow_fd *ffd,
 	else
 		r = 0;
 
+	assert(r < ndle);
 	e = &dles[r++];
 	e->type = DLEDSK(DLE_OBJ_DEL_ALLOCED);
 	memcpy(e->u.obj.hash, hash, (size_t)DIGEST_LEN);
 	e->u.obj.start = start;
 
+	assert(r <= ndle);
 	fellow_log_dle_submit(ffd, dles, r);
 }
 

src/fellow_log.c

@@ -3506,7 +3506,7 @@ static void
 fellow_log_dle_ban_imm(struct fellow_fd *ffd, enum dle_type type,
     const uint8_t *bans, uint16_t len, vtim_real t)
 {
-	static const unsigned nentries = FELLOW_DISK_LOG_BLOCK_ENTRIES + 1;
+	static const unsigned nentries = FELLOW_DISK_LOG_BLOCK_ENTRIES;
 	struct fellow_dle dle[nentries], *e;
 	int8_t n, cont;
 	uint8_t *ban;
@@ -3561,6 +3561,7 @@ fellow_log_dle_ban_imm(struct fellow_fd *ffd, enum dle_type type,
 	AZ(len);
 	AZ(cont);
 	assert(n > 0);
+	assert((uint8_t)n <= nentries);
 	fellow_log_dle_submit(ffd, dle, (uint8_t)n);
 }
 

src/fellow_log_storage.h

@@ -81,6 +81,9 @@ DLE_TYPE_LIM
 	- (sizeof(int8_t) + sizeof(uint16_t) + sizeof(vtim_real)))
 #define DLE_BAN_REG_NREGION 3
 
+// roundup number of DLEs needed for x regions
+#define DLE_N_REG(x) ((x + (DLE_REG_NREGION)) / DLE_REG_NREGION)
+
 struct fellow_dle_reg {
 	// 4 - for sanity check
 	uint8_t			hashpfx[DLE_REG_HASHPFXSZ];