Update gcc-unused

Fix new instances or changes in gcc flagged unused code.  These are
mostly related to variables which are not used when debugging is
disabled and the ASSERTs are compiled out.

cmd/zpool/zpool_main.c

@@ -2176,7 +2176,7 @@ get_interval_count(int *argcp, char **argv, unsigned long *iv,
     unsigned long *cnt)
 {
 	unsigned long interval = 0, count = 0;
-	int argc = *argcp, errno;
+	int argc = *argcp;
 
 	/*
 	 * Determine if the last argument is an integer or a pool name

module/zfs/dbuf.c

@@ -2303,7 +2303,7 @@ dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
 
 #ifdef ZFS_DEBUG
 	if (db->db_blkid == DMU_SPILL_BLKID) {
-		dnode_t *dn = db->db_dnode;
+		ASSERTV(dnode_t *dn = db->db_dnode);
 		ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
 		ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
 		    db->db_blkptr == &dn->dn_phys->dn_spill);
@@ -2382,7 +2382,7 @@ dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
 
 #ifdef ZFS_DEBUG
 	if (db->db_blkid == DMU_SPILL_BLKID) {
-		dnode_t *dn = db->db_dnode;
+		ASSERTV(dnode_t *dn = db->db_dnode);
 		ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
 		ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
 		    db->db_blkptr == &dn->dn_phys->dn_spill);

module/zfs/dmu.c

@@ -1146,8 +1146,8 @@ dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
 {
 	dmu_sync_arg_t *dsa = varg;
 	dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
-	dnode_t *dn = ((dmu_buf_impl_t *)db)->db_dnode;
 	blkptr_t *bp = zio->io_bp;
+	ASSERTV(dnode_t *dn = ((dmu_buf_impl_t *)db)->db_dnode);
 
 	if (zio->io_error == 0) {
 		if (BP_IS_HOLE(bp)) {

module/zfs/dmu_objset.c

@@ -954,7 +954,6 @@ dmu_objset_write_ready(zio_t *zio, arc_buf_t *abuf, void *arg)
 	blkptr_t *bp = zio->io_bp;
 	objset_t *os = arg;
 	dnode_phys_t *dnp = &os->os_phys->os_meta_dnode;
-	ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
 
 	ASSERT(bp == os->os_rootbp);
 	ASSERT(BP_GET_TYPE(bp) == DMU_OT_OBJSET);

module/zfs/dsl_dataset.c

@@ -1466,8 +1466,8 @@ static void
 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx)
 {
 	objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
-	uint64_t count;
 	int err;
+	ASSERTV(uint64_t count);
 
 	ASSERT(ds->ds_phys->ds_num_children >= 2);
 	err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
@@ -2474,7 +2474,6 @@ struct promotearg {
 };
 
 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
-static boolean_t snaplist_unstable(list_t *l);
 
 static int
 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)

module/zfs/sa.c

@@ -1121,9 +1121,9 @@ sa_byteswap(sa_handle_t *hdl, sa_buf_type_t buftype)
 {
 	sa_hdr_phys_t *sa_hdr_phys = SA_GET_HDR(hdl, buftype);
 	dmu_buf_impl_t *db;
-	sa_os_t *sa = hdl->sa_os->os_sa;
 	int num_lengths = 1;
 	int i;
+	ASSERTV(sa_os_t *sa = hdl->sa_os->os_sa);
 
 	ASSERT(MUTEX_HELD(&sa->sa_lock));
 	if (sa_hdr_phys->sa_magic == SA_MAGIC)
@@ -1224,7 +1224,7 @@ sa_idx_tab_rele(objset_t *os, void *arg)
 static void
 sa_idx_tab_hold(objset_t *os, sa_idx_tab_t *idx_tab)
 {
-	sa_os_t *sa = os->os_sa;
+	ASSERTV(sa_os_t *sa = os->os_sa);
 
 	ASSERT(MUTEX_HELD(&sa->sa_lock));
 	(void) refcount_add(&idx_tab->sa_refcount, NULL);
@@ -1260,10 +1260,10 @@ sa_handle_get_from_db(objset_t *os, dmu_buf_t *db, void *userp,
     sa_handle_type_t hdl_type, sa_handle_t **handlepp)
 {
 	int error = 0;
-	dmu_object_info_t doi;
 	sa_handle_t *handle;
-
 #ifdef ZFS_DEBUG
+	dmu_object_info_t doi;
+
 	dmu_object_info_from_db(db, &doi);
 	ASSERT(doi.doi_bonus_type == DMU_OT_SA ||
 	    doi.doi_bonus_type == DMU_OT_ZNODE);

module/zfs/vdev.c

@@ -1401,8 +1401,8 @@ vdev_validate(vdev_t *vd)
 void
 vdev_close(vdev_t *vd)
 {
-	ASSERTV(spa_t *spa = vd->vdev_spa);
 	vdev_t *pvd = vd->vdev_parent;
+	ASSERTV(spa_t *spa = vd->vdev_spa);
 
 	ASSERT(spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL);
 

module/zfs/zap_micro.c

@@ -1043,12 +1043,13 @@ zap_update(objset_t *os, uint64_t zapobj, const char *name,
 {
 	zap_t *zap;
 	mzap_ent_t *mze;
-	uint64_t oldval;
 	const uint64_t *intval = val;
 	zap_name_t *zn;
 	int err;
 
 #ifdef ZFS_DEBUG
+	uint64_t oldval;
+
 	/*
 	 * If there is an old value, it shouldn't change across the
 	 * lockdir (eg, due to bprewrite's xlation).

module/zfs/zil.c

@@ -78,8 +78,6 @@ boolean_t zfs_nocacheflush = B_FALSE;
 
 static kmem_cache_t *zil_lwb_cache;
 
-static boolean_t zil_empty(zilog_t *zilog);
-
 #define	LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \
     sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused))
 

module/zfs/zio.c

@@ -1939,12 +1939,12 @@ static void
 zio_ddt_ditto_write_done(zio_t *zio)
 {
 	int p = DDT_PHYS_DITTO;
-	zio_prop_t *zp = &zio->io_prop;
 	blkptr_t *bp = zio->io_bp;
 	ddt_t *ddt = ddt_select(zio->io_spa, bp);
 	ddt_entry_t *dde = zio->io_private;
 	ddt_phys_t *ddp = &dde->dde_phys[p];
 	ddt_key_t *ddk = &dde->dde_key;
+	ASSERTV(zio_prop_t *zp = &zio->io_prop);
 
 	ddt_enter(ddt);