Rename range_tree_verify to range_tree_verify_not_present

The range_tree_verify function looks for a segment in a
range tree and panics if the segment is present on the
tree. This patch gives the function a more descriptive
name.

Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes openzfs#8327

cmd/zdb/zdb.c

@@ -4858,7 +4858,8 @@ verify_checkpoint_sm_entry_cb(space_map_entry_t *sme, void *arg)
 	 * their respective ms_allocateable trees should not contain them.
 	 */
 	mutex_enter(&ms->ms_lock);
-	range_tree_verify(ms->ms_allocatable, sme->sme_offset, sme->sme_run);
+	range_tree_verify_not_present(ms->ms_allocatable,
+	    sme->sme_offset, sme->sme_run);
 	mutex_exit(&ms->ms_lock);
 
 	return (0);
@@ -5009,7 +5010,7 @@ verify_checkpoint_ms_spacemaps(spa_t *checkpoint, spa_t *current)
 			 * are part of the checkpoint were freed by mistake.
 			 */
 			range_tree_walk(ckpoint_msp->ms_allocatable,
-			    (range_tree_func_t *)range_tree_verify,
+			    (range_tree_func_t *)range_tree_verify_not_present,
 			    current_msp->ms_allocatable);
 		}
 	}

include/sys/range_tree.h

@@ -89,12 +89,13 @@ range_tree_t *range_tree_create_impl(range_tree_ops_t *ops, void *arg,
 range_tree_t *range_tree_create(range_tree_ops_t *ops, void *arg);
 void range_tree_destroy(range_tree_t *rt);
 boolean_t range_tree_contains(range_tree_t *rt, uint64_t start, uint64_t size);
+void range_tree_verify_not_present(range_tree_t *rt,
+    uint64_t start, uint64_t size);
 range_seg_t *range_tree_find(range_tree_t *rt, uint64_t start, uint64_t size);
 void range_tree_resize_segment(range_tree_t *rt, range_seg_t *rs,
     uint64_t newstart, uint64_t newsize);
 uint64_t range_tree_space(range_tree_t *rt);
 boolean_t range_tree_is_empty(range_tree_t *rt);
-void range_tree_verify(range_tree_t *rt, uint64_t start, uint64_t size);
 void range_tree_swap(range_tree_t **rtsrc, range_tree_t **rtdst);
 void range_tree_stat_verify(range_tree_t *rt);
 uint64_t range_tree_min(range_tree_t *rt);

module/zfs/metaslab.c

@@ -4256,14 +4256,16 @@ metaslab_check_free_impl(vdev_t *vd, uint64_t offset, uint64_t size)
 	msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
 
 	mutex_enter(&msp->ms_lock);
-	if (msp->ms_loaded)
-		range_tree_verify(msp->ms_allocatable, offset, size);
+	if (msp->ms_loaded) {
+		range_tree_verify_not_present(msp->ms_allocatable,
+		    offset, size);
+	}
 
-	range_tree_verify(msp->ms_freeing, offset, size);
-	range_tree_verify(msp->ms_checkpointing, offset, size);
-	range_tree_verify(msp->ms_freed, offset, size);
+	range_tree_verify_not_present(msp->ms_freeing, offset, size);
+	range_tree_verify_not_present(msp->ms_checkpointing, offset, size);
+	range_tree_verify_not_present(msp->ms_freed, offset, size);
 	for (int j = 0; j < TXG_DEFER_SIZE; j++)
-		range_tree_verify(msp->ms_defer[j], offset, size);
+		range_tree_verify_not_present(msp->ms_defer[j], offset, size);
 	mutex_exit(&msp->ms_lock);
 }
 

module/zfs/range_tree.c

@@ -511,13 +511,11 @@ range_tree_find(range_tree_t *rt, uint64_t start, uint64_t size)
 }
 
 void
-range_tree_verify(range_tree_t *rt, uint64_t off, uint64_t size)
+range_tree_verify_not_present(range_tree_t *rt, uint64_t off, uint64_t size)
 {
-	range_seg_t *rs;
-
-	rs = range_tree_find(rt, off, size);
+	range_seg_t *rs = range_tree_find(rt, off, size);
 	if (rs != NULL)
-		panic("freeing free block; rs=%p", (void *)rs);
+		panic("segment already in tree; rs=%p", (void *)rs);
 }
 
 boolean_t