range_tree: Provide more debug details upon unexpected add/remove

Sponsored-by: Klara, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <alexander.motin@TrueNAS.com>
Signed-off-by: Igor Ostapenko <igor.ostapenko@klarasystems.com>
Closes #17581

include/sys/metaslab_impl.h

@@ -568,6 +568,8 @@ typedef struct metaslab_unflushed_phys {
 	uint64_t	msp_unflushed_txg;
 } metaslab_unflushed_phys_t;
 
+char *metaslab_rt_name(metaslab_group_t *, metaslab_t *, const char *);
+
 #ifdef	__cplusplus
 }
 #endif

include/sys/range_tree.h

@@ -49,6 +49,9 @@ typedef enum zfs_range_seg_type {
 	ZFS_RANGE_SEG_NUM_TYPES,
 } zfs_range_seg_type_t;
 
+#define	ZFS_RT_NAME(rt)		(((rt)->rt_name != NULL) ? (rt)->rt_name : "")
+#define	ZFS_RT_F_DYN_NAME	(1ULL << 0) /* if rt_name must be freed */
+
 /*
  * Note: the range_tree may not be accessed concurrently; consumers
  * must provide external locking if required.
@@ -68,6 +71,9 @@ typedef struct zfs_range_tree {
 	void		*rt_arg;
 	uint64_t	rt_gap;		/* allowable inter-segment gap */
 
+	uint64_t	rt_flags;
+	const char	*rt_name;	/* details for debugging */
+
 	/*
 	 * The rt_histogram maintains a histogram of ranges. Each bucket,
 	 * rt_histogram[i], contains the number of ranges whose size is:
@@ -281,6 +287,9 @@ zfs_range_tree_t *zfs_range_tree_create_gap(const zfs_range_tree_ops_t *ops,
     uint64_t gap);
 zfs_range_tree_t *zfs_range_tree_create(const zfs_range_tree_ops_t *ops,
     zfs_range_seg_type_t type, void *arg, uint64_t start, uint64_t shift);
+zfs_range_tree_t *zfs_range_tree_create_flags(const zfs_range_tree_ops_t *ops,
+    zfs_range_seg_type_t type, void *arg, uint64_t start, uint64_t shift,
+    uint64_t flags, const char *name);
 void zfs_range_tree_destroy(zfs_range_tree_t *rt);
 boolean_t zfs_range_tree_contains(zfs_range_tree_t *rt, uint64_t start,
     uint64_t size);

include/sys/vdev_impl.h

@@ -651,6 +651,7 @@ uint64_t vdev_best_ashift(uint64_t logical, uint64_t a, uint64_t b);
 int param_get_raidz_impl(char *buf, zfs_kernel_param_t *kp);
 #endif
 int param_set_raidz_impl(ZFS_MODULE_PARAM_ARGS);
+char *vdev_rt_name(vdev_t *vd, const char *name);
 
 /*
  * Vdev ashift optimization tunables