Implement allocation size ranges and use for gang leaves

Signed-off-by: Paul Dagnelie <paul.dagnelie@klarasystems.com>

include/sys/metaslab.h

@@ -40,7 +40,7 @@ extern "C" {
 
 typedef struct metaslab_ops {
 	const char *msop_name;
-	uint64_t (*msop_alloc)(metaslab_t *, uint64_t);
+	uint64_t (*msop_alloc)(metaslab_t *, uint64_t, uint64_t, uint64_t *);
 } metaslab_ops_t;
 
 
@@ -85,7 +85,10 @@ uint64_t metaslab_largest_allocatable(metaslab_t *);
 
 int metaslab_alloc(spa_t *, metaslab_class_t *, uint64_t,
     blkptr_t *, int, uint64_t, blkptr_t *, int, zio_alloc_list_t *, zio_t *,
-	int);
+    int);
+int metaslab_alloc_range(spa_t *, metaslab_class_t *, uint64_t, uint64_t,
+    blkptr_t *, int, uint64_t, blkptr_t *, int, zio_alloc_list_t *, zio_t *,
+    int);
 int metaslab_alloc_dva(spa_t *, metaslab_class_t *, uint64_t,
     dva_t *, int, dva_t *, uint64_t, int, zio_alloc_list_t *, int);
 void metaslab_free(spa_t *, const blkptr_t *, uint64_t, boolean_t);
@@ -99,6 +102,7 @@ void metaslab_check_free(spa_t *, const blkptr_t *);
 
 void metaslab_stat_init(void);
 void metaslab_stat_fini(void);
+void metaslab_trace_move(zio_alloc_list_t *, zio_alloc_list_t *);
 void metaslab_trace_init(zio_alloc_list_t *);
 void metaslab_trace_fini(zio_alloc_list_t *);
 
@@ -129,6 +133,8 @@ uint64_t metaslab_group_get_space(metaslab_group_t *);
 void metaslab_group_histogram_verify(metaslab_group_t *);
 uint64_t metaslab_group_fragmentation(metaslab_group_t *);
 void metaslab_group_histogram_remove(metaslab_group_t *, metaslab_t *);
+void metaslab_group_alloc_increment_all(spa_t *, blkptr_t *, const void *,
+    int, int);
 void metaslab_group_alloc_decrement(spa_t *, uint64_t, const void *, int, int,
     boolean_t);
 void metaslab_group_alloc_verify(spa_t *, const blkptr_t *, const void *, int);

include/sys/zio.h

@@ -246,6 +246,7 @@ typedef uint64_t zio_flag_t;
 #define	ZIO_FLAG_REEXECUTED	(1ULL << 30)
 #define	ZIO_FLAG_DELEGATED	(1ULL << 31)
 #define	ZIO_FLAG_DIO_CHKSUM_ERR	(1ULL << 32)
+#define	ZIO_FLAG_PREALLOCATED	(1ULL << 33)
 
 #define	ZIO_ALLOCATOR_NONE	(-1)
 #define	ZIO_HAS_ALLOCATOR(zio)	((zio)->io_allocator != ZIO_ALLOCATOR_NONE)

man/man4/zfs.4

@@ -2499,20 +2499,6 @@ the xattr so as to not accumulate duplicates.
 .
 .It Sy zio_requeue_io_start_cut_in_line Ns = Ns Sy 0 Ns | Ns 1 Pq int
 Prioritize requeued I/O.
-.It Sy zio_dynamic_gang_headers_enable Ns = Ns Sy 0 Ns | Ns 1 Pq int
-Enable dynamically sized gang headers.
-.Pp
-When set to 0 (the default), the dynamic_gang_header feature will never be
-activated, even if it is enabled.
-All gang headers will store at most 3 children, regardless of the header's
-allocated size on disk.
-When set to 1, the dynamic_gang_header feature will be activated once a
-gang allocation is larger than 512 bytes.
-This will cause the gang header to store more more gang children on pools
-with larger ashifts.
-Enabling this flag and the feature will reduce multi-level gang trees,
-but can result in more IOs for individual gang blocks.
-.
 .It Sy zio_taskq_batch_pct Ns = Ns Sy 80 Ns % Pq uint
 Percentage of online CPUs which will run a worker thread for I/O.
 These workers are responsible for I/O work such as compression, encryption,