zfs recv hangs if max recordsize is less than received recordsize

- Some optimizations for bqueue enqueue/dequeue.
- Added a fix to prevent deadlock when both bqueue_enqueue_impl()
and bqueue_dequeue() waits for signal to be triggered.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes #13855

include/sys/bqueue.h

@@ -30,22 +30,22 @@ typedef struct bqueue {
 	kmutex_t bq_lock;
 	kcondvar_t bq_add_cv;
 	kcondvar_t bq_pop_cv;
-	uint64_t bq_size;
-	uint64_t bq_maxsize;
-	uint64_t bq_fill_fraction;
+	size_t bq_size;
+	size_t bq_maxsize;
+	uint_t bq_fill_fraction;
 	size_t bq_node_offset;
 } bqueue_t;
 
 typedef struct bqueue_node {
 	list_node_t bqn_node;
-	uint64_t bqn_size;
+	size_t bqn_size;
 } bqueue_node_t;
 
 
-int bqueue_init(bqueue_t *, uint64_t, uint64_t, size_t);
+int bqueue_init(bqueue_t *, uint_t, size_t, size_t);
 void bqueue_destroy(bqueue_t *);
-void bqueue_enqueue(bqueue_t *, void *, uint64_t);
-void bqueue_enqueue_flush(bqueue_t *, void *, uint64_t);
+void bqueue_enqueue(bqueue_t *, void *, size_t);
+void bqueue_enqueue_flush(bqueue_t *, void *, size_t);
 void *bqueue_dequeue(bqueue_t *);
 boolean_t bqueue_empty(bqueue_t *);
 

include/sys/fs/zfs.h

@@ -1758,9 +1758,9 @@ typedef enum {
  * against the cost of COWing a giant block to modify one byte, and the
  * large latency of reading or writing a large block.
  *
- * Note that although blocks up to 16MB are supported, the recordsize
- * property can not be set larger than zfs_max_recordsize (default 1MB).
- * See the comment near zfs_max_recordsize in dsl_dataset.c for details.
+ * The recordsize property can not be set larger than zfs_max_recordsize
+ * (default 16MB on 64-bit and 1MB on 32-bit). See the comment near
+ * zfs_max_recordsize in dsl_dataset.c for details.
  *
  * Note that although the LSIZE field of the blkptr_t can store sizes up
  * to 32MB, the dnode's dn_datablkszsec can only store sizes up to