Function dnode_dirty_l1range

freebsd/contrib/openzfs/module/zfs/dnode.c:1952–2016

* Dirty all the in-core level-1 dbufs in the range specified by start_blkid * and end_blkid. */

 * and end_blkid.
 */
static void
dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
    dmu_tx_t *tx)
{
	dmu_buf_impl_t *db_search;
	dmu_buf_impl_t *db;
	avl_index_t where;

	db_search = kmem_zalloc(sizeof (dmu_buf_impl_t), KM_SLEEP);

	mutex_enter(&dn->dn_dbufs_mtx);

	db_search->db_level = 1;
	db_search->db_blkid = start_blkid + 1;
	db_search->db_state = DB_SEARCH;
	for (;;) {

		db = avl_find(&dn->dn_dbufs, db_search, &where);
		if (db == NULL)
			db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);

		if (db == NULL || db->db_level != 1 ||
		    db->db_blkid >= end_blkid) {
			break;
		}

		/*
		 * Setup the next blkid we want to search for.
		 */
		db_search->db_blkid = db->db_blkid + 1;
		ASSERT3U(db->db_blkid, >=, start_blkid);

		/*
		 * If the dbuf transitions to DB_EVICTING while we're trying
		 * to dirty it, then we will be unable to discover it in
		 * the dbuf hash table. This will result in a call to
		 * dbuf_create() which needs to acquire the dn_dbufs_mtx
		 * lock. To avoid a deadlock, we drop the lock before
		 * dirtying the level-1 dbuf.
		 */
		mutex_exit(&dn->dn_dbufs_mtx);
		dnode_dirty_l1(dn, db->db_blkid, tx);
		mutex_enter(&dn->dn_dbufs_mtx);
	}

#ifdef ZFS_DEBUG
	/*
	 * Walk all the in-core level-1 dbufs and verify they have been dirtied.
	 */
	db_search->db_level = 1;
	db_search->db_blkid = start_blkid + 1;
	db_search->db_state = DB_SEARCH;
	db = avl_find(&dn->dn_dbufs, db_search, &where);
	if (db == NULL)
		db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
	for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) {
		if (db->db_level != 1 || db->db_blkid >= end_blkid)
			break;