Function metaslab_alloc

freebsd/contrib/openzfs/module/zfs/metaslab.c:5781–5836

}

int
metaslab_alloc(spa_t *spa, metaslab_class_t *mc, uint64_t psize, blkptr_t *bp,
    int ndvas, uint64_t txg, blkptr_t *hintbp, int flags,
    zio_alloc_list_t *zal, zio_t *zio, int allocator)
{
	dva_t *dva = bp->blk_dva;
	dva_t *hintdva = (hintbp != NULL) ? hintbp->blk_dva : NULL;
	int error = 0;

	ASSERT(bp->blk_birth == 0);
	ASSERT(BP_PHYSICAL_BIRTH(bp) == 0);

	spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);

	if (mc->mc_allocator[allocator].mca_rotor == NULL) {
		/* no vdevs in this class */
		spa_config_exit(spa, SCL_ALLOC, FTAG);
		return (SET_ERROR(ENOSPC));
	}

	ASSERT(ndvas > 0 && ndvas <= spa_max_replication(spa));
	ASSERT(BP_GET_NDVAS(bp) == 0);
	ASSERT(hintbp == NULL || ndvas <= BP_GET_NDVAS(hintbp));
	ASSERT3P(zal, !=, NULL);

	for (int d = 0; d < ndvas; d++) {
		error = metaslab_alloc_dva(spa, mc, psize, dva, d, hintdva,
		    txg, flags, zal, allocator);
		if (error != 0) {
			for (d--; d >= 0; d--) {
				metaslab_unalloc_dva(spa, &dva[d], txg);
				metaslab_group_alloc_decrement(spa,
				    DVA_GET_VDEV(&dva[d]), zio, flags,
				    allocator, B_FALSE);
				bzero(&dva[d], sizeof (dva_t));
			}
			spa_config_exit(spa, SCL_ALLOC, FTAG);
			return (error);
		} else {
			/*
			 * Update the metaslab group's queue depth
			 * based on the newly allocated dva.
			 */
			metaslab_group_alloc_increment(spa,
			    DVA_GET_VDEV(&dva[d]), zio, flags, allocator);
		}
	}
	ASSERT(error == 0);
	ASSERT(BP_GET_NDVAS(bp) == ndvas);

	spa_config_exit(spa, SCL_ALLOC, FTAG);

	BP_SET_BIRTH(bp, txg, 0);

	return (0);
}

void