Function arc_hdr_alloc

freebsd/contrib/openzfs/module/zfs/arc.c:3303–3346

}

static arc_buf_hdr_t *
arc_hdr_alloc(uint64_t spa, int32_t psize, int32_t lsize,
    boolean_t protected, enum zio_compress compression_type, uint8_t complevel,
    arc_buf_contents_t type, boolean_t alloc_rdata)
{
	arc_buf_hdr_t *hdr;
	int flags = ARC_HDR_DO_ADAPT;

	VERIFY(type == ARC_BUFC_DATA || type == ARC_BUFC_METADATA);
	if (protected) {
		hdr = kmem_cache_alloc(hdr_full_crypt_cache, KM_PUSHPAGE);
	} else {
		hdr = kmem_cache_alloc(hdr_full_cache, KM_PUSHPAGE);
	}
	flags |= alloc_rdata ? ARC_HDR_ALLOC_RDATA : 0;

	ASSERT(HDR_EMPTY(hdr));
	ASSERT3P(hdr->b_l1hdr.b_freeze_cksum, ==, NULL);
	HDR_SET_PSIZE(hdr, psize);
	HDR_SET_LSIZE(hdr, lsize);
	hdr->b_spa = spa;
	hdr->b_type = type;
	hdr->b_flags = 0;
	arc_hdr_set_flags(hdr, arc_bufc_to_flags(type) | ARC_FLAG_HAS_L1HDR);
	arc_hdr_set_compress(hdr, compression_type);
	hdr->b_complevel = complevel;
	if (protected)
		arc_hdr_set_flags(hdr, ARC_FLAG_PROTECTED);

	hdr->b_l1hdr.b_state = arc_anon;
	hdr->b_l1hdr.b_arc_access = 0;
	hdr->b_l1hdr.b_bufcnt = 0;
	hdr->b_l1hdr.b_buf = NULL;

	/*
	 * Allocate the hdr's buffer. This will contain either
	 * the compressed or uncompressed data depending on the block
	 * it references and compressed arc enablement.
	 */
	arc_hdr_alloc_abd(hdr, flags);
	ASSERT(zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt));

	return (hdr);
}

/*
 * Transition between the two allocation states for the arc_buf_hdr struct.