/**************************************************************** * * * Copyright 2005, 2012 Fidelity Information Services, Inc * * * * This source code contains the intellectual property * * of its copyright holder(s), and is made available * * under a license. If you do not know the terms of * * the license, please stop and do not read further. * * * ****************************************************************/ #ifndef __JNL_GET_CHECKSUM_H_ #define __JNL_GET_CHECKSUM_H_ #define INIT_CHECKSUM_SEED 0xFFFFFFFF #define SLICE_BY 4 #define TABLE_SIZE 256 #define BYTEMASK 0xFF GBLREF uint4 csum_table[SLICE_BY][TABLE_SIZE]; #ifdef BIGENDIAN #define LOBYTE 0 #define ADJUST_CHECKSUM(cursum, num4, newsum) \ { \ uint4 tmpsum = csum_table[LOBYTE + 0][(cursum ^ num4) & BYTEMASK] ^ \ csum_table[LOBYTE + 1][((cursum ^ num4) >> (1 * BITS_PER_UCHAR)) & BYTEMASK] ^ \ csum_table[LOBYTE + 2][((cursum ^ num4) >> (2 * BITS_PER_UCHAR)) & BYTEMASK] ^ \ csum_table[LOBYTE + 3][((cursum ^ num4) >> (3 * BITS_PER_UCHAR)) & BYTEMASK]; \ newsum = tmpsum ? tmpsum : INIT_CHECKSUM_SEED; \ } #else #define HIBYTE 3 #define ADJUST_CHECKSUM(cursum, num4, newsum) \ { \ uint4 tmpsum = csum_table[HIBYTE - 0][(cursum ^ num4) & BYTEMASK] ^ \ csum_table[HIBYTE - 1][((cursum ^ num4) >> (1 * BITS_PER_UCHAR)) & BYTEMASK] ^ \ csum_table[HIBYTE - 2][((cursum ^ num4) >> (2 * BITS_PER_UCHAR)) & BYTEMASK] ^ \ csum_table[HIBYTE - 3][((cursum ^ num4) >> (3 * BITS_PER_UCHAR)) & BYTEMASK]; \ newsum = tmpsum ? tmpsum : INIT_CHECKSUM_SEED; \ } #endif #define ADJUST_CHECKSUM_TN(cursum, tn, newsum) \ { \ uint4 tmpsum_tn; \ ADJUST_CHECKSUM(cursum, *(uint4 *)tn, tmpsum_tn); \ ADJUST_CHECKSUM(tmpsum_tn, *(uint4 *)((char *)tn+SIZEOF(uint4)), newsum); \ } #define COMPUTE_COMMON_CHECKSUM(common_cksum, prefix) \ { \ ADJUST_CHECKSUM_TN(INIT_CHECKSUM_SEED, &(prefix.tn), common_cksum); \ ADJUST_CHECKSUM(common_cksum, prefix.pini_addr, common_cksum); \ ADJUST_CHECKSUM(common_cksum, prefix.time, common_cksum); \ } #define COMPUTE_PBLK_CHECKSUM(blk_checksum, pblk_rec, common_cksum, jrec_checksum) \ { \ ADJUST_CHECKSUM(blk_checksum, (pblk_rec)->prefix.jrec_type, jrec_checksum); \ ADJUST_CHECKSUM(jrec_checksum, (pblk_rec)->blknum, jrec_checksum); \ ADJUST_CHECKSUM(jrec_checksum, (pblk_rec)->bsiz, jrec_checksum); \ ADJUST_CHECKSUM(jrec_checksum, (pblk_rec)->ondsk_blkver, jrec_checksum); \ ADJUST_CHECKSUM(jrec_checksum, common_cksum, jrec_checksum); \ } #define COMPUTE_AIMG_CHECKSUM(blk_checksum, aimg_rec, common_cksum, jrec_checksum) \ COMPUTE_PBLK_CHECKSUM(blk_checksum, aimg_rec, common_cksum, jrec_checksum); #define COMPUTE_LOGICAL_REC_CHECKSUM(jfb_checksum, jrec, common_cksum, jrec_checksum) \ { \ ADJUST_CHECKSUM(jfb_checksum, (jrec)->prefix.jrec_type, jrec_checksum); \ ADJUST_CHECKSUM(jrec_checksum, (jrec)->update_num, jrec_checksum); \ ADJUST_CHECKSUM(jrec_checksum, (jrec)->token_seq.token, jrec_checksum); \ ADJUST_CHECKSUM(jrec_checksum, (jrec)->strm_seqno, jrec_checksum); \ ADJUST_CHECKSUM(jrec_checksum, (jrec)->num_participants, jrec_checksum); \ ADJUST_CHECKSUM(jrec_checksum, common_cksum, jrec_checksum); \ } /* This macro is to be used whenever we are computing the checksum of a block that has been acquired. */ #define JNL_GET_CHECKSUM_ACQUIRED_BLK(cse, csd, csa, old_blk, bsize) \ { \ cache_rec_ptr_t cr; \ boolean_t cr_is_null; \ \ GBLREF uint4 dollar_tlevel; \ \ /* Record current database tn before computing checksum of acquired block. This is used \ * later by the commit logic to determine if the block contents have changed (and hence \ * if recomputation of checksum is necessary). For BG, we have two-phase commit where \ * phase2 is done outside of crit. So it is possible that we note down the current database \ * tn and then compute checksums outside of crit and then get crit and yet in the validation \ * logic find the block header tn is LESSER than the noted dbtn (even though the block \ * contents changed after the noted dbtn). This will cause us to falsely validate this block \ * as not needing checksum recomputation. To ensure the checksum is recomputed inside crit, \ * we note down a tn of 0 in case the block is locked for update (cr->in_tend is non-zero). \ */ \ assert((gds_t_acquired == cse->mode) || (gds_t_create == cse->mode) \ || (gds_t_recycled2free == cse->mode)); \ assert(cse->old_block == (sm_uc_ptr_t)(old_blk)); \ assert((bsize) <= csd->blk_size); \ /* Since this macro is invoked only in case of before-image journaling and since MM does not \ * support before-image journaling, we can safely assert that BG is the only access method. \ */ \ assert(dba_bg == csd->acc_meth); \ /* In rare cases cse->cr can be NULL even though this block is an acquired block. This is \ * possible if we are in TP and this block was part of the tree in the initial phase of the \ * transaction but was marked free (by another process concurrently) in the later phase of \ * the same TP transaction. But this case is a sureshot restart situation so be safe and \ * ensure recomputation happens inside of crit just in case we dont restart. Also add asserts \ * (using donot_commit variable) to ensure we do restart this transaction. \ */ \ cr = cse->cr; \ cr_is_null = (NULL == cr); \ assert(!cr_is_null || dollar_tlevel); \ DEBUG_ONLY(if (cr_is_null) TREF(donot_commit) |= DONOTCOMMIT_JNLGETCHECKSUM_NULL_CR;) \ cse->tn = ((cr_is_null || cr->in_tend) ? 0 : csd->trans_hist.curr_tn); \ /* If cr is NULL, it is a restartable situation. So dont waste time computing checksums. Also \ * if the db is encrypted, we cannot get at the encryption global buffer (jnl_get_checksum \ * requires this) since we dont even have a regular global buffer corresponding to this block \ * so there is no way jnl_get_checksum can proceed in that case. So it is actually necessary \ * to avoid computing checksums if cr is NULL. \ */ \ cse->blk_checksum = !cr_is_null ? jnl_get_checksum((uint4 *)(old_blk), csa, (bsize)) : 0; \ } uint4 jnl_get_checksum(uint4 *buff, sgmnt_addrs *csa, int bufflen); uint4 compute_checksum(uint4 init_sum, uint4 *buff, int bufflen); #endif