/* * updates the status of erased blocks */ void ssd_update_free_block_status(int blk, int plane_num, ssd_element_metadata *metadata, ssd_t *s) { int bitpos; // clear the bit corresponding to this block in the // free blocks list for future use bitpos = ssd_block_to_bitpos(s, blk); ssd_clear_bit(metadata->free_blocks, bitpos); metadata->block_usage[blk].state = SSD_BLOCK_CLEAN; metadata->block_usage[blk].bsn = 0; metadata->tot_free_blocks ++; metadata->plane_meta[plane_num].free_blocks ++; ssd_assert_free_blocks(s, metadata); // there must be no valid pages in the erased block ASSERT(metadata->block_usage[blk].num_valid == 0); ssd_assert_valid_pages(plane_num, metadata, s); }
int _ssd_alloc_log_block(int plane_num, int elem_num, ssd_t *s, int data_block){ ssd_element_metadata *metadata = &(s->elements[elem_num].metadata); unsigned char *free_blocks = metadata->free_blocks; int active_block = -1; int prev_pos; int bitpos; int index; if (plane_num != -1) { prev_pos = metadata->plane_meta[plane_num].block_alloc_pos; } else { prev_pos = metadata->block_alloc_pos; } // find a free bit bitpos = ssd_find_zero_bit(free_blocks, s->params.blocks_per_element, prev_pos); ASSERT((bitpos >= 0) && (bitpos < s->params.blocks_per_element)); // check if we found the free bit in the plane we wanted to if (plane_num != -1) { if (ssd_bitpos_to_plane(bitpos, s) != plane_num) { //printf("Error: We wanted a free block in plane %d but found another in %d\n", // plane_num, ssd_bitpos_to_plane(bitpos, s)); //printf("So, starting the search again for plane %d\n", plane_num); // start from the beginning metadata->plane_meta[plane_num].block_alloc_pos = plane_num * s->params.blocks_per_plane; prev_pos = metadata->plane_meta[plane_num].block_alloc_pos; bitpos = ssd_find_zero_bit(free_blocks, s->params.blocks_per_element, prev_pos); ASSERT((bitpos >= 0) && (bitpos < s->params.blocks_per_element)); if (ssd_bitpos_to_plane(bitpos, s) != plane_num) { plane_num = ssd_bitpos_to_plane(bitpos, s); } } metadata->plane_meta[plane_num].block_alloc_pos = \ (plane_num * s->params.blocks_per_plane) + ((bitpos+1) % s->params.blocks_per_plane); } else { metadata->block_alloc_pos = (bitpos+1) % s->params.blocks_per_element; } // find the block num active_block = ssd_bitpos_to_block(bitpos, s); if (active_block != -1) { plane_metadata *pm; // make sure we're doing the right thing ASSERT(metadata->block_usage[active_block].plane_num == ssd_bitpos_to_plane(bitpos, s)); ASSERT(metadata->block_usage[active_block].bsn == 0); ASSERT(metadata->block_usage[active_block].num_valid == 0); ASSERT(metadata->block_usage[active_block].state == SSD_BLOCK_CLEAN); if (plane_num == -1) { plane_num = metadata->block_usage[active_block].plane_num; } else { ASSERT(plane_num == metadata->block_usage[active_block].plane_num); } pm = &metadata->plane_meta[plane_num]; // reduce the total number of free blocks metadata->tot_free_blocks --; pm->free_blocks --; //assertion ssd_assert_free_blocks(s, metadata); // allocate the block ssd_set_bit(free_blocks, bitpos); metadata->block_usage[active_block].state = SSD_BLOCK_INUSE; metadata->block_usage[active_block].bsn = metadata->bsn ++; //ssd_assert_plane_freebits(plane_num, elem_num, metadata, s); } else { fprintf(outputfile3, "Error: cannot find a free block in ssd element %d\n", elem_num); exit(-1); } metadata->num_log++; index = ssd_index_search(s, metadata); metadata->log_data[index].bsn = active_block; metadata->log_data[index].data_block = data_block; return index; }
/* * migrate data from a cold block to "to_blk" */ int ssd_migrate_cold_data(int to_blk, double *mcost, int plane_num, int elem_num, ssd_t *s) { int i; int from_blk = -1; double oldest_erase_time = simtime; double cost = 0; int bitpos; #if SSD_ASSERT_ALL int f1; int f2; #endif ssd_element_metadata *metadata = &(s->elements[elem_num].metadata); // first select the coldest of all blocks. // one way to select is to find the one that has the oldest // erasure time. if (plane_num == -1) { for (i = 0; i < s->params.blocks_per_element; i ++) { if (metadata->block_usage[i].num_valid > 0) { if (metadata->block_usage[i].time_of_last_erasure < oldest_erase_time) { oldest_erase_time = metadata->block_usage[i].time_of_last_erasure; from_blk = i; } } } } else { #if SSD_ASSERT_ALL f1 = ssd_free_bits(plane_num, elem_num, metadata, s); ASSERT(f1 == metadata->plane_meta[metadata->block_usage[to_blk].plane_num].free_blocks); #endif bitpos = plane_num * s->params.blocks_per_plane; for (i = bitpos; i < bitpos + (int)s->params.blocks_per_plane; i ++) { int block = ssd_bitpos_to_block(i, s); ASSERT(metadata->block_usage[block].plane_num == plane_num); if (metadata->block_usage[block].num_valid > 0) { if (metadata->block_usage[block].time_of_last_erasure < oldest_erase_time) { oldest_erase_time = metadata->block_usage[block].time_of_last_erasure; from_blk = block; } } } } ASSERT(from_blk != -1); if (plane_num != -1) { ASSERT(metadata->block_usage[from_blk].plane_num == metadata->block_usage[to_blk].plane_num); } // next, clean the block to which we'll transfer the // cold data cost += _ssd_clean_block_fully(to_blk, metadata->block_usage[to_blk].plane_num, elem_num, metadata, s); #if SSD_ASSERT_ALL if (plane_num != -1) { f2 = ssd_free_bits(plane_num, elem_num, metadata, s); ASSERT(f2 == metadata->plane_meta[metadata->block_usage[to_blk].plane_num].free_blocks); } #endif // then, migrate the cold data to the worn out block. // for which, we first read all the valid data cost += metadata->block_usage[from_blk].num_valid * s->params.page_read_latency; // include the write cost cost += metadata->block_usage[from_blk].num_valid * s->params.page_write_latency; // if the src and dest blocks are on different planes // include the transfer cost also cost += ssd_crossover_cost(s, metadata, from_blk, to_blk); // the cost of erasing the cold block (represented by from_blk) // will be added later ... // finally, update the metadata metadata->block_usage[to_blk].bsn = metadata->block_usage[from_blk].bsn; metadata->block_usage[to_blk].num_valid = metadata->block_usage[from_blk].num_valid; metadata->block_usage[from_blk].num_valid = 0; for (i = 0; i < s->params.pages_per_block; i ++) { int lpn = metadata->block_usage[from_blk].page[i]; if (lpn != -1) { ASSERT(metadata->lba_table[lpn] == (from_blk * s->params.pages_per_block + i)); metadata->lba_table[lpn] = to_blk * s->params.pages_per_block + i; } metadata->block_usage[to_blk].page[i] = metadata->block_usage[from_blk].page[i]; } metadata->block_usage[to_blk].state = metadata->block_usage[from_blk].state; bitpos = ssd_block_to_bitpos(s, to_blk); ssd_set_bit(metadata->free_blocks, bitpos); metadata->tot_free_blocks --; metadata->plane_meta[metadata->block_usage[to_blk].plane_num].free_blocks --; #if SSD_ASSERT_ALL if (plane_num != -1) { f2 = ssd_free_bits(plane_num, elem_num, metadata, s); ASSERT(f2 == metadata->plane_meta[metadata->block_usage[to_blk].plane_num].free_blocks); } #endif ssd_assert_free_blocks(s, metadata); ASSERT(metadata->block_usage[from_blk].num_valid == 0); #if ASSERT_FREEBITS if (plane_num != -1) { f2 = ssd_free_bits(plane_num, elem_num, metadata, s); ASSERT(f1 == f2); } #endif *mcost = cost; // stat metadata->tot_migrations ++; metadata->tot_pgs_migrated += metadata->block_usage[to_blk].num_valid; metadata->mig_cost += cost; return from_blk; }
/* * vp * description: this routine allocates and initializes the ssd element metadata * structures. FIXME: if the systems is powered up, this init routine has to * populate the structures by scanning the summary pages (to implement this, * we can read from a disk checkpoint file). but, this is future work. */ void ssd_element_metadata_init(int elem_number, ssd_element_metadata *metadata, ssd_t *currdisk) { gang_metadata *g; unsigned int ppage; unsigned int i; unsigned int bytes_to_alloc; unsigned int tot_blocks = currdisk->params.blocks_per_element; unsigned int tot_pages = tot_blocks * currdisk->params.pages_per_block; unsigned int reserved_blocks, usable_blocks, export_size; unsigned int reserved_blocks_per_plane, usable_blocks_per_plane; unsigned int bitpos; unsigned int active_block; unsigned int elem_index; unsigned int bsn = 1; int plane_block_mapping = currdisk->params.plane_block_mapping; ////////////////////////////////////////////////////////////////////////////// // active page starts at the 1st page on the reserved section reserved_blocks_per_plane = (currdisk->params.reserve_blocks * currdisk->params.blocks_per_plane) / 100; usable_blocks_per_plane = currdisk->params.blocks_per_plane - reserved_blocks_per_plane; reserved_blocks = reserved_blocks_per_plane * currdisk->params.planes_per_pkg; usable_blocks = usable_blocks_per_plane * currdisk->params.planes_per_pkg; ////////////////////////////////////////////////////////////////////////////// // initialize the free blocks and free pages metadata->tot_free_blocks = reserved_blocks; ////////////////////////////////////////////////////////////////////////////// // assign the gang and init the element's free pages metadata->gang_num = elem_number / currdisk->params.elements_per_gang; currdisk->gang_meta[metadata->gang_num].elem_free_pages[elem_number] = \ metadata->tot_free_blocks * SSD_DATA_PAGES_PER_BLOCK(currdisk); g = &currdisk->gang_meta[metadata->gang_num]; elem_index = elem_number % currdisk->params.elements_per_gang; ////////////////////////////////////////////////////////////////////////////// // let's begin cleaning with the first plane metadata->plane_to_clean = 0; metadata->plane_to_write = 0; metadata->block_alloc_pos = 0; metadata->reqs_waiting = 0; metadata->tot_migrations = 0; metadata->tot_pgs_migrated = 0; metadata->mig_cost = 0; ////////////////////////////////////////////////////////////////////////////// // init the plane metadata for (i = 0; i < (unsigned int)currdisk->params.planes_per_pkg; i ++) { int blocks_to_skip; switch(plane_block_mapping) { case PLANE_BLOCKS_CONCAT: assert(!"Refresh Operations not supported with PLANE_BLOCKS_CONCAT mapping"); blocks_to_skip = (i*currdisk->params.blocks_per_plane + usable_blocks_per_plane); break; case PLANE_BLOCKS_PAIRWISE_STRIPE: assert(!"Refresh Operations not supported with PLANE_BLOCKS_PAIRWISE_STRIPE mapping"); blocks_to_skip = (i/2)*(2*currdisk->params.blocks_per_plane) + (2*usable_blocks_per_plane) + i%2; break; case PLANE_BLOCKS_FULL_STRIPE: blocks_to_skip = (currdisk->params.planes_per_pkg * usable_blocks_per_plane) + i; break; default: fprintf(stderr, "Error: unknown plane_block_mapping %d\n", plane_block_mapping); exit(1); } //metadata->plane_meta[i].active_page = blocks_to_skip*currdisk->params.pages_per_block; metadata->plane_meta[i].free_blocks = reserved_blocks_per_plane; metadata->plane_meta[i].valid_pages = 0; metadata->plane_meta[i].clean_in_progress = 0; metadata->plane_meta[i].clean_in_block = -1; metadata->plane_meta[i].block_alloc_pos = i*currdisk->params.blocks_per_plane; metadata->plane_meta[i].parunit_num = i / SSD_PLANES_PER_PARUNIT(currdisk); metadata->plane_meta[i].num_cleans = 0; metadata->plane_meta[i].dead_blocks = 0; } ////////////////////////////////////////////////////////////////////////////// // init the next plane to clean in a parunit for (i = 0; i < (unsigned int) SSD_PARUNITS_PER_ELEM(currdisk); i ++) { metadata->parunits[i].plane_to_clean = SSD_PLANES_PER_PARUNIT(currdisk)*i; } // since we reserve one page out of every block to store the summary info, // the size exported by the flash disk is little less. export_size = usable_blocks * SSD_DATA_PAGES_PER_BLOCK(currdisk); currdisk->data_pages_per_elem = export_size; //printf("res blks = %d, use blks = %d act page = %d exp size = %d\n", // reserved_blocks, usable_blocks, metadata->active_page, export_size); ////////////////////////////////////////////////////////////////////////////// // allocate the lba table if ((metadata->lba_table = (int *)malloc(export_size * sizeof(int))) == NULL) { fprintf(stderr, "Error: malloc to lba table in ssd_element_metadata_init failed\n"); #ifdef __x86_64__ fprintf(stderr, "Allocation size = %lu\n", export_size * sizeof(int)); #else fprintf(stderr, "Allocation size = %u\n", export_size * sizeof(int)); #endif exit(1); } ////////////////////////////////////////////////////////////////////////////// // allocate the free blocks bit map // what if the no of blocks is not divisible by 8? if ((tot_blocks % (sizeof(unsigned char) * 8)) != 0) { fprintf(stderr, "This case is not yet handled\n"); exit(1); } bytes_to_alloc = tot_blocks / (sizeof(unsigned char) * 8); if (!(metadata->free_blocks = (unsigned char *)malloc(bytes_to_alloc))) { fprintf(stderr, "Error: malloc to free_blocks in ssd_element_metadata_init failed\n"); fprintf(stderr, "Allocation size = %d\n", bytes_to_alloc); exit(1); } bzero(metadata->free_blocks, bytes_to_alloc); ////////////////////////////////////////////////////////////////////////////// // allocate the block usage array and initialize it if (!(metadata->block_usage = (block_metadata *)malloc(tot_blocks * sizeof(block_metadata)))) { fprintf(stderr, "Error: malloc to block_usage in ssd_element_metadata_init failed\n"); #ifdef __x86_64__ fprintf(stderr, "Allocation size = %lu\n", tot_blocks * sizeof(block_metadata)); #else fprintf(stderr, "Allocation size = %u\n", tot_blocks * sizeof(block_metadata)); #endif exit(1); } bzero(metadata->block_usage, tot_blocks * sizeof(block_metadata)); for (i = 0; i < tot_blocks; i ++) { int j; metadata->block_usage[i].block_num = i; metadata->block_usage[i].elem_num = elem_number; metadata->block_usage[i].page = (ssd_page_metadata*)malloc(sizeof(ssd_page_metadata) * currdisk->params.pages_per_block); // KJ: initialize all the page metadata bzero(metadata->block_usage[i].page, currdisk->params.pages_per_block * sizeof(ssd_page_metadata)); metadata->block_usage[i].entry_in_refresh_queue= 0; metadata->block_usage[i].total_pages_written = INITIAL_STRESSES*currdisk->params.pages_per_block; metadata->block_usage[i].least_retention_page = &metadata->block_usage[i].page[0]; metadata->block_usage[i].logical_stresses = INITIAL_STRESSES*currdisk->params.pages_per_block; metadata->block_usage[i].physical_stresses = INITIAL_STRESSES*currdisk->params.pages_per_block; assert(metadata->block_usage[i].page); for (j = 0; j < currdisk->params.pages_per_block; j ++) { metadata->block_usage[i].page[j].lpn = -1; metadata->block_usage[i].page[j].time_of_last_stress = 0; metadata->block_usage[i].page[j].retention_period = 1e10; metadata->block_usage[i].page[j].logical_stresses= INITIAL_STRESSES; metadata->block_usage[i].page[j].physical_stresses = INITIAL_STRESSES; metadata->block_usage[i].page[j].eqn_cycle = INITIAL_STRESSES; metadata->block_usage[i].page[j].stress_increment = 1; metadata->block_usage[i].page[j].recovery_period_total = 0; } // assign the plane number to each block switch(plane_block_mapping) { case PLANE_BLOCKS_CONCAT: metadata->block_usage[i].plane_num = i / currdisk->params.blocks_per_plane; break; case PLANE_BLOCKS_PAIRWISE_STRIPE: metadata->block_usage[i].plane_num = (i/(2*currdisk->params.blocks_per_plane))*2 + i%2; break; case PLANE_BLOCKS_FULL_STRIPE: metadata->block_usage[i].plane_num = i % currdisk->params.planes_per_pkg; break; default: fprintf(stderr, "Error: unknown plane_block_mapping %d\n", plane_block_mapping); exit(1); } // set the remaining life time and time of last erasure metadata->block_usage[i].rem_lifetime = SSD_MAX_ERASURES; metadata->block_usage[i].time_of_last_erasure = simtime; // set the block state metadata->block_usage[i].state = SSD_BLOCK_CLEAN; // init the bsn to be zero metadata->block_usage[i].bsn = 0; } //load the ssd state from the snapshot provided by trace_analyzer. if(ta_snapshotfile) ssd_init_stress_info_ta(currdisk,metadata,elem_number); else if(ds_snapshotfile) ssd_init_stress_info_ds(currdisk,metadata,elem_number); //check for dead block status. int dead_block_count = 0; for (i=0;i<currdisk->params.blocks_per_element;i++) { if (i < usable_blocks) //temporarily mark blocks as in use. metadata->block_usage[i].state = SSD_BLOCK_INUSE; if (ssd_block_dead(&metadata->block_usage[i],currdisk)) dead_block_count++; else metadata->block_usage[i].state = SSD_BLOCK_CLEAN; } fprintf(stderr,"Dead blocks in element #%d : %d\n",elem_number,dead_block_count); if (dead_block_count >= reserved_blocks) { //if dead blocks more than overprovisioned blocks, then simulation cannot proceed further. fprintf(stderr,"Total reserved blocks : %d\n",reserved_blocks); fprintf(stderr,"Unable to proceed further as dead blocks more than reserved blocks\n"); fprintf(outputfile,"Total reserved blocks : %d\n",reserved_blocks); fprintf(outputfile,"Unable to proceed further as dead blocks more than reserved blocks\n"); fclose(outputfile); exit(1); } ssd_assert_free_blocks(currdisk,metadata); ////////////////////////////////////////////////////////////////////////////// // initially, we assume that every logical page is mapped // onto a physical page. we start from the first phy page // and continue to map, leaving the last page of every block // to store the summary information. ppage = 0; i = 0; while (i < export_size) { int pgnum_in_gang; int pp_index; int plane_num; unsigned int block = SSD_PAGE_TO_BLOCK(ppage, currdisk); ASSERT(block < (unsigned int)currdisk->params.blocks_per_element); if (metadata->block_usage[block].state == SSD_BLOCK_DEAD) { //block dead. dont use this block for future. bitpos = ssd_block_to_bitpos(currdisk, block); ssd_set_bit(metadata->free_blocks, bitpos); ppage+=currdisk->params.pages_per_block; continue; } // if this is the last page in the block if (ssd_last_page_in_block(ppage, currdisk)) { // leave this physical page for summary page and // seal the block metadata->block_usage[block].state = SSD_BLOCK_SEALED; //metadata->block_usage[block].page[currdisk->params.pages_per_block-1].logical_stresses++; //metadata->block_usage[block].total_pages_written++; // go to next block ppage ++; block = SSD_PAGE_TO_BLOCK(ppage, currdisk); } // if this block is in the reserved section, skip it // and go to the next block. switch(plane_block_mapping) { case PLANE_BLOCKS_CONCAT: { assert(!"Unsupported plane block mapping PLANE_BLOCKS_CONCAT"); unsigned int block_index = block % currdisk->params.blocks_per_plane; if ((block_index >= usable_blocks_per_plane) && (block_index < currdisk->params.blocks_per_plane)) { // go to next block ppage = ssd_first_page_in_next_block(ppage, currdisk); continue; } } break; case PLANE_BLOCKS_PAIRWISE_STRIPE: { assert(!"Unsupported plane block mapping PLANE_BLOCKS_PAIRWISE_STRIPE"); unsigned int block_index = block % (2*currdisk->params.blocks_per_plane); if ((block_index >= 2*usable_blocks_per_plane) && (block_index < 2*currdisk->params.blocks_per_plane)) { ppage = ssd_first_page_in_next_block(ppage, currdisk); continue; } } break; case PLANE_BLOCKS_FULL_STRIPE: if ((block >= usable_blocks+dead_block_count) && (block < (unsigned int)currdisk->params.blocks_per_element)) { printf("Error: the control should not come here ...\n"); ppage = ssd_first_page_in_next_block(ppage, currdisk); continue; } break; default: fprintf(stderr, "Error: unknown plane_block_mapping %d\n", plane_block_mapping); exit(1); } // when the control comes here, 'ppage' contains the next page // that can be assigned to a logical page. // find the index of the phy page within the block pp_index = ppage % currdisk->params.pages_per_block; // populate the lba table metadata->lba_table[i] = ppage; pgnum_in_gang = elem_index * export_size + i; g->pg2elem[pgnum_in_gang].e = elem_number; // mark this block as not free and its state as 'in use'. // note that a block could be not free and its state be 'sealed'. // it is enough if we set it once while working on the first phy page. // also increment the block sequence number. if (pp_index == 0) { bitpos = ssd_block_to_bitpos(currdisk, block); ssd_set_bit(metadata->free_blocks, bitpos); metadata->block_usage[block].state = SSD_BLOCK_INUSE; metadata->block_usage[block].bsn = bsn ++; } // increase the usage count per block plane_num = metadata->block_usage[block].plane_num; metadata->block_usage[block].page[pp_index].lpn = i; metadata->block_usage[block].page[pp_index].time_of_last_stress = simtime; metadata->block_usage[block].num_valid ++; metadata->plane_meta[plane_num].valid_pages ++; // go to the next physical page ppage ++; // go to the next logical page i ++; } ssd_assert_free_blocks(currdisk,metadata); ////////////////////////////////////////////////////////////////////////////// // init the element's active page as well as the plane's active page. int total_blocks = currdisk->params.blocks_per_plane * currdisk->params.planes_per_pkg; for (i = 0; i < (unsigned int)currdisk->params.planes_per_pkg; i ++) { int blocks_to_skip; switch(plane_block_mapping) { case PLANE_BLOCKS_CONCAT: assert(!"Refresh Operations not supported with PLANE_BLOCKS_CONCAT mapping"); blocks_to_skip = (i*currdisk->params.blocks_per_plane + usable_blocks_per_plane); break; case PLANE_BLOCKS_PAIRWISE_STRIPE: assert(!"Refresh Operations not supported with PLANE_BLOCKS_PAIRWISE_STRIPE mapping"); blocks_to_skip = (i/2)*(2*currdisk->params.blocks_per_plane) + (2*usable_blocks_per_plane) + i%2; break; case PLANE_BLOCKS_FULL_STRIPE: /*blocks_to_skip = (currdisk->params.planes_per_pkg * usable_blocks_per_plane) + i + metadata->plane_meta[i].dead_blocks;*/ blocks_to_skip = i; for (;blocks_to_skip<total_blocks;blocks_to_skip+=currdisk->params.planes_per_pkg) if(metadata->block_usage[blocks_to_skip].state==SSD_BLOCK_CLEAN) break; break; default: fprintf(stderr, "Error: unknown plane_block_mapping %d\n", plane_block_mapping); exit(1); } metadata->plane_meta[i].active_page = blocks_to_skip*currdisk->params.pages_per_block; //metadata->plane_meta[i].free_blocks = reserved_blocks_per_plane-metadata->plane_meta[i].dead_blocks; } switch(plane_block_mapping) { case PLANE_BLOCKS_CONCAT: assert(!"Refresh Operations not supported with PLANE_BLOCKS_CONCAT mapping"); metadata->active_page = usable_blocks_per_plane * currdisk->params.pages_per_block; break; case PLANE_BLOCKS_PAIRWISE_STRIPE: assert(!"Refresh Operations not supported with PLANE_BLOCKS_PAIRWISE_STRIPE mapping"); metadata->active_page = (2 * usable_blocks_per_plane) * currdisk->params.pages_per_block; break; case PLANE_BLOCKS_FULL_STRIPE: //metadata->active_page = currdisk->params.planes_per_pkg * (usable_blocks_per_plane+metadata->plane_meta[0].dead_blocks) * currdisk->params.pages_per_block; metadata->active_page = metadata->plane_meta[0].active_page; break; default: fprintf(stderr, "Error: unknown plane_block_mapping %d\n", plane_block_mapping); exit(1); } //ASSERT(metadata->active_page == metadata->plane_meta[0].active_page); active_block = metadata->active_page / currdisk->params.pages_per_block; ////////////////////////////////////////////////////////////////////////////// // mark the block that corresponds to the active page // as not free and 'in_use'. ssd_assert_free_blocks(currdisk,metadata); switch(currdisk->params.copy_back) { case SSD_COPY_BACK_DISABLE: assert(!"Refresh Operation not supported for copy back disabled parameter"); bitpos = ssd_block_to_bitpos(currdisk, active_block); ssd_set_bit(metadata->free_blocks, bitpos); metadata->block_usage[active_block].state = SSD_BLOCK_INUSE; metadata->block_usage[active_block].bsn = bsn ++; break; case SSD_COPY_BACK_ENABLE: for (i = 0; i < (unsigned int)currdisk->params.planes_per_pkg; i ++) { int plane_active_block = SSD_PAGE_TO_BLOCK(metadata->plane_meta[i].active_page, currdisk); bitpos = ssd_block_to_bitpos(currdisk, plane_active_block); ssd_set_bit(metadata->free_blocks, bitpos); metadata->block_usage[plane_active_block].state = SSD_BLOCK_INUSE; metadata->block_usage[plane_active_block].bsn = bsn ++; metadata->tot_free_blocks --; metadata->plane_meta[i].free_blocks --; } ssd_assert_free_blocks(currdisk,metadata); break; default: fprintf(stderr, "Error: invalid copy back policy %d\n", currdisk->params.copy_back); exit(1); } ////////////////////////////////////////////////////////////////////////////// // set the bsn for the ssd element metadata->bsn = bsn; //printf("set the bsn to %d\n", bsn); }