static int vdi_co_write(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors) { BDRVVdiState *s = bs->opaque; uint32_t bmap_entry; uint32_t block_index; uint32_t sector_in_block; uint32_t n_sectors; uint32_t bmap_first = VDI_UNALLOCATED; uint32_t bmap_last = VDI_UNALLOCATED; uint8_t *block = NULL; int ret; logout("\n"); restart: block_index = sector_num / s->block_sectors; sector_in_block = sector_num % s->block_sectors; n_sectors = s->block_sectors - sector_in_block; if (n_sectors > nb_sectors) { n_sectors = nb_sectors; } logout("will write %u sectors starting at sector %" PRIu64 "\n", n_sectors, sector_num); /* prepare next AIO request */ bmap_entry = le32_to_cpu(s->bmap[block_index]); if (!VDI_IS_ALLOCATED(bmap_entry)) { /* Allocate new block and write to it. */ uint64_t offset; bmap_entry = s->header.blocks_allocated; s->bmap[block_index] = cpu_to_le32(bmap_entry); s->header.blocks_allocated++; offset = s->header.offset_data / SECTOR_SIZE + (uint64_t)bmap_entry * s->block_sectors; if (block == NULL) { block = g_malloc(s->block_size); bmap_first = block_index; } bmap_last = block_index; /* Copy data to be written to new block and zero unused parts. */ memset(block, 0, sector_in_block * SECTOR_SIZE); memcpy(block + sector_in_block * SECTOR_SIZE, buf, n_sectors * SECTOR_SIZE); memset(block + (sector_in_block + n_sectors) * SECTOR_SIZE, 0, (s->block_sectors - n_sectors - sector_in_block) * SECTOR_SIZE); ret = bdrv_write(bs->file, offset, block, s->block_sectors); } else { uint64_t offset = s->header.offset_data / SECTOR_SIZE + (uint64_t)bmap_entry * s->block_sectors + sector_in_block; ret = bdrv_write(bs->file, offset, buf, n_sectors); } nb_sectors -= n_sectors; sector_num += n_sectors; buf += n_sectors * SECTOR_SIZE; logout("%u sectors written\n", n_sectors); if (ret >= 0 && nb_sectors > 0) { goto restart; } logout("finished data write\n"); if (ret < 0) { return ret; } if (block) { /* One or more new blocks were allocated. */ VdiHeader *header = (VdiHeader *) block; uint8_t *base; uint64_t offset; logout("now writing modified header\n"); assert(VDI_IS_ALLOCATED(bmap_first)); *header = s->header; vdi_header_to_le(header); ret = bdrv_write(bs->file, 0, block, 1); g_free(block); block = NULL; if (ret < 0) { return ret; } logout("now writing modified block map entry %u...%u\n", bmap_first, bmap_last); /* Write modified sectors from block map. */ bmap_first /= (SECTOR_SIZE / sizeof(uint32_t)); bmap_last /= (SECTOR_SIZE / sizeof(uint32_t)); n_sectors = bmap_last - bmap_first + 1; offset = s->bmap_sector + bmap_first; base = ((uint8_t *)&s->bmap[0]) + bmap_first * SECTOR_SIZE; logout("will write %u block map sectors starting from entry %u\n", n_sectors, bmap_first); ret = bdrv_write(bs->file, offset, base, n_sectors); } return ret; }
static int vdi_co_write(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors) { BDRVVdiState *s = bs->opaque; uint32_t bmap_entry; uint32_t block_index; uint32_t sector_in_block; uint32_t n_sectors; uint32_t bmap_first = VDI_UNALLOCATED; uint32_t bmap_last = VDI_UNALLOCATED; uint8_t *block = NULL; int ret; logout("\n"); restart: block_index = sector_num / s->block_sectors; sector_in_block = sector_num % s->block_sectors; n_sectors = s->block_sectors - sector_in_block; if (n_sectors > nb_sectors) { n_sectors = nb_sectors; } logout("will write %u sectors starting at sector %" PRIu64 "\n", n_sectors, sector_num);   bmap_entry = le32_to_cpu(s->bmap[block_index]); if (!VDI_IS_ALLOCATED(bmap_entry)) {   uint64_t offset; bmap_entry = s->header.blocks_allocated; s->bmap[block_index] = cpu_to_le32(bmap_entry); s->header.blocks_allocated++; offset = s->header.offset_data / SECTOR_SIZE + (uint64_t)bmap_entry * s->block_sectors; if (block == NULL) { block = g_malloc(s->block_size); bmap_first = block_index; } bmap_last = block_index;   memset(block, 0, sector_in_block * SECTOR_SIZE); memcpy(block + sector_in_block * SECTOR_SIZE, buf, n_sectors * SECTOR_SIZE); memset(block + (sector_in_block + n_sectors) * SECTOR_SIZE, 0, (s->block_sectors - n_sectors - sector_in_block) * SECTOR_SIZE); ret = bdrv_write(bs->file, offset, block, s->block_sectors); } else { uint64_t offset = s->header.offset_data / SECTOR_SIZE + (uint64_t)bmap_entry * s->block_sectors + sector_in_block; ret = bdrv_write(bs->file, offset, buf, n_sectors); } nb_sectors -= n_sectors; sector_num += n_sectors; buf += n_sectors * SECTOR_SIZE; logout("%u sectors written\n", n_sectors); if (ret >= 0 && nb_sectors > 0) { goto restart; } logout("finished data write\n"); if (ret < 0) { return ret; } if (block) {   VdiHeader *header = (VdiHeader *) block; uint8_t *base; uint64_t offset; logout("now writing modified header\n"); assert(VDI_IS_ALLOCATED(bmap_first)); *header = s->header; vdi_header_to_le(header); ret = bdrv_write(bs->file, 0, block, 1); g_free(block); block = NULL; if (ret < 0) { return ret; } logout("now writing modified block map entry %u...%u\n", bmap_first, bmap_last);   bmap_first /= (SECTOR_SIZE / sizeof(uint32_t)); bmap_last /= (SECTOR_SIZE / sizeof(uint32_t)); n_sectors = bmap_last - bmap_first + 1; offset = s->bmap_sector + bmap_first; base = ((uint8_t *)&s->bmap[0]) + bmap_first * SECTOR_SIZE; logout("will write %u block map sectors starting from entry %u\n", n_sectors, bmap_first); ret = bdrv_write(bs->file, offset, base, n_sectors); } return ret; }