From fde9d56f5bf238bb126d9ddcf316083c40e6be28 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Mon, 25 Apr 2016 16:22:39 +0200 Subject: [PATCH] vdi: Implement .bdrv_co_pwritev() interface Signed-off-by: Kevin Wolf Reviewed-by: Fam Zheng --- block/vdi.c | 72 +++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 41 insertions(+), 31 deletions(-) diff --git a/block/vdi.c b/block/vdi.c index 8295511b72..e5fe4e8358 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -611,53 +611,55 @@ vdi_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, return ret; } -static int vdi_co_write(BlockDriverState *bs, - int64_t sector_num, const uint8_t *buf, int nb_sectors) +static int coroutine_fn +vdi_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes, + QEMUIOVector *qiov, int flags) { BDRVVdiState *s = bs->opaque; + QEMUIOVector local_qiov; uint32_t bmap_entry; uint32_t block_index; - uint32_t sector_in_block; - uint32_t n_sectors; + uint32_t offset_in_block; + uint32_t n_bytes; uint32_t bmap_first = VDI_UNALLOCATED; uint32_t bmap_last = VDI_UNALLOCATED; uint8_t *block = NULL; + uint64_t bytes_done = 0; int ret = 0; logout("\n"); - while (ret >= 0 && nb_sectors > 0) { - 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; - } + qemu_iovec_init(&local_qiov, qiov->niov); - logout("will write %u sectors starting at sector %" PRIu64 "\n", - n_sectors, sector_num); + while (ret >= 0 && bytes > 0) { + block_index = offset / s->block_size; + offset_in_block = offset % s->block_size; + n_bytes = MIN(bytes, s->block_size - offset_in_block); + + logout("will write %u bytes starting at offset %" PRIu64 "\n", + n_bytes, offset); /* 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; + uint64_t data_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; + data_offset = s->header.offset_data + + (uint64_t)bmap_entry * s->block_size; 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); + memset(block, 0, offset_in_block); + qemu_iovec_to_buf(qiov, bytes_done, block + offset_in_block, + n_bytes); + memset(block + offset_in_block + n_bytes, 0, + s->block_size - n_bytes - offset_in_block); /* Note that this coroutine does not yield anywhere from reading the * bmap entry until here, so in regards to all the coroutines trying @@ -667,12 +669,12 @@ static int vdi_co_write(BlockDriverState *bs, * acquire the lock and thus the padded cluster is written before * the other coroutines can write to the affected area. */ qemu_co_mutex_lock(&s->write_lock); - ret = bdrv_write(bs->file->bs, offset, block, s->block_sectors); + ret = bdrv_pwrite(bs->file->bs, data_offset, block, s->block_size); qemu_co_mutex_unlock(&s->write_lock); } else { - uint64_t offset = s->header.offset_data / SECTOR_SIZE + - (uint64_t)bmap_entry * s->block_sectors + - sector_in_block; + uint64_t data_offset = s->header.offset_data + + (uint64_t)bmap_entry * s->block_size + + offset_in_block; qemu_co_mutex_lock(&s->write_lock); /* This lock is only used to make sure the following write operation * is executed after the write issued by the coroutine allocating @@ -683,16 +685,23 @@ static int vdi_co_write(BlockDriverState *bs, * that that write operation has returned (there may be other writes * in flight, but they do not concern this very operation). */ qemu_co_mutex_unlock(&s->write_lock); - ret = bdrv_write(bs->file->bs, offset, buf, n_sectors); + + qemu_iovec_reset(&local_qiov); + qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes); + + ret = bdrv_co_pwritev(bs->file->bs, data_offset, n_bytes, + &local_qiov, 0); } - nb_sectors -= n_sectors; - sector_num += n_sectors; - buf += n_sectors * SECTOR_SIZE; + bytes -= n_bytes; + offset += n_bytes; + bytes_done += n_bytes; - logout("%u sectors written\n", n_sectors); + logout("%u bytes written\n", n_bytes); } + qemu_iovec_destroy(&local_qiov); + logout("finished data write\n"); if (ret < 0) { return ret; @@ -703,6 +712,7 @@ static int vdi_co_write(BlockDriverState *bs, VdiHeader *header = (VdiHeader *) block; uint8_t *base; uint64_t offset; + uint32_t n_sectors; logout("now writing modified header\n"); assert(VDI_IS_ALLOCATED(bmap_first)); @@ -914,7 +924,7 @@ static BlockDriver bdrv_vdi = { .bdrv_co_preadv = vdi_co_preadv, #if defined(CONFIG_VDI_WRITE) - .bdrv_write = vdi_co_write, + .bdrv_co_pwritev = vdi_co_pwritev, #endif .bdrv_get_info = vdi_get_info, -- 2.11.4.GIT