提交 0c7bfc32 编写于 作者: P Paolo Bonzini 提交者: Kevin Wolf

vdi: move end-of-I/O handling at the end

The next step is to take code that only triggers after the first operation,
and move it at the end of vdi_aio_read_cb and vdi_aio_write_cb.
Acked-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
上级 3d46a75a
......@@ -533,20 +533,7 @@ static int vdi_aio_read_cb(void *opaque, int ret)
uint32_t sector_in_block;
uint32_t n_sectors;
logout("%u sectors read\n", acb->n_sectors);
restart:
acb->nb_sectors -= acb->n_sectors;
if (acb->nb_sectors == 0) {
/* request completed */
ret = 0;
goto done;
}
acb->sector_num += acb->n_sectors;
acb->buf += acb->n_sectors * SECTOR_SIZE;
block_index = acb->sector_num / s->block_sectors;
sector_in_block = acb->sector_num % s->block_sectors;
n_sectors = s->block_sectors - sector_in_block;
......@@ -573,11 +560,16 @@ restart:
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
ret = bdrv_co_readv(bs->file, offset, n_sectors, &acb->hd_qiov);
}
if (ret >= 0) {
logout("%u sectors read\n", acb->n_sectors);
acb->nb_sectors -= acb->n_sectors;
acb->sector_num += acb->n_sectors;
acb->buf += acb->n_sectors * SECTOR_SIZE;
if (ret >= 0 && acb->nb_sectors > 0) {
goto restart;
}
done:
if (acb->qiov->niov > 1) {
qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
qemu_vfree(acb->orig_buf);
......@@ -609,56 +601,6 @@ static int vdi_aio_write_cb(void *opaque, int ret)
uint32_t n_sectors;
restart:
acb->nb_sectors -= acb->n_sectors;
acb->sector_num += acb->n_sectors;
acb->buf += acb->n_sectors * SECTOR_SIZE;
if (acb->nb_sectors == 0) {
logout("finished data write\n");
acb->n_sectors = 0;
ret = 0;
if (acb->header_modified) {
VdiHeader *header = acb->block_buffer;
logout("now writing modified header\n");
assert(VDI_IS_ALLOCATED(acb->bmap_first));
*header = s->header;
vdi_header_to_le(header);
acb->header_modified = 0;
acb->hd_iov.iov_base = acb->block_buffer;
acb->hd_iov.iov_len = SECTOR_SIZE;
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
ret = bdrv_co_writev(bs->file, 0, 1, &acb->hd_qiov);
}
if (ret >= 0 && VDI_IS_ALLOCATED(acb->bmap_first)) {
/* One or more new blocks were allocated. */
uint64_t offset;
uint32_t bmap_first;
uint32_t bmap_last;
g_free(acb->block_buffer);
acb->block_buffer = NULL;
bmap_first = acb->bmap_first;
bmap_last = acb->bmap_last;
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;
acb->bmap_first = VDI_UNALLOCATED;
acb->hd_iov.iov_base = (void *)((uint8_t *)&s->bmap[0] +
bmap_first * SECTOR_SIZE);
acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE;
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
logout("will write %u block map sectors starting from entry %u\n",
n_sectors, bmap_first);
ret = bdrv_co_writev(bs->file, offset, n_sectors, &acb->hd_qiov);
}
goto done;
}
logout("%u sectors written\n", acb->n_sectors);
block_index = acb->sector_num / s->block_sectors;
sector_in_block = acb->sector_num % s->block_sectors;
n_sectors = s->block_sectors - sector_in_block;
......@@ -709,11 +651,58 @@ restart:
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
ret = bdrv_co_writev(bs->file, offset, n_sectors, &acb->hd_qiov);
}
if (ret >= 0) {
acb->nb_sectors -= acb->n_sectors;
acb->sector_num += acb->n_sectors;
acb->buf += acb->n_sectors * SECTOR_SIZE;
logout("%u sectors written\n", acb->n_sectors);
if (ret >= 0 && acb->nb_sectors > 0) {
goto restart;
}
done:
logout("finished data write\n");
if (ret >= 0) {
ret = 0;
if (acb->header_modified) {
VdiHeader *header = acb->block_buffer;
logout("now writing modified header\n");
assert(VDI_IS_ALLOCATED(acb->bmap_first));
*header = s->header;
vdi_header_to_le(header);
acb->header_modified = 0;
acb->hd_iov.iov_base = acb->block_buffer;
acb->hd_iov.iov_len = SECTOR_SIZE;
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
ret = bdrv_co_writev(bs->file, 0, 1, &acb->hd_qiov);
}
if (ret >= 0 && VDI_IS_ALLOCATED(acb->bmap_first)) {
/* One or more new blocks were allocated. */
uint64_t offset;
uint32_t bmap_first;
uint32_t bmap_last;
g_free(acb->block_buffer);
acb->block_buffer = NULL;
bmap_first = acb->bmap_first;
bmap_last = acb->bmap_last;
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;
acb->bmap_first = VDI_UNALLOCATED;
acb->hd_iov.iov_base = (void *)((uint8_t *)&s->bmap[0] +
bmap_first * SECTOR_SIZE);
acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE;
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
logout("will write %u block map sectors starting from entry %u\n",
n_sectors, bmap_first);
ret = bdrv_co_writev(bs->file, offset, n_sectors, &acb->hd_qiov);
}
}
if (acb->qiov->niov > 1) {
qemu_vfree(acb->orig_buf);
}
......
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