qcow2: Implement .bdrv_co_pwritev()
This changes qcow2 to implement the byte-based .bdrv_co_pwritev
interface rather than the sector-based old one.
As preallocation uses the same allocation function as normal writes, and
the interface of that function needs to be changed, it is converted in
the same patch.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
diff --git a/block/qcow2.c b/block/qcow2.c
index 545dea0..cb55e2d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1544,23 +1544,21 @@
return ret;
}
-static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
- int64_t sector_num,
- int remaining_sectors,
- QEMUIOVector *qiov)
+static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
+ uint64_t bytes, QEMUIOVector *qiov,
+ int flags)
{
BDRVQcow2State *s = bs->opaque;
- int index_in_cluster;
+ int offset_in_cluster;
int ret;
- int cur_nr_sectors; /* number of sectors in current iteration */
+ unsigned int cur_bytes; /* number of sectors in current iteration */
uint64_t cluster_offset;
QEMUIOVector hd_qiov;
uint64_t bytes_done = 0;
uint8_t *cluster_data = NULL;
QCowL2Meta *l2meta = NULL;
- trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num,
- remaining_sectors);
+ trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes);
qemu_iovec_init(&hd_qiov, qiov->niov);
@@ -1568,22 +1566,21 @@
qemu_co_mutex_lock(&s->lock);
- while (remaining_sectors != 0) {
+ while (bytes != 0) {
l2meta = NULL;
trace_qcow2_writev_start_part(qemu_coroutine_self());
- index_in_cluster = sector_num & (s->cluster_sectors - 1);
- cur_nr_sectors = remaining_sectors;
- if (bs->encrypted &&
- cur_nr_sectors >
- QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster) {
- cur_nr_sectors =
- QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster;
+ offset_in_cluster = offset_into_cluster(s, offset);
+ cur_bytes = MIN(bytes, INT_MAX);
+ if (bs->encrypted) {
+ cur_bytes = MIN(cur_bytes,
+ QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
+ - offset_in_cluster);
}
- ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
- &cur_nr_sectors, &cluster_offset, &l2meta);
+ ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes,
+ &cluster_offset, &l2meta);
if (ret < 0) {
goto fail;
}
@@ -1591,8 +1588,7 @@
assert((cluster_offset & 511) == 0);
qemu_iovec_reset(&hd_qiov);
- qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
- cur_nr_sectors * 512);
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_bytes);
if (bs->encrypted) {
Error *err = NULL;
@@ -1611,8 +1607,9 @@
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size);
- if (qcow2_encrypt_sectors(s, sector_num, cluster_data,
- cluster_data, cur_nr_sectors,
+ if (qcow2_encrypt_sectors(s, offset >> BDRV_SECTOR_BITS,
+ cluster_data, cluster_data,
+ cur_bytes >>BDRV_SECTOR_BITS,
true, &err) < 0) {
error_free(err);
ret = -EIO;
@@ -1620,13 +1617,11 @@
}
qemu_iovec_reset(&hd_qiov);
- qemu_iovec_add(&hd_qiov, cluster_data,
- cur_nr_sectors * 512);
+ qemu_iovec_add(&hd_qiov, cluster_data, cur_bytes);
}
ret = qcow2_pre_write_overlap_check(bs, 0,
- cluster_offset + index_in_cluster * BDRV_SECTOR_SIZE,
- cur_nr_sectors * BDRV_SECTOR_SIZE);
+ cluster_offset + offset_in_cluster, cur_bytes);
if (ret < 0) {
goto fail;
}
@@ -1634,10 +1629,10 @@
qemu_co_mutex_unlock(&s->lock);
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
trace_qcow2_writev_data(qemu_coroutine_self(),
- (cluster_offset >> 9) + index_in_cluster);
- ret = bdrv_co_writev(bs->file->bs,
- (cluster_offset >> 9) + index_in_cluster,
- cur_nr_sectors, &hd_qiov);
+ cluster_offset + offset_in_cluster);
+ ret = bdrv_co_pwritev(bs->file->bs,
+ cluster_offset + offset_in_cluster,
+ cur_bytes, &hd_qiov, 0);
qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
goto fail;
@@ -1663,10 +1658,10 @@
l2meta = next;
}
- remaining_sectors -= cur_nr_sectors;
- sector_num += cur_nr_sectors;
- bytes_done += cur_nr_sectors * 512;
- trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_nr_sectors);
+ bytes -= cur_bytes;
+ offset += cur_bytes;
+ bytes_done += cur_bytes;
+ trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes);
}
ret = 0;
@@ -2008,19 +2003,19 @@
static int preallocate(BlockDriverState *bs)
{
- uint64_t nb_sectors;
+ uint64_t bytes;
uint64_t offset;
uint64_t host_offset = 0;
- int num;
+ unsigned int cur_bytes;
int ret;
QCowL2Meta *meta;
- nb_sectors = bdrv_nb_sectors(bs);
+ bytes = bdrv_getlength(bs);
offset = 0;
- while (nb_sectors) {
- num = MIN(nb_sectors, INT_MAX >> BDRV_SECTOR_BITS);
- ret = qcow2_alloc_cluster_offset(bs, offset, &num,
+ while (bytes) {
+ cur_bytes = MIN(bytes, INT_MAX);
+ ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes,
&host_offset, &meta);
if (ret < 0) {
return ret;
@@ -2046,8 +2041,8 @@
/* TODO Preallocate data if requested */
- nb_sectors -= num;
- offset += num << BDRV_SECTOR_BITS;
+ bytes -= cur_bytes;
+ offset += cur_bytes;
}
/*
@@ -2056,11 +2051,9 @@
* EOF). Extend the image to the last allocated sector.
*/
if (host_offset != 0) {
- uint8_t buf[BDRV_SECTOR_SIZE];
- memset(buf, 0, BDRV_SECTOR_SIZE);
- ret = bdrv_write(bs->file->bs,
- (host_offset >> BDRV_SECTOR_BITS) + num - 1,
- buf, 1);
+ uint8_t data = 0;
+ ret = bdrv_pwrite(bs->file->bs, (host_offset + cur_bytes) - 1,
+ &data, 1);
if (ret < 0) {
return ret;
}
@@ -3379,7 +3372,7 @@
.bdrv_set_key = qcow2_set_key,
.bdrv_co_preadv = qcow2_co_preadv,
- .bdrv_co_writev = qcow2_co_writev,
+ .bdrv_co_pwritev = qcow2_co_pwritev,
.bdrv_co_flush_to_os = qcow2_co_flush_to_os,
.bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes,
