From: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Introduce extended variants of bdrv_co_preadv and bdrv_co_pwritev
with qiov_offset parameter.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefa...@redhat.com>
Message-id: 20190604161514.262241-10-vsement...@virtuozzo.com
Message-Id: <20190604161514.262241-10-vsement...@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
include/block/block_int.h | 6 ++++++
block/io.c | 29 +++++++++++++++++++++++------
2 files changed, 29 insertions(+), 6 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 79a1fdb258..0422acdf1c 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -959,9 +959,15 @@ extern BlockDriver bdrv_qcow2;
int coroutine_fn bdrv_co_preadv(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
+int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
+ int64_t offset, unsigned int bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
+int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
+ int64_t offset, unsigned int bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
static inline int coroutine_fn bdrv_co_pread(BdrvChild *child,
int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
diff --git a/block/io.c b/block/io.c
index 237d7f40f5..0fa10831ed 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1614,7 +1614,8 @@ static void bdrv_padding_destroy(BdrvRequestPadding *pad)
*
* Function always succeeds.
*/
-static bool bdrv_pad_request(BlockDriverState *bs, QEMUIOVector **qiov,
+static bool bdrv_pad_request(BlockDriverState *bs,
+ QEMUIOVector **qiov, size_t *qiov_offset,
int64_t *offset, unsigned int *bytes,
BdrvRequestPadding *pad)
{
@@ -1623,11 +1624,12 @@ static bool bdrv_pad_request(BlockDriverState *bs,
QEMUIOVector **qiov,
}
qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head,
- *qiov, 0, *bytes,
+ *qiov, *qiov_offset, *bytes,
pad->buf + pad->buf_len - pad->tail, pad->tail);
*bytes += pad->head + pad->tail;
*offset -= pad->head;
*qiov = &pad->local_qiov;
+ *qiov_offset = 0;
return true;
}
@@ -1635,6 +1637,14 @@ static bool bdrv_pad_request(BlockDriverState *bs,
QEMUIOVector **qiov,
int coroutine_fn bdrv_co_preadv(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags)
+{
+ return bdrv_co_preadv_part(child, offset, bytes, qiov, 0, flags);
+}
+
+int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
+ int64_t offset, unsigned int bytes,
+ QEMUIOVector *qiov, size_t qiov_offset,
+ BdrvRequestFlags flags)
{
BlockDriverState *bs = child->bs;
BdrvTrackedRequest req;
@@ -1655,12 +1665,12 @@ int coroutine_fn bdrv_co_preadv(BdrvChild *child,
flags |= BDRV_REQ_COPY_ON_READ;
}
- bdrv_pad_request(bs, &qiov, &offset, &bytes, &pad);
+ bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad);
tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ);
ret = bdrv_aligned_preadv(child, &req, offset, bytes,
bs->bl.request_alignment,
- qiov, 0, flags);
+ qiov, qiov_offset, flags);
tracked_request_end(&req);
bdrv_dec_in_flight(bs);
@@ -2023,6 +2033,13 @@ out:
int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags)
+{
+ return bdrv_co_pwritev_part(child, offset, bytes, qiov, 0, flags);
+}
+
+int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
+ int64_t offset, unsigned int bytes, QEMUIOVector *qiov, size_t qiov_offset,
+ BdrvRequestFlags flags)
{
BlockDriverState *bs = child->bs;
BdrvTrackedRequest req;
@@ -2054,14 +2071,14 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
goto out;
}
- if (bdrv_pad_request(bs, &qiov, &offset, &bytes, &pad)) {
+ if (bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad)) {
mark_request_serialising(&req, align);
wait_serialising_requests(&req);
bdrv_padding_rmw_read(child, &req, &pad, false);
}
ret = bdrv_aligned_pwritev(child, &req, offset, bytes, align,
- qiov, 0, flags);
+ qiov, qiov_offset, flags);
bdrv_padding_destroy(&pad);
--
2.21.0
