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[Qemu-block] [PATCH v2 05/12] block/io: bdrv_co_do_copy_on_readv: use an
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-block] [PATCH v2 05/12] block/io: bdrv_co_do_copy_on_readv: use and support qiov_offset |
Date: |
Tue, 4 Jun 2019 19:15:07 +0300 |
Use and support new API in bdrv_co_do_copy_on_readv. Note that in case
of allocated-in-top we need to shrink read size to MIN(..) by hand, as
pre-patch this was actually done implicitly by qemu_iovec_concat (and
we used local_qiov.size).
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block/io.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/block/io.c b/block/io.c
index 7e53a11492..efd2b80293 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1161,7 +1161,8 @@ bdrv_driver_pwritev_compressed(BlockDriverState *bs,
uint64_t offset,
}
static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
- int64_t offset, unsigned int bytes, QEMUIOVector *qiov)
+ int64_t offset, unsigned int bytes,
+ QEMUIOVector *qiov, size_t qiov_offset)
{
BlockDriverState *bs = child->bs;
@@ -1173,7 +1174,6 @@ static int coroutine_fn
bdrv_co_do_copy_on_readv(BdrvChild *child,
void *bounce_buffer;
BlockDriver *drv = bs->drv;
- QEMUIOVector local_qiov;
int64_t cluster_offset;
int64_t cluster_bytes;
size_t skip_bytes;
@@ -1236,6 +1236,8 @@ static int coroutine_fn
bdrv_co_do_copy_on_readv(BdrvChild *child,
assert(skip_bytes < pnum);
if (ret <= 0) {
+ QEMUIOVector local_qiov;
+
/* Must copy-on-read; use the bounce buffer */
pnum = MIN(pnum, MAX_BOUNCE_BUFFER);
qemu_iovec_init_buf(&local_qiov, bounce_buffer, pnum);
@@ -1272,15 +1274,14 @@ static int coroutine_fn
bdrv_co_do_copy_on_readv(BdrvChild *child,
goto err;
}
- qemu_iovec_from_buf(qiov, progress, bounce_buffer + skip_bytes,
+ qemu_iovec_from_buf(qiov, qiov_offset + progress,
+ bounce_buffer + skip_bytes,
pnum - skip_bytes);
} else {
/* Read directly into the destination */
- qemu_iovec_init(&local_qiov, qiov->niov);
- qemu_iovec_concat(&local_qiov, qiov, progress, pnum - skip_bytes);
- ret = bdrv_driver_preadv(bs, offset + progress, local_qiov.size,
- &local_qiov, 0, 0);
- qemu_iovec_destroy(&local_qiov);
+ ret = bdrv_driver_preadv(bs, offset + progress,
+ MIN(pnum - skip_bytes, bytes - progress),
+ qiov, qiov_offset + progress, 0);
if (ret < 0) {
goto err;
}
@@ -1353,7 +1354,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild
*child,
}
if (!ret || pnum != bytes) {
- ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov);
+ ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, 0);
goto out;
}
}
--
2.18.0
- [Qemu-block] [PATCH v2 00/12] block: qiov_offset parameter for io, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 12/12] block/qcow2: implement .bdrv_co_pwritev(_compressed)_part, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 10/12] block/qcow2: refactor qcow2_co_preadv to use buffer-based io, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 08/12] block/io: bdrv_aligned_pwritev: use and support qiov_offset, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 07/12] block/io: bdrv_aligned_preadv: use and support qiov_offset, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 06/12] block/io: bdrv_co_do_copy_on_readv: lazy allocation, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 01/12] util/iov: introduce qemu_iovec_init_extended, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 02/12] util/iov: improve qemu_iovec_is_zero, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 05/12] block/io: bdrv_co_do_copy_on_readv: use and support qiov_offset,
Vladimir Sementsov-Ogievskiy <=
- [Qemu-block] [PATCH v2 11/12] block/qcow2: implement .bdrv_co_preadv_part, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 04/12] block: define .*_part io handlers in BlockDriver, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 03/12] block/io: refactor padding, Vladimir Sementsov-Ogievskiy, 2019/06/04
- [Qemu-block] [PATCH v2 09/12] block/io: introduce bdrv_co_p{read, write}v_part, Vladimir Sementsov-Ogievskiy, 2019/06/04
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 00/12] block: qiov_offset parameter for io, no-reply, 2019/06/05
- Re: [Qemu-block] [Qemu-devel] [PATCH v2 00/12] block: qiov_offset parameter for io, Stefan Hajnoczi, 2019/06/28