From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-devel@nongnu.org, qemu-block@nongnu.org
Cc: fam@euphon.net, kwolf@redhat.com, vsementsov@virtuozzo.com,
mreitz@redhat.com, stefanha@redhat.com, den@openvz.org,
jsnow@redhat.com
Subject: [Qemu-devel] [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 [thread overview]
Message-ID: <20190604161514.262241-6-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20190604161514.262241-1-vsementsov@virtuozzo.com>
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 <vsementsov@virtuozzo.com>
---
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
next prev parent reply other threads:[~2019-06-04 16:30 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-04 16:15 [Qemu-devel] [PATCH v2 00/12] block: qiov_offset parameter for io Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 01/12] util/iov: introduce qemu_iovec_init_extended Vladimir Sementsov-Ogievskiy
2019-06-05 11:54 ` Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 02/12] util/iov: improve qemu_iovec_is_zero Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 03/12] block/io: refactor padding Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 04/12] block: define .*_part io handlers in BlockDriver Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` Vladimir Sementsov-Ogievskiy [this message]
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 06/12] block/io: bdrv_co_do_copy_on_readv: lazy allocation Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 07/12] block/io: bdrv_aligned_preadv: use and support qiov_offset Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 08/12] block/io: bdrv_aligned_pwritev: " Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 09/12] block/io: introduce bdrv_co_p{read, write}v_part Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 10/12] block/qcow2: refactor qcow2_co_preadv to use buffer-based io Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 11/12] block/qcow2: implement .bdrv_co_preadv_part Vladimir Sementsov-Ogievskiy
2019-06-04 16:15 ` [Qemu-devel] [PATCH v2 12/12] block/qcow2: implement .bdrv_co_pwritev(_compressed)_part Vladimir Sementsov-Ogievskiy
2019-06-04 17:48 ` [Qemu-devel] [PATCH v2 00/12] block: qiov_offset parameter for io no-reply
2019-06-28 8:43 ` Stefan Hajnoczi
2019-07-25 8:28 ` Vladimir Sementsov-Ogievskiy
2019-07-29 15:24 ` Stefan Hajnoczi
2019-07-29 15:34 ` Vladimir Sementsov-Ogievskiy
2019-08-15 11:12 ` Vladimir Sementsov-Ogievskiy
2019-08-22 14:48 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2019-08-22 15:50 ` [Qemu-devel] " Stefan Hajnoczi
2019-08-22 17:24 ` Vladimir Sementsov-Ogievskiy
2019-08-22 17:39 ` Vladimir Sementsov-Ogievskiy
2019-08-22 17:59 ` Vladimir Sementsov-Ogievskiy
2019-08-23 16:21 ` Stefan Hajnoczi
2019-08-24 10:15 ` Vladimir Sementsov-Ogievskiy
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