From f1e8474115d6be7eda14092050ffa2b031afb729 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Thu, 9 Jun 2016 16:36:00 +0200
Subject: [PATCH] block: Introduce bdrv_preadv()
We already have a byte-based bdrv_pwritev(), but the read counterpart
was still missing. This commit adds it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/io.c | 20 +++++++++++++-------
include/block/block.h | 1 +
2 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/block/io.c b/block/io.c
index b3ff9bec38..72d72109a5 100644
--- a/block/io.c
+++ b/block/io.c
@@ -700,6 +700,18 @@ int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
}
}
+int bdrv_preadv(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
+{
+ int ret;
+
+ ret = bdrv_prwv_co(bs, offset, qiov, false, 0);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return qiov->size;
+}
+
int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
{
QEMUIOVector qiov;
@@ -707,19 +719,13 @@ int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
.iov_base = (void *)buf,
.iov_len = bytes,
};
- int ret;
if (bytes < 0) {
return -EINVAL;
}
qemu_iovec_init_external(&qiov, &iov, 1);
- ret = bdrv_prwv_co(bs, offset, &qiov, false, 0);
- if (ret < 0) {
- return ret;
- }
-
- return bytes;
+ return bdrv_preadv(bs, offset, &qiov);
}
int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
diff --git a/include/block/block.h b/include/block/block.h
index 9c3a62cc0a..9c63d07765 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -235,6 +235,7 @@ int bdrv_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags);
int bdrv_pread(BlockDriverState *bs, int64_t offset,
void *buf, int count);
+int bdrv_preadv(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
const void *buf, int count);
int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);