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authorVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>2019-05-06 17:27:39 +0300
committerMax Reitz <mreitz@redhat.com>2019-05-28 20:30:55 +0200
commitf24196d388ec781ce3ae99c1fb78ba9755785f91 (patch)
tree040436e09bc92779e9ea2c5dccd001b81a6ecdaf /block
parent6f13a316dd3a6916de4733e56585127445b19458 (diff)
qcow2: qcow2_co_preadv: improve locking
Background: decryption will be done in threads, to take benefit of it, we should move it out of the lock first. But let's go further: it turns out, that only qcow2_get_cluster_offset() needs locking, so reduce locking to it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20190506142741.41731-7-vsementsov@virtuozzo.com Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/qcow2.c12
1 files changed, 2 insertions, 10 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index 1413df1389..4a89850389 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1969,8 +1969,6 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
qemu_iovec_init(&hd_qiov, qiov->niov);
- qemu_co_mutex_lock(&s->lock);
-
while (bytes != 0) {
/* prepare next request */
@@ -1980,7 +1978,9 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
}
+ qemu_co_mutex_lock(&s->lock);
ret = qcow2_get_cluster_offset(bs, offset, &cur_bytes, &cluster_offset);
+ qemu_co_mutex_unlock(&s->lock);
if (ret < 0) {
goto fail;
}
@@ -1995,10 +1995,8 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
if (bs->backing) {
BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
- qemu_co_mutex_unlock(&s->lock);
ret = bdrv_co_preadv(bs->backing, offset, cur_bytes,
&hd_qiov, 0);
- qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
goto fail;
}
@@ -2014,11 +2012,9 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
break;
case QCOW2_CLUSTER_COMPRESSED:
- qemu_co_mutex_unlock(&s->lock);
ret = qcow2_co_preadv_compressed(bs, cluster_offset,
offset, cur_bytes,
&hd_qiov);
- qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
goto fail;
}
@@ -2055,11 +2051,9 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
}
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
- qemu_co_mutex_unlock(&s->lock);
ret = bdrv_co_preadv(s->data_file,
cluster_offset + offset_in_cluster,
cur_bytes, &hd_qiov, 0);
- qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
goto fail;
}
@@ -2094,8 +2088,6 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
ret = 0;
fail:
- qemu_co_mutex_unlock(&s->lock);
-
qemu_iovec_destroy(&hd_qiov);
qemu_vfree(cluster_data);