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| author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2019-05-06 17:27:39 +0300 |
|---|---|---|
| committer | Max Reitz <mreitz@redhat.com> | 2019-05-28 20:30:55 +0200 |
| commit | f24196d388ec781ce3ae99c1fb78ba9755785f91 (patch) | |
| tree | 040436e09bc92779e9ea2c5dccd001b81a6ecdaf | |
| parent | 6f13a316dd3a6916de4733e56585127445b19458 (diff) | |
| download | qemu-f24196d388ec781ce3ae99c1fb78ba9755785f91.zip qemu-f24196d388ec781ce3ae99c1fb78ba9755785f91.tar.gz qemu-f24196d388ec781ce3ae99c1fb78ba9755785f91.tar.bz2 | |
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>
| -rw-r--r-- | block/qcow2.c | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 1413df1..4a89850 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); |