diff options
Diffstat (limited to 'block/copy-on-read.c')
| -rw-r--r-- | block/copy-on-read.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/block/copy-on-read.c b/block/copy-on-read.c index 71560984f6..9cad9e1b8c 100644 --- a/block/copy-on-read.c +++ b/block/copy-on-read.c @@ -50,6 +50,8 @@ static int cor_open(BlockDriverState *bs, QDict *options, int flags, return -EINVAL; } + bs->supported_read_flags = BDRV_REQ_PREFETCH; + bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED | (BDRV_REQ_FUA & bs->file->bs->supported_write_flags); @@ -172,10 +174,14 @@ static int coroutine_fn cor_co_preadv_part(BlockDriverState *bs, } } - ret = bdrv_co_preadv_part(bs->file, offset, n, qiov, qiov_offset, - local_flags); - if (ret < 0) { - return ret; + /* Skip if neither read nor write are needed */ + if ((local_flags & (BDRV_REQ_PREFETCH | BDRV_REQ_COPY_ON_READ)) != + BDRV_REQ_PREFETCH) { + ret = bdrv_co_preadv_part(bs->file, offset, n, qiov, qiov_offset, + local_flags); + if (ret < 0) { + return ret; + } } offset += n; |