| Message ID | 20170804140826.1351-1-berrange@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Aug 04, 2017 at 09:28:54AM -0500, Eric Blake wrote: > On 08/04/2017 09:08 AM, Daniel P. Berrange wrote: > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > > --- > > > > - Clarify that @bytes matches @qiov total size (Kevin) > > > > include/block/block_int.h | 31 +++++++++++++++++++++++++++++++ > > 1 file changed, 31 insertions(+) > > [looks like the nongnu.org infrastructure is having heavy load today, so > mails are getting through more slowly than usual - leads to lots of > crossed emails, where I'm seeing replies or direct sends sooner than > list copies] > > > + /** > > + * @offset: position in bytes to write at > > + * @bytes: number of bytes to write > > + * @qiov: the buffers containing data to write > > + * @flags: zero or more of bits allowed by 'supported_write_flags' > > maybe s/of // > > > + * > > + * @offset and @bytes will be a multiple of 'request_alignment', > > + * but the length of individual @qiov elements does not have to > > + * be a multiple. > > + * > > + * @bytes will always equal the total size of @qiov, and will be > > + * no larger than 'max_transfer'. > > + * > > + * The buffer in @qiov may point directly to guest memory. > > + */ > > int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs, > > uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags); > > Do we make guarantees that the driver callback is never reached if the > image is currently read-only? If so, is that a guarantee worth documenting? bdrv_co_pwritev() returns EPERM if bs->read_only, so it looks like you are right we have a guarantee we can document > Reviewed-by: Eric Blake <eblake@redhat.com> Regards, Daniel
On Fri, Aug 04, 2017 at 03:08:26PM +0100, Daniel P. Berrange wrote: > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > --- > > - Clarify that @bytes matches @qiov total size (Kevin) > > include/block/block_int.h | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/include/block/block_int.h b/include/block/block_int.h index d4f4ea7584..4f7f20e56b 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -147,12 +147,43 @@ struct BlockDriver { int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); + + /** + * @offset: position in bytes to read at + * @bytes: number of bytes to read + * @qiov: the buffers to fill with read data + * @flags: currently unused, always 0 + * + * @offset and @bytes will be a multiple of 'request_alignment', + * but the length of individual @qiov elements does not have to + * be a multiple. + * + * @bytes will always equal the total size of @qiov, and will be + * no larger than 'max_transfer'. + * + * The buffer in @qiov may point directly to guest memory. + */ int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags); int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); int coroutine_fn (*bdrv_co_writev_flags)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags); + /** + * @offset: position in bytes to write at + * @bytes: number of bytes to write + * @qiov: the buffers containing data to write + * @flags: zero or more of bits allowed by 'supported_write_flags' + * + * @offset and @bytes will be a multiple of 'request_alignment', + * but the length of individual @qiov elements does not have to + * be a multiple. + * + * @bytes will always equal the total size of @qiov, and will be + * no larger than 'max_transfer'. + * + * The buffer in @qiov may point directly to guest memory. + */ int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- - Clarify that @bytes matches @qiov total size (Kevin) include/block/block_int.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)