Re: [Qemu-devel] [PATCH 13/22] block/raw-posix: implement .bdrv_detach/attach_aio_context()

[Paolo Bonzini]

Il 01/05/2014 16:54, Stefan Hajnoczi ha scritto:
> Drop the assumption that we're using the main AioContext for Linux AIO.
> Convert the Linux AIO event notifier to use aio_set_event_notifier().
>
> The .bdrv_detach/attach_aio_context() interfaces also need to be
> implemented to move the event notifier handler from the old to the new
> AioContext.
>
> Signed-off-by: Stefan Hajnoczi <address@hidden>

Is the same needed for raw-win32?

Paolo

> ---
>  block/linux-aio.c | 16 ++++++++++++++--
>  block/raw-aio.h   |  2 ++
>  block/raw-posix.c | 43 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 59 insertions(+), 2 deletions(-)
>
> diff --git a/block/linux-aio.c b/block/linux-aio.c
> index 53434e2..7ff3897 100644
> --- a/block/linux-aio.c
> +++ b/block/linux-aio.c
> @@ -177,6 +177,20 @@ out_free_aiocb:
>      return NULL;
>  }
>
> +void laio_detach_aio_context(void *s_, AioContext *old_context)
> +{
> +    struct qemu_laio_state *s = s_;
> +
> +    aio_set_event_notifier(old_context, &s->e, NULL);
> +}
> +
> +void laio_attach_aio_context(void *s_, AioContext *new_context)
> +{
> +    struct qemu_laio_state *s = s_;
> +
> +    aio_set_event_notifier(new_context, &s->e, qemu_laio_completion_cb);
> +}
> +
>  void *laio_init(void)
>  {
>      struct qemu_laio_state *s;
> @@ -190,8 +204,6 @@ void *laio_init(void)
>          goto out_close_efd;
>      }
>
> -    qemu_aio_set_event_notifier(&s->e, qemu_laio_completion_cb);
> -
>      return s;
>
>  out_close_efd:
> diff --git a/block/raw-aio.h b/block/raw-aio.h
> index 7ad0a8a..9a761ee 100644
> --- a/block/raw-aio.h
> +++ b/block/raw-aio.h
> @@ -37,6 +37,8 @@ void *laio_init(void);
>  BlockDriverAIOCB *laio_submit(BlockDriverState *bs, void *aio_ctx, int fd,
>          int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
>          BlockDriverCompletionFunc *cb, void *opaque, int type);
> +void laio_detach_aio_context(void *s, AioContext *old_context);
> +void laio_attach_aio_context(void *s, AioContext *new_context);
>  #endif
>
>  #ifdef _WIN32
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index 1688e16..9fef157 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -304,6 +304,29 @@ static void raw_parse_flags(int bdrv_flags, int 
> *open_flags)
>      }
>  }
>
> +static void raw_detach_aio_context(BlockDriverState *bs)
> +{
> +#ifdef CONFIG_LINUX_AIO
> +    BDRVRawState *s = bs->opaque;
> +
> +    if (s->use_aio) {
> +        laio_detach_aio_context(s->aio_ctx, bdrv_get_aio_context(bs));
> +    }
> +#endif
> +}
> +
> +static void raw_attach_aio_context(BlockDriverState *bs,
> +                                   AioContext *new_context)
> +{
> +#ifdef CONFIG_LINUX_AIO
> +    BDRVRawState *s = bs->opaque;
> +
> +    if (s->use_aio) {
> +        laio_attach_aio_context(s->aio_ctx, new_context);
> +    }
> +#endif
> +}
> +
>  #ifdef CONFIG_LINUX_AIO
>  static int raw_set_aio(void **aio_ctx, int *use_aio, int bdrv_flags)
>  {
> @@ -444,6 +467,8 @@ static int raw_open_common(BlockDriverState *bs, QDict 
> *options,
>      }
>  #endif
>
> +    raw_attach_aio_context(bs, bdrv_get_aio_context(bs));
> +
>      ret = 0;
>  fail:
>      qemu_opts_del(opts);
> @@ -1053,6 +1078,9 @@ static BlockDriverAIOCB *raw_aio_flush(BlockDriverState 
> *bs,
>  static void raw_close(BlockDriverState *bs)
>  {
>      BDRVRawState *s = bs->opaque;
> +
> +    raw_detach_aio_context(bs);
> +
>      if (s->fd >= 0) {
>          qemu_close(s->fd);
>          s->fd = -1;
> @@ -1448,6 +1476,9 @@ static BlockDriver bdrv_file = {
>      .bdrv_get_allocated_file_size
>                          = raw_get_allocated_file_size,
>
> +    .bdrv_detach_aio_context = raw_detach_aio_context,
> +    .bdrv_attach_aio_context = raw_attach_aio_context,
> +
>      .create_options = raw_create_options,
>  };
>
> @@ -1848,6 +1879,9 @@ static BlockDriver bdrv_host_device = {
>      .bdrv_get_allocated_file_size
>                          = raw_get_allocated_file_size,
>
> +    .bdrv_detach_aio_context = raw_detach_aio_context,
> +    .bdrv_attach_aio_context = raw_attach_aio_context,
> +
>      /* generic scsi device */
>  #ifdef __linux__
>      .bdrv_ioctl         = hdev_ioctl,
> @@ -1990,6 +2024,9 @@ static BlockDriver bdrv_host_floppy = {
>      .bdrv_get_allocated_file_size
>                          = raw_get_allocated_file_size,
>
> +    .bdrv_detach_aio_context = raw_detach_aio_context,
> +    .bdrv_attach_aio_context = raw_attach_aio_context,
> +
>      /* removable device support */
>      .bdrv_is_inserted   = floppy_is_inserted,
>      .bdrv_media_changed = floppy_media_changed,
> @@ -2115,6 +2152,9 @@ static BlockDriver bdrv_host_cdrom = {
>      .bdrv_get_allocated_file_size
>                          = raw_get_allocated_file_size,
>
> +    .bdrv_detach_aio_context = raw_detach_aio_context,
> +    .bdrv_attach_aio_context = raw_attach_aio_context,
> +
>      /* removable device support */
>      .bdrv_is_inserted   = cdrom_is_inserted,
>      .bdrv_eject         = cdrom_eject,
> @@ -2246,6 +2286,9 @@ static BlockDriver bdrv_host_cdrom = {
>      .bdrv_get_allocated_file_size
>                          = raw_get_allocated_file_size,
>
> +    .bdrv_detach_aio_context = raw_detach_aio_context,
> +    .bdrv_attach_aio_context = raw_attach_aio_context,
> +
>      /* removable device support */
>      .bdrv_is_inserted   = cdrom_is_inserted,
>      .bdrv_eject         = cdrom_eject,