Re: [Qemu-devel] [PATCH v8 12/16] blockdev: Keep track of monitor-owned BDS

[Fam Zheng]

On Wed, 01/27 18:59, Max Reitz wrote:
> Signed-off-by: Max Reitz <address@hidden>
> ---
>  blockdev.c                             | 26 ++++++++++++++++++++++++++
>  include/block/block_int.h              |  4 ++++
>  stubs/Makefile.objs                    |  1 +
>  stubs/blockdev-close-all-bdrv-states.c |  5 +++++
>  4 files changed, 36 insertions(+)
>  create mode 100644 stubs/blockdev-close-all-bdrv-states.c
> 
> diff --git a/blockdev.c b/blockdev.c
> index 09d4621..ac93f43 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -50,6 +50,9 @@
>  #include "trace.h"
>  #include "sysemu/arch_init.h"
>  
> +static QTAILQ_HEAD(, BlockDriverState) monitor_bdrv_states =
> +    QTAILQ_HEAD_INITIALIZER(monitor_bdrv_states);
> +
>  static const char *const if_name[IF_COUNT] = {
>      [IF_NONE] = "none",
>      [IF_IDE] = "ide",
> @@ -702,6 +705,19 @@ fail:
>      return NULL;
>  }
>  
> +void blockdev_close_all_bdrv_states(void)
> +{
> +    BlockDriverState *bs, *next_bs;
> +
> +    QTAILQ_FOREACH_SAFE(bs, &monitor_bdrv_states, monitor_list, next_bs) {
> +        AioContext *ctx = bdrv_get_aio_context(bs);
> +
> +        aio_context_acquire(ctx);
> +        bdrv_unref(bs);
> +        aio_context_release(ctx);
> +    }
> +}
> +
>  static void qemu_opt_rename(QemuOpts *opts, const char *from, const char *to,
>                              Error **errp)
>  {
> @@ -3875,12 +3891,15 @@ void qmp_blockdev_add(BlockdevOptions *options, Error 
> **errp)
>          if (!bs) {
>              goto fail;
>          }
> +
> +        QTAILQ_INSERT_TAIL(&monitor_bdrv_states, bs, monitor_list);
>      }
>  
>      if (bs && bdrv_key_required(bs)) {
>          if (blk) {
>              blk_unref(blk);
>          } else {
> +            QTAILQ_REMOVE(&monitor_bdrv_states, bs, monitor_list);
>              bdrv_unref(bs);
>          }
>          error_setg(errp, "blockdev-add doesn't support encrypted devices");
> @@ -3945,11 +3964,18 @@ void qmp_x_blockdev_del(bool has_id, const char *id,
>                         bdrv_get_device_or_node_name(bs));
>              goto out;
>          }
> +
> +        if (!blk && !bs->monitor_list.tqe_prev) {
> +            error_setg(errp, "Node %s is not owned by the monitor",
> +                       bs->node_name);
> +            goto out;
> +        }

Is this an extra restriction added by this patch? Deserve some words in the
commit message?

>      }
>  
>      if (blk) {
>          blk_unref(blk);
>      } else {
> +        QTAILQ_REMOVE(&monitor_bdrv_states, bs, monitor_list);
>          bdrv_unref(bs);
>      }
>  
> diff --git a/include/block/block_int.h b/include/block/block_int.h
> index 1e4c518..dd00d12 100644
> --- a/include/block/block_int.h
> +++ b/include/block/block_int.h
> @@ -445,6 +445,8 @@ struct BlockDriverState {
>      QTAILQ_ENTRY(BlockDriverState) device_list;
>      /* element of the list of all BlockDriverStates (all_bdrv_states) */
>      QTAILQ_ENTRY(BlockDriverState) bs_list;
> +    /* element of the list of monitor-owned BDS */
> +    QTAILQ_ENTRY(BlockDriverState) monitor_list;
>      QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
>      int refcnt;
>  
> @@ -707,4 +709,6 @@ bool bdrv_requests_pending(BlockDriverState *bs);
>  void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
>  void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
>  
> +void blockdev_close_all_bdrv_states(void);
> +
>  #endif /* BLOCK_INT_H */
> diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
> index d7898a0..e922de9 100644
> --- a/stubs/Makefile.objs
> +++ b/stubs/Makefile.objs
> @@ -1,5 +1,6 @@
>  stub-obj-y += arch-query-cpu-def.o
>  stub-obj-y += bdrv-commit-all.o
> +stub-obj-y += blockdev-close-all-bdrv-states.o
>  stub-obj-y += clock-warp.o
>  stub-obj-y += cpu-get-clock.o
>  stub-obj-y += cpu-get-icount.o
> diff --git a/stubs/blockdev-close-all-bdrv-states.c 
> b/stubs/blockdev-close-all-bdrv-states.c
> new file mode 100644
> index 0000000..12d2442
> --- /dev/null
> +++ b/stubs/blockdev-close-all-bdrv-states.c
> @@ -0,0 +1,5 @@
> +#include "block/block_int.h"
> +
> +void blockdev_close_all_bdrv_states(void)
> +{
> +}
> -- 
> 2.7.0
>