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Re: [Qemu-devel] [PATCH 1/9] block: Use BdrvChild callbacks for change_m
From: |
Max Reitz |
Subject: |
Re: [Qemu-devel] [PATCH 1/9] block: Use BdrvChild callbacks for change_media/resize |
Date: |
Tue, 29 Mar 2016 19:36:31 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0 |
On 22.03.2016 20:36, Kevin Wolf wrote:
> We want to get rid of BlockDriverState.blk in order to allow multiple
> BlockBackends per BDS. Converting the device callbacks in block.c (which
> assume a single BlockBackend) to per-child callbacks gets us rid of the
> first few instances.
>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
> block.c | 38 +++++++++++++++++++++++++-------------
> block/block-backend.c | 15 ++++++++++++++-
> include/block/block_int.h | 4 +++-
> 3 files changed, 42 insertions(+), 15 deletions(-)
>
> diff --git a/block.c b/block.c
> index fb37b91..1fb5dac 100644
> --- a/block.c
> +++ b/block.c
> @@ -1216,6 +1216,27 @@ void bdrv_unref_child(BlockDriverState *parent,
> BdrvChild *child)
> bdrv_root_unref_child(child);
> }
>
> +
> +static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load)
> +{
> + BdrvChild *c;
> + QLIST_FOREACH(c, &bs->parents, next_parent) {
> + if (c->role->change_media) {
> + c->role->change_media(c, load);
> + }
> + }
> +}
> +
> +static void bdrv_parent_cb_resize(BlockDriverState *bs)
> +{
> + BdrvChild *c;
> + QLIST_FOREACH(c, &bs->parents, next_parent) {
> + if (c->role->resize) {
> + c->role->resize(c);
> + }
> + }
> +}
> +
> /*
> * Sets the backing file link of a BDS. A new reference is created; callers
> * which don't need their own reference any more must call bdrv_unref().
> @@ -1674,9 +1695,7 @@ static int bdrv_open_inherit(BlockDriverState **pbs,
> const char *filename,
> }
>
> if (!bdrv_key_required(bs)) {
> - if (bs->blk) {
> - blk_dev_change_media_cb(bs->blk, true);
> - }
> + bdrv_parent_cb_change_media(bs, true);
> } else if (!runstate_check(RUN_STATE_PRELAUNCH)
> && !runstate_check(RUN_STATE_INMIGRATE)
> && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */
> @@ -2122,9 +2141,7 @@ static void bdrv_close(BlockDriverState *bs)
> bdrv_release_named_dirty_bitmaps(bs);
> assert(QLIST_EMPTY(&bs->dirty_bitmaps));
>
> - if (bs->blk) {
> - blk_dev_change_media_cb(bs->blk, false);
> - }
> + bdrv_parent_cb_change_media(bs, false);
This is probably unnecessary altogether, but I'm certain about it after
http://lists.nongnu.org/archive/html/qemu-block/2015-11/msg00349.html.
So I'll take a note of removing this then.
> if (bs->drv) {
> BdrvChild *child, *next;
> @@ -2605,9 +2622,7 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset)
> if (ret == 0) {
> ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
> bdrv_dirty_bitmap_truncate(bs);
> - if (bs->blk) {
> - blk_dev_resize_cb(bs->blk);
> - }
> + bdrv_parent_cb_resize(bs);
> }
> return ret;
> }
> @@ -2718,10 +2733,7 @@ int bdrv_set_key(BlockDriverState *bs, const char *key)
> bs->valid_key = 0;
> } else if (!bs->valid_key) {
> bs->valid_key = 1;
> - if (bs->blk) {
> - /* call the change callback now, we skipped it on open */
> - blk_dev_change_media_cb(bs->blk, true);
> - }
> + bdrv_parent_cb_change_media(bs, true);
Not sure why you removed the comment here. In case you send a v2, I'd
keep it.
Whichever way you decide:
Reviewed-by: Max Reitz <address@hidden>
> }
> return ret;
> }
> diff --git a/block/block-backend.c b/block/block-backend.c
> index 8b4eb1a..9d973ba 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -92,9 +92,15 @@ static void blk_root_inherit_options(int *child_flags,
> QDict *child_options,
> }
> static bool blk_drain_throttling_queue(BdrvChild *child);
>
> +static void blk_root_change_media(BdrvChild *child, bool load);
> +static void blk_root_resize(BdrvChild *child);
> +
> static const BdrvChildRole child_root = {
> .inherit_options = blk_root_inherit_options,
>
> + .change_media = blk_root_change_media,
> + .resize = blk_root_resize,
> +
> .drain_queue = blk_drain_throttling_queue,
> };
>
> @@ -553,6 +559,11 @@ void blk_dev_change_media_cb(BlockBackend *blk, bool
> load)
> }
> }
>
> +static void blk_root_change_media(BdrvChild *child, bool load)
> +{
> + blk_dev_change_media_cb(child->opaque, load);
> +}
> +
> /*
> * Does @blk's attached device model have removable media?
> * %true if no device model is attached.
> @@ -607,8 +618,10 @@ bool blk_dev_is_medium_locked(BlockBackend *blk)
> /*
> * Notify @blk's attached device model of a backend size change.
> */
> -void blk_dev_resize_cb(BlockBackend *blk)
> +static void blk_root_resize(BdrvChild *child)
> {
> + BlockBackend *blk = child->opaque;
> +
> if (blk->dev_ops && blk->dev_ops->resize_cb) {
> blk->dev_ops->resize_cb(blk->dev_opaque);
> }
> diff --git a/include/block/block_int.h b/include/block/block_int.h
> index 000d2c0..f60cb7c 100644
> --- a/include/block/block_int.h
> +++ b/include/block/block_int.h
> @@ -356,6 +356,9 @@ struct BdrvChildRole {
> void (*inherit_options)(int *child_flags, QDict *child_options,
> int parent_flags, QDict *parent_options);
>
> + void (*change_media)(BdrvChild *child, bool load);
> + void (*resize)(BdrvChild *child);
> +
> bool (*drain_queue)(BdrvChild *child);
> };
>
> @@ -695,7 +698,6 @@ bool blk_dev_has_tray(BlockBackend *blk);
> void blk_dev_eject_request(BlockBackend *blk, bool force);
> bool blk_dev_is_tray_open(BlockBackend *blk);
> bool blk_dev_is_medium_locked(BlockBackend *blk);
> -void blk_dev_resize_cb(BlockBackend *blk);
>
> void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int
> nr_sectors);
> bool bdrv_requests_pending(BlockDriverState *bs);
>
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Description: OpenPGP digital signature
- [Qemu-devel] [PATCH 0/9] block: Remove BlockDriverState.blk, Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 2/9] block: User BdrvChild callback for device name, Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 1/9] block: Use BdrvChild callbacks for change_media/resize, Kevin Wolf, 2016/03/22
- Re: [Qemu-devel] [PATCH 1/9] block: Use BdrvChild callbacks for change_media/resize,
Max Reitz <=
- [Qemu-devel] [PATCH 5/9] block: Avoid BDS.blk in bdrv_next(), Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 6/9] block: Remove bdrv_move_feature_fields(), Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 3/9] block jobs: Use BdrvChild callbacks for iostatus operations, Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 8/9] block: Don't return throttling info in query-named-block-nodes, Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 7/9] block: Avoid bs->blk in bdrv_next(), Kevin Wolf, 2016/03/22