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block-backend: Remember if attached device is non-qdev 

Almost all block devices are qdevified by now. This allows us to go back
from the BlockBackend to the DeviceState. xen_disk is the last device
that is missing. We'll remember in the BlockBackend if a xen_disk is
attached and can then disable any features that require going from a BB
to the DeviceState.

While at it, clearly mark the function used by xen_disk as legacy even
in its name, not just in TODO comments.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2016-09-29 18:47:03 +02:00
parent 2bf7e10f78
commit bbc8ea98bc
3 changed files with 23 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
block/block-backend.c
View File

@ -38,6 +38,7 @@ struct BlockBackend {
BlockBackendPublic public;
void *dev; /* attached device model, if any */
bool legacy_dev; /* true if dev is not a DeviceState */
/* TODO change to DeviceState when all users are qdevified */
const BlockDevOps *dev_ops;
void *dev_opaque;
@ -506,32 +507,38 @@ void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs)
}
}
/*
* Attach device model @dev to @blk.
* Return 0 on success, -EBUSY when a device model is attached already.
*/
int blk_attach_dev(BlockBackend *blk, void *dev)
/* TODO change to DeviceState *dev when all users are qdevified */
static int blk_do_attach_dev(BlockBackend *blk, void *dev)
{
if (blk->dev) {
return -EBUSY;
}
blk_ref(blk);
blk->dev = dev;
blk->legacy_dev = false;
blk_iostatus_reset(blk);
return 0;
}
/*
* Attach device model @dev to @blk.
* Return 0 on success, -EBUSY when a device model is attached already.
*/
int blk_attach_dev(BlockBackend *blk, DeviceState *dev)
{
return blk_do_attach_dev(blk, dev);
}
/*
* Attach device model @dev to @blk.
* @blk must not have a device model attached already.
* TODO qdevified devices don't use this, remove when devices are qdevified
*/
void blk_attach_dev_nofail(BlockBackend *blk, void *dev)
void blk_attach_dev_legacy(BlockBackend *blk, void *dev)
{
if (blk_attach_dev(blk, dev) < 0) {
if (blk_do_attach_dev(blk, dev) < 0) {
abort();
}
blk->legacy_dev = true;
}
/*
@ -585,6 +592,11 @@ BlockBackend *blk_by_dev(void *dev)
void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops,
void *opaque)
{
/* All drivers that use blk_set_dev_ops() are qdevified and we want to keep
* it that way, so we can assume blk->dev is a DeviceState if blk->dev_ops
* is set. */
assert(!blk->legacy_dev);
blk->dev_ops = ops;
blk->dev_opaque = opaque;
}

2
hw/block/xen_disk.c
View File

@ -1079,7 +1079,7 @@ static int blk_connect(struct XenDevice *xendev)
* so we can blk_unref() unconditionally */
blk_ref(blkdev->blk);
}
blk_attach_dev_nofail(blkdev->blk, blkdev);
blk_attach_dev_legacy(blkdev->blk, blkdev);
blkdev->file_size = blk_getlength(blkdev->blk);
if (blkdev->file_size < 0) {
BlockDriverState *bs = blk_bs(blkdev->blk);

4
include/sysemu/block-backend.h
View File

@ -107,8 +107,8 @@ BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk);
void blk_iostatus_disable(BlockBackend *blk);
void blk_iostatus_reset(BlockBackend *blk);
void blk_iostatus_set_err(BlockBackend *blk, int error);
int blk_attach_dev(BlockBackend *blk, void *dev);
void blk_attach_dev_nofail(BlockBackend *blk, void *dev);
int blk_attach_dev(BlockBackend *blk, DeviceState *dev);
void blk_attach_dev_legacy(BlockBackend *blk, void *dev);
void blk_detach_dev(BlockBackend *blk, void *dev);
void *blk_get_attached_dev(BlockBackend *blk);
BlockBackend *blk_by_dev(void *dev);