All callers will have to request permissions for all of their child
nodes. Block drivers that act as simply filters can use the default
implementation of .bdrv_child_perm().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Acked-by: NFam Zheng <famz@redhat.com>

The way that attaching bs->file worked was a bit unusual in that it was
the only child that would be attached to a node which is not opened yet.
Because of this, the block layer couldn't know yet which permissions the
driver would eventually need.

This patch moves the point where bs->file is attached to the beginning
of the individual .bdrv_open() implementations, so drivers already know
what they are going to do with the child. This is also more consistent
with how driver-specific children work.

For a moment, bdrv_open() gets its own BdrvChild to perform image
probing, but instead of directly assigning this BdrvChild to the BDS, it
becomes a temporary one and the node name is passed as an option to the
drivers, so that they can simply use bdrv_open_child() to create another
reference for their own use.

This duplicated child for (the not opened yet) bs is not the final
state, a follow-up patch will change the image probing code to use a
BlockBackend, which is completely independent of bs.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Refactor backup_start as backup_job_create, which only creates the job,
but does not automatically start it. The old interface, 'backup_start',
is not kept in favor of limiting the number of nearly-identical interfaces
that would have to be edited to keep up with QAPI changes in the future.

Callers that wish to synchronously start the backup_block_job can
instead just call block_job_start immediately after calling
backup_job_create.

Transactions are updated to use the new interface, calling block_job_start
only during the .commit phase, which helps prevent race conditions where
jobs may finish before we even finish building the transaction. This may
happen, for instance, during empty block backup jobs.
Reported-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Message-id: 1478587839-9834-6-git-send-email-jsnow@redhat.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

Bubble up the internal interface to commit and backup jobs, then switch
replication tasks over to using this methodology.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Message-id: 1477584421-1399-4-git-send-email-jsnow@redhat.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

After the next patch bdrv_drain_all will have to be called without holding any
AioContext.  Prepare to do this by adding an AioContext argument to
bdrv_reopen_multiple.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-15-git-send-email-pbonzini@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>

This will be needed in the next patch to retrieve the AioContext.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-14-git-send-email-pbonzini@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>

Without this change, there is a race condition in tests/test-replication.
Depending on how fast the failover job (active commit) runs, there is a
chance of two bad things happening:

1) replication_done can be called after the secondary has been closed
and hence when the BDRVReplicationState is not valid anymore.

2) two copies of the active disk are present during the
/replication/secondary/stop test (that test runs immediately after
/replication/secondary/start, which tests failover).  This causes the
corruption detector to fire.
Reviewed-by: NWen Congyang <wency@cn.fujitsu.com>
Reviewed-by: NChanglong Xie <xiecl.fnst@cn.fujitsu.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Message-Id: <1477565348-5458-2-git-send-email-pbonzini@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>

The replication driver only supports the 'top-id' parameter for the
secondary side; it must not be supplied for the primary side.
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NChanglong Xie <xiecl.fnst@cn.fujitsu.com>
Message-id: 1476247808-15646-1-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Signed-off-by: NChanglong Xie <xiecl.fnst@cn.fujitsu.com>
Signed-off-by: NWang WeiWei <wangww.fnst@cn.fujitsu.com>
Signed-off-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Message-id: 1469602913-20979-10-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>