qemu/include/block
Jeff Cody f8aa905a4f block: set device_list.tqe_prev to NULL on BDS removal
This fixes a regression introduced with commit 3f09bfbc7.  Multiple
bugs arise in conjunction with live snapshots and mirroring operations
(which include active layer commit).

After a live snapshot occurs, the active layer and the base layer both
have a non-NULL tqe_prev field in the device_list, although the base
node's tqe_prev field points to a NULL entry.  This non-NULL tqe_prev
field occurs after the bdrv_append() in the external snapshot calls
change_parent_backing_link().

In change_parent_backing_link(), when the previous active layer is
removed from device_list, the device_list.tqe_prev pointer is not
set to NULL.

The operating scheme in the block layer is to indicate that a BDS belongs
in the bdrv_states device_list iff the device_list.tqe_prev pointer
is non-NULL.

This patch does two things:

1.) Introduces a new block layer helper bdrv_device_remove() to remove a
    BDS from the device_list, and
2.) uses that new API, which also fixes the regression once used in
    change_parent_backing_link().

Signed-off-by: Jeff Cody <jcody@redhat.com>
Message-id: 0cd51e11c0666c04ddb7c05293fe94afeb551e89.1454376655.git.jcody@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-02-02 18:04:47 +01:00
..
accounting.h block: Update copyright of the accounting code 2015-11-12 16:22:47 +01:00
aio.h aio: Introduce aio-epoll.c 2015-11-09 09:59:47 +00:00
block_int.h block: Add "file" output parameter to block status query functions 2016-02-02 17:50:47 +01:00
block.h block: set device_list.tqe_prev to NULL on BDS removal 2016-02-02 18:04:47 +01:00
blockjob.h block: Add block job transactions 2015-11-12 16:22:44 +01:00
nbd.h nbd: Always call "close_fn" in nbd_client_new 2016-01-15 18:58:01 +01:00
qapi.h qmp: fill in the image field in BlockDeviceInfo 2015-04-28 15:36:09 +02:00
scsi.h typofixes - v4 2015-09-11 10:45:43 +03:00
snapshot.h migration: implement bdrv_all_find_vmstate_bs helper 2015-11-19 11:50:00 +01:00
thread-pool.h block: Rename BlockDriverCompletionFunc to BlockCompletionFunc 2014-10-20 13:41:27 +02:00
throttle-groups.h throttle: Remove throttle_group_lock/unlock() 2015-10-23 18:18:23 +02:00
write-threshold.h block: add event when disk usage exceeds threshold 2015-02-06 17:24:21 +01:00