block-backend: Allow more "can inactivate" cases

These two conditions corresponds to mirror job's source and target,
which need to be allowed as they are part of the non-shared storage
migration workflow: failing to inactivate either will result in a
failure during migration completion.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170823134242.12080-3-famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[eblake: improve comment grammar]
Signed-off-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Fam Zheng 2017-08-23 21:42:40 +08:00 committed by Eric Blake
parent c16de8f59a
commit ca2e214411
2 changed files with 18 additions and 5 deletions

View File

@ -70,6 +70,7 @@ struct BlockBackend {
int quiesce_counter;
VMChangeStateEntry *vmsh;
bool force_allow_inactivate;
};
typedef struct BlockBackendAIOCB {
@ -192,17 +193,28 @@ static void blk_root_activate(BdrvChild *child, Error **errp)
}
}
void blk_set_force_allow_inactivate(BlockBackend *blk)
{
blk->force_allow_inactivate = true;
}
static bool blk_can_inactivate(BlockBackend *blk)
{
/* Only inactivate BlockBackends for guest devices (which are inactive at
* this point because the VM is stopped) and unattached monitor-owned
* BlockBackends. If there is still any other user like a block job, then
* we simply can't inactivate the image. */
/* If it is a guest device, inactivate is ok. */
if (blk->dev || blk_name(blk)[0]) {
return true;
}
return false;
/* Inactivating means no more writes to the image can be done,
* even if those writes would be changes invisible to the
* guest. For block job BBs that satisfy this, we can just allow
* it. This is the case for mirror job source, which is required
* by libvirt non-shared block migration. */
if (!(blk->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED))) {
return true;
}
return blk->force_allow_inactivate;
}
static int blk_root_inactivate(BdrvChild *child)

View File

@ -241,5 +241,6 @@ void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg);
void blk_io_limits_disable(BlockBackend *blk);
void blk_io_limits_enable(BlockBackend *blk, const char *group);
void blk_io_limits_update_group(BlockBackend *blk, const char *group);
void blk_set_force_allow_inactivate(BlockBackend *blk);
#endif