Am 07.08.2018 um 06:33 hat John Snow geschrieben:
> Change the manual deferment to commit_complete into the implicit
> callback to job_exit.
>
> Signed-off-by: John Snow <[email protected]>
There is one tricky thing in this patch that the commit message could be
a bit more explicit about, which is moving job_completed() to a later
point.
This is the code that happens between the old call of job_completed()
and the new one:
/* If bdrv_drop_intermediate() didn't already do that, remove the commit
* filter driver from the backing chain. Do this as the final step so that
* the 'consistent read' permission can be granted. */
if (remove_commit_top_bs) {
bdrv_child_try_set_perm(commit_top_bs->backing, 0, BLK_PERM_ALL,
&error_abort);
bdrv_replace_node(commit_top_bs, backing_bs(commit_top_bs),
&error_abort);
}
bdrv_unref(commit_top_bs);
bdrv_unref(top);
As the comment states, bdrv_replace_node() requires that the permission
restrictions that the commit job made are already lifted. The most
important part is done by the explicit block_job_remove_all_bdrv() call
right before this hunk. It still leaves bjob->blk around, which could
have implications, but luckily we didn't take any permissions for that
one:
s = block_job_create(job_id, &commit_job_driver, NULL, bs, 0, BLK_PERM_ALL,
speed, JOB_DEFAULT, NULL, NULL, errp);
So I think we got everything out of the way and bdrv_replace_node() can
do what it wants to do.
Kevin
