Commits · 9c5e6594f15b7364624a3ad40306c396c93a2145 · Anton / libtcg

May 11, 2017

block: Fix write/resize permissions for inactive images · 9c5e6594

Kevin Wolf authored 7 years ago


Format drivers for inactive nodes don't need write/resize permissions on
their bs->file and can share write/resize with another VM (in fact, this
is the whole point of keeping images inactive). Represent this fact in
the op blocker system, so that image locking does the right thing
without special-casing inactive images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

9c5e6594

block: Inactivate parents before children · 38701b6a

Kevin Wolf authored 7 years ago


The proper order for inactivating block nodes is that first the parents
get inactivated and then the children. If we do things in this order, we
can assert that we didn't accidentally leave a parent activated when one
of its child nodes is inactive.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

38701b6a

block: Drop permissions when migration completes · cfa1a572

Kevin Wolf authored 7 years ago


With image locking, permissions affect other qemu processes as well. We
want to be sure that the destination can run, so let's drop permissions
on the source when migration completes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

cfa1a572

block: New BdrvChildRole.activate() for blk_resume_after_migration() · 4417ab7a

Kevin Wolf authored 7 years ago


Instead of manually calling blk_resume_after_migration() in migration
code after doing bdrv_invalidate_cache_all(), integrate the BlockBackend
activation with cache invalidation into a single function. This is
achieved with a new callback in BdrvChildRole that is called by
bdrv_invalidate_cache_all().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

4417ab7a

migration: Unify block node activation error handling · ace21a58

Kevin Wolf authored 7 years ago

Migration code activates all block driver nodes on the destination when
the migration completes. It does so by calling
bdrv_invalidate_cache_all() and blk_resume_after_migration(). There is
one code path for precopy and one for postcopy migration, resulting in
four function calls, which used to have three different failure modes.

This patch unifies the behaviour so that failure to activate all block
nodes is non-fatal, but the error message is logged and the VM isn't
automatically started. 'cont' will retry activating the block nodes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

ace21a58

iotests: Extend test 066 · aa93c834

Hanna Reitz authored 7 years ago


066 was supposed to be a test "for discarding preallocated zero
clusters", but it did so incompletely: While it did check the image
file's integrity after the operation, it did not confirm that the
clusters are indeed freed. This patch adds this test.

In addition, new cases for writing to preallocated zero clusters are
added.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

aa93c834

qcow2: Discard preallocated zero clusters · 293073a5

Hanna Reitz authored 7 years ago


In discard_single_l2(), we completely discard normal clusters instead of
simply turning them into preallocated zero clusters. That means we
should probably do the same with such preallocated zero clusters:
Discard them instead of keeping them allocated.

Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

293073a5

qcow2: Reuse preallocated zero clusters · 564a6b69

Hanna Reitz authored 7 years ago


Instead of just freeing preallocated zero clusters and completely
allocating them from scratch, reuse them.

We cannot do this in handle_copied(), however, since this is a COW
operation. Therefore, we have to add the new logic to handle_alloc() and
simply return the existing offset if it exists. The only catch is that
we have to convince qcow2_alloc_cluster_link_l2() not to free the old
clusters (because we have reused them).

Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

564a6b69

qcow2: Fix preallocation size formula · 92413c16

Hanna Reitz authored 7 years ago


When calculating the number of reftable entries, we should actually use
the number of refblocks and not (wrongly[1]) re-calculate it.

[1] "Wrongly" means: Dividing the number of clusters by the number of
    entries per refblock and rounding down instead of up.

Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

92413c16

tests: Add POSIX image locking test case 182 · de9efdb3