Commit Graph

1576 Commits

Author SHA1 Message Date
Kevin Wolf
4ec8df0183 block: Mark bdrv_co_create() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_create() need to hold a reader lock for the graph.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-17-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23 19:49:23 +01:00
Kevin Wolf
10e5d70787 block: Make bdrv_can_set_read_only() static
It is never called outside of block.c.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-2-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23 19:48:28 +01:00
Stefano Garzarella
60d90bf43c block: temporarily hold the new AioContext of bs_top in bdrv_append()
bdrv_append() is called with bs_top AioContext held, but
bdrv_attach_child_noperm() could change the AioContext of bs_top.

bdrv_replace_node_noperm() calls bdrv_drained_begin() starting from
commit 2398747128 ("block: Don't poll in bdrv_replace_child_noperm()").
bdrv_drained_begin() can call BDRV_POLL_WHILE that assumes the new lock
is taken, so let's temporarily hold the new AioContext to prevent QEMU
from failing in BDRV_POLL_WHILE when it tries to release the wrong
AioContext.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2168209
Reported-by: Aihua Liang <aliang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20230214171621.11574-1-sgarzare@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-17 14:33:58 +01:00
Kevin Wolf
321923010d block: Assert non-coroutine context for bdrv_open_inherit()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230126172432.436111-14-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-17 11:22:19 +01:00
Kevin Wolf
be1a732c9a block: Fix bdrv_co_create_opts_simple() to open images with no_co_wrapper
bdrv_co_create_opts_simple() runs in a coroutine. Therefore it is not
allowed to open images directly. Fix the call to use the corresponding
no_co_wrapper instead.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230126172432.436111-13-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-17 11:22:19 +01:00
Emanuele Giuseppe Esposito
c834dc0586 block: Convert bdrv_debug_event() to co_wrapper_mixed
bdrv_debug_event() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

Therefore turn it into a co_wrapper_mixed to move the actual function
into a coroutine where the lock can be taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-14-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Emanuele Giuseppe Esposito
2c75261cc2 block: Convert bdrv_lock_medium() to co_wrapper
bdrv_lock_medium() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

The only caller of this function is blk_lock_medium(). Therefore make
blk_lock_medium() a co_wrapper, so that it always creates a new
coroutine, and then make bdrv_lock_medium() a coroutine_fn where the
lock can be taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-13-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Emanuele Giuseppe Esposito
2531b390fb block: Convert bdrv_eject() to co_wrapper
bdrv_eject() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

The only caller of this function is blk_eject(). Therefore make
blk_eject() a co_wrapper, so that it always creates a new coroutine, and
then make bdrv_eject() coroutine_fn where the lock can be taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Emanuele Giuseppe Esposito
3d47eb0a2a block: Convert bdrv_get_info() to co_wrapper_mixed
bdrv_get_info() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-11-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Emanuele Giuseppe Esposito
82618d7bc3 block: Convert bdrv_get_allocated_file_size() to co_wrapper
bdrv_get_allocated_file_size() is categorized as an I/O function, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since it traverses the block nodes graph, which however is only
possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-10-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Emanuele Giuseppe Esposito
c86422c554 block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed
BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the
AioContext lock.

This is especially messy when a co_wrapper creates a coroutine and polls
in bdrv_open_driver, because this function has so many callers in so
many context that it can easily lead to deadlocks. Therefore the new
rule for bdrv_open_driver is that the caller must always hold the
AioContext lock of the given bs (except if it is a coroutine), because
the function calls bdrv_refresh_total_sectors() which is now a
co_wrapper.

Once the rwlock is ultimated and placed in every place it needs to be,
we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext
lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-7-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Emanuele Giuseppe Esposito
c057960c4e block: Rename refresh_total_sectors to bdrv_refresh_total_sectors
The name is not good, not the least because we are going to convert this
to a generated co_wrapper, which adds a _co infix after the first part
of the name.

No functional change intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-6-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Emanuele Giuseppe Esposito
1e97be9156 block: Convert bdrv_is_inserted() to co_wrapper
bdrv_is_inserted() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

At the same time, add also blk_is_inserted as co_wrapper_mixed, since it
is called in both coroutine and non-coroutine contexts.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally c_w_mixed_bdrv_rdlock calls AIO_WAIT_WHILE and it expects to
release the AioContext lock. Once the rwlock is ultimated and placed in
every place it needs to be, we will poll using AIO_WAIT_WHILE_UNLOCKED
and remove the AioContext lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-5-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Paolo Bonzini
3d65110f0c block: remove bdrv_coroutine_enter
It has only one caller---inline it and remove the function.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221215130225.476477-2-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-01-24 18:26:41 +01:00
Markus Armbruster
e2c1c34f13 include/block: Untangle inclusion loops
We have two inclusion loops:

       block/block.h
    -> block/block-global-state.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

       block/block.h
    -> block/block-io.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac.

Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
2023-01-20 07:24:28 +01:00
Kevin Wolf
1b3ff9feb9 block: GRAPH_RDLOCK for functions only called by co_wrappers
The generated coroutine wrappers already take care to take the lock in
the non-coroutine path, and assume that the lock is already taken in the
coroutine path.

The only thing we need to do for the wrapped function is adding the
GRAPH_RDLOCK annotation. Doing so also allows us to mark the
corresponding callbacks in BlockDriver as GRAPH_RDLOCK_PTR.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-19-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:08:23 +01:00
Kevin Wolf
303de47b2c Mark assert_bdrv_graph_readable/writable() GRAPH_RD/WRLOCK
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-16-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:08:23 +01:00
Emanuele Giuseppe Esposito
3f35f82e04 block: assert that graph read and writes are performed correctly
Remove the old assert_bdrv_graph_writable, and replace it with
the new version using graph-lock API.

See the function documentation for more information.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-14-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:08:23 +01:00
Emanuele Giuseppe Esposito
1af8239235 block: remove unnecessary assert_bdrv_graph_writable()
We don't protect bdrv->aio_context with the graph rwlock,
so these assertions are not needed

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-13-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:08:23 +01:00
Emanuele Giuseppe Esposito
2931250780 block: wrlock in bdrv_replace_child_noperm
Protect the main function where graph is modified.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:08:23 +01:00
Kevin Wolf
e135505588 block: Fix locking in external_snapshot_prepare()
bdrv_img_create() polls internally (when calling bdrv_create(), which is
a co_wrapper), so it can't be called while holding the lock of any
AioContext except the current one without causing deadlocks. Drop the
lock around the call in external_snapshot_prepare().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-11-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:08:23 +01:00
Emanuele Giuseppe Esposito
741443eb43 block: convert bdrv_create to co_wrapper
This function is never called in coroutine context, therefore
instead of manually creating a new coroutine, delegate it to the
block-coroutine-wrapper script, defining it as co_wrapper.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-14-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:43 +01:00
Emanuele Giuseppe Esposito
2475a0d0f4 block: bdrv_create_file is a coroutine_fn
It is always called in coroutine_fn callbacks, therefore
it can directly call bdrv_co_create().

Rename it to bdrv_co_create_file too.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-9-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:43 +01:00
Emanuele Giuseppe Esposito
84bdf21f97 block: distinguish between bdrv_create running in coroutine and not
Call two different functions depending on whether bdrv_create
is in coroutine or not, following the same pattern as
generated_co_wrapper functions.

This allows to also call the coroutine function directly,
without using CreateCo or relying in bdrv_create().

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-8-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:43 +01:00
Emanuele Giuseppe Esposito
a212e675cd block: avoid duplicating filename string in bdrv_create
We know that the string will stay around until the function
returns, and the parameter of drv->bdrv_co_create_opts is const char*,
so it must not be modified either.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-7-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:43 +01:00
Kevin Wolf
606ed756c1 block: Remove poll parameter from bdrv_parent_drained_begin_single()
All callers of bdrv_parent_drained_begin_single() pass poll=false now,
so we don't need the parameter any more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221118174110.55183-16-kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
2398747128 block: Don't poll in bdrv_replace_child_noperm()
In order to make sure that bdrv_replace_child_noperm() doesn't have to
poll any more, get rid of the bdrv_parent_drained_begin_single() call.

This is possible now because we can require that the parent is already
drained through the child in question when the function is called and we
don't call the parent drain callbacks more than once.

The additional drain calls needed in callers cause the test case to run
its code in the drain handler too early (bdrv_attach_child() drains
now), so modify it to only enable the code after the test setup has
completed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221118174110.55183-15-kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
a82a3bd135 block: Remove ignore_bds_parents parameter from drain_begin/end.
ignore_bds_parents is now ignored during drain_begin and drain_end, so
we can just remove it there. It is still a valid optimisation for
drain_all in bdrv_drained_poll(), so leave it around there.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221118174110.55183-13-kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
57e05be343 block: Call drain callbacks only once
We only need to call both the BlockDriver's callback and the parent
callbacks when going from undrained to drained or vice versa. A second
drain section doesn't make a difference for the driver or the parent,
they weren't supposed to send new requests before and after the second
drain.

One thing that gets in the way is the 'ignore_bds_parents' parameter in
bdrv_do_drained_begin_quiesce() and bdrv_do_drained_end(): It means that
bdrv_drain_all_begin() increases bs->quiesce_counter, but does not
quiesce the parent through BdrvChildClass callbacks. If an additional
drain section is started now, bs->quiesce_counter will be non-zero, but
we would still need to quiesce the parent through BdrvChildClass in
order to keep things consistent (and unquiesce it on the matching
bdrv_drained_end(), even though the counter would not reach 0 yet as
long as the bdrv_drain_all() section is still active).

Instead of keeping track of this, let's just get rid of the parameter.
It was introduced in commit 6cd5c9d7b2 as an optimisation so that
during bdrv_drain_all(), we wouldn't recursively drain all parents up to
the root for each node, resulting in quadratic complexity. As it happens,
calling the callbacks only once solves the same problem, so as of this
patch, we'll still have O(n) complexity and ignore_bds_parents is not
needed any more.

This patch only ignores the 'ignore_bds_parents' parameter. It will be
removed in a separate patch.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221118174110.55183-12-kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
299403aeda block: Remove subtree drains
Subtree drains are not used any more. Remove them.

After this, BdrvChildClass.attach/detach() don't poll any more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221118174110.55183-11-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
92140b9f3f stream: Replace subtree drain with a single node drain
The subtree drain was introduced in commit b1e1af394d as a way to avoid
graph changes between finding the base node and changing the block graph
as necessary on completion of the image streaming job.

The block graph could change between these two points because
bdrv_set_backing_hd() first drains the parent node, which involved
polling and can do anything.

Subtree draining was an imperfect way to make this less likely (because
with it, fewer callbacks are called during this window). Everyone agreed
that it's not really the right solution, and it was only committed as a
stopgap solution.

This replaces the subtree drain with a solution that simply drains the
parent node before we try to find the base node, and then call a version
of bdrv_set_backing_hd() that doesn't drain, but just asserts that the
parent node is already drained.

This way, any graph changes caused by draining happen before we start
looking at the graph and things stay consistent between finding the base
node and changing the graph.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221118174110.55183-10-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
631086deef block: Don't use subtree drains in bdrv_drop_intermediate()
Instead of using a subtree drain from the top node (which also drains
child nodes of base that we're not even interested in), use a normal
drain for base, which automatically drains all of the parents, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221118174110.55183-9-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
d22933acd2 block: Drain individual nodes during reopen
bdrv_reopen() and friends use subtree drains as a lazy way of covering
all the nodes they touch. Turns out that this lazy way is a lot more
complicated than just draining the nodes individually, even not
accounting for the additional complexity in the drain mechanism itself.

Simplify the code by switching to draining the individual nodes that are
already managed in the BlockReopenQueue anyway.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221118174110.55183-8-kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
2e117866d7 block: Fix locking for bdrv_reopen_queue_child()
Callers don't agree whether bdrv_reopen_queue_child() should be called
with the AioContext lock held or not. Standardise on holding the lock
(as done by QMP blockdev-reopen and the replication block driver) and
fix bdrv_reopen() to do the same.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221118174110.55183-7-kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
2f65df6e16 block: Remove drained_end_counter
drained_end_counter is unused now, nobody changes its value any more. It
can be removed.

In cases where we had two almost identical functions that only differed
in whether the caller passes drained_end_counter, or whether they would
poll for a local drained_end_counter to reach 0, these become a single
function.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20221118174110.55183-5-kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Kevin Wolf
5e8ac21717 block: Revert .bdrv_drained_begin/end to non-coroutine_fn
Polling during bdrv_drained_end() can be problematic (and in the future,
we may get cases for bdrv_drained_begin() where polling is forbidden,
and we don't care about already in-flight requests, but just want to
prevent new requests from arriving).

The .bdrv_drained_begin/end callbacks running in a coroutine is the only
reason why we have to do this polling, so make them non-coroutine
callbacks again. None of the callers actually yield any more.

This means that bdrv_drained_end() effectively doesn't poll any more,
even if AIO_WAIT_WHILE() loops are still there (their condition is false
from the beginning). This is generally not a problem, but in
test-bdrv-drain, some additional explicit aio_poll() calls need to be
added because the test case wants to verify the final state after BHs
have executed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221118174110.55183-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Vladimir Sementsov-Ogievskiy
fb0ff4d1ba block: refactor bdrv_list_refresh_perms to allow any list of nodes
We are going to increase usage of collecting nodes in a list to then
update, and calling bdrv_topological_dfs() each time is not convenient,
and not correct as we are going to interleave graph modifying with
filling the node list.

So, let's switch to a function that takes any list of nodes, adds all
their subtrees and do topological sort. And finally, refresh
permissions.

While being here, make the function public, as we'll want to use it
from blockdev.c in near future.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221107163558.618889-5-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Vladimir Sementsov-Ogievskiy
f1316edbfc block: bdrv_refresh_perms(): allow external tran
Allow passing external Transaction pointer, stop creating extra
Transaction objects.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221107163558.618889-4-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Vladimir Sementsov-Ogievskiy
f38eaec4c3 block: drop bdrv_remove_filter_or_cow_child
Drop this simple wrapper used only in one place. We have too many graph
modifying functions even without it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221107163558.618889-3-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Vladimir Sementsov-Ogievskiy
00eb93b588 block: Inline bdrv_detach_child()
The only caller is bdrv_root_unref_child(), let's just do the logic
directly in it. It simplifies further conversion of
bdrv_root_unref_child() to transaction actions.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221107163558.618889-2-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Hanna Reitz
d5f8d79c2f block: Make bdrv_child_get_parent_aio_context I/O
We want to use bdrv_child_get_parent_aio_context() from
bdrv_parent_drained_{begin,end}_single(), both of which are "I/O or GS"
functions.

Prior to 3ed4f708fe, all the implementations were I/O code anyway.
3ed4f708fe has put block jobs' AioContext field under the job mutex, so
to make child_job_get_parent_aio_context() work in an I/O context, we
need to take that lock there.

Furthermore, blk_root_get_parent_aio_context() is not marked as
anything, but is safe to run in an I/O context, so mark it that way now.
(blk_get_aio_context() is an I/O code function.)

With that done, all implementations explicitly are I/O code, so we can
mark bdrv_child_get_parent_aio_context() as I/O code, too, so callers
know it is safe to run from both GS and I/O contexts.

Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221107151321.211175-2-hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-11-10 14:58:34 +01:00
Claudio Fontana
c551fb0b53 module: add Error arguments to module_load and module_load_qom
improve error handling during module load, by changing:

bool module_load(const char *prefix, const char *lib_name);
void module_load_qom(const char *type);

to:

int module_load(const char *prefix, const char *name, Error **errp);
int module_load_qom(const char *type, Error **errp);

where the return value is:

 -1 on module load error, and errp is set with the error
  0 on module or one of its dependencies are not installed
  1 on module load success
  2 on module load success (module already loaded or built-in)

module_load_qom_one has been introduced in:

commit 28457744c3 ("module: qom module support"), which built on top of
module_load_one, but discarded the bool return value. Restore it.

Adapt all callers to emit errors, or ignore them, or fail hard,
as appropriate in each context.

Replace the previous emission of errors via fprintf in _some_ error
conditions with Error and error_report, so as to emit to the appropriate
target.

A memory leak is also fixed as part of the module_load changes.

audio: when attempting to load an audio module, report module load errors.
Note that still for some callers, a single issue may generate multiple
error reports, and this could be improved further.
Regarding the audio code itself, audio_add() seems to ignore errors,
and this should probably be improved.

block: when attempting to load a block module, report module load errors.
For the code paths that already use the Error API, take advantage of those
to report module load errors into the Error parameter.
For the other code paths, we currently emit the error, but this could be
improved further by adding Error parameters to all possible code paths.

console: when attempting to load a display module, report module load errors.

qdev: when creating a new qdev Device object (DeviceState), report load errors.
      If a module cannot be loaded to create that device, now abort execution
      (if no CONFIG_MODULE) or exit (if CONFIG_MODULE).

qom/object.c: when initializing a QOM object, or looking up class_by_name,
              report module load errors.

qtest: when processing the "module_load" qtest command, report errors
       in the load of the module.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220929093035.4231-4-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-06 09:48:50 +01:00
Claudio Fontana
dbc0e80553 module: rename module_load_one to module_load
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220929093035.4231-3-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-06 09:48:50 +01:00
Stefan Hajnoczi
d5ab9490cd Block layer patches
- Cleanup bs->backing and bs->file handling
 - Refactor bdrv_try_set_aio_context using transactions
 - Changes for improved coroutine_fn consistency
 - vhost-user-blk: fix the resize crash
 - io_uring: Use of io_uring_register_ring_fd() led to breakage, revert
 - vvfat: Fix some problems with r/w mode
 - Code cleanup
 - MAINTAINERS: Fold "Block QAPI, monitor, ..." into "Block layer core"
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Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into staging

Block layer patches

- Cleanup bs->backing and bs->file handling
- Refactor bdrv_try_set_aio_context using transactions
- Changes for improved coroutine_fn consistency
- vhost-user-blk: fix the resize crash
- io_uring: Use of io_uring_register_ring_fd() led to breakage, revert
- vvfat: Fix some problems with r/w mode
- Code cleanup
- MAINTAINERS: Fold "Block QAPI, monitor, ..." into "Block layer core"

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# gpg: Signature made Thu 27 Oct 2022 14:29:38 EDT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* tag 'for-upstream' of https://repo.or.cz/qemu/kevin: (58 commits)
  block/block-backend: blk_set_enable_write_cache is IO_CODE
  monitor: switch to *_co_* functions
  vmdk: switch to *_co_* functions
  vhdx: switch to *_co_* functions
  vdi: switch to *_co_* functions
  qed: switch to *_co_* functions
  qcow2: switch to *_co_* functions
  qcow: switch to *_co_* functions
  parallels: switch to *_co_* functions
  mirror: switch to *_co_* functions
  block: switch to *_co_* functions
  commit: switch to *_co_* functions
  vmdk: manually add more coroutine_fn annotations
  qcow2: manually add more coroutine_fn annotations
  qcow: manually add more coroutine_fn annotations
  blkdebug: add missing coroutine_fn annotation for indirect-called functions
  qcow2: add coroutine_fn annotation for indirect-called functions
  block: add missing coroutine_fn annotation to BlockDriverState callbacks
  coroutine-io: add missing coroutine_fn annotation to prototypes
  coroutine-lock: add missing coroutine_fn annotation to prototypes
  ...

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-30 15:15:12 -04:00
Alberto Faria
ce47ff20b9 block: switch to *_co_* functions
Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-16-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Emanuele Giuseppe Esposito
142e690712 block: remove bdrv_try_set_aio_context and replace it with bdrv_try_change_aio_context
No functional change intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221025084952.2139888-11-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Emanuele Giuseppe Esposito
a41cfda126 block: rename bdrv_child_try_change_aio_context in bdrv_try_change_aio_context
No functional changes intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221025084952.2139888-10-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Emanuele Giuseppe Esposito
d2aafbb68a block: remove all unused ->can_set_aio_ctx and ->set_aio_ctx callbacks
Together with all _can_set_ and _set_ APIs, as they are not needed
anymore.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221025084952.2139888-9-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Emanuele Giuseppe Esposito
f8be48adf0 block: use the new _change_ API instead of _can_set_ and _set_
Replace all direct usage of ->can_set_aio_ctx and ->set_aio_ctx,
and call bdrv_child_try_change_aio_context() in
bdrv_try_set_aio_context(), the main function called through
the whole block layer.

From this point onwards, ->can_set_aio_ctx and ->set_aio_ctx
won't be used anymore.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221025084952.2139888-8-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Emanuele Giuseppe Esposito
27633e740e block: implement .change_aio_ctx in child_of_bds
bdrv_child_cb_change_aio_ctx() is identical to
bdrv_child_cb_can_set_aio_ctx(), as we only need
to recursively go on the parent bs.

Note: bdrv_child_try_change_aio_context() is not called by
anyone at this point.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221025084952.2139888-6-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00