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>
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>
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>
In some places we are sure we are always running in a
coroutine, therefore it's useless to call the generated_co_wrapper,
instead call directly the _co_ function.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-9-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The only difference is that blk_ checks if the block is available,
but this check is already performed above in blk_check_byte_request().
This is in preparation for the graph rdlock, which will be taken
by both the callers of blk_check_byte_request() and blk_getlength().
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-8-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
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>
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>
BlockDriver->bdrv_io_unplug 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.
The only caller of this function is blk_io_unplug(), therefore make
blk_io_unplug() a co_wrapper, so that we're always running in 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: <20230113204212.359076-4-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
BlockDriver->bdrv_io_plug 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.
The only caller of this function is blk_io_plug(), therefore make
blk_io_plug() a co_wrapper, so that we're always running in 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: <20230113204212.359076-3-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In order to write the bitmap table to the image file, it is converted to
big endian. If the write fails, it is passed to clear_bitmap_table() to
free all of the clusters it had allocated before. However, if we don't
convert it back to native endianness first, we'll free things at a wrong
offset.
In practical terms, the offsets will be so high that we won't actually
free any allocated clusters, but just run into an error, but in theory
this can cause image corruption.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230112191454.169353-2-kwolf@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
After recent header file inclusion rework the build fails when the blkio
module is enabled:
../block/blkio.c: In function ‘blkio_detach_aio_context’:
../block/blkio.c:321:24: error: implicit declaration of function ‘bdrv_get_aio_context’; did you mean ‘qemu_get_aio_context’? [-Werror=implicit-function-declaration]
321 | aio_set_fd_handler(bdrv_get_aio_context(bs),
| ^~~~~~~~~~~~~~~~~~~~
| qemu_get_aio_context
../block/blkio.c:321:24: error: nested extern declaration of ‘bdrv_get_aio_context’ [-Werror=nested-externs]
../block/blkio.c:321:24: error: passing argument 1 of ‘aio_set_fd_handler’ makes pointer from integer without a cast [-Werror=int-conversion]
321 | aio_set_fd_handler(bdrv_get_aio_context(bs),
| ^~~~~~~~~~~~~~~~~~~~~~~~
| |
| int
In file included from /home/pipo/git/qemu.git/include/qemu/job.h:33,
from /home/pipo/git/qemu.git/include/block/blockjob.h:30,
from /home/pipo/git/qemu.git/include/block/block_int-global-state.h:28,
from /home/pipo/git/qemu.git/include/block/block_int.h:27,
from ../block/blkio.c:13:
/home/pipo/git/qemu.git/include/block/aio.h:476:37: note: expected ‘AioContext *’ but argument is of type ‘int’
476 | void aio_set_fd_handler(AioContext *ctx,
| ~~~~~~~~~~~~^~~
../block/blkio.c: In function ‘blkio_file_open’:
../block/blkio.c:821:34: error: passing argument 2 of ‘blkio_attach_aio_context’ makes pointer from integer without a cast [-Werror=int-conversion]
821 | blkio_attach_aio_context(bs, bdrv_get_aio_context(bs));
| ^~~~~~~~~~~~~~~~~~~~~~~~
| |
| int
Fix it by including 'block/block-io.h' which contains the required
declarations.
Fixes: e2c1c34f13
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 2bc956011404a1ab03342aefde0087b5b4762562.1674477350.git.pkrempa@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221221131435.3851212-4-armbru@redhat.com>
There is a defined RETRY_ON_EINTR() macro in qemu/osdep.h
which handles the same while loop.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/415
Signed-off-by: Nikita Ivanov <nivanov@cloudlinux.com>
Message-Id: <20221023090422.242617-3-nivanov@cloudlinux.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[thuth: Dropped the hunk that changed socket_accept() in libqtest.c]
Signed-off-by: Thomas Huth <thuth@redhat.com>
In commit da0bd74434 we refactored bdrv_drain_all_begin() to pull out
the non-polling part into bdrv_drain_all_begin_nopoll(). This change
broke record-and-replay, because the "return early if replay enabled"
check is now in the sub-function bdrv_drain_all_begin_nopoll(), and
so it only causes us to return from that function, and not from the
calling bdrv_drain_all_begin().
Fix the regression by checking whether replay is enabled in both
functions.
The breakage and fix can be tested via 'make check-avocado': the
tests/avocado/reverse_debugging.py:ReverseDebugging_X86_64.test_x86_64_pc
tests/avocado/reverse_debugging.py:ReverseDebugging_AArch64.test_aarch64_virt
tests were both broken by this.
Fixes: da0bd74434 ("block: Factor out bdrv_drain_all_begin_nopoll()")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Fabiano Rosas <farosas@suse.de>
Message-id: 20221220174638.2156308-1-peter.maydell@linaro.org
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>
Take the rdlock already, before we add the assertions.
All these functions either read the graph recursively, or call
BlockDriver callbacks that will eventually need to be protected by the
graph rdlock.
Do it now to all functions together, because many of these recursively
call each other.
For example, bdrv_co_truncate calls BlockDriver->bdrv_co_truncate, and
some driver callbacks implement their own .bdrv_co_truncate by calling
bdrv_flush inside. So if bdrv_flush asserts but bdrv_truncate does not
take the rdlock yet, the assertion will always fail.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-18-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>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-15-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
Block layer graph operations are always run under BQL in the main loop.
This is proved by the assertion qemu_in_main_thread() and its wrapper
macro GLOBAL_STATE_CODE.
However, there are also concurrent coroutines running in other iothreads
that always try to traverse the graph. Currently this is protected
(among various other things) by the AioContext lock, but once this is
removed, we need to make sure that reads do not happen while modifying
the graph.
We distinguish between writer (main loop, under BQL) that modifies the
graph, and readers (all other coroutines running in various AioContext),
that go through the graph edges, reading ->parents and->children.
The writer (main loop) has "exclusive" access, so it first waits for any
current read to finish, and then prevents incoming ones from entering
while it has the exclusive access.
The readers (coroutines in multiple AioContext) are free to access the
graph as long the writer is not modifying the graph. In case it is, they
go in a CoQueue and sleep until the writer is done.
If a coroutine changes AioContext, the counter in the original and new
AioContext are left intact, since the writer does not care where the
reader is, but only if there is one.
As a result, some AioContexts might have a negative reader count, to
balance the positive count of the AioContext that took the lock. This
also means that when an AioContext is deleted it may have a nonzero
reader count. In that case we transfer the count to a global shared
counter so that the writer is always aware of all readers.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-3-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>
Provide a separate function that just quiesces the users of a node to
prevent new requests from coming in, but without waiting for the already
in-flight I/O to complete.
This function can be used in contexts where polling is not allowed.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-2-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_can_store_new_dirty_bitmap and bdrv_remove_persistent_dirty_bitmap
check if they are running in a coroutine, directly calling the
coroutine callback if it's the case.
Except that no coroutine calls such functions, therefore that check
can be removed, and function creation can be offloaded to
c_w.
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: <20221128142337.657646-15-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Extend the regex to cover also return type, pointers included.
This implies that the value returned by the function cannot be
a simple "int" anymore, but the custom return type.
Therefore remove poll_state->ret and instead use a per-function
custom "ret" field.
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: <20221128142337.657646-13-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Right now, we take the first parameter of the function to get the
BlockDriverState to pass to bdrv_poll_co(), that internally calls
functions that figure in which aiocontext the coroutine should run.
However, it is useless to pass a bs just to get its own AioContext,
so instead pass it directly, and default to the main loop if no
BlockDriverState is passed as parameter.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-12-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In preparation to the incoming new function specifiers,
rename g_c_w with a more meaningful name and document it.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-10-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
These functions end up calling bdrv_create() implemented as generated_co_wrapper
functions.
In addition, they also happen to be always called in coroutine context,
meaning all callers are coroutine_fn.
This means that the g_c_w function will enter the qemu_in_coroutine()
case and eventually suspend (or in other words call qemu_coroutine_yield()).
Therefore we can mark such functions coroutine_fn too.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-6-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Avoid mixing bdrv_* functions with blk_*, so create blk_* counterparts
for bdrv_block_status_above and bdrv_is_allocated_above.
Note that since blk_co_block_status_above only calls the g_c_w function
bdrv_common_block_status_above and is marked as coroutine_fn, call
directly bdrv_co_common_block_status_above() to avoid using a g_c_w.
Same applies to blk_co_is_allocated_above.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-5-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
These functions end up calling bdrv_common_block_status_above(), a
generated_co_wrapper function.
In addition, they also happen to be always called in coroutine context,
meaning all callers are coroutine_fn.
This means that the g_c_w function will enter the qemu_in_coroutine()
case and eventually suspend (or in other words call qemu_coroutine_yield()).
Therefore we can mark such functions coroutine_fn too.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-3-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_common_block_status_above() is a g_c_w, and it is being called by
many "wrapper" functions like bdrv_is_allocated(),
bdrv_is_allocated_above() and bdrv_block_status_above().
Because we want to eventually split the coroutine from non-coroutine
case in g_c_w, create duplicate wrappers that take care of directly
calling the same coroutine functions called in the g_c_w.
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: <20221128142337.657646-2-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
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>
The next patch adds a parent drain to bdrv_attach_child_common(), which
shouldn't be, but is currently called from coroutines in some cases (e.g.
.bdrv_co_create implementations generally open new nodes). Therefore,
the assertion that we're not in a coroutine doesn't hold true any more.
We could just remove the assertion because there is nothing in the
function that should be in conflict with running in a coroutine, but
just to be on the safe side, we can reverse the caller relationship
between bdrv_do_drained_begin() and bdrv_do_drained_begin_quiesce() so
that the latter also just drops out of coroutine context and we can
still be certain in the future that any drain code doesn't run in
coroutines.
As a nice side effect, the structure of bdrv_do_drained_begin() is now
symmetrical with bdrv_do_drained_end().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221118174110.55183-14-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>
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>
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>
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>
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>
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>
bdrv_drain_invoke() has now two entirely separate cases that share no
code any more and are selected depending on a bool parameter. Each case
has only one caller. Just inline the function.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20221118174110.55183-6-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
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>
We want to change .bdrv_co_drained_begin() back to be a non-coroutine
callback, so in preparation, avoid yielding in its implementation.
Because we increase bs->in_flight and bdrv_drained_begin() polls, the
behaviour is unchanged.
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: <20221118174110.55183-2-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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Merge tag 'pull-misc-2022-12-14' of https://repo.or.cz/qemu/armbru into staging
Miscellaneous patches for 2022-12-14
# gpg: Signature made Wed 14 Dec 2022 15:23:02 GMT
# gpg: using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg: issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653
* tag 'pull-misc-2022-12-14' of https://repo.or.cz/qemu/armbru:
ppc4xx_sdram: Simplify sdram_ddr_size() to return
block/vmdk: Simplify vmdk_co_create() to return directly
cleanup: Tweak and re-run return_directly.cocci
io: Tidy up fat-fingered parameter name
qapi: Use returned bool to check for failure (again)
sockets: Use ERRP_GUARD() where obviously appropriate
qemu-config: Use ERRP_GUARD() where obviously appropriate
qemu-config: Make config_parse_qdict() return bool
monitor: Use ERRP_GUARD() in monitor_init()
monitor: Simplify monitor_fd_param()'s error handling
error: Move ERRP_GUARD() to the beginning of the function
error: Drop a few superfluous ERRP_GUARD()
error: Drop some obviously superfluous error_propagate()
Drop more useless casts from void * to pointer
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The has_FOO for pointer-valued FOO are redundant, except for arrays.
They are also a nuisance to work with. Recent commit "qapi: Start to
elide redundant has_FOO in generated C" provided the means to elide
them step by step. This is the step for qapi/block*.json.
Said commit explains the transformation in more detail.
There is one instance of the invariant violation mentioned there:
qcow2_signal_corruption() passes false, "" when node_name is an empty
string. Take care to pass NULL then.
The previous two commits cleaned up two more.
Additionally, helper bdrv_latency_histogram_stats() loses its output
parameters and returns a value instead.
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221104160712.3005652-11-armbru@redhat.com>
[Fixes for #ifndef LIBRBD_SUPPORTS_ENCRYPTION and MacOS squashed in]
Cc: Fam Zheng <fam@euphon.net>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221122134917.1217307-3-armbru@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
This simplifies error checking.
Cc: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221121085054.683122-7-armbru@redhat.com>
include/qapi/error.h on ERRP_GUARD():
* It must be used when the function dereferences @errp or passes
* @errp to error_prepend(), error_vprepend(), or error_append_hint().
* It is safe to use even when it's not needed, but please avoid
* cluttering the source with useless code.
Clean up some of this clutter.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221121085054.683122-3-armbru@redhat.com>
bdrv_*() APIs expect a valid BlockDriverState. Calling them with bs=NULL
leads to undefined behavior.
Jonathan Cameron reported this following NULL pointer dereference when a
VM with a virtio-blk device and a memory-backend-file object is
terminated:
1. qemu_cleanup() closes all drives, setting blk->root to NULL
2. qemu_cleanup() calls user_creatable_cleanup(), which results in a RAM
block notifier callback because the memory-backend-file is destroyed.
3. blk_unregister_buf() is called by virtio-blk's BlockRamRegistrar
notifier callback and undefined behavior occurs.
Fixes: baf422684d ("virtio-blk: use BDRV_REQ_REGISTERED_BUF optimization hint")
Co-authored-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221121211923.1993171-1-stefanha@redhat.com>
