Most block driver implementations don't have any reason for their
BlockDriver to be public. The only exceptions are bdrv_file, bdrv_raw
and bdrv_qcow2, which are actually used in other source files.
Make all other BlockDriver definitions static if they aren't yet.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230905130607.35134-3-kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When commit 5e5733e599 created block/meson.build, the list of
unconditionally added files was in alphabetical order. Later commits
added new files in random places. Reorder the list to be alphabetical
again. (As for ordering foo.c against foo-*.c, there are both ways used
currently; standardise on having foo.c first, even though this is
different from the original commit 5e5733e5999.)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230905130607.35134-2-kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The commit 5d8813593f ("block/qapi: Let bdrv_query_image_info()
recurse") removed the loop where we set the 'bs0' variable, so now it
is just the same as 'bs'.
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20230901184605.32260-3-farosas@suse.de>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The last call site of this function has been removed by commit
c04d0ab026 ("qemu-img: Let info print block graph").
Reviewed-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Message-ID: <20230901184605.32260-2-farosas@suse.de>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_open_child() may return NULL.
Usually return value is checked for this function.
Check for return value is more reliable.
Fixes: 24bc15d1f6 ("vmdk: Use BdrvChild instead of BDS for references to extents")
Signed-off-by: Dmitry Frolov <frolov@swemel.ru>
Message-ID: <20230831125926.796205-1-frolov@swemel.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In block/iscsi.c we use a raw malloc() call, which is unusual
given the project standard is to use the glib memory allocation
functions. Document why we do so, to avoid it being converted
to g_malloc() by mistake.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-ID: <20230727150705.2664464-1-peter.maydell@linaro.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
CoMutex has poor performance when lock contention is high. The tracked
requests list is accessed frequently and performance suffers in QEMU
multi-queue block layer scenarios.
It is not necessary to use CoMutex for the requests lock. The lock is
always released across coroutine yield operations. It is held for
relatively short periods of time and it is not beneficial to yield when
the lock is held by another coroutine.
Change the lock type from CoMutex to QemuMutex to improve multi-queue
block layer performance. fio randread bs=4k iodepth=64 with 4 IOThreads
handling a virtio-blk device with 8 virtqueues improves from 254k to
517k IOPS (+203%). Full benchmark results and configuration details are
available here:
980c40845d
In the future we may wish to introduce thread-local tracked requests
lists to avoid lock contention completely. That would be much more
involved though.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230808155852.2745350-3-stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230808155852.2745350-2-stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Use autofree heap allocation instead of variable-length array on the
stack. Here we don't expect the bitmap size to be enormous, and
since we're about to read/write it to disk the overhead of the
allocation should be fine.
The codebase has very few VLAs, and if we can get rid of them all we
can make the compiler error on new additions. This is a defensive
measure against security bugs where an on-stack dynamic allocation
isn't correctly size-checked (e.g. CVE-2021-3527).
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[PMM: expanded commit message]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-ID: <20230811175229.808139-1-peter.maydell@linaro.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Francisco Iglesias <frasse.iglesias@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The ongoing QEMU multi-queue block layer effort makes it possible for multiple
threads to process I/O in parallel. The nbd block driver is not compatible with
the multi-queue block layer yet because QIOChannel cannot be used easily from
coroutines running in multiple threads. This series changes the QIOChannel API
to make that possible.
In the current API, calling qio_channel_attach_aio_context() sets the
AioContext where qio_channel_yield() installs an fd handler prior to yielding:
qio_channel_attach_aio_context(ioc, my_ctx);
...
qio_channel_yield(ioc); // my_ctx is used here
...
qio_channel_detach_aio_context(ioc);
This API design has limitations: reading and writing must be done in the same
AioContext and moving between AioContexts involves a cumbersome sequence of API
calls that is not suitable for doing on a per-request basis.
There is no fundamental reason why a QIOChannel needs to run within the
same AioContext every time qio_channel_yield() is called. QIOChannel
only uses the AioContext while inside qio_channel_yield(). The rest of
the time, QIOChannel is independent of any AioContext.
In the new API, qio_channel_yield() queries the AioContext from the current
coroutine using qemu_coroutine_get_aio_context(). There is no need to
explicitly attach/detach AioContexts anymore and
qio_channel_attach_aio_context() and qio_channel_detach_aio_context() are gone.
One coroutine can read from the QIOChannel while another coroutine writes from
a different AioContext.
This API change allows the nbd block driver to use QIOChannel from any thread.
It's important to keep in mind that the block driver already synchronizes
QIOChannel access and ensures that two coroutines never read simultaneously or
write simultaneously.
This patch updates all users of qio_channel_attach_aio_context() to the
new API. Most conversions are simple, but vhost-user-server requires a
new qemu_coroutine_yield() call to quiesce the vu_client_trip()
coroutine when not attached to any AioContext.
While the API is has become simpler, there is one wart: QIOChannel has a
special case for the iohandler AioContext (used for handlers that must not run
in nested event loops). I didn't find an elegant way preserve that behavior, so
I added a new API called qio_channel_set_follow_coroutine_ctx(ioc, true|false)
for opting in to the new AioContext model. By default QIOChannel uses the
iohandler AioHandler. Code that formerly called
qio_channel_attach_aio_context() now calls
qio_channel_set_follow_coroutine_ctx(ioc, true) once after the QIOChannel is
created.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20230830224802.493686-5-stefanha@redhat.com>
[eblake: also fix migration/rdma.c]
Signed-off-by: Eric Blake <eblake@redhat.com>
Place data_start/data_end calculation after reading the image header
to s->header. Set s->data_start to the offset calculated in
parallels_test_data_off(). Call bdrv_check() if data_off is incorrect.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
data_off field of the parallels image header can be corrupted. Check if
this field greater than the header + BAT size and less than file size.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
bdrv_co_getlength() should be used in coroutine context. Replace
bdrv_getlength() by bdrv_co_getlength() in parallels_check_outside_image().
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Repair an image at opening if the image is unclean or out-of-image
corruption was detected.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Cluster offsets must be unique among all the BAT entries. Find duplicate
offsets in the BAT and fix it by copying the content of the relevant
cluster to a newly allocated cluster and set the new cluster offset to the
duplicated entry.
Add host_cluster_index() helper to deduplicate the code.
When new clusters are allocated, the file size increases by 128 Mb. Call
parallels_check_leak() to fix this leak.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
In the next patch we will need the offset of the data area for host cluster
index calculation. Add this field and setting up code.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
In the on of the next patches we need to repair leaks without changing
leaks and leaks_fixed info in res. Also we don't want to print any warning
about leaks. Add "explicit" argument to skip info changing if the argument
is false.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Initially data_end is set to the data_off image header field and must not
be greater than the file size.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
The BDRVParallelsState structure contains data_end field that is measured
in sectors. In parallels_open() initially this field is set by data_off
field from parallels image header.
According to the parallels format documentation, data_off field contains
an offset, in sectors, from the start of the file to the start of the
data area. For "WithoutFreeSpace" images: if data_off is zero, the offset
is calculated as the end of the BAT table plus some padding to ensure
sector size alignment.
The parallels_open() function has code for handling zero value in
data_off, but in the result data_end contains the offset in bytes.
Replace the alignment to sector size by division by sector size and fix
the comparision with s->header_size.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
This patch is technically necessary as git patch rendering could result
in moving some code from one place to the another and that hits
checkpatch.pl warning. This problem specifically happens within next
series.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
When target image is using subclusters, and we align the request during
copy-on-read, it makes sense to align to subcluster_size rather than
cluster_size. Otherwise we end up with unnecessary allocations.
This commit renames bdrv_round_to_clusters() to bdrv_round_to_subclusters()
and utilizes subcluster_size field of BlockDriverInfo to make necessary
alignments. It affects copy-on-read as well as mirror job (which is
using bdrv_round_to_clusters()).
This change also fixes the following bug with failing assert (covered by
the test in the subsequent commit):
qemu-img create -f qcow2 base.qcow2 64K
qemu-img create -f qcow2 -o extended_l2=on,backing_file=base.qcow2,backing_fmt=qcow2 img.qcow2 64K
qemu-io -c "write -P 0xaa 0 2K" img.qcow2
qemu-io -C -c "read -P 0x00 2K 62K" img.qcow2
qemu-io: ../block/io.c:1236: bdrv_co_do_copy_on_readv: Assertion `skip_bytes < pnum' failed.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230711172553.234055-3-andrey.drobyshev@virtuozzo.com>
This is going to be used in the subsequent commit as requests alignment
(in particular, during copy-on-read). This value only makes sense for
the formats which support subclusters (currently QCOW2 only). If this
field isn't set by driver's own bdrv_get_info() implementation, we
simply set it equal to the cluster size thus treating each cluster as
having a single subcluster.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230711172553.234055-2-andrey.drobyshev@virtuozzo.com>
As Hanna pointed out, it is not clear in the code why qemu_open()
can fail, and why blkio_set_int("fd") is not enough to discover
the `fd` property support.
Let's fix them by adding more details in the code comments.
Suggested-by: Hanna Czenczek <hreitz@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20230803082825.25293-3-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
libblkio drivers take ownership of `fd` only after a successful
blkio_connect(), so if it fails, we are still the owners.
Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk")
Suggested-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-id: 20230803082825.25293-2-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Please include these bug fixes in QEMU 8.1. Thanks!
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Merge tag 'block-pull-request' of https://gitlab.com/stefanha/qemu into staging
Pull request
Please include these bug fixes in QEMU 8.1. Thanks!
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# gpg: Signature made Thu 27 Jul 2023 01:00:53 PM PDT
# gpg: using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
* tag 'block-pull-request' of https://gitlab.com/stefanha/qemu:
block/blkio: use blkio_set_int("fd") to check fd support
block/blkio: fall back on using `path` when `fd` setting fails
block/blkio: retry blkio_connect() if it fails using `fd`
block/blkio: move blkio_connect() in the drivers functions
block: Fix pad_request's request restriction
block/file-posix: fix g_file_get_contents return path
block/blkio: do not use open flags in qemu_open()
block/blkio: enable the completion eventfd
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Setting the `fd` property fails with virtio-blk-* libblkio drivers
that do not support fd passing since
https://gitlab.com/libblkio/libblkio/-/merge_requests/208.
Getting the `fd` property, on the other hand, always succeeds for
virtio-blk-* libblkio drivers even when they don't support fd passing.
This patch switches to setting the `fd` property because it is a
better mechanism for probing fd passing support than getting the `fd`
property.
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20230727161020.84213-5-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
qemu_open() fails if called with an unix domain socket in this way:
-blockdev node-name=drive0,driver=virtio-blk-vhost-user,path=vhost-user-blk.sock,cache.direct=on: Could not open 'vhost-user-blk.sock': No such device or address
Since virtio-blk-vhost-user does not support fd passing, let`s always fall back
on using `path` if we fail the fd passing.
Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk")
Reported-by: Qing Wang <qinwang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20230727161020.84213-4-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
libblkio 1.3.0 added support of "fd" property for virtio-blk-vhost-vdpa
driver. In QEMU, starting from commit cad2ccc395 ("block/blkio: use
qemu_open() to support fd passing for virtio-blk") we are using
`blkio_get_int(..., "fd")` to check if the "fd" property is supported
for all the virtio-blk-* driver.
Unfortunately that property is also available for those driver that do
not support it, such as virtio-blk-vhost-user.
So, `blkio_get_int()` is not enough to check whether the driver supports
the `fd` property or not. This is because the virito-blk common libblkio
driver only checks whether or not `fd` is set during `blkio_connect()`
and fails with -EINVAL for those transports that do not support it
(all except vhost-vdpa for now).
So let's handle the `blkio_connect()` failure, retrying it using `path`
directly.
Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk")
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20230727161020.84213-3-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This is in preparation for the next patch, where for virtio-blk
drivers we need to handle the failure of blkio_connect().
Let's also rename the *_open() functions to *_connect() to make
the code reflect the changes applied.
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20230727161020.84213-2-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
bdrv_pad_request() relies on requests' lengths not to exceed SIZE_MAX,
which bdrv_check_qiov_request() does not guarantee.
bdrv_check_request32() however will guarantee this, and both of
bdrv_pad_request()'s callers (bdrv_co_preadv_part() and
bdrv_co_pwritev_part()) already run it before calling
bdrv_pad_request(). Therefore, bdrv_pad_request() can safely call
bdrv_check_request32() without expecting error, too.
In effect, this patch will not change guest-visible behavior. It is a
clean-up to tighten a condition to match what is guaranteed by our
callers, and which exists purely to show clearly why the subsequent
assertion (`assert(*bytes <= SIZE_MAX)`) is always true.
Note there is a difference between the interfaces of
bdrv_check_qiov_request() and bdrv_check_request32(): The former takes
an errp, the latter does not, so we can no longer just pass
&error_abort. Instead, we need to check the returned value. While we
do expect success (because the callers have already run this function),
an assert(ret == 0) is not much simpler than just to return an error if
it occurs, so let us handle errors by returning them up the stack now.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-id: 20230714085938.202730-1-hreitz@redhat.com
Fixes: 18743311b8
("block: Collapse padded I/O vecs exceeding IOV_MAX")
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The g_file_get_contents() function returns a g_boolean. If it fails, the
returned value will be 0 instead of -1. Solve the issue by skipping
assigning ret value.
This issue was found by Matthew Rosato using virtio-blk-{pci,ccw} backed
by an NVMe partition e.g. /dev/nvme0n1p1 on s390x.
Signed-off-by: Sam Li <faithilikerun@gmail.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20230727115844.8480-1-faithilikerun@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
qemu_open() in blkio_virtio_blk_common_open() is used to open the
character device (e.g. /dev/vhost-vdpa-0 or /dev/vfio/vfio) or in
the future eventually the unix socket.
In all these cases we cannot open the path in read-only mode,
when the `read-only` option of blockdev is on, because the exchange
of IOCTL commands for example will fail.
In order to open the device read-only, we have to use the `read-only`
property of the libblkio driver as we already do in blkio_file_open().
Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk")
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2225439
Reported-by: Qing Wang <qinwang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20230726074807.14041-1-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Until libblkio 1.3.0, virtio-blk drivers had completion eventfd
notifications enabled from the start, but from the next releases
this is no longer the case, so we have to explicitly enable them.
In fact, the libblkio documentation says they could be disabled,
so we should always enable them at the start if we want to be
sure to get completion eventfd notifications:
By default, the driver might not generate completion events for
requests so it is necessary to explicitly enable the completion
file descriptor before use:
void blkioq_set_completion_fd_enabled(struct blkioq *q, bool enable);
I discovered this while trying a development version of libblkio:
the guest kernel hangs during boot, while probing the device.
Fixes: fd66dbd424 ("blkio: add libblkio block driver")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20230725103744.77343-1-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Our code relies on a sentinel cookie value of zero for deciding when a
packet has been handled, as well as relying on array indices between 0
and MAX_NBD_REQUESTS-1 for dereferencing purposes. As long as we can
symmetrically convert between two forms, there is no reason to go with
the odd choice of using XOR with a random pointer, when we can instead
simplify the mappings with a mere offset of 1.
Using ((uint64_t)-1) as the sentinel instead of NULL such that the two
macros could be entirely eliminated might also be possible, but would
require a more careful audit to find places where we currently rely on
zero-initialization to be interpreted as the sentinel value, so I did
not pursue that course.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230608135653.2918540-7-eblake@redhat.com>
[eblake: enhance commit message]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Externally, libnbd exposed the 64-bit opaque marker for each client
NBD packet as the "cookie", because it was less confusing when
contrasted with 'struct nbd_handle *' holding all libnbd state. It
also avoids confusion between the noun 'handle' as a way to identify a
packet and the verb 'handle' for reacting to things like signals.
Upstream NBD changed their spec to favor the name "cookie" based on
libnbd's recommendations[1], so we can do likewise.
[1] https://github.com/NetworkBlockDevice/nbd/commit/ca4392eb2b
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230608135653.2918540-6-eblake@redhat.com>
[eblake: typo fix]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
blk_io_plug_call() is invoked outside a blk_io_plug()/blk_io_unplug()
section while opening the NVMe drive from:
nvme_file_open() ->
nvme_init() ->
nvme_identify() ->
nvme_admin_cmd_sync() ->
nvme_submit_command() ->
blk_io_plug_call()
blk_io_plug_call() immediately invokes the given callback when the
current thread is not plugged, as is the case during nvme_file_open().
Unfortunately, nvme_submit_command() calls blk_io_plug_call() with
q->lock still held:
...
q->sq.tail = (q->sq.tail + 1) % NVME_QUEUE_SIZE;
q->need_kick++;
blk_io_plug_call(nvme_unplug_fn, q);
qemu_mutex_unlock(&q->lock);
^^^^^^^^^^^^^^^^^^^^^^^^^^^
nvme_unplug_fn() deadlocks trying to acquire q->lock because the lock is
already acquired by the same thread. The symptom is that QEMU hangs
during startup while opening the NVMe drive.
Fix this by moving the blk_io_plug_call() outside q->lock. This is safe
because no other thread runs code related to this queue and
blk_io_plug_call()'s internal state is immune to thread safety issues
since it is thread-local.
Reported-by: Lukáš Doktor <ldoktor@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Lukas Doktor <ldoktor@redhat.com>
Message-id: 20230712191628.252806-1-stefanha@redhat.com
Fixes: f2e590002b ("block/nvme: convert to blk_io_plug_call() API")
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
When QEMU is built with --enable-modules, the module_block.py script
parses block/*.c to find block drivers that are built as modules. The
script generates a table of block drivers called block_driver_modules[].
This table is used for block driver module loading.
The blkio.c driver uses macros to define its BlockDriver structs. This
was done to avoid code duplication but the module_block.py script is
unable to parse the macro. The result is that libblkio-based block
drivers can be built as modules but will not be found at runtime.
One fix is to make the module_block.py script or build system fancier so
it can parse C macros (e.g. by parsing the preprocessed source code). I
chose not to do this because it raises the complexity of the build,
making future issues harder to debug.
Keep things simple: use the macro to avoid duplicating BlockDriver
function pointers but define .format_name and .protocol_name manually
for each BlockDriver. This way the module_block.py is able to parse the
code.
Also get rid of the block driver name macros (e.g. DRIVER_IO_URING)
because module_block.py cannot parse them either.
Fixes: fd66dbd424 ("blkio: add libblkio block driver")
Reported-by: Qing Wang <qinwang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20230704123436.187761-1-stefanha@redhat.com
Cc: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
- Re-enable the graph lock
- More fixes to coroutine_fn marking
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Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into staging
Block layer patches
- Re-enable the graph lock
- More fixes to coroutine_fn marking
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# gpg: Signature made Wed 28 Jun 2023 04:13:56 PM CEST
# gpg: using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg: issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
* tag 'for-upstream' of https://repo.or.cz/qemu/kevin: (23 commits)
block: use bdrv_co_debug_event in coroutine context
block: use bdrv_co_getlength in coroutine context
qcow2: mark more functions as coroutine_fns and GRAPH_RDLOCK
vhdx: mark more functions as coroutine_fns and GRAPH_RDLOCK
vmdk: mark more functions as coroutine_fns and GRAPH_RDLOCK
dmg: mark more functions as coroutine_fns and GRAPH_RDLOCK
cloop: mark more functions as coroutine_fns and GRAPH_RDLOCK
block: mark another function as coroutine_fns and GRAPH_UNLOCKED
bochs: mark more functions as coroutine_fns and GRAPH_RDLOCK
vpc: mark more functions as coroutine_fns and GRAPH_RDLOCK
qed: mark more functions as coroutine_fns and GRAPH_RDLOCK
file-posix: remove incorrect coroutine_fn calls
Revert "graph-lock: Disable locking for now"
graph-lock: Unlock the AioContext while polling
blockjob: Fix AioContext locking in block_job_add_bdrv()
block: Fix AioContext locking in bdrv_open_backing_file()
block: Fix AioContext locking in bdrv_open_inherit()
block: Fix AioContext locking in bdrv_reopen_parse_file_or_backing()
block: Fix AioContext locking in bdrv_attach_child_common()
block: Fix AioContext locking in bdrv_open_child()
...
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
bdrv_co_debug_event was recently introduced, with bdrv_debug_event
becoming a wrapper for use in unknown context. Because most of the
time bdrv_debug_event is used on a BdrvChild via the wrapper macro
BLKDBG_EVENT, introduce a similar macro BLKDBG_CO_EVENT that calls
bdrv_co_debug_event, and switch whenever possible.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-13-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_co_getlength was recently introduced, with bdrv_getlength becoming
a wrapper for use in unknown context. Switch to bdrv_co_getlength when
possible.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-12-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-11-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-10-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-9-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-8-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-7-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-5-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-4-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Stefan Hajnoczi