This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_filter_bs() need to hold a reader lock for the graph because
it calls bdrv_filter_child(), which accesses bs->file/backing.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-4-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_has_zero_init() need to hold a reader lock for the graph because
it calls bdrv_filter_bs(), which accesses bs->file/backing.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-3-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_probe_blocksizes() need to hold a reader lock for the graph because
it calls bdrv_filter_bs(), which accesses bs->file/backing.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-2-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
- One patch to make qcow2's discard-no-unref option do better what it is
supposed to do (i.e. prevent fragmentation)
- Two fixes for zoned requests
-----BEGIN PGP SIGNATURE-----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=5w7S
-----END PGP SIGNATURE-----
Merge tag 'pull-block-2023-11-06' of https://gitlab.com/hreitz/qemu into staging
Block patches:
- One patch to make qcow2's discard-no-unref option do better what it is
supposed to do (i.e. prevent fragmentation)
- Two fixes for zoned requests
# -----BEGIN PGP SIGNATURE-----
#
# iQJGBAABCAAwFiEEy2LXoO44KeRfAE00ofpA0JgBnN8FAmVJHbgSHGhyZWl0ekBy
# ZWRoYXQuY29tAAoJEKH6QNCYAZzfLn4QAKxuUYZaXirv6K4U2tW4aAJtc5uESdwv
# WYhG7YU7MleBGCY0fRoih5thrPrzRLC8o1QhbRcA36+/PAZf4BYrJEfqLUdzuN5x
# 6Vb1n3NRUzPD1+VfL/B9hVZhFbtTOUZuxPGEqCoHAmqBaeKuYRT1bLZbtRtPVLSk
# 5eTMiyrpRMlBWc7O71eGKLqU4k0vAznwHBGf2Z93qWAsKcRZCwbAWYa7Q6rJ9jJ8
# 1jNsQuAk0p74/uGEpFhoEVrFEcV6pMbI4+jB9i0t9YYxT0tLIdIX1VUx+AHJfItk
# IF2stB6SFOaAy2W3Fn+0oJvz40aMLzg9VjEeTpGmdlKC67ZTYa6Obwzy5WNLPIap
# k7VUheUEe8qoKUtxQNxGLR/HKEJSFXyhU0lgAGxE1gl2xc1QFFFsrimpwFd3d37j
# 3PwfhjARHonf4ZXgsvtIjb7nG9seMZYO7Vht0OztJyW8c2XN5OFVPir9xLbd9VUg
# wZNGB8jAsHgj77+S/mRIwpP+laKL8wB7zYZ1mgFI98QJIYqL8tGdV/IiUhLljHzc
# XAmwekOhBMMbgHhliBy9zDuTy59+zZ0FoxZPn/JvBjqBAkEnz9EbhHxi2imQg+1d
# XSoLbx1X1yEbepWz8mCGiveLIPkt+3qMJuuQF76nURaA+nm3tCl/nKca6QLnVKzU
# 2QtPWS0qRmwd
# =5w7S
# -----END PGP SIGNATURE-----
# gpg: Signature made Tue 07 Nov 2023 01:09:12 HKT
# gpg: using RSA key CB62D7A0EE3829E45F004D34A1FA40D098019CDF
# gpg: issuer "hreitz@redhat.com"
# gpg: Good signature from "Hanna Reitz <hreitz@redhat.com>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: CB62 D7A0 EE38 29E4 5F00 4D34 A1FA 40D0 9801 9CDF
* tag 'pull-block-2023-11-06' of https://gitlab.com/hreitz/qemu:
file-posix: fix over-writing of returning zone_append offset
block/file-posix: fix update_zones_wp() caller
qcow2: keep reference on zeroize with discard-no-unref enabled
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
raw_co_zone_append() sets "s->offset" where "BDRVRawState *s". This pointer
is used later at raw_co_prw() to save the block address where the data is
written.
When multiple IOs are on-going at the same time, a later IO's
raw_co_zone_append() call over-writes a former IO's offset address before
raw_co_prw() completes. As a result, the former zone append IO returns the
initial value (= the start address of the writing zone), instead of the
proper address.
Fix the issue by passing the offset pointer to raw_co_prw() instead of
passing it through s->offset. Also, remove "offset" from BDRVRawState as
there is no usage anymore.
Fixes: 4751d09adc ("block: introduce zone append write for zoned devices")
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Message-Id: <20231030073853.2601162-1-naohiro.aota@wdc.com>
Reviewed-by: Sam Li <faithilikerun@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
When the zoned request fail, it needs to update only the wp of
the target zones for not disrupting the in-flight writes on
these other zones. The wp is updated successfully after the
request completes.
Fixed the callers with right offset and nr_zones.
Signed-off-by: Sam Li <faithilikerun@gmail.com>
Message-Id: <20230825040556.4217-1-faithilikerun@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[hreitz: Rebased and fixed comment spelling]
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
When the discard-no-unref flag is enabled, we keep the reference for
normal discard requests.
But when a discard is executed on a snapshot/qcow2 image with backing,
the discards are saved as zero clusters in the snapshot image.
When committing the snapshot to the backing file, not
discard_in_l2_slice is called but zero_in_l2_slice. Which did not had
any logic to keep the reference when discard-no-unref is enabled.
Therefor we add logic in the zero_in_l2_slice call to keep the reference
on commit.
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1621
Signed-off-by: Jean-Louis Dupond <jean-louis@dupond.be>
Message-Id: <20231003125236.216473-2-jean-louis@dupond.be>
[hreitz: Made the documentation change more verbose, as discussed
on-list]
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
NVMeQueuePair::reqs has length NVME_NUM_REQS, which less than
NVME_QUEUE_SIZE by 1.
Fixes: 1086e95da1 ("block/nvme: switch to a NVMeRequest freelist")
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Maksim Davydov <davydov-max@yandex-team.ru>
Message-id: 20231017125941.810461-5-vsementsov@yandex-team.ru
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
qemu_uuid_unparse() includes a trailing NUL when writing the uuid
string and the buffer size should be UUID_FMT_LEN + 1 bytes. Add a
define for this size and use it where required.
Cc: Fam Zheng <fam@euphon.net>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: "Denis V. Lunev" <den@openvz.org>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Some blockdevs block migration because they do not support sharing across
hosts and/or do not support dirty bitmaps. These prohibitions do not apply
if the old and new qemu processes do not run concurrently, and if new qemu
starts on the same host as old, which is the case for cpr. Narrow the scope
of these blockers so they only apply to normal mode. They will not block
cpr modes when they are added in subsequent patches.
No functional change until a new mode is added.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1698263069-406971-4-git-send-email-steven.sistare@oracle.com>
To start out, only actively-synced is returned.
For example, this is useful for jobs that started out in background
mode and switched to active mode. Once actively-synced is true, it's
clear that the mode switch has been completed. Note that completion of
the switch might happen much earlier, e.g. if the switch happens
before the job is ready, once all background operations have finished.
It's assumed that whether the disks are actively-synced or not is more
interesting than whether the mode switch completed. That information
can still be added if required in the future.
In presence of an iothread, the actively_synced member is now shared
between the iothread and the main thread, so turn accesses to it
atomic.
Requires to adapt the output for iotest 109.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-ID: <20231031135431.393137-10-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In preparation to turn BlockJobInfo into a union with @type as the
discriminator. That requires it to be an enum. Even without that
requirement, it's nicer to have an enum instead of a str here.
No functional change is intended.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20231031135431.393137-7-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
which allows switching the @copy-mode from 'background' to
'write-blocking'.
This is useful for management applications, so they can start out in
background mode to avoid limiting guest write speed and switch to
active mode when certain criteria are fulfilled.
In presence of an iothread, the copy_mode member is now shared between
the iothread and the main thread, so turn accesses to it atomic.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-ID: <20231031135431.393137-6-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In preparation to allow changing the copy_mode via QMP. When running
in an iothread, it could be that copy_mode is changed from the main
thread in between reading copy_mode in bdrv_mirror_top_pwritev() and
reading copy_mode in bdrv_mirror_top_do_write(), so they might end up
disagreeing about whether copy_to_target is true or false. Avoid that
scenario by determining copy_to_target only once and passing it to
bdrv_mirror_top_do_write() as an argument.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20231031135431.393137-5-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In preparation to allow switching to active mode without draining.
Initialization of the bitmap in mirror_dirty_init() still happens with
the original/backing BlockDriverState, which should be fine, because
the mirror top has the same length.
Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-ID: <20231031135431.393137-4-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In preparation to allow switching from background to active mode. This
ensures that setting actively_synced will not be missed when the
switch happens after the job is ready.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20231031135431.393137-3-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
virtio-blk and virtio-scsi invoke virtio_irqfd_notify() to send Used
Buffer Notifications from an IOThread. This involves an eventfd
write(2) syscall. Calling this repeatedly when completing multiple I/O
requests in a row is wasteful.
Use the defer_call() API to batch together virtio_irqfd_notify() calls
made during thread pool (aio=threads), Linux AIO (aio=native), and
io_uring (aio=io_uring) completion processing.
Behavior is unchanged for emulated devices that do not use
defer_call_begin()/defer_call_end() since defer_call() immediately
invokes the callback when called outside a
defer_call_begin()/defer_call_end() region.
fio rw=randread bs=4k iodepth=64 numjobs=8 IOPS increases by ~9% with a
single IOThread and 8 vCPUs. iodepth=1 decreases by ~1% but this could
be noise. Detailed performance data and configuration specifics are
available here:
https://gitlab.com/stefanha/virt-playbooks/-/tree/blk_io_plug-irqfd
This duplicates the BH that virtio-blk uses for batching. The next
commit will remove it.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230913200045.1024233-4-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The networking subsystem may wish to use defer_call(), so move the code
to util/ where it can be reused.
As a reminder of what defer_call() does:
This API defers a function call within a defer_call_begin()/defer_call_end()
section, allowing multiple calls to batch up. This is a performance
optimization that is used in the block layer to submit several I/O requests
at once instead of individually:
defer_call_begin(); <-- start of section
...
defer_call(my_func, my_obj); <-- deferred my_func(my_obj) call
defer_call(my_func, my_obj); <-- another
defer_call(my_func, my_obj); <-- another
...
defer_call_end(); <-- end of section, my_func(my_obj) is called once
Suggested-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230913200045.1024233-3-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Prepare to move the blk_io_plug_call() API out of the block layer so
that other subsystems call use this deferred call mechanism. Rename it
to defer_call() but leave the code in block/plug.c.
The next commit will move the code out of the block layer.
Suggested-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230913200045.1024233-2-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
blk_insert_bs() requires that the caller holds the AioContext lock for
the node to be inserted. Since commit c066e808e1, neglecting to do so
causes a crash when the child has to be moved to a different AioContext
to attach it to the BlockBackend.
This fixes qmp_blockdev_insert_anon_medium(), which is called for the
QMP commands 'blockdev-insert-medium' and 'blockdev-change-medium', to
correctly take the lock.
Cc: qemu-stable@nongnu.org
Fixes: https://issues.redhat.com/browse/RHEL-3922
Fixes: c066e808e1
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231013153302.39234-2-kwolf@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason. This allows migration to own the Error object, so that if
an error occurs in migrate_add_blocker, migration code can free the Error
and clear the client handle, simplifying client code. It also simplifies
the migrate_del_blocker call site.
In addition, this is a pre-requisite for a proposed future patch that would
add a mode argument to migration requests to support live update, and
maintain a list of blockers for each mode. A blocker may apply to a single
mode or to multiple modes, and passing Error** will allow one Error object
to be registered for multiple modes.
No functional change.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Tested-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1697634216-84215-1-git-send-email-steven.sistare@oracle.com>
bdrv_graph_wrlock() can't run in a coroutine (because it polls) and
requires holding the BQL. We already have GLOBAL_STATE_CODE() to assert
the latter. Assert the former as well and add a no_coroutine_fn marker.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-23-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Almost all functions that access the child links already take the graph
lock now. Add locking to the remaining users and finally annotate the
struct field itself as protected by the graph lock.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-22-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_specific_info() need to hold a reader lock for the graph.
This removes an assume_graph_lock() call in vmdk's implementation.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-20-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_apply_auto_read_only() need to hold a reader lock for the graph
because it calls bdrv_can_set_read_only(), which indirectly accesses the
parents list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-19-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_op_is_blocked() need to hold a reader lock for the graph
because it calls bdrv_get_device_or_node_name(), which accesses the
parents list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-18-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It still has an assume_graph_lock() call, but all of its callers are now
properly annotated to hold the graph lock. Update the function to be
GRAPH_RDLOCK as well and remove the assume_graph_lock().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-17-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
qcow2_inactivate() need to hold a reader lock for the graph because it
calls bdrv_get_device_or_node_name(), which accesses the parents list of
a node.
qcow2_do_close() is a bit strange because it is called from different
contexts. If close_data_file = true, we know that we were called from
non-coroutine main loop context (more specifically, we're coming from
qcow2_close()) and can safely drop the reader lock temporarily with
bdrv_graph_rdunlock_main_loop() and acquire the writer lock.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-16-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
qcow2_signal_corruption() need to hold a reader lock for the graph
because it calls bdrv_get_node_name(), which accesses the parents list
of a node.
For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-15-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_amend_options() need to hold a reader lock for the graph. This
removes an assume_graph_lock() call in crypto's implementation.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-14-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_parent_name() need to hold a reader lock for the graph
because it accesses the parents list of a node.
For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-13-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_primary_child() need to hold a reader lock for the graph
because it accesses the children list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-12-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_refresh_filename() need to hold a reader lock for the graph
because it accesses the children list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-11-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_snapshot_fallback() need to hold a reader lock for the graph
because it accesses the children list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-8-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_parent_cb_resize() need to hold a reader lock for the graph.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-7-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Draining recursively traverses the graph, therefore we need to make sure
that also such accesses to the graph are protected by the graph rdlock.
There are 3 different drain callers to consider:
1. drain in the main loop: no issue at all, rdlock is nop.
2. drain in an iothread: rdlock only works in main loop or coroutines,
so disallow it.
3. drain in a coroutine (regardless of AioContext): the drain mechanism
takes care of scheduling a BH in the bs->aio_context that will
then take care of perform the actual draining. This is wrong,
because as pointed in (2) if bs->aio_context is an iothread then
rdlock won't work. Therefore change bdrv_co_yield_to_drain to
schedule the BH in the main loop.
Caller (2) also implies that we need to modify test-bdrv-drain.c to
disallow draining in the iothreads.
For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-6-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_first_blk() and bdrv_is_root_node() need to hold a reader lock
for the graph. These functions are the only functions in block-backend.c
that access the parent list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-5-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230904100306.156197-5-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230904100306.156197-4-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Include both coroutine and non-coroutine versions, the latter being
co_wrapper_mixed_bdrv_rdlock of the former.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230904100306.156197-3-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_block_status exists as a wrapper for bdrv_block_status_above, but
the name of the (hypothetical) coroutine version, bdrv_co_block_status,
is squatted by a random static function. Rename it to
bdrv_co_do_block_status.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230904100306.156197-2-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Once extended mode is enabled, we need to accept 64-bit status replies
(even for replies that don't exceed a 32-bit length). It is easier to
normalize narrow replies into wide format so that the rest of our code
only has to handle one width. Although a server is non-compliant if
it sends a 64-bit reply in compact mode, or a 32-bit reply in extended
mode, it is still easy enough to tolerate these mismatches.
In normal execution, we are only requesting "base:allocation" which
never exceeds 32 bits for flag values. But during testing with
x-dirty-bitmap, we can force qemu to connect to some other context
that might have 64-bit status bit; however, we ignore those upper bits
(other than mapping qemu:allocation-depth into something that
'qemu-img map --output=json' can expose), and since that only affects
testing, we really don't bother with checking whether more than the
two least-significant bits are set.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20230925192229.3186470-22-eblake@redhat.com>
Update the client code to be able to send an extended request, and
parse an extended header from the server. Note that since we reject
any structured reply with a too-large payload, we can always normalize
a valid header back into the compact form, so that the caller need not
deal with two branches of a union. Still, until a later patch lets
the client negotiate extended headers, the code added here should not
be reached. Note that because of the different magic numbers, it is
just as easy to trace and then tolerate a non-compliant server sending
the wrong header reply as it would be to insist that the server is
compliant.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230925192229.3186470-21-eblake@redhat.com>
[eblake: fix trace format]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Instead of ignoring the low-level error just to refabricate our own
message to pass to the caller, we can just plumb the caller's errp
down to the low level.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230925192229.3186470-20-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Local variables shadowing other local variables or parameters make the
code needlessly hard to understand. Tracked down with -Wshadow=local.
Clean up: delete inner declarations when they are actually redundant,
else rename variables.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230921121312.1301864-7-armbru@redhat.com>
Local variables shadowing other local variables or parameters make the
code needlessly hard to understand. Tracked down with -Wshadow=local.
Clean up: delete inner declarations when they are actually redundant,
else rename variables.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230921121312.1301864-6-armbru@redhat.com>
Local variables shadowing other local variables or parameters make the
code needlessly hard to understand. Tracked down with -Wshadow=local.
Clean up: rename both the pair of parameters and the pair of local
variables. While there, move the local variables to function scope.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230921121312.1301864-5-armbru@redhat.com>
The marking should be extended transitively to all functions that call
these ones, so that static analysis can be done much more efficiently.
However, this is a start and makes it possible to use vrc's path-based
searches to find potential bugs where coroutine_fns call blocking functions.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Widen the length field of NBDRequest to 64-bits, although we can
assert that all current uses are still under 32 bits: either because
of NBD_MAX_BUFFER_SIZE which is even smaller (and where size_t can
still be appropriate, even on 32-bit platforms), or because nothing
ever puts us into NBD_MODE_EXTENDED yet (and while future patches will
allow larger transactions, the lengths in play here are still capped
at 32-bit). There are no semantic changes, other than a typo fix in a
couple of error messages.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230829175826.377251-23-eblake@redhat.com>
[eblake: fix assertion bug in nbd_co_send_simple_reply]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Add the constants and structs necessary for later patches to start
implementing the NBD_OPT_EXTENDED_HEADERS extension in both the client
and server, matching recent upstream nbd.git (through commit
e6f3b94a934). This patch does not change any existing behavior, but
merely sets the stage for upcoming patches.
This patch does not change the status quo that neither the client nor
server use a packed-struct representation for the request header.
While most of the patch adds new types, there is also some churn for
renaming the existing NBDExtent to NBDExtent32 to contrast it with
NBDExtent64, which I thought was a nicer name than NBDExtentExt.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20230829175826.377251-22-eblake@redhat.com>
Once the 64-bit headers extension is enabled, the data layout we send
over the wire for a client request depends on the mode negotiated with
the server. Rather than adding a parameter to nbd_send_request, we
can add a member to struct NBDRequest, since it already does not
reflect on-wire format. Some callers initialize it directly; many
others rely on a common initialization point during
nbd_co_send_request(). At this point, there is no semantic change.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20230829175826.377251-21-eblake@redhat.com>
The upcoming patches for 64-bit extensions requires various points in
the protocol to make decisions based on what was negotiated. While we
could easily add a 'bool extended_headers' alongside the existing
'bool structured_reply', this does not scale well if more modes are
added in the future. Better is to expose the mode enum added in the
recent commit bfe04d0a7d out to a wider use in the code base.
Where the code previously checked for structured_reply being set or
clear, it now prefers checking for an inequality; this works because
the nodes are in a continuum of increasing abilities, and allows us to
touch fewer places if we ever insert other modes in the middle of the
enum. There should be no semantic change in this patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230829175826.377251-20-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
* regular calculation of cluster used bitmap of the image file
* cluster allocation on the base of that bitmap (effectively allocation of
new clusters could be done inside the image if that offset space is unused)
* support of DISCARD and WRITE_ZEROES operations
* image check bugfixes
* unit tests fixes
* unit tests covering new functionality
-----BEGIN PGP SIGNATURE-----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=FUWj
-----END PGP SIGNATURE-----
Merge tag 'pull-parallels-2023-09-20-v2' of https://src.openvz.org/scm/~den/qemu into staging
Parallels format driver:
* regular calculation of cluster used bitmap of the image file
* cluster allocation on the base of that bitmap (effectively allocation of
new clusters could be done inside the image if that offset space is unused)
* support of DISCARD and WRITE_ZEROES operations
* image check bugfixes
* unit tests fixes
* unit tests covering new functionality
# -----BEGIN PGP SIGNATURE-----
#
# iQHDBAABCgAtFiEE9vE2f3B8+RUZInytPzClrpN3nJ8FAmUL7u4PHGRlbkBvcGVu
# dnoub3JnAAoJED8wpa6Td5yfdaUL/RW+nOYlFNXlrjOVeasgGLkAKrKBja8O3/As
# aRo0DLZKITK8qbLEBAeTDyCpN9LLwy7WdUR1uT4V54FzE5zZP6HAdBEoj9AsaW/9
# wsTF+oyKeqmXw2y348t+lclp8eREHySecwiVhaxTpG9J2TQfDP/D2yhzRU88P7nH
# rbVZjOF2yOthzW6Y8h8e/LMd8rfODO053tYaMEBngjirBZnhESH3mAm1WB5mYs+q
# 2++4XQZcFFKWFp952MaEDphpwYdh80E65g4vth80JrDTyyMH0KZE9cQqbFb5UgZv
# aV1/DCaH0WTSDbjCaI/SrmqKXrO0Mkd/y/ShoQpTu7qJO/FbaClA58f+KfGE7VBd
# Fa5pM+JN12UVNxnNIF/Oe+wAiVUJYKtLaDMKibj+MUjM5sE/ZRLqzFLktDbQT0kS
# Qvs1u8HTvirJpvxOkJv4cEuNw07JERCzpl/qPF6XkS9rcKeIormhftaaRmjILxS/
# KEmDVNj63g1D0XDY3WTF7LHLNjtXpw==
# =FUWj
# -----END PGP SIGNATURE-----
# gpg: Signature made Thu 21 Sep 2023 03:21:18 EDT
# gpg: using RSA key F6F1367F707CF91519227CAD3F30A5AE93779C9F
# gpg: issuer "den@openvz.org"
# gpg: Good signature from "Denis V. Lunev <den@openvz.org>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: F6F1 367F 707C F915 1922 7CAD 3F30 A5AE 9377 9C9F
* tag 'pull-parallels-2023-09-20-v2' of https://src.openvz.org/scm/~den/qemu: (22 commits)
tests: extend test 131 to cover availability of the write-zeroes
parallels: naive implementation of parallels_co_pwrite_zeroes
tests: extend test 131 to cover availability of the discard operation
parallels: naive implementation of parallels_co_pdiscard
parallels: improve readability of allocate_clusters
parallels: naive implementation of allocate_clusters with used bitmap
parallels: update used bitmap in allocate_cluster
parallels: accept multiple clusters in mark_used()
tests: test self-cure of parallels image with duplicated clusters
tests: fix broken deduplication check in parallels format test
parallels: collect bitmap of used clusters at open
parallels: add test which will validate data_off fixes through repair
parallels: fix broken parallels_check_data_off()
tests: ensure that image validation will not cure the corruption
parallels: create mark_used() helper which sets bit in used bitmap
parallels: refactor path when we need to re-check image in parallels_open
parallels: return earlier from parallels_open() function on error
parallels: return earler in fail_format branch in parallels_open()
parallels: invent parallels_opts_prealloc() helper to parse prealloc opts
parallels: fix memory leak in parallels_open()
...
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
- Graph locking part 4 (node management)
- qemu-img map: report compressed data blocks
- block-backend: process I/O in the current AioContext
-----BEGIN PGP SIGNATURE-----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=qTNA
-----END PGP SIGNATURE-----
Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into staging
Block layer patches
- Graph locking part 4 (node management)
- qemu-img map: report compressed data blocks
- block-backend: process I/O in the current AioContext
# -----BEGIN PGP SIGNATURE-----
#
# iQJFBAABCAAvFiEE3D3rFZqa+V09dFb+fwmycsiPL9YFAmULHnURHGt3b2xmQHJl
# ZGhhdC5jb20ACgkQfwmycsiPL9aB5hAAqH8To7WIUtg1rj1PY809ck78ghm18PKg
# TNdN7IbrXQghX5foh2VgPwVVl+JaW2CSrJYWQcAO6AbvFduNIi9iKzI6RT0xKXpb
# b8oQXS7zntFzwBv8ohOU5NSVJOgVmNP4h5qJIMmXgB9ZcLFG40zggVH2qQT7guUf
# 9MAc81kI/d5vvSHY0ZjdHjNOgwG4q1j8yytL7OFqWUfB8sXloUCA9lT7w4jIYD8L
# v2StUOLWB01Zts2o8SCNaFxuajs6wUee8b/DM1cyPyLy4KtOdXvLKhq2NlXpLo2i
# aZFr4PtizTVwrQZIJttA9jqM+QCsDOsiSat3BLNNsKUaCWHZB0rOGLCzMCtisyOo
# 4PzuL4UI21ik2zieO1qVM+Thqvw16kHtp6dD9pGk4X4ogGreGYEIxzBl79luR+AV
# NCRizoeFWTHKymS1tSoKrWT9ZNHcLmwemO6Tt1rMYk9jV3T4uY5e1NwxaUavEfsX
# f8dLfQjhNiySOoDknT1OSerBOVdTXURS2ri5H3GZxrxvJ4jOeFkn52C8r3YlZ3Wp
# Cr9LCUJZeXgwY+Q1JQ3D4VLY8aZ83txpw6XKEy0eTEv5wxkBj5LWhXx7hNb5F3lg
# bqaRYijVJn+P82wVxlftIzMfNeVBFHzFE90taPV5grJjr8lgrGBFmD7Puc97kfDX
# oTDBwRxJeew=
# =qTNA
# -----END PGP SIGNATURE-----
# gpg: Signature made Wed 20 Sep 2023 12:31:49 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: (28 commits)
block: mark aio_poll as non-coroutine
block-backend: process zoned requests in the current AioContext
block-backend: process I/O in the current AioContext
test-bdrv-drain: avoid race with BH in IOThread drain test
block: remove AIOCBInfo->get_aio_context()
qemu-img: map: report compressed data blocks
block: add BDRV_BLOCK_COMPRESSED flag for bdrv_block_status()
block: Mark bdrv_add/del_child() and caller GRAPH_WRLOCK
block: Mark bdrv_unref_child() GRAPH_WRLOCK
block: Mark bdrv_root_unref_child() GRAPH_WRLOCK
block: Take graph rdlock in bdrv_change_aio_context()
block: Take graph rdlock in bdrv_drop_intermediate()
block: Mark bdrv_parent_cb_change_media() GRAPH_RDLOCK
block: Mark bdrv_child_perm() GRAPH_RDLOCK
block: Mark bdrv_get_cumulative_perm() and callers GRAPH_RDLOCK
block: Mark bdrv_parent_perms_conflict() and callers GRAPH_RDLOCK
block: Mark bdrv_attach_child() GRAPH_WRLOCK
block: Call transaction callbacks with lock held
block: Mark bdrv_attach_child_common() GRAPH_WRLOCK
block: Mark bdrv_replace_child_tran() GRAPH_WRLOCK
...
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
- Fix for file-posix's zoning code crashing on I/O errors
- Throttling refactoring
-----BEGIN PGP SIGNATURE-----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=oKgk
-----END PGP SIGNATURE-----
Merge tag 'pull-block-2023-09-01' of https://gitlab.com/hreitz/qemu into staging
Block patches
- Fix for file-posix's zoning code crashing on I/O errors
- Throttling refactoring
# -----BEGIN PGP SIGNATURE-----
#
# iQJGBAABCAAwFiEEy2LXoO44KeRfAE00ofpA0JgBnN8FAmTxnMISHGhyZWl0ekBy
# ZWRoYXQuY29tAAoJEKH6QNCYAZzfYkUP+gMG9hhzvgjj/tw9rEBQjciihzcQmqQJ
# 2Mm37RH2jj5bnnTdaTbMkcRRwVhncYSCwK9q5EYVbZmU9C/v4YJmsSEQlcl7wVou
# hbPUv6NHaBrJZX9nxNSa2RHui6pZMLKa/D0rJVB7NjYBrrRtiPo7kiLVQYjYXa2g
# kcCCfY4t3Z2RxOP31mMXRjYlhJE9bIuZdTEndrKme8KS2JGPZEJ9xjkoW1tj96EX
# oc/Cg2vk7AEtsFYA0bcD8fTFkBDJEwyYl3usu7Tk24pvH16jk7wFSqRVSsDMfnER
# tG8X3mHLIY0hbSkpzdHJdXINvZ6FWpQb0CGzIKr+pMiuWVdWr1HglBr0m4pVF+Y4
# A6AI6VX2JJgtacypoDyCZC9mzs1jIdeiwq9v5dyuikJ6ivTwEEoeoSLnLTN3AjXn
# 0mtQYzgCg5Gd6+rTo7XjSO9SSlbaVrDl/B2eXle6tmIFT5k+86fh0hc+zTmP8Rkw
# Knbc+5Le95wlMrOUNx2GhXrTGwX510hLxKboho/LITxtAzqvXnEJKrYbnkm3WPnw
# wfHnR5VQH1NKEpiH/p33og6OV/vu9e7vgp0ZNZV136SnzC90C1zMUwg2simJW701
# 34EtN0XBX8XBKrxfe7KscV9kRE8wrWWJVbhp+WOcQEomGI8uraxzWqDIk/v7NZXv
# m4XBscaB+Iri
# =oKgk
# -----END PGP SIGNATURE-----
# gpg: Signature made Fri 01 Sep 2023 04:11:46 EDT
# gpg: using RSA key CB62D7A0EE3829E45F004D34A1FA40D098019CDF
# gpg: issuer "hreitz@redhat.com"
# gpg: Good signature from "Hanna Reitz <hreitz@redhat.com>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: CB62 D7A0 EE38 29E4 5F00 4D34 A1FA 40D0 9801 9CDF
* tag 'pull-block-2023-09-01' of https://gitlab.com/hreitz/qemu:
tests/file-io-error: New test
file-posix: Simplify raw_co_prw's 'out' zone code
file-posix: Fix zone update in I/O error path
file-posix: Check bs->bl.zoned for zone info
file-posix: Clear bs->bl.zoned on error
block/throttle-groups: Use ThrottleDirection instread of bool is_write
fsdev: Use ThrottleDirection instread of bool is_write
throttle: use THROTTLE_MAX/ARRAY_SIZE for hard code
throttle: use enum ThrottleDirection instead of bool is_write
cryptodev: use NULL throttle timer cb for read direction
test-throttle: test read only and write only
throttle: support read-only and write-only
test-throttle: use enum ThrottleDirection
throttle: introduce enum ThrottleDirection
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The zero flag is missed in the Parallels format specification. We can
resort to discard if we have no backing file.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
* Discarding with backing stores is not supported by the format.
* There is no buffering/queueing of the discard operation.
* Only operations aligned to the cluster are supported.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Replace 'space' representing the amount of data to preallocate with
'bytes'.
Rationale:
* 'space' at each place is converted to bytes
* the unit is more close to the variable name
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
The access to the bitmap is not optimized completely.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
We should extend the bitmap if the file is extended and set the bit in
the image used bitmap once the cluster is allocated. Sanity check at
that moment also looks like a good idea.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
This would be useful in the next patch in allocate_clusters(). This
change would not imply serious performance drawbacks as usually image
is full of data or are at the end of the bitmap.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
If the operation is failed, we need to check image consistency if the
problem is not about memory allocation.
Bitmap adjustments in allocate_cluster are not performed yet.
They worth to be separate. This was proven useful during debug of this
series. Kept as is for future bissecting.
It should be specifically noted that used bitmap must be recalculated
if data_off has been fixed during image consistency check.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Once we have repaired data_off field in the header we should update
s->data_start which is calculated on the base of it.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
This functionality is used twice already and next patch will add more
code with it.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
More conditions follows thus the check should be more scalable.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
At the beginning of the function we can return immediately until we
really allocate s->header.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
We do not need to perform any deallocation/cleanup if wrong format is
detected.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
This patch creates above mentioned helper and moves its usage to the
beginning of parallels_open(). This simplifies parallels_open() a bit.
The patch also ensures that we store prealloc_size on block driver state
always in sectors. This makes code cleaner and avoids wrong opinion at
the assignment that the value is in bytes.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
We should free opts allocated through qemu_opts_create() at the end.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Parallels driver indeed support Parallels Dirty Bitmap Feature in
read-only mode. The patch adds bdrv_supports_persistent_dirty_bitmap()
callback which always return 1 to indicate that.
This will allow to copy CBT from Parallels image with qemu-img.
Note: read-write support is signalled through
bdrv_co_can_store_new_dirty_bitmap() and is different.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Old code is ugly and contains tabulations. There are no functional
changes in this patch.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Process zoned requests in the current thread's AioContext instead of in
the BlockBackend's AioContext.
There is no need to use the BlockBackend's AioContext thanks to CoMutex
bs->wps->colock, which protects zone metadata.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230912231037.826804-5-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Switch blk_aio_*() APIs over to multi-queue by using
qemu_get_current_aio_context() instead of blk_get_aio_context(). This
change will allow devices to process I/O in multiple IOThreads in the
future.
I audited existing blk_aio_*() callers:
- migration/block.c: blk_mig_lock() protects the data accessed by the
completion callback.
- The remaining emulated devices and exports run with
qemu_get_aio_context() == blk_get_aio_context().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230912231037.826804-4-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The synchronous bdrv_aio_cancel() function needs the acb's AioContext so
it can call aio_poll() to wait for cancellation.
It turns out that all users run under the BQL in the main AioContext, so
this callback is not needed.
Remove the callback, mark bdrv_aio_cancel() GLOBAL_STATE_CODE just like
its blk_aio_cancel() caller, and poll the main loop AioContext.
The purpose of this cleanup is to identify bdrv_aio_cancel() as an API
that does not work with the multi-queue block layer.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230912231037.826804-2-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Functions qcow2_get_host_offset(), get_cluster_offset(),
vmdk_co_block_status() explicitly report compressed cluster types when data
is compressed. However, this information is never passed further. Let's
make use of it by adding new BDRV_BLOCK_COMPRESSED flag for
bdrv_block_status(), so that caller may know that the data range is
compressed. In particular, we're going to use this flag to tweak
"qemu-img map" output.
This new flag is only being utilized by qcow, qcow2 and vmdk formats, as only
those support compression.
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Message-ID: <20230907210226.953821-2-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The functions read the parents list in the generic block layer, so we
need to hold the graph lock already there. The BlockDriver
implementations actually modify the graph, so it has to be a writer
lock.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-22-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_unref_child(). These callers will typically
already hold the graph lock once the locking work is completed, which
means that they can't call functions that take it internally.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-21-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_root_unref_child(). These callers will
typically already hold the graph lock once the locking work is
completed, which means that they can't call functions that take it
internally.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-20-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_child_perm() need to hold a reader lock for the graph because
some implementations access the children list of a node.
The callers of bdrv_child_perm() conveniently already hold the lock.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-16-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The function reads the parents list, so it needs to hold the graph lock.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-14-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_attach_child_common(). These callers will
typically already hold the graph lock once the locking work is
completed, which means that they can't call functions that take it
internally.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-13-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_attach_child_common(). These callers will
typically already hold the graph lock once the locking work is
completed, which means that they can't call functions that take it
internally.
Note that the transaction callbacks still take the lock internally, so
tran_finalize() must be called without the lock held. This is because
bdrv_append() also calls bdrv_replace_node_noperm(), which currently
requires the transaction callbacks to be called unlocked. In the next
step, both of them can be switched to locked tran_finalize() calls
together.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-11-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_unref() is called by a lot of places that need to hold the graph
lock (it naturally happens in the context of operations that change the
graph). However, bdrv_unref() takes the graph writer lock internally, so
it can't actually be called while already holding a graph lock without
causing a deadlock.
bdrv_unref() also can't just become GRAPH_WRLOCK because it drains the
node before closing it, and draining requires that the graph is
unlocked.
The solution is to defer deleting the node until we don't hold the lock
any more and draining is possible again.
Note that keeping images open for longer than necessary can create
problems, too: You can't open an image again before it is really closed
(if image locking didn't prevent it, it would cause corruption).
Reopening an image immediately happens at least during bdrv_open() and
bdrv_co_create().
In order to solve this problem, make sure to run the deferred unref in
bdrv_graph_wrunlock(), i.e. the first possible place where we can drain
again. This is also why bdrv_schedule_unref() is marked GRAPH_WRLOCK.
The output of iotest 051 is updated because the additional polling
changes the order of HMP output, resulting in a new "(qemu)" prompt in
the test output that was previously on a separate line and filtered out.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230911094620.45040-6-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When the permission related BlockDriver callbacks are called, we are in
the middle of an operation traversing the block graph. Polling in such a
place is a very bad idea because the graph could change in unexpected
ways. In the future, callers will also hold the graph lock, which is
likely to turn polling into a deadlock.
So we need to get rid of calls to functions like bdrv_getlength() or
bdrv_truncate() there as these functions poll internally. They are
currently used so that when no parent has write/resize permissions on
the image any more, the preallocate filter drops the extra preallocated
area in the image file and gives up write/resize permissions itself.
In order to achieve this without polling in .bdrv_check_perm, don't
immediately truncate the image, but only schedule a BH to do so. The
filter keeps the write/resize permissions a bit longer now until the BH
has executed.
There is one case in which delaying doesn't work: Reopening the image
read-only. In this case, bs->file will likely be reopened read-only,
too, so keeping write permissions a bit longer on it doesn't work. But
we can already cover this case in preallocate_reopen_prepare() and not
rely on the permission updates for it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It's essentially the same code in preallocate_check_perm() and
preallocate_close(), except that the latter ignores errors.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-3-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
Kevin Wolf
Stefan Hajnoczi
Naohiro Aota
Sam Li
Jean-Louis Dupond
Vladimir Sementsov-Ogievskiy
Cédric Le Goater
Steve Sistare
Fiona Ebner
Emanuele Giuseppe Esposito
Paolo Bonzini
Eric Blake
Markus Armbruster
Denis V. Lunev
Andrey Drobyshev via
Fabiano Rosas
Dmitry Frolov
Peter Maydell
Philippe Mathieu-Daudé
Michael Tokarev