qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter. Drop the include, and add it
to the places that actually need it.
While there, drop superfluous includes of both headers, and
separate #include from file comment with a blank line.
This cleanup makes the number of objects depending on qemu/option.h
drop from 4545 (out of 4743) to 284 in my "build everything" tree.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-20-armbru@redhat.com>
[Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]
This cleanup makes the number of objects depending on qapi/error.h
drop from 1910 (out of 4743) to 1612 in my "build everything" tree.
While there, separate #include from file comment with a blank line,
and drop a useless comment on why qemu/osdep.h is included first.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-5-armbru@redhat.com>
[Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]
Allow block driver to map and unmap a buffer for later I/O, as a performance
hint.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180116060901.17413-5-famz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
'qemu-img info' makes sense even when BLK_PERM_CONSISTENT_READ cannot be
granted because of a block job in a running qemu process. It already
sets BDRV_O_NO_IO to indicate that it doesn't access the guest visible
data at all.
Check the BDRV_O_NO_IO flags in blk_new_open(), so that I/O related
permissions are not unnecessarily requested and 'qemu-img info' can work
even if BLK_PERM_CONSISTENT_READ cannot be granted.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
On one hand, it is a good idea for bdrv_next() to return a strong
reference because ideally nearly every pointer should be refcounted.
This fixes intermittent failure of iotest 194.
On the other, it is absolutely necessary for bdrv_next() itself to keep
a strong reference to both the BB (in its first phase) and the BDS (at
least in the second phase) because when called the next time, it will
dereference those objects to get a link to the next one. Therefore, it
needs these objects to stay around until then. Just storing the pointer
to the next in the iterator is not really viable because that pointer
might become invalid as well.
Both arguments taken together means we should probably just invoke
bdrv_ref() and blk_ref() in bdrv_next(). This means we have to assert
that bdrv_next() is always called from the main loop, but that was
probably necessary already before this patch and judging from the
callers, it also looks to actually be the case.
Keeping these strong references means however that callers need to give
them up if they decide to abort the iteration early. They can do so
through the new bdrv_next_cleanup() function.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110172545.32609-1-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
If a BlockBackend has I/O limits set then its ThrottleGroupMember
structure uses the AioContext from its attached BlockDriverState.
Those two contexts must be kept in sync manually. This is not
ideal and will be fixed in the future by removing the throttling
configuration from the BlockBackend and storing it in an implicit
filter node instead, but for now we have to live with this.
When you remove the BlockDriverState from the backend then the
throttle timers are destroyed. If a new BlockDriverState is later
inserted then they are created again using the new AioContext.
There are a couple of problems with this:
a) The code manipulates the timers directly, leaving the
ThrottleGroupMember.aio_context field in an inconsisent state.
b) If you remove the I/O limits (e.g by destroying the backend)
when the timers are gone then throttle_group_unregister_tgm()
will attempt to destroy them again, crashing QEMU.
While b) could be fixed easily by allowing the timers to be freed
twice, this would result in a situation in which we can no longer
guarantee that a valid ThrottleState has a valid AioContext and
timers.
This patch ensures that the timers and AioContext are always valid
when I/O limits are set, regardless of whether the BlockBackend has a
BlockDriverState inserted or not.
[Fixed "There'a" typo as suggested by Max Reitz <mreitz@redhat.com>
--Stefan]
Reported-by: sochin jiang <sochin.jiang@huawei.com>
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: e089c66e7c20289b046d782cea4373b765c5bc1d.1510339534.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
When you set I/O limits using block_set_io_throttle or the command
line throttling.* options they are kept in the BlockBackend regardless
of whether a BlockDriverState is attached to the backend or not.
Therefore when removing the limits using blk_io_limits_disable() we
need to check if there's a BDS before attempting to drain it, else it
will crash QEMU. This can be reproduced very easily using HMP:
(qemu) drive_add 0 if=none,throttling.iops-total=5000
(qemu) drive_del none0
Reported-by: sochin jiang <sochin.jiang@huawei.com>
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 0d3a67ce8d948bb33e08672564714dcfb76a3d8c.1510339534.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
I/O requests hang after stop/cont commands at least since QEMU 2.10.0
with -drive iops=100:
(guest)$ dd if=/dev/zero of=/dev/vdb oflag=direct count=1000
(qemu) stop
(qemu) cont
...I/O is stuck...
This happens because blk_set_aio_context() detaches the ThrottleState
while requests may still be in flight:
if (tgm->throttle_state) {
throttle_group_detach_aio_context(tgm);
throttle_group_attach_aio_context(tgm, new_context);
}
This patch encloses the detach/attach calls in a drained region so no
I/O request is left hanging. Also add assertions so we don't make the
same mistake again in the future.
Reported-by: Yongxue Hong <yhong@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20171110151934.16883-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
In blk_remove_bs, all I/O should be completed before removing throttle
timers. If there has inflight I/O, removing throttle timers here will
cause the inflight I/O never return.
This patch add bdrv_drained_begin before throttle_timers_detach_aio_context
to let all I/O completed before removing throttle timers.
[Moved declaration of bs as suggested by Alberto Garcia
<berto@igalia.com>.
--Stefan]
Signed-off-by: Zhengui <lizhengui@huawei.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1508564040-120700-1-git-send-email-lizhengui@huawei.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move the CoMutex and CoQueue inits inside throttle_group_register_tgm()
which is called whenever a ThrottleGroupMember is initialized. There's
no need for them to be separate.
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
timer_cb() needs to know about the current Aio context of the throttle
request that is woken up. In order to make ThrottleGroupMember backend
agnostic, this information is stored in an aio_context field instead of
accessing it from BlockBackend.
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit eliminates the 1:1 relationship between BlockBackend and
throttle group state. Users will be able to create multiple throttle
nodes, each with its own throttle group state, in the future. The
throttle group state cannot be per-BlockBackend anymore, it must be
per-throttle node. This is done by gathering ThrottleGroup membership
details from BlockBackendPublic into ThrottleGroupMember and refactoring
existing code to use the structure.
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
These two conditions corresponds to mirror job's source and target,
which need to be allowed as they are part of the non-shared storage
migration workflow: failing to inactivate either will result in a
failure during migration completion.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170823134242.12080-3-famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[eblake: improve comment grammar]
Signed-off-by: Eric Blake <eblake@redhat.com>
The logic will be fixed (extended), move it to a separate function.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170823134242.12080-2-famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
As in the case of nbd_export_new(), bdrv_invalidate_cache() can be
called when migration is still in progress. In this case we are not
ready to tighten the shared permissions fenced by blk->disable_perm.
Defer to a VM state change handler.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170815130740.31229-4-famz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
blk_truncate() itself will pass that value to bdrv_truncate(), and all
callers of blk_truncate() just set the parameter to PREALLOC_MODE_OFF
for now.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
For block drivers that just pass a truncate request to the underlying
protocol, we can now pass the preallocation mode instead of aborting if
it is not PREALLOC_MODE_OFF.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Change the 'int count' parameter in *pwrite_zeros, *pdiscard related
functions (and some others) to 'int bytes', as they both refer to bytes.
This helps with code legibility.
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Message-id: 20170609101808.13506-1-el13635@mail.ntua.gr
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
block_acct_destroy is called unconditionally in blk_delete, but there is
no BlockAcctStats function that is called unconditionally in blk_new.
Split block_acct_init in two, so that it will be possible to create a
QemuMutex in block_acct_init and destroy it in block_acct_cleanup.
Cc: Alberto Garcia <berto@igalia.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-19-pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Another possibility is to use tg->lock, which we're holding anyway in
both schedule_next_request and throttle_group_co_io_limits_intercept.
This would require open-coding the CoQueue however, so I've chosen this
alternative.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-10-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
blk->name isn't an array, but a pointer that can be NULL. Checking for
an anonymous BB must involve a NULL check first, otherwise we get
crashes.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
With image locking, permissions affect other qemu processes as well. We
want to be sure that the destination can run, so let's drop permissions
on the source when migration completes.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Instead of manually calling blk_resume_after_migration() in migration
code after doing bdrv_invalidate_cache_all(), integrate the BlockBackend
activation with cache invalidation into a single function. This is
achieved with a new callback in BdrvChildRole that is called by
bdrv_invalidate_cache_all().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
For one thing, this allows us to drop the error message generation from
qemu-img.c and blockdev.c and instead have it unified in
bdrv_truncate().
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-3-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
blk_name() is not modifying data passed to it through pointer and it
returns also a pointer to const so the argument can be made const for
code safeness.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When a block device that is part of a throttle group is hot-unplugged,
we forgot to remove it from the throttle group. This leaves stale
memory around, and causes an easily reproducible crash:
$ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio \
-device virtio-scsi-pci,bus=pci.0 -drive \
id=drive_image2,if=none,format=raw,file=file2,bps=512000,iops=100,group=foo \
-device scsi-hd,id=image2,drive=drive_image2 -drive \
id=drive_image3,if=none,format=raw,file=file3,bps=512000,iops=100,group=foo \
-device scsi-hd,id=image3,drive=drive_image3
{'execute':'qmp_capabilities'}
{'execute':'device_del','arguments':{'id':'image3'}}
{'execute':'system_reset'}
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1428810
Suggested-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170406190847.29347-1-eblake@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
BDRV_POLL_WHILE waits for the started I/O by releasing bs's ctx then polling
the main context, which relies on the yielded coroutine continuing on bs->ctx
before notifying qemu_aio_context with bdrv_wakeup().
Thus, using qemu_coroutine_enter to start I/O is wrong because if the coroutine
is entered from main loop, co->ctx will be qemu_aio_context, as a result of the
"release, poll, acquire" loop of BDRV_POLL_WHILE, race conditions happen when
both main thread and the iothread access the same BDS:
main loop iothread
-----------------------------------------------------------------------
blockdev_snapshot
aio_context_acquire(bs->ctx)
virtio_scsi_data_plane_handle_cmd
bdrv_drained_begin(bs->ctx)
bdrv_flush(bs)
bdrv_co_flush(bs) aio_context_acquire(bs->ctx).enter
...
qemu_coroutine_yield(co)
BDRV_POLL_WHILE()
aio_context_release(bs->ctx)
aio_context_acquire(bs->ctx).return
...
aio_co_wake(co)
aio_poll(qemu_aio_context) ...
co_schedule_bh_cb() ...
qemu_coroutine_enter(co) ...
/* (A) bdrv_co_flush(bs) /* (B) I/O on bs */
continues... */
aio_context_release(bs->ctx)
aio_context_acquire(bs->ctx)
Note that in above case, bdrv_drained_begin() doesn't do the "release,
poll, acquire" in BDRV_POLL_WHILE, because bs->in_flight == 0.
Fix this by using bdrv_coroutine_enter and enter coroutine in the right
context.
iotests 109 output is updated because the coroutine reenter flow during
mirror job complete is different (now through co_queue_wakeup, instead
of the unconditional qemu_coroutine_switch before), making the end job
len different.
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Usually guest devices don't like other writers to the same image, so
they use blk_set_perm() to prevent this from happening. In the migration
phase before the VM is actually running, though, they don't have a
problem with writes to the image. On the other hand, storage migration
needs to be able to write to the image in this phase, so the restrictive
blk_set_perm() call of qdev devices breaks it.
This patch flags all BlockBackends with a qdev device as
blk->disable_perm during incoming migration, which means that the
requested permissions are stored in the BlockBackend, but not actually
applied to its root node yet.
Once migration has finished and the VM should be resumed, the
permissions are applied. If they cannot be applied (e.g. because the NBD
server used for block migration hasn't been shut down), resuming the VM
fails.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Kashyap Chamarthy <kchamart@redhat.com>
Allow block backends to forward drain requests to their devices/users.
The initial intended purpose for this patch is to allow BBs to forward
requests along to BlockJobs, which will want to pause if their associated
BB has entered a drained region.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20170316212351.13797-3-jsnow@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
We have an errp and bdrv_root_attach_child can fail permission check,
error_abort is not the best choice here.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The HMP command 'qemu-io' is a bit tricky because it wants to work on
the original BlockBackend, but additional permissions could be required.
The details are explained in a comment in the code, but in summary, just
request whatever permissions the current qemu-io command needs.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
For meaningful error messages in the permission system, we need to get
some human-readable description of the parent of a BdrvChild.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Some devices allow a media change between read-only and read-write
media. They need to adapt the permissions in their .change_media_cb()
implementation, which can fail. So add an Error parameter to the
function.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
We can figure out the necessary permissions from the flags that the
caller passed.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Now that blk_insert_bs() requests the BlockBackend permissions for the
node it attaches to, it can fail. Instead of aborting, pass the errors
to the callers.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
We want every user to be specific about the permissions it needs, so
we'll pass the initial permissions as parameters to blk_new(). A user
only needs to call blk_set_perm() if it wants to change the permissions
after the fact.
The permissions are stored in the BlockBackend and applied whenever a
BlockDriverState should be attached in blk_insert_bs().
This does not include actually choosing the right set of permissions
everywhere yet. Instead, the usual FIXME comment is added to each place
and will be addressed in individual patches.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
The BlockBackend can now store the permissions that its user requires.
This is necessary because nodes can be ejected from or inserted into a
BlockBackend and all of these operations must make sure that the user
still gets what it requested initially.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
When attaching a node as a child to a new parent, the required and
shared permissions for this parent are checked against all other parents
of the node now, and an error is returned if there is a conflict.
This allows error returns to a function that previously always
succeeded, and the same is true for quite a few callers and their
callers. Converting all of them within the same patch would be too much,
so for now everyone tells that they don't need any permissions and allow
everyone else to do anything. This way we can use &error_abort initially
and convert caller by caller to pass actual permission requirements and
implement error handling.
All these places are marked with FIXME comments and it will be the job
of the next patches to clean them up again.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-16-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-15-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
qcow2_create2 calls this. Do not run a nested event loop, as that
breaks when aio_co_wake tries to queue the coroutine on the co_queue_wakeup
list of the currently running one.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-4-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
blk_eject is only used by scsi-disk and atapi, and in both cases we
only attempt to invoke blk_eject if we have a bona-fide change in
tray state.
The "issue" here is that the tray state does not generate a QMP event
unless there is a medium/BDS attached to the device, so if libvirt et al
are waiting for a tray event to occur from an empty-but-closed drive,
software opening that drive will not emit an event and libvirt will
wait forever.
Change this by modifying blk_eject to always emit an event, instead of
conditionally on a "real" backend eject.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1373264
Reported-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1478553214-497-2-git-send-email-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
We want the BDS event loop to run exclusively in the iothread that
owns the BDS's AioContext. This macro will provide the synchronization
between the two event loops; for now it just wraps the common idiom
of a while loop around aio_poll.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-Id: <1477565348-5458-8-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Unlike tracked_requests, this field also counts throttled requests,
and remains non-zero if an AIO operation needs a BH to be "really"
completed.
With this change, it is no longer necessary to have a dummy
BdrvTrackedRequest for requests that are never serialising, and
it is no longer necessary to poll the AioContext once after
bdrv_requests_pending(bs) returns false.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-Id: <1477565348-5458-5-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
All read/write functions already have a single coroutine-based function
on the BlockBackend level through which all requests go (no matter what
API style the external caller used) and which passes the requests down
to the block node level.
This patch exports a bdrv_co_ioctl() function and uses it to extend this
mode of operation to ioctls.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
All read/write functions already have a single coroutine-based function
on the BlockBackend level through which all requests go (no matter what
API style the external caller used) and which passes the requests down
to the block node level.
This patch extends this mode of operation to discards.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
