It is generally not expected that io_submit() fails other than with
-EAGAIN, but corner cases like SELinux refusing I/O when permissions are
revoked are still possible. In this case, we shouldn't abort, but just
return an I/O error for the request.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1470741619-23231-1-git-send-email-kwolf@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
If a qdev block device is created with an anonymous BlockBackend (i.e.
a node name rather than a BB name was given for the drive property),
qdev used to return an empty string when the property was read. This
patch fixes it to return the node name instead.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Commit 0d978913 changed blockdev-backup to accept arbitrary node names
instead of device names (i.e. root nodes) for the backup target.
However, it forgot to make the same change in transactions and to update
the documentation. This patch fixes these omissions.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Block patches (v2) for the block queue.
# gpg: Signature made Wed Jul 13 13:41:53 2016 CEST
# gpg: using RSA key 0x3BB14202E838ACAD
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>"
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1 1829 F407 DB00 61D5 CF40
# Subkey fingerprint: 58B3 81CE 2DC8 9CF9 9730 EE64 3BB1 4202 E838 ACAD
* mreitz/tags/pull-block-for-kevin-2016-07-13:
iotests: Make 157 actually format-agnostic
vvfat: Fix qcow write target driver specification
hmp: show all of snapshot info on every block dev in output of 'info snapshots'
hmp: use snapshot name to determine whether a snapshot is 'fully available'
qemu-iotests: Test naming of throttling groups
blockdev: Fix regression with the default naming of throttling groups
vmdk: fix metadata write regression
Improve block job rate limiting for small bandwidth values
qcow2: Fix qcow2_get_cluster_offset()
qemu-io: Use correct range limitations
qcow2: Avoid making the L1 table too big
qemu-img: Use strerror() for generic resize error
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
werror/rerror are now available as qdev options. The stats-* options are
removed without an existing replacement; they should probably be
configurable with a separate QMP command like I/O throttling settings.
Removing id is left for another day because this involves updating
qemu-iotests cases to use node-name for everything. Before we can do
that, however, all QMP commands must support node-name.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The rerror/werror policies are implemented in the devices, so that's
where they should be configured. In comparison to the old options in
-drive, the qdev properties are only added to those devices that
actually support them.
If the option isn't given (or "auto" is specified), the setting of the
BlockBackend is used for compatibility with the old options. For block
jobs, "auto" is the same as "enospc".
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Commit implemented the 'enospc' policy as 'ignore' if the error was not
ENOSPC. The QAPI documentation promises that it's treated as 'stop'.
Using the common block job error handling function fixes this and also
adds the missing QMP event.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
As cache.writeback is a BlockBackend property and as such more related
to the guest device than the BlockDriverState, we already removed it
from the blockdev-add interface. This patch adds the new way to set it,
as a qdev property of the corresponding guest device.
For example: -drive if=none,file=test.img,node-name=img
-device ide-hd,drive=img,write-cache=off
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
If a node name instead of a BlockBackend name is specified as the driver
for a guest device, an anonymous BlockBackend is created now.
The order of operations in release_drive() must be reversed in order to
avoid a use-after-free bug because now blk_detach_dev() frees the last
reference if an anonymous BlockBackend is used.
usb-storage uses a hack where it forwards its BlockBackend as a property
to another device that it internally creates. This hack must be updated
so that it doesn't drop its original BB before it can be passed to the
other device. This used to work because we always had the monitor
reference around, but with node-names the device reference is the only
one now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This is the final patch for converting the common I/O path to take
a BdrvChild parameter instead of BlockDriverState.
The completion of this conversion means that all users that perform I/O
on an image need to actually hold a reference (in the form of BdrvChild,
possible as part of a BlockBackend) to that image. This also protects
against inconsistent use of BlockBackend vs. BlockDriverState functions
because direct use of a BlockDriverState isn't possible any more and
blk->root is private for block-backends.c.
In addition, we can now distinguish different users in the I/O path,
and the future op blockers work is going to add assertions based on
permissions stored in BdrvChild.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Just like block jobs, the HMP commit command should use its own
BlockBackend for doing I/O on BlockDriverStates.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
This does some easy conversions from bdrv_* to blk_* functions in
vhdx_create(). We should avoid bypassing the BlockBackend layer whenever
possible.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
The blkreplay driver only forwards the requests it gets, so converting
it to byte granularity is trivial.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
vvfat uses a temporary qcow file to cache written data in read-write
mode. In order to do things properly, this should show up in the BDS
graph and I/O should go through BdrvChild like for every other node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
BlockBackend has only a single pointer to its guest device, so it makes
sure that only a single guest device is attached to it. device-add
returns an error if you try to attach a second device to a BB. In order
to make the error message nicer, -device that manually connects to a
if=none block device get a different message than -drive that implicitly
creates a guest device. The if=... option is stored in DriveInfo.
However, since blockdev-add exists, not every BlockBackend has a
DriveInfo any more. Check that it exists before we dereference it.
QMP reproducer resulting in a segfault:
{"execute":"blockdev-add","arguments":{"options":{"id":"disk","driver":"file","filename":"/tmp/test.img"}}}
{"execute":"device_add","arguments":{"driver":"virtio-blk-pci","drive":"disk"}}
{"execute":"device_add","arguments":{"driver":"virtio-blk-pci","drive":"disk"}}
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Block patches
# gpg: Signature made Thu Jun 16 15:21:35 2016 CEST
# gpg: using RSA key 0x3BB14202E838ACAD
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>"
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1 1829 F407 DB00 61D5 CF40
# Subkey fingerprint: 58B3 81CE 2DC8 9CF9 9730 EE64 3BB1 4202 E838 ACAD
* mreitz/tags/pull-block-for-kevin-2016-06-16:
hbitmap: add 'pos < size' asserts
iotests: Add test for oVirt-like storage migration
iotests: Add test for post-mirror backing chains
block/null: Implement bdrv_refresh_filename()
block/mirror: Fix target backing BDS
block: Allow replacement of a BDS by its overlay
rbd:change error_setg() to error_setg_errno()
iotests: 095: Clean up QEMU before showing image info
block: Create the commit block job before reopening any image
block: Prevent sleeping jobs from resuming if they have been paused
block: use the block job list in qmp_query_block_jobs()
block: use the block job list in bdrv_drain_all()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
snapshot=on creates a temporary overlay that is always opened with
cache=unsafe (the cache mode specified by the user is only for the
actual image file and its children). This means that we must not inherit
the BDRV_O_NATIVE_AIO flag for the temporary overlay because trying to
use Linux AIO with cache=unsafe results in an error.
Reproducer without this patch:
$ x86_64-softmmu/qemu-system-x86_64 -drive file=/tmp/test.qcow2,cache=none,aio=native,snapshot=on
qemu-system-x86_64: -drive file=/tmp/test.qcow2,cache=none,aio=native,snapshot=on: aio=native was
specified, but it requires cache.direct=on, which was not specified.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We don't really want to go through the block layer in order to read from
or write to the vmstate in a qcow2 image. Doing so required a few ugly
hacks like saving and restoring the old image size (because writing to
vmstate offsets would increase the image size) or disabling the "reads
after EOF = zeroes" logic. When calling the right functions directly,
these hacks aren't necessary any more.
Note that .bdrv_vmstate_load/save() return 0 instead of the number of
bytes in case of success now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
The return value of .bdrv_load/save_vmstate() can be any non-negative
number in case of success now. It used to be bytes/-errno.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
We already have a byte-based bdrv_pwritev(), but the read counterpart
was still missing. This commit adds it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
linux-aio uses a BH in order to make sure that the remaining completions
are processed even in nested event loops of completion callbacks in
order to avoid deadlocks.
There is no need, however, to have the BH overhead for the first call
into qemu_laio_completion_bh() or after all pending completions have
already been processed. Therefore, this patch calls directly into
qemu_laio_completion_bh() in qemu_laio_completion_cb() and cancels
the BH after qemu_laio_completion_bh() has processed all pending
completions.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
If block drivers say that they can do an alignment < 512 bytes, let's
just suppose they mean it. raw-posix used to be an offender with respect
to this, but it can actually deal with byte-aligned requests now.
The default is still 512 bytes for any drivers that only implement
sector-based interfaces, but it is 1 now for drivers that implement
.bdrv_co_preadv.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
The raw-posix block driver actually supports byte-aligned requests now
on non-O_DIRECT images, like it already (and previously incorrectly)
claimed in bs->request_alignment.
For some block drivers this means that a RMW cycle can be avoided when
they write sub-sector metadata e.g. for cluster allocation.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
In order to use the modern byte-based .bdrv_co_preadv/pwritev()
interface, this patch switches raw-posix to coroutine-based interfaces
as a first step. In terms of semantics and performance, it doesn't make
a difference with the existing code whether we go from a coroutine to a
callback-based interface already in block/io.c or only in linux-aio.c
As there have been concerns in the past that this change may be a step
in the wrong direction with respect to a possible AIO fast path, the
old callback-based interface for linux-aio is left around and can be
reactivated when a fast path (e.g. directly from virtio-blk dataplane,
bypassing the whole block layer) is implemented.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This patch makes bdrv_aligned_preadv() ready to accept byte-aligned
requests. Note that this doesn't mean that such requests are actually
made. The caller still ensures that all requests are aligned to at least
512 bytes.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
In a first step to convert the common I/O path to work on bytes rather
than sectors, this converts the copy-on-read logic that is used by
bdrv_aligned_preadv().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
If no -t option is specified, bool writethrough stayed uninitialised.
Initialise it as false, which makes cache=writeback the default cache
mode.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This changes qcow2 to implement the byte-based .bdrv_co_pwritev
interface rather than the sector-based old one.
As preallocation uses the same allocation function as normal writes, and
the interface of that function needs to be changed, it is converted in
the same patch.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This will allow copy on write operations where the overwritten part of
the cluster is not aligned to sector boundaries.
Also rename the function because it has nothing to do with sectors any
more.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reading from qcow2 images is now byte granularity.
Most of the affected code in qcow2 actually gets simpler with this
change. The only exception is encryption, which is fixed on 512 bytes
blocks; in order to keep this working, bs->request_alignment is set for
encrypted images.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This patch changes the units that qcow2_get_cluster_offset() uses
internally, without touching the interface just yet. This will be done
in another patch.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This options allows to flush the image periodically during write tests.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
With this new option, qemu-img bench can be told to advance the current
offset after each request by a different value than the buffer size.
This is useful for controlling the conditions for cluster allocation in
image formats (e.g. qcow2 cluster allocation with COW in front of the
request, or COW areas that aren't overwritten immediately).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This patch adds an option the specify the offset of the first request
made by qemu-img bench. This allows to benchmark misaligned requests.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This extends qemu-img bench with an option that makes it use sequential
writes instead of reads for the test run.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This adds a qemu-img command that allows doing some simple benchmarks
for the block layer without involving guest devices and a real VM.
For the start, this implements only a test of sequential reads.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Drivers that implement .bdrv_co_pwritev() get the flags passed as an
argument to said function, but we also unconditionally emulate the flags
anyway. We shouldn't do that.
Fix this by clearing all flags that the driver supports natively after
it returns from .bdrv_co_pwritev().
Fixes: 4df863f3 ('block: Make supported_write_flags a per-bds property')
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
The code to exit the loop after bdrv_snapshot_delete_by_id_or_name()
returned failure was duplicated. The first copy of it was too early so
that the AioContext lock would not be freed. This patch removes it so
that only the second, correct copy remains.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This creates a new BlockBackend for copying data from an images to the
migration stream on the source host. All I/O for block migration goes
through BlockBackend now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This converts the loading part of block migration to use BlockBackend
interfaces rather than accessing the BlockDriverState directly.
Note that this takes a lazy shortcut. We should really use a separate
BlockBackend that is configured for the migration rather than for the
guest (e.g. writethrough caching is unnecessary) and holds its own
reference to the BlockDriverState, but the impact isn't that big and we
didn't have a separate migration reference before either, so it must be
good enough, I guess...
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
There is a single remaining user in qemu-img, and another one in a test
case, both of which can be trivially converted to using BlockJob.blk
instead.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This changes the commit block job to use the job's BlockBackend for
performing its I/O. job->bs isn't used by the commit code any more
afterwards.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This changes the backup block job to use the job's BlockBackend for
performing its I/O. job->bs isn't used by the backup code any more
afterwards.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Now that we pass the job to the function, bs is implied by that.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
This changes the mirror block job to use the job's BlockBackend for
performing its I/O. job->bs isn't used by the mirroring code any more
afterwards.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
We had to forbid mirroring to a target BDS that already had a BB
attached because the node swapping at job completion would add a second
BB and we didn't support multiple BBs on a single BDS at the time. Now
we do, so we can lift the restriction.
As we allow additional BlockBackends for the target, we must expect
other users to be sending requests. There may no requests be in flight
during the graph modification, so we have to drain those users now.
The core part of this patch is a revert of commit 40365552.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This changes the streaming block job to use the job's BlockBackend for
performing the COR reads. job->bs isn't used by the streaming code any
more afterwards.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This adds a new BlockBackend field to the BlockJob struct, which
coexists with the BlockDriverState while converting the individual jobs.
When creating a block job, a new BlockBackend is created on top of the
given BlockDriverState, and it is destroyed when the BlockJob ends. The
reference to the BDS is now held by the BlockBackend instead of calling
bdrv_ref/unref manually.
We have to be careful when we use bdrv_replace_in_backing_chain() in
block jobs because this changes the BDS that job->blk points to. At the
moment block jobs are too tightly coupled with their BDS, so that moving
a job to another BDS isn't easily possible; therefore, we need to just
manually undo this change afterwards.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The existing users of the function are:
1. blk_new_open(), which already enabled the write cache
2. Some test cases that don't care about the setting
3. blockdev_init() for empty drives, where the cache mode is overridden
with the value from the options when a medium is inserted
Therefore, this patch doesn't change the current behaviour. It will be
convenient, however, for additional users of blk_new() (like block
jobs) if the most sensible WCE setting is the default.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
So far, bdrv_close_all() first removed all root BlockDriverStates of
BlockBackends and monitor owned BDSes, and then assumed that the
remaining BDSes must be related to jobs and cancelled these jobs.
This order doesn't work that well any more when block jobs use
BlockBackends internally because then they will lose their BDS before
being cancelled.
This patch changes bdrv_close_all() to first cancel all jobs and then
remove all root BDSes from the remaining BBs.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
When draining intermediate nodes (i.e. nodes that aren't the root node
for at least one of their parents; with node references, the user can
always configure the graph to create this situation), we need to
propagate the .drained_begin/end callbacks all the way up to the root
for the drain to be effective.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
When changing the BlockDriverState that a BdrvChild points to while the
node is currently drained, we must call the .drained_end() parent
callback. Conversely, when this means attaching a new node that is
already drained, we need to call .drained_begin().
bdrv_root_attach_child() takes now an opaque parameter, which is needed
because the callbacks must also be called if we're attaching a new child
to the BlockBackend when the root node is already drained, and they need
a way to identify the BlockBackend. Previously, child->opaque was set
too late and the callbacks would still see it as NULL.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Until now, bdrv_drained_begin() used bdrv_drain() internally to drain
the queue. This is kind of backwards and caused quiescing code to be
duplicated because bdrv_drained_begin() had to ensure that no new
requests come in even after bdrv_drain() returns, whereas bdrv_drain()
had to have them because it could be called from other places.
Instead move the bdrv_drain() code to bdrv_drained_begin() and make
bdrv_drain() a simple wrapper around bdrv_drained_begin/end().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
This adds a common function that is called when attaching a new child to
a parent, removing a child from a parent and when reconfiguring the
graph so that an existing child points to a different node now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
The bdrv_next() users all leaked the BdrvNextIterator after completing
the iteration. Simply changing bdrv_next() to free the iterator before
returning NULL at the end of list doesn't work because some callers exit
the loop before looking at all BDSes.
This patch moves the BdrvNextIterator from the heap to the stack of
the caller and switches to a bdrv_first()/bdrv_next() interface for
initialising the iterator.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Block patches
# gpg: Signature made Thu May 19 16:58:53 2016 CEST using RSA key ID E838ACAD
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>"
* mreitz/tags/pull-block-for-kevin-2016-05-19:
qemu-iotests: Fix regression in 136 on aio_read invalid
qemu-iotests: Simplify 109 with unaligned qemu-img compare
qemu-io: Fix recent UI updates
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This covers some more write_zeroes cases which are relevant for the
recent qcow2 optimisations that check the allocation status of the
backing file for partial cluster write_zeroes requests.
This needs to be separate from 034 because we can only support qcow2 in
this test case for multiple reasons: We check the allocation status
after write_zeroes with 'qemu-img map' and the optimised behaviour that
produces zero clusters is only implemented in qcow2; second, the map
command returns offsets that are qcow2 specific; and finally, we also
use 512 byte clusters which aren't supported for formats like qed.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
In order to correctly check whether a given cluster is read as zero, we
don't only need to check whether bdrv_get_block_status_above() sets
BDRV_BLOCK_ZERO, but also if all sectors for the whole cluster have the
same status.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
This patch removes the remaining users of bs->blk, which will allow us
to have multiple BBs on top of a single BDS. In the meantime, all checks
that are currently in place to prevent the user from creating such
setups can be switched to bdrv_has_blk() instead of accessing BDS.blk.
Future patches can allow them and e.g. enable users to mirror to a block
device that already has a BlockBackend on it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
query-named-block-nodes should not return information that is related
to the attached BlockBackend rather than the node itself, so throttling
information needs to be removed from it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
We need to introduce a separate BdrvNextIterator struct that can keep
more state than just the current BDS in order to avoid using the bs->blk
pointer.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
In many cases we just want to know whether a BDS has at least one BB
attached, without needing to know the exact BB that is attached. In
contrast to bs->blk, this is still a valid question when more than one
BB can be attached, so just answer it by checking the parents list.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Since virtio-blk implements request merging itself these days, the only
remaining users are test cases for the function. That doesn't make the
function exactly useful any more.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Block jobs don't actually make use of the iostatus for their BDSes, but
they manage a separate block job iostatus. Still, they require that it
is enabled for the source BDS and they enable it automatically for the
target and set the error handling mode - which ends up never being used
by the job.
This patch removes all of the BDS iostatus handling from the block job,
which removes another few bs->blk accesses.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
When block job errors were introduced, we assigned the iostatus of the
target BDS "just in case". The field has never been accessible for the
user because the target isn't listed in query-block.
Before we can allow the user to have a second BlockBackend on the
target, we need to clean this up. If anything, we would want to set the
iostatus for the internal BB of the job (which we can always do later),
but certainly not for a separate BB which the job doesn't even use.
As a nice side effect, this gets us rid of another bs->blk use.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
In order to get rid of bs->blk for bdrv_get_device_name() and
bdrv_get_device_or_node_name(), ask all parents for their name and
simply pick the first one.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
We want to get rid of BlockDriverState.blk in order to allow multiple
BlockBackends per BDS. Converting the device callbacks in block.c (which
assume a single BlockBackend) to per-child callbacks gets us rid of the
first few instances.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Checking whether there are throttled requests requires going to the
associated BlockBackend, which we want to avoid.
All users of bdrv_requests_pending() in block/io.c already call
bdrv_parent_drained_begin() first, which restarts all throttled
requests, so no throttled requests can be left here and this is removal
of dead code.
The remaining users (assertions during graph manipulation in block.c)
don't care about requests that are still queued in the BlockBackend and
haven't been issued for a BlockDriverState yet.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
This reverts commit 76b223200e.
Now that I/O throttling is fully done on the BlockBackend level, there
is no reason any more to block I/O throttling for nodes with multiple
parents as the parents don't influence each other any more.
Conflicts:
block.c
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
This moves the throttling related part of the BDS life cycle management
to BlockBackend. The throttling group reference is now kept even when no
medium is inserted.
With this commit, throttling isn't disabled and then re-enabled any more
during graph reconfiguration. This fixes the temporary breakage of I/O
throttling when used with live snapshots or block jobs that manipulate
the graph.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
So far, bdrv_parent_drained_begin/end() was called for the duration of
the actual bdrv_drain() at the beginning of a drained section, but we
really should keep parents quiesced until the end of the drained
section.
This does not actually change behaviour at this point because the only
user of the .drained_begin/end BdrvChildRole callback is I/O throttling,
which already doesn't send any new requests after flushing its queue in
.drained_begin. The patch merely removes a trap for future users.
Reported-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
This removes the last part of I/O throttling from block/io.c and moves
it to the BlockBackend.
Instead of having knowledge about throttling inside io.c, we can call a
BdrvChild callback .drained_begin/end, which happens to drain the
throttled requests for BlockBackend parents.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
BlockBackends use it to get a back pointer from BdrvChild to
BlockBackend in any BdrvChildRole callbacks.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
This patch changes where the throttling state is stored (used to be the
BlockDriverState, now it is the BlockBackend), but it doesn't actually
make it a BB level feature yet. For example, throttling is still
disabled when the BDS is detached from the BB.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Kevin Wolf