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2016-11-14block-backend: Always notify on blk_ejectJohn Snow
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>
2016-10-28block: introduce BDRV_POLL_WHILEPaolo Bonzini
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>
2016-10-28block: add BDS field to count in-flight requestsPaolo Bonzini
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>
2016-10-27block: Use blk_co_ioctl() for all BB level ioctlsKevin Wolf
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>
2016-10-27block: Use blk_co_pdiscard() for all BB level discardKevin Wolf
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>
2016-10-27block: Use blk_co_flush() for all BB level flushesKevin Wolf
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 flushes. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-07block: Add qdev ID to DEVICE_TRAY_MOVEDKevin Wolf
The event currently only contains the BlockBackend name. However, with anonymous BlockBackends, this is always the empty string. Add the qdev ID (or if none was given, the QOM path) so that the user can still see which device caused the event. Event generation has to be moved from bdrv_eject() to the BlockBackend because the BDS doesn't know the attached device, but that's easy because blk_eject() is the only user of it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-10-07block-backend: Remember if attached device is non-qdevKevin Wolf
Almost all block devices are qdevified by now. This allows us to go back from the BlockBackend to the DeviceState. xen_disk is the last device that is missing. We'll remember in the BlockBackend if a xen_disk is attached and can then disable any features that require going from a BB to the DeviceState. While at it, clearly mark the function used by xen_disk as legacy even in its name, not just in TODO comments. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-10-07block: Add node name to BLOCK_IO_ERROR eventKevin Wolf
The event currently only contains the BlockBackend name. However, with anonymous BlockBackends, this is always the empty string. Add the node name so that the user can still see which block device caused the event. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-10-07block: use aio_bh_schedule_oneshotPaolo Bonzini
This simplifies bottom half handlers by removing calls to qemu_bh_delete and thus removing the need to stash the bottom half pointer in the opaque datum. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-29block: Use 'detect-zeroes' option for 'blockdev-change-medium'Kevin Wolf
Instead of modifying the new BDS after it has been opened, use the newly supported 'detect-zeroes' option in bdrv_open_common() so that all requirements are checked (detect-zeroes=unmap requires discard=unmap). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-09-29block-backend: remove blk_flush_allJohn Snow
We can teach Xen to drain and flush each device as it needs to, instead of trying to flush ALL devices. This removes the last user of blk_flush_all. The function is therefore removed under the premise that any new uses of blk_flush_all would be the wrong paradigm: either flush the single device that requires flushing, or use an appropriate flush_all mechanism from outside of the BlkBackend layer. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-23block: Add blk_by_dev()Kevin Wolf
This finds a BlockBackend given the device model that is attached to it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-09-05block: remove BlockDriver.bdrv_write_compressedPavel Butsykin
There are no block drivers left that implement the old .bdrv_write_compressed interface, so it can be removed. Also now we have no need to use the bdrv_pwrite_compressed function and we can remove it entirely. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block: Convert bdrv_pwrite_compressed() to BdrvChildPavel Butsykin
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Eric Blake <eblake@redhat.com> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block: switch blk_write_compressed() to byte-based interfacePavel Butsykin
This is a preparatory patch, which continues the general trend of the transition to the byte-based interfaces. bdrv_check_request() and blk_check_request() are no longer used, thus we can remove them. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block: Accept node-name for block-streamKevin Wolf
In order to remove the necessity to use BlockBackend names in the external API, we want to allow node-names everywhere. This converts block-stream to accept a node-name without lifting the restriction that we're operating at a root node. In case of an invalid device name, the command returns the GenericError error class now instead of DeviceNotFound, because this is what qmp_get_root_bs() returns. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com>
2016-07-20block: Convert BB interface to byte-based discardsEric Blake
Change sector-based blk_discard(), blk_co_discard(), and blk_aio_discard() to instead be byte-based blk_pdiscard(), blk_co_pdiscard(), and blk_aio_pdiscard(). NBD gets a lot simpler now that ignoring the unaligned portion of a byte-based discard request is handled under the hood by the block layer. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-6-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert bdrv_aio_discard() to byte-basedEric Blake
Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_aio_discard() with a new byte-based bdrv_aio_pdiscard(), which silently ignores any unaligned head or tail. Driver callbacks will be converted in followup patches. Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1468624988-423-5-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert bdrv_discard() to byte-basedEric Blake
Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_discard() with a new byte-based bdrv_pdiscard(), which silently ignores any unaligned head or tail. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-3-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert bdrv_co_discard() to byte-basedEric Blake
Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_co_discard() with a new byte-based bdrv_co_pdiscard(), which silently ignores any unaligned head or tail. Driver callbacks will be converted in followup patches. By calculating the alignment outside of the loop, and clamping the max discard to an aligned value, we can simplify the actions done within the loop. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-2-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-13block/qdev: Allow configuring rerror/werror with qdev propertiesKevin Wolf
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>
2016-07-13coroutine: move entry argument to qemu_coroutine_createPaolo Bonzini
In practice the entry argument is always known at creation time, and it is confusing that sometimes qemu_coroutine_enter is used with a non-NULL argument to re-enter a coroutine (this happens in block/sheepdog.c and tests/test-coroutine.c). So pass the opaque value at creation time, for consistency with e.g. aio_bh_new. Mostly done with the following semantic patch: @ entry1 @ expression entry, arg, co; @@ - co = qemu_coroutine_create(entry); + co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry2 @ expression entry, arg; identifier co; @@ - Coroutine *co = qemu_coroutine_create(entry); + Coroutine *co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry3 @ expression entry, arg; @@ - qemu_coroutine_enter(qemu_coroutine_create(entry), arg); + qemu_coroutine_enter(qemu_coroutine_create(entry, arg)); @ reentry @ expression co; @@ - qemu_coroutine_enter(co, NULL); + qemu_coroutine_enter(co); except for the aforementioned few places where the semantic patch stumbled (as expected) and for test_co_queue, which would otherwise produce an uninitialized variable warning. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Convert bdrv_co_preadv/pwritev to BdrvChildKevin Wolf
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>
2016-07-05block: Convert bdrv_pwrite_zeroes() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Switch transfer length bounds to byte-basedEric Blake
Sector-based limits are awkward to think about; in our on-going quest to move to byte-based interfaces, convert max_transfer_length and opt_transfer_length. Rename them (dropping the _length suffix) so that the compiler will help us catch the change in semantics across any rebased code, and improve the documentation. Use unsigned values, so that we don't have to worry about negative values and so that bit-twiddling is easier; however, we are still constrained by 2^31 of signed int in most APIs. When a value comes from an external source (iscsi and raw-posix), sanitize the results to ensure that opt_transfer is a power of 2. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Give nonzero result to blk_get_max_transfer_length()Eric Blake
Making all callers special-case 0 as unlimited is awkward, and we DO have a hard maximum of BDRV_REQUEST_MAX_SECTORS given our current block layer API limits. In the case of scsi, this means that we now always advertise a limit to the guest, even in cases where the underlying layers previously use 0 for no inherent limit beyond the block layer. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25block: Make blk_co_preadv/pwritev() publicKevin Wolf
Also add trace points now that the function can be directly called. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com>
2016-05-25block: Default to enabled write cache in blk_new()Kevin Wolf
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>
2016-05-25block: Rename blk_write_zeroes()Eric Blake
Commit 983a1600 changed the semantics of blk_write_zeroes() to be byte-based rather than sector-based, but did not change the name, which is an open invitation for other code to misuse the function. Renaming to pwrite_zeroes() makes it more in line with other byte-based interfaces, and will help make it easier to track which remaining write_zeroes interfaces still need conversion. Reported-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-05-25block: Fix reconfiguring graph with drained nodesKevin Wolf
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>
2016-05-25block: Drop errp parameter from blk_new()Max Reitz
blk_new() cannot fail so its Error ** parameter has become superfluous. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25block: Make bdrv_open() return a BDSMax Reitz
There are no callers to bdrv_open() or bdrv_open_inherit() left that pass a pointer to a non-NULL BDS pointer as the first argument of these functions, so we can finally drop that parameter and just make them return the new BDS. Generally, the following pattern is applied: bs = NULL; ret = bdrv_open(&bs, ..., &local_err); if (ret < 0) { error_propagate(errp, local_err); ... } by bs = bdrv_open(..., errp); if (!bs) { ret = -EINVAL; ... } Of course, there are only a few instances where the pattern is really pure. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25block: Drop blk_new_with_bs()Max Reitz
Its only caller is blk_new_open(), so we can just inline it there. The bdrv_new_root() call is dropped in the process because we can just let bdrv_open() create the BDS. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25block: Fix bdrv_next() memory leakKevin Wolf
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>
2016-05-19block: Remove BlockDriverState.blkKevin Wolf
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>
2016-05-19block: Avoid bs->blk in bdrv_next()Kevin Wolf
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>
2016-05-19block: Add bdrv_has_blk()Kevin Wolf
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>
2016-05-19block: Remove bdrv_aio_multiwrite()Kevin Wolf
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>
2016-05-19block: User BdrvChild callback for device nameKevin Wolf
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>
2016-05-19block: Use BdrvChild callbacks for change_media/resizeKevin Wolf
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>
2016-05-19block: Decouple throttling from BlockDriverStateKevin Wolf
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>
2016-05-19block: Drain throttling queue with BdrvChild callbackKevin Wolf
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>
2016-05-19block: Introduce BdrvChild.opaqueKevin Wolf
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>
2016-05-19block: Move I/O throttling configuration functions to BlockBackendKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19block: Move actual I/O throttling to BlockBackendKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19block: Move throttling fields from BDS to BBKevin Wolf
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>
2016-05-19block: Convert throttle_group_get_name() to BlockBackendKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19block: Introduce BlockBackendPublicKevin Wolf
Some features, like I/O throttling, are implemented outside block-backend.c, but still want to keep information in BlockBackend, e.g. list entries that allow keeping a list of BlockBackends. In order to avoid exposing the whole struct layout in the public header file, this patch introduces an embedded public struct where such information can be added and a pair of functions to convert between BlockBackend and BlockBackendPublic. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19block: Make sure throttled BDSes always have a BBKevin Wolf
It was already true in principle that a throttled BDS always has a BB attached, except that the order of operations while attaching or detaching a BDS to/from a BB wasn't careful enough. This commit breaks graph manipulations while I/O throttling is enabled. It would have been possible to keep things working with some temporary hacks, but quite cumbersome, so it's not worth the hassle. We'll fix things again in a minute. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>