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2016-05-25blockjob: Remove BlockJob.bsKevin Wolf
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>
2016-05-25backup: Use BlockBackend for I/OKevin Wolf
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>
2016-05-25stream: Use BlockBackend for I/OKevin Wolf
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>
2016-05-25block: Convert block job core to BlockBackendKevin Wolf
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>
2016-05-25block: Cancel jobs first in bdrv_close_all()Kevin Wolf
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>
2016-05-25block: keep a list of block jobsAlberto Garcia
The current way to obtain the list of existing block jobs is to iterate over all root nodes and check which ones own a job. Since we want to be able to support block jobs in other nodes as well, this patch keeps a list of jobs that is updated every time one is created or destroyed. Signed-off-by: Alberto Garcia <berto@igalia.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: 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 bdrv_new_root()Max Reitz
It is unused now, so we may just as well drop it. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@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: 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>
2016-05-19blockjob: Don't set iostatus of targetKevin Wolf
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>
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: throttle-groups: Use BlockBackend pointers internallyKevin Wolf
As a first step towards moving I/O throttling to the BlockBackend level, this patch changes all pointers in struct ThrottleGroup from referencing a BlockDriverState to referencing a BlockBackend. This change is valid because we made sure that throttling can only be enabled on BDSes which have a BB attached. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-12quorum: implement bdrv_add_child() and bdrv_del_child()Wen Congyang
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com> Signed-off-by: Gonglei <arei.gonglei@huawei.com> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com> Message-id: 1462865799-19402-3-git-send-email-xiecl.fnst@cn.fujitsu.com Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12Add new block driver interface to add/delete a BDS's childWen Congyang
In some cases, we want to take a quorum child offline, and take another child online. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com> Signed-off-by: Gonglei <arei.gonglei@huawei.com> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 1462865799-19402-2-git-send-email-xiecl.fnst@cn.fujitsu.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12block: Honor BDRV_REQ_FUA during write_zeroesEric Blake
The block layer has a couple of cases where it can lose Force Unit Access semantics when writing a large block of zeroes, such that the request returns before the zeroes have been guaranteed to land on underlying media. SCSI does not support FUA during WRITESAME(10/16); FUA is only supported if it falls back to WRITE(10/16). But where the underlying device is new enough to not need a fallback, it means that any upper layer request with FUA semantics was silently ignoring BDRV_REQ_FUA. Conversely, NBD has situations where it can support FUA but not ZERO_WRITE; when that happens, the generic block layer fallback to bdrv_driver_pwritev() (or the older bdrv_co_writev() in qemu 2.6) was losing the FUA flag. The problem of losing flags unrelated to ZERO_WRITE has been latent in bdrv_co_do_write_zeroes() since commit aa7bfbff, but back then, it did not matter because there was no FUA flag. It became observable when commit 93f5e6d8 paved the way for flags that can impact correctness, when we should have been using bdrv_co_writev_flags() with modified flags. Compare to commit 9eeb6dd, which got flag manipulation right in bdrv_co_do_zero_pwritev(). Symptoms: I tested with qemu-io with default writethrough cache (which is supposed to use FUA semantics on every write), and targetted an NBD client connected to a server that intentionally did not advertise NBD_FLAG_SEND_FUA. When doing 'write 0 512', the NBD client sent two operations (NBD_CMD_WRITE then NBD_CMD_FLUSH) to get the fallback FUA semantics; but when doing 'write -z 0 512', the NBD client sent only NBD_CMD_WRITE. The fix is do to a cleanup bdrv_co_flush() at the end of the operation if any step in the middle relied on a BDS that does not natively support FUA for that step (note that we don't need to flush after every operation, if the operation is broken into chunks based on bounce-buffer sizing). Each BDS gains a new flag .supported_zero_flags, which parallels the use of .supported_write_flags but only when accessing a zero write operation (the flags MUST be different, because of SCSI having different semantics based on WRITE vs. WRITESAME; and also because BDRV_REQ_MAY_UNMAP only makes sense on zero writes). Also fix some documentation to describe -ENOTSUP semantics, particularly since iscsi depends on those semantics. Down the road, we may want to add a driver where its .bdrv_co_pwritev() honors all three of BDRV_REQ_FUA, BDRV_REQ_ZERO_WRITE, and BDRV_REQ_MAY_UNMAP, and advertise this via bs->supported_write_flags for blocks opened by that driver; such a driver should NOT supply .bdrv_co_write_zeroes nor .supported_zero_flags. But none of the drivers touched in this patch want to do that (the act of writing zeroes is different enough from normal writes to deserve a second callback). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: Make supported_write_flags a per-bds propertyEric Blake
Pre-patch, .supported_write_flags lives at the driver level, which means we are blindly declaring that all block devices using a given driver will either equally support FUA, or that we need a fallback at the block layer. But there are drivers where FUA support is a per-block decision: the NBD block driver is dependent on the remote server advertising NBD_FLAG_SEND_FUA (and has fallback code to duplicate the flush that the block layer would do if NBD had not set .supported_write_flags); and the iscsi block driver is dependent on the mode sense bits advertised by the underlying device (and is currently silently ignoring FUA requests if the underlying device does not support FUA). The fix is to make supported flags as a per-BDS option, set during .bdrv_open(). This patch moves the variable and fixes NBD and iscsi to set it only conditionally; later patches will then further simplify the NBD driver to quit duplicating work done at the block layer, as well as tackle the fact that SCSI does not support FUA semantics on WRITESAME(10/16) but only on WRITE(10/16). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12Allow users to specify the vmdk virtual hardware version.Janne Karhunen
Vmdk images have metadata to indicate the vmware virtual hardware version image was created/tested to run with. Allow users to specify that version via new 'hwversion' option. [ kwolf: Adjust qemu-iotests common.filter ] Signed-off-by: Janne Karhunen <Janne.Karhunen@gmail.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: Remove BlockDriver.bdrv_read/writeKevin Wolf
There are no block drivers left that implement the old .bdrv_read/write interface, so it can be removed now. This gets us rid of the corresponding emulation functions, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
2016-05-12block: Introduce .bdrv_co_preadv/pwritev BlockDriver functionKevin Wolf
Many parts of the block layer are already byte granularity. The block driver interface, however, was still missing an interface that allows making use of this. This patch introduces a new BlockDriver interface, which is based on coroutines, vectored, has flags and uses a byte granularity. This is now the preferred interface for new drivers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
2016-05-12block: Rename bdrv_co_do_preadv/writev to bdrv_co_preadv/writevKevin Wolf
It used to be an internal helper function just for implementing bdrv_co_do_readv/writev(), but now that it's a public interface, it deserves a name without "do" in it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
2016-05-12block: plug whole tree at once, introduce bdrv_io_unplugged_begin/endPaolo Bonzini
Extract the handling of io_plug "depth" from linux-aio.c and let the main bdrv_drain loop do nothing but wait on I/O. Like the two newly introduced functions, bdrv_io_plug and bdrv_io_unplug now operate on all children. The visit order is now symmetrical between plug and unplug, making it possible for formats to implement plug/unplug. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: introduce bdrv_no_throttling_begin/endPaolo Bonzini
Extract the handling of throttling from bdrv_flush_io_queue. These new functions will soon become BdrvChildRole callbacks, as they can be generalized to "beginning of drain" and "end of drain". Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: move restarting of throttled reqs to block/throttle-groups.cPaolo Bonzini
We want to remove throttled_reqs from block/io.c. This is the easy part---hide the handling of throttled_reqs during disable/enable of throttling within throttle-groups.c. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-04-11block: Fix bdrv_drain in coroutineFam Zheng
Using the nested aio_poll() in coroutine is a bad idea. This patch replaces the aio_poll loop in bdrv_drain with a BH, if called in coroutine. For example, the bdrv_drain() in mirror.c can hang when a guest issued request is pending on it in qemu_co_mutex_lock(). Mirror coroutine in this case has just finished a request, and the block job is about to complete. It calls bdrv_drain() which waits for the other coroutine to complete. The other coroutine is a scsi-disk request. The deadlock happens when the latter is in turn pending on the former to yield/terminate, in qemu_co_mutex_lock(). The state flow is as below (assuming a qcow2 image): mirror coroutine scsi-disk coroutine ------------------------------------------------------------- do last write qcow2:qemu_co_mutex_lock() ... scsi disk read tracked request begin qcow2:qemu_co_mutex_lock.enter qcow2:qemu_co_mutex_unlock() bdrv_drain while (has tracked request) aio_poll() In the scsi-disk coroutine, the qemu_co_mutex_lock() will never return because the mirror coroutine is blocked in the aio_poll(blocking=true). With this patch, the added qemu_coroutine_yield() allows the scsi-disk coroutine to make progress as expected: mirror coroutine scsi-disk coroutine ------------------------------------------------------------- do last write qcow2:qemu_co_mutex_lock() ... scsi disk read tracked request begin qcow2:qemu_co_mutex_lock.enter qcow2:qemu_co_mutex_unlock() bdrv_drain.enter > schedule BH > qemu_coroutine_yield() > qcow2:qemu_co_mutex_lock.return > ... tracked request end ... (resumed from BH callback) bdrv_drain.return ... Reported-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Message-id: 1459855253-5378-2-git-send-email-famz@redhat.com Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-03-30block: Remove bdrv_(set_)enable_write_cache()Kevin Wolf
The only remaining users were block jobs (mirror and backup) which unconditionally enabled WCE on the BlockBackend of the target image. As these block jobs don't go through BlockBackend for their I/O requests, they aren't affected by this setting anyway but always get a writeback mode, so that call can be removed. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30block: Remove BDRV_O_CACHE_WBKevin Wolf
The previous patches have successively made blk->enable_write_cache the true source for the information whether a writethrough mode must be implemented. The corresponding BDRV_O_CACHE_WB is only useless baggage we're carrying around, so now's the time to remove it. At the same time, we remove the 'cache.writeback' option parsing on the BDS level as the only effect was setting the BDRV_O_CACHE_WB flag. This change requires test cases that explicitly enabled the option to drop it. Other than that and the change of the error message when writethrough is enabled on the BDS level (from "Can't set writethrough mode" to "doesn't support the option"), there should be no change in behaviour. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30block: Remove bdrv_parse_cache_flags()Kevin Wolf
All users are converted to bdrv_parse_cache_mode() now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30block: Introduce bdrv_co_writev_flags()Kevin Wolf
This function will allow drivers to implement BDRV_REQ_FUA natively instead of sending a separate flush after the write. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30block/qapi: Use blk_enable_write_cache()Kevin Wolf
Now that WCE is handled on the BlockBackend level, the flag is meaningless for BDSes. As the schema requires us to fill the field, we return an enabled write cache for them. Note that this means that querying the BlockBackend name may return writethrough as the cache information, whereas querying the node-name of the root of that same BlockBackend will return writeback. This may appear odd at first, but it actually makes sense because it correctly repesents the layer that implements the WCE handling. This becomes more apparent when you consider nodes that are the root node of multiple BlockBackends, where each BB can have its own WCE setting. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30block: Move enable_write_cache to BB levelKevin Wolf
Whether a write cache is used or not is a decision that concerns the user (e.g. the guest device) rather than the backend. It was already logically part of the BB level as bdrv_move_feature_fields() always kept it on top of the BDS tree; with this patch, the core of it (the actual flag and the additional flushes) is also implemented there. Direct callers of bdrv_open() must pass BDRV_O_CACHE_WB now if bs doesn't have a BlockBackend attached. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30block: Add bdrv_parse_cache_mode()Kevin Wolf
It's like bdrv_parse_cache_flags(), except that writethrough mode isn't included in the flags, but returned as a separate bool. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30block: add flush callbackPavel Dovgalyuk
This patch adds callback for flush request. This callback is responsible for flushing whole block devices stack. bdrv_flush function does not proceed to underlying devices. It should be performed by this callback function, if needed. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-30block: move encryption deprecation warning into qcow codeDaniel P. Berrange
For a couple of releases we have been warning Encrypted images are deprecated Support for them will be removed in a future release. You can use 'qemu-img convert' to convert your image to an unencrypted one. This warning was issued by system emulators, qemu-img, qemu-nbd and qemu-io. Such a broad warning was issued because the original intention was to rip out all the code for dealing with encryption inside the QEMU block layer APIs. The new block encryption framework used for the LUKS driver does not rely on the unloved block layer API for encryption keys, instead using the QOM 'secret' object type. It is thus no longer appropriate to warn about encryption unconditionally. When the qcow/qcow2 drivers are converted to use the new encryption framework too, it will be practical to keep AES-CBC support present for use in qemu-img, qemu-io & qemu-nbd to allow for interoperability with older QEMU versions and liberation of data from existing encrypted qcow2 files. This change moves the warning out of the generic block code and into the qcow/qcow2 drivers. Further, the warning is set to only appear when running the system emulators, since qemu-img, qemu-io, qemu-nbd are expected to support qcow2 encryption long term now that the maint burden has been eliminated. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-30block: add flag to indicate that no I/O will be performedDaniel P. Berrange
When opening an image it is useful to know whether the caller intends to perform I/O on the image or not. In the case of encrypted images this will allow the block driver to avoid having to prompt for decryption keys when we merely want to query header metadata about the image. eg qemu-img info This flag is enforced at the top level only, since even if we don't want todo I/O on the 'qcow2' file payload, the underlying 'file' driver will still need todo I/O to read the qcow2 header, for example. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-30block: Remove blk_set_bs()Kevin Wolf
The function is unused since commit f21d96d0 ('block: Use BdrvChild in BlockBackend'). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-03-30block: Remove bdrv_make_anon()Kevin Wolf
The call in hmp_drive_del() is dead code because blk_remove_bs() is called a few lines above. The only other remaining user is bdrv_delete(), which only abuses bdrv_make_anon() to remove it from the named nodes list. This path inlines the list entry removal into bdrv_delete() and removes bdrv_make_anon(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-22include/qemu/iov.h: Don't include qemu-common.hMarkus Armbruster
qemu-common.h should only be included by .c files. Its file comment explains why: "No header file should depend on qemu-common.h, as this would easily lead to circular header dependencies." qemu/iov.h includes qemu-common.h for QEMUIOVector stuff. Move all that to qemu/iov.h and drop the ill-advised include. Include qemu/iov.h where the QEMUIOVector stuff is now missing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22Use scripts/clean-includes to drop redundant qemu/typedefs.hMarkus Armbruster
Re-run scripts/clean-includes to apply the previous commit's corrections and updates. Besides redundant qemu/typedefs.h, this only finds a redundant config-host.h include in ui/egl-helpers.c. No idea how that escaped the previous runs. Some manual whitespace trimming around dropped includes squashed in. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>