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path: root/include/sysemu/block-backend.h
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2017-02-28hmp: Request permissions in qemu-ioKevin Wolf
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>
2017-02-28block: Allow error return in BlockDevOps.change_media_cb()Kevin Wolf
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>
2017-02-28block: Add error parameter to blk_insert_bs()Kevin Wolf
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>
2017-02-28block: Add permissions to blk_new()Kevin Wolf
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>
2017-02-28block: Add permissions to BlockBackendKevin Wolf
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>
2017-02-21block: document fields protected by AioContext lockPaolo Bonzini
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: 20170213135235.12274-19-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@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>
2016-10-07block-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>
2016-09-29block: 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>
2016-09-23qdev-monitor: Add blk_by_qdev_id()Kevin Wolf
This finds the BlockBackend attached to the device model identified by its qdev ID. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@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: 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>
2016-07-05block: 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>
2016-05-25block: 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: 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: 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: 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>
2016-05-19block: 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: 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 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: 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>
2016-05-19block: 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>
2016-05-12block: Kill unused sector-based blk_* functionsEric Blake
Now that there are no remaining clients, we can drop the sector-based blk_read(), blk_write(), blk_aio_readv(), and blk_aio_writev(). Sadly, there are still remaining sector-based interfaces, such as blk_*discard(), or blk_write_compressed(); those will have to wait for another day. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: Introduce byte-based aio read/writeEric Blake
blk_aio_readv() and blk_aio_writev() are annoying in that they can't access sub-sector granularity, and cannot pass flags. Also, they require the caller to pass redundant information about the size of the I/O (qiov->size in bytes must match nb_sectors in sectors). Add new blk_aio_preadv() and blk_aio_pwritev() functions to fix the flaws. The next few patches will upgrade callers, then finally delete the old interfaces. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: Switch blk_*write_zeroes() to byte interfaceEric Blake
Sector-based blk_write() should die; convert the one-off variant blk_write_zeroes() to use an offset/count interface instead. Likewise for blk_co_write_zeroes() and blk_aio_write_zeroes(). Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: Switch blk_read_unthrottled() to byte interfaceEric Blake
Sector-based blk_read() should die; convert the one-off variant blk_read_unthrottled(). Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: Allow BDRV_REQ_FUA through blk_pwrite()Eric Blake
We have several block drivers that understand BDRV_REQ_FUA, and emulate it in the block layer for the rest by a full flush. But without a way to actually request BDRV_REQ_FUA during a pass-through blk_pwrite(), FUA-aware block drivers like NBD are forced to repeat the emulation logic of a full flush regardless of whether the backend they are writing to could do it more efficiently. This patch just wires up a flags argument; followup patches will actually make use of it in the NBD driver and in qemu-io. Signed-off-by: Eric Blake <eblake@redhat.com> Acked-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Kevin Wolf <kwolf@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>
2016-03-17block: Add blk_next_root_bs()Max Reitz
This function iterates over all BDSs attached to a BB. We are going to need it when rewriting bdrv_next() so it no longer uses bdrv_states. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17blockdev: Remove blk_hide_on_behalf_of_hmp_drive_del()Max Reitz
We can basically inline it in hmp_drive_del(); monitor_remove_blk() is called already, so we just need to call bdrv_make_anon(), too. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17blockdev: Split monitor reference from BB creationMax Reitz
Before this patch, blk_new() automatically assigned a name to the new BlockBackend and considered it referenced by the monitor. This patch removes the implicit monitor_add_blk() call from blk_new() (and consequently the monitor_remove_blk() call from blk_delete(), too) and thus blk_new() (and related functions) no longer take a BB name argument. In fact, there is only a single point where blk_new()/blk_new_open() is called and the new BB is monitor-owned, and that is in blockdev_init(). Besides thus relieving us from having to invent names for all of the BBs we use in qemu-img, this fixes a bug where qemu cannot create a new image if there already is a monitor-owned BB named "image". If a BB and its BDS tree are created in a single operation, as of this patch the BDS tree will be created before the BB is given a name (whereas it was the other way around before). This results in minor change to the output of iotest 087, whose reference output is amended accordingly. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17blockdev: Separate BB name managementMax Reitz
Introduce separate functions (monitor_add_blk() and monitor_remove_blk()) which set or unset a BB name. Since the name is equivalent to the monitor's reference to a BB, adding a name the same as declaring the BB to be monitor-owned and removing it revokes this status, hence the function names. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17block: Add blk_commit_all()Max Reitz
Later, we will remove bdrv_commit_all() and move its contents here, and in order to replace bdrv_commit_all() calls by calls to blk_commit_all() before doing so, we need to add it as an alias now. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-14block: Introduce blk_set_allow_write_beyond_eof()Kevin Wolf
We check that the guest can't write beyond the end of its disk, but for other internal users it can make sense to allow growing a file. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-02-23include: Clean up includesPeter Maydell
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. NB: If this commit breaks compilation for your out-of-tree patchseries or fork, then you need to make sure you add #include "qemu/osdep.h" to any new .c files that you have. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-02-02block: Add blk_remove_all_bs()Max Reitz
When bdrv_close_all() is called, instead of force-closing all root BlockDriverStates, it is better to just drop the reference from all BlockBackends and let them be closed automatically. This prevents BDS from getting closed that are still referenced by other BDS, which may result in loss of cached data. This patch adds a function for doing that, but does not yet incorporate it in bdrv_close_all(). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-02-02block: Remove BDS close notifierMax Reitz
It is unused now, so we can remove it. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-02-02block: Add BB-BDS remove/insert notifiersMax Reitz
bdrv_close() no longer signifies ejection of a medium, this is now done by removing the BDS from the BB. Therefore, we want to have a notifier for that in the BB instead of a close notifier in the BDS. The former is added now, the latter is removed later. Symmetrically, another notifier list is added that is invoked whenever a BDS is inserted. We will need that for virtio-blk and virtio-scsi, which can then remove their op blockers on BDS ejection and set them up on insertion. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-01-15nbd-server: do not exit on failed memory allocationPaolo Bonzini
The amount of memory allocated in nbd_co_receive_request is driven by the NBD client (possibly a virtual machine). Parallel I/O can cause the server to allocate a large amount of memory; check for failures and return ENOMEM in that case. Cc: qemu-block@nongnu.org Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-22block-backend: add blk_get_max_iov()Stefan Hajnoczi
Add a function to query BlockLimits.max_iov. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-11-17block: add blk_abort_aio_requestPeter Lieven
Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 1447345846-15624-3-git-send-email-pl@kamp.de Signed-off-by: John Snow <jsnow@redhat.com>
2015-11-11block: Add blk_get_refcnt()Alberto Garcia
This function returns the reference count of a given BlockBackend. For convenience, it returns 0 if the BlockBackend pointer is NULL. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: dfdd8a17dbe3288842840636d2cfe5bb895abcb0.1446475331.git.berto@igalia.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-11-11block: Add functions for inheriting a BBRSMax Reitz
In order to open a BDS which inherits a BB's root state, blk_get_open_flags_from_root_state() is used to inquire the flags to be passed to bdrv_open(), and blk_apply_root_state() is used to apply the remaining state after the BDS has been opened. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>