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>
Now that blk_insert_bs() requests the BlockBackend permissions for the
node it attaches to, it can fail. Instead of aborting, pass the errors
to the callers.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
We want every user to be specific about the permissions it needs, so
we'll pass the initial permissions as parameters to blk_new(). A user
only needs to call blk_set_perm() if it wants to change the permissions
after the fact.
The permissions are stored in the BlockBackend and applied whenever a
BlockDriverState should be attached in blk_insert_bs().
This does not include actually choosing the right set of permissions
everywhere yet. Instead, the usual FIXME comment is added to each place
and will be addressed in individual patches.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
The BlockBackend can now store the permissions that its user requires.
This is necessary because nodes can be ejected from or inserted into a
BlockBackend and all of these operations must make sure that the user
still gets what it requested initially.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
This function removes the BlockDriverState associated with the given
BlockBackend from that BB and sets the BDS pointer in the BB to NULL.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
