As part of the required changes, this fixes a bug where specifying an
invalid driver would result in the block layer probing the image format;
now it will result in an error, unless "<unset>" is specified as the
driver name. Fixing this would require further work on the xen_disk code
which does not seem worth it (at this point and for this patch).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1423162705-32065-7-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This patch fixes two issues with persistent grants and the disk PV backend
(Qdisk):
- Keep track of memory regions where persistent grants have been mapped
since we need to unmap them as a whole. It is not possible to unmap a
single grant if it has been batch-mapped. A new check has also been added
to make sure persistent grants are only used if the whole mapped region
can be persistently mapped in the batch_maps case.
- Unmap persistent grants before switching to the closed state, so the
frontend can also free them.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-by: George Dunlap <george.dunlap@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: George Dunlap <george.dunlap@eu.citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Device models should access their block backends only through the
block-backend.h API. Convert them, and drop direct includes of
inappropriate headers.
Just four uses of BlockDriverState are left:
* The Xen paravirtual block device backend (xen_disk.c) opens images
itself when set up via xenbus, bypassing blockdev.c. I figure it
should go through qmp_blockdev_add() instead.
* Device model "usb-storage" prompts for keys. No other device model
does, and this one probably shouldn't do it, either.
* ide_issue_trim_cb() uses bdrv_aio_discard() instead of
blk_aio_discard() because it fishes its backend out of a BlockAIOCB,
which has only the BlockDriverState.
* PC87312State has an unused BlockDriverState[] member.
The next two commits take care of the latter two.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The patch is big, but all it really does is replacing
dinfo->bdrv
by
blk_bs(blk_by_legacy_dinfo(dinfo))
The replacement is repetitive, but the conversion of device models to
BlockBackend is imminent, and will shorten it to just
blk_legacy_dinfo(dinfo).
Line wrapping muddies the waters a bit. I also omit tests whether
dinfo->bdrv is null, because it never is.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
On BlockBackend destruction, unref its BlockDriverState. Replaces the
callers' unrefs.
This turns the pointer from BlockBackend to BlockDriverState into a
strong reference, managed with bdrv_ref() / bdrv_unref(). The
back-pointer remains weak.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Convenience function blk_new_with_bs() creates a BlockBackend with its
BlockDriverState. Callers have to unref both. The commit after next
will relieve them of the need to unref the BlockDriverState.
Complication: due to the silly way drive_del works, we need a way to
hide a BlockBackend, just like bdrv_make_anon(). To emphasize its
"special" status, give the function a suitably off-putting name:
blk_hide_on_behalf_of_do_drive_del(). Unfortunately, hiding turns the
BlockBackend's name into the empty string. Can't avoid that without
breaking the blk->bs->device_name equals blk->name invariant.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
A block device consists of a frontend device model and a backend.
A block backend has a tree of block drivers doing the actual work.
The tree is managed by the block layer.
We currently use a single abstraction BlockDriverState both for tree
nodes and the backend as a whole. Drawbacks:
* Its API includes both stuff that makes sense only at the block
backend level (root of the tree) and stuff that's only for use
within the block layer. This makes the API bigger and more complex
than necessary. Moreover, it's not obvious which interfaces are
meant for device models, and which really aren't.
* Since device models keep a reference to their backend, the backend
object can't just be destroyed. But for media change, we need to
replace the tree. Our solution is to make the BlockDriverState
generic, with actual driver state in a separate object, pointed to
by member opaque. That lets us replace the tree by deinitializing
and reinitializing its root. This special need of the root makes
the data structure awkward everywhere in the tree.
The general plan is to separate the APIs into "block backend", for use
by device models, monitor and whatever other code dealing with block
backends, and "block driver", for use by the block layer and whatever
other code (if any) dealing with trees and tree nodes.
Code dealing with block backends, device models in particular, should
become completely oblivious of BlockDriverState. This should let us
clean up both APIs, and the tree data structures.
This commit is a first step. It creates a minimal "block backend"
API: type BlockBackend and functions to create, destroy and find them.
BlockBackend objects are created and destroyed exactly when root
BlockDriverState objects are created and destroyed. "Root" in the
sense of "in bdrv_states". They're not yet used for anything; that'll
come shortly.
A root BlockDriverState is created with bdrv_new_root(), so where to
create a BlockBackend is obvious. Where these roots get destroyed
isn't always as obvious.
It is obvious in qemu-img.c, qemu-io.c and qemu-nbd.c, and in error
paths of blockdev_init(), blk_connect(). That leaves destruction of
objects successfully created by blockdev_init() and blk_connect().
blockdev_init() is used only by drive_new() and qmp_blockdev_add().
Objects created by the latter are currently indestructible (see commit
48f364d "blockdev: Refuse to drive_del something added with
blockdev-add" and commit 2d246f0 "blockdev: Introduce
DriveInfo.enable_auto_del"). Objects created by the former get
destroyed by drive_del().
Objects created by blk_connect() get destroyed by blk_disconnect().
BlockBackend is reference-counted. Its reference count never exceeds
one so far, but that's going to change.
In drive_del(), the BB's reference count is surely one now. The BDS's
reference count is greater than one when something else is holding a
reference, such as a block job. In this case, the BB is destroyed
right away, but the BDS lives on until all extra references get
dropped.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Creating an anonymous BDS can't fail. Make that obvious.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is the next step for decoupling block accounting functions from
BlockDriverState.
In a future commit the BlockAcctStats structure will be moved from
BlockDriverState to the device models structures.
Note that bdrv_get_stats was introduced so device models can retrieve the
BlockAcctStats structure of a BlockDriverState without being aware of it's
layout.
This function should go away when BlockAcctStats will be embedded in the device
models structures.
CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Keith Busch <keith.busch@intel.com>
CC: Anthony Liguori <aliguori@amazon.com>
CC: "Michael S. Tsirkin" <mst@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: Peter Maydell <peter.maydell@linaro.org>
CC: Michael Tokarev <mjt@tls.msk.ru>
CC: John Snow <jsnow@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Alexander Graf <agraf@suse.de>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: Benoît Canet <benoit.canet@nodalink.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The middle term goal is to move the BlockAcctStats structure in the device models.
(Capturing I/O accounting statistics in the device models is good for billing)
This patch make a small step in this direction by removing a reference to BDRV.
CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Keith Busch <keith.busch@intel.com>
CC: Anthony Liguori <aliguori@amazon.com>
CC: "Michael S. Tsirkin" <mst@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: John Snow <jsnow@redhat.com>
CC: Richard Henderson <rth@twiddle.net>
CC: Markus Armbruster <armbru@redhat.com>
CC: Alexander Graf <agraf@suse.de>i
Signed-off-by: Benoît Canet <benoit.canet@nodalink.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The Error object was leaked after failed bdrv_new(). While there,
streamline control flow a bit.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Implement discard support for xen_disk. It makes use of the existing
discard code in qemu.
The discard support is enabled unconditionally. The tool stack may
provide a property "discard-enable" in the backend node to optionally
disable discard support. This is helpful in case the backing file was
intentionally created non-sparse to avoid fragmentation.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
This patch adds an errp parameter to bdrv_new() and updates all its
callers. The next patches will make use of this in order to check for
duplicate IDs. Most of the callers know that their ID is fine, so they
can simply assert that there is no error.
Behaviour doesn't change with this patch yet as bdrv_new() doesn't
actually assign errors to errp.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQIcBAABAgAGBQJTB8hAAAoJEH8JsnLIjy/WQdgP/jEu5baA1/qKanDsS9l+81u1
/sIYSWpHDEJ0uavqTMBeyMOwkzel7SZRusIwA/d5pMqxbY6/86YJumTTozFWvtqc
IABqHtRKCxjcLdZRPbkuNAOiw6p76vSZa543o2t8OAhK2DIFy530wWXeoQEYvuJX
4pOh0lTradOrF1z6uW4ozgQ1efPppwh/iqwfWWNJVTgfnWxJk6qQaATEgkuSdsUN
Wp78UzOxLGO6JKJB6kP3LfNL0ANTYHpfH2/wkE6cW6TkSUduOm6hIBY+tb9khqYt
INOKxqFADK6EOgjvJBsZuZUtOnHK5oM921LepN/mOPAs6gKcn2j+FfqJrl3I1/5M
AXM3M0FPuijEKPGWw7pCLt7j84KJkD9a/rsKO37yRzw17fOma2Rpr4TrX43BF+5t
CGqQ7PzDJ6Fng4EXjyNDzviwXIK8xmG1tfn92tq/BUd6OuM9MCyzEGvEiGOMBoXv
w4iOV7UC+1P3TjnTBhMlBVGywSfdOJoHr9k4lXGNp0h8fPhM9rfruI3BFysxaas6
GmKbd7yvKwXOTptd3I9SB8BzVUL3CcD3FK24+cWKAl8GgyiDIWRlvBYyMp3p8Z8f
NDzcxYP6aRGsoddvpIWr3Tz89hw5wTW5u3RmNgxJUguz6HYKFbl30dpGT+96q2BN
YIAANTdPxn7BP6r3glQH
=ZaDG
-----END PGP SIGNATURE-----
Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
Block patches
# gpg: Signature made Fri 21 Feb 2014 21:42:24 GMT using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
* remotes/kevin/tags/for-upstream: (54 commits)
iotests: Mixed quorum child device specifications
quorum: Simplify quorum_open()
quorum: Add unit test.
quorum: Add quorum_open() and quorum_close().
quorum: Implement recursive .bdrv_recurse_is_first_non_filter in quorum.
quorum: Add quorum_co_flush().
quorum: Add quorum_invalidate_cache().
quorum: Add quorum_getlength().
quorum: Add quorum mechanism.
quorum: Add quorum_aio_readv.
blkverify: Extract qemu_iovec_clone() and qemu_iovec_compare() from blkverify.
quorum: Add quorum_aio_writev and its dependencies.
quorum: Create BDRVQuorumState and BlkDriver and do init.
quorum: Create quorum.c, add QuorumChildRequest and QuorumAIOCB.
check-qdict: Test termination of qdict_array_split()
check-qdict: Adjust test for qdict_array_split()
qdict: Extract non-QDicts in qdict_array_split()
qemu-config: Sections must consist of keys
qemu-iotests: Check qemu-img command line parsing
qemu-img: Allow -o help with incomplete argument list
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Allow bdrv_open() to handle references to existing block devices just as
bdrv_file_open() is already capable of.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Make bdrv_open() take a pointer to a BDS pointer, similarly to
bdrv_file_open(). If a pointer to a NULL pointer is given, bdrv_open()
will create a new BDS with an empty name; if the BDS pointer is not
NULL, that existing BDS will be reused (in the same way as bdrv_open()
already did).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_acct_done was called unconditional. But in case the ioreq has no
segments there is no matching bdrv_acct_start call. This could lead to
bogus accounting values.
Found by code inspection.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
IF_NONE allows read-only, which makes forbidding it in this place
for other types pretty much pointless.
Instead, make sure that all devices for which the check would have
errored out check in their init function that they don't get a read-only
BlockDriverState. This catches even cases where IF_NONE and -device is
used.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Commit 4472beae modified the semantics of ioreq_{un,}map so that they are
idempotent if called when they're not needed (ie., twice in a row). However,
it neglected to handle the case where batch mapping is not being used (the
default), and one of the grants fails to map. In this case, ioreq_unmap will
be called to unwind and unmap any mappings already performed, but ioreq_unmap
simply returns due to the aforementioned change (the ioreq has not already
been marked as mapped).
The frontend user can therefore force xen_disk to leak grant mappings, a
per-domain limited resource.
Fix by marking the ioreq as mapped before calling ioreq_unmap in this
situation.
Signed-off-by: Matthew Daley <mattjd@gmail.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Add an Error ** parameter to bdrv_open, bdrv_file_open and associated
functions to allow more specific error messages.
Signed-off-by: Max Reitz <mreitz@redhat.com>
We call bdrv_attach_dev when initializing whether or not bs is created
locally, so call bdrv_detach_dev and let the refcnt handle the
lifecycle.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Manage BlockDriverState lifecycle with refcnt, so bdrv_delete() is no
longer public and should be called by bdrv_unref() if refcnt is
decreased to 0.
This is an identical change because effectively, there's no multiple
reference of BDS now: no caller of bdrv_ref() yet, only bdrv_new() sets
bs->refcnt to 1, so all bdrv_unref() now actually delete the BDS.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Support backend option "direct-io-safe". This is documented as
follows in the Xen backend specification:
* direct-io-safe
* Values: 0/1 (boolean)
* Default Value: 0
*
* The underlying storage is not affected by the direct IO memory
* lifetime bug. See:
* http://lists.xen.org/archives/html/xen-devel/2012-12/msg01154.html
*
* Therefore this option gives the backend permission to use
* O_DIRECT, notwithstanding that bug.
*
* That is, if this option is enabled, use of O_DIRECT is safe,
* in circumstances where we would normally have avoided it as a
* workaround for that bug. This option is not relevant for all
* backends, and even not necessarily supported for those for
* which it is relevant. A backend which knows that it is not
* affected by the bug can ignore this option.
*
* This option doesn't require a backend to use O_DIRECT, so it
* should not be used to try to control the caching behaviour.
Also, BDRV_O_NATIVE_AIO is ignored if BDRV_O_NOCACHE, so clarify the
default flags passed to the qemu block layer.
The original proposal for a "cache" backend option has been dropped
because it was believed too wide, especially considering that at the
moment the backend doesn't have a way to tell the toolstack that it is
capable of supporting it.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
We may want to include a driver in the whitelist for read only tasks
such as diagnosing or exporting guest data (with libguestfs as a good
example). This patch introduces a readonly whitelist option, and for
backward compatibility, the old configure option --block-drv-whitelist
is now an alias to rw whitelist.
Drivers in readonly list is only permitted to open file readonly, and
returns -ENOTSUP for RW opening.
E.g. To include vmdk readonly, and others read+write:
./configure --target-list=x86_64-softmmu \
--block-drv-rw-whitelist=qcow2,raw,file,qed \
--block-drv-ro-whitelist=vmdk
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
