bdrv_default_perms() can decide which permission profile to use based on
the BdrvChildRole, so block drivers do not need to select it explicitly.
The blkverify driver now no longer shares the WRITE permission for the
image to verify. We thus have to adjust two places in
test-block-iothread not to take it. (Note that in theory, blkverify
should behave like quorum in this regard and share neither WRITE nor
RESIZE for both of its children. In practice, it does not really
matter, because blkverify is used only for debugging, so we might as
well keep its permissions rather liberal.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-30-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Note that some filters have secondary children, namely blkverify (the
image to be verified) and blklogwrites (the log). This patch does not
touch those children.
Note that for blkverify, the filtered child should not be format-probed.
While there is nothing enforcing this here, in practice, it will not be:
blkverify implements .bdrv_file_open. The block layer ensures (and in
fact, asserts) that BDRV_O_PROTOCOL is set for every BDS whose driver
implements .bdrv_file_open. This flag will then be bequeathed to
blkverify's children, and they will thus (by default) not be probed
either.
("By default" refers to the fact that blkverify's other child (the
non-filtered one) will have BDRV_O_PROTOCOL force-unset, because that is
what happens for all non-filtered children of non-format drivers.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-27-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For now, it is always set to 0. Later patches in this series will
ensure that all callers pass an appropriate combination of flags.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-6-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The commit, mirror, and blkreplay block nodes are filters, so they should
be marked as such.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-2-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch enables making snapshots with blkreplay used in
block devices.
This function is required to make bdrv_snapshot_goto without
calling .bdrv_open which is not implemented.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
These files can not be executed on the host, so they should not be
marked as executable.
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
.bdrv_close handler is optional after previous commit, no needs to keep
empty functions more.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Other I/O functions are already using a BdrvChild pointer in the API, so
make discard do the same. It makes it possible to initiate the same
permission checks before doing I/O, and much easier to share the
helper functions for this, which will be added and used by write,
truncate and copy range paths.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Update the rest of the filter drivers to support
BDRV_REQ_WRITE_UNCHANGED. They already forward write request flags to
their children, so we just have to announce support for it.
This patch does not cover the replication driver because that currently
does not support flags at all, and because it just grabs the WRITE
permission for its children when it can, so we should be fine just
submitting the incoming WRITE_UNCHANGED requests as normal writes.
It also does not cover format drivers for similar reasons. They all use
bdrv_format_default_perms() as their .bdrv_child_perm() implementation
so they just always grab the WRITE permission for their file children
whenever possible. In addition, it often would be difficult to
ascertain whether incoming unchanging writes end up as unchanging writes
in their files. So we just leave them as normal potentially changing
writes.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180421132929.21610-7-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The blkreplay driver is not a protocol so it should implement bdrv_open
instead of bdrv_file_open and not provide a protocol_name.
Attempts to invoke this driver using protocol syntax
(i.e. blkreplay:<filename:options:...>) will now fail gracefully:
$ qemu-img info blkreplay:foo
qemu-img: Could not open 'blkreplay:foo': Unknown protocol 'blkreplay'
Signed-off-by: Fabiano Rosas <farosas@linux.vnet.ibm.com>
Reviewed-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Change the 'int count' parameter in *pwrite_zeros, *pdiscard related
functions (and some others) to 'int bytes', as they both refer to bytes.
This helps with code legibility.
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Message-id: 20170609101808.13506-1-el13635@mail.ntua.gr
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The block layer takes care of removing the bs->file child if the block
driver's bdrv_open()/bdrv_file_open() implementation fails. The block
driver therefore does not need to do so, and indeed should not unless it
sets bs->file to NULL afterwards -- because if this is not done, the
bdrv_unref_child() in bdrv_open_inherit() will dereference the freed
memory block at bs->file afterwards, which is not good.
We can now decide whether to add a "bs->file = NULL;" after each of the
offending bdrv_unref_child() invocations, or just drop them altogether.
The latter is simpler, so let's do that.
Cc: qemu-stable <qemu-stable@nongnu.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
All callers will have to request permissions for all of their child
nodes. Block drivers that act as simply filters can use the default
implementation of .bdrv_child_perm().
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: 20170213135235.12274-15-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This patch fixes bug with stopping and restarting replay
through monitor.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20160926080815.6992.71818.stgit@PASHA-ISP>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Another step towards killing off sector-based block APIs.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1468624988-423-11-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
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>
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>
The blkreplay driver only forwards the requests it gets, so converting
it to byte granularity is trivial.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Another step on our continuing quest to switch to byte-based
interfaces.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Rename to bdrv_pwrite_zeroes() to let the compiler ensure we
cater to the updated semantics. Do the same for bdrv_co_write_zeroes().
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch introduces block driver that implement recording
and replaying of block devices' operations.
All block completion operations are added to the queue.
Queue is flushed at checkpoints and information about processed requests
is recorded to the log. In replay phase the queue is matched with
events read from the log. Therefore block devices requests are processed
deterministically.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
[ kwolf: Rebased onto modified and already applied part of the series ]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
