The proper order for inactivating block nodes is that first the parents
get inactivated and then the children. If we do things in this order, we
can assert that we didn't accidentally leave a parent activated when one
of its child nodes is inactive.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
With image locking, permissions affect other qemu processes as well. We
want to be sure that the destination can run, so let's drop permissions
on the source when migration completes.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Instead of manually calling blk_resume_after_migration() in migration
code after doing bdrv_invalidate_cache_all(), integrate the BlockBackend
activation with cache invalidation into a single function. This is
achieved with a new callback in BdrvChildRole that is called by
bdrv_invalidate_cache_all().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
It can be used outside of block.c for making user friendly messages.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Noticed while checking Coccinelle results. Naming a label 'out:'
when it is only used on error paths is weird. Also, we had some
dead stores to 'ret'. Meanwhile we know that snapshot_options
is NULL on success and that QDECREF(NULL) is safe. So merge the
two exit paths into one by careful control over bs_snapshot.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-8-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
We now have macros in place to make it less verbose to add a scalar
to QDict and QList, so use them.
Patch created mechanically via:
spatch --sp-file scripts/coccinelle/qobject.cocci \
--macro-file scripts/cocci-macro-file.h --dir . --in-place
then touched up manually to fix a couple of '?:' back to original
spacing, as well as avoiding a long line in monitor.c.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-7-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
We have macros in place to make it less verbose to add a subtype
of QObject to both QDict and QList. While we have made cleanups
like this in the past (see commit fcfcd8ffc, for example), having
it be automated by Coccinelle makes it easier to maintain.
Patch created mechanically via:
spatch --sp-file scripts/coccinelle/qobject.cocci \
--macro-file scripts/cocci-macro-file.h --dir . --in-place
then I verified that no manual touchups were required.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-5-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
As long as BDRV_O_INACTIVE is set, the image file is only opened so we
have a file descriptor for it. We're definitely not supposed to modify
the image, it's still owned by the migration source.
This commit is an addition to 09e0c771 but the assert() is added to
bdrv_truncate().
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Message-id: 1491405505-31620-3-git-send-email-den@openvz.org
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Add missing error messages for the block driver implementations of
.bdrv_truncate(); drop the generic one from block.c's bdrv_truncate().
Since one of these changes touches a mis-indented block in
block/file-posix.c, this patch fixes that coding style issue along the
way.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-5-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Add an Error parameter to the block drivers' bdrv_truncate() interface.
If a block driver does not set this in case of an error, the generic
bdrv_truncate() implementation will do so.
Where it is obvious, this patch also makes some block drivers set this
value.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-4-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
For one thing, this allows us to drop the error message generation from
qemu-img.c and blockdev.c and instead have it unified in
bdrv_truncate().
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-3-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reproducer:
$ ./qemu-img info ''
qemu-img: ./block.c:1008: bdrv_open_driver: Assertion
`!drv->bdrv_needs_filename || bs->filename[0]' failed.
[1] 26105 abort (core dumped) ./qemu-img info ''
This patch fixes this to be:
$ ./qemu-img info ''
qemu-img: Could not open '': The 'file' block driver requires a file
name
Cc: qemu-stable <qemu-stable@nongnu.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This reverts commit e3e0003a8f.
This commit was necessary for the 2.9 release because we were unable to
fix the underlying issue(s) in time. However, we will be for 2.10.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Introduce check function for setting read_only flags. Will return < 0 on
error, with appropriate Error value set. Does not alter any flags.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: e2bba34ac3bc76a0c42adc390413f358ae0566e8.1491597120.git.jcody@redhat.com
The BDRV_O_ALLOW_RDWR flag allows / prohibits the changing of
the BDS 'read_only' state, but there are a few places where it
is ignored. In the bdrv_set_read_only() helper, make sure to
honor the flag.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: be2e5fb2d285cbece2b6d06bed54a6f56520d251.1491597120.git.jcody@redhat.com
A few block drivers will set the BDS read_only flag from their
.bdrv_open() function. This means the bs->read_only flag could
be set after we enable copy_on_read, as the BDRV_O_COPY_ON_READ
flag check occurs prior to the call to bdrv->bdrv_open().
This adds an error return to bdrv_set_read_only(), and an error will be
return if we try to set the BDS to read_only while copy_on_read is
enabled.
This patch also changes the behavior of vvfat. Before, vvfat could
override the drive 'readonly' flag with its own, internal 'rw' flag.
For instance, this -drive parameter would result in a writable image:
"-drive format=vvfat,dir=/tmp/vvfat,rw,if=virtio,readonly=on"
This is not correct. Now, attempting to use the above -drive parameter
will result in an error (i.e., 'rw' is incompatible with 'readonly=on').
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 0c5b4c1cc2c651471b131f21376dfd5ea24d2196.1491597120.git.jcody@redhat.com
We have a helper wrapper for checking for the BDS read_only flag,
add a helper wrapper to set the read_only flag as well.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 9b18972d05f5fa2ac16c014f0af98d680553048d.1491597120.git.jcody@redhat.com
In case of block migration, there may be writes to BlockBackends that do
not have the write permission taken. Before this issue is fixed (which
is not going to happen in 2.9), we therefore cannot assert that this is
the case.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20170411145050.31290-1-mreitz@redhat.com
Tested-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The fact that the bs->aio_context is changing can confuse the dataplane
iothread, because of the now fine granularity aio context lock.
bdrv_drain should rather be a bdrv_drained_begin/end pair, but since
bs->aio_context is changing, we can just use aio_disable_external and
bdrv_parent_drained_begin.
Reported-by: Ed Swierk <eswierk@skyportsystems.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
-blockdev and blockdev_add convert their arguments via QObject to
BlockdevOptions for qmp_blockdev_add(), which converts them back to
QObject, then to a flattened QDict. The QDict's members are typed
according to the QAPI schema.
-drive converts its argument via QemuOpts to a (flat) QDict. This
QDict's members are all QString.
Thus, the QType of a flat QDict member depends on whether it comes
from -drive or -blockdev/blockdev_add, except when the QAPI type maps
to QString, which is the case for 'str' and enumeration types.
The block layer core extracts generic configuration from the flat
QDict, and the block driver extracts driver-specific configuration.
Both commonly do so by converting (parts of) the flat QDict to
QemuOpts, which turns all values into strings. Not exactly elegant,
but correct.
However, A few places access the flat QDict directly:
* Most of them access members that are always QString. Correct.
* bdrv_open_inherit() accesses a boolean, carefully. Correct.
* nfs_config() uses a QObject input visitor. Correct only because the
visited type contains nothing but QStrings.
* nbd_config() and ssh_config() use a QObject input visitor, and the
visited types contain non-QStrings: InetSocketAddress members
@numeric, @to, @ipv4, @ipv6. -drive works as long as you don't try
to use them (they're all optional). @to is ignored anyway.
Reproducer:
-drive driver=ssh,server.host=h,server.port=22,server.ipv4,path=p
-drive driver=nbd,server.type=inet,server.data.host=h,server.data.port=22,server.data.ipv4
both fail with "Invalid parameter type for 'data.ipv4', expected: boolean"
Add suitable comments to all these places. Mark the buggy ones FIXME.
"Fortunately", -drive's driver-specific options are entirely
undocumented.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1490895797-29094-5-git-send-email-armbru@redhat.com
[mreitz: Fixed two typos]
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
While it is true that bdrv_set_aio_context only works on a single
BlockDriverState subtree (see commit message for 53ec73e, "block: Use
bdrv_drain to replace uncessary bdrv_drain_all", 2015-07-07), it works
at the AioContext level rather than the BlockDriverState level.
Therefore, it is also necessary to trigger pending bottom halves too,
even if no requests are pending.
For NBD this ensures that the aio_co_schedule of a previous call to
nbd_attach_aio_context is completed before detaching from the old
AioContext; it fixes qemu-iotest 094. Another similar bug happens
when the VM is stopped and the virtio-blk dataplane irqfd is torn down.
In this case it's possible that guest I/O gets stuck if notify_guest_bh
was scheduled but doesn't run.
Calling aio_poll from another AioContext is safe if non-blocking; races
such as the one mentioned in the commit message for c9d1a56 ("block:
only call aio_poll on the current thread's AioContext", 2016-10-28)
are a concern for blocking calls.
I considered other options, including:
- moving the bs->wakeup mechanism to AioContext, and letting the caller
check. This might work for virtio which has a clear place to wakeup
(notify_place_bh) and check the condition (virtio_blk_data_plane_stop).
For aio_co_schedule I couldn't find a clear place to check the condition.
- adding a dummy oneshot bottom half and waiting for it to trigger.
This has the complication that bottom half list is LIFO for historical
reasons. There were performance issues caused by bottom half ordering
in the past, so I decided against it for 2.9.
Fixes: 9972354856
Reported-by: Max Reitz <mreitz@redhat.com>
Reported-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Tested-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170314111157.14464-2-pbonzini@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
bdrv_child_set_perm alone is not very usable because the caller must
call bdrv_child_check_perm first. This is already encapsulated
conveniently in bdrv_child_try_set_perm, so remove the other prototypes
from the header and fix the one wrong caller, block/mirror.c.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In bdrv_open_inherit(), the filename is refreshed after opening the
backing file, but we neglected to do the same when the backing file
changes later.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
All callers pass false now, so the parameter can go away again.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1488317230-26248-14-git-send-email-armbru@redhat.com>
The next few commits will put the errors to use where appropriate.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488317230-26248-13-git-send-email-armbru@redhat.com>
When adding an Error parameter, bdrv_replace_in_backing_chain() would
become nothing more than a wrapper around change_parent_backing_link().
So make the latter public, renamed as bdrv_replace_node(), and remove
bdrv_replace_in_backing_chain().
Most of the callers just remove a node from the graph that they just
inserted, so they can use &error_abort, but completion of a mirror job
with 'replaces' set can actually fail.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Instead of just trying to change parents by parent over to reference @to
instead of @from, and abort()ing whenever the permissions don't allow
this, do proper permission checking beforehand and pass any error to the
callers.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
change_parent_backing_link() will need to update multiple BdrvChild
objects at once. Checking permissions reference by reference doesn't
work because permissions need to be consistent only with all parents
moved to the new child.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Aborting on error in bdrv_append() isn't correct. This patch fixes it
and lets the callers handle failures.
Test case 085 needs a reference output update. This is caused by the
reversed order of bdrv_set_backing_hd() and change_parent_backing_link()
in bdrv_append(): When the backing file of the new node is set, the
parent nodes are still pointing to the old top, so the backing blocker
is now initialised with the node name rather than the BlockBackend name.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Not all callers of bdrv_set_backing_hd() know for sure that attaching
the backing file will be allowed by the permission system. Return the
error from the function rather than aborting.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This adds an assertion that ensures that the necessary resize permission
has been granted before bdrv_truncate() is called.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Now that the backing file child role implements .attach/.detach
callbacks, nothing prevents us from modifying the graph even if that
involves changing backing file links.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Backing files are somewhat special compared to other kinds of children
because they are attached and detached using bdrv_set_backing_hd()
rather than the normal set of functions, which does a few more things
like setting backing blockers, toggling the BDRV_O_NO_BACKING flag,
setting parent_bs->backing_file, etc.
These special features are a reason why change_parent_backing_link()
can't handle backing files yet. With abstracting the additional features
into .attach/.detach callbacks, we get a step closer to a function that
can actually deal with this.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
bdrv_append() cares about isolation of the node that it modifies, but
not about activity in some subtree below it. Instead of using the
recursive bdrv_requests_pending(), directly check bs->in_flight, which
considers only the node in question.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
When the parents' child links are updated in bdrv_append() or
bdrv_replace_in_backing_chain(), this should affect all child links of
BlockBackends or other nodes, but not on child links held for other
purposes (like for setting permissions). This patch allows to control
the behaviour per BdrvChildRole.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Instead of just telling that there was some conflict, we can be specific
and tell which permissions were in conflict and which way the conflict
is.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
For meaningful error messages in the permission system, we need to get
some human-readable description of the parent of a BdrvChild.
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>
Now that all block drivers with children tell us what permissions they
need from each of their children, bdrv_attach_child() can use this
information and make the right requirements while trying to attach new
children.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
All block drivers that can have child nodes implement .bdrv_child_perm()
now. Make this officially a requirement by asserting that only drivers
without children can omit .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>
vvfat is the last remaining driver that can have children, but doesn't
implement .bdrv_child_perm() yet. The default handlers aren't suitable
here, so let's implement a very simple driver-specific one that protects
the internal child from being used by other users as good as our
permissions permit.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Almost all format drivers have the same characteristics as far as
permissions are concerned: They have one or more children for storing
their own data and, more importantly, metadata (can be written to and
grow even without external write requests, must be protected against
other writers and present consistent data) and optionally a backing file
(this is just data, so like for a filter, it only depends on what the
parent nodes need).
This provides a default implementation that can be shared by most of
our format drivers.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Most filters need permissions related to read and write for their
children, but only if the node has a parent that wants to use the same
operation on the filter. The same is true for resize.
This adds a default implementation that simply forwards all necessary
permissions to all children of the node and leaves the other permissions
unchanged.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
In many cases, the required permissions of one node on its children
depend on what its parents require from it. For example, the raw format
or most filter drivers only need to request consistent reads if that's
something that one of their parents wants.
In order to achieve this, this patch introduces two new BlockDriver
callbacks. The first one lets drivers first check (recursively) whether
the requested permissions can be set; the second one actually sets the
new permission bitmask.
Also add helper functions that drivers can use in their implementation
of the callbacks to update their permissions on a specific child.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
When attaching a node as a child to a new parent, the required and
shared permissions for this parent are checked against all other parents
of the node now, and an error is returned if there is a conflict.
This allows error returns to a function that previously always
succeeded, and the same is true for quite a few callers and their
callers. Converting all of them within the same patch would be too much,
so for now everyone tells that they don't need any permissions and allow
everyone else to do anything. This way we can use &error_abort initially
and convert caller by caller to pass actual permission requirements and
implement error handling.
All these places are marked with FIXME comments and it will be the job
of the next patches to clean them up again.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
It will have to return an error soon, so prepare the callers for it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
Block layer patches
# gpg: Signature made Fri 24 Feb 2017 18:08:26 GMT
# gpg: using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6
* remotes/kevin/tags/for-upstream:
tests: Use opened block node for block job tests
vvfat: Use opened node as backing file
block: Add bdrv_new_open_driver()
block: Factor out bdrv_open_driver()
block: Use BlockBackend for image probing
block: Factor out bdrv_open_child_bs()
block: Attach bs->file only during .bdrv_open()
block: Pass BdrvChild to bdrv_truncate()
mirror: Resize active commit base in mirror_run()
qcow2: Use BB for resizing in qcow2_amend_options()
blockdev: Use BlockBackend to resize in qmp_block_resize()
iotests: Fix another race in 030
qemu-img: Improve documentation for PREALLOC_MODE_FALLOC
qemu-img: Truncate before full preallocation
qemu-img: Add tests for raw image preallocation
qemu-img: Do not truncate before preallocation
qemu-iotests: redirect nbd server stdout to /dev/null
qemu-iotests: add ability to exclude certain protocols from tests
qemu-iotests: Test 137 only supports 'file' protocol
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This function allows to create more or less normal BlockDriverStates
even for BlockDrivers that aren't globally registered (e.g. helper
filters for block jobs).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This is a function that doesn't do any option parsing, but just does
some basic BlockDriverState setup and calls the .bdrv_open() function of
the block driver.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This fixes the use of a parent-less BdrvChild in bdrv_open_inherit() by
converting it into a BlockBackend. Which is exactly what it should be,
image probing is an external, standalone user of a node. The requests
can't be considered to originate from the format driver node because
that one isn't even opened yet.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This is the part of bdrv_open_child() that opens a BDS with option
inheritance, but doesn't attach it as a child to the parent yet.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The way that attaching bs->file worked was a bit unusual in that it was
the only child that would be attached to a node which is not opened yet.
Because of this, the block layer couldn't know yet which permissions the
driver would eventually need.
This patch moves the point where bs->file is attached to the beginning
of the individual .bdrv_open() implementations, so drivers already know
what they are going to do with the child. This is also more consistent
with how driver-specific children work.
For a moment, bdrv_open() gets its own BdrvChild to perform image
probing, but instead of directly assigning this BdrvChild to the BDS, it
becomes a temporary one and the node name is passed as an option to the
drivers, so that they can simply use bdrv_open_child() to create another
reference for their own use.
This duplicated child for (the not opened yet) bs is not the final
state, a follow-up patch will change the image probing code to use a
BlockBackend, which is completely independent of bs.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
qobject_to_qdict(obj) returns NULL when obj isn't a QDict. Check
that instead of qobject_type(obj) == QTYPE_QDICT.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1487363905-9480-8-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Current implementation invalidates firstly parent bds and then its
children. This leads to the following bug:
after incoming migration, in bdrv_invalidate_cache_all:
1. invalidate parent bds - reopen it with BDRV_O_INACTIVE cleared
2. child is not yet invalidated
3. parent check that its BDRV_O_INACTIVE is cleared
4. parent writes to child
5. assert in bdrv_co_pwritev, as BDRV_O_INACTIVE is set for child
This patch fixes it by just changing invalidate sequence: invalidate
children first.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170131112308.54189-1-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
In bdrv_find_backing_image(), if we are searching an image for a backing
file that contains a protocol, we currently only compare unmodified
paths.
However, some management software will change the backing filename to be
a relative filename in a path. QEMU is able to handle this fine,
because internally it will use path_combine to put together the full
protocol URI.
However, this can lead to an inability to match an image during a QAPI
command that needs to use bdrv_find_backing_image() to find the image,
when it is searched by the full URI.
When searching for a protocol filename, if the straight comparison
fails, this patch will also compare against the full backing filename to
see if that is a match.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Message-id: c2d025adca8a2b665189e6f4cf080f44126d0b6b.1485392617.git.jcody@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Introduce rules in the top level Makefile that are able to generate
trace.[ch] files in every subdirectory which has a trace-events file.
The top level directory is handled specially, so instead of creating
trace.h, it creates trace-root.h. This allows sub-directories to
include the top level trace-root.h file, without ambiguity wrt to
the trace.g file in the current sub-dir.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170125161417.31949-7-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
options must be non-NULL here, because a NULL value is replaced with
qdict_new earlier in the function. Reported by Coverity.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Some block drivers may not be loaded yet, but qemu supports them
nonetheless. bdrv_iterate_format() should report them, too.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20161012204907.25941-3-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
bdrv_iterate_format() did not actually sort the formats by name but by
"pointer interpreted as string". That is probably not what we intended
to do, so fix it (by changing qsort_strcmp() so it matches the example
from qsort()'s manual page).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20161012204907.25941-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This makes sure that the image we are streaming into is open in
read-write mode during the operation.
Operation blockers are also set in all intermediate nodes, since they
will be removed from the chain afterwards.
Finally, this also unblocks the stream operation in backing files.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When a BlockDriverState is about to be reopened it can trigger certain
operations that need to write to disk. During this process a different
block job can be woken up. If that block job completes and also needs
to call bdrv_reopen() it can happen that it needs to do it on the same
BlockDriverState that is still in the process of being reopened.
This can have fatal consequences, like in this example:
1) Block job A starts and sleeps after a while.
2) Block job B starts and tries to reopen node1 (a qcow2 file).
3) Reopening node1 means flushing and replacing its qcow2 cache.
4) While the qcow2 cache is being flushed, job A wakes up.
5) Job A completes and reopens node1, replacing its cache.
6) Job B resumes, but the cache that was being flushed no longer
exists.
This patch splits the bdrv_drain_all() call to keep all block jobs
paused during bdrv_reopen_multiple(), so that step 4 can never happen
and the operation is safe.
Note that this scenario can only happen if both bdrv_reopen() calls
are made by block jobs on the same backing chain. Otherwise there's no
chance that the same BlockDriverState appears in both reopen queues.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
aio_poll is not thread safe; for example bdrv_drain can hang if
the last in-flight I/O operation is completed in the I/O thread after
the main thread has checked bs->in_flight.
The bug remains latent as long as all of it is called within
aio_context_acquire/aio_context_release, but this will change soon.
To fix this, if bdrv_drain is called from outside the I/O thread,
signal the main AioContext through a dummy bottom half. The event
loop then only runs in the I/O thread.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-18-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
After the next patch bdrv_drain_all will have to be called without holding any
AioContext. Prepare to do this by adding an AioContext argument to
bdrv_reopen_multiple.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-15-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
The event currently only contains the BlockBackend name. However, with
anonymous BlockBackends, this is always the empty string. Add the qdev
ID (or if none was given, the QOM path) so that the user can still see
which device caused the event.
Event generation has to be moved from bdrv_eject() to the BlockBackend
because the BDS doesn't know the attached device, but that's easy
because blk_eject() is the only user of it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Recently we moved a few options from QemuOptsLists in blockdev.c to
bdrv_runtime_opts in block.c in order to make them accissble using
blockdev-add. However, this has the side effect that these options are
missing from query-command-line-options now, and libvirt consequently
disables the corresponding feature.
This problem was reported as a regression for the 'discard' option,
introduced in commit 818584a4. However, it is more general than that.
Fix it by adding bdrv_runtime_opts to the list of QemuOptsLists that are
returned in query-command-line-options. For the future, libvirt is
advised to use QMP schema introspection for block device options.
Reported-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Michal Privoznik <mprivozn@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
This enables its use for nested child nodes. The compatibility
between the 'discard' and 'detect-zeroes' setting is checked in
bdrv_open_common() now as the former setting isn't available before
calling bdrv_open() any more.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Amongst others, this means that you can now use the 'detect-zeroes'
option for non-top-level nodes in blockdev-add, like the QAPI schema
promises.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
bdrv_reopen_queue_child() assumes that a BlockDriverState is never
added twice to BlockReopenQueue.
That's however not the case: commit_start() adds 'base' (and its
children) to a new reopen queue, and then 'overlay_bs' (and its
children, which include 'base') to the same queue. The effect of this
is that the first set of options is ignored and overriden by the
second.
We fixed this by swapping the order in which both BDSs were added to
the queue in 3db2bd5508. This patch
checks if a BDS is already in the reopen queue and keeps its options.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds the "read-only" option to the QDict. One important effect of
this change is that when a child inherits options from its parent, the
existing "read-only" mode can be preserved if it was explicitly set
previously.
This addresses scenarios like this:
[E] <- [D] <- [C] <- [B] <- [A]
In this case, if we reopen [D] with read-only=off, and later reopen
[B], then [D] will not inherit read-only=on from its parent during the
bdrv_reopen_queue_child() stage.
The BDRV_O_RDWR flag is not removed yet, but its keep in sync with the
value of the "read-only" option.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We're only doing this immediately before opening the image, but
bs->open_flags is used earlier in the function. At the moment this is
not causing problems because none of the checked flags are modified by
update_flags_from_options(), but this will change when we introduce
the "read-only" option.
This patch calls update_flags_from_options() at the beginning of the
function, immediately after creating the QemuOpts.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If an image is opened with snapshot=on, its flags are modified by
bdrv_backing_options() and then bs->open_flags is updated accordingly.
This last step is unnecessary if we calculate the new flags before
setting bs->open_flags.
Soon we'll introduce the "read-only" option, and then we'll need to
be able to modify its value in the QDict when snapshot=on. This is
more cumbersome if bs->options is already set. This patch simplifies
that. Other than that, there are no semantic changes. Although it
might seem that bs->options can have a different value now because
it is stored after calling bdrv_backing_options(), this call doesn't
actually modify them in this scenario.
The code that sets BDRV_O_ALLOW_RDWR is also moved for the same
reason.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is unnecessary and has been unused since 5433c24f0f.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Extend the current module interface to allow for block drivers to be
loaded dynamically on request. The only block drivers that can be
converted into modules are the drivers that don't perform any init
operation except for registering themselves.
In addition, only the protocol drivers are being modularized, as they
are the only ones which see significant performance benefits. The format
drivers do not generally link to external libraries, so modularizing
them is of no benefit from a performance perspective.
All the necessary module information is located in a new structure found
in module_block.h
This spoils the purpose of 5505e8b76f (block/dmg: make it modular).
Before this patch, if module build is enabled, block-dmg.so is linked to
libbz2, whereas the main binary is not. In downstream, theoretically, it
means only the qemu-block-extra package depends on libbz2, while the
main QEMU package needn't to. With this patch, we (temporarily) change
the case so that the main QEMU depends on libbz2 again.
Signed-off-by: Marc Marí <markmb@redhat.com>
Signed-off-by: Colin Lord <clord@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1471008424-16465-4-git-send-email-clord@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
[mreitz: Do a signed comparison against the length of
block_driver_modules[], so it will not cause a compile error when
empty]
Signed-off-by: Max Reitz <mreitz@redhat.com>
The builtin NBD server uses its own BlockBackend now instead of reusing
the monitor/guest device one.
This means that it has its own writethrough setting now. The builtin
NBD server always uses writeback caching now regardless of whether the
guest device has WCE enabled. qemu-nbd respects the cache mode given on
the command line.
We still need to keep a reference to the monitor BB because we put an
eject notifier on it, but we don't use it for any I/O.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
All .bdrv_co_write_zeroes callbacks nowadays work perfectly even
with backing store attached. If future new callbacks would be unable to do
that - they have a chance to block this in bdrv_get_info().
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1468503209-19498-6-git-send-email-den@openvz.org
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Jeff Cody <jcody@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Some guests (win2008 server for example) do a lot of unnecessary
flushing when underlying media has not changed. This adds additional
overhead on host when calling fsync/fdatasync.
This change introduces a write generation scheme in BlockDriverState.
Current write generation is checked against last flushed generation to
avoid unnessesary flushes.
The problem with excessive flushing was found by a performance test
which does parallel directory tree creation (from 2 processes).
Results improved from 0.424 loops/sec to 0.432 loops/sec.
Each loop creates 10^3 directories with 10 files in each.
This affected some blkdebug testcases that were expecting error logs from
failure-injected flushes which are now skipped entirely
(tests 026 071 089).
This also affects the performance of block jobs and thus BLOCK_JOB_READY
events for driver-mirror and active block-commit commands now arrives
faster, before QMP send successfully returns to caller (tests 141 144).
Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1468870792-7411-5-git-send-email-den@openvz.org
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <famz@redhat.com>
CC: John Snow <jsnow@redhat.com>
Signed-off-by: John Snow <jsnow@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>
No code changes, just moved from one file to another.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Using int for values that are only used as booleans is confusing.
While at it, rearrange a couple of members so that all the bools
are contiguous.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It makes more sense to have ALL block size limit constraints
in the same struct. Improve the documentation while at it.
Simplify a couple of conditionals, now that we have audited and
documented that request_alignment is always non-zero.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We want to eventually stick request_alignment alongside other
BlockLimits, but first, we must ensure it is populated at the
same time as all other limits, rather than being a special case
that is set only when a block is first opened.
Now that all drivers have been updated to supply an override
of request_alignment during their .bdrv_refresh_limits(), as
needed, the block layer itself can defer setting the default
alignment until part of the overall bdrv_refresh_limits().
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
error_propagate() already ignores local_err==NULL, so there's no
need to check it before calling.
Coccinelle patch used to perform the changes added to
scripts/coccinelle/error_propagate_null.cocci.
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1465855078-19435-2-git-send-email-ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
It's possible that an AioContext notifier user was close to finishing
when .detach_aio_context() or .attached_aio_context() is called. In
that case they may call bdrv_remove_aio_context_notifier() during the
callback.
Use safe iteration to avoid crashing when the notifier list is modified
during iteration. We must not only handle the case where the current
aio notifier is removed during a callback but also the one where any
other aio notifier is removed.
The next patch adds an AioContext notifier for block jobs and they
really could be terminating just as .detach_aio_context() is invoked.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1466096189-6477-6-git-send-email-stefanha@redhat.com
Kevin Wolf
Fam Zheng
Eric Blake
Denis V. Lunev
Max Reitz
Jeff Cody
Markus Armbruster
Paolo Bonzini
Peter Maydell
Vladimir Sementsov-Ogievskiy
Daniel P. Berrange
Alberto Garcia
Marc Mari
Wen Congyang
Evgeny Yakovlev
Eduardo Habkost
Stefan Hajnoczi