There are BDS children that the general block layer code can access,
namely bs->file and bs->backing. Since the introduction of filters and
external data files, their meaning is not quite clear. bs->backing can
be a COW source, or it can be a filtered child; bs->file can be a
filtered child, it can be data and metadata storage, or it can be just
metadata storage.
This overloading really is not helpful. This patch adds functions that
retrieve the correct child for each exact purpose. Later patches in
this series will make use of them. Doing so will allow us to handle
filter nodes in a meaningful way.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Providing an empty string for the backing file parameter like so:
qemu-img create -f qcow2 -b '' /tmp/foo
allows the flow of control to reach and subsequently fail an assert
statement because passing an empty string to
bdrv_get_full_backing_filename_from_filename()
simply results in NULL being returned without an error being raised.
To fix this, let's check for an empty string when getting the value from
the opts list.
Reported-by: Attila Fazekas <afazekas@redhat.com>
Fixes: https://bugzilla.redhat.com/1809553
Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Message-Id: <20200813134722.802180-1-ckuehl@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Move the create-config logic to meson.build; create a
configuration_data object and let meson handle the
quoting and output.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unaligned requests will automatically be aligned to bl.request_alignment
and we can't extend write requests to access space beyond the end of the
image without resizing the image, so if we have the WRITE permission,
but not the RESIZE one, it's required that the image size is aligned.
Failing to meet this requirement could cause assertion failures like
this if RESIZE permissions weren't requested:
qemu-img: block/io.c:1910: bdrv_co_write_req_prepare: Assertion `end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE' failed.
This was e.g. triggered by qemu-img converting to a target image with 4k
request alignment when the image was only aligned to 512 bytes, but not
to 4k.
Turn this into a graceful error in bdrv_check_perm() so that WRITE
without RESIZE can only be taken if the image size is aligned. If a user
holds both permissions and drops only RESIZE, the function will return
an error, but bdrv_child_try_set_perm() will ignore the failure silently
if permissions are only requested to be relaxed and just keep both
permissions while returning success.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200716142601.111237-2-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Creating an image that requires format probing of the backing image is
potentially unsafe (we've had several CVEs over the years based on
probes leaking information to the guest on a subsequent boot, although
these days tools like libvirt are aware of the issue enough to prevent
the worst effects). For example, if our probing algorithm ever
changes, or if other tools like libvirt determine a different probe
result than we do, then subsequent use of that backing file under a
different format will present corrupted data to the guest.
Fortunately, the worst effects occur only when the backing image is
originally raw, and we at least prevent commit into a probed raw
backing file that would change its probed type.
Still, it is worth starting a deprecation clock so that future
qemu-img can refuse to create backing chains that would rely on
probing, to encourage clients to avoid unsafe practices. Most
warnings are intentionally emitted from bdrv_img_create() in the block
layer, but qemu-img convert uses bdrv_create() which cannot emit its
own warning without causing spurious warnings on other code paths. In
the end, all command-line image creation or backing file rewriting now
performs a check.
Furthermore, if we probe a backing file as non-raw, then it is safe to
explicitly record that result (rather than relying on future probes);
only where we probe a raw image do we care about further warnings to
the user when using such an image (for example, commits into a
probed-raw backing file are prevented), to help them improve their
tooling. But whether or not we make the probe results explicit, we
still warn the user to remind them to upgrade their workflow to supply
-F always.
iotest 114 specifically wants to create an unsafe image for later
amendment rather than defaulting to our new default of recording a
probed format, so it needs an update. While touching it, expand it to
cover all of the various warnings enabled by this patch. iotest 301
also shows a change to qcow messages.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-11-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For now, this is a mechanical addition; all callers pass false. But
the next patch will use it to improve 'qemu-img rebase -u' when
selecting a backing file with no format.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Message-Id: <20200706203954.341758-10-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Back in commit 6e6e55f5 (Jul 2017, v2.10), we tweaked the code to warn
if the backing file could not be opened but the user gave a size,
unless the user also passes the -u option to bypass the open of the
backing file. As one common reason for failure to open the backing
file is when there is mismatch in the requested backing format in
relation to what the backing file actually contains, we actually want
to open the backing file and ensure that it has the right format in as
many cases as possible. iotest 301 for qcow demonstrates how
detecting explicit format mismatch is useful to prevent the creation
of an image that would probe differently than the user requested. Now
is the time to finally turn the warning an error, as promised.
Note that the original warning was added prior to our documentation of
an official deprecation policy (eb22aeca, also Jul 2017), and because
the warning didn't mention the word "deprecated", we never actually
remembered to document it as such. But the warning has been around
long enough that I don't see prolonging it another two releases.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-7-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
During 'qemu-img create ... 2>&1', if --quiet is not in force, we can
end up with buffered I/O in stdout that was produced before failure,
but which appears in output after failure. This is confusing; the fix
is to flush stdout prior to attempting anything that might produce an
error message. Several iotests demonstrate the resulting ordering
change now that the merged outputs now reflect chronology. (An even
better fix would be to avoid printf from within block.c altogether,
but that's much more invasive...)
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-2-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away, even when we need to keep error_propagate() for other
error paths.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-38-armbru@redhat.com>
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away. The previous commit did that with a Coccinelle script I
consider fairly trustworthy. This commit uses the same script with
the matching of return taken out, i.e. we convert
if (!foo(..., &err)) {
...
error_propagate(errp, err);
...
}
to
if (!foo(..., errp)) {
...
...
}
This is unsound: @err could still be read between afterwards. I don't
know how to express "no read of @err without an intervening write" in
Coccinelle. Instead, I manually double-checked for uses of @err.
Suboptimal line breaks tweaked manually. qdev_realize() simplified
further to placate scripts/checkpatch.pl.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away. Convert
if (!foo(..., &err)) {
...
error_propagate(errp, err);
...
return ...
}
to
if (!foo(..., errp)) {
...
...
return ...
}
where nothing else needs @err. Coccinelle script:
@rule1 forall@
identifier fun, err, errp, lbl;
expression list args, args2;
binary operator op;
constant c1, c2;
symbol false;
@@
if (
(
- fun(args, &err, args2)
+ fun(args, errp, args2)
|
- !fun(args, &err, args2)
+ !fun(args, errp, args2)
|
- fun(args, &err, args2) op c1
+ fun(args, errp, args2) op c1
)
)
{
... when != err
when != lbl:
when strict
- error_propagate(errp, err);
... when != err
(
return;
|
return c2;
|
return false;
)
}
@rule2 forall@
identifier fun, err, errp, lbl;
expression list args, args2;
expression var;
binary operator op;
constant c1, c2;
symbol false;
@@
- var = fun(args, &err, args2);
+ var = fun(args, errp, args2);
... when != err
if (
(
var
|
!var
|
var op c1
)
)
{
... when != err
when != lbl:
when strict
- error_propagate(errp, err);
... when != err
(
return;
|
return c2;
|
return false;
|
return var;
)
}
@depends on rule1 || rule2@
identifier err;
@@
- Error *err = NULL;
... when != err
Not exactly elegant, I'm afraid.
The "when != lbl:" is necessary to avoid transforming
if (fun(args, &err)) {
goto out
}
...
out:
error_propagate(errp, err);
even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().
Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly. I don't know what exactly "when strict" does, only that
it helps here.
The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err". For
an example where it's too narrow, see vfio_intx_enable().
Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there. Converted manually.
Line breaks tidied up manually. One nested declaration of @local_err
deleted manually. Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
When creating an image fails because the format doesn't support option
"backing_file" or "backing_fmt", bdrv_img_create() first has
qemu_opt_set() put a generic error into @local_err, then puts the real
error into @errp with error_setg(), and then propagates the former to
the latter, which throws away the generic error. A bit complicated,
but works.
Now that qemu_opt_set() returns a useful value, we can simply ignore
the generic error instead.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-16-armbru@redhat.com>
The function has only one user: bdrv_co_block_status(). Inline it to
simplify reviewing of the following patches, which will finally drop
unallocated_blocks_are_zero field too.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-3-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
'force' option will be used for some unsafe amend operations.
This includes things like erasing last keyslot in luks based formats
(which destroys the data, unless the master key is backed up
by external means), but that _might_ be desired result.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-4-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Commit 93676c88 relaxed our NBD client code to request export names up
to the NBD protocol maximum of 4096 bytes without NUL terminator, even
though the block layer can't store anything longer than 4096 bytes
including NUL terminator for display to the user. Since this means
there are some export names where we have to truncate things, we can
at least try to make the truncation a bit more obvious for the user.
Note that in spite of the truncated display name, we can still
communicate with an NBD server using such a long export name; this was
deemed nicer than refusing to even connect to such a server (since the
server may not be under our control, and since determining our actual
length limits gets tricky when nbd://host:port/export and
nbd+unix:///export?socket=/path are themselves variable-length
expansions beyond the export name but count towards the block layer
name length).
Reported-by: Xueqiang Wei <xuwei@redhat.com>
Fixes: https://bugzilla.redhat.com/1843684
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200610163741.3745251-3-eblake@redhat.com>
Implementations should decide the necessary permissions based on @role.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-35-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-33-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-32-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-31-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Replace child_file by child_of_bds in all remaining places (excluding
tests).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-28-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-25-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Make all parents of backing files pass the appropriate BdrvChildRole.
By doing so, we can switch their BdrvChildClass over to the generic
child_of_bds, which will do the right thing when given a correct
BdrvChildRole.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-24-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-23-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This callback can be used by BDSs that use child_of_bds with the
appropriate BdrvChildRole for their children.
Also, make bdrv_format_default_perms() use it for child_of_bds children
(just a temporary solution until we can drop bdrv_format_default_perms()
altogether).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-20-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We can be less restrictive about pure data children than those with
metadata on them, so let bdrv_default_perms_for_storage() handle
metadata children differently from pure data children.
As explained in the code, the restrictions on metadata children are
strictly stricter than those for pure data children, so in theory we
just have to distinguish between pure-data and all other storage
children (pure metadata or data+metadata). In practice, that is not
obvious, though, so we have two independent code paths for metadata and
for data children, and data+metadata children will go through both
(without the path for data children doing anything meaningful).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-19-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Right now, bdrv_format_default_perms() is used by format parents
(generally). We want to switch to a model where most parents use a
single BdrvChildClass, which then decides the permissions based on the
child role. To do so, we have to split bdrv_format_default_perms() into
separate functions for each such role.
Note that bdrv_default_perms_for_storage() currently handles all DATA |
METADATA children. A follow-up patch is going to split it further into
one function for each case.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-18-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Right now, bdrv_format_default_perms() is used by format parents
(generally). We want to switch to a model where most parents use a
single BdrvChildClass, which then decides the permissions based on the
child role. To do so, we have to split bdrv_format_default_perms() into
separate functions for each such role.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-17-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_format_default_perms() has one code path for backing files, and one
for storage files. We want to pull them out into their own functions,
so make sure they are completely distinct before so the next patches
will be a bit cleaner.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-16-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Any current user of child_file, child_format, and child_backing can and
should use this generic BdrvChildClass instead, as it can handle all of
these cases. However, to be able to do so, the users must pass the
appropriate BdrvChildRole when the child is created/attached. (The
following commits will take care of that.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-15-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Make bdrv_child_cb_detach() call bdrv_backing_detach() for children with
a COW role (and drop the reverse call from bdrv_backing_detach()), so it
can be used for any child (with a proper role set).
Because so far no child has a proper role set, we need a temporary new
callback for child_backing.detach that ensures bdrv_backing_detach() is
called for all COW children that do not have their role set yet.
(Also, move bdrv_child_cb_detach() down to group it with
bdrv_inherited_options() and bdrv_child_cb_attach().)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-14-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Make bdrv_child_cb_attach() call bdrv_backing_attach() for children with
a COW role (and drop the reverse call from bdrv_backing_attach()), so it
can be used for any child (with a proper role set).
Because so far no child has a proper role set, we need a temporary new
callback for child_backing.attach that ensures bdrv_backing_attach() is
called for all COW children that do not have their role set yet.
(Also, move bdrv_child_cb_attach() down to group it with
bdrv_inherited_options().)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-13-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Let child_file's, child_format's, and child_backing's .inherit_options()
implementations fall back to bdrv_inherited_options() to show that it
would really work for all of these cases, if only the parents passed the
appropriate BdrvChildRole and parent_is_format values.
(Also, make bdrv_open_inherit(), the only place to explicitly call
bdrv_backing_options(), call bdrv_inherited_options() instead.)
This patch should incur only two visible changes, both for child_format
children, both of which are effectively bug fixes:
First, they no longer have discard=unmap set by default. This reason it
was set is because bdrv_inherited_fmt_options() fell through to
bdrv_protocol_options(), and that set it because "format drivers take
care to send flushes and respect unmap policy". None of the drivers
that use child_format for their children (quorum and blkverify) are
format drivers, though, so this reasoning does not apply here.
Second, they no longer have BDRV_O_NO_IO force-cleared. child_format
was used solely for children that do not store any metadata and as such
will not be accessed by their parents as long as those parents do not
receive I/O themselves. Thus, such children should inherit
BDRV_O_NO_IO.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-12-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
After the series this patch belongs to, we want to have a common
BdrvChildClass that encompasses all of child_file, child_format, and
child_backing. Such a single class needs a single .inherit_options()
implementation, and this patch introduces it.
The next patch will show how the existing implementations can fall back
to it just by passing appropriate BdrvChildRole and parent_is_format
values.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-11-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The other two .inherit_options implementations specify exactly for what
case they are used in their name, so do it for this one as well.
(The actual intention behind this patch is to follow it up with a
generic bdrv_inherited_options() that works for all three cases.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-10-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We plan to unify the generic .inherit_options() functions. The
resulting common function will need to decide whether to force-enable
format probing, force-disable it, or leave it as-is. To make this
decision, it will need to know whether the parent node is a format node
or not (because we never want format probing if the parent is a format
node already (except for the backing chain)).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-9-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For now, all callers (effectively) pass 0 and no callee evaluates thie
value. Later patches will change both.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-8-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For now, all callers pass 0 and no callee evaluates this value. Later
patches will change both.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-7-mreitz@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>
This structure nearly only contains parent callbacks for child state
changes. It cannot really reflect a child's role, because different
roles may overlap (as we will see when real roles are introduced), and
because parents can have custom callbacks even when the child fulfills a
standard role.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200513110544.176672-4-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Right now, all users of bdrv_make_empty() call the BlockDriver method
directly. That is not only bad style, it is also wrong, unless the
caller has a BdrvChild with a WRITE or WRITE_UNCHANGED permission.
(WRITE_UNCHANGED suffices, because callers generally use this function
to clear a node with a backing file after a commit operation.)
Introduce bdrv_make_empty() that verifies that it does.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200429141126.85159-2-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that there are no clients of bdrv_has_zero_init_truncate, none of
the drivers need to worry about providing it.
What's more, this eliminates a source of some confusion: a literal
reading of the documentation as written in ceaca56f and implemented in
commit 1dcaf527 claims that a driver which returns 0 for
bdrv_has_zero_init_truncate() must not return 1 for
bdrv_has_zero_init(); this condition was violated for parallels, qcow,
and sometimes for vdi, although in practice it did not matter since
those drivers also lacked .bdrv_co_truncate.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200428202905.770727-10-eblake@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that node level interface bdrv_truncate() supports passing request
flags to the block driver, expose this on the BlockBackend level, too.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The previous few commits have made this more obvious, and removed the
one exception. Time to clarify the documentation, and drop dead error
checking.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-13-armbru@redhat.com>
bdrv_root_attach_child promises to drop child_bs reference on failure.
It does it on first handled failure path, but not on the second. Fix
that.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200324155921.23822-1-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of checking the .bdrv_co_create_opts to see if we need the
fallback, just implement the .bdrv_co_create_opts in the drivers that
need it.
This way we don't break various places that need to know if the
underlying protocol/format really supports image creation, and this way
we still allow some drivers to not support image creation.
Fixes: fd17146cd9
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1816007
Note that technically this driver reverts the image creation fallback
for the vxhs driver since I don't have a means to test it, and IMHO it
is better to leave it not supported as it was prior to generic image
creation patches.
Also drop iscsi_create_opts which was left accidentally.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200326011218.29230-3-mlevitsk@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
[mreitz: Fixed alignment, and moved bdrv_co_create_opts_simple() and
bdrv_create_opts_simple from block.h into block_int.h]
Signed-off-by: Max Reitz <mreitz@redhat.com>
This will allow the reuse of a single generic .bdrv_co_create
implementation for several drivers.
No functional changes.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
