Like other error paths, this one needs to call tran_finalize() and clean
up the BlockReopenQueue, too.

Fixes: CID 1452772
Fixes: 72373e40
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210503110555.24001-3-kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

The error path needs to call tran_finalize(), too.

Fixes: CID 1452773
Fixes: 548a74c0
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210503110555.24001-2-kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

They are unused now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-3-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

Stop including sysemu/sysemu.h in files that don't need it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-2-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

Now, bdrv_node_check_perm() is called only with fresh cumulative
permissions, so its actually "refresh_perm".

Move permission calculation to the function. Also, drop unreachable
error message and rewrite the remaining one to be more generic (as now
we don't know which node is added and which was already here).

Add also Virtuozzo copyright, as big work is done at this point.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-37-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

We don't have bdrv_replace_child(), so it's time for
bdrv_replace_child_safe() to take its place.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-36-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Old interfaces dropped, nobody directly calls
bdrv_child_set_perm_abort() and bdrv_child_set_perm_commit(), so we can
use personal state structure for the action and stop exploiting
BdrvChild structure. Also, drop "_safe" suffix which is redundant now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-35-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

bdrv_replace_child() has only one caller, the second argument is
unused. Inline it now. This triggers deletion of some more unused
interfaces.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-34-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

bdrv_check_perm_common() has only one caller, so no more sense in
"common".

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-33-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-32-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Move bdrv_reopen_multiple to new paradigm of permission update:
first update graph relations, then do refresh the permissions.

We have to modify reopen process in file-posix driver: with new scheme
we don't have prepared permissions in raw_reopen_prepare(), so we
should reconfigure fd in raw_check_perm(). Still this seems more native
and simple anyway.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-31-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

During reopen we may add backing bs from other aio context, which may
lead to changing original context of top bs.

We are going to move graph modification to prepare stage. So, it will
be possible that bdrv_flush() in bdrv_reopen_prepare called on bs in
non-original aio context, which we didn't aquire which leads to crash.

To avoid this problem move bdrv_flush() to be a separate reopen stage
before bdrv_reopen_prepare().

This doesn't seem correct to acquire only one aio context and not all
contexts participating in reopen. But it's not obvious how to do it
correctly, keeping in mind:

 1. rules of bdrv_set_aio_context_ignore() that requires new_context
    lock not being held

 2. possible deadlocks because of holding all (or several?) AioContext
    locks

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-30-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Split out no-perm part of bdrv_set_backing_hd() as a separate
transaction action. Note the in case of existing BdrvChild we reuse it,
not recreate, just to do less actions.

We don't need to create extra reference to backing_hd as we don't lose
it in bdrv_attach_child().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-29-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

To be used in further commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-28-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

To be used in the further commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-27-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

This argument is always NULL. Drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-26-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Using bdrv_replace_node() for removing filter is not good enough: it
keeps child reference of the filter, which may conflict with original
top node during permission update.

Instead let's create new interface, which will do all graph
modifications first and then update permissions.

Let's modify bdrv_replace_node_common(), allowing it additionally drop
backing chain child link pointing to new node. This is quite
appropriate for bdrv_drop_intermediate() and makes possible to add
new bdrv_drop_filter() as a simple wrapper.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-24-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-23-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

bdrv_append is not very good for inserting filters: it does extra
permission update as part of bdrv_set_backing_hd(). During this update
filter may conflict with other parents of top_bs.

Instead, let's first do all graph modifications and after it update
permissions.

append-greedy-filter test-case in test-bdrv-graph-mod is now works, so
move it out of debug option.

Note: bdrv_append() is still only works for backing-child based
filters. It's something to improve later.

Note2: we use the fact that bdrv_append() is used to append new nodes,
without backing child, so we don't need frozen check and inherits_from
logic from bdrv_set_backing_hd().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-22-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Split part of bdrv_replace_node_common() to be used separately.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-21-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Split no-perm part of bdrv_attach_child as separate transaction action.
It will be used in later commits.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-20-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Split out no-perm part of bdrv_root_attach_child() into separate
transaction action. bdrv_root_attach_child() now moves to new
permission update paradigm: first update graph relations then update
permissions.

qsd-jobs test output updated. Seems now permission update goes in
another order. Still, the test comment say that we only want to check
that command doesn't crash, and it's still so.

Error message is a bit misleading as it looks like job was added first.
But actually in new paradigm of graph update we can't distinguish such
things. We should update the error message, but let's not do it now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210428151804.439460-19-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

inore_children thing doesn't help to track all propagated permissions
of children we want to ignore. The simplest way to correctly update
permissions is update graph first and then do permission update. In
this case we just referesh permissions for the whole subgraph (in
topological-sort defined order) and everything is correctly calculated
automatically without any ignore_children.

So, refactor bdrv_replace_node_common to first do graph update and then
refresh the permissions.

Test test_parallel_exclusive_write() now pass, so move it out of
debugging "if".

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-18-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

To be used in the following commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-17-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Add new interface, allowing use of existing node list. It will be used
to fix bdrv_replace_node() in the further commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-16-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Refactor calling driver callbacks to a separate transaction action to
be used later.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-15-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Rewrite bdrv_check_perm(), bdrv_abort_perm_update() and bdrv_set_perm()
to update nodes in topological sort order instead of simple DFS. With
topologically sorted nodes, we update a node only when all its parents
already updated. With DFS it's not so.

Consider the following example:

    A -+
    |  |
    |  v
    |  B
    |  |
    v  |
    C<-+

A is parent for B and C, B is parent for C.

Obviously, to update permissions, we should go in order A B C, so, when
we update C, all parent permissions already updated. But with current
approach (simple recursion) we can update in sequence A C B C (C is
updated twice). On first update of C, we consider old B permissions, so
doing wrong thing. If it succeed, all is OK, on second C update we will
finish with correct graph. But if the wrong thing failed, we break the
whole process for no reason (it's possible that updated B permission
will be less strict, but we will never check it).

Also new approach gives a way to simultaneously and correctly update
several nodes, we just need to run bdrv_topological_dfs() several times
to add all nodes and their subtrees into one topologically sorted list
(next patch will update bdrv_replace_node() in this manner).

Test test_parallel_perm_update() is now passing, so move it out of
debugging "if".

We also need to support ignore_children in
bdrv_parent_perms_conflict()

For test 283 order of conflicting parents check is changed.

Note also that in bdrv_check_perm() we don't check for parents conflict
at root bs, as we may be in the middle of permission update in
bdrv_reopen_multiple(). bdrv_reopen_multiple() will be updated soon.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-14-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Each of them has only one caller. Open-coding simplifies further
pemission-update system changes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-13-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

We are going to drop recursive bdrv_child_* functions, so stop use them
in bdrv_child_try_set_perm() as a first step.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-12-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Split out non-recursive parts, and refactor as block graph transaction
action.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-11-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Add additional check that node parents do not interfere with each
other. This should not hurt existing callers and allows in further
patch use bdrv_refresh_perms() to update a subtree of changed
BdrvChild (check that change is correct).

New check will substitute bdrv_check_update_perm() in following
permissions refactoring, so keep error messages the same to avoid
unit test result changes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-10-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

These functions are called only from bdrv_reopen_multiple() in block.c.
No reason to publish them.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-8-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Passing parent aio context is redundant, as child_class and parent
opaque pointer are enough to retrieve it. Drop the argument and use new
bdrv_child_get_parent_aio_context() interface.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-7-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Add new handler to get aio context and implement it in all child
classes. Add corresponding public interface to be used soon.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-6-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

We have too much comments for this feature. It seems better just don't
do it. Most of real users (tests don't count) have to create additional
reference.

Drop also comment in external_snapshot_prepare:
 - bdrv_append doesn't "remove" old bs in common sense, it sounds
   strange
 - the fact that bdrv_append can fail is obvious from the context
 - the fact that we must rollback all changes in transaction abort is
   known (it's the direct role of abort)

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-5-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

QemuOpts is usually created merging the QemuOptsList of format
and protocol. So, when the format calls bdr_create_file(), the 'opts'
parameter contains a QemuOptsList with a combination of format and
protocol default values.

The format properly removes its options before calling
bdr_create_file(), but the default values remain in 'opts->list'.
So if the protocol has options with the same name (e.g. rbd has
'cluster_size' as qcow2), it will see the default values of the format,
since for overlapping options, the format wins.

To avoid this issue, lets convert QemuOpts to QDict, in this way we take
only the set options, and then convert it back to QemuOpts, using the
'create_opts' of the protocol. So the new QemuOpts, will contain only the
protocol defaults.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20210308161232.248833-1-sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

bdrv_set_backing_hd now returns status, let's use it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20210202124956.63146-6-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

Some error messages contain ambiguous representations of the 'node-name'
parameter. This can be particularly confusing when exchanging QMP
messages (C = client, S = server):

C: {"execute": "block_resize", "arguments": { "device": "my_file", "size": 26843545600 }}
S: {"error": {"class": "GenericError", "desc": "Cannot find device=my_file nor node_name="}}
                                                                               ^^^^^^^^^

This error message suggests one could send a message with a key called
'node_name':

C: {"execute": "block_resize", "arguments": { "node_name": "my_file", "size": 26843545600 }}
                                               ^^^^^^^^^

but using the underscore is actually incorrect, the parameter should be
'node-name':

S: {"error": {"class": "GenericError", "desc": "Parameter 'node_name' is unexpected"}}

This behavior was uncovered in bz1651437, but I ended up going down a
rabbit hole looking for other areas where this miscommunication might
occur and changing those accordingly as well.

Fixes: https://bugzilla.redhat.com/1651437


Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Message-Id: <20210305151929.1947331-2-ckuehl@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

This function wraps bdrv_co_delete_file for the common case of removing a file,
which was just created by format driver, on an error condition.

It hides the -ENOTSUPP error, and reports all other errors otherwise.

Use it in luks driver

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20201217170904.946013-3-mlevitsk@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Now bdrv_append returns status and we can drop all the local_err things
around it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20210202124956.63146-3-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>