Commit Graph

825 Commits

Author SHA1 Message Date
Markus Armbruster
9fe0753321 blockdev: Fix block_resize error reporting for op blockers
When block_resize() runs into an op blocker, it creates an error like
this:

        error_setg(errp, "Device '%s' is in use", device);

Trouble is @device can be null.  My system formats null as "(null)",
but other systems might crash.  Reproducer:

1. Create two block devices

    -> {"execute": "blockdev-add", "arguments": {"driver": "file", "node-name": "blk0", "filename": "64k.img"}}
    <- {"return": {}}
    -> {"execute": "blockdev-add", "arguments": {"driver": "file", "node-name": "blk1", "filename": "m.img"}}
    <- {"return": {}}

2. Put a blocker on one them

    -> {"execute": "blockdev-mirror", "arguments": {"job-id": "job0", "device": "blk0", "target": "blk1", "sync": "full"}}
    {"return": {}}
    -> {"execute": "job-pause", "arguments": {"id": "job0"}}
    {"return": {}}
    -> {"execute": "job-complete", "arguments": {"id": "job0"}}
    {"return": {}}

   Note: job events elided for brevity.

3. Attempt to resize

    -> {"execute": "block_resize", "arguments": {"node-name": "blk1", "size":32768}}
    <- {"error": {"class": "GenericError", "desc": "Device '(null)' is in use"}}

Broken when commit 3b1dbd11a6 made @device optional.  Fixed in commit
ed3d2ec98a (block: Add errp to b{lk,drv}_truncate()), except for this
one instance.

Fix it by using the error message provided by the op blocker instead,
so it fails like this:

    <- {"error": {"class": "GenericError", "desc": "Node 'blk1' is busy: block device is in use by block job: mirror"}}

Fixes: 3b1dbd11a6 (qmp: Allow block_resize to manipulate bs graph nodes.)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2024-03-09 18:56:37 +03:00
Peter Krempa
72098a3aba stream: Allow users to request only format driver names in backing file format
Introduce a new flag 'backing-mask-protocol' for the block-stream QMP
command which instructs the internals to use 'raw' instead of the
protocol driver in case when a image is used without a dummy 'raw'
wrapper.

The flag is designed such that it can be always asserted by management
tools even when there isn't any update to backing files.

The flag will be used by libvirt so that the backing images still
reference the proper format even when libvirt will stop using the dummy
raw driver (raw driver with no other config). Libvirt needs this so that
the images stay compatible with older libvirt versions which didn't
expect that a protocol driver name can appear in the backing file format
field.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <bbee9a0a59748a8893289bf8249f568f0d587e62.1701796348.git.pkrempa@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2024-01-26 11:16:58 +01:00
Peter Krempa
4b028cbe75 commit: Allow users to request only format driver names in backing file format
Introduce a new flag 'backing-mask-protocol' for the block-commit QMP
command which instructs the internals to use 'raw' instead of the
protocol driver in case when a image is used without a dummy 'raw'
wrapper.

The flag is designed such that it can be always asserted by management
tools even when there isn't any update to backing files.

The flag will be used by libvirt so that the backing images still
reference the proper format even when libvirt will stop using the dummy
raw driver (raw driver with no other config). Libvirt needs this so that
the images stay compatible with older libvirt versions which didn't
expect that a protocol driver name can appear in the backing file format
field.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <2cb46e37093ce793ea1604abc8bbb90f4c8e434b.1701796348.git.pkrempa@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2024-01-26 11:16:58 +01:00
Stefan Hajnoczi
c43d5bc858 block: remove bdrv_co_lock()
The bdrv_co_lock() and bdrv_co_unlock() functions are already no-ops.
Remove them.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20231205182011.1976568-8-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-12-21 22:49:27 +01:00
Stefan Hajnoczi
b49f4755c7 block: remove AioContext locking
This is the big patch that removes
aio_context_acquire()/aio_context_release() from the block layer and
affected block layer users.

There isn't a clean way to split this patch and the reviewers are likely
the same group of people, so I decided to do it in one patch.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Message-ID: <20231205182011.1976568-7-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-12-21 22:49:27 +01:00
Stefan Hajnoczi
6bc30f1949 graph-lock: remove AioContext locking
Stop acquiring/releasing the AioContext lock in
bdrv_graph_wrlock()/bdrv_graph_unlock() since the lock no longer has any
effect.

The distinction between bdrv_graph_wrunlock() and
bdrv_graph_wrunlock_ctx() becomes meaningless and they can be collapsed
into one function.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231205182011.1976568-6-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-12-21 22:49:27 +01:00
Kevin Wolf
755ae3811f block: Fix AioContext locking in qmp_block_resize()
The AioContext must be unlocked before calling blk_co_unref(), because
it takes the AioContext lock internally in blk_unref_bh(), which is
scheduled in the main thread. If we don't unlock, the AioContext is
locked twice and nested event loops such as in bdrv_graph_wrlock() will
deadlock.

Cc:  <qemu-stable@nongnu.org>
Fixes: https://issues.redhat.com/browse/RHEL-15965
Fixes: 0c7d204f50
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20231208124352.30295-1-kwolf@redhat.com>
2023-12-12 07:43:15 -05:00
Kevin Wolf
6bc0bcc89f block: Fix deadlocks in bdrv_graph_wrunlock()
bdrv_graph_wrunlock() calls aio_poll(), which may run callbacks that
have a nested event loop. Nested event loops can depend on other
iothreads making progress, so in order to allow them to make progress it
must not hold the AioContext lock of another thread while calling
aio_poll().

This introduces a @bs parameter to bdrv_graph_wrunlock() whose
AioContext is temporarily dropped (which matches bdrv_graph_wrlock()),
and a bdrv_graph_wrunlock_ctx() that can be used if the BlockDriverState
doesn't necessarily exist any more when unlocking.

This also requires a change to bdrv_schedule_unref(), which was relying
on the incorrectly taken lock. It needs to take the lock itself now.
While this is a separate bug, it can't be fixed a separate patch because
otherwise the intermediate state would either deadlock or try to release
a lock that we don't even hold.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231115172012.112727-3-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[kwolf: Fixed up bdrv_schedule_unref()]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-21 12:45:21 +01:00
Kevin Wolf
ccd6a37947 block: Mark bdrv_replace_node() GRAPH_WRLOCK
Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_replace_node(). Its callers may already want
to hold the graph lock and so wouldn't be able to call functions that
take it internally.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-17-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-07 19:14:20 +01:00
Kevin Wolf
79bb762727 block: Mark bdrv_chain_contains() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_chain_contains() need to hold a reader lock for the graph because
it calls bdrv_filter_or_cow_bs(), which accesses bs->file/backing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-11-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-07 19:14:19 +01:00
Kevin Wolf
ad74751fc0 block: Mark bdrv_skip_filters() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_skip_filters() need to hold a reader lock for the graph because it
calls bdrv_filter_child(), which accesses bs->file/backing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-9-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-07 19:14:19 +01:00
Kevin Wolf
430da832af block: Mark bdrv_skip_implicit_filters() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_skip_implicit_filters() need to hold a reader lock for the graph
because it calls bdrv_filter_child(), which accesses bs->file/backing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-8-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-07 19:14:19 +01:00
Kevin Wolf
372b69f503 block: Mark bdrv_filter_or_cow_bs() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_filter_or_cow_bs() need to hold a reader lock for the graph because
it calls bdrv_filter_or_cow_child(), which accesses bs->file/backing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-7-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-07 19:14:19 +01:00
Kevin Wolf
067179868e block: Mark bdrv_has_zero_init() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_has_zero_init() need to hold a reader lock for the graph because
it calls bdrv_filter_bs(), which accesses bs->file/backing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-3-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-07 19:14:19 +01:00
David Woodhouse
d3256f88d9 hw/xen: automatically assign device index to block devices
There's no need to force the user to assign a vdev. We can automatically
assign one, starting at xvda and searching until we find the first disk
name that's unused.

This means we can now allow '-drive if=xen,file=xxx' to work without an
explicit separate -driver argument, just like if=virtio.

Rip out the legacy handling from the xenpv machine, which was scribbling
over any disks configured by the toolstack, and didn't work with anything
but raw images.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-11-07 08:54:20 +00:00
Fiona Ebner
61a3a5a76a blockjob: introduce block-job-change QMP command
which will allow changing job-type-specific options after job
creation.

In the JobVerbTable, the same allow bits as for set-speed are used,
because set-speed can be considered an existing change command.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20231031135431.393137-2-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 18:20:25 +01:00
Fiona Ebner
302823854b blockdev: mirror: avoid potential deadlock when using iothread
The bdrv_getlength() function is a generated co-wrapper and uses
AIO_WAIT_WHILE() to wait for the spawned coroutine. AIO_WAIT_WHILE()
expects the lock to be acquired exactly once.

Fix a case where it may be acquired twice. This can happen when the
source node is explicitly specified as the @replaces parameter or if the
source node is a filter node.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-ID: <20231019131936.414246-4-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:36 +01:00
Kevin Wolf
277f2007ce block: Mark bdrv_op_is_blocked() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_op_is_blocked() need to hold a reader lock for the graph
because it calls bdrv_get_device_or_node_name(), which accesses the
parents list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-18-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-12 16:31:33 +02:00
Kevin Wolf
b7cfc7d58e block: Mark bdrv_refresh_filename() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_refresh_filename() need to hold a reader lock for the graph
because it accesses the children list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-11-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-12 16:31:33 +02:00
Kevin Wolf
15f3f1fe57 block: Mark bdrv_get_xdbg_block_graph() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_xdbg_block_graph() need to hold a reader lock for the graph
because it accesses the children list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-10-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-12 16:31:33 +02:00
Kevin Wolf
a32e781838 block: Mark bdrv_snapshot_fallback() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_snapshot_fallback() need to hold a reader lock for the graph
because it accesses the children list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-8-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-12 16:31:33 +02:00
Kevin Wolf
2b3912f135 block: Mark bdrv_first_blk() and bdrv_is_root_node() GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_first_blk() and bdrv_is_root_node() need to hold a reader lock
for the graph. These functions are the only functions in block-backend.c
that access the parent list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-5-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-12 16:31:33 +02:00
Kevin Wolf
9def6082cf block: Mark bdrv_add/del_child() and caller GRAPH_WRLOCK
The functions read the parents list in the generic block layer, so we
need to hold the graph lock already there. The BlockDriver
implementations actually modify the graph, so it has to be a writer
lock.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-22-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-09-20 17:46:01 +02:00
Kevin Wolf
bce73bc25b block: Mark bdrv_get_cumulative_perm() and callers GRAPH_RDLOCK
The function reads the parents list, so it needs to hold the graph lock.

This happens to result in BlockDriver.bdrv_set_perm() to be called with
the graph lock held. For consistency, make it the same for all of the
BlockDriver callbacks for updating permissions and annotate the function
pointers with GRAPH_RDLOCK_PTR.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-15-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-09-20 17:46:01 +02:00
Eric Blake
bd1386cce1 cutils: Adjust signature of parse_uint[_full]
It's already confusing that we have two very similar functions for
wrapping the parse of a 64-bit unsigned value, differing mainly on
whether they permit leading '-'.  Adjust the signature of parse_uint()
and parse_uint_full() to be like all of qemu_strto*(): put the result
parameter last, use the same types (uint64_t and unsigned long long
have the same width, but are not always the same type), and mark
endptr const (this latter change only affects the rare caller of
parse_uint).  Adjust all callers in the tree.

While at it, note that since cutils.c already includes:

    QEMU_BUILD_BUG_ON(sizeof(int64_t) != sizeof(long long));

we are guaranteed that the result of parse_uint* cannot exceed
UINT64_MAX (or the build would have failed), so we can drop
pre-existing dead comparisons in opts-visitor.c that were never false.

Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20230522190441.64278-8-eblake@redhat.com>
[eblake: Drop dead code spotted by Markus]
Signed-off-by: Eric Blake <eblake@redhat.com>
2023-06-02 12:27:19 -05:00
Kevin Wolf
c6e0a6de62 block: Take main AioContext lock when calling bdrv_open()
The function documentation already says that all callers must hold the
main AioContext lock, but not all of them do. This can cause assertion
failures when functions called by bdrv_open() try to drop the lock. Fix
a few more callers to take the lock before calling bdrv_open().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230525124713.401149-4-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30 17:21:23 +02:00
Vladimir Sementsov-Ogievskiy
d53c89aed1 blockdev: qmp_transaction: drop extra generic layer
Let's simplify things:

First, actions generally don't need access to common BlkActionState
structure. The only exclusion are backup actions that need
block_job_txn.

Next, for transaction actions of Transaction API is more native to
allocated state structure in the action itself.

So, do the following transformation:

1. Let all actions be represented by a function with corresponding
   structure as arguments.

2. Instead of array-map marshaller, let's make a function, that calls
   corresponding action directly.

3. BlkActionOps and BlkActionState structures become unused

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20230510150624.310640-7-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-19 19:12:12 +02:00
Vladimir Sementsov-Ogievskiy
c85feafa98 blockdev: use state.bitmap in block-dirty-bitmap-add action
Other bitmap related actions use the .bitmap pointer in .abort action,
let's do same here:

1. It helps further refactoring, as bitmap-add is the only bitmap
   action that uses state.action in .abort

2. It must be safe: transaction actions rely on the fact that on
   .abort() the state is the same as at the end of .prepare(), so that
   in .abort() we could precisely rollback the changes done by
   .prepare().
   The only way to remove the bitmap during transaction should be
   block-dirty-bitmap-remove action, but it postpones actual removal to
   .commit(), so we are OK on any rollback path. (Note also that
   bitmap-remove is the only bitmap action that has .commit() phase,
   except for simple g_free the state on .clean())

3. Again, other bitmap actions behave this way: keep the bitmap pointer
   during the transaction.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20230510150624.310640-6-vsementsov@yandex-team.ru>
[kwolf: Also remove the now unused BlockDirtyBitmapState.prepared]
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-19 19:12:12 +02:00
Vladimir Sementsov-Ogievskiy
c85f34cf89 blockdev: transaction: refactor handling transaction properties
Only backup supports GROUPED mode. Make this logic more clear. And
avoid passing extra thing to each action.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20230510150624.310640-5-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-19 19:12:12 +02:00
Vladimir Sementsov-Ogievskiy
30c96b5559 blockdev: qmp_transaction: refactor loop to classic for
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230510150624.310640-4-vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-19 19:12:12 +02:00
Vladimir Sementsov-Ogievskiy
240396965f blockdev: transactions: rename some things
Look at qmp_transaction(): dev_list is not obvious name for list of
actions. Let's look at qapi spec, this argument is "actions". Let's
follow the common practice of using same argument names in qapi scheme
and code.

To be honest, rename props to properties for same reason.

Next, we have to rename global map of actions, to not conflict with new
name for function argument.

Rename also dev_entry loop variable accordingly to new name of the
list.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230510150624.310640-3-vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-19 19:12:12 +02:00
Vladimir Sementsov-Ogievskiy
8187f63c9c blockdev: refactor transaction to use Transaction API
We are going to add more block-graph modifying transaction actions,
and block-graph modifying functions are already based on Transaction
API.

Next, we'll need to separately update permissions after several
graph-modifying actions, and this would be simple with help of
Transaction API.

So, now let's just transform what we have into new-style transaction
actions.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20230510150624.310640-2-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-19 19:12:12 +02:00
Kevin Wolf
533c6e4ee8 block: Mark bdrv_recurse_can_replace() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_recurse_can_replace() need to hold a reader lock for the graph
because it accesses the children list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230504115750.54437-20-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-10 14:16:54 +02:00
Kevin Wolf
0c7d204f50 block: Don't call no_coroutine_fns in qmp_block_resize()
This QMP handler runs in a coroutine, so it must use the corresponding
no_co_wrappers instead.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2185688
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230504115750.54437-5-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-10 14:16:53 +02:00
Kevin Wolf
e2626874a3 block: Fix use after free in blockdev_mark_auto_del()
job_cancel_locked() drops the job list lock temporarily and it may call
aio_poll(). We must assume that the list has changed after this call.
Also, with unlucky timing, it can end up freeing the job during
job_completed_txn_abort_locked(), making the job pointer invalid, too.

For both reasons, we can't just continue at block_job_next_locked(job).
Instead, start at the head of the list again after job_cancel_locked()
and skip those jobs that we already cancelled (or that are completing
anyway).

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230503140142.474404-1-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-10 14:16:35 +02:00
Emanuele Giuseppe Esposito
1e97be9156 block: Convert bdrv_is_inserted() to co_wrapper
bdrv_is_inserted() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

At the same time, add also blk_is_inserted as co_wrapper_mixed, since it
is called in both coroutine and non-coroutine contexts.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally c_w_mixed_bdrv_rdlock calls AIO_WAIT_WHILE and it expects to
release the AioContext lock. Once the rwlock is ultimated and placed in
every place it needs to be, we will poll using AIO_WAIT_WHILE_UNLOCKED
and remove the AioContext lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-5-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Markus Armbruster
e2c1c34f13 include/block: Untangle inclusion loops
We have two inclusion loops:

       block/block.h
    -> block/block-global-state.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

       block/block.h
    -> block/block-io.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac.

Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
2023-01-20 07:24:28 +01:00
Kevin Wolf
e135505588 block: Fix locking in external_snapshot_prepare()
bdrv_img_create() polls internally (when calling bdrv_create(), which is
a co_wrapper), so it can't be called while holding the lock of any
AioContext except the current one without causing deadlocks. Drop the
lock around the call in external_snapshot_prepare().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221207131838.239125-11-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:08:23 +01:00
Kevin Wolf
d22933acd2 block: Drain individual nodes during reopen
bdrv_reopen() and friends use subtree drains as a lazy way of covering
all the nodes they touch. Turns out that this lazy way is a lot more
complicated than just draining the nodes individually, even not
accounting for the additional complexity in the drain mechanism itself.

Simplify the code by switching to draining the individual nodes that are
already managed in the BlockReopenQueue anyway.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221118174110.55183-8-kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15 16:07:42 +01:00
Markus Armbruster
238e9202a2 qapi transaction: Elide redundant has_FOO in generated C
The has_FOO for pointer-valued FOO are redundant, except for arrays.
They are also a nuisance to work with.  Recent commit "qapi: Start to
elide redundant has_FOO in generated C" provided the means to elide
them step by step.  This is the step for qapi/transaction.json.

Said commit explains the transformation in more detail.  The invariant
violations mentioned there do not occur here.

In qmp_transaction(), we can't just drop parameter @has_props, since
it's used to track whether @props needs to be freed.  Replace it by a
local variable.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221104160712.3005652-27-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2022-12-14 20:05:07 +01:00
Markus Armbruster
54fde4ff06 qapi block: Elide redundant has_FOO in generated C
The has_FOO for pointer-valued FOO are redundant, except for arrays.
They are also a nuisance to work with.  Recent commit "qapi: Start to
elide redundant has_FOO in generated C" provided the means to elide
them step by step.  This is the step for qapi/block*.json.

Said commit explains the transformation in more detail.

There is one instance of the invariant violation mentioned there:
qcow2_signal_corruption() passes false, "" when node_name is an empty
string.  Take care to pass NULL then.

The previous two commits cleaned up two more.

Additionally, helper bdrv_latency_histogram_stats() loses its output
parameters and returns a value instead.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221104160712.3005652-11-armbru@redhat.com>
[Fixes for #ifndef LIBRBD_SUPPORTS_ENCRYPTION and MacOS squashed in]
2022-12-14 20:03:25 +01:00
Markus Armbruster
04658a5b90 blockdev: Clean up abuse of DriveBackup member format
drive-backup argument @format defaults to the format of the source
unless @mode is "existing".

drive_backup_prepare() implements this by copying the source's
@format_name to DriveBackup member @format.  It leaves @has_format
false, violating the "has_format == !!format" invariant.  Unclean.
Falls apart when we elide @has_format (commit after next): then QAPI
passes @format, which is a string constant, to g_free().  iotest 056
duly explodes.

Clean it up.  Since the value stored in member @format is not actually
used outside this function, use a local variable instead of modifying
the QAPI object.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Cc: qemu-block@nongnu.org
Message-Id: <20221104160712.3005652-9-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2022-12-13 18:31:37 +01:00
Alberto Faria
247cf5c035 monitor: switch to *_co_* functions
Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-25-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Emanuele Giuseppe Esposito
142e690712 block: remove bdrv_try_set_aio_context and replace it with bdrv_try_change_aio_context
No functional change intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20221025084952.2139888-11-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Emanuele Giuseppe Esposito
6f592e5aca job.c: enable job lock/unlock and remove Aiocontext locks
Change the job_{lock/unlock} and macros to use job_mutex.

Now that they are not nop anymore, remove the aiocontext
to avoid deadlocks.

Therefore:
- when possible, remove completely the aiocontext lock/unlock pair
- if it is used by some other function too, reduce the locking
  section as much as possible, leaving the job API outside.
- change AIO_WAIT_WHILE in AIO_WAIT_WHILE_UNLOCKED, since we
  are not using the aiocontext lock anymore

The only functions that still need the aiocontext lock are:
- the JobDriver callbacks, already documented in job.h
- job_cancel_sync() in replication.c is called with aio_context_lock
  taken, but now job is using AIO_WAIT_WHILE_UNLOCKED so we need to
  release the lock.

Reduce the locking section to only cover the callback invocation
and document the functions that take the AioContext lock,
to avoid taking it twice.

Also remove real_job_{lock/unlock}, as they are replaced by the
public functions.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20220926093214.506243-19-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-07 12:11:41 +02:00
Emanuele Giuseppe Esposito
880eeec613 jobs: group together API calls under the same job lock
Now that the API offers also _locked() functions, take advantage
of it and give also the caller control to take the lock and call
_locked functions.

This makes sense especially when we have for loops, because it
makes no sense to have:

for(job = job_next(); ...)

where each job_next() takes the lock internally.
Instead we want

JOB_LOCK_GUARD();
for(job = job_next_locked(); ...)

In addition, protect also direct field accesses, by either creating a
new critical section or widening the existing ones.

Note: at this stage, job_{lock/unlock} and job lock guard macros
are *nop*.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20220926093214.506243-12-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-07 12:11:41 +02:00
Emanuele Giuseppe Esposito
9624112441 jobs: add job lock in find_* functions
Both blockdev.c and job-qmp.c have TOC/TOU conditions, because
they first search for the job and then perform an action on it.
Therefore, we need to do the search + action under the same
job mutex critical section.

Note: at this stage, job_{lock/unlock} and job lock guard macros
are *nop*.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220926093214.506243-9-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-07 12:11:41 +02:00
Denis V. Lunev
b2aaf35477 block: pass OnOffAuto instead of bool to block_acct_setup()
We would have one more place for block_acct_setup() calling, which should
not corrupt original value.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
CC: Peter Krempa <pkrempa@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: John Snow <jsnow@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220824095044.166009-2-den@openvz.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-09-30 18:02:30 +02:00
Marc-André Lureau
f793dde091 Replace qemu_gettimeofday() with g_get_real_time()
GLib g_get_real_time() is an alternative to gettimeofday() which allows
to simplify our code.

For semihosting, a few bits are lost on POSIX host, but this shouldn't
be a big concern.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220307070401.171986-5-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:37 +02:00
Emanuele Giuseppe Esposito
c5be7445b7 assertions for blockdev.h global state API
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20220303151616.325444-22-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-03-04 18:18:25 +01:00