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2022-12-15block: GRAPH_RDLOCK for functions only called by co_wrappersKevin Wolf
The generated coroutine wrappers already take care to take the lock in the non-coroutine path, and assume that the lock is already taken in the coroutine path. The only thing we need to do for the wrapped function is adding the GRAPH_RDLOCK annotation. Doing so also allows us to mark the corresponding callbacks in BlockDriver as GRAPH_RDLOCK_PTR. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221207131838.239125-19-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15Mark assert_bdrv_graph_readable/writable() GRAPH_RD/WRLOCKKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221207131838.239125-16-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: assert that graph read and writes are performed correctlyEmanuele Giuseppe Esposito
Remove the old assert_bdrv_graph_writable, and replace it with the new version using graph-lock API. See the function documentation for more information. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221207131838.239125-14-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: remove unnecessary assert_bdrv_graph_writable()Emanuele Giuseppe Esposito
We don't protect bdrv->aio_context with the graph rwlock, so these assertions are not needed Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221207131838.239125-13-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: wrlock in bdrv_replace_child_nopermEmanuele Giuseppe Esposito
Protect the main function where graph is modified. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221207131838.239125-12-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: Fix locking in external_snapshot_prepare()Kevin Wolf
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>
2022-12-15block: convert bdrv_create to co_wrapperEmanuele Giuseppe Esposito
This function is never called in coroutine context, therefore instead of manually creating a new coroutine, delegate it to the block-coroutine-wrapper script, defining it as co_wrapper. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20221128142337.657646-14-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: bdrv_create_file is a coroutine_fnEmanuele Giuseppe Esposito
It is always called in coroutine_fn callbacks, therefore it can directly call bdrv_co_create(). Rename it to bdrv_co_create_file too. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20221128142337.657646-9-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: distinguish between bdrv_create running in coroutine and notEmanuele Giuseppe Esposito
Call two different functions depending on whether bdrv_create is in coroutine or not, following the same pattern as generated_co_wrapper functions. This allows to also call the coroutine function directly, without using CreateCo or relying in bdrv_create(). Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20221128142337.657646-8-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: avoid duplicating filename string in bdrv_createEmanuele Giuseppe Esposito
We know that the string will stay around until the function returns, and the parameter of drv->bdrv_co_create_opts is const char*, so it must not be modified either. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20221128142337.657646-7-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: Remove poll parameter from bdrv_parent_drained_begin_single()Kevin Wolf
All callers of bdrv_parent_drained_begin_single() pass poll=false now, so we don't need the parameter any more. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221118174110.55183-16-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>
2022-12-15block: Don't poll in bdrv_replace_child_noperm()Kevin Wolf
In order to make sure that bdrv_replace_child_noperm() doesn't have to poll any more, get rid of the bdrv_parent_drained_begin_single() call. This is possible now because we can require that the parent is already drained through the child in question when the function is called and we don't call the parent drain callbacks more than once. The additional drain calls needed in callers cause the test case to run its code in the drain handler too early (bdrv_attach_child() drains now), so modify it to only enable the code after the test setup has completed. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221118174110.55183-15-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>
2022-12-15block: Remove ignore_bds_parents parameter from drain_begin/end.Kevin Wolf
ignore_bds_parents is now ignored during drain_begin and drain_end, so we can just remove it there. It is still a valid optimisation for drain_all in bdrv_drained_poll(), so leave it around there. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221118174110.55183-13-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>
2022-12-15block: Call drain callbacks only onceKevin Wolf
We only need to call both the BlockDriver's callback and the parent callbacks when going from undrained to drained or vice versa. A second drain section doesn't make a difference for the driver or the parent, they weren't supposed to send new requests before and after the second drain. One thing that gets in the way is the 'ignore_bds_parents' parameter in bdrv_do_drained_begin_quiesce() and bdrv_do_drained_end(): It means that bdrv_drain_all_begin() increases bs->quiesce_counter, but does not quiesce the parent through BdrvChildClass callbacks. If an additional drain section is started now, bs->quiesce_counter will be non-zero, but we would still need to quiesce the parent through BdrvChildClass in order to keep things consistent (and unquiesce it on the matching bdrv_drained_end(), even though the counter would not reach 0 yet as long as the bdrv_drain_all() section is still active). Instead of keeping track of this, let's just get rid of the parameter. It was introduced in commit 6cd5c9d7b2d as an optimisation so that during bdrv_drain_all(), we wouldn't recursively drain all parents up to the root for each node, resulting in quadratic complexity. As it happens, calling the callbacks only once solves the same problem, so as of this patch, we'll still have O(n) complexity and ignore_bds_parents is not needed any more. This patch only ignores the 'ignore_bds_parents' parameter. It will be removed in a separate patch. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221118174110.55183-12-kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: Remove subtree drainsKevin Wolf
Subtree drains are not used any more. Remove them. After this, BdrvChildClass.attach/detach() don't poll any more. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221118174110.55183-11-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15stream: Replace subtree drain with a single node drainKevin Wolf
The subtree drain was introduced in commit b1e1af394d9 as a way to avoid graph changes between finding the base node and changing the block graph as necessary on completion of the image streaming job. The block graph could change between these two points because bdrv_set_backing_hd() first drains the parent node, which involved polling and can do anything. Subtree draining was an imperfect way to make this less likely (because with it, fewer callbacks are called during this window). Everyone agreed that it's not really the right solution, and it was only committed as a stopgap solution. This replaces the subtree drain with a solution that simply drains the parent node before we try to find the base node, and then call a version of bdrv_set_backing_hd() that doesn't drain, but just asserts that the parent node is already drained. This way, any graph changes caused by draining happen before we start looking at the graph and things stay consistent between finding the base node and changing the graph. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221118174110.55183-10-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: Don't use subtree drains in bdrv_drop_intermediate()Kevin Wolf
Instead of using a subtree drain from the top node (which also drains child nodes of base that we're not even interested in), use a normal drain for base, which automatically drains all of the parents, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221118174110.55183-9-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: Drain individual nodes during reopenKevin Wolf
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>
2022-12-15block: Fix locking for bdrv_reopen_queue_child()Kevin Wolf
Callers don't agree whether bdrv_reopen_queue_child() should be called with the AioContext lock held or not. Standardise on holding the lock (as done by QMP blockdev-reopen and the replication block driver) and fix bdrv_reopen() to do the same. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221118174110.55183-7-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>
2022-12-15block: Remove drained_end_counterKevin Wolf
drained_end_counter is unused now, nobody changes its value any more. It can be removed. In cases where we had two almost identical functions that only differed in whether the caller passes drained_end_counter, or whether they would poll for a local drained_end_counter to reach 0, these become a single function. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20221118174110.55183-5-kwolf@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: Revert .bdrv_drained_begin/end to non-coroutine_fnKevin Wolf
Polling during bdrv_drained_end() can be problematic (and in the future, we may get cases for bdrv_drained_begin() where polling is forbidden, and we don't care about already in-flight requests, but just want to prevent new requests from arriving). The .bdrv_drained_begin/end callbacks running in a coroutine is the only reason why we have to do this polling, so make them non-coroutine callbacks again. None of the callers actually yield any more. This means that bdrv_drained_end() effectively doesn't poll any more, even if AIO_WAIT_WHILE() loops are still there (their condition is false from the beginning). This is generally not a problem, but in test-bdrv-drain, some additional explicit aio_poll() calls need to be added because the test case wants to verify the final state after BHs have executed. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221118174110.55183-4-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: refactor bdrv_list_refresh_perms to allow any list of nodesVladimir Sementsov-Ogievskiy
We are going to increase usage of collecting nodes in a list to then update, and calling bdrv_topological_dfs() each time is not convenient, and not correct as we are going to interleave graph modifying with filling the node list. So, let's switch to a function that takes any list of nodes, adds all their subtrees and do topological sort. And finally, refresh permissions. While being here, make the function public, as we'll want to use it from blockdev.c in near future. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221107163558.618889-5-vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: bdrv_refresh_perms(): allow external tranVladimir Sementsov-Ogievskiy
Allow passing external Transaction pointer, stop creating extra Transaction objects. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221107163558.618889-4-vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: drop bdrv_remove_filter_or_cow_childVladimir Sementsov-Ogievskiy
Drop this simple wrapper used only in one place. We have too many graph modifying functions even without it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221107163558.618889-3-vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: Inline bdrv_detach_child()Vladimir Sementsov-Ogievskiy
The only caller is bdrv_root_unref_child(), let's just do the logic directly in it. It simplifies further conversion of bdrv_root_unref_child() to transaction actions. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221107163558.618889-2-vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-11-10block: Make bdrv_child_get_parent_aio_context I/OHanna Reitz
We want to use bdrv_child_get_parent_aio_context() from bdrv_parent_drained_{begin,end}_single(), both of which are "I/O or GS" functions. Prior to 3ed4f708fe1, all the implementations were I/O code anyway. 3ed4f708fe1 has put block jobs' AioContext field under the job mutex, so to make child_job_get_parent_aio_context() work in an I/O context, we need to take that lock there. Furthermore, blk_root_get_parent_aio_context() is not marked as anything, but is safe to run in an I/O context, so mark it that way now. (blk_get_aio_context() is an I/O code function.) With that done, all implementations explicitly are I/O code, so we can mark bdrv_child_get_parent_aio_context() as I/O code, too, so callers know it is safe to run from both GS and I/O contexts. Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221107151321.211175-2-hreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-11-06module: add Error arguments to module_load and module_load_qomClaudio Fontana
improve error handling during module load, by changing: bool module_load(const char *prefix, const char *lib_name); void module_load_qom(const char *type); to: int module_load(const char *prefix, const char *name, Error **errp); int module_load_qom(const char *type, Error **errp); where the return value is: -1 on module load error, and errp is set with the error 0 on module or one of its dependencies are not installed 1 on module load success 2 on module load success (module already loaded or built-in) module_load_qom_one has been introduced in: commit 28457744c345 ("module: qom module support"), which built on top of module_load_one, but discarded the bool return value. Restore it. Adapt all callers to emit errors, or ignore them, or fail hard, as appropriate in each context. Replace the previous emission of errors via fprintf in _some_ error conditions with Error and error_report, so as to emit to the appropriate target. A memory leak is also fixed as part of the module_load changes. audio: when attempting to load an audio module, report module load errors. Note that still for some callers, a single issue may generate multiple error reports, and this could be improved further. Regarding the audio code itself, audio_add() seems to ignore errors, and this should probably be improved. block: when attempting to load a block module, report module load errors. For the code paths that already use the Error API, take advantage of those to report module load errors into the Error parameter. For the other code paths, we currently emit the error, but this could be improved further by adding Error parameters to all possible code paths. console: when attempting to load a display module, report module load errors. qdev: when creating a new qdev Device object (DeviceState), report load errors. If a module cannot be loaded to create that device, now abort execution (if no CONFIG_MODULE) or exit (if CONFIG_MODULE). qom/object.c: when initializing a QOM object, or looking up class_by_name, report module load errors. qtest: when processing the "module_load" qtest command, report errors in the load of the module. Signed-off-by: Claudio Fontana <cfontana@suse.de> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220929093035.4231-4-cfontana@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-06module: rename module_load_one to module_loadClaudio Fontana
Signed-off-by: Claudio Fontana <cfontana@suse.de> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220929093035.4231-3-cfontana@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-30Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into stagingStefan Hajnoczi
Block layer patches - Cleanup bs->backing and bs->file handling - Refactor bdrv_try_set_aio_context using transactions - Changes for improved coroutine_fn consistency - vhost-user-blk: fix the resize crash - io_uring: Use of io_uring_register_ring_fd() led to breakage, revert - vvfat: Fix some problems with r/w mode - Code cleanup - MAINTAINERS: Fold "Block QAPI, monitor, ..." into "Block layer core" # -----BEGIN PGP SIGNATURE----- # # iQJFBAABCAAvFiEE3D3rFZqa+V09dFb+fwmycsiPL9YFAmNazhIRHGt3b2xmQHJl # ZGhhdC5jb20ACgkQfwmycsiPL9ZyTw/8Dfck/SuxfyeLlnQItkjaV4cnqWOU8vHs # 9x0KhlptCs+HXdF/3iicpA0lHojn7mNnbdFGjPRY4E0LriQv91TQ5ycdEmrseFPf # sgeQlgdKCVU/pHjZ2wYarm2pE43Cx85a5xuufmw+7w49dNNZn14l4t+DgviuClVM # nuVaogfZFbYyetre+Qd2TgLl+gJ+0d4o7Zs5lSWLrT8t0L9AGkcWPA7Nrbl6loIE # dOautV4G7jLjuMiCeJZOGcnuRVe3gCQ5rCGBFzzH4DUtz4BmiYx4hd3LMEsP0PMM # CrsfDZS04Ztybl9M7TmJuwkAm1gx1JDMOuJuh18lbJocIOBvhkKKxY2wI5LIdZVI # ZntmU36RowkX+GGu/PYpYyMjBDClJppZCl7vnjyLYsVt6r0Vu6SmlHpJhcRYabhe # 96Kv1LXH9A6+ogKPU3Layw6JGjg01GNr1ALuT7PO3pGto/JshmOuBEJJDucoF84M # 5AfxFCohMROVldwblA6M0eKnlQBgtr5BvtgbV54BBo88VlFJgDJFQn7R09cTFUEo # UwaJoS+nIaiZ0bQQVZhZloVppUaTdVJojzfVRCZZctga96/tu1HSFnGLnbEFpUN3 # KOf+XnVNS6Ro+nPSDf9bMjbIom2JicGFfV+6yMgIoxY/d5UA2dTZfefil4TAlSod # 6PsTgg+jrm8= # =/Fw0 # -----END PGP SIGNATURE----- # gpg: Signature made Thu 27 Oct 2022 14:29:38 EDT # gpg: using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6 # gpg: issuer "kwolf@redhat.com" # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full] # Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6 * tag 'for-upstream' of https://repo.or.cz/qemu/kevin: (58 commits) block/block-backend: blk_set_enable_write_cache is IO_CODE monitor: switch to *_co_* functions vmdk: switch to *_co_* functions vhdx: switch to *_co_* functions vdi: switch to *_co_* functions qed: switch to *_co_* functions qcow2: switch to *_co_* functions qcow: switch to *_co_* functions parallels: switch to *_co_* functions mirror: switch to *_co_* functions block: switch to *_co_* functions commit: switch to *_co_* functions vmdk: manually add more coroutine_fn annotations qcow2: manually add more coroutine_fn annotations qcow: manually add more coroutine_fn annotations blkdebug: add missing coroutine_fn annotation for indirect-called functions qcow2: add coroutine_fn annotation for indirect-called functions block: add missing coroutine_fn annotation to BlockDriverState callbacks coroutine-io: add missing coroutine_fn annotation to prototypes coroutine-lock: add missing coroutine_fn annotation to prototypes ... Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-27block: switch to *_co_* functionsAlberto Faria
Signed-off-by: Alberto Faria <afaria@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221013123711.620631-16-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: remove bdrv_try_set_aio_context and replace it with ↵Emanuele Giuseppe Esposito
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>
2022-10-27block: rename bdrv_child_try_change_aio_context in bdrv_try_change_aio_contextEmanuele Giuseppe Esposito
No functional changes intended. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-10-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: remove all unused ->can_set_aio_ctx and ->set_aio_ctx callbacksEmanuele Giuseppe Esposito
Together with all _can_set_ and _set_ APIs, as they are not needed anymore. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-9-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: use the new _change_ API instead of _can_set_ and _set_Emanuele Giuseppe Esposito
Replace all direct usage of ->can_set_aio_ctx and ->set_aio_ctx, and call bdrv_child_try_change_aio_context() in bdrv_try_set_aio_context(), the main function called through the whole block layer. From this point onwards, ->can_set_aio_ctx and ->set_aio_ctx won't be used anymore. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-8-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: implement .change_aio_ctx in child_of_bdsEmanuele Giuseppe Esposito
bdrv_child_cb_change_aio_ctx() is identical to bdrv_child_cb_can_set_aio_ctx(), as we only need to recursively go on the parent bs. Note: bdrv_child_try_change_aio_context() is not called by anyone at this point. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-6-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27bdrv_change_aio_context: use hash table instead of list of visited nodesEmanuele Giuseppe Esposito
Minor performance improvement, but given that we have hash tables available, avoid iterating in the visited nodes list every time just to check if a node has been already visited. The data structure is not actually a proper hash map, but an hash set, as we are just adding nodes and not key,value pairs. Suggested-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-4-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: use transactions as a replacement of ->{can_}set_aio_context()Emanuele Giuseppe Esposito
Simplify the way the aiocontext can be changed in a BDS graph. There are currently two problems in bdrv_try_set_aio_context: - There is a confusion of AioContext locks taken and released, because we assume that old aiocontext is always taken and new one is taken inside. - It doesn't look very safe to call bdrv_drained_begin while some nodes have already switched to the new aiocontext and others haven't. This could be especially dangerous because bdrv_drained_begin polls, so something else could be executed while graph is in an inconsistent state. Additional minor nitpick: can_set and set_ callbacks both traverse the graph, both using the ignored list of visited nodes in a different way. Therefore, get rid of all of this and introduce a new callback, change_aio_context, that uses transactions to efficiently, cleanly and most importantly safely change the aiocontext of a graph. This new callback is a "merge" of the two previous ones: - Just like can_set_aio_context, recursively traverses the graph. Marks all nodes that are visited using a GList, and checks if they *could* change the aio_context. - For each node that passes the above check, drain it and add a new transaction that implements a callback that effectively changes the aiocontext. - Once done, the recursive function returns if *all* nodes can change the AioContext. If so, commit the above transactions. Regardless of the outcome, call transaction.clean() to undo all drains done in the recursion. - The transaction list is scanned only after all nodes are being drained, so we are sure that they all are in the same context, and then we switch their AioContext, concluding the drain only after all nodes switched to the new AioContext. In this way we make sure that bdrv_drained_begin() is always called under the old AioContext, and bdrv_drained_end() under the new one. - Because of the above, we don't need to release and re-acquire the old AioContext every time, as everything is done once (and not per-node drain and aiocontext change). Note that the "change" API is not yet invoked anywhere. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20221025084952.2139888-3-eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block.c: assert bs->aio_context is written under BQL and drainsEmanuele Giuseppe Esposito
Also here ->aio_context is read by I/O threads and written under BQL. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20221025084952.2139888-2-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: refactor bdrv_remove_file_or_backing_child to bdrv_remove_childVladimir Sementsov-Ogievskiy
Now the function can remove any child, so give it more common name. Drop assertions and drop bs argument which becomes unused. Function would be reused in a further commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220726201134.924743-16-vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: Manipulate bs->file / bs->backing pointers in .attach/.detachVladimir Sementsov-Ogievskiy
bs->file and bs->backing are a kind of duplication of part of bs->children. But very useful diplication, so let's not drop them at all:) We should manage bs->file and bs->backing in same place, where we manage bs->children, to keep them in sync. Moreover, generic io paths are unprepared to BdrvChild without a bs, so it's double good to clear bs->file / bs->backing when we detach the child. Detach is simple: if we detach bs->file or bs->backing child, just set corresponding field to NULL. Attach is a bit more complicated. But we still can precisely detect should we set one of bs->file / bs->backing or not: - if role is BDRV_CHILD_COW, we definitely deal with bs->backing - else, if role is BDRV_CHILD_FILTERED (it must be also BDRV_CHILD_PRIMARY), it's a filtered child. Use bs->drv->filtered_child_is_backing to chose the pointer field to modify. - else, if role is BDRV_CHILD_PRIMARY, we deal with bs->file - in all other cases, it's neither bs->backing nor bs->file. It's some other child and we shouldn't care OK. This change brings one more good thing: we can (and should) get rid of all indirect pointers in the block-graph-change transactions: bdrv_attach_child_common() stores BdrvChild** into transaction to clear it on abort. bdrv_attach_child_common() has two callers: bdrv_attach_child_noperm() just pass-through this feature, bdrv_root_attach_child() doesn't need the feature. Look at bdrv_attach_child_noperm() callers: - bdrv_attach_child() doesn't need the feature - bdrv_set_file_or_backing_noperm() uses the feature to manage bs->file and bs->backing, we don't want it anymore - bdrv_append() uses the feature to manage bs->backing, again we don't want it anymore So, we should drop this stuff! Great! We could probably keep BdrvChild** argument to keep the int return value, but it seems not worth the complexity. Finally, we now set .file / .backing automatically in generic code and want to restring setting them by hand outside of .attach/.detach. So, this patch cleanups all remaining places where they were set. To find such places I use: git grep '\->file =' git grep '\->backing =' git grep '&.*\<backing\>' git grep '&.*\<file\>' Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220726201134.924743-14-vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27Revert "block: Pass BdrvChild ** to replace_child_noperm"Vladimir Sementsov-Ogievskiy
That's a preparation to previously reverted "block: Let replace_child_noperm free children". Drop it too, we don't need it for a new approach. This reverts commit be64bbb0149748f3999c49b13976aafb8330ea86. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220726201134.924743-13-vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27Revert "block: Restructure remove_file_or_backing_child()"Vladimir Sementsov-Ogievskiy
That's a preparation to previously reverted "block: Let replace_child_noperm free children". Drop it too, we don't need it for a new approach. This reverts commit 562bda8bb41879eeda0bd484dd3d55134579b28e. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220726201134.924743-12-vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27Revert "block: Let replace_child_tran keep indirect pointer"Vladimir Sementsov-Ogievskiy
That's a preparation to previously reverted "block: Let replace_child_noperm free children". Drop it too, we don't need it for a new approach. This reverts commit 82b54cf51656bf3cd5ed1ac549e8a1085a0e3290. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220726201134.924743-11-vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27Revert "block: Let replace_child_noperm free children"Vladimir Sementsov-Ogievskiy
We are going to reimplement this behavior (clear bs->file / bs->backing pointers automatically when child->bs is cleared) in a nicer way, see further commit "block: Manipulate bs->file / bs->backing pointers in .attach/.detach". With this revert we bring back a problem that was fixed by b0a9f6fed3d8. Still the problem was mostly theoretical, we don't have concrete bugs fixed by b0a9f6fed3d8, we don't have a specific test. Probably some accidental failures of iotests are related. Alternatively, we may merge this and following three reverts into final "block: Manipulate ..." to avoid any kind of regression. But seems that in this case having separate clear revert commits is better. This reverts commit b0a9f6fed3d80de610dcd04a7e66f9f30a04174f. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220726201134.924743-10-vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: introduce bdrv_open_file_child() helperVladimir Sementsov-Ogievskiy
Almost all drivers call bdrv_open_child() similarly. Let's create a helper for this. The only not updated drivers that call bdrv_open_child() to set bs->file are raw-format and snapshot-access: raw-format sometimes want to have filtered child but don't set drv->is_filter to true. snapshot-access wants only DATA | PRIMARY Possibly we should implement drv->is_filter_func() handler, to consider raw-format as filter when it works as filter.. But it's another story. Note also, that we decrease assignments to bs->file in code: it helps us restrict modifying this field in further commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220726201134.924743-3-vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: Refactor get_tmp_filename()Bin Meng
At present there are two callers of get_tmp_filename() and they are inconsistent. One does: /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ char *tmp_filename = g_malloc0(PATH_MAX + 1); ... ret = get_tmp_filename(tmp_filename, PATH_MAX + 1); while the other does: s->qcow_filename = g_malloc(PATH_MAX); ret = get_tmp_filename(s->qcow_filename, PATH_MAX); As we can see different 'size' arguments are passed. There are also platform specific implementations inside the function, and the use of snprintf is really undesirable. The function name is also misleading. It creates a temporary file, not just a filename. Refactor this routine by changing its name and signature to: char *create_tmp_file(Error **errp) and use g_get_tmp_dir() / g_mkstemp() for a consistent implementation. While we are here, add some comments to mention that /var/tmp is preferred over /tmp on non-win32 hosts. Signed-off-by: Bin Meng <bin.meng@windriver.com> Message-Id: <20221010040432.3380478-2-bin.meng@windriver.com> [kwolf: Fixed incorrect errno negation and iotest 051] Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27block: Ignore close() failure in get_tmp_filename()Bin Meng
The temporary file has been created and is ready for use. Checking return value of close() does not seem useful. The file descriptor is almost certainly closed; see close(2) under "Dealing with error returns from close()". Let's simply ignore close() failure here. Suggested-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20221010040432.3380478-1-bin.meng@windriver.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-26block: add BDRV_REQ_REGISTERED_BUF request flagStefan Hajnoczi
Block drivers may optimize I/O requests accessing buffers previously registered with bdrv_register_buf(). Checking whether all elements of a request's QEMUIOVector are within previously registered buffers is expensive, so we need a hint from the user to avoid costly checks. Add a BDRV_REQ_REGISTERED_BUF request flag to indicate that all QEMUIOVector elements in an I/O request are known to be within previously registered buffers. Always pass the flag through to driver read/write functions. There is little harm in passing the flag to a driver that does not use it. Passing the flag to drivers avoids changes across many block drivers. Filter drivers would need to explicitly support the flag and pass through to their children when the children support it. That's a lot of code changes and it's hard to remember to do that everywhere, leading to silent reduced performance when the flag is accidentally dropped. The only problematic scenario with the approach in this patch is when a driver passes the flag through to internal I/O requests that don't use the same I/O buffer. In that case the hint may be set when it should actually be clear. This is a rare case though so the risk is low. Some drivers have assert(!flags), which no longer works when BDRV_REQ_REGISTERED_BUF is passed in. These assertions aren't very useful anyway since the functions are called almost exclusively by bdrv_driver_preadv/pwritev() so if we get flags handling right there then the assertion is not needed. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20221013185908.1297568-7-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-07jobs: group together API calls under the same job lockEmanuele Giuseppe Esposito
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>
2022-10-07block: add missing coroutine_fn annotationsPaolo Bonzini
Callers of coroutine_fn must be coroutine_fn themselves, or the call must be within "if (qemu_in_coroutine())". Apply coroutine_fn to functions where this holds. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20220922084924.201610-3-pbonzini@redhat.com> [kwolf: Fixed up coding style] Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>