sched/wqueue: restore -ENOENT from work_cancel() for unqueued work - #20112
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work_cancel() used to return -ENOENT when the work structure was not in the queue, and callers depend on that: aio_cancel() tears down the AIO container (file_put() + aioc_free()) only when work_cancel() reports success, because a work item that is not queued may already be executing on a worker thread (see the comment in fs/aio/aio_cancel.c). Since commit 6f72f54 ("sched/wqueue: Refactor delayed and periodical workqueue") work_cancel() returns OK unconditionally, and commit d2e01b9 ("sched/wqueue: harden custom queue lifecycle") kept that behaviour and dropped -ENOENT from the function documentation. Under SMP the LTP aio_cancel tests then free the aio container and its file while the lpwork thread is still executing aio_write_worker() on it, which ends in a page fault in file_write() (f_inode == NULL) and a panic. Return -ENOENT again when the work is not queued, and document it. For the synchronous variant "not queued" alone does not tell whether the callback is running: the worker scan does, so report OK when a running callback was found and waited for, and -ENOENT only when the work was neither queued nor running. Assisted-by: Claude Code Signed-off-by: raiden00pl <raiden00@railab.me>
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michallenc
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Sep 11, 2026
xiaoxiang781216
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Sep 13, 2026
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Summary
work_cancel() used to return -ENOENT when the work structure was not in the queue, and callers depend on that: aio_cancel() tears down the AIO container (file_put() + aioc_free()) only when work_cancel() reports success, because a work item that is not queued may already be executing on a worker thread (see the comment in fs/aio/aio_cancel.c).
Since commit 6f72f54 ("sched/wqueue: Refactor delayed and periodical workqueue") work_cancel() returns OK unconditionally, and commit d2e01b9 ("sched/wqueue: harden custom queue lifecycle") kept that behaviour and dropped -ENOENT from the function documentation. Under SMP the LTP aio_cancel tests then free the aio container and its file while the lpwork thread is still executing aio_write_worker() on it, which ends in a page fault in file_write() (f_inode == NULL) and a panic.
Return -ENOENT again when the work is not queued, and document it. For the synchronous variant "not queued" alone does not tell whether the callback is running: the worker scan does, so report OK when a running callback was found and waited for, and -ENOENT only when the work was neither queued nor running.
taken from #20030
Impact
required for SMP intel64 to pass LPT tests
Testing
CI pass: https://github.com/apache/nuttx/actions/runs/34236734404/job/102183306099?pr=20030