kernel.git/io_uring/io_uring.h, branch linux-6.4.y

io_uring: fix false positive KASAN warnings

2023-09-13T07:48:39Z

commit 569f5308e54352a12181cc0185f848024c5443e8 upstream. io_req_local_work_add() peeks into the work list, which can be executed in the meanwhile. It's completely fine without KASAN as we're in an RCU read section and it's SLAB_TYPESAFE_BY_RCU. With KASAN though it may trigger a false positive warning because internal io_uring caches are sanitised. Remove sanitisation from the io_uring request cache for now. Cc: stable@vger.kernel.org Fixes: 8751d15426a31 ("io_uring: reduce scheduling due to tw") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/c6fbf7a82a341e66a0007c76eefd9d57f2d3ba51.1691541473.git.asml.silence@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: Create a helper to return the SQE size

2023-05-04T14:19:05Z

Create a simple helper that returns the size of the SQE. The SQE could have two size, depending of the flags. If IO_URING_SETUP_SQE128 flag is set, then return a double SQE, otherwise returns the sizeof of io_uring_sqe (64 bytes). Signed-off-by: Breno Leitao Reviewed-by: Christoph Hellwig Reviewed-by: Pavel Begunkov Link: https://lore.kernel.org/r/20230504121856.904491-2-leitao@debian.org Signed-off-by: Jens Axboe

io_uring: add irq lockdep checks

2023-04-12T18:09:41Z

We don't post CQEs from the IRQ context, add a check catching that. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/f23f7a24dbe8027b3d37873fece2b6488f878b31.1681210788.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: reduce scheduling due to tw

2023-04-06T22:23:28Z

Every task_work will try to wake the task to be executed, which causes excessive scheduling and additional overhead. For some tw it's justified, but others won't do much but post a single CQE. When a task waits for multiple cqes, every such task_work will wake it up. Instead, the task may give a hint about how many cqes it waits for, io_req_local_work_add() will compare against it and skip wake ups if #cqes + #tw is not enough to satisfy the waiting condition. Task_work that uses the optimisation should be simple enough and never post more than one CQE. It's also ignored for non DEFER_TASKRUN rings. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/d2b77e99d1e86624d8a69f7037d764b739dcd225.1680782017.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: add tw add flags

2023-04-06T22:23:28Z

We pass 'allow_local' into io_req_task_work_add() but will need more flags. Replace it with a flags bit field and name this allow_local flag. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/4c0f01e7ef4e6feebfb199093cc995af7a19befa.1680782017.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: refactor io_cqring_wake()

2023-04-06T22:23:28Z

Instead of smp_mb() + __io_cqring_wake() in __io_cq_unlock_post_flush() use equivalent io_cqring_wake(). With that we can clean it up further and remove __io_cqring_wake(). Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/662ee5d898168ac206be06038525e97b64072a46.1680782017.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: cap io_sqring_entries() at SQ ring size

2023-04-03T13:16:15Z

We already do this manually for the !SQPOLL case, do it in general and we can also dump the ugly min3() in io_submit_sqes(). Signed-off-by: Jens Axboe

io_uring: encapsulate task_work state

2023-04-03T13:16:15Z

For task works we're passing around a bool pointer for whether the current ring is locked or not, let's wrap it in a structure, that will make it more opaque preventing abuse and will also help us to pass more info in the future if needed. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/1ecec9483d58696e248d1bfd52cf62b04442df1d.1679931367.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: mark task TASK_RUNNING before handling resume/task work

2023-02-06T15:23:21Z

Just like for task_work, set the task mode to TASK_RUNNING before doing any potential resume work. We're not holding any locks at this point, but we may have already set the task state to TASK_INTERRUPTIBLE in preparation for going to sleep waiting for events. Ensure that we set it back to TASK_RUNNING if we have work to process, to avoid warnings on calling blocking operations with !TASK_RUNNING. Fixes: b5d3ae202fbf ("io_uring: handle TIF_NOTIFY_RESUME when checking for task_work") Reported-by: kernel test robot Link: https://lore.kernel.org/oe-lkp/202302062208.24d3e563-oliver.sang@intel.com Signed-off-by: Jens Axboe

io_uring: refactor req allocation

2023-01-29T22:17:41Z

Follow the io_get_sqe pattern returning the result via a pointer and hide request cache refill inside io_alloc_req(). Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/8c37c2e8a3cb5e4cd6a8ae3b91371227a92708a6.1674484266.git.asml.silence@gmail.com Signed-off-by: Jens Axboe