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path: root/include/linux/io_uring.h
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2022-05-11fs,io_uring: add infrastructure for uring-cmdJens Axboe
file_operations->uring_cmd is a file private handler. This is somewhat similar to ioctl but hopefully a lot more sane and useful as it can be used to enable many io_uring capabilities for the underlying operation. IORING_OP_URING_CMD is a file private kind of request. io_uring doesn't know what is in this command type, it's for the provider of ->uring_cmd() to deal with. Co-developed-by: Kanchan Joshi <joshi.k@samsung.com> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220511054750.20432-2-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-26io_uring: add io_uring_get_opcodeDylan Yudaken
In some debug scenarios it is useful to have the text representation of the opcode. Add this function in preparation. Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220426082907.3600028-3-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-03-10io_uring: add support for registering ring file descriptorsJens Axboe
Lots of workloads use multiple threads, in which case the file table is shared between them. This makes getting and putting the ring file descriptor for each io_uring_enter(2) system call more expensive, as it involves an atomic get and put for each call. Similarly to how we allow registering normal file descriptors to avoid this overhead, add support for an io_uring_register(2) API that allows to register the ring fds themselves: 1) IORING_REGISTER_RING_FDS - takes an array of io_uring_rsrc_update structs, and registers them with the task. 2) IORING_UNREGISTER_RING_FDS - takes an array of io_uring_src_update structs, and unregisters them. When a ring fd is registered, it is internally represented by an offset. This offset is returned to the application, and the application then uses this offset and sets IORING_ENTER_REGISTERED_RING for the io_uring_enter(2) system call. This works just like using a registered file descriptor, rather than a real one, in an SQE, where IOSQE_FIXED_FILE gets set to tell io_uring that we're using an internal offset/descriptor rather than a real file descriptor. In initial testing, this provides a nice bump in performance for threaded applications in real world cases where the batch count (eg number of requests submitted per io_uring_enter(2) invocation) is low. In a microbenchmark, submitting NOP requests, we see the following increases in performance: Requests per syscall Baseline Registered Increase ---------------------------------------------------------------- 1 ~7030K ~8080K +15% 2 ~13120K ~14800K +13% 4 ~22740K ~25300K +11% Co-developed-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: remove files pointer in cancellation functionsHao Xu
When doing cancellation, we use a parameter to indicate where it's from do_exit or exec. So a boolean value is good enough for this, remove the struct files* as it is not necessary. Signed-off-by: Hao Xu <haoxu@linux.alibaba.com> [axboe: fixup io_uring_files_cancel for !CONFIG_IO_URING] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: extract io_uring_files_cancel() in io_uring_task_cancel()Hao Xu
Extract io_uring_files_cancel() call in io_uring_task_cancel() to make io_uring_files_cancel() and io_uring_task_cancel() coherent and easy to read. Signed-off-by: Hao Xu <haoxu@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11io_uring: unify files and task cancelPavel Begunkov
Now __io_uring_cancel() and __io_uring_files_cancel() are very similar and mostly differ by how we count requests, merge them and allow tctx_inflight() to handle counting. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1a5986a97df4dc1378f3fe0ca1eb483dbcf42112.1618101759.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-18io_uring: remove structures from include/linux/io_uring.hStefan Metzmacher
Link: https://lore.kernel.org/r/8c1d14f3748105f4caeda01716d47af2fa41d11c.1615809009.git.metze@samba.org Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-07io_uring: index io_uring->xa by ctx not filePavel Begunkov
We don't use task file notes anymore, and no need left in indexing task->io_uring->xa by file, and replace it with ctx. It's better design-wise, especially since we keep a dangling file, and so have to keep an eye on not dereferencing it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-04io_uring: destroy io-wq on execPavel Begunkov
Destroy current's io-wq backend and tctx on __io_uring_task_cancel(), aka exec(). Looks it's not strictly necessary, because it will be done at some point when the task dies and changes of creds/files/etc. are handled, but better to do that earlier to free io-wq and not potentially lock previous mm and other resources for the time being. It's safe to do because we wait for all requests of the current task to complete, so no request will use tctx afterwards. Note, that io_uring_files_cancel() may leave some requests for later reaping, so it leaves tctx intact, that's ok as the task is dying anyway. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-23io_uring: ensure io-wq context is always destroyed for tasksJens Axboe
If the task ends up doing no IO, the context list is empty and we don't call into __io_uring_files_cancel() when the task exits. This can cause a leak of the io-wq structures. Ensure we always call __io_uring_files_cancel(), even if the task context list is empty. Fixes: 5aa75ed5b93f ("io_uring: tie async worker side to the task context") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-21io_uring: remove io_identityJens Axboe
We are no longer grabbing state, so no need to maintain an IO identity that we COW if there are changes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-21io_uring: tie async worker side to the task contextJens Axboe
Move it outside of the io_ring_ctx, and tie it to the io_uring task context. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-10io_uring: provide FIFO ordering for task_workJens Axboe
task_work is a LIFO list, due to how it's implemented as a lockless list. For long chains of task_work, this can be problematic as the first entry added is the last one processed. Similarly, we'd waste a lot of CPU cycles reversing this list. Wrap the task_work so we have a single task_work entry per task per ctx, and use that to run it in the right order. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-04io_uring: properly handle SQPOLL request cancelationsJens Axboe
Track if a given task io_uring context contains SQPOLL instances, so we can iterate those for cancelation (and request counts). This ensures that we properly wait on SQPOLL contexts, and find everything that needs canceling. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17io-wq: inherit audit loginuid and sessionidJens Axboe
Make sure the async io-wq workers inherit the loginuid and sessionid from the original task, and restore them to unset once we're done with the async work item. While at it, disable the ability for kernel threads to write to their own loginuid. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17io_uring: use percpu counters to track inflight requestsJens Axboe
Even though we place the req_issued and req_complete in separate cachelines, there's considerable overhead in doing the atomics particularly on the completion side. Get rid of having the two counters, and just use a percpu_counter for this. That's what it was made for, after all. This considerably reduces the overhead in __io_free_req(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17io_uring: assign new io_identity for task if members have changedJens Axboe
This avoids doing a copy for each new async IO, if some parts of the io_identity has changed. We avoid reference counting for the normal fast path of nothing ever changing. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17io_uring: store io_identity in io_uring_taskJens Axboe
This is, by definition, a per-task structure. So store it in the task context, instead of doing carrying it in each io_kiocb. We're being a bit inefficient if members have changed, as that requires an alloc and copy of a new io_identity struct. The next patch will fix that up. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17io_uring: COW io_identity on mismatchJens Axboe
If the io_identity doesn't completely match the task, then create a copy of it and use that. The existing copy remains valid until the last user of it has gone away. This also changes the personality lookup to be indexed by io_identity, instead of creds directly. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17io_uring: move io identity items into separate structJens Axboe
io-wq contains a pointer to the identity, which we just hold in io_kiocb for now. This is in preparation for putting this outside io_kiocb. The only exception is struct files_struct, which we'll need different rules for to avoid a circular dependency. No functional changes in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30io_uring: move io_uring_get_socket() into io_uring.hJens Axboe
Now we have a io_uring kernel header, move this definition out of fs.h and into io_uring.h where it belongs. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30io_uring: don't rely on weak ->files referencesJens Axboe
Grab actual references to the files_struct. To avoid circular references issues due to this, we add a per-task note that keeps track of what io_uring contexts a task has used. When the tasks execs or exits its assigned files, we cancel requests based on this tracking. With that, we can grab proper references to the files table, and no longer need to rely on stashing away ring_fd and ring_file to check if the ring_fd may have been closed. Cc: stable@vger.kernel.org # v5.5+ Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>