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2025-02-12io_uring/waitid: setup async data in the prep handlerJens Axboe
This is the idiomatic way that opcodes should setup their async data, so that it's always valid inside ->issue() without issue needing to do that. Fixes: f31ecf671ddc4 ("io_uring: add IORING_OP_WAITID support") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-02-12io_uring/waitid: don't abuse io_tw_statePavel Begunkov
struct io_tw_state is managed by core io_uring, and opcode handling code must never try to cheat and create their own instances, it's plain incorrect. io_waitid_complete() attempts exactly that outside of the task work context, and even though the ring is locked, there would be no one to reap the requests from the defer completion list. It only works now because luckily it's called before io_uring_try_cancel_uring_cmd(), which flushes completions. Fixes: f31ecf671ddc4 ("io_uring: add IORING_OP_WAITID support") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-23io_uring/alloc_cache: get rid of _nocache() helperJens Axboe
Just allow passing in NULL for the cache, if the type in question doesn't have a cache associated with it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring: Move old async data allocation helper to headerGabriel Krisman Bertazi
There are two remaining uses of the old async data allocator that do not rely on the alloc cache. I don't want to make them use the new allocator helper because that would require a if(cache) check, which will result in dead code for the cached case (for callers passing a cache, gcc can't prove the cache isn't NULL, and will therefore preserve the check. Since this is an inline function and just a few lines long, keep a second helper to deal with cases where we don't have an async data cache. No functional change intended here. This is just moving the helper around and making it inline. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-9-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-06io_uring: move struct io_kiocb from task_struct to io_uring_taskJens Axboe
Rather than store the task_struct itself in struct io_kiocb, store the io_uring specific task_struct. The life times are the same in terms of io_uring, and this avoids doing some dereferences through the task_struct. For the hot path of putting local task references, we can deref req->tctx instead, which we'll need anyway in that function regardless of whether it's local or remote references. This is mostly straight forward, except the original task PF_EXITING check needs a bit of tweaking. task_work is _always_ run from the originating task, except in the fallback case, where it's run from a kernel thread. Replace the potentially racy (in case of fallback work) checks for req->task->flags with current->flags. It's either the still the original task, in which case PF_EXITING will be sane, or it has PF_KTHREAD set, in which case it's fallback work. Both cases should prevent moving forward with the given request. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-06io_uring: move cancelations to be io_uring_task basedJens Axboe
Right now the task_struct pointer is used as the key to match a task, but in preparation for some io_kiocb changes, move it to using struct io_uring_task instead. No functional changes intended in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15io_uring: remove struct io_tw_state::lockedPavel Begunkov
ctx is always locked for task_work now, so get rid of struct io_tw_state::locked. Note I'm stopping one step before removing io_tw_state altogether, which is not empty, because it still serves the purpose of indicating which function is a tw callback and forcing users not to invoke them carelessly out of a wrong context. The removal can always be done later. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/e95e1ea116d0bfa54b656076e6a977bc221392a4.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-15io_uring/waitid: always remove waitid entry for cancel allJens Axboe
We know the request is either being removed, or already in the process of being removed through task_work, so we can delete it from our waitid list upfront. This is important for remove all conditions, as we otherwise will find it multiple times and prevent cancelation progress. Remove the dead check in cancelation as well for the hash_node being empty or not. We already have a waitid reference check for ownership, so we don't need to check the list too. Cc: stable@vger.kernel.org Fixes: f31ecf671ddc ("io_uring: add IORING_OP_WAITID support") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-21io_uring: add IORING_OP_WAITID supportJens Axboe
This adds support for an async version of waitid(2), in a fully async version. If an event isn't immediately available, wait for a callback to trigger a retry. The format of the sqe is as follows: sqe->len The 'which', the idtype being queried/waited for. sqe->fd The 'pid' (or id) being waited for. sqe->file_index The 'options' being set. sqe->addr2 A pointer to siginfo_t, if any, being filled in. buf_index, add3, and waitid_flags are reserved/unused for now. waitid_flags will be used for options for this request type. One interesting use case may be to add multi-shot support, so that the request stays armed and posts a notification every time a monitored process state change occurs. Note that this does not support rusage, on Arnd's recommendation. See the waitid(2) man page for details on the arguments. Signed-off-by: Jens Axboe <axboe@kernel.dk>