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2025-02-28io_uring/nop: use io_find_buf_node()Caleb Sander Mateos
Call io_find_buf_node() to avoid duplicating it in io_nop(). Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Link: https://lore.kernel.org/r/20250301001610.678223-2-csander@purestorage.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-02-27io_uring/nop: reuse req->buf_indexKeith Busch
There is already a field in io_kiocb that can store a registered buffer index, use that instead of stashing the value into struct io_nop. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250224213116.3509093-3-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-21io_uring/nop: ensure nop->fd is always initializedJens Axboe
A previous commit added file support for nop, but it only initializes nop->fd if IORING_NOP_FIXED_FILE is set. That check should be IORING_NOP_FILE. Fix up the condition in nop preparation, and initialize it to a sane value even if we're not going to be directly using it. While in there, do the same thing for the nop->buffer field. Reported-by: syzbot+9a8500a45c2cabdf9577@syzkaller.appspotmail.com Fixes: a85f31052bce ("io_uring/nop: add support for testing registered files and buffers") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-07io_uring/rsrc: add & apply io_req_assign_buf_node()Ming Lei
The following pattern becomes more and more: + io_req_assign_rsrc_node(&req->buf_node, node); + req->flags |= REQ_F_BUF_NODE; so make it a helper, which is less fragile to use than above code, for example, the BUF_NODE flag is even missed in current io_uring_cmd_prep(). Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20241107110149.890530-4-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-06io_uring/rsrc: split io_kiocb node type assignmentsJens Axboe
Currently the io_rsrc_node assignment in io_kiocb is an array of two pointers, as two nodes may be assigned to a request - one file node, and one buffer node. However, the buffer node can co-exist with the provided buffers, as currently it's not supported to use both provided and registered buffers at the same time. This crucially brings struct io_kiocb down to 4 cache lines again, as before it spilled into the 5th cacheline. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-02io_uring/rsrc: add io_rsrc_node_lookup() helperJens Axboe
There are lots of spots open-coding this functionality, add a generic helper that does the node lookup in a speculation safe way. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-02io_uring/rsrc: unify file and buffer resource tablesJens Axboe
For files, there's nr_user_files/file_table/file_data, and buffers have nr_user_bufs/user_bufs/buf_data. There's no reason why file_table and file_data can't be the same thing, and ditto for the buffer side. That gets rid of more io_ring_ctx state that's in two spots rather than just being in one spot, as it should be. Put all the registered file data in one locations, and ditto on the buffer front. This also avoids having both io_rsrc_data->nodes being an allocated array, and ->user_bufs[] or ->file_table.nodes. There's no reason to have this information duplicated. Keep it in one spot, io_rsrc_data, along with how many resources are available. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-02io_uring/rsrc: get rid of per-ring io_rsrc_node listJens Axboe
Work in progress, but get rid of the per-ring serialization of resource nodes, like registered buffers and files. Main issue here is that one node can otherwise hold up a bunch of other nodes from getting freed, which is especially a problem for file resource nodes and networked workloads where some descriptors may not see activity in a long time. As an example, instantiate an io_uring ring fd and create a sparse registered file table. Even 2 will do. Then create a socket and register it as fixed file 0, F0. The number of open files in the app is now 5, with 0/1/2 being the usual stdin/out/err, 3 being the ring fd, and 4 being the socket. Register this socket (eg "the listener") in slot 0 of the registered file table. Now add an operation on the socket that uses slot 0. Finally, loop N times, where each loop creates a new socket, registers said socket as a file, then unregisters the socket, and finally closes the socket. This is roughly similar to what a basic accept loop would look like. At the end of this loop, it's not unreasonable to expect that there would still be 5 open files. Each socket created and registered in the loop is also unregistered and closed. But since the listener socket registered first still has references to its resource node due to still being active, each subsequent socket unregistration is stuck behind it for reclaim. Hence 5 + N files are still open at that point, where N is awaiting the final put held up by the listener socket. Rewrite the io_rsrc_node handling to NOT rely on serialization. Struct io_kiocb now gets explicit resource nodes assigned, with each holding a reference to the parent node. A parent node is either of type FILE or BUFFER, which are the two types of nodes that exist. A request can have two nodes assigned, if it's using both registered files and buffers. Since request issue and task_work completion is both under the ring private lock, no atomics are needed to handle these references. It's a simple unlocked inc/dec. As before, the registered buffer or file table each hold a reference as well to the registered nodes. Final put of the node will remove the node and free the underlying resource, eg unmap the buffer or put the file. Outside of removing the stall in resource reclaim described above, it has the following advantages: 1) It's a lot simpler than the previous scheme, and easier to follow. No need to specific quiesce handling anymore. 2) There are no resource node allocations in the fast path, all of that happens at resource registration time. 3) The structs related to resource handling can all get simplified quite a bit, like io_rsrc_node and io_rsrc_data. io_rsrc_put can go away completely. 4) Handling of resource tags is much simpler, and doesn't require persistent storage as it can simply get assigned up front at registration time. Just copy them in one-by-one at registration time and assign to the resource node. The only real downside is that a request is now explicitly limited to pinning 2 resources, one file and one buffer, where before just assigning a resource node to a request would pin all of them. The upside is that it's easier to follow now, as an individual resource is explicitly referenced and assigned to the request. With this in place, the above mentioned example will be using exactly 5 files at the end of the loop, not N. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/nop: add support for testing registered files and buffersJens Axboe
Useful for testing performance/efficiency impact of registered files and buffers, vs (particularly) non-registered files. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-10io_uring: support to inject result for NOPMing Lei
Support to inject result for NOP so that we can inject failure from userspace. It is very helpful for covering failure handling code in io_uring core change. With nop flags, it becomes possible to add more test features on NOP in future. Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20240510035031.78874-3-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-10io_uring: fail NOP if non-zero op flags is passed inMing Lei
The NOP op flags should have been checked from beginning like any other opcode, otherwise NOP may not be extended with the op flags. Given both liburing and Rust io-uring crate always zeros SQE op flags, just ignore users which play raw NOP uring interface without zeroing SQE, because NOP is just for test purpose. Then we can save one NOP2 opcode. Suggested-by: Jens Axboe <axboe@kernel.dk> Fixes: 2b188cc1bb85 ("Add io_uring IO interface") Cc: stable@vger.kernel.org Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20240510035031.78874-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: kill extra io_uring_types.h includesPavel Begunkov
io_uring/io_uring.h already includes io_uring_types.h, no need to include it every time. Kill it in a bunch of places, it prepares us for following patches. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/94d8c943fbe0ef949981c508ddcee7fc1c18850f.1655384063.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: move nop into its own fileJens Axboe
Signed-off-by: Jens Axboe <axboe@kernel.dk>