From 53db8a71ecb42c2ec5e9c6925269a750255f9af5 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 4 Apr 2025 14:50:59 -0600 Subject: [PATCH] io_uring: add support for IORING_OP_PIPE This works just like pipe2(2), except it also supports fixed file descriptors. Used in a similar fashion as for other fd instantiating opcodes (like accept, socket, open, etc), where sqe->file_slot is set appropriately if two direct descriptors are desired rather than a set of normal file descriptors. sqe->addr must be set to a pointer to an array of 2 integers, which is where the fixed/normal file descriptors are copied to. sqe->pipe_flags contains flags, same as what is allowed for pipe2(2). Future expansion of per-op private flags can go in sqe->ioprio, like we do for other opcodes that take both a "syscall" flag set and an io_uring opcode specific flag set. Signed-off-by: Jens Axboe --- include/uapi/linux/io_uring.h | 2 + io_uring/opdef.c | 7 ++ io_uring/openclose.c | 133 ++++++++++++++++++++++++++++++++++ io_uring/openclose.h | 3 + 4 files changed, 145 insertions(+) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 8f1fc12bac46..130f3bc71a69 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -73,6 +73,7 @@ struct io_uring_sqe { __u32 futex_flags; __u32 install_fd_flags; __u32 nop_flags; + __u32 pipe_flags; }; __u64 user_data; /* data to be passed back at completion time */ /* pack this to avoid bogus arm OABI complaints */ @@ -283,6 +284,7 @@ enum io_uring_op { IORING_OP_EPOLL_WAIT, IORING_OP_READV_FIXED, IORING_OP_WRITEV_FIXED, + IORING_OP_PIPE, /* this goes last, obviously */ IORING_OP_LAST, diff --git a/io_uring/opdef.c b/io_uring/opdef.c index 489384c0438b..db36433c2294 100644 --- a/io_uring/opdef.c +++ b/io_uring/opdef.c @@ -569,6 +569,10 @@ const struct io_issue_def io_issue_defs[] = { .prep = io_prep_writev_fixed, .issue = io_write, }, + [IORING_OP_PIPE] = { + .prep = io_pipe_prep, + .issue = io_pipe, + }, }; const struct io_cold_def io_cold_defs[] = { @@ -815,6 +819,9 @@ const struct io_cold_def io_cold_defs[] = { .cleanup = io_readv_writev_cleanup, .fail = io_rw_fail, }, + [IORING_OP_PIPE] = { + .name = "PIPE", + }, }; const char *io_uring_get_opcode(u8 opcode) diff --git a/io_uring/openclose.c b/io_uring/openclose.c index e3357dfa14ca..4dd461163457 100644 --- a/io_uring/openclose.c +++ b/io_uring/openclose.c @@ -6,6 +6,8 @@ #include #include #include +#include +#include #include #include @@ -302,3 +304,134 @@ int io_install_fixed_fd(struct io_kiocb *req, unsigned int issue_flags) io_req_set_res(req, ret, 0); return IOU_OK; } + +struct io_pipe { + struct file *file; + int __user *fds; + int flags; + int file_slot; + unsigned long nofile; +}; + +int io_pipe_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + + if (sqe->fd || sqe->off || sqe->addr3) + return -EINVAL; + + p->fds = u64_to_user_ptr(READ_ONCE(sqe->addr)); + p->flags = READ_ONCE(sqe->pipe_flags); + if (p->flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT | O_NOTIFICATION_PIPE)) + return -EINVAL; + + p->file_slot = READ_ONCE(sqe->file_index); + p->nofile = rlimit(RLIMIT_NOFILE); + return 0; +} + +static int io_pipe_fixed(struct io_kiocb *req, struct file **files, + unsigned int issue_flags) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + struct io_ring_ctx *ctx = req->ctx; + int ret, fds[2] = { -1, -1 }; + int slot = p->file_slot; + + if (p->flags & O_CLOEXEC) + return -EINVAL; + + io_ring_submit_lock(ctx, issue_flags); + + ret = __io_fixed_fd_install(ctx, files[0], slot); + if (ret < 0) + goto err; + fds[0] = ret; + files[0] = NULL; + + /* + * If a specific slot is given, next one will be used for + * the write side. + */ + if (slot != IORING_FILE_INDEX_ALLOC) + slot++; + + ret = __io_fixed_fd_install(ctx, files[1], slot); + if (ret < 0) + goto err; + fds[1] = ret; + files[1] = NULL; + + io_ring_submit_unlock(ctx, issue_flags); + + if (!copy_to_user(p->fds, fds, sizeof(fds))) + return 0; + + ret = -EFAULT; + io_ring_submit_lock(ctx, issue_flags); +err: + if (fds[0] != -1) + io_fixed_fd_remove(ctx, fds[0]); + if (fds[1] != -1) + io_fixed_fd_remove(ctx, fds[1]); + io_ring_submit_unlock(ctx, issue_flags); + return ret; +} + +static int io_pipe_fd(struct io_kiocb *req, struct file **files) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + int ret, fds[2] = { -1, -1 }; + + ret = __get_unused_fd_flags(p->flags, p->nofile); + if (ret < 0) + goto err; + fds[0] = ret; + + ret = __get_unused_fd_flags(p->flags, p->nofile); + if (ret < 0) + goto err; + fds[1] = ret; + + if (!copy_to_user(p->fds, fds, sizeof(fds))) { + fd_install(fds[0], files[0]); + fd_install(fds[1], files[1]); + return 0; + } + ret = -EFAULT; +err: + if (fds[0] != -1) + put_unused_fd(fds[0]); + if (fds[1] != -1) + put_unused_fd(fds[1]); + return ret; +} + +int io_pipe(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + struct file *files[2]; + int ret; + + ret = create_pipe_files(files, p->flags); + if (ret) + return ret; + files[0]->f_mode |= FMODE_NOWAIT; + files[1]->f_mode |= FMODE_NOWAIT; + + if (!!p->file_slot) + ret = io_pipe_fixed(req, files, issue_flags); + else + ret = io_pipe_fd(req, files); + + io_req_set_res(req, ret, 0); + if (!ret) + return IOU_OK; + + req_set_fail(req); + if (files[0]) + fput(files[0]); + if (files[1]) + fput(files[1]); + return ret; +} diff --git a/io_uring/openclose.h b/io_uring/openclose.h index 8a93c98ad0ad..4ca2a9935abc 100644 --- a/io_uring/openclose.h +++ b/io_uring/openclose.h @@ -13,5 +13,8 @@ int io_openat2(struct io_kiocb *req, unsigned int issue_flags); int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); int io_close(struct io_kiocb *req, unsigned int issue_flags); +int io_pipe_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_pipe(struct io_kiocb *req, unsigned int issue_flags); + int io_install_fixed_fd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); int io_install_fixed_fd(struct io_kiocb *req, unsigned int issue_flags); -- 2.50.1