From: Jens Axboe <[email protected]>
To: io-uring <[email protected]>
Cc: Pavel Begunkov <[email protected]>,
Christian Brauner <[email protected]>
Subject: Re: [PATCH] io_uring/openclose: add support for IORING_OP_FIXED_FD_INSTALL
Date: Thu, 7 Dec 2023 20:13:20 -0700 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
Here's a sample test case showing the various transformations and
testing validity.
/* SPDX-License-Identifier: MIT */
/*
* Description: test installing a direct descriptor into the regular
* file table
*
*/
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include "liburing.h"
#include "helpers.h"
static int no_fd_install;
static void io_uring_prep_fixed_fd_install(struct io_uring_sqe *sqe, int fd)
{
memset(sqe, 0, sizeof(*sqe));
sqe->opcode = IORING_OP_FIXED_FD_INSTALL;
sqe->fd = fd;
}
int main(int argc, char *argv[])
{
struct io_uring_sqe *sqe;
struct io_uring_cqe *cqe;
struct io_uring ring;
int ret, fds[2];
char buf[32];
if (argc > 1)
return T_EXIT_SKIP;
ret = io_uring_queue_init(1, &ring, 0);
if (ret) {
fprintf(stderr, "ring setup failed: %d\n", ret);
return T_EXIT_FAIL;
}
if (pipe(fds) < 0) {
perror("pipe");
return T_EXIT_FAIL;
}
/* register read side */
ret = io_uring_register_files(&ring, &fds[0], 1);
if (ret) {
fprintf(stderr, "failed register files %d\n", ret);
return T_EXIT_FAIL;
}
/* close normal descriptor */
close(fds[0]);
/* normal read should fail */
ret = read(fds[0], buf, 1);
if (ret != -1) {
fprintf(stderr, "unexpected read ret %d\n", ret);
return T_EXIT_FAIL;
}
if (errno != EBADF) {
fprintf(stderr, "unexpected read failure %d\n", errno);
return T_EXIT_FAIL;
}
/* verify we can read the data */
sqe = io_uring_get_sqe(&ring);
io_uring_prep_read(sqe, 0, buf, sizeof(buf), 0);
sqe->flags = IOSQE_FIXED_FILE;
io_uring_submit(&ring);
/* put some data in the pipe */
write(fds[1], "Hello", 5);
ret = io_uring_wait_cqe(&ring, &cqe);
if (ret) {
fprintf(stderr, "wait cqe %d\n", ret);
return T_EXIT_FAIL;
}
if (cqe->res != 5) {
fprintf(stderr, "weird pipe read ret %d\n", cqe->res);
return T_EXIT_FAIL;
}
io_uring_cqe_seen(&ring, cqe);
/* fixed pipe read worked, now re-install as a regular fd */
sqe = io_uring_get_sqe(&ring);
io_uring_prep_fixed_fd_install(sqe, 0);
sqe->flags = IOSQE_FIXED_FILE;
io_uring_submit(&ring);
ret = io_uring_wait_cqe(&ring, &cqe);
if (ret) {
fprintf(stderr, "wait cqe %d\n", ret);
return T_EXIT_FAIL;
}
if (cqe->res == -EINVAL) {
no_fd_install = 1;
return T_EXIT_SKIP;
}
if (cqe->res < 0) {
fprintf(stderr, "failed install fd: %d\n", cqe->res);
return T_EXIT_FAIL;
}
/* stash new pipe read side fd in old spot */
fds[0] = cqe->res;
io_uring_cqe_seen(&ring, cqe);
write(fds[1], "Hello", 5);
/* normal pipe read should now work with new fd */
ret = read(fds[0], buf, sizeof(buf));
if (ret != 5) {
fprintf(stderr, "unexpected read ret %d\n", ret);
return T_EXIT_FAIL;
}
/* close fixed file */
sqe = io_uring_get_sqe(&ring);
io_uring_prep_close_direct(sqe, 0);
io_uring_submit(&ring);
ret = io_uring_wait_cqe(&ring, &cqe);
if (ret) {
fprintf(stderr, "wait cqe %d\n", ret);
return T_EXIT_FAIL;
}
if (cqe->res) {
fprintf(stderr, "close fixed fd %d\n", cqe->res);
return T_EXIT_FAIL;
}
io_uring_cqe_seen(&ring, cqe);
write(fds[1], "Hello", 5);
/* normal pipe read should still work with new fd */
ret = read(fds[0], buf, sizeof(buf));
if (ret != 5) {
fprintf(stderr, "unexpected read ret %d\n", ret);
return T_EXIT_FAIL;
}
/* fixed fd pipe read should now fail */
sqe = io_uring_get_sqe(&ring);
io_uring_prep_read(sqe, 0, buf, sizeof(buf), 0);
sqe->flags = IOSQE_FIXED_FILE;
io_uring_submit(&ring);
/* put some data in the pipe */
write(fds[1], "Hello", 5);
ret = io_uring_wait_cqe(&ring, &cqe);
if (ret) {
fprintf(stderr, "wait cqe %d\n", ret);
return T_EXIT_FAIL;
}
if (cqe->res != -EBADF) {
fprintf(stderr, "weird pipe read ret %d\n", cqe->res);
return T_EXIT_FAIL;
}
io_uring_cqe_seen(&ring, cqe);
return T_EXIT_PASS;
}
--
Jens Axboe
next prev parent reply other threads:[~2023-12-08 3:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-08 3:11 [PATCH] io_uring/openclose: add support for IORING_OP_FIXED_FD_INSTALL Jens Axboe
2023-12-08 3:13 ` Jens Axboe [this message]
2023-12-08 21:14 ` Christian Brauner
2023-12-08 21:49 ` Jens Axboe
2023-12-08 21:56 ` Christian Brauner
2023-12-08 22:06 ` Jens Axboe
2023-12-08 22:08 ` Christian Brauner
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