linux-stable/io_uring/statx.c
Dylan Yudaken aebb224fd4 io_uring: for requests that require async, force it
Some requests require being run async as they do not support
non-blocking. Instead of trying to issue these requests, getting -EAGAIN
and then queueing them for async issue, rather just force async upfront.

Add WARN_ON_ONCE to make sure surprising code paths do not come up,
however in those cases the bug would end up being a blocking
io_uring_enter(2) which should not be critical.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20230127135227.3646353-3-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:26 -07:00

73 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/io_uring.h>
#include <uapi/linux/io_uring.h>
#include "../fs/internal.h"
#include "io_uring.h"
#include "statx.h"
struct io_statx {
struct file *file;
int dfd;
unsigned int mask;
unsigned int flags;
struct filename *filename;
struct statx __user *buffer;
};
int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_statx *sx = io_kiocb_to_cmd(req, struct io_statx);
const char __user *path;
if (sqe->buf_index || sqe->splice_fd_in)
return -EINVAL;
if (req->flags & REQ_F_FIXED_FILE)
return -EBADF;
sx->dfd = READ_ONCE(sqe->fd);
sx->mask = READ_ONCE(sqe->len);
path = u64_to_user_ptr(READ_ONCE(sqe->addr));
sx->buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
sx->flags = READ_ONCE(sqe->statx_flags);
sx->filename = getname_flags(path,
getname_statx_lookup_flags(sx->flags),
NULL);
if (IS_ERR(sx->filename)) {
int ret = PTR_ERR(sx->filename);
sx->filename = NULL;
return ret;
}
req->flags |= REQ_F_NEED_CLEANUP;
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
int io_statx(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_statx *sx = io_kiocb_to_cmd(req, struct io_statx);
int ret;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
ret = do_statx(sx->dfd, sx->filename, sx->flags, sx->mask, sx->buffer);
io_req_set_res(req, ret, 0);
return IOU_OK;
}
void io_statx_cleanup(struct io_kiocb *req)
{
struct io_statx *sx = io_kiocb_to_cmd(req, struct io_statx);
if (sx->filename)
putname(sx->filename);
}