linux/io_uring/advise.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

100 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/io_uring.h>
#include <uapi/linux/fadvise.h>
#include <uapi/linux/io_uring.h>
#include "io_uring.h"
#include "advise.h"
struct io_fadvise {
struct file *file;
u64 offset;
u32 len;
u32 advice;
};
struct io_madvise {
struct file *file;
u64 addr;
u32 len;
u32 advice;
};
int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise);
if (sqe->buf_index || sqe->off || sqe->splice_fd_in)
return -EINVAL;
ma->addr = READ_ONCE(sqe->addr);
ma->len = READ_ONCE(sqe->len);
ma->advice = READ_ONCE(sqe->fadvise_advice);
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
#else
return -EOPNOTSUPP;
#endif
}
int io_madvise(struct io_kiocb *req, unsigned int issue_flags)
{
#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise);
int ret;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice);
io_req_set_res(req, ret, 0);
return IOU_OK;
#else
return -EOPNOTSUPP;
#endif
}
int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise);
if (sqe->buf_index || sqe->addr || sqe->splice_fd_in)
return -EINVAL;
fa->offset = READ_ONCE(sqe->off);
fa->len = READ_ONCE(sqe->len);
fa->advice = READ_ONCE(sqe->fadvise_advice);
return 0;
}
int io_fadvise(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise);
int ret;
if (issue_flags & IO_URING_F_NONBLOCK) {
switch (fa->advice) {
case POSIX_FADV_NORMAL:
case POSIX_FADV_RANDOM:
case POSIX_FADV_SEQUENTIAL:
break;
default:
return -EAGAIN;
}
}
ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
if (ret < 0)
req_set_fail(req);
io_req_set_res(req, ret, 0);
return IOU_OK;
}