linux/io_uring/sync.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

113 lines
2.8 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 <linux/fsnotify.h>
#include <uapi/linux/io_uring.h>
#include "io_uring.h"
#include "sync.h"
struct io_sync {
struct file *file;
loff_t len;
loff_t off;
int flags;
int mode;
};
int io_sfr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);
if (unlikely(sqe->addr || sqe->buf_index || sqe->splice_fd_in))
return -EINVAL;
sync->off = READ_ONCE(sqe->off);
sync->len = READ_ONCE(sqe->len);
sync->flags = READ_ONCE(sqe->sync_range_flags);
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);
int ret;
/* sync_file_range always requires a blocking context */
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
ret = sync_file_range(req->file, sync->off, sync->len, sync->flags);
io_req_set_res(req, ret, 0);
return IOU_OK;
}
int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);
if (unlikely(sqe->addr || sqe->buf_index || sqe->splice_fd_in))
return -EINVAL;
sync->flags = READ_ONCE(sqe->fsync_flags);
if (unlikely(sync->flags & ~IORING_FSYNC_DATASYNC))
return -EINVAL;
sync->off = READ_ONCE(sqe->off);
sync->len = READ_ONCE(sqe->len);
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
int io_fsync(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);
loff_t end = sync->off + sync->len;
int ret;
/* fsync always requires a blocking context */
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
ret = vfs_fsync_range(req->file, sync->off, end > 0 ? end : LLONG_MAX,
sync->flags & IORING_FSYNC_DATASYNC);
io_req_set_res(req, ret, 0);
return IOU_OK;
}
int io_fallocate_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);
if (sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
return -EINVAL;
sync->off = READ_ONCE(sqe->off);
sync->len = READ_ONCE(sqe->addr);
sync->mode = READ_ONCE(sqe->len);
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
int io_fallocate(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);
int ret;
/* fallocate always requiring blocking context */
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
ret = vfs_fallocate(req->file, sync->mode, sync->off, sync->len);
if (ret >= 0)
fsnotify_modify(req->file);
io_req_set_res(req, ret, 0);
return IOU_OK;
}