Commit aebb224f authored by Dylan Yudaken's avatar Dylan Yudaken Committed by Jens Axboe
Browse files

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: default avatarDylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20230127135227.3646353-3-dylany@meta.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 6bb30855

io_uring/advise.c

+2 −2
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	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;
@@ -51,8 +52,7 @@ int io_madvise(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise);

	int ret;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	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);

io_uring/fs.c

+10 −10
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ int io_renameat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	}



	req->flags |= REQ_F_NEED_CLEANUP;

	req->flags |= REQ_F_FORCE_ASYNC;

	return 0;

}
@@ -82,8 +83,7 @@ int io_renameat(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_rename *ren = io_kiocb_to_cmd(req, struct io_rename);

	int ret;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	ret = do_renameat2(ren->old_dfd, ren->oldpath, ren->new_dfd,

				ren->newpath, ren->flags);
@@ -123,6 +123,7 @@ int io_unlinkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
		return PTR_ERR(un->filename);



	req->flags |= REQ_F_NEED_CLEANUP;

	req->flags |= REQ_F_FORCE_ASYNC;

	return 0;

}
@@ -131,8 +132,7 @@ int io_unlinkat(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_unlink *un = io_kiocb_to_cmd(req, struct io_unlink);

	int ret;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	if (un->flags & AT_REMOVEDIR)

		ret = do_rmdir(un->dfd, un->filename);
@@ -170,6 +170,7 @@ int io_mkdirat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
		return PTR_ERR(mkd->filename);



	req->flags |= REQ_F_NEED_CLEANUP;

	req->flags |= REQ_F_FORCE_ASYNC;

	return 0;

}
@@ -178,8 +179,7 @@ int io_mkdirat(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_mkdir *mkd = io_kiocb_to_cmd(req, struct io_mkdir);

	int ret;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	ret = do_mkdirat(mkd->dfd, mkd->filename, mkd->mode);
@@ -220,6 +220,7 @@ int io_symlinkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	}



	req->flags |= REQ_F_NEED_CLEANUP;

	req->flags |= REQ_F_FORCE_ASYNC;

	return 0;

}
@@ -228,8 +229,7 @@ int io_symlinkat(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_link *sl = io_kiocb_to_cmd(req, struct io_link);

	int ret;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	ret = do_symlinkat(sl->oldpath, sl->new_dfd, sl->newpath);
@@ -265,6 +265,7 @@ int io_linkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	}



	req->flags |= REQ_F_NEED_CLEANUP;

	req->flags |= REQ_F_FORCE_ASYNC;

	return 0;

}
@@ -273,8 +274,7 @@ int io_linkat(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_link *lnk = io_kiocb_to_cmd(req, struct io_link);

	int ret;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	ret = do_linkat(lnk->old_dfd, lnk->oldpath, lnk->new_dfd,

				lnk->newpath, lnk->flags);

io_uring/net.c

+2 −2
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
		return -EINVAL;



	shutdown->how = READ_ONCE(sqe->len);

	req->flags |= REQ_F_FORCE_ASYNC;

	return 0;

}
@@ -99,8 +100,7 @@ int io_shutdown(struct io_kiocb *req, unsigned int issue_flags) 
	struct socket *sock;

	int ret;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	sock = sock_from_file(req->file);

	if (unlikely(!sock))

io_uring/splice.c

+3 −4
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ static int __io_splice_prep(struct io_kiocb *req, 
	if (unlikely(sp->flags & ~valid_flags))

		return -EINVAL;

	sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in);

	req->flags |= REQ_F_FORCE_ASYNC;

	return 0;

}
@@ -52,8 +53,7 @@ int io_tee(struct io_kiocb *req, unsigned int issue_flags) 
	struct file *in;

	long ret = 0;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	if (sp->flags & SPLICE_F_FD_IN_FIXED)

		in = io_file_get_fixed(req, sp->splice_fd_in, issue_flags);
@@ -94,8 +94,7 @@ int io_splice(struct io_kiocb *req, unsigned int issue_flags) 
	struct file *in;

	long ret = 0;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);



	if (sp->flags & SPLICE_F_FD_IN_FIXED)

		in = io_file_get_fixed(req, sp->splice_fd_in, issue_flags);

io_uring/statx.c

+2 −2
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	}



	req->flags |= REQ_F_NEED_CLEANUP;

	req->flags |= REQ_F_FORCE_ASYNC;

	return 0;

}
@@ -56,8 +57,7 @@ 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;



	if (issue_flags & IO_URING_F_NONBLOCK)

		return -EAGAIN;

	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);