linux-stable/io_uring/splice.c
Ming Lei 0d98c50908 io_uring/rsrc: pass 'struct io_ring_ctx' reference to rsrc helpers
`io_rsrc_node` instance won't be shared among different io_uring ctxs,
and its allocation 'ctx' is always same with the user's 'ctx', so it is
safe to pass user 'ctx' reference to rsrc helpers. Even in io_clone_buffers(),
`io_rsrc_node` instance is allocated actually for destination io_uring_ctx.

Then io_rsrc_node_ctx() can be removed, and the 8 bytes `ctx` pointer will be
removed from `io_rsrc_node` in the following patch.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241107110149.890530-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-07 15:24:33 -07:00

148 lines
3.5 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/splice.h>
#include <uapi/linux/io_uring.h>
#include "io_uring.h"
#include "splice.h"
struct io_splice {
struct file *file_out;
loff_t off_out;
loff_t off_in;
u64 len;
int splice_fd_in;
unsigned int flags;
struct io_rsrc_node *rsrc_node;
};
static int __io_splice_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
sp->len = READ_ONCE(sqe->len);
sp->flags = READ_ONCE(sqe->splice_flags);
if (unlikely(sp->flags & ~valid_flags))
return -EINVAL;
sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in);
sp->rsrc_node = NULL;
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
int io_tee_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
return -EINVAL;
return __io_splice_prep(req, sqe);
}
void io_splice_cleanup(struct io_kiocb *req)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
io_put_rsrc_node(req->ctx, sp->rsrc_node);
}
static struct file *io_splice_get_file(struct io_kiocb *req,
unsigned int issue_flags)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
struct io_ring_ctx *ctx = req->ctx;
struct io_rsrc_node *node;
struct file *file = NULL;
if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
return io_file_get_normal(req, sp->splice_fd_in);
io_ring_submit_lock(ctx, issue_flags);
node = io_rsrc_node_lookup(&ctx->file_table.data, sp->splice_fd_in);
if (node) {
node->refs++;
sp->rsrc_node = node;
file = io_slot_file(node);
req->flags |= REQ_F_NEED_CLEANUP;
}
io_ring_submit_unlock(ctx, issue_flags);
return file;
}
int io_tee(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
struct file *out = sp->file_out;
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
struct file *in;
ssize_t ret = 0;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
in = io_splice_get_file(req, issue_flags);
if (!in) {
ret = -EBADF;
goto done;
}
if (sp->len)
ret = do_tee(in, out, sp->len, flags);
if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
fput(in);
done:
if (ret != sp->len)
req_set_fail(req);
io_req_set_res(req, ret, 0);
return IOU_OK;
}
int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
sp->off_in = READ_ONCE(sqe->splice_off_in);
sp->off_out = READ_ONCE(sqe->off);
return __io_splice_prep(req, sqe);
}
int io_splice(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
struct file *out = sp->file_out;
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
loff_t *poff_in, *poff_out;
struct file *in;
ssize_t ret = 0;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
in = io_splice_get_file(req, issue_flags);
if (!in) {
ret = -EBADF;
goto done;
}
poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
if (sp->len)
ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
fput(in);
done:
if (ret != sp->len)
req_set_fail(req);
io_req_set_res(req, ret, 0);
return IOU_OK;
}