linux/io_uring/fs.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

294 lines
6.8 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 <uapi/linux/io_uring.h>
#include "../fs/internal.h"
#include "io_uring.h"
#include "fs.h"
struct io_rename {
struct file *file;
int old_dfd;
int new_dfd;
struct filename *oldpath;
struct filename *newpath;
int flags;
};
struct io_unlink {
struct file *file;
int dfd;
int flags;
struct filename *filename;
};
struct io_mkdir {
struct file *file;
int dfd;
umode_t mode;
struct filename *filename;
};
struct io_link {
struct file *file;
int old_dfd;
int new_dfd;
struct filename *oldpath;
struct filename *newpath;
int flags;
};
int io_renameat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_rename *ren = io_kiocb_to_cmd(req, struct io_rename);
const char __user *oldf, *newf;
if (sqe->buf_index || sqe->splice_fd_in)
return -EINVAL;
if (unlikely(req->flags & REQ_F_FIXED_FILE))
return -EBADF;
ren->old_dfd = READ_ONCE(sqe->fd);
oldf = u64_to_user_ptr(READ_ONCE(sqe->addr));
newf = u64_to_user_ptr(READ_ONCE(sqe->addr2));
ren->new_dfd = READ_ONCE(sqe->len);
ren->flags = READ_ONCE(sqe->rename_flags);
ren->oldpath = getname(oldf);
if (IS_ERR(ren->oldpath))
return PTR_ERR(ren->oldpath);
ren->newpath = getname(newf);
if (IS_ERR(ren->newpath)) {
putname(ren->oldpath);
return PTR_ERR(ren->newpath);
}
req->flags |= REQ_F_NEED_CLEANUP;
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
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;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
ret = do_renameat2(ren->old_dfd, ren->oldpath, ren->new_dfd,
ren->newpath, ren->flags);
req->flags &= ~REQ_F_NEED_CLEANUP;
io_req_set_res(req, ret, 0);
return IOU_OK;
}
void io_renameat_cleanup(struct io_kiocb *req)
{
struct io_rename *ren = io_kiocb_to_cmd(req, struct io_rename);
putname(ren->oldpath);
putname(ren->newpath);
}
int io_unlinkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_unlink *un = io_kiocb_to_cmd(req, struct io_unlink);
const char __user *fname;
if (sqe->off || sqe->len || sqe->buf_index || sqe->splice_fd_in)
return -EINVAL;
if (unlikely(req->flags & REQ_F_FIXED_FILE))
return -EBADF;
un->dfd = READ_ONCE(sqe->fd);
un->flags = READ_ONCE(sqe->unlink_flags);
if (un->flags & ~AT_REMOVEDIR)
return -EINVAL;
fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
un->filename = getname(fname);
if (IS_ERR(un->filename))
return PTR_ERR(un->filename);
req->flags |= REQ_F_NEED_CLEANUP;
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
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;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
if (un->flags & AT_REMOVEDIR)
ret = do_rmdir(un->dfd, un->filename);
else
ret = do_unlinkat(un->dfd, un->filename);
req->flags &= ~REQ_F_NEED_CLEANUP;
io_req_set_res(req, ret, 0);
return IOU_OK;
}
void io_unlinkat_cleanup(struct io_kiocb *req)
{
struct io_unlink *ul = io_kiocb_to_cmd(req, struct io_unlink);
putname(ul->filename);
}
int io_mkdirat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_mkdir *mkd = io_kiocb_to_cmd(req, struct io_mkdir);
const char __user *fname;
if (sqe->off || sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in)
return -EINVAL;
if (unlikely(req->flags & REQ_F_FIXED_FILE))
return -EBADF;
mkd->dfd = READ_ONCE(sqe->fd);
mkd->mode = READ_ONCE(sqe->len);
fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
mkd->filename = getname(fname);
if (IS_ERR(mkd->filename))
return PTR_ERR(mkd->filename);
req->flags |= REQ_F_NEED_CLEANUP;
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
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;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
ret = do_mkdirat(mkd->dfd, mkd->filename, mkd->mode);
req->flags &= ~REQ_F_NEED_CLEANUP;
io_req_set_res(req, ret, 0);
return IOU_OK;
}
void io_mkdirat_cleanup(struct io_kiocb *req)
{
struct io_mkdir *md = io_kiocb_to_cmd(req, struct io_mkdir);
putname(md->filename);
}
int io_symlinkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_link *sl = io_kiocb_to_cmd(req, struct io_link);
const char __user *oldpath, *newpath;
if (sqe->len || sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in)
return -EINVAL;
if (unlikely(req->flags & REQ_F_FIXED_FILE))
return -EBADF;
sl->new_dfd = READ_ONCE(sqe->fd);
oldpath = u64_to_user_ptr(READ_ONCE(sqe->addr));
newpath = u64_to_user_ptr(READ_ONCE(sqe->addr2));
sl->oldpath = getname(oldpath);
if (IS_ERR(sl->oldpath))
return PTR_ERR(sl->oldpath);
sl->newpath = getname(newpath);
if (IS_ERR(sl->newpath)) {
putname(sl->oldpath);
return PTR_ERR(sl->newpath);
}
req->flags |= REQ_F_NEED_CLEANUP;
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
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;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
ret = do_symlinkat(sl->oldpath, sl->new_dfd, sl->newpath);
req->flags &= ~REQ_F_NEED_CLEANUP;
io_req_set_res(req, ret, 0);
return IOU_OK;
}
int io_linkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_link *lnk = io_kiocb_to_cmd(req, struct io_link);
const char __user *oldf, *newf;
if (sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in)
return -EINVAL;
if (unlikely(req->flags & REQ_F_FIXED_FILE))
return -EBADF;
lnk->old_dfd = READ_ONCE(sqe->fd);
lnk->new_dfd = READ_ONCE(sqe->len);
oldf = u64_to_user_ptr(READ_ONCE(sqe->addr));
newf = u64_to_user_ptr(READ_ONCE(sqe->addr2));
lnk->flags = READ_ONCE(sqe->hardlink_flags);
lnk->oldpath = getname(oldf);
if (IS_ERR(lnk->oldpath))
return PTR_ERR(lnk->oldpath);
lnk->newpath = getname(newf);
if (IS_ERR(lnk->newpath)) {
putname(lnk->oldpath);
return PTR_ERR(lnk->newpath);
}
req->flags |= REQ_F_NEED_CLEANUP;
req->flags |= REQ_F_FORCE_ASYNC;
return 0;
}
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;
WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
ret = do_linkat(lnk->old_dfd, lnk->oldpath, lnk->new_dfd,
lnk->newpath, lnk->flags);
req->flags &= ~REQ_F_NEED_CLEANUP;
io_req_set_res(req, ret, 0);
return IOU_OK;
}
void io_link_cleanup(struct io_kiocb *req)
{
struct io_link *sl = io_kiocb_to_cmd(req, struct io_link);
putname(sl->oldpath);
putname(sl->newpath);
}