aio: lift iov_iter_init() into aio_setup_..._rw()

the only non-trivial detail is that we do it before rw_verify_area(),
so we'd better cap the length ourselves in aio_setup_single_rw()
case (for vectored case rw_copy_check_uvector() will do that for us).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2015-03-20 20:17:32 -04:00
parent ac15ac0669
commit 4c185ce06d

View File

@ -1357,7 +1357,8 @@ static ssize_t aio_setup_vectored_rw(struct kiocb *kiocb,
unsigned long *nr_segs,
size_t *len,
struct iovec **iovec,
bool compat)
bool compat,
struct iov_iter *iter)
{
ssize_t ret;
@ -1378,6 +1379,7 @@ static ssize_t aio_setup_vectored_rw(struct kiocb *kiocb,
/* len now reflect bytes instead of segs */
*len = ret;
iov_iter_init(iter, rw, *iovec, *nr_segs, *len);
return 0;
}
@ -1385,14 +1387,18 @@ static ssize_t aio_setup_single_vector(struct kiocb *kiocb,
int rw, char __user *buf,
unsigned long *nr_segs,
size_t len,
struct iovec *iovec)
struct iovec *iovec,
struct iov_iter *iter)
{
if (len > MAX_RW_COUNT)
len = MAX_RW_COUNT;
if (unlikely(!access_ok(!rw, buf, len)))
return -EFAULT;
iovec->iov_base = buf;
iovec->iov_len = len;
*nr_segs = 1;
iov_iter_init(iter, rw, iovec, *nr_segs, len);
return 0;
}
@ -1438,10 +1444,10 @@ static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode,
if (opcode == IOCB_CMD_PREADV || opcode == IOCB_CMD_PWRITEV)
ret = aio_setup_vectored_rw(req, rw, buf, &nr_segs,
&len, &iovec, compat);
&len, &iovec, compat, &iter);
else
ret = aio_setup_single_vector(req, rw, buf, &nr_segs,
len, iovec);
len, iovec, &iter);
if (!ret)
ret = rw_verify_area(rw, file, &req->ki_pos, len);
if (ret < 0) {
@ -1463,10 +1469,9 @@ static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode,
file_start_write(file);
if (iter_op) {
iov_iter_init(&iter, rw, iovec, nr_segs, len);
ret = iter_op(req, &iter);
} else {
ret = rw_op(req, iovec, nr_segs, req->ki_pos);
ret = rw_op(req, iter.iov, iter.nr_segs, req->ki_pos);
}
if (rw == WRITE)