Commit 95e49cf8 authored by Jens Axboe's avatar Jens Axboe
Browse files

iov_iter: add iter_iov_addr() and iter_iov_len() helpers 



These just return the address and length of the current iovec segment
in the iterator. Convert existing iov_iter_iovec() users to use them
instead of getting a copy of the current vec.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e4d3202c

fs/read_write.c

+5 −6
Original line number Diff line number Diff line
@@ -749,15 +749,14 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, 
		return -EOPNOTSUPP;



	while (iov_iter_count(iter)) {

		struct iovec iovec = iov_iter_iovec(iter);

		ssize_t nr;



		if (type == READ) {

			nr = filp->f_op->read(filp, iovec.iov_base,

					      iovec.iov_len, ppos);

			nr = filp->f_op->read(filp, iter_iov_addr(iter),

						iter_iov_len(iter), ppos);

		} else {

			nr = filp->f_op->write(filp, iovec.iov_base,

					       iovec.iov_len, ppos);

			nr = filp->f_op->write(filp, iter_iov_addr(iter),

						iter_iov_len(iter), ppos);

		}



		if (nr < 0) {
@@ -766,7 +765,7 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, 
			break;

		}

		ret += nr;

		if (nr != iovec.iov_len)

		if (nr != iter_iov_len(iter))

			break;

		iov_iter_advance(iter, nr);

	}

include/linux/uio.h

+2 −0
Original line number Diff line number Diff line
@@ -70,6 +70,8 @@ struct iov_iter { 
};



#define iter_iov(iter)	(iter)->__iov

#define iter_iov_addr(iter)	(iter_iov(iter)->iov_base + (iter)->iov_offset)

#define iter_iov_len(iter)	(iter_iov(iter)->iov_len - (iter)->iov_offset)



static inline enum iter_type iov_iter_type(const struct iov_iter *i)

{

io_uring/rw.c

+13 −14
Original line number Diff line number Diff line
@@ -447,26 +447,25 @@ static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter) 
	ppos = io_kiocb_ppos(kiocb);



	while (iov_iter_count(iter)) {

		struct iovec iovec;

		void __user *addr;

		size_t len;

		ssize_t nr;



		if (iter_is_ubuf(iter)) {

			iovec.iov_base = iter->ubuf + iter->iov_offset;

			iovec.iov_len = iov_iter_count(iter);

			addr = iter->ubuf + iter->iov_offset;

			len = iov_iter_count(iter);

		} else if (!iov_iter_is_bvec(iter)) {

			iovec = iov_iter_iovec(iter);

			addr = iter_iov_addr(iter);

			len = iter_iov_len(iter);

		} else {

			iovec.iov_base = u64_to_user_ptr(rw->addr);

			iovec.iov_len = rw->len;

			addr = u64_to_user_ptr(rw->addr);

			len = rw->len;

		}



		if (ddir == READ) {

			nr = file->f_op->read(file, iovec.iov_base,

					      iovec.iov_len, ppos);

		} else {

			nr = file->f_op->write(file, iovec.iov_base,

					       iovec.iov_len, ppos);

		}

		if (ddir == READ)

			nr = file->f_op->read(file, addr, len, ppos);

		else

			nr = file->f_op->write(file, addr, len, ppos);



		if (nr < 0) {

			if (!ret)
@@ -482,7 +481,7 @@ static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter) 
			if (!rw->len)

				break;

		}

		if (nr != iovec.iov_len)

		if (nr != len)

			break;

	}

mm/madvise.c

+4 −5
Original line number Diff line number Diff line
@@ -1456,7 +1456,7 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec, 
		size_t, vlen, int, behavior, unsigned int, flags)

{

	ssize_t ret;

	struct iovec iovstack[UIO_FASTIOV], iovec;

	struct iovec iovstack[UIO_FASTIOV];

	struct iovec *iov = iovstack;

	struct iov_iter iter;

	struct task_struct *task;
@@ -1503,12 +1503,11 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec, 
	total_len = iov_iter_count(&iter);



	while (iov_iter_count(&iter)) {

		iovec = iov_iter_iovec(&iter);

		ret = do_madvise(mm, (unsigned long)iovec.iov_base,

					iovec.iov_len, behavior);

		ret = do_madvise(mm, (unsigned long)iter_iov_addr(&iter),

					iter_iov_len(&iter), behavior);

		if (ret < 0)

			break;

		iov_iter_advance(&iter, iovec.iov_len);

		iov_iter_advance(&iter, iter_iov_len(&iter));

	}



	ret = (total_len - iov_iter_count(&iter)) ? : ret;