Commit 7b7699c0 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 

Pull iov_iter fixes from Al Viro:
 "Fixes for io-uring handling of iov_iter reexpands"

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  io_uring: reexpand under-reexpanded iters
  iov_iter: track truncated size
parents 70868a18 89c2b3b7

fs/io_uring.c

+2 −0
Original line number Original line Diff line number Diff line
@@ -3480,6 +3480,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags) 
		if (req->flags & REQ_F_NOWAIT)

		if (req->flags & REQ_F_NOWAIT)

			goto done;

			goto done;

		/* some cases will consume bytes even on error returns */

		/* some cases will consume bytes even on error returns */

		iov_iter_reexpand(iter, iter->count + iter->truncated);

		iov_iter_revert(iter, io_size - iov_iter_count(iter));

		iov_iter_revert(iter, io_size - iov_iter_count(iter));

		ret = 0;

		ret = 0;

	} else if (ret == -EIOCBQUEUED) {

	} else if (ret == -EIOCBQUEUED) {
@@ -3619,6 +3620,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) 
	} else {

	} else {

copy_iov:

copy_iov:

		/* some cases will consume bytes even on error returns */

		/* some cases will consume bytes even on error returns */

		iov_iter_reexpand(iter, iter->count + iter->truncated);

		iov_iter_revert(iter, io_size - iov_iter_count(iter));

		iov_iter_revert(iter, io_size - iov_iter_count(iter));

		ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);

		ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);

		return ret ?: -EAGAIN;

		return ret ?: -EAGAIN;

include/linux/uio.h

+5 −1
Original line number Original line Diff line number Diff line
@@ -47,6 +47,7 @@ struct iov_iter { 
		};

		};

		loff_t xarray_start;

		loff_t xarray_start;

	};

	};

	size_t truncated;

};

};





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

static inline enum iter_type iov_iter_type(const struct iov_iter *i)
@@ -254,9 +255,11 @@ static inline void iov_iter_truncate(struct iov_iter *i, u64 count) 
	 * conversion in assignement is by definition greater than all

	 * conversion in assignement is by definition greater than all

	 * values of size_t, including old i->count.

	 * values of size_t, including old i->count.

	 */

	 */

	if (i->count > count)

	if (i->count > count) {

		i->truncated += i->count - count;

		i->count = count;

		i->count = count;

	}

	}

}





/*

/*

 * reexpand a previously truncated iterator; count must be no more than how much

 * reexpand a previously truncated iterator; count must be no more than how much
@@ -264,6 +267,7 @@ static inline void iov_iter_truncate(struct iov_iter *i, u64 count) 
 */

 */

static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)

static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)

{

{

	i->truncated -= count - i->count;

	i->count = count;

	i->count = count;

}

}